Maastricht University

About: Maastricht University is a education organization based out in Maastricht, Limburg, Netherlands. It is known for research contribution in the topics: Population & Health care. The organization has 19263 authors who have published 53291 publications receiving 2266866 citations. The organization is also known as: Universiteit Maastricht & UM.

Physical exercise habit: on the conceptualization and formation of habitual health behaviours

Abstract: An observation one can make when reviewing the literature on physical activity is that healthenhancing exercise habits tend to wear off as soon as individuals enter adolescence. Therefore, exercise habits should be promoted and preserved early in life. This article focuses on the formation of physical exercise habits. First, the literature on motivational determinants of habitual exercise and related behaviours is discussed, and the concept of habit is further explored. Based on this literature, a theoretical model of exercise habit formation is proposed. More specifically, expanding on the idea that habits are the result of automated cognitive processes, it is argued that physical exercise habits are capable of being automatically activated by the situational features that normally precede these behaviours. These habits may enhance health as a result of consistent performance over a long period of time. Subsequently, obstacles to the formation of exercise habits are discussed and interventions that may anticipate these obstacles are presented. Finally, implications for theory and practice are briefly discussed.

Aspirin plus Heparin or Aspirin alone in women with recurrent miscarriage

Abstract: Background Aspirin and low-molecular-weight heparin are prescribed for women with unexplained recurrent miscarriage, with the goal of improving the rate of live births, but limited data from randomized, controlled trials are available to support the use of these drugs. Methods In this randomized trial, we enrolled 364 women between the ages of 18 and 42 years who had a history of unexplained recurrent miscarriage and were attempting to conceive or were less than 6 weeks pregnant. We then randomly assigned them to receive daily 80 mg of aspirin plus open-label subcutaneous nadroparin (at a dose of 2850 IU, starting as soon as a viable pregnancy was demonstrated), 80 mg of aspirin alone, or placebo. The primary outcome measure was the live-birth rate. Secondary outcomes included rates of miscarriage, obstetrical complications, and maternal and fetal adverse events. Results Live-birth rates did not differ significantly among the three study groups. The proportions of women who gave birth to a live infant were 54.5% in the group receiving aspirin plus nadroparin (combination-therapy group), 50.8% in the aspirin-only group, and 57.0% in the placebo group (absolute difference in live-birth rate: combination therapy vs. placebo, −2.6 percentage points; 95% confidence interval [CI], −15.0 to 9.9; aspirin only vs. placebo, −6.2 percentage points; 95% CI, −18.8 to 6.4). Among 299 women who became pregnant, the live-birth rates were 69.1% in the combination-therapy group, 61.6% in the aspirin-only group, and 67.0% in the placebo group (absolute difference in live-birth rate: combination therapy vs. placebo, 2.1 percentage points; 95% CI, −10.8 to 15.0; aspirin alone vs. placebo −5.4 percentage points; 95% CI, −18.6 to 7.8). An increased tendency to bruise and swelling or itching at the injection site occurred significantly more frequently in the combination-therapy group than in the other two study groups. Conclusions Neither aspirin combined with nadroparin nor aspirin alone improved the live-birth rate, as compared with placebo, among women with unexplained recurrent miscarriage. (Current Controlled Trials number, ISRCTN58496168.)

What makes a tutor effective? A structural-equations modeling approach to learning in problem-based curricula.

Abstract: Purpose To test and further develop a causal model of the influence of tutor behaviors on student achievement and interest in the context of problem-based learning. Method Data from 524 tutorial groups involving students participating in the four-year undergraduate health sciences curriculum at the University of Limburg in 1992-93 were analyzed. The tutorial groups were guided by 261 tutors. Overall, 3,792 data records were studied, with each student participating in an average of 2.3 groups. Correlations among tutors' social-congruence, expertise-use, and cognitive-congruence behaviors, small-group functioning, and student' self-study time, intrinsic interest in subject matter, and level of achievement were analyzed using structural-equations modeling. This statistical technique allows the investigator to test causal hypotheses on correlational data by comparing the structure of data with a theoretical model. Results After minor adaptations, the hypothesized causal model of the effective tutor fitted the data extremely will. Each tutor's level of expertise use and social congruence not only directly affected his or her level of cognitive congruence but also affected other elements of the model. Level of social congruence influenced group functioning in a direct fashion, while expertise use had a slightly negative effect on the students' level of self-study time and a slightly positive effect on level of achievement. As hypothesized, the level of cognitive congruence influenced tutorial-group functioning. Level of group functioning affected self-study time and intrinsic interest. Finally, time spent on self-study influenced level of achievement. Conclusion The results suggest that subject-matter expertise; a commitment to students' learning and their lives in a personal, authentic way; and the ability to express oneself in the language used by the student are all determinants of learning in problem-based curricula. The theory of the effective tutor, presented in this article, merges two different perspectives prevalent in the literature. One perspective emphasizes the personal qualities of the tutor: his or her ability to communicate with students in an informal way, coupled with an empathic attitude that enables the tutor to encourage student learning by creating an atmosphere in which open exchange of ideas is facilitated. The other stresses the tutor's subject-matter knowledge as a determinant of learning. The data presented in this article suggest that what is needed, really, is much of both.

Analysis of DNA methylation in cancer: location revisited

Abstract: Changes in DNA methylation in cancer have been heralded as promising targets for the development of powerful diagnostic, prognostic, and predictive biomarkers. Despite the existence of more than 14,000 scientific publications describing DNA methylation-based biomarkers and their clinical associations in cancer, only 14 of these biomarkers have been translated into a commercially available clinical test. Methodological and experimental obstacles are both major causes of this disparity, but the genomic location of a DNA methylation-based biomarker is an intrinsic and essential property that also has an important and often overlooked role. Here, we examine the importance of the location of DNA methylation for the development of cancer biomarkers, and take a detailed look at the genomic location and other relevant characteristics of the various biomarkers with commercially available tests. We also emphasize the value of publicly available databases for the development of DNA methylation-based biomarkers and the importance of accurate reporting of the full methodological details of research findings.

Increased depressive ratings in patients with hepatitis C receiving interferon-alpha-based immunotherapy are related to interferon-alpha-induced changes in the serotonergic system.

Abstract: There is now evidence that repeated administration of interferon-alpha (IFN-alpha) to patients with chronic active hepatitis and cancers induces depressive symptoms. There is also evidence that induction of the cytokine network modulates the serotonergic system and that major depression is related to activation of the cytokine network and disturbances in the serotonergic metabolism. The aims of this study were to examine the effects of IFN-alpha-based immunotherapy on the development of depressive symptoms in relation to its effects on plasma tryptophan and kynurenine and serum serotonin (5-HT). Eighteen patients affected by chronic active hepatitis C were treated with IFN-alpha (3-6 million units subcutaneously three to six times a week for 6 months) and had measurements of the previous parameters before starting immunotherapy and 2, 4, 16, and 24 weeks later. Severity of depression and anxiety were measured with the Montgomery-Asberg Depression Rating Scale (MADRS) and the Hamilton Rating Scale for Anxiety (HAM-A) scale, respectively. Immunochemotherapy with IFN-alpha (1) significantly increased the MADRS and HAM-A scores and serum kynurenine concentrations and (2) significantly reduced plasma tryptophan and serum 5-HT concentrations. IFN-alpha-based immunotherapy significantly increased the kynurenine per tryptophan quotient, which estimates the activity of indoleamine 2,3-dioxygenase, the major tryptophan-catabolizing enzyme, which is induced by IFNs. There are significant relationships between the IFN-alpha-induced changes in the MADRS score and serum kynurenine (positive) and 5-HT (negative) concentrations. Immunotherapy with IFN-alpha significantly increases the severity of depressive symptoms. The latter is related to changes in the serotonergic system, such as depletion of serum 5-HT and induction of the catabolism of tryptophan to kynurenine. It is suggested that the IFN-alpha-induced changes in the serotonergic turnover could play a role in the development of IFN-alpha-induced depressive symptoms.