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Medicinas Complementares
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1.
Mutagenesis ; 11(4): 363-81, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8671761

RESUMO

A coordinated study was carried out on the development, evaluation and application of biomonitoring procedures for populations exposed to environmental genotoxic pollutants. The procedures used involved both direct measurement of DNA or protein damage (adducts) and assessment of second biological effects (mutation and cytogenetic damage). Adduct detection at the level of DNA or protein (haemoglobin) was carried out by 32P-postlabelling, immunochemical, HPLC or mass spectrometric methods. Urinary excretion products resulting from DNA damage were also estimated (immunochemical assay, mass spectrometry). The measurement of adducts was focused on those from genotoxicants that result from petrochemical combustion or processing, e.g. low-molecular-weight alkylating agents, PAHs and compounds that cause oxidative DNA damage. Cytogenetic analysis of lymphocytes was undertaken (micronuclei, chromosome aberrations and sister chromatid exchanges) and mutation frequency was estimated at a number of loci including the hprt gene and genes involving in cancer development. Blood and urine samples from individuals exposed to urban pollution were collected. Populations exposed through occupational or medical sources to larger amounts of some of the genotoxic compounds present in the environmental samples were used as positive controls for the environmentally exposed population. Samples from rural areas were used as negative controls. The project has led to new, more sensitive and more selective approaches for detecting carcinogen-induced damage to DNA and proteins, and subsequent biological effects. These methods were validated with the occupational exposures, which showed evidence of DNA and/or protein and/or chromosome damage in workers in a coke oven plant, garage workers exposed to diesel exhaust and workers exposed to ethylene oxide in a sterilization plant. Dose reponse and adduct repair were studied for methylated adducts in patients treated with methylating cytostatic drugs. The biomonitoring methods have also demonstrated their potential for detecting environmental exposure to genotoxic compounds in nine groups of non-smoking individuals, 32P-postlabelling of DNA adducts being shown to have the greatest sensitivity.


Assuntos
Carcinógenos Ambientais/toxicidade , Monitoramento Ambiental/métodos , Antineoplásicos Alquilantes/toxicidade , Proteínas Sanguíneas/efeitos dos fármacos , Estudos de Casos e Controles , Adutos de DNA/sangue , Dano ao DNA , Exposição Ambiental , Epicloroidrina/toxicidade , Óxido de Etileno/toxicidade , Humanos , Cloreto de Metileno/toxicidade , Mutagênicos/toxicidade , Óxidos de Nitrogênio/toxicidade , Exposição Ocupacional , Petróleo/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Estireno , Estirenos/toxicidade
2.
Toxicol In Vitro ; 10(3): 359-69, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20650216

RESUMO

Tracheal organ cultures and isolated tracheal epithelial cells are frequently used to study effects of carcinogens and retinoids on both proliferation and differentiation of respiratory tract epithelial cells. For each of these in vitro models, optimal culture conditions have been established, varying in type of culture medium and composition of growth factor and hormone supplementation, which by themselves may influence cellular proliferation and differentiation. In this study, we investigated the influence of medium composition and growth factor supplementation on the effect of benzo[a]pyrene (B[a]P) and vitamin A on cellular proliferation and differentiation in hamster tracheal epithelium in organ culture. In tracheae cultured in Ham's F12 medium, cell proliferation was decreased by B[a]P relative to untreated controls, whereas vitamin A in combination with B[a]P increased cell proliferation compared with that in tracheae treated with B[a]P alone. The effects in tracheae cultured in CMRL-1066 medium were just the opposite: B[a]P increased cell proliferation and vitamin A decreased B[a]P-induced proliferation. To explain this difference in cell proliferation, the effects of various growth factors (epidermal growth factor and transferrin) and medium components (nucleotides, NAD(+)/NADP and CaCl(2).2H(2)O) on B[a]P and vitamin A-induced cell proliferation were investigated. The main factor responsible for the different effects on cell proliferation appeared to be the concentration of Ca(2+) in the culture medium; addition of CaCl(2).2H(2)O to Ham's F12 medium resulted in effects of B[a]P and vitamin A on cell proliferation comparable with those observed in tracheae cultured in CMRL-1066 medium. These results clearly show that the composition of the culture medium, and particularly the concentration of Ca(2+), strongly influences the effect of vitamin A and B[a]P on cell proliferation in hamster tracheal epithelium in organ culture.

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