Showing papers in "Free Radical Biology and Medicine in 1990"

TL;DR: The conclusion is reached that MDA determination and the TBA test can offer, at best, a narrow and somewhat empirical window on the complex process of lipid peroxidation.

TL;DR: The demonstration shows that oxidative modification of proteins "marks" them for degradation by most common proteases and especially by the cytosolic multicatalytic proteinase from mammalian cells, and contributes substantially to the intracellular pool of catalytically inactive and less active, thermolabile forms of enzymes.

TL;DR: Free radicals are found to be involved in both initiation and promotion of multistage carcinogenesis, and antioxidants, the free radical scavengers, are shown to be anticarcinogens.

TL;DR: The purpose of this review is to consider whether an essential biochemical function of zinc (Zn) is to serve as an antioxidant; critical antioxidant functions for Zn may still be uncovered.

TL;DR: The quantum mechanic, thermodynamic, and kinetic aspects of the reactions of dioxygen with biomolecules; the involvement of transition metals in biomolecule oxidation; and the biological implications of metal catalyzed oxidations are discussed.

TL;DR: The present article summarizes very recent developments related to the mechanism of oxidation of LDL by cells, receptor-mediated uptake of oxidized LDL in macrophages, the mechanisms of phosphatidylcholine hydrolysis during LDL oxidation, and other biologic actions of oxidizing LDL including cytotoxicity, altered eicosanoid metabolism, and effects on the secretion of growth factors and chemotactic factors.

TL;DR: Dietary phytic acid may lower the incidence of colonic cancer and protect against other inflammatory bowel diseases, and a multitude of other industrial applications are based on the antioxidant function of phYtic acid.

TL;DR: The sensitivity of mitochondrial DNA to damage by mutagens predisposes mitochondria to injury on exposure of cells to genotoxins or oxidative stress, which may contribute to cellular aging and promotion of cancer.

TL;DR: The superoxide anions scavenging activity and antioxidation of seven flavonoids (quercetin, rutin, morin, acacetin, hispidulin, hesperidin, and naringin) were studied in this paper.

TL;DR: The role of reactive oxygen species in airway disease has been largely neglected, but appears to be an important area for future study and radical scavengers or antioxidants could play a useful role in therapy.

TL;DR: A chronic exposure to O3 can cause or exacerbate lung diseases, including perhaps an increased lung tumor incidence in susceptible animal models, and dietary antioxidants, for example, vitamin E, vitamin C, and selenium, can offer a protection against O3 effects.

TL;DR: Intracolonic free radical formation may explain the high incidence of cancer in the colon and rectum, compared to other regions of the GI tract, as well as the observed correlations of a higher incidence of colon cancer with red meat in the diet, which increases stool iron, and with excessive fat in the diets, which may increase the fecal content of procarcinogens and bile pigments.

TL;DR: The in vivo activities of enzymes supporting redox cycling of estrogens and free radical generation is correlated with induction of kidney tumors in Syrian hamsters, suggesting a role of free radicals in the induction of tumors by estrogen.

TL;DR: Phenols isolated from the traditional medicinal plant Picrorhiza kurroa inhibit the release of superoxide anion by activated human neutrophils, but leave the phagocytotic capacity intact.

TL;DR: Several mechanisms leading to toxicity are described in this review and several antioxidants are discussed which may be beneficial as therapeutics in several lung diseases.

TL;DR: This manuscript suggests, for the first time, mechanisms that rationalize the production of HNE from PUFA that undergo autoxidation that require an n-6 fatty acid and iron catalysis.

TL;DR: The results reported here suggest that following chemotherapy both stimulated and unstimulated human polymorphonuclear leukocytes generate increased amounts of superoxide anion and hydrogen peroxide, accompanied by increased formation of lipid peroxidation products as measured by thiobarbituric acid assay.

TL;DR: Experiments at various levels of organization including subcellular systems, intact animals, and human subjects in the clinical setting, support the view that coenzyme Q, mainly in its reduced state, may act as an antioxidant protecting a number of cellular membranes from free radical damage.

TL;DR: Oxidative damage may contribute to many of the toxic responses produced by TCDD and its bioisosteres, and may be common to most of the tissue-damaging effects.

TL;DR: Results indicated that antioxidant enzymes exhibit a mixed pattern of age-related alterations, and suggest that rates of prooxidant generation may be more crucial than antioxidant levels as possible longevity determinants.

TL;DR: A review of the human disease/treatment literature suggests that further tightening of the scientific design of such trials is still badly needed; hopefully better experimental design will be applied when products such as PEG conjugates or genetically engineered polymers are ready for testing.

TL;DR: Evidence pointing toward the significance of free radicals formation in drug toxicity is summarized and the role of decreased free radical formation and enhanced free radical scavenging and detoxification in the development of anticancer drug resistance by a spectrum of tumor cell types is evaluated.

TL;DR: While SOD was protective at low doses in all models, protection was lost at higher doses in the isolated rat and rabbit hearts, and exacerbation of damage was seen in the in vivo rabbit hearts.

TL;DR: The large volume of circumstantial evidence presented here indicates that hyperthyroid muscular tissues undergo several biochemical changes that predispose them to free radical-mediated injury.

TL;DR: A major finding in the antioxidant enzymatic defense of insects is that these insects are lutein accumulators, a good quencher of activated forms of oxygen and free radicals.

TL;DR: It is proposed that B-ring oxidized oxysterols of human blood represent past interception of blood and tissue oxidants in vivo by cholesterol as an ordinary aspect of oxygen metabolism and constitute as in vivo antioxidant system.

TL;DR: Differences in the antioxidant potency of ubiquinols in membranes are suggested to result from differences in partitioning into membranes, intramembrane mobility and non-uniform distribution of Ubiquinols resulting in differing efficiency of interaction with oxygen and lipid radicals as well as different efficiency of ubiqu inols in regeneration of endogenous vitamin E.

TL;DR: It is demonstrated that the extracellular production of active oxygen species by dietary flavonols is not likely to occur in vivo but the potential for intracellular redox cycling may have toxicologic significance.

TL;DR: The plant-phenol 4-hydroxy-3-methoxyacetophenone (trivial name apocynin) is a strong inhibitor of neutrophil superoxide anion (O2-) release in vitro and was tested in collagen-induced arthritis in rats.

TL;DR: While the hrMn-SOD protects the reperfused heart at lower doses, it may exacerbate the damage at higher doses, giving an even sharper bell-shaped curve than seen with the hrCu,Zn- SOD.