DNAJA1 positively regulates amino acid-stimulated milk protein and fat synthesis in bovine mammary epithelial cells.

Several cellular processes, including the recovery of misfolded proteins, the folding of polypeptide chains, transit of polypeptides across the membrane, construction and disassembly of protein complexes, and modulation of protein control, are carried out by DnaJ homolog subfamily A member 1 (DNAJA1), which belongs to the DnaJ heat-shock protein family. It is unknown if DNAJA1 regulates the production of milk in bovine mammary epithelium cells (BMECs). Methionine and leucine increased DNAJA1 expression and nuclear location, as seen by us. In contrast to DNAJA1 knockdown, overexpression of DNAJA1 boosted the production of milk proteins and fats as well as mammalian target of rapamycin (mTOR) and sterol regulatory element binding protein-1c (SREBP-1c). As a result of amino acids, mTOR and SREBP-1c gene expression are stimulated, and DNAJA1 is a positive regulator of BMECs' amino acid-induced controlled milk protein and fat production.

Risk Prediction Score for HIV Infection: Development and Internal Validation with Cross-Sectional Data from Men Who Have Sex with Men in China.

Receptive anal intercourse, multiple partners, condomless sex, sexually transmitted infections (STIs), and drug/alcohol addiction are familiar factors that correlate with increased human immunodeficiency virus (HIV) risk among men who have sex with men (MSM). To improve estimation to HIV acquisition, we created a composite score using questions from routine survey of 3588 MSM in Beijing, China. The HIV prevalence was 13.4%. A risk scoring tool using penalized maximum likelihood multivariable logistic regression modeling was developed, deploying backward step-down variable selection to obtain a reduced-form model. The full penalized model included 19 sexual predictors, while the reduced-form model had 12 predictors. Both models calibrated well; bootstrap-corrected c-indices were 0.70 (full model) and 0.71 (reduced-form model). Non-Beijing residence, short-term living in Beijing, illegal drug use, multiple male sexual partners, receptive anal sex, inconsistent condom use, alcohol consumption before sex, and syphilis infection were the strongest predictors of HIV infection. Discriminating higher-risk MSM for targeted HIV prevention programming using a validated risk score could improve the efficiency of resource deployment for educational and risk reduction programs. A valid risk score can also identify higher risk persons into prevention and vaccine clinical trials, which would improve trial cost-efficiency.

Poppers use and risky sexual behaviors among men who have sex with men in Beijing, China.

BACKGROUND: Although poppers are increasingly popular among MSM in China, little is known about the patterns of poppers use. The objectives of this study were to describe the patterns of poppers use and examine its association with sexual behaviors and HIV infection among MSM in Beijing, China. METHODS: As part of a multi-component HIV intervention trial, 3588 MSM were surveyed between March 2013 and March 2014 in Beijing, China. Blood samples were collected and tested for HIV and syphilis. The questionnaire collected information about socio-demographic and behavioral characteristics. Univariate and multivariable logistic regression analyses were performed to evaluate the correlates of poppers use. RESULTS: Over a quarter of men (27.5%) reported having used at least one type of drugs in the past three months. Poppers were the most popular one (26.8%). Poppers use was correlated with a higher HIV prevalence [odds ratio (OR): 1.38, 95% confidence interval (CI): 1.11-1.70]. Demographic and sexual behavioral factors associated with poppers use included: younger age [adjusted OR (AOR): 1.56, 95% CI: 1.25-1.94], higher education (AOR: 1.61, 95% CI: 1.33-1.96), alcohol use (AOR: 1.32, 95% CI: 1.10-1.60), seeking male partners mainly via the internet (AOR: 1.60, 95% CI: 1.28-2.00), multiple male sex partnership (AOR: 2.22, 95% CI: 1.90-2.60), and unprotected receptive anal intercourse (AOR: 1.52, 95% CI: 1.28-1.81). CONCLUSIONS: In this study, poppers use was positively associated with HIV infection and unprotected anal intercourse. Intervention efforts should be devoted to promote safer sex and HIV testing and counseling among MSM who use poppers.

Correlates of unprotected anal intercourse: the influence of anal sex position among men who have sex with men in Beijing, china.

Understanding barriers to consistent condom use among men who have sex with men (MSM) requires consideration of the context in which risk behaviors occur. Anal sex position is one such context. This pooled cross-sectional study used survey data from 1,230 MSM and their 2,618 reported male sexual partnerships. Overall, nearly half of the participants engaged in unprotected anal intercourse (UAI) with at least one of upto three partners in the past 6 months. "Insertive" men engaged in less UAI (39 %) than "receptive" (53 %) or "versatile" (51 %) men. Regardless of sexual position, UAI was associated with cohabiting with a male or female partner and perceiving great or moderate risk of HIV from male contact at the individual level, and steady (vs. casual) partnership at the dyad level. However, early MSM anal sex debut, high number of male partners, alcohol use, receiving and buying condoms, HIV testing, and MSM sex-seeking venues were found to be only statistically significantly correlated with UAI among some but not all sexual positions, implying that interventions to increase condom use should take into account how anal sex position may influence willingness and ability to engage in safer sex. Dyad level data appear to provide additional insight into the influence of sexual positions, and should be used to complement individual data for future intervention designs.

HIV-testing behavior and associated factors among MSM in Chongqing, China: results of 2 consecutive cross-sectional surveys from 2009 to 2010.

The high and climbing human immunodeficiency virus (HIV) rates among Chinese men who have sex with men (MSM) bring huge pressure and challenge to acquired immune deficiency syndrome response work in China. This study examined HIV-testing behavior and describes the characteristics of recently tested MSM in Chongqing to address targeting HIV prevention interventions. Two consecutive cross-sectional surveys were conducted among Chongqing MSM using respondent-driven sampling in 2009 and 2010. Information was collected regarding details on demographic characteristics, sexual practices with male and female partners, and HIV-testing experiences. Univariate and multivariate logistic regression analyses were performed to identify factors independently associated with recent HIV testing.The final sample size included in our analyses was 992. The overall HIV prevalence was 13.4%, and HIV prevalence increased significantly from 11.6% in 2009 to 15.4% in 2010 (P = 0.08). The overall rate of HIV testing in the past 12 months was 44.6%, and the self-reported rates decreased significantly from 47.8% in 2009 to 41.1% in 2010 (P = 0.03). Factors independently associated with recent HIV testing included living in Chongqing >1 year (adjusted odds ratio [AOR] 1.8, 95% confidence interval [CI] 1.1-2.9), the age of most recent male partner ≤ 25 (AOR 1.5, 95% CI 1.1-2.1), not having unprotected insertive anal sex with most recent male partner in the past 6 months (AOR 1.5, 95% CI 1.1-2.0), disclosing HIV status to most recent male partner (AOR 2.8, 95% CI 2.0-3.8), and holding lower level of HIV-related stigma (AOR 1.1 per scale point, 95% CI 1.0-1.1). The extremely high HIV prevalence and low annual testing level put MSM at high risk of HIV infection and transmission, and it is a priority to promote regular HIV testing among this group in order to control the spread of HIV in Chongqing, China.