Whether conventional hypothermic CPB induces myocyte apoptosis in dog hearts and modulation of bcl-2, bcl-xl, bax, bad, and caspase-3 pathways in this setting was investigated. Ten healthy adult dogs were randomized into sham-operated and CPB groups. Samples of left ventricle were obtained before, during and 3 h after CPB. In situ TUNEL was used to detect apoptotic myocytes. Immunohistochemistry and flow cytometry were employed for detection of expressions of bcl-2, bcl-xl, bax and bad proteins. Z-DEVD-AMC substrate cleavage and TBARS methods were used to measure the activity of caspase-3 and the content of lipid peroxide in LV myocardium, respectively. After CPB, the number of apoptotic myocytes in CPB group was significantly increased. The results of immunohistochemistry demonstrated that bcl-2, bcl-xl, bax and bad proteins were constitutionally present on the sarcolemma of the LV myocytes. FACS results showed that, after CPB, expressions of bax and bad in CPB group were significantly upregulated, while the expressions of bcl-2 and bcl-xl were not significantly changed in both groups. The activity of caspase-3 and the content of lipid peroxide in LV myocardium in CPB group were also significantly increased after CPB. The present study shows that there exists myocardiocyte apoptosis in dog hearts undergoing conventional hypothermic CPB and the myocyte apoptosis is initiated by ischemia and performed during reperfusion. Moreover, the CPB-induced myocyte apoptosis was associated with upregulation of expressions of bax and bad proteins, activation of caspase-3 and increase of oxidative stress.
Animals ; Apoptosis ; Cardiopulmonary Bypass ; Caspases ; metabolism ; Dogs ; Female ; Hypothermia, Induced ; Lipid Peroxidation ; Male ; Myocytes, Cardiac ; metabolism ; pathology ; Proto-Oncogene Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; genetics ; metabolism ; Random Allocation ; bcl-2-Associated X Protein

Objective To investigate the effect of manually reverse mixing times on erythrocyte sedimenta-tion rate(ESR).Methods The ESR samples of 200 subjects were manually mixed for 3,6,9,12 and 15 times before detection.The ESR results of each group were collected,and the samples were manually mixed for 12 times as the reference standard.R(4.2.1)software was used for data analysis,Shapiro-Wilk was used for normal distribution test,Friedman test was used for multi-group comparison,and Spearman correlation analy-sis was used to analyze the correlation between different manually reverse mixing times and ESR.Results Be-fore specimen analysis,200 subjects were divided into 5 groups according to the manually reverse mixing for 3,6,9,12 and 15 times.The median ESR of each group was 13.0,11.5,11.0,8.0 and 11.0 mm/h in turn.Friedman test showed that there were significant differences in ESR results among the 5 groups(P＜0.05).There were significant differences in ESR results between manually reverse mixing for 3 and 6 times and man-ually reverse mixing for 12 times(P＜0.05).Spearman correlation analysis showed that there was a negative correlation between the manually reverse mixing times and ESR(r=-1.000,P=0.017).Conclusion Speci-mens can be fully mixed by manually reverse mixing for 9 times.Too few times of manually reverse mixing can lead to high ESR.Clinical laboratories should pay attention to the pre-treatment of specimens to ensure the quality of the whole test process.