Academic Ceremonies May 2011

“Kinetics and effects of orally administered ATP”

“VEGF and NOTCH in Blood Vessels, an Intricate and Fascinating Interplay”

The NOTCH pathway comprises a highly conserved intercellular signaling mechanism. In vertebrates, NOTCH pathway components are expressed in various organs including blood vessels, where they play essential roles in neovascularization and atherosclerosis. Our studies provide a detailed molecular analysis of Notch-signaling interaction with Vascular Endothelial Growth Factor (VEGF) in Endothelial Cells and the role of metalloproteinase ADAM10 in this process.  
The new insights in VEGF and Notch signaling and their instructive role in blood vessel growth can be used to improve the efficacy of current cardiovascular therapies.  By targeting these molecules growth of blood vessels (tissue revascularization) can be stimulated or blocked, as for instance in tumor growth or atherosclerosis.  

Key words:

NOTCH pathway, molecular analysis, VEGF, vascular biology

“Regional Sustainable Development: Barriers in Practice; Findings from policy, citizens, practitioners and monitoring”

This research into the implementation problems of sustainability policy has found an important barrier: the frequent lack of vision on the desired future.  This also turns out to be the opinion of the interviewed Limburg citizens. A central characteristic of sustainable development is in fact an integral vision and the authorities should be leading there. Limburg citizens also see a role for business, education and research, as well as for the citizens themselves. The research also showed that Limburg citizens are not yet sustainable, whereas almost 80% of the interviewed people claim to find sustainability important. This difference between thinking and doing is among others a result of the fact that people don’t know what they should pay attention to and that they don’t have concrete examples. 

Key words:

policy for sustainability, sustainable development, Limburg, authorities

“Vitamine D as an immune modulator in multiple sclerosis”

Multiple Sclerosis (MS) is an incurable, invalidating inflammatory disease of the brains that especially affects young adults. At the beginning of the disease process there is an important role for specific immune cells (T cells) that attack the brain. In experimental research vitamin D inhibits these bad T cells which could possibly be favourable for MS patients. This dissertation shows that MS patients who suffer from many MS attacks have lower vitamin D levels in their blood, as well as patients with a more disturbed balance between good and bad T cells. Giving extra vitamin D to a small group of patients was safe and showed subtle indications for an improvement of this balance. To further study this effect the SOLAR study was developed. In this first large-scale clinical study into the effects of vitamin D in MS 348 European MS patients are administered high doses of vitamin D or placebo. The results of the SOLAR study may lead to an expansion of the up to now limited treatment arsenal in MS.

Key words:

vitamin D, multiple sclerosis, immune system, therapy

“Werken naar vermogen: vermogen om te werken”

“Teaching and assessment of professional behaviour: Rhetoric and Reality”

Training in professional behaviour and the assessment thereof in medical programmes increasingly gains interest, among others as a result of the new Higher Education and Research Act. This Act establishes that students who don’t function well (in this case show unprofessional behaviour) in some cases have to quite their study programme. Professional behaviour can be described as behaviour that shows and expresses the standards and values of the professional practice. This is expressed by dealing with ‘tasks and work’, with ‘others’ and with ‘the personal functioning’. This dissertation describes the theoretical and practical aspects of learning from and dealing with (un)professional behaviour in the (basic and continued) medical programme and as a practitioner. It also describes how professional behaviour can contribute to patient safety and quality of care, for example by means of a complaints analysis.

Key words:

(un)professional behaviour, medical programme, physicians

“Risk for psychosis: A Life Span Perspective”

Schizophrenia is a disease of all ages, but it usually originates at the young adult age. We studied differences in vulnerabilities for schizophrenia throughout the life span. Although the incidence of schizophrenia strongly decreases with age, the risk continues to exist at a very late age. Patients, who developed a first psychosis at an early age have a more serious type of the disease, with more serious symptoms and more memory and attention problems. Men run a risk that is twice as high as women’s to develop this serious early generated schizophrenia. From middle age, however, women run a relatively higher risk. Defective hearing is one of the environmental factors that contribute to the development of psychosis in younger people. Although vulnerability for psychosis originates already early in the developing brain, the timing is further determined by a complex mix of environmental factors, hormonal and age-related changes.

Key words:

psychosis, life span, risk factors

“Revalideren is goed schakelen”

“Intracellular glycation and endothelial dysfunction; role of methylglyoxal”

People with diabetes have an increased risk of developing cardiovascular diseases. The mechanisms as a result of which the high glucose levels in their blood can cause this damage are still largely unknown, but the formation of glycated proteins appears to play an important role here. This research shows that the substance methylglyoxal, a waste product in the decomposition of glucose, is an important precursor of glycation, and that accumulation of methylglyoxal in the cell can cause a decreased blood vessel function in diabetic rats. Furthermore it turns out that the detoxification of methylglyoxal by means of the enzyme glyoxalasis leads to less glycated proteins, an improved blood vessel function and even to reduced kidney damage. As a result of this finding a reduction of methylglyoxal formation may even become a therapeutic intervention in the future, which can combat the diabetes induced cardiovascular diseases.

Key words:

diabetes, vascular complications

“Elaboration during problem-based, small group discussion; a new approach to study collaborative learning”

“Currency crises and their Early Warning Systems”

“Indicators of energy balance and risk of epigenetic instability in colorectal cancer”

“Macrophages and modified lipoproteins: modulation of inflammation?”

“Imaging imagination; a Multi-method investigation into the brain dynamics of visual mental imagery”

Why is one person much better at visualizing the way home or his partner’s face than the other? The studies in this dissertation show that an area in the most anterior part of the brain functions as a police officer that directs other areas, for example areas that encode faces or the spatial environment, and integrates information.  It also turns out that all these areas communicate with each other in a specific order and that this communication takes place by certain patters of brain waves. This information can help us better understand the interaction between our imagination, the perception of reality and our memory.  

Key words:

fMRI, EEG, connectiviteit, voorstellingsvermogen

“Prevention of long-term sickness absence and major depression through early intervention”

Treatment and reintegration of employees that are absent and also suffer from psychological complaints still turn out complicated.  In this project the effectiveness of a preventive strategy, consisting of a screening and early intervention, was investigated for the prevention of long-term sickness absence and depression. The studied group consisted of employees with a high risk of future sickness absence and mild depressive complaints. The results show that the preventive strategy is effective in both preventing long-term sickness absence and reducing depressive complaints. Therefore, this strategy is a good starting point for applying a more proactive approach in occupational health care.

Key words:

prevention, long-term sickness absence, depressive complaints, intervention

“Strategic asset allocation; The effect of uncertainty on portfolio choice”

Long term investors (such as pension funds) use an econometric forecasting model for future share returns to determine their portfolios.  Such a forecasting model shows that shares are less risky and therefore more appealing to long term investors than to short term investors. However, my dissertation shows that in fact there is much uncertainty for the long term whether (i) the used forecasting model is the right model, (ii) if the used model parameters are correct, and (iii) if the model is stable over time. That is why shares often turn out more risky and unappealing for the long term than for the short term.

Key words:

Long-term investment, forecasting of shares, financing, econometrics 

“The role of private actors in the provision of public goods with applications to infrastructure and financial stability; accounting and financial approaches to assess macroeconomic perspectives”

“Selective Search in Games of Different Complexity”

Since computers emerged computer scientists have used board games as pilots for artificial intelligence. Their programmes use a virtual tree to find a move. In this tree each side-branch represents a choice made by a player during the game. This dissertation studies how selective search methods can find the best move in a faster way. Selective search methods are intended to explore only the important parts of the tree, but they take the risk of overlooking the best move.  The selective search methods we developed solved that the African board game Fanorona, broke the record in the game SameGame – a version of BubbleBreaker – and realized that computers play more strongly in Stratego and Halma.

Key words:

artificial intelligence, board games

“Cannulation practice and complications in hemodialysis vascular access”

The condition for a good hemodialysis treatment is a good vascular access. There are 2 types of internal vascular access, namely the autogenous arteriovenous fistula (AVF; connection between artery and vein) and the arteriovenous graft (AVG; a plastic vessel prosthesis that is inserted between an artery and a vein). In the course of one year the vascular access undergoes cannulation 312 times on average. There are few data about the damage this does to the vascular wall of a vascular access. This study shows that faulty cannulation of a newly placed AVF occurs twice as often as that of a prosthesis vascular access. Research into the two different cannulation techniques, namely the rope-ladder cannulation technique (the entire length of the vascular access is used for cannulation) and the buttonhole cannulation technique (repeatedly cannulating in the same place which generates a channel of scar tissue to the vascular access, comparable with an earring hole) showed that despite more faulty cannulations hypodermic hematomas and aneurysmata occurred significantly less often in the buttonhole group. However, the risk of infection is greater with the buttonhole technique. 

Key words:

hemodialysis, vascular access, cannulation

“Midwives, obstetrics, fear and trust. A four-part invention”

“Empirical studies on audit quality in the Belgian market for audit services”

This dissertation studies the influence of various factors on the audit quality. Based on data from the Belgian audit services market this research comes to the following conclusions.  Firstly, it turns out that accountants’ offices use the experience of partners to control risks that are attached to audits. Secondly, the research shows that accountant fees can lead to economic dependence between accountants and customers, which has negative consequences for the audit quality. Finally, the research shows that competition on the market for audit services contributes to a higher quality of these audits.

Key words:

Belgian audit services, audit quality

“Staphylococcus aureus prevalence, antibiotic resistance and genetic background in different patient populations in the Netherlands”

“Venous thromboembolism, cancer and inflammation: an update. The Good, the Bad and the Ugly”

“Ecologische psychiatrie: De context van ervaren”