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Biomedical subjects

J Soucek

Publications and source records attributed to J Soucek.

At least 55 records · Page 3Linked to original sources
PubMed1981

Inhibitory effect of bovine seminal ribonuclease on activated lymphocyte and lymphoblastoid cell lines in vitro.

The native dimer bovine seminal ribonuclease, AS RNase, and its four modified derivatives (carboxymethylated, succinylated, oxidated and reduced) were examined for their effects on PHA- or PWM-stimulated human lymphocytes, mixed lymphocyte cultures and lymphoblastoid cell line line (Molt-3, RAJI, UHKT-2 and UHKT-5). Among all substances tested the native AS RNase exerted the strongest suppressive effect on PHA-, PWM-, and MLR- stimulated lymphocytes. At concentrations of 5 and 100 microgram/ml AS RNase inhibited lymphocyte stimulation in MLR by 40 and 95%. The carboxymethylated and reduced derivatives possessed inhibitory effect one order lower, while the succinylated derivative showed a negligible effect, and the oxidated derivative was ineffective. The inhibitory effect on PHA-stimulated lymphocytes was not reduced when AS RNase was added to lymphocyte culture 24 or 48 h later. Likewise, the 20-fold increase in PHA concentration did not cause any decrease in inhibitory effect of AS RNase. AS RNase added to transformed lymphocytes simultaneously with 3H-TdR did not affect the thymidine uptake. As RNase also had the strongest inhibitory effect on growth, viability and the DNA synthesis in all lymphoblastoid cell lines tested. After 72 h cultivation with AS RNase at a concentration of 100 microgram/ml, the DNA synthesis decreased by more than 90% in Molt-3 and UHKT-2 cells. Simultaneously reduction in cell count and increased numbers of dead cells compared to control cultures were found. Carboxymethylated derivative at the same concentration inhibited thymidine incorporation into the DNA by 70% but did not cause any cytotoxic effect. Other derivatives showed negligible or null effects. These results are in agreement with some data published earlier, that the dimer of seminal ribonuclease exerts a significant antitumour effect. The immunosuppressive effects of AS RNase observed in the present paper suggest that this compound is one of the components of seminal plasma which may take part in suppression of immune responses of the female reproductive tract to spermatozoa.

Animals↗
PubMed1979

The binding of bull seminal ribonuclease and its carboxymethylated derivative to human leukaemic cells.

The binding of AS RNase and CM-AS RNase to leukaemic cells from patients with chronic lymphatic leukaemia was detected by indirect immunofluorescence. Leucocytes from normal donors or from patients with other hemoblastoses did not bind RNase. Experiments with lymphocytes from leukaemic patients and the lymphoblastoid cell lines in tissue culture revealed that both AS RNase solutions are probably bound mainly to leukaemic B lymphocytes.

Animals↗
PubMed1978

Isolation of alpha-1 fetoprotein.

A suitable method of the isolation of alpha-1 fetoprotein for the needs of enzyme immunoassay of this oncofetal antigen is described. By combining isoelectric focusing and "indirect" affinity chromatography the preparation of alpha-1 fetoprotein was obtained that was not contaminated with IgG, contrary to the isolation performed by means of "direct" affinity chromatography on a carrier with coupled anti-alpha-1 fetoprotein antibodies, or other immunochemical methods that usually yielded contaminated preparations. Neither disc electrophoresis in PAA gel, immunoelectrophoresis, double radial immunodiffusion, nor biological experiments revealed any traces of ballast proteins in the resulting preparation; it seems suitable both for the preparation of monovalent antisera of a sufficient avidity, and as a standard for enzyme immunoassay.

Chromatography, Affinity↗
PubMed1977

Isolation of multiple forms of dihydrofolate reductase from mouse liver.

Dihydrofolate reductase isolated from the liver of normal adult mice was focused on a LKB analytic column. Separation was carried out in a sucrose gradient and a pH gradient was formed within limits of pH 7-10 by means of 1% ampholin. 48 hours' separation yielded two enzyme fractions focusing at pH 8.1 and pH 8.7 respectively, 80% of the total activity being found in the latter fraction. If the original enzyme was preincubated with NADPH, a further activity zone, at pH 7.5, was formed after isoelectric focusing and the other two peaks were depressed. The form of the enzyme focusing at pH 8.7 had higher specific activity than the form focusing at pH 8.1. Neither of these forms of the enzyme was as pure as the enzyme prepared by affinity chromatography. This was also confirmed by double radial immunodiffusion. Degree of Methotrexate inhibition and potassium chloride activation of the two fractions isolated by isoelectric focusing was the same.

Animals↗