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Biomedical subjects

L Jarczyk

Publications and source records attributed to L Jarczyk.

32 records · Page 2Linked to original sources
PubMed1988

Pharmacokinetics of nicotine, cotinine, and 3'-hydroxycotinine in cigarette smokers.

The trans-isomer of 3'-hydroxycotinine has recently been identified as a major metabolite of nicotine in urine of cigarette smokers. We, therefore, investigated the pharmacokinetics of 3'-hydroxycotinine in six male smokers after intravenous infusion of nicotine, cotinine, and 3'-hydroxycotinine. Serum concentrations of 3'-hydroxycotinine were lower than those of cotinine throughout the observation period of 60 h after infusion of nicotine or cotinine, whereas the amounts excreted in the urine were similar or higher than those of cotinine. The following means and ranges for the pharmacokinetic parameters were derived from the 3'-hydroxycotinine infusion experiment: half-life (t1/2 beta) = 5.9 (4.2-9.5) h; apparent volume of distribution (Vd) = 0.87 (0.51-1.14) l/kg; total clearance (Cl total) = 1.79 (1.08-2.59) ml/min/kg; renal clearance (Clr) = 1.31 (0.85-1.78) ml/min/kg; percentage of renal clearance (Clr/Cl total) = 75.4 +/- 12.8 (60.3-98.2). The high percentage of renal clearance suggests that further metabolization of this compound is limited. No evidence for a mutagenic activity of 3'-hydroxycotinine or of urine extracts from subjects dosed with hydroxycotinine was found with the S. typhimurium (TA 98) microsome assay.

Adult↗
PubMed1988

Investigation of inorganic deposits in selected organic matrices.

Inorganic deposits in the wall of human and animal arteries and in experimental tumor (Morris hepatoma 7777) were examined using proton induced X-ray emission (PIXE) and PIXE in combination with proton microprobe (micro-PIXE) techniques. The sections adjacent to the irradiated ones part were submitted to histological investigations and one part of the material was additionally investigated by infrared (IR) spectroscopy. For identification of mineral deposits, the micro-PIXE method appeared the most sensitive. The mineral deposits were detected in the artery samples, even in those without visible morphological changes, as well as in tumor samples. The deposites showed different localization and composition, depending on age and type of vessel. There were also differences between human and animal arteries. IR spectroscopy revealed the presence of carbonate apatite within the artery samples from old individuals. Matching of histological observations with data obtained by micro-PIXE method allows a better correlation of morphological and analytical results.

Animals↗
PubMed1985

Elemental composition of the human atherosclerotic artery wall.

The elemental composition of the human atherosclerotic popliteal artery was examined using the proton-induced X-ray-emission (PIXE) method. The application of a narrow proton beam (3 X 10 micron 2) enabled us to determine not only the concentrations of Cl, K, Ca, Fe, Cu, Zn, Br and Pb, but also their localization in different artery-wall regions. The highest mean concentrations of Cl, K, Zn and Br were found in the tunica media. In the investigated sections the distribution of Ca and Fe varied: sometimes, these elements were prevalent in the tunica intima, whereas in other cases, the highest concentrations were observed in the tunica media or tunica adventitia. The concentration profiles of each element were characterized by many sharp, narrow peaks. The highest concentrations of Ca and Fe showed such high levels that only one explanation is possible, i.e. the presence of crystals. The correlation of Ca peaks with those of Zn and Fe is discussed. The usefulness of the micro-PIXE method for the investigation of biomedical materials is also considered.

Aged↗
PubMedDate not supplied

Physicochemical characterization of the inorganic phases in the aortic wall of young individuals.

The autopsy samples of human aortic wall were investigated to determine the structure of the inorganic deposits formed at the onset of the mineralization process. The studies were concentrated on the material for which histochemical staining of randomly selected sections did not reveal the presence of minerals. The highly mineralized human media samples as well as broad spectrum of model compounds were investigated for comparative purposes. It was found that the inorganic phase at the onset of tunica media mineralization is composed of a few compounds including octacalcium phosphate as the predominant Ca-P compound, and a Mg-compound, probably magnesium carbonate or double/triple salts containing magnesium carbonate.

Adolescent↗
PubMedDate not supplied

Artery wall calcification: correlation of atherosclerosis with mineralization.

Popliteal arteries from 14 individuals (17-85 y old) were investigated. The concentrations and localizations of P, S, Cl, K, Ca, Fe, Cu, Zn and Br were measured by means of PIXE and micro-PIXE methods. The presence of PO4(3-) and CO3(2-) groups was assessed using the IR technique. The amount of P and Ca increased with age approaching at places 9% and 20% and mineral deposits were detected in tunica media. At the same time an increase in the Ca/P ratio and in the crystallinity of deposits was observed. The samples from old individuals also contained more CO3(2-) groups. The concentrations and localization of Zn and Br showed artery wall layer-dependent changes. In some places of the artery wall, minerals were also found in young persons. They were not correlated with places of blood vessel branching.

Adolescent↗