Showing papers in "Chemico-Biological Interactions in 1992"

TL;DR: It is concluded that the mechanism of Microcystis toxicity to the hepatocyte is through cytoskeletal damage leading to loss of cell morphology, cell to cell adhesion and finally cellular necrosis.

TL;DR: Reactive oxygen metabolites affect binding of ligands to membrane receptors and also coupling of receptors to G-proteins and effector enzymes, thus affecting another pharmacological messenger system.

TL;DR: The findings suggest that the ability of cigarette smoke to cause DNA single strand breaks in cultured lung cells is due to mechanisms involving hydroxyl radical attack on DNA and endonuclease activation, and that hydroquinone is an important contributor to the DNA damaging effect of cigarette Smoke on human lung cells.

TL;DR: Caffeic acid esters which are present in Propolis possess chemopreventive properties when tested in short-term assay systems, and indicate that MC, PEC and PEDMC were not mutagenic in the Salmonella tester system.

TL;DR: This review offers an overview of the state of the art of monitoring free radical damage in vivo, with special emphasis on the analytical aspects of non-invasive methods.

TL;DR: There appears to be a good correlation between hepatotoxicity of PAs in experimental rodents and genotoxicity in the wing spot test of Drosophila, which suggests that PAs are bioactivated along similar pathways in the mammalian liver and in the somatic cells of Dosophila.

TL;DR: The induction of MT expression by arsenite (As3+) in rat liver in vivo constitutes an unusual mechanism of enhancement of MT gene expression and appears to be mediated by processes not specifically associated with binding of arsenite to MT in vivo.

TL;DR: Characterization of PFDA covalent binding to albumin in vitro showed that cysteine significantly decreased binding with no effect of methionine, suggesting protein sulfhydryl groups are involved, and PFDA need not be metabolically activated to form covalents adducts.

TL;DR: In this article, the stabilities of the nitrenium ions derived from the food carcinogens can be easily understood using the semi-empirical AM1 molecular orbital procedure.

TL;DR: The determination of the relative amounts of ebselen selenol and diselenide under typical peroxidase assay conditions implies that the selenl is the predominant molecular species responsible for the glutathione--(70%)--and dithiothreitol--(96%)--dependent peroxIDase activity of ebselsen.

TL;DR: Using NPQ as a model for other PAH o-quinones, N-acetyl-L-cysteine, L-Cysteine and GSH conjugates of NPQ were synthesized and characterized by [1H]- and [13C]NMR and evidence for Michael type 1,4-addition products was obtained.

TL;DR: It is proposed that the failure of Clara cells to conjugate trichloroethanol leads to an accumulation of chloral which results in cytotoxicity which suggests that this lesion may be related to the development of lung tumours in mice exposed to trich chloroethylene by inhalation.

TL;DR: The results suggest that the reductive stress (excessive NADH formation) during allyl alcohol metabolism can release ferrous iron from ferritin and can reduce chelated ferric iron.

TL;DR: In this article, the authors showed that EO reactions with calf thymus DNA in aqueous solution at neutral pH and 37 degrees C for 10 hours resulted in the following 2-hydroxyethyl (HE) adducts (nmol/mg DNA): 7-HE-Gua (330), 3-HE -Ade (39), 1-HE ade (28), N6-he-dAdo (6.2), 3 -HE-Cyt (3.1), 3HE-Ura (0.8), and 3

TL;DR: This investigation demonstrates, for the first time, the identity and quantity of ebselsen selenol in the reaction of ebselen with thiols and also describes a convenient assay for its quantification.

TL;DR: The overall thermodynamics of N-hydroxylation were almost insensitive to the structure of the amine while differences in the energetics of nitrenium ion formation varied from 0 to 35 kcal mol-1.

TL;DR: It is shown that I3C can elicit both inductive and suppressive effects on the constitutive P450s that participate in carcinogen and steroid hormone metabolism, and may contribute to the anti-carcinogenic properties of this compound.

TL;DR: Calculated thermodynamic data clearly indicate that PE is a better complexing agent than PS, and Interestingly, mercury complexation with ligands or membranes can be completely reversed by addition of decimolar NaCl solutions.

TL;DR: From a study of 239 aromatic and heteroaromatic compounds causing skin cancer in mice, a quantitative structure-activity relationship has been derived and the results are discussed in terms of the bay region concept for carcinogenic activity.

TL;DR: This investigation determines for a large variety of aromatic amines the bioavailability of the N-hydroxyarylamine--the genotoxic metabolite--and the utility of electronic descriptors for prediction of theN-oxidation.

TL;DR: Ethanol had only a moderate effect on viability in aerobiosis, but accelerated the loss of hypoxic cells, which was 96% after 3 h of incubation, and the conversion of xanthine oxidase of hepatocytes cytosol was converted from D into O form by human plasma or serum.

TL;DR: Mt, which has been shown to be an excellent antioxidant in in vitro experiments, does not seem to play any major role against oxidative stress in Zn and Cd challenged cells.

TL;DR: A potential role for endogenous glutathione (GSH) in the detoxification of the electrophilic metabolite 3-NNB is established and the chemical reaction of this compound with biological thiols, including GSH, is examined.

TL;DR: The results suggest that P-450IIE1 catalyses the cytotoxic activation of CCl4, DMN, BB and naphthalene but not of lactonitrile or cyclophosphamide, and the administration of DEDC and its metabolites, disulfiram or CS2, inactivates P- 450IIE 1 so that the hepatocytes become resistant to these hepatotoxins.

TL;DR: The results give evidence that the DNA cannot be the only cellular target for the antitumor drug cisplatin, but that it also effects other intracellular lesions which cause structural alterations of cellular organelles independently of the primary molecular attack at nuclear DNA strands.

TL;DR: In a study of monozygotic twin pairs discordant for tobacco smoking the resolving power of the monitoring was increased and in vivo doses of methylators from the smoke could be more easily monitored through their adducts to Hb.

TL;DR: In vitro and in vivo study results have confirmed the formation of protein adducts following a single i.p. administration of [14C]TNT to rats and showed that there was a linear increase of covalentAdducts in globin during the first 2 h of incubation; the concentration of cavalent adductions was slightly higher than that with plasma proteins.

TL;DR: Reactive intermediates in the secondary metabolism of 1,2-D ICB lead to more covalent binding than those derived from 1,4-DICB, which correlates very well with their reported hepatotoxic potency.

TL;DR: The results with the lung are consistent with an increased presystemic clearance of BP in the intestine and are discussed in terms of the role of induction of intestinal CYP1A1 activity in the decreased lymphatic and venous transport of unmetabolized BP to the lung.

TL;DR: The results demonstrated an extremely high resistance of the liver against intracellular reactive oxygen formation (even with impaired detoxification systems) and can serve as reference for the evaluation of potential contributions of reactive oxygen to liver injury in various disease states.