Individual and Contextual Factors of Sexual Risk Behavior in Youth Perinatally Infected with HIV

Abstract This study prospectively examines the effects of maternal and child HIV infection on youth penetrative and unprotected penetrative sex, as well as the role of internal contextual, external contextual, social and self-regulatory factors in influencing the sexual behaviors of HIV?infected (PHIV+), HIV?affected (uninfected with an HIV+ caregiver), and HIV unaffected (uninfected with an HIV? caregiver) youth over time. Data (N=420) were drawn from two longitudinal studies focused on the effects of pediatric or maternal HIV on youth (51% female; 39% PHIV+) and their caregivers (92% female; 46% HIV+). PHIV+ youth were significantly less likely to engage in penetrative sex than HIV? youth at follow-up, after adjusting for contextual, social, and self-regulatory factors. Other individual- and contextual-level factors such as youth alcohol and marijuana use, residing with a biological parent, caregiver employment, caregiver marijuana use, and youth self-concept were also associated with penetrative sex. Youth who used alcohol were significantly more likely to engage in unprotected penetrative sex. Data suggest that, despite contextual, social, and self-regulatory risk factors, PHIV+ youth are less likely to engage in sexual behavior compared to HIV? youth from similar environments. Further research is required to understand delays in sexual activity in PHIV+ youth and also to understand potential factors that promote resiliency, particularly as they age into older adolescence and young adulthood.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98470/1/apc%2E2012%2E0005.pd

Wpływ diet wysokotłuszczowych na wydzielanie i metabolizm androgenów w gonadach i prostacie

Les graisses alimentaires consommées influencent la composition lipidique du plasma et du tissu adipeux, la concentration plasmatique des hormones stéroïdiennes ainsi que la fluidité des membranes cellulaires. Une alimentation riche en graisses génère un stress oxydatif qui conduit à des phénomènes de peroxydation lipidique. En effet, il a été démontré que le cholestérol favorise la production de radicaux libres tandis que la vitamine E est un puissant antioxydant. Le stress oxydatif est connu pour perturber la stéroïdogenèse, d'autre part certains acides gras sont capables de stimuler l apoptose dans les cellules de Leydig. Par ailleurs, la consommation de régimes hyper-lipidiques influence également la fertilité par l intermédiaire de la leptine. Dans ce travail, nous avons étudié l effet de régimes hyper-lipidiques (supplémenté avec du cholestérol et/ou de la vitamine E) sur la sécrétion et le métabolisme des androgènes, le niveau d apoptose dans les testicules et la prostate. Nous avons caractérisé le niveau d expression du gène ob (codant pour la leptine) et de la GSTa dans les testicules, des récepteurs testiculaires et prostatiques aux androgènes (AR), les concentrations plasmatiques des gonadotropines (LH et FSH), testostérone, œstradiole et HDL. Nos travaux démontrent qu une alimentation hyper-lipidique module la stéroïdogenèse testiculaire, l expression des protéines pro- et antiapoptotique, les ARs au niveau des testicules et de la prostate ainsi que le taux d ARNm du gène ob dans les testicules. En conclusion, nos résultats montrent que la consommation de régimes riches en graisses perturbe les fonctions gonadique et prostatiqueDietary fatty acids consumption affects plasma lipid and adipose tissue composition, steroid hormone concentration in plasma; they may change also cell membrane fluidity. High-fat diets generate an oxidative stress via free radical surproduction which induce lipids peroxydation. Oxidative stress disturbs testicular steroidogenesis, moreover some fatty acids are able to induce Leydig cells apoptosis. In the other side it was already showed that vitamin E plays an antioxidant-protecting role while cholesterol favours free radicals production. In addition hyperlipidic diets intake seem to affect fertility by leptin mediation. The goal of this work was to determine influence of high-fat diets, its fatty acids composition and cholesterol and/or vitamin E supplementation on androgens secretion and metabolism and characterise theirs effect on programmed cell death in testes and prostate. We have examined also ob gene expression (coded for leptin) and GSTa protein level in testis, androgen receptor expression (AR) in testis and prostate as well as gonadotropines (LH, FSH), sex hormones (estradiol, testosterone) and HDL fraction of cholesterol levels in plasma. The present work show that high-fat diets intake can modulate testicular steroidogenesis, influence on protein pro- and antiapoptotic and AR levels in testis and prostate and on ob gene mRNA level in testis. These results confirm therefore that dietary lipids with or without cholesterol and/or vitamin E addition can disturb testis and prostate functionsLYON1-BU.Sciences (692662101) / SudocSudocFranceF