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BACKGROUND:Mesenchymal stem cels can differentiate into cardiomyocytesin vitro induced by different methods, such as chemical drug induction, autologous transplantationin vivo, andin vitro simulation of cardiac-like microenvironment, but these inducible methods show low induction rate, complex operation, and toxic side effects. OBJECTIVE:To investigate the role of H9C2 cellculture medium in the differentiation of mesenchymal stem cels into cardiomyocyte-like cels. METHODS: Mesenchymal stem cels were obtained by the whole bone marrow adherent culture and H9C2 cellculture medium was prepared as a culture medium. Then mesenchymal stem cels were co-cultured with H9C2 cellculture medium for 1, 3, 5, 7 days. H9C2 cels cultured in 10% Dulbecco’s modified Eagle’s medium/Ham’s nutrient mixture F-12 served as positive control groups, while mesenchymal stem cels cultured in 10%Dulbecco’s modified Eagle’s medium/Ham’s nutrient mixture F-12 as negative control group. Immunofluorescence and western blot assay were used to detect expression of myocardial celljunction protein (desmin) and troponin T. Real-time quantitative PCR was applied to detect mRNA expression of myocardial celltrait genes, α-cardiac myosin heavy chain and β-myosin heavy chain. RESULTS AND CONCLUSION:After co-culture of H9C2 cellculture medium and mesenchymal stem cels for 7 days, the troponin T positive cels were up to (16±7)%, which was significantly higher than that of non-induced mesenchymal stem cels. Compared with the negative control group, the expression of troponin T protein and desmin after induction were significantly increased (P < 0.05) by western-blot detection; real-time PCR showed that the mRNA expression ofα-cardiac myosin heavy chain and β-myosin heavy chain in differentiated cels were both up-regulated (P < 0.05). These findings suggest that H9C2 cellculture medium may induce the differentiation of mesenchymal stem cels into cardiomyocyte-like cels.
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BACKGROUND:The treatment of autologous pericardium transplantation has been widely applied in clinics, mainly involving cardiovascular repair and reconstruction, the treatment of ocular surface disease. The study addressing protection effects of autologous pericardium transplantation on the heart with ischemia injury is rarely reported. The investigations on the safety and protection effects of autologous pericardial transplantation on the heart with ischemia injury are of important significance. OBJECTIVE:To explore effect of autologous pericardial transplantation on cardiac electrical activity and the protective effects on myocardial ischemia. METHODS:Rongchang pork pigs and Sprague-Dawley rats were randomly divided into three groups:autologous pericardium transplantation, myocardial ischemia, and myocardial ischemia+autologous pericardium transplantation. The model of myocardial ischemia was established by ligation of the left anterior descending coronary artery in the groups of myocardial ischemia and myocardial ischemia+autologous pericardium transplantation. The model of transplantation was established by autologous pericardium transplant with flap in the groups of autologous pericardium transplantation and myocardial ischemia+autologous pericardium transplantation. RESULTS AND CONCLUSION:Porcine electrocardiogram monitoring results showed that, superventricular premature beat was frequently observed in each group of pigs;the ventricular premature beat was occasional observed in autologous pericardium transplantation group, ventricular tachycardia and ventricular fibril ation did not appear. Compared with myocardial ischemia group, the ventricular premature beat decreased and the heart function was improved in myocardial ischemia+autologous pericardium transplantation group (P<0.05). Rat electrocardiogram monitoring results showed that, the ventricular fibril ation did not appear in autologous pericardium transplantation group, the lethal ventricular fibril ation did not appear in myocardial ischemia and myocardial ischemia+autologous pericardium transplantation groups. Compared with myocardial ischemia group, the heart function was improved, the apoptosis index decreased, the expressions of Bcl-2 protein increased, the expressions of Caspase-3 protein decreased in myocardial ischemia+autologous pericardium transplantation group (P<0.05). The autologous pericardium transplantation with flap cannot induce malignant ventricular arrhythmia and is relatively safe;the ventricular premature beat is reduced, the cardiac function is improved, which is possibly related to the inhibition of apoptosis in myocardial ischemic area.
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BACKGROUND: Electrical stimulation at different intensity, frequency and time on the human body may produce a variety of pathophysiological reactions. OBJECTIVE: To observe the effects of surface electric-impulse stimulation on heart rhythm and heart rate in mice. METHODS: Thirty Kunming mice were randomly divided into three groups, each group contained 10 mice. Electrical stimulation at different voltage, time and frequency was respectively applied to the three groups. The stimulus power was supplied by BL-420F Data Acquisition & Analysis System. The II lead electrocardiogram was recorded. The systemic reactions and local body changes of mice were observed.