The effect of exposure of Aedes aegypti larvae for 72h to sub-lethal concentrations of the herbicide glyphosate and the polycyclic aromatic hydrocarbon benzo[a]pyrene on their subsequent tolerance to the chemical insecticides imidacloprid, permethrin and propoxur, detoxification enzyme activities and transcription of detoxification genes was investigated. Bioassays revealed a significant increa...

The mixed-function oxidases containing cytochrome P450 are the primary systems that metabolize xenobiotics including drugs and carcinogens and endogenous substrates such as steroids [l-3]. The mixed-function oxidases may be key determinants of the rates of drug metabolism [2] and carcinogen susceptibility [3-S]. A major class of carcinogens to which humans are exposed is the polycyclic aromatic...

Degradation of polycyclic aromatic hydrocarbons (PAH) such as phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chryzene, benzo[b]fluoranthene, benzo[e]pyrene, benzo[k]fluoranthene and benzo[a]pyrene) in the surface layer (5 cm) of soil polluted with aircraft fuel in an amount of 10 ml/kg was analyzed. The direct influence of solubility in water on the degree of its loss was p...

The metabolism of benzo(a)pyrene by human liver microsomes and human lymphocytes has been analyzed by high-pressure liquid chromatography. Human liver forms seven known metabolites and at least five additional unidentified metabolites that migrate as distinct peaks. Lymphocytes incubated with benzo(a)pyrene for 30 min do not form dihydrodiols. Lymphocytes incubated for 24 hr with benzo(a)pyrene...

The current study was conducted to evaluate the effects of three generation sources smoke (poplar, haloxylon, and white paper), smoking duration (2 4 h) meat contents (55 80%) on Polycyclic Aromatic Hydrocarbons (PAHs) levels sausages. results showed that there are a positive correlation between lignin content PAHs level smokes smoked total in both sausages increased significantly as from 2 h. ...

Human placenta is a readily available organ that responds to maternal environmental insult and has been previously used to investigate metabolism and bioactivation of procarcinogens, for example, benzo[a]pyrene. HPLC in combination with synchronous fluorescence spectroscopy was used to examine 28 placentas for the presence of benzo[a]pyrene diol epoxide-DNA adducts, and 10 of these were found t...

The hamster embryo cell bioassay has been used to study the effect of metal salts on morphological transformation. A synergistic enhancement of the transformation frequency was found for the combined treatment with organic carcinogens [benzo(a)pyrene, N-hydroxy-2-acetylaminofluorene, and 4-nitroquinoline 1-oxide] and nickel sulfate, cadmium acetate, or potassium chromate. Chromic chloride and z...

The present study was designed to determine the systemic influence of ultraviolet (UVB) irradiation upon subsequent carcinogenesis induced by benzo(a)pyrene. The source of UV irradiation consisted of six Westinghouse FS-40 fluorescent sunlamps. Female BALB/c mice received five 30-min dorsal UVB radiation treatments per week for 13 wk. At the end of 13 wk, irradiated and unirradiated mice receiv...

The in vitro oxidation of the two polycyclic aromatic hydrocarbons anthracene and benzo[a]pyrene, which have ionization potentials of <=7.45 eV, is catalyzed by laccases from Trametes versicolor. Crude laccase preparations were able to oxidize both anthracene and the potent carcinogen benzo[a]pyrene. Oxidation of benzo[a]pyrene was enhanced by the addition of the cooxidant 2,2(prm1)-azinobis(3-...

The tumorigenicity of two coal tar mixtures was compared to that of benzo[a]pyrene after 2 years of feeding. Mixture 1, a composite of coal tar from seven coal gasification plant waste sites, was fed to female B6C3F1 mice (48 mice per group) for 2 years at doses of 0.0, 0.01, 0.03, 0.1, 0.3, 0.6 and 1.0%. Mixture 2, which was composed of coal tar from two of the seven waste sites and another si...