Academic Ceremonies March 2011

“Visual Vestibular Mismatch: A poorly understood presentation of balance system disease”

The inner ear balance system stabilizes the eyes and the body in space.  Vision also analyzes environmental movement. Balance system disease or injury can cause disagreement or “mismatch” between the balance system information and environmental visual information. If the brain then relies on visual information, this can cause unsteadiness, but a copy of the mismatch is also sent to the nausea and anxiety centers of the brain. This mismatch (i.e. not the disease itself) can in some patients cause severe symptoms (nausea, vomiting, anxiety, newly developed motion sickness, panic disorder and sweating), which are genuine and do not suggest psychiatric disease.   Astronauts also have similar symptoms during and just after spaceflight, because the balance system is confused by the lack of gravity in space.  

Key words:

ziekte van het evenwichtssysteem, visuele informatie over de omgeving

“Cardiovascular prevention; nurses and doctors working together”

Prevention of cardiovascular diseases is very important. High-risk patients need to be traced and guided. The GP practice is the primary place for that, in cases of complicating problems patients are referred to the specialist. The prevention of cardiovascular diseases will be improved when practice nurses in the GP practice carry out the regular protocol check in patients. Almost all patients are satisfied about this; smokers form an exception; they experience less understanding for their situation and feel corrected more often than non-smokers. Motivating talks, self-management programmes and automated risk profiles could further improve the prevention by practice nurses. That also applies to the after-care track by special-ised nurses in the hospital.

Key words:

cardiovascular diseases, prevention, practice nurses

“Nuclear Structure at the Crossroad of Premature Aging and Lipodystrophy”

“Food intake meeting ENERGY AND REWARD HOMEOSTASIS”

The current obesity epidemic is mainly caused by a strong increase in the food consumption. Examples of factors that influence the food intake are changes in concentrations of hormones related to appetite and satiation, meal pattern, ‘reward homeostasis’ of food, and stress. Results of the studies described in this dissertation show that the relation between hormone concentration changes and appetite/satiation is too limited (30-70%) to give the hormone concentration changes the predicate ‘biomarker’ for satiation.  It also turns out that the control of the food intake should be bigger when the meal lasts longer; the increased food intake of going out for dinner should therefore be attributed to environmental factors. People often appear to eat while they are not hungry; people eat to experience the ‘reward homeostasis’ afterwards. This is reinforced in conditions of acute stress. Acute stress stimulates food and energy intake, particularly in obese persons with an ‘apple’ figure. Possible functional food that could influence the stress response has not been found yet. On the contrary, stress even appeared to dominate for example the very satiating effect of protein.

Key words:

obesity, food intake, appetite, hormones, reward homeostatis, stress

“Circulating Matrix Gla-protein: a biomarker for vascular disease”

MGP is a protein that protects the vessel wall against arteriosclerosis. Vitamin K is necessary to activate it. This dissertation describes the development of test methods to measure MGP in blood, and we show that these tests can be used for the diagnosis of cardiovascular diseases. With one test (t-ucMGP) you can quickly identify patients with calcified blood vessels. Another test (dp-ucMGP) can be used to estimate the vitamin K status of the blood vessel wall and consequently the risk of arteriosclerosis. Vitamin K supplement scan positively influence this test and possibly also inhibit the development of arteriosclerosis. 

Key words:

Vascular disease, vitamin K, arteriosclerosis

“Perception and action in nicotine addiction; fMRI and behavioral studies of sensorimotor and multisensory processes in smokers and non-smokers”

The present thesis employs functional magnetic resonance imaging (fMRI) and behavioral experiments to explore perceptual and action-related processes in nicotine addiction. Due to smokers’ experience with the sensorimotor and multisensory activities of seeing, reaching for and acting upon smoking paraphernalia, the corresponding perceptual and action representations are particularly enhanced on the neural and behavioral level. The correlations between smoking-related automatized behavior, test scores indicating the individual severity of nicotine addiction and the response of smokers’ action-related brain regions to smoking cues demonstrate the relevance of these findings for both future research and clinical practice. The behavioral and brain responses to smoking cues studied in this thesis can initiate the development of a marker for the degree of nicotine addiction, therapy success or relapse risk for smokers trying to quit smoking.

Key words:

fMRI, behavorial experiments, nicotine addiction

“Nutritional Modulation of Intestinal Inflammation”

Millions of people throughout the world suffer from a chronic intestinal inflammation: Crohn’s disease & colitis ulcerosa). This dissertation studies if certain nutrients can influence the intestinal inflammation. The most important finding is that addition of calcium to food can decrease the inflammation in rats. Calcium inhibits the diarrhoea, lowers the intestinal permeability, and relieves certain inflammatory processes in the intestinal wall of the rats.  Possibly also influence on the intestinal mucus layer and intestinal bacteria plays a role in this protective effect of calcium. Since the same mechanisms can also work in humans, calcium supplements can be promising as an additional therapy for patients with chronic intestinal inflammation.

This PhD research was conducted within TI Food and Nutrition.

Key words:

intestinal inflammation, food, calcium

“Polymorphisms in interstitial lung diseases; Friend or foe ?”

Besides known lung diseases, such as asthma and COPD, there are also so-called diffuse or interstitial lung diseases. Possible causes for the development of interstitial lung diseases are genetic factors and contact with xenobiotic substances via inhaled air or the blood stream. In that way, medicine can have a damaging effect on the lungs. This dissertation shows a.o. that preliminary determination of certain genetic features is very valuable to prevent medicine toxicity. In the future, this information can be recorded in the form of a ‘medical passport’ so that individual tailor-made care can be provided.  

Key words:

interstitial lung diseases, genetic features, medicine toxicity

“Can we account for individual productivity differences in scientific research? An illustrative analysis of publication records of French university and CNRS physicists”

“Modulators of bleeding tendency in severe factor V deficiency”

“The origins, evolution and functions of p53”

“Beyond Booms: Fundamentals and Mechanisms of Housing Markets in Decline”

Housing markets are more risky than they appear to be. When the first lines of this dissertation were written, residential real estate seemed to be a safe asset class, characterized by steady positive returns and low risk. The following years proved this perception to be wrong – and so does this research. Mispricings of homes are found to occur often and to persist for long periods of time. Real options amplify these deviations from fundamentals and thereby increase house price volatility. Demographics ultimately determine the demand for housing services. Against common belief, an aging society does not necessarily demand less housing. Human capital is the key demand factor, not age. Finally, drops in aggregate house prices increase the inequalities within cities with declining population numbers, which is a discomforting result, given Europe’s challenging demographic outlook.

Key words:

housing markets, mispricings of homes, human capital

“Prevention of anxiety disorders; Is screening and offering a child-or-parent-focused intervention (cost-)effective?”

This study shows that preventive interventions in anxiety disorders are effective as well as cost-effective. Applying a screening procedure followed by offering an intervention also turns out useful and cost-effective. Applying the screening procedure and offering the parent intervention appears the most cost-effective if at least one of the parents suffered from anxiety. However, the strength of these findings was modest, and the results need to be corroborated and further supported by future longitudinal anxiety prevention research that studies the effects during longer periods of time.

"From settings limits to shaping practices; Trust and accountability in health care for older people”

This dissertation studied the role of age as a value judgement in the medical decision making process. The debate about the role of age forms the basis for this study.  The objective was not to draw lines, but to promote elderly-sensitive medicine, recognizing that more health care is not always better. The discussion was also taken to a societal level. With the formation of health care practices, we do not want to force the results of an ethical debate on doctors, but on the contrary, use their practices and insights. That’s why we have studied both the decision-making processes and the arguments. The most important question is whether we can trust doctors and whether their decisions can pass the test. That’s why we developed a framework based on ‘accountability’ of and ‘trust’ in doctors in the care for the elderly.

Key words:

care for the elderly, age discrimination, trust, elderly-sensitive medicine

“ARE YOU BEING SERVED?”

“Connectivity and Growth in Sub-Saharan Africa: the role of communication satellites”

The thesis explores the importance of the strategic application of Information and Communication Technologies (ICTs) to Sub Saharan African (SSA) economies to enhance growth opportunities in the region.  
We conclude that in order for ICTs to make a meaningful contribution to economic growth in Africa, there is a need to contain and reinvest resources in the sector on the continent. African service providers need to curb the drain of meager resources to foreign satellite and fibre optic providers, so that they can compete favorably in international telephony pricing and extend their services to hard-to-reach rural areas as well, where services like telemedicine have failed to take root and contribute positively partly because of high connectivity charges.

Key words:

information and communication technologies, economic growth, Sub Saharan Africa