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Biomedical subjects

E Nagy

Publications and source records attributed to E Nagy.

At least 217 records · Page 12Linked to original sources
PubMed1991

Growth inhibition of murine mammary carcinoma by monoclonal IgE antibodies specific for the mammary tumor virus.

Two IgE-producing hybridomas were established from spleen cells of Balb/c mice, which had been immunized with mouse mammary tumor virus (MMTV). These IgE monoclonal antibodies (mAbs) reacted specifically with the major envelope glycoprotein (gp36) of MMTV, as established by the immunoblot assay and by passive cutaneous anaphylaxis. The effect of the IgE mAbs (produced by clone A8) on the growth of the MMTV-secreting mammary adenocarcinoma H2712 was investigated in syngeneic C3H/HeJ mice. The mice were inoculated s.c. with either 10(5) (approximately 100 x LD50) or 10(6) (approximately 1000 x LD50) tumor cells and received repeated i.p. injections of 25 micrograms anti-gp36 IgE mAbs at 4-day intervals for 8 weeks. This treatment prevented the development of subcutaneous tumors in 50% of the animals. Similar protection was observed when the tumor cells (10(5)/animal) were injected i.p. 4 days prior to the beginning of the i.p. treatment consisting of injections of 25 micrograms mAbs at 4-day intervals for 6 weeks. However, these mAbs did not protect C3H/HeJ mice against the MMTV-negative MA16/c carcinoma cells. Hence, these results support the view that IgE-mediated cytotoxic mechanisms may play an immunologically specific antitumor surveillance role and that laboratory-induced antitumor IgE mAbs have the potential of specific therapeutic agents for in vivo destruction of tumor cells.

Animals↗
PubMed1991

Sequence analysis of infectious pancreatic necrosis virus genome segment B and its encoded VP1 protein: a putative RNA-dependent RNA polymerase lacking the Gly-Asp-Asp motif.

The genome segment B sequence of infectious pancreatic necrosis virus was determined for both the Jasper and Sp serotypes. The sequences are 2784 and 2630 bp long, respectively, and contain a single large open reading frame encoding the VP1 protein, the putative RNA-dependent RNA polymerase (RdRp) of IPNV. The proteins exhibit an 88% homology with each other, but only 41% with infectious bursal disease virus (IBDV) VP1, another member of the Birnaviridae. Despite the low overall homology between the IPNV and IBDV VP1 proteins, homologous regions were detected within the central portion of the proteins. The carboxy-proximal regions of the VP1, which contain very low amino acid homology, displayed evidence of conservation in structural features such as a hydrophilic, highly basic domain. Consensus sequences associated with GTP-binding proteins and RdRps were also detected in VP1. However, unlike the RdRps associated with single-stranded plus RNA viruses, the birnavirus RdRp lacks the Gly-Asp-Asp motif characteristic of this enzyme family.

Amino Acid Sequence↗
PubMed1991

An improved dot-blot method for virus detection in chicken embryo fibroblast cultures.

A simplified dot-blot procedure is described for the detection of fowlpox virus (FPV) in infected monolayers of chicken embryo fibroblasts (CEF) cultured in 96-well microtiter plates. The relative resistance of DNA to hot NaOH, which hydrolyzes other macromolecules including RNA and protein, was exploited to solubilize virus infected cells and denature intracellular DNA in a simple, quick manner. Moreover, there was no need to purify virus or isolate viral DNA from cellular DNA prior to dot blotting. After incubation of CEF with FPV, the extracellular fluid from infected cells was collected for storage in 96-well microtiter plates. The remaining cell monolayers in each well were then solubilized with hot NaOH. The solubilized and denatured DNA was transferred to a nylon membrane using a dot-blot vacuum filtration manifold. Hybridization was carried out with a 32P-labeled FPV DNA probe. With this methodology it was possible to detect specific viral DNA sequences following the infection of cell monolayers with as little as 1 infectious unit per well. The ability to detect specific viral DNA sequences in infected cells, without the need to isolate pure viral DNA, made it possible to analyze large numbers of samples in a single experiment. Moreover, sufficient fowlpox virus was present in the extracellular media from each well for further amplification and analysis of selected samples.

Animals↗
PubMed1991

Inactivation of metronidazole by Enterococcus faecalis.

The in-vitro inactivation of metronidazole by different clinical isolates of Enterococcus faecalis was investigated by means of association experiments in which Ent. faecalis strains and Bacteroides fragilis group strains were cultured in the same liquid medium. All of the tested Ent. faecalis strains (20 isolates) were able to protect the B. fragilis group strains against the killing effect of metronidazole at a concentration four or eight times higher than the normal MIC. Different strains of Streptococcus (14), Staphylococcus aureus (10), Staph, epidermidis (10) and Escherichia coli (8) failed to exhibit the same effect. When Ent. faecalis strains were cultured anaerobically for 24 h in the presence of 4 mg metronidazole/l, either alone or together with different B. fragilis group strains, no metronidazole could be detected subsequently in the culture supernatants by HPLC. Concomitantly an increase of four or five logs in the viable counts of the co-cultured Bacteroides strains was observed compared with Bacteroides strains cultured alone. Sonicated cell extracts of Ent. faecalis cultured either aerobically or anaerobically were found to inactivate metronidazole to the same extent, whereas the culture supernatants had no such effect.

Bacteriological Techniques↗
PubMed1991

Characterization of the VPg-dsRNA linkage of infectious pancreatic necrosis virus.

By the use of strong denaturing agents, a genome-linked protein (VPg)-RNA complex was purified from infectious pancreatic necrosis virus. Ribonuclease treatment of 125I-labelled VPg-RNA released a 90K polypeptide identical to the minor structural polypeptide VP1 (the putative RNA polymerase), as determined by peptide mapping. The polypeptide is linked to the RNA by a serine-5' GMP phosphodiester bond. The results identify birnaviruses as the only dsRNA viruses with a VPg, the size of which is the largest of the VPgs of RNA viruses.

Electrophoresis, Agar Gel↗
PubMed1991

Synthesis of Newcastle disease virus (NDV)-like envelopes in insect cells infected with a recombinant baculovirus expressing the haemagglutinin-neuraminidase of NDV.

Electron microscopical examination of negatively stained extracellular fluids (ECF) from Spodoptera frugiperda cell cultures infected with a recombinant baculovirus expressing the Newcastle disease virus (NDV) haemagglutinin-neuraminidase (HN) revealed NDV-like envelopes which resembled the envelopes of authentic NDV. Immunogold staining with anti-NDV HN monoclonal antibodies demonstrated HN antigen in spikes on the NDV-like envelopes. The ECF from the recombinant-infected cultures also contained baculovirus particles which resembled standard baculovirus particles except that some showed polar protrusions of the envelope. It was concluded that the HN of NDV, in the absence of the matrix protein, might be able to initiate and control the production of viral envelopes which are morphologically identical to those of authentic NDV.

Animals↗
PubMed1991

Placental lactogen is a haemopoietic hormone.

The anaemia and thrombocytopenia of hypophysectomized (Hypox) rats could be corrected readily by daily treatment with human placental lactogen. Spontaneous DNA synthesis in the bone marrow of Hypox rats was grossly impaired, which was also normalized by placental lactogen. Human placental lactogen exerted a direct mitogenic effect on rat bone marrow cells in vitro. These results indicate that placental lactogen is a potent haemopoietic hormone.

Anemia↗
PubMed1991

Antibiosis between bacteria isolated from the vagina of women with and without signs of bacterial vaginosis.

Lactobacilli from women with and without bacterial vaginosis (BV) were tested for H2O2 production. Thirty-seven (79%) of the 47 strains of lactobacilli isolated from the women without BV produced H2O2, while only nine (23%) of the 39 strains of lactobacilli obtained from women with BV did so. Five of 20 H2O2-producing and two of 26 non-producing strains of Lactobacillus exhibited antibiosis against four of 12 strains of peptostreptococci and two of 10 strains of Mobiluncus spp. None of a further 41 different anaerobic and facultative anaerobic bacterial strains were inhibited by any of the isolates of lactobacilli tested. Some strains of Gardnerella vaginalis, Bacteriodes spp., Mobiluncus spp. and Peptostreptococcus spp. inhibited the growth of three strains of lactobacilli belonging to different species. When the pH of the culture medium was increased from 6.0 to 6.5 this led to a decrease in the number of strains inhibited and/or the size of the growth-inhibitory zones. Different concentrations of H2O2 did not inhibit any of the strains tested. The growth-inhibitory effect of lactobacilli could not be related to their bacteriocin production. Increasing the iron content of the medium by adding FeCl3 (0.01 mM-1 mM) decreased or completely abolished the antibiosis.

Antibiosis↗
PubMed1991

Electron microscopic investigation of lysogeny of Clostridium difficile strains isolated from antibiotic-associated diarrhea cases and from healthy carriers.

An electron microscopic investigation was performed on 28 Clostridium difficile strains isolated from 15 antibiotic-associated diarrhea cases and from 13 healthy infants. Through the use of supernatants of the cultures induced by mitomycin C (1 or 3 micrograms/ml), 18 of the 28 C. difficile strains proved to harbor phage particles with a different morphology and size. Most of the phages revealed belonged in phage group B1 with a non-contractile tail. Seven of the 11 toxin-producing, lysogenic C. difficile strains carried a defective phage structure (120 nm-long tail with an incomplete head capsule) alone or together with other normal phages. With different C. difficile strains as indicator, plaque formation could not be detected in any of the lysates.

Anti-Bacterial Agents↗
PubMed1991

Hypophysectomized rats depend on residual prolactin for survival.

Hypophysectomized (Hypox) female Fischer 344 rats had 10-20% lactogenic activity in their serum when compared to controls by the Nb2 lymphoma proliferation assay. If such animals were treated daily with a rabbit antirat PRL serum, their serum lactogenic activity diminished further; severe anemia and immunological anergy developed; and death occurred within 8 weeks. In contrast, untreated Hypox animals increased gradually their serum lactogenic activity, starting on the 7th week after pituitary removal, which rose up to 50% of control levels by week 9. Hypox animals showed normochromic normocytic anemia, a grossly reduced immunocompetence, decreased body, thymus, spleen, adrenal, and ovary weights, and decreased DNA and RNA synthesis in the thymus, spleen, and bone marrow. However, the condition of Hypox animals did not deteriorate further over the 9-week experimental period. All the hematological deficiencies and decrease in organ weights observed in Hypox rats were normalized after grafting with syngeneic pituitaries (SPG). These effects of SPG could be inhibited by additional treatment with antirat PRL serum. Treatment of Hypox animals with ovine PRL had a restoring effect similar to SPG, which was not inhibited by additional antirat PRL serum treatment. Rat and ovine PRL and GH and human placental lactogen all stimulated the incorporation of 3H-thymidine by rat bone marrow cells in vitro. These results indicate that PRL has a multiple trophic effect and is capable of maintaining vital bodily functions for long periods of time.

Anemia↗
PubMed1991

Effect of daptomycin, metronidazole and mezlocillin combinations on mixed bacterial cultures involving facultative and anaerobic bacteria.

The in vitro activities of different daptomycin concentrations in combination with metronidazole (4 mg/l) or/and mezlocillin (8 mg/l) were investigated on mixed bacterial cultures involving gram-positive facultative cocci. Bacteroides fragilis group strains and Escherichia coli. When Streptococcus faecalis alone or together with E. coli was cultured with B. thetaiotaomicron the colony counts of the latter were 4 log units higher after incubation in the presence of daptomycin and metronidazole than when it was cultured alone. After the addition of mezlocillin, this effect disappeared and all 3 strains were killed. When the same antibiotic combinations were used in the presence of beta-lactamase producing Staphylococcus aureus, the activity of mezlocillin was decreased significantly. The colony counts of the co-cultured B. thetaiotaomicron and E. coli proved to be 2 log and 6 log higher, respectively, than those observed after they were cultured alone. The antimicrobial susceptibilities of the clinical isolates tested here in mixed cultures of up to 3 strains were modified significantly by interactions between the strains and the antibiotics used.

Bacteriological Techniques↗
PubMed1991

Prolactin deficiency in rheumatoid arthritis.

Prolactin and growth hormone were determined from the sera of 48 patients with rheumatoid arthritis (RA) and 23 controls by radioimmunoassay and by the Nb2 lymphoma proliferation bioassay. A highly significant deficiency was found in the bioactivity of circulating prolactin (PRL) in patients with RA, whereas immunoactive PRL was near normal. Only age matched male patients showed significantly lower serum PRL levels by radioimmunoassay. Patients with RA with anemia and high reticulocyte counts had bioactivity of PRL elevated and those with anemia and low reticulocyte counts had a decreased bioactivity of PRL when compared to patients without anemia. Prolactin isolated from the sera of 5 patients with RA showed decreased bioactivity in comparison with PRL separated from 5 sex matched controls. Serum factors capable of enhancing or inhibiting the response of Nb2 cells to ovine PRL were also discovered. Our results indicate that RA is associated with PRL deficiency.

Anemia↗
PubMed1991

Short clinical report: a new case with de novo partial 9p monosomy.

A female patient is described with a karyotype 46,XX,del (9) (p22) showing characteristic dysmorphic phenotype: trigonocephaly, prominent forehead, long philtrum, small mouth, high arched palate, low set ears, short neck, widely spaced nipples, long fingers and toes, omphalocele. The first Hungarian case of 9p monosomy syndrome is reported here.

Abnormalities, Multiple↗
PubMed1990

[Two cases of hyperthyroidism and ophthalmopathy following hypothyroidism].

Two cases of Graves' disease emerging in previously hypothyroid patients are described. After two years of thyroid hormone substitution due to 'idiopathic' hypothyreosis (patient 1) and Hashimoto's thyroiditis (patient 2), the substitution had to be stopped. The persisting clinical and laboratory signs of immune hyperthyreosis, including positivity for TBII and TSAb, were accompanied by the signs of mild ophthalmopathy. The antibody-spectrum changes during the course of the disease are discussed.

Adult↗
PubMed1990

Concentration gradients for HVA, 5-HIAA, ascorbic acid, and uric acid in cerebrospinal fluid.

Concentrations of HVA, 5-HIAA, ascorbic acid, and uric acid in the lumbar and cisternal cerebrospinal fluid (CSF) were measured in psychiatric and neurologically impaired patients. The concentration of HVA is 6.1 times and of 5-HIAA 2.7 times higher in cisternal than in lumbar samples, the cisternal level of uric acid is half that of the lumbar region, but no significant differences were found in ascorbic acid concentrations. Correlation between lumbar and cisternal metabolite concentrations is high for 5-HIAA and ascorbic acid, and is less for HVA and uric acid. In cisternal CSF there is a significant correlation between levels of HVA-5-HIAA, 5-HIAA-ascorbic acid, and 5-HIAA-uric acid. These correlations disappear in lumbar CSF. These findings indicate that extrapolations to cisternal neurotransmitter metabolite concentration from lumbar measures are unwarranted for HVA, but not for 5-HIAA.

Adult↗
PubMed1990

In vitro activity of daptomycin-metronidazole combinations against mixed bacterial cultures: reduced activity of metronidazole against Bacteroides species in the presence of Enterococcus faecalis.

The in vitro activity of daptomycin-metronidazole combinations against mixed cultures of gram-positive facultative cocci and strains of the Bacteroides fragilis group was investigated. Metronidazole did not influence the high activity of daptomycin against strains of Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis in the absence or presence of the co-cultured Bacteroides strains. In contrast, the Enterococcus faecalis isolates protected the co-cultured Bacteroides strains against the killing effect of metronidazole, even at a concentration four- or eightfold the MIC of metronidazole. Killing curve experiments confirmed this protective effect of different isolates of Enterococcus faecalis.

Anti-Bacterial Agents↗
PubMed1990

Cloning and expression of NDV hemagglutinin-neuraminidase cDNA in a baculovirus expression vector system.

The hemagglutinin-neuraminidase (HN) gene of the Hitchner B1 strain of Newcastle disease virus (NDV) was cloned as a cDNA and inserted into a baculovirus expression vector. The recombinant HN (recHN) expressed in Spodoptera frugiperda cells had both hemagglutinating and neuraminidase activities both of which were inhibited by polyclonal anti-NDV sera or a monoclonal antibody (MAb) against HN. Infected insect cells could hemadsorb chicken red blood cells suggesting that the recHN is properly glycosylated and transported to the cell surface. A 67-kDa recHN precursor and a 74-kDa, presumably mature, recHN from infected cells were detected by Western blot analysis and were found to comigrate with similar proteins from NDV-infected chick embryo fibroblast cells. The kinetics of synthesis of recHN was similar to that for polyhedrin and some HN appeared in the extracellular medium. HN was copurified with extracellular virus (ECV) from the extracellular medium and was used to immunize chickens. The anti recHN serum was specific to NDV in both ELISA and Western blot analysis.

Animals↗