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  • Author or Editor: A. Lázár x
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Individual differences in human sleep EEG spindling were shown to be associated with psychometric measures of cognitive ability. Previous results revealed a frequency-and region specificity of this effect, suggesting that only fast, but not slow spindle-related oscillatory activity over the frontal region correlated with cognitive performance. Our aim is to test the hypothesis that region-specific spindle-type oscillatory activity is related to specific cognitive abilities reflecting the cortical localization of the corresponding cognitive function. The visuospatial abilities are the focus of the present report. Nineteen healthy volunteers were tested with the Rey-Osterrieth Complex Figure (ROCF) test and memory performances correlated with the spindle analysis of the second night’s polysomnographic recordings. Correlations were age-corrected and subjected to descriptive data analysis. ROCF recall performances at 3 and 30 minutes delay, correlated positively and significantly with fast sleep spindle density measured over the right parietal area. No significant relationship between recognition performance and sleep EEG variables emerged. Slow spindle density did not correlate with test performances. Our findings converge with other data suggesting the involvement of right parietal functioning in visuospatial abilities. Moreover, these results support the hypothesis that region-specific differences in fast sleep spindling could be markers of specific neuropsychological performances.

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Authors: György Lázár and A Sebészeti Klinika orvosai
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Abstract  

Valency changes of iron and tin in framework-substituted microporous and mesoporous molecular sieves (Fe-ETS-10, Fe-ZSM-5, Fe-AlPO-11, Sn-ZSM-12 and Sn-MCM-41) have been studied under reducing and oxidizing conditions by in situ Mössbauer spectroscopy. It is demonstrated that the structure of the host matrices strongly influences the stabilization and the oxidation state of the ions. Debye temperature, D, data also are estimated, they support the suggested structural assignment of various species.

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The effect of potassium channel blockers tetraethylammonium and 4-aminopyridine was examined on the elevated K+ concentration-induced microglial activation on rat hippocampal slice preparations. Microglial cells were detected by immunohistochemistry with a monoclonal antibody (OX 42) raised against a type 3 complement receptor. During activation the morphology of the microglial cells changes and the staining intensity increases. The degree of microglial activation was determined by measuring the integrated optical density of the cells. Tetraethylammonium and 4-aminopyridine failed to reduce the elevated K+ concentration-induced microglial activation. Both potassium channel blockers, when applied on the hippocampal slices without K+, caused significantly increased microglial activation as compared to the control slices. In order to check whether the functional alteration of the neuronal population induced by 4-aminopyridine caused the activation of the microglial cells, Schaffer collaterals were cut to block spreading of epileptiform hyperactivity of the CA3 pyramidal cells to the CA1 region. No significant differences were found in microglial activation between the CA3 and CA1 regions, indicating that the effect of 4-aminopyridine on microglial cells is independent of the epileptiform activity caused by the drug.

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Purpose

Suprapubic bladder aspiration is an invasive procedure in which a needle is used to obtain a urine sample directly from the bladder. Its advantages are sensitivity (detection of significant bacteriuria is close to 100%), suitability for cultivation of anaerobic bacteria, and low risk of contamination. Our purpose was to characterize the microbiology and epidemiology of urine samples obtained through this procedure in the Clinical Center of the University of Szeged’s Institute of Clinical Microbiology between 2008 and 2017.

Materials and methods

Over the 10-year period, patient data were collected and suprapubic bladder aspirations were performed, and the samples are processed in accordance with routine laboratory procedures in clinical bacteriology.

Results

Of 187 urine samples obtained from 148 patients, 32.6% (n = 61) were culture-positive (defined as 102 colony forming units/ml or more).

Conclusions

This method should be considered an important sampling procedure in the differential diagnostics of upper urinary tract infections, particularly in children <2 years of age, and in older people, hospitalized patients.

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Authors: K. Lázár, A. M.-Szeleczky, G. Vorbeck, R. Fricke, A. Vondrova and J. Cejka

Abstract  

Ferrisilicates of MFI structure (HZSM-5) with Si/Fe ratios of 27.5, 35 and 67 have been studied by in situ Mössbauer spectroscopy, and the results are correlated with studies on catalytic conversions of toluene. Various species of iron ions are identified from 300 K spectra recorded after combinations of evacuation and reduction at 570 and 670 K, respectively. The roles of identified species are suggested in catalytic processes.

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Authors: Bernadett Borda, Cs. Lengyel, T. Várkonyi, É. Kemény, A. Ottlakán, A. Kubik, Cs. Keresztes and Gy. Lázár

New-onset diabetes after transplantation (NODAT) is one of the frequent complications following kidney transplantation. Patients were randomized to receive cyclosporine A- or tacrolimus-based immunosuppression. Fasting and oral glucose tolerance tests were performed, and the patients were assigned to one of the following three groups based on the results: normal, impaired fasting glucose/impaired glucose tolerance (IFG/IGT), or NODAT. NODAT developed in 14% of patients receiving cyclosporine A-based immunosuppression and in 26% of patients taking tacrolimus (p = 0.0002). Albumin levels were similar, but uric acid level (p = 0.002) and the age of the recipient (p = 0.003) were significantly different comparing the diabetic and the normal groups. Evaluation of tissue samples revealed that acute cellular rejection (ACR) and interstitial fibrosis/tubular atrophy (IF/TA) were significantly different in the NODAT group. The pathological effect of new-onset diabetes after kidney transplantation can be detected in the morphology of the renal allograft earlier, before the development of any sign of functional impairment.

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Summary  

The associations between cancer mortality and median radon levels were examined in 34 Hungarian small villages (with population less than 5000) during the 1984-2000 period. The yearly averages of radon activity concentrations were measured in more than 70 homes in totally 5,081 houses in each village. There were no significant differences in the age distribution and the cancer mortality rate between the studied villages and all Hungarian villages with less than 5000 inhabitants. A previous cohort study in two neighboring villages in Hungary revealed a lower cancer incidence rate among women aged 30-64 in medium radon level (110-185 Bq . m-3). The aim of this study was checking the results of the previous study. Cancer mortality rate was examined in two groups: below and above the median value (110 Bq . m-3) of radon level. The lower or higher radon levels of homes do not result in significant differences concerning cancer mortality rate of males. However, the middle-aged group (30-64 years) of women had more lethal cancer cases in the lower radon level groups (59-109 Bq . m-3) than in the higher ones (110-226 Bq . m-3), the relative cancer risk was 1.3 (95% CI 1.1 to 1.6).

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Authors: David Tarnoki, A.D. Tarnoki, Zs. Lazar, Cs. Korom, V. Berczi, I. Horvath and K. Karlinger

Genetic effects that contribute to the risk of developing chronic obstructive pulmonary disease (COPD) have been reported. Our purpose was to estimate the possible genetic influence on CT features related to COPD in twins.

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Authors: A. Bikov, Zs Lazar, K. Schandl, B. Antus, G. Losonczy and Ildiko Horvath

Exercise-caused metabolic changes can be followed by monitoring exhaled volatiles; however it has not been previously reported if a spectrum of exhaled gases is modified after physical challenge. We have hypothesized that changes in volatile molecules assessed by an electronic nose may be the reason for the alkalization of the exhaled breath condensate (EBC) fluid following physical exercise.Ten healthy young subjects performed a 6-minute running test. Exhaled breath samples pre-exercise and post-exercise (0 min, 15 min, 30 min and 60 min) were collected for volatile pattern (“smellprint”) determination and pH measurements (at 5.33 kPa CO2), respectively. Exhaled breath smellprints were analyzed using principal component analysis and were related to EBC pH.Smellprints (p=0.04) and EBC pH (p=0.01) were altered during exercise challenge. Compared to pre-exercise values, smellprints and pH differed at 15 min, 30 min and 60 min following exercise (p<0.05), while no difference was found at 0 min post-exercise. In addition, a significant correlation was found between volatile pattern of exhaled breath and EBC pH (p=0.01, r=−0.34).Physical exercise changes the pattern of exhaled volatiles together with an increase in pH of breath. Changes in volatiles may be responsible for increase in EBC pH.

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