[Effects of low-frequency ultrasound on tumors cells in experimental animals]

The effect of low-frequency ultrasound was studied in different conditions in 197 in vitro experiments according to the histological form of the tumor. It was found that ultrasound with a frequency of 26.6--40.5 kHz, intensity of 2--8 Wt/cm2, and fluctuation amplitude of the end of the smooth cylindrical instrument-wave guide of 60--80 mcm caused destruction of the cells of malignant tumors of humans, whatever the histological form. Experiments with transplanted tumors--Zaidel's ascitic hematoma and sarcoma M-l of rats (202 rats) showed that after transplantation of a tumor cell suspension exposed to sonic waves for 5--7 minutes a tumor does not develop in highly susceptible experimental animals.