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Biomedical subjects

M Makarewicz

Publications and source records attributed to M Makarewicz.

9 recordsLinked to original sources
PubMed2003

Isotopic composition and origin of uranium and plutonium in selected soil samples collected in Kosovo.

Soil samples collected from locations in Kosovo where depleted uranium (DU) ammunition was expended during the 1999 Balkan conflict were analysed for uranium and plutonium isotopes content (234U, 235U, 236U, 238U, 238Pu, (239 + 240)Pu). The analyses were conducted using gamma spectrometry (235U, 238U), alpha spectrometry (238Pu, (239 + 240)Pu), inductively coupled plasma-mass spectrometry (ICP-MS) (234U, 235U, 236U, 238U) and accelerator mass spectrometry (AMS) (236U)). The results indicated that whenever the U concentration exceeded the normal environmental values (approximately 2 to 3 mg/kg) the increase was due to DU contamination. 236U was also present in the released DU at a constant ratio of 236U (mg/kg)/238U (mg/kg) = 2.6 x 10(-5), indicating that the DU used in the ammunition was from a batch that had been irradiated and then reprocessed. The plutonium concentration in the soil (undisturbed) was about 1 Bq/kg and, on the basis of the measured 238Pu/(239 + 240)Pu, could be entirely attributed to the fallout of the nuclear weapon tests of the 1960s (no appreciable contribution from DU).

Environmental Monitoring↗
PubMed2001

Preparation and characterization of a set of IAEA reference air filters for quality control in air-pollution studies.

Several sets of reference air filters were prepared as part of an IAEA evaluation of the performance of laboratories involved in air-pollution studies. Each set comprised three polycarbonate membrane filters, two of which were loaded with urban air particulate matter (APM) obtained in Vienna or Prague, and one unloaded filter. The filters were loaded by filtration of a suspension of the APM materials in water. The homogeneity both of bulk APM materials and of the loaded filters was evaluated and found suitable by determining several elements by instrumental neutron-activation analysis (INAA), proton-induced X-ray emission (PIXE), and micro-X-ray energy-dispersive fluorescence analysis (micro-EDXRF). After evaluation of the homogeneity, INAA, PIXE, EDXRF, atomic absorption spectrometry (AAS), inductively coupled plasma optical emission spectrometry (ICP-OES), and ICP mass spectrometry (ICP-MS) were used to characterize the filter materials and establish "target values" and their associated standard deviations for 15 elements. Problems encountered during the preparation of these unique, simulated air filters and the criteria for setting both the target values and standard deviations are presented.

Air Pollutants↗
PubMed1998

Platelet-activating factor receptor-antagonist (BN 52021) stabilizes the oxidative-antioxidative balance and attenuates the morphological changes in the gastrointestinal tract in experimental hemorrhagic shock.

The influence of the platelet-activating factor receptor-antagonist (BN 52021) and polyelectrolyte solution (PES) on the morphology and oxidant-antioxidant equilibrium in the gastrointestinal wall in hemorrhagic shock was examined in rats. The animals were divided into five groups: I - control, II - sham operation, III - untreated hemorrhagic shock lasting 75 minutes, IV - shock treated with PES, and V - shock treated with BN 52021 and PES. The most expressed morphological changes were found in the small intestine in group IV (shock treated with PES) and in group III (untreated shock). Morphological changes were well correlated with the malondialdehyde (MDA) level reflecting oxidative tissue injury and with the antioxidative potential: sulfhydryl compounds (-SH) level, and superoxide dismutase (SOD) activity. The signs of morphological and biochemical injury to the gastrointestinal tract in animals from group V (treated with BN 52021 and PES) were significantly less expressed than those in groups III and IV. The results suggest an essential role of PAF in oxygen radicals-mediated gastrointestinal injury and a beneficial effect of the early application of BN 52021 in hemorrhagic shock.

Animals↗
PubMed1995

Oxygen-derived free radicals in kidney in experimental hemorrhagic shock treated by PAF-receptor antagonist BN 52021.

Renal damage in rat hemorrhagic shock model was assessed by estimation of the reactive oxygen metabolites generation (malondialdehyde measured as thiobarbituric acid reactive substances) and antioxidative potential (activity of Cu-, Zn- superoxide dismutase, activity of glutathione reductase and level of sulfhydryl compounds). It was found that treatment with BN 52021 (a platelet-activating factor antagonist), and polyelektrolyte solution had had a beneficial effect in comparison with both the untreated shock and shock treated by reperfusion only.

Analysis of Variance↗
PubMed1995

Ethanol ingestion decreases superoxide dismutase activity and diminishes -SH compounds in the liver and red blood cells in rats.

SOD activity and -SH compounds in the liver and RBCs, and some hematological parameters were investigated in control rats and in those submitted to chronic (3 months) intoxication with ethanol. We found significantly lower SOD activity and a decrease in -SH groups in the liver and RBCs of ethanol-treated rats in comparison with the control group. The hemoglobin content and mean corpuscular hemoglobin concentration were reduced, while mean corpuscular volume of RBCs was increased when compared with the control group.

Alcoholic Intoxication↗
PubMed1994

Enhanced sensitivity for the determination of selenium by INAA.

A working analytical procedure for selenium determinations by INAA, using gamma spectrometry with a germanium well-type detector, is presented. The spectral line at 400.7 keV is employed, enhanced with the effect of energy summing in true coincidence of cascade photons. The main advantage of the method is high efficiency and reliable, interference-free results; potential drawbacks are increases in input count rate and pile-up losses, decrease in resolution, and sensitivity to errors in sample-to-detector geometry. The procedure is applied to certification analysis of reference materials, large-area biomonitoring by oak leave samples, and determination of separated proteins.

Animals↗
PubMed1994

Detection and determination of selenoproteins by nuclear techniques.

Microbeam X-ray spectrometry, energy-dispersive X-ray fluorescence analysis, and neutron activation analysis were evaluated for the detection of selenium contained in the selenoprotein glutathione peroxidase. The glutathione peroxidase had been previously separated using polyacrylamide gel electrophoresis. The use of Bragg-reflected polarized X-ray beams was employed in the X-ray fluorescence measurements to minimize the problem of scatter owing to the gel matrix. Current detection limits of selenium in a gel matrix are 2.1 ng in the bench-top microbeam X-ray system and 30-60 ng using XRF with polarized beams. Neutron activation analysis was used for quality-control measurements, with a detection limit here of < 0.08 ng. The work has in principle established the feasibility of such an approach.

Animals↗