[Immunobiologically active compounds from skin].

This paper describes physiochemical and biological properties of 3 immunologically active compounds extracted by acetone from porcine skin. High pressure gel chromatography confirmed their heterogeneity. RP-HPLC of compound 2 (C2 or K-activin) also characterizes it as a heterogeneous entity. It was shown to inhibit proliferation of cultured fibroblasts from human fetuses and exhibit weak activity in general anaphylactic reaction (anaphylactic shock) and skin anaphylactic reaction. A summary of data on immunologically active compounds are presented with special emphasis laid on acetone-extractable K-activin.

[Discovery of "masked" ribonucleases in highly purified preparations of RNA]. / Obnaruzhenie "skrytykh" ribonukleaz v vysokoochishchennykh preparatakh RNK.

It was found that RNA preparations isolated with the help of various inhibitors of RNAses from different eukariotic tissues, followed by thorough deproteinization contain particular ribonucleases ("masked" RNAses). These RNAses were supposed to be connected with RNA molecules and are not active. They may be activated by changes of RNA molecule conformation. Apparently the "marked" RNAses can take part in (a) processing of large precursor RNA molecules; (b) regulation of gene expression by means of specially cut RNA fragments.

[Interaction of T-activin with peritoneal macrophages]. / Vzaimodeistvie T-aktivina s peritoneal'nym makrofagami.

The action of T-activin on peritoneal macrophages of CBA mice after its introduction into the animals has been studied. In intact mice the phagocytic activity of macrophages and their resistance to the cytopathogenic action of Salmonella typhimurium live cells remains unchanged. The injection of corpuscular pertussis vaccine into mice leads to a decrease in the resistance of macrophages to the action of salmonellae. The simultaneous injection of T-activin into mice in doses of 0.1 and 1.0 microgram per animal abolishes the damaging action of the vaccine. The analysis of the in vitro action of T-activin on macrophages of intact mice revealed that the preliminary incubation of cells with the preparation sharply increases their resistance to the action of salmonellae, while its introduction simultaneously with bacteria or after them rapidly leads to the death of macrophages. The action of T-activin is supposed to be linked with triggering the biosynthetic processes mediating the resistance of macrophages to the cytopathogenic action of salmonellae.

[Analysis of immunoregulatory peptides of the thymus using high performance liquid chromatography]. / Analiz immunoreguliatornykh peptidov timusa metodom vysokoéffektivnozhidkostnoi khromatografii.

High performance liquid chromatography (gel filtration and chromatography in the reverse phase) was applied to analyse a composition of the heterogenous immunoregulating peptide preparation T-activine isolated from calf thymus. Gel chromatography at high pressure on the column TSK G2000 SW enabled to separate T-activine into 3 subfractions at a preparative scale. Physico-chemical properties and biological activity of these fractions were studied in vitro. Subfraction B with molecular mass of 1.0-3.5 kD and pI below 5.9 proved to be the most active.

[Effect of T-activin and hydrocortisone on transplantation immunity]. / Vliianie T-aktivina i gidrokortizona na transplantatsionnyi imunitet.

The response of thymectomized and lethally irradiated adult CBA mice to C57Bl/6 mouse skin grafts was studied after recipient protection by syngeneic bone marrow treated in vitro with T-activin, an active factor of the calf thymus with a molecular weight from 1500 to 6000 dalton, and with hydrocortisone for 30 min at 37 degrees C. Bone marrow cells treated with T-activin coupled with hydrocortisone or with T-activin alone induced the development of transplantation immunity in 85 and 80% of the recipients, respectively. Syngeneic bone marrow cells from hydrocortisone-treated donors recovered transplantation immunity in all the donors.