摘要: This paper was about the study on the mechanism of Microtus fortis against Schistosoma japonicum. Firstly, we confirmed that Microtus fortis came from epidemic region (Dongting Lake beaches) and non epidemic region (Qingtong Gorge in Ningxia province) were both resistant to Schistosoma japonicum infection after re infection tests for several times. It seemed that their resistant ability was inheritable rather than acquired. Secondly, it was demonstrated by in vivo check up and in vitro killing assay that there were some native antibodies of IgG3 subclass specifically to the schistosomula and adult worm of Schistosoma japonicum in Microtus fortis, which probably played an important role in resisting Schistosoma japonicum associated with complement. It was shown that macrophages and eosinophils in abdominal cavity of Microtus fortis had native ability of adhering to the schistosomula of Schistosoma japonicum. Then, the adult worm cDNA library of Schistosoma japonicum was screened with sera from Microtus fortis . Five positive clones were obtained, four of which were identified as new genes. Full length cDNA of the two new genes were isolated by RACE. DNA vaccine was constructed with one named EST mfs 3. After the Kunming mice immunized with this vaccine, the worm reduction rate and the egg reduction rate were 28.4% and 21.73% compared with that in control group respectively. This kind of DNA based EST mfs 3 vaccine was highly expressed in E.coli and induecd strong immune response in challenged group. Finally, two groups of cDNA probes prepared from liver and lung of Microtus fortis with or without Schistosoma japonicum infection were hybridized to the cDNA chip prepared from rat respectively. 156 and 332 genes revealed differential expression in infectious group compared with normal group. In conclusion, there would be many factors contribute to the mechanism of Microtus fortis against Schistosoma japonicum. We should stress the essentials and make further research on how to take advantage of them to defend us from Schistosoma japonicum infection.
摘要: The bio pathological changes in the closed breeding Microtus fortis (as a laboratory animal) were observed. Forty six cases of Microtus fortis were divided into 3 different age groups, and investigated by the pathological technique combined with the electron microscopey. Results showed pathologic changes of closed breeding Microfus fortis were located mainly in liver and lung with close relation to aging. Eight types of pathological changes were found. There were breast carcinoma and cryptorechism in indivignal cases. The electron microscopic characteristics of the breast carcinoma were different from that of KM mouse. Therefore, for establishing a standardized laboratory animal, it is necessary to do pathological monitoring for Micritus fortis as a routine, and then in term of the results of which the germs may be screened.
摘要: ConA(20μg/g) was injected to abdomen cavity of closed breeding Microtus fortis and after 24h Microtus fortis chromosomes was made through its marrow cells in general. The result showed there were more cells in spliting than that which was not injected in ConA (control group) to closed breeding Microtus fortis. In addition, there were no differences in shape of chromosome both the group ConA and the control group.