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Biomedical subjects

E Kiss

Publications and source records attributed to E Kiss.

At least 91 records · Page 5Linked to original sources
PubMed1997

Effect of anti-thyroid peroxidase (TPO) antibodies on TPO activity measured by chemiluminescence assay.

A chemiluminescence method was developed to measure thyroid peroxidase (TPO) activity and the inhibitory effect of anti-TPO antibodies in purified porcine TPO. The TPO preparation was characterized kinetically and controlled by Western-blotting technique. The chemiluminescence method proved to be reproducible and much more sensitive than the widely used guaiacol method, being able to detect TPO concentrations of 2.21 x 10(-5) g/L vs 6.63 x 10(-2) g/L with the latter. Otherwise, the determinations with the two methods correlated well (r = 0.76). Investigating the effect of IgGs from 23 hypothyroid patients on measured TPO activity, we detected inhibition in 19 cases with the chemiluminescence technique (15 with the guaiacol method). Anti-TPO antibodies showed competitive inhibition of TPO activity with respect to the substrate guaiacol. In both systems, the inhibition is present in the IgG F(ab')2 fragment. We conclude that the high sensitivity of chemiluminescence detection allows routine determination of the inhibition of TPO activity by anti-TPO antibodies.

Animals↗
PubMed1997

Inhibitory effect of pentoxifylline on HLA-DR expression and glycosaminoglycan synthesis of retrobulbar fibroblasts induced by interferon gamma.

Glycosaminoglycan (GAG) accumulation produced by retroocular fibroblasts (REF) has been observed in patients with thyroid-associated ophthalmopathy (TAO). Various cytokines are able to express HLA-DR molecules and stimulate the REF to proliferate GAG and free oxygen radicals. Pentoxifylline (Ptx) is known to have complex immunomodulatory effects on production of cytokines including interferon gamma (IFN-gamma). Ptx has been assumed to inhibit the cytokine-induced production of GAG and HLA-DR expression. We wished to determine whether Ptx has an effect on the IFN-gamma induced HLA-DR expression and influences the spontaneous and cytokine-induced GAG synthesis of REF. REF derived from extraocular muscles of healthy subjects were cultured without and with IFN-gamma. The effect of Ptx on expression of HLA-DR molecules and the production of GAG by REF was determined. Glycosaminoglycan was measured by incorporation of (3H)glycosamine into GAG. HLA-DR expression was analysed by fluorescence activated cell sorter. IFN-gamma (50, 100 and 500 U/ml) induced an increase in expression of HLA-DR molecules of REF. Ptx was proved not to be toxic for cultured cells. This drug was able to dose-dependently inhibit HLA-DR expression of REF. Both spontaneous and IFN-gamma-induced GAG synthesis of REF was inhibited by Ptx (100, 500 and 1000 mg/l, respectively). Due to in vitro inhibitory effects, Ptx is potentially able to modify the antigen presentation and the GAG synthesis by REF and it might be a useful therapeutical drug in the treatment of TAO.

Cells, Cultured↗
PubMed1997

[Hair colorants].

The properties, mode of action and its duration of the preparations used for hair dyeing are described, together with their chemical components, and also preparations of herbal origin. The chemical reactions are described in detail which lead the development of a color polymer occurring during hair dyeing. The studies are presented which are used for toxicological assessment of the raw materials which are the components of the colorants, and the list is included of hair colorants permitted for use in Poland.

Animals↗
PubMed1996

Calculation of modified capacity factor in micellar electrokinetic chromatography.

In addition to the expression k' = (tm-t(o))/t(o) (1-tm/tmc), we propose the expression k" = (tm-t(o))/(tmc-t(o)) to calculate the capacity factor in micellar electrokinetic chromatography (MEKC), where tm, t(o), and tmc are the migration time of the analyte, the flow marker, and the micelles, respectively. The k' and k" values that were obtained from simulated data as well as from MEKC analysis of different peptides (in 100 mM sodium dodecyl sulfate/0.1 N sodium borate buffer at pH 11.0) were calculated and compared. The k" value is equal to zero for an analyte remaining in the aqueous phase whereas it is equal to one for an analyte always staying in the micellar phase. By applying k" a finite capacity factor can be obtained for an analyte, indicating its partition between the two moving phases (aqueous and micellar) even in those cases when tm equals tmc. The slope of the curve k" as a function of tm is constant through the whole migration window and therefore peak compression does not occur when applying k" to calculate the capacity factor. A given difference in k" corresponds the same difference in migration times and this value does not depend on the position within the migration window. Since k" is a normalized parameter it is easy to evaluate the significance of a given difference in capacity factor or to estimate the relative position of an analyte with a given capacity factor in the migration window by applying k". Therefore, k" seems to be an adequate parameter to calculate the capacity factor in MEKC and, similar to K', it also refers to the hydrophobicity of the analyte.

Chromatography↗
PubMed1996

A longitudinal study of phenylketonuria based on the data of the Budapest Screening Center.

Between 1975 and 1994 about 1.5 million neonates were screened by Guthrie tests at the phenylketonuria (PKU) Centre in Budapest. In this period 160 children with PKU were found. The corresponding incidence rate is about 1:9000. In a cumulative longitudinal design we investigated 56 patients with classical PKU between the ages of 3 months and 20.5 years. Treatment started at a mean age of 16.9 days (SD = 8.8). On average, pretreatment phenylalanine (Phe) levels were 1956 mumol/l (SD = 864), measured with the fluorometric method. Their Phe levels, physical growth, intellectual development, and performances in achievement tests were analysed. For the entire sample 45% of half year median Phe levels were in the recommended range, 33% represented poor dietary control, 22% were classified as intermediate. Physical growth was not significantly different from the Hungarian average. Mean verbal as well as nonverbal IQs were in the middle of the normal range. For an extended sample of 131 patients not followed longitudinally, mean recent IQ was 99.6 (SD = 16.3). Data concerning educational career were available for 107 patients. Normal schools were attended by 88 patients, 19 were in need of special elementary education. From 40 patients who had already finished elementary school, 17 underwent secondary school education, 1 is a university student, 15 are skilled workers, 4 were semi-skilled, and 4 are unemployed for reasons unrelated to their intellectual status.

Female↗
PubMed1996

CR1 density polymorphism and expression on erythrocytes of patients with systemic lupus erythematosus.

The present study investigated the expressed number of CR1 on erythrocytes (E) in relationship of the CR1 density genotype from 46 patients with systemic lupus erythematosus (SLE) and 47 healthy volunteers. The CR1 genotype was determined by a method based on polymerase chain reaction (PCR) amplification of the genomic DNA fragment of 1.8 kb separated by HindIII endonuclease digestion and agarose gel electrophoresis. Our data supported the earlier results that the number of binding sites/E for monoclonal anti-CR1 decreased among SLE patients compared with normal individuals having the same alleles for the CR1/E density. At the same time the novelty of our recent results was that the decreased expression of CR1 on E correlated significantly with kidney involvement in patients homozygous for the CR1/E high density allele (HH). These data suggest that the deficiency of the detectable number of CR1 on erythrocytes is acquired in this SLE population.

Erythrocytes↗
PubMed1995

[Diagnostic errors in symptom-poor hyperthyroidism in the aged].

The diagnosis of hyperthyreoidism manifesting in the elderly meets difficulty in many cases. Lack of some characteristic symptoms observable in younger patients can be misleading. The authors summarize the data of ten clinical cases where the hyperthyreoidism appeared in occult form, reminding rather for heart disease or malignant tumours. The assay of thyroid hormones and the level of antithyreoglobulin and anti-thyreoid peroxidase antibodies was unavoidable in order to establish correct diagnosis. Though the early diagnosis and treatment may enhance the life expectancy of the patients and may considerably decrease the cardial and the consecutive cerebral complications. The authors analyse the reasons and possible pathomechanism of the formation of atypical hyperthyreoidism occurring in the elderly.

Age Factors↗
PubMed1995

Correlation of IgG Fc receptors on granulocytes with serum immune complex level in systemic lupus erythematosus.

The expression of Fc gamma RI, Fc gamma RII and Fc gamma RIII on granulocytes in the blood of patients with systemic lupus erythematosus was investigated. The relationship between the receptor expression and serum immune complex (IC) concentration was analysed. The decrease in mean fluorescence intensity of both Fc gamma RII and Fc gamma RIII of patients' granulocytes stained by specific monoclonal antibodies (using MoAb IV.3 and 3G8) was significant. The detected decrease of Fc gamma RII was inversely correlated with the high circulating IC level in patients' sera.

Antigen-Antibody Complex↗
PubMed1995

Effects of Levosimendan, a cardiotonic agent targeted to troponin C, on cardiac function and on phosphorylation and Ca2+ sensitivity of cardiac myofibrils and sarcoplasmic reticulum in guinea pig heart.

A new cardiotonic agent, (R)-[[4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)-phenyl] hydrazono]propanedinitrile (Levosimendan), has been developed and screened for its ability to bind to cardiac troponin C. In perfused hearts, low concentrations of 0.03 or 0.1 mumol/L Levosimendan increased +dP/dt, but did not affect the speed of relaxation and produced only a slight increase in spontaneous heart rate in the hearts perfused with 0.1 mumol/L of the drug. In these same hearts, perfusion with 0.03 mumol/L Levosimendan did not alter the 32P incorporation into troponin I or C protein, whereas a slight but significant increase was noted for phospholamban, with no detectable change in tissue cAMP levels. Administration of 0.1 or 0.3 mumol/L Levosimendan significantly increased myocardial cAMP levels as well as the phosphorylation of phospholamban, troponin I, and C protein. Levosimendan (0.03 to 10 mumol/L) reversibly increased force generated by detergent-extracted fiber bundles over a range of submaximally activating free Ca2+ concentrations with no significant effect on maximum force or on Ca2+ binding to myofilament troponin C. There was no direct effect of Levosimendan on Ca2+ uptake by vesicles of sarcoplasmic reticulum (SR). In contrast, under conditions optimal for cAMP-dependent phosphorylation, Levosimendan slightly but significantly lowered the concentration of Ca2+, yielding half-maximal uptake rates by the SR vesicles. Our results indicate that at low concentrations Levosimendan acts preferably as a Ca2+ sensitizer, whereas at higher concentrations its action as a phosphodiesterase inhibitor contributes to the positive inotropic effect.

Analysis of Variance↗
PubMed1995

Differential changes in cardiac phospholamban and sarcoplasmic reticular Ca(2+)-ATPase protein levels. Effects on Ca2+ transport and mechanics in compensated pressure-overload hypertrophy and congestive heart failure.

The objective of this study was to elucidate the role of the sarcoplasmic reticulum (SR) in the transition from compensated pressure-overload hypertrophy (increased left ventricular [LV] mass, normal LV function, and no pulmonary congestion) to congestive heart failure (increased LV mass, depressed LV function, and pulmonary congestion). To address this issue, the descending thoracic aorta was banded for 4 and 8 weeks in adult guinea pigs, and the changes in isovolumic LV mechanics, SR Ca2+ transport, and SR protein levels were determined and compared with age-matched sham-operated control animals. A subgroup of the 8-week banded animals manifested the congestive heart failure phenotype with diminished developed LV pressure normalized by LV mass, reduced rates of LV pressure development and relaxation, and markedly increased lung weight-to-body weight ratios. The cardiac mechanical and morphometric changes were associated with depressed protein levels of the SR Ca(2+)-ATPase (85% of the control) and phospholamban (65% of the control) assessed by quantitative immunoblotting. Resultant rates of SR Ca2+ uptake (Vmax) and the affinity of SR Ca(2+)-ATPase for Ca2+ (EC50) were significantly depressed [32 +/- 6 nmol Ca2+.min-1.mg-1 and 0.59 +/- 0.12 (mumol/L)/L, respectively] compared with the 8-week sham-operated control animals [40 +/- 1 nmol Ca2+.min-1.mg-1 and 0.40 +/- 0.05 (mumol/L)/L, respectively]. We conclude that this model of pressure overload-induced cardiac failure is associated with (1) diminished LV force development, rates of pressure development, and decay; (2) depressed protein expression of the Ca(2+)-cycling proteins SR Ca(2+)-ATPase and phospholamban; and (3) decreased Vmax and affinity of the SR Ca(2+)-ATPase for Ca2+.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

[Draize test and alternative methods for evaluating irritation from chemical substances].

The eye irritancy test in rabbits (Draize test) is currently the method used to evaluate the hazard or safety of chemical substances. To reduce the need for animal testing some new procedures as alternative were elaborated. We present a review of method used as well as evaluation of sensitivity and repeatability of alternative tests applied in laboratories of European Economic Communities.

Animal Testing Alternatives↗
PubMed1995

[Formaldehyde determination in shampoos, bath preparations and dish washing liquids by colorimetric methods].

In the years 1992-1993 in cooperation with Province Sanitary-Epidemiological Stations 2415 samples of shampoos and bath preparations for adults and children as well as of dish washing liquids, imported and produced in Poland, were analysed. The colorimetric method either with the chromotropic acid or acetylacetone was used. Among polish preparations, only in 6% samples of cosmetic products for children the level of formaldehyde exceeded permitted level of 50 mg/kg. In all cosmetic products for adults as well as in all samples of dish washing liquids the content of formaldehyde was below permitted level 500 mg/kg. Among imported products, 40% of samples of cosmetics for children, 3%--for adults and 2% of dish washing liquids revealed formaldehyde level above permitted values. It is advisable to determine periodically formaldehyde content in particular cosmetic products, such as shampoos and bath preparations, mainly used by children.

Adult↗
PubMed1994

[Memory clinic: a new special unit, basic principles and first experiences of its function].

Memory Clinic is a special unit of the National Institute of Psychiatry and Neurology in Hungary since January, 1992. Authors describe the methods of clinical investigation and the frames of therapy. In the first year 315 patients were examined, that underlines the authority of establishing such a special centre. A high proportion of the patients were in their active working period (age average were 55 years in the outpatient, and 56 in hospitalized patients). In the etiologic spectrum the organic cerebral lesions were the most frequent, but were not the only reasons. Depression was a very frequently observed associated symptom. The function of the new unit has interdisciplinary characteristics: modern organic examinations joined with psychotherapy-oriented therapeutic regime. There seems to have a chance for collaboration with other establishing Memory Clinics in the world.

Aged↗