Structural alterations to chromosomes constitute a significant portion of the genetic damage produced by most mutagenic agents. The pioneering experiments of Muller (1), in the case of ionizing radiations, and of Auerbach (2), in the case of nitrogen mustards, showed that chromosome aberrations are, quantitatively, a significant class of mutational events for both physical and chemical mutagens...

A large and extensive body of data on the use of human liver S9 fractions in the Salmonella mutagenicity test (Ames test) is presented; the data were obtained from a collaborative study by JEMS/BMS (Bacterial Mutagenicity Test Study Group) members and the Human and Animal Bridging Research Organization (HAB). In this study, the mutagenicity of 58 chemicals, many of which were judged to be human...

Positive results in the Ames test correlate well with carcinogenic potential in rodents. This correlation is not perfect because mutations are only one of many stages in tumour development. Also, situations can be envisaged where the mutagenic response may be specific to the bacteria or the test protocol, e.g., bacterial-specific metabolism, exceeding a detoxification threshold, or the inductio...

A method is described for concentrating mutagens/carcinogens from human urine about 200-fold for subsequent assay in the Salmonella/mammalian microsome mutagenicity test. The method is also applicable for other aqueous liquids and for other in vitro tests for mutagens/carcinogens. The urine (up to 500 ml) is put through a column with a 1.5-cm3 bed volume of XAD-2 (styrene-divinylbenzene polymer...

As micronuclei (MN) derive from chromosomal fragments and whole chromosomes lagging behind in anaphase, the MN assay can be used to show both clastogenic and aneugenic effects. The distinction between these phenomena is important, since the exposure studied often induces only one type of MN. This particularly concerns the use of MN as a biomarker of genotoxic exposure and effects, where differe...

Acrylamide is one of the most important contaminants in the environment. Acrylamide was shown to be a neurotoxicant, reproductive toxicant, and carcinogen in animals. There is consensus among international food safety groups that acrylamide in the diet should be assessed. In the present study, we surveyed by Gas Chromatography-Mass Spectrometry (GC-MS) the levels of acrylamide in 23 foods marke...

A recent analysis by Kirkland et al. [Kirkland, D., Aardema, M., Henderson, L. and Müller, L. (2005) Evaluation of the ability of a battery of 3 in vitro genotoxicity tests to discriminate rodent carcinogens and non-carcinogens. I. Sensitivity, specificity and relative predictivity. Mutat. Res. 584, 1-256] demonstrated an extremely high false positive rate for in vitro genotoxicity tests when c...

Most of the many published guidelines on how to conduct mutagenicity tests do not give advice or references on statistical analysis of data. The U.K. Environmental Mutagen Society decided to address this omission, and in 1985 established 8 working groups comprising genetic toxicologists from all sectors of the science, plus at least 2 statisticians per group, to produce statistics guidelines on...

Figure 1: Protein 1CRN, Crambin, is a 46 amino acid protein composed of two alpha helices and a short anti-parallel beta sheet (1(a)). When rigidity analysis is performed on the non-mutated form of Crambin, the majority of the atoms in the proteins core are part of a single large rigid cluster (shown in purple))(1(b)). KINARI-Mutagen was used to generate several in-silico mutants of crambin. Wh...

Thirty compounds of various chemical classes were investigated for mutagenicity in a collaborative study (three laboratories) using Salmonella typhimurium TA102. With five compounds, hydrazine sulfate, phenylhydrazine, hydralazine, glutardialdehyde, and glyoxal, mutagenicity was detected by all laboratories. Formaldehyde was assessed as weakly mutagenic in only one of three laboratories. The re...