高强度聚焦超声联合超声造影剂消融兔肝后细胞凋亡和增殖细胞核抗原表达的研究

目的：探讨高强度聚焦超声（HIFU）联合超声造影剂消融技术对兔肝组织细胞凋亡和增殖细胞核抗原（PCNA）表达的影响。方法：40只新西兰纯种大白兔分为A、B组，A组兔肝接受HIFU辐照前，经耳缘静脉注射生理盐水；B组接受辐照前注射超声造影剂SonoVue。A、B组均在辐照后5min、1d、3d、7d、14d分别处死4只动物，将肝取出体外观察，取靶区及周围组织（距靶区边缘5mm以内），HE染色观察组织病理学改变，原位末端标记法（TUNEL）检测细胞凋亡，免疫组织化学方法检测细胞PCNA表达。结果：HIFU辐照后3d、7d、14dB组辐照区域边缘纤维包裹带宽度大于A组（P〈0．05）。HIFU辐照后1d、3d、7d、14dB组靶区周围组织（距靶区边缘5mm以内）凋亡细胞数和PCNA阳性细胞指数较A组增高（P〈0．05）。结论：与单纯HIFU相比，HIFU联合超声造影剂促进了消融后坏死区域机化包裹，增加了HIFU靶区周围细胞凋亡，提高了细胞增殖能力，为进一步增强HIFU消融作用提供了实验数据。

Study of apoptosis and expression of proliferating cell nuclear antigen in rabbit liver after high intensity focused ultrasound ablation combined with ultrasound contrast agent

Objective To study apoptosis and expression of proliferating cell nuclear antigen(PCNA) after high intensity focused ultrasound(HIFU) ablation combined with ultrasound contrast agent on rabbit liver. Methods Forty rabbits were divided into two groups (group A and group B) randomly.Eevery group includes 20 rabbits.Rabbits were anesthetized and underwent laparotomy.The rabbits in group A were given normal saline 0.2 ml/kg before HIFU ablation,while those in group B were given ultrasound contrast agent SonoVue 0.2 ml/kg before the HIFU exposure.Four rabbits of group A and group B were sacrificed respectively on 5 min,1 d,3 d,7 d and 14 d after the ablation of HIFU and the livers were taken out of the body.The tissue samples,including the targeted tissue and the untargeted tissue distant from the rim of necrosis tissue within 5mm,were taken for HE staining examined by the light microscope,detection of PCNA expression by immunohistochemical staining and observation of apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP-end labeling(TUNEL).Results Light microscope showed the fibra band in the rim of the targeted area in group B was wider than that in group A on 3 d,7 d and 14 d after the HIFU ablation (P<0.05). The number of apoptosis cells and the PCNA positive index in surrounding area of group B were higher than those in group A on 1 d,3 d,7 d,14 d following HIFU ablation (P<0.05).Conclusions Compared to the single HIFU ablation,HIFU combined with the ultrasound contrast agent can promote the organization and fibra encapsulation of coagulated area.And apoptosis and cell proliferation in surrouding area are also enhanced,which provide experimental evidence for new methods to improve the HIFU effects.