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Biomedical subjects

E Ujhelyi

Publications and source records attributed to E Ujhelyi.

At least 55 records · Page 3Linked to original sources
PubMed1989

Complement-dependent cytotoxicity of antibodies reactive with HIV-induced cell surface antigens in HIV-carrying haemophiliacs.

Sera obtained from HIV-infected as well as uninfected haemophiliacs and from healthy subjects were investigated for the presence of lymphocytotoxic antibodies. Using the 51Cr-release test, HIV-infected haemophiliacs were found to produce serum antibodies exerting complement-dependent cytotoxic effect on HIV-infected T4 cells. The antibodies were reactive mainly when HIV-infected target cells were stimulated with concanavalin-A. Results of complement-dependent antibody cytotoxicity and indirect membrane immunofluorescence tests suggest that envelope antigen(s) of HIV may be the target(s) for cytotoxic antibodies.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Pitfalls in HIV serology: reagent-dependent changes in sensitivity and specificity of ELISA kits.

Using confirmed positive and false-positive serum samples stored in deep frozen state we studied the reproducibility of the results obtained by different anti-HIV enzyme immunoassay (EIA) kits. Experiences obtained with 3 kits are presented. Two types of observations were made: (a) significant inter-lot, intra-lot and even inter-box sensitivity difference was found with some kits and (b) reactivity of the plates for true-positive and false-positive sera independently changed among different lots of the same kit: while reactivity for true positive sera was constant, a significant decrease or increase in reactivity for false-positive sera was found. These observations point to poor reproducibility of some commercial anti-HIV EIA kits that can cause serious difficulties in screening laboratories.

Enzyme-Linked Immunosorbent Assay↗
PubMed1988

Diffusion of HIV-1 virus into non-habitual categories at risk in European countries.

The ECP Working Group on AIDS has evaluated the available data on seropositivity to HIV-1 supplied by research groups in 12 Eastern and Western European countries. The period covered is 1985 and 1986. A significantly elevated incidence of seropositives was observed in both females and males in heterosexual contact with members of high risk groups. In contrast heterosexuals with no such contact had an incidence below 1%. For male homosexuals from Italy, Denmark and Switzerland the trend was no detectable increase in prevalence from 1985 to 1986. Hungary and Poland now have a few per cent seropositive male homosexuals, but no seropositives were found in a group of Polish drug abusers.

Bisexuality↗
PubMed1988

Prevalence of HIV-antibodies in patients with haemophilia in Hungary.

Incidence of HIV antibodies have been studied in 617 patients with congenital bleeding disorders. Screening was performed with the Organon ELISA test, repeatedly positive samples were tested with four different confirmatory assays. HIV antibodies were found in 3/356 patients with haemophilia A, 21/114 patients with haemophilia B, 3/123 patients with von Willebrand disease and in 1/24 patients with other types of congenital coagulation disorders. All the 28 seropositive patients were treated with imported coagulation factor, mostly with factor IX concentrates. No patient treated exclusively with nationally produced factor preparations between 1981 and 1985 was found to be anti-HIV positive.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Enhancing effect of alpha-interferon on the C2 synthesis by cultured human monocytes.

C2 synthesis by human peripheral blood monocytes cultured in the presence of human alpha-interferon (IFN-alpha) was studied. IFN-alpha was added in different amounts (1-1000 IU/ml) to the cultures on day 3 and was removed on day 7. As control, mock interferon (m-IFN) was also tested. C2 content of the culture supernatants was measured by immunohaemolytic method. IFN-alpha was found to enhance C2 synthesis in a dose-dependent way. The enhancing effect could be observed even after the removal of IFN-alpha. C2 production by the cultured monocytes was increased by m-IFN as well; the extent of enhancement however, was found to be significantly lower than that induced by the corresponding amount of IFN-alpha. In contrast to the enhancing effect on C2 production, IFN-alpha did not influence total protein synthesis in the cultures, suggesting a selective stimulatory action on the C2 gene.

Biological Assay↗
PubMed1987

A simple method for detecting HIV antibodies hidden in circulating immune complexes.

A method previously used for studying the specificity of antibody components of circulating immune complexes in different diseases has been applied to analyse circulating immune complexes in HIV-infected patients. Antibodies against HIV antigens hidden in circulating immune complexes were studied in 14 sera from 13 patients with asymptomatic HIV infection (group 1) and in 11 sera from seven patients with HIV symptoms (group 2). HIV antigen-coated wells from the Vironostika kit as well as core and envelope antigen-coated beads from the Abbott confirmatory kit were used as solid-phase antigen. Using the Vironostika plates, HIV antibodies were demonstrated in circulating immune complexes in three and five sera in groups 1 and 2, respectively. Anti-core antibodies hidden in circulating immune complexes were present in three out of eight and two out of nine sera, respectively, in groups 1 and 2, whereas anti-envelope antibodies were present in circulating immune complexes in one out of eight and six out of nine sera in the same groups. These findings demonstrate that not only core-anti-core but also envelope-anti-envelope immune complexes are present in the sera of HIV infected patients.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Hepatoprotective effects of prostacyclins on CCl4-induced liver injury in rats.

Certain biochemical parameters of acute liver injury induced by carbon tetrachloride were investigated in rats treated with prostacyclin (PGI2) and two of its derivatives. Serum glutamate oxalacetate transaminase elevation and both triglyceride accumulation and reduction of glycogen content in liver were significantly suppressed by PGI2, 7-oxo-PGI2, and 20-methyl-13,14-didehydro-2,4-m-interphenylene-PGI2 48 hr after the injury. Prostacyclins partially restored some of the parameters of injury even in doses of 10 micrograms/kg ip. When the compounds were given 24 hr after CCl4 intoxication, much more pronounced protection was observed than in the case of treatments 1 hr before administration of the hepatotoxin. Thus, all tested prostacyclins exerted significant protective effects on acute liver damage which is obtained mainly in the second phase of the injury.

Animals↗
PubMed1985

Immunological alterations in anti-HTLV-III negative haemophiliacs and homosexual men in Hungary.

Hungary can be considered as a low risk area for AIDS since no patient with full-blown AIDS or AIDS-related complex has been found in the country. A complex clinical and immunological (T cell subsets, DNCB sensitization test, circulating immune complexes, acid-labile alpha interferon) investigation was performed between November, 1983 and June, 1984 in order to study whether alterations found in symptom-free homosexuals and haemophiliacs in the risk areas for AIDS can be observed in Hungary as well. 38 patients with mild haemophilia, 35 patients with severe haemophilia and 40 homosexual men were investigated in parallel to 37 heterosexual blood donors as controls. Anti-HTLV-III antibodies were measured later in the stored serum aliquots from the same subjects by the indirect membrane immunofluorescence assay. Although specific anti-HTLV-III antibodies were not detected in the haemophiliacs or homosexuals, immunological alterations characteristic for the members of AIDS risk groups in the high risk areas (decrease in the percentage of OKT4 cells and/or decrease of the OKT4/8 ratio) were found in one-third of the homosexuals and haemophiliacs tested. In addition, a significant part of these subjects did not develop delayed type hypersensitivity skin reaction on DNCB rechallenge. These findings indicate that an immunodeficiency independent of HTLV-III infection can be present in two major AIDS risk groups, in homosexual men and haemophiliacs.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Alterations of markers during hepatocarcinogenesis in rats.

Fischer 344 male rats were treated with N-nitrosodiethylamine, and two weeks later promotion was effected by treatment with N-2-acetylaminofluorene for 14 days. At midpoint of the promotion protocol, one group of rats was subjected to partial hepatectomy (model A); others were treated with either carbon tetrachloride (model B) or thioacetamide (model C). Alterations in the activities of marker enzymes (glucose-6-phosphatase, gamma-glutamyl transpeptidase, cytochrome P-450, N-demethylase) during hepatocarcinogenesis were followed biochemically. The highest incidences of liver foci and of hepatocellular carcinomas were observed in model A, and these showed a good correlation with long-lasting elevated gamma-glutamyl transpeptidase activity. Analysis of the marker alterations suggests that there are three stages in hepatocarcinogenesis: (1) depression resulting from the toxic action of the initiator; (2) recovery and adaptation to cellular injury; and (3) long-lasting adverse alterations in the activities of the marker enzymes after promotion. The loss of certain non-histone proteins soon after promotion was also observed. Comparative studies of the individual actions of initiators and promoters on marker enzymes indicated that both contribute to the marker changes during hepatocarcinogenesis.

2-Acetylaminofluorene↗
PubMed1984

Effect of PGI2 in carbon tetrachloride-induced liver injury.

The hepatoprotective effect of prostacycline was studied after in vitro and in vivo CCl4 liver injury. It was found that PGI2 could partly restore the amino acid incorporation after in vitro CCl4 poisoning. In the in vivo system PGI2 was capable of decreasing the elevated SGOT levels and the accumulated triglyceride in the liver, and to increase hepatic glycogen content 24 hours after CCl4 injury.

Alanine Transaminase↗
PubMed1980

Morphological and biochemical study of the hepatoprotective effect of AICA-phosphate.

The hepatoprotective effect and the possible mechanism of action of AICA-phosphate (AIP) were studied. Both the morphological and biochemical data proved the protective i.e. the connective tissue reducing effect of AIP in cirrhotic rat liver. Labelled AIP incorporated very intensively into microsomal RNA, suggesting that the compound may take part in the de novo purine synthesis. The increased rate of protein synthesis can be the consequence of the incorporation into RNA, promoting the regenerative processes in injured cells.

Aminoimidazole Carboxamide↗
PubMed1979

Spontaneous and chemically-induced transformation of mouse fibroblasts in culture. Biochemical aspects of the transformed cells.

Fibroblast cultures were established from the lung tissue of CBA T6T6 mouse embryos. Lines characterized by infinite growth transformation (MFL) were used as untreated controls till the 21st and 29th passages, respectively. After that period, an unrestrained growth transformation developed spontaneously. The cell line was then designated as STMFL. At the 8th passage of an MFL, 20-methylcholanthrene (MC) treatment was performed. The treatment resulted in a cell line (MCMFL) characterized also by unrestrained growth transformation. The nuclear protein pattern obtained by two-dimensional gel electrophoresis showed differences between STFL and MCMFL. The activity of two microsomal enzymes - aryl hydrocarbon hydroxylase and ethylmorphin demethylase - measured in the exponential growth stage of the cultures showed a decrease in the case of STMFL, compared to the MFL, and practically disappeared in the case of MCMFL.

Animals↗
PubMed1978

Morphological and biochemical studies on the effect of agents with liver protecting properties.

The liver protective effect of Aicaphosphate in CC1(4)-induced acute, as well as CC1(4)-and thioacetamide-induced subacute and chronic liver damages is demonstrated. The effect of the protective drugs was studied in the forms of pre-, simultaneous and delayed treatment in acute and chronic liver damages induced by various toxic agents. The degree of liver damage was determined by morphological and biochemical methods, complementary to each other. For the completion of histological studies and morphometry used for the determination of the degree of fibrosis biochemical investigations are performed. In acute liver damage the determination of DNA, protein and lipid contents of the liver tissue and the radioactive aminoacid incorporation rate should be carried out with a simultaneous analysis of the serum enzymes. In chronic liver damage, the measurement of the hydroxyproline and DNA contents of the liver give useful data for the determination of the severity of the lesion and the effect of the protective drugs, respectively.

Acetamides↗