【Abstract】Objective To investigate the expressions of TNF-α and superoxide dismutase (SOD) mRNA in myocardium of rats with obstructive jaundice (OJ). Methods The expressions of TNF-α and SOD mRNA were semi-quantitatively analyzed after amplification of cDNA in myocardium of the rats with OJ by RTPCR. Results The expression of TNF-α mRNA increased and that of SOD mRNA decreased in the myocardium of rats with OJ. The level of plasm TNF-α increased and SOD synthesis in myocardium decreased. Conclusion The injury of myocardium in OJ is correlated with increasing expression of TNF-α mRNA and decreasing expression of SOD mRNA.
Abstract： Objective To investigate the effect of salvianolate on myocardium against ischemiareperfusion injury (IRI) in valve replacement with cardiopulmonary bypass (CPB), its outcome and mechanism, and the applicability and safety of salvianolate as a protection agent for CPB central muscles. Methods Thirty patients undergoing cardiac valve replacement were randomly divided into two groups by lot. In the control group, there were 15 patients including 5 males and 10 females, while in the 15 patients in the trial group, 7 were male and 8 were female. Salvianolate of 200 mg was given to the patients in the trial group intravenously. Hemodynamic parameters, blood gas analysis results, recovery of heartbeat, the dosage of dopamine used, and assisted ventilation time were recorded for both groups before aorta clamping, 2 h, 8 h, and 24 h after aorta declamping. Besides, ICU detention time, the amount of urine in 24 hours, and the amount of drainage in 24 hours after operation were also recorded. Blood samples were taken to determine serum cardial troponin I(cTnI), creatine kinase MB isoenzyme (CK-MB), malondialdehude (MDA), and superoxide dismutase (SOD) in both groups respectively at different times including after the induction of anesthesia, aorta opening, termination of CPB, end of operation, and one day after operation. Results There was no significant difference in hemodynamic parameters, the dosage of dopamine used, spontaneous recovery of heartbeat, and the amount of urine in 24 hours and drainage after operation for 24 hours between the two groups (Pgt;0.05). The rate of ventricular rhythm, blood lactic acid level, the time of assisted ventilation and ICU detention time for the trial group were significantly lower than those for the control group (Plt;0.05), while partial pressure of oxygen in artery(PaO2) was significantly lower in the trial group 8 h after aorta declamping (Plt;0.05). The levels of serum CK-MB, cTnI, and MDA after operation for both groups were higher than those before operation; and those levels for the trial group were significantly lower than the control group at various time points (Plt;0.05). The concentration of SOD decreased after operation in both groups (Plt;0.05), and it was higher in the trial group than the control group at different time points. The decrease of SOD level in the trial group was less than that in the control group. Conclusion Salvianolate can protect myocardium from ischemiareperfusion injury in cardiac valve replacement with CPB effectively, through promoting the activity of antioxidative enzymes and eliminating oxygen free radicals. Patients can be treated with salvianolate for antimyocardial ischemia reperfusion injury.
Objective To compare the effects of two kinds of cannulation sites on the myocardial oxygen metabolism during left ventricular assistance to provide experimental basis for clinical selection of proper cannulation sites. Methods Twelve mongrel dogs were randomized equally into the left atrium to aorta group （LA group） and left ventricle to aorta group （LV group）, and underwent left ventricular assistance. At different times before and during left ventricular assistance, the heart rate, coronary sinus flow rate and blood gas were determined and coronary sinus oxygen saturation, arteriovenous oxygen difference and myocardial oxygen consumption were calculated. Results There was no statistical difference of heart rate in both groups（P〉0. 05）. The coronary sinus flow rate and mean myocardial oxygen consumption reduced in both groups after left ventricular assistance, whereas the effect was more remarkable in the LV group （P〈0.01）. Conclusion Both cannulation methods could reduce the myocardial oxygen consumption during left ventricular assistance, and the effect is more apparent in left ventricular cannulation.
Objective To summarize the experience of emergency coronary artery bypass grafting(CABG) on serious myocardium ischemia in early post CABG. Methods Between 1998 and 2002, emergency redo CABG was performed in 13 patients with serious early post operative myocardium ischemia. The causes included vein graft embolize(4 cases),uncompleted revascularize(3 cases), graft spasm(1 case) and anastomose stenosis or occlusion (5 cases). The grafts was 1 3(1.8±0.9) during redo CABG. Results There were 6 deaths, the mortality was 46%. The mean follow up was 31 months. There was no recurrence of angina. NYHA function was Ⅰ Ⅱ. Conclusion Emergency CABG is an important method in saving the patients with severe myocardium ischemia in early post CABG. The perioperative prevention and early treatment should be emphasized.
Objective To investigate the molecular mechanism of multiple cellular factors expressed shortly after ischemia reperfusion (IR) injury from the pathway of nuclear factor kappa B (NF κB). Methods The isolated heart models were established and sixty six rats were randomly divided into experimental group and control group. The deoxyribonucleic acid (DNA) binding activities of NF κB, the inhibitory kappa B (IκBα) levels in cytoplasm and tumor necrosis factor α (TNF α) messenger ribonucleic acid (mRNA) expressions were determined after 5, 15 min ischemia in experimental group, both after 0, 5, 15, 30 min ischemia and concomitantly 5, 15, 30, 45, 60 min reperfusion in control group. Results Augment of DNA binding activities of NF κB and reduction of IκBα in cytoplasm shortly after ischemia results were observed in control group. The level of IκBα was restored after reperfusion, the DNA binding activities of NF κB was further augmented. DNA binding activities of NF κB and TNF α mRNA expressions were lower in experimental group than those in control group. Conclusions NF κB in IR myocardium is activated by two different pathways: p65 p50 heterodimers and p50 p50 homodimers. In addition, the results suggest that early activation of NF κB induced by ischemia in the myocardium could be a signal mechanism for controlling and regulating immediate gene expressions during ischemia reperfusion.
【Abstract】 Objective To investigate the biocharacteristics of c-kit+ human amniotic fluid-derived mesenchymal stemcells (HAFMSCs) and its capacity to differentiate into cardiomyocytes in vitro. Methods Fifty samples of human amnioticfluid were obtained from amniocenteses or voluntary termination of pregnancy and were expanded in vitro. c-kit+ HAFMSCs were sorted by flow cytometry and were recultured in the same media. c-kit+ HAFMSCs were amplified and identified, then exposed to osteogenic , adi pogenic, and myogenic media. The flow cytometry, and immunocytochemistry were used for identifying the cell phenotype, von Kossa staining for osteogenic differentiation, oil red O staining for adi pogenic differentiation, and real-time fluorescent quantitative PCR for the expressions of NKx2.5, Tbx5, GATA-4, and α-MHC genes. Results After the selection procedure, the percentage of c-kit+ HAFMSCs was 3.07% ± 1.03% of the total adherent cells. The cells expressed MSCs markers (CD29, CD44, CD73, CD90, CD105), and did not express hematopoietic stem cells markers (CD34, CD45). The cells were positive for human leukocyte antigen (HLA)-ABC, and negative for HLA-DR. They also expressed Oct-4, which characterized the undifferentiated stem cell state. The growth curves of c-kit+ HAMFSCs at passages 5, 10, and 15 were similar. Li pid droplet was observed by oil red O staining and calcium deposition by von Kossa staining in the cells at 21 days after adi pogenic and osteogenic induction. The myocardium special gene expressions of Tbx5, Nkx2.5, GATA-4, and α-MHC were significantly ber after myogenic induction than those before myogenic induction (P lt; 0.05). Conclusion Selected c-kit+ HAFMSCs by flow cytometry is a group of pure MSCs, which has potential to differentiate into cardiomyocytes and can be used as seeding cells for myocardium regeneration treatment.
Objective Endoplasmic reticulum stress (ERS) mediated apoptosis is one of the eukaryotic cellularapoptotic pathways, to investigate the potential role of ERS during myocardium apoptosis in rats with severe burninjury. Methods Sixty-four 7-week-old male Wistar rats, weighing 200-220 g, were randomly divided into 2 groups. Thirtypercentage of total body surface area full-thickness thermal injury was produced in 32 rats of burn group, while sham burn wasproduced in 32 rats of control group. The heart tissues were harvested from 8 rats in each group at 1, 4, 7, and 14 days after burnto observe the changes of myocardium ultrastructure with transmission electron microscope (TEM). Myocardium apoptosis wasdetected with TUNEL assay. The expressions of glucose regulated protein 78 (GRP 78), C/EBP-homologous protein (CHOP),and cleaved Caspase 12 in different pathways of ERS were analysed with Western blot. Results All rats survived during theexperiment. Apoptotic changes of cardiomyocytes were observed in burn group, and the apoptosis index in burn group wassignificantly higher than that in control group at each time point (P lt; 0.05), and it reached peak at 7 days after burn injury(P lt; 0.05). The expressions of myocardial GRP 78, CHOP, and cleaved Caspase 12 showed persistent elevation in burn group.The expressions of GRP 78 and cleaved Caspase 12 in burn group were significantly higher than those in control group at eachtime point (P lt; 0.05), while the expression of CHOP was higher than that in control group at the other time points (P lt; 0.05)except 1st day after burn injury. Conclusion ERS and CHOP, Caspase 12 mediated apoptotic pathway are activated inmyocardium after severe burn injury, and this may be one pathway of myocardium apoptosis.
Objective To investigate the effects of tissue inhibitor-3 of matrix metalloproteinases(TIMP-3) genetransfected vascular smooth muscle cells(VSMCs) transplantation on heart structure after acute myocardial infarction (AMI) in rats and to explore the potential mechanisms. Methods Sixty-one female Wistar rats were produced AMI models by ligating the descending left coronary artery. Fifty-four rats were survived and divided into 3 groups randomly(n=18): 0.5 ml PBS containing 1×106 TIMP-3 gene-transfected VSMCs(group A), 1×106 VSMCs(group B) or 0.5 ml PBS without cell(group C) were injected into the ischemic myocardium immediately. Ischemic myocardium samples were harvested at 1 weekafter operation. The heart structure was observed through the tissue morphologic examination. The activity of TIMP-3 gene-transfected VSMCs were measured by immunohistochemical method. Proteins of TIMP-3 and matrix metalloproteinase 9(MMP-9) were determined by Western blot. Results VSMCs were cultivated and had a high purity(98%). TIMP-3 gene was transfected into VSMCs successfully. One week after operation in groups A, B and C, the average percentage of infarction myocardium size 〖KG6〗and left ventricle free wal area were 28.73%±1.56%, 39.63%±1.84% and 46.32%±2.16% separately.Group A was significantly lower than groups B and C(P＜0.01), group B was significantly lower than group C(P＜0.01). In groups A, B and C the averageleft ventricle volume indexes were 5.27±0.21 mm3／g, 6.69±0.34 mm3／g and 9.67±0.88 mm3／g respectively. Group A was significantly smaller than groups B and C(P＜0.01), group B was significantly smaller than group C(P＜0.01). The immunohistochemical observation confirmed that the implanted VSMCs and TIMP-3 gene were survival in ischemic area. The protein content of TIMP-3 in ischemicmyocardium was significantly higher in group A (300 704.8±3 692.8) than in groups B and C(195 548.8±3 014.2，177 991.1±2 502.1)(P＜0.01), the protein content of MMP-9 in ischemic myocardium was significantly lower in group A(594 827.4±5 708.5) than in groups B and C(921 461.4±8 887.4，1 044 445.0±8 788.6)(P＜0.01). Conclusion Implanted TIMP3 gene transfected VSMCs in ischemic myocardium can conspicuously reduce the myocardium remodeling after AMI.
ObjectiveTo investigate the expression of tumor necrosis factor α(TNF-α ) in isolated rat heart at different time points after myocardial hypoxia/reoxygenation. MethodsThe isolated langendorff perfused rat heart model was established. Forty-eight SD rats were randomly divided into four groups: a sham group, hypoxia/reoxygenation groups including a H/R 0.5 h group, a 1 h group and a 2 h group. The heart rate(HR), the 1eft ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentrations of TNF-α and creatine kinase-MB(CK-MB) in myocardium, mRNA expression of TNF-α in myocardium were tested. Ultra structure of myocardium was observed under electron microscope. ResultsThe levels of LVDP, ±dp/dtmax, and HR of hypoxia/reoxygenation group were significantly lower than those in the sham group(P<0.05).The levels of TNF-α and CK-MB and the expressions of TNF-α at mRNA level in the hypoxia/reoxygenation group were higher than those in the sham group(P<0.05).There were significant differences in the above parameters among the H/R 0.5 h group, the 1 h group, the 2 h group(P<0.05).The concentrations of TNF-α and CK-MB, the mRNA expression of TNF-α were higher in the I/R 2 h group than those in the other two groups. ConclusionThe high expression of TNF-α in myocardium after myocardial hypoxia/reoxygenation in rats is related to the degree of myocardium damage and may lead to myocardial injury.
Congestive heart failure is a complication of myocardial infarction threatening human health. Although the pharmacotherapy is effective, it is still a worldwide challenge to thoroughly repair the injured myocardium induced by myocardial infarction. It has been demonstrated that mesenchymal stem cells (MSCs) can repair infarcted myocardium. Much evidence shows that MSCs can generate new myocardial cells in both human and animals' hearts. This review aims at discussing the therapeutic progress of the congestive heart failure treated with MSCs.