Effects of Local Pancreatic Renin-Angiotensin System on the Microcirculation of Rat with Severe Acute Pancreatitis

Severe acute pancreatitis (SAP) is normally related to multiorgan dysfunction and local complications. Studies have found that local pancreatic renin-angiotensin system (RAS) was significantly upregulated in drug-induced SAP. The present study aimed to investigate the effects of angiotensin II receptors inhibitor valsartan on dual role of RAS in SAP in a rat model and to elucidate the underlying mechanisms. 3.8% sodium taurocholate (1 ml/kg) was injected to the pancreatic capsule in order for pancreatitis induction. Rats in the sham group were injected with normal saline in identical locations. We also investigated the regulation of experimentally induced SAP on local RAS expression in the pancreas through determination of the activities of serum amylase, lipase and myeloperoxidase, histological and biochemical analysis, radioimmunoassay, fluorescence quantitative PCR and Western blot analysis. The results indicated that valsartan could effectively suppress the local RAS to protect against experimental acute pancreatitis through inhibition of microcirculation disturbances and inflammation. The results suggest that pancreatic RAS plays a critical role in the regulation of pancreatic functions and demonstrates application potential as AT1 receptor antagonists. Moreover, other RAS inhibitors could be a new therapeutic target in acute pancreatitis.

Activity of CDK1 in S phase cell checkpoint / 肿瘤研究与临床

Objective To investigate the phosphorylation and dephosphorylation of CDK1 based on the specific cell cycle apoptosis in Molt-4 cells and active variety of CDK1 in cell cycle specific apoptosis.Methods The exponential phase of growth Molt-4 cells (the human acute lymphoblastic leukemia cell line) were induced with dose response and time course of Camptothecin (CPT).The specific cell cycle apoptosis was detected with API method,then cell apoptosis was verified with post sorting confocal method.Meanwhile,the phosphorylation and dephosphorylation of CDK1 were detected by the protein electrophoretic analysis (Western blot).Results The specific cell cycle apoptosis occurred on exponential phase of growth Molt-4 cells after CPT treatment.When Molt-4 cells occured S-phase apoptosis, the apoptosis cell phosphorylation of CDK1-Thr161 band was more narrow than that of control cells, the apoptosis cell phosphorylation of CDK1-Thr15 band almost had the same band with control cells.Conclusion Cell apoptosis frequently developed in different cell cycle phase. API assay is quick and efficient method to analyze specific cell cycle apoptosis. When cell apoptosis take place in S-phase,the phosphorylation activity of CDK1 is inhibited.

Empirical study on the apoptosis of gastric cancer cells induced by taxol / 肿瘤研究与临床

Objective To investigate apoptosis of gastric cancer cells induced by taxol,and its specific apoptotic cell cycle phase. Methods The apoptosis rate of gastric cancer cell line MKN-28 induced by taxol was detected with Sub-G1 method.The specific apoptotic cell cycle phase Was detected with API and PSC method.The sensitivity of 20 cases clinic gastric cancer specimens induced by taxol was detected with the method MTT.Results With the Sub-G1 method the MKN-28 cells were induced by 10 μg/ml taxol,after 10 h,the apoptosis rate reached its top apex;with the API method and the PSC method,the specific apoptosts took place in G_2/M phase;the chemotherapy sensitivity of 16 cases out of 20 cases clinic gastnc cancer specimens exceed 50%with the method MTT. Conclusion Taxol could induce gastric cancer cells to aimptosis and the apoptosis takes place in G_2/M phase;Taxol is sensitive to clinic gastric cancer speclmens.

Effect of survivin shRNA on chemotherapy resistance in GBC-SD cells / 中华肝胆外科杂志

Objective To investingate the effect of survivin shRNA on chemotherapy resistance in GBC-SD cells. Methods They were divided into three groups of GBC-SD, GBC-SD/EGFP and GBC-SD/survivin. MTT assay was used to detect cell viability in the 3groups. mRNA and protein of survivin were tested by RT-PCR and Western blot. Then the cells were treated with proper construction DDP. The cell survival rate and IC_(50) were determined with MTT, cell apoptosis detected by FACS and the alteration of nucleus observed by TUNEL. Meanwhile, caspase-3 activity was determined using the colorimetric method. Results Cell viability was reduced remarkably in GBC-SD/survivin and survivin expression was decreased obviously. After being treated with DDP, cell survival rate and IC_(50) were decreased obviously in GBC-SD/survivin, apoptotic rate elevated remarkably compared with other groups. There were brownly nucleuses in three groups. Caspase-3 activity increased first and then decreased, but it exceeded in GBC-SD/survivin than that in other two groups. Conclusion The survivin shRNA can down-regulate the expression of survivin in GBC-SD cells remarkably and improve the sensibility to chemotherapy.

Dual effect of Molt-4 cell lines onset with Roscovitine / 肿瘤研究与临床

Objective To investigate the effect of Mlot-4 cells onset with Roscovitine (ROSC)as some Cyclin-dependent kinases(CDK),inhibitor.Methods The logarithmic growth phase Molt-4 cells treated with ROSC at a final concentration ranging between 1～20 μmol/L and harvested in different time point,DNA assay of single cells by flow cytometry was used to detect the effect of cell cycle arrest and Annexin-V/FITC assay was used to detect the effect of cell apoptosis. Results It showed that ROSC exerted strong inhibitory effect on proliferation and cell cycle progression of Molt-4 Accumulation of G2/M arrested cells starting 6 h after onset of 10 μmol/L and 20 μmol/L ROSC;at the same time,the cell apoptosis of Molt-4 would be detected,According with the time and concentration changing,the cell apoptosis rate would rise.Conclusion It is concluded that Roscovitine(ROSC)as some Cyclin-dependent kinases(CDK),inhibitor,It has dual effects to Molt-4 cells,not only the effect of cell cycle arrest but also the effect of cell apoptosis.