Search

The influence of microorganisms on the course of tumor processes in laboratory animals was studied. The study revealed that the inoculation of Bordetella pertussis decreased survival time both in mice with implanted mastocytoma cells P-815 and in Syrian golden hamsters with implanted transformed hamster fibroblastomas. The smallpox vaccine virus was found to stimulate the development of virus-induced Rauscher leukosis in mice. The mechanisms of the co-carcinogenic action of microorganisms is discussed.

In the human fibroblasts culture, transformed by the material from malignant paraganglioma culture, there was found the RNA- and DNA containing virus synthesis. The RNA-containing virus with a buoyant density of 1.16--1.18 g/ml shows no hemagglutinating activity, it fails to infect newborn Syrian hamsters, and produces no transformation-destruction changes in mammalian tissue culture. The DNA-containing virus with a buoyant density of 1.24--1.28 g/ml would agglutinate the guinea-pig and group 0 human erythrocytes, produces lesions in newborn Syrian hamsters, and cytodestructive changes in the culture of rat and mice embryonal cells and in cells of a transplantable line Vero. In terms of its properties it may be referred to human viruses of the Papova group. A combined action of DNA- and RNA-containing viruses produces a transformation effect on embryonal hamster cells and the cells of a transplantable line Vero.

Human papovavirus isolated from human malignant paraganglioma was found to have pathologic relevance to golden hamsters of varying age inducing sarcomas in adults, when given intracerebrally, and lesions of central nervous system in newborns inoculated subcutaneously. T-antigen, immunologically related to that of SV40 was detected in tumor cells. Infectious papovavirus, identical to human one, was isolated from brain tissues of sick hamsters.