Plasma Phospholipid Transfer Protein Promotes Platelet Aggregation.

It remains unclear whether plasma phospholipid transfer protein (PLTP) is involved in hyper-coagulation or hypo-coagulation. This study investigated the direct effect of PLTP on platelet aggregation and the underlying mechanism. Washed platelets from humans or mice and mouse platelet-rich plasma and human recombinant PLTP were isolated. PLTP is present in human platelets. We assessed adenosine diphosphate (ADP)-, collagen- and thrombin-induced platelet aggregation, phosphatidylserine externalization and photothrombosis-induced cerebral infarction in mice. PLTP over-expression increased platelet aggregation, while PLTP deficiency had the opposing reaction. Human recombinant PLTP increased both mouse and human platelet aggregation in a dose-dependent manner. Phosphatidylserine externalization provides a water/lipid surface for the interaction of coagulation factors, which accelerates thrombosis. Compared with wild-type controls, platelets from PLTP transgenic mice had significantly more phosphatidylserine on the exterior surface of the plasma membrane, whereas platelets from PLTP-deficient mice had significantly less phosphatidylserine on the surface, thus PLTP influences fibrinogen binding on the plasma membrane. Moreover, recombinant PLTP together with ADP significantly increased phosphatidylserine exposure on the plasma membrane of PLTP-deficient platelets, thereby increasing fibrinogen binding. PLTP over-expression significantly accelerated the incidence of photothrombosis-induced infarction in mice, whereas PLTP deficiency significantly reduced the frequency of infarction. We concluded that PLTP promotes phosphatidylserine externalization at the plasma membrane of platelets and accelerates ADP- or collagen-induced platelet aggregation. This effect plays an important role in the initiation of thrombin generation and platelet aggregation under sheer stress conditions. Thus, PLTP is involved in hyper-coagulation. Therefore, PLTP inhibition could be a novel approach for countering thrombosis.

Factors influencing HIV infection in men who have sex with men in China.

To identify risk factors for HIV infection among men who have sex with men (MSM) and to provide a theoretical basis for prevention interventions. Between December 2011 and August 2012, a case-control study was conducted among MSM who underwent voluntary counselling and testing for HIV. Confirmed HIV-positive MSM were included in the case group, and HIV-negative MSM were included in the control group. Information on possible risk factors was collected by a survey questionnaire and a qualitative interview. The results of a conditional logistic regression showed that the following were influencing factors for HIV infection: average monthly income between 2001 and 3000 Yuan (odds ratio (OR)=6.341, 95% CI: 1.714-12.544), only sometimes using condoms when having anal sex with men in the last 6 months (OR=7.601, 95% CI: 1.359-23.083), having HIV-positive sex partners (OR=5.273, 95% CI: 1.572-17.691), rectal trauma with bleeding in the last 6 months (OR=2.947, 95% CI: 1.308-6.638), not using condoms at last sexual encounter (OR=1.278, 95% CI: 1.012-5.595), engaging in commercial sex (OR=5.925, 95% CI: 1.923-13.890) and having more than 16 sex partners in the last 6 months (OR=1.175, 95% CI: 1.021-1.353). These seven factors were the risk factors of HIV infection (OR>1). However, having anal sex less than 10 times in the previous 1 month (OR=0.002, 95% CI: 0.000-0.287) was a protective factor against HIV infection among MSM (OR<1), and insertive (OR=0.116, 95% CI: 0.000-0.236) (OR<1) anal intercourse influenced HIV infection. Interventions should be targeted at MSM whose average monthly income is between 2001 and 3000 Yuan, and who engage in commercial sex. In addition, the importance of using condoms at every sexual encounter should be emphasised in health education, as should the treatment of rectal trauma with bleeding. Finally, MSM should decrease the number of sex partners and frequency of anal sex to decrease the rate of HIV infection.

[Loss to follow-up and associated factors in a cohort study among men who have sex with men].

OBJECTIVE: To explore the associated factors on loss to follow-up among men who have sex with men (MSM) in a prospective cohort study. METHODS: We recruited eligible HIV-negative MSM at baseline in eight cities from June to October 2009. Interviewer-administrated questionnaire and blood testings for HIV, syphilis and human simplex virus type 2, were accomplished upon enrollment, 6-month and 12-month follow-up visits in the program. Loss to follow-up was recorded at each visit in this cohort. Univariate and multivariate statistical analysis were conducted to examine the associated factors on loss to follow-up. RESULTS: A total of 3196 eligible MSM were enrolled at the baseline study. During one year of follow-up, 894 (28.0%) of them dropped out thoroughly while 2302 (72.1%) showed up at least on one visit. Factors as MSM who were at age 25 or younger, resided locally less than 1 year, being unemployed, self-recognized as heterosexuality or bisexuality, never taking HIV testing in the past year, having had sex with women in the past 6 months etc., were more likely to withdraw from the follow-up visits. Conclusion Age, length of residency, sex orientation and history of HIV testing were associated with the loss of follow-up among MSM cohort in our study. These factors should be considered in this kind of study design in the future.

[Male circumcision is an effective "surgical vaccine" for HIV prevention and reproductive health].

Recent randomized controlled clinical trials in Africa have demonstrated that adult male circumcision (MC) efficiently decreases the rate of HIV, HPV and HSV-2 infections. Many studies have clearly shown that MC is a simple, safe, and cost-effective method for the prevention of sexually transmitted diseases and urinary tract infection, and for improving genital hygiene. While a 30% MC prevalence exists worldwide, only 5% or less of the Chinese males have undergone circumcision. In this review, we report recent trends in international MC and HIV prevention efforts, as well as the potential benefits and importance of promoting MC in China. We appeal to medical and public health authorities to pay close attention to the international experience in MC and HIV prevention.

[Promoting male circumcision in China for preventing HIV infection and improving reproductive health].

The incidence of heterosexually transmitted HIV infection is rapidly increasing in China, which reached 44.7% among the HIV-positive patients in 2007. With a view to the reduction of HIV transmission and improvement of reproductive health in the Chinese population, this paper introduces the latest evidence obtained from the international epidemiological studies and randomized controlled clinical trials on the preventive effect of male circumcision (MC) on HIV transmission, and elucidates the cellular and molecular mechanisms of HIV transmission through the foreskin. Four studies published during 1997-2007 demonstrated that the mean prevalences of redundant prepuce and phimosis in 15,109 Chinese males aged 3-23 years in 4 areas of China were 43.90 and 11.55% , respectively, while the rate of MC was only 2.66%. As MC is a simple, inexpensive and highly effective technique in HIV prevention, we appeal to the policy-makers in China to conduct a practical program for promoting MC and enhancing male productive health in combination with other approaches to the prevention of HIV infection. MC for neonates, children, adolescents and adults should be included in the health insurance program, and free and timely MC should be performed for the male adults with the high risk of HIV infection and the normal ones whose wives are HIV-positive. Further investigations should be carried out on the epidemiology of redundant prepuce and phimosis, the acceptance and socio-cultural context of MC and the development of simpler and safer methods for MC.

[The analysis of human immunodeficiency virus-1 subtypes in Yunnan province].

OBJECTIVE: To analyze the geographical distribution and risk factors of HIV-1 subtypes in Yunnan province. METHODS: Blood samples from 1319 HIV positives were collected in Yunnan Province from 2001 to 2006. The nested polymerase chain reaction was used to amplify the gag (p24)-protease fragments from RNA extracted from plasma or sera. The sequences were used for subtype determination by phylogenetic tree analysis. RESULTS: Among 1319 samples studied, the subtypes has been successfully obtained from 644 samples that were constituted of seven subtypes: CRF08_BC, CRF07_BC, CRF07/08_BC, CRF01_AE, C, B' and URFB/C. C/CRF07_BC/CRF08_BC were distributed in the whole province, but CRF01_AE were mainly distributed in the boarding areas with Myanmar such as Dehong, Baoshan, Xishuangbanna and Puer. Moreover, injecting drugs users accounted for 61.6% (270/438) among C/CRF07_BC/CRF08_BC infections, while only 8.5% (15/177) among CRF01_AE infections. CONCLUSION: Our data indicated that at least seven subtypes were identified in Yunnan province, the relationship between subtypes and transmission routes were analyzed, and the geographic difference of subtypes was also observed.

[Epidemiologic study on STD/HIV infections among tin mining workers in Gejiu, Yunnan province].

OBJECTIVE: To estimate human immunodeficiency virus (HIV)/sexually transmitted diseases (STDs) related knowledge, the prevalence and risk factors for HIV/STDs among tin miners in Gejiu, Yunnan Province. METHODS: A cross-sectional study was conducted in tin miners working at 5 mining regions from March to June 2006 in Gejiu City, Yunnan Province. A total of 1796 miners were enrolled in the study, and a standardized questionnaire was administered probing socio-demographic factors, knowledge of HIV/STDs and sexual behavior. 7 ml-volume venous blood and 15 ml urine specimens were collected for HIV/STDs testing. RESULTS: Twelve participants [0.7%] (12/1760) were identified HIV positive. While, the positive proportions for syphilis, herpes simplex virus type-2 (HSV-2), Neisseria gonorrhea and Chlamydia trachoma were 1.8% (31/1760), 9.6% (169/1760), 0.8% (14/1773), 4.8% (85/1773), respectively. The total prevalence of STDs was 14.9% (264/1776). Factors associated with HIV infection were illegal drug use (adjusted OR = 17.8; 95% CI: 4.0 - 78.8), frequencies of visiting female sex workers in the past twelve months (adjusted OR = 8.7; 95% CI: 1.9 - 39.0), tattoos (adjusted OR = 6.6; 95% CI: 1.8 - 24.0), surgical operation experiences (adjusted OR = 6.0; 95% CI: 1.6 - 22.5) and toothbrush sharing (adjusted OR = 5.6; 95% CI: 1.0 - 31.3). Factors associated with STDs infection were race (adjusted OR = 2.0; 95% CI: 1.5 - 2.7), age (adjusted OR = 1.7; 95% CI: 1.0 - 2.9), illegal drug use (adjusted OR = 2.3; 95% CI: 1.0 - 5.2), living with spouses (adjusted OR = 1.4; 95% CI: 1.1 - 1.9) and visiting female sex workers (adjusted OR = 1.9; 95% CI: 1.4 - 2.6). Only 4.1% (49/1201) of respondents aware the correct transmission routes of HIV. 21.6% (339/1569) of the miners who had previous sexual experience self-reported visiting female sex workers. CONCLUSION: HIV and other STDs are highly prevalent amongst miners in this region. In addition, the awareness of HIV/STDs is low and multiple routes of HIV transmission, such as heterosexual intercourse and IDU, were also observed in these study subject. HIV/STDs interventions should therefore be reinforced among the miners in this region.

[Study on sexual behavior and HIV/STIs among miners in Yunnan province].

OBJECTIVE: This paper aims to describe human immunodeficiency virus/sexual transmitted infections (HIV/STIs) related knowledge, attitudes, practice and the prevalence of HIV/STIs amongst miners. METHODS: Two focus-group related discussions with a total number of 13 members including Community Advisory Boards (CAB) and 12 miners were conducted in a mining township in Yunnan province. Questionnaire surveys and HIV/STIs tests were conducted among 233 miners recruited by cluster sampling in two towns where the mines were located. RESULTS: The average age of respondents was 28 year old with 82.8% of them younger than 35 year old. 95.3% of the respondents attended the education level of junior middle school. AIDS related knowledge among miners was low. The percentage of right answers to the routes of transmission was only 54.4%. The ratio of self-reported prostitutes visits was 9.0%. The prevalence rates of Neisseria gonrrhoeae, HIV and Chlamydia trachomatis were 0.4%, 0.4%and 8.2% respectively. The correlation between Chlamydia trachomatis infection and education (P = 0.0347) was significant, and so was that between Chlamydia trachomatis infection and marriage status (P = 0.032). CONCLUSION: This study showed that the awareness of HIV/STIs prevention was limited and the rate of condom use was low, suggesting that miners needed to be viewed as a key population in HIV/STIs prevention and control.