Schistosoma japonicum Katsurade is a major threat to the heath of Chinese people and prevent social economies ...
Wan-xian WANG,Yi YANG,Yong ZHANG,Qian CHEN,Xu LIU,Xiu-li XIANG,Hui-dong JIANG,Wen CHEN and Wei-lin YUN Institute of Biology and Science,Hubei University,Wuhan 430062,China
This paper has analyzed allelopathic effects ofNerium indicum on Oncomelania hupensis through triterpene sapogenins, a potential molluscicide. The snails were treated under six various concentrations （0, 20, 40, 60, 80, 100 mg/L） of triterpene sapogenins and five periods （1, 2, 3, 4, 5 days）. The mortality of snails was positively correlated with the concentration of triterpene sapogenins and exposure time. The results ofprobit analysis showed that the LD50 （Lethal Dose, 50%） oftriterpenoid saponins from N. indicum by immersion for 2, 3, 4, 5 days were 78.31, 30.26, 20.50, 14.19 mg/L, respectively. And the corresponding 95% confidence intervals were 63.60-108.19, 9.49-44.42, 2.86-30.90, 0.23-22.79 mg/L, respectively. The observations of both scanning electron microscope and transmission electron microscope proved that 40 mg/L triterpene sapogenins could cause apparent damage to the structure of soft tissue, liver and intestine of O. hupensis. The esterase （EST） isozyme electrophoresis in liver of O. hupensis treated by 40 mg/L of the concentrations lixivium of the triterpene sapogenins from N. indicum was analyzed for 24, 48, 72, 96, 120 h, respectively. The activity of enzyme was higher than control water group after been treated up to 24-48 h, and then lowered and disappeared after 72 h. It was implicated that the extracted triterpene sapogenin from N. indicum were promising for controlling the snail, which were also providing the foundation for constructing plant community of oleander to control O. hupensis.
The expression vector of anti Hantavirus(HV) capsid protein scFv was constructed by DNA recombination and PCR technique,and expressed in E.coli . The expressed scFv was fused with the phage GeneⅢ protein, and located on the surface of phage.The sequencing of scFv demonstrated that the sequence of scFv is consistent with that of cloned antibody variable region from F3 strain hybridom against HV capsid protein.The expressed scFv was proved to be able to bind HV antigen by ELISA.
