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Using a novel and highly selective technique, we measured monoester metabolites of seven commonly used phthalates in urine samples from a reference population of 289 adult humans. This analytical approach allowed us to directly measure the individual phthalate metabolites responsible for the animal reproductive and developmental toxicity while avoiding(More)
BACKGROUND Numerous studies have associated bladder cancer with exposure to carcinogens present in tobacco smoke and other environmental or occupational exposures. Approximately 50% of all humans inherit two deleted copies of the GSTM1 gene which encodes for the carcinogen-detoxification enzyme glutathione S-transferase M1. Recent findings suggest that the(More)
The changes in the phosphorus metabolism of a xenografted hypopharynx carcinoma (Hyp 1), sensitive to cisplatin (CDDP), were compared to those occurring in two sublines of the tumour, characterised by moderate or high resistance to CDDP (Hyp 1/H and Hyp I/R) following, i.p. administration of 4, 8 or 12 mg CDDP/kg-. The investigations were performed by in(More)
We developed a sensitive and accurate analytical method for quantifying methyleugenol (ME) in human serum. Our method uses a simple solid-phase extraction followed by a highly specific analysis using isotope dilution gas chromatography-high resolution mass spectrometry. Our method is very accurate; its limit of detection is 3.1 pg/g and its average(More)
Carcinogenic arylamines are acetylated by the hepatic N-acetyltransferase. This enzyme is polymorphic in humans and in some epidemiological studies, the slow-acetylator phenotype has been associated with higher risk of bladder cancer and lower risk of colorectal cancer. The presence of two germline copies of any of several mutant alleles of the NAT2 gene(More)
Human cytochrome P4502E1 (CYP2E1) is inducible by ethanol and is involved in metabolism of many known carcinogens including N-nitrosodimethylamine, butadiene, benzene, and carbon tetrachloride. A 50-fold variability in CYP2E1 enzyme activity in humans has been observed but it is unknown whether the basis for this variation is genetic or environmental.(More)
Dose-response relationships for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) suggest a differential sensitivity of liver cell types to the induction of cytochrome P450 gene expression, and that the induction of hepatic protein CYP1A2 causes sequestration of TCDD. In addition, immunolocalization of hepatic CYP1A1/1B1/1A2 proteins is not uniform after exposure(More)
One of the current knowledge gaps in the evaluation of risk for human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the relationship between gene expression induced by TCDDmore complex biological responses such as altered growth, differentiation, and neoplasia. This study investigates the dose-dependent expression of CYP1A1, CYP1A2,CYP1B1 in the(More)
Studies were completed in F344/N rats and B6C3F1 mice to determine the effect of dose, dose rate, route of administration, and rodent species on formation of total and individual benzene metabolites. Oral doses of 50 mg/kg or higher saturated the capacity for benzene metabolism in both rats and mice, resulting in an increased proportion of the administered(More)