Comparative study of the cytotoxicity induced by chrysotile asbestos, rock wool and substitute fibers in vitro / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the cytotoxicity induced by chrysotile asbestos (CA), rock wool (RW) and wollastonite (WS).</p><p><b>METHODS</b>V79 cells were divided into 4 groups. i.e. CA group, WS group, RW group and control group (200 microl PBS). The exposure concentration of dusts was 100 mg/L, The cell viability was detected by MTT and lactate dehydrogenase (LDH) activity assays. The technique of scanning electron microscopy was used to examine the change of V79 cells.</p><p><b>RESULTS</b>SiO2 was main constituent for 3 kinds of dusts. In MTT assay, the cell viability of RW and WS groups was 64.8% and 65.7%, respectively, which were significantly higher than that (54.5%) of CA group (P < 0.01). In LDH assay, the LDH activity of RW and WS groups [(15.7 +/- 50.9), (12.3 +/- 3.7) U/L, respectively] was significantly lower than that [(20.2 +/- 0.9) U/L] of CA group (P < 0.05). In scanning electron microscopy examination, it was found that the two ends of V79 cells in CA group contained a great deal of fibers remaining bodies, but the V79 cell appearance in RW and WS groups was normal.</p><p><b>CONCLUSION</b>The cytotoxicity induced by RW and WS is significantly lower than that induced by CA for V79 cell.</p>

Sharing of needles and paraphernalia injection in new and long-term injection drug users in Sichuan, China / 中华流行病学杂志

Objective To examine the prevalence and correlates for needle-sharing among new and long-term injection drug users (IDUs) in Sichuan province, China. Methods Three consecutive cross-sectional surveys were conducted in 6 prefectures of Sichuan province, from 2003 to 2005.Questionnaire-based interviews provided information including socio-demographics, drug-use, sexual behaviors, and HIV-related services. Multivariable logistic regression methodology was used for data analysis. Results Of 3852 eligible participants, the rates of needle-sharing in the last 6 months for IDUs with a less than one year, one to three year, and more than three year injection history were 19.9%,29.1%, and 36.3%, respectively. Needle-sharing for IDUs with a less than one-year injection history was independently associated with factors as: being female, having minority background, higher frequency of injection, sharing injecting equipments, ever having had a non-regular sex partner, or a regular sex partner who injected drugs, never had a test on HIV, being recruited in 2005, and from Zigong prefectm'es of Sichuan. Needle-sharing for IDUs with a 1-3 year injection history were independently associated with receiving less education, having higher frequency of injecting behavior, sharing injecting equipments,ever having had a non-regular sex partner/a regular sex partner who injected drugs, ever having had unprotected sex with a non-regular sex partner, ever having had unprotected sex with a commercial sex partner or client, never attended skill training for HIV/STD prevention, being recruited in 2005 and 2004,and being recruited from Deyang, Zigong, and Liangshan prefectures. Needle-sharing for IDUs with a more than three-year injection history was independently associated with factors as: less education, higher frequency of injecting, sharing injecting equipment, ever had a non-regular sex partner, ever had unprotected sex with a non-regular sex partner, ever had unprotected sex with a commercial sex partner or client, having had regular sex partners who inject drugs, never attended needle exchange programs, being recruited in 2005 and 2004, and being recruited from Deyang, Zigong, and Liangshan prefectures. Conclusion The rates for both needle/paraphernalia sharing and unprotected sex behaviors were high in the IDUs in Sichuan province. These rates were higher among longer-term IDUs than in new IDUs. Our data underlined that better targeted, in-depth and sustained comprehensive intervention packages which including needle exchange, condom promotion along with distribution, and education, were urgently needed to reduce both IDU-related and sex-related risk behaviors among both new and longer term IDUs.

A study on acquired immune deficiency syndrome related behaviors in male clients of female sex workers / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the socio-demographic characteristics, acquired immune deficiency syndrome (AIDS) related behaviors of male clients of female sex workers and their determinants.</p><p><b>METHODS</b>Contacting subjects through 5 ways including volunteers of female sex workers (FSWs), sexually transmitted disease (STD) clinics, long-distance bus stations, long-distance cargo station while adopting methods as snowballing, employing an anonymous questionnaire. Data was analyzed by logistic regression analysis.</p><p><b>RESULTS</b>(1) The majority of clients were 25-45 years old, married and of junior high school or above educational levels; (2) Among male clients of FSWs, numbers of having had commercial sexual intercourse was between 1 to 240, averaged 24 in the previous year. It significantly related to their occupation and the experience of their friends or colleagues who ever visited female sex workers; (3) 27.98% of them used condom every time during commercial sexual intercourse, which significantly related to the score of knowledge on AIDS, concourse of sex intercourse and inhabitation; (4) 28.36% of them had ever contracted STD, which significantly related to the frequency of commercial sexual intercourse in the previous year, risk awareness of being infected with human immunodeficiency virus, and frequency of condom use during commercial sexual intercourse.</p><p><b>CONCLUSION</b>The proportion of always using condom was low among male clients of FSWs, and had had STDs. And it's necessary for active and specific intervention programs to them.</p>