Résumé
Objective To investigate the role of andrographolide (AP) in protection of carbon tetrachloride (CCl4)-induced acute liver injury in mice and the possible mechanisms. Methods The mice were randomly divided into five groups, including two groups with different doses of AP (50 mg/kg and100 mg/kg), a control group, a CCl4 model group, and a silymarin group. Serum levels of alanine aminotransferase (ALT), aspartateminotransferase (AST), hepatic malondialdehyde (MDA), and glutathione (GSH) were examined. Pathological changes in the liver were observed. RT-PCR was used to detect the expressions of tumor necrosis factor-a (TNF-α) and heme oxygenase-1 (HO-1) mRNA. Results As compared with CCl4 model group, serum levels of ALT and AST and hepatic MDA activity were significantly decreased in AP group (100 mg·kg-1), along with a remarkable increase in hepatic GSH content. Pretreatment with AP at a high dose alleviated histopathological changes induced by CCl4. A markedly increased level of TNF-a induced by CCl4 was reduced by AP, while HO-1at transcriptional level was dramatically elevated following AP pretreatment. Conclusions AP plays a role in protection of CCl4-induced acute liver injury by inhibiting lipid peroxidation and reducing formation of free radicals, the mechanism may be involved in inhibition of TNF-αand activation of HO-1.
Résumé
Objective To evaluate the theoretical knowledge level of Chinese nursing students based on the problem-based learning(PBL)versus traditional teaching methods. Methods Databases including CNKI (1979-2013.03),VIP (1989-2013.03)and Wanfang (1982-2013.03)were searched (up to March,2013)for controlled studies comparing PBL and traditional teaching methods. The quality of included studies was critically evaluated and the data were analyzed by Stata 10.0 software. Results A total of 659 articles were retrieved but only 22 were included. Meta-analyses showed that there were significant differences between PBL and traditional teaching methods in improving theoreti-cal knowledge of nursing students(SMD merge=0.79,95%CI(0.55,1.03),P=0.000). Conclusions PBL can improve the theoretical scores of Chinese nursing students. However,the above conclusion needs to be confirmed by more large-scale randomized controlled trials of higher quality due to the limitation of studies include in this paper.