Studies on an Ascites (Reticuloendothelial Cell?) Sarcoma of the Rat234

Abstract

A transmissible ascites sarcoma of the rat (so-called Yoshida sarcoma) is descr. The ascitic fluid contains 0.5-1.0 million tumor cells/cu. mm. Intraperit. transplantation with 0.01-0.05 cc. tumor ascites (=10-50 million cells ) has been continued up to now. The transplantation rate throughout 320 generations is 91%. Tumor animals die from tumor invasion within 12 days. 125 rats received a single tumor cell transplant in the abdominal cavity, and in 69 the tumor grew. Transplantation with completely cell-free material was always negative. It was confirmed by phase-contrast-microscopic observation that the mitosis of the tumor cell is completed within 1 hr. The number of chromosomes of the tumor cells varies from 32-50, while 42 makes the peak of the variation curve. V-shaped chromosomes were found in 42% of the tumor cells. Steps of screening-test employing the tumor animals were descr. and a remarkable effect of methyl-bis-([beta]-chlorethyl)-amine N-oxide was discussed.