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Biomedical subjects

I Mécs

Publications and source records attributed to I Mécs.

At least 19 recordsLinked to original sources
PubMed1991

Interactions between human and porcine interferons.

To investigate the possible interactions between human and porcine interferons (IFNs) in vitro, human transformed (FL) and nontransformed (HEF) cells were treated with either HuIFN alpha and/or gamma and porcine alpha and/or gamma. In both cases the antiproliferative activity was measured to determine the effects of different combinations between human and porcine IFNs on cell proliferation. Combinations of human and porcine IFNs acted mostly antagonistically with exception of IFN combination Hu-alpha/Po-gamma which showed a synergic cooperativity in therms of antiproliferative activity on human transformed cells.

Amniotic Fluid↗
PubMed1989

Effect of storage and 60Co irradiation on the antiviral activity and subtype pattern of native human interferon-alpha preparations.

The stability of native human leukocyte IFN-alpha was investigated after one year storage at different temperatures, or after sterilization with 60Co-irradiation by determining the total antiviral activity of samples. Inactivation of VSV and Aujeszky virions by 60Co-irradiation was directly related to the radiolysis of samples, indicating the uselessness of this procedure for sterilization of IFN-alpha preparations. The presence and proportion of subtypes in the stored or irradiated preparations (with 50 and 25-70% inactivation, respectively) was analysed by chromatofocusing, comparing their patterns with that of the untreated controls. A logarithmic correlation was found between the pI values and temperature/irradiation sensitivity of subtypes.

Antiviral Agents↗
PubMed1987

Glucocorticoid-induced low molecular mass anti-inflammatory factors which do not inhibit phospholipase A2.

The peritoneal lavage fluid of dexamethasone (DXM)-pretreated rats was filtered through an Amicon YM-10 membrane (cutsize 10 kD). The retentate inhibited dextran oedema. Its 40 kD fraction (lipocortin) obtained by molecular sieving on Sephadex (SG)-75, suppressed carrageenin-induced foot swelling and phospholipase A2 (PLA2) activity, but it had no effect on the dextran response. The Amicon filtrate was chromatographed on SG-25 gel and yielded 6 and 2 kD fractions suppressing dextran and serotonin (5-HT) oedema but not carrageenin inflammation and PLA2 activity. These fractions may be active fragments of vasocortin, a glucocorticoid-induced mediator regulating vascular permeability.

Adrenalectomy↗
PubMed1985

Direct evidence for the anti-inflammatory effect of human interferon-alpha in CFLP mice. Brief report.

In CFLP mice, intravenously administered partially purified interferon-alpha (IFN-alpha 2 X 10(6) mu/mg protein), prepared from human leukocytes, reduced carrageenan-induced paw swelling and produced slight irritation when injected into the footpad. Anti-human IFN-alpha serum abolished the anti-inflammatory effect but did not influence local phlogogenic activity. Highly purified human IFN-alpha (1.2 X 10(8) mu/mg protein) was also found to be anti-inflammatory after intravenous administration, and devoid of irritative effect at the injection site. These results suggest that human IFN-alpha possesses a direct inhibitory effect on acute inflammation in mice, and the irritation appearing at the site of its application might be due to some impurities being present in the partially purified preparations.

Animals↗
PubMed1985

Effect of amino acids on the expression of antiviral activity of different types of human interferon. I. Effect of single amino acids.

It has been observed that certain amino acids may influence the antiviral activity of different types of human interferon (IFN). The effect may be enhancing or inhibitory. A qualitative survey is provided on all three types of human IFN using 23 different amino acids. A more detailed study was carried out with 10 amino acids which proved to be active towards HuIFN-alpha. Their influences on the synergistic antiviral effects of HuIFN-alpha and HuIFN-gamma were also investigated. The dose-dependence curves of their effects on HuIFN-alpha were established.

Amino Acids↗
PubMed1985

Effect of amino acids on the expression of antiviral activity of different types of human interferon. II. Effects of various amino acid pairs.

Seven amino acids which influence the antiviral activity of IFN-alpha were tested in various pairs on human leukocyte and immune IFN and on their synergistic antiviral effect. Different kinds of interactions were observed between amino acids, ranging from extinction through competition to synergism. In some cases, different types of interactions could be observed in relation to HuIFN-alpha and HuIFN-gamma. It has been reported that certain amino acids influence the antiviral activity of human interferons (IFNs). Some of them are even capable of affecting synergistic cooperation between HuIFN-alpha and HuIFN-gamma. In our experiments we tested whether these effects can be modified further by applying two amino acids simultaneously. We hoped to shed light on the problem of their mode of action by analysing their interactions.

Amino Acids↗
PubMed1984

Semi-crude human leukocyte interferon production in a simple medium.

Semi-crude human leukocyte interferon (specific activity at least 10(5) international units per mg protein) was produced by replacement of priming medium with protein poor medium before the production period. A simpler medium than Eagle's medium was suitable to obtain substantial quantities of interferon.

Blood↗
PubMed1982

In vivo hyporesponsiveness induced by Sendai virus in CFLP mice.

Sendai and Semliki Forest viruses (SFV) raised the interferon (IFN) level in blood and suppressed the acute inflammatory response induced by carrageenan in CFLP mice. After Sendai virus had been inoculated, unresponsiveness developed to repeated challenge either with the same virus or with SFV. The hyporeactive state culminated 48 hr after first virus inoculation. It was characterized (1) by absence of IFN induction and (2) by disappearance of the virus-induced anti-inflammatory effect. In contrast, the anti-inflammatory effect of indomethacin and dexamethasone remained unchanged. In addition, peripheral white blood cells were counted upon Sendai virus inoculation either in normal or in hyporesponsive mice. Six hr after inoculation, Sendai virus induced a marked granulocytosis with lymphopenia. In hyporesponsive mice leukocytosis was observed. Repeated Sendai virus injection was followed by a less pronounced granulocytosis, while the decreased number of mononuclear cells remained unchanged. These alterations in mice inoculated with Sendai virus offers a model of hyporesponsiveness established in vivo.

Animals↗
PubMed1981

On the anti-inflammatory effect of sendai virus inoculation.

Sendai virus given intravenously into CFLP mice produced dose-related suppression of the acute inflammation produced by carrageenan and 5-HT. The inhibition correlated with interferon levels in the blood, suggesting that interferon may account for the virus-induced anti-inflammatory effect.

Animals↗
PubMed1979

Antiviral effect of 3-[bis-(2-hydroxyethyl)-amino]-acetophenone-[4,5-diphenyl-oxyazolyl-(2)]hydrazone (IMET 98/69) in mice.

The potential in vivo antiviral activity of 3-[bis-(2-hydroxyethyl)-amino]-acetophenone-[4,5-diphenyl-oxazolyl-(2)]-hydrazone (IMET 98/69) was evaluated on model infections in mice. Animals treated subcutaneously (s.c.) with 1 mmole of the drug per kg body weight once daily for five days were significantly protected against a lethal infection with cardioviruses, Semliki forest virus and vaccinia virus. In influenza A and B virus models no antiviral activity was observed either after s.c. or oral treatment.

Administration, Oral↗
PubMed1976

Potentiation of poly I:C induced viral resistance by polycationic modified polypeptides.

The potentiation of polyI:C induced viral resistance by various side group modified polycationic polyglutamic acid derivatives was investigated. It was established that the efficacy of the various polycationic substances depends primarily on their macromolecular properties. Viscosity and the degree of cationic substitution have been found to be of paramount importance. The maximal potentiating efficacy, expressed as the minimum protective dose of polyI:C necessary for complete protection of cells in the presence of the polycations, was exerted by compounds of highest viscosity and degree of subsitution. The potentiating efficacy of the polycationic derivatives tested could only be observed in a relatively narrow range of concentration, depending on their viscosity and degree of substitution. In view of the extremely low minimal protective dose of polyI:C (10(-5) mug/ml) in the presence of our most effective compound it is assumed that the action of a few molecules of polyI:C may be sufficient to render a cell resistant against viral infection. Within the limits of the described experiments, the efficacy of polycationic derivatives did not seem to be influenced by the modification (e.g. quaternarization) of the cationic group.

Chemical Phenomena↗
PubMed1976

Regulation of resistance to various toxicants by PCN (pregnenolone-16alpha-carbonitrile) and thyroxine.

In rats, PCN (the most potent catatoxic steroid known to date) at the usual dose level powerfully inhibited the toxicity of antazoline, carbamazepine, cocaine, guanethidine, ibuprofen, ketamine, LSD, nembutal and reserpine, whereas (except in the case of nembutal) thyroxine sensitized the animals to intoxication with these same compounds. Even much lower doses of PCN or thyroxine exerted similar but weaker effects. PCN-induced resistance to the various substrates was generally not altered by concurrent administration of thyroxine but in a few cases its protective action was partially or totally inhibited, depending upon the respective dose levels of both compounds.

Animals↗
PubMed1976

Enhancement of interferon induction in mice by polycationic modified polypeptides.

Combined intraperitoneal treatment of mice with poly I: C and a polycationic modified polypeptide (poly-DMAE-glutamine) was investigated. It was established that the presence of appropriate amounts of poly-DMAE-glutamine produced markedly enhanced serum interferon levels as compared to those produced by poly I: C alone. Similar combinations injected into mice produced full protection against lethal doses of mouse-virulent Semliki forest virus.

Animals↗