Induction of transplantable malignant tumours in mice by repeated short exposures to continuous wave (25 kHz) ultrasound

摘要

40 Balb/C female mice were subjected to continuous wave ultrasound (25 KHz) exposure through the shaven abdomen at the rate of 60 s/day/mouse and 17 times within a span of 51 days. The treated animals along with an equal number of control (not exposed to ultrasound) ones were kept under observation till death or sacrificed for investigation. The exposed animals aged at a much faster rate (vis-h-vis control ones) with significant loss of hair, loss of mobility and wrinkled skin and died much earlier (life span 0.92 +/- 0.4 years vis-h-vis 2.0 +/- 0.5 years of the control ones). The exposed animals produced large amount of fluid with many abnormal carcinoma-like cells in the peritoneal cavity and each one of the 7 out of 10 animals sacrificed for investigation (vis-ci-vis none in the respective control group) exhibited development of at least one tumour. The ultrasound-induced tumour cells could be transplanted from one. strain of mice (Balb/C) to another strain (ICR) and vice-versa without any single failure for several times in succession. [References: 16]