Showing papers in "Chemico-Biological Interactions in 1986"

TL;DR: Results indicate that beta-lyase plays a key role in the metabolism and mutagenicity of haloalkenylcysteines when tested in S. typhimurium systems, and may provide a molecular explanation for the nephrocarcinogenicity of these compounds.

TL;DR: The results indicate that the fungus C. elegans metabolized pyrene to non-toxic metabolites (glucoside conjugates) as well as to compounds which have been suggested to be biologically active in higher organisms.

TL;DR: The relative contents of cis-trans and trans-trans dienes in lipid extracts of tissue reflect the tissue contents of hydrogen donors as already established for model experiments with polyunsaturated fatty acids in vitro.

TL;DR: Although a large variation was observed in rates of conversion between microsomes treated with different (or no) inducers, the rate of covalent binding to microsomal protein was remarkably constant.

TL;DR: Results demonstrate that meso-anthracenic benzylic acetates, sulfates and bromides are mutagenic, whereas benzyLic acetate esters attached to other carbon atoms are inactive.

TL;DR: The best protection against smoke-induced loss of EIC was provided by two biologically important antioxidant species: glutathione and ascorbic acid, which provide almost complete protection to alPI under the experimental conditions used.

TL;DR: In the reactions of styrene oxide with DNA the dominant product isolated was 7-alkylguanine but N2-alkymidine was also detected and the relative yields of alkylated deoxynucleosides were dG greater than dC greater than tA greater than T.

TL;DR: Some relationships exist between reduction potential and reported antimicrobial activity and a possible mechanism of drug action is addressed.

TL;DR: The results indicate that hormonal activity and carcinogenicity of estrogens are separable properties and in immature female rats, uterine wet weight increases illustrate that 2-fluoroestradiol is a potent estrogen.

TL;DR: These studies indicate that DNA damage is not as major a consequence following some metal treatments in human cells as it appears to be in rodent cells, and suggests that rodent models for risk estimation of metal-induced tumorigenesis may not always be appropriate for extrapolation to humans.

TL;DR: The feasibility of an oxygen-independent mechanism of chloroform bioactivation was indicated by the covalent binding to lipid and protein occurring in anaerobic incubations of CHCl3 and microsomes in the presence of NADPH.

TL;DR: 1,6- and 1,8-dinitropyrene are reduced to a greater extent than 1-nitropyrene and1,3-d initropyrene, which corresponds to their relative biological potencies as mutagens and carcinogens.

TL;DR: The results indicate that other control systems, in addition to the content of individual P-450-forms in the regulatory systems, are involved in the in vivo transformation of phenanthrene by cod to the 1,2-dihydrodiol metabolite.

TL;DR: It is strongly suggested that further metabolism of BPDE involves hydroxylation at the 1- and 3-positions to yield the corresponding triol-epoxides and various BP-pentols.

TL;DR: The oxidation of the phenacetin metabolites p-phenetidine and acetaminophen by peroxidases was investigated and the radical concentration was dependent on the square root of the enzyme concentration, indicating second-order decay of the radical, as is consistent with its dimerization or disproportionation.

TL;DR: The introduction of a 2-hydroxyethyl function into phosphate strongly decreases the stability of the phosphate link of DNA, resulting in DNA single strand breaks, in analogy to RNA phosphotriesters which have been found earlier to be highly unstable because of the presence of the ribose 2'-OH-group.

TL;DR: 1-Naphthol was metabolised by horseradish peroxidase (HRP) in a H2O2-dependent reaction to methanol-soluble and covalently bound products to stimulate oxidised glutathione (GSSG) formation.

TL;DR: Seven macrocyclic diesters analogous to hepatotoxic pyrrolizidine alkaloids have been tested in male weanling Wistar rats, and acute hepatotoxicity was dose related, and associated with the formation of pyrrolic metabolites in the liver.

TL;DR: The strong inhibition on Tris-diol formation by several vitamins, antioxidants and trace metals shows similarity with their effect on AFB1-DNA adduct formation and it is suggested that these agents may have potential anticarcinogenic activity against AFB1.

TL;DR: Complications can arise in the interpretation of experimental work using these radioactive compounds by purifying the compounds by high performance liquid chromatography (HPLC) before use together with identification of the DNA components with which the 3H is associated by chromatographic analysis.

TL;DR: It is suggested that there is no direct role for the Ah receptor in the regulation of these cytochrome P-450 monooxygenase activities by isosafrole.

TL;DR: Although the binding affinities of the two sets of ligands are dependent only on substituent pi-values, their enzyme induction activities are both substituents and chlorine substitution pattern-dependent.

TL;DR: The mustard adducts are notably more labile than simple alkyl substituted guanosines and deoxyguanosines, and they are also formed in aqueous reactions but they rapidly underwent secondary reactions.

TL;DR: The solvolysis in aqueous dioxane of (+/-)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydro-BP (BPDE I), the ultimate carcinogen of BP, was accelerated in presence of selected flavonoids, and this could be the basis for the anti-carcinogenic nature of these flav onoids.

TL;DR: The photoreduction of crystal violet to a carbon-centered radical was detected directly by electron spin resonance (ESR) spectroscopy under anaerobic conditions and crystal violet was found to convert oxygen to superoxide anion and hydrogen peroxide in the presence of light.

TL;DR: Data indicate that suramin, by interfering with both the uptake and intralysosomal digestion of protein, and sodium aurothiomalate, by inhibiting digestion of captured protein, disturb the normal pathway of yolk sac-mediated protein utilization with a consequent diminution of the supply of amino acids to the conceptus at a critical stage of development.

TL;DR: Ferric σ-phenyl complexes of hemoglobin and liver cytochrome P -450 are formed in vivo upon administration of C 6 H 5 NHNH 2 to rats, and about 15% of the remaining cy tochrome P-450 existed as a cyt.- P - 450-Fe(III)-C 6 H 7 H 5 complex, a new example of cyto Chrome -450-Fe-metabolite complex which is stable in vivo.

TL;DR: It is found that a general QSAR equation, covering a diverse range of structures, correlates the biological activity reported by Muller and Greff with a single physicochemical parameter, TB'.

TL;DR: The results demonstrate a compartmentalization ofdolichol and dolichyl-P distribution, and the induction studies suggest that hepatocytes possess separate regulating mechanisms for these two compounds.