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Biomedical subjects

E Nagy

Publications and source records attributed to E Nagy.

At least 109 records · Page 6Linked to original sources
PubMed1999

The associations of viral and mycoplasmal antibody titers with respiratory disease and weight gain in feedlot calves.

Blood samples from 32 groups of calves (n = 700) were taken on arrival and after 28-35 days at the feedlot. Eleven groups were housed in feedlots in Ontario, and 21 groups in feedlots in Alberta. Serum antibody titers to bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), parainfluenza virus type 3 (PIV-3), infectious bovine rhinotracheitis virus (IBRV), Mycoplasma dispar and M. bovis, plus data on bovine corona virus (BCV) from a previous study were investigated for their association with the risk of bovine respiratory disease (BRD), and with 28-day weight change, both before and after controlling for titers to Pasteurella haemolytica and Haemophilus somnus. Exposure to IBRV and M. bovis was infrequent, and although exposure to PIV-3 was more common, none of these agents had important associations with BRD. Higher titers to BVDV, BRSV, and BCV on arrival were associated with reduced risks of BRD and increased weight gains. However, there was some variation in these relationships and higher arrival titers to BVDV and BRSV in a subset of the calves were associated with increased risks of BRD. Titer increases to BVDV were associated with a higher risk of BRD and lower weight gains. Titer increases to BRSV were not usually associated with the occurrence of BRD, but titer increases to BRSV in a subset of calves that were vaccinated against BRSV, on arrival, were associated with an elevated risk of BRD. Of all the agents studied, BVDV had the most consistent associations with elevated risk of BRD and lower weight gains. Higher BRSV arrival titers were related to lower risk of BRD and higher weight gains; in some instances titer increases to BRSV were associated with higher BRD risk. Higher titers to BCV on arrival were related to reduced risks of BRD. Practical ways of adequately preventing the negative effects of these agents are still needed.

Animals↗
PubMed1999

Formation of virus-like particles when the polyprotein gene (segment A) of infectious bursal disease virus is expressed in insect cells.

The baculovirus expression vector system was used to examine the expression of the full-length infectious bursal disease virus (IBDV) segment A cDNA, which encodes the structural proteins in a polyprotein precursor that is autocatalytically cleaved to VPX, VP3, and VP4. No VP2 was observed in lysates of recombinant baculovirus infected cells indicating the lack of processing of VPX to VP2 in this system. Virus-like particles (VLP) were purified from the infected insect cells, and on negative staining electron microscopy, looked very similar to authentic IBDV particles in shape and size, suggesting that processing of VPX to VP2 is not necessary for capsid assembly.

Animals↗
PubMed1998

The iron chelator pyridoxal isonicotinoyl hydrazone (PIH) protects plasmid pUC-18 DNA against *OH-mediated strand breaks.

Pyridoxal isonicotinoyl hydrazone (PIH) has previously been studied for use in iron chelation therapy in iron-overload diseases. It is an efficient in vitro antioxidant due to its Fe(III) complexing activity (Schulman, H. M., et al. Redox Report 1:373-378; 1995). Pathologies associated with iron-overload include hepatic and other cancers. Since oxidative alterations of DNA can be linked to the development of cancer, we decided to study whether PIH protects DNA against in vitro oxidative stress. We report here that pUC-18 plasmid DNA is damaged by *OH radicals generated from Fe(II) plus H2O2 or from Fe(II) plus hypoxanthine/xanthine oxidase. The DNA damage was quantified by determining the diminution of supercoiled DNA forms after oxidative attack using agar gel electrophoresis. Micromolar amounts of PIH (20-30 microM) were able to half-protect DNA from iron (1-7.5 microM)-mediated *OH formation. The antioxidant capacity of PIH was significantly higher than that of some of its analogs and desferrioxamine. PIH and some of its analogues could also inhibit the oxidative degradation of 2-deoxyribose caused by Fenton reagents. Since we observed that PIH enhances the Fe(II) autoxidation rate, measured by the ferrozine technique, PIH may limit *OH formation and consequently DNA damage by decreasing the amount of Fe(II) available to catalyze Fenton reactions.

Antioxidants↗
PubMed1998

[Complex treatment of infected necrotizing pancreatitis].

Pancreatic necrosis associated with septic conditions is the leading cause of mortality in acute pancreatitis. Since 1986, 155 patients with infected pancreatic necrosis have been treated. The mean APACHE II score was 18.5 (range 11-32). In all cases, the infected pancreatic necrosis was combined with retroperitoneal abscesses. The surgical treatment was performed on average 18.5 days (range 8-25 days) after the onset of acute pancreatitis. The operative management consisted of wide-ranging necrosectomy in the total affected area, combined with widespread lavage and suction drainage. In 69 of the 155 cases (45%), some other surgical intervention (distal pancreatic resection, splenectomy, cholecystectomy, sphincteroplasty or colon resection) was also performed. Following surgery supportive therapy was applied in all patients, which also consisted orf immunonutrition (glutamine and arginine supplementation) and modification of cytokine production by petoxyfillin and dexamethasone from 1992. TNF and IL-6 serum levels were measured by ELISA and in vitro stimulation of leukocytes were induced by E. coli LPS. Following surgery, continuous lavage and suction drainage were applied for an average of 41.5 days (range 21-90 days), with an average of 9.5 (range 5-20) litres of saline per day. The bacteriologic findings revealed mainly enteral bacteria, but Candida infection was also frequently detected. The incidence of fungal infection was 20%. Thirty-two patients (21%) had to undergo reoperation. The cytokine production capacity (TNF and IL-6) was shown to correlate with the prognosis. As a consequence of pentoxifyllin and dexamethasone therapy, the TNF production generally dropped to the normal level. The overall hospital mortality was 6.4% (10 patients died). In our experience, infected pancreatic necrosis responds well to aggressive surgical treatment, continuous, long-standing lavage and suction drainage, together with supportive therapy consisting of immunonutrition and modification of cytokine production, combined with adequate antibiotic and antifungal medication.

Adult↗
PubMed1998

Induction of release of tumor necrosis factor and IL-6 from human mononuclear cells by Bacteroides strains.

The role of anaerobic Gram-negative bacteria in inducing cytokines during mixed infections involving aerobic and anaerobic bacteria is relatively poorly defined. The purpose of this study was to establish whether or not intact Bacteroides fragilis and related species, isolated from severe infections and from the faeces of healthy persons are capable of releasing tumor necrosis factor (TNF) and IL-6 from human mononuclear cells and whole blood. The purified lipopolysaccharides of Bacteroides fragilis strain (No. 7), extracted by the aqueous phenol method from BHI cultures and from BHI culture supplemented with 5% horse serum, were also tested. TNF release was detected by the WEHI 164-dependent bioassay and IL-6 production by the B-9 cell-dependent bioassay. Heat-inactivated Bacteroides strains belonging to different species were able to induce TNF (1x10(1)-5x10(2) U/mL) and IL-6 (1x10(1)-5x10(5) pg/mL) release from human mononuclear cells. When whole blood was used, the production of TNF and IL-6 was more pronounced (very probably because of the presence of certain serum factors). The culturing conditions (the presence of 5% horse serum in the BHI broth) influenced the inducing activity of almost all strains tested. The isolated lipopolysaccharide of Bacteroides fragilis strain No. 7 proved to have a rough profile on PAGE. There were no differences in TNF and IL-6 induction when the lipopolysaccharides of the strain was cultured in BHI or in BHI supplemented with 5% horse serum. Bacteroides strains often outnumber Enterobacteriaceae in the faeces and in mixed infections, and their role in inducing and/or modulating the host response in septic shock should not be overlooked.

Journal Article↗
PubMed1998

The frequency and the role of Chlamydia trachomatis infection in premature labor.

OBJECTIVE: The importance of Chlamydia trachomatis (C. tr.) infection in the etiology of premature labor was examined in a prospective, representative, multicenter study. METHOD: Specimens were collected from 6161 subjects in seven centers and examined by the Gen-Probe method. RESULTS: The infection rate was 5.74%. There were no significant correlations between low birth weight, premature rupture of the membranes, dysmaturity and C. tr. infection. In cases of threatening premature labor, the infection rate was significantly higher in C. tr.-positive patients. In the event of combined low birth weight and perinatal death, the maternal C. tr. infection rate was significantly higher than in normal pregnancies. C. tr.-positive patients treated with roxithromycin had term deliveries. A correlation between poor social circumstances and a high C. tr. infection rate could be proved. CONCLUSION: Cases with a poor obstetric history and/or socially high-risk patients should be screened for C. tr. infection, and in positive cases treatment is recommended.

Anti-Bacterial Agents↗
PubMed1998

Imuthiol inhibits the etoposide-induced apoptosis in HL-60 cells.

Imuthiol (sodium-diethyl-dithiocarbamate, DTC) has been proven to possess immunomodulatory properties, this effect, however, varies in different model systems. This study was performed to assess the possible effect of imuthiol on etoposide-induced apoptosis in the human promyelocytic leukemia cell line, HL-60. In vitro pre-treatment with imuthiol at concentrations between 50 and 100 microM significantly inhibited etoposide-induced apoptosis of HL-60 cells, the inhibition appeared to be dose dependent. This effect may be associated with the immunomodulatory activity of imuthiol.

Apoptosis↗
PubMed1998

Growth characteristics of fowl adenovirus type 8 in a chicken hepatoma cell line.

Fowl adenoviruses, many of which appear to be non-pathogenic, are ubiquitous in birds. In addition, the genome of these viruses is large, making them ideal candidates for construction as vectors for foreign genes. Current methods to cultivate fowl adenoviruses use primary cell cultures derived from embryonated chicken eggs. In order to provide a more suitable culture method, the growth of fowl adenovirus type 8 (FAdV-8) was investigated in CH-SAH, a continuous hepatoma cell line. A one step growth curve demonstrated release of extracellular virus beginning by 18 h p.i. and with a final yield about 100 fold higher than that in chicken embryo liver cells. Viral DNA synthesis was first detected 8 h prior to this. The CH-SAH cell line supported the production of progeny viruses similar to the wild-type virus after being transfected with purified FAdV-8 DNA. This study demonstrated that the continuous hepatoma cell line is an appropriate in vitro host for FAdV-8.

Animals↗
PubMed1998

Inter-strain comparison by pyrolysis mass spectrometry of Staphylococcus aureus isolates associated with nosocomial infection.

Pyrolysis mass spectrometry was used to characterise Staphylococcus aureus isolates from an outbreak of postoperative wound infections on a mixed surgical ward. The PyMS results were compared with those of phage typing. Both suggested a single strain of S. aureus, of phage type 3C, 55, 71, was responsible for six of the 13 wound infections. PyMS differentiated an isolate from a member of staff of similar phage type to the epidemic strain, which had previously been considered to be the point source for the outbreak. PyMS is a rapid and inexpensive technique for investigating nosocomial outbreaks, including those caused by S. aureus and, in this instance, was more discriminatory than phage typing.

Bacterial Typing Techniques↗
PubMed1998

The change of attitude of Hungarian physicians towards the importance of risk factors of coronary heart disease over the period 1985-1996.

Cardiovascular mortality in Hungary is still increasing, while it shows a continual decrease in the developed Western world. The authors examined, by means of a questionnaire, the attitude of physicians, in a large county hospital, to prevention of cardiovascular diseases and promotion of a healthy way of life. The questionnaire was answered by 170 physicians, 107 (63%) males and 63 (37%) females. Eighty-six percent of them believed coronary heart disease to be preventable. Twenty-six percent of the physicians currently smoked, and 53% did not know their own cholesterol level. As a cardiovascular mortality risk factor smoking was considered the most important risk factor, with sedentary lifestyle the second, high cholesterol level the third, and hypertension being only the fourth. Hungarian hospital physicians' rating of the effect of reducing the risk factors for coronary heart disease was similar to those results published in 1986 of American doctors, there being no significant difference in the importance attributed to smoking and elevated blood cholesterol. American doctors believed that hypertension had a more important effect on coronary heart disease than did Hungarian physicians, whilst the Hungarians attributed greater importance to a diet high in fat, being overweight, having a sedentary life-style, stress, elevated triglyceride level and type A behaviour. The results of this present study which related to the doctors attitudes towards health education for their patients were compared to results obtained from a study relating to physicians in the same hospital in 1985. Only in two aspects was a significant change observed. According to the authors' opinion greater efforts should be made regarding physician education on the subject of disease prevention. Additionally the employment of well educated nurses with specific training in preventive medicine could improve the effectiveness of the prevention of coronary heart disease.

Attitude of Health Personnel↗
PubMed1998

In-vitro selection of porin-deficient mutants of two strains of Klebsiella pneumoniae with reduced susceptibilities to meropenem, but not to imipenem.

We have evaluated the ability of imipenem and meropenem to select, in vitro, resistant mutants of two clinical isolates of Klebsiella pneumoniae producing both SHV and TEM beta-lactamases. Only meropenem selected mutants of both isolates for which the MICs of meropenem, but not imipenem, were markedly higher than those for the parent strains; the MICs of several other beta-lactam antibiotics, including beta-lactam/beta-lactamase inhibitor combinations, for these mutants were also higher than those for the parent strains. In contrast, the MICs for the imipenem-selected mutants were the same as, or similar to, those for the parent strains. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis revealed that an outer membrane protein in both parent strains was absent in the meropenem-selected mutants, but not in the imipenem-selected mutants. This protein is likely to be a porin, the absence of which is presumably associated with impaired beta-lactam permeability and, therefore, the reduced susceptibilities to these antibiotics exhibited by the mutant strains. We believe that this is the first report of the in-vitro selection of porin-deficient mutants of K. pneumoniae following exposure to meropenem.

Drug Resistance, Microbial↗
PubMed1998

Sequence and transcriptional analysis of terminal regions of the fowl adenovirus type 8 genome.

Fowl adenovirus (FAdV) type 1, CELO strain has no homologies to mastadenovirus E1A, E1B, E3 and E4, which regulate virus gene expression, DNA replication and virus-host interaction. Similarly, the right 5 kb and left 15 kb ends of CELO virus DNA are non-homologous to mastadenoviruses. To compare CELO virus with another FAdV, 7.5 kb of the left and 17 kb of the right ends of FAdV type 8 (strain A-2A) were sequenced and nine and 17 open reading frames (ORFs), respectively, were found. This FAdV-8 genome was similar to CELO virus in that (1) the central region contained the major structural protein genes including the fibre, pVIII, 100K, late 33K and pIVa2 genes, which were in the same order as in mastadenoviruses, (2) no homologues of mastadenovirus E1A, E1B, E3 and E4 were found in the ends, and (3) the left 6 kb and the right 13 kb ends showed no homology to mastadenoviruses. Several genomic features were unique to FAdV-8 compared to CELO virus. FAdV-8 contained one fibre gene in contrast to two in CELO virus. Three of eight unassigned ORFs in the left and five of 13 unassigned ORFs in the right ends were unique compared to CELO virus. Two sets of tandem repeats, one with five identical 33 bp repeats and the other with more than ten identical 135 bp repeats, mapped between 4.5 and 7.5 kb from the right terminus. No virus-associated RNA gene was found. Fifteen of 16 unique FAdV-8 ORFs tested were, as determined by RT-PCR, transcribed early.

Aviadenovirus↗
PubMed1998

Isolation, identification and increasing importance of 'free-living' amoebae causing human disease.

Amphizoic small amoebic protozoa are capable of existing both in 'free-living' and in 'parasitic' form depending on the actual conditions. Two genera (Naegleria and Acanthamoeba) have become recognised as opportunist human parasites. Since the first description in 1965 of a lethal case of primary amoebic meningoencephalitis (PAM) caused by Naegleria, many more (mostly lethal) cases have been reported, while granulomatous amoebic encephalitis (GAE), as well as eye (keratinitis, conjunctivitis, etc.), ear, nose, skin and internal organ infections caused by Acanthamoeba have also occurred in rapidly increasing numbers. Both pathogenic and non-pathogenic species of Naegleria and Acanthamoeba are found worldwide in water, soil and dust, where they provide a potential source of infection. Successful differential diagnosis and appropriate (specific) therapy depends on precise laboratory identification of the 'free-living' amoebae. In most cases, isolation from the environment can be achieved, but identification and differentiation of the pathogenic and non-pathogenic strains is not easy. The methods presently available do not fulfil completely the requirements for specificity, sensitivity and reliability. Morphological criteria are inadequate, while thermophilic character, pH dependency and even virulence in infected mice, are not unambiguous features of pathogenicity of the different strains. More promising are molecular methods, such as restriction endonuclease digestion of whole-cell DNA or mitochondrial DNA, as well as iso-enzyme profile analysis after iso-electric focusing and staining for acid phosphatase and propionyl esterase activity. Use of appropriate monoclonal antibodies has also yielded promising results in the differentiation of human pathogenic and non-pathogenic strains. However, quicker, simpler, more specific and reliable methods are still highly desirable. The significance of endosymbiosis (especially with Legionella strains) is not well understood. The results of a systematic survey in Hungary for the isolation and identification of 'free-living' amoebae, including an investigation of the Hungarian amoebic fauna, the isolation of possibly pathogenic Naegleria strains and of some Acanthamoeba strains from eye diseases, as well as the finding of a case of endosymbiosis, are also reported here.

Acanthamoeba↗
PubMed1998

Detection of bovine torovirus in fecal specimens of calves with diarrhea from Ontario farms.

Breda virus (BRV), a member of the genus Torovirus, is an established etiological agent of disease in cattle. BRV isolates have been detected in the stools of neonatal calves with diarrhea in both Iowa and Ohio and in several areas of Europe. However, this virus has been reported only once in Canada. Therefore, a study was performed to determine the extent to which bovine torovirus is present in calves with diarrhea from farms in southern Ontario. A total of 118 fecal samples from symptomatic calves and 43 control specimens from asymptomatic calves were examined by electron microscopy (EM) and reverse transcription-PCR (RT-PCR) for the presence of torovirus. Torovirus RNA was detected in 43 of the 118 diarrheic samples (36.4%) by RT-PCR with primers designed in the conserved 3' end of the torovirus genome. By EM, torovirus particles were observed in 37 of the 118 specimens (31.4%). All but one of these samples were also positive by RT-PCR. The incidence of torovirus in the asymptomatic control specimens by RT-PCR was only 11.6%. To establish the identity of the particles observed in the diarrheic specimens, five of the amplicons from samples positive by both RT-PCR and EM were cloned and sequenced. Nucleotide sequence analysis revealed that the bovine torovirus found in southern Ontario manifests between 96 and 97% sequence identity to the BRV type 1 strain found in Iowa. This study shows that bovine torovirus is a common virus in the fecal specimens of calves with diarrhea from farms in southern Ontario and thus may be an important pathogen of cattle.

Animals↗
PubMed1998

Epidemiological study of Chlamydia trachomatis infection in pregnant women in Hungary.

A multicentre survey was carried out in order to determine the prevalence and risk factors of Chlamydia trachomatis infection in the pregnant population in Hungary. The nucleic acid hybridisation method (PACE 2 Gen-Probe) was applied for the examination of C trachomatis. The overall average prevalence of C trachomatis cases during an 18 month survey on 6161 pregnant women was 5.87%. There were significant differences in the proportions of chlamydial infection in the different survey centres, and also in the different age groups and the different family status groups. The perinatal mortality rate exhibited a significantly higher prevalence (8.52%) among C trachomatis positive than among negative patients (2.03%). In the anamnestic histories of C trachomatis infected patients, the frequency of premature uterine activity was 8.13%, in contrast with 5.18% in the non-infected group (p < 0.05). We suggest that all pregnant women be tested for C trachomatis infection.

Adolescent↗
PubMed1998

Heterogeneous signal pathways through TSH receptors in porcine thyroid cells following stimulation with Graves' immunoglobulin G.

OBJECTIVE: We compared different signal transduction pathways through thyroid stimulating hormone receptor (TSH-R) in porcine thyroid cells (PTC) following stimulation with thyroid stimulating hormone (TSH) and 11 thyroid stimulating immunoglobulin samples (TSI) obtained from patients with Graves' disease. DESIGN: Following stimulation with TSI, the level of inositol trisphosphate (IP3) and [Ca2+]i, as well as the membrane bound protein kinase C (PKC) activity and the intensity of the arachidonic acid (AA) cascade, were determined in PTC. RESULTS: Seven out of eleven TSI samples activated PTC through IP3 generation, elevated [Ca2+]i from the intracellular pools, exhibited verapamil-insensitive membrane-bound PKC activation, and enhanced release of [14C]AA derivates (however, one of the samples was also able to take up Ca2+ from the extracellular space). Four out of eleven TSI samples did not activate the phospholipase C (PLC) system in which case the Ca2+ signal occurred only in the presence of extracellular Ca2+, the membrane bound PKC activation was verapamil sensitive, and in two of these four TSI samples, the AA release was extremely high. CONCLUSIONS: The simultaneous examination of the majority of the known signal pathways using TSI samples showed that TSI samples from different patients activate thyroid cells through different pathways. Their effects differ from that of TSH and, to a certain extent, from each other. The results give a certain new insight into the intracellular mechanisms exerted by TSI.

Adult↗