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B Taródi

Publications and source records attributed to B Taródi.

17 recordsLinked to original sources
PubMed2006

Prevalence and avidity of human herpesvirus-6 specific IgG antibodies in pregnant women in Hungary.

The prevalence, the level and the avidity of human herpesvirus-6 (HHV-6) specific IgG were examined in pregnant women and age-matched female blood donors. The study group consisted of 180 women (age 14-45); 60 women with normal pregnancy, 60 pregnant women with fetuses suspected of having any viral infection and 60 healthy blood donors with no history of pregnancy. Plasma or serum samples were tested for HHV-6 IgG antibodies by an immunofluorescence assay. Ninety-eight percent of blood donors and 97% of 120 pregnant women had IgG antibodies to HHV-6. The rate of seropositivity in women with normal pregnancies and women with fetuses suspected to have viral infection was the same. Pregnant women (n = 120) had significantly lower antibody titer than blood donors. No significant differences were found in the same respect between the two groups of pregnant women. Low avidity of IgG antibodies to HHV-6 was detected in 5% of pregnant women.

Adolescent↗
PubMed2001

Human cytomegalovirus gB genotype 1 is dominant in congenital infections in South Hungary.

On the basis of the sequence variation of the glycoprotein B (gB) gene, human cytomegalovirus (HCMV) can be classified into four gB genotypes. Genotyping of HCMV from congenital infections was carried out on the assumption that the envelope gB may influence the outcome of prenatal infection. Sixty-three pregnant women were included in the study: 40 pregnant women whose fetuses were strongly suspected of having viral infection, and 23 women with normal pregnancies, from whom amniotic fluid was taken for fetal karyotype assessment. The amniotic fluid, fetal blood, blood, and urine of the newborns were examined for HCMV DNA by a nested polymerase chain reaction, and the gB genotype was determined by restriction fragment length polymorphism. HCMV DNA was detected in 12 cases in which the fetuses were suspected of having a viral infection and in 3 of the normal pregnancies. All the HCMV DNA had identical genotype, gB1. These data clearly indicate the dominance of the gB1 genotype in congenital HCMV infections. The clinical outcome of these pregnancies, however, cannot be predicted on the basis of the involvement of this genotype.

Amniotic Fluid↗
PubMed1995

Study on the glycoprotein nature of chicken IFNs by chemical cleavage and inhibition of glycosylation.

The considerable molecular heterogeneity of chicken IFNs suggested the possible glycoprotein nature of these IFNs. The carbohydrate-specific oxidation and cleavage by neuraminidase indicated that fibroblast IFN may contain sugar moieties. Among the antimetabolites preventing glycosylation, monensin diminished IFN production. However, since it had the same effect on unglycosylated human leukocyte IFN, the drug very probably blocks intracellular transport. It rather proved that chicken IFNs are also secretory proteins. Tunicamycin diminished the formation of leukocyte IFN, but the decrease in titre of this IFN is due to the inhibition of protein synthesis. It is suggested that chicken fibroblast IFN is a glycoprotein, while leukocyte IFN lacks a sugar moiety. The IFN produced on induction with mitogen is closely related to leukocyte IFN, and therefore it seems that the chicken IFN system does not involve the conventional gamma type.

Animals↗
PubMed1993

The inhibitory effect of interferon-alpha on the serotonin-induced impairment of human NK cell activity in whole blood.

Serotonin (5-HT) at a concentration of 10(-4) to 10(-10) M impaired the cytotoxicity of human natural killer cells in whole blood. 5-HT added at the onset of the short-term cytotoxic assay had a pronounced inhibitory effect. It is very likely that the 5-HT2 receptor is involved in the inhibition of cytotoxicity because ketanserin, an inhibitor of the 5-HT2 receptor, partially prevented the effect of 5-HT. Treatment with 10(2)-10(4) IU/ml of interferon-alpha before or after the application of 5-HT decreased its inhibitory effect on the cytotoxicity. Radioligand binding studies revealed that the antagonistic effect of interferon was not due to the competition for the 5-HT2 receptors. Cycloheximide, an inhibitor of protein synthesis, did not block the suppression of natural killer activity by 5-HT, but it exerted a blocking effect on the acquisition of resistance to 5-HT induced by interferon.

Cells, Cultured↗
PubMed1988

Analysis of an adenovirus type 12 temperature-sensitive mutant defective in interferon induction.

Among several temperature sensitive mutants of human adenovirus type 12 (Ad12), H12ts15 was found to be defective in induction of interferon (IFN) in chick cells. This mutant was characterized as late mutant which synthesized defective III.a and penton-base antigens and failed to assemble into infectious particles at restrictive temperature. Moreover, its defect was manifested at permissive temperature, at which defective particles were readily formed. Temperature shift experiments revealed that an early event, but neither virus adsorption nor penetration, was blocked in the process of IFN induction. Therefore, it can be assumed that conformation of the adeno virion is important for IFN induction in chick cells. Conformation alteration caused by defective structural components of the capsid at restrictive temperature prevented IFN induction. This change, however, did not affect infectivity under similar conditions.

Adenoviruses, Human↗
PubMed1987

The role of interferon in the adenovirus-induced augmentation of granulocyte-mediated cytotoxicity in chicken.

The effects of human adenoviruses on the granulocyte-mediated natural cytotoxicity of chicken leukocytes were investigated. A significant, but transient augmentation of granulocyte cytotoxicity was observed 24 h after virus injection, followed by a relatively long period of its suppression. A good correlation was found between the augmented cytotoxicity and interferon induction. The interferon-inducing capacity of adenovirus type 6 and type 12 in vitro similarly ran parallel with their ability to stimulate granulocyte-mediated cytotoxicity. An adenovirus-induced elevation of cytotoxicity was not observed when IFN production was inhibited by pretreatment of the leukocytes with monoclonal antibody specific for bursal cells and monocytes. In addition, anti-IFN antibody abrogated the stimulation of cytotoxicity as well. During the in vitro experiments in which granulocyte-specific monoclonal antibody was applied, evidence was found that the effector cell activity is associated with the granulocytes. These results suggest that both the in vitro and the in vivo adenovirus-induced augmentation of granulocyte-mediated cytotoxicity is due to the IFN-inducing capacity of the virus. In chickens, the rapid augmentation of the granulocyte cytotoxicity may be important in the acute stage of infection, increasing the resistance to the virus in question and also to bacterial infections.

Adenoviridae Infections↗
PubMed1986

Production and characterization of interferon induced in chicken leukocytes by concanavalin A.

Interferon (IFN) was induced in chicken peripheral blood leukocytes by exposure to Concanavalin A (Con A). It has reached a maximum level 96 hr after stimulation with the optimum dose of 10 micrograms/ml. The IFN was partially purified by chromatography on controlled-pore glass adsorbent and was characterized as a fairly acid-stable and heat-resistant, trypsin-sensitive and species-specific substance with Mr of 20,500 Da. Antiviral response by this type of IFN in chick fibroblast culture developed within several hours. This study provides first evidence of the presence of IFN in supernatants of mitogen-stimulated chicken peripheral leukocytes.

Animals↗
PubMed1985

Effect of arginine-butyrate on interferon induction by adenovirus.

Treatment of human adenovirus type 12 infected chick cells with a low concentration of arginine-butyrate strongly inhibited interferon formation. At this concentration, as evaluated by the rate of protein synthesis the drug exerted no significant toxic effect on the cells. The early virus gene expression, not being affected in the butyrate-treated chick cells, it is autonomous and is not influenced by the effect of butyrate on chick cells. This is at variance with what has been observed in other semipermissive systems infected with adenovirus.

Adenoviruses, Human↗
PubMed1983

Different interferon-inducing ability of human adenovirus types in chick embryo cells.

Human adenovirus (Ad) types differ in their ability to induce interferon (IFN) in chick cells. Of 12 types investigated, Ad8, Ad12, Ad 18 and Ad 31 proved to be more effective IFN inducers than Ad2, Ad3, Ad4, Ad5, Ad6, Ad7, Ad15 and Ad19. Ultraviolet (UV) irradiation decreased the IFN-inducing ability of the more effective inducers only, indicating that transcription of viral DNA might play a role in IFN induction by these types. DNAs isolated from Ad2, Ad5 and Ad12 alike induced low amounts of IFN in chick cells. The IFN-inducing capacity of phage DNA was similar to that of adenovirus DNA, but induction by non-viral DNA (prokaryotic and eukaryotic) did not result in detectable IFN production. It is assumed that viral DNA and virus particles promote IFN production in different ways. Probably the viral component responsible for IFN induction by the effective Ad types differs from those having lower IFN-inducing ability.

Adenoviruses, Human↗
PubMed1982

Structural polypeptides of type 12 human adenovirus.

Similarities in the trypsin sensitivity of certain polypeptides of adenovirus types 5 and 12 (Ad5 and Ad12) have been used to identify some capsid polypeptides of Ad12. One of the polypeptides suggested to be the IIIa of Ad12 has proved to be the major structural phosphoprotein as in the case of Ad5.

Adenoviruses, Human↗
PubMed1982

Preparative separation of intact incomplete and empty adenovirus type 2 particles.

Complete adenovirus type 2 virions containing the whole genome were resistant to while empty capsids lacking DNA were breakable at a separation procedure involving customary CsCl gradient centrifugation. A purification method was developed using CsCl density gradient centrifugation in 5% glycerol which retained the integrity of incomplete particles as well as empty capsids. This procedure enabled to study the biological and physicochemical properties of different adenovirus type 2 particles.

Adenoviruses, Human↗
PubMed1980

Membrane characteristics of the hemA mutant of Bacillus subtilis.

The membrane of the delta-aminolaevulinic acid synthase (EC. 2.3.1.37) deficient mutant of Bacillus subtilis growing in the presence of delta-aminolaevulinic acid differs only to a limited extent from the wild type. In haemin-containing medium, however, significant differences are observed as regards the osmotic stability of the protoplasts and the membrane protein composition.

5-Aminolevulinate Synthetase↗
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↗
PubMed1977

The effect of interferon on chicken spleen lymphocytes.

The inhibitory activity of chicken interferon has been investigated on phytohemagglutinin (PHA)-induced DNA synthesis of chicken spleen lymphocytes inoculated with type 12 adenovirus and was purified by selective adsorption on Na-Al-silicate. As a control, the culture fluid of chicken leukocytes purified in the same manner was used. In some instances the control preparation also showed a slight inhibitory effect. To prove that the immunosuppressive activity of our interferon preparation was indeed due to its interferon content both the interferon and the control preparation were purified further by chromatography on Sephadex G 100 superfine gel. Only the fractions with antiviral activity of interferon preparation inhibited the PHA-response of the lymphocytes. The fractions with the same molecular weight of control preparation were without effect.

Adenoviridae↗
PubMed1975

Physico-chemical characteristics of interferons induced by human adenovirus in chick fibroblasts and leucocytes.

The physico-chemical characteristics of interferons with different anti-viral activities produced in chick fibroblast cells and leucocytes in response to the human adenovirus type 12 were investigated. The molecular weights of interferons produced by chick fibroblasts and leucocytes were similar: the main anti-viral activity was found at 27000 and 32000 and a low-titered shoulder at 28000 and 23000 respectively. Under our experimental conditions no oligomeric structure of interferons could be detected. The isoelectric pattern of leucocyte interferon was slightly different from that of the fibroblast interferon.

Adenoviridae↗