急性心肌梗死患者胰岛素抵抗与Killip分级的关系及临床意义

目的：分析86例非糖尿病患者急性心肌梗死(AMI)入院时胰岛素抵抗、胰岛素敏感指数与Killip分级的相互关系及临床意义。方法：对56例健康正常人(A组)，86例非糖尿病急性心梗患者根据入院时Killip分级分组，其中KillipⅠ级(B组)54例，KillipⅡ级(C组)15例，KillipⅢ级以上组(D组)17例，分别检测其空腹血糖(FBG)、空腹胰岛素(FINS)水平，计算胰岛素敏感指数(ISI)，以稳态模型(Homa Model)公式评估胰岛素抵抗(IR)及计算住院病死率。结果：B、C、D组的IR水平显著高于A组(P＜0．05--0．01)，B、C、D组的ISI水平显著低于A组(P＜0．05--0．01)，IR及ISI水平B、C、D三组间两两比较差异均有显著性(P＜0．05--0．01)；多元Logistic回归分析显示入院时的IR与Killip分级和住院病死率呈正相关(P＜0．01)，结论：AMI患者入院时的胰岛素抵抗性可预示AMI的严重程度，胰岛素抵抗性越强则病情越严重。     

低分子肝素治疗不宜溶栓的急性心肌梗死24例疗效观察

目的：观察低分子肝素(LMWH)治疗急性心肌梗死(AMI)的疗效及安全性。方法：AMI不适合溶栓者47例。随机分为A、B两组，在常规治疗的基础上，A组加腹壁皮下注射LMWH 0.4mL(4100 AxaIU)，每组12h 1次，连续7d，B组加用肝素钠25mg(3125IU),每4h 1次，静脉滴注。连续7d，观察用药前后心绞痛发生频率及心功酶变化情况。结果：A组梗死后心绞痛发作次数明显减少，治疗14d后心肌酶基本恢复正常，亦没出现严重出血情况。结论：对未能溶栓的AMI患者加用LMWH治疗，具有较好抗栓作用和安全性。     

硝苯地平控释片治疗无痛性心肌缺血对左心功能的影响

硝苯地平（２０ｍｇ，ｑ１２ｈ×３ｗｋ）治疗无痛性心肌缺血２３例（男１５例，女８例，年龄５５±９．４ａ），对左心功能和ＲＡＡ检测结果显示：治疗后ＨＲ、ＳＢＰ、ＤＢＰ和ＭＡＰ均降低，以ＤＢＰ和ＭＡＰ降低显著（Ｐ＜０．０５）；缺血型ＳＴ段明显改善（Ｐ＜０．０１）；核素心功能ＬＶＥＦ、ＳＶ、ＥＲ和ＲＣＯ均升高（Ｐ＜０．０５～０．０１）；血浆ＰＲＡ和ＡｎｇⅡ降低明显（Ｐ＜０．０５）。表明该药有良好的降压和改善左心功能效应。     

Effects of atorvastatin on release of endothelial microparticles and myocardial apoptosis in rats with acute myocardial infarction

AIM: To investigate the effect of atorvastatin(AT) on the release of endothelial microparticles(EMP) and myocardial apoptosis in the rats with myocardial infarction. METHODS: SD male rats(n=24) were randomly divided into 3 groups:sham operation(sham) group, myocardial infarction(MI) group and MI+AT group. The rat model of acute myocardial infarction was prepared by coronary artery ligation. At 2 h and 24 h after modeling, the peripheral blood was collected to detect creatine kinase-MB(CK-MB) and cardiac troponin T(cTnT). The circulating levels of EMP were measured by flow cytometry. The myocardial apoptosis was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling(TUNEL) assay. RESULTS: At 2 h after modeling, the level of CK-MB was significantly increased in MI group compared with sham group, and the level of EMP and the myocardial apoptotic rate were significantly increased in MI group and MI+AT group compared with sham group. At 24 h after modeling, the level of EMP was significantly increased in MI group compared with sham group. The levels of CK-MB, cTnT, EMP and the myocardial apoptotic rate were significantly decreased in MI+AT group compared with MI group. Moreover, the level of CK-MB in MI group was significantly increased at 24 h compared with that at 2 h after modeling. The levels of CK-MB, cTnT and EMP were significantly decreased in MI+AT group at 24 h compared with those at 2 h after modeling. CONCLUSION: Ator-vastatin may reduce the level of EMP and the myocardial apoptotic rate in the rats with acute myocardial infarction, indicating that atorvastatin plays a role in protecting endothelium.     

β-Fg C448 G/A基因多态性、Fg水平与心肌梗死发生率的关系

目的:探讨β-Fg C 448 G/A基因多态性对血浆Fg水平的影响及其与心肌梗死(MI)发生率的关系.方法:应用多聚酶链反应-限制性片段长度多态性(PCR-RFLPs)的方法分析β-Fg C448 G/A基因多态性;比浊法测定血浆Fg水平.结果:75例MI患者(病例组)血浆Fg水平(3.73±1.08) g/L高于156例对照者(对照组)血浆Fg水平(3.08±0.71) g/L(P＜0.01).A448基因携带者血浆Fg水平高于GG基因型者(P＜0.05).病例组与对照组A448等位基因频率分别为0.313、0.276,二者比较有统计学意义(P＜0.01).结论:β-Fg C 448 G/A基因多态性与血浆Fg水平关联,A448基因携带者血浆Fg水平增高使MI易感性增加.     

MicroRNA profile analysis of ischemic myocardial tissues from rats with acute myocardial infarction

AIM：To identify differentially expressed microRNAs (miRNAs) in ischemic myocardial tissues from the rats with acute myocardial infarction (AMI) by miRNA array technique, and to predict their targets and analyze their functions using bioinformatics. METHODS：The rat models of AMI (n=3) were prepared by ligaturing the left anterior descending coronary artery (LAD) of Wistar rats. Electrocardiogram and blood pressure were detected during the operation, and the myocardial infarct size was measured by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. Ischemic myocardial tissues were isolated from the infarct area 4 h after ischemia. The same procedure in sham group (n=3) was performed except for ligaturing LAD. Total RNA was extracted from ischemic and normal myocardial tissues. miRNA was isolated from total RNA, labeled with Cy3 and hybridized on miRNA array. Real-time PCR was applied to verify the reliability of miRNA array results. The targets of differentially expressed miRNAs were predicted and their functions were analyzed by bioinformatics. RESULTS：Rat model of AMI was successfully prepared and verified by electrocardiogram detection, blood pressure measurement and pathological observation. Compared with sham group, microarray screening showed that total 11 AMI-related miRNAs were selected, including 6 up-regulated and 5 down-regulated. Three of them (rno-miR-181c, rno-miR-146b and rno-miR-208) were related to the cardiovascular functions, while the functions of the others (rno-miR-672*, rno-miR-743b, rno-miR-128, rno-miR-138-1*, rno-miR-336, rno-miR-138-2*, rno-miR-325-3p and rno-miR-3572) were unknown and might be novel AMI-related biomarkers. Parts of the miRNA targets were also related to the cardiovascular functions. CONCLUSION：Differentially expressed miRNAs in AMI rats may serve as novel biomarkers for diagnosis of AMI and potential targets for treatment of AMI.     

慢性心衰大鼠心肌miRNA-1、miRNA-133/Caspases表达差异研究

目的 探讨慢性心衰大鼠心肌miRNA-1、miRNA-133/Caspases表达差异。方法 30只SD大鼠随机分为正常组10只,模型组20只。正常组等容量生理盐水腹腔注射,模型组予阿霉素腹腔注射造模;采用心脏彩超检测心功能,采用生理记录仪记录血流动力学,心脏切片行Tunel染色检测细胞凋亡,采用Real-time PCR法检测miRNA-1、miRNA-133、Caspase-3mRNA、Caspase-9mRNA表达;采用Western blot及免疫组化法检测心肌组织Caspase-3、Caspase-9蛋白表达水平。结果 与正常组比,模型组大鼠左室舒张期内径（LVIDd）、左室收缩末期内径（LVESD）、左心室终末舒张压（LVEDP）明显增大（P<0.05）,而左心室短轴缩短率（LVFS）、左室射血分数（LVEF）、心输出量（CO）、左心室平均压（LVAP）、左心室内压最大上升速率（dp/dtmax）及左心室内压最大下降速率（-dp/dtmax）下降（P<0.01）,Tunel染色示心肌凋亡明显。miRNA-1、Caspase-3mRNA、Caspase-9mRNA、Caspase-3蛋白、Caspase-9蛋白表达增加（P<0.01）,miRNA-133表达下降（P<0.01）。结论 miRNA-1、Caspase-3、Caspase-9在心肌凋亡中表达增加,miRNA-133表达下降。     

热应激对动物心肌细胞影响研究进展

热应激是动物饲养过程中经常遇到的难题,给畜牧业带来了较大的损失。由于心脏对热的敏感性较高,当动物机体遭受热应激损害时,首当其冲的器官往往是心脏。所以,如何提高心脏抵抗热应激的损伤,成为养殖业日益关注的焦点。论文从热应激对心脏的影响、心肌细胞在热应激作用下的组织形态学变化、热应激损伤心肌细胞的机制、热应激作用下心肌细胞的自我保护及如何提高心肌细胞对热应激的抵抗能力方面,结合近年来的研究做一综述。