[Induction of sarcomas by a nontumorigenic type of foreign body and glutaraldehyde].

Nontumorigenic form of cellophane has been implanted subcutaneously into rats, and simultaneously an injection of 0.5 ml 2.5% buffered glutaraldehyde has been given at the site of implantation.

[Effect of gonadectomy on the carcinogenesis induced by a foreign body implant].

The incidence of tumors arising near a plate in male rats castrated before and after its being implanted into the loose connective tissue was studied. Tumors occurred in 26 animals out of 49 in control (group 3) (53.2%); in 16 out of 28 rats castrated one month after implantation (group 2) (57.

[Effect of nitrosoethylurea on sarcomagenesis induced by a foreign body].

Subcutaneous administration to rats of an intact cellophane plate gave rise to sarcomas in 60% of cases, the latent period being 16.5 month. Meanwhile administration of minced cellophane did not produce tumors.

[Scanning electron microscopic study of films of the loose connective tissue of mice exposed to DMBA].

Under examination by scanning electron microscopy were film samples of the subcutaneous connective tissue. The surface of the films from intact mice was even and smooth, fibroblasts have a spread pattern. Following the saline injection the film was even, collagen fibres, differing in the character of surface and the size of diameter, were readily seen.

[Teratoid formation after implanting early embryos].

The ability of embryos of different age to form teratoids upon their transplantation under the renal capsule was studied in the CBA mice. The teratoids were shown to form most actively upon transplantation of 10 days old embryos; 7 days old embryos, besides teratoids, may give origin to rapidly growing teratomas. The number of differentiated tissues in teratoids increases with the age of transplanted embryo.