[Mammary gland tumors of rats born to parents irradiated before conception]. / Ob opukholiakh molochnykh zhelez u krys, rozhdennykh ot roditelei, obluchennykh do zachatiia.

The effect of exposure of male or female rats to radiation 5 days before conception on the frequency of development of mammary tumors in their progeny is described. It was shown that mammary tumor incidence and the rate of their development increase in a population of female rats - descendants of one of parents exposed. Irradiation of would-be mothers produced a stronger blastogenic reaction in their progeny than that of fathers.

[Tumors in animals irradiated during embryogenesis]. / Ob opukholiakh u zhivotnykh, obluchennykh v émbriogeneze.

In experiments on 465 male and female white non-lineal rats irradiated in their embryonal (7th day--240 rats), organogenesis (14th day--105 rats) and foetal periods of embryogenesis (19th day--120 rats) with 60Co--rays in a dose of 100 r, its actual power 168 r/m, and on 73 control rats the authors have studied the frequency and terms of tumors appearance. A group comprising 219 experimental rats and 53 control animals, died during a period of 200--600 days following their birth, was analysed. Irradiation at different stages of embryogenesis would provide a statistically significant increase in the frequency of tumors and shorten the terms of their appearance. In control animals tumors arose in 16,9% (in 9 of 53 animals). Embryonal and foetal periods of embryogenesis proved to be mostly susceptible as evidenced by the yield of radiation tumors. In animals exposed to irradiation in their embryonal period tumors arose in 64,5% (in 69 of 107 rats), in the foetal period--in 62,8% (in 44 of 70 rats), and during the period of organogenesis--in 42,8% (in 18 of 42 rats). Rats exposed to irradiation in the embryonal and foetal period of embryogenesis developed tumors to the 120--180th day of the experiment, while in the organogenesis period--to the 400th day. Maximum tumor appearance was observed in the last third of the lifetime. Male rats irradiated in the period of embryogenesis developed tumors of the mammary gland and bones, females- ovarian and bone tumors, which were absent in control animals.

[Relationship between the number of mast cells and neoplastic prolideration of the mammary gland epithelium]. / O sootnochenii mezhdu soderzhaniem tuchnykh kletok i neoplasticheskoi proliferatsiei epiteliia molochnykh zhelez.

The results of the experiments make it possible to regard the number of mast in mammary glands as an index correlating with the intensity of the proliferative reaction of the mammary gland epithelium reflecting the course of the pathological process in the tissue. This index is higher to the moment of benign tumor formation. The second more intensive rise of this index characterizes malignant transformation of the epithelium. A decrease of the mast cells level since the moment of malignant transformation and their rather low content in malignant tumors manifest the decompensation of the organism antiblastic system.