中文摘要：

目的探讨高强度聚焦超声（HIFU）消融兔肝组织后细胞凋亡和增殖细胞核抗原（PCNA）表达的变化。 方法24只新西兰大白兔肝组织接受HIFU辐照，辐照后5min，1、3、6、9、14d分别处死4只动物，取出肝脏，HE染色观察组织病理改变，透射电镜观察细胞超微结构变化，原位末端标记法（TUNEL）检测细胞凋亡，免疫组织化学方法检测PCNA表达。 结果HE染色显示HIFu辐照后靶区边缘形成纤维包裹带，随时间逐渐加宽（P〈0．05）。电镜发现辐照后靶区周围组织有凋亡小体生成，TUNEL检测凋亡指数于辐照后3d最高。辐照后靶区周围组织出现PCNA阳性细胞，PCNA阳性细胞指数于辐照后6d达到峰值。 结论HIFU辐照后凝固坏死区域逐渐机化包裹，靶区周围组织出现凋亡细胞和PCNA阳性细胞，数量随时间变化，为进一步控制和增强HIFu消融作用提供实验基础。

英文摘要：

Objective To study apoptosis and proliferative cell nuclear antigen （PCNA） expression after HIFU ablation on rabbit livers. Methods Twenty-four rabbits underwent laparotomy and HIFU ablation on livers. Rabbits were killed on 5 min, 1 d, 3 d, 6 d, 9 d and 14 d after HIFU ablation. Tissue samples were examined by light microscope with HE （hematoxylin and eosin） stain and by transmission electron microscope. PCNA expression was detected by immunohistochemical stain and apoptosis was observed using terminal deoxynucleotidyl transferasemediated dUTP-end labeling （TUNEL） . Results A fibra band was detected by light microscope on the rim of the targeted area after HIFU ablation. Apoptosis bodies were observed in surrounding tissues on electron microscope and apoptosis index reached peak value on 3 d after HIFU. PCNA positive index in surrounding areas was the highest on 6 d after HIFU. Conelusions After HIFU ablation, coagulated areas were organized and fibra-encapsuled gradually. Apoptosis and cell proliferation were detected in surrouding areas, which provide new methods to control HIFU effects.