127 research outputs found
The effect of a daily quiz (TOPday) on self-confidence, enthusiasm, and test results for biomechanics
Many students in Biomedical Sciences have difficulty understanding biomechanics. In a second-year course, biomechanics is taught in the first week and examined at the end of the fourth week. Knowledge is retained longer if the subject material is repeated. However, how does one encourage students to repeat the subject matter? For this study, we developed ‘two opportunities to practice per day (TOPday)’, consisting of multiple-choice questions on biomechanics with immediate feedback, which were sent via e-mail. We investigated the effect of TOPday on self-confidence, enthusiasm, and test results for biomechanics. All second-year students (n = 95) received a TOPday of biomechanics on every regular course day with increasing difficulty during the course. At the end of the course, a non-anonymous questionnaire was conducted. The students were asked how many TOPday questions they completed (0–6 questions [group A]; 7–18 questions [group B]; 19–24 questions [group C]). Other questions included the appreciation for TOPday, and increase (no/yes) in self-confidence and enthusiasm for biomechanics. Seventy-eight students participated in the examination and completed the questionnaire. The appreciation for TOPday in group A (n = 14), B (n = 23) and C (n = 41) was 7.0 (95 % CI 6.5–7.5), 7.4 (95 % CI 7.0–7.8), and 7.9 (95 % CI 7.6–8.1), respectively (p < 0.01 between A and C). Of the students who actively participated (B and C), 91 and 80 % reported an increase in their self-confidence and enthusiasm, respectively, for biomechanics due to TOPday. In addition, they had a higher test result for biomechanics (p < 0.01) compared with those who did not actively participate (A). In conclusion, the teaching method ‘TOPday’ seems an effective way to encourage students to repeat the subject material, with the extra advantage that students are stimulated to keep on practising for the examination. The appreciation was high and there was a positive association between active participation, on the one hand, and self-confidence, enthusiasm, and test results for biomechanics on the other
Acute Effects of Morning Light on Plasma Glucose and Triglycerides in Healthy Men and Men with Type 2 Diabetes
Both Paraoxonase-1 Genotype and Activity Do Not Predict the Risk of Future Coronary Artery Disease; the EPIC-Norfolk Prospective Population Study
Paraoxonase-1 (PON1) is an antioxidant enzyme, that resides on high-density lipoprotein (HDL). PON1-activity, is heavily influenced by the PON1-Q192R polymorphism. PON1 is considered to protect against atherosclerosis, but it is unclear whether this relation is independent of its carrier, HDL. In order to evaluate the atheroprotective potential of PON1, we assessed the relationships among PON1-genotype, PON1-activity and risk of future coronary artery disease (CAD), in a large prospective case-control study. Methodology/Principal Findings: Cases (n = 1138) were apparently healthy men and women aged 45-79 years who developed fatal or nonfatal CAD during a mean follow-up of 6 years. Controls (n = 2237) were matched by age, sex and enrollment time. PON1-activity was similar in cases and controls (60.7 +/- 645.3 versus 62.6 +/- 645.8 U/L, p = 0.3) and correlated with HDL-cholesterol levels (r = 0.16, p < 0.0001). The PON1-Q192R polymorphism had a profound impact on PON1-activity, but did not predict CAD risk (Odds Ratio [OR] per R allele 0.98[0.84-1.15], p = 0.8). Using conditional logistic regression, quartiles of PON1-activity showed a modest inverse relation with CAD risk (OR for the highest versus the lowest quartile 0.77[0.63-0.95], p = 0.01; p-trend = 0.06). PON1-activity adjusted for Q192R polymorphism correlated better with HDL-cholesterol (r = 0.26, p < 0.0001) and more linearly predicted CAD risk (0.79[0.64-0.98], p = 0.03; p-trend = 0.008). However, these relationships were abolished after adjustment for HDL (particles-cholesterol-size) and apolipoprotein A-l (0.94[0.74-1.18], p-trend = 0.3). Conclusions/Significance: This study, shows that PON1-activity inversely relates to CAD risk, but not independent of HDL, due to its close association with the HDL-particle. These data strongly suggest that a low PON1-activity is not a causal factor in atherogenesi
Nasopharyngeal Myoepithelial Carcinoma Mimicking Nasopharyngeal Carcinoma
AbstractMyoepithelial carcinoma (malignant myoepithelioma) (MC) is a rare tumor, defined as a malignant salivary neoplasm composed almost exclusively of tumor cells with myoepithelial differentiation. It can arise in unusual location sites, such as the nasopharynx, and may be difficult to approach. Nasopharyngeal MC can sometimes present as a nasopharyngeal mass which may be mistaken for primary nasopharyngeal carcinoma (NPC). The treatment strategy for nasopharyngeal MC is different from NPC, and maximal surgical resection of the main lesion is still considered as the mainstay of therapy. Herein we present a 32-year-old man with a nasopharyngeal mass which was initially mistaken as NPC, and which was later confirmed as MC after a comprehensive review of the pathology
Relative risk for cardiovascular atherosclerotic events after smoking cessation: 6–9 years excess risk in individuals with familial hypercholesterolemia
BACKGROUND: Smoking history is often di- or trichotomized into for example "never, ever or current smoking". However, smoking must be treated as a time-dependent covariate when lifetime data is available. In particular, individuals do not smoke at birth, there is usually a wide variation with respect to smoking history, and smoking cessation must also be considered. METHODS: Therefore we analyzed smoking as a time-dependent risk factor for cardiovascular atherosclerotic events in a cohort of 2400 individuals with familial hypercholesterolemia who were followed from birth until 2004. Excess risk after smoking-cessation was modelled in a Cox regression model with linear and exponential decaying trends. The model with the highest likelihood value was used to estimate the decay of the excess risk of smoking. RESULTS: Atherosclerotic events were observed in 779 patients with familial hypercholesterolemia and 1569 individuals had a smoking history. In the model with the highest likelihood value the risk reduction of smoking after cessation follows a linear pattern with time and it appears to take 6 to 9 years before the excess risk is reduced to zero. The risk of atherosclerotic events due to smoking was estimated as 2.1 (95% confidence interval 1.5; 2.9). CONCLUSION: It was concluded that excess risk due to smoking declined linearly after cessation in at least six to nine years
Complement factor H contributes to mortality in humans and mice with bacterial meningitis
Background The complement system is a vital component of the inflammatory response occurring during bacterial meningitis. Blocking the complement system was shown to improve the outcome of experimental pneumococcal meningitis. Complement factor H (FH) is a complement regulatory protein inhibiting alternative pathway activation but is also exploited by the pneumococcus to prevent complement activation on its surface conferring serum resistance. Methods In a nationwide prospective cohort study of 1009 episodes with community-acquired bacterial meningitis, we analyzed whether genetic variations in CFH influenced FH cerebrospinal fluid levels and/or disease severity. Subsequently, we analyzed the role of FH in our pneumococcal meningitis mouse model using FH knock-out (Cfh−/−) mice and wild-type (wt) mice. Finally, we tested whether adjuvant treatment with human FH (hFH) improved outcome in a randomized investigator blinded trial in a pneumococcal meningitis mouse model. Results We found the major allele (G) of single nucleotide polymorphism in CFH (rs6677604) to be associated with low FH cerebrospinal fluid concentration and increased mortality. In patients and mice with bacterial meningitis, FH concentrations were elevated during disease and Cfh−/− mice with pneumococcal meningitis had increased mortality compared to wild-type mice due to C3 depletion. Adjuvant treatment of wild-type mice with purified human FH led to complement inhibition but also increased bacterial outgrowth which resulted in similar disease outcomes. Conclusion Low FH levels contribute to mortality in pneumococcal meningitis but adjuvant treatment with FH at a clinically relevant time point is not beneficial
SCN5A mutation type and topology are associated with the risk of ventricular arrhythmia by sodium channel blockers
Background: Ventricular fibrillation in patients with Brugada syndrome (BrS) is often initiated by premature ventricular contractions (PVCs). Presence of SCN5A mutation increases the risk of PVCs upon exposure to sodium channel blockers (SCB) in patients with baseline type-1 ECG. In patients without baseline type-1 ECG, however, the effect of SCN5A mutation on the risk of SCB-induced arrhythmia is unknown. We aimed to establish whether presence/absence, type, and topology of SCN5A mutation correlates with PVC occurrence during ajmaline infusion. Methods and results: We investigated 416 patients without baseline type-1 ECG who underwent ajmaline testing and SCN5A mutation analysis. A SCN5A mutation was identified in 88 patients (S+). Ajmaline-induced PVCs occurred more often in patients with non-missense mutations (Snon-missense) or missense mutations in transmembrane or pore regions of SCN5A-encoded channel protein (Smissense-TP) than patients with missense mutations in intra-/extracellular channel regions (Smissense-IE) and patients without SCN5A mutation (S−) (29%, 24%, 9%, and 3%, respectively; P < 0.001). The proportion of patients with ajmaline-induced BrS was similar in different mutation groups but lower in S− (71% Snon-missense, 63% Smissense-TP, 70% Smissense-IE, and 34% S−; P < 0.001). Logistic regression indicated Snon-missense and Smissense-TP as predictors of ajmaline-induced PVCs. Conclusions: SCN5A mutation is associated with an increased risk of drug-induced ventricular arrhythmia in patients without baseline type-1 ECG. In particular, Snon-missense and Smissense-TP are at high risk
Soluble ST2 plasma concentrations predict mortality in severe sepsis
Patients with sepsis-after surviving the initial hyperinflammatory phase-display features consistent with immunosuppression, including hyporesponsiveness of immunocompetent cells to bacterial agents. Immunosuppression is thought to be facilitated by negative regulators of toll-like receptors, including membrane-bound ST2. We investigated the release of soluble ST2 (sST2), a decoy receptor that inhibits membrane-bound ST2 signaling, during sepsis. The study population comprised 95 patients with severe sepsis admitted to one of two intensive care units (ICUs) at the day the diagnosis of severe sepsis was made. Blood was obtained daily from admission (day 0) until day 7 and finally at day 14. Twenty-four healthy subjects served as controls. sST2 and cytokines were measured in serum. Mortality among patients was 34% in the ICU and 45% in the hospital. On admission, sepsis patients had higher sST2 levels [10,989 (7,871-15,342) pg/ml, geometric mean (95% confidence interval, CI)] than controls [55 (20-145) pg/ml, P < 0.0001]. Serum sST2 remained elevated in patients from day 0 to 14 and correlated with disease severity scores (P < 0.001) and cytokine levels on day 0 and during course of disease (P < 0.0001). Nonsurvivors displayed elevated sST2 levels compared with survivors of the intensive care unit (P < 0.0001). Sepsis results in sustained elevation of serum sST2 levels, which correlates with disease severity and mortalit
Haplotype association analyses in resources of mixed structure using Monte Carlo testing
<p>Abstract</p> <p>Background</p> <p>Genomewide association studies have resulted in a great many genomic regions that are likely to harbor disease genes. Thorough interrogation of these specific regions is the logical next step, including regional haplotype studies to identify risk haplotypes upon which the underlying critical variants lie. Pedigrees ascertained for disease can be powerful for genetic analysis due to the cases being enriched for genetic disease. Here we present a Monte Carlo based method to perform haplotype association analysis. Our method, hapMC, allows for the analysis of full-length and sub-haplotypes, including imputation of missing data, in resources of nuclear families, general pedigrees, case-control data or mixtures thereof. Both traditional association statistics and transmission/disequilibrium statistics can be performed. The method includes a phasing algorithm that can be used in large pedigrees and optional use of pseudocontrols.</p> <p>Results</p> <p>Our new phasing algorithm substantially outperformed the standard expectation-maximization algorithm that is ignorant of pedigree structure, and hence is preferable for resources that include pedigree structure. Through simulation we show that our Monte Carlo procedure maintains the correct type 1 error rates for all resource types. Power comparisons suggest that transmission-disequilibrium statistics are superior for performing association in resources of only nuclear families. For mixed structure resources, however, the newly implemented pseudocontrol approach appears to be the best choice. Results also indicated the value of large high-risk pedigrees for association analysis, which, in the simulations considered, were comparable in power to case-control resources of the same sample size.</p> <p>Conclusions</p> <p>We propose hapMC as a valuable new tool to perform haplotype association analyses, particularly for resources of mixed structure. The availability of meta-association and haplotype-mining modules in our suite of Monte Carlo haplotype procedures adds further value to the approach.</p
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