心脏移植受体的超微结构改变

目的：观察心脏移植标本的超微结构变化。方法：通过移植后心脏的心内膜活检，经固定、常规则超薄切片制备，JEM－2000EX透射电镜检查。结果：移植后的早期阶段，未见明显移植排斥反应的心脏心内膜活检显示间质水肿，偶尔可见毛细血管内皮细胞的肿胀。心肌细胞和内皮细胞内溶酶体明显增多。在早期细胞排斥反应阶段，电镜检查可发现显著的心肌细胞坏死和变性，并可确定浸润炎细胞的性质。在血管排斥反应阶段，辨认内皮细胞增生、内皮细胞损伤和基底膜的改变，在患有移植性冠状动脉病的病人，其缺血性心脏具有显著特点：肌动蛋白丝的缺失比肌球蛋白丝更明显，肌微丝相对较粗大。结论：这些改变对于进一步确诊心脏移植受体的排斥和局部缺血是有用的形态学特征。

Ultrastructural changes in cardiac transplant recipients

Objective: The ultrastructural changes of transplanted hearts were examined. Methods: The endomyocardial biopsy specimens of explanted hearts from cardiac transplant recipients were collected. The tissues were fixed and ultrathin sections prepared as routine. Sections were examined under a JEM 2000EX transmission electron microscope. Results: In the early posttransplant period,endomyocardial biopsy specimens from negative transplanted hearts often showed interstitial edema and occasional endothelial cell swelling of capillaries. The lysosomes within myocytes were distinctly increased. During early cellular rejection episodes, the myocyte necrosis and degeneration can be found by electron microscopy and the nature of the infiltrating cells confirmed. In episodes of vascular rejection, endothelial activation,endothelial cell damage,and basement membrane changes can be identified without difficulty.The myofilament composition of ischemic hearts in patients with allograft coronary artery disease is distinctive: there is a disproportionate loss of actin over myosin,giving a coarse appearance to the myofilaments. Conclusion: These ultrastructural changes are useful in further defining the morphologic features associated with rejection and ischemia in cardiac transplant recipients.