Author
Bruce N. Ames
Other affiliations: Boston Children's Hospital, Laboratory of Molecular Biology, Lawrence Berkeley National Laboratory ...read more
Bio: Bruce N. Ames is an academic researcher from Children's Hospital Oakland Research Institute. The author has contributed to research in topics: DNA damage & Oxidative stress. The author has an hindex of 158, co-authored 506 publications receiving 129010 citations. Previous affiliations of Bruce N. Ames include Boston Children's Hospital & Laboratory of Molecular Biology.
Topics: DNA damage, Oxidative stress, Cancer, DNA, Lipid peroxidation
Papers published on a yearly basis
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TL;DR: 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.
Abstract: We describe in this paper the general methods for using the Salmonella/microsome test as a mutagenesis screening system. The methods described include the standard plate test, the use and storage of the bacterial tester strains, preparation and use of the liver homogenates (S/sub 9/), and the methods of inducing the rats for elevated microsomal enzyme activity. The application of this test system to screening large numbers of compounds, and the interpretation of test results is also discussed.
7,323 citations
TL;DR: 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.
Abstract: The methods for detecting carcinogens and mutagens with the Salmonella mutagenicity test were described previously (Ames et al., 1975b). The present paper is a revision of the methods. Two new tester strains, a frameshift strain (TA97) and a strain carrying an ochre mutation on a multicopy plasmid (TA102), are added to the standard tester set. TA97 replaces TA1537. TA1535 and TA1538 are removed from the recommended set but can be retained at the option of the investigator. TA98 and TA100 are retained. We discuss other special purpose strains and present some minor changes in procedure, principally in the growth, storage, and preservation of the tester strains. Two substitutions are made in diagnostic mutagens to eliminate MNNG and 9-aminoacridine. Some test modifications are discussed.
7,256 citations
TL;DR: 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.
Abstract: Metabolism, like other aspects of life, involves tradeoffs. Oxidant by-products of normal metabolism cause extensive damage to DNA, protein, and lipid. We argue that this damage (the same as that produced by radiation) is a major contributor to aging and to degenerative diseases of aging such as cancer, cardiovascular disease, immune-system decline, brain dysfunction, and cataracts. Antioxidant defenses against this damage include ascorbate, tocopherol, and carotenoids. Dietary fruits and vegetables are the principal source of ascorbate and carotenoids and are one source of tocopherol. Low dietary intake of fruits and vegetables doubles the risk of most types of cancer as compared to high intake and also markedly increases the risk of heart disease and cataracts. Since only 9% of Americans eat the recommended five servings of fruits and vegetables per day, the opportunity for improving health by improving diet is great.
6,007 citations
TL;DR: Sucrose gradient centrifugation is found to be a suitable method for determining sedimentation coefficients of enzymes in protein mixtures and the sedimentation behavior of several of the enzymes in the pathway of histidine biosynthesis in S. typhimurium has been determined.
5,232 citations
TL;DR: 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.
Abstract: Beckman, Kenneth B., and Bruce N. Ames. The Free Radical Theory of Aging Matures. Physiol. Rev. 78: 547–581, 1998. — The free radical theory of aging, conceived in 1956, has turned 40 and is rapidl...
3,812 citations
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TL;DR: Human lymphocytes were exposed to X-irradiation or treated with H2O2 and the extent of DNA migration was measured using a single-cell microgel electrophoresis technique under alkaline conditions and this technique appears to be sensitive and useful for detecting damage and repair in single cells.
10,170 citations
TL;DR: There is growing evidence that aging involves, in addition, progressive changes in free radical-mediated regulatory processes that result in altered gene expression.
Abstract: At high concentrations, free radicals and radical-derived, nonradical reactive species are hazardous for living organisms and damage all major cellular constituents. At moderate concentrations, how...
9,131 citations
TL;DR: Evidence that the appropriate and inappropriate production of oxidants, together with the ability of organisms to respond to oxidative stress, is intricately connected to ageing and life span is reviewed.
Abstract: Living in an oxygenated environment has required the evolution of effective cellular strategies to detect and detoxify metabolites of molecular oxygen known as reactive oxygen species. Here we review evidence that the appropriate and inappropriate production of oxidants, together with the ability of organisms to respond to oxidative stress, is intricately connected to ageing and life span.
8,665 citations
TL;DR: The p53 mutational spectrum differs among cancers of the colon, lung, esophagus, breast, liver, brain, reticuloendothelial tissues, and hemopoietic tissues as mentioned in this paper.
Abstract: Mutations in the evolutionarily conserved codons of the p53 tumor suppressor gene are common in diverse types of human cancer. The p53 mutational spectrum differs among cancers of the colon, lung, esophagus, breast, liver, brain, reticuloendothelial tissues, and hemopoietic tissues. Analysis of these mutations can provide clues to the etiology of these diverse tumors and to the function of specific regions of p53. Transitions predominate in colon, brain, and lymphoid malignancies, whereas G:C to T:A transversions are the most frequent substitutions observed in cancers of the lung and liver. Mutations at A:T base pairs are seen more frequently in esophageal carcinomas than in other solid tumors. Most transitions in colorectal carcinomas, brain tumors, leukemias, and lymphomas are at CpG dinucleotide mutational hot spots. G to T transversions in lung, breast, and esophageal carcinomas are dispersed among numerous codons. In liver tumors in persons from geographic areas in which both aflatoxin B1 and hepatitis B virus are cancer risk factors, most mutations are at one nucleotide pair of codon 249. These differences may reflect the etiological contributions of both exogenous and endogenous factors to human carcinogenesis.
8,063 citations