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Objective:To explore the influence of neuregulin- 1 (NRG-1)intervention on pacing threshold of low voltage area in rats after myocardial infarction.Methods:Myocardial infarction model of rat was established via an-terior descending coronary artery ligation.The 34 rats with myocardial infarction were randomly and averagely di-vided into two groups:NRG-1 group (received NRG-1peritoneal injection)and control group (received peritoneal injection of normal saline of the same volume).After two weeks,pacing thresholds were tested in low voltage area related with infarct in rats after myocardial infarction,and Cx43 (an integral membrane protein of the connexin family)expression was measured in low voltage area.Results:After drug intervention two weeks,compared with control group,there was significant reduction in pacing threshold [(1.466±0.503)V vs.(0.7167±0.194)V,P =0.002]in NRG-1 group;there was significant rise in Cx43 expression [(0.30±0.15)vs.(0.95±0.20),P <0.001] in low voltage area in NRG-1 group.Conclusion:Neuregulin-1 significantly reduces pacing threshold of low voltage area in rats after myocardial infarction,the mechanism may be related to increase Cx43 expression and improve e-lectrical conductivity of myocardial cells.
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Uterine leiomyoma is the most common benign tumour of reproductive system of wommen.In recent years,the mini-trauma technology represented by laparoscope and hysteroscope is popularized in the application to treatment of uterine leiomyoma,such as LH,LM,HM and UAE put forward recently,etc.They all have many advantages,little trauma,less pain,rapid recovery and shorter duration of hospitalization.But indication,method of operation and complication have nothing in common with each other.This text is a survey at the point.
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Objectives This study aimed at finding cut if reperfusion could be identified by long term VLP,using digital Holter ECG.Methods 24 hour 3 channel digital Holter recorders were performed on 38 patients with AMI before thrombolytic therapy,then the patients were divided into successful reperfusion group and unsuccessful reperfusion group.Every parameter was comparied between the two groups.Results VLP parameters showed a gradual improvement in the acute phase of MI in patients with successful reperfusion compared with those of unsuccessful reperfusion and that a significant difference between these two groups became evident from 2～3 hour after thrombolysis.Conclusions Our investigation certifies that successful reperfusion reduces VLP positive rate significantly 2～3 hours after thrombolysis.Thus,long term ventricular late potential may be helpful for identification of the reperfusion in AMI patients.In the mean time,Our study is performed before the formation of myocardial fibrous scar in AMI patients,it breaks up the traditional concept that VLP only developed from the formation of myocardial fibrous scar.
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Objective To construct a novel VP 1 gene vaccine against coxsackievirus B 2 and to evaluate the effect of the cell-mediated immunity induced by it.Methods The immunodominant capsid protein VP 1 gene of CVB 2 was amplified by reverse transcript polymerase chain reaction (RT-PCR) and pcDNA 3-CVB 2VP 1was constructed by molecular cloning.The cytotoxic T lymphocyte (CTL) activity was measured by standard 51Cr-release cytotoxicity assay eight weeks after BALB/c mice were immuned by pcDNA 3-CVB 2VP 1.Results The eukaryotic expression vector was pcDNA 3 and subcloning fragment was CVB 2VP 1.The CTL activity of pcDNA 3-CVB 2VP 1 group was higher than that of the control (P
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Objective To observe the change of matrix metalloproteinase-13(MMP-13)in right atrial myocardium after acute atrial fibrillation in rabbits and evaluate the effect of irbesartan on the atrial remodeling following atrial fibrillation.Methods From Jan.2005 to Jun.2005,60 rabbits were randomly divided into groups of no drug(n=30)and receiing drug(n=30),the receiving drug group taking irbesartan for 3 weeks(30mg/kg).Each group was randomly divided into groups of control(n=10),atrial fibrillation control(n=10),8 h after atrial fibrillation(n=10).The amount of MMP-13、tissue inhibitors of metalloproteinase-3(TIMP-3)、angiotension receptor 1(AT1)and angiotension receptor 2(AT2)in right atrial myocardium measured by immunohistochemical stain.The amount of angiotension Ⅱ(AngⅡ)in right atrial myocardium was measured by radioimmunoassays.Results The amount of MMP-13 in ND3 was higher than in ND1(P
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Objective To study the effects of intrinsic ganglionated plexi on the susceptibility to atrial fibrillation(AF)in canines induced by rapid atrial pacing.Methods Atrial efficient refractory period(AERP)and the dispersion of AERP were obtained in 13 healthy mongrel dogs before paced at 600 bpm.The fat pads containing the ganglionated plexi located on the junction of right superior pulmonary vein and atrium in 7 dogs were excided(denervation group),while the fat pad in the other 6 dogs were kept(control group).The time for the emerge of sustained AF was recorded.Atrial efficient refractory period(AERP)and the dispersion of AERP were also determined.Results There was statistical difference in the time for the emergence of sustained AF.In denervation group,it took more time than the control group(120?67 h vs 80?52 h,P