METOKI Rikiya Department of Urology, Tohoku Univ. Sch. Med., 医学部, 助手 (20174328)
KAN Mikio Research Institute for Tuberculosis and Cancer, Tohoku Univ., 抗酸菌病研究所, 助手 (70125524)
TAKAYAMA Kazuyoshi Institute of High Speed Mechanics,Tohoku Univ., 高速力学研究所, 教授 (40006193)
|Budget Amount *help
¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1986: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1985: ¥4,400,000 (Direct Cost: ¥4,400,000)
The biological effect of underwater shock waves (SW) was studied through following categories : 1) in vitro basical experiments, 2) animal experiments and 3) studies on clinical application of extracorporeal SW lithotripsy. The SW was generated by micro-explosions using chemical explosive pellets of lead azide (10mg), or silver azide (10mg).
1) In vitro experiments: Cavitation bubbles were observed at the focal area, when the SW was focused using ellipsoidal reflecter. And, if the bubble was exposed by another SW, jet-flow generated from the bubble. These two phenomena, caviatation and jet-flow, seemed to associate with the deleterious effect of SW in biological materials. Cultured tumor-cells, when exposed by focused SW, decreased in number, but proliferative ability remained in the 50 times-SW exposure. However, in the case of 100 times-exposure, the ability was lost. The data suggest the possibility of SW-application to cancer therapy. 2) Animal experiments: In the 100-200 times-exposure to the dog kidney, almost no changes occurred including other abdominal organds. However, in the 500 times-SW exposure, bleeding lesions were observed. But after 3 months, no pathological changes were observed except minor scarring lesions. 3) studies on clinical application: Studies on renal function using the uptake rate of 99mTc-DMSA, no statistical change was observed between pre- and post -SW treatment. However, in the cases with stagnated disintegrated fragments in the ureter, which caused hydronephrosis, the renal function decreased markedly. The data suggest that clinical problems in the SW lithotripsy is not the SW itself, but the post-operative hydronephrosis, if exists.