超声波空化效应对体外培养细胞细胞膜作用的实验研究

目的 研究超声空化作用对体外培养细胞细胞膜的生物学效应。方法 将大鼠肺动脉血管平滑肌细胞悬液分为对照组、单纯超声辐照组和造影剂 超声辐照组3组，后两组均给予频率为665kHz、声强为0．5w／cm^2的超声波辐照20s，实验后立即和继续培养24h后用扫描电镜观察细胞膜结构有无改变。结果 单纯超声辐照组细胞及细胞膜的结构与对照组比较无显著改变。造影剂 超声辐照组约20％的细胞膜表面出现了大小约1～2μm的小孔，24h后再次观察细胞膜表面恢复正常。结论 空化效应使细胞膜上出现可逆性小孔，致细胞膜的通透性增高可能是超声造影剂增强基因转染的主要机制。     

Characteristic echographic features of circumscribed cancer

Of 964 amputated breast cancers which had been examined preoperatively by ultrasound and mammography, 147 breast (17.0%) contained macroscopically circumscribed tumors and 596 cases (69.0%) showed infiltrative tumors on examination of the cut surface. It is well known that infiltrative types of cancer show ultrasonic images that usually possess clear cut signs of malignancy, such as jagged augmented boundary echoes and acoustic shadows. On the other hand, circumscribed types of cancer do not usually show such signs, but exhibit lobulated shapes and strong, coarse and non-uniform internal echoes. These latter features are intermediate between those of infiltrative cancers and those of solid benign tumors. As such circumscribed cancers are often difficult to diagnose correctly by ultrasonic techniques. The diagnostic accuracy rates by ultrasound were 88.0% in the infiltrative types and 69.4% in the circumscribed types. The ultrasonic pictures of the 147 cases of such circumscribed tumors are classified and discussed.