AIM To establish a new, simple, stable and classical experimental model of acute edematous pancreatitis. METHODS Male mice were injected intraperitoneally 2?200 mg?(100 g) -1 body weight of L-arginine in an 1 h interval, as a 20% solution in 0.15 mol?L -1 NaCl. Control mice received the same quantity of 0.15 mol?L -1 NaCl. The mice were killed at 6, 12, 24, 48, 72 h following L-arginine administration. The serum amylase level, wet/dry weight ratio of the pancreas, histologic were assessed. RESULTS The serum level of amylase was significantly elevated at 6 h,reached the peak level at 24 h, normalized at 72 h. Histologic examination revealed interstitial edema and inflammatory cell infiltration reached the peak level at 24 h and decreased at 48,72 h. The wet/dry weight ratio of the pancreas changed in accordance with the interstitial edema. CONCLUSIONS The present study has demonstrated that the administration of excessive doses of arginine induces a new, noninvasive experimental model of acute edematous pancreatitis.

[ ABSTRACT] AIM:To investigate the effect of phycocyanin on the apoptosis of human laryngeal cancer HEP-2 cells and to explore the inhibitory mechanism of phycocyanin to tumor.METHODS:Highly purified phycocyanin was ex-tracted from spirulina.The effects of phycocyanin at different concentrations on the growth of human laryngeal cancer HEP-2 cells were detected by MTT assay.In addition, the cell structures were observed under electron microscope.The cell ap-optosis was analyzed by flow cytometry.The production of reactive oxygen species ( ROS) was measured by flow cytometry. Enzymatic activities of caspase-3,-8 and-9 were measured by chemical colorimatry.The expression of Bax, Bcl-2, Fas, P53, caspase-3 and caspase-9 at mRNA and protein levels was determined by RT-PCR and Western blot.RESULTS:MTT test confirmed that phycocyanin inhibited the cell activity of HEP-2 cells with time and dose dependent manners.The result of electron microscope observation and flow cytometry indicated that phycocyanin induced the apoptosis of HEP-2 cells.The intracellular content of ROS was increased.The activities of caspase-3, -8 and -9 were increased.RT-PCR showed that the mRNA expression of Bax, Fas, P53, caspase-3, caspase-9 was increased and Bcl-2 was decreased.The results of Western blot were consistent with the results of RT-PCR.CONCLUSION:Phycocyanin might induce apoptosis of HEP-2 cells by down-regulating Bcl-2, up-regulating Bax, Fas and P53, and the transduction of apoptotic signals in the human laryngeal cancer cells.

Objective To find out current distribution of Oncomelania snails and Schistosoma infection in snails in Zhejiang Province, so as to improve the project of schistosomiasis control. Methods Investigation spots were selected by stratified cluster sampling method, 100 villages of 34 counties were selected from 7 106 villages of 55 counties as survey spots. Synchronously systematic and environmental samplings were used for the survey. Snails were dissected to determine the infection status and spots with sham snails were set to assess the quality of the survey. Results The result showed that snails were found in 223 strips, 1 572 frames and 73 300 m 2 area in 32 villages of 21 counties. Snails were found in an area covering 72 640 m 2 in 29 villages of 18 counties in hilly region, which accounted for 99.1% of total snail habitats. The significantly larger area with snails was revealed in hilly region than that in water network region (t=3.04, P