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Biomedical subjects

L Borecký

Publications and source records attributed to L Borecký.

At least 73 records · Page 4Linked to original sources
PubMed1977

The cell-growth inhibitory effect of interferon. Studies of a resistant cell-subline.

Studies performed in the CSV subline of mouse L-cells suggest that activated endogenous and/or exogenous viral infection might be the factor that modifies the cell surface and, in consequence, the sensitivity of the cell to the cell-growth inhibitory action of interferon. In contrast with the parental L-cells, the CSV subline obtained by prolonged passage of L-cells in the presence of interferon shows an altered electron microscopic morphology, absence of C type particles and a decreased agglutinability with Concanavalin A. It is resistant to the cell-growth inhibitory effect of interferon but retains the sensitivity toward its antiviral effect. However, the sensitivity of the CSV subline toward the cell-growth inhibitory effect of interferon increased significantly after treatment with 5-iododexyuridine, infection with the Harvey strain of mouse sarcoma virus and/or prolonged passages in vitro. In this respect, the CSV subline resembles the primary mouse embryonic cells. Since sensitivity of CSV cells increased also after treatment with cyclic 3'-5' adenosine monophosphate and/or prostaglandin E2, it is possible that the cell-growth inhibitory effect of interferon is mediated through the "second messenger" system.

Animals↗
PubMed1977

Effect of impulsin treatment of interferon production and antiviral resistance of mice.

The effect of N-(2-hydroxyethyl)-palmitamide (Impulsin, Spofa)--an active endogenous compound which is recommended for preventing virus infection of the respiratory tract--on interferon production in mice stimulated with double stranded RNA and on the course of disease caused by encephalomyocarditis virus (EMC) was studied. Impulsin itself did not stimulate interferon production in mice treated per os or intravenously. But repeated application of this drug per os induced a macrophage activation, reflected by enhanced interferon production in vitro. When the interferon stimulation was delayed until 4 to 10 days after the first dose of Impulsin, interferon response to ds-RNA was slightly increased. After this phase of enhanced activity a decreased production of interferon was observed. Impulsin was not significantly effective in protecting mice from lethal dose of EMC virus. Application of this drug had an inhibitory effect on the toxicity of ds-RNA. A possible explanation of the mechanism by which Impulsin decreased the toxicity of virus in the organism is discussed.

Animals↗
PubMed1977

Use of bacteriophage nucleic acid inducers of interferon in man.

The interest in therapeutic exploration of phage ds-RNAs is motivated by their antiviral and immunoregulatory activities. Preliminary studies in man indicate that topical application of native ds-RNAs represents no health-hazard to patients and may be beneficial in the therapy of viral skin and eye diseases.

Animals↗
PubMed1977

Purification of mouse interferon on specifically purified immunoadsorbent.

A one-step purification procedure using affinity chromatography on purified anti-interferon antibodies makes possible to obtain highly purified interferon preparations. Antibodies against purified mouse fibroblast interferon were covalently bound to activated CNBr-Sepharose 4B. This immunoadsorbent had a binding capacity of 125,800 mouse fibroblast interferon units per 4.8 ml of gel. The binding capacity for mouse leukocytes was similar while for serum interferon it was lower. When analyzed in polyacrylamide gel, the electrophoretic profiles of purified IF had a similar shape to that of unpurified IF. The results of this purification procedure are not influenced by volume, biological activity and/or purity of the starting material.

Animals↗
PubMed1977

Levels of complement during interferon induction.

Further data were obtained in support of the finding that the levels of interferon and complement show a negative correlation after induction of interferon in vivo. Experiments with selective chelating agents showed that the activation of complement occurs by the by-pass mechanism. Preliminary results indicate that interferon itself can reduce the level of complement in vivo. Experiments are underway to verify in rats the results obtained in mice.

Animals↗
PubMed1977

Some biological activites of rabbit anti-interferon serum.

After prolonged immunization of rabbits with a semipurified mouse interferon preparation in Freund-incomplete and/or Al-Span-Oil-adjuvant a specific interferon neutralizing immunoglobulin was obtained from antiserum. The specific activity of the antiserum and immunoglobulin was confirmed in tests in which the interaction of antibodies with the cell-surface was ruled out. The antiserum (and the immunoglobulin) neutralized both the anti-viral and the cell-growth inhibitory activity of interferon. The "slow" and the "fast" fractions of purified interferon preparations were equally sensitive toward the neutralizing effect of antibodies. On the other side, the reaction of heat-inactivated interferon with the antiserum did not diminish its neutralizing activity suggesting a destruction of interferon-antigenic sites.

Immune Sera↗
PubMed1976

Some biological activities of rabbit anti-interferon serum.

After prolonged immunization of rabbits with a semipurified mouse interferon preparation in Freund's incomplete or Al-Span-Oil adjuvant, a specific interferon-neutralizing immunoglobulin was obtained from antiserum with a capacity of neutralizing about 49000 mouse interferon units per ml. The specific activity of the antiserum and immunoglobulin was confirmed in tests in which the interaction of antibodies with the cell surface was ruled out. The antiserum (and the immunoglobulin) neutralized both the antiviral and the cell-growth inhibitory activities of interferon. The "slow" and the "fast" fractions of purified interferon preparations were equally sensitive to the neutralizing effect of antibodies. On the other hand, the reaction of heat-inactivated interferon with the antiserum did not diminish the neutralizing activity of the latter, suggesting a destruction of interferon antigenic sites.

Animals↗
PubMed1976

Affinity chromatography of mouse interferon: a modified purification procedure utilizing specifically purified antibodies.

Interferon preparations of a high degree of purity were obtained by a one-step procedure using affinity chromatography on specifically purified immunoadsorbent. The procedure consisted of binding interferon harvested from serum-free medium and purified by Zn-acetate precipitation and SP-Sephadex chromatography to CNBr-activated Sepharose 4B (Column No. 1). In the next step, antiinterferon globulin was purified by affinity chromatography on Column No. 1 with the bound interferon. In this way, antibodies against purified interferon, which were free from non-antibody components, were obtained. The purified antibodies were then coupled to CNBr-activated Sepharose 4B forming Column No. 2. The latter had a binding capacity of 125 800 mouse interferon units per 4.8 ml of gel. This capacity was not altered during an 8-month period of use. The gel was capable to bind interferons obtained from fibroblasts and leukocytes and, partially, from serum. The resulting purified, products were similar, i.e. they were not influenced by volume, interferon activity, or purity of the starting material. The electrophoretic profiles of the products had a similar shape irrespective of the origin of the starting material.

Animals↗
PubMed1976

Increased resistance of an interferon-resistant cell subline to the toxic effect of double-stranded RNA.

The toxicity of double-stranded (ds) f2-phage RNA for interferon-treated L cells and an interferon-resistant subline of L cells (CVS cells) was compared. The interferon-resistant subline proved to be about 20 times more resistant to ds RNA than the parent L cells. The degree of toxicity of ds RNA was dependent on the concentration of interferon to which the cells were exposed.

Animals↗