中文摘要：

目的比较靶向和非靶向微泡联合尿激酶超声溶栓的电镜表现。方法将精氨酸-甘氨酸-天冬氨酸-丝氨酸片段（RGDS）与尿激酶（UK）以及超声微泡（SonoVue）通过机械振荡法,制备成靶向微泡。于30只新西兰大白兔单侧股动脉制备在体混合性血栓,并分为单纯超声辐照组（US组）、超声辐照＋非靶向微泡造影剂＋UK组（US＋M＋UK组）、超声辐照＋靶向微泡造影剂＋UK组（US＋RGDS＋UK组）。通过超声及多普勒血流仪观察溶栓效果,然后对股动脉离体标本行HE染色,并观察电镜表现。结果溶栓20 min后,与US组和US＋M＋UK组比较,US＋RGDS＋UK组血流量明显恢复（P均〈0.05）,US组与US＋M＋UK组比较差异无统计学意义（P均〉0.05）。US＋M＋UK组HE染色显示管腔内充满血栓,血小板梁呈颗粒状、不致密,扫描电镜示粗大束状的胶原纤维上疏松附着少量细小纤维蛋白丝,大部分断裂;透射电镜示血栓大部分溶解为空泡状,可见白细胞或血小板降解的碎片。US＋RGDS＋UK组HE染色显示血栓完全溶解;扫描电镜示血栓的纤维网状结构被破坏,纤维蛋白完全的溶解;透射电镜示血栓降解为高电子密度的颗粒。结论血栓结构的空泡化、纤维蛋白网架结构完全崩解和纤维蛋白的完全溶解是靶向微泡和UK联合溶栓的主要电镜改变。

英文摘要：

Objective To explore the electron microscopy changes of thrombolysis using targeted and non-targeted microbubble combined with urokinase with diagnostic ultrasound in vivo.Methods Targeted microbubble with urokinase（UK）were prepared by Arg-Gly-Asp-Ser segments（RGDS）,UK and microbubble through acoustic vibration.Thrombi were prepared in 30 New Zealand white rabbits with unilateral femoral artery,and all rabbits were divided into ultrasound（US）group,ultrasound＋non-targeted microbubble＋UK（US＋M＋UK） group and ultrasound ＋ targeted microbubble＋UK（US＋RGDS＋UK） group.The effect of thrombolysis was observed by ultrasound and Doppler flowmetry.The femoral artery was stained with HE and observed by electron microscopy.Results The blood flow of US＋RGDS＋UK group were significantly restored（all P〈0.05） after 20 min compared with that of US group and US＋M＋UK group,and there were no significant differences between US group and US＋M＋UK group（all P〉0.05）.In US＋M＋UK group,HE staining shown that thrombi were filled in the lumens and platelet beams were grainy and not dense in HE staining.Scanning electron microscopy showed that a small amount of fine loose fibrin strands were attached while most of them were broken.Transmission electron microscopy revealed most of the thrombi were dissolved,and white blood cells or platelets degradation fragments were visible.In US＋RGDS＋UK group,HE staining shown that thrombi were completely dissolved,and destruction of fibrin and complete dissolution of fibrous network were observed by scanning electron microscopy.Transmission electron microscopy revealed that thrombi were degraded into particles of high electron density.Conclusion The major electron microscope changes of targeted microbubble and UK combined with diagnostic ultrasound are vacuolation of thrombus structure,complete disintegration of fibrin network structure and complete dissolution of fibrin.