The effects of let-7c-1 on the learning and memory of epileptic rats induced by PTZ / 中国神经精神疾病杂志

Objective To explore the effect of let-7c-1 on the learning and memory of PTZ-induced epileptic rats and its relevant mechanism.Methods A model of temporal lobe epilepsy (TLE) was induced via PTZ kindling in SD male rats.The epileptic rats were divided into epilepsy group,agomir-control group,let-7c-1 agomir group (12 rats for each).Twelve rats were served as a negative control group.The behavior and the expression levesl of let-7c-1,Bcl-2 protein and Caspase3 were evaluated at 28 days following PTZ.Results Compared to the negative group,the escape latency of epilepsy group was prolonged and the crossing times as well as the quadrant total distance in the target were reduced (P＜0.05).However,those parameters were not significantly different between the epilepsy group and the agmoir-control group (P＞0.05).Compared to the agmoir-control group,the escape latency of let-7c-1 agomir group was prolonged and the crossing times as well as the quadrant total distance in the target were reduced (P＜ 0.05).The expression levels of let-7c-1 and let-7c-1 were 1.35±0.32 in agmoir-control group and 62.53±21.01 in agomir group (F=50.97,P＜0.05).The expression levels of let-7c-1 were higher in let-7c-1 agomir group than in other groups (P＜0.05).Compared to the negative group,the expressions of Bcl-2 protein in other groups were decreased (P＜0.05) and the Caspase3 protein were increased (P＜0.05).Compared to the agomir-control group,the expression of Bcl-2 protein was significantly decreased and the expression of Caspase3 protein was significantly increased in let-7c-1 agomir group (P＜0.05).Conclusions The present study shows that let-7c-1 may impair the learning and memory of PTZ-induced epileptic rats through decreasing the Bcl-2 protein and increasing Caspase3 protein in the hippocampus.

Cell-specific roles of domains I and II of HCV 5'untranslated region in the translation initiation activity / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the roles of Domain I and Domain II of hepatitis C virus (HCV) 5' untranslated region (UTR) in the translation initiation activity of HCV 5'UTR in different host cell lines.</p><p><b>METHODS</b>The eukaryotic expression plasmid pCMVNCRLuc (pCN1), in which full-length HCV 5'UTR regulates firefly luciferase expression, was modified by deleting Domain I and the downstream single-stranded sequence (43 bp in total) from the UTR (pCNl-d2), Domain I with the downstream single-stranded sequence and Domain II (118 bp in total) from the UTR (pCNl-d3), or the total UTR (pCNl-d5). The modified plasmids were transfected via liposome into different cell lines with pRL-TK plasmid co-transfected as the normalization control. At 36 h after the transfection, the total cellular RNA was harvested for semi-quantitative RT-PCR, and the relative expression activities of luciferase were assayed with a dual luciferase reporter gene assay system. The translation initiation activities of the truncated HCV 5'UTRs in different translation systems were analyzed.</p><p><b>RESULTS</b>Deletion of Domain I and the downstream single-stranded sequence caused no significant changes of the translational activity of HCV 5'UTR in Hela or C6 cells, but decreased the translational activity by 46% in L-02 cells and increased the translational activity by 46% in 293T cells. Deletion of both Domain I and Domain II resulted in decreased translational activity of HCV 5'UTR by 51% in HeLa cells, but increased the translational activity by 40% in L-02 cells, 60% in C6 cells and 135% in 293T cells.</p><p><b>CONCLUSIONS</b>Domain I and Domain II of HCV 5'UTR perform cell type-specific roles in HCV IRES-driven translation initiation.</p>

Detection of Salmonella in Food with Phage / 昆明医科大学学报

Objective To investigate the pollution condition of Salmonella in food with phage. Methods Salmonella in 413 samples of food were detected by the diagnosis of Salmonella phage with biochemical and serological identification. Results 119 Salmonella were detected in 99 positive samples and the isolating rate was 24%. Conclusion The disservice of Salmonella is mainly from the meat food and eggs. The detection method of phage is fast,convenient and reliable.

Construction and expression of anti-clenbuterol single chain Fv recombinant vector / 生物工程学报

To construct the recombinant vector pBV220-scFv and express anti-clenbuterol (CBL) scFv antibody in Escherichia coli, we amplified the scFv gene using plasmid pCANTABSE-CBL as a template, recombined it with pPICZalphaA, then amplified the scFv-His-tag gene from plasmid pPICZalphaA-scFv and linked it with expression plasmid pBV220. We identified the recombinant plasmid by restrictive enzyme digestion, PCR amplification and sequence analysis. Finally, we transformed the recombinant vector into E. coli DH5alpha that was temperature-induced and expressed recombinant protein. We identified the recombinant protein by SDS-PAGE, Western blotting and indirect competitive ELISA. The results show that recombinant plasmid pBV220-scFv contained the inserted fragment with highest homology about 99.8%. The expression of scFv induced by temperature show 37 kD Mw and anti-His-tag mAb recognized-activity by SDS-PAGE and Western blotting respectively, and could competitively combine with CBL, the IC50 is 4.55 ng/mL. The recombinant plasmid pBV220-scFv is constructed and expresses the scFv gene of CBL in E. coli successfully. This study suggests the corresponding immunoassay methods could be set up by the recombinant scFv.