Association of homocysteine and smoking with cerebral microemboli in patients with mechanical heart valves: a transcranial Doppler study.

Objectives: Microembolic signals (MES) on transcranial Doppler (TCD) predict stroke and cognitive decline. Plasma levels of total homocysteine (tHcy), a prothrombotic factor, are higher in patients with microemboli in carotid stenosis and in patients with paradoxical embolism. In this study we assessed the association between the level of tHcy and the number of MES in patients with mechanical heart valves (MHVs). Methods: TCD monitoring was performed to detect MES before and after breathing 100% oxygen and repeated every 2-4 weeks up to six times. Results: Twenty-five patients with MHVs (mean age: 63.60±10.15 years) participated in this study; 15 were men (66.47±7.25 years) and 10 were women (59.30±12.60 years). In total, there were 126 study visits. In multiple regression, higher tHcy was associated with more MES in both preoxygenation (OR 1.34 (95% CI 1.07 to 1.68, P=0.009)) and postoxygenation (OR 1.40 (95% CI 1.07 to 1.83, P=0.01)) phases. Current smoking and the length of time between the operation and monitoring also correlated with a higher number of MES before and after breathing oxygen, particularly in women. Conclusions: Higher tHcy and smoking were associated with a higher MES count in both preoxygenation and postoxygenation phases. Because smoking can be stopped and hyperhomocysteinaemia is treatable, these are clinically important findings.

Assessing the change in attitudes, knowledge, and perspectives of medical students towards chiropractic after an educational intervention.

Objective : We assessed the change in attitudes, knowledge, and perspectives of medical students towards chiropractic after a 1-hour educational intervention. Methods : A mixed-methods approach was used with a 52-item cross-sectional paper survey and 1 focus group of third-year medical students. The views of these medical students towards chiropractic were assessed previously in their second-year of medical school. ANOVA and the Wilcoxon rank-sum test were used to assess between-group differences between the medical students' views before and after the educational intervention. The constant comparative method for analyzing qualitative data was used to identify emergent themes from the focus group transcript. Results : Of 112 third-year medical students, 58 completed the survey (51.7% response rate). The focus group consisted of 6 medical students. Self-reported understanding of chiropractic and number of attitude-positive responses were significantly higher in the group after the educational session. The average number of correct responses assessing knowledge on chiropractic also was significantly higher. Focus group themes were that medical students wanted exposure to chiropractic in clinical settings, had negative attitudes towards chiropractic formed from hidden curriculum, had concerns regarding evidence and safety of chiropractic, and thought that timing of the session on chiropractic was too late in the curriculum. Conclusions : The attitudes and knowledge of medical students towards chiropractic improved immediately after a 1-hour educational intervention. Formally educating medical students on chiropractic may help minimize hidden curriculum issues regarding chiropractic, as identified by the medical students, and facilitate collaboration between medical and chiropractic providers.

Assessing the attitudes, knowledge and perspectives of medical students to chiropractic.

OBJECTIVE: To assess second-year medical students' views on chiropractic. METHODS: A three-step triangulation approach was designed, comprising a 53-item survey, nine key informant interviews and one focus group of 8 subjects. ANOVA was used to assess attitude-response survey totals over grouping variables. Constant comparison method and NVivo was used for thematic analysis. RESULTS: 112 medical students completed the survey (50% response rate). Subjects reporting no previous chiropractic experience/exposure or interest in learning about chiropractic were significantly more attitude-negative towards chiropractic. Thematically, medical students viewed chiropractic as an increasingly evidence-based complementary therapy for low back/chronic pain, but based views on indirect sources. Within formal curriculum, they wanted to learn about clinical conditions and benefits/risks related to treatment, as greater understanding was needed for future patient referrals. CONCLUSION: The results highlight the importance of exposure to chiropractic within the formal medical curriculum to help foster future collaboration between these two professions.

OBJECTIF: Évaluer les opinions des étudiants de deuxième année de médecine sur la chiropratique. MÉTHODOLOGIE: Une approche de triangulation en trois étapes a été conçue, comprenant un questionnaire de 53 points, neuf entretiens avec des informateurs clés et un groupe de réflexion de 8 participants. La méthode analytique ANOVA a été utilisée pour évaluer le nombre de réponses d'un sondage sur les attitudes par les variables de regroupement. La méthode de comparaison constante et le logiciel NVivo ont été utilisés pour l'analyse thématique. RÉSULTATS: 112 étudiants en médecine ont rempli le questionnaire (taux de réponse 50 %). Les répondants n'ayant signalé aucune expérience ou exposition en chiropratique ni un intérêt à apprendre la chiropratique avaient une attitude significativement plus négative à l'égard de la chiropratique. Sur le plan thématique, les étudiants en médecine considèrent la chiropratique de plus en plus comme une thérapie complémentaire fondée sur des preuves, pour la lombalgie ou les douleurs chroniques, mais ces opinions étaient basées sur des sources indirectes. Dans le contexte d'un programme d'études officiel, les étudiants voulaient en apprendre davantage sur les conditions cliniques et les avantages et risques liés au traitement, car une plus grande compréhension était nécessaire pour l'aiguillage des patients futurs. CONCLUSION: Les résultats mettent en évidence l'importance de l'exposition à la chiropratique dans le contexte du programme d'études officiel en médecine pour aider à favoriser la collaboration future entre ces deux professions.

Major Mycobacterium tuberculosis lineages associate with patient country of origin.

Over recent years, there has been an increasing acknowledgment of the diversity that exists among Mycobacterium tuberculosis clinical isolates. To facilitate comparative studies aimed at deciphering the relevance of this diversity to human disease, an unambiguous and easily interpretable method of strain classification is required. Presently, the most effective means of assigning isolates into a series of unambiguous lineages is the method of Gagneux et al. (S. Gagneux et al., Proc. Natl. Acad. Sci. USA 103:2869-2873, 2006) that involves the PCR-based detection of large sequence polymorphisms (LSPs). In this manner, isolates are classified into six major lineages, the majority of which display a high degree of geographic restriction. Here we describe an independent replicate of the Gagneux study carried out on 798 isolates collected over a 6-year period from mostly foreign-born patients resident on the island of Montreal, Canada. The original trends in terms of bacterial genotype and patient ethnicity are remarkably conserved within this Montreal cohort, even though the patient distributions between the two populations are quite distinct. In parallel with the LSP analysis, we also demonstrate that "clustered" tuberculosis (TB) cases defined through restriction fragment length polymorphism (RFLP) analysis (for isolates with >or=6 IS6110 copies) or RFLP in combination with spoligotyping (for isolates with <6 IS6110 copies) do not stray across the LSP-defined lineage boundaries. However, our data also demonstrate the poor discriminatory power of either RFLP or spoligotyping alone for these low-IS6110-copy-number isolates. We believe that this independent validation of the LSP method should encourage researchers to adopt this system in investigations aimed at elucidating the role of strain variation in TB.