Vitamin D receptor gene polymorphisms and susceptibility to Mycobacterium malmoense pulmonary disease

Polymerase chain reaction using sequence-specific primers was utilized to ascertain the prevalence of 3 polymorphisms of the vitamin D receptor (VDR) gene (FokI F/f, ApaI A/a, and TaqI T/t) in 56 patients with Mycobacterium malmoense pulmonary disease. When compared with 101 controls, M. malmoense patients displayed an increased prevalence of Apa1 A (P=.03; Fisher's exact test), TaqI t (P=.04), and the At VDR haplotype (P=.04), and they displayed a decreased prevalence of FokI f (P=.04). Only 4 (7%) of 56 patients (vs. 29 [28%] of 101 controls) were both positive for FokI f and negative for At (P=.001). This indicates that polymorphisms in the VDR (or in closely linked genes) modulate the susceptibility to M. malmoense and that susceptibility involves multiple genetic and environmental factors.     

Prevalence and Correlates of Sexual Partner Concurrency Among Australian Gay Men Aged 18–39 Years

Mathematical models predict higher rates of HIV and sexually transmitted infections (STIs) in populations with higher rates of concurrent sexual partnerships. Although gay men and other men who have sex with men (MSM) have disproportionately high rates of HIV/STIs, little is known about the prevalence and correlates of sexual concurrency in these populations. This paper reports findings from a national community-based survey of 1,034 Australian gay-identified men aged 18–39 years, who gave detailed information about their sexual partners over the past 12 months. In all, 237 (23 %) reported two or more concurrent sexual partners. For their most recent period of concurrency, 44 % reported three or more partners and 66 % reported unprotected sex with one or more of their partners. A multivariate logistic regression found sexual concurrency was significantly more likely among men on higher incomes (P = 0.02), who first had anal sex at a relatively young age (P = 0.03), and who reported a large number of partners in the past 12 months (P < 0.001). Age, education, HIV status, and other sociodemographic and sexual behavior variables were not significant correlates. However, men who reported sexual concurrency were significantly more likely to have been diagnosed with an STI in the past 12 months (P = 0.04). Findings from this study suggest sexual concurrency is common among younger Australian gay men. With many of these men not always using condoms, health agencies should consider the potential impact of concurrency on HIV/STI epidemics among gay men and other MSM.     

Morality,Responsibility and Risk: The Importance of Alternative Perspectives in Vaccination Research

Background

The four papers presented in this special section together provide a striking example of the importance of eliciting people’s understandings and meanings of vaccinations, from parents and children to health and medical professionals.

Purpose

This commentary reflects on the findings of the papers in this special section and considers them within a broader sociocultural view on vaccination research.

Methods

The four papers in the special section were integrated with previous research and scholarship on public health and vaccinations.

Results

The studies demonstrate how both uptake of vaccinations and their meanings vary by cultural context, most notably across Eastern and Western Europe, and the fundamental role that political, economic and healthcare systems play. Nevertheless, there are many similarities across seemingly diverse contexts. Three specific tensions are apparent across the findings (and within other vaccination research). These tensions revolve around (1) responsible citizen versus responsible individual, (2) scientific knowledge versus lay understandings and (3) uncertainty and risk versus certainty and trust.

Conclusion

Threaded through these tensions are discourses around citizenship, trust, morality, gender and power that are important to consider in research on vaccinations.     

TIDAL WAVES: Network mechanisms in the neuroendocrine control of prolactin release

Neuroendocrine tuberoinfundibular dopamine (TIDA) neurons tonically inhibit pituitary release of the hormone, prolactin. Through the powerful actions of prolactin in promoting lactation and maternal behaviour while suppressing sexual drive and fertility, TIDA neurons play a key role in reproduction. We summarize insights from recent in vitro studies into the membrane properties and network behaviour of TIDA neurons including the observations that TIDA neurons exhibit a robust oscillation that is synchronized between cells and depends on intact gap junction communication. Comparisons are made with phasic firing patterns in other neuronal populations. Modulators involved in the control of lactation – including serotonin, thyrotropin-releasing hormone and prolactin itself – have been shown to change the electrical behaviour of TIDA cells. We propose that TIDA discharge mode may play a central role in tuning the amount of dopamine delivered to the pituitary and hence circulating prolactin concentrations in different reproductive states and pathological conditions.     

Mandibular flexure and its significance on implant fixed prostheses: a review

Purpose: The aims of this review are to determine the effect of mandibular flexure on the “implant‐framework system,” and analyze the existing literature on the topic. Materials and Methods: A MEDLINE and PubMed search was conducted to identify any articles in English related to the topic published up to May 2010 using the search words “mandible,”“dental implants,”“dental impression technique,”“jaw movement,”“dental stress analysis,” and “mechanical stress.” Results: The search identified 40 and 36 articles from MEDLINE and PubMed, respectively. Twenty articles met the inclusion criteria. Conclusions: Mandibular flexure is a multifactorial phenomenon, and the effect of the implant‐framework system in this is unclear. Studies have focused mainly on the fully edentulous mandible. These have found that mandibular flexure should be taken into consideration when designing a prosthesis and have suggested that dividing the prosthesis at the symphysis region, or into multiple implant fixed dental prostheses, may minimize the effect of mandibular flexure on the implant prosthesis. At this time, no studies have investigated the effect of mandibular flexure on long‐span, unilateral, implant fixed prostheses. The clinical significance of mandibular flexure on the success of dental implant treatment is at this time unclear, and further research is needed.