Examination of leukaemic blasts sensitivity to cytostatic drugs using two short-term laboratory methods.

The authors examined acute leukaemia cells sensitivity to anticancer drugs using 2 short-time methods: 1. Measurement of the inhibition of 3HTdr incorporation during 2 h incubation with cytostatic; 2. Evaluation of the cell viability in short-term (5 days) liquid culture.

Heterospecific activity of rat interferon.

In the experiments performed in vitro and in vivo it has been found that the rat and rat embryo fibroblasts cultured in vitro after the induction with virus produce interferon which displays the antiviral activity not only in the homologous cells but also in the heterologous ones. When analysed by chromatography on Sephadex G-100 it was shown that the rat serum contains two interferon populations differing in the molecular weight and both active in the homologous and heterologous cells. The interferon with the heterospecific activity has been used in the experimental therapy of mice infected with Encephalomyocarditis Virus (EMC), Vesicular Stomatitis Virus (VSV) and Influenza Virus, and was found to be effective.

Rat interferons. Homologous and heterologus rat serum activity.

Serum proteins from normal rat serum and induced with Sindbis virus were separated on Sephadex G-100. Interferon activity was studied in a system of homologous REC and heterologous LG cells. Proteins of normal serum as well as induced serum emerged in two peaks separated by a deep saddle.

Rat interferons. IV. Sialoproteins in rat serum.

Introduction of virus as inductor of interferon into rats caused a decline in serum levels of sialic acid in blood taken at the time of maximum interferon activity. Differences in the acute phase proteins were dependent on the type of virus used for induction. NDV injected intravenously did not lower serum levels of seromucoid, but given together with DMSO markedly depressed the content of this protein in the serum.