1.超声背向散射积分与线粒体相关性研究 　2.超声微泡造影剂介导GFP基因转染骨骼肌研究

【作者】 宫琳；

【导师】 王志刚；

【作者基本信息】 重庆医科大学 ， 影像医学， 2004， 硕士

【摘要】 背景：有关心肌组织超声背向散射积分(ultrasonic integrated backscatter，IBS)的实验和临床研究已有较多报道，但心肌组织中何为对IBS起最主要的散射体目前还不太清楚。线粒体是心肌细胞中最丰富的细胞器之一；对作用于心肌细胞的损伤因子最早产生反应而表现出形态变化；其径线远小于诊超声波波长而符合成为散射体的条件，所以本研究拟行动物实验，旨在判断线粒体是否为心肌中对IBS起主要作用的散射体。目的: 探讨心肌超声背向散射积分与心肌线粒体的关系。方法: 健康杂种犬12只（平均体重15.8±2.5kg），随机分为2组，分别静脉注射10﹪氯化钙10ml、10﹪氯化钾10ml，使心脏停搏于收缩、舒张状态，用HP-5500型超声诊断仪，于停搏即刻、停搏后30min、停搏后60min分别从胸骨旁乳头肌短轴观采集射频图像，并用声学密度定量（AD）技术获得感兴趣区心肌IBS值，在上述各时间点取心肌组织行透射电镜观察，用计算机图像分析系统测量并计算线粒体体视<WP=7>学参数。结果：随着犬心脏停搏时间延长，心肌线粒体肿胀、出现空泡，基质内电子密度降低，嵴排列紊乱、变短、消失；线粒体体视学参数：体密度(Vv)、表面积密度(Sv)、平均体积()、平均表面积()均增大（P<0.05），比表面(Rsv) 减小（P<0.05），数密度(Nv)无明显改变（P>0.05）；收缩状态与舒张状态IBS值均减小（P<0.05）。IBS与Vv、Sv、、、Rsv的相关性均具有显著性意义。结论：心肌IBS的改变与心肌线粒体的改变相关，线粒体可能是心肌组织中对IBS起较主要作用的散射体之一。更多还原

【Abstract】 Objective：Ultrasonic integrated backscatter（IBS）is produced by ultrasound backscattering from ultrastructures. Identifying which ultrastructure in the myocardium is the major scatterer remains an unsolved problem. Since mitochondria are abundant in the myofibers, we postulated mitochondria might be one of the major scatterers. Furthermore, mitochondria are so sensitive that it may change firstly in morphology when the myofibers are subjected to some lesion factors. So, we designed an experiment at the level of sub-cells to cause mitochondrial morphological alteration by cardiac anoxia and to explore the relationship between the values of myocardial ultrasonic integrated backscatter and mitochondria. Then we can take further steps to determine whether mitochondria are one of the major scatterers in the myocardium.Methods：Hearts of 12 dogs were arrested at systolic or diastolic state using Hyper-calcium or hyper-potassium solution and cardiac <WP=11>radio-frequency images were acquired at points of 0, 30 and 60 minutes after arrest. IBS were obtained with “Acoustic Densitometry Technique”. Tissue specimens of corresponding time were excised and observed under electronic microscope. Stereological parameters of the mitochondria were measured with Computer Imaging Analysis System.Results：With arresting time prolongation, the swollen mitochondria with electron-lucent and cristallin-chaotic appeared in some myofibers. Mitochondrial volume density (Vv), surface density(Sv), average volume(), average surface area () all increased（P<0.05）; specific surface (Rsv) decreased（P<0.05） but numerical density(Nv) changed little（P>0.05）. IBS decreased at both states（P<0.05）. Alteration of IBS correlated well with those of Vv, Sv, , , Rsv.Conclusions：The mitochondria may be an important scatterer in the myocardium.更多还原