BACKGROUND:In 1990s,overseas researchers use balloon occlusion method for establishing closed-chest animal models of myocardial infarction. But,ventricular fibrillation and thrombosis of intraoperative factors reduce the success rate of establishing the models. Currently,there are a few reports on establishing the large animal models. OBJECTIVE:We used balloon occlusion method for establishing closed-chest swine models of myocardial infarction,and explored ways to improve the success rate of modeling. DESIGN,TIME AND SETTING:The randomized controlled animal study of pathology observation was performed at the Department of Cardiology,First Affiliated Hospital of Kunming Medical College and Research Room of Pathology,Kunming Medical College from July 2008 to May 2009. MATERIALS:Fifteen Diannan small-ear pigs weighing 19-25 kg,aged 8-11 months,were divided into three groups:sham operation group,ischemia-reperfusion group,and ischemic postconditioning group,with 5 pigs in each group.METHODS:After the coronary occlusion and reperfusion period,the prophylactic use of lidocaine (1.0-2.0 mg/kg) infusion to control arrhythmia,and use of heparin to prevent and treat the thrombosis. A balloon catheter was positioned in the distal end of the first diagonal branch of the left anterior descending (LAD) artery under fluoroscopic guidance. In the sham operation group,the balloon was only placed to the LAD,did not block coronary artery. In the ischemia-reperfusion group,inflatable balloon occlusion was done for 60 minutes in the LAD after the balloon removed. In ischemic postconditioning group,after the balloon was inflated and occluded the LAD for 60 minutes,ischemic postconditioning was elicited by eight cycles of 30-second reperfusion,followed by 30-second reocclusion.MAIN OUTCOME MEASURES:Coronary angiography,electrocardiogram (ECG) and cardiac enzymes test was conducted to evaluate models of myocardial infarction. After three days,cardiac 2,3,5-triphenyltetrazolium chloride (TTC) staining and pathological examination was done to verily myocardial infarction.RESULTS:In the sham operation group,all pigs survived. In the ischemia-reperfusion group,4 pig models of myocardial infarction were successfully established,and one died of refractory ventricular fibrillation. In the ischemic postconditioning group,models of myocardial infarction after ischemia were successfully established. Following distal left anterior descending artery occlusion,the ECG leads V13 on the ST-segment elevation,the sick rational Q-wave formed;myocardial enzyme evolution of myocardial infarction in the human body was basically the same process. The site of myocardial infarction,basically the same parts,was located in apical,left ventricular anterior wall,and the former interval. TTC staining was normal myocardium brick red,myocardial infarct area appeared pale;pathological examination revealed a normal structure of myocardial infarct damage,cytoplasm condensed,dyeing deepening,transverse striations disappeared,nuclear enrichment,dissolution,fragmentation,many erythrocytes around the infarct area with abundant granulation tissue and a large infiltration of inflammatory cells.CONCLUSION:The described model presents a less invasion to the animals,and is the closest to the process of clinical practice.Intraoperative use of lidocaine and heparin for controlling arrhythmia and thrombosis of the models is successfully established as an effective manner. Ischemic postconditioning may be one of the factors for improving the modeling success rate.

BACKGROUND: Recent trials and clinical studies have shown that intracoronary transplantation of bone marrow-derived mesenchymal stem cells (MSCs) improves cardiac function following acute myocardial infarction (AMI). However, whether homing of MSCs into the infarcted myocardium or not is still unknown.OBJECTIVE: To study the homing of MSCs intracoronary administration in porcine myocardial infarction model using in vivo magnetic resonance imaging tracking.METHODS: Porcine MSCs were isolated and cultured by the whole bone marrow method. Following labeling by superparamagnetic iron oxide (SPIO), MSCs were treated with trypsinization to adjust the concentration at 10~(10)/L. Myocardial infarction was induced in all 10 pigs. At one week after modeling, the labeled MSCs were delivered via intracoronary infusion with standard over-the-wire (OTW) balloon angioplasty catheters. Prussian blue staining was used to evaluate labeling efficiency, and double echo steady state was used to scan four-chamber and cor biloculare at long axis view, which was considered as locating phase to obtain image of left ventricle at short axis view. RESULTS AND CONCLUSION: MSCs could be efficiently and safely labeled with SPIO. Intracoronary transplantation of MSCs is able to home the sites of myocardial injury and the border between infarcted and normal tissue. MRI can track SPIO-labeled MSCs delivered through intracoronary and were confirmed on pathology. After 5 weeks the injected labeled cells could still be detected with MRI.

OBJECTIVETo determine the optimal concentration and processing time of EMS mutation for suspension cells from Pinellia ternata.

METHODUnder four EMS concentration gradients (0.1% , 0.2%, 0.4%, 0.6%) and three processing time gradients (0.5, 1.0, 2.0 h), the suspension cells of P. ternata were mutagenized.

RESULT AND CONCLUSIONThe results showed that the survival rate was significantly different under the different concentrations of EMS and the different processing time. In the same processing time, the EMS concentrations were increased, but the suspension cells survival rate decreased gradually. The optimum EMS concentration for the mutagenesis was 0.4% and the best processing time was 1 hour.

Cell Survival ; drug effects ; genetics ; Dose-Response Relationship, Drug ; Ethyl Methanesulfonate ; pharmacology ; Mutagenesis ; drug effects ; Mutation ; drug effects ; Pinellia ; cytology ; drug effects ; genetics ; physiology ; Suspensions ; Temperature ; Time Factors

OBJECTIVETo study the total RNA and mRNA differential expression in leaves of Pinellia ternata under high temperature, provide more information of the molecular mechanism of the sprout tumble.

METHODThe total RNA and mRNA differential expression in leaves of P. ternata at different stress time was analyzed.

RESULTThe results showed that the trend of total RNA content was divided into three descending stages and two ascending stages, the total RNA content was the highest at 0, 6 h, but it was the lowest at and 42 h, as well as when the sprout tumbled. The differential display showed that the polymorphism and type of bands of the sample at 6 h were similar to those at 0 h. But the bands numbers at other time were far less than those at 0, 6 h. And there were some different mRNA differential expression bands between the different samples.

CONCLUSIONIn the process of the sprout tumble caused by high temperature stress, the RNA and mRNA differential expression in leaves of P. ternata changed.

Gene Expression Regulation, Plant ; Hot Temperature ; Pinellia ; genetics ; metabolism ; Plant Leaves ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; RNA, Plant ; genetics ; metabolism