Biomedical subjects

B Wiadrowska

Publications and source records attributed to B Wiadrowska.

At least 19 recordsLinked to original sources

PubMed2001

Studies of early hepatocellular proliferation and peroxisomal proliferation in Wistar rats treated with herbicide diclofop.

A study was performed to determine whether diclofop (2-(4-(2,4-dichlorophenoxy) phenoxy)propionic acid), introduced as a herbicide, exhibits the properties of peroxisome proliferators (PPs). Diclofop was administered orally at 7-56 mg/kg body weight per day to male Wistar rats for 2, 4, 7 or 14 consecutive days and some effects regarded as early hepatic markers of PPs were studied. The early changes in rat liver, produced by short-term treatment with diclofop consisted of mitogenesis and, time- and dose-related increase in liver weight. Hepatomegaly was typically associated with proliferation of smooth endoplasmic reticulum (SER) and peroxisomes. The parallel biochemical measurements showed that there was a dose-dependent increase in peroxisomal palmitoyl-CoA oxidation and catalase activity in treated rats. Markers of hepatocellular proliferation (S- and M-phase) indicated that mitogenesis was transient and declined despite continuation of diclofop treatment. The threshold exposure level for the palmitoyl-CoA oxidation (one of the peroxisome proliferation markers) was approximately the same (14 mg/kg body weightxper day) as for the stimulation of mitogenesis in Wistar rats. However, for hepatomegaly and catalase activity the threshold exposure level was 7 mg/kg body weightxper day. The results presented here demonstrate clearly that diclofop belongs to a class of rodent PPs.

Animals↗

PubMed2001

[Comparative study of the effect of synthetic pyrethroids on the induction of genetic changes in mice somatic and sex cells depending on the exposure route].

Synthetic pyrethroid insecticides are widely used in the protection of fruits and vegetables as well as in the public hygiene due to their strong neurotoxic activity against insects. The induction of genetic changes in somatic and sex cells in male mice after different routes of exposure to permethrin and fenvalerate was studied. The male 8-10 weeks old mice were intraperitoneally exposed to 20 and 40 mg/kg bw of fenvalerate and 125 and 250 mg/kg bw of permethrin. Another groups of mice were exposed per os to fenvalerate and permethrin in the doses of 50, 100 and 200, 400 mg/kg bw respectively. For the sperm anomalies testing the exposure was repeated for five consecutive days followed by the 35 days waiting period after which the gonads were removed and spermatozoa prepared from the epididymis. The changed spermatozoa were counted in the smears after staining in the 0.5% eosin Y solution and the results compared with the number of normal cells. For the testing of the effect of pyrethroids on the micronuclei frequency in the bone marrow cells the tested substances were administered twice in 24 hours intervals and the bone marrow was sampled after 6 and 24 hours from the femur bone. The polychromatic erythrocytes and the presence of micronuclei were evaluated in the bone marrow smears. The results showed the difference in the action of the pyrethroids on the genetic material of the tested cells and the effect of the route of exposure. Permethrin induced the lesions in the sex cells regardless the route of exposure, however a substantial increase in the micronuclei frequency in the bone marrow was observed after oral exposure only. No signs of cytotoxicity accompanied the sperm anomalies and micronuclei induction. Fenvalerate induced changes in sperm cells after intraperitoneal exposure only. No increase in the micronuclei frequency in the polychromatic erythrocytes of the bone marrow was observed after per os or intraperitoneal exposure. The intraperitoneal exposure to this pyrethroid resulted in cytotoxicity in both bone marrow and sex cells.

Administration, Oral↗

PubMed1998

[The evaluation of urine and hair total mercury content in occupationally exposed and non-exposed people].

The study aimed at the evaluation of total mercury content in hair and urine of the workers occupationally exposed to various levels of mercury vapours. The hair and urine were taken from the workers employed in Chemical Plant Oświecim and from thermometer factory in Warsaw. The urine and hair of non-exposed Warsaw inhabitants served as a reference. Mercury levels in hair and urine were determined with atomic absorption spectrometry. The highest mercury concentration in hair (range 1.13-325.16 micrograms/g) and urine (range 15.7-800 ng/mg of creatinine) of workers employed in processing chloroalkali in Chemical Plant Oświecim. The results also suggest that the average mercury concentration in hair (0.17 and 1.0 microgram/g) and urine (0.4 and 2.36 ng/mg of creatinine) of non-occupationally exposed inhabitants from Warsaw and Oświecim does not endanger human population. Nevertheless a positive correlation between distance from chloroalkali plant in Oświecim and mercury content in the specimens from inhabitants has been observed.

Adolescent↗

PubMed1998

[The effect of nuarimol on the mutagenic activity of n-nitrosodimethylamine and 2-acetylaminofluorene in mouse erythrocytes].

Nuarimol, the structural analogue of DDT, similarly to other polychlorinated aromatic hydrocarbons, induces monoxygenase activity. N-nitrosodimethylamine (NDMA) and 2-acetylaminofluorene (2-AAF) belong to chemical compounds exhibiting strong mutagenic and carcinogenic properties followed the metabolic activation. Genotoxic activity of promutagens, including NDMA and 2-AAF depends on the activity of monoxygenase enzymes. The study aimed at clarification of the effect of nuarimol on the mutagenic activity of NDMA and 2-AFF in in vivo micronucleus test. The experiments were performed on Swiss mice, which were exposed to nuarimol or Aroclor 1254 (as the positive control) followed by the exposure to NDMA or 2-AAF. The micronuclei were counted in the bone marrow polychromatic erythrocytes and in the erythrocytes of the peripheral blood. The results show that NDMA as well as 2-AAF induce failures in the genetic material in the bone marrow cells. Nuarimol given to the mice before the exposure to NDMA or 2-AAF did not cause changes in the micronuclei frequency. However, the prior intoxication by Aroclor 1254 resulted in the increase of the number of erythrocytes with micronuclei induced by NDMA in bone marrow and peripheral blood. This effect has not been observed in the mice intoxicated by 2-AAF prior to Aroclor 1254.

2-Acetylaminofluorene↗

PubMed1997

The effect of fenarimol on marker enzymes in rat liver in two-stages model of hepatocarcinogenesis.

The two-stage model for the development of early markers of hepatocarcinogenesis was applied to assess the potential of fungicide fenarimol (alpha-(2-chlorophenyl)-alpha-(4-chlorophenyl)-5-pirimidinemethanol++ +) as a possible promoter in this process. In this experiment the rats were subjected to partial hepatectomy (to induce proliferation), followed by the single (50 mg/kg bw) dose of diethylnitrosamine (DEN) (initiator) and then, followed by the 26 weeks exposure to fenarimol administered in the olive oil suspension (250 mg/kg daily). The activities of gamma-glutamyltransferase (GGTase), glucose-6-phosphatase (G-6-Pase) and alkaline phosphatase (APase) regarded as markers of early stages of hepatocarcinogenesis were measured biochemically and histochemically in the livers of exposed rats as well as in the respective positive and negative controls. Rats exposed to 2-acetylaminofluorene (2-AAF), instead of fenarimol, served as positive controls. It was found that in the full initiation/promotion regimen both 2-AAF and fenarimol induced the increase of GGTase activity in the liver and formation of GGTase-positive hepatocytes. However the exposure to fenarimol alone also increased GGTase activity, although this response was not observed in rats exposed to 2-AAF alone. The possible mechanisms and explanation for such types of responses were discussed, and conclusion has been drawn that fenarimol did not affect the rat hepatocarcinogenesis induced by PH and DEN.

Alkaline Phosphatase↗

PubMed1997

[The effect of permethrin and DDT on the activity of cytochrome P-450 1A and 2B molecular forms in rat liver].

The effect of permethrin on relative liver weight (RLW) and the activity of hepatic monooxygenase system related to cytochrome P-4502B and 2A was studies. The effect of permethrin was compared with DDT used as phenobarbital-type of monooxygenase inducer (induces cyt. P-4502B). Male Wistar rats received permethrin and DDT for 4 days at 24 h intervals in daily oral doses of 1/10, 1/50 and 1/100 LD50. 3-methylocholantrene and phenobarbital which served as inducers of cytochrome P-4501A and 2B, respectively and were used as positive controls. The activities of cytochrome(s) P-450 were measured by 7-pentoxy- and 7-etoxyresofurin O-dealkylation by S-9 fraction of rat liver; these two compounds have been shown to be the substrates for reactions mediated by cytochrome P-4502B and 2A. Thus this biochemical procedure permits to determine whether tested compound belongs to one of two main types of inducers of the cytochrome P-450 monoxygenase system. Treatment of rats with both pesticides resulted in significant increase in RLW, to 30 and 15% of control, respectively. In animals treated with permethrin the metabolism of 7-pentoxyresofurin increased in a dose dependent manner. Phenobarbital and the highest dose of permethrin (620 mg/kg b.w. x day-1) induced similar (about 30-fold) increase in O-dealkylation of 7-pentoxyresofurin. DDT stimulated metabolism of 7-pentoxyresofurin to much higher degree as compared with phenobarbital. It should be noted that both pesticides induced only slight increase in O-dealkylation of 7-etoxyresofurin (cyt. P-4501A-mediated reaction). The present results indicate that permethrin as well as DDT shows the ability to induce the phenobarbital-type of cytochrome P-4502B.

Animals↗

PubMed1996

[Induction of micronuclei in erythrocytes of bone marrow and peripheral blood in laboratory mice following acute and subchronic exposure to DDT(fenarimol and nuarimol)].

The frequency of micronuclei was assessed in polychromatic erythrocytes of bone marrow and normochromatic erythrocytes in peripheral blood of mice following exposure to fenarimol (50, 100, 200 mg/kg b.w.) and nuarimol (100, 200, 400 mg/kg b.w.) for 21 days. Mitomycin C (2 mg/kg b.w.), cyclophosphamide (25 mg/kg b.w.) and colchicyne (2 mg/kg b.w.) were administered to the positive control mice for 5 days. These results obtained in this experiment were compared with the incidence of micronuclei in bone marrow and peripheral blood in mice exposed twice (two consecutive injections, 24 hours interval) to fenarimol and nuarimol and mitomycin C, cyclophosphamide and colchicine. The results show that fenarimol and nuarimol did not cause micronuclei induction in the bone marrow and peripheral blood of mice under the conditions of these experiments. However, mitomycin C, cyclophosphamide and colchicine induced of micronuclei in the investigated tissues. Moreover, the positive relationship between frequencies of micronuclei in normochromatic erythrocytes in peripheral blood and time of exposure was observed.

Animals↗

PubMed1993

[Content of mercury in human hair of Warsaw residents exposed occupationally and non-occupationally].

The concentrations of mercury in the hair of workers employed in the fluorescent tubes plant in Warsaw were determined and compared with the results obtained in our previous studies in the years 1970/1980. Total mercury in the hair was analysed by means of flameless atomic absorption spectrometry. The average mercury concentrations in the non-exposed population was at a similar level (0.17 microgram/g) as in the results obtained in 1970/80. The average concentrations of total mercury in the hair of exposed subjects were approximately 30 times lower than in the years 1970/80 and ranged from 0.38 to 1.42 micrograms/g. This substantial reduction in Hg concentration in the hair of exposed people was due to improvements in the technological process.

Adult↗

PubMed1992

[Changes in activity of G-6-pase, APase, and gamma-GTPase in liver and blood serum of rats exposed to nuarimol and NDEA].

The effect of simultaneous administration of N-diethylnitrosamine (NDEA) and Nuarimol on the activity of gamma-GTPase, G-6-Pase ans APase in the liver and serum of Wistar rats was investigated in the 2-weeks experiment. The two-stage hepato-cancerogenesis model was used with NDEA as initiating agent. The possible promoting potential of Nuarimol (DDT analogue) was checked in this experiment. gamma-GTPase and G-6-Pase activities were measured by biochemical and histochemical methods and AP-ase activity was measured by a biochemical method only. The occurrence of gamma-GTPase positive foci found by histochemical methods was partly confirmed by colorimetric methods. This suggest the need for further examination of this enzyme in conditions of prolonged exposure to Nuarimol.

Alkaline Phosphatase↗

PubMed1988