ETIOLOGY AND DEVELOPMENT OF CONGENITAL HEART DISEASE

遗传性心血管病变特异性缺陷犬的品系 研究圆锥动脉干隔的发病机制 缺损（包括法洛四联症、室间隔缺损和 永存动脉干）、肺动脉瓣发育不良和未闭 动脉导管 比较受影响品系与正常品系的胚胎 对照胚胎在可比的发展阶段，调查 通过经典的胚胎学研究进展的时间进程， 发育中的心脏的形状和形式异常， 研究细胞增殖，差异细胞死亡， 和细胞间基质的形成 畸形 所用的方法包括蜡板重建的 从连续切片中发育心脏，透射电子显微镜， 显微解剖心脏的扫描电子显微镜和Quantimet 分析细胞与细胞外基质的相对体积， 从发育中的心脏的选定区域的切片。 定量 有丝分裂活性和细胞死亡的形态计量学研究利用细胞学 技术. 放射自显影用于评估细胞复制 （氚化胸苷掺入DNA） 地区

Strains of dogs with hereditary lesion-specific defects in cardiovascular development are used to study the pathogenesis of conotruncal septum defects (including tetralogy of fallot, ventricular septal defect, and persistent truncus arteriosus), pulmonary valve dysplasia, and patent ductus arteriosus. Comparing embryos from affected strains with normal control embryos at comparable stages of development, the investigations progress through classical embryologic studies of the time course of abnormalities in the shape and form of the developing heart, to investigation of the roles of cell proliferation, differential cell death, and formation of intercellular matrix in the genesis of these malformations. Methods used include wax plate reconstruction of the developing heart from serial sections, transmission electron microscopy, scanning electron microscopy of microdissected hearts, and Quantimet analysis of the relative volumes of cell vs extracellular matrix in sections from selected areas of the developing heart. Quantitative morphometric studies of mitotic activity and cell death utilize cytologic techniques. Autoradiography is used to assess cell replication (incorporation of tritiated thymidine into DNA) in sections from selected areas.