ABSTRACTS EXPERIMENTAL STUDIES; TUMORS IN ANIMALS Production of Cancer in Rabbits by Painting with Tobacco Tar. 11. The Appearance of Isolated Tumors in an Irritated Area, LO-FU-HUA. Uber die Erzeugung von Krebs durch Tabakteerpinselung bei Kaninchen. 11. Uber das Solitarauftreten einzelner Tumoren auf einer diffus gereizten Korperstelle, Frankfurt. Ztschr. f. Path. 47: 52-62,1934. It is well known that the malignant change sets in here and there at isolated points in a tar-painted area, never involving the entire irritated field. In the author’s experi- ments with tobacco tar the same scattered development of tumors was observed, and he asks what may be the reason therefor. This apparently random localization cannot be explained by the distribution of the hair follicles, for all tar carcinomas do not arise from these structures, and not every hair follicle suffers the malignant change. It seems more probable that tumors develop in minute wounds (scratches, etc.), as has been suggested by several investigators, though here again it is to be noted that the carcinoma develops, not throughout the whole length of the wound, but only at one point. The author adopts the view of Ribbert and of Borst, that new growths can arise only from specially predisposed cells, and that unless an irritant comes into contact with these sensitized elements no neoplasm will appear. Cells which possess this pathological attribute without definite morphological indication of its presence may be described as tumor anlagen of the second order, while those with appreciable evidence of its existence may be assigned to the first order. The former group, which constitutes the foundation for all experimental carcinogenesis, must be widely distributed, as tumors can be elicited at so many different sites, and it is probabIe that these anlagen of the second order are responsible for neoplasms which arise at a distance from the tarred area. In addition to this local predisposition, there exists, no doubt, a general susceptibility, for every irritated regenerative lesion does not end in cancer. Yet this explanation does not cover the entire case, for it still does not tell why a neoplasm does not involve an entire regenerating wound; the presence of general susceptibility must be assumed, since a neoplasm has arisen, but why should it appear at only one small point in the wound? No matter how important a factor regeneration may be, it would not be possible to elicit a tumor at any particular selected site in the body, even in the presence of constitu- tional predisposition. For the primary cause of neoplasia is not regeneration, but some characteristic idiosyncrasy of the chromosomes. WM. H. WOGLOM Experimental Production of Bone Sarcoma in the Rabbit with Radium, 0. SCHURCHAND E. UEHLINQER.Experimentelle Erzeugung von Knochensarkom durch Radium beim Kaninchen, Schweiz. med. Wchnschr. 15: 664-667, 1934. The authors give a preliminary account of an osteogenic sarcoma in the femur of a rabbit, first discovered nineteen months after 3 micrograms of mesothorium (in vaseline) had been deposited in the marrow cavity. Death occurred two months later, as a con- sequence of generalized metastasis. The experiment shows, first, that a purely exogenous stimulus can initiate osteogenic sarcoma and secondly, that such a neoplasm can be evoked by a very small dose of radia- tion acting over a long period of time. Further discussion is postponed until observations on all the animals treated have been finished. [The authors refer to Martland’s observations (Am. J. Cancer 15: 2435, 1931) on hone sarcoma in the human subject following the accidental ingestion of radio-active materials, but have missed the description by Sabin, Doan, and Forkner (J. Exper. 677 ABSTRACTS Med. 56: 267, 1932) of similar neoplasms produced in the rabbit by intravenous injection of these agents.] WM. H. WOOLOM Malignant Tumors Produced in the Rabbit by Irradiation of Infiammatory Foci, A. LACASSAQNE.Tumeurs malignes provoquhes, chez le lapin, par l’irradiation de foyers inflammatoires, Compt. rend. Acad. d. sc. 196: 09-71, 1933. To five sarcomas that ocourred about x-rayed abscesses in rabbits (Compt. rend. Sow de biol. 112: 562, 1933. Abst. in Am. J. Cancer 18: 628, 1933), the author now adds a carcinoma and a sarcoma, which developed after irradiation of the site where sterile diatomaceous earth had been injected into two rabbits. Thus irradiation of an inflam- matory focus, whether this be infected or sterile, appears to initiate malignancy. [The development of epithelioma at the mouth of a fistulous tract in the gum of H young man, after five to six years’ daily exposure to x-rays, is of interest in this connec- tion (Gricouroff: Bull. Assoc. frang. p. 1’Btude du cancer 23: 97, 1934. Abst. in Am. J. Cancer 21: 681, 1934).] WM. H. WOOLOM Attempts to Produce Neoplasms of the Renal Pelvis by the Use of Foreign Bodies and Tar, P. BRUNI. Tentativi di produzione di neoplasie della pelvi renale con corpi estranei e con catrame, Ann. ital. di chir. 12: 366-376, 1933. This is the report of an experiment carried out on only ten animals. Stones of cement and of cement mixed with tar were introduced into the renal pelves of four guinea- pigs and six rats. In no case were neoplastic growths of the pelvis found on autopsy three months later. Inflammatory lesions of the connective tissue and hyperplastic epithelial changes were observed. [No tumors should be expected at the end of three months’ irritation in either guinea- pigs or rats. Taenia crassicollis requires at least eight months to produce sarcoma of t,he liver in rats, and 1 : 2 : 5 : 6-dibenaanthracene takes the same period to induce sarcoma of the subcutaneous tissues in rats.] JEANNETTEMUNRO Parasites and Tumor Growth, R. HOEPPLI.Chinese M. J. 47: 1075-1111, 1933. This is a review of caaes of natural infestation with parasites in which these organisme appeared to play an etiological r61e in the development of malignant new growths, and of cases of experimental tumor production by parasites. The conclusion is drawn that various ecto- and endo- parasites, as well as certain bacteria, are capable of initiating malignant disease in man and other vertebrates. The response of the host’s tissues is essentially the same in all cases, leading through chronic inflammation to cell proliferation and ultimately to neoplasia. The tumor, which is only an indirect result of the infestation, is probably caused by glandular secretions orthe end products of metabolism, mere mechanical irritation appearing to be a less important factor, Susceptibility on the part of the host is a necessary antecedent, for wide varia- tions are found between different species, different strains of the same species, different individuals of the same strain, and different organs and tissues of the same individual. There is no fundamental difference in the development of a tumor due to a parasitic agent, and of one caused by a chemical such as tar. No true malignant neoplasm has yet been discovered in an invertebrate, and within the group of vertebrates tumors are much more common in birds and mammals than in the reptiles and amphibia, an observation indicating that predisposition to new growths in vertebrates is in inverse .proportion to the power of regeneration. A thirteen-page bibliography brings the article to a close. WM. H. WO~LOM Decrease in the Resistance to Tumors Produced by Tumor Filtrates. Experimental Investigation, LUIOISPADAFINA. La chute des rhsistances antinboplasiques avec le filtrat tumoral: recherches exp6rimentales1 Cancer 11 : 1-24, 1934. One of the most interesting of recent discoveries is the demonstration of substances in or between tumor cells, which exert a stimulating action upon the neoplasm. These have been found not only in carcinomas and sarcomas of mammals (rats, mice) but in chicken sarcoma as well, and they appear to be operative both in vivo and in vitro. EXPERIMENTAL STUDIES ; TUMORS IN ANIMALS 679 They are characteristic, moreover, of the malignant cell, for all attempts to disclose their presence in normal tissues have failed; the latter, indeed, appear to contain an inhibiting substance. In a series of 4 experiments, totalling 73 mice in all, the author showed that prelimi- nary injection of filtrates of the Ehrlich mouse carcinoma enhanced the growth rate and metastasis of this neoplasm, and that the resistance conferred by normal tissues could be decreased by similar treatment. WM. H. WOGLOM Hormonal Regulation of Tumor Growth and Metabolism, MAX REISS, HERMANN DRUCKREYAND ADOLF HOCHWALD.Beitriige zur hormonalen Steuerung des Tumorwachstums und Reines Stoffwechsels, Ztschr. f. d. ges. exper. Med. 90: 408-420, 1933. For years the Jensen sarcoma has grown vigorously and at all seasons in 100 per cent of 60 to 100 gm. rats of the author's strain, whereas in older ones the percentage of SUC- cess has been smaller and subject to seasonal fluctuations. This can hardly be ex- plained otherwise than by reference to some endocrine influence, and attention was first directed to the hypophysis because of the relation which it bears to body growth. Some 300 rats of 60 to 120 gm. were hypophysectomized and inoculated, some before, some after the extirpation, with the Jensen rat sarcoma. It may be said at once that the tumor took in all cases, though its subsequent growth was profoundly influenced. The most distinct effect occurred when grafts were introduced about two to three weeks after operation; here the sarcoma grew until it had attained the size of a pea, or of a cherry at the most, and then regressed entirely. The longer the interval since extirpa- tion, the shorter was the life of the tumor. Where excision was practised in rats already bearing a tumor the growth of the sarcoma was inhibited from then on, but complete regression did not take place if a nodule was larger than a cherry three weeks after opera- tion.