新生大鼠心肌细胞的体外培养和生物学观察

体外分离培养心肌细胞,为心肌组织工程提供种子细胞。采用胰酶连续消化法,分离新生大鼠心室肌细胞并在体外培养,倒置显微镜下观察细胞形态和搏动情况,并通过免疫组化染色法,检测心肌细胞的α肌节型肌动蛋白及连接蛋白Cx43。结果表明:培养2d后,心肌细胞开始自发搏动,在培养过程中心肌细胞的搏动频率逐渐加快,细胞聚集成团,随后成簇同步搏动,心肌细胞搏动可维持60d以上;α肌节型肌动蛋白及连接蛋白Cx43的表达量也逐渐增加。本研究体外培养出了状态良好的心肌细胞,在体外二维培养环境下,心肌细胞也有一定程度的生长发育,为心肌组织工程种子细胞来源的研究提供了实验依据。

遗传性心肌病基因谱的新基因座位于7号染色体

Background -Genetic mutations are the most common cause of hypertrophic cardiomyopathy(HCM) and an increasingly recognized cause of dilated cardiomyopathy. Autosomal dominant HCM is caused by mutations in sarcomere proteins; such mutations are not universally present, however, and fail to account for ≈=40%of cases of phenotypic HCM. To add further complexity, other genetic origins can mimic the gross clinical phenotype of HCM, and mutations in sarcomere genes have been demonstrated to cause dilated cardiomyopathy. Methods and Results -To explore novel genetic causes of inherited cardiomyopathies, genome-wide linkage analysis was used to study one kindred(4 generations, 32 individuals) with predominant clinical features of left ventricular hypertrophy in addition to cardiac dilation, end-stage heart failure, and sudden death. Of note, histopathology from 2 family members did not demonstrate myocyte disarray and fibrosis, indicating that this phenotype is not typical sarcomere mutation HCM. Direct DNA sequencing was performed on sarcomere genes known to cause HCM and dilated cardiomyopathy, and no mutations were identified. Linkage was then established to a novel locus on chromosome 7(7p12.1-7q21). A maximum 2-point logarithm of odds score of 4.11 was obtained. Recombination events refine the disease interval between D7S506 and D7S3314, corresponding to a distance of 27.2 megabases. Conclusions -The discovery of a novel genetic locus in this family provides more evidence that molecular pathways leading to inherited cardiac hypertrophy extend beyond the sarcomere. Identification of the causal gene mutation and additional genotype-phenotype correlation studies will provide fundamental insight into mechanisms of cardiac remodeling.

THE BI DIRECTIONAL REGULATION OF FILAMIN ON THE ATPase ACTIVITY OF SMOOTH MUSCLE MYOSIN

The aim of this study is to investigate the functional relationship between filamin, a known actin binding protein, and myosin and the effects of filamin on the interaction between myosin and actin. Methods.Ultra centrifugation method was used to investigate the binding of filamin to both phosphorylated and unphosphorylated myosins. Mg ATPase activities of both phosphorylated and unphosphorylated myosins in the presence and absence of actin were measured to observe the effects resulted from filamin actin and filamin myosin interactions. Results. It was found that filamin is also a myosin binding protein. Filamin inhibited the actin activated Mg ATPase activity of phosphorylated myosin and stimulated Mg ATPase of phosphorylated myosin in the absence of actin; in addition, filamin stimulated Mg ATPase activity of unphosphorylated myosin in both the presence or absence of actin. Conclusion. The results suggest that the effects of filamin on the myosin Mg ATPase activities are bi directional, i.e., stimulatory via binding to myosin and inhibitory via binding to actin.

肥厚型心肌病分子机制及法医病理学意义

肥厚型心肌病(hypertrophic cardiomyopathy,H C M)被证实是引发35岁以下青年人(尤其是运动员)心源性猝死(sudden cardiac death,S C D)的首要原因。约60%的H C M患者由编码肌小节蛋白的基因突变导致,呈常染色体显性遗传模式。P肌球蛋白重链基因、肌球蛋白结合蛋白C基因、肌钙蛋白T基因、肌钙蛋白I基因被认为是引起H C M最常见的突变基因。基因检测在H C M的临床诊断中已趋于常态化,但在法医工作中应用较少,如果基因检测技术能够应用于法医病理学诊断,将会给H C M猝死案件的死亡原因确认工作提供便利。更重要的是,通过猝死者的基因检测结果尽早进行家庭成员的危险评估才能降低猝死的发生率。本文主要综述j H C M的分子机制进展以及该疾病在法医病理学诊断中的应用价值。

肥厚型心肌病诊治进展研究

肥厚型心肌病（HCM）是以左心室肥厚为特点,无心室腔扩张及其他导致心室肥厚的心脏疾病或系统性病变表现的一种疾病。多发于青壮年,60%~70%为家族遗传,30%~40%为散发性。HCM临床症状各异,有的无任何症状,有的有心悸;还有的有劳力性呼吸困难、易疲劳、心前区闷痛、晕厥甚至猝死,还有患者晚期会出现左心衰的表现[1]。随着人们生活节奏及环境等外力因素的改变,该病的发生率在不断增高。