Showing papers in "Free Radical Biology and Medicine in 1989"

TL;DR: N-acetylcysteine is a powerful scavenger of hypochlorous acid (H--OCl); low concentrations are able to protect alpha 1-antiproteinase against inactivation by HOCl.

TL;DR: The many reports indicating that carotenoids may possess some anticarcinogenic properties may well be related to their ability to interact with and quench various radical species that can be generated within cells.

TL;DR: Although homolytic reactions of PUFA hydroperoxides have received the most attention, hydroper oxides are also susceptible to heterolytic transformations, such as nucleophilic displacement and acid-catalyzed rearrangement.

TL;DR: The intent of this and its companion paper is to review the biochemical processes which may give rise to free radical reactions in the CNS, the environment of the ischemic cell as it may affect the generation of oxygen radicals and the catalysis of lipid peroxidation reactions, and the pathophysiological consequences of these phenomena.

TL;DR: Recent investigations have provided compelling evidence for the view that oxygen radical-mediated processes play a key pathophysiological role during the acute phase of CNS trauma or stroke and may serve as an avenue for therapeutic attempts aimed at limiting neural degeneration and improving neurological recovery.

TL;DR: The evidence for a relationship between radical formation and the biological activity of the antitumor quinones is evaluated and it is suggested that cardiotoxicity and skin toxicity may also be related to oxygen radical formation.

TL;DR: Desferrioxamine (deferoxamine) is an inhibitor of iron-dependent free radical reactions that has been used to investigate the role of such reactions in several animal model systems for human disease as mentioned in this paper.

TL;DR: The detailed chemical mechanisms by which quinoid compounds exert cytotoxic, mutagenic and carcinogenic effects are considered individually in relation to redox cycling, alterations of thiol balance and Ca++ homeostasis, and covalent binding.

TL;DR: Circumstantial evidence implicates oxysterols of the human diet and those formed in vivo with human health disorders, but recent work also supports an hypothesis that some oxysterol be endogenous intracellular regulators of de novo sterol biosynthesis.

TL;DR: Several methods based on HPLC or GC-MS have been developed to qualitatively and quantitatively measure the aldehydes in tissues, cells and cell fractions exposed to various pro-oxidative stimuli and this could be of great importance for in vivo studies.

TL;DR: In this article, the chemical nature of alpha, β-unsaturated aldehydes and some of their toxicological effects based on their ability to function as direct-acting alkylating agents are described.

TL;DR: Thiyl radicals and "active oxygen" species are formed in this process, and it is suggested that these substances are responsible for initiating the tissue damage provoked by thiols and disulphides.

TL;DR: The interaction of oxidants with ion balance and cytoskeleton is discussed andabolically generated oxidants have been implicated as one factor that directs the initiation of certain developmental events.

TL;DR: By use of the CL-HPLC system, the presence of PCOOH in human blood plasma is confirmed quantitatively and the high specificity for hydroperoxide base enables a sensitive assay for a large range ofPCOOH.

TL;DR: The two-step initiation-promotion protocol for the induction of skin tumors in mice is a convenient model to elucidate what molecular events are involved in the multistage process of carcinogenesis and how they can be modulated.

TL;DR: The relative proportions and specific activities of xanthine oxidase and dehydrogenase determined by the fluorometric pterin assay are comparable with the spectrophotometric measurement of activities present in rat liver, intestine, kidney, and plasma.

TL;DR: In this review a very brief description of oxygen pathology is given together with data on the relevance of in vivo tissue pO2 levels, and the evidence for the current status of the radical theory is reviewed.

TL;DR: The results suggest that there is not any correlation between the SOD, CAT, and GSH-Px activities and the peroxidative status of the organs; thus, the age-related increase in the MDA content proposed as a criterion of aging process should be considered with caution.

TL;DR: It is found that purified bacterial alginate scavenges free radicals released by triggered macrophages as detected by lucigenin amplified chemiluminescence (CL) and reduction of cytochrome c.

TL;DR: It is proposed that macroxyproteinase is responsible for catalyzing most of the selective degradation of oxidatively denatured proteins in red blood cells, and it is suggested that M.O.P. may perform the same function in other eucaryotic cells and tissues.

TL;DR: Based on experiments with isolated hepatocytes a three-zone-model of liver injury due to hypoxia and reoxygenation is presented, with a zone where the cells die by hypoxIA and a zoneWhere cell injury occurs upon reoxyGENation, mediated by reactive oxygen species possibly liberated by xanthine oxidase.

TL;DR: The 21-aminosteroids U74006F and U74500A have been examined for their ability to scavenge the lipid peroxyl (LOO·) and phenoxy (phO·) radicals as discussed by the authors.

TL;DR: It is established, for the first time, a reliable method to quantitate hydrogen peroxide (H2O2) generated in aqueous extracts of cigarette smoke tar by differential pulse polarography using an automatic reference subtraction system.

TL;DR: The level of nitrosamine-induced lipid peroxidation parallels hepatocarcinogenicity in rats, and provides further evidence that free radical damage and DNA alkylation are involved in carcinogenesis induced by nitrosamines.

TL;DR: There was no effect of oxygen on BT production over a range of pH values (4-12) and it was determined that oxygen does not react with the phenoxyl radical with a rate constant greater than 10(3) M-1 s-1.

TL;DR: It is suggested that in light of the threshold phenomenon of vitamin E prevention of potentially severe oxidative stress-induced cytotoxicity, its use as a protective agent against an oxidative challenge in vivo should be reassessed.

TL;DR: The superoxide-induced destruction of DMPO--OH may well lead to erroneous conclusions regarding the primary radicals produced, and might be operative under circumstances where elevated rates of superoxide production take place, such as during oxygen consumption "burst" in phagocytosis, degranulation, or paraquat intoxication.