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B Nagy

Publications and source records attributed to B Nagy.

188 records · Page 11Linked to original sources
PubMedDate not supplied

Genetic evidence that the elevated levels of Escherichia coli helicase II antagonize recombinational DNA repair.

Some phages survive irradiation much better upon multiple than upon single infection, a phenomenon known as multiplicity reactivation (MR). Long ago MR of UV-irradiated lambda red phage in E. coli cells was shown to be a manifestation of recA-dependent recombinational DNA repair. We used this experimental model to assess the influence of helicase II on the type of recombinational repair responsible for MR. Since helicase II is encoded by the SOS-inducible uvrD gene, SOS-inducing treatments such as irradiating recA(+) or heating recA441 cells were used. We found: i) that MR was abolished by the SOS-inducing treatments; ii) that in uvrD background these treatments did not affect MR; and iii) that the presence of a high-copy plasmid vector carrying the uvrD(+) allele together with its natural promoter region was sufficient to block MR. From these results we infer that helicase II is able to antagonize the type of recA-dependent recombinational repair acting on multiple copies of UV-damaged lambda DNA and that its anti-recombinogenic activity is operative at elevated levels only.

Adenosine Triphosphatases↗
PubMedDate not supplied

Demonstration of antibodies against Candida guilliermondii var. guilliermondii in asymptomatic infertile men.

Candida guilliermondii (C.g.) occurs mostly in animals, but it can affect humans too. Using serological screening methods studies have been carried out in 57 (30 normozoospermic and 27 oligozoospermic) asymptomatic infertile men, of whom 15 (26.3%; 9 oligozoospermic and 6 normozoospermic) were found to have responded to Candida guilliermondii var. guilliermondii. Sperm parameters (cell count, motility, morphology) were determined and various tests (hypo-osmotic swelling test, bovine mucus penetration, swim-up and testosterone examinations) were also performed. In the C.g.-infected and non-infected groups no significant difference was observed in any of the parameters. Precipitation was performed with a special antigen and in the positive group agglutination titres ranged from 0 to 1/320. Comparing C.g. titres with sperm parameters, only the swim-up technique showed noticeable alteration (P = 0.003). One month following ketoconazole treatment, the patients showed no precipitation reactions and their agglutination titres were < 1/80. Our results suggest that for the diagnosis of male infertility a serologic screening for C.g. is essential. As C.g. can also be sexually transmitted, both the husband and wife must be treated, if infection occurs.

Antibodies, Fungal↗
PubMedDate not supplied

Enterotoxigenic Escherichia coli (ETEC) in farm animals.

Animal diseases due to enterotoxigenic Escherichia coli (ETEC) typically appear as severe watery diarrhoea during the first few days of life (also a few days after weaning in pigs). ETEC adhere to the small intestinal microvilli without inducing morphological lesions and produce enterotoxins acting locally on enterocytes. This action results in the hypersecretion (of water and electrolytes) and reduced absorption. Adhesins and toxins are the two prominent virulence attributes of ETEC and the level of knowledge of these factors determines the chances for successful prevention and therapy of the disease. For animal ETEC the most common adhesins are the fimbriae (pili) on the surface: F4(K88), F5(K99), F6(987P), F41, F42, F165, F17 and F18. Enterotoxins (extracellular proteins or peptides) of animal ETEC are classified as heat-labile (LT) and heat-stable (ST) enterotoxins with further subdivisions (LTh-I, LTp-I, LTIIa, LTIIb, STaH, STaP, STb) according to antigenic and biological differences. Fimbriae and LT enterotoxins are made up of large molecular weight proteins which facilitate their utilisation in vaccines and their detection using immunodiagnostic systems. The adhesive fimbriae and enterotoxins of animal ETEC are plasmid determined (except F41 and F17). Virulence gene probes (DNA hybridisation, PCR) are specific and sensitive diagnostic and epidemiologic tools for the detection of ETEC. Based on genetic typing, the ETEC, in spite of limited serogroups, seem to represent a population of E. coli with a diverse genetic background.

Animals↗
PubMedDate not supplied

[A statistical epidemiologic study of arterial pressure in schoolchildren in Harghita County to establish normal values].

The epidemiological study was organized in schools in urban and rural areas. The study is readily reproducible and can be carried out longitudinally in the course of several years. Blood pressure was determined in children ranging in age from 7 to 14 years, and included 1838 children from urban areas--954 boys and 884 girls, and 1622 from rural areas--838 boys and 784 girls, per total 3460 children. Recording was done in the classroom in a quiet, friendly atmosphere, eliminating all psychical factors that might influence pressure, and was never taken before or after physical education. The pressure gage was applied on the right arm the cuff being adjusted to a child's arm. Pressure was determined thrice by two doctors independently, according to the Korotkov method, phase IV representing diastolic pressure. The data were processed statistically calculating the mean and standard deviation per determinations, per age, and finally calculating the proportions (individual values in the range of initial variations that correspond to percentages of 5, 25, 50, 75, 90, 95) of the total population analyzed. The tables give the results of systolic and diastolic pressure values in children in urban and in rural areas, as well as percentile curves of the systolic and diastolic pressure per sex. On the basis of the results children were considered to be candidates to high blood pressure whose systolic and/or diastolic tension in terms of age and sex was situated at percentage 95 or higher.

Adolescent↗
PubMedDate not supplied

Fibronectin on the bronchoalveolar surface in children with recurrent obstructive bronchitis.

Fibronectin is normally present in the lower respiratory tract. Significantly increased levels of it were detected in the lavage fluid in patients with interstitial lung diseases. Because this molecule appears to mediate a number of components of the inflammatory process, we evaluated the status of fibronectin in plasma and bronchoalveolar lavage in patients with recurrent obstructive bronchitis when signs of severe chronic mucosal inflammation were observed bronchoscopically. There was no considerable difference in plasma concentrations of fibronectin obtained from healthy children and patients. A comparison of lavage fibronectin/albumin ratios with plasma fibronectin/albumin ratios suggested significant local production, especially when the lavage and plasma ratios were measured in the same patients. Phagocytic activity of alveolar macrophages and blood granulocytes from the same patients was enhanced at both concentrations of fibronectin used. This concentrations referred to values quantified in the lavage fluid. The metabolism of fibronectin seems to be an important factor in tracing the inflammation process not only in adults with chronic interstitial lung diseases, but also in children with recurrent obstructive bronchitis.

Albumins↗
PubMedDate not supplied

Effect of experimental airway inflammation on bronchial hyper-responsiveness induced by Broncho-Vaxom in dogs.

We studied correlation between airway hyper-responsiveness induced by local exposure to a macrophage inductor Broncho-Vaxom and the development of airway inflammation in dogs. To detect airway inflammation, bronchoalveolar lavage and biopsy of airway mucosa were performed. The airway responsiveness was registered by capnograph measuring gas-exchange disturbances during obstructive reactions provocated by inhalation of various concentrations of acetylcholine aerosol. Broncho-Vaxom generated a protracted airway inflammation characterized by a slight and reversible increase in the number of neutrophils at 24 h after induction, and by a long-lasting influx of macrophages peaked about at the second week. The number of macrophages turned to initial levels 3 weeks later. Macrophages migrating to the bronchoalveolar surface were activated because peroxidase positivity and bearing C3b receptors of these cells increased gradually during the inflammatory process. Airway responsiveness measured at 3, 6 and 24 h after induction did not differ significantly from baseline values, but hyper-responsiveness was developed at 96 h using 0.5 and 1.0% acetylcholine aerosol (p less than 0.01 and p less than 0.001) during the non-purulent, macrophage-mediated inflammation. This situation modelled by Broncho-Vaxom induction is very similar to those observed in children with recurrent obstructive bronchitis. The results suggest that a macrophage-mediated inflammation caused by antigens, infections or pollutants may generate a long-lasting airway hyper-responsiveness.

Acetylcholine↗