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Revised methods for the Salmonella mutagenicity test.
Two new tester strains, a frameshift strain and a strain carrying an ochre mutation on a multicopy plasmid (TA102), are added to the standard tester set and two substitutions are made in diagnostic mutagens to eliminate MNNG and 9-aminoacridine. Expand
The free radical theory of aging matures.
The status of the free radical theory of aging is reviewed, by categorizing the literature in terms of the various types of experiments that have been performed, which include phenomenological measurements of age-associated oxidative stress, interspecies comparisons, dietary restriction, and the ongoing elucidation of the role of active oxygen in biology. Expand
Methods for detecting carcinogens and mutagens with the Salmonella/mammalian-microsome mutagenicity test.
The methods described include the standard plate test, the use and storage of the bacterial tester strains, preparation and use of the liver homogenates, and the methods of inducing the rats for elevated microsomal enzyme activity. Expand
Publisher Summary This chapter discusses the assay of inorganic phosphate, total phosphate, and phosphatases. The phosphomolybdate complex is reduced by ascorbic acid. The method is about seven timesExpand
Oxidants, antioxidants, and the degenerative diseases of aging.
It is argued that this damage to DNA, protein, and lipid is a major contributor to aging and to degenerative diseases of aging such as cancer, cardiovascular disease, immune-system decline, brain dysfunction, and cataracts. Expand
Bilirubin is an antioxidant of possible physiological importance.
The data support the idea of a "beneficial" role for bilirubin as a physiological, chain-breaking antioxidant. Expand
Folate deficiency causes uracil misincorporation into human DNA and chromosome breakage: implications for cancer and neuronal damage.
  • B. Blount, M. Mack, +6 authors B. Ames
  • Biology, Medicine
  • Proceedings of the National Academy of Sciences…
  • 1 April 1997
Both high DNA uracil levels and elevated micronucleus frequency (a measure of chromosome breaks) are reversed by folate administration, which could contribute to the increased risk of cancer and cognitive defects associated with folate deficiency in humans. Expand
Uric acid provides an antioxidant defense in humans against oxidant- and radical-caused aging and cancer: a hypothesis.
It is shown that, at physiological concentrations, urate reduces the oxo-heme oxidant formed by peroxide reaction with hemoglobin, protects erythrocyte ghosts against lipid peroxidation, and protects ERYthrocytes from peroxidative damage leading to lysis. Expand
Oxidative damage and mitochondrial decay in aging.
Evidence supports the suggestion that age-associated accumulation of mitochondrial deficits due to oxidative damage is likely to be a major contributor to cellular, tissue, and organismal aging. Expand
Normal oxidative damage to mitochondrial and nuclear DNA is extensive.
The oxidized base, 8-hydroxydeoxyguanosine (oh8dG), 1 of approximately 20 known radiation damage products, has been assayed in the DNA of rat liver and may be responsible for the observed high mutation rate of mtDNA. Expand