Factors associated with unprotected anal intercourse among male students who have sex with men in three Northern regions of China.

BACKGROUND: Unprotected anal intercourse (UAI) has previously been associated with human immunodeficiency virus (HIV) infection. Male students who have sex with men (SMSM) are at increased exposure to experience UAI. The aim of this study was to investigate the status of UAI and related factors among SMSM in three northern regions of China. METHODS: From November 2018 to January 2019, SMSM, 18 years or older, studying or living in Beijing, Tianjin, or Shijiazhuang, who had anal sex in the past 6 months were recruited by community-based organizations to participate in an unmatched, case-control study. Detailed demographic and behavioral information were collected via self-administrated electronic questionnaires and factors related to UAI were assessed using uni- and multivariate logistic regression analyses. RESULTS: Among the 511 SMSM included in the study, 210 (41.1%) reported UAI in the past 6 months. SMSM who had sexual partners at least 10 years older than themselves (odds ratio [OR] = 2.277, 95% confidence interval [CI]: 1.380-3.756), used vacant capsules before sexual activity (OR = 3.858, 95% CI: 1.472-10.106), had a self-perceived moderate-HIV risk (OR = 2.128, 95% CI: 1.403-3.227), and unprotected, first anal intercourse (OR = 2.236, 95% CI: 1.506-3.320) had increased odds of UAI. CONCLUSIONS: Factors associated with increased odds of engaging in UAI in the past 6 months among SMSM included having older sexual partners, using vacant capsules, having a self-perceived moderate risk of HIV, and unprotected, first anal intercourse. Continuing education on risk reduction, including improving condom decision making in age-discordant relationships could help address the sexual risk behaviors among SMSM.

Endothelialization and in-stent restenosis on the surface of glycoprotein IIIa monoclonal antibody eluting stent.

Since the percutaneous transtuminal coronary angioplasty was introduced into China in 1984, this procedure has become widely accepted as an important step in coronary revascularization. This study shows the effect of the monoclonal antibody (mAb) on the platelet glycoprotein IIIa receptor during endothelialization and in-stent restenosis by implanting the mAb-eluting stents into iliac arteries of rabbits. The hard tissue cross sections of the stent-implanted arterial segments were made by polymethylmethacrylate embedding. Arterial intima proliferation was observed and analyzed. The endothelialization of the stent surface was observed using scanning electron microscope, whereas the ultrastructure of the neointima was observed using transmission electron microscope. After one month of stent implantation, the surfaces of both groups were covered by intact endothelial layers, but the neointimal areas and the ratio of stenosis were significantly lesser in the mAb-eluting stent group (p < 0.01). After 3 months, the ratio of stenosis in the mAb-eluting stent group was 14.67 ± 0.79, whereas that of the bare stent group was 21.58 ± 1.76 (p < 0.01). Therefore, the mAb eluting from the stent surface has the potential to accelerate endothelialization, prevent thrombosis formation due to the interaction of stent with blood, and decrease the stenosis ratio by inhibiting neointima proliferation.