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Biomedical subjects

J K Piotrowski

Publications and source records attributed to J K Piotrowski.

At least 37 records · Page 2Linked to original sources
PubMed1989

Renal binding of cadmium in the rat following intragastric exposure.

Renal binding of cadmium was compared in groups of rats administered cadmium intragastrically or subcutaneously in doses resulting in similar renal cadmium concentrations. In rats administered cadmium intragastrically the renal concentrations of copper and metallothionein were lower, suggesting disturbance in copper metabolism. These changes were alleviated gradually in the post-exposure period. In experiments with 64Cu it has been shown that intragastric exposure to cadmium reduced copper absorption to about 21% of that in the control rats, thus explaining the poor copper availability for renal binding of cadmium in the form of Cd,Cu-metallothionein. Changes in zinc uptake were less strongly marked and were limited to slight decrease of zinc content in the kidneys.

Animals↗
PubMed1989

Cadmium and metallothionein levels in the liver of humans exposed to environmental cadmium in Upper Silesia, Poland.

The area of Upper Silesia is the most industrialized region in Poland. The concentrations of cadmium (Cd), zinc (Zn), copper (Cu) and metallothionein (MT) in autopsy samples (n = 29) of liver from the inhabitants of that area were determined. The metal levels varied in the ranges of 0.5-11.9 micrograms Cd/g, 45.3-221.6 micrograms Zn/g, 1.4-10.3 micrograms Cu/g. The concentration of MT determined by the Hg-method was high: 0.38-2.86 mumol Hg/g. A positive linear relationship was observed between Zn and MT levels.

Adult↗
PubMed1989

Dynamics of glutathione levels in liver and indicatory enzymes in serum in acetaminophen intoxication in mice.

Acetaminophen (AA) was administered i.p. to Swiss mice as a single dose 100, 200, 300, 400 and 600 mg/kg. At different time periods after administration, the mice were sacrificed. Serum glutamate-pyruvate transaminase (SGPT) and sorbitol dehydrogenase (SDH) as well as glutathione (GSH) levels in the liver were determined. It was found that the effective dose ranged within 200-600 mg/kg. Changes in GSH level occurred shortly after acetaminophen administration, whereas changes in the activity of indicatory enzymes were slightly delayed compared to this process. Conditions allowing for parallel observations of all three indices under investigation occurred 4 hrs after acetaminophen administration. With regard to glutathione, directly measured decrease, as compared to control levels, may be used as the yardstick of the changes. Changes in the activity of indicatory enzymes may be better expressed in the dose-response arrangement. For all the indices determined 4 hrs after acetaminophen administration, ED50 is in the range 200-300 mg/kg.

Acetaminophen↗
PubMed1988

Cadmium, zinc, copper and metallothionein levels in human liver.

The concentrations of cadmium, zinc, copper and metallothionein in the autopsy samples of liver among the inhabitants of Lódź (Poland) were determined. The cadmium levels were low in the range of 1.5 to 5.8 micrograms/g. The concentration of metallothionein determined by the Hg-method was high (0.160-1.665 mumol Hg/g); it was mainly a Zn-thionein. The percentage of hepatic zinc bound in the MT-fraction increased with the overall content of zinc in the liver. The elevation of zinc in the liver occurs in the proportion required for the saturation of metal-binding ligands of metallothionein. The role of cadmium remains less clear. Our results suggest that the metallothionein level in the liver increase significantly in response to elevated cadmium concentrations. This response, however, is in high excess to the demand which is justified stoichiometrically.

Adult↗
PubMed1988

Kinetic interpretation of the exposure test for styrene.

The excretion kinetics of mandelic and phenylglyoxylic acids investigated over three subsequent days after cessation of styrene inhalation could be expressed by biphasic functions, similar for both metabolites; the half-times for the first and the second phases were 2.5 and 30 h, respectively. The possibility of styrene accumulation in exposure repeated daily was assessed by kinetic modelling; it appears negligible if measurements are based on urine samples collected at the end of the working shift. The above contention has been examined in workers exposed to styrene in the polyester industry: concentrations of styrene in air monitored continuously varied from 26 to 130 mg/m3. The relationship between styrene concentration and rate of urinary excretion of the total amount of mandelic and phenylglyoxylic acids was rectilinear and demonstrated a reasonable agreement between experimental and industrial data. The trends of concentrations within the day and week gave no indication of substantial styrene cumulation under repeated industrial exposure.

Air Pollutants, Occupational↗
PubMed1987

Intestinal absorption of cadmium and inorganic mercury in the rat: no major involvement of metallothionein.

The intestinal absorption of cadmium and inorganic mercury was studied in adult rats, administered the metal salts intragastrically or parenterally in repeated or single doses. The intestines contained only small proportion of the body burden; no major change was found in the intestinal level of metallothionein, copper and zinc. Therefore, no major role can be ascribed to intestinal metallothionein in limiting absorption of high oral doses of cadmium and mercury.

Animals↗
PubMed1985

Review of the health effects of methylmercury.

The study critically reviews recent data relating to the health effects of methylmercury in man and the attendant dose-response relationships. New data obtained from animal studies, including pre-and postnatal exposure, are also examined. The consumption of fish and fish produce represents the major source of methylmercury exposure in the general population. Reported mercury concentrations in fish throughout the world are examined, particularly in the Mediterranean Sea. Here there is limited knowledge of methylmercury intake in critically exposed populations such as fishermen, employees of the fish industries and their families. The measurement of mercury in hair is now regarded as the most useful indicator of exposure but more experimental data are still required to increase the value of this index. The threshold levels of methylmercury in blood, hair and for dietary intake, as estimated by the World Health Organization, have been largely endorsed. However, new information from Japan and Canada suggests the existence of a latency period for some effects, so that the frequency or probability of their occurrence is inversely related to the duration of exposure. Incorporation of such findings would therefore lead to the designation of lower threshold values than are presently recognized. Pregnant women and the fetus have been identified as groups that are at special risk. The fetal blood mercury level is up to twice that of the mother and the sensitivity of both mother and fetus may be higher than in non-pregnant adults. This should be taken into account when assigning protective threshold concentrations.

Animals↗
PubMed1985

Evaluation of low exposure to styrene. I. Absorption of styrene vapours by inhalation under experimental conditions.

Volunteers (six men and one woman) were exposed by inhalation to styrene within the concentration range of 20 to 200 mg/m3. The average retention of styrene vapours in the respiratory tract was 71%. The yield of styrene metabolism measured within 24 h was 39 and 17% for mandelic acid and phenylglyoxylic acid, respectively. The determination of mandelic acid in urine collected immediately after the exposure was applied as exposure test. The excretion rate of this metabolite assured the best correlation with the absorbed dose. The relative standard deviations of the test related to actual dose level vary, depending on the analysed concentration range, from 0.21 to 0.33. Quantitative interpretation of the test is possible for styrene concentrations in the air exceeding 20 mg/m3. The concentration amounting to 100 mg/m3 (TLV) corresponds with the mandelic acid excretion rate of 15 mg per hour.

Air Pollutants, Occupational↗
PubMed1984

Urinary mandelic acid as an exposure test for ethylbenzene.

Absorption of ethylbenzene and excretion of mandelic acid were investigated under controlled conditions in six volunteers, exposed at concentrations of 18, 34, 80, and 200 mg/m3. Retention of ethylbenzene vapours in the lungs was 49 +/- 5%. Elimination of mandelic acid was found to be biphasic, with biological half-life values of 3.1 and 24.5 h. Total excreted mandelic acid accounts for 55 +/- 2% of retained ethylbenzene. The results obtained were applied to devise an exposure test for ethylbenzene, which would enable the precise evaluation of exposure at low ethylbenzene, vapour concentrations (+/- 13%). Exposures, carried out dermally, gave a rationale for the exclusion of the skin as a route of entry of ethylbenzene vapours into the body.

Adult↗
PubMed1980

Mercury-binding, copper-zinc proteins from rat kidney. Amino acid composition, molecular wieght and metal content.

Three isoforms of mercury-binding, copper-zinc protein were isolated from kidney of rats exposed to mercuric chloride. They contained 56-67 micrograms Hg/mg protein, 23.7-43.9 micrograms Cu/mg and 1.8-5.4 micrograms Zn/mg protein. Amino acid composition of isoforms 1, 2 and 3 was very similar, and also close to that of hepatic [Hg,Zn]- and [Cd,Zn]-metallothionein. Isoforms 1, 2 and 3 contained 29.7, 27.2 and 29.3 mol% cysteine, respectively. The molecular weight of isoforms 1, 2 and 3 was 6580, 6880 and 7000, respectively.

Amino Acids↗
PubMed1978

Effect of selenium on the organ distribution and binding of bismuth in rat tissues.

Subcutaneous administration of bismuth, both single and multiple, resulted in deposition of this metal mainly in the kidneys which contained over 50% of the 'accessible pool' of bismuth. In the kidneys bismuth was bound mainly by the soluble fraction in which it was complexed with a protein of molecular weight of about 7000. Multiple administration of bismuth increased the level of this protein. Selenite administration brought about an increase in the 'accessible pool' of bismuth, probably due to a drop in excretion, and also changes in the organ distribution of this metal. The retention in the kidneys was diminished while those in the liver and in other tissues were augmented. These changes were accompanied by a change in the chemical form of bismuth present in the kidneys manifested by the total disappearance of the protein complex of molecular weight of 7000. The increased synthesis of this protein due to bismuth administration was not abolished completely.

Animals↗
PubMed1977

The levels of metallothionein-like proteins in animal tissues.

The level of metallothionein-like proteins was determined in different tissues of 6 animal species. The highest concentrations were found in pig and rat tissues. The organs richest in metallothionein-like proteins included: kidneys (101-305 microgram/g), intestine (127-257 microgram/g) and liver (54-496 microgram/g).

Animals↗