The aim of this study was to determine the differences in phototaxis between Oncomelania hupensis (O .h .) hupensis and O .h .robertsoni as well as four related geographic strains of male and female snails and Schistosoma japonicum-infected and-uninfected snails .Field collection of O . hupensis was performed in S . j aponicum-endemic areas of Xingzi and Yushan counties in Jiangxi Province ,China ,as well as Tianquan and Pengshan counties in Sichuan Province ,China .Infected and uninfected snails were screened using the cercariae escaping method ,with artificial separation of male and female snails . The experiment was carried out in an in-house constructed dark phototaxis experiment box using white light as the main source of light at the most suitable light intensity .Under a light intensity of 1 500 Lux for 30 minutes ,all of the snails from the experimental group showed obvious phototaxis .The statistical analysis showed no significant difference in the phototaxis index between male and female snails ,and there was also no significant difference in the phototaxis index between different geograph-ical strains of the same subspecies of snails .A significant difference in phototaxis was observed between the two subspecies during the 30-minute experimental period :O .h .hupensis displayed a higher phototaxis index than that of O .h .robertsoni , whereas S .japonicum-infected snails showed a lower phototaxis index than that of uninfected snails .A difference in phototaxis was found between different subspecies of O .hupensis and within the same subspecies .All uninfected snails displayed the same phototaxis index .When snails were infected with S .japonicum ,phototaxis reduced .

Objective To investigate the effect of CXCL12 on the secretion of CXCL8 from colon cancer cells and the mechanism of co-regulation of proliferation and metastasis of colon cancer.Methods The expression levels of CXCL8 and CXCl12 in 5 human colon cancer cell lines (DLD-1,HT29,WiDr,CaCo-2,Colo320),fibroblasts,and human umbilical vein endothelial cells (HUVEC) were studied by Western blotting,respectively.ELISA,proliferation and invasion assay were used to explore the role of CXCL12 and CXCL8 for metastatic process of colon cancer and interaction between colon cancer cell and stromal cell in the microenvironment,respectively.Results The expression of CXCL8 was detected in all colon cancer cell lines,fibroblasts and HUVEC,while CXCL12 was expressed only in DLD-1 cell and fibroblast.The secretion level of CXCL8 in CaCo-2,WiDr,HT-29 and HUVEC (2.54-fold vs.control,2.07-fold vs.control,1.87-fold vs.control,2.79-fold vs.control) was enhanced by CXCL12 that derived from fibroblasts(P ＜ 0.01).CXCL8 could significantly promote the proliferation,migration of HUVEC (P ＜0.01).CXCL8 and CXCL12 enhanced proliferation of HUVEC (P ＜ 0.01),invasion of HUVEC and HT-29 (P ＜ 0.01) in a concentration-dependent manner.Conclusion Fibroblasts derived CXCL12 enhanced the CXCL8 secretion in colon cancer cells,and CXCL8 and CXCL12 can promote the proliferation and invasion of colon cancer cells.

Objective To investigate the expressions of PGE2 and COX-2 between colorectal cancer tissue and normal colorectal mucosa tissue,and its relation to clinical pathology and significance.Methods 115 colon cancerous tissues and 69 normal colon tissues were collected in our hospital from Jan 2010 to Sept 2011.Immunohistochemistry was used to detect the PGE2 and COX-2 expression in both of the colorectal cancer and normal tissues.Results Positive expressions of PGE2 and COX-2 were 87.8％ (101/115) and 80.9％ (93/115) in the colorectal cancer tissue,and 8.7％ (6/69),21.7％ (15/69) in normal colorectal mucosa tissue respectively (x2 =110.96,62.194,all P ＜ 0.05).Expressions of PGE2 and COX-2 were closely associated with,tumor invasion,differentiation,lymph node metastasis and TNM stage (P ＜ 0.05).The Spearman rank correlation analysis indicated that the PGE2 and COX-2 expressions in tissues were closely correlated (r =0.987,P ＜ 0.05).Survival rate of the patients in both negative expressions of PGE2 and COX-2 (63.6％) were higher than that of both positive expressions (37.8％,P ＜ 0.05).Conclusion High PGE2 and COX-2 expressions in colorectal cancer tissues predicts poor patients' survival.