【摘要】 目的探讨应用纳米重组tPA基因质粒预防狗实验性机械瓣膜置换术后血栓形成。方法建立狗心脏三尖瓣机械瓣膜置换术模型;构建重组tPA基因质粒,用壳聚糖为材料制备纳米微粒包裹基因质粒并制备成转基因药物,在心脏三尖瓣机械瓣膜置换术同时注射心肌以转染心肌组织,观察动物存活时间及其抗凝效果;用免疫组织化学技术观察心肌细胞tPA蛋白表达;检测凝血酶原时间、INR和纤溶降解产物D-二聚体含量;动物死亡和观察期结束后取心脏观察血栓形成状况。结果成功建立狗心脏三尖瓣机械瓣膜置换术模型;成功构建了纳米重组tPA基因质粒并成功转染心肌细胞;实验组动物健康存活均达到观察期12周,而对照组动物平均存活(40.33±9.67)d,实验组与对照组相比存活时间显著延长(P<0.01);静脉血D-二聚体含量检测显示,实验组于术后1周增高并且持续增高至12周,显著高于对照组(P<0.01);实验组和对照组观察各期凝血酶原时间和国际标准化比值(INR)无显著变化(P>0.05);心脏解剖显示实验组动物瓣膜周围及心腔内未见血栓形成,而对照组动物可见血栓形成。结论构建的纳米重组tPA基因质粒可预防实验性机械瓣膜置换术血栓形成,这为应用基因药物防治人类疾病提供实验基础。更多还原

【Abstract】 【Objective】To elucidate the transfection of nano tPA gene plasmid to prevent thrombosis after tricuspid mechanical valve replacement in dogs.【Methods】A dog model of tricuspid mechanical valve replacement was constructed.A constructed chitosan nano tPA gene plasmid was used to transfect the dog cardiocytes at the same time of tricuspid replacement.The effect of this gene on survival time of dogs , anticoagulation result(prothrombin time, INR and D-dimer contents, thrombosis in heart), the expressions of tPA were observed with the methods of clinical laboratory, routine pathology and immunohistochemical stain.【Results】Nano tPA gene plasmid was successfully constructed and transfected into cadiocytes.The gene could significantly increased the survival time and serum level of D-dimer(P <0.01) and could prevent thrombosis of mechanical valve, but there was not significant difference of prothrombin time and INR between two groups(P >0.05).ConclusionThe constructed nano tPA gene plasmid could prevent thrombosis after mechanical valve replacement, which provide the bases for prevention of human disease using genetic drugs.更多还原