Translesion synthesis is an important mechanism in response to unrepaired DNA lesions during replication. The DNA polymerase zeta (Polzeta) mutagenesis pathway is a major error-prone translesion synthesis mechanism requiring Polzeta and Rev1. In addition to its dCMP transferase, a non-catalytic function of Rev1 is suspected in cellular response to certain types of DNA lesions. However, it is no...

Aminobiphenyls (ABPs) in tobacco have been implicated in bladder cancer etiology in smokers. N-Acetylation of ABPs in the liver, predominantly by the N-acetyltransferase 2 (NAT2) isozyme, represents a detoxification pathway, whereas O-acetylation of N-hydroxy-ABPs in the bladder, predominantly by the N-acetyltransferase 1 (NAT1) isozyme, represents a bioactivation pathway. We and others have de...

Background. We tested the hypothesis that secondarily produced free radicals can be detected in venous coronary effluent without the need for direct exposure of postischemic tissue to the spin trapping agent a-phenyl-tert-butylnitrone (PBN). Methods and Results. The left anterior descending coronary artery (LAD) of pigs was ligated for 15, 30, 40, or 60 minutes, and the tissue was subsequently ...

Several compounds originating from cruciferous vegetables and citrus fruits bind to and activate the aryl hydrocarbon receptor (AhR). This receptor plays an important role in the toxicity of the known tumour promoter and potent AhR-agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). However, vegetables and fruits are generally considered as healthy. Therefore, besides the AhR activation, the na...

Several oxygen adducts are formed when oxygen is diffused into the interplanar spacings of solid -Fe II Pc suspended in water. The constraints imposed by the solid matrix induce formation of interesting oxygen adducts which cannot be synthesized by regular solution chemistry. One of the oxygen adducts exhibits low-spin to high-spin transition with considerable thermal hysteresis.

Antitumor activity of the adduct between Carboplatin and alpha-cyclodextrin has been tested against Sarcoma 180 (S(180)) and Ehrlich ascites carcinoma (EAC) murine tumors. The preliminary toxicity has also been evaluated by histological examinations of the treated animals. The results show the adduct has less antitumor efficacy than and similar toxicity to Carboplatin.

Because chemical species with DNA-damaging and mutagenic activity are formed in sorbate-nitrite mixtures and because sorbic acid sometimes coexists with nitrite occurring naturally or incorporated as a food additive, the study of sorbate-nitrite interactions is important. Here, the alkylating potential of the products resulting from such interactions was investigated. Drawn were the following c...

Urocanase is inactivated in vivo and is reactivated by ultraviolet radiation. The chemistry of this photoregulation of urocanase was studied. Purified enzyme was inactivated by 25 pM sulfite (tl,z, 15 min). Dialyzed sulfite-treated inactive enzyme was photoactivatable. The activity can be cycled repeatedly by alternate ultraviolet light and sulfite treatments. Active enzyme binds 5 times more [...