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Biomedical subjects

I Mucsi

Publications and source records attributed to I Mucsi.

At least 37 records · Page 2Linked to original sources
PubMed1983

Inhibition of the adhesion of E. coli on cultured human epithelial cells in the presence of promethazine or imipramine.

The adhesion and multiplication of E. coli strain K12 with a derepressed synthesis of sex pili and of a nephropathogenic E. coli strain isolated from the urine of a patient with pyelonephritis, were demonstrated on the surface of cultured HEp-2 cells. The adhesion of the two E. coli strans was inhibited in the presence of 0.5-5.0 micrograms/ml promethazine or imipramine, but the multiplication of the bacteria on the monolayers was not decreased significantly in the presence of the two drugs. A scanning electronmicroscopic technique was developed to study bacterial adhesion and colony formation on epithelial cells.

Adhesiveness↗
PubMed1982

The effect of rutin-N-mustard on the survival of NK/Ly ascites tumour-bearing mice.

A newly synthetized rutin derivative, rutin-N-mustard, showed a marked antiproliferative effect on NK/Ly ascites tumour cells in vivo. When administered i.p. or i.v., this compound increased the survival time of the animals, but oral administration had no such effect. The drug was not able to kill the tumour cells, since the chromium release from the rutin-N-mustard-treated tumour cells was the same as in the case of the controls. Tumour growth was completely inhibited in the animals when the cells were pretreated with 100 mg/kg rutin-N-mustard before transplantation. The results also showed that rutin-N-mustard has little effect on the xenogenization of NK/Ly tumour cells. We presume that the antiproliferative action of rutin-N-mustard is due to its alkylating activity.

Administration, Oral↗
PubMed1979

Interferon induction by adenoviruses.

All human, simian, bovine and avian adenovirus types tested so far and the canine hepatitis virus induce interferon production in chick cells. This finding indicated this property to be characteristic for viruses belonging to the adenovirus group. Trypsin treatment, which had no effect upon the infectivity, diminished or eliminated the interferon-inducing abilities of crude adenoviruses, and thus the need for a trypsin-sensitive protein in interferon induction was suggested. T antigen and interferon were formed simultaneously in chick embryo fibroblast cells infected with human adenovirus type 12, and therefore the adenovirus-specific T antigen was resistant to the action of endogenous interferon synthetized by the same cells. In chicks inoculated with human types, the appearance of interferon was biphasic: an 'early' and a 'late' interferon could be demonstrated with maximum titre 4 and 10 hr, respectively, after virus infection. In chicks infected with adenoviruses, first interferon production and then a decreased primary immune response to sheep red blood cells was observed. It was assumed that in adenovirus-infected chicks the interferon produced by viral stimulus resulted in a transient immunosuppression.

Adenoviridae↗
PubMed1978

Effect of treatment with certain flavonoids on Mengo virus-induced encephalitis in mice.

Among the four flavonoids tested quercetin and morin proved to be significantly effective against lethal Mengo virus-induced encephalitis in mice when the drugs were adminsitered orally (p.o.). With subcutaneous (s.c.) administration all four drugs failed to prevent mortality in the infected mice. Quercetin produced maximum protective response in intraperitoneally (i.p.) or intranasally (i.nas.) infected mice when administered twice daily at doses of 20 mg/kg for a period of not less than four days. Single injections of the full daily dose of drug failed to prevent deaths in mice. Treatment must be begun at the time of, or prior to, virus inoculation. Delayed initiation of treatment was ineffective in preventing mortality.

Administration, Intranasal↗
PubMed1976

Use of elution marker for the intratypic characterization of poliovirus strains.

Elution marker was used for intratypic characterization of poliovirus strains with Al(OH)3 gel as adsorbent. The virion suspensions to be tested were partially purified by chromatography and labelled with 32P. In the labelled preparations of wild virus strains practically all radioactivity was found in virus-specific bond, whereas in those of the vaccine strains and isolates of vaccine origin a considerable, but variable, proportion of the activity was bound to residual cell components. For this reason, the EC50 value (i.e. the phosphate molarity corresponding to the 50% adsorption equilibrium of virions), for the vaccine and vaccine-like strains showed a wide scattering. The activity bound to cell components was removable from the gel with 0.005 M phosphate buffer, whereas the elution maxima for all the poliovirus strains examined so far were over 0.02 M. The elution marker was calculated for 25 type-2 and 30 type-3 strains, all isolated during or soon after vaccination periods from cases suspect of poliomyelitis, both with and without taking into account the cell-bound activity. In the latter case, the EC50 values agreed with that for the corresponding reference vaccine strain much better than in the former; furthermore, the type-2 reference vaccine strain and the type-2 isolates, indistinguishable from the wild reference strain by the original method, could easily be differentiated on the basis of the corrected EC50 value. The possibility that the lack of an appreciable proportion of cell-bound radioactivity may reflect the pathogenicity of poliovirus strains is discussed.

Adsorption↗
PubMed1973

Effect of human adenoviruses on the response of chickens to sheep erythrocytes.

Human adenovirus types 6, 8, and 12 were immunosuppressive in chickens. A single intravenous injection of adenoviruses markedly depressed the 19S hemolytic plaque-forming cell response in the spleen to the immunization with sheep red blood cells. Hemagglutinin production was also decreased in adenovirus type 6-infected chickens. Adenoviruses caused a transient immunosuppression in chickens which could be detected 2 to 3 days after the virus infection, and no depressive effect was found 16 to 20 days after virus injection. The possible mechanism of immunosuppression observed is discussed.

Adenoviridae↗
PubMedDate not supplied

Extracellular signal-regulated kinase and the small GTP-binding protein p21Rac1 are involved in the regulation of gene transcription by angiotensin II.

To study the role of extracellular-signal-regulated kinase (ERK) cascade and the small GTP-ase proteins in the activation of the c-fos promoter by angiotensin II (AII), transient transfection experiments were performed in CHO cells stably expressing the rat AT(1A) receptor. In this system AII activated ERK in 1 min and also increased the transcriptional activity of the c-fos promoter-luciferase reporter gene construct. The activation of the promoter proved to be dependent on the Ras-Raf-ERK cascade as cotransfection of expression vectors known to specifically inhibit this cascade blocked the effect of AII. Dominant-negative p21Rac1 mutant partially blocked the activation of the c-fos promoter by AII. However, activation of the c-fos promoter was independent of protein kinase C (PKC) as bisindolylmaleimide I, a specific PKC inhibitor did not block the effect of AII. These results suggest that AII activates the transcription of the c-fos through the Ras-Raf-ERK cascade. Furthermore, p21Rac1 is involved in the modulation of the c-fos promoter by AII.

Angiotensin II↗
PubMedDate not supplied

Antitumor activity of benzo[a]phenothiazines.

We have previously reported on the diverse biological activities of benzo[a]phenothiazines, such as the induction of antitumor and antimutagenic activity in vivo, and differentiation and apoptosis in vitro. The relationship of radical generation and pi-spin density or dipole moment was investigated, using quantum-chemical calculation with UHF/PM3. These data suggest that the origin of radical generation by active benzo[a]phenothiazines, which affect such biological activities might be N-atom at position 12.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Membrane associated antitumor effects of crocine-, ginsenoside- and cannabinoid derivates.

In the present work a systematic study was initiated with crocine, ginsenoside and cannabinoid derivatives on multidrug resistant mouse lymphoma cells, viral tumor antigen expression and some human leukocyte functions. Among saffron derivatives, crocin and picrocrocin, triglucosyl and diglucosyl crocetin were ineffective on the reversal of multidrug resistance of lymphoma cells. Ginsenoside increased drug accumulation and tumor antigen expression at 2.0-20.0 micrograms/mL. Some cannabinoid derivatives such as cannabinol, cannabispirol and cannabidiol increased drug accumulation, while cannabidiolic acid, delta-9-THC and tetrahydro-cannabidiolic acid reduced drug accumulation of the human mdr1-gene transfected mouse lymphoma cells. The reversal of multidrug resistance is the result of the inhibition of the efflux pump function in the tumor cells. Crocetin esters were less potent than crocin itself in the inhibition of EBV early antigen expression. However crocin and diglucosylcrocetin inhibited early tumor antigen expression of adenovirus infected cells, but triglucosylcrocetin was less effective at 0.01-1.0 microgram/mL. The crocin had no antiviral effect [on HSV-2 infected vero cells] up to 25 micrograms/mL concentration. Ginsenosides had a moderate inhibitory effect except ginsenoside Rb1 (was the less effective) on the drug efflux pump. Among the cannabinoid derivatives the cannabinol and cannabispirol increased drug accumulation, while cannabidiolic acid and delta-8-THC, delta-9-THC and tetrahydro-cannabinol reduced drug accumulation in multidrug resistant mouse lymphoma cells. It is interesting that ginsenosides had a chemical structure-dependent immunomodulating effect by enhancing the activity of NK-cells and ADCC activities.

Animals↗
PubMedDate not supplied

Biological activity of feijoa peel extracts.

Fractionated extracts of Feijoa peels were studied for cytotoxic activity, anti-human immunodeficiency virus (HIV) activity and antibacterial activity. Two most cytotoxic fractions A3 of acetone extract and M2 of methanol extract had potent inhibitory activity against Gram-positive and Gram-negative bacteria as well as fungi tested. Fraction A4 of acetone extract showed multidrug resistance (MDR)-reversal activity comparable with that of verapamil (positive control). These results indicate the therapeutic value of Feijoa peel extracts as potential antimicrobial and MDR-modulating agents.

Anti-Bacterial Agents↗