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Biomedical subjects

E Katona

Publications and source records attributed to E Katona.

At least 19 recordsLinked to original sources
PubMed2005

Factor XIII in bronchoalveolar lavage fluid from children with chronic bronchoalveolar inflammation.

BACKGROUND: Extravascular activation of the coagulation system and consequent fibrin deposition is involved in the pathomechanism of chronic bronchoalveolar inflammatory diseases. The turnover of extravascular fibrin is attenuated by its cross-linking with activated factor XIII (FXIII). OBJECTIVES: Determination of cellular and plasmatic forms of FXIII and their correlation with D-dimer level in the bronchoalveolar lavage fluid (BALF) from healthy children and from children with bronchoalveolar inflammation. PATIENTS AND METHODS: Highly sensitive immunoassays were used for the quantitation of cellular and plasma FXIII and D-dimer in the BALF of children with recurrent wheezy bronchitis and fibrosing alveolitis. BALF was investigated for FXIII-containing cells by flow cytometry. RESULTS AND CONCLUSIONS: In the BALF of controls a low amount of the cellular form of FXIII (FXIII A2) and D-dimer were measured, while plasma FXIII (FXIII A2B2) was absent. Alveolar macrophages represented the single cell population in BALF that contained FXIII. In the BALF of both patients' groups the concentration and the total amount of FXIII A2 was significantly elevated, and plasma FXIII also appeared in the BALF of most patients. The D-dimer concentration was also elevated in the patients' groups and it correlated both with plasma FXIII and neutrophil count. These findings suggest that FXIII A2 is released from activated or injured alveolar macrophages into the bronchoalveolar lining fluid and in bronchoalveolar inflammatory diseases, FXIII A2B2 also leaks out from the capillaries. By cross-linking fibrin and inhibitors of fibrinolysis to fibrin, FXIII might be a key regulator of fibrin turnover in the extravascular compartment.

Adolescent↗
PubMed2002

The epidemiology of hypertension and its associated risk factors in the city of Debrecen, Hungary.

The purpose of this work was to estimate the prevalence of hypertension and cardiovascular risk factors and its association with sociodemographic, behavioural and lifestyle characteristics among the adult population of the city of Debrecen, Hungary.A cross-sectional study was conducted in 1996. Amongst 21 800 inhabitants aged 30-65 y risk screening for cardiovascular disease (CVD) was estimated by a questionnaire that included sociodemographic, lifestyle characteristics, family history of CVD and results of self-reported data of body weight, height and blood pressure. Of the total of 19 961 surveyed sample, 37.02% were considered to be hypertensive, 53.73% were overweight, 32.18% were current smokers and 58.85% were physically inactive. Hypertensives were older than normotensives (50.81+/-9.01 vs 44.78+/-8.97 y, P<0.001). The prevalence of various risk factors amongst hypertensives as compared to normotensives were overweight (68.49 vs 45.06%, P<0.0001), current smoking (28.38 vs 34.41%, P<0.0001), physical inactivity (64.78 vs 55.36%, P<0.001), and high alcohol consumption (1.91 vs 1.06%, P<0.01). Of the hypertensives 37.11% were on drug therapy. Of those on therapy, only 17.03% had normal blood pressure. Being overweight and having low physical activity was positively associated with hypertension (OR=2.25, CI=2.11-2.40) and (OR=1.26, CI=1.15-1.38). Manual work, a family history of CVD, low education, and the male gender were also associated with hypertension and more CVD risk factors. These findings illustrate a very high prevalence of hypertension and CVD risk factors in Debrecen, indicating the importance of the need for more effective prevention programmes and control of hypertension in Hungary.

Adult↗
PubMed2001

[Changes in lipid profile and paraoxonase activity in obese patients as a result of orlistat treatment].

257 patients from 33 centres were involved in a six-month study, the aim of which was to assess the effect of orlistat together with a diet. The authors examined how the treatment effected the anthropometrical and lipid parameters, extending the study to the aspect of paraoxonase activity in case of 25 patients. 44 patients dropped out during the study period due to the lack of sufficient diet compliance, whereas 3 patients had to stop the therapy because of the adverse event of flatus with discharge. On the average, the body mass of the patients decreased from 100.8 +/- 18.9 to 91.3 +/- 18.6 kg, i.e. by 9.5 kgs, while their BMI was reduced from 36.1 +/- 5.6 to 32.5 +/- 5.2 kg/m2 and the circumference of the waist changing from 119.1 +/- 20 to 108.3 +/- 15.1 cm, i.e. by 10.8 cms. The blood sugar level significantly decreased from 5.7 to 5.4, while the cholesterol concentration significantly dropped from 5.9 to 5.5, the triglyceride level being reduced from 2.4 to 2.1 mmol/l and blood pressure falling significantly from 136.6/86.9 to 129.9/81.6. All the above changes showed a significant decrease. However, the HDL-cholesterol level did not change. The serum paraoxonase activity significantly increased (143 +/- 49 vs 166 +/- 43 UL) along with the standardised values for HDL (PON/HDL), even compared to the control diet group. From the above results it may be concluded that orlistat tends to have an antioxidant effect.

Abdomen↗
PubMed2001

[Epidemiology of hypertension in adolescence and factors influencing blood pressure].

The authors summarize the determining and influencing factors of adolescent hypertension. An overview of the definition and prevalence of hypertension in adolescence is given and the predictive role of the adolescent hypertension on the incidence of adult cardiovascular diseases is pointed out. According to the previous literature data, adult hypertension is more frequent in those people who have had hypertension in their adolescence. There are no widely used, population-based nomograms of adolescent hypertensives available. According to the opinion of the authors, a population-based hypertension screening program would help in delineating the factors influencing adolescent blood pressure, and the most frequent risk factors for hypertension in Hungary. With the follow-up and appropriate treatment of the hypertensives the reduction of target-organ damages may be possible.

Adolescent↗
PubMed2000

Val34Leu polymorphism of plasma factor XIII: biochemistry and epidemiology in familial thrombophilia.

Val34Leu polymorphism of the A subunit of coagulation factor XIII (FXIII-A) is located in the activation peptide (AP) just 3 amino acids away from the thrombin cleavage site. This mutation has been associated with a protective effect against occlusive arterial diseases and venous thrombosis; however, its biochemical consequences have not been explored. In the current study it was demonstrated that the intracellular stability and the plasma concentration of FXIII of different Val34Leu genotypes are identical, which suggests that there is no difference in the rate of synthesis and externalization of wild-type and mutant FXIII-A. In contrast, the release of AP by thrombin from the Leu34 allele proceeded significantly faster than from its wild-type Val34 counterpart. By molecular modeling larger interaction energy was calculated between the Leu34 variant and the respective domains of thrombin than between the Val34 variant and thrombin. In agreement with these findings, the activation of mutant plasma FXIII by thrombin was faster and required less thrombin than that of the wild-type variant. Full thrombin activation of purified plasma FXIII of different genotypes, however, resulted in identical specific transglutaminase activities. Similarly, the mean specific FXIII activity in the plasma was the same in the groups with wild-type, heterozygous, and homozygous variants. Faster activation of the Leu34 allele hardly could be associated with its presumed protective effect against venous thrombosis. No such protective effect was observed in a large group of patients with familial thrombophilia.

Adult↗
PubMed2000

Prevalence of cardiovascular risk factors of the smokers and non-smokers in the city of Debrecen, Hungary.

The aim of our study was to compare the major cardiovascular disease (CVD) risk factors of smokers and non-smokers. Risk screening of CVD was estimated by a questionnaire, via interview. Random samples of 20 000 inhabitants of Debrecen, Hungary, aged 30-65 y, took part in the study. 19 922 questionnaires were considered appropriate for further evaluation. 32.2% of the participants (n=6410) were smokers, whose data were compared to those of the 68.8% of non-smokers (n=13 512). There were more male smokers than female (39.3% vs 27.7%), (P<0.001). 36.5% of males and 58.9% of females had not previously smoked regularly (P<0.001). 24.2% of males and only 13.3% of females were able to stop smoking (P<0.001). 8.7% of the participants smoked more than 20 cigarettes per day (14.8% of males, 5.0% of females), (P<0.001). Smokers were younger, with a mean age of 43.4 y vs 47.1 y for non-smokers (P<0.01). The ex-smokers and non-smokers had a higher body mass index than light, moderate and heavy smokers (26. 75+/-4.1 kg/m2 and 26.09+/-4.3 kg/m2 vs 24.87+/-3.9 kg/m2 and 24. 89+/-4.2 kg/m2 and 25.32+/-4.3 kg/m2, respectively), (P<0.001). The results of the last measured blood pressures did not differ between the two groups. 94.8% of smokers and 93.6% of non-smokers did not perform any regular leisure time exercises (P<0.01). 39.8% of smokers regularly ate fatty food, in comparison to 28.0% of non-smokers (P<0.001). 30.6% of smokers vs 28.6% of non-smokers were factory workers while 69.4% of smokers vs 71.4% of non-smokers did sedentary jobs (P<0.001). 2.3% of smokers vs 0.9% of non-smokers admitted regular consumption of alcohol (P<0.001). Amongst the parents and brothers/sisters of smokers the prevalence of heart attack was higher 19.7% vs 18.7%, than for those of non-smokers (P<0. 05). We observed an accumulation of cardiovascular risk factors in the case of smokers, which indicates the higher susceptibility of smokers to CVD.

Adult↗
PubMed2000

A simple, quick one-step ELISA assay for the determination of complex plasma factor XIII (A2B2).

A new highly sensitive sandwich ELISA assay was developed for the determination of plasma factor XIII (FXIII). Plasma FXIII is a tetrameric complex of two types of subunits (A2B2). A biotinylated monoclonal capture-antibody against the B-subunit and a peroxidase-labelled monoclonal tag-antibody against the A-subunit were added to the plasma dilution and the amount of the complex attached to streptavidin-coated microplate was quantitated by measuring peroxidase activity. Only the tetrameric plasma FXIII reacted in the assay, non-complexed A or B subunits showed no reaction. The assay is linear up-to 40 microg/L of FXIII in the assay mixture. It is a quick one-step assay which can be performed within two hours. At normal and low FXIII concentration within batch reproducibility was 2.0% and 3.3%, day to day variation was 5.5% and 8.7%, respectively. Its high sensitivity allows reliable measurement at FXIII concentrations below 1% of normal average. Plasma samples can be stored for the assay at -20 degrees C for at least one month. Plasma levels of healthy individuals were normally distributed and no gender difference was observed. A reference interval of 14-28 mg/L (67-133%) was established.

Antibodies, Monoclonal↗
PubMed2000

A modified, optimized kinetic photometric assay for the determination of blood coagulation factor XIII activity in plasma.

BACKGROUND: Blood coagulation factor XIII (FXIII) is a zymogen that is transformed into an active transglutaminase by thrombin and Ca(2+). FXIII plays an essential role in fibrin stabilization and in the protection of fibrin from proteolytic degradation. No convenient method has been available for the measurement of FXIII activity in plasma. The aim of the present study was to improve and optimize a kinetic photometric FXIII assay originally developed in our laboratory. METHODS: In the assay, FXIII was activated by thrombin and Ca(2+). Fibrin polymerization was prevented by an inhibitory tetrapeptide. Glycine-ethyl ester and a glutamine residue of a synthetic dodecapeptide served as acyl acceptor and acyl donor transglutaminase substrates, respectively. The amount of ammonia released during the reaction was monitored using glutamate dehydrogenase and NADPH. RESULTS: The use of a new glutamine substrate and optimization of activator and substrate concentrations increased sensitivity. Substitution of NADPH for NADH and introduction of an appropriate blank eliminated systemic overestimation of FXIII activity. The recovery of FXIII was 96%, the assay was linear up to 470 U/L, the detection limit was 1 U/L, and the imprecision (CV) was <8% even at very low FXIII activities. A reference interval of 108-224 U/L (69-143%) was established. The results correlated well with results obtained by an immunoassay specific for plasma FXIII. CONCLUSIONS: The optimized FXIII assay is a simple, rapid method for the diagnosis of inherited or acquired FXIII deficiencies and increased FXIII concentrations. It can be easily adapted to clinical chemistry analyzers.

Adult↗
PubMed1999

Serum paraoxonase activity changes in uremic and kidney-transplanted patients.

Serum paraoxonase (PON) is a high-density lipoprotein (HDL)-associated hydrolase, which inhibits low-density lipoprotein oxidation. Uremic and kidney-transplanted patients have an increased risk of atherosclerosis, to which an increased lipoprotein oxidation may contribute. The aim of our study was to determine whether the PON activity or phenotype is altered in uremic and kidney-transplanted patients, and to compare the values with those of healthy controls. 117 uremic patients on long-term hemodialysis treatment, 115 renal-transplanted patients, and 110 healthy controls were involved in the study. The PON activity was significantly reduced in the uremic patients compared to controls (PON 101.36+/-30. 12 vs. control 188.05+/-58.96 U/ml; p < 0.001), while in kidney-transplanted patients the values were almost identical to those of controls (PON 161.5+/-35.39 U/ml). The different immunosuppressive drug combinations did not influence PON activity. To assess whether the altered PON activity was due to a decrease HDL level, we standardized the enzyme activity for the HDL concentration (PON/HDL ratio). We found that the standardized enzyme activity was lower in the uremic (102.7+/-54.8) and kidney-transplanted patients (144.5+/-32.7) when compared to controls (194.5+/-94.5; p < 0.001). The phenotypic distribution of PON in uremic, renal transplant and control patients are as follows: AA 66.67, 56.48 and 66.67%; AB 31. 62, 33.3 and 26.67%; BB 1.71, 10.19 and 6.67%. We conclude that the decreased PON/HDL and PON/apoA-1 ratios may lead to a reduction in the antioxidant capacity of HDL, which might contribute to the accelerated development of atherosclerosis in uremic and kidney-transplanted patients.

Adult↗
PubMed1998

Development of ELISA and enzyme-linked immunofiltration assay (ELIFA) methods for monitoring cyclodextrin glycosyltransferase (CGTase) production and bacterial growth in Bacillus macerans batch cultures.

Immunochemical methods were developed for monitoring cyclodextrin (CD) glycosyltransferase (CGTase) production and growth of an industrial CD-producing Bacillus macerans strain. Extracellular concentrations of CGTase released into a non-transparent culture medium during a 44 h long fermentation were detected by an indirect antigen inhibition enzyme-linked immunosorbent assay (ELISA). The ELISA was sensitive (minimal detection level 6 ng ml-1) and highly reproducible (coefficients of variation < or = 1.2 and 5.9%, within-runs and between-runs, respectively) compared to assays of CGTase activity (coefficients of variation < or = 4.2 and 7.0%, respectively). The ELISA, in combination with enzyme activity measurements, was useful to detect the decrease in the specific CGTase activities after 36 h of incubation, which was clearly indicative of the proteolytic degradation of CGTase. B. macerans cell numbers were estimated using an enzyme-linked immunofilter assay (ELIFA). The assay took less than 1 h and the coefficients of variation within and between-runs (2.9-6.4%) were considerably less than for viable counting (10.6-15.4%). In the exponential phase of growth, ELIFA results correlated more closely with the cell counting based on total protein than with viable counts. Nevertheless, in the phase of cell lysis, the bacterial cell number was systematically underestimated by ELIFA in comparison to both viable cell number and total protein determinations. Thus cell antigens detected with immunological procedures might be lost during the transition from vegetative cells to spores. On the other hand, the ELIFA procedure was specific for B. macerans cells and was a better indicator of the onset of the different growth phases than the cell numbers calculated from the protein assay.

Bacillus↗
PubMed1998

Epitope specificity of monoclonal and polyclonal antibodies to human elastin.

Polyclonal (pAb) and monoclonal (mAb) anti-human aorta elastin antibodies were reacted with a series of overlapping hexapeptides along the human tropoelastin sequence covering exons 2-7 and 23-36 from the N-terminus to the C-terminus, advancing 1 amino acid residue each time. ELISA indicated reactive epitopes. mAb A2.1 recognized sequences containing Ala-Lys, mAb G8.1, A7.1 and pAb, hydrophobic sequences. None of them reacted with the hexapeptide VGVAPG, or with desmosine or isodesmosine. pAb L85 reacted with a His-containing sequence coded in exon 26A. pAb kappaE(L), kappaE(S) and L85 reacted with the Cys-containing sequence of exon 36. A synthetic 14-residue peptide containing the three proximal tyrosines coded in exon 13 did not react with any of the antisera tested. It appears therefore that the most frequently recognized epitopes are hydrophobic sequences. One polyclonal antibody detected several isoforms of tropoelastin in the medium of cultured vascular smooth muscle cells. Monoclonal and polyclonal antibodies stained elastic fibers on tissue sections, suggesting that the epitopes recognized are available on the native fibers for reaction with the antibodies.

Amino Acid Sequence↗
PubMed1995

Relationship between photosynthetic electron transport and pH gradient across the thylakoid membrane in intact leaves.

Under conditions (0.2% CO2; 1% O2) that allow high rates of photosynthesis, chlorophyll fluorescence was measured simultaneously with carbon assimilation at various light intensities in spinach (Spinacia oleracea) leaves. Using a stoichiometry of 3 ATP/CO2 and the known relationship between ATP synthesis rate and driving force (Delta pH), we calculated the light-dependent pH gradient (Delta pH) across the thylakoid membrane in intact leaves. These Delta pH values were correlated with the photochemical (qP) and nonphotochemical (qN) quenching of chlorophyll fluorescence and with the quantum yield of photosystem II (phiPSII). At Delta pH > 2.1 all three parameters (qP, qN, and phiPSII) changed very steeply with increasing DeltapH (decreasing pH in the thylakoid). The observed pH dependences followed hexacooperative titration curves with slightly different pKa values. The significance of the steep pH dependences with slightly different pKa values is discussed in relation to the regulation of photosynthetic electron transport in intact leaves.

Journal Article↗
PubMed1994

[Correlation between adhesive factors of primary hemostasis and liver fibrogenesis in alcoholic live cirrhosis].

Colchicine administration is able to reduce collagen production and the fibrogenetic process in alcoholic liver diseases in the same time. The decrease of the serum lipid peroxidation capacity along with type III procollagen propeptide level was associated with the simultaneous reduction of plasmatic von Willebrand factor, fibronectin and beta-thromboglobulin levels. This observation suggest a connection between the regulation of primary haemostasis and liver fibrogenesis.

Colchicine↗
PubMed1994

Substance use among Hungarian students.

There is very little empirical data on drug and alcohol use among Hungarian adolescents. The purpose of this pilot project was to develop instrumentation and methods that could be used to assess legal and illegal substance use among Hungarian adolescents. A Hungarian translation of The American Drug and Alcohol Survey was developed and adapted to the unique circumstances of Hungarian patterns of use. This survey was tested with 234 students, 135 females and 99 males, from Grades 8 and 11 enrolled in public schools, in Györ, Hungary during 1991-1992. The students reported little or no substance use other than use of alcohol and tobacco. Older students were more likely than younger students to be involved with alcohol and cigarettes. Females and males were equally likely to try alcohol, but males were more likely to have been drunk than females. Despite the low reported use of substances other than alcohol and tobacco, students demonstrated attitudes toward drug use that may place them "at risk" for future use.

Adolescent↗
PubMed1992

[The value of acetazolamide provocation combined with blood flow tests in the diagnosis of ischemic cerebrovascular diseases].

In 28 (3 normal, 11 TIA, 14 completed stroke) patients 99mTc-HMPAO rCBF SPECT studies were performed at rest and after acetazolamide administration. For the investigations, a one-day protocol (the stress study directly followed the rest investigation) was used. The reconstructed and normalized slices were evaluated visually and semiquantitatively with a side difference analysis method. In the group of TIA patients, the abnormal results of the rCBF investigations increased from 55% to 82% after acetazolamide provocation. The corresponding results in the completed stroke group were 80% and 87%. After acetazolamide stimulation, hypoperfusion appeared or become more pronounced in the majority of the TIA group patients in contrast with the completed stroke patients with an unchanged or decreased perfusion abnormality. The semiquantitative evaluation method was mostly effective in the TIA group, where predominantly a one-sided cerebrovascular disorder was suspected. It was concluded that the 99mTc-HMPAO studies allow demonstration of the acetazolamide-induced cerebral perfusion alterations, and this method can be useful in the diagnosis and management of cerebrovascular disorders.

Acetazolamide↗
PubMed1992

[Determination of the cerebrovascular reserve capacity by using acetazolamide as well as transcranial Doppler and SPECT tests].

The aim of this study was the development of a simple bedside test to assess cerebrovascular reserve capacity using transcranial Doppler sonography. We tried to validate the increase in blood flow velocity as cerebrovascular reserve capacity in 20 (3 normal, 7 TIA, 10 completed stroke) patients. They were studied using transcranial Doppler sonography and rCBF SPECT before and after injection of 1 g acetazolamide. Their increases in blood flow velocity and changes in cerebral blood flow correlated significantly in the symptomatic hemispheres (p less than 0.001). Blood flow velocity between the two hemispheres (symptomatic and asymptomatic) was not significantly different at rest. We offer these simple and reliable methods in clinical studies to clarify the frequency of ischemic stroke of hemodynamic origin.

Acetazolamide↗
PubMed1992

[SPECT follow-up of cerebral blood circulation after stroke].

rCBF SPECT investigations with 99mTc-HMPAO were performed in 22 completed ischemic stroke patients on average 2.5, 16.8 and 38.0 days after stroke onset. As control group, 12 neurologically healthy volunteers were examined with the same method. The overall sensitivity of the rCBF SPECT method in the detection of cerebral blood flow abnormalities was 91%, with a specificity of 83% and an accuracy of 88%. The rCBF study was highly effective, particularly in the acute phase of the disease. Regional increased tracer uptake or a false normal 99mTc-HMPAO distribution due to the developing hyperemia mostly complicated the rCBF image interpretations in the subacute period. In the chronic phase, the spatial resolution of the SPECT system limited the detection of the continuously retracted stroke lesions.

Blood Flow Velocity↗