Showing papers in "Chemico-Biological Interactions in 1990"

TL;DR: Uric acid is an end-product of purine metabolism in Man, and has been suggested to act as an antioxidant in vivo in humans, and products of attack upon uric acid by various oxidants were measured by high performance liquid chromatography.

TL;DR: A number of antiparasitic agents have been shown to exert their actions through a free radical metabolism: nitro compounds used against trypanosomatids, anaerobic protozoa and helminths; crystal violet used in blood banks to prevent blood transmission of Chagas' disease; the antimalarial primaquine, chloroquinine, and quinhasou; and quInones active in vitro and in vivo against different parasites.

TL;DR: Treatments affecting the loss of cytochrome P-450 in rat hepatocyte culture are reviewed and the way in which these have produced an understanding of the mechanisms involved are discussed extensively.

TL;DR: A number of determinants of GST isoenzyme patterns and/or activities are dealt with, including tissue distribution, developmental patterns, hormonal influences, induction and inhibition, and current knowledge on specific properties of class alpha, class mu and class pi isoenzymes is presented.

TL;DR: The results indicate a specific interaction of chlorophenols with the T4 binding site of TTR, indicating a competitive type of inhibition.

TL;DR: Structural and thermodynamic features of the binding interactions of DNA with bleomycin, its metal complexes, and adducts of metallobleomycins are reviewed, and the DNA cleavage reaction involving iron-bleomycin is examined.

TL;DR: Findings suggest that hydroquinone and catechol may be responsible for the ability of cigarette smoke to cause 8-OHdG formation in DNA, and this oxidative DNA-damage is due to the action of hydroxyl radicals formed during dissociation of hydrogen peroxide.

TL;DR: The superoxide dismutase-dependent inhibition of H2O2 formation as well as NADPH oxidation during the autoxidation of naphthohydroquinones--except those with a hydroxyl substituent in the benzene ring--seems to apply to those organic substrates which can break down with simultaneous formation of a semiquinone and O2-..

TL;DR: The presented results demonstrate that glutathione-dependent metabolism of trichloroethene is a minor route in the biotransformation of this haloalkene in rats.

TL;DR: It is found that forms of cytochrome P-450 capable of mediating the O-dealkylation of the short-chain phenoxazone ethers methoxy-, ethoxy- and propoxyresorufin were highly induced by 3-methylcholanthrene-type inducers and by Aroclor-1254 in all species tested, although there were species differences in the relative turnover rates for the various substrates.

TL;DR: High affinity minor groove binding to DNA was established through the observation of an intense induced dichroism and is sufficient to produce a potent cytotoxic effect.

TL;DR: It has been proven experimentally that also reperfusion or revascularization after time-limited ischemia add to the tissue damages observed, due to the formation of O2-radicals, as well as the prerequisites for the production of these radicals are generated during tissue ischemIA.

TL;DR: In addition to the metal-removing ability, the antioxidant properties of the chelating agents may play an important role in manifestation of their beneficial effect in metal intoxications.

TL;DR: This review focuses on the preparation of PTC and the use of these cells, and important criteria such as the viability (survival time) of the cells and the parameters to assess toxicity.

TL;DR: Tetrachlorohydroquinone, which has previously been identified as a metabolite of pentachlorophenol, induces DNA strand breaks in isolated DNA and in human fibroblasts, indicating that at least part of the strand break formation in human cells is also due to the action of hydroxyl radicals.

TL;DR: The structure and the chemistry of the major serum albumin adduct of aflatoxin B1 (lysine-AFB1) were investigated and the quantification of lysine- AFB1 was demonstrated in biological samples.

TL;DR: It is shown that TCDD has a long-lasting effect on thymocyte abundance together with a transient effect on cell proliferation, and may also more permanently disturb the normal process of elimination by means of selection.

TL;DR: A purely chemical system for NAD(P)H oxidation to biologically active NAD( P)+ has been developed and characterized and a tentative scheme for the chain length occurring in the system is proposed according to stoichiometry of reactions involved.

TL;DR: To the authors' knowledge this is the first demonstration of the metabolism of a polynuclear aromatic hydrocarbon by a freshwater green alga through a dioxygenase pathway and subsequent conjugation and excretion.

TL;DR: Because the pyrrolic derivatives thus formed were easily recognised and unrelated to any physiological compound, the recovery method described provided a way to monitor animals for previous exposure to toxic pyrrolizidine alkaloids.

TL;DR: The chromate toxicity in mitochondria may be due to NADH depletion as a result of direct oxidation by Cr(V) as well as reduced formation of NADH due to specific enzyme inhibition.

TL;DR: It is indicated that during short-term incubations bull-head hepatocytes metabolize BP and BP-7,8-diol primarily to conjugated derivatives, and the usefulness of thin-layer chromatography for the convenient determination of the rate of BP-9,10-dihydrodiol metabolism is demonstrated.

TL;DR: It is demonstrated that during exposure of hepatocytes to NAPQI, dramatic changes in cellular energy metabolism occur and these biochemical alterations may be caused by a rapid decrease in mitochondrial function, and they may play an important role in the initiation of NAPZI-induced cytotoxicity.

TL;DR: The results provide evidence that essential determinants for inhibition of O2(-)-release are the OH-groups located in the B-ring of the flavonoid molecule.

TL;DR: Important determinants of peroxidation are prooxidant-dependent, and not only include alpha-tocopherol and sulfhydryl groups, but also membrane integrity, propagation reactions and the availability of catalytic transition metals.

TL;DR: The method used in the present study is well suited for studies of metabolism in avian embryos in ovo and proved to be at least two orders of magnitude less toxic than TCB in a chick embryo test.

TL;DR: The results supported the view that a proportion of the reactive metabolites from the alkaloids monocrotaline and anacrotine would be able to survive long enough to be transported from the liver to the lungs of a rat.

TL;DR: OXANO.

TL;DR: This paper investigated the mitoxantrone free radical anion generated electrochemically and found that in the presence of oxygen it behaved like other semiquinones, indicating the ability to redox cycle.

TL;DR: The activated microsomal glutathione transferase is generally more sensitive to the effect of inhibitors than the unactivated enzyme, and the I50 values were decreased upon activation of the enzyme, except for S-hexylglutathione, where a slight increase was noted.