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ABSTRACTS EXPERIMENTAL STUDIES; ANIMAL TUMORS Relation of Carcinogenicity of Mineral Oils to Certain Physical and Chemical Characteristics of These Oils, R. LYTH. J. Industrial Hygiene 15: 226-237, 1933. (Refractive index - 1 The refractivity of a mineral oil seems to afford a Density probable indication of its carcinogenicity. When the refractivity was less than 0.5500 the sample proved inactive, while with values higher than 0.5600 the oil was highly potent. Of oils lying between these extremes, those with low values were almost inert but those with intermediate or high values, while likely to be carcinogenic, were not necessarily so, as in the case of Pennsylvanian and certain mildly treated oils. The iodine value of an oil also appeared to furnish a guide to its carcinogenicity, provided that it had not been treated. If the value was above 26 the oil was likely to be active, and if the value was above 30 it was almost certain to be so. As in the preceding test, the shale oils were characterized by the highest values, while the Russian oils had the lowest. Pennsylvanian samples occupied a position slightly higher than would be expected if their iodine values were directly related to carcinogenic potency. In the case of treated oils the iodine values were less reliable, for mild treatment was found to decrease activity out of all proportion to the fall in iodine value. Still, when a large decrease in iodine value occurred, complete absence of car- cinogenic power could be anticipated. Permanganate oxidation values were subject to such great variation, in spite of all precautions, that they were of no use in forecasting carcinogenicity. The carcjnogenic potency of the various samples had been determined in mice by Twort and his collaborators, and their figures are utilized in this paper. WM. H. WOQLOM Changes in the Liver of Mice Following the Ingestion of Hydrocarbon Oils, J. M. TWORTAND C. C. TWORT.Lancet 1: 448, 1932. In the course of their post-mortem studies of mice treated by skin applications of various carcinogenic and non-carcinogenic agents, the authors have observed certain characteristic microscopic changes in the liver following applications of mineral oils. A periportal infiltration of small round cells, with a few polynuclears intermixed, is succeeded by the appearance of cells giving a definite bichromate reaction. These cells are not unlike endothelial cells in appearance and some of them are similar to the foam cells found in xanthomas. Ultimately the cell is completely replaced by fat, with the resulting picture of a type of fatty infiltra- tion. The authors consider it probable that the chemical substance responsible for these changes gains access to the internal organs by way of the alimentary tract, for there is no doubt that much of the material painted on the skin is ingested by the animal. This condition was not induced by applications of gas tars, synthetic tars, or saponifiable oils. Two photomicrographs show the changes described. 645 31 646 ABSTRACTS Sympathectomy and Evolution of Tar Tumors in the Rabbit, AYANDIOTAVARES AND ERNESTOMORAIS. La sympathicectomie et 1’6volution des tumeurs du goudron chea le Lapin, Compt. rend. SOC.de biol. 113: 530-532, 1933. If sympathectomy exerts any effect at all upon the origin and development of tar cancer in the rabbit, which is doubtful, it tends to retard; in any case, the stimulating effect reported by some other investigators was not observed. Upon tumors already present at the time of operation, however, sympathec- tomy seemed to exert a repressing influence, though it must be borne in mind that regression is a common occurrence in tar carcinoma of the rabbit. WY. H. WOQLOM Influence of Denervation of the Ear on the Development of Tar Tumors, AYANDIO TAVARES.De l’influence de 1’6nervation auriculaire sur le d6veloppement des tumeurs du goudron, Compt. rend. SOC.de biol. 113: 763-764, 1933. The results of tar painting after combined sympathectomy and resection of the anterior auricular nerve did not differ from those accompanying sympathectomy alone. Nodules appeared first on the denervated ear in one rabbit, on both ears at the same time in a second, and almost simultaneously in a third. After resection of the anterior auricular nerve only, the results in four surviving rabbits out of 6 were discordant. Severance of both the anterior and posterior auricular nerves, which, between them, supply practically the entire ear, seemed to accelerate the development of cancer, a result which does not accord with the experience of previous investigators. It ia not entirely clear to the abstractor how many rabbite were employed in this last experiment, but the number appears to have been 15, of which 5 died before the fortieth day. WY. H. WOQLOM Prevention of Tar Cancer with Salts of Barium, J. MAISINAND J. DETROUX. La prophylaxie du cancer du goudron B hide de sels de Baryum, Compt. rend. SOC.de biol. 113: 926-928, 1933. Three groups of mice were painted three times a week for four months with tar. One lot received thrice weekly one drop of a solution of barium saccharate (4.8 X lo-‘ molecular) by mouth, a second received similarly a 4.8 X LO-6 solution, while the third served as controls. All were maintained on the same diet. On the 240th day 5.5 per cent of the first group, 8 per cent of the second, and 37.5 per cent of the third had developed cancer. The result shows that mice can be protected against tar cancer and suggests the extreme importance of diet, and particularly of the drinking water, for pro- phylaxis in man. [The number of mice in the various groups is not given.] WY. H. WOQLOM Importance of the Anion and of its Dose in the Barium Salts Employed to Prevent Tar Cancer, J. DETROUX.Au sujet de l’importance de l’anion du sel employ6 et de sa dose, dans la prophylaxie du cancer du goudron & l’aide de sels de baryum, Compt. rend. SOC.de biol. 113: 928-930, 1933. These experiments, carried out in conjunction with Maisin (see preceding abstract), were planned to determine the optimum dose of barium for preventing tar cancer in mice. One group served as controls; a second was given one drop of barium chloride solution (1 : 10,000) by mouth three times a week; a third, 1 drop of a 1 : 20,000 solution at similar intervale; a fourth, 1 drop of a 1 : 30,000 solution in the same manner; and a fifth, one drop daily of a 1 : 1,OOO,OOO solution. All the mice were kept on the same diet, and painted thrice weekly with tar for fpur months. EXPERIMENTAL STUDIES ; ANIMAL TUMORS 647 It was found that the animals which received the largest amount of barium (one drop of a 1 : 10,000 solution three times a week) developed cancer more rap- idly and in larger numbers (62 per cent) than the controls (37.5 per cent). In those of the two lots following, development of the carcinoma was slightly inhibited, while in the mice of the last group (1 drop daily of a 1 : 1,000,000 solution) the appearance of cancer was somewhat delayed and the number of carcinomas was distinctly lower (12 per cent) than in the controls (37.5 per cent). Hence there is an activating and an inhibiting dose of barium [or possibly the barium has nothing to do with the results]. In a second series of experiments, where the chloride was replaced by the gluconate, it appeared that the amount of barium which activated when admin- istered as the chloride inhibited when given in the form of gluconate. The anion of the barium salt employed evidently plays an important rBle in prophylaxis. [The number of animals in the various groups is not given.] WM.H. WOQLOM Influence of Temperature on the Virus of Mouse Sarcoma, A. BESREDKAAND L. GROSS.De l'influence de la temperature sur le virus du sarcome des Souris, Compt. rend. SOC.de biol. 113: 48-49, 1933. A fine emulsion of mouse sarcoma was heated for thirty minutes before inocu- lstion. Temperatures above 42O were fatal, as was exposure to 37" for twenty- four hours. The material was attenuated after having been kept for forty-eight hours in the icebox (4" C.) and inactivated after from three to six days. The in- jection of dried material produced only a transient granuloma. [The abstractor sees no need to assume the presence of a virus in explaining these results.] War. H. WOQLOM Are Mouse Tumors Caused by an Extra-ceUular Agent? E. HARDEAND P. HENRI. Lee tumeurs des Souris ont-elles pour origine des causes extra-cellulaires? Compt. rend. SOC.de biol. 113: 700-703, 1933. Frankel (Ztschr. f. Krebsforsch. 36: 252, 1932 and 37: 121, 1932, abst. in Am. J. Cancer 16: 1000, 1263, 1932) and Besredka and Gross [see abstract immediately preceding] suggest the existence of an extracellular etiological agent in consequence of their success in transferring neoplasms with blood, liver, and various other or- gans from tumor-bearers. Frankel later asserted that he had produced bilateral growth by injecting tumor into one flank of a mouse and normal brain into the other [an experiment purporting to demonstrate the neurotropism of the agent]. Harde and Henri have repeated this work, injecting a sarcoma [unspecified] or carcinoma 63 on one side and normal brain on the other; the result was entirely negative in all 37 mice inoculated, and the authors were then informed by Frankel that he himself had been unable to repeat his first success. Livers from animals bearing an American mouse sarcoma [180 11 were intro- duced into 6 mice; in 2 of these a tumor arose at the inoculation site, but micro- scopic metastases were discovered in one of the organs employed.

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