[GANN, 58, 247-251; June, 1967] UDC 616-006-022.7:576.858.5.093.2 INCUBATION PERIOD FOR TUMOR INDUCTION BY ADENOVIRUS TYPE 12 (Plate XXXVI)

Adenovirus type 12 was inoculated intraperitoneally into newborn hamsters. At selected periods, the soft peritoneal tissues were excised and transplanted subcutaneously into 16to 29-day-old hamsters. With the tissues taken at 6 hours or more after the virus inoculation, tumors developed at the transplanted site. The period from virus inoculation to excision and transplantation of the soft peritoneal tissues, and from transplantation to development of grossly recognizable tumors ranged from 24 to 38 days, which correspond to the average latent period for tumor development in hamsters intraperitoneally inoculated with the virus at birth. The virus was not isolated from the soft peritoneal tissues similarly excised from hamsters inoculated with the virus at birth. None of 10 young adult hamsters injected with the virus developed any visible tumors during 46 to 367 days of observation. These results would imply that (1) the tumors developed at the site of tissue transplantation originate from the cells in the transplanted tissues, which would have been already neoplastically transformed or destined by the virus; and (2) transformation or transition of the target cells to malignant cells will be completed in 6 hours after the virus inoculation.