Academic Ceremonies February 2014

“Fetal development after antenatal exposures: Chorioamnionitis and maternal glucocorticoids”

In the Western world, nearly 13% of all children are born prematurely. Preterm birth causes 75% of neonatal deaths. Causes of preterm birth include chorioamnionitis, an infection of the amniotic fluid and placental membranes. By using a sheep model, this PhD dissertation studied how chorioamnionitis can affect foetal lung and brain development and the foetal immune system, and how these effects can contribute to neonatal diseases after birth. This study shows that exposure to chorioamnionitis can result in an underdevelopment of lung structures and thyme and splenic changes, inducing some sort of chronic inflammation which inflicts even further damage. The foetal brain suffers damage as well, which may result in neurological complications. By a better understanding of the way chorioamnionitis disturbs organ development, more specific therapies can be tested next to halt this development or to reduce the inflammation and its damaging effects.

Key words:

preterm birth, chorioamnionitis

“Ultra low-field strenght intraoperative MRI for Glioblastoma Surgery”

This PhD dissertation evaluates the added value of brain scanners used in operating rooms to the treatment of malignant brain tumours. This study aims to investigate various aspects of this treatment method. Firstly, it focuses on the reliability of volume measurements to determine the extent to which tumour resection has been achieved. Secondly, it addresses the question to what extent tissue abnormalities detected by intra-operative scanning actually correspond with tumour tissue.  Furthermore, this thesis describes an interim report of a study comparing this treatment method using a scanner to the standard treatment method. This thesis finds that these (expensive) scanners appear to be of little added value to the treatment of this type of tumours. Therefore, it is not necessary for other centres to purchase them.

Key words:

hersenscanner, behandeling hersentumoren

“Free as a bird?; the effect of choice restrictions on Consumer decision making”

Almost every decision that an individual makes is—in one way or the other—restricted. They can be internal,   (e.g., dieting restrictions) or external (e.g., limited assortment variety in supermarkets). We focus on the impact of such choice restrictions on consumer decision making. Specifically, we show that dieting increases individuals’ need for variety when selecting food. Further, we demonstrate that—for dieters—repeated exposure to pictures of skinny models can result in weight gain rather than loss. Finally, we highlight that mere exposure to images (e.g., advertisements with limited variety) that signal restricted choice prompts individuals to seek variety (e.g., choose many different candy bars) in a subsequent decision This dissertation is of practical relevance to various different parties—brands and retailers as well as the government and organizations concerned with human well-being—in the marketplace.

Key words:

choice restriction, dieting, thin models, variety-seeking behavior, assortment variety

“It’s in the way that you use it; usage behavior, sales performance, and their Interrelationships” 

In this dissertation big data and advanced econometric methods are used to analyze the digital traces of product and service usage.  In one study the effectiveness of free-trial promotions to acquire new customers is examined. Customers attracted with free trials (e.g., three-month trials for digital TV), churn earlier and use core parts of the service less than regular customers (e.g., TV or video-on-demand usage), yet respond stronger to marketing communication, offering ways to improve their value.  In a second study, the author addresses the rapid digitization of the entertainment industry. One of the conclusions here is that online music piracy cannibalizes sales. However, piracy also fosters consumers’ engagement with artists so that some pirates will buy in the future, reducing the negative effect of piracy about 55%.

Key words:

digital traces, costumers’ usage, data analyzing, marketing communication

“The Nature and Consequences of School Choiche”

In a school system like the Netherlands, where school choice is free, parents can choose the school that they believe provides the best education. This doctoral thesis investigates how parents choose schools and how school quality influences the cognitive development of children. The results firstly suggest that free school choice might not only foster competition, but also provide incentives for schools to specialize to meet the demands of a heterogeneous society. Secondly we show that in particular children with lower initial levels of cognitive ability benefit from attending a school with higher CITO scores.

Key words:

school choice, cognitive development, CITO scores, peer effects

“Integrating personalised perspectives into Child and Youth Health Care: A long and winding road?"

With the current boom in the basic sciences, especially those linked to human genome, it is important to ensure that all branches of health care benefit from it. The thesis focuses on the pathway of translation of innovations into Child and Youth Health Care (CYHC). The first step of introduction of genome advances could be of use for family history as it combines information about both: environment and genetic profile of the child. If such information becomes more widely used it could facilitate not only early detection of diseases (esp. psychosocial ones), but also assist in prevention strategies. In the last part of the thesis attention is paid to the current crisis of trust between parents and CYHC physicians, which is partially caused by the current reforms in the sector) and the possible directions for improving the situation.

Key words:

human genome, innovations, Child and Youth Health Care

“Identification and regulation of (novel) human adipokines; A proteomic approach”

“Application of toxicogenomics to study direct immunotoxicants”

“Childhood obesity prevention; Rationale, implementation and effectiveness of the Lifestyle Triple P intervention”

This PhD research, too, shows that parents play an important role in the development of childhood obesity. Parents of obese children are often unaware of their child’s overweight, and they experience more problems raising their children. Children who are raised with both strict and involved styles eat healthier, are more physically active and weigh less. Furthermore, an intervention to prevent further weight gain in obese children (Lifestyle Triple P) was evaluated. This intervention is based on the Positive Pedagogic Programme (Triple P) and is aimed at parents of obese children aged 4–8 years. Half of the 86 families participating received the intervention, which included group sessions and individual sessions by telephone addressing three themes: parenting, nutrition and physical exercise.  The control group only received brochures on these themes.  Although the intervention showed positive effects on both children and parents’ behaviour, such as soft drink consumption, it proved to be ineffective in reducing further weight gain.

Key words:

children, obesity, lifestyle intervention

“Screening modalities for colorectal cancer: Results from a workplace based cohort in the Netherlands”

Population screening by means of the faecal occult blood test (FOBT) was launched in the Netherlands in January 2014, making colorectal cancer screening a highly topical subject. Early detection of tumours and their pre-stages (intestinal polyps) by means of the faecal test and coloscopy can dramatically reduce the incidence and mortality of colorectal cancer. In the Netherlands, 2400 lives could be saved. This dissertation investigates the feasibility and diagnostic benefits of screening via colonoscopy in a defined population group. It also evaluates alternative screening methods, such as an immunological FOBT (FIT), lifestyle/risk factors and sigmoidoscopy. Further, faeces and blood were collected to identify and evaluate non-invasive markers for adenomas and/or colorectal cancer, as it is important to minimise patient discomfort and stress during examinations as far as possible.

Key words:

colorectal cancer screening, colonoscopy, FOBT, sigmoidoscopy

“Physiotherapy in shoulder impingement syndrome” 

“The epithelial-dendritic cell interface in pulmonary disease”

Asthma affects millions of people worldwide, and the incidence of this multi-faceted syndrome continues to rise. This thesis investigates the role of airway epithelial cells, which first encounter inhaled particles and pathogens, in the modulation of immune cell activities. The results demonstrate that specific airway epithelial signaling molecules orchestrate the downstream responses of innate and adaptive immune cells, thereby regulating pulmonary inflammation, the development of allergic asthma, and even the response to corticosteroids, a common treatment for asthma. This suggests that manipulation of a single cell type in the lung could have multiple effects for the control of pulmonary disease.

Key words:

asthma, airway epithelial cells

“Let’s talk about sex! Sexual health and sexual dysfunction among adolescents”

In research and practice, sexual dysfunctions (SDs) among young people (for example pain during sexual intercourse, erection problems et cetera) are not often associated with sexual health. This PhD dissertation focuses on evaluating and increasing young people’s knowledge of SDs, describing potential relationships between disgust and SDs, and treatment options for young people suffering from SDs. Results show that discussing SDs is still taboo, and current treatment options are not sufficient to help young people. A new treatment method called “Brief Sex Counselling” could provide a solution.

Key words:

young people, sexual health, sexual dysfunction, knowledge, treatment  

“Surface electrical stimulation of the neck for oropharyngeal dysphagia in Parkinson’s disease: therapeutic aspects and reliability of measurement”

This PhD dissertation describes a randomised controlled trial evaluating surface electrical stimulation therapy of the neck for oropharyngeal dysphagia in idiopathic Parkinson’s disease (IPD) and intrarater and interrater reliability for measurements in videofluoroscopy of swallowing. 
The methodological designs studied showed no significant effects of this form of therapy. Apparently, this form of therapy does not improve swallowing function in IPD. This thesis reports positive effects of logopedic swallowing rehabilitation. However, it is necessary to study the exact content, frequency and duration of swallowing rehabilitation in order to be able to design a clinical decision-making model for treatment options in this patient population.

Key words:

electrical stimulation therapy, oropharyngeal dysphagia

“Small fiber neuropathy and sodium channels; a paradigm shift”

Small fiber neuropathy, a disorder mainly affecting the small nerve fibers of the skin, can result in neuropathic pain (pain originating in the nerve system) and autonomic disorders in which automatic functions such as heart rhythm or sweat patterns are abnormal. There is increasing evidence of an underlying hereditary cause. This PhD dissertation has conducted research into the SCN9A gene, which encodes the voltage-gated NaV1.7 sodium channels. Various mutations in this sodium channel gene are found to cause neurons to become hyperexcitable, stay open longer or fire excessively. Furthermore, functional effects of channel mutations are shown to depend on the cells in which these mutations occur. The results offer an explanation for the symptoms of small fiber neuropathy and a lead for the development of new therapies.

Key words:

small fiber neuropathy, hereditary, SCN9A gene

“Alles van Waarde is Weerloos …”

“Bone imaging and strength in chronic obstructive Pulmonary disease”

Chronic obstructive pulmonary disease (COPD) is a lung disease predominantly caused by smoking. COPD patients often suffer from osteoporosis and arteriosclerosis.  This PhD dissertation describes a new method for the assessment of osteoporosis on chest computed tomography. Chest computed tomography is also used to assess arteriosclerosis. The study results show a relation between osteoporosis and arteriosclerosis. They also show that arteriosclerosis is an accurate predictor of death.  This thesis finds that chest computed tomography provides information not only on pulmonary disorders, but also on non-pulmonary disorders, such as osteoporosis and arteriosclerosis.

Key words:

COPD, CT scan, osteoporosis, arteriosclerosis

“The Role of biomarkers in preclinical and prodromal Alzheimer’s disease”

This dissertation investigates how abnormalities in proteins in the cerebrospinal fluid and atrophy on brain scans can best be used in diagnosing Alzheimer’s disease in people without dementia and in predicting the course of the disease. The results show that such abnormalities and atrophy, both individually and combined, are good predictors of deterioration in mental capacity in cognitively normal elderly people and in elderly people with mild cognitive impairment. In addition, the severity of the abnormalities predicts the rate of cognitive deterioration. Further research into the relative importance of abnormalities in proteins in the cerebrospinal fluid and atrophy on brain scans is needed to ensure optimal use of these measures in clinical practice.

Key words:

Alzheimer’s disease, cognitive disorders, diagnosis, biomarkers

“Crossmodal effects on texture perception and Processing”

Not much is known about the representation of visual and tactile texture information in the brain. We aimed to investigate how physical texture characteristics are represented in the brain when they are explored by touch and vision and what the effect of perceptual judgments are on the representation of texture information in the brain. The results showed that visual and tactile texture information interact not only at the perceptual but also at the cortical level, already at an early processing stage. Furthermore, the findings indicate that the cortical processing of surface textures depends on the focus of attention, e.g. whether we judge the roughness of a texture or its spatial density. Understanding the influence of visual information on the processing of tactile textures might have perceptual relevance for applications of virtual environments.

Key words:

surface texture, representation, brain

“The Value of Optical Coherence Tomography in Anterior Segment Surgery”

“Feelings of cancer risk; Moving beyond the traditional cognitive approach”

The decision to adopt a healthier lifestyle often depends on, among other things, cognitive probability beliefs about contracting a disease (“How big are my risks of getting lung cancer if I keep smoking?”). However, affective probability beliefs also play an important role. That is why in daily life people often say they know they have a certain risk of getting a disease, but they have a feeling that it won’t come to that and vice versa. The findings of this PhD dissertation show that affective probability beliefs have a stronger impact on people’s health behaviour than cognitive probability beliefs. It is shown that narrative messages may be more effective in appealing to these feelings of risk than the often rational approach of current risk communication messages.

Key words:

Risk perception, cancer prevention, feeling versus thinking, explanation of behaviour, health education 

“The Fracture Liaison Service: From risk evaluation towards risk reduction?”

This PhD dissertation investigated the timing and risk factors for a subsequent non-vertebral fracture and death in patients who sustained a recent initial non-vertebral fracture. A comparison of patients who were evaluated and treated at the Osteoporosis Outpatient Clinic (= Fracture Liaison Service=FLS) to patients who were not treated at the FLS showed a reduction in mortality by 33% and a reduction in subsequent non-vertebral fractures by 35%. An evaluation of 5 FLSs in the Netherlands showed that osteoporosis specialist nurses play a central role. It also indicated that, despite one guideline, the FLSs differed in the performance of patient selection, clinical risk factors and prevalence of clinical risk factors. The results of this thesis suggest that implementing a FLS is of clinical importance, and more concrete and standardised guidelines are needed to organise evaluation of patients at the time of fracture in daily practice.

Key words:

non-vertebral fracture, risk factors, FLS

“Willingness to pay for physician services in Ukraine and other central and eastern European countries: application of stated preferences techniques to the assessment of patient charges”

In this dissertation, experimental techniques are being used to elicit stated preferences for physician services in six Central and Eastern European countries: Bulgaria, Hungary, Lithuania, Poland, Romania, and Ukraine.  Information about patients’ willingness to pay helps to understand how the introduction of formal patient charges would affect the use of physician services in these countries. The study also provides evidence on what health care consumers are willing to pay for and how this willingness varies across countries and between population groups. The results suggest that official patient charges are an acceptable policy tool if quality and access improvements are made.

Key words:

Central and Eastern Europe, physician services, payment

“How relations, time & size matter in medical education”

Maastricht University offers a learning format called Problem-based learning (PBL), which allows students to learn collaboratively within working groups comprising approximately 10 students. This PhD dissertation describes collaborative learning among students both inside and outside the formally organised university activities, and investigates ways to improve collaborative learning processes. Nowadays, the Maastricht University Medical School enrols approximately 300 students yearly. As a consequence, students who are not familiar to each other participate in collaborative learning groups. This is contradictory, as it is common knowledge that, for instance, knowing someone’s communication style results in more effective collaboration. For that reason, a group of medical students enrolled in a curriculum year were divided into two small subgroups comprising 50 students each, and one large subgroup comprising 200 students. The groups which change every course period again were only composed of students allocated to the same subgroup. The study shows that collaboration between students allocated to the two small subgroups was more effective. Therefore, it is well-advised to divide a large group of students enrolled in a curriculum year into smaller subgroups, which is a simple and inexpensive way to improve collaborative learning processes.

Key words:

medical education, PBL, collaborate

“A place called home; The role of identification in the post-dissolution phase of a customer relationship with a place brand”

This dissertation describes the cognitive process of identification with place brands and its effects on behaviour. More and more places are engaging in branding efforts in order to attract prospective
residents but struggle when it comes to the application of product and services marketing
tools to the context of place branding and the role of residents in the branding process. The results of this research show thatthe cognitive process in a place branding context is differently structured than in the context of products and services  Furthermore inhabitants can function as place brand ambassadors even if they no longer live in a place.

Trefwoorden:

place branding, identification, relationship marketing 

“Sleep problems in individuals with genetic disorders associated with intellectual disability”

Although the prevalence of long-term sleep problems in individuals with intellectual disabilities is high, these problems are generally underdiagnosed. The ability of a questionnaire to assess sleep problems was studied. The prevalence of sleep problems in three syndromes, namely Cri du Chat syndrome, Jacobsen syndrome and Prader-Willi syndrome, and associated variables were studied by using this questionnaire. Although the prevalence of sleep problems is high, it is not higher than the prevalence in individuals with intellectual disabilities not associated with a genetic syndrome. Respiratory disorders are a risk factor requiring further research. It was the first time a systematic survey into sleep problems was carried out in patients with Jacobsen syndrome.

Key words:

sleep problems, Cri du Chat syndrome, Jacobsen syndrome, Prader-Willi syndrome, intellectual disability