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Biomedical subjects

J Petrík

Publications and source records attributed to J Petrík.

6 recordsLinked to original sources
PubMed2005

Simple solid-phase extraction method for determination of polychlorinated biphenyls and selected organochlorine pesticides in human serum.

A simple off-line solid-phase extraction (SPE) method for isolation of polychlorinated biphenyls (PCBs) and selected organochlorine pesticides (OCPs) from human serum has been developed. The procedure includes denaturation of serum proteins by a mixture of water-1-propanol, application of the sample by aspiration twice repeatedly through the SPE column and elution with a mixture of n-hexane-dichlormethane. After final clean-up the compounds of interest were analysed by gas chromatography with micro-electron capture detection (GC-microECD). The recoveries achieved for PCB congeners using spiked porcine serum samples were 99-120% and for OCPs 88-115%. Relative standard deviations (RSD) ranged from 3 to 7%. The method was applied to real human serum samples and the recoveries of analytes in the serum were proportionally recalculated considering the recovery of the internal standard PCB-174. PCB-103 served as a syringe standard to correct volume of samples analysed. The aim of this study was to develop an effective off-line SPE procedure by optimization of existing SPE methods to supply laborious, solvent- and time-consuming liquid-liquid extraction (LLE) in routine analytical process.

Animals↗
PubMed2001

Atmospheric mercury levels in the Slovak Republic.

Total mercury concentrations (as a sum of vapor and particulate mercury) were measured in 24-h samples of ambient air in 20 different localities of the Slovak Republic eight times during the period 1996-1997. Vapor mercury was analyzed on site by atomic fluorescence with amalgamation technique. Particulate mercury was determined by vapor hydride atomic absorption spectrometry after wet digestion of filters with particulate air samples. The results showed that 34% of the 160 individual total mercury concentrations exceeded 5 ng/m3--the ambient air quality guideline value recommended by the WHO. The range of total mercury concentrations in the ambient air of Slovakia was: 1.13-3.98 ng/m3 (geom. mean 2.63) in the background area; 2.25-5.27 ng/m3 (geom. mean 3.64) in the agricultural areas; 1.73-20.53 ng/m3 (geom. mean 4.57) in the urban areas; and 1.53-39.85 ng/m3 (geom. mean 5.28) in the industrial areas. The highest mercury levels occurred in areas with metallurgical industry and coal combustion. The predominant form of mercury present in air was vapor mercury. The particulate fraction of mercury in ambient air (as a percentage of total mercury) varied widely from 0.4% to 42.1% (geom. mean = 4.4%). This fraction was lower in agricultural areas (2.3%) than in urban areas (5.3%). Although the atmospheric vapor mercury concentrations were slightly higher in summer than in winter, a direct correlation of vapor mercury concentrations and ambient air temperature was not found. Furthermore, the particulate mercury concentrations did not correlate with total particulate levels.

Agriculture↗
PubMed1991

[Problems in indications for vascular reconstructive surgery].

The authors discuss examinations made before a planned vascular reconstruction operation. As the number of vascular reconstruction operations is steadily increasing, and the operations affect the entire organism, and the operations are associated with a relatively high mortality rate, the authors try to reduce the latter by the correct classification into a risk group, select the correct order of surgical operations, and last not least, on the basis of these conclusions they try to define also the surgical procedure proper during reconstruction. As atherosclerotic affections can be isolated or combined, the authors divide the patients into three groups. The first group can be subjected to a reconstruction operation without special preparation. The second group comprises patients where it is either necessary to confirm or rule out affection of extracranial cerebral arteries and the third group comprises patients where it is necessary to confirm or rule out affection of the coronary arteries. The aim of this comprehensive procedure is to reduce as much as possible the surgical mortality.

Adult↗
PubMed1978

Effect of 5-bromo-2'-deoxyuridine on the in vitro DNA synthesizing activity of polyoma virus-infected cells.

The in vitro synthesizing activity of uninfected and polyoma virus-infected mouse embryo (ME) cells was investigated by measuring the incorporation of 3H-thymidine (dTR) into acidinsoluble material in cell-free extracts. The character of the enzyme reaction was described in uninfected cells and an activating effect of 0.01 M dithiothreitol (DTT) was observed. A variation of the enzyme activity in the course of cultivation of ME cells in primary culture was demonstrated. The induction of the DNA synthesizing activity due to polyoma virus infection was markedly increased in the presence of 5-bromo-2-deoxyuridine (BUDR), what emphasizes the importance of the de novo synthesized viral and/or cellular DNA in the regulation of induction enzymes participating in DNA synthesis.

Bromodeoxyuridine↗
PubMedDate not supplied

Levels of PCBs and some organochlorine pesticides in the human population of selected areas of the Slovak Republic. I. Blood.

Fifty samples of human blood collected in 1992 from the general human population living in five selected areas of the Slovak Republic (the Michalovce, Velký Krtís and Nitra District, Myjava area and Bratislava) were analysed for polychlorinated biphenyls (IUPAC Nos. 28, 52, 77, 101, 105, 114, 118, 123, 126, 138 (+163), 153, 156, 157, 167, 169, 180 and 189) and some organochlorine pesticides (HCB, gamma-HCH, p,p'-DDE and p,p'-DDT). PCB levels (the sum of the congeners analysed) in serum lipids averaged for all the samples analysed were 1.79 micrograms.g-1 (range: 0.53-9.20 micrograms.g-1, median: 1.33 micrograms.g-1), HCB 5.38 micrograms.g-1 (0.16-23.20 micrograms.g-1, 4.27 micrograms.g-1), gamma-HCH 0.012 microgram.g-1 (< 0.01-0.18 microgram.g-1), p,p'-DDE 6.05 micrograms.g-1 (1.30-34.80 micrograms.g-1, 4.39 micrograms.g-1) and p,p'-DDT 0.27 microgram.g-1 (< 0.01-0.79 microgram.g-1, 0.23 microgram.g-1). About three times higher levels of PCBs were found in the samples from the district where PCB formulations had been produced (the Michalovce District).

Adipose Tissue↗