[Antigenic rearrangement in the liver of mice and rats as a result of simultaneous effect of the carcinogens].

The antigenic structure of the livers of mice and rats after a single hepatocarcinogenic treatment was investigated using the immunodiffuse and immunofluorescent methods. The next day after carcinogen application changes characteristic of hepatocellular tumors were observed: decrease in the synthesis of organospecific antigens and intensification of the synthesis of heteroorganic antigens.

[Study of populations of nuclear RNA of rat liver cells after short-term exposure to a carcinogen].

RNA-DNA hybridization in a solution with DNA excess was employed. Rat's livers were given one injection of 4-dimethylaminoazobenzene, and, when compared 24 hours afterwards with livers from normal untreated rats, demonstrated an altered transcription. The hybridization capacity of the nuclear RNA isolated from carcinogen-treated livers is lower than that of the control RNA.

[Effect of preparations of messenger RNA from the spleens of immunized rats on antibody synthesis in rat lymphosarcoma].

Messenger RNA was isolated from spleen polysomes of rats immunized with sheep red cells, two methods being employed: a sorption of mRNA on on membrane filters, and poly(U)-cellulose affinity chromatography. The rat transplantable lymphosarcoma cells treated with this RNA started hemolysine synthesis which persisted throughout many cell generations in transplantation of the tumor. The probability is discussed of m-RNA not only functioning as a template for antibody synthesis but also deblocating appropriate genes in recipient cells.

[Membrane antigens of Zajdela ascitic hepatoma].

The membrane antigens of Zajdela ascitic hepatoma cells were investigated. Living cells were studied by immunofluorescence method, and solublized membrane preparations by the precipitation reacting in agar gel. Testing of the tumor cells with organospecific anti-kidney serum caused a specific fluorescence of tumor cells surface.