Inhibition of Experimental Production of Liver Cancer by Liver Feeding :

EXPERIMENTAL STUDIES: ANIMAL TUMORS Early Effects of Carcinogenic Agents, N. BROCK, H. DRUCKREY, A N D H. HAMPERL. Zur Wirkungsweise cancerogener Stoffe. In order to eliminate the effects of a solvent, as well as the trauma and infection inseparable from repeated injections, crystals of benzpyrene were deposited in the peritoneal cavity of rats as a thick watery suspension contained in collodion sacs. The dose lay between 5007 and 25 mg., of which it is estimated that something like l y escaped daily in solution. The first change to be noted was the formation of a connective-tissue capsule, in which the cells nearest the sac were undergoing fatty " degeneration." As benzpyrene continued to escape, the zone of necrobiosis widened and chronic inflammatory changes appeared, while damage to the connective tissues outside this area was evinced by the presence of swollen and coarsely granular cells. By the time the connective-tissue capsule had attained macroscopic thickness the areas of fatty " degeneration " exhibited a strong violet fluorescence in ultraviolet light. I n other words, benzpyrene had passed into solution in the fat. The tumors appeared suddenly after the lapse of from eight to twelve months, and showed no relation, in latent period and proliferative vigor, to the amount of benzpyrene employed. All were sarcomas, and in none could the agent be demonstrated by ultraviolet light. These growths appeared to develop a t the periphery of the capsule, where the concentration of benzpyrene was lowest and cell death accordingly had not taken place. Thus the primary effect of the carcinogenic compound, as others have indicated, was severe cell injury of a type which could not be distinguished from that caused by any other deleterious influence. The article closes with a grave warning against the use of benzpyrene for the treatment of cancer, as recommended by Bauer (Arch. klin. Chir. 189: 123, 1937. Abst. in Am. J. Cancer 32: 135, 1938). The compound t h u s used is no more specific than any other caustic, or than heavy radiation, and infinitely more dangerous. For if man is as susceptible as certain of the laboratory animals the patient will pay for the removal of of his spontaneous neoplasm with the acquisition of a benzpyrene tumor. WM. H. M'OGLOM Occurrence of Subcutaneous Sarcomas in the Rat after Repeated Injections of Glucose Solution, T. NONAKA. Production of Sarcoma in the Mouse and Rat by Repeated Subcutaneous Injections of Concentrated Glucose Solution, N . TAKIZAWA. Uber die Erzeugung des Sarkoms der Maus und Ratte durch wiederholte subkutane Injektion der konzentrierten Zuckerlosungen, Gann 32; 236237, 1938. Production of Mouse Sarcoma through Subcutaneous Injections of Concentrated Glucose Solution, N . TAKIZAWA. Uber die Erzeugung des Maussarkoms durch die Subcutane lnjektion der konzentrierten Zuckerlosung, Gann 33: 193-195, 1939. These three papers are all in confirmation of Nishiyama's work showing that daily subcutaneous injections for over one year of concentrated glucose solution result in the production of sarcoma a t the injection site (Gann 32: 85, 1938. Abst. in Am. J. Cancer 36: 616, 1939). In Nonaka's experiment sarcoma was found in 3 out of 4 rats that survived 400-500 days. Two of these sarcomas were transplantable. Takizawa produced tumors in both rats and mice. He noted, as did Nishiyama, that the simultaneous feeding of o-aminoazotoluol tended to increase the rate of sarcoma production. 571 Arch. f. klin. Chir. 194: 250-263, 1939. Photomicrographs and a bibliography accompany the article. Cann 32: 234-235, 1938. The sarcomas were carried through many generations of mice.