Regulatory role of interleukin-10 and interferon-gamma in severe hepatic central and peripheral fibrosis in humans infected with Schistosoma japonicum.

BACKGROUND: Schistosoma japonicum is the most pathogenic agent of hepatosplenic schistosomiasis. It causes fibrosis of the central (CentF) and peripheral (PerF) portal areas. We investigated whether CentF and PerF in Chinese fishermen infected with S. japonicum were associated with an abnormal production of cytokines and chemokines that, in experimental models, have been implicated in the regulation of fibrosis. METHODS: Cytokines were measured by enzyme-linked immunosorbent assay in cultures of peripheral blood mononuclear cells from 127 patients, after stimulation with S. japonicum egg antigens. Data were analyzed by logistic regression that included age, sex, number of treatment episodes, alcohol use, and exposure as covariates. RESULTS: CentF was associated with low levels of interleukin (IL)-10 (P= .0004), regulated on activation normally T cell expressed and secreted (P= .0004), and macrophage inflammatory protein-1alpha (P= .007). In a multivariate analysis, only IL-10 was associated with CentF (odds ratio [OR], 10.8; 95% confidence interval [CI], 3.2-38; P= .0004). Splenomegaly was also associated with low IL-10 production and, independently, with CentF. In multivariate analysis, PerF was associated with low production of interferon (IFN)-gamma (OR, 8.2; 95% CI, 2-33; P= .0035) but not with production of IL-10. CONCLUSIONS: IL-10 is associated with protection against central fibrosis, because of its anti-inflammatory and antifibrosis effects. IFN-gamma is associated with protection against PerF, which depends more on egg load and egg-associated toxicity.

STUDIES ON MOLLUSCICIDING ACTION OF STREPTOMYCES DIASTATOCHROMOGENES / 中国血吸虫病防治杂志

A strain of actinomyces (named as 218 powder) was seperated from snail-inhabitated soil and was identified as streptomyces diatatochromogenes. The corrected mortality rate of snails exposed to 0. 1 % concentration of the shaking fermentation liquid was 96% -100%, and that of the snails exposed to 10 mg/L of 218 powder as industrial product for 48 h in the laboratory was 98.0%. The hatching rate of snail eggs exposed to 100 mg/L of the bacterial powder for 48 h was 9. 0%. The corrected mortality of snails exposed to 75 mg/L of bacterial powder for 48 h in the field was 96. 9%, and this biological molluscicide did not damage plants but had some slow acting toxicity to fish.

STUDY ON ERYTHROCYTE IMMUNE FUNCTION OF RABBITS WITH SCHISTOSOMA JAPONICUM INFECTION / 中国血吸虫病防治杂志

0.05), and the all had significant differences in 2 to 4 months post-infection compared with the normal controls (P

EXPERIMENTAL STUDY ON SUSCEPTIBILITY OF PRAZIQUANTEL AGAINST SCHISTOSOMA JAPONICUM IN REPEATED CHEMOTHERAPY AREAS IN DONGTING LAKE REGION / 中国血吸虫病防治杂志

Objective To explore susceptibility of praziquantel(PQT) against Schistosoma japonicum in the repeated chemotherapy areas in Dongting Lake region of China. Methods Sixty mice were divided into two groups, and infected respectively by cercariae released from the infected snails which were collected from new and old endemic areas. After 5 weeks, the mice in each group were divided into control groups and treatment groups (PQT group). The mice in each PQT group were treated with a single oral dose of praziquantel (600 mg/kg). Three weeks post treatment, mice were dissected, and the number of adults, the stool eggs per gram (EPG), the liver EPG and the hatching rates were observed. Results The worm reduction rates of the PQT groups of new and old epidemic areas were 98.24% and 98.71% respectively, and the stool egg reduction rates 99.94% and 99.64%, the liver egg reduction rates 75.85% and 73.10%,and there were no significant differences between the new and old endemic areas. The stool hatching test was positive in the control groups, and negative in the PQT groups. Conclusion Susceptibility of praziquantel against Schistosoma japonicum does not decrease in repeated chemotherapy areas in Dongting Lake region.