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001-es BibID:	BIBFORM041289
Első szerző:	Szűcs Sándor (biokémikus, vegyész)
Cím:	Simultaneous determination of styrene, toluene, and xylene metabolites in urine by gas chromatography/mass spectrometry / Szűcs Sándor, Tóth László, Legoza József, Sárváry Attila, Ádány Róza
Dátum:	2002
ISSN:	0340-5761
Megjegyzések:	Exposure to styrene, toluene, and xylene (STX) frequently occurs in various industrial settings leading to several adverse health effects. Therefore, the biological monitoring by determination of urinary mandelic acid (MA) and phenylglyoxylic acid (PGA), hippuric acid (HA), and 2-, 3-, and 4-methylhippuric acids (2-, 3-, and 4-MHAs), the metabolites of STX, is required or at least recommended in case of workers exposed by these agents. Considering the fact that co-exposure to STX frequently occurs, methods that have been described for the separate analysis of these compounds in urine samples cannot be used effectively for monitoring. Therefore, a reliable gas chromatographic/mass spectrometric (GC/MS) method was developed for the simultaneous identification and quantification of these metabolites. Following solid phase extraction of the urine samples, the extracts were silylated and analyzed by GC/MS using a HP-5MS capillary column. The method was evaluated for linearity, limits of detection and quantification, and specificity, as well as for precision, extraction efficiency, and stability at three different concentrations prepared in urine. The assay was linear up to 0.16 mg/ml for MA, and 0.32 mg/ml for PGA, HA, and 2-, 3- and 4-MHAs. The limits of detection and quantification of STX metabolites varied between 0.001 and 0.02 mg/ml, and from 0.01 to 0.04 mg/ml, respectively. The within-day and between-day precision, determined at low, medium, and high concentrations, ranged from 2 to 12% and 2 to 19%, respectively. The extraction efficiency was 70-80%. No degradation of the metabolites occurred in the urine samples under the possible working conditions. The method was applied for the analysis of the urine samples from exposed workers. The cost- and time-effectiveness, the technical advantages and validity parameters of this GC/MS analysis make it suitable for biological monitoring of mixed exposure to styrene, toluene and xylene.
Tárgyszavak:	Orvostudományok Egészségtudományok idegen nyelvű folyóiratközlemény külföldi lapban Styrene Toluene Xylene Metabolites Gas chromatography/mass spectrometry
Megjelenés:	Archives Of Toxicology. - 76 : 10 (2002), p. 560-569. -
További szerzők:	Tóth László (orvos) Legoza József Sárváry Attila (1971-) (népegészségtan szakorvos) Ádány Róza (1952-) (megelőző orvostan és népegészségtan szakorvos)
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001-es BibID:	BIBFORM004640
Első szerző:	Szűcs Sándor (biokémikus, vegyész)
Cím:	Single-cell measurement of superoxide anion and hydrogen peroxide production by human neutrophils with digital imaging fluorescence microscopy / Sándor Szűcs, György Vámosi, Róbert Póka, Attila Sárváry, Helga Bárdos, Margit Balázs, János Kappelmayer, László Tóth, János Szöllősi, Róza Ádány
Dátum:	1998
ISSN:	0196-4763
Megjegyzések:	Besides flow cytometry, fluorescence microscopy combined with computerized image analysis offers an alternative tool for assessing phagocyte oxidant generation at the single-cell level. This technique provides an opportunity for the direct visualization of cells and simultaneous measurement of cellular fluorescence intensity. Thus, we developed a simple method for the quantitative evaluation of intracellular superoxide anion and hydrogen peroxide production with image cytometry by using hydroethidine and dihydrorhodamine 123 dyes, respectively. Human neutrophils stimulated with phorbol dibutyrate and labeled by these fluorogenic substrates showed intense, well recognizable red or green fluorescence. The intensity of signals from individual granulocytes of cytospin preparations were quantitatively measured in digitized images. There was a great heterogeneity in response to the stimulus within the granulocyte population as shown by the integrated fluorescence intensity values. In agreement with the results of parallel flow cytometric experiments, this simple image analysis performed on cells of cytospin preparations was able to detect the defects in the oxidative metabolism of neutrophils from patients with cervix carcinoma. We demonstrated that even minor alterations in superoxide anion/hydrogen peroxide generation can be detected by image cytometry as efficiently as by flow cytometry. This result validates imaging microscopy as an alternative to flow cytometry in such experiments. In addition, the image cytometric technique allows the observation of the kinetics of free radical production in individual cell under adherent conditions. Therefore, we carried out image analysis of the oxidative burst of neutrophils adherent to uncoated glass and fibronectin- and type IV collagen-coated surfaces in response to stimulation with phorbol dibutyrate or N-formyl-methionyl-leucyl-phenylalanine. We elaborated a calibration technique for the quantitative measurement of the ethidium bromide generation mediated by superoxide anion within individual adherent granulocytes. The ethidium bromide production varied between 0.48 and 1.17 amol/cell/min.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban analysis Anions Carcinoma Dyes epidemiology Ethidium Flow Cytometry Fluorescence Human Hungary Hydrogen Peroxide Image Cytometry Image Processing Computer-Assisted Kinetics metabolism methods Microscopy Microscopy Fluorescence Neutrophils Superoxides Support Non-U.S.Gov't egyetemen (Magyarországon) készült közlemény
Megjelenés:	Cytometry. - 33 : 1 (1998), p. 19-31. -
További szerzők:	Vámosi György (1967-) (biofizikus) Póka Róbert (1960-) (szülész-nőgyógyász, klinikai onkológus) Sárváry Attila (1971-) (népegészségtan szakorvos) Bárdos Helga (1969-) (megelőző orvostan és népegészségtan szakorvos) Balázs Margit (1952-) (sejtbiológus, molekuláris genetikus) Kappelmayer János (1960-) (laboratóriumi szakorvos) Tóth László (orvos) Szöllősi János (1953-) (biofizikus) Ádány Róza (1952-) (megelőző orvostan és népegészségtan szakorvos)
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