[Behavioral characteristics of men who have sex with men with sadomasochism associated with bleeding].

OBJECTIVE: To investigate the behavioral characteristics of men who have sex with men (MSM)with sadomasochism associated bleeding and to analyze the relationship with HIV/AIDS high risk behavior. METHODS: Using modified snowball sampling methods (target sampling methods) to carry out a cross-sectional study on persons with behavior of sadomasochism that associated with bleeding in MSM, using a valid questionnaire. Another control group without the related behavior was set up. SPSS 13.0 was used. RESULTS: People practicing sadomasochism associated with bleeding had higher percentage in the following indicators: number of accumulated same gender sexual partners (median = 20), anal intercourse (median = 10), oral intercourse (median = 10), hand intercourse (median = 15) with same gender sexual partners, number of same gender sexual partners in the previous six months (median = 4), numbers of anal intercourse (median = 3), hand intercourse (median = 3), were more than in the control group. People with sadomasochism associated bleeding had higher rates in the following behaviors: condom was ever broken or slipped in the previous six months (22.6%), suffering from disease of sexual transmitted infections (28.0%), involving in group-sex intercourse (34.8%), having sex with same sex strangers at the place for MSM in the previous six months (62.2%), ever having initiative or passive behavior of oral-anal sex (64.0%), fist-sex (18.9%), finger-sex (66.7%), bleeding during sexual intercourse(58.3%), first coition object was pupil (33.8%), having strong suicide attempts (33.3%) and suicide attempt (23.6%) etc. were more than in the control group. CONCLUSION: MSM who had the behavior of sadomasochism which associated with bleeding had the higher percentage of HIV/AIDS high risk behaviors than the persons without those behaviors. The latter group called for special concern on interventions.

[Experimental and clinical studies on the effect of sodium dodecylbenzene sulfonate in in vitro killing Demodex and in treating demodicidosis].

OBJECTIVE: To observe the effect of sodium dodecylbenzene sulfonate (SDBS) in killing Demodex in vitro and in the treatment of demodicidosis. METHODS: (1) The experiment of in vitro killing Demodex with 1% and 2% SDBS was conducted. (2) A clinical trial was carried out to evaluate the therapeutic effect in the treatment of demodicidosis with 2% SDBS and 2% metronidazole emulsion. Patients with demodicidosis were randomly divided into trial and control groups (31 cases each). They were treated with 2% SDBS ointment and 2% metronidazole ointment twice a day in the early morning and evening respectively for eight weeks consecutively. Inflammatory lesions of face, Demodex infestation and scores of erythema were measured to evaluate the effect before and after treatment. (3) Follow-up was carried out for two months to evaluate the effect and side effects after 8 weeks' treatment. RESULTS: (1) 2% SDBS killed all Demodex in vitro after 5 h, there was significant difference between the 2% SDBS and 2% metronidazole (69.4%), or between SDBS and peanut oil (9.1%) (P < 0.05). There was no significant difference in killing Demodex folliculorum and Demodex brevis with 2% SDBS. (2) Clinical observation showed that there was a significant difference in facial inflammatory lesions, Demodex infestation and scores of erythema before and after treatment with 2% SDBS (P < 0.05). The effective rate was 87.1%, 65.5% in 2% SDBS group and 2% metronidazole group respectively, with a significant difference between the two groups (P < 0.05). Follow up showed same results. (3) A slight burning sensation was the only side-effect in 3 cases with 2% SDBS ointment. CONCLUSION: Sodium dodecylbenzene sulfonate has the effect of in vitro killing Demodex and is highly effective in the treatment of demodicidosis.