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Biomedical subjects

V Lackovic

Publications and source records attributed to V Lackovic.

At least 37 records · Page 2Linked to original sources
PubMed1982

Production of interferon and other lymphokines during murine tumour growth. III. Characterization of microbial growth inhibitory activity in cell-free supernatants of rat Zajdela ascites hepatoma.

A microbial growth inhibitory factor (MGIF) detected in the cell-free fluid of Zajdela ascites hepatoma of the rat was characterized by means of gel filtration, ion exchange chromatography and isoelectric focusing. It was shown that MGIF is a nondialysable protein with a molecular weight of about 19,000 to 25,000. Charge heterogeneity was revealed by isoelectric focusing which demonstrated pI of 3.8--4.5 and 5.0--6.0. MGIF seems to differ from tumour cell-derived MIF detected in the same ascitic fluids.

Ammonium Sulfate↗
PubMed1981

Accelerated appearance of an ascitic tumour after long-term application of interferon to NZB/W mice.

In two similarly designed experiments female NZB/W mice treated with mouse L-cell interferon developed an ascitic tumour when the treatment was begun at 3.5 months of age. But no tumour appeared within a 6 months' observation period when 6 months old mice were used. A transient rise of anti-DNA antibodies preceded the tumour appearance in mice. The ascitic tumour was sensitive to antimetabolites and insensitive, or marginally sensitive, to alkylating agents or interferon. The tumour cells were adapted to growth in suspension in vitro. They caused tumour growth in various inbred and random-bred mouse lines. Attempts to transfer the tumour to Swiss mice with cell free preparations were unsuccessful.

Animals↗
PubMed1980

The cell growth inhibitory and antiviral effects of interferon in cloned transformed mouse cells.

Eight clones and two subclones of SV40- and seven clones and one subclone of 20-methylcholanthrene-transformed C3H mouse embryonic fibroblasts were compared in tests for sensitivity to the antiviral and cell-growth inhibitory activities of a partially purified mouse L-cell interferon. While the sensitivity of clones and subclones to the antiviral activity of interferon was comparable to that of parent lines, the cell-growth inhibitory activity of interferon in the SV40 clones showed more than 100-fold variation and the methylcholanthrene-transformed cells could be divided into two groups in this respect. No correlation of sensitivity to the cell-growth inhibitory effect of interferon with the chromosome number, interferon-producing capacity or tumorigenicity of the clones could be detected. However, the cells of the interferon-sensitive clones No. 36 of the methylcholanthrene-transformed line were destroyed by macrophages at higher percentage binding of 125I-labeled soybean lectin. These results suggest that (1) the cell-growth inhibitory effect of interferon might be mediated by a specific type of receptors, and (2) N-acetyl-galactosamine present on the surface of interferon-resistant cells in a higher concentration than on interferon-sensitive cells hinders the recognition of cells both by macrophages and by interferon.

Animals↗
PubMed1980

Production of interferon and other lymphokines during murine tumour growth. I. Lymphokines in cell--free fluid of rat Zajdela ascites hepatoma.

Cell-free ascites of rat Zajdela hepatoma was assayed for the presence of lymphokine-like factors. Macrophage migration inhibitory and microbial growth inhibitory cytokines were detected with peak activities at day 4-8 and 10-11 after tumour inoculation, respectively. Occasionally, skin reactive activity was found, whereas only borderline titres of an interferon-like substance were demonstrated. Preliminary studies indicated that both migration inhibitory and microbial growth inhibitory factors are proteins resembling the corresponding lymphocyte-derived lymphokines. The cellular site of formation of these factors remains to be determined.

Animals↗
PubMed1980

Production of interferon and other lymphokines during murine tumour growth. II. Induction of an interferon by Ehrlich ascites cells in outbred mice.

A viral inhibitor produced in the peritoneal cavity of outbred Swiss mice inoculated with allogeneic Ehrlich ascites cells was identified as an interferon. It was antigenically related to viral interferons of type 1 and seems to be produced by macrophages. The interferon activity in the peritoneum reached maximal levels at 24 hr after tumour challenge. Interferon induction by Ehrlich ascites cells was not inhibited in lipopolysaccharide-hyporeactive mice. In addition, cell growth inhibition, enhanced interferon production after priming with small doses of this interferon, and increased susceptibility of cells treated with this interferon to the toxic effect of double-stranded RNA was demonstrated.

Animals↗
PubMed1979

Production of antiviral and migration inhibitory activities in the peritoneum of mice after inoculation with allogenic Ehrlich ascites tumor cells.

Peritoneal inoculation of Ehrlich ascites cells into mice stimulates the appearance of migration inhibitory factor (MIF) not only in the peritoneum but also in the circulation of mice. Whereas the MIF-activity in the peritoneum reached maximum at 6 days and disappeared within 17 days, the MIF-activity of sera reached maximum levels at about 11 days after intraperitoneal inoculation of tumor cells (10(6) of EAC per mouse). In addition, an antiviral activity of peritoneal exudates was observed in the early stage (24--72 h) of tumor challenge. The time-course of appearance of both MIF and AV-inhibitor are presented. A significant decrease of MIF-activity was noted when the tumor-inoculated mice were treated with ds-RNA, antithymocyte serum and cyclophosphamide, respectively. The appearance of antiviral activity in the peritoneum of tumor-inoculated mice seems to be macrophage-dependent. Although the antiviral factor meets several criteria of interferons, further studies are required for its characterization.

Animals↗
PubMed1979

Long-term culture of guinea pig tongue cells: a suitable interferon system.

The interferon system was investigated in a long-term culture of guinea pig tongue (GPT) cells. Interferon synthesis was induced with Newcastle disease virus (B strain) and f2 phage double-stranded RNA. Guinea pig interferons were about 2 times more active in cell cultures established from guinea pig embryos than in the GPT cells. Human leukocyte and mouse peritoneal cell interferons were active in this cell system also.

Animals↗
PubMed1979

The effect of native and sonicated double-stranded polyribonucleotides on the course of spontaneous autoimmune disease in NZB and NZB/Swiss F1 mice.

The administration of sonicated fractions of f2 phage polyribonucleotides caused an increased weight loss and deterioration of the clinical state in female NZB mice. Discontinuance of the treatment resulted in an improvement of both the clinical state and the genetically determined autoimmune disorders of these mice. Some potential explanations of this effect are discussed.

Animals↗
PubMed1978

Results of a five-year study of the curative effect of double stranded ribonucleic acid in viral dermatoses and eye diseases.

Double stranded RNA obtained from non-permissive E. coli cells infected with f2-phage was tested in 5 hospitals in viral dermtoses such as herpes simplex recidivans, herpes zoster, male genikeratonconjunctivitis herpetica and conjunctivitis lignosa. The results of clinical tests indicate that the preparation of phage double stranded RNA applied topically is harmless for man and has, in the majority of cases, a beneficial effect in the disease. This conclusion was based on the judgment of physicians, opinion of patients expressed in a questionnaire, and, results of a double-blind experiment.

Clinical Trials as Topic↗
PubMed1978

[Effect of sodium chloride on the secretory activity on the kidney juxtaglomerular cells and on the adrenal glomerular zone in the adult male rabbit].

Experiments were carried out on the adult male rabbits. The animals were divided in three experimental groups and one control group. The animals of all experimental groups were given NaCl, through different ways. The degree of granularity of juxtaglomerular cells was evaluated by counting the JGI (juxtaglomerular index) according to HARTROFT. In all experimental groups, the JGI was lowered. The lowest was found in the first experimental group, that was given NaCl drinking fluid. The width of the zona glomerulosa was measured microscopically on the adrenal gland tissue colored by HE. It was smaller in all experimental groups. The smallest was in the first experimental group of animals. The diminution of the zona glomerulosa corresponds with the decrease of granularity of juxtaglomerular cells.

Adrenal Cortex↗
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↗