Apoptosis and the activity of ceramide, Bax and Bcl-2 in the lungs of neonatal rats exposed to limited and prolonged hyperoxia

BACKGROUND: The aim of the study is to examine the effect of limited and prolonged hyperoxia on neonatal rat lung. This is done by examining the morphologic changes of apoptosis, the expression of ceramide, an important mediator of apoptosis, the expression of inflammatory mediators represented by IL-1β and the expression of 2 proto-oncogenes that appear to modulate apoptosis (Bax and Bcl-2). METHODS: Newborn rats were placed in chambers containing room air or oxygen above 90% for 7 days. The rats were sacrificed at 3, 7 or 14 days and their lungs removed. Sections were fixed, subjected to TUNEL, Hoechst, and E-Cadherin Staining. Sections were also incubated with anti-Bcl-2 and anti-Bax antisera. Bcl-2 and Bax were quantitated by immunohistochemistry. Lipids were extracted, and ceramide measured through a modified diacylglycerol kinase assay. RT-PCR was utilized to assess IL-1β expression. RESULTS: TUNEL staining showed significant apoptosis in the hyperoxia-exposed lungs at 3 days only. Co-staining of the apoptotic cells with Hoechst, and E-Cadherin indicated that apoptotic cells were mainly epithelial cells. The expression of Bax and ceramide was significantly higher in the hyperoxia-exposed lungs at 3 and 14 days of age, but not at 7 days. Bcl-2 was significantly elevated in the hyperoxia-exposed lungs at 3 and 14 days. IL-1β expression was significantly increased at 14 days. CONCLUSION: Exposure of neonatal rat lung to hyperoxia results in early apoptosis documented by TUNEL assay. The early rise in Bax and ceramide appears to overcome the anti-apoptotic activity of Bcl-2. Further exposure did not result in late apoptotic changes. This suggests that apoptotic response to hyperoxia is time sensitive. Prolonged hyperoxia results in acute lung injury and the shifting balance of ceramide, Bax and Bcl-2 may be related to the evolution of the inflammatory process

Intravaginal and Menstrual Practices among Women Working in Food and Recreational Facilities in Mwanza, Tanzania: Implications for Microbicide Trials

Intravaginal and menstrual practices may potentially influence results of trials of microbicides for HIV prevention through effects on the vaginal environment and on adherence to microbicide and placebo products. As part of the feasibility study for the Microbicides Development Programme Phase 3 trial of a vaginal microbicide in Mwanza, a variety of quantitative and qualitative methods were used to describe these practices, associations with behaviour and underlying social norms among women working in food and recreational facilities. Intravaginal cleansing by inserting fingers and either water alone or soap and water was thought necessary to remove “uchafu” (dirt), referring to vaginal secretions, including menstrual blood and post-coital discharge. Vaginal cleansing was carried out within 2 hours after 45% of sex acts. Sexual enhancement practices were less common. Intravaginal and menstrual practices and associated behaviours and demographic factors should be measured and monitored throughout microbicide trials to enable analyses of their impacts on microbicide effectiveness

Female Condom Use and Adoption Among Men and Women in a General Low-Income Urban U.S. Population

© 2015, Springer Science+Business Media New York. HIV prevention is increasingly focused on antiretroviral treatment of infected or uninfected persons. However, barrier methods like male condoms (MC) and female condoms (FC) remain necessary to achieve broad reductions in HIV and other sexually transmitted infections (STI). Evidence grows suggesting that removal of basic obstacles could result in greater FC use and reduced unprotected sex in the general population. We conducted four annual cross-sectional surveys (2009–2012) of urban residents (N = 1614) in low-income neighborhoods of a northeastern U.S. city where prevalence of HIV and other STIs is high. Findings indicate slow FC uptake but also heterosexual men’s willingness to use them. Factors associated with men’s and women’s FC use included positive FC attitudes, network exposure, and peer influences and norms. These results suggest that men can be supporters of FC, and reinforce the need for targeted efforts to increase FC use in both men and women for HIV/STI prevention