1. health and fitness
2. disease
3. cancer

Abstract book
Wetenschapsdag
v r i j d a g 5 m a a r t 2 010
W e t e n s c h a p s d a g V C W 2 01 0
Foto: Digidaan
Vaste Commissie voor
de Wetenschapsbeoefening
(VCW)
Omslag Abstract boek 2010.indd 1
22-02-2010 16:09:24
Omslag Abstract boek 2010.indd 2
22-02-2010 16:09:24
Abstract book
Wetenschapsdag vrijdag 5 maart 2010
12:00 - 17:30 uur
VUmc Amstelzaal, Foyer & Waver
Vaste Commissie voor de Wetenschapsbeoefening (VCW)
Wet en s ch ap s d ag V C W 2 0 1 0 3
4
Inhoudsopgave
Pag. 6 Voorwoord
Pag. 7
Programma VUmc Wetenschapsdag 2010
Pag. 8
VCW-leden
Abstracts
Pag. 9CCA/V-ICI: Cancer Center Amsterdam, VUmc Institute for Cancer and
Immunology
Pag. 56
Emgo+: Institute for Research in Extramural Medicine
Pag. 88 ICaR-VU: Institute for Cardiovascular Research VU
Pag. 118
MOVE
Pag. 122 NCA: Neuroscience Campus Amsterdam
Index
Pag. 152
Namen van de onderzoekers per onderzoeksinstituut, titel van het onderzoek
Wet en s ch ap s d ag V C W 2 0 1 0 5
Voorwoord
Voor het vierde achtereenvolgende jaar organiseert de VCW de VUmc Wetenschapsdag.
Onderzoekers krijgen de kans om een tipje op te lichten van het onderzoek waar ze mee bezig
zijn. En die kans wordt met beide handen aangegrepen. Dit jaar hebben we een recordaantal
van ruim 140 abstracts mogen ontvangen, meer dan een verdubbeling ten opzichte van de eerste
wetenschapsdag in 2007!
Met trots presenteert de VCW deze bundeling van (een groot deel van) het onderzoek dat binnen
de onderzoeksinstituten, de VU en het VU medisch centrum plaatsvindt.
Het is een hele klus om alle abstracts in korte tijd te lezen en om uit al dit hoogstaand werk
abstracts te nomineren voor een prijs. Daarom is dit jaar de hulp ingeroepen van de onderzoeksinstituten die een voorselectie hebben gemaakt. Het is te meer moeilijk omdat het voor
de auteurs ook lastig blijkt hun werk buiten de eigen discipline begrijpelijk te presenteren.
Dat hopen we in de toekomst nog te kunnen verbeteren.
Veel succes met uw onderzoek. We hopen dat het bijdraagt aan de handhaving van de positie
van het VUmc in de nationale CWTS ranking, waarin we al enkele jaren ‘slechts één ander
UMC voor ons hebben’, zoals de voorzitter van de raad van bestuur het onlangs uitdrukte.
Namens de Vaste Commissie voor de Wetenschapsbeoefening
Prof. dr. M.A. Blankenstein, voorzitter
6
Programma VUmc Wetenschapsdag
Vrijdag 5 maart 2010 van 12.00 –18.00 uur
VUmc Amstelzaal, Foyer & Waver
12.00 – 13.00 uur Posterpresentatie & lunch
13.00 – 13.05 uur Opening door prof. dr. V.W.M. van Hinsbergh
13.05 – 13.30 uurDr. Jolanda van der Velden, afdeling Fysiologie/ICaR-VU;
‘A translational approach to hypertrophic cardiomyopathy’
13.30 – 14.00 uur Prof. dr. Allard van der Beek, afdeling Sociale Geneeskunde/
EMGO+; ‘Werk & Gezondheid: Uitdagingen in Onderzoek’
14.00 – 15.00 uur Voordrachten door genomineerden:
14.00 – 14.20 uurMichiel Pegtel; ‘Viral miRNAs expressed in B cells are
delivered to- and act in recipient cells; evidence for
functional miRNA transfer via exosomes’
14.20 – 14.40 uur Willem de Haan; ‘Functional brain networks and dementia’
14.40 – 15.00 uurRinske Nijland (MSc); ‘Presence of finger extension and
shoulder abduction within 72 hours post-stroke predicts
functional recovery’
15.00 – 15.30 uur Theepauze
15.30 – 16.10 uur Voordrachten door genomineerden:
15.30 – 15.50 uurJacqueline Vink; ‘A pathway analysis of genome-wide
association results reveals the importance of inflammation
in Major Depressive Disorder’
15.50 – 16.10 uurM. Wijdenes-Pijl; ‘Impact of communicating familial risk of
diabetes on illness perceptions and self-reported
behavioural outcomes: a randomized controlled trial’
16.10 – 16.50 uur Prof. dr. P.T. Cohen-Kettenis, afdeling Medische Psychologie; ‘Over zijn zijn en haar zijn: 25 jaar onderzoek naar
genderdysforie’
16.50 – 17.05 uurUitreiking Vumc Wetenschapsprijzen:
drie beste abstracts
17.05 – 17.15 uur Uitreiking VUmc Posterprijs: de beste poster
17.15 – 18.00 uur Borrel
Informatie over de selectieprocedure
De onderzoeksinstituten hebben voorafgaand aan de Wetenschapsdag 2010 ieder drie abstracts voorgedragen aan de Vaste
Commissie voor de Wetenschapsbeoefening (VCW). Uit deze selectie heeft de VCW vijf onderzoekers de kans geboden om het
betreffende onderzoek te presenteren op de Wetenschapsdag. De betreffende abstracts zijn te herkennen aan de toevoeging op
het nummer bij het posterbord.
Deze vijf presentaties worden door de jury, bestaande uit VCW-leden, beoordeeld en hieruit worden de beste drie beloond met
een geldprijs. Tevens wordt op de Wetenschapsdag de beste poster geselecteerd door de jury en beloond met een geldprijs.
Wet en s ch ap s d ag V C W 2 0 1 0 7
VCW leden
Prof. dr. M.A. Blankenstein (voorzitter)
ma.blankenstein@VUmc.nl
Klinische Chemie
Prof. dr. J. van Dieën
j.vandieen@fbw.VU.nl
Bewegingswetenschappen, MOVE
Dr. M.L. Drent
ml.drent@VUmc.nl
Endocrinologie
Prof. dr. A.J.G. Horrevoets
aj.horrevoets@VUmc.nl
Moleculaire Celbiologie en Immunologie
Prof. dr. R.J.A. van Moorselaar
rja.vanMoorselaar@VUmc.nl
Urologie
Prof. dr. P.J.F. Snijders
pjf.snijders@VUmc.nl
Moleculaire Pathologie, CCA/V-ICI
Prof. dr. F.J. Snoek
fj.snoek@VUmc.nl
Medische psychologie
Prof. dr. B.M.J. Uitdehaag
bmj.uitdehaag@VUmc.nl
Epidemiologie
Prof. dr. ir. R. de Vet
hcw.devet@VUmc.nl
EMGO+
E. Dijkstra (secretaris)
e.dijkstra@VUmc.nl
8
CCA/V-ICI
1. FANCM phosphorylation in response to camptothecin
Sheba Agarwal, Jurgen Steltenpool, Martin Rooimans, Anneke Oostra, Hans Joenje,
Johan de Winter.
Department of Clinical Genetics, VU University Medical Center, Amsterdam.
Introduction
Several FA proteins, most notably FANCD2, are modified either in response to DNA damaging
agents or in S phase. FANCM, a member of the FA core complex, is also modified. Recently the
FANCM-deficient patient cell line (EUFA867) was shown to be sensitive to camptothecin: a topoI
inhibitor that causes replication blockage. In this study, we investigated FANCM modification in
response to camptothecin.
Methods
We have used wild type lymphoblasts and HeLa cells. FANCM was immunoprecipitated from the
cell lysates and modification was visible as a band-shift on Western blot analysis. We also utilized
fluorescence affinity cell sorting, immunofluorescence and siRNA depletion experiments.
Results
As with MMC, FANCM is phosphorylated in response to camptothecin. FANCM phosphorylation is
absolutely dependent on FAAP24. FANCM is phosphorylated as early as 1 hour after camptothecin
treatment. While phosphorylation is maintained up to 24 hours with 5 µM camptothecin,
modification of FANCM disappears after 3 hours with 20 µM camptothecin. However, FANCD2
mono-ubiquitination is induced around 8 hours post treatment, suggesting that FANCM
phosphorylation is not directly coupled to FANCD2 modification. In contrast to previous studies,
cells treated with 20 µM are stalled in S phase, but they do not show FANCM phosphorylation.
Camptothecin-treated cells elicit a dose-dependent DNA damage response suggesting that at high
concentrations of camptothecin, the phophorylation of FANCM is dispensable and the damage is
possibly repaired by homologous recombination.
Conclusions
The ubiquitination of FANCD2 is not directly coupled to FANCM phosphorylation. We hypothesize
that there is a threshold of damage for FANCM phosphorylation response, beyond which FANCM
is either dephosphorylated or degraded.
Wet en s ch ap s d ag V C W 2 0 1 0 9
CCA/V-ICI
2. 6
-Thioguanine is an effective and tolerable rescue
drug in the treatment of ulcerative colitis
D.P. van Asseldonk1, B. Jharap1, N.K.H. de Boer1, D.J. Kuik2, B.D. Westerveld3, F.J.G.M. Kubben4,
M.G.V.M. Russel5, A.A. van Bodegraven1 C.J. Mulder1.
1 Department of Pathology and
2 Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
3 Gastroenterology and Hepatology, Isala Clinics, Zwolle
4 Gastroenterology and Hepatology, Maasstad Hospital, Rotterdam
5 Gastroenterology and Hepatology, Twente Medical Spectrum, Enschede.
Introduction
6-Mercaptopurine and its pro-drug azathioprine are important in the treatment of ulcerative
colitis (UC). Unfortunately, a substantial number of patients withdraws these conventional
thiopurines due to intolerance or resistance. 6-Thioguanine (6-TG) may be an appropriate secondline drug in the treatment of UC. The aim of this study was to assess the efficacy and tolerability
of 6-TG in UC patients.
Methods
A retrospective cohort study of IBD patients using 6-TG after failing conventional thiopurine
therapy was conducted. All UC patients who initiated 6-TG therapy between 2001 and 2007 were
included in the analysis. Clinical efficacy and tolerability was assessed after a minimum of one
months and compared with baseline.
Results
Fifty-three patients, of whom three were lost to follow-up, received 6-TG. Of the remaining fifty
patients, 27 were male. The mean daily 6-TG dose was 19.9 mg (SD 2.4). The median treatment
duration was 25 months (1.2-73.8). Overall, after a median treatment duration of 13 months, an
amelioration of endoscopically assessed mucosal inflammation was seen (P=0.047). Eleven (22%)
of the fifty patients eventually withdrew 6-TG therapy due to resistance (n=7) and adverse events
(n=4). Ultrasonography (n=30) showed hepatosplenomegaly (HSM) in one patient. Liver biopsy
analysis (n=18) revealed no nodular regenerative hyperplasia.
Conclusions
In UC patients intolerant of or resistant to conventional thiopurines, 6-TG seems an effective
rescue drug which may induce mucosal repair. Moreover, 6-TG is well-tolerated by the majority of
these patients and seems to be safe.
10
CCA/V-ICI
3. Liver
histology of IBD patients who are treated
with 6-thioguanine due to failure of conventional
thiopurines reveals very few cases of nodular
regenerative hyperplasia
D.P. van Asseldonk1, B. Jharap1, N.K.H. de Boer1, P.E. Zondervan2, E. Bloemena3,
G. den Hartog4, B.D. Westerveld5, J.J. Kolkman6, L.G.J.B. Engels7,
A.A. van Bodegraven1, C.J. Mulder1.
1
2
3
4
5
6
7
Gastroenterology and Hepatology, VU University Medical Center, Amsterdam
Pathology, Erasmus Medical Center,Rotterdam
Pathology, VU University Medical Center, Amsterdam
Gastroenterology and Hepatology, Rijnstate Hospital, Arnhem
Gastroenterology and Hepatology, Isala Clinics, Zwolle
Gastroenterology and Hepatology, Twente Medical Spectrum, Enschede
Gastroenterology and Hepatology, Orbis Medical Center, Sittard.
Introduction
6-Thioguanine (6-TG) has been proposed as a rescue drug in patients with inflammatory bowel
disease (IBD). The aim of this study was to assess short-term hepatotoxicity of 6-TG therapy in a
large population of IBD patients previously failing conventional thiopurine therapy.
Methods
A prospective multi-center cohort study was performed, including IBD patients treated with 6-TG
in an aimed dose of 0.3mg/kg for at least six months, who underwent a liver biopsy. The liver
specimens were stained with H&E, trichrome and reticuline.
Results
From 99 patients with a mean age of 43.8 years (SD 12.0) 99 liver biopsy specimens were
obtained. Sixty-one patients (62%) had Crohn’s disease and 38 (38%) had ulcerative colitis. Except
for two patients, all were pretreated with azathioprine and/or 6-mercaptopurine. The mean 6-TG
dose was 0.28mg/kg (SD 0.07) and the median 6-TG treatment duration to the first liver biopsy,
was 25 months (range 6-65). Liver histology revealed no abnormalities in 51 specimens (51.5%);
mild steatosis in 14 (14.1%); mild fibrosis in 3 (3.0%); severe steatosis in 2 (2.0%); steatohepatitis
in 2 (2.0%) sinus dilatation in 8 (8.1%); cholangitis/PSC in 4 (4.0%); aspecific regeneration in 11
(11.1%) and nodular regenerative hyperplasia (NRH) in 4 (4.0%).
Conclusions
This large, prospective study reveals very few cases of NRH (4%) in a specific IBD population
who had been failing conventional thiopurine therapy and were subsequently treated with 6-TG.
Aspecific findings with unknown clinical implications were observed in about half of the patients.
Wet en s ch ap s d ag V C W 2 0 1 0 11
CCA/V-ICI
4. O
ccurrence of menarche, regularity of menstrual
cycles, and amenorrhoea in a cohort of childhood
cancer survivors: a pilot study
M.H. van den Berg1, A. Overbeek1, F.E. van Leeuwen2, C.B. Lambalk3, G.J. Kaspers1,
E. van Dulmen-den Broeder1.
1 Department of Paediatric Oncology/Hematology, VU University Medical Center, Amsterdam
2 Department of Epidemiology, Netherlands Cancer Institute
3 Department of Obstetrics and Gynaecology, VU University Medical Center, Amsterdam.
Objective
To evaluate the effects of treatment of childhood cancer on the occurrence of menarche,
regularity of menstrual cycles, and amenorrhoea in a cohort of female childhood cancer survivors
(CCS).
Patients and methods
The study cohort consists of female 5-year CCSs treated at VU University Medical Center in
Amsterdam for any type of childhood cancer, and an age-matched control group consisting of
sisters of CCSs. Data of 72 survivors and 72 controls regarding menarche and irregularity of
menstrual cycles were obtained by questionnaire. Furthermore, in order to specifically evaluate
the effect of treatment on age at menarche, this outcome was also evaluated in a subgroup of
CCSs that was diagnosed and treated before menarche (n=47).
Results
At time of study median (IQR) age of CCSs and controls was 26.3 (10.2) and 26.1 (10.2) years
respectively. Age at diagnosis was 8.3 (10.7) years. Oral contraceptives were used by 54% of CCS
and 64% of controls. These differences, as well as the differences in education level and marital
status, between CCSs and controls were not statistically significant. Seven CCSs (10%) and one
control (1%) reported never to have reached menarche (p=0.03). No significant difference between
CCSs who were treated before menarche and controls was found regarding age at menarche.
Oligomenorrhoea (cycle ≥ 36 days) was significantly more frequently present in survivors (20% vs.
7%, p = 0.04). Prolonged cessation of menses (> 12 months) for reasons other than pregnancy,
lactation, or nonstop use of hormonal contraceptives was reported by two survivors and none of
the controls.
Conclusion
Damage to the reproductive system seems to occur more in CCSs compared to controls.
Menarche was more frequently absent in CCSs compared to controls and treatment appeared
to result in more irregular cycles. However, treatment does not seem to delay menarche. In a
nationwide study, which is currently being performed, the afore-mentioned outcomes will be
re-evaluated in a larger study population and in relation to treatment history.
12
CCA/V-ICI
5. Q
uality of life in motion: a combined physical
exercise and psychosocial intervention program for
childhood cancer patients
K.I. Braam1, E.M. van Dijk2, E. van Dulmen-den Broeder1, M.A. Veening1, P.J.M. Helders3,
G. Sinnema4, M. Bierings5, J. Huisman2, T. Takken3, G.J.L. Kaspers1.
1
2
3
4
Department of Pediatric Oncology/Hematology
Department of Medical Psychology, VU University Medical Center, Amsterdam
Department of Pediatric Physiotherapy and Exercise Physiology
Department of Medical Psychology, 5Department of Pediatric Immunology and Hematology,
Wilhelmina’s Children’s Hospital, University Medical Centre Utrecht.
Introduction
Both during and after treatment, the level of physical fitness has shown to be reduced in
childhood cancer patients (CCP), leading to physical inactivity, obesity, fatigue, poor skeletal
and/or mental health, and ultimately to a compromised Health-related Quality Of Life (HrQOL).
The aim of this study is to evaluate the effectiveness of an integrated physical exercise and
psychosocial training program, implemented during or following treatment to improve physical
fitness of CCP. Secondary outcomes are fatigue, body composition, daily physical activity,
depression, HrQOL, and self-perception. Potential applications: In addition to, or shortly after
standard care, this intervention may improve both physical and mental health outcomes of CCP.
Methods
Childhood cancer patients (8-18 years) are eligible to participate in this multi-center trial, during
or within the first year following chemo- and/or radiotherapy treatment. Exclusion criteria are:
bone marrow transplantation and/or growth hormone use, motor inability to perform exercises,
and/or mental retardation. One hundred patients will be randomized to either the intervention,
or the control group. Groups are stratified by: cancer, age group, and study-inclusion phase. The
intervention consists of an integrated physical and psychosocial training program (12-weeks) and
a booster session, whereas the control group receives care-as-usual. Physical performance tests,
blood tests, a DEXA scan and questionnaires will be performed on four occasions: at baseline,
after 12 to 14 weeks, 6 to 9 months from baseline and 12 months from baseline. Until now
twelve patients have been enrolled into the trial. This study is financially supported by the Dutch
Cancer Society (VU2009-4305).
Wet en s ch ap s d ag V C W 2 0 1 0 13
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6. C
CL27 stimulates the secretion of cytokines involved
in granulation tissue formation
L.J. van den Broek1, K.L. Kroeze1, M. Breetveld1, S.C. Sampat1, R.J. Scheper2, S. Gibbs1.
1 Department of Dermatology, VU University Medical Center, Amsterdam
2 Department of Pathology, VU University Medical Center, Amsterdam.
Introduction
The function of CCL27 in wound healing is partly unknown. CCL27 is expressed in the basal layer
of the epidermis and up regulated in wounds. Our results show a significant increase of CCL27 in
burn wound fluid compared excision wound fluid. The incidence of hypertrophic scars after burn
injury is high compared to excision wounds. A function for CCL27 in this process is imaginable.
The goal of this research is to study the role of CCL27 in wound healing.
Methods
The expression of CCR10, the receptor for CCL27, is determined on keratinocytes, endothelial
cells (HMVEC), granulocytes, monocytes en stem cells derived from the dermis (DSC) and adipose
tissue (ASC) using flow cytometry. The effect of CCL27 on these cells is studied. We studied the
migration potential and the secretion of cytokines involved in granulation tissue formation
(Il-6, IL-8, CXCL1, CCL2, CCL5 en CCL20).
Results
All cell types studied express the receptor CCR10. CCL27 is only a chemo-attractant for
keratinocytes. Interestingly, CCL27 stimulates monocytes and ASCs to secrete cytokines involved
in granulation tissue formation. CCL27 has no effect on the production of these cytokines by
granulocytes, HMVECs en DSCs. Notably CCL27 seems to have a positive effect on the survival of
HMVECs.
Conclusions
Our results show a potential novel role for CCL27 in skin wound healing. CCL27 is a chemoattractant for keratinocytes and therefore may stimulate re-epithelization. CCL27 is able to
increase the secretion of cytokines involved in granulation tissue formation and therefore may
indirectly be involved in scar formation.
14
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7. C
andidate driver genes in focal chromosomal
aberrations of stage II colon cancer
R.P.M. Brosens1,4*, J.C. Haan2*, B. Carvalho2, F. Rustenburg2, H. Grabsch3, A.F. Engel4,
M.A. Cuesta1, M. Flens5, G.A. Meijer2, B. Ylstra2.
*These authors contributed equally to this work
1
2
3
4
5
Department of Surgery, VU University Medical Center, Amsterdam, The Netherlands
Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands
Pathology and Tumour Biology, Leeds Institute of Molecular Medicine, University of Leeds, UK
Department of Surgery, Zaans Medical Centre, Zaandam, The Netherlands
Department of Pathology, Zaans Medical Centre, Zaandam, The Netherlands.
Introduction
Forty percent of all colon cancer patients are stage II, 25% of which will relapse and die of their
disease. As in many cancers, colon carcinomas harbour large chromosomal aberrations. However,
looking at these alterations it is difficult to pinpoint actual cancer genes. Chromosomal copy
number aberrations of 3Mb or smaller in size, so called focal aberrations, are a recently
discovered, common phenomenon in cancer. Inherent to their limited size, focal aberrations
harbour one or very few genes only. The aim of this study was to identify recurrent focal
chromosomal aberrations and candidate driver genes in a well defined series of stage II colon
cancers and assess their potential clinical value.
Methods
Aberrations were analyzed for 38 formalin fixed paraffin embedded colon cancer samples using
matched normal mucosa as a reference by oligo array comparative genomic hybridization.
Validation of focal aberrations and identification of candidate genes were done using publicly
available copy number and mutation data of colorectal cancer, breast cancer, pancreatic cancer
and glioblastomas. In total, we identified 81 focal chromosomal aberrations harbouring 177
candidate genes.
Results
The focal amplifications identified seem to be highly colon cancer specific and overlapped with
previously identified focal amplifications in colorectal cancer, but not with cancers from other
sites. In contrast, identified focal deletions seem to be less tumour type specific and overlapped
also with focal deletions previously identified in cancers from other sites. The focal deletions
detected are significantly enriched for cancer genes and genes frequently mutated in colorectal
cancer. A list of focal aberrations and candidate cancer driver genes is presented. Loss of 5q34
and gain of 13q22.1 were identified as independent prognostic factors of patient survival in this
series of patients.
Conclusions
Focal chromosomal copy number aberrations in stage II colon cancer seem biologically important,
are enriched in cancer genes which contribute to and drive the process of colorectal cancer
development.
Wet en s ch ap s d ag V C W 2 0 1 0 15
CCA/V-ICI
8. IS-pro: high throughput fingerprinting of
the intestinal microbiome
Dries Budding1, Matthijs Grasman2, Ad van Bodegraven2, Paul Savelkoul1.
1 Medical Microbiology & Infection control, VU University Medical Menter
2 Gastro-enterology & Hepatology, VU University Medical Center, Amsterdam.
Introduction
Large scale sequencing efforts have offered many new insights into the gut microbiota in health
and disease and have generated many hypotheses as to potential causal relationships. The
complex and expensive nature of these techniques, however, restricts implementation to a small
number of highly specialized laboratories and limits research to small sample numbers. We have
developed a novel high-throughput bacterial profiling method, IS-pro. This PCR-based method
combines highly specific species identification with instant taxonomic classification at the phylum
level. Phylum sorting is of great value, as shifts associated with diseased states can best be
identified at this taxonomic level and even unknown species can be classified. The highthroughput nature of the technique makes IS-pro suitable not only for use in research efforts, but
also as a routine clinical tool in diagnostics and follow up.
Methods
The discriminatory potential of IS-pro was calculated with an in silico database of 342 bacterial
species. In-vitro validation was performed with monocultures and mixes of cultured bacteria.
Finally, we performed in vivo validation with 100 colonic mucosal biopsies of 20 healthy
individuals obtained from 5 locations throughout the colon: Caecum, hepatic flexure, splenic
flexure, sigmoid and rectum.
Results
In silico evaluation showed that IS-pro can theoretically discriminate >50.000 bacterial species.
In vitro testing showed lower detection limit to be 10 bacteria/_l. No interactions were found
between species belonging to the same phylum, nor were interactions found between the
different phyla. In vivo validation on duplicate samples showed excellent reproducibility of IS-pro.
A high level of correlation of mucosal samples throughout the colon was identified by IS-pro,
corresponding well with current knowledge and further underlining the reproducibility of the
technique.
Conclusions
IS-pro has a very high discriminatory potential, and is well suited for analysis of the complex
microbiota of the human gut. Because of its simplicity, IS-pro can be performed in general clinical
microbiological laboratories and can make analysis of the human intestinal microbiota broadly
accessible to clinical practitioners.
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9. P
rospective screening for speech and swallowing
problems in head and neck cancer patients via
a touch screen computer assisted data collection
system
Ingrid C. Cnossen SLP MSc1, Remco de Bree MD PhD1, Rico N. Rinkel SLP MD1, Derek H.F. Rietveld
MD2, Jan Buter MD3, Johannes A. Langendijk MD PhD4, C. René Leemans MD PhD1,
Irma M. Verdonck-de Leeuw SLP PhD1.
1
2
3
4
Department of Otolaryngology/Head and Neck Surgery
Department of Radiation Oncology
Department of Medical Oncology, VU University Medical Center, Amsterdam
Department of Radiation Oncology, University Medical Center Groningen/University of
Groningen, Groningen.
Introduction
Head and neck squamous cell cancer (HNSCC) patients often have to deal with side-effects of
treatment, such as pain, fatigue, dry mouth, speech and swallowing problems, negatively affecting
health-related quality of life. It is estimated that 34% - 71% of HNSCC patients have speech and
swallowing problems after treatment (after surgery and / or chemoradiation treatment). We
investigated prospectively the prevalence of speech and swallowing problems in patients with head
and neck squamous cell carcinoma (HNSCC) from baseline (before attending the oncology clinic) to
follow-up via a newly developed touch screen computer system (OncoQuest), which is linked to the
hospital patient information system.
Methods
The EORTC QLQ-C30 and EORTC QLQ-H&N35 health related quality of life questionnaires (including
Speech and Swallowing subscales) and the Hospital Anxiety and Depression Scale (HADS) were
completed by 55 HNSCC patients via OncoQuest, a touch screen computer-assisted data collection
system before their first visit and during follow-up. The patient group consisted of 38 males
and 17 females (mean age 63 years). Median time since diagnosis at follow-up was four months.
Tumor site included larynx / hypopharynx (n=22), oral / oropharynx (n=18), and other (n=15).
Tumor stage included stage I (n=20), II (n=13), III (n=13), and IV (n=9). Patients were treated by
surgery (n=9), radiotherapy (n=22), surgery and radiotherapy (n=9), or chemoradiation (n=15).
Results
No swallowing or speech problems at baseline or follow-up were noted in 22% (swallowing) and
18% (speech) of the patients; 47% (swallowing) and 22% (speech) had normal scores at baseline
and developed problems at follow-up; 4% had swallowing and 13% had speech problems at
baseline and returned to normal scores at follow-up; and 27% (swallowing) and 47% (speech) had
persistent problems from baseline to follow-up. Speech and swallowing problems were related
to tumour stage (more swallowing problems in higher stage) and site (more speech problems in
laryngeal cancer), and affected global quality of life and emotional well-being (HADS score).
Wet en s ch ap s d ag V C W 2 0 1 0 17
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Conclusion
Speech and swallowing problems in HNSCC patients are common and have a significant impact
on quality of life and emotional well-being. Identifying speech and swallowing complaints through
routine screening with the use of OncoQuest improves early detection and may enable adequate
referral to speech and swallowing rehabilitation.
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10. Secretion
of virulence factors by pathogenic
mycobacteria: how do type VII secretion systems
recognize their substrates?
Maria H. Daleke1, Roy Ummels1, Alessandro Cascioferro2, Riccardo Manganelli2, Wilbert Bitter1.
1D
epartment of Medical Microbiology and Infection Control, VU University Medical Center,
Amsterdam, The Netherlands
2 Department of Histology, Microbiology and Medical Biotechnologies, University of Padua, Padua,
Italy.
Introduction
Pathogenic mycobacteria such as Mycobacterium tuberculosis and M. marinum secrete virulence
factors via a new secretion system, called type VII secretion. One of these type VII secretion
systems, ESX-5, secretes members of the unique PE and PPE protein families. How these proteins
are recognized by the ESX-5 secretion machinery is not understood. However, since some PE
and PPE proteins have been implied in mycobacterial virulence, it is crucial to understand how
they are secreted to be able to design intervention strategies. We therefore aim our research at
identifying the ESX-5 secretion signal.
Methods
Multiple deletions were made in genes encoding PE and PPE proteins known to be secreted by
ESX-5, and the effect on secretion was analyzed in both wild-type M. marinum and in an ESX-5
mutant.
Results
We show that deletion of the N-terminal domain of PE proteins abolishes ESX-5 dependent
secretion. Moreover, the PE domain alone is already sufficient to allow secretion by ESX-5.
Interestingly, deletion of the conserved N-terminus of a PPE family member also resulted in
abolished secretion, suggesting a similar role for the PPE domain in targeting these proteins to
the ESX-5 machinery.
Conclusions
Our data suggest that the conserved PE and PPE domains share a common function, targeting PE
and PPE proteins to the ESX-5 secretion system, respectively. Small deletions and point mutations
in the PE and PPE domains are currently being generated to identify the ESX-5 secretion signal.
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11. S plit course concurrent radiotherapy and
chemotherapy in anal cancer: a single-institution
experience
Judi N.A. van Diessen¹, Otto W.M. Meijer¹, Epie Boven².
1 Department of Radiation Oncology, VU University Medical Center, Amsterdam
2 Department of Clinical Oncology, VU University Medical Center, Amsterdam.
Introduction
Including a treatment break in definitive chemoradiotherapy for anal cancer could be considered
suboptimal on radiobiological grounds. We analyzed our results with respect to tumor control
and treatment toxicity.
Methods
From January 1990 to June 2008, 62 patients were treated with 2 cycles of combined
5-fluorouracil (5-FU), Mitomycin-C (MMC) and radiotherapy (RT), delivered by split course
containing a gap of 4 weeks with an overall treatment time of 58 days. Tumors were staged as
T1 in 3.2%, T2 in 46.8%, T3 in 27.4%and T4 in 22.6%. The majority (72.6%) was N0. Pelvis and
elective inguinal lymph nodes received 24 Gy. The primary tumor and involved nodes were
boosted to a total dose of 48 Gy.
Results
Median follow-up was 37 months (range 1-165); eighteen patients (29%) experienced residual
or relapsed disease; mainly occurring within the first 2 years. Univariate analysis revealed a
significant influence of N-stage on locoregional control; no correlation was seen with gender,
T- and N- stage and stage grouping. Five-year local control and LRC rates were 77.6% and 79.2%.
Five-year overall survival, disease-free survival and colostomy-free survival were 75.5%, 70.0%
and 68.6%. Treatment was well tolerated, also in the elderly. Grade 3/4 acute skin and GI toxicity
was experienced in both 3.2% of the patients. Hematologic toxicity, specifically grade 3/4
thrombopenia and leucopenia was seen in 12.9% and 8.1%. Fecal incontinence, an important late
side effect, was not seen.
Conclusion
Split course chemoradiotherapy reveals good locoregional control without compromising anal
function.
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12. M
ultiple ligands in the mycobacterial cell envelope
determine the interaction between Mycobacterium
tuberculosis and the C-type lectin DC-SIGN
Nicole Driessen1, Jeroen Geurtsen1, Jeroen den Dunnen2, Roy Ummels1, Janneke Maaskant1,
Theo Geijtenbeek2, Wilbert Bitter1, Christina Vandenbroucke-Grauls1, Ben Appelmelk1.
1 Dept. of Medical Microbiology and Infection Control
2 Dept. of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam.
Introduction
DC-SIGN is a mannose-binding C-type lectin and the major receptor for Mycobacterium tuberculosis present on dendritic cells (DCs). It is also expressed on alveolar macrophages, but only
upon M. tuberculosis infection. The interaction of M. tuberculosis with DC-SIGN influences
the outcome of the immune response. In recent years, a variety of mycobacterial ligands for
DC-SIGN have been identified. These include the glycolipids mannose-capped lipoarabinomannan
(ManLAM) and phosphatidylinositol hexamannoside (PIM6). Here, we investigated the interaction
of DC-SIGN with these latter two glycolipids. Our aim was to find out how these molecules
contribute to the interaction between Mycobacterium and DC-SIGN.
Methods
Purified ManLAM, PIM6, and related glycolipids were coated on beads and examined for their
binding to DCs and to a Raji cell line expressing DC-SIGN using fluorescence-activated cell sorting
(FACS). Next, mutant strains in M. bovis BCG were created which do not produce ManLAM or PIM6
or neither of these. The mutant strains were studied for their binding to DC-SIGN.
Results
Our results demonstrate that DC-SIGN has a high affinity for ManLAM and PIM6, but not for less
mannosylated structures. Strikingly, the mutant strains, even the double knockout which neither
synthesizes ManLAM nor PIM6, did not bind less to DC-SIGN and dendritic cells as compared to
the parent strain.
Conclusion
Mycobacterial ManLAM and PIM6 are both DC-SIGN ligands. Nevertheless, ManLAM and PIM6 do
not dominate the Mycobacterium-DC-SIGN interaction. Hence, other mycobacterial ligands, such
as mannosylated proteins and/or α-glucan, probably also play a role.
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13. M
ir-21 as Determinant of Gemcitabine Resistance in
Pancreatic Adenocarcinoma
A. Erozencil1, E. Giovannetti1,2, N. Funel2, M. Del Chiaro2, G.J. Peters1.
1 Dept. Medical Oncology, VU University Medical Center, the Netherlands
2 University of Pisa, Italy.
Introduction
Mir-21 was reported to be overexpressed and contribute to invasion and gemcitabine resistance
in pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to evaluate whether
mir-21 expression was associated with the overall survival (OS) of PDAC patients treated with
gemcitabine and provide mechanistic insights for new therapeutic targets.
Methods
Mir-21 expression was evaluated in pancreatic cells (7 PDAC cell lines, 7 primary PDAC cultures,
fibroblasts and a normal pancreatic ductal cell line) and 30 laser-microdissected PDAC tissues by
quamtitative PCR. The role of mir-21 on the pharmacological effects of gemcitabine was studied
in cells transfected with a specific mir-21 precursor (pre-mir). Modulation of apoptosis and Akt
activation was analyzed by Annexin V and ELISA assays. Inhibitors of PI3K and mTOR (LY204002
and rapamycin) were used to test whether modulation of these signalling pathways affected
molecular mechanisms activated by mir-21 and gemcitabine activity.
Results
Patients with lower mir-21 expression had a significantly longer OS than patients with high
mir-21 levels (19 vs. 13 months; p=0.016). Mir-21 expression in the primary cultures correlated
with expression in their respective tissues, and with gemcitabine resistance in all the PDAC
cells. The treatment with gemcitabine resulted in a significant increase of mir-21 expression,
ranging from 2 to 19-fold in 13 PDAC cell lines. Pre-mir21 transfection significantly decreased
apoptosis induction by gemcitabine in 2 selected PDAC cell lines (LPC028 and LPC067), while
metalloproteinase-2/-9, and VEGF expression were up-regulated. Addition of inhibitors of PI3K
(LY294002) and mTOR (rapamycin) resulted in a decrease of phospho-AKT and overcame
pre-mir21 induced resistance in LPC006 and LPC028.
Conclusions
Mir-21 expression correlates with OS in PDAC patients. Furthermore, mir-21 contributes to
chemoresistance in PDAC cells by modulation of apoptosis and Akt phosphorylation. Mir-21 may
have an important role in the development of new targeted combinations against PDAC.
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14. S entinel node biopsy and ultrasound guided fine
needle aspiration cytology in the detection of occult
lymph node metastases in oral and oropharyngeal
cancer
Géke B. Flach1, Elisabeth Bloemena2,6, Annelies van Schie3, Otto S. Hoekstra3,
Jonas A. Castelijns4, Isaac van der Waal5,6, C. René Leemans1, Remco de Bree1.
1
2
3
4
5
6
Otolaryngology/Head and Neck Surgery
Pathology
Nuclear Medicine and PET-research
Radiology,
Oral and Maxillofacial Surgery/Oral Pathology VU University Medical Center, Amsterdam
Oral and Maxillofacial Surgery/Oral Pathology, VU University Medical Center and Academic
Center for Dentistry Amsterdam (ACTA), Amsterdam.
Introduction
Management of the clinically N0 neck in patients with oral and oropharyngeal cancer remains
controversial. In patients scheduled for transoral excision, the choice is between elective neck
dissection and watchful waiting. A reliable diagnostic technique in the detection of occult lymph
node metastases will reduce the risk of both, over- and undertreatment. Currently the most
reliable method is ultrasound guided fine needle aspiration cytology (USgFNAC). However, in
multi-institutional studies the sensitivity is variable (42-73%). Sentinel node biopsy (SNB) might
be more sensitive. The aim of this study is to evaluate the feasibility of SNB in oral and
oropharyngeal cancer and to compare SNB with USgFNAC in the detection of occult lymph node
metastases.
Methods
Patients scheduled for transoral excision of a T1-T2 oral or oropharyngeal carcinoma and a
clinically N0 neck were included. All patients underwent both diagnostic examinations, USgFNAC
and SNB. If lymph node metastases were detected the patients underwent a neck dissection. The
reference standard was 6 months of follow-up.
Results
Forty-five patients were included. Tumors were located on the lateral tongue (22), floor of
mouth (17), inferior alveolar process (3), cheek (2) and the soft palate (1). With USgFNAC in 2
patients lymph node metastases were detected, in 35 patients cytology was tumor-negative and
in 8 patients no FNAC was performed. The SN could be harvested in 44 patients. SNB showed
metastases in 9 patients. In 1 patient the SN was tumor-negative, but another excised lymph
node showed a metastasis. Of the 35 metastases-free patients, 1 developed a delayed lymph
node metastasis after 3 months of follow-up. The sensitivity of USgFNAC was 0.18 (2/11) and of
SNB was 0.82 (9/11).
Conclusions
SNB is feasible in oral and oropharyngeal carcinomas. In the detection of occult lymph node
metastases SNB is more sensitive as compared to USgFNAC.
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15. T
he novel proteasome inhibitor 5-Amino-8Hydroxyquinole (5AHQ) overcomes Bortezomib
resistance in malignant hematological cell line
models harboring mutations in the PSMB5 gene
Niels E. Franke1, Johan van Meerloo1, Linda Slot1, Xiaoming Li3, Tabitha E Wood3, Katarina
Vojtekova1, Sue Ellen Verbrugge2, Gertjan L. Kaspers1, Robert A. Batey4, Aaron D. Schimmer3,
Gerrit Jansen2, Jacqueline Cloos1.
1
2
3
4
Pediatric Oncology/Hematology
Rheumatology, VU University Medical Center, Amsterdam, Netherlands,
Princess Margaret Hospital/Ontario Cancer Institute
Department of Chemistry, University of Toronto, Toronto, Canada.
Introduction
A significant proportion of patients show acquired resistance to the proteasome inhibitor
Bortezomib (BTZ, Velcade®), which inhibits the catalytic ß5 subunit of the proteasome. The aim of
our current study was to further elucidate the molecular basis of BTZ resistance in hematologicical
cell line models and investigate whether the resistant phenotype could be overcome by the
second generation proteasome inhibitor 5-amino-8-hydroxyquinole (5AHQ), which inhibits the
non-catalytic α7 subunit of the proteasome (Li et al. ASH 2008).
Methods
Previously we reported the development a model system of three different BTZ-resistant cell lines,
including acute myeloid leukemia; THP-1 (Oerlemans & Franke et al. Blood 2008), T-cell acute
lymphoblastic leukemia; CCRF-CEM-C7 and multiple myeloma; RPMI-8226 cell line (Franke et al.
ASH 2008) after chronic exposure to stepwise increasing concentrations of BTZ. We determined
sensitivity to 5AHQ using a 4-day cytotoxicity assay (MTT) in our modelsystem.
Results
Cells were initially selected for growth at 7 nM BTZ to acquire low levels of BTZ resistance (2-3
fold higher IC50 concentrations) and subsequently challenged to concentrations of BTZ up to
500 nM to provoke higher resistance levels. Sequencing of the PSMB5 gene, encoding for the
ß5 proteasome subunit, revealed a series of mutations in individual BTZ-resistant subclones all
residing within the BTZ binding pocket. Strikingly, all BTZ-resistant selectants retained parental
cell line sensitivity towards 5AHQ.
Conclusions
Together, these data indicate that in vitro selection of low and high levels of BTZ resistance in
three hematological cell lines provokes multiple mutations in the PSMB5 gene, leading to amino
acid substitutions at key positions in BTZ binding pocket of the proteasome ß5 subunit. 5AHQ
can bypass this mode of BTZ resistance, which supports further preclinical development of this
drug and its analogues. This study is supported by VUmc - Stichting Translational Research (STR)
and The Netherlands Organization for Health Research and Development (ZonMw), The Leukemia
and Lymphoma Society and the Ontario Institute for Cancer Research through funding from the
Ministry of Research and Innovation, Province of Ontario.
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16. C
yanovirin: a novel way to prevent
Mycobacterium tuberculosis infection?
Jeroen Geurtsen1, Nicole Driessen1, Bas Gillisen1, Janneke Maaskant1, Simone Vink1,
Astrid van der Sar1, Christina Vandenbroucke-Grauls1, and Ben Appelmelk1.
1D
epartment of Medical Microbiology and Infection Control, VU University Medical Center,
Amsterdam.
Introduction
Cyanovirin (CV-N) is a mannose-binding lectin that efficiently blocks HIV-1 infection. It does so
by interacting with the viral surface and block target-cell entry via C-type lectins. Like HIV-1,
Mycobacterium tuberculosis, i.e. the causative agent of human tuberculosis, expresses a large
number of mannosylated surface structures and uses C-type lectins to gain cell access. This
suggests that CV-N, in analogy with its ability to block HIV-1, may also block M. tuberculosis
infection. Here we provide evidence that CV-N indeed exhibits this activity. This is the first report
on a compound that simultaneously inhibits M. tuberculosis and HIV-1 infection.
Methods
Binding of CV-N to mycobacteria was investigated using enzyme-linked immunosorbent assays
(ELISA) and Western blotting. The ability of CV-N to block the interaction of mycobacteria with
C-type lectins was determined using ELISA and in whole-cell binding assays. The influence of
CV-N on infection was determined in in vitro infection assays and in a zebrafish infection model.
Results
Our results demonstrate that CV-N efficiently interacts with M. tuberculosis. We identify the
glycolipid lipoarabinomannan as its major ligand and show that CV-N successfully competes with
C-type lectins DC-SIGN and mannose receptor for binding. Furthermore, we demonstrate that
CV-N inhibits mycobacterial infections both in vitro and in vivo.
Conclusions
CV-N and CV-N-like molecules form an interesting class of compounds that may be used to
combat both HIV-1 and M. tuberculosis. Furthermore, these findings indicate that a vaccine
directed against surface-exposed mannose-containing (lipo)glycans, e.g. lipoarabinomannan, may
allow for the development of a sterilizing tuberculosis vaccine.
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17. E fficacy of voice therapy in patients after treatment
of early glottic cancer
Christine D.L. van Gogh, M.D.1, Irma M. Verdonck-de Leeuw, S.L.P., Ph.D.1,
Rico N.P.M. Rinkel, M.D.1, M. Diana de Bruin, S.L.P., M.A.1, Johannes A. Langendijk, M.D., Ph.D.2,
Dirk J. Kuik, M.Sc.3, Hans F. Mahieu, M.D., Ph.D.4
1D
epartment of Otorhinolaryngology, Head and Neck Surgery, VU University Medical Center,
Amsterdam
2 Department of Radiation Oncology, University of Groningen Medical Center, Groningen
3 Department of Clinical Epidemiology and Biostatistics, VU University Medical Center,
Amsterdam
4 Voice Clinic, dept. Otorhinolaryngology, Meander Medical Centre, Amersfoort.
Introduction
After treatment of early glottic cancer a considerable number of patients end up with voice
problems interfering with daily life activities. The purpose of this randomized and controlled
study is to assess the efficacy of voice therapy in these patients.
Methods
Of 177 patients, 6 to 120 months after treatment of early glottic cancer, 70 patients (40%)
suffered from voice impairment based on a 5-item screening questionnaire. About 60% of these
70 patients were not interested in participating in the study. Twenty-three patients, willing to
participate, were randomly assigned to a voice therapy group (n=12) or a control group (n=11).
Multidimensional voice analysis (self-reported Voice Handicap Index (VHI), acoustic and
perceptual voice quality analysis, videolaryngostroboscopy, and Voice Range Profile (VRP)) was
conducted twice: before and after voice therapy or with 3 months in between for the controls.
Results
Statistical analysis of the difference scores (post- minus pre-measurement), showed significant
voice improvement after voice therapy on the total VHI-score, percent jitter and noise to
harmonics ratio in the voice signal and on the perceptual rating of vocal fry.
Conclusions
Voice therapy proved to be effective in patients with voice problems after treatment of early
glottic cancer. Improvement was not only noticed by the patients (VHI) but was also confirmed by
objective voice parameters.
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18. Personalized therapy in recurrent colorectal cancer
Jeroen A.C.M. Goos1,2, Remond J.A. Fijneman1, Albert A. Geldof2, Gerrit A. Meijer1,
Otto S. Hoekstra2.
1 Dept. of Pathology
2 Dept. of Nuclear Medicine & PET Research, De Boelelaan 1117, 1081 HV Amsterdam.
Introduction
In The Netherlands every day 13 people die as a consequence of metastases of colorectal cancer
(CRC), of which the vast majority (± 70%) is located in the liver. Selection of patients eligible for
liver resection usually is performed by positron emission tomography (PET).
Aims
1) Identify novel biomarkers for CRC liver metastases and subsequently develop suitable tracers
for PET imaging. 2) Validate 18FLT, an existing PET tracer, for its prognostic relevance in patients
with CRC liver metastases.
Methods
1) Immunohistochemical analysis is performed on tissue microarrays (TMAs) containing both
primary CRC and metastatic specimens, followed by correlation of biomarker expression to
patient survival data. Promising biomarkers will be used to develop suitable PET tracers against
by assessment of radiochemistry. Newly developed tracers will be validated in in vitro and in
vivo models. 2) The prognostic relevance of 18FLT will be validated prospectively in a multicenter
cohort clinical trial.
Results
The biomarker studies reveals to what extent (novel) biomarkers in primary CRC (preferably
linked to drug targets) are correlated to their expression in CRCLMs, allowing molecular
diagnosis of the primary tumor to predict image-ability (and potential drug-ability) of CRCLMs.
In parallel, this study reveals the added prognostic value of 18FLT PET compared to the “gold
standard” 18FDG PET.
Conclusion
This study contributes to the improvement of personalized therapy for patients with recurrent
CRC and CRCLMs by validating the prognostic relevance of 18FLT PET and other (newly developed)
PET tracers.
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19. E pstein Barr virus genome elimination by small
molecules as treatment for EBV-driven lymphomas
and carcinomas
Astrid Greijer1, Iwan de Esch2, Sabine Fleig1, Jalenka van Wijk1, Rob Leurs2,
Jaap Middeldorp1.
1 Department of Pathology, VU University Medical Center, Amsterdam
2 Division of Medical Chemistry FEW, Chemistry, VU, Amsterdam.
Introduction
Epstein-Barr virus (EBV) is a human herpesvirus causal for several types of lymphoma and
carcinoma. EBV associated tumors are aggressive and current therapies are not adequate. Our
study aims to develop a new therapy for deleting the EBV genome from tumor cells, thereby
eliminating their tumorigenic character. Maintenance of the viral genome is dependent on the
viral EBNA1 protein, which acts as a glue between the viral DNA and host chromosomes. This
essential interaction is a potent target for therapeutic intervention, which may be achieved by
special designed small molecules.
Methods
Structure-Based Drug Design (SBDD) and Fragment-Based Drug Discovery (FBDD) approaches
using the crystal structure of the EBNA1/ ori-P DNA complex revealed specific small molecules.
The candidate small molecules were functionally tested in screens analyzing EBNA1/ori-P DNA
complex formation by high throughput ELISA and a bandshift assay (EMSA). Eradication of the
EBV genome was analyzed in a cell model system in which GFP intensity correlates with the
quantity of the viral genome.
Results
Our preliminary studies testing 20 lead compounds already revealed two unique candidate
compounds proved to be effective in disrupting the EBNA1/ori-P complex. Analysis of these
molecules in a cell culture model shows a gradual loss of the EBV episome.
Conclusions
This multidisciplinary approach proved a good basis for further design and optimization of new
small molecule drugs. This new therapy will specifically decrease the EBV-driven tumour growth
while circumventing major side effects. In addition, changes in behaviour of tumour cells having
lost the EBV genome, will aid to understanding EBV-driven oncogenesis.
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20. PI3K signalling in HPV mediated transformation
F.E. Henken, P.J.F. Snijders, C.J.L.M. Meijer, R.D.M. Steenbergen.
Department of Pathology, Unit of Molecular Pathology
VU University Medical Center, Amsterdam.
Introduction
Several observations suggest that the phosphoinositide-3 kinase (PI3K) signalling pathway might
be involved in high-risk human papillomavirus (hrHPV)-mediated cervical carcinogenesis. For
example, gain of a chromosome 3q locus harbouring the PIK3CA gene (encoding the active
subunit of PI3K), as well as PIK3CA overexpression, is common in cervical carcinomas. However,
there is no functional evidence to support an active role of PI3K signalling in HPV-mediated
transformation.
Methods
To analyse the functional role of the PI3K signalling, we used a longitudinal in vitro model of
primary keratinocytes transfected with full length hrHPV mimicking the consecutive stages of
hrHPV-induced malignant transformation.
Results
Different passages of hrHPV-transfected human keratinocytes representing an immortal (passage
40-50) and subsequent anchorage independent phenotype (passage 100-120), respectively,
were tested for activation of the PI3K pathway by analysing phosphorylation of downstream
effector PKB/AKT. Phosphorylation of PKB/AKT increased with passage. Upon treatment with
the PI3K inhibitor LY294002 PKB/AKT phosphorylation was strongly reduced at both stages of
transformation. Functionally, treatment of cells with LY294002 reduced proliferation and in late
passage cells also the capacity of cells to form colonies in soft agar as well as cellular migration.
The same phenotypic effects were seen upon siRNA-mediated silencing of PIK3CA, whereas
PIK3CA overexpression showed the reverse. Finally inhibition of PI3K also resulted in reduced
differentiation of keratinocytes on organotypic raft cultures.
Conclusions
The present data indicate that the activation of the PI3K/PKB pathway, regulated by PIK3CA, plays
a prominent functional role in HPV-induced cervical carcinogenesis.
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21. A
norectal function evaluation in 600 patients:
difference between fecal incontinent continent
patients and determination of predictive factors
for fecal incontinence
T.J. Lam1, D.J. Kuik2, R.J.F. Felt-Bersma1.
1 Department of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam
2 Department of Clinical Epidemiology and Biostatistics, VU University Medical Center,
Amsterdam.
Aim
1. To investigate the diagnostic potential of anorectal function tests in patients with fecal
incontinence (FI) compared to patients without FI.
2. To conduct a model in order to determine predicting factors for FI.
Methods
Between 2003-2009, all third referral patients were evaluated according to our anorectal function
protocol including anorectal manometry (ARM) and anal endosonography (EUS). ARM includes for
instance maximal basal pressure (MBP), maximal squeeze pressure (MSP), sphincter length (SL),
rectal sensitivity (first sensation, urge and maximal tolerable volume (MTV)). EUS detects internal
(ISD) and external (ESD) sphincter defects.
Results
In total, 285(48%) patients of the 600 evaluated patients, had complaints of FI. Males and females
were analyzed separately. Incontinent and continent patients showed an overlap in tests results.
Females with FI had more watery stool, a lower MBP (39 vs 53mmHg; P<0.001) and MSP (29 vs
40mmHg; P<0.001), a shorter SL (3.0 vs 3.2cm; P=0.01), a lower MTV (184 vs 215ml; P<0.001),
and more sphincter defects (53% vs 49%) which was mainly due to combined ISD/ESD (17% vs 7%;
P=0.01).
Males with FI had a lower MBP (45 vs 55mmHg; P=0.03) and MSP (43 vs 65mmHg; P=0.02).
Six predictors were identified by logistic regression analysis and included patient’s age, stool
consistency, MBP, MSP, MTV and combined ISD/ESD. The area under the ROC-curve was 0.84.
When probability was >0.4, FI was predicted with sensitivity of 86% and negative predictive value
of 82%.
Conclusion
Incontinent and continent patients have an overlap in ARM and EUS. Female patients with FI have
a lower MBP and MSP, a shorter SL, a lower MTV and more often watery stool. Male patients
with FI have a lower MSP. Our predictor model shows a relatively high sensitivity and NPV for
predicting FI in females.
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22. W
arsaw breakage syndrome, a novel cohesinopathy
associated with mutations in the XPD helicase
family member DDX11/ChlR1
Petra van der Lelij1, Krystyna H. Chrzanowska2, Barbara C. Godthelp3, Martin A. Rooimans1,
Anneke B. Oostra1, Markus Stumm4, Ma_gorzata Z. Zdzienicka5, Hans Joenje1 and
Johan P. de Winter1.
1
2
3
4
5
Department of Clinical Genetics, VU University Medical Center, Amsterdam, The Netherlands
Department of Medical Genetics, The Children’s Memorial Health Institute, Warsaw, Poland
Department of Toxicogenetics, Leiden University Medical Center, Leiden, The Netherlands
Institute of Human Genetics, Otto-von-Guericke-University, Germany
Department of Molecular Cell Genetics, Nicolaus Copernicus University, Bydgoszcz, Poland.
Introduction
The iron-sulfur-containing DNA helicases XPD, FANCJ, DDX11, and RTEL represent a small
subclass of superfamily 2 helicases. XPD and FANCJ have been connected to the genetic
instability syndromes xeroderma pigmentosum and Fanconi anemia. Here we report a human
individual suspected to suffer from a chromosomal instability syndrome. Cells derived from
the patient showed defects in sister chromatid cohesion, a phenotype not common for genetic
instability syndromes, but specific for the ‘cohesinopathy’ Roberts syndrome.
Methods
Based upon the extreme cohesion defects in the cells of this patient, a candidate gene approach
was used, in which we investigated the expression of a whole set of proteins involved in sister
chromatid cohesion.
Results
By Western blot analysis, an extremely low expression of the helicase DDX11 was detected in the
patient cells. Mutational analysis showed biallelic mutations in the DDX11 gene.
Conclusions
Defective DDX11 is associated with a unique cellular phenotype in which features of Fanconi
anemia (drug-induced chromosomal breakage) and Roberts syndrome (sister chromatid cohesion
defects) co-exist. The DDX11 deficient patient represents a novel cohesinopathy, next to Cornelia
de Lange and Roberts syndrome, and shows that DDX11 functions at the interface between DNA
repair and sister chromatid cohesion.
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23. F unctional identification of genes and/or signalling
pathways involved in chemoradiation resistance in
head and neck cancer
Sanne Martens-de Kemp1, Arjen Brink1, Ida van der Meulen2, Joop Kuik3, Boudewijn Braakhuis1,
Victor van Beusechem2, Ruud Brakenhoff1.
1 Dept. Otolaryngology/Head and Neck Surgery
2 Dept. Medical Oncology
3 Dept Clinical Epidemiology and Biostatistics
VU University Medical Center, Amsterdam.
Introduction
Patients with advanced head and neck squamous cell carcinoma (HNSCC) are increasingly
treated with chemoradiation, but cure rates are low. Currently, there are no strong response
predictors that allow personalized treatment. We performed a functional genetic siRNA screen
to identify genes that can be used to predict upfront which tumors are likely to be eradicated by
chemoradiation.
Methods
A suitable HNSCC cell line was reverse transfected with a genome-wide library of short interfering
RNAs (siRNAs), followed by cisplatin (IC20 and IC80) or mock treatment. Genes influencing
cellular response to cisplatin were identified by comparing cell viability between the different
conditions. The screen was carried out in duplicate and data were analyzed by Z-score calculation.
Results
Scrambled siRNAs and siRNAs targeting genes known to influence cell viability or cisplatin
sensitivity were included as controls, and gave the expected results. We found 246 siRNAs that
appeared to influence cisplatin response significantly. Some of these siRNAs target genes are
already known to cause sensitivity to cisplatin, indicating the reliability of the experimental
setup. We also obtained a list of 80 genes that influenced basic cell viability of HNSCC cells,
independent of cisplatin.
Conclusions
By specifically knocking down all human genes in HNSCC cells, we obtained an unbiased list of
246 candidate genes that seem to influence the cellular response to cisplatin. Refined statistical
analysis combined with bioinformatics, the exclusion of off-target effects, as well as confirmation
of the hits in multiple cell lines are needed to validate these results.
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24. Molecular classification of familial breast cancer
Maarten Massink, Hanne Meijers, Quinten Waisfisz.
Department of Clinical Genetics, section Oncogenetics, VU University Medical Center, Amsterdam.
Introduction
Breast cancer is the leading cause of cancer related death in women world-wide. In the western
world about one in eight women develop breast cancer, accounting for one third of total cancer
incidence in woman. About ten percent of breast cancer cases cluster in families. At present only
15-20% of these familial breast cancers have been elucidated and are due to highly penetrant
germline mutations in the BRCA1 and BRCA2 genes. The identification of these genes has greatly
affected the clinical management of families with clustering of breast cancer, and has led to
improvements in the prospects of women at very high risk. The identification of novel breast
cancer susceptibility genes by means of conventional genome-wide linkage analysis in multiple
case families has been proven difficult. However, gene expression and genomic differences
between hereditary and sporadic breast tumours have been reported. Research data suggests
that mutations in the BRCA1/BRCA2 genes lead to different somatic alterations in the genomes
that progress through a specific developmental pathway leading to cancer. These differences
could give clues for further research targeted at defining tumour markers that can be used as
predictors and classifiers or in the drug target finding process.
Methods
In this study a unique series of BRCA1/BRCA2 related breast cancers will be compared with breast
cancers from families found negative for mutations of BRCA1 and BRCA2 and sporadic cases.
This will be done using SNP arrays for copy number and LOH analysis and gene expression microarrays. The correlation of these data will allow for molecular classification and identification of
distinct classes of non-BRCA1/BRCA2 breast cancers and guide new searches for causative breast
cancer susceptibility genes. Also the possibilities for devising molecular classifiers for BRCA1
breast cancers, as reported in literature, will be extensively studied.
Results/Conclusions
Preliminary results suggest that the underlying ‘intrinsic ’subtype of breast cancer, as shown
by Perou et al., have a greater impact on tumour phenotype than mutation status. Since BRCA1
tumours largely cluster to one of these subtypes, this should be accounted for when searching
for BRCA1 specific classifiers.
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25. P
rospective evaluation of quality of life in long term
oral and oropharyngeal cancer survivors and the
need for supportive care
Inge M. Oskam, M.D.1, Irma M. Verdonck-de Leeuw, Ph.D.1, Neil Aaronson, Ph.D.2,
Dirk J. Kuik, M.Sc.3, Remco de Bree, M.D.1, Ph.D., Rietveld, M.D.4,
Johannes A. Langendijk M.D., Ph.D.5, C. René Leemans, M.D., Ph.D.1
1D
epartment of Otolaryngology-Head and Neck Surgery, VU University Medical Center,
Amsterdam
2 Division of Psychosocial Research and Epidemiology, the Netherlands Cancer Institute,
Amsterdam
3 Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
4 Department of Radiation Oncology, VU University Medical Center, Amsterdam
5 Department of Radiation Oncology, University Medical Center Groningen.
Introduction
To evaluate long term (8-11 years) changes in health related quality of life (HRQOL) in oral/
oropharyngeal cancer survivors and their need for and use of supportive care.
Methods
Between 1999 and 2001, 80 advanced oral or oropharyngeal cancer patients treated with freeflap reconstruction and postoperative radiotherapy were included in a prospective study of whom
27 patients were long term (8-11 year) survivors. HRQOL of 26 patients was assessed by the
EORTC QLQ-C30 and QLQ-H&N35 questionnaires at 4 points in time, pretreatment (baseline), and
at 6 months, 12 months, and 8-11 years follow up. A study specific questionnaire was developed
to evaluate the need for and use of allied health services, peer contact, psychosocial care and
complementary care.
Results
Several aspects of HRQOL were significantly (p<0.05) deteriorated at long term follow up compared
to baseline or short term follow up in the first year after treatment: social functioning, global
quality of life, swallowing, coughing, feeling ill, problems with teeth, opening mouth, dry mouth,
sexuality, constipation and speech. During treatment patients most frequently needed a dental
hygienist (77%), a, physical therapist (73%), a speech therapist (42%), a dietician (38%) and a special
diet (62%). Eight to eleven years after treatment the need for and use of supportive care was less.
Most frequently patients still needed a dental hygienist (46%) and a physical therapist (23%).
Conclusions
To our knowledge this is the first paper that prospectively describes HRQOL in a homogeneous
patient group with a follow up of more than eight years. A significant worse HRQOL was seen
at 8-11 years follow up compared to pre-treatment levels. Head and neck specific symptoms
deteriorated persistently during time.
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26. R
elationships, pregnancies and childwish in
childhood cancer survivors: a pilot study
A. Overbeek1, M.H. van den Berg1, F.E. van Leeuwen2, C.B. Lambalk3, G.J. Kaspers1,
E. van Dulmen-den Broeder1.
1 Department of Paediatric Oncology/Hematology, VU University Medical Center
2 Department of Epidemiology, Netherlands Cancer Institute
3 Department of Obstetrics and Gynaecology, VU University Medical Center, Amsterdam.
Introduction
Childhood cancer and its treatment may have an enormous impact on psychological and
social development. Previous research shows that cancer survivors have a lower educational
and employment status than age-matched peers and achieve fewer milestones in social and
psychosexual development. Additionally, survivors are less likely to marry and to have offspring.
Methods
The study cohort consists of 5-year survivors of childhood cancer treated at VU University Medical
Center for any type of cancer and an age-matched group of sibling controls. Data are collected
by means of a questionnaire and include information on relationships, wish to have children, and
pregnancies. To date data collection has been completed for 72 survivors and 72 age-matched
controls.
Results
Median age at diagnosis was 8.3 (0-17) years. At time of study survivors and controls were aged
26.3 (18-46) and 26.1 (18-45) years, respectively. Educational level was similar in both groups.
Significantly less CCS were in a committed relationship and the rate of virginity was significantly
higher compared to controls. The percentage of CCS who were either pregnant or already had a
child at time of study was significantly lower compared to the control group. Of those survivors
and controls who did not yet have a child at time of study, 36% versus 2.5% indicated they did
not have a wish to have children. After excluding CCS and controls who were not in a committed
relationship at time of study, there was no significant difference in the wish to have children.
Conclusions
This pilot study shows that CCS are less likely to be in a committed relationship, to have had
sexual intercourse and to have been pregnant compared to sibling controls. Additionally, a
childwish seems to be less common in CCS compared to controls. In a nationwide studya, which
is currently being performed, all these outcomes will be re-evaluated in a larger study population
and in relation to treatment history.
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27. V
iral miRNAs expressed in B cells are delivered toand act in recipient cells; evidence for functional
miRNA transfer via exosomes
D. Michiel Pegtel1, Thomas Würdinger3,5, Kat Cosmopoulos2, David A. Thorley-Lawson2,
Monique van Eijndhoven1, Erik Hopmans1, Tanja D. de Gruijl4, Jelle L. Lindenberg4, and
Jaap M. Middeldorp1.
1D
epartment of Pathology, Cancer Center Amsterdam, VU University Medical Center, Amsterdam,
The Netherlands
2 Department of Pathology, Jaharis Building, Tufts University School of Medicine, Boston,
Massachusetts, USA
3 Neuro-oncology Research Group, Department of Neurosurgery, VU University Medical Center,
Amsterdam, The Netherlands
4 Department of Medical Oncology, VU University Medical Center, Amsterdam,The Netherlands
5 Molecular Neurogenetics Unit, Massachusetts General Hospital, Harvard Medical school,
Boston,USA.
Introduction
Non-coding regulatory microRNAs (miRNAs) of cellular- and viral origin control gene expression
by repressing the translation of messenger RNAs (mRNAs) into protein. Surprisingly, viral miRNAs
are present in secreted vesicles from infected B cells known as exosomes which are present in
both human sera and culture media. This suggests a novel function for miRNAs outside the cells
in which they were produced.
Methods
To investigate whether transferred EBV-miRNAs can act in uninfected recipient cells, we mimicked
miRNA transference through exosomes using a novel co-culture model in vitro, luciferase miRNAbased reporter assays and quantitative mature-miRNA multiplex RT-PCR.
Results
We demonstrate that EBV-encoded miRNAs are secreted in large amounts by infected B cells
through exosomes. The released exosomes are efficiently internalized by neighboring recipient
cells, including primary monocyte-derived dendritic cells (MoDC). To further investigate whether
miRNA-mediated gene silencing may have a role in inter-cellular communication, we designed
reporter-assays in which we express full-length 3’-UTR luciferase target constructs in recipient
cells. Accumulation of EBV-miRNA copy numbers in MoDC upon exosome transfer was measured
by quantitative RT-PCR and lead to a dose-dependent, miRNA-mediated repression of specific
EBV-miRNA target genes, including CXCL11/ITAC, an immuno-regulatory gene commonly downregulated in primary EBV-associated lymphomas. Finally, we demonstrate that Epstein Barr virus
(EBV) BART-miRNAs are expressed by infected circulating B cells in humans and also present in
relevant amounts in circulating non-infected non-B cells.
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Conclusions
Collectively, our studies show that primary MoDCs, upon exosome internalization transport
exosome-associated exogenous viral miRNAs to the cellular compartments that mediate
miRNA-dependent gene silencing. Thus, viral miRNAs may exploit a novel miRNA-mediated
communication pathway between human lymphocytes and monocytes. This work is funded by a NWO-Veni grant awarded to D. Michiel Pegtel
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28. T
runcating TP53 mutations have prognostic
significance in head and neck squamous cell
carcinoma
Marlon van der Plas¹, Ruud H. Brakenhoff1, Dirk J. Kuik2, Marijke Buijze1, Elisabeth Bloemena3,4,
Peter J.F. Snijders4, C. René Leemans1, Boudewijn J.M. Braakhuis1.
1 Department of Otolaryngology/Head-Neck Surgery, VU University Medical Center, Amsterdam
2 Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam
3 Department of Maxillofacial Surgery/Oral Pathology, Academic Center of Dentistry Amsterdam
(ACTA)
4 Department of Pathology, VU University Medical Center, Amsterdam.
Introduction
TP53 is a key gene in cellular homeostasis and is frequently mutated in head and neck squamous
cell carcinoma (HNSCC). There is a variety of TP53 mutations, each of which may have its own
biological and clinical consequences. Aim of the study was to assess the prognostic significance
of TP53 mutations in HNSCC and to identify the most relevant mutation category.
Methods
The TP53 mutation status was investigated in 141 consecutive HNSCC with known HPV-status and
this was correlated with overall and progression-free survival. Patients were treated by surgery
followed by radiotherapy on indication. Four mutation classifications were investigated.
Results
A TP53 mutation was found in 88 (62.4%) of the carcinomas and was not associated with overall
survival (Hazard ratio (HR) 1.65 with 95% confidence intervals (CI): 0.89 and 3.07, p=0.113).
Patients with a mutation resulting into a truncated protein (N=36), had a significantly worse
overall survival (HR: 2.54 [1.28 - 5.05] p=0.008), as compared with wild type TP53.
A missense (i.e. non-truncating) mutation did not effect prognosis as compared to wild type
TP53 (overall survival HR: 1.15 [0.56 - 2.36] p=0.704). Other ways of classification (disruptive
vs. non-disruptive, hotspot vs. non-hotspot and DNA-binding vs. non-DNA-binding) were less
discriminative and HPV-status was confounding in these associations.
Conclusions
Truncating mutations in the TP53 gene are an important independent predictor for a poor
prognosis of HNSCC patients primarily treated by surgery followed by radiotherapy on indication.
A loss of function mutation leads to a more aggressive type of disease.
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29. Treatment of Osteosarcoma Lung Metastases
J. Posthuma de Boer1, M. N. Helder1, V.W. van Beusechem2, G.J.L. Kaspers3, B.J. van Royen1.
1 Department of Orthopaedic Surgery, VU University Medical Center, Amsterdam
2 Department of Medical Oncology, VU University Medical Center, Amsterdam
3 Department of Pediatric Oncology/Haematology, VU University Medical Center, Amsterdam.
Introduction
Osteosarcoma is the most common primary bone tumor in children and adolescents. It has a
worldwide incidence of 4 per million, with a peak incidence at the age 15-19 years. This type of
tumor has a high tendency to systemic spread; more than 60% of all patients develop metastatic
disease. Approximately 80% of all metastases arise in the lungs. Despite aggressive multi-agent
treatment regimens there is a high mortality rate in patients with distant metastases.
The overall 5-year survival rate is 65%. For patients with recurrent or spread disease, the survival
rates are around 20%. Metastatic disease is less sensitive to chemotherapeutic treatment.
Over the last two decades there has been little improvement in survival rates for patients with
osteosarcoma. There is a necessity for novel treatment modalities.
The aim of this study is to enhance the treatment of osteosarcoma lung metastases.
Methods
siRNA (kinase) screen: Screen 800 kinases for their effect on cell death after treatment with
doxorubicin. Identify kinases in osteosarcoma cells that influence the sensitivity of OS to
doxorubicin. If you can target molecules that cause insensitivity to chemotherapy, you sensitise
OS cell to chemotherapy, and enhance the cytotoxic effect of doxorubicin. This could lead to
better outcome rates or perhaps dose reduction of doxorubicin which gives serious adverse
effects. Surface proteomics: Define surface molecules and secretory molecules specific for
metastasising osteosarcoma cells. Asses their use as target for targeted (gene) therapy, or as a
therapeutic target itself. Mouse model for human OS lung metastases in nude mice: Upon tail
vein injection with human OS cells with high metastasising potential, lung tumors will develop
after 7 weeks. Mice are sacrificed after 10 weeks. This model provides a good validation tool for
in vitro results. By stably transducing metastasising OS cells with a fLuc.MC construct, these cells
will omit photons upon administration with D-luciferin, allowing for Bioluminescence imaging of
the tumors in mice and real-time follow up of tumor burden and possible therapeutic effects.
Conclusions
In vitro and In vivo experiments are ongoing.
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30. S tructured life review using autobiographical
retrieval practice in depressed palliative head and
neck and lung cancer patients
Irene Riepma1,2, Bas Steunenberg1, Remco de Bree2, Rene Leemans2, Annemarie Beckers3,
Egbert Smit3, Pim Cuijpers1, Michiel van den Brekel4, Ernst Bohlmeijer5, Vincent Willemsen6,
Irma Verdonck- de Leeuw1,2.
1
2
3
4
5
6
Department of Clinical Psychology, VU University
Department of Otolaryngology – Head & Neck Surgery, VU University Medical Center
Department of Pulmonary Diseases, VU University Medical Center
Department of Otolaryngology – Head & Neck Surgery, Netherlands Cancer Institute
Department of Mental Health, University Twente
Ingeborg Douwes Centrum, Center for Psychosocial Care, Amsterdam.
Introduction
Incurable ill cancer patients often experience feelings of depression and emotional distress. In
clinical practice there is an urgent need for evidence based interventions. The goal of this study
is to assess effectiveness of a structured life review protocol in palliative cancer patients.
Methods
150 head and neck or lung cancer patients with depressive symptoms who are treated without
curative intent, will be randomized into an intervention group, receiving the Life Review Therapy
(4 sessions in the home situation of the patient), and a control group (waiting list). The Life
Review therapy focuses on retrieving positive memories from the past and generating a coherent
and meaningful autobiography. This enables re-evaluation of life events and reconstruction of the
story of life, including the diagnosis of incurable cancer. Outcome measures include specificity of
autobiographical memory, depression, emotional distress, and quality of life.
Results
A pilot study is ongoing. Preliminary findings indicate that structured screening of quality of life
in clinical practice and prompt referral is needed to include patients timely. Patients and also
their partners appreciate the intervention targeting depressed feelings of the patient, indicating
that patients as well as their partners may benefit.
Conclusions
Based on the pilot study, the intervention protocol will be optimalized. OncoQuest (a touch
screen computer system) will be used to screen for depressive symptoms in clinical practice.
Outcome measures will be extended to assess emotional distress and quality of life of patients’
relatives as well. The randomized controlled trial will start in April 2010.
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31. D
evelopment of a genome wide screen to identify
genes involved in modulating p53 transcriptional
activity in lung cancer
Ellen Siebring-van Olst1, E.F. Smit1, V.W. van Beusechem2.
1 Department of Pulmonary Diseases, VU University Medical Center, Amsterdam
2 Department of Medical Oncology, VU University Medical Center, Amsterdam.
Introduction
Lung cancer remains the major cause of cancer related deaths throughout the world. Therapeutic
options are limited. Cisplatin, a DNA-damaging agent, is the cornerstone in the treatment of
advanced non small cell lung cancer (NSCLC), yet is effective in only 30% of these patients. p53,
a well known tumor suppressor protein, is involved in both DNA-repair and apoptosis. Loss
of p53 is associated with an adverse clinical outcome. In this project, we hypothesize that up
regulating p53 activity will render NSCLC more sensitive to treatment and thus favor clinical
outcome. We aim to identify genes that modulate p53 activity by a functional genomics approach
using RNAi technology. For this, a new assay has to be developed.
Methods
Choice of cell line: A549 (adenocarcinoma of the lung) with a luciferase p53 activity reporter.
Functional genomics: the Human siGenome SMARTpool library consisting of siRNA’s against
21.000 gene transcripts and the CCA RIFOL screening facility will be used.
Results
A suitable home made luciferase reagent and protocol have been developed for use in a genome
wide screening setting. The luciferase assay shows satisfying stability for more than two hours.
Both up- and down regulation of p53 activity in A549 are readily detectable by this assay.
Conclusions
An in-house developed screening method will identify modulators of p53 activity in A549. Hits
will be validated and effect on chemosensitivity will be assessed in a variety of NSCLC cell lines.
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32. H
igh aldehyde dehydrogenase activity is general
marker for normal hematopoietic stem cells but not
leukemic stem cells in Acute Myeloid Leukemia
Gerrit-Jan Schuurhuis, Lisa Min, Monique Terwijn, Angele Kelder, Sander Snel, Gert Ossenkoppele,
Linda Smit.
Department of Hematology, VU University Medical Center, Amsterdam.
Introduction
Only a minority of cells, the leukemic stem cells (LSCs), within Acute Myeloid Leukemia (AML)
are typically responsible for tumor growth and maintenance. Many patients experience a relapse
after therapy which originates mainly from the outgrowth of therapy resistant LSC. Therefore,
eradication of the LSCs is necessary to cure leukemia. Both the normal hematopoietic stem cells
(HSCs) and LSCs co-exist in the bone marrow (BM) of leukaemia patients and therefore success
of an anti-stem-cell strategy relies on specific induction of LSC death while sparing the normal
HSC. In AML, apart from the CD34+CD38- and the side population (SP) compartment, the high
aldehyde dehydrogenase (ALDH) activity compartment contains the LSCs. ALDH is a detoxifying
enzyme responsible for the oxidation of intracellular aldehydes. High ALDH activity results in
resistance to alkylating agents such as the active derivatives of cyclophosphamide.
Results
We have previously shown that CD34+CD38- and SP LSCs can be identified and discriminated
from HSCs using stem cell-associated cell surface markers, including C-type lectin-like molecules
(CLL-1), lineage markers, such as CD7, CD19, and CD56 and recently cell size characteristics as
measured by flow cytometry. Here we have analyzed ALDH activity in normal HSCs and LSCs, both
present within the same BM, in 23 AML patient samples. In 7 AML cases, a high SSCloALDHbr cell
population was identified (>5%).
We show that in 9 BM AML samples, defined as CD34min (ie <1% CD34+ cells, in which the
CD34+CD38- cells are all normal HSC), the ALDH activity is lower in the LSC then in the HSC. In
9 BM AML patients, defined as CD34+ and with both normal and leukemic CD34+CD38- present,
we show that the marker positive CD34+CD38- LSCs have lower ALDH activity then the marker
negative CD34+CD38- HSCs. Altogether, we show that a common feature of all AML cases is
that the HSCs that co-exist with LSC in the BM of AML patients have a higher ALDH activity as
compared to their malignant counterparts.
Conclusion
In conclusion, high ALDH activity is an unique marker of normal HSC within the AML BM at
diagnosis. Consequently, AML patients with high ALDH activity in the normal HSC might benefit
from treatment with alkylating agents such as mafosfamide, whereby the difference between the
ALDH activity in LSC and HSC defines the therapeutic window. At present, drugs, known to be
dependent on low ALDH for proper activity, are tested for their LSC specific killing while sparing
the normal HSC.
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33. M
ethylation of WNT/_-catenin pathway regulators in
cervical carcinomas
S. Snellenberg, W.F. van der Meide, C.J.L.M. Meijer, P.J.F. Snijders, R.D.M. Steenbergen.
Department of Pathology, VU University Medical center, Amsterdam.
Introduction
The incidence of adenocarcinoma (AdCA) in relation to squamous cell carcinoma (SCC) of the
cervix has increased during the last half century. Particularly AdCA and its precursor lesion,
adenocarcinoma in situ (ACIS), are frequently missed in current screening programs. High-risk
human papillomavirus (hrHPV) testing improves early detection of ACIS/AdCA. However, only a
fraction of hrHPV positive women have or will develop ACIS/AdCA, therefore additional ACIS/
AdCA specific biomarkers are needed. Present results show that (epi)genetic signatures differ
between SCC and AdCA. This opens possibilities for novel biomarkers enabling specific detection
of ACIS/AdCA in hrHPV positive women. Since aberrant activation of the Wnt/_-catenin signaling
pathway is common in human AdCAs and promoter methylation can be reliably detected in
cervical scrapes, we analysed potential methylation events in the Wnt/_-catenin pathway.
Method
Five negative modulators of the Wnt/_-catenin pathway (DKK3, SFRP2, SFRP4, APC and WNT5A)
were tested for DNA methylation in AdCA using methylation specific PCR (MSP). DKK3 and SFRP2
were further evaluated using quantitative MSP (qMSP) on hrHPV positive cervical biopsies showing
the following histologies: SCC (n=20), AdCA (n=50), ACIS (n=22) and normal biopsies (n=21).
Results
The frequency of DKK3 and SFRP2 methylation was significantly higher in AdCA compared to
SCCs (each 84% vs. 25%; p£0.001). In ACIS, frequency of DKK3 and SFRP2 methylation were 41%
and 45%, respectively. In comparison, DKK3 and SFRP2 methylation was only detected in 10% and
0%, respectively, of normal biopsies.
Conclusion
Promoter methylation of DKK3 and SFRP2 is specifically associated with cervical AdCA and may
thereby contribute to a biomarker panel for the early detection of ACIS and AdCA in hrHPV
positive women.
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34. F ingerprinting the human gut microbiome:
evaluation of a Terminal Restriction Fragment
Length Polymorphism (T-RFLP) kit on human
gastrointestinal biopsies
D. Soeltan-Kaersenhout1, Adriaan A. van Bodegraven2, P.H.M. Savelkoul1*.
1 Department of Clinical Microbiology and Infection Control
2 Department of Gastroenterology and Hepatology, VU University Medical Center Amsterdam,
the Netherlands.
Shifts in microbial composition of the human gut are thought to play a causal role in the
development and sustenance of intestinal disorders such as inflammatory bowel disease (IBD)
and colon cancer. Because of the limitations of culture techniques, molecular methods have
become the prime choice for obtaining a rapid view of the diversity of the microbial composition
of the human gut. Terminal restriction fragment length polymorphism (T-RFLP) is a molecular
fingerprinting method for characterization of complex microbial communities. In this study, the
performance of a recently developed T-RFLP kit was evaluated on human colon biopsies. The kit
provides a PCR mix which amplifies the 16S rRNA gene with two different fluorescently labelled
primers (FAM/NED). After amplification, an endonuclease mixture containing MspI and HinPI1 is
added to each PCR vial.
Subsequently, the molecular weight of the labelled terminal restriction fragments is retrieved in
an automated DNA sequencer. In theory, each species will produce a unique combination of a
FAM and a NED peak in the resulting electropherogram.
The sensitivity of the kit was determined by analysis of a dilution series of quantified bacterial
cultures of three common inhabitants of the human gut: Bacteroides vulgatus, Bifidobacterium
adolescentis & Escherichia coli. In addition, a total of 100 mucosal colon biopsies from 20 healthy
individuals were tested. Duplicate DNA samples were analyzed to examine the reproducibility
of the patterns. The sensitivity of the kit proved to be 1,000 colony forming units per microliter
(CFU/uL) for E. coli and 100 CFU/uL for B. vulgatus. At a concentration of 100,000 CFU/uL
for B. adolescentis, the FAM-labelled fragment alone was barely detected. Subsequent primer
sequence alignment showed suboptimal priming of the reverse primer with Bifidobacterium spp.
Human intestinal biopsy sample profiles were highly reproducible (approximately 95%). Intra- and
interindividual differences were found and comparable to previous results obtained with our
in-house T-RFLP test. However, the sensitivity of the kit is not very high with a maximum of 100
CFU/uL for B. vulgatus. Moreover, the poor detection of Bifidobacterium spp. is not favourable
considering the proposed importance of this genus in health and disease of the human gut. This
should be improved before the T-RFLP kit is suited for testing human gastrointestinal samples. In
general, the ready-to-use T-RFLP kit allows for a rapid and simple way to obtain T-RFLP profiles.
This is of importance for high throughput analyses in a clinical setting.
*corresponding author. E-mail: p.savelkoul@vumc.nl
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35. T
wo sides of a coin; bacterial and host genes
involved in granuloma formation
Esther J.M. Stoop1, Fredericke Hannes1, Annemarie H. Meijer2, Christina M.J.E. VandenbrouckeGrauls1, Wilber Bitter1 and Astrid M. van der Sar1.
1D
epartment of Medical Microbiology and Infection control, VU University Medical Center,
Amsterdam
2 Institute of Biology, Leiden University, Leiden.
Introduction
Mycobacterium tuberculosis causes tuberculosis, which is characterized by granuloma formation.
Despite decades of investigation, it is still not exactly known how mycobacteria establish
infection. The currently used live vaccine strain has delayed granuloma formation. This is due to
a partial deletion of the ESX1 region; a genetic locus encoding a secretion system responsible for
secretion of virulence proteins. Unfortunately, the efficacy of the vaccine does not reach 100%.
Our aim is to identify mycobacterial genes involved in granuloma formation.
Methods
In this study, we make use of the Mycobacterium marinum - zebrafish model. M. marinum is
closely related to M. tuberculosis and causes fish tuberculosis. We are screening a random mutant
library of M. marinum in order to identify mutants impaired in granuloma formation.
Additionally, a micro-array study was performed on zebrafish infected with either wild-type
bacteria or a granuloma mutant, in order to identify zebrafish genes that are upregulated upon
mycobacterial granuloma formation.
Results
Upon screening 200 mutants, we identified four mutants with reduced granuloma formation. Two
of the four mutants have a mutation in ESX1 related genes. Interestingly, the other two mutants
are not ESX1 related.
Furthermore, we have demonstrated that matrix metallo protease 13 (MMP13) is specifically
upregulated when granulomas are formed.
Conclusion
Our zebrafish embryo screen identifies bacterial genes necessary for granuloma formation.
Besides ESX1 related genes, which we expected, we have found new genes that are involved in
granuloma formation.
Furthermore, we investigate zebrafish genes that are upregulated upon granuloma formation and
the possibility to use these genes as markers in our granuloma studies.
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36. M
icroRNA profiling for reducing colorectal cancer
death by improving early diagnosis
Lisette Timmer1, Anne Bolijn1, Edwin Cuppen2, Gerrit Meijer1 and Begoña Diosdado1.
1 Department of Pathology, VU University Medical Center, Amsterdam
2 Hubrecht Institute, Utrecht.
Introduction
Colorectal cancer (CRC) is the second leading cause of cancer death in the Western world. Better
understanding of the molecular biology of CRC and development of a screening test based on
biomarkers that are directly shed from the tumor into stool will make it possible to reduce the
high number of CRC-related deaths. Recently, a novel class of non-coding RNAs called microRNAs
(miRNAs) have shown to be master regulators of central mechanisms of tumorigenesis. Besides
their biological importance, their potential in diagnostics and therapeutics has become evident. In
CRC, although differentially expressed miRNAs have been identified, their causative role in CRC
adenoma to carcinoma progression has not been elucidated. In addition, miRNAs may provide
new biomarkers for early detection of CRC.
Aim
To investigate the contribution of miRNAs in colorectal adenoma to carcinoma progression in
order to develop a small RNA based stool test for early detection of CRC.
Methods
Differentially expressed miRNAs between adenomas and carcinomas will be obtained using
miRNAs expression microarrays. Further DNA copy number changes and epigenetic changes will
be correlated to their expression and a miRNA library will be used to determine their contribution
to the pathogenesis of the disease. Last, a predictive classifier based on the miRNA expression
signatures, which can discriminate between colorectal adenomas and carcinomas, will be
determined.
Preliminary results
We have identified the expression of 117 differentially expressed (p<0.05) miRNAs during
adenoma to carcinoma progression. The identification of the cause of their altered expression
and their target genes lead us to unravel that the expression of the miRNA cluster miR-17-92
is associated to DNA copy number gain of 13q during colorectal adenoma to carcinoma
progression. Last, we already found a predictive classifier that distinguished 41 small non-coding
RNA molecules, which can predict whether a colorectal tumor is an adenoma or a carcinoma.
Further validation of these results has been started.
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37. D
ifferences in FIT results between screening and
referred colorectal cancer patients are explained by
differences in tissue tumor stage
S.T. van Turenhout1, L.G.M. van Rossum2, F.A. Oort1, R.J.F. Laheij2, A.F. van Rijn3, P. Fockens3,
G.A. Meijer4, J.B.M.J. Jansen2, E. Dekker3 and C.J.J. Mulder1.
1
2
3
4
Gastroenterology and Hepatology, VU University Medical Center, Amsterdam
Gastroenterology and Hepatology, Radboud University Nijmegen Medical Center
Gastroenterology and Hepatology, Academic Medical Center, Amsterdam
Pathology, VU University Medical Center, Amsterdam.
Introduction
Studying immunochemical faecal occult blood tests (FITs) in patients referred for colonoscopy
compared with average-risk subjects in screening studies, has the important advantage that
colonoscopy is performed in all subjects. Although (some) outcome measures might be
overestimated in referral populations with higher prevalence of colorectal cancer (CRC), we
hypothesise that differences can be explained by differences in tumour stage distribution.
Methods
This study aimed to compare quantitative FIT results according to tissue tumour stage in
a referral population and a screening population. Between June 2006 and February 2007 a
population-based screening study randomly assigned individuals to perform a FIT (OC-Sensor®).
This was also used in a prospective study started in patients referred for elective colonoscopy.
Cases with FIT values ≥50ng/ml were compared. Differences in log(FIT values) per T-stage
between the two groups were analysed with the t-test and logistic regression analysis.
Results
94 CRC patients were included: 28 screening cases (64% male; mean age 63, SD 6.4) and
66 referral cases (45% male; mean age 67, SD 9.2). The overall average log(FIT value) was
significantly higher in the referral population (613ng/ml (6.5) vs 767ng/ml). According to
T-stage, no significant difference in log(FIT values) existed between both populations (p=0.98
(T1), p=0.50 (T2) and p=0.22 (T3+T4)).
Conclusion
This study suggests that population differences in performance of the FIT mainly result from
differences in tumour stage distribution. Therefore, studies on FIT performance in referral
populations are valuable at least until screening data are available.
Wet en s ch ap s d ag V C W 2 0 1 0 47
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38. P
erformance of an integrated risk profile for
selection of high risk individuals for colorectal
cancer screening
S.T. van Turenhout1, I. Stegeman2,3, F.A. Oort1, B.S. Ferket2, C.K. van Kalken2, G.A. Meijer4,
R.A. Kraaijenhagen2, C.J.J. Mulder1.
1
2
3
4
Gastroenterology and Hepatology, VU University Medical Center, Amsterdam
NDDO Institute for Prevention and Early Diagnostics (NIPED), Amsterdam
Clinical Epidemiology and Biostatistics, Academic Medical Center, Amsterdam
Pathology, VU University Medical Center, Amsterdam.
Background
Screening by fecal occult blood tests (FOBTs) can decrease colorectal cancer (CRC) mortality, but
the positive predictive value (PPV) for advanced neoplasia (AN) is low. It would probably be more
effective to include an individual CRC risk profile. A multiple disease risk profiling program
including CRC screening, the PreventionCompass (PC), is evaluated for PPV of AN.
Methods
CRC risk profiling was offered to participants of the PC (50-75 years old). The probability for
advanced neoplasia (AN) was calculated based on an immunochemical fecal occult blood test
(FIT) and different risk factors: first degree relative with CRC, calcium intake, smoking, alcohol,
BMI, physical activity, history of IBD, previous colonoscopies, use of aspirin or NSAIDs. Individuals
with FIT results ≥50 ng/ml were included, and PPV of FIT and risk factors was compared to FIT
screening only.
Results
1,699 participants completed CRC risk profiling, and 166 (10%) were referred for colonoscopy.
Complete data were available for 129 referred subjects at time of analysis. 110 (85%) of this
subgroup underwent colonoscopy. PPV for AN was 31% (n=34; PPV for CRC 5%, PPV for advanced
adenoma 25%).
The PPV for AN in FIT positive participants with none or low levels of risk factors (18%) was
significantly lower (p=0.008), compared to FIT positive participants with high levels of risk factors
(47%). The OR for AN in the last group was 4.13 compared to the first group (p= 0.011).
Conclusion
In a screening program, including a CRC risk profile in addition to FIT can significantly increase
the PPV for advanced neoplasm’s.
48
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39. B
aseline RANKL: OPG ratio and markers of
bone and cartilage degradation predict annual
radiological progression over 11 years in
rheumatoid arthritis
Lilian H.D. van Tuyl1, Alexandre E. Voskuyl1, Maarten Boers1, Piet Geusens2,
Robert B.M. Landewe2, Ben A.C. Dijkmans1, Willem F. Lems1.
1 VU University Medical Center, Amsterdam
2 University Medical Center Maastricht, Maastricht.
Introduction
Traditional predictors of radiological progression in rheumatoid arthritis (RA) are mostly markers
of inflammation. We investigated to what extent baseline measurements of the ratio of receptoractivator of nuclear-factor-_B-ligand (RANKL) / osteoprotegerin (OPG) and C-terminal cross linking
of type-I and type-II (CTX-I and CTX-II) in addition to traditional markers of disease severity, could
predict annual radiological progression.
Method
A cohort of 155 early, active RA patients was followed for 11 years. Urine was sampled at
baseline and after 3 months from start of treatment and analyzed for CTX-I and CTX-II. Baseline
serum samples were analyzed for RANKL and OPG. A digital database of frequent radiographs
and baseline measures of traditional markers of disease severity were available. Individual annual
progression rates were calculated and used as outcome variable. Multiple linear regression
analyses identified the strongest predictors.
Results
In multivariable analyses the RANKL:OPG-ratio and CTX-I or CTX-II proved to be independent
predictors of annual radiological damage over 11 years. The prediction of annual radiological
progression was strongest when the RANKL:OPG-ratio and CTX-I or CTX-II were evaluated in the
same model (36 to 39% explained variance). Adding the effect of treatment at 3 months to the
baseline models improved the predictive ability of the models up to 46%.
Conclusion
Unfavorable baseline levels of the RANKL:OPG-ratio as well as CTX-I (markers of bone resorption)
and CTX-II (a marker of predominantly cartilage degradation) in patients with early, active,
untreated RA are strong independent predictors of rapid and persistent damage progression over
11 years follow up.
Wet en s ch ap s d ag V C W 2 0 1 0 49
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40. M
easurement of [11C]docetaxel uptake and tumour
perfusion in lung cancer using PET-CT
Astrid A. van der Veldt1, Mark Lubberink1, Emile F.I. Comans1,
Henri N.J.M. Greuter1, Robert C. Schuit1, Arthur van Lingen1, S. Nafees F. Rizvi1,
Martien P.J. Mooijer1, Anneloes Y. Rijnders1, Albert D. Windhorst1, Egbert F. Smit2,
N. Harry Hendrikse1, Adriaan A. Lammertsma1.
1 Department of Nuclear Medicine & PET Research
2 Department of Pulmonology, VU University Medical Center, Amsterdam.
Introduction
Although docetaxel has anti-tumour activity in lung cancer (LC), a number of patients does not
benefit from this treatment due to tumour resistance. Positron emission tomography (PET) is a
non-invasive imaging technique that allows for quantification of [11C]docetaxel kinetics. Imaging
of [11C]docetaxel may be useful for personalized treatment planning. The purpose of the present
study was to assess [11C]docetaxel uptake in LC and to investigate whether it was related to
tumour perfusion.
Methods
Fourteen patients with advanced LC underwent dynamic PET-CT scans with [11C]docetaxel
(60 min) and H215O (10 min). Lesions were delineated on the CT scan and projected onto the
dynamic PET frames. [11C]docetaxel uptake in tumours was quantified using the net influx rate
(Ki). Tumour perfusion was quantified by applying the standard single tissue compartment model
to the H215O data.
Results
In total, 24 lesions were defined, including primary tumours and metastases. Clearance of [11C]
docetaxel from plasma was rapid and later PET frames suffered from high liver uptake. Therefore,
only the first 10 min of data were used for further analysis. The median net influx rate of [11C]
docetaxel was 0.009 min-1 (range, 0-0.022). The inter-and intra-individual variability of [11C]
docetaxel uptake was high. [11C]docetaxel uptake was highly correlated with tumour perfusion
(Pearson’s correlation coefficient, p<0.001).
Conclusions
Measurement of [11C]docetaxel uptake in LC is feasible. The inter-lesion variability of [11C]
docetaxel uptake may reflect differential sensitivity to docetaxel treatment. [11C]docetaxel uptake
depends on tumour perfusion, suggesting that combination therapy consisting of docetaxel and
antiangiogenic agents may affect docetaxel delivery to tumours which could have therapeutic
implications.
50
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41. Methylation pattern of high risk flat lesions in CRC
Quirinus J.M. Voorham1, Beatriz Carvalho1, Angela J. Spiertz2, Nicole C.T. van Grieken1,
Sarah Derks2, Heike I. Grabsch3, Bjørn Rembacken4, Martin Kliment5, Adriaan P. de Bruïne2, Chris J.
Mulder6, Manon van Engeland2, Gerrit A. Meijer1
1
2
3
4
5
6
Dept of Pathology, VU University Medical Center, Amsterdam, The Netherlands
Dept of Pathology, University Maastricht, Maastricht, The Netherlands
Pathology and Tumour Biology, Leeds Institute of Molecular Medicine, University of Leeds, UK
Centre for Digestive Diseases, Leeds General Infirmary, Leeds, UK
Gastroenterology, Hospital Vitkovice, Ostrava, Czech Republic
Dept of Gastroenterology, VU University Medical Center, Amsterdam, The Netherlands.
Introduction
Flat colorectal adenomas are considered to have a different molecular pathogenesis than regular
polypoid-shaped lesions and are associated with more aggressive clinical behaviour. In CRC
development methylation is an early event, but little is known about promoter hypermethylation
in flat lesions. The Aim of this study is to analyze the methylation status of 10 CRC-related genes
in flat lesions and compare this to established methylation patterns of polypoid lesions.
Methods
86 FFPE flat adenomas, (classified according to the Paris classification) and 17 flat carcinomas
were analysed. Promoter methylation status of 10 genes (O6MGMT, hMLH1, APC, p14ARF, p16INK4A,
RASSF1A, GATA-4, GATA-5, CHFR and HLTF) was studied by methylation-specific PCR (MSP).
Results
The methylation frequency of these genes in flat adenomas was comparable to that observed in
polypoid adenomas except for GATA-5 (P=0.001) which was significantly less frequent methylated
in flat adenomas. For the flat carcinomas the promoter region of CHFR was less frequently
methylation compared to polypoid carcinomas (P=0.01).
Conclusions
For these 10 genes methylation status was similar for flat and polypoid lesions, except for lower
promoter methylation of GATA-4 in flat adenomas and CHFR in flat carcinomas. This is consistent
with methylation being an early event in pathogenesis of both flat and polypoid colorectal
carcinomas.
Wet en s ch ap s d ag V C W 2 0 1 0 51
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42. IFN signature determines responder statua on B cell
depletion in Rheumatoid Arthritis patients
Saskia Vosslamber1, Hennie Raterman2, Tineke v.d. PouwKraan, Michael T. Nurmohamed3,
Willem F. Lems2, Ben A.C. Dijkmans2, Alexandre Voskuyl2, Cor Verweij1.
1 Department of Pathology
2 Department of Rheumatology, VU University Medical Center, Amsterdam.
Introduction
B cells are supposed to play an important role in rheumatoid arthritis (RA). Accordingly,
rituximab, a chimeric monoclonal antibody against CD20, effectively depletes B cells ameliorates
disease although a subset of patients don’t respond. We aimed to identify biomarkers and
biological processes underlying non-responsiveness. Therefore, the effect of rituximab on
gene-expression levels in peripheral blood (PB) was studied.
Methods
RNA was isolated from PB samples collected from 13 RA patients before, three and six months
after start of treatment. Gene-expression profiling was performed using Illumina HumanHT 12-vs
bead chips. Additional, RNA was isolated from PB collected before start of treatment in a second
cohort of 10 RS patients. Gene expression levels of a selection of type-I IFN-response genes (IRG)
were measured using Fluidigm technology, a Taqman realtime PCR-based multiplex array. Clinical
responder status was determined after three and six months by change in disease activity score
(∆DAS28).
Results
Pharmacogenomics revealed 16 B-cell related genes that were significantly down-regulated after
three months in all patients. Subsequent analysis of expression profiles of patients ranked by
increasing ∆DAS after six months learned that a good response (∆DAS28>1.2) is observed for
patients with a low expression level of IRG at baseline (P=0.0065). An increase in IRG-expression
was observed only for good responders (∆DAS28>1.2), whereas no induction or decrease was
found for non-responders. Classifying patients based on baseline IRG profile (IRGhigh or IRGlow)
showed that all IRGhigh classified patients (100%) have a ∆DAS28<1.2 whereas 87.5% of the IRGlow
classified patients have a ∆DAS28>1.2. Same positive predictive value of IRGhigh classification was
observed in a second cohort of 10 RA patients.
Conclusions
The IFN response gene signature at baseline is associated with responder status upon B cell
depletion therapy in rheumatoid arthritis.
52
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43. IRF5
genetics predicts clinical responsiveness to
IFN-ß in Multiple Sclerosis
Saskia Vosslamber1, Laura van der Voort2, Roel Heijmans1, Bart Crusius1, Bernard Uitdehaag2,
Joep Killestein2, Chris H. Polman2, Cornelis L. Verweij1.
1 Dept. of Pathology
2 Dept. of Neurology, VU University Medical Center, Amsterdam.
Introduction
Interferon-_ (IFN-_) treatment is beneficial for a majority of Relapsing-Remitting Multiple Sclerosis
(RRMS) patients. However, a significant proportion of patients show poor clinical response.
In the search for predictive biomarkers, we previously showed that type-I IFN activity at start
of treatment correlates with pharmacological response (PhR). Genetic variation in IRF5, a
transcription factor involved in regulation of type_I IFN activity, was shown to be associated
with heterogeneous PhR. We hypothesize that genetic variation in IRF5 may predict clinical
responsiveness to IFN-_ treatment in RRMS patients.
Methods
RNA and DNA were isolated from peripheral blood (PB) from 30 RRMS patients (test cohort)
before and during IFN-_ treatment. DNA was also isolated from PB of 176 additional patients.
Gene expression of a set of IFN response genes was measured using Taqman Low Density
Arrays. PhR was determined as the ratio of gene expression during and before treatment.
IRF5 single nucleotide polymorphisms (SNP) rs2004640 and rs4728142 were determined in
all patients. Change in number of T2 lesions on MRI during treatment was used as readout for
clinical responsiveness in the test cohort and time to first relapse as a surrogate marker for IFN-_
responsiveness in the validation cohort.
Results
Respectively nine and five patients of the test cohort were homozygous for the risk allele of
rs2004640 or rs4728142. All those patients (100%) developed new T2 lesions during IFN-_
treatment. For rs2004640 we found that development of new T2 lesions reached statistical
significance (p=0.024). Moreover, number of annualized T2 lesions was also higher (p=0.020).
This finding was supported by a low pharmacological response in these patients. In the additional
cohort, time to first relapse was significant shorter for patients homozygous for the risk allele of
rs2004640 (p=0.030) or rs4728142 (p=0.067).
Conclusions
IRF5 polymorphisms are associated with the development of new T2 lesions and the shorter time
to first relapse during IFN-ß treatment.
Wet en s ch ap s d ag V C W 2 0 1 0 53
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44. Q
uantitative proteomics of genetic mouse models
for human breast cancer: identification of BRCA1associated proteins involved in DNA-repair
Marc.O. Warmoes1, Janneke Jaspers2, Maarten P.G. Massink3, Thang Pham1, Sander Piersma1,
Epie Boven1, Hanne Meijers-Heijboer3, Quinten Waisfisz3, Jos Jonkers2, Connie R. Jimenez1.
1O
ncoproteomics Laboratory, Department of Medical Oncology, VU University Medical Center,
Amsterdam
2 NKI, Molecular Biology, Amsterdam
3 Department Clinical Genetics, VU University Medical Center, Amsterdam.
Introduction
Breast cancer is the most common malignancy in women in the western world. The outcome of
breast cancer would be strongly improved if patients could be diagnosed and treated early. This
especially holds for patients with hereditary breast cancer. The aim of this study is to identify novel
protein biomarkers for early diagnosis of BRCA1 deficient breast cancer and for drug sensitivity.
Methods
We used in-depth proteome profiling of tumor tissues of mouse breast cancer models to identify
BRCA1-associated proteins. To this end, we analyzed tumor tissue lysates from a panel of genetic
mouse models that develop BRCA1 proficient and deficient mammary cancers. Total tumor tissue
lysates were fractionated using SDS-PAGE followed by tryptic in-gel digestion, nanoLC-MS/MS and
database searching. Normalized spectral counting was used for protein quantification and beta
binomial statistics to discover significantly regulated proteins. Ingenuity Pathway Analysis (IPA)
was used to support data interpretation.
Results
The total dataset contained 3836 identified proteins of which 804 were significantly regulated
between the BRCA1 deficient and proficient groups (p<0.05), including proteins previously
implicated in BRCA1 breast cancer. Pathway analysis revealed that many up-regulated proteins
were involved in DNA-repair. Integration with transcriptomics data obtained for a series of
human genetic and sporadic breast cancer tissues indicated a large overlap of BRCA1 protein
and RNA candidates. Moreover, the BRCA1-associated mouse proteins could almost perfectly
classify human basal BRCA1 tumors. Currently, selected candidates are being followed up using
immunohistochemical staining of a set of human BRCA1 deficient and sporadic tumors.
Conclusions
We conclude that proteomics of genetic mouse models for genetic breast cancer is a powerful
strategy to discover novel candidate BRCA1 DNA-repair-deficiency proteins with human
relevance. Further validation studies are required to investigate whether these candidates are
robust biomarkers for early detection of BRCA1 tumors and whether they are also indicative for
sensitivity to PARP inhibition in non-BRCA1-deficient-tumors.
54
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45. M
ycobacteria deficient for the type VII secretion
system ESX-5 are hypervirulent in zebrafish
E.M. Weerdenburg1, A.M. Abdallah2, N. N. van der Wel2, W. Bitter1, A.M. van der Sar1.
1D
epartment of Medical Microbiology and Infection Control, VU University Medical Center,
Amsterdam
2 The Netherlands Cancer Institute, Amsterdam.
Introduction
Mycobacteria contain specialized protein secretion systems encoded by ESX loci. One of these
secretion systems, ESX-5, is conserved in pathogenic mycobacterial species and responsible for
the secretion of PE and PPE proteins. In macrophage studies using the pathogenic mycobacterial
species M. marinum, ESX-5 has been found to play a role in mycobacterial spread, induction of
cell death and the suppression of inflammatory cytokine release.
Methods
To investigate the role of ESX-5 in vivo, we infected zebrafish embryos and adult zebrafish with
M. marinum wildtype and ESX-5 mutant strains. Mycobacterial growth, granuloma formation and
survival of zebrafish were evaluated.
Results
In zebrafish embryos, the ESX-5 mutant strain was attenuated in growth compared to the
wildtype strain. In addition, the ESX-5 mutant strain was slightly attenuated in its capacity to
induce granuloma formation. In adult zebrafish however, a dramatically different outcome of the
infections was observed. Fish infected with the ESX-5 mutant strain showed reduced survival,
early onset of granulomas, and enhanced bacterial growth compared to fish infected with the
wildtype strain.
Conclusion
Although the ESX-5 mutant strain of M. marinum is attenuated in macrophages and zebrafish
embryos, it is hypervirulent in adult zebrafish. In contrast to adult zebrafish, embryos lack an
adaptive immune system. It is therefore possible that proteins secreted by ESX-5 play a role in
modulation of the adaptive immune system. Taken together, our infection studies in zebrafish
embryos and adult zebrafish indicate an important role for ESX-5 in the virulence of M. marinum.
Wet en s ch ap s d ag V C W 2 0 1 0 55
EMGO+
46. E ffect of medication review and cognitive behaviour
treatment by community pharmacists of patients
discharged from the hospital on drug related
problems and compliance
Abeer Ahmad1, Jacqueline Hugtenburg1, Laura M.C. Welschen2 , Jacqueline Dekker3, Giel Nijpels2.
1D
epartment of Clinical Pharmacology and Pharmacy and the EMGO Institute for Health and Care
Research, VU University Medical Center, Amsterdam
2 Department of General Practice and the EMGO Institute for Health and Care Research,
VU University Medical Center, Amsterdam
3 Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care
Research, VU University Medical Center, Amsterdam.
Introduction
Drug related problems ( DRPs), like contra-indications, interactions and adverse drug reactions
are common among elderly patients who are discharged from the hospital. Causes are
prescription errors and non-compliance. The aim of this study is to examine the effect of
medication review and cognitive behaviour treatment of discharged patients by community
pharmacists to minimize DRPs.
Methods
Community pharmacists will be randomized into a control and intervention group. 342 Patients,
aged over 60 years, discharged from the hospital using five or more prescription drugs will
be asked to participate in the study. The control group will receive usual care according to the
Dutch Pharmacy Standard. The medication of patients randomised to the intervention group will
be reviewed by the community pharmacist with use of the national guidelines for the treatment
of diseases. Pharmacy technicians will counsel patients at home at baseline and at 1,3,6,9 and
12 months, using Cognitive Behaviour Treatment. The outcome measures are the difference in
occurrence of DRPs between intervention and control group and adherence with drug use.
Results
The results will be expected at the end of March 2010
Conclusions
It is expected that combining medication review and Cognitive Behaviour Treatment may decrease
DRP and improve compliance.
56
EMGO+
47. C
are for stroke in long term care facilities in the
Netherlands
Suzanne van Almenkerk, MSc, Miranda G. Dik, PhD, Cees M.P.M. Hertogh, MD,
Prof, Martin Smalbrugge, MD, PhD, Jan A. Eefsting, MD, Prof.
Institute for research in Extramural Medicine, VU University Medical Center, Department of
Nursing Home Medicine, Amsterdam.
Introduction
Forty percent of nursing home residents has stroke as the main cause of dependency. Currently,
the care offered to them focuses mainly on physical disabilities, although many of them also
suffer from cognitive, emotional and/or behavioural changes. In addition, they may also need
assistance with regard to the planning and decision making concerning their care and (medical)
treatment. The main objective of this project is to develop guidelines for a care and treatment
program for stroke patients who are living in nursing homes.
Methods
The care and treatment program will be based on two parts of the study. First, the functioning
of the residents will be explored in several domains (physical, cognitive, emotional, social
and communicative). Also current care and treatment will be described, especially with regard
to medical decision making and use of restraints. The relation to patient characteristics and
other determinants will be examined, as well the evaluation of the patient’s capacity. For this
quantitative part of the study observation lists were filled out by nursing assistants and nursing
home physicians. 17 nursing homes agreed to participate and 275 patients were included.
Second, the needs for care will be studied from the perspective of the patient, the family and the
professional. There will be a focus on the need for information and the participation in medical
decision-making. The results will be compared to current care and treatment to discover ‘unmet
needs’. For this qualitative part of the study a selection of 14 patients and their formal and
informal caregivers was interviewed on their (un)met needs.
Concept guidelines, based on the data analysis will be presented to a multidisciplinary panel of
experts.
Results
Data collection was completed in 2009. The data will be analyzed in 2010.
Conclusions
Not yet available.
Wet en s ch ap s d ag V C W 2 0 1 0 57
EMGO+
48. C
lient Participation in Elderly Care: Residents
Improving the Meals
Vivianne Baur1, Tineke Abma2
1 Department of Medical Humanities, VU University Medical Center, Amsterdam
2 Department of Medical Humanities, VU University Medical Center, Amsterdam.
Introduction
In institutional elderly care, client councils exist as a formal structure for clients to participate
in policy planning and practice improvements within the organization. However, our recent
research has shown that client councils experience a lack of influence. Therefore, our current
interactive research projects focus on innovative forms of client participation in which dialogue
and partnership between residents, managers and employees in residential care homes is central.
The project we present here concerns a group of seven female residents who became partners of
managers and employees in improving the meals.
Methods
We used the interactive and participative research methodology of responsive evaluation. The
four steps of responsive evaluation we followed are; 1) creating good social conditions with
stakeholders, 2) generating issues of all stakeholder groups, 3) homogeneous dialogues amongst
residents and 4) heterogeneous dialogue between the residents, managers and employees.
Responsive evaluation has a strong link with action research, since stakeholders work together on
practice improvements (improving meals).
Results
Through the systematic and responsive facilitation of dialogue and action, a learning process was
enhanced in this organization. These residents developed a sense of relational empowerment:
they gained trust that they stood strong together and that they were able to improve the meals,
not only for themselves but also for the other residents. Managers and employees learned that
the experiential knowledge of residents can be a guide for practice improvements and they
learned how they can work together with residents as partners.
Conclusions
This research shows how this kind of client participation can be a catalyst for a culture change
from supply-driven care to dialogical and participative care and services in the context of
long term institutional elderly care. Enhancing client participation thus means that residents,
employees and managers become partners in joint practice improvements.
58
EMGO+
49. B
ody composition as determinant of thrombin
generation in plasma – The Hoorn Study
Hanneke J.B.H. Beijers1, Isabel Ferreira2,3,4, Henri M. Spronk4,5, Bert Bravenboer1,
Jacqueline M. Dekker6, Giel. Nijpels6, Hugo ten Cate2,4,6 and Coen D.A. Stehouwer2,4.
1
2
3
4
5
6
Department of Medicine, Catharina Hospital, Eindhoven
Department of Medicine, Maastricht University Medical Center (MUMC+)
Department of Clinical Epidemiology and Medical Technology Assessment, MUMC+
Cardiovascular Research Institute Maastricht, MUMC+
Laboratory for Clinical Thrombosis and Haemostasis, MUMC+,
Institute for Research in Extramural Medicine, VU Medical Center, Amsterdam.
Introduction
Obesity is associated with cardiovascular disease (CVD), which might be partially explained by a
prothrombotic state. The extent to which different regions of body fat and lean masses contribute
to a prothombotic state are unknown, however. We have therefore investigated, in a populationbased cohort, the association between body composition and thrombin generation in plasma.
In addition, we evaluated the role of low-grade inflammation (high-sensitivity C-reactive protein
(hsCRP)) as potential explanatory mechanism of any such associations.
Methods
We studied 588 individuals (mean age 69.7±6.5 years, 300 women) in whom total and regional
body composition were assessed by means of whole body dual-energy absorptiometry. Thrombin
generation was measured using the Calibrated Automated Thrombogram, a method which
generates a thrombin generation curve that mimics the overall plasma coagulability when a
thrombogenic stimulus appears. The area under this curve is the endogenous thrombin potential
(ETP) and represents the total amount of active thrombin formed after activation of the
coagulation cascade. Data were analyzed with multiple linear regression models in men and
women separately.
Results
After adjustment for age, prior CVD, glucose metabolism and smoking status, total body fat %
was positively associated with ETP in women (standardized regression coefficient (ß): 0.20 (95%CI:
0.09; 0.32)), but not in men (-0.02 (-0.15; 0.11)). Detailed analyses of regional body composition
in women showed that trunk (0.23 (0.05; 0.40)) but not peripheral fat mass (-0.02 (-0.18; 0.15))
was adversely associated with ETP, whereas there was a trend towards an inverse, and thus
protective, association between peripheral lean mass and ETP (-0.12 (-0.25; 0.01)). The strength
of the associations between total body fat % or trunk fat mass and ETP were attenuated when
further adjusted for hsCRP (0.13 (0.01; 0.26) and 0.10 (-0.04; 0.23) respectively).
Conclusions
Obesity, in particular central obesity, is associated with higher levels of thrombin generation in
elderly women, but not in men, and this association is partially explained by obesity-related
low-grade inflammation.
Wet en s ch ap s d ag V C W 2 0 1 0 59
EMGO+
50. A
dvance directives for euthanasia in dementia:
what is their feasibility in practice?
Marike E. de Boer1, Cees M.P.M. Hertogh1, Rose-Marie Dröes2, Cees Jonker1, Jan Eefsting1.
1 Institute for Research in Extramural Medicine, VU University Medical Center, Department of
Nursing Home Medicine, Amsterdam
2 Department of Psychiatry/Alzheimer Center, VU University Medical Center, Amsterdam.
Introduction
Advance directives are developed as a way of allowing people to give directions for future care
and medical decisions in cases of incompetence. Since the new euthanasia law (2002) euthanasia
based upon an advance directive for euthanasia (ADE) in cases of dementia is possible as long as
also the other requirements of due care are met by the physician. As data is limited, our study
aimed at investigating their use and feasibility in daily practice.
Methods
434 nursing home physicians completed a survey about the use of advance directives their
experiences in treating people with dementia who had an ADE. Based upon the presented cases
additional interviews were conducted with 12 physicians and 9 relatives.
Results
Although physicians and relatives have positive attitudes towards advance directives in general,
compliance with ADE’s is very rare, suggesting hesitation to perform euthanasia in cases of
dementia. Arguments for this hesitancy can be found in the specific (ethical) dilemma’s which the
execution of these requests generates in practice for both physicians and relatives.
Conclusions
Although the enactment of the Dutch euthanasia law allows for euthanasia in incompetent
patients with dementia based on an ADE, in practice this has not lead to obvious changes in
compliance with ADEs of patients with advanced dementia in comparison to data from before
2002. In view of the explanations given for the reticent attitudes of physicians, questions can be
raised regarding the feasibility of ADEs of people with dementia in the role they have currently
been adjudged.
60
EMGO+
51. C
omorbidity and risk indicators of alcohol use
disorders among persons with anxiety and/or
depressive disorders
Lynn Boschloo1,2, Nicole Vogelangs1,2, Johannes H. Smit1,2, Wim van den Brink3, Dick J. Veltman
Aartjan T.F Beekman1,2, Brenda WJH Penninx1,2,4,5.
1
2
3
4
5
,
1,3
Department of Psychiatry and
EMGO Institute for Health and Care Research, VU University Medical Center
Academic Medical Center University of Amsterdam, Department of Psychiatry
Department of Psychiatry, University Medical Center Groningen, Groningen
Department of Psychiatry, Leiden University Medical Center, Leiden.
Introduction
This study examines comorbidity and risk indicators of alcohol use disorders among anxious
and/or depressed persons, also considering temporal sequencing of disorders.
Methods
Baseline data from the Netherlands Study of Depression and Anxiety (NESDA) were used,
including 2329 persons with lifetime anxiety (social phobia, generalized anxiety disorder, panic
disorder, agoraphobia) and/or depressive (major depressive disorder, dysthymia) disorder and
652 controls. Lifetime diagnoses of alcohol abuse and dependence were established, as well as
information about socio-demographic, vulnerability, addiction-related and anxiety/depressionrelated characteristics. Temporal sequencing of disorders was established retrospectively, using
age of onset.
Results
Of persons with combined anxiety/depression 20.3% showed alcohol dependence versus 5.5%
of controls. Prevalence of alcohol abuse was similar across groups (±12%). Independent risk
indicators of alcohol dependence among anxious and/or depressed persons were male gender,
vulnerability factors (family history of alcohol dependence or anxiety/depression, openness to
experience, low conscientiousness, being single, and childhood trauma), addiction-related factors
(smoking, illicit drug use) and early anxiety/depression onset. Persons with secondary alcohol
dependence were more neurotic, more often single and lonelier, while persons with primary
alcohol dependence were more often male and more extravert.
Conclusions
Alcohol dependence, but not abuse, is more prevalent in anxious and/or depressed persons.
Persons with comorbid alcohol dependence constitute a distinct subgroup of anxious and/
or depressed persons, characterized by addiction-related habits and vulnerability. However,
considerable variation in characteristics exists depending on temporal sequencing of disorders.
This knowledge may improve identification and treatment of those anxious and/or depressed
patients who are additionally suffering from alcohol dependence.
Wet en s ch ap s d ag V C W 2 0 1 0 61
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52. P
atient participation in end-of-life decision-making:
design of a study
L. Brom1, H.R.W. Pasman1, M.L Rurup1, G.A.M Widdershoven, B.D. Onwuteaka-Philipsen1.
1D
epartment of Public and Occupational Health, EMGO Institute for Health and Care Research,
VU University Medical Center
2 Department of Medical Humanities, EMGO Institute for Health and Care Research,
VU Medical Center.
Introduction
Several decision-making models on patient participation exist. The shared decision-making model
is often considered ideal. However, results of empirical studies have given rise to the question
whether this model is the most suitable in all situations or in all patient groups. Aim of this study
is which decision-making models for patient participation can be recognized in practice in end-oflife decision-making and how appropriate these models are for different patient groups.
Methods
This qualitative prospective study will start with patients who suffer from Glioblastoma
Multiforme (glial brain tumour) in whom it has to be decided whether or not to start a (second
line) treatment aimed at prolonging life. Observations and in-depth interviews will be used to
study patient participation and patient-physician communication. Observations will give insight
into actual communication; in-depth interviews into experiences and preferences. The first
interview with patients will take place previous to a non-treatment decision, in order to
investigate patient’s preference concerning participation in non-treatment decisions (e.g. active,
shared, passive). Patient and physician will be interviewed separately after a non-treatment
decision to discuss perceived participation in decision-making. Patients will be followed in time
to get insight in preferences in decision-making and if these preferences change in course of
an illness trajectory. Based on first data analyses regarding brain tumour patients, other patient
groups in whom non-treatment decisions have to be made will be studied.
Results
Not available yet, data collection will start March 2010.
Conclusion
Not available yet.
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53. Need for ethics support
Linda Dauwerse, Tineke Abma, Bert Molewijk, Guy Widdershoven.
Institute for Research in Extramural Medicine, VU University Medical Center.
Introduction
Starting from the assumption that ethics is inherent to care, we investigated the need for ethics
support in the Netherlands. This is important because there are several initiatives in the field
of ethics support, but it is unknown to what extent these initiatives meet the needs of different
stakeholders. Publications about the need for clinical ethics support are scarce. The aim of this
article is to stimulate the development of a positive critical attitude for ethics support and to tune
research literature and clinical activities to the needs of different stakeholders.
Methods
An emergent mixed methods design was used in which quantitative and qualitative methods
complemented each other. All Dutch intramural health care institutions (N = 2137) with a
diversity of sectors, were included. Concrete activities were: questionnaires directed to board
members (BM) and people within the institution which are specifically involved with ethics (BI),
heterogeneous focusgroups and open interviews.
Results
In general BM show there is a need for an integrated structure of ethics support (68%) because
ethics is inherent to care and ethics support helps to realize important organizational goals.
On the other hand there is no need for a separate service for ethics support and existing other
structures should be used (32%). Likewise, BI indicate there is no real need for ethics consultants
(81%) and ethics committees (71%), which are more separate structures of ethics support. Only
18% without ethics consultant misses it and for ethics committees this percentage is 32%.
Explanations show that these kind of structures often are isolated and they do not stimulate
integral responsibility. Moral deliberation is an integrated structure of ethics support and 43% of
the health care institutions (HCI) without moral deliberation misses it. Furthermore, 41% of the
BI depict a need for moral deliberation because it is a dynamic way to make ethical issues more
explicit. It is notable that many of the HCI with a specific structure of ethics support, do not label
this structure as important. Explanations show that they are not that important because they are
unknown and there are many other structures which operate as ethics support such as individuals
(e.g. pastoral care, trusts persons) and groups (e.g. multidisciplinary team meetings). Specific for
moral deliberation in that it is sometimes not that important (yet) because it is still developing.
Conclusions
The need for ethics support is multidimensional and illustrated by several considerations.
Wet en s ch ap s d ag V C W 2 0 1 0 63
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54. T
he Imagination method; A new approach for
caregivers of people with Dementia in nursing
homes
A.M. van Dijk, R.M. Dröes, J.C.M. van Weert.
Department of Psychiatry/Alzheimer Center, EMGO, VU University Medical Center Amsterdam &
Amsterdam School of Communication Research UvA.
Background
The Imagination method, developed by Theater Veder, is being implemented on a large scale
in nursing homes with residents with dementia. Caregivers are trained in the use of theatrical
stimuli in combination with elements of proven care methods, such as Reminiscence and
Validation Therapy. The purpose is to stimulate the reciprocity in care relations of caregivers and
persons with dementia (PwD’s) and to enhance the personal identity and self-esteem of people
with dementia by activating their long term memory.
Methods
Phase 1: Definition of the Imagination method based on participant observation and literature
study.
Phase 2: Process-evaluation of the implementation by means of interviews with key figures
(e.g. managers, nurse assistents, activity therapists).
Phase 3: Impact of the Imagination method on people with dementia and caregivers:
- 70 PwD’s receiving an Imagination method-activity will be compared with 70 PwD’s receiving a
usual (reminiscence) activity. Three measures will take place: (1) pretest; (2) during the activity
(3) posttest. Different aspects of behavior and quality of life will be measured.
- Caregivers and volunteers who have been trained will be interviewed regarding job satisfaction
and attitude towards PwD’s and the applicability and usefulness of the Imagination method.
Results
Based on systematic participant observation, a detailed description was made of the Imagination
method. The process-evaluation of the implementation resulted in an inventory of facilitators and
barriers of implementation of the Imagination method.
Conclusion
Preliminary studie results of phase 1 and 2 are presented.
Study results of the impact study (phase 3) are expected in December 2010.
This project is funded by the transition program in long term care from the Ministry of public
Health, Welfare and Sports.
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55. E xploring the association between chronic diseases,
multimorbidity and comorbidity and self-rated
health in the older population
Henrike Galenkamp1, Arjan W. Braam2,4, Martijn Huisman1,2,3, Dorly J.H. Deeg1,2.
1 E MGO Institute for Health and Care Research, Department of Epidemiology & Biostatistics,
VU University Medical Center, Amsterdam
2 EMGO Institute for Health and Care Research, Department of Psychiatry
3 Department of Sociology, VU University, Amsterdam
4 Altrecht Mental Health Care, Department of Emergency Psychiatry, Utrecht.
Introduction
Research has shown that self-rated health is a strong predictor of mortality. Considering the
high prevalence of multimorbidity in the older population, we investigated the impact of chronic
diseases, multimorbidity (i.e. the occurrence of more than one disease) and comorbidity (i.e. the
occurrence of diseases together with a specific disease) on self-rated health.
Methods
Cross-sectional data were used from 2,046 men and women, aged 57-97 years, who participated
in the Longitudinal Aging Study Amsterdam (LASA). We assessed the presence of chronic nonspecific lung disease (CNSLD), cardiac disease, peripheral atherosclerosis, stroke, diabetes
mellitus, arthritis, and cancer. SRH was measured with the question ‘How is your health in
general?’ which included five response categories. For the analyses, linear regression models
were used.
Results
Independent effects on SRH were of quite similar magnitude: CNSLD: 0.37 (95% CI: 0.27-0.47),
cardiac disease: 0.38 (0.30-0.46), peripheral atherosclerosis: 0.43 (0.31-0.56), diabetes: 0.41
(0.30-0.51), stroke: 0.39 (0.26-0.53), arthritis: 0.42 (0.35-0.49), and cancer: 0.26 (0.16-0.36).
Cancer showed the smallest impact on SRH. Having one, two, three, four, or more diseases led to
cumulative increases in SRH (i.e. worsening health) of 0.40 (95% CI: 0.31-0.49), 0.79 (0.69-.0.89),
1.14 (1.02-1.25), 1.35 (1.19-1.51) and 1.90 (1.65-2.14), respectively. There were no substantial
differences between the diseases with respect to the relative impact of comorbidity (number of
other diseases).
Conclusions
These results suggest that SRH is to some extent sensitive to the complexity of health problems,
as the number of diseases has a negative impact on SRH, regardless of the type of disease.
Wet en s ch ap s d ag V C W 2 0 1 0 65
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56. H
ealth under construction: short- and long term
effects of a lifestyle intervention for construction
workers with an elevated risk of cardiovascular
disease
Iris Groeneveld1, 2, Karin Proper1, 2, Allard van der Beek1, 2, Vincent Hildebrandt2, Willem van
Mechelen1, 2.
1D
epartment of Public and Occupational Health, EMGO Institute for Health and Care Research,
VU University Medical Center, Amsterdam
2 Body@Work, Research Centre Physical Activity, Work and Health, TNO-VUmc, Amsterdam.
Introduction
More than 60% of male construction workers in the Netherlands are overweight or obese and
more than a quarter is at risk for cardiovascular disease (CVD). The aim of this study was to
evaluate the effectiveness of a motivational interviewing-based lifestyle intervention for
construction workers at risk for CVD.
Methods
816 Male construction workers with an elevated CVD risk were individually randomized into the
intervention or control group. The 6-month intervention consisted of three face-to-face and four
telephone contacts with an occupational health professional, in which personal determinants and
barriers for behavior change were discussed in the style of motivational interviewing. Participants
chose to aim at either energy balance or smoking behavior. The control group received usual
care. At 6 and 12 months, physical activity, dietary intake and smoking were assessed by means
of a questionnaire. In addition, body weight, cholesterol, blood pressure, and HbA1c were
measured according to a standardized protocol. In order to determine the intervention effects,
linear and logistic regression analyses were performed in both the energy balance and the
smoking subgroup.
Results
The intervention had a statistically significant effect on fruit intake at 6 months (β =1.7, 95% CI
0.6; 2.9), and on snack intake at 6 (β =-1.9, 95% CI -3.7; -0.02) and 12 months (β =-1.9, 95% CI
-3.6; -0.3). Smoking was also significantly favorably influenced by the intervention (OR=0.3, 95%
CI 0.1; 0.7). As a result of the intervention, body weight was lost at 6 months (β =-1.9, 95% CI
-2.6; -1.2); a statistically significant effect that was sustained until 12 months (β -1.8, 95% CI -2.6;
-1.1).
Conclusions
This lifestyle intervention was effective in lowering CVD risk. Implementation in the occupational
health setting is therefore recommended.
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57. A
n individually-based lifestyle intervention for
workers at risk for cardiovascular disease:
a process evaluation
Iris Groeneveld, Karin Proper, Saida Absalah, Allard van der Beek, Willem van Mechelen.
Department of Public and Occupational Health, EMGO Institute for Health and Care Research, VU
University Medical Center, Amsterdam.
Introduction
In the Health under Construction Study, 27 occupational health professionals (counselors)
performed a six-month motivational interviewing-based lifestyle intervention for construction
workers. The intervention was aimed at changing dietary, physical activity, and smoking behavior,
and thereby lowering cardiovascular disease risk. The purpose of this process evaluation was
to evaluate the counselors’ adherence to the intervention protocol, their competence, and the
associations between adherence, competence and body weight at follow up.
Methods
With respect to adherence to the intervention protocol, the number of counseling sessions
and the prescribed items discussed in the first session were registered by the counselors. The
adherence to motivational interviewing was determined by expert scoring of 19 audio-taped
fragments. Counselors’ competence in listening, supporting, motivating, and informing was rated
by both participants and counselors. Associations between adherence, competence, and body
weight at follow-up were determined by linear regression analyses.
Results
Two-thirds of all participants attended five or more sessions, and 38.5% attended all seven
sessions. In 90.2% of all cases, the counselor discussed all four prescribed items in the first
session. Adherence to motivational interviewing was concluded from only one audio-taped
fragment. 86.3 percent of all participants agreed with the counselor being competent. Neither
counselors’ competence, nor number of sessions or items discussed, was significantly associated
with body weight loss.
Conclusions
Performing five sessions and discussing four prescribed items was feasible for the counselors,
whereas adhering to motivational interviewing was not. Still, participants were positive about
the counselors’ competence and willing to attend the counseling sessions. Investigators are
encouraged to report the evaluation of their intervention process, in order to improve future
lifestyle interventions in research or in practice.
Wet en s ch ap s d ag V C W 2 0 1 0 67
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58. T
ype 2 diabetes changes the association between
pulse pressure and incident chronic kidney disease
– the AusDiab study
Katja van den Hurk1, Dianna J. Magliano2, Marjan Alssema1, Markus P. Schlaich2, Robert C. Atkins2,
Anne T. Reutens2, Giel Nijpels3, Jacqueline M. Dekker1, Jonathan E. Shaw2.
1D
epartment of Epidemiology and Biostatistics and the EMGO Institute for Health and Care
Research, VU University Medical Center, Amsterdam
2 Baker IDI Heart and Diabetes Institute, Melbourne, Australia
3 Department of General Practice and the EMGO Institute for Health and Care Research.
Background
Pulse pressure (PP) is increasingly recognised as a risk factor for chronic kidney disease (CKD)
and it predicts CVD mortality in individuals with type 2 diabetes (T2DM), but not in those without
T2DM. We examined whether PP was also differently associated with incident CKD, for individuals
with as compared to without T2DM. Furthermore, we investigated whether PP was stronger
associated with CKD than was systolic (SBP) or diastolic (DBP) blood pressure.
Methods
We included 5554 participants of the national, population based Australian Diabetes, Obesity
and Lifestyle Study (AusDiab, 47% male, 5.8% T2DM) who took part in the 5-year follow-up
and had a glomerular filtration rate (eGFR) ≥60 ml/min and no microalbuminuria at baseline.
Associations of baseline PP, SBP and DBP with 5-year incident CKD (stage 3-5=eGFR <60 ml/min)
were stratified for T2DM status and adjusted for baseline age, sex, eGFR and use of hypertension
medication. We also restricted analyses to those with SBP>140 mmHg to examine the OR of CKD
in participants with an above or below mean DBP (70 mmHg) or high or low PP (80 mmHg), with
complementary adjustment for SBP.
Results
He adjusted OR (95% CI) per SD difference of baseline PP was 1.29 (1.09-1.53) in non-T2DM, and
significantly stronger (p for interaction <0.10) in T2DM 1.94 (1.14-3.29). Further adjustments
for mean arterial pressure, heart rate, prior CVD, glucose or lipid levels, use of lipid or glucose
lowering medication, BMI, salt or alcohol intake, or exercise time did not alter the results.
SBP, but not DBP, showed similar associations as for PP with CKD: OR for non-T2DM 1.26 (1.071.50), and for T2DM 1.64 (0.97-2.76). In T2DM, SBP and DBP interact (p=0.088), and within those
with high SBP, the OR for CKD was 5.25 (1.35-20.36) with a below mean DBP and 11.04 (2.1756.26) with a high PP.
Conclusions
We conclude that PP is associated with 5-year incident CKD. This association is stronger with the
presence of T2DM. Both PP and SBP are strong predictors of CKD risk. In T2DM however, having a
low DBP on top of a high SBP significantly increased CKD risk independent of SBP, which indicates
that PP might better predict incident CKD in T2DM patients.
This work was funded by the Diabetes Research Foundation grant no. 2005.00.010,
the EMGO+ travel grant, and the EFSD Albert Renold Fellowship.
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59. A
bdominal obesity, television viewing time and
prospective declines in exercise over five years for
men and women: the AusDiab study
Jeroen Lakerveld, MSc1, David W. Dunstan, PhD2,3,4,5, Sandra Bot, PhD1,6, J. Salmon, PhD2,3,
Jacqueline Dekker, PhD6, Giel Nijpels, PhD1, Neville Owen, PhD2,4.
1D
epartment of General Practice and the EMGO Institute for Health and Care Research,
VU University Medical Center, Amsterdam, the Netherlands
2 Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
3 School of Exercise and Nutrition Sciences, Deakin University, Melbourne, Australia
4 The University of Queensland, School of Population Health, Cancer Prevention Research Centre,
Brisbane, Australia,
5 Vario Health Institute, Edith Cowan University, Perth, Australia,
6 Department of Epidemiology and Biostatistics and the EMGO Institute for Health and Care
Research, VU University Medical Center, Amsterdam, the Netherlands.
Purpose
To examine the prospective associations of abdominal obesity status and television (TV) viewing
time with five-year reductions in exercise levels for men and women. METHODS: We used
data from the Australian Diabetes, Obesity and Lifestyle Study (AusDiab), a population-based
cohort study with measures collected at baseline in 1999-2000 and at follow-up in 2004-2005.
Abdominal obesity status was determined by objectively-measured waist circumference, and
TV viewing time and exercise level were assessed using established interviewer-administered
questionnaires. In data from 2 544 men and 3 174 women aged ≥25 years, odds ratios (ORs)
of 5-year reductions from sufficient to insufficient or no physical activity, and from insufficient
to no activity were estimated with logistic regression. We adjusted for sociodemographic
characteristics.
Results/Findings
The adjusted ORs of reducing exercise levels from baseline to the follow-up survey was 1.44
(1.13 – 1.84) and 1.56 (1.25 – 1.98) for obese men and women, respectively, compared to those
with a normal waist circumference. Women, but not men, with higher levels of TV viewing time
had higher risk of reducing their exercise levels (OR 1.52; 1.05 – 2.22), independent of waistcircumference status.
Conclusions
Abdominal obesity is associated prospectively with reductions in exercise level, and prolonged TV
viewing time can have an additional adverse influence for women.
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60. P
revalence of Undernutrition in Dutch Hospital
Outpatients
Eva Leistra1, Floor Neelemaat1, Anja Evers2, Myriam van Zandvoort3, Peter Weijs1,
Marian van Bokhorst-de van der Schueren1, Marjolein Visser4, Hinke Kruizenga1.
1
2
3
4
Nutrition and Dietetics, VU University Medical Center, Amsterdam
Dutch Malnutrition Steering Group, Amsterdam
Nutrition and Dietetics, Leids University Medical Center, Leiden
Health Sciences, Faculty of Earth and Life Sciences, VU University, Amsterdam.
Introduction
The prevalence of undernutrition in hospital inpatients is high. Early detection and treatment
in the hospital outpatient clinic may help to reduce this problem. The aim of this study was
to assess the prevalence of undernutrition in hospital outpatients in the Netherlands and to
determine high risk departments.
Methods
This cross-sectional multicenter study was conducted in 9 Dutch hospitals. Patients who visited
the outpatient clinic on one of the study days in the period March-May 2008 received a short
questionnaire and height and weight were measured. Patients were classified as severely
undernourished (BMI<18.5 kg/m2 and/or unintentional weight loss ≥5% in the last month or
≥10% in the last six months), moderately undernourished (5-10% unintentional weight loss in the
last six months) or not undernourished. Descriptive statistics and logistic regression analysis
were used to determine prevalence and high-risk departments.
Results
A total of 2288 patients (47.5% male; mean age 56.5±16.3 years) from 23 different outpatient
departments were included in the study, of which 5% were severely undernourished and 2%
were moderately undernourished. The prevalence of severe undernutrition was highest in the
outpatient departments of oral maxillofacial surgery (17%), oncology (10%), rehabilitation (8%),
gastroenterology (7%) and pulmonology (7%). Undernutrition in general (both moderate and
severe) was significantly higher in the departments of oral maxillofacial surgery (OR 2.66 (1.007.04)) and oncology (OR 2.66 (1.60-4.42)) compared to the other departments. Only 17% of
severely undernourished and 4% of moderately undernourished patients reported to receive
dietetic treatment.
Conclusions
The prevalence of undernutrition in hospital outpatients is generally low but largely undertreated.
Future screening and treatment should focus on high risk departments.
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61. S creening on undernutrition is mandatory in Dutch
hospitals
Eva Leistra1, Anja Evers1, Jan Maarten van den Berg2, Ellen van der Heijden1, Chris Mulder1,
Annette de Bruijne-Dobben2, Hinke Kruizenga1.
1 Dutch Malnutrition Steering Group, Amsterdam
2 Health Care Inspectorate, Utrecht.
Introduction
In the past years, the Dutch Malnutrition Steering Group (DMG) gained attention for the problem
of disease related undernutrition in The Netherlands. Between 2006 and 2009 DMG performed an
implementation project on early detection and treatment of undernutrition in hospitals.
The implementation objectives of this project were adapted by the Health Care Inspectorate (HCI)
as part of the Performance Indicators for Risk Steering Supervision. Aim of this study was to
evaluate the results of 2007 and 2008.
Methods
As of 2007 Dutch hospitals annually have to report on the percentage of patients screened
on undernutrition at hospital admission to the HCI. In addition, as of 2008 hospitals annually
have to report on undernutrition treatment on 4 measure days (expressed as percentage of
undernourished patients with a protein intake of 1.2-1.5 g/kg on the fourth day of admission).
Results of 2007 and 2008 are presented.
Results
In 2007, 81 out of 100 hospitals reported to have implemented systematic screening before or
during 2007, of which 72 hospitals reported on undernutrition screening. In 2008, 96 out of
100 hospitals reported on screening and 58 hospitals reported on treatment undernutrition. The
number of patients reported about increased between 2007 (n=316,767) and 2008 (n=793,901).
Mean percentage of patients screened at admission was 54% (± 27.5) in 2007 and 56% (± 25.5)
in 2008, and respectively 19% (± 10.5) and 17% (± 8.4) of patients were screened as severely
undernourished. Respectively 11 hospitals (15%) and 19 hospitals (20%) reported a screening
percentage of over 80%. While the number of hospitals reporting on undernutrition treatment
increased during the four trimesters of 2008, percentage of patients with adequate protein intake
decreased.
Conclusions
Screening and treatment of undernutrition have become mandatory performance indicators in
Dutch hospital care. A substantial increase in hospitals and patients reported about and a slight
increase in percentage of screening is observed between 2007 and 2008. Expected is that these
numbers and percentage patients with adequate treatment will further increase in the next years.
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62. T
reating Moroccan and Turkish migrants with
depression and anxiety disorders
Annelies van Loon1, Anneke van Schaik1, Jack Dekker2, Aartjan Beekman1,3, Jochanan Huijser2.
1 GGZinGeest, Amsterdam
2 Arkin Academy, Arkin Mental Health Institute, Amsterdam
3 Department of Psychiatry, VU University Medical Center, Amsterdam.
Introduction
Since the sixties of the last century, many people from Morocco and Turkey have migrated into
the Netherlands. In the last decade, Moroccan and Turkish patients have found their way to
organizations for mental health care. However, they often drop-out from treatment. Problems
in the communication with therapists and different expectations regarding treatment seem to
be causal factors for the early drop-out from therapy. Courses have been developed for training
cultural competence of therapists. Yet, the effectiveness of increased cultural competence of
therapists in reducing drop-out from treatment has not been studied.
Methods
A randomized clinical trial will be performed. Turkish and Moroccan adult patients who are
referred to an outpatient clinic for mood and anxiety disorders will be randomly assigned to
mental health workers who are trained in a cultural module and to those who are not.
Intervention: The therapists wil be trained in the Cultural Formulation and in techniques bridging
the (cultural) gaps between them and their Turkish and Moroccan patients.
The study inclusion will start in january 2010. The target number of participants is 150 patients,
75 for each group.
Measures: Drop-out from treatment is the primary outcome measure.
Secundary outcome measures: no-show, treatment modalities offered, patients perspective of
care, severity of depressive and anxiety symptoms and general functioning.
Results and conclusions
The study will give an answer to the question whether increasing cultural competence of
therapists reduces drop-out from treatment in Moroccan and Turkish out-patients with depressive
and anxiety disorders .
Funding: Netherlands Organization for Health Research and Development (ZonMw).
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63. D
ementelCoach: effect of telephone coaching on
carers of community dwelling people with dementia
L.D. Van Mierlo1, H.G. Van der Roest12, F.J.M. Meiland¹, R.M. Dröes12.
1V
U University Medical Center, Department of Psychiatry, Alzheimer Center, EMGO Institute for
Health and Care Research, Amsterdam
2 VU University Medical Center, Department of Nursing Home Medicine, Alzheimer Center, EMGO
Institute for Health and Care Research, Amsterdam.
Introduction
Taking care of community dwelling people with dementia is often a burdensome task for informal
carers. Though a lot of effective support services are available, many carers do not use them.
In the region Amersfoort/Leusden (NL) a new intervention is started to provide emotional, social
and practical support by telephone coaching. The project is called DementelCoach. This study
evaluates the impact of this new intervention on informal carers and the trained telecoaches.
Methods
The telephone coaching is offered to informal carers once in every two to three weeks during a
period of 20 weeks. A pretest-posttest control group design is used to evaluate the study. Three
groups are compared: a group who receives telephone coaching, a group who receives telephone
coaching and day care and a group who receives day care only.
To gain insight into the effectiveness of the Dementelcoach intervention, the effect of coaching
on the burden and health problems of the informal caregivers will be investigated. To gain
insight in the effect of the intervention (including the training) on the professional carers,
work satisfaction, work experience and self-esteem are investigated. Finally, the content of the
telephone coaching will be investigated.
Results
Preliminary study results will be presented.
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64. E ffects of hearing impairment on psychosocial
health, need for recovery after work, and
health care use and costs in adults aged between
18-70 years: results from an internet-based
national survey on hearing
J. Nachtegaal, J.M. Festen, S.E. Kramer.
Department of ENT/Audiology, EMGO+ Institute for Health and Care Research, VU University
Medical Center, Amsterdam.
Introduction
To gain more insight into the effects of hearing impairment among adults (18-70 yrs) on various
aspects of life, the National Longitudinal Study on Hearing (NL-SH), was set up.
Methods
Both normally hearing and hearing-impaired persons are participating. Hearing status is
measured using an Internet speech-in-noise test. Information about psychosocial health, work
situation, and health care use were collected by means of questionnaires. The first study
addressed the association between hearing status and psychosocial health (N= 1511). Next, the
relationship between hearing status and need for recovery after work among working participants
(N=926) was studied. Finally, health care use and health care costs of normally hearing and
hearing-impaired people were compared (N=1295).
Results
Significant adverse associations between hearing status and the variables distress, somatisation,
depression, and loneliness were found. Different age groups exhibited different associations.
Also, a significant association between hearing status and need for recovery was found, poorer
hearing leading to a higher need for recovery. Additionally, poorer hearing increased the odds
for risky levels of need for recovery. Finally, hearing-impaired people had significantly more
contacts with primary, secondary, and occupational health care than normally hearing people
during a 7-months period. Comparison of health care costs displayed a similar pattern. However,
when hearing-related contacts were excluded from the analyses, differences were not statistically
significant anymore.
Conclusion
The NL-SH increases the insight into the effects from hearing impairment in adults younger than
70. Adverse associations with psychosocial health, need for recovery, overall health care use and
costs were found.
74
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65. N
eurobiological correlates of disruptive behaviour
disorder in a normal population; differences
between boys and girls
E Platje, LMC Nauta-Jansen, RRJM Vermeiren, ThAH Doreleijers, PAC van Lier, T Frijns, JM Koot and
W Meeus.
Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam.
Disruptive behaviour disorders (DBD) are thought to be related to hypo-activity of the HPA-axis
and it’s end product cortisol. Low cortisol levels may lead to fearlessness and/or sensation
seeking, which could in turn lead to antisocial behaviour. Results on HPA axis activity in DBD
however are inconsistent, particularly in normal population samples. Explanations for this
inconsistency may be the low prevalence of DBD in such samples and the heterogeneity of DBD.
Also, little is known about possible sex differences.
This study therefore aims to investigate the relation between cortisol and disruptive behaviour in
a normal population sample, with over-sampling of high-risk boys and girls.
Participants were 219 boys and 153 girls, with a mean age of 14,0 (±0,5) years, of whom half was
at high risk of developing DBD (TRF T-score ≥60). Disruptive behaviour was assessed as a DBD
diagnosis (DSM-IV) and as aggression and delinquency (CBCL and YSR). The Cortisol Awakening
Response (CAR) was measured in saliva.
A decreased CAR was found in DBD girls, but not in DBD boys, as compared to control girls and
boys. Aggressive behaviour in girls (CBCL) was related to a decreased CAR, whereas delinquency
in both boys and girls (CBCL) was related to an increased CAR.
The relation between disruptive behaviour and cortisol is dependant on sex and type of
disruptive behaviour. Longitudinal studies on behaviour and neurobiology should provide further
insight in sex differences in mechanisms underlying the development of DBD.
Wet en s ch ap s d ag V C W 2 0 1 0 75
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66. T
he short-term influence of age at retirement on
self-perceived health
Kelly J. Rijs1, R. Cozijnsen2, D.J.H. Deeg3.
1 L ongitudinal Aging Study Amsterdam, EMGO-Institute of Health and Care Research,
VU University Medical Center, Amsterdam
2 Department of Sociology, VU University Amsterdam
3 Longitudinal Aging Study Amsterdam, EMGO-Institute of Health and Care Research,
VU University Medical Center, Amsterdam.
Introduction
Because of the ongoing public debate about increasing the age at retirement, it is important to
determine the health consequences of age at retirement. The purpose of this study is to examine
the effect of age at retirement on change in self-perceived health during the retirement transition.
Methods
Subjects were 200 persons from the Longitudinal Aging Study Amsterdam (LASA), who retired
between ages 55 and 64 years. Multinomial logistic regression analysis was applied to test
the effect of age at retirement on change in self-perceived health. Health, demographical,
socio-psychological, job, and retirement characteristics were tested for confounding and effect
modification.
Results
It was found that persons with a higher age at retirement were more likely to experience a
decrease in self-perceived health during the retirement transition, compared to an unchanged
self-perceived health. Possible buffers are a high level of education and high self-esteem.
No effect was found for persons who retired more than two years ago. These effects were
independent of confounders.
Conclusions
The results contribute to our understanding of the health consequences of age at retirement. We
conclude that persons retiring at a higher age are more likely to experience a decrease in SPH,
which might lead to higher health care costs.
76
EMGO+
67. S tereotyping of patients’ communication behaviour
by physicians: a qualitative study
H. Jolanda van Rijssen1,2, Antonius J.M. Schellart1,2, Marianne Berkhof1,2, Johannes R. Anema1,2,
Allard J. van der Beek1,2.
1D
epartment of Public and Occupational Health, EMGO Institute for Health and Care Research,
VU University Medical Center, Amsterdam
2 Research Center for Insurance Medicine, collaboration between AMC-UWV-VUmc-UMCG,
Amsterdam.
Introduction
The objectives of this paper were to qualitatively explore: (1) the origins of stereotypes to classify
claimants with regard to their way of communicating; (2) the content of those stereotypes; (3)
the advantages and disadvantages of stereotyping; and (4) how physicians minimise undesired
influences of stereotypes.
Methods
Data were collected in three focus group meetings with physicians performing medical disability
assessments of sick-listed employees (i.e. claimants). Data were qualitatively analysed in four
steps along the lines of the grounded theory and the principle of constant comparison using
Atlas.ti.
Results
22 Dutch social insurance physicians participated. Most physicians reported that they use
classifications of claimants to adapt their communication behaviour. The discussion revealed
that physicians’ stereotypes originate from information in claimants’ files and first impressions.
Regarding stereotype content, physicians seemed to compare claimants to the stereotype of the
‘perfect claimant’, who takes up little time and provides unambiguous information. The main
advantages of classifying were that it provides a framework for the assessment interview and
it is interesting to check if the stereotype is right. Disadvantages were that stereotypes often
prove incorrect and they do not give the complete picture. Physicians try to minimise undesired
influences of stereotypes by being aware of counter transference, very formal assessments, and
showing compassion.
Conclusions
Physicians adapt their communication style to the degree of ‘perfectness’ of the claimant’s
communication, but they try to minimise the influence of stereotypes in claimant interviews.
It is recommended to address this issue in communication skills training.
Wet en s ch ap s d ag V C W 2 0 1 0 77
EMGO+
68. D
esign of the Double Blind, Randomized
Intervention study in Kids (DRINK study) on
the effect of sugary drinks on body weight and
fat mass
Janne C. de Ruyter, Margreet R. Olthof, Martijn B. Katan.
Department of Health Sciences, EMGO Institute for Health and Care Research, VU University
Amsterdam.
Background
It is widely thought that intake of liquid sugars does not cause satiation and is not compensated
by reduced caloric intake from other foods. Therefore sugar-sweetened beverages are thought to
be particularly fattening. However, trial evidence is inconclusive because previous studies were
too small and not blinded. Hence outcomes may have been determined by effects of behavioural
cues and expectations on food intake rather than by physiological mechanisms.
Objective
Effect of replacing beverages with sugar by sugar-free alternatives on body weight and fat mass
in children in a double-blind trial.
Design
Individually randomized, double blind, controlled trial in free-living school children.
Setting and subjects
641 healthy children aged 5-10 years at eight schools in the Zaanstreek, Purmerend en Haarlem
were randomized, stratified for school, body mass index, age and gender. Children were only
included if they already habitually drank sugary drinks.
Interventions
We designed, tested and produced custom-made lemonades containing 10% sugar and equivalent
lemonades with sweeteners. Both were produced in 4 flavours. Individually labelled cans are
delivered to the schools (bi) weekly and consumed daily during the morning break at school, or
at home during weekends and holidays. Children receive one 250 mL can per day of sugary or
sugar-free lemonade for 18 months.
Outcomes
We assess Z-score of body mass index for age and fat mass from four skinfolds, bioelectrical
impedance and waist circumference at 0, 6, 12 and 18 months.
Funding
ZonMw, Nederlandse Hartstichting, and KNAW. No industry funding.
78
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69. C
ompetence in mental health care: philosophical
theory and medical practice
Andrea Ruissen.
Institute for Research in Extramural Medicine, VU University Medical Center, Amsterdam.
Patient competence or (decision-making) capacity is a complex concept. In international literature
there is no consensus about the meaning of the word. There is however agreement about some
boundary conditions and assessment criteria, and about the moral dimension of the concept.
This study aims to investigate what competence means for the patient, his family and his
healthcare workers. It aims to combine philosophical analysis and empirical research.
Already some research has been performed on competence in patient groups with cognitive
problems, such as persons with dementia or psychosis. We chose to study the people with an
obsessive compulsive disorder. They have less evident problems in decision-making, but do
regularly avoid health care.
To study above issues, we will use responsive methodology, combining semi-structured individual
interviews, focus group interviews and literature research.
In the first project medical doctors in obsessive compulsive disorder outpatients clinics will be
recruited, who doubt the competence of one of their patients. Interviews will be held with the
doctor, patient, family and a paramedic. In the second project focus groups will be organized
with stakeholders. Qualitative methods will be used to analyse the data from those projects. In
the third project a guideline for assessing competence in mental health care will be designed.
The projects will be alternated with philosophical, medical and juridical literature research. The
structure of the project as a whole implies a constant and structured interaction between theory
and practice.
Wet en s ch ap s d ag V C W 2 0 1 0 79
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70. T
he development of a lifestyle intervention in order
to improve older workers’ vitality by using the
Intervention Mapping Protocol
Jorien E. Strijk1, Karin I. Proper1, Allard J. van der Beek1, Willem van Mechelen1.
Department of Public and Occupational Health, EMGO Institute, VU University Medical Center,
Amsterdam.
Purpose
The purpose of this study is to develop and evaluate a lifestyle intervention to improve older
workers’ vitality.
Methods
Using the Intervention Mapping (IM) protocol, a lifestyle intervention was developed based on
information obtained from 1) literature 2) a short lifestyle questionnaire which was aimed at
indentifying main lifestyle problems, and 3) in total 5 focus group (FG) interviews among 36
older workers (aged 45+ years) which were aimed at identifying: a) key determinants of lifestyle
behaviour b) definition of vitality and, c) ideas about how vitality can be improved by lifestyle.
Based on literature and FG interviews, vitality consist of both mental (mental health, well-being
and positive emotions) and physical factors (good health and freedom from fatigue). Lifestyle
problems identified were: Insufficient levels of leisure time physical activity, sedentary behaviour
and not eating the daily recommended amount of fruit and vegetables.
Vitality can be stimulated by a lifestyle intervention aimed at improving: 1) mental factors of
vitality by relaxation exercises (yoga), 2) physical factors of vitality by improve health related
by increasing aerobic fitness, muscle strength, and flexibility and 3) both mental and physical
factors by increasing intakes of fruit by providing free fruit at the workplace.
Results
The lifestyle intervention will consist of 1) three visits to a Personal Vitality Coach (PVC) combined
with 2) Vitality Exercise Programme (VEP), and 3) free fruit at the workplace.
Conclusion
The lifestyle intervention will be evaluated in a RCT among 450 older workers of two major
academic hospitals in the Netherlands.
80
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71. A
ssociations between VO2max and vitality in older
workers: the Vital@Work Study
Jorien E. Strijk, Linda Klaver, Allard J. van der Beek, Willem van Mechelen, Karin I. Proper.
Department of Public and Occupational Health, EMGO Institute, VU University Medical Center,
Amsterdam.
Background
Vitality is closely related to health and is characterised by perceived energy level, fatigue and
feeling fit. These subjective factors can be stimulated by physical activity. Since vigorous physical
activity is strongly related to one’s aerobic fitness (VO2max), it is supposed that VO2max is also
related to vitality. Therefore, the aim of this study was to investigate the association between
vitality and VO2max in older workers.
Methods
Participants (n=427) were aged 45 years and over and worked for at least 16 hours a week at
a large hospital in the Netherlands. VO2max was estimated at baseline using the 2-km UKK walk
test. Vitality was measured by both the UWES Vitality Scale and the RAND-36 Vitality Scale.
Associations were analysed using linear regression analyses. Significance level was defined as
p<0.05.
Results
Linear regression models, adjusted for age, showed a significant association between VO2max and
vitality measured with the RAND-36 Vitality Scale (β = 0.446; 95% CI: 0.220-0.673). There was no
significant association between VO2max and vitality measured with the UWES (β = -0.005;
95% CI:-0.019 – 0.008), after adjusting for age, gender and chronic diseases.
Conclusions
There was an association between VO2max and vitality measured by the RAND-36 Vitality Scale, but
there was no association between VO2max and vitality measured by the UWES Vitality Scale. These
results suggest that the two measurements of vitality (i.e. UWES and RAND-36) measure different
constructs of vitality: e.g. a mental component (UWES Vitality Scale) and a physical component
(RAND-36 Vitality Scale). These findings deserve further exploration in future research.
Wet en s ch ap s d ag V C W 2 0 1 0 81
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72. T
he development of an occupational health
guideline to improve workers’ physical activity and
dietary behaviour in order to prevent weight gain
L.M. Verweij1,2, K.I. Proper1,2, A. Weel3, C.J.T. Hulshof3, W. van Mechelen1,2.
1D
epartment of Public and Occupational Health, EMGO Institute, VU University Medical Center,
Amsterdam
2 Body@Work, TNO-VUmc, Research Center on Physical Activity, Work and Health, Amsterdam
3 Netherlands Society of Occupational Medicine (NVAB), Utrecht.
Purpose
The prevalence of overweight and obesity has reached epidemic proportions, also in the
Netherlands. Weight gain prevention interventions have shown to be feasible within the
occupational health services, but are hardly being implemented by occupational physicians (OPs)
due to a lack of methods and materials. The aim of this study is to 1) develop, 2) evaluate, and 3)
implement a weight gain prevention guideline to be used by OPs.
Methods
Following the standard template of the Netherlands Society of Occupational Medicine (NVAB)
and using the Intervention Mapping (IM) protocol, a draft guideline was developed based on
1) literature, 2) face-to-face interviews with four employers on their current lifestyle policy,
and feasibility of the draft guideline, 3) five focus group interviews among 33 employees on
conditions and barriers to participate, 4) input from an external project group consisting of 8 OPs
and lifestyle experts, and 5) input from 15 independent lifestyle experts.
Results
Based on all sources mentioned above, the developed guideline consists of clear cut
recommendations for OPs to 1) advise employers to promote employees’ physical activity and
diet and 2) counsel employees to adopt a physically active and healthy diet behaviour. Tools to
implement recommendations consist of a minimal intervention strategy to counsel employees,
and a scan to assess the obesogenic environment.
Conclusion
The guideline is now being evaluated in a RCT among 20 OPs and 500 employees. If proven
effective, this weight gain prevention guideline will be implemented on a larger scale within the
occupational health services in the Netherlands.
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73. D
ignity for nursing home patients:
design of the study
Mariska Vlug1, Mette Rurup1, Roeline Pasman1, Dick Willems2, Martien Muller3,
Bregje Onwuteaka-Philipsen1
1D
epartment of Public and Occupational Health, EMGO Institute for Health and Care Research;
VU University Medical Center, Amsterdam
2 Department of Nursing Home Medicine, EMGO Institute for Health and Care Research;
VU University Medical Center, Amsterdam
3 Department of General Practice, Division Clinical Methods and Public Health; Academic Medical
Center/University of Amsterdam, Amsterdam
Introduction
Preserving dignity is frequently mentioned by patients when considering the end of life and is a
central goal in palliative care. An empirical model of dignity has been developed in terminally ill
cancer patients, but it is unclear whether this model is appropriate for other patient groups. The
aim of this study is to further develop the dignity model in the nursing home setting by assessing
which factors are especially relevant to dignity in this setting.
Methods
30 nursing home patients from 4 nursing homes in the Netherlands, who are recently admitted
to a nursing home will be followed using in-depth interviews. They will be interviewed every
6 months, over a maximum period of 4 years. Questions will focus on what constitutes dignity
for the patients in relation to their health and the care given. In the follow-up interviews the focus
will be on changes in the situation of patients and the relation with perceived dignity. If a patient
has become incompetent or has deceased, a relative will be interviewed. For each patient a
nursing home physician and nurse will be interviewed 3 months after admission and shortly after
the patient has deceased. It will be assessed which themes of the dignity model are especially
influential in perceived personal dignity (over time) of nursing home patients.
Results
Not available yet, data collection will start April 2010.
Conclusions
Not available yet.
Wet en s ch ap s d ag V C W 2 0 1 0 83
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74. T
he relationship between heart rate and cortisol
levels and re-offending in delinquent male
adolescents
M. de Vries-Bouw1, A. Popma1, L.M.C. Nauta-Jansen1, R. Vermeiren1,2, Th.A.H. Doreleijers.1
1 VU University Medical Center Amsterdam/De Bascule, Duivendrecht
2 LUMC, Leiden.
Introduction
Longitudinal research on the relation between decreased (re)activity of neurobiological stress
factors (i.e. heart rate, cortisol) and the persistence of juvenile delinquency is scarce, and results
are rather inconsistent. Therefore, the present prospective longitudinal study aims to advance
existing knowledge by examining in delinquent male adolescents whether heart rate and cortisol
were related to the persistence of delinquent behavior.
Methods
Participants were 112 boys (mean age 13,7 years) attending a delinquency diversion program
after committing a minor offense. Heart rate and salivary cortisol were measured at initial
assessment in resting conditions and in response to a standardized public speaking task.
Official registered re-offending was examined after 5-year follow-up.
Results
An overall re-offending rate of 68% and a violent re-offending rate of 48% were found. A
significant correlation (r = -,306) between lower stress-induced heart rate levels and the
frequency of overall re-offending was found, the correlation with violent re-offending (r = -,193)
was statistically non-significant. No correlations were found between resting heart rate or cortisol
levels (basal and responsive) and re-offending.
Discussion
Neurobiological stress factors in resting conditions have limited value for predicting persistent
delinquent behavior. However, heart rate responsivity to stress, but not cortisol, does relate to
re-offending. This study is the first that found evidence for reactive heart rate to be related to
future antisocial behavior, but this finding needs further exploration. Cortisol might be more
specific to certain particular types of antisocial behavior, like reactive aggression.
84
EMGO+
75. Impact of communicating familial risk of diabetes
on illness perceptions and self-reported behavioural
outcomes: a randomized controlled trial
M. Wijdenes-Pijl1,2, D.R.M. Timmermans1,2, L. Claassen1,2, A.C.J.W. Janssens3, G. Nijpels1,4, J.M.
Dekker2, T.M. Marteau5, L. Henneman1,2.
1D
epartment of Public and Occupational Health, VU University Medical Center, Amsterdam,
The Netherlands
2 EMGO Institute, VU University Medical Center, Amsterdam, The Netherlands
3 Department of Public Health, Erasmus University Medical Center, Rotterdam, The Netherlands
4 Department of General Practice, VU University Medical Center, Amsterdam, The Netherlands
5 Psychology and Genetics Research Group, King’s College, London, United Kingdom
Purpose
Family history is an important risk factor for diabetes type 2, reflecting genetic predisposition,
shared environment and common behaviour. The aim in this study was to assess the potential
effectiveness of communicating familial risk of diabetes on illness perceptions and self-reported
behavioural outcomes
Methods
Individuals with a positive family history of diabetes were randomized to receive risk information
based on familial and general risk factors (n=59) or general risk factors alone (n=59). The
information was provided during a personal consultation. behavioural intentions, self-reported
behaviours (diet, physical activity), causal beliefs, perceived consequences of diabetes, personal
control over preventing diabetes, and perceived susceptibility were assessed using questionnaires
(at baseline, 1-week- and 3-months follow-up).
Results
Compared to those receiving information based on general risk factors alone, those receiving
information on familial risk perceived heredity to be a more important cause of diabetes (p<0.01)
at 1-week follow-up, and perceived greater control over preventing diabetes (p<0.05). Although
at 1-week follow-up there were no differences in intentions to change behaviour between the
two groups, at 3-months follow-up the intervention group reported having eaten more healthily
(p=0.01).
Conclusions
Communicating familial risks of developing diabetes increased personal control and thus did not
result in fatalism. Although the intervention did not influence intentions to change behaviour,
there was some evidence to suggest that it might increase healthy behaviour. More research is
needed to confirm these findings in a larger sample, using objective measures of health-related
behaviours.
Wet en s ch ap s d ag V C W 2 0 1 0 85
EMGO+
76. L ower appendicular skeletal muscle mass,
appendicular fat mass and trunk fat mass and
mortality in community-dwelling older men
and women
Hanneke Wijnhoven1, Marieke Snijder2, Marian van Bokhorst-de van der Schueren3, Dorly Deeg4,
Marjolein Visser1,4.
1D
epartment of Health Sciences and the EMGO Institute for Health and Care Research, Faculty of
Earth and Life Sciences, VU University, Amsterdam
2 Department of Public Health, Academic Medical Center, University of Amsterdam, Amsterdam
3 Department of Nutrition and Dietetics, VU University Medical Center, Amsterdam
4 Department of Epidemiology and Biostatistics, EMGO Institute for Health and Care Research,
VU University Medical Center, Amsterdam.
Introduction
The increased mortality risk at low body mass index is well established for older persons. It is,
however, unclear which underlying body mass components explain this elevated mortality risk.
Therefore, we examined associations of lower levels of appendicular skeletal muscle mass (MM),
appendicular fat mass (FM) and trunk FM determined by dual energy x-ray absorptiometry with
12-year all-cause mortality in community-dwelling older men and women.
Methods
Data were used of the Longitudinal Aging Study Amsterdam, a random population-based cohort
study (55-85 years) in the Netherlands. 477 community-dwelling persons ≥65 years of the second
examination round in 1995-96 were included and followed until 2007 for their vital status.
Results
Twelve-year mortality rates were 133/242 (55%) in men and 92/235 (39%) in women. In men,
lower appendicular skeletal MM, lower appendicular FM and lower trunk FM were associated
with a higher mortality risk after adjustment height and age, although statistically significant for
appendicular skeletal MM only. Below the point were the mortality hazard started to increase,
the hazard ratio (HR) per one unit SD decrease was 1.58, 95% CI 1.04-2.52. In women, lower
appendicular FM and lower trunk FM, but not lower appendicular skeletal MM, were associated
with a higher mortality risk. After adjustment for height and age, only the association with trunk
FM was statistically significant (HR 1.61, 95% CI 1.02-2.53). Adjustment for weight change in the
previous 3 years attenuated these associations.
Conclusions
In community-dwelling older persons, in men low levels of appendicular skeletal MM and in
women low levels of trunk FM are found to be associated with an increased mortality risk. Future
studies are needed to confirm or falsify these findings.
86
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77. A
ssistive technology as an alternative to physical
restraints in nursing homes for people with
dementia
Drs. S.A. Zwijsen1, drs. S. te Boekhorst1, prof. dr. C.M.P.M. Hertogh1, prof. dr. A.L Francke2.
1D
epartmentof nursing home medicine, Institute for Research in Extramural Medicine,
VU University Medical Center, Amsterdam
2 The Netherlands Institute for Health Services Research (NIVEL), Utrecht.
Introduction
Assistive technology (AT) is proposed as an alternative to physical restraints in nursing home care
for people with dementia. The number of nursing homes implementing assistive technology is
steadily rising. However, research on usability and effectivity is lacking.
Methods
Residents, proxies and professional caregivers of seven nursing homes were involved in this
study. Interviews and focus group discussions were held with professional caregivers and
proxies of residents to examine the experiences and opinions regarding restraint use and AT.
Data on quality of life and functioning of residents with AT or physical restraints was provided
by their professional caregivers in three measurements. Professional caregivers also filled in a
questionnaire on their own vision on AT, job satisfaction and moral distress.
Results
The term restraint is ambiguous to caregivers; their view on the restraining qualities of
a intervention differs from the legal definition. This discrepancy creates difficulties when
implementing policy to reduce physical restraint use. Moreover, AT was used supplementary
to existing measures rather than as an alternative. Technical shortcomings and organisational
difficulties are other impeding factors when aiming at substituting physical restraints with
assistive technology.
The quantitative data are not yet fully analysed. Therefore, there are no results on the effectivity
of AT use yet.
Conclusion
AT wasn’t used as an alternative to restraints. A better supported and more useable description
of restraints and a better considered policy on AT use could lead to AT use as an alternative to
restraints instead of just supplementary to existing measures.
Wet en s ch ap s d ag V C W 2 0 1 0 87
ICaR-VU
78. P
lasma albumin and transferrin levels mark
pulmonary permeability and lung injury in
hypovolemic patients with or at risk for ARDS
Jurjan Aman1, M. van der Heijden1,2, A. van Lingen3, A.R.J. Girbes2, G.P. van Nieuw Amerongen1,
V.W.M. van Hinsbergh1, A.B.J. Groeneveld2.
Departments of
1 Physiology,
2 Intensive Care
3 Nuclear Medicine, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
Pulmonary vascular permeability plays a key role in the pathophysiology of acute lung injury and
the acute respiratory distress syndrome (ARDS). Since increased pulmonary permeability induces
protein-rich fluid extravasation, we evaluated the predictive values of plasma protein levels for
pulmonary vascular permeability and ARDS.
Methods
This study included 83 mechanically ventilated, hypovolemic patients with or at risk for ARDS.
Pulmonary vascular permeability was studied by the 67Gallium-transferrin pulmonary leak index
(PLI). ARDS was diagnosed according to the American European Consensus Conference (AECC)
criteria and the Lung Injury Score (LIS). Before and after fluid loading, we measured plasma
albumin and transferrin levels, and determined the PLI, the AECC diagnosis and the LIS.
Results
Plasma albumin and transferrin levels were lower in patients with ARDS than in patients without.
They inversely related to the PLI (standardized regression coefficient (src) -0.30 for albumin, -0.30
for transferrin) and the LIS (src -0.21 for albumin), irrespective of sepsis and fluid loading. Plasma
albumin and transferrin levels had negative predictive values of 90-98% for elevated pulmonary
vascular permeability and ARDS according to AECC and LIS.
Conclusions
In critically ill patients with presumed hypovolemia, decreased plasma levels of albumin and
transferrin parallel increased pulmonary vascular permeability and lung injury irrespective of
underlying disease and fluid status. Because of high negative predictive values, normal albumin
and transferrin levels may help to exclude ARDS.
(NHS grants 2003T3201 & 2003T032, ECCRN 2007 Levi Montalcini Award)
88
ICaR-VU
79. V
alidation of ultrastructural analysis of
mitochondrial deposits in cardiomyocytes as
a method of detecting early acute myocardial
infarction in humans
Mark P.V. Begieneman1,2,3, Frank R.W. van de Goot1,2,3, Jan Fritz1, Rence Rozendaal1,
Paul A.J. Krijnen1,3, Hans W.M. Niessen1,3,4.
Departments of
1 Pathology and
4 Cardiac Surgery,
3 ICaR-VU, VU University Medical Center, Amsterdam and
2 Dutch Forensic Institute, The Hague.
Introduction
At a macroscopic level acute myocardial infarction (AMI) can be identified using an LDH
staining method. LDH decoloration does occur 3 hours after onset of AMI. In ischemic hearts
ultrastructural changes occur in the mitochondria, including formation of small osmiophilic
amorphous densities (deposits). In the present study ultrastructural analysis of mitochondrial as
a method for the detection of early AMI was evaluated.
Methods
In 24 AMI patients and 6 controls electron microscopical analysis was perform-ed in the right and
left ventricle of the heart of infarcted patients and non-infarcted controls. LDH staining was done
to indicate AMI, when no decolori-sation was found, AMI was clinically diagnosed by ECG. In AMI
heart tissue was sampled from suspect areas related to corresponding atherosclerotic changed
coronary arteries at risk and/or signs of older infarctions (replacement fibrosis).
Results
In the infarction area of patients with a LDH diagnosed AMI the percentage of positive
mitochondria was significantly higher compared to corresponding heart tissue in control patients
(64±2% vs 48±2%, p<0.000, factor 1.33) and compared to non-infarcted areas (right ventricle)
within these AMI patients (64±2% vs 50±2%, p<0.000, factor 1.28). Also in patients with a
clinically diagnosed AMI but no LDH decoloration, a significant higher percentage of positive
mitochondria was found in the left ventricle compared to controls (61±2% vs 48±2%, p<0.000,
factor 1.27) and non-infarcted areas (right ventricle) (61±2% vs 41±2%, p<0.000, factor 1.47).
In 8 out of 11 (73%) patients the positive predictive was 89.47%, meaning that in 89.47% of the
cases the finding absolutely indicates AMI.
Conclusions
Electron microscopical changes in mitochondria can be used for the diagnosis of AMI less than
3 hours old when LDH staining is negative. However, in approximately 25% of the patients with
an infarction of less than 3 hours old we could not detect ultrastructural evidence for myocardial
infarction. When using this method it is recommended to take samples from non-infarcted tissue
from the same patient to indicate the “background” signal caused by autolysis level.
Wet en s ch ap s d ag V C W 2 0 1 0 89
ICaR-VU
80. A
ltered myocardial substrate metabolism is
associated with myocardial dysfunction in early
diabetic cardiomyopathy in rats: studies using
positron emission tomography
Charissa E. van den Brom1,2, Marc C. Huisman3, Ronald Vlasblom1,2, Nicky M. Boontje2, Suzanne
Duijst1,2, Mark Lubberink3, Carla F.M. Molthoff3, Adriaan A. Lammertsma3, Jolanda van der
Velden2, Christa Boer4, D. Margriet Ouwens5, Michaela Diamant1.
Departments of
1 Internal Medicine/Diabetes Center, 2 Physiology, 3 Nuclear Medicine & PET Research, 4
Anesthesiology, ICaR-VU, VU University Medical Center, Amsterdam, 5 Department of Molecular
Cell Biology, LUMC, Leiden.
Background
In vitro data suggest that changes in myocardial substrate metabolism may contribute to
impaired myocardial function in diabetic cardiomyopathy (DCM). The purpose of the present
study was to study in a rat model of early DCM, in vivo changes in myocardial substrate
metabolism and their association with myocardial function.
Methods
Zucker diabetic fatty (ZDF) and Zucker lean (ZL) rats underwent echocardio-graphy followed by
[11C]palmitate positron emission tomography (PET) under fasting, and [18F]-2-fluoro-2-deoxyD-glucose PET under hyperinsulinemic euglycemic clamp conditions. Left ventricular tissue was
used for morphometric and molecular analyses.
Results
PET data showed a 66% decrease in insulin-mediated myocardial glucose utilization and a
41% increase in fatty acid (FA) oxidation in ZDF vs. ZL rats (both p<0.05). Echocardiography
showed diastolic and systolic dysfunction in ZDF vs. ZL rats. Myocardial functional changes were
significantly associated with whole-body insulin sensitivity and decreased myocardial glucose
utilization. ZDF hearts showed a 68% decrease in glucose transporter-4 mRNA expression
(p<0.05), a 22% decrease in glucose transporter-4 protein expression (p=0.10), unchanged levels
of pyruvate dehydrogenase kinase-4 protein expression, a 57% decreased phosphorylation of
AMP activated protein kinase alfa1/2 (p<0.05) and a 2.4-fold increased abundance of the FA
transporter CD36 to the sarcolemma (p<0.01) vs. ZL hearts, which are compatible with changes
in substrate metabolism. Finally, in ZDF vs. ZL hearts a 2.4-fold reduced insulin-mediated
phosphorylation of Akt was found (p<0.05).
Conclusion
Using PET and echocardiography, we found increases in myocardial FA oxidation with a
concomitant decrease of insulin-mediated myocardial glucose utilization in early DCM. In
addition, the latter was associated with impaired myocardial function. These in vivo data expand
previous in vitro findings showing that early alterations in myocardial substrate metabolism
contribute to myocardial dysfunction.
90
ICaR-VU
81. T
he development of hypertrophy in familial
hypertrophic cardiomyopathy is related to
myocardial fibrosis: medium term follow-up in
genotyped hypertrophic cardiomyopathy mutation
carriers without prior hypertrophy
Wessel P. Brouwer1,5, Tjeerd Germans1, A.J. Houweling2, I. Christiaans4,
J. van der Velden3, A.A.M Wilde4,5, Albert C. van Rossum1,5.
1
2
3
4
5
epartment of Cardiology
D
Department of Cardiogenetics
Department of Physiology, ICaR-VU, VU University Medical Center Amsterdam
Department of Cardiology, Academic Medical Center Amsterdam
Interuniversity Cardiology Institute of the Netherlands (ICIN), Utrecht.
Introduction
Hypertrophic cardiomyopathy (HCM) is a disease characterized by the development of left
ventricular hypertrophy and is associated with heart failure, onset of atrial fibrillation and
ventricular arrythmias. In this study, we monitored the development of hypertrophy in genotyped
HCM patients without hypertrophy and aimed to identify risk factors for the development of
hypertrophy. Therefore we used cardiovascular magnetic resonance (CMR).
Methods
Nineteen HCM carriers (14 MyBPC mutations and 5 TPM1 mutations) were included in the study
(age 42±14 years, 5 male). CMR cine and Late Gadolinium Enhancement (LGE) imaging was
performed at baseline and after 29±9 months to determine LV mass, maximal wall thickness
(using short-axis images) and the amount of myocardial fibrosis. Data were compared with a
paired Student’s T-test. A P-value <0.05 was considered significant.
Results
LV mass showed a non-significant decline from 101±23 g to 96±19 g during follow-up,
while maximal wall thickness tended to increase from 12±2.7 mm to 12.6±2.9 mm (P = ns).
Three MyBPC carriers, already displaying LGE at baseline, developed HCM phenotype
(>15mm wall thickness) during follow-up. Also, the amount of LGE tended to increase
(1.17 ± 1.5 g vs 1.98 ± 1.51 g).
Conclusions
In this study, LV mass tended to remain constant during follow-up. However, a subset of three
MyBPC carriers made a transition towards HCM phenotype, which was concomitant with the
presence of LGE.
Wet en s ch ap s d ag V C W 2 0 1 0 91
ICaR-VU
82. P
ulse rate variability corresponds with heart rate
variability in the evaluation of autonomic function
C.S.E. Bulte, S.W.M. Keet, S.A. Loer, C. Boer, R.A. Bouwman.
Department of Anesthesiology, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
Autonomic function is assessed by determining heart rate variability (HRV) from R-R intervals
obtained with an ECG. These measurements are however sensitive to perioperative environmental
disturbances such as movement artifacts and electrical interference due to diathermy.
We hypothesized that pulse rate variability (PRV) derived from continuous blood pressure
measurements may provide a feasible alternative for HRV obtained with ECG.
Methods
In healthy male subjects HRV and PRV were recorded simultaneously using an ECG monitor and
a plethysmography-based blood pressure measurement device (Nexfin, BMEYE, the Netherlands).
Spectral analysis was used to calculate the power in three frequency bands: very-low-frequency
(VLF; 0-0.04 Hz), low-frequency (LF; 0.04-0.12 Hz) and high-frequency (HF; 0.12-0.40 Hz).
Correlation and level of agreement between ECG and Nexfin were analyzed using Spearman’s
correlation coefficient and Bland-Altman plots.
Results
Eighteen subjects aged 24±5 years were included. Correlation coefficients between HRV and PRV
were 0.998 in the VLF and LF band and 0.993 in the HF band (all P<0.01). The bias, limits of
agreement (LOA) and percentage errors are shown in the table below.
Bias±SD (ms2)
LOA (ms2)
Error (%)
VLF
-12±34
-80 to 56
3
LF
-5±76
-154 to 145
9
HF
-348±509
-1345 to 650
29
Conclusions
Our data show that PRV derived from non-invasive blood pressure waveforms corresponds well
with traditional HRV derived from ECG. These results indicate that under standard conditions
blood pressure waveforms may replace HRV in the evaluation of autonomic function.
92
ICaR-VU
83. M
ulti drug resistance protein expression on
adipose tissue derived stem cells
A. van Dijk1, B. Naaijkens1, W.J.F.M. Jurgens2, R. Oerlemans3, G. Scheffer1, J. Aznou1, M. Brouwer1,
F.C. Visser4, G.J. Schuurhuis5, F.J. van Milligen1, H.W.M. Niessen1,6.
Depts. of
1 Pathology
2 Plastic surgery
3 Rheumatology
4 Cardiology
5 Hematology and
6 Cardiac Surgery, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
The efflux of Hoechst dye, which is caused by the presence of Multi drug resistance (MDR)
proteins, is a characteristic of stem cells. However, only little research has been done to
investigate the expression of MDR proteins in adipose tissue derived stem cells (ASC).
In this study, we therefore investigated the expression and activity of MDR proteins in ASC. Since
expression of these proteins might protect the cells in harmful conditions, we further studied
whether these proteins protected ASC during ischemia.
Methods
BCRP, MRP-1, MRP-4 en PGP protein expression was investigated over time (passage 2-6) using
both western blot analysis and immunohistochemical staining of cytospin slides. Activity of the
proteins was investigated by FACS analysis of MDR protein specific substrate extrusion. Ischemia
was mimicked using metabolic inhibition.
Results
Protein expression of BCRP, MRP-1 and MRP-4, but not of PGP, was shown on ASC. This
expression was found to decrease during culture. Furthermore, ischemia induced protein
expression of these proteins.
It was also shown using a substrate extrusion assay that the MDR proteins indeed were
functionally active. Finally, it was shown that BCRP protects ASC for ischemia, namely when the
BCRP protein is blocked, more stem cells die after 1 hour of ischemia.
Conclusion
ASC express BCRP, MRP-1 and MRP-4 protein, however expression decreases during culture. MDR
proteins protect stem cells in harmful environments like ischemia. Therefore, transplantation of
ASC in ischemic environments like myocardial infarctions, is optimal when expression of these
proteins are high, thus in early passage.
Wet en s ch ap s d ag V C W 2 0 1 0 93
ICaR-VU
84. D
ifferentially methylated region in intron 1 of
STOX1 explains parent-of-origin effect seen in preeclampsia linkage analysis
Marie van Dijk, Cees Oudejans.
Department of Clinical Chemistry, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
The 10q22 chromosomal region with genomic linkage to pre-eclampsia shows a parent-of-origin
effect with maternal transmission. By studying the methylation status of the CpG island within the
STOX1 promoter region, we and others have been unable to identify a differentially methylated
region (DMR) explaining this parent-of-origin effect. Recently, in intron 2 of stox1 in mice, a
tissue-specific DMR has been identified. Furthermore, in human lymphoblastoid cells a differential
allelic expression ratio was detected for STOX1 SNPs. Both of these studies indicate the existence
of a DMR in humans leading to differential expression, and potentially explain the parent-oforigin effect observed.
Methods
By computational analysis a region within intron 1 of the STOX1 gene was identified as a
potential CpG island. This was confirmed using CT-converted DNA of buffycoat samples as a
source of cells in which differential expression was observed. Normal and androgenetic early
placenta samples were tested in the same manner along with term placenta, SGHPL5 cells and
adult tissue samples.
Results
The methylation pattern identified in term placenta and adult tissue is consistent with an
imprinted gene in which 50% of the alleles are methylated in tissues expressing STOX1, while
80% of the alleles are methylated in tissue with very low levels of STOX1 expression (liver). In
early placenta only 20% of the alleles were methylated, while androgenetic placentas, consisting
of paternal alleles only, showed a two-fold increase in methylation. SGHPL5 cells, representing
extravillous trophoblasts, were also 50% methylated. This indicates that in early placenta, in
contrast to term and adult tissue, only some cell types (extravillous trophoblasts among others),
are subject to imprinting.
Conclusions
This study confirms that the parent-of-origin effect observed in the pre-eclampsia linkage analysis
is caused by a DMR within STOX1, leading to cell type-specific imprinting in the early placenta.
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ICaR-VU
85. S arcomeric function and protein phosphorylation
in patients with primary hypertrophic and dilated
cardiomyopathy
Sabine J. van Dijk, Rozemarije A. Holewijn, Anouk Tebeest, Cris dos Remedios, Ger J.M. Stienen,
Jolanda van der Velden.
Institute for Cardiovascular Research, VU University Medical Center, Amsterdam.
Introduction
Hypertrophic cardiomyopathy (HCM) is characterized by asymmetrical left ventricular wall and
septal hypertrophy, while in dilated cardiomyopathy (DCM) the heart remodels eccentric. Previous
studies using recombinant protein and animal models have suggested that HCM is associated
with hypercontractility of the sarcomere, while DCM is characterized by hypocontractility.
However, these studies lack information on post-translational protein phosphorylation, which may
significantly modulate myofilament function.
Methods
In the present study, we investigated the relation between contractile function and
phosphorylation of the β-adrenergic target proteins myosin binding protein C (cMyBP C) and
troponin I (cTnI) in explanted HCM (n=8) and DCM (n=5) hearts in comparison to healthy donor
hearts (n=8).
Results
Cardiomyocyte force measurements demonstrated a lower maximal force in HCM (25.3 kN/
m2) than in donor (34.7 kN/m2) and DCM (30.0 kN/m2). Both HCM and DCM displayed a higher
Ca2+ sensitivity of force compared to donor (pCa50 5.59; 5.60and 5.54, respectively), which was
associated with lower phosphorylation of cMyBP-C and cTnI in both cardiomyopathy groups.
Incubation with protein kinase A (PKA), to mimic β adrenergic stimulation, evoked a larger
decrease in Ca2+ sensitivity in DCM compared to HCM and donor (ΔpCa50: 0.24 compared to 0.14
and 0.06). After PKA treatment, Ca2+ sensitivity was comparable in HCM and donor and lower in
DCM.
Conclusions
Although Ca2+ sensitivity in both cardiomyopathies was higher compared to donor, the
maximal force generating capacity in HCM was reduced, reflecting hypocontractility rather than
hypercontractility. In DCM Ca2+ sensitivity was decreased relative to donor and HCM only after
β-adrenergic stimulation, indicating that DCM displays hypocontractile characteristics solely after
stress.
Wet en s ch ap s d ag V C W 2 0 1 0 95
ICaR-VU
86. A
ltered cross-talk between perivascular adipose
tissue and resistance arteries in muscle blunts
insulin-mediated vasoreactivity in db/db mice
R.I. Meijer1,2, W. Bakker1, C.A.F. Alta1, P. Sipkema1, C.D.A. Stehouwer3, E.H. Serne2,
Y.M. Smulders2, V.W.M. van Hinsbergh1, E.C. Eringa1.
1 Laboratory for Physiology and
2 Department of Internal Medicine, ICaR-VU, VU University Medical Center, Amsterdam
3 Department of Internal Medicine, Maastricht University Medical Center, Maastricht.
Introduction
Obesity is characterized by disturbed vascular insulin signaling which contributes to muscle
insulin resistance. We have previously proposed that accumulation of perivascular adipose tissue
in muscle impairs insulin-mediated vasoreactivity, and we tested this hypothesis in the current
study. The aim was to test the hypotheses that mPAT controls insulin-mediated vasoreactivity
through the excretion of adiponectin and activation of AMPK, and that this interaction is blunted
in obese, insulin-resistant db/db mice.
Methods
Responses to insulin of muscle arterioles from lean (C57Bl/6) mice were studied in the pressure
myograph in the presence of mPAT of lean or obese, insulin-resistant db/db mice. Compound C
(an AMPK inhibitor) was used to study the role of AMPK in effects of mPAT. Interaction of mPAT
with vasodilator effects of insulin was further investigated by Western blot analysis of AMPK and
Akt phosphorylation.
Results
Db/db mice were obese, insulin-resistant and hyperglycaemic. In muscles of db/db mice, we found
a marked increase in mPAT around muscle arterioles, which was accompanied by enlargement of
adipocytes. MPAT of lean mice induced insulin-mediated vasodilatation (58+34% at 2 nM of insulin).
MPAT of lean mice increased by activated AMPK as indicated by phosphorylation at Thr172, and
AMPK inhibition abolished insulin-mediated vasodilatation in the presence of mPAT (4+2% at 2 nM).
Moreover, mPAT of lean mice secretes the endogenous AMPK agonist adiponectin which we found
in mPAT-conditioned medium. MPAT of db/db mice did not induce insulin-mediated vasodilatation
(-5+3 %, P<0.05 vs. mPAT of lean mice), which was accompanied by a blunted secretion of adiponectin (502+115 vs. 178+33, P=0.02). In the presence of mPAT of db/db mice, insulin-mediated
activation of Akt in muscle resistance arteries was reduced from 9.7-fold to 5.3-fold (P=0.02).
Conclusions
MPAT isolated from lean mice controls insulin-mediated vasodilation through activation of AMPK
and secretion of adiponectin. Induction of insulin-mediated vasodilatation is blunted in mPAT
of db/db mice, which is associated with impairment of adiponectin secretion by mPAT and
decreased Akt activation in muscle resistance arteries. This blunted crosstalk between mPAT and
muscle resistance arteries likely contributes to reduced delivery of nutrients to muscle in obesity.
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ICaR-VU
87. P
ositive predictive value of computed tomography
coronary angiography for detection of significant
coronary artery disease and its relationship with
plaque composition in clinical practice
Jan G.J. Groothuis1, Aernout M. Beek1, Martijn R. Meijerink2, Stijn L. Brinckman1,
Martijn W. Heymans3, Cornelis van Kuijk2, Albert C. van Rossum1.
Departments of
1 Cardiology
2 Radiology
3 Clinical Epidemiology and Biostatistics, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
Several studies have investigated the diagnostic accuracy of computed tomography coronary
angiography (CTCA) for detection of significant coronary artery disease (CAD). Although the
negative predictive value of CTCA was consistently high, a wide range of positive predictive
values (PPV) was reported. Most of these studies were performed in patients already referred for
invasive coronary angiography and prevalence of significant CAD was high. Thus, PPV of CTCA
in patients that undergo CTCA as part of a clinical diagnostic evaluation remains unclear. This
study investigated the PPV of CTCA for the detection of significant CAD in patients with low to
intermediate pre-test probability CAD that were referred for non-invasive evaluation of chest pain.
Additionally, the relationship between plaque composition and PPV in this patient group was
investigated.
Methods
181 patients underwent 64-slice CTCA. CTCA was scored per segment as normal, non-obstructive
CAD or obstructive CAD (>50% diameter stenosis). Plaque composition was scored per segment
as calcified, mixed or non-calcified plaque. All patients with obstructive CAD underwent invasive
coronary angiography (CA). Significant CAD was defined as >50% diameter stenosis on CA.
Results
According to CTCA, 65 (35.9%) patients had obstructive CAD. Of 147 segments with obstructive
CAD, 46 (31.3%) comprised calcified, 89 (60.5%) mixed and 12 (8.2%) non-calcified plaque. In
26 (14.4%) patients, significant CAD was found by CA. The PPV for detection of significant CAD
per patient and per vessel were 40.0% (95% CI: 30.6-50.2%) and 30.4% (95% CI: 23.9-37.9%),
respectively. The PPV per segment of non-calcified plaque (50%) was significantly higher than
calcified plaque (17%), p=0.019.
Conclusions
In patients with low to intermediate probability CAD that are referred for non-invasive evaluation
of chest pain, the PPV of CTCA for detection of significant CAD is low. This may be explained by
the low prevalence of significant CAD in this patient group. Additionally, in these patients only a
small number of obstructive plaques was non-calcified, that had a significantly higher PPV than
calcified plaques.
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ICaR-VU
88. NOX5
expression in human cardiomyocytes is
increased after acute myocardial infarction
Nynke E. Hahn1,4, Paul A.J. Krijnen1,4, Tsukasa Kawahara5, René J.P. Musters3,4, Hans W.M.
Niessen1,2,4, Christof Meischl1,4.
Depts. of
1 Pathology
2 Cardiac Surgery and
3 Physiology
4 ICaR-VU, VU University Medical Center, Amsterdam
5 Department of Pathology and Laboratory Medicine, Emory University School of Medicine,
Atlanta, USA.
Introduction
Reactive oxygen species (ROS)-based signaling has been shown to play an important role in
cardiomyocytes under different (patho)physiological conditions and the family of NADPH oxidases
(NOXes) are a known to be a central source of these second messengers. The principal NOXes in
the cardiovascular system are NOX1, NOX2 and NOX4. Recently, the calcium-regulated NOX5 has
been demonstrated in human blood vessels; however, nothing is known yet about the expression
of NOX5 in cardiomyocytes. Because cardiac contraction is highly dependent on intracellular
calcium levels and intracellular calcium regulation, we have analyzed the expression of NOX5 in
cardiomyocytes.
Methods
NOX5 expression was analyzed in both isolated bovine and human cardiomyocytes by Western
blot and digital imaging microscopy. Furthermore, NOX5 expression in heart tissue samples from
patients who had died of acute myocardial infarction (AMI) was studied by immunohistochemical
analysis.
Results
In isolated bovine and human cardiomyocytes NOX5 expression was detected. Digital imaging
microscopical and immunohistochemical studies demonstrated NOX5 expression at the site of
intercalated discs in both bovine and human cardiomyocytes. In patients with AMI a significant
increase in NOX5-positive cardiomyocytes was found in the infarcted heart tissue.
Conclusion
NOX5 is expressed in cardiomyocytes at the site of intercalated discs, and this expression
was increased in patients with AMI. Further studies have to elucidate the (patho)physiological
significance of these findings.
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89. C
hronic treatment with low-dose bisoprolol
improves survival and cardiac function in
experimental pulmonary arterial hypertension
M. Louis Handoko1,2 & Frances S. de Man1, J.J.M. van Ballegoij1,2, I. Schalij2, P.E. Postmus2,
W.J. van der Laarse1, J. van der Velden1, N. Westerhof1,2, W.J. Paulus1, A. Vonk-Noordegraaf2.
Departments of
1 Physiology and
2 Pulmonology, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
Pulmonary arterial hypertension (PH) eventually leads to right heart failure. The use of betablockers in PH is strongly discouraged, because of their negative inotropic and chronotropic
effects. However, use of beta-blockers in chronic (left) heart failure is safe and significantly
reduces mortality. We investigated whether chronic low-dose treatment with bisoprolol
(a selective β1-adrenergic receptor antagonist) has cardiac-specific beneficial effects in
experimental PH.
Methods
Progressive PH in rats was induced by a single injection of monocrotaline (60 mg/kg). Pressuretelemetry in PH-rats revealed that 10 mg/kg bisoprolol was the lowest dose that could blunt heart
rate response during daily activity. Ten days after monocrotaline-injection, echocardiography
was performed, and PH-rats were randomized for bisoprolol-treatment (oral gavage; n=7/
group). At end-of-study (body mass loss >5%), echocardiography was repeated with additional
pressure-volume measurements. Rats were euthanized; heart and lungs were harvested for
histomorphological analyses.
Results
Echocardiography confirmed the PH-status at start of treatment. Bisoprolol delayed disease
progression and improved survival (p<0.05). Compared to control, RV systolic pressure and
arterial elastance (Ea; measure for vascular resistance) more than tripled in PH. However, RV
afterload was unaffected by bisoprolol-treatment. Bisoprolol increased cardiac contractility (Ees)
and relaxation (Eed; both p<0.01), and partially restored ventriculo-arterial coupling (Ees/Ea) and
cardiac output (both p<0.05). Histology revealed significantly less cardiac fibrosis and less RV
myocardial inflammation in bisoprolol-treated PH-rats.
Conclusions
In experimental PH, treatment with bisoprolol improves survival, ventriculo-arterial coupling and
reduces RV diastolic dysfunction. These promising results suggest a therapeutic role for betablockers in PH that warrants further clinical investigation.
Wet en s ch ap s d ag V C W 2 0 1 0 99
ICaR-VU
90. T
he reproducibility of non-standardized autonomic
function testing in the preoperative assessment
screening clinic
Sander W.M. Keet, Carolien S.E. Bulte, Christa Boer, R. Arthur Bouwman.
Department of Anesthesiology, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
Autonomic function testing specifically requires standard environmental test conditions.
Consequently, autonomic function testing is difficult to implement in preoperative patient
assessment, although its predictive value for peri-operative hemodynamic stability has been
suggested. We aimed to compare results of testing under non-standardized and standardized test
conditions.
Methods
Eighteen healthy male subjects (19-34 years) were studied during standard test conditions (08:0010:30 a.m., quiet ambiance, temperature 19-22oC and overnight fasted). Autonomic function
was assessed using an ECG-monitor and a continuous non-invasive blood pressure measurement
device (Nexfin HD, BMEYE, Amsterdam, the Netherlands). Blood pressure and heart rate responses
were measured during deep breathing (E/I-ratio (0.1 Hz)), Valsalva manoeuvre (Valsalva-ratio),
sustained handgrip and after standing. Heart rate variability (HRV) analysis comprised evaluation
of the very low (VLF; 0.0-0.04 Hz), low (LF; 0.04-0.12 Hz) and high frequency band (HF; 0.120.4 Hz) during 5 minutes at rest. All tests were repeated under non-standardized, non-fasted
conditions.
Results
Intra-class correlation (ICC) coefficients were calculated for all autonomic function tests. The ICC
for LF and HF were 0.78 (95%CI; 0.43-0.92) and 0.71 (95%CI; 0.36-0.88), respectively, whereas
the ICC for VLF was 0.52 (95%CI; 0.08-0.79). The E/I-ratio revealed an ICC of 0.80 (95%CI; 0.530.92), the Valsalva-ratio ICC was 0.62 (95%CI; 0.20-0.84) and the handgrip test had an ICC of
0.61 (95%CI; 0.19-0.85). P<0.05 for all above mentioned ICC values. The ICC of the responses to
standing was low.
Conclusions
We demonstrated in healthy volunteers that the reproducibility for most autonomic function tests
under standardized and non-standardized conditions is clinical acceptable. These data suggest
that implementation of autonomic function assessment may be feasible in preoperative patient
risk assessment.
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91. K
LF2-induced actin shear fibres control both
alignment to flow and JNK signaling in vascular
endothelium
Thomas A. Leyen1, Reinier A. Boon1,2, Ruud D. Fontijn1, Joost O. Fledderus2, Josefien M.C. Baggen1,
Oscar L. Volger1,2, Geerten P. van Nieuw Amerongen3 and Anton J.G. Horrevoets1.
Departments of 1Molecular Cell Biology and Immunology and 3Physiology, VUmc, ICaR-VU,
Amsterdam and the 2Department of Medical Biochemistry, Academic Medical Center, Amsterdam.
Introduction
Absence of shear flow at arterial bends and bifurcations induces atherosclerotic lesions. Krüppellike factor 2 (KLF2) is a major effector of the beneficial effects of shear stress on endothelial cells
by affecting proteins related the cytoskeleton. We set out to explore the implications of this on
anti-inflammatory effects of endothelium.
Methods
Human HUVEC, microvascular, and arterial endothelium grown on fibronectin-coated coverslips
were transduced with KLF2-expressing or anti-KLF2 silencer RNA lentiviral vectors and exposed to
arterial levels of flow in IBIDI laminar flow chambers. The cells were fluorescently stained for focal
adhesion proteins and analyzed by 3-colour Confocal scanning or Deconvoluting microscopy.
Effects on signalling and transcriptome were determined by quantitative Western blotting and
real-time PCR.
Results
Both flow and KLF2-induced specific actin shear fibres are thick cables connected at both ends
to focal adhesions running across the basal membrane of the cells. The coinciding changes in
focal adhesion complexes regulate actin-structure modulating proteins. KLF2-induced fibers are
essential for flow alignment and contain force-generating phosphomyosin. Fibers were formed
independent from Rho kinase and quite distinct from conventional stress fibers, but similar to
fibers in ex vivo arteries and veins. The presence of actin shear fibres affects the expression of a
panel of proinflammatory genes, by suppressing signaling through c-jun N-terminal kinase (JNK)
and its target pro-inflammatory transcription factor ATF2.
Conclusions
KLF2 directs actin architecture through regulation of focal adhesion activity in various endothelial
cells, which is essential for its anti-inflammatory effects on endothelium.
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92. Interventricular synchrony in chronic thromboembolic pulmonary hypertension recovers after
endarterectomy
G.J. Mauritz1, J.T. Marcus2, J. Bosboom2, A. Vonk Noordegraaf1.
1 Depts. of Pulmonology and
2 Physics & Medical Technology, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
In Pulmonary Hypertension, the Right Ventricular (RV) pressure overload induces interventricular
mechanical asynchrony which impairs the function of RV and LV. The aim was to assess if in
Chronic Thrombo-Embolic Pulmonary Hypertension (CTEPH) the Left-Right (L-R) mechanical
synchrony recovers after removal of the thrombo-emboli out of the pulmonary arteries
(endarterectomy).
Methods
MRI tagging delivers ‘magnetic markers’ to the myocardium, which are detected through the
cardiac cycle and register myocardial contraction (fig 1). Nine CTEPH patients underwent MRI
myocardial tagging before, and 1 year after endarterectomy. By using Harmonic Phase analysis,
myocardial circumferential shortening of LV and RV free wall and the septum were calculated.
Results
Fig 1: RV and
LV in CTEPH
Fig 2: Circumferential short-
ening before endarterectomy
Fig 3: Same patient, after
endarterectomy (‘post’)
At baseline (fig 2) the RV reaches its peak circumferential shortening later than the septum and
the LV. This L-R delay decreased from 95±61 ms at baseline, to 2±47 ms after endarterectomy
(p<0.05), as shown in fig 3. Peak RV shortening increased from 12±3 % at baseline, to 16±3%
(p<0.05). Cardiac output increased from 3.7±0.9 l/min to 4.8±0.6 l/min (p<0.01).
Conclusions
After endarterectomy, the L-R synchrony and the RV contractile function are recovering.
RV function is influenced by the pulmonary vascular bed.
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93. O
nset time of retrograde flow in the pulmonary
artery in pulmonary arterial hypertension: an
estimator for pulmonary arterial pressure?
F. Helderman1,2, G.J. Mauritz1, J.T. Marcus2, K. Andringa2, N. Westerhof1,
A. Vonk Noordegraaf1.
1 Departments of Pulmonology and
2 Physics & Medical Technology, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
In the pulmonary artery of Pulmonary Arterial Hypertension (PAH) patients, a 3-dimensional
(3D) flow vortex might be detectable from regional retrograde flow in a cross section of the
pulmonary artery. The aim of this study was to assess if mean pulmonary artery pressure (mPAP)
could be estimated from the onset of retrograde flow in the pulmonary artery using a 2D MRI
flow map.
Methods
In 37 PAH patients and 8 healthy controls, 2D MR phase-contrast velocity quantification was
applied in the main pulmonary artery. The onset time of the retrograde flow (Retrograde Onset
Time = ROT) as fraction of cardiac cycle time, and cross sectional area (CSA) of the main
pulmonary artery were measured.
Results
Regression analysis revealed an negative association between mPAP and ROT (r=0.74; p<0.001),
which means that the larger the mPAP, the earlier starts retrograde flow. A positive association
between mPAP and CSA (r=0.68; p<0.001) was found. With cut-off values of 0.38 for ROT, and
626 mm2 for CSA, these variables could predict PAH with both 100% sensitivity, and 75 and 100
% specificity, respectively.
Model of the recirculation
zone in the pulmonary
artery of a PAH patient
(b), which explains early
retrograde flow and is
consistent with a 3D flow
vortex.
Conclusions
Early retrograde flow in PAH is detectable with MRI flow mapping. ROT and CSA are non-invasive
estimators for mPAP.
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94. Microvascular dysfunction in skin and muscle
Rick I. Meijer*, Michiel P. de Boer*, Etto C. Eringa, Yvo M. Smulders,
Erik H. Serné. *Both authors contributed equally.
Institute for Cardiovascular Research, VU University Medical Center, Amsterdam.
Introduction
The microvasculature in the skin has often been used as a representation of systemic
microvascular function, using capillary video microscopy. The skin is however not the main
site of interest for microvascular function, because of its limited importance in peripheral
vascular resistance and insulin mediated capillary recruitment. The microvasculature in the skin
is specialised in processes such as heat exchange, making it a distinct vascular bed from the
microvasculature in skeletal muscle. Skeletal muscle is, in contrast, the most important site for
peripheral vascular resistance and insulin mediated capillary recruitment. The microvasculature
in skeletal muscle is however hard to image non-invasively. Recently Contrast Enhanced
UltraSonography (CEUS) has been applied to examine the microcirculation in skeletal muscle, thus
creating a method to study the site of interest with a high resolution and small burden for the
participants.
A direct comparison between capillary video microscopy and CEUS, to study whether the
microcirculation in skin and in skeletal muscle exhibit equal responses to insulin, and thus
whether microvascular dysfunction exhibits similar characteristics in skin and skeletal muscle,
has never been made.
Methods
Twenty healthy participants with a BMI ranging from 20-35 kg/m2 will be studied. Participants
will undergo capillary video microscopy and CEUS, before, and during euglycaemic
hyperinsulinaemic clamping, in a randomised order. Outcomes will be the amount of recruitment
with each of the measurements. A Pearson’s correlation coefficient will be performed to study
whether the two different sites of the microcirculation exhibit a similar direction of change, and if
these changes are correlated.
Results
Analysis of the data is currently being performed. Preliminary analyses show a good correlation
between M-value (insulin-sensitivity) and insulin augmented capillary recruitment using capillary
video microscopy as well as CEUS.
Conclusions
Skin and skeletal muscle exhibit a similar microvascular response to hyperinsulinemia within one
subject.
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95. The post-MI mouse heart is hypothyroid
Christine J. Pol1, Marian J. Zuidwijk1, Ellen Kaptein2, Alice Muller1,
Theo J. Visser2, Dirk J. Duncker2 and Warner S. Simonides1.
1 Laboratory for Physiology, ICaR-VU, VU University Medical Center, Amsterdam,
2 Experimental Cardiology, Thoraxcenter, Erasmus University Medical Center,
3 Department of Internal Medicine, Erasmus University Medical Center, Rotterdam.
Introduction
After myocardial infarction (MI), left ventricular (LV) remodelling occurs as a compensatory
mechanism. Post-MI remodelling of the LV in mice is associated with induction of the enzyme
deiodinase type III (D3), which inactivates thyroid hormone (T3). This suggests that cardiac T3
signalling is impaired. The aim of this study was to explore the time course of D3 induction
following MI and analyze the impact on T3 signaling.
Methods
D3 activity and mRNA expression were determined at 3, 5 or 7 days post-MI in the LV in mice.
A plasmid (pT3R) was constructed in which Firefly (FLuc) and Renilla (RLuc) luciferase genes
are driven by a T3-responsive and a control promoter. T3-dependent transcription activity was
assessed by direct injection of the pT3R in the LV wall of mice during sham or MI operation.
Luciferase activities were determined in LV homogenates after two weeks.
Results
MI and sham surgery induced D3 activity and mRNA expression around 25 fold over baseline at
day 3 and remained elevated in MI, but returned to baseline at day 5 in Sham. Compared to sham
operated mice, FLuc activity in LV homogenates was significant decreased by 35% in MI operated
mice (p=0.002); whereas a minimal infarcted area did not lead to a reduction.
Conclusions
D3 is transiently increased post-surgery but remains elevated after MI. After a large MI; the D3
induction results in lower cardiac T3-dependent transcription activity. The post-MI heart can
be considered hypothyroid since a comparison of euthyroid and hypothyroid mice revealed a
decrease of the FLuc activity of 45%.
Contact: c.pol@vumc.nl
Supported by NHF grant 2006B240.
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96. T
he glucagon-like peptide receptor agonist
Exenatide protects against glucocorticoid induced
glucose intolerance and islet-cell dysfunction
in humans
DH van Raalte1, RE van Genugten1, MML Linssen2, DM Ouwens3, M Diamant1.
1 Diabetes Center, ICaR-VU, VU University Medical Center, Amsterdam, The Netherlands
2 Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands
3 Deutsches Diabetes Zentrum, Düsseldorf, Germany
Introduction
Glucocorticoids (GC) induce glucose intolerance by impairing islet-cell function and insulin
sensitivity. To date, no preventive measures exist to mitigate the adverse metabolic effects of GC
treatment. The gut hormone glucagon-like peptide (GLP)-1 and its receptor agonists (RA) lower
blood glucose by enhancing insulin- and inhibiting glucagon secretion. We hypothesized that
GLP-1 RA treatment may prevent GC-induced glucose intolerance.
Methods
Using a cross-over design, 8 healthy males in random order, received for 2 consecutive days
either 1) 80mg oral prednisolone QD and exenatide infusion (PRED+EXE), or 2) 80mg oral PRED
QD and saline infusion (PRED+SAL), or 3) oral placebo-PRED QD and saline infusion (PLAC+SAL).
On day 1, glucose tolerance was assessed following a standardized-meal-test. On day 2, β-cell
function was measured during a combined euglycemic-hyperinsulinemic-hyperglycemic clamp
with arginine stimulation.
Results
PRED+SAL treatment increased postprandial glucose levels (vs. PLAC+SAL, p=0.009), which was
prevented by concomitant EXE infusion (PRED+EXE). PRED+SAL decreased 1st-phase glucosestimulated C-peptide secretion and disposition index (DI: 1st phase C-pep secretion multiplied by
insulin sensitivity) (vs. PLAC+SAL, p<0.05 and p=0.03 respectively), but did not affect 2nd-phase
glucose-stimulated or arginine-stimulated C-peptide secretion. EXE infusion prevented both the
PRED-induced reduction in 1st phase C-peptide secretion and DI (vs. PRED+SAL, both p<0.01) and
augmented 2nd phase and arginine-stimulated C-peptide secretion. PRED increased postprandial
glucagon levels non-significantly (vs. PLAC+SAL, p=0.1), which was attenuated by EXE (vs.
PRED+SAL p=0.06).
Conclusion
In summary, PRED impaired glucose tolerance in healthy humans. Concomitant treatment with the
GLP-1RA EXE prevented the harmful effects of PRED on glucose tolerance by improving islet-cell
balance.
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97. Pressure-volume loop evaluation of CRT in endstage heart failure. A comparison of patients with a
narrow, intermediate and broad QRS complex
G.J. de Roest, C.P. Allaart, S.A. Kleijn, J.G.F. Bronzwaer, M.L. Hendriks, C.C. de Cock,
A.C. van Rossum.
Department of Cardiology, ICaR-VU, VU University Medical Center, Amsterdam.
Background
Controversy exists concerning the response to CRT in patients with narrow QRS complexes.
Recently, improved acute hemodynamic response has been observed of CRT in patients with
narrow QRS complexes, while others found no improvement in peak oxygen consumption after
CRT on the long term in these patients. This study therefore evaluates the comprehensive
pressure-volume response to CRT in multiple locations, both in patients with and without
conduction delay.
Methods
Sixty-four patients with symptomatic end-stage drug refractory heart failure were included
in the present study and were subdivided according QRS duration (1: QRS<120ms (n=16); 2:
120ms≤QRS <150ms (n=18); 3: QRS≥150ms(n=30)). Patients underwent pressure-volume loop
evaluation to assess the response to multiple site biventricular pacing.
Results
During biventricular pacing with LV stimulation in the posterior position CO increased in the
narrow QRS group +5% (p=ns) and SW decreased -1% (p=ns). In the intermediate and broad QRS
group, CO showed an increase of +39% (p=0.003) and +41% (p=0.004) and SW +42% (p=0.001)
and +47%, (p=0.001), respectively.
Hemodynamic function deteriorated even more in the ‘narrow’ QRS group during LV anterior
pacing site (CO -12%, p=0.050; SW -17%, p=0.009). In contrast, LV anterior pacing in both the
intermediate and broad QRS group improved CO and SW, although less than PLRVA (ΔCO -13%;
p=0.016 and ΔSW -14%; p=0.003).
Conclusions
In a large proportion of conventional CRT candidates a clear hemodynamic response to
biventricular pacing was observed. In addition, hemodynamic response to CRT in the narrow QRS
group is lacking. Moreover when CRT is applied in these patients in the anterior region of the LV,
cardiac function is decreased. These findings suggest that applying CRT in the narrow QRS is not
appropriate and might even be associated with worsening of heart failure.
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98. L evel of agreement between the Clauss fibrinogen
test and rotational thromboelastometry FIBTEM test
in cardiothoracic surgery
Johannes W.A. Romijn1, Steven B. Nicia1, Alexander B.A. Vonk2, Albertus Beishuizen3,
Christa Boer1.
Departments of
1 Anesthesiology
2 Cardio-Thoracic Surgery and
3 Intensive Care Medicine, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
Fibrinogen is one of the first coagulation factors that reach a critical level during perioperative
bleeding. In cardiac surgery, fibrinogen levels are mainly monitored through routine laboratory
tests, although fibrinogen testing using rotational thromboelastometry may be a time saving
alterative. The aim of the present study was to evaluate the level of agreement between both
tests in the cardiothoracic surgical setting.
Methods
Citrated blood was drawn from 23 patients undergoing cardiac surgery before cardiopulmonary
bypass (pre-CPB), after protamine administration (post-CPB) and at 3 (T=3) and 24 (T=24) hours
postoperatively. Blood samples were analyzed by the Clauss test and thromboelastometry
fibrinogen test (FIBTEM test; ROTEM Delta, Pentapharm, Germany). Data are represented as mean
± SD.
Results
Fibrinogen decreased from 3.2±0.7 (pre-CBP) to 1.8±0.4 g/l (post-CPB), and increased above 2
g/l postoperatively. This was paralleled by FIBTEM values of 16.7±5.2 (pre-CBP), 9.7±3.4 (postCBP), 12.4±5.3 (T=3) and 17.6±5.3 mm (T=24). There was a good correlation between the FIBTEM
and Claus test for fibrinogen (r=0.81; P<0.001). Using a cut-off value of 2g/l plasma fibrinogen,
the specificity and sensitivity of the Clauss test were 31% and 78%, respectively, for post-CPB
administration of plasma as source of fibrinogen. The FIBTEM test revealed a specificity of 92%
and a sensitivity of 56% as predictor for FFP administration.
Conclusion
In conclusion, there is a high level of agreement between the Clauss and FIBTEM fibrinogen tests.
Our findings suggest that the FIBTEM test provides a time saving alterative for the Clauss test to
monitor the functional fibrinogen capacity during cardiothoracic surgery.
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99. Iron deficiency is common in pulmonary arterial
hypertensive patients
Gerrina Ruiter1,2, Yeun Ying Wong1,2, Ingrid Schalij2, Pieter E. Postmus1,
Willem J. van der Laarse2, Anton Vonk-Noordegraaf1.
1 Department of Pulmonology and
2 Department of Physiology, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
In pulmonary arterial hypertension (PAH), elevated right ventricular (RV) pressure results in
adaptation and hypertrophy of the myocardial wall, which in the end causes progressive right
heart failure. During the disease, patients become increasingly exercise intolerant and
maintaining their physical activity is a major goal in PAH treatment. In left heart failure, iron
deficiency is found to be a detrimental factor in exercise performance that can be reversed by
iron suppletion. This study was performed to investigate whether iron deficiency is present in
the PAH population.
Methods
All idiopathic PAH patients attending our center between May 2009 and December 2009 were
analysed for serum iron status through standard haematology measurements. Iron deficiency was
defined as serum ferritin levels below 20 μg/l, serum iron lower than 10 μmol/l, and decreased
transferrin saturation. Iron data were correlated with the clinical and hemodynamical status of
these patients.
Results
From 55 idiopathic PAH patients (14 male, 41 female), blood samples were collected. Iron
deficiency was found in 19 patients (35%) (4 male, 15 female). Ten of these patients had normal
Hb concentration (>8.5 mmol/l in male and >7.5 mmol/l in females). Blood iron parameters were
significantly lower in the iron deficient group compared to non-iron deficient PAH patients (p
<0.05). Iron deficient patients had reduced six minute walking distances compared to non-iron
deficient PAH patients (380m vs 463m, p <0.05). No correlation was found between iron status
and NT-proBNP levels. However, a negative correlation was found between serum ferritin levels
and NYHA classification (r = – 0.343, p <0.05) and six minute walking distance (6MWD) (r = –
0.342, p <0.05).
Conclusions
Iron deficiency is a common feature in our population of idiopathic PAH patients (35%).
The incidence increases with disease severity and is correlated with a decrease in exercise
performance (6MWD). Whether treatment with iron suppletion is beneficial for these patients
requires further research.
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100. B
ronchial perfusion in the lungs observed by
contrast-enhanced MRI
N. Saouti1, A. Vonk Noordegraaf1, M. Ingrisch3, J.T. Marcus2.
1 Department of Pulmonology and
2 Department of Physics & Medical Technology, ICaR-VU, VU University Medical Center,
Amsterdam
3 Ludwig-Maximilian University, Munich, Germany.
Introduction
The aim is to visualize the pulmonary perfusion by the pulmonary and bronchial system
separately, using the later contrast arrival time via the bronchial system.
Methods
Included were 7 patients with whole left or right pulmonary artery atresia, and 6 chronic
thromboembolic pulmonary hypertension (CTEPH) patients. 3D dynamic contrast-enhanced (DCE)
MRI with 1 s temporal resolution was applied.
Results
In the PA atresia patients, only after bolus passage through the left ventricle, thus in the
bronchial phase, perfusion started in the obstructed lung. The average onset-time delay between
obstructed and open lung was 5.5±1.1 s.
A: Pulmonary phase in a CTEPH patient. An
obstructed ROI in the right lower lobe, and
an open ROI in the left middle lobe are shown.
B:Bronchial phase: the obstructed ROI shows
bronchial perfusion. C: SI-curves of main Pulmonary Artery (black
line) and Aorta (grey).
D: SI-curves of open (black) and obstructed
(grey) region, as displayed in A and B.
The CTEPH patients showed some lung regions with obstructed pulmonary arteries (perfusion
image A). Only in the bronchial phase of the contrast bolus passage, perfusion started also in
the obstructed lung region (B). The average onset-time delay between obstructed and open lung
regions was 5.3±1.9 s.
Conclusion
Bronchial perfusion in an obstructed lung region can be visualized with DCE-MRI, by using the
delayed onset-timing of the perfusion signal.
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101. H
igh tidal volume ventilation partly prevents
sepsis induced myocardial depression
Lonneke Smeding1, R.R. Lamberts2. W.J. van der Laarse2, F.B. Plötz1, M.C.J. Kneyber1,
A.B.J. Groeneveld3.
1 Department of Pediatric Intensive Care
2 Department of Physiology and
3 Department of Intensive Care, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
Mechanical ventilated patients often require inotropic support. Septic patients frequently have
impaired cardiac function and are in need of mechanical ventilation. However, the role of
mechanical ventilation (MV) in myocardial depression is not well understood. We hypothesized
that MV enhances sepsis-induced myocardial depression.
Methods
Sepsis was induced in male wistar rats (300±25g) with ip injection of LPS. Healthy and septic
rats were randomized to one of three ventilation groups (n=6 per group); (1) non-injurious
ventilation (low tidal volume, LTV; 6 ml/kg + 5 cm H2O PEEP), (2) injurious ventilation (high tidal
volume, HTV; 19 ml/kg + 5 cm H2O PEEP) and (3) spontaneous breathing. Cardiac output (CO),
central venous pressure (CVP) and mean airway pressure were measured in vivo. After 4 hours of
ventilation, animals were sacrificed and cardiac function was measured ex vivo in a Langendorff
setup. Cardiac wet to dry weight ratios were calculated to identify cardiac edema.
Results
Cardiac output in vivo was lower during HTV ventilation than during LTV ventilation (p<0.001).
CVP did not differ between ventilation strategies while mean airway pressure was higher during
HTV ventilation than during LTV ventilation (p<0.001). Ex vivo, cardiac function of septic animals
was depressed compared to healthy controls (p<0,001). In septic animals, cardiac function was
better in HTV ventilated animals than non ventilated animals (p<0.05). Ventilation lowered cardiac
wet/dry ratio (p<0.05).
Conclusions
In contrast to our hypothesis, MV did not enhance sepsis-induced myocardial depression.
High tidal volume ventilation decreases cardiac edema by decreasing transmural pressures for
coronary outflow and thereby partly prevents sepsis induced myocardial depression.
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102. C
omparison of noninvasive continuous arterial
waveform analysis (nexfin hd) with transthoracic
doppler echocardiography for monitoring of
cardiac output
R.A. Bouwman1, A.G.E van der Spoel1, A.C. Folkers2, A.J. Voogel2, C. Boer1.
1 Department of Anesthesiology, VU University Medical Center, ICaR-VU, Amsterdam
2 Spaarne Ziekenhuis, Department of Cardiology, Hoofddorp.
Introduction
Non-invasive methods for cardiac output monitoring has become increasingly important to avoid
the risk of invasive techniques. The Nexfin HD monitor uses the volume-clamp method of
Penaz and the Physiocal criteria of Wesseling et al. and computes cardiac output (CO) from
continuous reconstructed brachial artery blood pressure waveforms. In this study, we compared
the CO derived from Nexfin blood pressure measurements obtained with the Nexfin with the CO
obtained with transthoracic Doppler echocardiography (TTE).
Methods
In 33 patients scheduled for routine TTE examination CO was simultaneously measured with
Doppler ultrasound and derived from Nexfin HD (BMEYE, Amsterdam, the Netherlands) blood
pressure measurements. Correlation and level of agreement between Nexfin and TTE were
analyzed using Pearson correlation coefficient and Bland-Altman plots.
Results
There was no difference in mean CO measurements derived from the Nexfin and TTE (Nexfin: 5.3
± 1.4 L/min vs. TTE: 5.8 ± 1.3 L/min, P > 0.05). The Pearson correlation coefficient for Nexfin vs
TTE was 0.68 (CI: 0.43 – 0.83, P < 0.0001). Bland-Altman analysis revealed a bias of 0.52 ± 1.1 L/
min and limits of agreement of -1.6 – 2.6 L/min with a percentage error of 38%.
Conclusions
Considering limits of precision of CO measurements with Doppler echocardiography (±30%),
our data show that the agreement between non-invasive cardiac output measurement with the
Nexfin and TTE is reasonable. These results may suggest clinical applicability of Nexfin CO
measurements and warrant validation in more diverse patients groups under various clinical
conditions.
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103. C
arotid intima media thickness in rheumatoid
arthritis as compared to control cubjects:
a meta-analysis
Alper M van Sijl1, Mike JL Peters, Dirk L Knol2, Riekie C de Vet2, Miguel A Gonzalez-Gay4,
Yvo M Smulders3, Ben AC Dijkmans1, Mike T Nurmohamed1,3.
1 Department of Rheumatology,
2 Department of Epidemiology and Biostatistics,
3 Department of Internal Medicine and EMGO-institute, ICaR-VU, VU University Medical Center,
Amsterdam, The Netherlands
4 Rheumatology Division, Hospital Xeral-Calde, Lugo, Spain.
Introduction
Rheumatoid arthritis (RA) is associated with increased risk of cardiovascular disease.
Carotid intima media thickness (cIMT) is frequently used to identify populations at elevated
cardiovascular risk. A systematic literature search and meta-analysis were performed to evaluate
cIMT difference between RA and controls.
Methods
The literature was screened to identify all available studies comparing cIMT in RA patients
and controls. Random-effects meta-analysis was performed to estimate the overall mean cIMT
difference between both groups. Meta-regression was performed to assess the influence of
age and the degree of comparability regarding established cardiovascular risk factors on cIMT
difference. Potential publication bias was examined by a funnel plot and Egger test.
Results
From 22 studies, cIMT data was available from 1,384 RA patients and 1,147 controls. In 17 of
the studies, RA patients had a statistically significantly greater cIMT. The overall mean cIMT
difference was 0.09mm (95%-CI): 0.07-0.11mm). Heterogeneity was observed (I2 72.5%, p<0.001).
A likely source of heterogeneity was the difference in cardiovascular risk factors between
RA patients and controls at baseline, but not age. The Funnel plot did not show a skewed or
asymmetrical shape, which was supported by the Egger’s test (p=0.87).
Conclusions
Our observations support the current evidence base for an increased cardiovascular burden
in RA and support the use of cIMT in observational studies in RA patients. The next step is to
determine it’s utility as a surrogate cardiovascular risk marker in RA in prospective studies.
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104. C
oronary microvascular dysfunction in
hypertrophic cardiomyopathy is related to
contractile dysfunction independent from
myocardial Injury: a PET and CMR study
Stefan A.J. Timmer1, Tjeerd Germans1, Marco J.W. Götte1, Iris K. Rüssel1, Mark Lubberink2, Jurrien
M. ten Berg3, Folkert J. ten Cate4, Adriaan A. Lammertsma2, Paul Knaapen1 and Albert C. van
Rossum1.
1 Department of
2 Department of
Amsterdam
3 Department of
4 Department of
Cardiology and
Nuclear Medicine & PET Research, ICaR-VU, VU University Medical Center,
Cardiology, St. Antonius Hospital, Nieuwegein
Cardiology, Thoraxcenter Erasmus Medical Center, Rotterdam.
Introduction
To investigate the spatial relationships between hyperemic myocardial blood flow (hMBF), systolic
function, and morphological tissue alterations in patients with hypertrophic cardiomyopathy
(HCM) and control subjects.
Methods
Nineteen patients with HCM were studied with [15O]water PET during rest and adenosine
administration to assess myocardial perfusion. CMR was performed to derive delayed contrast
enhancement (DCE) images and to calculate contractile function (Ecc) with tissue tagging. Eleven
healthy subjects underwent similar PET and CMR scanning protocols and served as a control
group.
Results
In the HCM group, hMBF averaged 2.46 ± 0.91 mL/min/g and mean Ecc was -14.7 ± 3.4%, both
being decreased compared to the control group (3.97 ± 1.48 mL/min/g and -17.7 ± 3.2%
respectively, both P < 0.001). DCE was only present in HCM patients, averaging 6.2 ± 10.3%
of myocardial mass. In the HCM group, Ecc and DCE in the septum (-13.7 ± 3.6% and 10.2 ±
13.6%) significantly differed from the lateral wall (-16.0 ± 2.8% and 2.4 ± 5.9%, both P < 0.001).
In general, hMBF and Ecc were reduced in segments displaying DCE, compared to nonenhanced
segments (both P < 0.001). In the HCM group, univariate analysis revealed relations of hMBF with
Ecc (r=-0.45, P<0.001) and DCE (r = -0.31, P < 0.001). Multivariate analysis revealed that Ecc was
independently related to hMBF (β = -0.37, P < 0.001) and DCE (β = 0.28, P < 0.001).
Conclusions
In HCM, hyperemic MBF is impaired and related to systolic function, independent from the
presence of DCE. When present, DCE reflected a progressed disease state as characterized by an
increased perfusion deficit and contractile dysfunction.
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105. H
yperemic myocardial blood flow assessment of
the right ventricle by supine exercise in PET in
PAH patients
YY Wong1,3, P Raijmakers2, M Lubberink2, N Westerhof3, A Vonk-Noordegraaf1.
1 Department of Pulmonology
2 Department of Nuclear Medicine & PET Research and
3 Department of Physiology, ICaR-VU, VU University Medical Center, Amsterdam.
Introduction
In pulmonary arterial hypertension (PAH), the use of vasodilatory pharmaceuticals to assess
hyperaemic myocardial perfusion using H215O-PET may cause hypotension and pulmonary
afterload reduction. Assessment of myocardial perfusion during exercise circumvents these
adverse effects and reflects a physiological cardiac response physical activity. We study the
feasibility of using a recumbent bike during dynamic PET to induce stress left and right
ventricular blood flow (MBF) in PAH patients.
Methods
PAH patients (n=6) underwent a H215O-PET scan at rest and during supine exercise, at 40% of
maximal obtained load on cardiopulmonary exercising test (ranging 13 to 40W). Steady state
exercise lasted 10 min during the scan. Flow ratio was the ratio of stress to rest flow. During
right heart catheterisation performed within a month prior to PET, pulmonary arterial pressure
(PAP) was measured in both conditions. Heart rate and systemic blood pressure (BP) were also
monitored. Rate pressure product (RPP) was calculated as the product of heart rate during PET
and systolic BP or PAP.
Results
LVFW
RVFW
LV
MBF
MBF
RPP
(ml.min-1.g-1)
(beats·mmHg.min-1)
Rest
0.89 (0.14)
0.61 (0.14)
7859 (1289)
Stress
1.41 (0.40)*
1.25 (0.35)*
14000 (1812)
Flow Ratio
1.56 (0.28)
2.11 (0.57)
Correlation rest – stress, MBF vs RPP
R=0.50, p<0.01
RV
RPP
5645 (1313)
11574 (2546)
R=0.77, p<0.01
Mean (SD); * p<0.01 (paired-t-test).
Conclusions
RVFW flow is measured for the first time in PAH. Performing submaximal exercise on recumbent
bike during H215O-PET is feasible to assess hyperemic MBF in PAH patients. MBF in both the LV
and RV increased significantly during exercise. Furthermore, there was a positive correlation
between MBF and the RPP in both the LV an RV.
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106. R
elationship between obesity and microvascular
function: the Amsterdam growth and health
longitudinal study
Nienke J. Wijnstok1,2, Trynke Hoekstra1,3, Jos WR. Twisk1,3, Etto C. Eringa4, Yvo M. Smulders2,
Erik H. Serné2.
1D
epartment of Health Sciences and the EMGO Institute for Health and Care Research, Faculty of
Earth and Life Sciences, VU University Amsterdam
2 Department of Internal Medicine
3 Department of Epidemiology and Biostatistics and
4 Laboratory of Physiology, ICaR-VU, VUmc, Amsterdam.
Introduction
Obesity is a well-known risk factor for cardiovascular diseases (CVD) and type 2 diabetes mellitus
(DM2), but the mechanisms linking obesity to CVD and DM2 remain unclear. We have previously
proposed that microvascular dysfunction in obesity, i.e. decreased vasodilation and capillary
recruitment, underlies insulin resistance and hypertension in these subjects. Here we tested
the hypothesis that, even within an apparently healthy population, body fatness determines
microvascular function. The aim of this study was to investigate whether body fatness is related
to microvascular function in a healthy cohort.
Methods
In 2006, 344 participants of the Amsterdam Growth And Health Longitudinal Study took part
in the 9th follow-up. Both microvascular parameters (using nailfold capillaroscopy), and body
fatness (obtained with DXA scan) were obtained in 259 participants, 121 men and 138 women.
Results
Metabolic characteristics (such as cholesterol and triglycerides) of the participants were within the
normal range of a healthy population. None of the participants had the metabolic syndrome. The
relationship between total body fatness (total fatness) and absolute increase of capillary perfusion
after arterial occlusion was non-significant, but showed a positive trend for both men (β=.19)
and women (β=.24). The relationship describing the effect of body fat distribution (trunk/total
fatness) on microvascular function is again non-significant, but shows a negative trend for men
(β=-.21) and women (β=-.14). Analyses with other measures of microvascular function yielded
similar results (data not shown).
Conclusion
In this population, there is no significant relationship between microvascular function and body
fatness. Our results do show a negative trend for body fat distribution on microvascular function,
confirming negative effects of abdominal obesity. Total body fatness shows no negative effects
on the vasculature.
116
ICaR-VU
107. P
ancreatic fat content and abdominal fat
compartments in relation to beta-cell function in
subjects with Impaired glucose metabolism
N.J. van der Zijl1, G.H. Goossens2, C.C.M. Moors2, D.H. van Raalte1, P.J. Pouwels1, M.H.A. Muskiet1,
E.E. Blaak2, M. Diamant1.
1 VU University Medical Center, ICaR-VU, Amsterdam
2 Maastricht University, Maastricht.
Introduction
We hypothesized that gradual worsening of the glucometabolic state, i.e. impaired fasting
glucose (IFG) and/or impaired glucose tolerance (IGT), is paralleled by increased fat deposition
in the pancreas and declining beta-cell function. Associations of insulin sensitivity and beta-cell
function with body fat compartments were assessed.
Methods
Subjects with normal glucose tolerance (NGT, n=16), IFG (n=28) and IFG/IGT (n=19) underwent a)
MRI for quantification of visceral fat compartments (VAT), b) proton-MR spectroscopy, to assess
pancreatic (PFC) and liver (LFC) fat content and c) a combined euglycaemic-hyperinsulinaemic and
hyperglycaemic clamp, with subsequent arginine-stimulation.
Results
Subjects with IFG (52% males; age 57 ±8 yrs; BMI 28.9 ±4 kg/m2), and IFG/IGT (63% males; age
56 ±6 yrs; BMI 28.5 ±4 kg/m2) were more insulin resistant (P<0.001) compared to NGT (60%
males; age 55 ±7 yrs; BMI 27.5 ±3 kg/m2). With worsening of the glucometabolic state, glucosestimulated C-peptide secretion (P<0.03), also after adjustment for insulin sensitivity (disposition
index) (P<0.001), deteriorated. PFC increased: 7.6% (2.9-13.4), 12.1% (5.1-17.5), 22.4% (7.3-36.2)
P=0.021, for NGT, IFG, and IFG/IGT, respectively. All fat compartments were negatively correlated
with insulin sensitivity (PFC (P=0.041), LFC (P<0.001) and VAT (P=0.004)). No significant
associations were found between fat compartments and C-peptide secretion. However, the
disposition index was inversely correlated with PFC (P<0.05), LFC (P<0.02) and VAT (P<0.03).
Conclusions
Pancreatic fat content gradually increased with deterioration of the glucometabolic state. Overall
inverse correlations of fat compartments with the disposition index might reflect deleterious
effects of fatty acid spill-over on beta-cell function and insulin sensitivity in this population.
Wet en s ch ap s d ag V C W 2 0 1 0 117
MOVE
108. T
he feasibility of a newly developed portable setup for measuring 3D kinematics of the upper limb
in stroke patients
Joost van Kordelaar (MSc); Erwin van Wegen (PhD); Gert Kwakkel (PhD).
Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam.
Introduction
It is largely unknown what is improving in the motor control in stroke patients demonstrating
functional recovery of the upper extremity. Although many interventions are aimed at restoring
quality of motor control, effects in terms of motor control are poorly investigated. In order to
increase our insights into motor recovery after stroke, kinematical studies should be incorporated
into clinical trials. The present study investigates the feasibility, reliability and validity of a
portable set-up to conduct 3D kinematical measurements on the upper extremity in patients’ own
environment of admission.
Methods
Upper limb kinematics are measured with the subject seated at a table with a height of 76 cm.
3D kinematic data are collected using an electromagnetic movement tracking device (Polhemus
Liberty) and according to the ISB recommendations.
Systematic and random error in the position and orientation data was determined using a
calibration frame and Optotrak data as a golden standard. In addition, it was examined to what
extent, the systematic and random errors yielded deviations in the most important outcome
measures.
Results
Systematic errors in position data increased as a function of the distance to the transmitter.
However, the sensors stayed relatively close to the transmitter throughout the measurement and,
thus, the reliability of the outcome measures remained largely unaffected.
Conclusions
The present study showed that reliable and valid kinematic measurements can be performed
using the proposed portable experimental set-up. Therefore, this set-up may be regarded as a
feasible application for clinical trials to assess kinematic changes in motor control.
118
MOVE
109. F orce transmission following tendon transfer in
the rat
Huub Maas, Peter A. Huijing.
Research Institute MOVE, Faculteit Bewegingswetenschappen, Vrije Universiteit, Amsterdam.
Introduction
The outcome of tendon transfer surgeries can be surprisingly variable. One of the potential
causes of unexpected results is the formation of scar tissue and, consequently, changes in
muscular force transmission. The aim of this study was to understand the effects of connective
tissue adhesions on force transmission between the transferred flexor carpi ulnaris muscle (FCU)
and surrounding tissues.
Methods
FCU was transferred to the distal tendons of extensor carpi radialis (ECR) muscles in Wistar rats
(n = 8). Five weeks postoperatively, force transmission from FCU was evaluated. Supramaximal
stimulation of ulnar and median nerves excited all palmar muscles in the antebrachium
maximally and simultaneously. Forces exerted at the distal tendons of FCU-ECR, m. palmaris
longus (PL) and m. extensor carpi ulnaris (ECU) were measured for various distal positions of
FCU-ECR. FCU length-force data were collected (1) with minimally disrupted connective tissues, (2)
after dissection of the tendon up to the FCU muscle belly, and (3) after partial dissection of FCU
muscle belly.
Results
Length-force characteristics of FCU following tendon transfer to ECR were significantly different
from those in FCU muscle of control rats: lower optimal force (1.52 N compared to 3.41 N),
higher passive force at optimum length (0.98 N compared to 0.07 N) and a reduced length range
between optimum and slack length (3.5 mm compared to 5.0 mm). Passive and active lengthforce characteristics were substantially changed by freeing the FCU-ECR tendon and FCU muscle
belly from surrounding tissues.
Conclusions
Following the tendon transfer, both the muscle belly and tendon of the transferred FCU were
linked mechanically to surrounding structures by new layers of connective tissue (‘scar tissue’).
These post-surgical adhesions affect the mechanical characteristics of the transferred muscle and,
hence, its function during movement.
Supported by EU Marie Curie International Reintegration Grant IRG-203846
Email: h.maas@fbw.vu.nl
Wet en s ch ap s d ag V C W 2 0 1 0 119
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110. P
resence of finger extension and shoulder
abduction within 72 hours post-stroke predicts
functional recovery
Rinske Nijland (MSc)1, Erwin van Wegen (PhD)1, Barbara Harmeling–van der Wel2, Gert Kwakkel
(PhD)1.
1 Department of Rehabilitation Medicine, VU University Medical Center, Amsterdam
2 Department of Rehabilitation Medicine and Physical Therapy, Erasmus MC University Hospital,
Rotterdam.
Introduction
In acute stroke rehabilitation, early prediction of final outcome is paramount for management
decisions like discharge and multidisciplinary intervention planning at stroke units. The aim of
the present study was therefore to determine if outcome in terms of upper limb function at 6
months after stroke can be predicted in a hospital stroke unit using clinical parameters measured
within 72 hours after stroke. In addition, the effect of time of assessment on the accuracy of
prediction was investigated by retesting on days 5 and 9 post stroke.
Methods
Candidate clinical parameters were measured in 188 stroke patients, within 72 hours and at 5
and 9 days post stroke. Logistic regression analysis was used for model development, to predict
upper limb function at 6 months measured with the Action Research Arm Test (ARAT).
Results
Patients with an upper limb motor deficit who exhibit some voluntary extension of the fingers
and some abduction of the hemiplegic shoulder on day 2, measured with respectively the FuglMeyer motor assessment the Motricity Index have a probability of 0.98 to regain some dexterity
at 6 months, whereas the probability was 0.25 for those without this voluntary motor activity.
Sixty percent of patients with some early finger extension achieved full recovery at 6 months
in terms of ARAT score. Retesting the model on days 5 and 9 resulted in a gradual decline in
probability from 0.25 to 0.14 for those without voluntary motor activity of shoulder abduction
and finger extension, whereas the probability remained 0.98 for those with motor activity.
Conclusions
Based on two simple bedside tests: finger extension, measured with the Fugl-Meyer motor
assessment and shoulder abduction, measured with the Motricity Index, functional recovery of
the hemiplegic arm at 6 months can be predicted within 72 hours after stroke onset.
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111. B
iomechanical and cellular response of goat
intervertebral discs to loading in a novel organ
culture system
C.P.L. Paul, H.A. Zuiderbaan, D.B Zandieh, A.J. van der Veen, T.H. Smit, M.N. Helder,
B.J. van Royen, M.M. Mullender.
Department of Orthopedics, VU University Medical Center, Amsterdam.
Introduction:
The main function of the intervertebral disc (IVD) is to withstand and transfer high magnitude
forces, while maintaining flexibility of the spine. However, the response of the IVD to different
dynamic loading conditions is still largely unknown. We developed a novel loaded disc culture
system (LDCS) to study the effects of loading on IVD’s over a 7-day culture period.
Methods:
Fresh IVD’s (L1-5) were harvested under sterile
conditions goats obtained from a local abattoir.
IVD’s were assigned to one of
6
experimental groups (3-6; figure 1). Discs were cultured
and loaded for 7 days in the LDCS, after which IVD
stiffness was calculated, cell viability, GAG content
Figure 1: Schematic of loading groups: static (3);
and gene expression was measured in the nucleus (NP)
low dynamic (4); high dynamic (5); high dynamic
prolonged (6). One loading cycle lasted 24 hours.
and annulus (AF) region.
All loading was axial, dynamic loading had a
frequency of 1Hz.
Results:
Fresh discs (1) mean cell viability was 79.4% (NP) and 77.7% (AF). At day seven, cell viability of
the unloaded group dropped by half in both regions and the static group (3) showed a drop only
in the AF region. Low dynamic load did not influence cell viability, though high dynamic and
prolonged high dynamic loading showed increasing cell death (figure 2). GAG content remained unchanged after 7 days for all
groups. IVD stiffness depends on load magnitude and
no significant changes were observed after 7-days.
Relative gene expression analyses revealed no significant
changes in any of the loading groups after 7 days.
Discussion:
Different responses of caprine lumbar IVD’s were
observed depending on the applied loading conditions.
This study shows that the LDCS together with caprine
IVD’s is an excellent comparative model for studies on
load induced disc degeneration.
Wet en s ch ap s d ag V C W 2 0 1 0 Figure 2: Mean ± SEM cell viability in NP (left) and
AF (right) region of the six experimental groups.
All bars indicate significant differences when
compared to day 0 or load group, with p<0.05.
121
NCA
112. W
axing and waning of neuronal network
oscillations
Oscar J. Avella Gonzalez1, Ronald van Elburg2, Huibert Mansvelder1, Jaap van Pelt1, Arjen van
Ooyen1.
1C
omputational Neuroscience Group, Department of Integrative Neurophysiology, CNCR,
Neuroscience Campus Amsterdam
2 Department of Artificial Intelligence, University of Groningen.
Introduction
Experimental observations have reported modulation of cortical oscillations, as phases of high
synchronization (waxing) followed by periods of reduced synchronization (waning). Although
the phenomenon is present in almost all frequency bands, it is still not understood how this
is driven. Here we study whether this phenomenon can occur in a network of inhibitory (I) and
excitatory (E) cells and what the effect is of external inputs
Methods
Using the simulation program NEURON, we model a network of Ne excitatory and Ni inhibitory
cells such that Ne/Ni=4. The cells have a single compartment and include passive channels and
voltage dependent Na+, K+ channels. Synaptic connections are random, projecting GABA synapses
from I to I and I to E cells and AMPA synapses from E to E and E to I cells. To stimulate the
network, each cell receives a baseline of current and a stream of spikes delivered at random
intervals across the simulated period.
Results
We show that in a stable oscillatory network, waxing and waning occurs without the need
for other synaptic mechanisms than the spike generating K+ and Na+ channels (Fig.1). The
phenomenon can be modulated by changing the characteristics of the external input, such as
number of spikes, mean inter-spike interval, randomness and whether E or I cells receive the
external input.
A. B.
Figure 1. A. Raster plots of E (top) and I (middle) populations, during waxing and waning of a
beta oscillation, and firing rate histograms (bottom). B. Wavelet transform of the activity in the
E population for the same time period as shown in A.
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113. E nhancing structural plasticity after focal brain
lesions
Markus Butz, Arjen van Ooyen.
Neuroinformatics group, Neuroscience Campus VU University Amsterdam.
Introduction
Lesion-induced cortical remapping has been observed after digit amputation or after focal
retinal lesions. Cortical remapping not only involves adaptations in synaptic strengths (synaptic
plasticity) but also anatomical changes (structural plasticity) arising from axonal sprouting and
spine turnover. The mechanisms that drive structural plasticity are still unclear. Activity and
neurons aspiring to maintain homeostasis in activity seem to be crucially involved in ruling
structural plasticity. The question that motivates our theoretical modelling study is under which
conditions structural plasticity can compensate for a focal lesion and how this compensation
process is influenced by stimulations with additional afferent activity.
Methods
To answer these questions, we used a recurrent network model and cut off the input to a
subset of neurons simulating a cortical deafferentation. We implemented activity dependent
and homeostatic rules by which model neurons change the number of their axonal terminals or
dendritic spines (pre- and postsynaptic elements). Vacant pre- and postsynaptic elements merge
and form synapses. The loss of synaptic elements causes the breaking of synapses. Structural
change ceases when all neurons have reached homeostasis in electrical activity.
Results
Structural plasticity can compensate for focal lesions. Interestingly, reorganization depends on
both the size of the lesion and the age of the network at the onset of the lesion. Stimulations
lead to a transient increase in synapses. An optimal and permanent reorganization is, however,
reached when stimulation is interrupted by short pauses (10%-20% of stimulation time).
Conclusions
Our model makes testable predictions on the optimal timing of therapy to maximize the outcome
of the rehabilitation. As lesions of the brain (such as stroke or multiple sclerosis) also cause
dramatic changes of the circuitry of the affected anatomic areas, this model has potential impact
for designing new concepts in neurological rehabilitation.
Wet en s ch ap s d ag V C W 2 0 1 0 123
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114. E merging synaptic connectivity in simulated
networks of outgrowing neurons with realistic
morphologies using NETMORPH
Jaap van Pelt, Sander de Ridder, Sacha Hoedemaker, Frank Postma, Randal A. Koene,
Arjen van Ooyen.
Computational Neuroscience Group, Department of Integrative Neurophysiology, CNCR,
Neuroscience Campus Amsterdam.
Introduction
Geometry plays an important role in the formation of synaptic connectivity in neuronal networks.
Both the spatial distributions of cell types and the detailed morphology of their axonal and
dendritic branching patterns critically determine the number and the locations of synaptic
connections. This study aims at getting insight in how neuronal morphology impacts on neuronal
network connectivity.
Methods
A computational approach is followed using NETMORPH (Koene et al., 2009) as a simulation
tool for the developmental generation of 3D large-scale neuronal networks with realistic neuron
morphologies. Neuronal morphogenesis is simulated through the actions of individual growth
cones (elongation, branching and turning). Synapses are formed when axonal and dendritic
branches come sufficient close to each other.
Results
Connectivity properties were analysed with emphasis on the small-worldness of the network.
All the simulated networks showed small-world connectivity. Euclidean distances from synaptic
locations to postsynaptic somata showed realistic distributions.
Conclusions
Our preliminary findings indicate that realistic neuronal morphologies, simple synapse formation
rules and independently outgrowing neurons can already create networks with realistic
connectivity patterns and small-world properties. Our study provides insight into the impact of
neuronal geometry on network connectivity.
Acknowledgment - This work was supported by EU MC-RTN NEURoVERS-it (019247), and BIO-ICT Project SECO (216593).
Literature - RA Koene, B Tijms, P van Hees, F Postma, A de Ridder, G Ramakers, J van Pelt, A van Ooyen. NETMORPH: A framework
for the stochastic generation of large scale neuronal networks with realistic neuron morphologies. Neuroinformatics 7 (2009)
195-210.
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NCA
115. T
he attention-gated reinforcement learning model
(AGREL) can explain experimentally observed
changes in tuning curves that follow category
learning
Lawrence A. Watling1, Huibert Mansvelder1, Pieter R. Roelfsema1,2, Arjen van Ooyen1.
1C
omputational Neuroscience Group, Department of Integrative Neurophysiology, CNCR,
Neuroscience Campus Amsterdam
2 Vision & Cognition Group, Netherlands Institute for Neurosciences, Amsterdam.
Introduction
Here we propose a new role for cortical feedback connections in learning. Our aim is to
understand the neuronal plasticity that underlies animal learning in classification tasks. In the
attention-gated reinforcement learning model (AGREL) [1], stimuli are presented to the lowest
layer, which represents a sensory area of the cortex. Activity is then propagated to the highest
layer, which represents the motor cortex. The network has to choose one out of a number of
actions that correspond to the various stimulus categories. This choice is made in the highest
layer of the network, where neurons engage in a competition so that one action is selected. A
reward is delivered if this action is correct, and no reward is delivered in case of an error. The
distinguishing feature of AGREL is that the neurons that win the competition in the motor cortex
feed back to lower layers, just as is observed for attentional effects in neurophysiology. The
feedback connections allow the network to target the lower level neurons that drove the current
output, which in combination with the global reward factor enable the network to selectively
enhance connections from neurons that were responsible for the successful behavior.
Results
In computer simulations of the AGREL model, we show that AGREL is able to closely replicate
the experimentally observed changes in tuning curves found in a series of categorization tasks,
using face, orientation, motion and animal stimuli. Additionally, we show that the removal of the
feedback connections prevents such changes in tuning properties from occurring.
Conclusions
AGREL is a biologically realistic learning scheme that integrates the role of cortical feedback
connections, selective attention, synaptic plasticity, and reward signals into a coherent
framework. AGREL is able to explain the experimentally observed changes in tuning curves of
cortical cells in a wide variety of learning tasks.
[1] Roelfsema, P. & Van Ooyen, A: Attention-gated reinforcement learning of internal representations for classification. Neural
Computation, 2005, 17(10), 2176-2214
Wet en s ch ap s d ag V C W 2 0 1 0 125
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116. T
he olfactory bulb as an initial site of α-synuclein
pathology in Parkinson’s disease
Wilma D.J. van de Berg1, Angela Ingrassia1, Evelien Huisman1, Salome Zweekhorst1, M. Verhoog1,
Annemieke M. Rozemuller2,3, Piet Hoogland1, Henk J. Groenewegen1.
1D
epartments of Anatomy & Neurosciences and
2 Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam
3 The Netherlands Brain Bank, Amsterdam.
Introduction
Patho-anatomical studies suggest that the distribution pattern of α-synuclein-positive Lewy
bodies and neurites in Parkinson’s disease is not random but follows a predictable sequence.
The olfactory bulb is one of the brain regions revealing α-synuclein pathology in early PD and
‘healthy’ elderly. The aim of the present study was to investigate the pattern of α-synuclein
pathology in elderly with α-synuclein pathology in the olfactory bulb.
Methods
The study population consisted of 95 non-demented and 18 demented elderly, 36 PD, 21 PD
with dementia (PDD) and 16 Dementia with Lewy bodies (DLB) cases of which olfactory bulb
tissue, brainstem, limbic and cortical brain regions was available at the Netherlands Brain bank.
Prevalence and distribution pattern of α-synuclein pathology was assessed in 12 brain regions
and staged according to the guidelines of Braak (2006) and BrainNet Europe Consortium (2009).
Results
α-Synuclein pathology was present in the olfactory bulb in 24% of the non-demented, 17% of the
demented individuals and in all PD, PDD and DLB patients. Among the 97 cases with pathology,
86 were consistent with the progression of pathology described by Braak. Eleven cases could not
be classified according to Braak PD staging protocol. In these cases, α-synuclein pathology was
confined to the olfactory bulb, limbic brain regions or absent in the dorsal motor nucleus.
Conclusions
The pattern of progression suggested by Braak is upheld in 89% of cases with α-synuclein
pathology in the olfactory bulb. However, our results provide also evidence for alternatives routes
of progression in the brain.
126
NCA
117. P
roteomic analysis of the locus ceruleus in
Parkinson’s disease
Karin D. van Dijk1,2, Silvina Fratantoni3, Thang V. Pham3, Sander R. Piersma3,
Henk J. Groenewegen1, Henk W. Berendse2, Connie R. Jimenez3, Wilma D.J. van de Berg1.
1 Dept. of Anatomy and Neurosciences
2 Dept. of Neurology, Neuroscience Campus Amsterdam
3 OncoProteomics Laboratory of the Dept. of Medical Oncology, VU University Medical Center,
Amsterdam.
Introduction
Parkinson’s disease (PD) is pathologically hallmarked by Lewy bodies composed of abnormal
protein aggregates and the loss of catecholaminergic neurons in the substantia nigra and locus
ceruleus. In this study, we aimed to identify proteins involved in PD pathology and pathogenesis
that may serve as future biomarkers enabling a more accurate early diagnosis and/or monitoring
of the disease progression.
Methods
Post-mortem locus ceruleus tissue of 6 PD patients and 6 age- and gender-matched controls
was excised and homogenized in sample buffer. Proteins were fractionated using 1D-gelelectrophoresis followed by in-gel tryptic digestion and nanoLC-FTMS. Databases were used for
peptide and protein identifications. Locus ceruleus proteomes of PD patients were compared to
controls by the number of spectral counts using a beta-binomial model.
Results
The number of spectral counts was significantly different between PD patients and controls for
87 out of 2495 identified proteins with 33 up-regulated and 54 down-regulated proteins. Sixty
out of 87 differentially expressed proteins are implicated in processes that are considered to
be involved in the pathogenesis of PD. The processes that were most significant to the dataset
included oxidative phosphorylation, mitochondrial dysfunction and alpha-adrenergic signaling.
In addition, network analysis suggested a potential pathogenetic role for aminoacyl-tRNAsynthetases.
Conclusions and future directions
Proteins that were differentially expressed in PD patients compared to controls included
proteins involved in known and potentially novel pathogenetic mechanisms. A selection of the
differentially expressed proteins will be validated in tissue and cerebrospinal fluid to evaluate
whether they may serve as biomarkers for PD.
Wet en s ch ap s d ag V C W 2 0 1 0 127
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118. G
ene expression patterns in the olfactory bulb of
Parkinson patients
Angela Ingrassia1, Anke Dijkstra1, Patrizia Rizzu2, Zoltán Bochdanovits2, Annemieke M.
Rozemuller3, Pieter Voorn1, Henk Groenewegen1, Peter Heutink2, Wilma D.J. van de Berg1.
Dept. of
1 Anatomy and Neurosciences
2 Clinical Genetics and
3 Pathology, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam.
Introduction
The olfactory bulb is one of the first brain structures to reveal α-synuclein pathology in Parkinson
Disease (PD). α-synuclein pathology is also present in ~22% of aged “healthy” individuals which
may represent the preclinical stage of PD (incidental cases).
To unravel pathogenic processes involved in PD, we analyzed gene expression profiles in
olfactory bulbs of neuropathologically confirmed PD patients, incidentals, and age- and gendermatched controls.
Methods
RNAs were isolated from post-mortem olfactory bulb tissue obtained from the Netherlands Brain
Bank and hybridized on Affymetrix HG 133 plus 2.0 chip arrays. Sixteen cases (4 controls, 6
incidentals, and 6 PD cases) were analyzed using an ANCOVA test (co-variable: RIN; FDR=0.1)
after log2 and quantile normalization, using Partek Genomics Suite software. Ingenuity Pathway
Analysis software was used for network analysis.
Results
Gene expression levels were significantly different between PD patients and controls for 1836
genes and between incidentals and controls for 42 genes. These genes most significant to
the dataset are involved in DNA replication, protein folding, ion transport, nucleid acid and
carbohydrate metabolism. The expression of PARK2 and MAPT was significantly lower in PD
patients compared to controls, but not to incidentals. The expression level of others genes
associated with monogenic forms of PD, such as UCHL1 and LRRKs was unchanged in PD and
incidentals compared to controls.
Conclusions
Our data show that the expression patterns of a selective number of genes involved in DNA
replication, protein folding and ion transport may be already altered in the preclinical stage of
PD.
128
NCA
119. Y
oung children born small for gestational age
(SGA): II. Promising preliminary results derived
from functional magnetic resonance imaging
(fMRI)
HMA de Bie1, KJ Oostrom2, J. Jeltes2, M. Boersma3, DJ Veltman4, HA Delemarre-van de Waal5.
1
2
3
4
Department of Paediatric Endocrinology
Department of Paediatric Psychology
Department of Clinical Neurophysiology
Department of Psychiatry, VU University Medical Center Amsterdam, Amsterdam,
The Netherlands and
5 Department of Paediatrics, Leiden University Medical Center, Leiden, Amsterdam.
Introduction
Paediatric brain imaging studies show continued growth and specialization from childhood to
adolescence. In children with endocrine abnormalities, aberrant hormone activities may interfere
with brain development and subsequently cognition. For instance growth factors are suggested
to be important and receptors are found throughout the brain. In this study we focus on brain
development and cognition of young children born SGA without postnatal catch up growth. Being
born SGA is associated with cognitive impairment. Since short SGA children can be treated with
growth hormone (GH), of which the effect on cognition is still under debate.
fMRI allows non-invasive assessment of brain functioning and is an exciting tool in neuroscience:
It allows us to “watch the brain thinking”. Especially in longitudinal designs combined with
neuropsychological tests, it may contribute to better understanding of functional brain
maturation.
Methods
A dummy scanner was built to accustom children to MRI-experiences. To track brain activity
associated with declarative memory processes, we designed the Amsterdam visual encoding task
(AVET), suitable to children aged 4 to 7 years. Also, a comprehensive neuropsychological test
battery including intelligence and memory measures was administered. Actual functional and
structural MR-imaging was performed using a 1.5-Tesla sonata MR scanner. Data were analyzed
using Statistical Parametric Mapping (SPM5) software.
Results
Preliminary fMRI data from 40 out of 44 children (mean age 5.6 years, range 4.1-7.6 years)
reveal robust activity of the (para)hippocampal areas during encoding versus baseline. Statistical
analyses on differences in brain structure and/or activity between children with and without GH
treatment are not yet reliable, due to small numbers. More data are currently gathered in our
department.
Conclusion
Preliminary results provide sufficient evidence that fMRI is a suitable diagnostic procedure for
brain maturation, and – eventually - for the evaluation of GH effects in SGA, even if children are
still very young.
Wet en s ch ap s d ag V C W 2 0 1 0 129
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120. Y
oung children born small for gestational age
(SGA): I. A study on brain development, behaviour
and cognition
J Jeltes1, HMA de Bie2, M Boersma3, J Huisman1, HA Delemarre-van de Waal4, KJ Oostrom1.
1
2
3
Department of Pediatric Psychology
Department of Pediatric Endocrinology
Department of Clinical Neurophysiology, VU University Medical Center Amsterdam, Amsterdam,
The Netherlands and
4 Department of Pediatrics, Leiden University Medical Center, Leiden, Amsterdam.
Introduction
SGA may adversely affect long-term neurodevelopmental outcome. However, given the heterogeneous nature of SGA, the specific subgroups of SGA children most likely to experience cognitive
impairment and behavioural difficulties have not been well defined. In this study we focus on
children born SGA who do not catch up in height and thus remain short, but in whom there is no
growth hormone (GH) deficiency. In these children, GH therapy seems to work not only in terms
of catching up growth, but – perchance - also in terms of neurodevelopment through its impact
on insulin-like growth factor IGF-I.
Design
Cognition and behaviour in SGA children (4 to 7 years) is studied, by using a prospective, longitudinal, controlled design. Children are assessed shortly before start of GH-treatment, 1 and
3 years later. Control groups are gender and age matched 1) classmates born appropriate for
gestational age (AGA); 2) SGA children choosing not to use GH therapy; and 3) children born SGA
with complete catch-up. Both fetal, maternal, placental and demographic factors, and that of
undergoing GH treatment are independent factors. Children are recruited from different medical
centres across the Netherlands.
Methods
At each assessment, children undergo neuropsychological assessment as well as functional and
structural brain imaging. The neuropsychological assessment battery covers domains of intelligence, learning and memory, attention, visuomotor integration, fine motor skills and academic
achievement. At each assessment, parents and teachers fill out behaviour questionnaires.
Results
So far 12 SGA children who do not catch-up (of whom 11 undergo and 1 choose not to undergo
GH therapy); 20 catch-up SGA and 13 healthy AGA’s have been included. Preliminary analyses of
neuropsychological data are currently carried out.
The outcomes of this study are aimed to facilitate clinical decisions on the important issue of
proceeding GH treatment in young children born SGA.
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121. C
ell-type specific differences in splicing of mutant
mtAspRS mRNA
Laura van Berge, Stephanie Dooves, Gert C. Scheper, Marjo S. van der Knaap.
Department of Pediatrics / Child neurology VU University Medical Centere, Amsterdam.
Introduction
Leukoencephalopathy with brain stem and spinal cord involvement and elevated lactate (LBSL)
was identified in 2003 on the basis of characteristic magnetic resonance imaging (MRI) and
spectroscopy (MRS) findings. Patients with LBSL suffer from a childhood onset slowly progressive
cerebellar ataxia, spasticity and dorsal column dysfunction. Very striking is the involvement of
specific motor and sensory tracts in the white matter. The fact that long tracts are affected in
LBSL patients suggests that the disease is (partly) due to an axonal defect, but the nature of the
defect is unclear.
LBSL is caused by mutations in the gene DARS2, which encodes the enzyme mitochondrial
aspartyl-tRNA synthetase (mtAspRS). Almost all patients with LBSL have one mutation that
affects splicing of the third exon of mtAspRS mRNA, whereas the other mutation varies. It
has been suggested that splicing efficiencies differ between neural cells and other cell types.
We hypothesize that the splicing could be more “unfortunate” in neural cells, leading to the
production of a smaller amount of the normal protein. This could play a role in the selective
vulnerability of the white matter in LBSL.
Methods
To study this hypothesis, we made constructs that upon transfection into cells allow
quantification of the splicing efficiency of exon 3. Constructs were made with the wild type
sequence and with mutations that are found in patients. These constructs were tested in several
cell types of neural and non-neural origin.
Results
As expected, the mutations that occur in LBSL patients lead to increased skipping of exon 3.
The unfavourable effect on splicing was greater in nervous system-derived cells (neuroblastoma,
astrocytoma and oligodendrocytoma) than in, for example, kidney- or ovary-derived cells. The
effect appeared to be somewhat more pronounced in neuroblastoma cells than in the glial cell
types.
Conclusions
The increased skipping of the third exon of DARS2 in neuroblastoma cells compared to nonneural cells could fit with the hypothesized neuronal / axonal defect in LBSL. Yet unknown
changes in neurons and their axons could lead to the involvement of tracts as is seen in this
disease.
Wet en s ch ap s d ag V C W 2 0 1 0 131
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122. B
rain metabolism measurements using
microdialysis in patients undergoing awake
craniotomy
S.M. Bossers1, S.M. Peerdeman2, A. Schauer1, P. Oedayrajsingh Varma1, J.C. Baaijen2, P.C. De Witt
Hamer2, C. Boer1.
1 Depts. of Anesthesiology and
2 Neurosurgery, Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam.
Introduction
Anesthesia has profound effects on cerebral blood flow and induces a shift in brain metabolism.
Commonly, measurements of brain metabolism are performed by neuroimaging techniques,
but these methods are not applicable in the perioperative setting. We therefore measured
brain metabolism during awake craniotomy and under propofol anaesthesia using cerebral
microdialysis, and particularly focused on alterations in the glycolitic metabolism of the brain.
Methods
Patients undergoing awake craniotomy who were eligible for microdialysis catheter placement
in the area that was going to be resected were included. A microdialysis catheter (CMA, Solna,
Sweden) was inserted in the brain insterstitium during surgery. Measurements were performed
under anaesthesia and awake craniotomy. Samples were drawn with frequencies between 10
and 60 minutes and changes in lactate, pyruvate, glucose, glycerol and glutamate levels were
monitored. Data are represented as mean ± SD or as percentage change.
Results
In five out of ten included patients measurements were performed in both the awake and asleep
phases. During anesthesia, the lactate/pyruvate ratio decreased from 0.04 ± 0.02 (awake) to 0.03
± 0.02 (asleep). The glucose/lactate ratio however increased by 19% from 0.52 ± 0.28 (awake) to
0.61 ± 0.36 (asleep). Finally, the glucose/pyruvate ratio showed a decrease of 12%.
Conclusions
Our data show a reduction in brain metabolism after induction of anesthesia as reflected by
decreased lactate/pyruvate and glucose/pyruvate ratios. The lowered conversion of pyruvate to
lactate may be due to increased oxygen delivery during the sleeping phase, which increases the
passage from the glycolitic pathway to the citric acid cycle. This is also reflected by the increased
glucose/lactate ratio. Our data point towards metabolic alterations during anesthesia, and future
studies should reveal how these changes are related to the depth of anesthesia.
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123. A
bnormal maturation and function of astrocytes
and oligodendrocytes in vanishing white matter
disease
Marianna Bugiani1,2, Ilja Boor1, Nienke Postma1, Barbara van Kollenburg1, Elly Hol3, Gert Scheper1,
Steven Goldman4, Marjo van der Knaap1.
1
2
3
4
Department of Pediatrics/Child Neurology and
Pathology, VU University Medical Center, Amsterdam, The Netherlands
Netherlands Institute for Brain Research, Amsterdam, The Netherlands
Department of Neurology, Center for Translational Neuromedicine, University of Rochester,
Rochester, NY, USA.
Introduction
Vanishing white matter disease (VWM) is one one the most prevalent childhood
leukoencephalopathies. It is caused by mutations in any of the genes encoding the five subunits
of the eukaryotic translation initiation factor eIF2B. VWM is characterized by progressive
cerebellar ataxia and less prominent spastisticy. Typical to VWM are episodes of major
neurological deterioration triggered by minor stresses as fever and mild trauma. The episodes
of major deterioration correlate pathologically with the appearance and extension of cystic
rarefaction and cavitation of the white matter, in which dysmorphic astrocytes and insufficient
gliosis are a major feature. Around cavitated areas, hypomyelination and myelin loss coexist with
a striking increase in the density of oligodendro-cytes. These findings suggest that a functional
impairment and/or a maturation defect of macroglial cells might contribute to the pathogenesis
of VWM.
Methods
Maturation of astrocytes and oligodendrocytes in the brain of 5 VWM patients was studied using
immunohistochemistry, Western blot and microarray analysis, and qPCR.
Results
We show that astrocytes do proliferate in VWM, but do not reach full maturity and overexpress
the delta isoform of the GFAP protein together with the stress protein alpha B-crystallin, a finding
that might explain their abnormal morphology and dysfunction. VWM astrocytes also abnormally
express the enzyme galactocerebrosidase, which is typical of normal oligodendrocytes.
Oligodendrocytes are immature in VWM, and many fail to go beyond the status of progenitors.
Conclusions
Our data suggest that the myelinogenic program per se is not perturbed in VWM, but expression
of myelin proteins is impaired possibly due to an aberrant post-translational control. This
combination of findings is not found in controls and other genetic white matter disorders, and
thus appears to be specific of WM.
Wet en s ch ap s d ag V C W 2 0 1 0 133
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124. C
linical microdialysis of testosterone: preliminary
results
H.N. Bui1,2, V.L. Wester2, A.C. Heijboer1, M.A. Blankenstein1, W. de Ronde2.
1 Dept of Clinical Chemistry
2 Dept of Endocrinology, VU University Medical Center, Amsterdam.
Introduction
For diagnostic purposes, plasma total-testosterone levels are generally assessed. However, the
primary site of action of testosterone is in tissue, evaluation of the distribution of testosterone in
tissue and its conversion to other hormones could give enhanced insight into the (patho)physiology. Clinical microdialysis allows for sampling at tissue level based on diffusion. We established
such a technique and present its preliminary evaluation.
Methods
A CMA20 microdialysis probe was continuously perfused with Ringer’s lactate containing
0.6nmol/L D5-testosterone as internal reference. At a flow-rate of 10µL/min, in vitro experiments
showed a testosterone recovery of 19%. Tubing was minimized to limit absorption. Microdialysis
was performed on the vastus lateralis muscle in two healthy male volunteers for 4h, preceded by
1h for stabilization. A 15min sample interval was used. Additionally, blood and saliva specimens
were drawn in each interval. 1h after the onset of dialysis, 100mg testosterone gel was applied to
the back skin in an attempt to vary systemic testosterone levels. Testosterone was analyzed using
a highly sensitive assay involving derivatization and ID-LC-MS/MS.
Results
Testosterone profiles in the microdialysis, plasma, and saliva samples from both volunteers were
comparable. Testosterone levels increased after cutaneous administration, although this effect
was more prominent in saliva (200%) than in microdialysate (70%) and plasma (60%).
Conclusions
The initial results of clinical microdialysis are promising. Low testosterone levels and increased
concentrations after supplementation could be reliably detected. Further research is necessary
to thoroughly evaluate the microdialysis procedure. Hopefully, in vivo experiments in the near
future will enrich our knowledge about testosterone at the tissue level.
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125. R
elationship between serum insulin-like growth
factor-1 concentration and mortality in an elderly
population
C.C. van Bunderen1, I.C. van Nieuwpoort1,2, N.M. van Schoor3, D.J.H. Deeg3, P. Lips1,3, M.L. Drent1,2.
1 Department of Endocrinology
2 Neuroscience Campus Amsterdam
3 EMGO+ Institute for Health and Care Research, VU University Medical Center, Amsterdam.
Introduction
Aging is a natural process associated with various physiologic and endocrine changes. In the
last decade, numerous studies have investigated the effect of IGF-1 concentration on aging and
several age-related diseases, e.g. cardiovascular disease and cancer. Findings on IGF-1 activity
and mortality however are conflicting and controversial. A U-shaped relationship is occasionally
hypothesized.
The aim of the present study is to investigate the relationship between serum IGF-1 concentration
and all-cause mortality in community dwelling older persons.
Methods
Data were used from the Longitudinal Aging Study Amsterdam (LASA), an ongoing multidisciplinary cohort study in the general Dutch population of older persons
(≥ 65 years). The mortality information was ascertained over 11 years of follow-up. A Cox proportional hazards model was used to determine the association of quintiles of IGF-1 levels and
all-cause mortality.
Results
Overall, there were 633 deaths (268 women and 365 men) in a total of 1273 subjects. A significant association was found between all-cause mortality and IGF-1 concentration in the lowest
versus the middle quintile with a hazard ratio (HR) of 1.53 (95% CI 1.21-1.94; p<0.001). After
adjustment for potential confounders this relation only moderately attenuated, HR 1.28 (95% CI
1.01-1.63; p=0.043). No significant HR was found for all-cause mortality in subjects with IGF-1
concentration in the highest versus the middle quintile, HR 1.17 (95% CI 0.90-1.53; p=0.239).
Conclusions
These findings suggest that in community dwelling older persons low concentration of IGF-1,
even within the normal range, is associated with an increased mortality risk.
Wet en s ch ap s d ag V C W 2 0 1 0 135
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126. S CAP deletion in astrocytes causes startle-induced
dystonia, reduced brain size and early lethality
Nutabi Camargo1, Rick Dijkhuizen2, Wim Otte2, David H. Gutmann3, August B. Smit1 and
Mark H. G. Verheijen1.
1 Dept. Molecular and cellular Neurobiology, Center for Neurogenomics and Cognitive Research,
Neuroscience Campus Amsterdam, VU University, Amsterdam, the Netherlands
2 Image Sciences Institute, UMC Utrecht, The Netherlands
3 Dept. of Neurology, Washington University School of Medicine, St. Louis, Missouri. USA.
Introduction
The brain is remarkably different in lipid composition than other organs. It is enriched in polyunsaturated fatty acids (PUFAs) and cholesterol; and with 2% of the total body weight the brain
contains about a quarter of the total amount of cholesterol in the body. Many neurodevelopmental and neurodegenerative diseases are associated with disrupted lipid metabolism, e.g.
Niemman Pick C and Alzheimer disease. Astrocytes have been shown to play a pivotal role in
maturation of neuronal circuitry and in synaptic function by producing and secreting lipids.
Here we ask the question what the consequence is of disrupted lipid supply by astrocytes for
functioning of the brain.
Methods
In this study we made use of transgenic mice in which lipid synthesis is compromised in
astrocytes as a consequence of the deletion of SCAP (Sterol regulatory element binding proteincleavage activating protein), a protein essential for lipid synthesis. These animals were used
to study the role of astrocytes as lipid suppliers to the developing and adult brain. Molecular,
histological and behavioural approaches are used to characterize the deficits in these animals and
an effort is made in trying to rescue the observed abnormalities.
Results
We found that SCAP knockout animals show a startle-induced dystonia (hyperekplexia). The
number of these events increased with age and correlates with early lethality. In addition, the
SCAP mutants had smaller brains. Both grey ad white matters are importantly reduced.
Conclusions
These results give strong evidence of a pivotal role for astrocyte derived lipids on brain
development and function in vivo. Moreover, understanding the molecular mechanisms of lipid
production may bring an important tool for treatment of lipid-associated pathologies in the brain.
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127. H
igh Performance Computing on the GRID at the
VUmc
Keith S. Cover, Bob W van Dijk.
Department of Physics and Medical Technology, VU University Medical Center, Amsterdam,
The Netherlands.
Introduction
High performance computing (HPC) on the GRID allows hundreds or thousands of data sets, such
as MRI scans, to be processed tens or hundreds of times faster by using tens or hundreds of
computers in parallel. Currently, a common way to process data in medical research is to develop
shell scripts under Linux to process a data set. This same script then needs to be applied to
hundreds or thousands of data sets. The cluster computers available to the VUmc are particularly
well suited to handling these sorts of problems.
Methods
While the standard tools for using HPC are available on the clusters, VUmc has developed an
application called MirageGRID, that makes it easier for researchers in medicine to use HPC.
MirageGRID is built on the JavaGAT GRID middle ware developed by the VU’s computer science
department. MirageGRID takes care of many of the complicated steps in HPC such as copying
data sets to and from the cluster computers to any point on the internet. It also avoids a complicated job description language in favour of a simple text file listing the job names and parameters. The VUmc has recently installed the neuGRID cluster that can run programs 12 to 100 times
faster and has up to 8GB of memory per job. In special cases, the VUmc has access to the DAS3
cluster in the Computer Science Department of the VU University. DAS3 can run data analysis
80 to 320 times faster. In the near future the VUmc plans to install a cluster with up to 32GB of
memory available to each job enabling it to run a few jobs requiring large amounts of memory.
Plans are also in the works to have the Sara cluster available via MirageGRID.
Results
Projects using MirageGRID have already resulted in two publications (Sluimer et al. Eur Radiol.
2009; Roosendaal et al. Neuroimage 2009;44:1397) and several other are in the works.
Calculations for the two publications took thousands of hours of computation time each but were
completed in a weekend. Projects currently using MirageGRID are (1) a reproducibility study of
fully automated atrophy measures using 1900 MRI scans (2) synchronisation measures of MEG
data from 360 healthy subjects and (3) modelling of radiation doses in radiotherapy.
Conclusions
With the ever increasing amount of data flowing from medical research, and the ever decreasing
cost of computer hardware and, HPC is fast becoming a invaluable tool to medical research. The
VUmc is well positioned to take advantage of the opportunities being presented by HPC on the
GRID.
Contact: bw.dijk@vumc.nl
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128. T
issue transglutaminase promotes myelination by
oligodendrocytes in vitro and in vivo: of therapeutic
interest for multiple sclerosis
Miriam van Strien1, Wia Baron2, Jan Bauer3, John Bol1, John Breve1, Erik Bakker4, Rob Binnekade1,
Benjamin Drukarch1, Anne-Marie van Dam1.
1
2
3
4
VU University Medical Center, Dept. Anatomy & Neurosciences, Amsterdam
University Medical Center Groningen, Dept. Membrane Cell Biology, Groningen
Center for Brain Research, Dept. Neuroimmunology, Vienna, Austria;
Academic Medical Center, Dept. Medical Physics, Amsterdam.
Introduction
Multiple Sclerosis (MS) is a chronic neuroinflammatory disease resulting in severe disabilities of
mainly the sensory and motor systems. A neuropatholo-gical hallmark of MS is the loss of myelin
and oligodendrocytes leading to impaired axonal transport. As a mechanism of restoration,
spontaneous myelin repair occurs in MS giving rise to so-called shadow plaques. However, this
remyelination is only partially successful as most oligodendrocyte progenitor cells remain in
an undifferentiated state which results in a failure to generate myelinating oligodendrocytes.
Tissue transglutaminase (TG2) is a multifunction-al enzyme mainly known for its protein crosslinking and GTPase activity. Among other functions, TG2 has been shown to play a role in cell
differentiation (e.g. neurons, astrocytes and granulocytes). Moreover, a link between transglutaminase and myelination has been suggested for peripheral Schwann cells.
In light of the alleged role in both differentiation and myelination, we hypothesize that TG2 is
involved in myelin formation by oligodendrocytes and could thereby stimulate (re)myelination.
Methods
Rat oligodendrocyte precursor cells (OPCs) were cultured in vitro and studied throughout
development. Our data shows that TG2 protein and mRNA are dramatically elevated during
the early stages of oligodendrocyte development. When TG2 activity is pharmacologically
inhibited by cystamine or KCC009, the number of oligodendrocytes producing myelin basic
protein as well as the formation of myelin sheets was significantly decreased, indicating that
TG2 is involved in regulating oligodendrocyte differentiation and subsequent myelin formation.
Additionally, we persued to study the role of TG2 activity in remyelination in vivo. TG2
knockout and wild-type mice were fed with 0.2% cuprizone for 35 days to induce demyelination.
Subsequent remyelination of the corpus callosum was studied by proteolipid protein (PLP) in
situ hybridization. In addition, motor behaviour of the mice was studied using a Rotarod. Our
data showed a clear reduced amount of PLP expressing oligodendrocytes in TG2 knock-out mice
compared to wild-type mice during the remyelination phase. Furthermore, TG2 knock-out mice
showed impaired recovery of motor performance.
Conclusions
We conclude that TG2 plays a prominent role in OPC differentiation into myelin forming OLG.
Therefore, manipulating TG2 activity may represent an interesting new target for remyelination in
demyelinating diseases.
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129. P
oor impulse control as a risk factor for nicotine
dependence
L. Diergaarde, T. Pattij, Y. Van Mourik, A.N.M. Schoffelmeer, and T.J. De Vries.
Dept. of Anatomy & Neurosciences, Neuroscience Campus Amsterdam, VU University Medical
Center, Amsterdam.
Introduction
Tobacco prices in the Netherlands have increased substantially over recent years. Nonetheless,
approximately 1/3 of the Dutch population continues smoking, indicating that smokers are willing to pay a high price for their addiction. This stresses the importance of research focusing on
potential risk factors for nicotine dependence, including impaired impulse control. Recently, we
developed a rodent paradigm for studying nicotine consumption (i.e. number of nicotine infusions) as a function of nicotine price (i.e. number of nose pokes responses per nicotine infusion).
Employing a behavioural economics approach, we determined whether impaired impulse control
underlies an insensitivity of nicotine consumption to price increments.
Methods
Male rats were trained on a delay discounting task, to measure impulsive decision making.
Hereafter, high- and low-impulsive rats were selected and were trained to nose poke for intravenous nicotine. Upon stable self-administration on a fixed ratio 1 (1 nose poke response required
for 1 nicotine infusion) schedule , the response requirement was increased every 3rd session.
Demand curves, depicting the relationship between the price of nicotine and consumption thereof, were produced using Hursh’ exponential demand equation.
Results
Nicotine consumption in rats nicely appeared to nicely fit the exponential demand equation,
thereby demonstrating the validity of our model. For high-impulsive rats, the decrease in consumption was proportionally less than the increase in price, reflecting inelastic nicotine demand.
Conclusions
The paradigm employed in this experiment seems well suited for studying nicotine demand in
rats. Moreover, we show that poor impulse control precedes an inelastic demand for nicotine,
indicating that this behavioural trait represents a risk factor for nicotine dependence.
Together, our findings suggest that treating impulsive behaviour in individual smokers, rather
than increasing tobacco taxes, may be more effective in reducing smoking rates.
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130. N
ew genetic cause of recessive osteogenesis
imperfecta and update on classification
F.S. Van Dijk1, I.M. Nesbitt2, E.H. Zwikstra1, P.G.J. Nikkels3, S.R. Piersma4, S.A. Fratantoni4,
C.R. Jimenez4 , M. Huizer1 , A.C. Morsman2 , M.H.H. van Roij1, M.W. Elting1, J.I.M.L. Verbeke5,
L.C.D. Wijnaendts6, N.J. Shaw7, W. Högler7, C. McKeown8, E.A. Sistermans1, A. Dalton2,
R.R. van Rijn9, J.M. Cobben10, H. Meijers-Heijboer1, G. Pals11.
1 Department of Clinical Genetics, VU University Medical Center, Amsterdam, the Netherlands
2 Sheffield Molecular Genetics Service, Sheffield Children’s Hospital, South Yorkshire,
United Kingdom
3 Department of Pathology, University Medical Center Utrecht, the Netherlands
4 Oncoproteomics Laboratory, Department of Medical Oncology, VU University Medical Center,
the Netherlands
5 Department of Radiology, VU University Medical Center, Amsterdam, the Netherlands
6 Department of Pathology, VU University Medical Center, Amsterdam, the Netherlands
7 Department of Pediatric Endocrinology, Birmingham Children’s Hospital, United Kingdom
8 West Midlands Regional Genetic Service, Birmingham Women’s Hospital, United Kingdom
9 Department of pediatric radiology, Academic Medical Center, Amsterdam, the Netherlands
10 Department of Pediatric genetics, Emma Children Hospital, AMC, Amsterdam, the Netherlands
11 Center for Connective Tissue Research, Department of Clinical Genetics, VU University Medical
Center, Amsterdam, the Netherlands.
Introduction
Osteogenesis imperfecta (OI) can be defined as a heterogeneous group of diseases characterized
by susceptibility to bone fractures with variable severity and presumed or proven defects in
collagen type I biosynthesis.
Methods
OI is in most cases caused by heterozygous COL1A1/2 mutations. Recently, CRTAP and LEPRE1
mutations have been described to cause autosomal recessive lethal/severe OI.
Results
We detected PPIB mutations as a third new genetic cause of autosomal recessive severe OI.
Details concerning this new genetic cause and the clinical details of the affected individuals will
be presented.
Conclusions
We present PPIB mutations as a new genetic cause of OI and we conclude that differentiation
between autosomal dominant OI caused by COL1A1/2 mutations and autosomal recessive OI
caused by CRTAP, LEPRE1 and PPIB mutations is not possible based on clinical, histological or
biochemical characteristics. In the light of this, we propose a revised classification of OI.
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131. D
ifferences in RNA quality in human brain
structures?
Anke Dijkstra, Wilma D. van de Berg.
Department of Anatomy & Neurosciences, Neuroscience Campus Amsterdam, VU University
Medical Center Amsterdam.
Introduction
Genome-wide microarray techniques on human post-mortem tissue are often used to identify differently expressed genes in several diseases. In these experiments, the quality of the RNA is of
utmost importance. Degradation of RNA occurs after death and is likely to be influenced by several factors, such as agonal state. To assess the RNA quality, the RNA Integrity Number (RIN) is
the current standard. We hypothesize that some regions of the brain are more susceptible to RNA
degradation than others, and therefore that the RIN differs between brain regions.
Methods
We used post-mortem material from the Netherlands Brainbank (NHB). From 14 cases, we collected structures throughout the brain, and individuals with at least 3 of the 4 structures present
were included in our study. The structures are olfactory bulb (OB) medulla oblongata (MO), substantia nigra (SN) and amygdala (AM). After the RNA was isolated, the RIN was determined using
Agilent Bioanalyser. We used an ANOVA and Pearson correlation to determine if there was a difference and correlation of RIN between brain structures.
Results
The RIN of the structures vary between 4.6 and 8.3.
Table 1 summarizes the means (M) and standard deviations (SD)
of the RIN of the different brain areas. There is no significant
difference in RIN between brain structures F(3)=2.03, p=0.13.
We have found a significant correlation between MO and AM,
r=0.84, p=0.01.
Conclusions
There are no differences in RIN between the OB, SN, MO and
AM. In future research, we will include structures of the diencephalon and neo-cortex in the analysis.
Wet en s ch ap s d ag V C W 2 0 1 0 OB
SN
MO
AM
N
9
14
12
10
M
7.13
6.91
6.35
6.72
SD
0.64
0.69
0.71
1.02
Table 1. Mean and standard
deviations of Rin between structures.
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132. 7
Tesla 3D-FLAIR: high sensitivity in cortical regions
in multiple sclerosis
W.L. de Graaf1, J. Zwanenburg2, F. Visser2, M.P. Wattjes1, J.Geurts1, P. Pouwels1,
C. H. Polman1, F. Barkhof1, P.R. Luijten2, J.A. Castelijns1.
1 VU University Medical Center Amsterdam
2 University Medical Center Utrecht.
In Multiple Sclerosis (MS) increasing attention is given to demyelinating aspects in the cortical
region of the brain. At 1.5T, cortical lesions are best visualized with Fluid Attenuated Inversion
Recovery (FLAIR) and Double Inversion Recovery (DIR) sequences. At higher field, the gain in SNR
can be used to increase spatial resolution, which may enhance the sensitivity of these sequences.
In this study at 7T, the sensitivity of 3D-MP-FLAIR is compared with PD/T2 and 3D-T1 weighted
imaging. Data are compared with 3D-FLAIR, PD/T2, and T1 images of the same 5 MS patients and
5 healthy controls scanned at 3T. Images are evaluated for quality and artefacts. Lesions were
scored and classified per location in consensus between a biomedical engineer and a radiologist:
peri-ventricular (PV), deep white matter (DWM), juxta-cortical (JC), mixed grey/white matter (type
I) and grey matter lesions (type II). Other lesion types were infrequently found but were not used
for this comparison.
The images at 7T with higher spatial resolution show high contrast between cerebral structures.
At 7T FLAIR, the outer cortical layers appear hyper-intense, which cannot be seen at 3T.
In the healthy controls in total only two atypical lesions were found, which were visible on all
sequences and at both field strengths. Provisional analysis shows a higher sensitivity for lesion
detection for all 7T sequences. Especially around the cortex, lesion detection is substantially
improved as compared with 3T. Despite the lack in grey/white contrast on some image types,
FLAIR,PD/T2 and T1 at ultra-high field increase accuracy and reliability in lesion classification.
The higher sensitivity at 7T is particularly seen for cortical lesions, which are smaller than WM
lesions. The performed examinations were obtained in clinically feasible scan times.
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133. Functional brain networks and dementia
Willem de Haan1, Kees Stam2.
1 Dept. Neurology/Alzheimer center, VU University Medical Center,
2 Dept. Clinical Neurophysiology/MEG centre, VU University Medical Center.
Introduction
Brain functions often seem to be localized to specialized regions. Without an efficient interaction
between those different regions, however, we are lost. Our brain is also a very complex, dynamic
network that uses synchronization as a method to bind different modalities and achieve a
coherent cognitive state. Could it be that the symptoms of dementia are primarily a consequence
of the loss of synchronization, and therefore miscommunication between different brain regions
or circuits, a so-called ‘disconnection syndrome’? To answer these questions, we apply complex
network theory to neuroscience data, and this enables us to focus on interaction between brain
regions in health and disease.
Methods
Electro-encephalography (EEG) and magneto-encephalography (MEG) recordings were performed
on awake, alert persons in an eyes-closed no-task condition. Both healthy persons as well as
patients with Alzheimer’s disease (AD) and Frontotemporal dementia (FTLD) were investigated.
Functional brain networks are formed by measuring the interaction between different brain
areas. These networks can then be characterized by properties like size, clustering, robustness,
synchronizability, and many more. This results in a quantitative and meaningful picture of how
(in)efficient functional brain networks are operating.
Results
Functional brain networks in healthy persons show a so called ‘small world’ network architecture,
presumably optimal for efficient information circulation. In AD, the networks becomes more
random and chaotic, while in FTLD there seems to be an opposite shift, towards a more rigid and
ordered type of network.
Conclusions
Communication between brain areas is different in dementia. Network analysis is able to
demonstrate functional brain network changes in different neurodegenerative disease processes.
This approach might become a useful clinical tool for diagnostic, prognostic or monitoring
purposes, but could also improve our understanding of the complex coordination of thought
processes.
Wet en s ch ap s d ag V C W 2 0 1 0 143
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134. P
athology of neurodegenerative diseases:
Identifying new disease mechanisms and innovative
drug targets
Annemieke J.M. Rozemuller, Saskia M. van der Vies, Jeroen J.M. Hoozemans, Rob Veerhuis1,
Anna Carrano, Elise S. van Haastert, David Hondius & Marlies Jacobs.
Departments of Pathology and 1Clinical Chemistry, VU University Medical Center & Neuroscience
Campus Amsterdam.
Introduction
Neurodegenerative disorders like Alzheimer’s disease, Parkinson’s disease and prion diseases
have a major impact on the growing aging population of our society. These disorders are often
characterized by the aggregation and accumulation of misfolded proteins, which are very toxic
to cells, especially neurons. In Alzheimer’s disease these protein aggregates are associated with
specific disease mechanisms that contribute to Alzheimer’s disease at a very early stage.
Methods
We search for new innovative drug targets using advanced screening tools such as Genomics,
Proteomics and Kinomics. New identified possible drug targets are investigated with
immunohistochemical techniques and Western blot analysis using brain tissue derived from
different neurodegenerative disorders. New potential drugs or leads are investigated in human
brain derived cell cultures obtained after surgery or after autopsy.
Results
By studying the disease mechanisms that contribute to the development of Alzheimer’s diseases
at early stages of the disease process we have gained insight into the role of protein misfolding
and protein aggregation, the (disturbed) A_ removal across the blood brain barrier, the aberrant
cell cycle control in neurons and the neuroinflammatory response.
Conclusions
The pathological process in Alzheimer disease and other neurodegenerative disorders, observed
after neuropathological examination, starts decades before the onset of clinical signs. Research
on early pathological mechanisms using brain tissue and investigating their contribution to
neurodegeneration is hence of utmost importance to identify early biomarkers for clinical and
pathological diagnosis and for the development of new therapeutic strategies for the treatment
or prevention of neurodegenerative disorders.
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NCA
135. Identification and functional analysis of a novel
splice variant of the creatine transporter gene
Joseph D.T. Ndika, Cristina Martinez-Muñoz, Warsha A. Kanhai, Cornelis Jakobs,
Gajja S. Salomons.
Clinical Chemistry, Metabolic Unit, VU University Medical Center, Amsterdam.
Introduction
Mutations in the X-linked creatine transporter gene (SLC6A8) leads to cerebral creatine deficiency,
mental retardation, speech and language delay, autistic-like behaviour and epilepsy. Insight into
the mechanism(s) of how the transporter is regulated is largely unknown. Previously we identified
a novel splice variant (SLC6A8C) of the creatine transporter gene (SLC6A8) which contains IVS4
and exons 5-13 of SLC6A8, including part of the 3’ UTR. The splice variant is evolutionary
conserved and predict a truncated protein identical to the SLC6A8 transporter1. In the present
study, we report the identification of an alternatively spliced variant of the SLC6A8C (C) mRNA the SLC6A8Cdel9 (Cdel9) splice variant.
Method
Identification and expression profiling of del9 were done by RT-PCR and sequencing. Growth
curves and creatine uptake assays were performed to investigate function of splice variants.
Results
Cdel9 corresponds with the C variant, except for a deletion of exon 9 but without a frame shift.
Cdel9 mRNA has a different expression pattern to that of the C mRNA. It is not expressed in
either primary fibroblasts or other human tissues, but rather in fast-growing cells (e.g.
keratinocytes, cancer cells), suggesting an effect on cell cycle progression. Preliminary data
show that co-expression of either C or Cdel9 together with SLC6A8 seems to have a cell cycle
progression delay in comparison to cells expressing only Cdel9, C, SLC6A8 or co-expressing the
C and Cdel9 variants. Hence suggesting a possible regulatory effect of the splice variants on
the creatine transporter. Pilot studies in HeLa cells and mouse fibroblasts show higher creatine
uptake in cells co-expressing Cdel9 and SLC6A8 compared to those expressing only SLC6A8.
Conclusions
C and Cdel9 seem to have an effect on cell division, and a possible additional role of the Cdel9
splice variant in the regulation of creatine uptake by the creatine transporter. Currently to
substantiate these findings Phoenix cells are now being used to produce ecotropic retroviruses,
allowing stable (co)transfections and expression of either splice variant together with SLC6A8 in
3T3 Swiss mouse fibroblasts.
Reference: Martinez-Muñoz et al. (2008) Gene 418: 53-59
Wet en s ch ap s d ag V C W 2 0 1 0 145
NCA
136. G
enetic correlations of brain lesion distribution in
Multiple Sclerosis - a candidate gene study
M.H. Sombekke1, M.M. Vellinga1, B.M.J. Uitdehaag1, D. Tejedor2, D. Arteta2, A. Martínez2,
F. Barkhof1, C.H. Polman1, J.J.G. Geurts1, H. Vrenken1.
1M
S Center Amsterdam, VU University Medical Center, Amsterdam, The Netherlands,
2 Progenika Biopharma, S.A., Derio, Spain.
Introduction
In multiple sclerosis (MS), the total volume of brain lesions and their anatomical distribution are
highly variable. Elucidating this variability may contribute to understanding clinical heterogeneity
in MS. We hypothesized that spatial distribution may reveal immunological patterns of
inflammation driven by genetic predisposition. The aim of this study was to investigate relations
between candidate genes and lesion distribution in MS.
Material and Methods
In 208 patients we related genotypes in 69 single nucleotide polymorphisms (SNPs) to the spatial
distribution of T2 brain lesions. Magnetic resonance imaging was performed at either 1.0 or 1.5
Tesla. Lesions were manually outlined and binary lesion masks were produced and registered to
a common space. Using the Randomise software, the lesion masks were then related to genotype
using a voxel-wise nonparametric General Linear Model approach, followed by clusterwise
analysis. For genotyping we used a DNA-chip that contains a set of genes previously published in
relationship to different phenotypes of MS.
Results
11 SNPs showed significant clusters of increased or decreased lesion probability for one of the
genotypes in several, predominantly periventricular brain regions. When statistically controlling
for the effects of total lesion volume only rs2227139, located within MHC class II region, retained
its clusters of significantly increased lesion probability for the heterozygote genotype compared
to the other two genotypes.
Conclusion
Several associations between genotypes of selected SNPs and altered lesion probability
were found. Rs2227139 in the MHC class II gene complex is associated with a asymmetrical
preferential periventricular lesion location, retaining significance even after correction for total
lesion load.
146
NCA
137. Irreversible active-site inhibition of tissue
transglutaminase prevents cross-linking of
α-synuclein in a cellular model of Parkinson’s
disease
Robin Verhaar, Cornelis A. M. Jongenelen, Anne-Marie van Dam, Micha M. M. Wilhelmus,
Benjamin Drukarch.
Department of Anatomy and Neurosciences, Neuroscience Campus Amsterdam, VU University
Medical Center, Amsterdam.
Introduction
Parkinson’s disease is a neurodegenerative syndrom characterized by the degeneration of catecholaminergic neurons in the brain. Another major hallmark of the disease is the presence of
amyloidogenic depositions called Lewy Bodies, which primarily consist of aggregated α-synuclein.
This protein is ubiquitously expressed in neurons and has an important role in vesicle transport
in the presynaps. The intrinsically disordered conformation of _-synuclein, however, makes it
prone to aggregation, resulting in cellular toxicity. Therefore, factors that stimulate α-synuclein
aggregation are primary targets for the development of disease modifying therapies. Tissue
transglutaminase (tTG) is an enzyme implicated in α-synuclein aggregation. tTG catalyzes the
formation of covalent ε-(γ-glutamyl)lysine isopeptide and (γ-glutamyl)polyamine bonds, which
promote protein aggregation. Recently, several peptidergic irreversible active-site inhibitors have
been developed that selectively block tTG activity. In this study, our aim was to investigate whether tTG inhibition could modulate α-synuclein aggregation.
Results
Using differentiated wild-type and α-synuclein overexpressing SH-SY5Y cells, in parallel experiments, we established the effect of the novel tTG inhibitors Z006, B003 and KCC009 on intracellular tTG activity and α-synuclein aggregation. We found that in contrast to Z006 and B003,
KCC009 had no effect on either tTG activity or α-synuclein aggregation. Moreover, this effect of
Z006 and B003 on α-synuclein aggregation was observed both following treatment with the calcium ionophore A23187 or the PD mimetic MPP+. Furthermore, using a tTG specific biotinylated
substrate and activation of tTG with A23871 and MPP+, intra- and intermolecular cross-linking of
α-synuclein was found in cells, which was blocked by co-incubation with Z006 or B003, but not
by KCC009.
Conclusion
Our results demonstrate that in a cellular context, α-synuclein is a substrate for tTG and that
(some) tTG blockers inhibit tTG mediated cross-linking and aggregation of α-synuclein. Therefore
we conclude that tTG is a promising target for pharmacological intervention in α-synuclein aggregation in PD and that cellular models may help to identify candidate drugs.
Wet en s ch ap s d ag V C W 2 0 1 0 147
NCA
138. A
pathway analysis of genome-wide association
results reveals the importance of inflammation in
Major Depressive Disorder
Jacqueline M. Vink1,2, Christel M. Middeldorp1,2,3, Jan H. Smit2,4,5, Frans G. Zitman6,
Harold Snieder7, Nicole Vogelzangs4,5, Patrick Sullivan8, Jouke Jan Hottenga1,2, Gonneke
Willemsen1,5, Dorret I. Boomsma1,2,5, Brenda Penninx2,4,5,6,7, Eco J.C. de Geus1,2,5.
1
2
3
4
5
Department of Biological Psychology, VU University, Amsterdam, the Netherlands
Neuroscience Campus Amsterdam, VU University Medical Center, Amsterdam, The Netherlands
De Bascule, Academic Center for Child and Adolescent Psychiatry, Amsterdam, The Netherlands
Department of Psychiatry VU University Medical Center Amsterdam, The Netherlands
EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam,
The Netherlands
6 Department of Psychiatry, Leiden University Medical Center, The Netherlands
7 Unit of Genetic Epidemiology & Bioinformatics, Department of Epidemiology, University Medical
Centre Groningen, University of Groningen, The Netherlands
8 Departments of Genetics, Psychiatry & Epidemiology, University of North Carolina, Chapel Hill,
USA.
Introduction
The genetic variants in the biological pathways contributing to major depressive disorder (MDD)
remain to be elucidated.
Methods
The present study used genome-wide SNP data in 1738 patients with clinical MDD and 1802
control subjects to select 685 genes that showed a significant gene-based association with
MDD and could be placed in known biological pathways. These pathways were defined within
the Ingenuity Knowledge Base according to the extensive literature on shared gene ontology,
co-expression of genes and protein-protein interaction.
Results
Pathway analysis suggested an overrepresentation of MDD genes in gene networks involved
in inflammation. Specifically, the genome-wide association results were enriched for genes
interacting with TNFα.
Conclusions
The findings support the cytokine hypothesis of depression and suggest that genetic variation in
inflammatory networks plays a role in the risk for MDD. The findings may also help explain part
of the well documented co-morbidity of MDD to somatic diseases
148
NCA
139. A
ccumulation of tissue transglutaminase and
calreticulin positive secretory-like granules in
melanized neurons in Parkinson’s disease
Micha M.M. Wilhelmus1, Robin Verhaar1, John G.J.M. Bol1, Cornelis A.M. Jongenelen1,
René J.P. Musters2, Jeroen J.M. Hoozemans3, Benjamin Drukarch1.
1 Department of Anatomy and Neurosciences, NCA, VU University Medical Center Amsterdam
2 Department of Physiology, VU University Medical Center Amsterdam, and
3 Department of Pathology, VU University Medical Center Amsterdam.
Introduction
Parkinson’s disease (PD) is characterized by degeneration of melanized neurons in the brain.
Tissue transglutaminase (tTG) is a calcium-dependent enzyme that is assumed to modulate cell
survival and apoptotic pathways depending on the type of stress(or) and cellular location of tTG.
Details about the cellular location of tTG in PD, however are scant. Therefore, we aimed to study
the cellular location of tTG in neuronal cells upon PD-associated cell stress.
Methods
We used immunohistochemistry and immunofluorescence in both a Parkinsonian cell system,
based on exposure of differentiated SH-SY5Y cells to the neurotoxin 1-methyl-4-phenylpyridinium
(MPP+), and on paraffin embedded, well-characterized, human brain tissue.
Results
We observed a granular staining pattern for tTG, only present in melanized neurons in PD
brains. Similar tTG-positive granules were observed in MPP+-treated cells, which also contained
endoplasmic reticulum (ER) associated proteins, in particular calreticulin, protein disulphide
isomerase (PDI), Erp57, phosphatidylinositol-3 receptor 1 (IP3R1), and fibronectin, and were
present in cells showing no signs of apoptosis. We confirmed these findings in the tTG-positive
granules in melanized neurons in PD brains.
Conclusions
We conclude that the colocalization of tTG with the protein folding machinery suggests a so
far unrecognized role of this protein with protein quality control, at least under pathological
conditions.
Wet en s ch ap s d ag V C W 2 0 1 0 149
NCA
140. A
n important role for mesolimbic mu-opioid
receptors in amphetamine-induced inhibitory
control deficits
Joost Wiskerke, Dustin Schetters, Inge van Es, Yvar van Mourik, Bjornar R.O. den Hollander, Anton
N.M. Schoffelmeer, Tommy Pattij.
Neuroscience Campus Amsterdam, Department of Anatomy and Neurosciences, VU University
Medical Center, Amsterdam.
Introduction
It is well known that addictive substances such as amphetamine acutely affect impulsive behavior
in both animals and humans. This phenomenon is known to depend critically on enhanced
mesolimbic dopamine transmission, but the exact neuronal mechanisms remain largely unknown.
Therefore, we here aimed at studying the neurobiological mechanisms underlying the effects of
amphetamine in two rat models of impulsivity, the 5-choice serial reaction time task (5-CSRTT)
and the delayed reward task (DRT), which provide measures of respectively inhibitory control
and impulsive choice. We specifically tested the role of the endogenous opioid system in
amphetamine-induced impulsivity as there is ample evidence indicating an important role for this
neurotransmitter system in the behavioral and neurochemical effects of amphetamine.
Methods
Separate groups of male Wistar rats were trained in either a 5-CSRTT or a DRT. Upon stable
baseline performance in these tasks, the effects of different opioid ligands on amphetamineinduced impulsivity were assessed using within-subjects designs. Compounds were either
injected systemically or infused intracranially.
Results
Amphetamine-induced decrements in inhibitory control, but not amphetamine-induced decreases
in impulsive choice, could dose-dependently be attenuated by pre-treatment with the opioid
receptor antagonist naloxone and not with selective delta- or kappa-opioid receptor antagonists.
This indicates that particularly mu-opioid receptors are involved in these effects. Naloxone also
completely prevented inhibitory control deficits induced by GBR-12909, a selective dopamine
transporter inhibitor, suggesting an important role for a ‘mu-opioid-dopamine’ interaction in
amphetamine-induced impulsivity. Intracranial infusion experiments subsequently indicated
involvement of at least mu-receptors in the nucleus accumbens shell and ventral tegmental area,
but not the nucleus accumbens core.
Conclusions
Together, these results indicate an important role for mesolimbic mu-opioid receptors in
amphetamine-induced decrements in inhibitory control.
150
NCA
141. L abel-free brain imaging in vivo with cellular
resolution using third-harmonic generation
microscopy
Stefan Witte1,3, Adrian Negrean1,2,3, Hans Lodder2,3, Guilherme Testa Silva2,3, Christiaan de Kock2,3,
Huib Mansvelder2,3, Marloes Groot1,3.
1Biophysics, Laser Center Vrije Universiteit
2 Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research
3 Neuroscience Campus Amsterdam.
Introduction
Laser-based imaging is an attractive tool for medical diagnostics, as it allows tissue screening
with cellular resolution through a noninvasive ‘optical biopsy’ without cutting away tissue. Twophoton microscopy is a well-established 3D-imaging technique, but requires fluorescent dyes to
provide image contrast. This leads to complications with toxicity, dye diffusion, and bleaching.
Here we demonstrate that a technique known as optical third-harmonic generation (THG) enables
high-resolution deep-tissue imaging without external contrast agents. Since THG is sensitive to
discontinuities, THG microscopy provides an intrinsic probe of tissue structure.
Methods
We use a multi-photon laser-scanning microscope, which we customized for THG imaging.
In addition, electrophysiology equipment is employed for whole-cell patch clamp recordings.
Imaging experiments are performed both on acute mouse brain slices and on living anesthetized
mice.
Results
THG microscopy provides ‘shadow contrast’ images, where the somata of
neurons appear as dark shadows in a highly structured THG background
(Figure 1). Backward detection (essential for in vivo imaging) is facilitated
through backscattering of the produced THG photons by the tissue. Subcellular resolution imaging has been achieved down to a depth of 350 µm
in acute mouse brain slices, as well as in living anesthetized mice. A patchclamp pipette is clearly visible in the THG image (Fig. 1), enabling dye-free
targeted patching at >200 µm depths.
Figure 1: THG image of a
patched neuron.
Conclusions
THG microscopy is found to be a powerful and versatile tool for brain imaging, with excellent
prospects for optical biopsies, as well as for laser-guided microsurgery and tissue manipulation.
Wet en s ch ap s d ag V C W 2 0 1 0 151
Index
Per onderzoeksinstituut op alfabetische volgorde van de naam van de onderzoeker
Nr.
Naam onderzoeker
abstract CCA/V-ICI
1
Agarwal, S.
2
Asseldonk, D.P. van
Titel abstract
FANCM phosphorylation in response to camptothecin
6-Thioguanine is an effective and tolerable rescue drug in the treatment of ulcerative colitis
3
Asseldonk, D.P. vanLiver histology of IBD patients who are treated with 6-thioguanine due to failure of conventional thiopurines reveals
very few cases of nodular regenerative hyperplasia
4
Berg, M.H. van denOccurrence of menarche, regularity of menstrual cycles,
and amenorrhoea in a cohort of childhood cancer survivors:
a pilot study
5
Braam, K.I.Quality of life in motion: a combined physical exercise and
psychosocial intervention program for childhood cancer
patients
6
Broek, L.I. van den CCL27 stimulates the secretion of cytokines involved in
granulation tissue formation
7
Budding, D.IS-pro: high throughput fingerprinting of the intestinal
microbiome
8
Cnossen, I.C.Prospective screening for speech and swallowing problems
in head and neck cancer patients via a touch screen computer assisted data collection system
9
Daleke, M.H.Secretion of virulence factors by pathogenic mycobacteria:
how do type VII secretion systems recognize their substrates?
10
Diessen, J.N.A. vanSplit course concurrent radiotherapy and chemotherapy in
anal cancer: a single-institution experience
11
Driessen, N.Multiple ligands in the mycobacterial cell envelope , determine the interaction between Mycobacterium tuberculosis
and the C-type lectin DC-SIGN
12
Erozenci, A.Mir-21 as determinant of gemcitabine resistance in pancreatic adenocarcinoma
13
Flach, G.B.Sentinel node biopsy and ultrasound guided fine needle
aspiration cytology in the detection of occult lymph node
metastases in oral and oropharyngeal cancer
14
Franke, N.E.The novel proteasome inhibitor 5-Amino-8-Hydroxyquinole
(5AHQ) overcomes bortezomib resistance in malignant
hematological cell line models harboring mutations in the
PSMB5 Gene
152
Nr.
Naam onderzoeker
abstract CCA/V-ICI
Titel abstract
15Geurtsen, J.Cyanovirin: a novel way to prevent Mycobacterium tuberculosis infection?
16
Gogh, Ch.D.L. vanEfficacy of voice therapy in patients after treatment of early
glottic cancer
17
Goos, J.A.C.M.
18
Greijer, A.Epstein Barr virus genome elimination by small molecules
as treatment for EBV-driven lymphomas and carcinomas
19
Haan, J.C.Candidate driver genes in focal chromosomal aberrations of
stage II colon cance
20
Henken, F.E.
21
Lam, T.J.Anorectal function evaluation in 600 patients: difference
between fecal incontinent continent patients and determination of predictive factors for fecal incontinence
22
Lelij, P. van derWarsaw breakage syndrome, a novel cohesinopathy associated with mutations in the XPD helicase family member
DDX11/ChlR1
23
Martens-de Kemp, S.Functional identification of genes and/or signalling pathways involved in chemoradiation resistance in head and
neck cancer
24
Massink, M.
25
Oskam, I.M.Prospective evaluation of quality of life in long term oral
and oropharyngeal cancer survivors and the need for supportive care
26
Overbeek, A.Relationships, pregnancies and childwish in childhood cancer survivors: a pilot study
27
Pegtel, M.D.Viral miRNAs expressed in B cells are delivered to- and act
in recipient cells; evidence for functional miRNA transfer via
exosomes
28
Plas, M. van derTruncating TP53 mutations have prognostic significance in
head and neck squamous cell carcinoma
29
Posthuma de Boer, JTreatment of osteosarcoma lung metastases
30
Riepma, I.Structured life review using autobiographical retrieval practice in depressed palliative head and neck and lung cancer
patients
31
Siebring-van Olst, E.Development of a genome wide screen to identify genes
involved in modulating p53 transcriptional activity in lung
cancer
Personalized therapy in recurrent colorectal cancer
PI3K signalling in HPV mediated transformation
Molecular classification of familial breast cancer
Wet en s ch ap s d ag V C W 2 0 1 0 153
Nr.
Naam onderzoeker
abstract CCA/V-ICI
Titel abstract
32
Smit, L.High aldehyde dehydrogenase activity is general marker
for normal hematopoietic stem cells but not leukemic stem
cells in Acute Myeloid Leukemia
33
Snellenberg, S.Methylation of WNT/_-catenin pathway regulators in cervical
carcinomas
34
Soeltan-Kaersenhout, D.Fingerprinting the Human Gut Microbiome: Evaluation of
a Terminal Restriction Fragment Length Polymorphism
(T-RFLP) Kit on Human Gastrointestinal Biopsies
35
Stoop, E.I.M.Two sides of a coin; bacterial and host genes involved in
granuloma formation
36
Timmer, L.MicroRNA profiling for reducing colorectal cancer death by
improving early diagnosis
37
Turenhout, S.T. vanDifferences in FIT results between screening and referred
colorectal cancer patients are explained by differences in
tissue tumor stage
38
Turenhout, S.T. vanPerformance of an integrated risk profile for selection of
high risk individuals for colorectal cancer screening
39
Tuyl, L.H.D. vanBaseline RANKL:OPG ratio and markers of bone and
cartilage degradation predict annual radiological
progression over 11 years in rheumatoid arthritis
40
Veldt, A.A. van derMeasurement of [11C]docetaxel uptake and tumour perfusion in lung cancer using PET-CT
41
Voorham, Q.J.M.
42
Vosslamber, S.IFN signature determines responder statua on B cell
depletion in Rheumatoid Arthritis patients
43
Vosslamber, S.IRF5 genetics predicts clinical responsiveness to IFN-_ in
Multiple Sclerosis
44
Warmoes, M.O.Quantitative proteomics of genetic mouse models for
human breast cancer: identification of BRCA1-associated
proteins involved in DNA-repair
45
Weerdenburg, E.M.Mycobacteria deficient for the type VII secretion system
ESX-5 are hypervirulent in zebrafish
Methylation pattern of high risk flat lesions in CRC
154
Nr.
Naam onderzoeker
abstract EMGO+
Titel abstract
46
Ahmad, A.Effect of medication review and cognitive behaviour treatment by community pharmacists of patients discharged
from the hospital on drug related problems and compliance
47
Almenkerk, S. vanCare for stroke in long term care facilities in the
Netherlands
48
Baur, V.E.Client participation in elderly care: residents improving the
meals
49
Beijers, H.J.B.H.Body composition as determinant of thrombin generation in
plasma – The Hoorn Study
50
Boer, M.E. deAdvance directives for euthanasia in dementia: what is their
feasibility in practice?
51
Boschloo, L. Comorbidity and risk indicators of alcohol use disorders
among persons with anxiety and/or depressive disorders
52
Brom, L.Patient participation in end-of-life decision-making: design
of a study
53
Dauwerse, L. 54
Dijk, A.M. vanThe Imagination method; a new approach for caregivers of
people with dementia in nursing homes
55
Galenkamp, H.Exploring the association between chronic diseases, multimorbidity and comorbidity and self-rated health in the older
population
56
Groeneveld, I.F.Health under construction: short- and long term effects of
a motivational interviewing-based lifestyle intervention for
construction workers with an elevated risk of cardiovascular
disease
57
Groeneveld, I.F.An individually-based lifestyle intervention for workers at
risk for cardiovascular disease: a process evaluation
58
Hurk, K. van den Type 2 Diabetes changes the association between pulse
pressure and incident chronic kidney disease – The AusDiab
Study
59
Lakerveld, J.Abdominal obesity, television viewing time and prospective
declines in exercise over five years for men and women:
the AusDiab Study
60
Leistra, E.
61
Leistra, E.Screening on undernutrition is mandatory in Dutch
hospitals
62
Loon, A. vanTreating Moroccan and Turkish migrants with depression
and anxiety disorders
Need for ethics support
Prevalence of undernutrition in Dutch hospital outpatients
Wet en s ch ap s d ag V C W 2 0 1 0 155
Nr.
Naam onderzoeker
abstract EMGO+
Titel abstract
63
Mierlo, L. vanDementelCoach: effect of telephone coaching on carers of
community dwelling people with dementia
64
Nachtegaal, J.Effects of hearing impairment on psychosocial health, need
for recovery after work, and health care use and costs in
adults aged between 18-70 years: results from an internetbased national survey on hearing
65
Platje, E.Neurobiological correlates of disruptive behaviour disorder
in a normal population; differences between boys and girls
66
Rijs, K.J.The short-term influence of age at retirement on self-perceived health
67
Rijssen, H.J. vanStereotyping of patients’ communication behaviour by physicians: a qualitative study
68
Ruyter, J.C. deDesign of the Double blind, Randomized Intervention study
in Kids (DRINK study) on the effect of sugary drinks on
body weight and fat mass
69
Ruissen, A. Competence in mental health care: philosophical theory and
medical practice
70
Strijk, J.E.The development of an Lifestyle intervention in order to
improve older workers’ vitality by using the Intervention
Mapping Protocol
71
Strijk, J.E.Associations between VO2max and vitality in older workers:
the Vital@Work Study
72
Verweij, L.M.The development of an occupational health guideline to
improve workers’ physical activity and dietary behaviour in
order to prevent weight gain
73
Vlug, M.G.
74
Vries-Bouw, M. deThe relationship between heart rate and cortisol levels and
re-offending in delinquent male adolescents
75
Wijdenes-Pijl, M.Impact of communicating familial risk of diabetes on illness
perceptions and self-reported behavioural outcomes: a randomized controlled trial
76
Wijnhoven, H.Lower appendicular skeletal muscle mass, appendicular fat
mass and trunk fat mass and mortality in community-dwelling older men and women
77
Zwijsen, S.Assistive technology as an alternative to physical restraints
in nursing homes for people with dementia
Dignity for nursing home patients: design of the study
156
Nr.
Naam onderzoeker
abstract ICaR-VU
Titel abstract
78
Aman, J.Plasma albumin and transferrin levels mark pulmonary permeability and lung injury in hypovolemic patients with or at
risk for ARDS.
79
Begieneman, M.P.V.Validation of ultrastructural analysis of mitochondrial
deposits in cardiomyocytes as a method of detecting early
acute myocardial infarction in humans.
80
Brom, Ch.E. van denAltered myocardial substrate metabolism is associated with
myocardial dysfunction in early diabetic cardiomyopathy in
rats: studies using positron emission tomography.
81
Brouwer, W.P.The development of hypertrophy in familial hypertrophic
cardiomyopathy is related to myocardial fibrosis: medium
term follow-up in genotyped hypertrophic cardiomyopathy
mutation carriers without prior hypertrophy
82
Bulte, C.S.E.Pulse rate variability corresponds with heart rate variability
in the evaluation of autonomic function
83
Dijk, A. vanMulti drug resistance protein expression on adipose tissue
derived stem cells
84
Dijk, M. vanDifferentially methylated region in intron 1 of STOX1
explains parent-of-origin effect seen in pre-eclampsia linkage analysis
85
Dijk, S.J. vanSarcomeric function and protein phosphorylation in patients
with primary hypertrophic and dilated cardiomyopathy
86
Eringa, E.C.Altered cross-talk between perivascular adipose tissue and
resistance arteries in muscle blunts insulin-mediated vasoreactivity in db/db mice
87
Groothuis, J.G.J.Positive predictive value of computed tomography coronary
angiography for detection of significant coronary artery disease and its relationship with plaque composition in clinical
practice
88
Hahn, N.E.NOX5 expression in human cardiomyocytes is increased
after acute myocardial infarction
89
Handoko, M.L.Chronic treatment with low-dose bisoprolol improve survival and cardiac function in experimental pulmonary arterial
hypertension
90
Keet, S.W.M.The reproducibility of non-standardized autonomic function
testing in the preoperative assessment screening clinic
91
Leyen, T.A.KLF2-Induced actin shear fibres control both alignment to
flow and JNK signaling in vascular endothelium
Wet en s ch ap s d ag V C W 2 0 1 0 157
Nr.
Naam onderzoeker
abstract ICAR VU
Titel abstract
92
Marcus, J.T.Interventricular synchrony in chronic thrombo-embolic pulmonary hypertension recovers after endarterectomy
93
Mauritz, G.J.Onset time of retrograde flow in the pulmonary artery in
pulmonary arterial hypertension: an estimator for pulmonary arterial pressure?
94
Meijer, R.I.
Microvascular dysfunction in skin and muscle
95
Pol, C.J.
The post-MI mouse heart is hypothyroid
96
Raalt, D.H. vanThe glucagon-like peptide receptor agonist exenatide protects against glucocorticoid-induced glucose intolerance
and Islet-cell dysfunction in humans
97
Roest, G.J. dePressure-volume loop evaluation of CRT in end-stage heart
failure. A comparison of patients with a narrow, intermediate and broad QRS complex
98
Romijn, J.W.A.Level of agreement between the Clauss Fibrinogen Test and
Rotational Thromboelastometry FIBTEM tTest in cardiothoracic surgery
99
Ruiter, G.Iron deficiency is common in pulmonary arterial hypertensive patients
100
Saouti, N.Bronchial perfusion in the lungs observed by contrastenhanced MRI
101
Smeding, L.High tidal volume ventilation partly prevents sepsis induced
myocardial depression
102
Spoel, A.G.E. van derComparison of noninvasive continuous arterial WaveForm
analysis (Nexfin HD) with transthoracic doppler echocardiography for monitoring of cardiac output
103
Sijl, A.M. vanCarotid intima media thickness in Rheumatoid Arthritis as
compared to control subjects: a meta-analysis
104
Timmer, S.A.J.Coronary microvascular dysfunction in hypertrophic cardiomyopathy is related to contractile dysfunction independent
from myocardial injury: a PET and CMR Study
105
Wong, Y.Y.Hyperemic myocardial blood flow assessment of the right
ventricle by supine exercise in PET in PAH Patients
106
Wijnstok, N.J.Relationship between obesity and microvascular function:
the Amsterdam growth and health longitudinal study
107
Zijl, N.J. van derPancreatic fat content and abdominal fat compartments in
relation to beta-cell function in subjects with impaired
glucose metabolism
158
Nr.
Naam onderzoeker
abstract MOVE
Titel abstract
108
van Kordelaar, J.The feasibility of a newly developed portable set-up for
measuring 3D kinematics of the upper limb in stroke
patients
109
Maas, H.
110
Nijland, R.Presence of finger extension and shoulder abduction within
72 hours post-stroke predicts functional recovery
111
Paul, C.P.L.Biomechanical and cellular response of goat intervertrebral
discs to loading in a novel organ culture system
Force transmission following tendon transfer in the rat
Wet en s ch ap s d ag V C W 2 0 1 0 159
Nr.
Naam onderzoeker
abstract NCA
Titel abstract
112
Avella Gonzalez, O.Waxing and waning of neuronal network oscullations
116
Berg, W.D.J. van deThe olfactory bulb as an initial site of a-ynuclein pathology in Parkonson’s disease
121
Berge, L. vanCell-type specific differences in splicing of mutant mtAspRS
mRNA
119
Bie, H.M.A. deYoung children born small for gestational age (SGA): II.
Promising preliminary results derived from functional
magnetic resonance imaging (fMRI)
122
Bossers, S.M.Brain metabolism measurements using microdialysis in
patients undergoing awake craniotomy
123
Bugiani, M.Abnormal maturation and function of astrocytes and oligodendrocytes in vanishing white matter disease
124
Bui, H.N.
125
Bunderen, C.C. vanRelationship between serum insulin-like growth factor-1
concentration and mortality in an elderly population
113
Butz, M.
126
Camargo, N.SCAP deletion in astrocytes causes startle-induced dystonia,
reduced brain size and early lethality
127
Cover, K.S.
128
Dam, A-M. vanTissue Transglutaminase promotes myelination by
oligodendrocytes in vitro and in vivo: of therapeutic interest
for Multiple Sclerosis
129
Diergaarde, L.Poor impulse control as a risk factor for nicotine dependence
130
Dijk, F.S. vanNew genetic cause of recessive osteogenesis imperfecta
and update on classification
117
Dijk, K.D. vanProteomic analysis of the locus ceruleus in Parkinson’s
disease
131
Dijkstra, A.A.
132
Graaf, W.L. de7 Tesla 3D-FLAIR: high sensitivity in cortical regions in
Multiple Sclerosis
133
Haan, W. de
134
Hoozemans, J.J.M.Pathology of neurodegenerative diseases. Identifying new
disease mechanisms and innovative drug targets
118
Ingrassia, A.M.T.Gene expression patterns in the olfacotry bulb of Parkinson
patients
Clinical microdialysis of testosterone: preliminary results
Enhancing structural plasticity after focal brain lesions
High performance computing on the GRID at the Vumc
Differences in RNA quality in human brain structures?
Functional brain networks and dementia
160
Nr.
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abstract NCA
Titel abstract
120
Jeltes, J.Young children born small for gestational age (SGA): I. A
study on brain development, behaviour and cognition
135
Ndika, J.D.T.Identification and functional analysis of a novel splice variant of the creatine transporter gene
114
Pelt, J. vanEmerging synaptic connectivity in simulated networks of
outgrowing neurons with realistic morphologies using
NETMORPH
136
Sombekke, M.Genetic correlations of brain lesion distribution in Multiple
Sclerosis - a candidate gene study
137
Verhaar, R.Irreversible active-site inhibition of tissue transglutaminase
prevents cross-linking of ?-synuclein in a cellular model of
Parkinson’s disease
138
Vink, J.M.A pathway analysis of genome-wide association results
reveals the importance of inflammation in Major Depressive
Disorder
115
Watling, L.A.The Attention-Gated Reinforcement Learning Model can
explain experimentally observed changes in tuning curves
that follow category learning
139
Wilhelmus, M.M.M.Accumulation of tissue transglutaminase and calreticulin
positive secretory-like granules in melanized neurons in
Parkinson’s disease
140
Wiskerke, J.An important role for mesolimbic mu-opioid receptors in
amphetamine-induced inhibitory control deficits
141
Witte, S.Label-free brain imaging in vivo with cellular resolution
using third-harmonic generation microscopy
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Omslag Abstract boek 2010.indd 1
22-02-2010 16:09:24