[In vitro Effect of Hypericin against Toxoplasma gondii Tachyzoites].

Objective: To investigate the killing effect of hypericin on tachyzoites of Toxoplasma gondii RH strain in vitro. Methods: Normal saline （group A） and different concentrations of hypericin (5 µg/ml, group B; 50 µg/ml, group C; 500 µg/ml, group D） were added to T. gondii tachyzoites in 24-well plate（1×10(6)/well）. The tachyzoites were harvested after 2, 4 and 6 h, and underwent the following treatment: trypan blue staining to calculate the dyeing rate, Giemsa staining to observe the morphological and structural alterations of tachyzoites, and transmission electron microscopy to observe the ultrastructure of tachyzoites. In addition, flow cytometry was performed to calculate the survival rate of YFP-carrying Toxoplasma with the same treatment. Results: The trypan blue dyeing rate at 2 h after treatment in groups B, C and D was（11.0±3.6）%, （25.0±6.3）% and（40.0±2.7）% respectively, with a significant difference of group D versus B and C （P<0.01）, and groups C and D versus group A ［（6.0±3.0）%）］. The dyeing rate at 4 h and 6 h in group D was（97.0±2.0）% and （98.0±1.7）%, respectively, both significantly higher than that of groups C ［（30.0±7.2）%, （42.7±5.5）%ï¼½, B ［（20.0±3.0）%, （34.0±6.6）%ï¼½ and A ［（10.0±1.0）%, （19.3±4.9）%］（P<0.01）. Giemsa staining showed gradual end swelling and necrosis of tachyzoites with increased treatment duration and dosage. Transmission electron microscopy showed swelling of worm body, gap between cell membrane and matrix, increase and enlargement of vacuoles inside worm body, disruption of cell membrane, and dissolving of inner structures, with increased treatment duration. Flow cytometry showed significant difference of tachyzoite survival rate at 2, 4 and 6 h after hypericin treatment with that of the control group（P<0.01）. The survival rate of group C at 2 h after hypericin treatment was（7.9±1.9）%, significantly lower than that of groups B ［（38.1±5.5）%ï¼½ and A ［（81.8±6.0）%ï¼½ （P<0.01）. No tachyzoite was found to survive in group D at 2 h and in group C at 4 h. The survival rate of group B at 4 and 6 h after hypericin treatment was（14.3±7.9）% and （1.4±1.8）%, respectively, both significantly lower than that of group A［（73.8±11.3）% and（64.1±14.4）%, respectivelyï¼½ （P<0.01）. Conclusion: Hypericin has a remarkable killing effect on T. gondii tachyzoites, and the efficacy positively correlates with the dose and treatment duration.

[Survey and treatment of pulmonary acariasis among the workers involving in traditional Chinese medicinal materials].

OBJECTIVE: To investigate the prevalence of pulmonary acariasis among the employees working on traditional Chinese medicinal materials and observe the effect of treatment. METHODS: History inquiry, detection of mites in sputum, blood examination for eosinophils and specific antibodies, x-ray chest film were carried out for 327 workers involving in traditional Chinese medicinal materials. Mites were found in sputum in 121 persons who were then treated with metronidazole, twice a day with a daily dosage of 0.8g for seven days as a course of treatment. Two courses were conducted with an interval of 7-10 day. Prevalence and morbidity in different groups of occupation, age, and sex were analyzed. RESULTS: The overall infection rate of mites in sputum was 37.0% (121/327) with an average morbidity of 12.5% (41/327). Among the four types of worker investigated, the highest infection rate (51.8%), and morbidity (18.6%) were in those working in transfer warehouse; the second highest infection rate (40.7%) and morbidity (15.7%) were in employees in factory of Chinese traditional medicine. Both groups showed a significant difference with others (chi2inf=11.36, P< 0.01; chi2inc=11.36, P<0.01). Higher morbidity was found in the middle-aged ones and those with more years of service. No difference was found between males and females (chi2=0.31, P>0.05). After treatment with metronidazole, 88.4% showed negative in sputum examination for mites and the efficacy of the treatment for pulmonary acariasis was 92.3%. CONCLUSIONS: Employees engaged in traditional Chinese medicinal materials are one of the groups at the highest risk of pulmonary acariasis. Metronidazole is effective in treating the infection.

[Studies of di-n-butyl phthalate-OP emulsion in the treatment of demodicidosis].

OBJECTIVE: To observe the curative effect of di-n-butyl phthalate-OP emulsion in the treatment of demodicidosis. METHODS: 447 cases with Demodex infection on face were treated with di-n-butyl phthalate-OP emulsion. Among them, 30 cases suffering from acne, tetter and pustule were also randomly observed. 20 days after treatment negative conversion rate and the therapeutic effect were evaluated. At the same time, the effect of this solution was compared with that of other three medicaments (FuManLing, 2% metronidazole and 8% metronidazole preparations). In vitro test of mites-killing, toxicity test in experimental animals and the safety evaluation for local application were also performed. RESULTS: Results showed that the negative conversion rate was 92.8% (415/447), effective rate for the cases showing evident face damage was 90.0% (27/30). The result also indicated that the OP emulsion medicament was more effective than other three medicaments (P < 0.01). In vitro test showed that this medicament killed all mites within 1 hour. Toxicity test in animals showed that its LD50 was in safe range. It showed no evident stimulation and hypersensitivity by local use. CONCLUSION: Di-n-butyl phthalate-OP emulsion is promising to be developed as a safe, effective therapeutic medicament on demodicidosis.