Differences in risky sexual behaviors and HIV prevalence between men who have sex with men and transgender women in the Midwest Brazil.

Men who have sex with men (MSM) and transgender women (TW) are disproportionally affected by HIV infection. This cross-sectional study evaluated the HIV-1/2 prevalence, risk factors and HIV molecular features of MSM and TW from Midwest Brazil. Four hundred and thirty participants (278 MSM and 152 TW) from Mato Grosso do Sul, Brazil, were interviewed and tested for HIV-1/2 infection between November 2011 and September 2013. Participants who were assigned male at birth, older than 18 years old and self-declared as MSM or TW were recruited from LGBT+ associations, as well as public (parks, square, streets, etc) and private [nightclubs, saunas, brothels, etc] places. The prevalence of HIV-1 was 14.4% (9.0% among MSM and 24% among TW; p<0.001). The factor independently associated with HIV-1 infection among MSM was being 30 years-old or older. Among TW, having suffered sexual coercion, lifetime syphilis infection and hepatitis C virus exposure were associated with HIV-1 infection. Phylogenetic analyses classified 65% sequences as subtype B and 35% as possible recombinants. All but one recombinant sample were from TW individuals. High HIV-1 prevalences were observed in both groups, highlighting the urgent need to devise specific HIV interventions targeting these key populations. Notably, TWs are more vulnerable to HIV infection, which was associated with sexual violence and co-infection with other STIs. With regard to MSM, being 30 years old or older was significanty associated to HIV, reinforcing the idea that MSM are less exposed [or exposed later] to STIs than TWs, although MSM are clearly more vulnerable than the general population.

Sex-specific effects of dehydroepiandrosterone (DHEA) on glucose metabolism in the CNS.

DHEA is a neuroactive steroid, due to its modulatory actions on the central nervous system (CNS). DHEA is able to regulate neurogenesis, neurotransmitter receptors and neuronal excitability, function, survival and metabolism. The levels of DHEA decrease gradually with advancing age, and this decline has been associated with age related neuronal dysfunction and degeneration, suggesting a neuroprotective effect of endogenous DHEA. There are significant sex differences in the pathophysiology, epidemiology and clinical manifestations of many neurological diseases. The aim of this study was to determine whether DHEA can alter glucose metabolism in different structures of the CNS from male and female rats, and if this effect is sex-specific. The results showed that DHEA decreased glucose uptake in some structures (cerebral cortex and olfactory bulb) in males, but did not affect glucose uptake in females. When compared, glucose uptake in males was higher than females. DHEA enhanced the glucose oxidation in both males (cerebral cortex, olfactory bulb, hippocampus and hypothalamus) and females (cerebral cortex and olfactory bulb), in a sex-dependent manner. In males, DHEA did not affect synthesis of glycogen, however, glycogen content was increased in the cerebral cortex and olfactory bulb. DHEA modulates glucose metabolism in a tissue-, dose- and sex-dependent manner to increase glucose oxidation, which could explain the previously described neuroprotective role of this hormone in some neurodegenerative diseases.

DHEA administration modulates stress-induced analgesia in rats.

An important aspect of adaptive stress response is the pain response suppression that occurs during or following stress exposure, which is often referred to as acute stress-induced analgesia. Dehydroepiandrosterone (DHEA) participates in the modulation of adaptive stress response, changing the HPA axis activity. The effect of DHEA on the HPA axis activity is dependent on the state and uses the same systems that participate in the regulation of acute stress-induced analgesia. The impact of DHEA on nociception has been studied; however, the effect of DHEA on stress-induced analgesia is not known. Thus, the aim of the present study was to evaluate the effect of DHEA on stress-induced analgesia and determine the best time for hormone administration in relation to exposure to stressor stimulus. The animals were stressed by restraint for 1h in a single exposure and received treatment with DHEA by a single injection before the stress or a single injection after the stress. Nociception was assessed with a tail-flick apparatus. Serum corticosterone levels were measured. DHEA administered before exposure to stress prolonged the acute stress-induced analgesia. This effect was not observed when the DHEA was administered after the stress. DHEA treatment in non-stressed rats did not alter the nociceptive threshold, suggesting that the DHEA effect on nociception is state-dependent. The injection of DHEA had the same effect as exposure to acute stress, with both increasing the levels of corticosterone. In conclusion, acute treatment with DHEA mimics the response to acute stress indexed by an increase in activity of the HPA axis. The treatment with DHEA before stress exposure may facilitate adaptive stress response, prolonging acute stress-induced analgesia, which may be a therapeutic strategy of interest to clinics.

Syphilis infection, sexual practices and bisexual behaviour among men who have sex with men and transgender women: a cross-sectional study.

OBJECTIVES: Men who have sex with men (MSM) and transgender women (TW) are highly vulnerable groups to sexually transmitted infections (STIs). This study aims to assess the prevalence of syphilis infection, sexual behaviour and identify factors associated with syphilis in MSM and TW in Campo Grande, Central Brazil. METHODS: Between 2009 and 2011, 430 MSM/TW participants were interviewed and tested for syphilis. Univariable and multivariable regression analyses were done to assess associations with syphilis infection. RESULTS: A total of 430 MSM/TW (278 MSM and 152 TW) were included in the study. The overall prevalence of lifetime syphilis and active syphilis was 34.7% (26.3% among MSM; 50.0% among TW) and 17.5% (12.3% among MSM; 27.0% among TW), respectively (p<0.001). In multivariable regression analysis, being 20-24 years and ≥30 years, having engaged in a variety of sexual practices and with a history of genital/anal ulcer in the last 12 months were associated with lifetime syphilis infection in the MSM group. Among TW participants, being ≥30 years of age, having more than 10 male sexual partners in last week and being infected with HIV were associated with lifetime syphilis. Factors associated with active syphilis among MSM were massage parlour/sauna recruitment and alcohol consumption at least once a week. Having sex with female partners in the past 12 months was predictive for active syphilis among TW. CONCLUSIONS: The prevalence of syphilis infection and risk sexual behaviour were high in the two samples, especially among TW. High levels of bisexual behaviours and low rates of consistent condom use indicate potential HIV/STIs transmission into the heterosexual population. This finding indicates the need and urgency for implementing more effective integrated programmes targeting MSM/TW for the prevention of syphilis and other STIs.