Increasingly sensitive assays are needed to understand and evaluate the effects of chemical exposures on individuals and populations. Several assays have been developed to measure the environmental dietary carcinogen, aflatoxin, and its metabolites in biological specimens. One, the 8,9-dihydro-8-(N7-guanyl)-9-hydroxy-aflatoxin B1 nucleic acid adduct, has been shown to be both highly correlated ...

4-Hydroxy-2-nonenal (HNE) is a major lipid peroxidation product formed during oxidative stress. Because of its reactivity with nucleophilic compounds, particularly metabolites and proteins containing thiol groups, HNE is cytotoxic. The aim of this study was to assess the extent and time course for the formation of HNE-modified proteins during ischemia and ischemia plus reperfusion in isolated r...

We found previously that the human lung benzo(a)pyrene (BP)-7,8-diol-9,10-epoxide-N(2)-deoxyguanosine (BPDE-dG) adduct concentrate in the target bronchial cells. This adduct is now considered to be critical event in tumorigenesis by BP. In this study, we investigate the contribution of cigarette smoke on the BPDE-dG formation. In a cell-free system, the amount of (-)-anti-BPDE-dG adduct increas...

In the liver microsome cyanide (CN)-trapping assays, piperazinecontaining compounds formed significant N-methyl piperazine CN adducts. Two pathways for the N-methyl piperazine CN adduct formation were proposed: 1) The a-carbon in the N-methyl piperazine is oxidized to form a reactive iminium ion that can react with cyanide ion; 2) N-dealkylation occurs followed by condensation with formaldehyde...

Benzo[a]pyrene (BaP) is a human carcinogen that covalently binds to DNA after activation by cytochrome P450 (P450). Here, we investigated whether NADH:cytochrome b5 reductase (CBR) in the presence of cytochrome b5 can act as sole electron donor to human P450 1A1 during BaP oxidation and replace the canonical NADPH:cytochrome P450 reductase (POR) system. We also studied the efficiencies of the c...

The unexpected finding of the shortest H?+?H?? intermolecular distance for non-ionic species has been found in a trivial phosphinophenol borane adduct solid state.

We found previously that the human lung benzo(a)pyrene (BP)-7,8-diol-9,10-epoxide-N-deoxyguanosine (BPDE-dG) adduct concentrate in the target bronchial cells. This adduct is now considered to be critical event in tumorigenesis by BP. In this study, we investigate the contribution of cigarette smoke on the BPDE-dG formation. In a cell-free system, the amount of ( )-anti-BPDE-dG adduct increased ...

Development of methods to evaluate certain classes of polycyclic aromatic compounds (PAC) detected in complex mixtures to which humans are exposed would greatly improve the diagnostic potential of 32P-postlabeling analysis. Identification of DNA adduct patterns or specific exposure-related marker adducts would strengthen associations between observed DNA adducts and exposures to different envir...

Acrolein is a representative carcinogenic aldehyde found ubiquitously in the environment and formed endogenously through oxidation reactions, such as lipid peroxidation and myeloperoxidase-catalyzed amino acid oxidation. It shows facile reactivity toward DNA to form an exocyclic DNA adduct. To verify the formation of acrolein-derived DNA adduct under oxidative stress in vivo, we raised a novel ...

The reaction of cytochrome c and H(2)O(2) is known to form a protein-centred radical that can be detected with the spin trap 2-methyl-2-nitrosopropane (MNP). To characterize the MNP/tyrosyl adduct structure that had previously been determined incorrectly [Barr, Gunther, Deterding, Tomer and Mason (1996) J. Biol. Chem. 271, 15498-15503], we eliminated unreasonable structure models by ESR studies...