心脏直视手术围手术期CK及CK-MB的动态变化

目的观察血清肌酸磷酸激酶(CK)及其同工酶(MB)在CPB心脏直视手术围手术期的动态变化,以了解其在围术期的变化规律,为临床诊断治疗提供依据。方法20例患者分别在术前1d,术后1h、1d(约15~18h)、2、3、4、5、6d晨分别取静脉血,留肝素化血浆测心肌酶,并同时作标准12导联EKG,20例患者分为冠状动脉搭桥术和先天型心脏病修复术2组。结果2组患者术前心肌酶均在正常范围,术后1h同时升高到术前的2~43倍,与术前相比有显著性差异(P<0.05),2组间心肌酶的释放量没有显著性差异(P>0.05),术后CHD组的5种心肌酶较CABG组的要稍微高一些,而CHD组较CABG组恢复的快一些。结论2组术前心肌酶均在正常范围,CK-MB释放术后1h达高峰,恢复最快,CK次之,术后心肌酶释放的高峰时间和恢复次序基本一致,心脏术后心肌酶升高的倍数如大于5倍尚不能诊断PMI,CK及CK-MB对CPB心脏直视手术后围术期心肌损伤的程度有较高的特异性和敏感度。     

Effects of pretreatment with captopril on the infarct size and myocardial cell apoptosis in experimental rabbits

AIM:To investigate the effects of pretreatment of captopril on the infarct size and myocardial cell apoptosis in rabbits. METHODS:Rabbits were randomly divided into sham-operated control group (SO), acute infarct group (AI) and captopril pretreatment group (CP). The rabbits of CP group were treated with captopril (25 mg·kg^-1.d^-1) for 1 week before harvest. The left circumflex branch of coronary (LCX) was ligated to develop acute ischemic model. The systolic and diastolic function of left ventricle(LV) was measured before and at 15, 30, 60 min after ligating LCX, and the blood viscosity and hematocrit before and at 60 min after ligating LCX were measured also. 6 hours later LCX ligation, the hearts were harvested for determining the infarction size, which was expressed as the ratio of infarct area to the total ischemic area, and evaluating apoptosis index expressed as the percentage of myocardial cells with TUNEL positive staining. RESULTS:1.Compared with AI group, captopril pretreatment significantly reduced the infarction size (16.60%±0.94% vs 36.24%±1.94%, P＜0.05), and improved the LV function and viscosity of blood. 2. Apoptosis of myocardial cell was found in the myocardium surrounding to the infarction area, however, the apoptosis index of CP group was significantly lower than that of AI group (26.30%±0.71% vs 42.44%±2.32%,P＜0.05).CONCLUSION:Apoptosis of myocardial cell exists in the area surrounding the infarction. Captopril pretreatment can reduce infarction size and myocardial apoptosis index, and improve the LV function as well as blood viscosity in this acute ischemic model.     

MSC-conditioned medium activates Nrf2/ARE pathway to protect H9c2 cells against oxidative stress

AIM: To investigate the protective effect of mesenchymal stem cell (MSC)-conditioned medium (MSCCM) on myocardial cell line H9c2 and its mechanism. METHODS: Verification of MSC was performed by flow cytometry analysis, followed by MTT assay to determine the optimal incubation time of MSCCM with myocardial cells. The cells were divided into 4 groups: normal (N) group, model (M) group, M+MSCCM group and MSCCM group. The cells in M+MSCCM group and MSCCM group were pre-incubated with MSCCM for 24 h. The cells in M group and M+MSCCM group were treated with 300 μmol/L H₂O₂ for 4 h to imitate oxidative injury of myocardial cells. Mitochondrial membrane potential and apoptotic rate of injured myocardial cells were detected by flow cytometry. The ROS production was measured by fluorescence microscopy. The nuclear translocation of Nrf2 and expression of HO-1 was examined by Western blot. RESULTS: No difference of mitochondrial membrane potential, apoptotic rate or ROS production between MSCCM group and N group was observed (P>0.05). The mitochondrial membrane potential depolarization, apoptotic rate and ROS production in M+MSCCM group were significantly lower than those in M group (P<0.01). The nuclear translocation of Nrf2 and expression of HO-1 in the myocardial cells were increased with MSCCM incubation time prolonged. CONCLUSION: MSCCM protects the myocardial cells against oxidative injury induced by H₂O₂. The anti-oxidative mechanism would be associated with the activation of Nrf2/ARE pathway.     

Salvia extract promotes angiogenesis of myocardium in rats with myocardial infarction

AIM: To determine the effect of salvia extract on angiogenesis of the myocardium in the rats with myocardial infarction (MI) and to analyze its possible mechanism. METHODS: Left coronary artery of Sprague-Dawley rats was ligated to establish a MI model. The rats were randomly divided into MI model group, 3 different dose groups of salvia (10, 20 and 40 mg·kg^-1·d^-1), and sham operation group. Each group consisted of 8 rats. The rats in all treatment groups were orally administered with the salvia extract, and the rats in MI group and sham operation group were fed with the same volume of saline. The rats were sacrificed 4 weeks later. The hemodynamic changes of the rats were determined, and the segmental heart samples were used for morphological observation by hematoxylin and eosin staining, Masson staining, or electron microscopic analysis. The expression of vascular endothelial growth factor (VEGF) and cluster of differentiation 34 (CD34) was analyzed according to immunohistochemistry. RESULTS: Compared with sham operation group, the morphological changes of the myocardium in MI group were disordered, part of myocardial cell outline disappeared, and obvious fibrosis in the necrosis myocardial tissue and fuzzy or disappearing microvascular ultrastructure were also observed. Compared with MI group, the number of new microvessels in all the treatment groups increased obviously, and the morphological changes of the endothelial cells were relatively complete according to electron microscopy. Compared with sham operation group, the protein expression of VEGF and CD34 in the cytoplasm of the myocardial tissues in MI group increased only a little. Compared with MI group, the protein expression of VEGF and CD34 in the cytoplasm of the myocardial tissues in all treatment groups increased significantly (P<0.01). CONCLUSION: Salvia extract obviously promotes angiogenesis of the myocardial tissues in the rats after myocardial infarction.     

美洲斑潜蝇在忻定盆地的发生及综合治理

关洲斑潜绳(Liriomyza Sativae Blanchard),1997年传入山西忻州市忻定盆地,以后相继分布于全市所辖县(市)。据3年观察年生7～8代,4月下旬至5月上旬由温室迁出露地,9月下旬至1O月上旬从露地进入温室,温室繁殖代数为2～3代,露地为5代。危害高峰期3个,1～2月温室高峰期;5月上旬至6月上旬为露地第一高峰期;7月下旬至8月下旬为第二高峰期。这3个高峰期危害的主要作物有5科18种,且豆类>瓜类>茄科>十字花科。为控制其危害提出一道防线、二期控制的策略。一道防线是加强植物检疫,二期控制是越冬期控制温室虫源,高峰期统防统治,压低虫量,减少损失。     

急性非ST段抬高性心肌梗死患者冠状动脉病变特点及其临床意义

目的分析急性非ST段抬高性心肌梗死患者冠状动脉病变特点及其临床意义。方法选择冠状动脉造影资料与临床资料完整的急性非ST段抬高性心肌梗死83例,以及同期急性ST段抬高性心肌梗死109例,分别就冠状动脉病变支数、狭窄程度、侧枝循环形成情况及临床特征进行对比分析。结果急性非ST段抬高性心肌梗死患者单支病变较ST段抬高性心肌梗死患者少(P<0.05),非ST段抬高性心肌梗死患者三支病变较ST段抬高性心肌梗死患者多(P<0.05),非ST段抬高性心肌梗死患者≥90%的狭窄病变较ST段抬高性心肌梗死患者多,但<90%的狭窄病变较ST段抬高性心肌梗死患者少(P<0.05),而两组间血管100%闭塞情况相似(P>0.05);非ST段抬高性心肌梗死患者Ⅱ级以上的侧枝循环较ST段抬高性心肌梗死患者多见(P<0.05);非ST段抬高性心肌梗死患者既往心绞痛与陈旧性心肌梗死病史多见(P<0.05),肌酸激酶同工酶峰值较ST段抬高性心肌梗死组明显要低(P<0.01),急性肺水肿、心源性休克、致死性心律失常等严重急性并发症比ST段抬高性心肌梗死组明显要少(P<0.05),左心室射血分数、住院期间死亡率和随访3年的冠心病死亡率与ST段抬高性心肌梗死组相似(P>0.05),而梗死后心绞痛比ST段抬高性心肌梗死组则明显增多(P<0.05)。结论急性非ST段抬高性心肌梗死冠状动脉病变相对复杂,多支及严重狭窄病变多,发作前多已有缺血预适应,且侧枝循环多见,这是心肌梗死形成非ST段抬高的主要原因,也决定了非ST段抬高性心肌梗死患者的临床特征。     

激光扫描共聚焦显微镜检测Fluo-3 AM 负载大鼠心肌微血管内皮细胞最佳浓度和时间的探讨

为了探讨 Ca2+荧光探针 Fluo-3 AM 对大鼠心肌微血管内皮细胞(Rat Myocardial Microvascular Endothelial Cells RMMECs)最佳装载浓度和时间。将 Fluo-3 AM 分别稀释成1、2、3、4、5μM/L,每一浓度的探针分别装载细胞5、10、15、20 min,应用激光扫描共聚焦显微镜检测细胞内荧光信号的强度、位置、装载探针后细胞的形态来观察装载效果。结果表明：1～3μM/L的Fluo-3AM负载5~20 min均不出现荧光信号;4μM/L 的 Fluo-3AM 负载5~10 min 时即出现荧光信号;5μM/L 的 Fluo-3 AM 孵育细胞15 min后出现清晰且分布均匀的荧光信号。Fluo-3AM对贴壁生长的RMMECs负载效果主要受探针浓度和负载时间的影响。     

Effect of age on myocardial function assessed by two-dimensional speckle-tracking echocardiography in healthy beagle dogs

ObjectivesThe objective of this study was to evaluate the effect of age on myocardial function assessed by two-dimensional speckle-tracking echocardiography (2D-STE) in healthy dogs.AnimalsThirty-two healthy Beagles were used.MethodsMyocardial function was assessed in each dog by using 2D-STE, and the results were compared between young and old dogs.ResultsThe myocardial deformations in systole, besides the apical rotation rate, were not significantly different between young and old dogs. In contrast, the early diastolic circumferential strain rate, basal rotation rate, and torsion rate were significantly lower in old dogs than in young dogs (P = 0.03, P = 0.033, and P = 0.015, respectively). Late diastolic longitudinal and radial strain rates were significantly higher in old dogs than in young dogs (P = 0.002 and P = 0.018, respectively).ConclusionsYoung and old dogs showed similar systolic myocardial deformations, but significant differences in the values of some diastolic deformation variables were found between young and old dogs, highlighting the need for using age-matched control subjects in studies of diastolic function.     

Long-term insulin treatment improves postischemic cardiac structure and function via increasing serum BNP levels

AIM：To investigate the influence of long-term insulin treatment on postischemic cardiac structural and functional changes, and to further explore the underlying mechanisms. METHODS：Adult male SD rats were randomly divided into 4 groups (8~10 rats per group): sham group, myocardial infarction (MI) + saline (1 mL·kg-1·d-1, hypodermic injection for 4 weeks) group, MI + insulin (2 U·kg-1·d-1, hypodermic injection for 4 weeks) group and MI + insulin (2 U·kg-1·d-1, hypodermic injection for 4 weeks) + wortmannin ［a phosphatidylinositol 3-kinase (PI3K) inhibitor; 15 μg·kg-1·d-1, intraperitoneal injection 15 min before each insulin treatment］ group. The rats in the latter 3 groups were subject to ligation of the left anterior descending coronary artery, while those in sham group underwent the same surgical procedures without tying the sutures. The cardiac structural and functional changes were observed by echocardiogram, heart catheterization and microscopy with HE and Masson trichrome staining. Blood glucose was determined by Roche blood glucose meter, and the serum levels of insulin and brain natriuretic peptide (BNP) were detected by ELISA. The protein expression and phosphorylation of PI3K, Akt, glycogen synthase kinase 3β (GSK3β) and p38 mitogen-activated protein kinase (p38 MAPK) in myocardial tissues were detected by Western blotting. The mRNA expression of BNP, β-myosin heavy chain (β-MHC) and atrial natriuretic peptide (ANP) in myocardial tissues was determined by real-time fluorescence quantitative PCR. RESULTS：At the end of the 4th week, MI rats receiving long-term insulin treatment showed decreased ratio of heart length/heart weight, smaller systolic left ventricle cavity, thicker systolic interventricular septum, and increased cardiac ejection fraction, left ventricular development pressure and instantaneous first derivate of left ventricle pressure (P<0.05 vs MI + saline group). Moreover, insulin treatment significantly increased the phosphorylation of PI3K and Akt and the serum level of BNP, and inhibited the phosphorylation of p38 MAPK (P<0.05 vs MI + saline group), but did not change the mRNA expression of BNP in myocardial tissues. The effects of insulin on BNP were not blocked by wortmannin (P>0.05 vs MI + insulin group). CONCLUSION：Insulin improves postischemic cardiac structure and function by increasing serum BNP levels possibly independent of PI3K-Akt signaling pathway.