1,720,973 research outputs found

    Ochratoxin A and zearalenone: a comparative study on genotoxic effects and cell death induced in bovine lymphocytes

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    Ochratoxin A (OTA) and zearalenone (ZEA), two naturally occurring contaminants of animal feed, have been implicated in several mycotoxicoses in farm livestock but there is little information on their genotoxicity and toxicity in these species. Therefore, we investigated on the cytogenetic and cytotoxic effects of both OTA and ZEA in in vitro cultures of bovine lymphocytes. We determined chromosome aberrations (CAs) and sister chromatid exchanges (SCEs) as well as the mitotic index (MI) and cell viability following OTA and ZEA treatment. This report is the first to provide evidence of a statistically significant increase of structural CAs and of SCEs/cell associated with a reduction of the MI in all OTA- and ZEA-treated bovine lymphocyte cultures and a clear reproducible reducing effect of OTA on cell viability mediated by enhanced apoptosis. OTA-induced programmed cell death was not limited to bovine lymphocytes, as comparable data were demonstrated in the human leukemic T-cell line Jurkat. (C) 2003 Elsevier B.V. All rights reserved

    Treatment with 3-aminobenzamide negates the radiofrequency-induced adaptive response in two cell models

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    In previous investigations, we demonstrated that pre-exposure of different cell cultures to radiofrequency fields can reduce the damage induced by genotoxic agents, an effect resembling the so-called adaptive response. In this study, we pre-exposed human peripheral blood lymphocytes and Chinese hamster lung fibroblast cell line to 1950 MHz, UMTS (Universal Mobile Telecommunication System) signal, for 20 h, and then treated cultures with Mitomycin-C. After confirming the induction of an adaptive response in terms of the reduction of micronuclei formation, we observed that such a response was negated by treatments with 3-aminobenzamide. Since 3-aminobenzamide is an inhibitor of poly (ADP-ribose) polymerase enzyme, which is involved in DNA repair, these results support the possible involvement of DNA repair mechanisms in radiofrequency-induced adaptive response

    Carnitine prevents clastogenic effects induced by hydrogen peroxide in mammalian cells

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    Carnitine is a small essential molecule that regulates the substrate flux and energy balance across cell membranes by modulating both the transport of long-chain fatty acids into mitochondria and their subsequent β-oxidation. Although humans are capable to synthesize it endogenously, approximately 75% of body carnitine sources come from diet and particularly from food of animal origin such as meat, poultry, fish and dairy products. Due to its intrinsic interaction with the bioenergetics processes, carnitine plays an important role in diseases associated with metabolic compromise, especially mitochondria-related disorders. It has been reported that administration of carnitine by diet or at pharmacological doses can have significant benefit in several physiopathological situations such as ischemia, myocardial injury and neurodegenerative diseases, but there is no data on the possible protective role of carnitine against other oxidative stress-induced pathologies associated with an altered chromosome stability such as cancer. Therefore, we analysed the potential capability of carnitine to protect mammalian cells from genetic instability induced by H2O2, using Chinese Hamster Ovary (CHO) cells as a mammalian cell model having a stable karyotype and the chromosome aberration test as genetic end point. Our results showed that in the absence of carnitine H2O2 induced a high and dose-depend-ent induction of structural chromosome aberrations in the concentration range 0.1-0.4 mM whereas at the same H2O2 doses, a pre-treatment with 4 mM carnitine produced a strong decrease either of the percent of cells with aberrations or of the aberration frequency. The observed carnitine-mediated prevention of H2O2-induced chromosome aberrations reaches almost the control value in the cultures treated with 0.1 mM of H2O2 thus evidencing a reduction of about 70%. These data, together with preliminary results showing that carnitine is not able to protect cells from the inhibition of cell growth caused by H2O2, suggest that carnitine protects mammalian cells from H2O2–induced clastogenic damage and this effect is reproducible and highly specific

    Chromosome aberrations in cattle with chronic enzootic haematuria

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    Chromosomal aberrations were investigated in 56 cattle with chronic enzootic haematuria (CEH) raised on pastures giving access to bracken fern. Of these animals, 27 were slaughtered and showed neoplastic lesions of the urinary bladder. Tumour tissue from 11 of the 27 cattle contained bovine papillomavirus type 2 (BPV-2) DNA. Increased numbers of chromosomal aberrations were seen in all animals with CEH, as compared with 30 control cattle that had had no access to bracken fern. The highest clastogenic effect was observed in cattle with Urinary bladder cancer and evidence of BPV-2 DNA, suggesting that BPV-2 and bracken fern act synergistically in the production of chromosomal instability. In 19 of 20 animals with CEH, two bracken fern toxic compounds (quercitin and ptaquiloside) were demonstrated in urine, serum and milk. (C) 2004 Elsevier Ltd. All rights reserved
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