[Analysis of karyotype and preparation of C-band and G-band in Schistosoma japonicum].

Chromosomes of Schistosoma japonicum were prepared by usual air drying method, C-band and G-band were made by modified BSG method and enzyme digestion method respectively. Results showed that the karyotype of S. japonicum was 4m + 6Sm + 4St + 2sex chromosome and the C-band formula was 2n = 5CIt + 4CI(+) + 3CI + 2CT +2CT.

[Studies on haemocytes of Oncomelania hupensis].

OBJECTIVES: To establish method for collecting haemocytes of Oncomelania hupensis and study its morphology and immunological importance. METHODS: Referring to the method of haemocytes collection from peripheral lymphoid organ, suspension technique was used for collection of haemocytes from snails, which were then Giemsa-stained and observed under microscope. Stained by gentian violet, number of haemocytes was counted and compared with that of conventional squashing method and needling method by ANOVA and Dunnett-t test. Supernatant from freeze thawing haemocytes was applied for the tests of immuno-precipitation, bacteriostasis, and phagocytosis. SDS-PAGE was used to analyze relative molecular mass of protein ingredients. RESULTS: Four kinds of haemocytes were found: round cells with filiform filopodia, acidophilic and basophilic round cells both without filiform filopodia, and spindle cells. The average diameter of the 4 type cells was 10.93, 6.13, 6.08, and 11:06 microm, and occupied 50%, 30%, 5%, and 15% respectively. The mean of haemocytes received from suspension, squashing and needling methods was 15 000, 6 600 and 300/ml respectively. ANOVA analysis showed F=281.47, P<0.01, and Dunnett-t test revealed t1=15.67, P<0.01 between suspension and squashing methods, and t2=24.50, P<0.01 between suspension and needling method. The supernatant of haemocytes showed precipitation with SEA, bacteriostasis with Staphylococcus aureus and Escherichia coli, and 86% phagocytosis and 46% bactericide to Candida albicans. SDS-PAGE revealed approximate Mr 112 300, 107 100, 972 00, 73 500, 600 00, 12 000 of the protein ingredients of the haemocytes. CONCLUSIONS: Large amount of haemocytes has been obtained from the snails by suspension method, and the cells show immunological activities.