Ames bacterial test

Valeraldehyde caused chromosomal and DNA effects in mammalian cells in culture but was not mutagenic in an Ames bacterial test." ... 

No evidence of mutagenicity was seen in Ames bacterial tests. 

A most interesting side feature is that Naessens claims that the condition of somatids in the blood can be used to detect the initiation of cancer up to 18 months before chnical symptoms appear (Walters, 1993, p. 31). It may also be mentioned in passing that there is the Ames bacterial test, which serves as an indicator of possible cancer activity in the body (Heinerman, 1984, p. 152). 

The long latent periods involved in development of cancers make correlation of chemical exposures and disease extremely difficult. This can be countered pardy with tests on naturally short-Hved animals. Tests on bacteria, eg, the Ames test, may permit rapid detection of cancer potential, although there is no direct relationship between the results of bacterial tests and the effects of the tested chemicals on humans (56). 

The Ames salmonella-microsome test is a principal sensitive mutagen screening test. Compounds are tested on the mutants of Salmonella typhimurium for reversion from a histidine requirement back to prototrophy. A positive result is seen by the growth of revertant bacteria (which do not require an external histidine source). A microsomal activation system should be included in this assay. The use of five different bacterial test strains are generally required. 

A variety of methods are available to test a chemical for mutagenicity, i.e., its effect on the genetic material. The Ames Test has gained most recognition as a shortterm test [23],This is a bacterial test which allows fast performance and requires limited expense. Its correlation with the mutagenicity of mammals or even with a carcinogenic effect on mammals or humans has repeatedly been tested [24], but remains controversial. 

Cyclopentane was not mutagenic in the Ames bacterial assay it was also negative in vitro in the mouse lymphoma assay and in the micronucleus test. ... 

Ames, B.N., Lee, F.D. and Durston, W.E. (1973) An improved bacterial test system for the detection and classification of mutagens and carcinogens. Proceeding of the National Academy of Sciences of the United States of America, 70, 782-786. 

Other, more sensitive, tests have been suggested for the evaluation of potential carcinogenic risk of exposure to chemicals. These include the bacterial mutagenesis test devised by Dr. Bruce Ames ( ). This test has been applied to many of the amines listed in Table 1, both alone and after reaction with nitrite in weakly acid solution, followed by neutralization and application to the bacteria. In Table 3 are given the results of a number of such tests, together with comparison of the results of chronic... 

De Flora, S., Zanacchi, R, Camoirano, A., Bennicelli, C. Badolati, G.S. (1984) Genotoxic activity and potency of 135 compounds in the Ames reversion test and in a bacterial DNA-repair test. Matot. Res., 133, 161-198... 

In a bacterial test system [ames test] no increase of mutagenicity was detected without or in presence of a metabolic system [3.213]. 

Four bioassays a) 30 min acute bacterial test (Vibrio fischeri) b) 72h algal test (Pseudokirchneriella subcapitata) c) Acute (24h) and chronic (28d) crustacean test (Daphnia magna) d) 48h plate incorporation AMES test (Salmonella typhimurium his-with TA 97a, 98, 100, 102) Industrial solid waste leachates Batch leaching test with demineralized water followed by paper filtration (crude leachate), Liquid/liquid extraction (organic extract), lyophilization (lyophilized extract. pH adjusted according to tolerance of organisms and 0.22 pm filtration for AMES test... 

The stepwise procedure usually starts with the determination of the LD50, a short term repeated exposure test in rodents and the evaluation of genotoxicity by an in vitro bacterial test system (Ames-test) and for cytogenicity in mammalian cells. In case of indication for genotoxicity the results are verified in vivo usually by the mouse bone marrow micronucleus test. For further evaluation the compound additional tests including studies on toxicokinetics or the toxic mechanisms will follow. Such information provides information on the reactivity of the test compound, its... 

In vitro tests in bacteria, for example the well-known Ames test, and tests in mammahan cells are used to show if a chemical is able to damage DNA and cause a mutation, fn the bacterial tests, extracts from mammalian liver (usually from a rat) have to be added to provide the enzymes that convert chemicals into products that might react with DNA. 

The micronucleus assay is one type of study recommended by the FDA Redbook and ICH guidelines as part of a standard genetic toxicology battery. The other assays include the Ames (bacterial reverse mutation) and mouse lymphoma tests. 

Cytogenetic examination of bone marrow cells showed no increase in aberrations in maternal and neonatal rats following maternal oral exposure to a DeBDE and NoBDE mixture. In vitro assays found that DeBDE did not induce gene mutations in several bacterial tests (Ames assays) or in mammalian cells. DeBDE also did not induce chromosomal aberrations in Chinese hamster ovary cells. However, exposure to the congeners 2,2, 4,4 -tetra-BDE, 3,4-diBDE, and 2-monoBDE caused increased recombinogenic activity at the HGPRT locus in several cell lines. 

Using the Ames Salmonella test, prometryn was not mutagenic when tested up to the cytotoxic solubility limits. Prometryn was negative for bacterial DNA repair and gene mutation in an unscheduled DNA synthesis test using rat hepatocytes. 

Ames test. A simple bacterial test for carcinogens, based on the assumption that carcinogens are mutagens. Named after its inventor Bruce Ames. Somewhat less favored than it used to be, because of the idea that compounds causing cells to grow more rapidly will sometimes result in cancer. 

The Ames test is thus typically a bacterial test to assess the genotoxicity of chemicals or environmental compounds but it can be used also to detect the presence of mutagens (and hence reflect a mutagen exposure) in human body fluids, especially in the urine. The Ames test thus can be used as a tool for human biomonitoring studies as well. 

Bacterial mutagenicity Ames Salmonella) test Gene mutations 471 870.5100... 

As with most bacterial tests, plate-counting techniques are used to determine the number of revertant bacteria. For the Ames test, plate counting requires a 48-hour growth period, plus time to count both the test plates and control plates used to monitor spontaneous reversion. 

The testing of these representative materials in vitro in bacterial test systems (Ames assay) and in vivo in mammalian (micronucleus test) systems showed no evidence of mutagenic or genotoxic potential. These results are further supported by the lack of positive findings in the Base test. 

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