Zebra mussels, Dreissena polymorpha, were exposed to four directly acting reference clastogens (mitomycin C, bleomycin, dimethylarsinic acid and potassium chromate) under laboratory conditions. The aim was to examine the inducibility of micronuclei (MN) in haemocytes and gill cells. Positive responses were observed in both tissues for all four substances used under the given test conditions. Th...

In vitro cytogenetics has been established as a valid method for evaluating the genotoxic potential of chemical agents. Armstrong et al have described a simple, quantitative approach to in vitro cytotoxicity and genotoxicity testing by using Chinese hamster ovary (CHO) cells. This approach can also be sensitive and repeatable in an inter-laboratory setting, a prerequisite for routine testing of...

The thymine analog 5-chlorouridine, first reported in the 1950s as anti-tumor agent, is known as an effective mutagen, clastogen and toxicant as well as an effective inducer of sister-chromatid exchange. Recently, the first microorganism with a chemically different genome was reported; the selected Escherichia coli strain relies on the four building blocks 5-chloro-2'-deoxyuridine (ClU), A, C a...

Mutagens can be carcinogens, and traditionally, they have been identified in vitro using the Salmonella 'Ames' reverse mutation assay. However, prokaryotic DNA packaging, replication and repair systems are mechanistically very different to those in the humans we inevitably seek to protect. Therefore, for many years, mammalian cell line genotoxicity assays that can detect eukaryotic mutagens as ...

The potential reversibility of glandular stomach lesions induced by the clastogen, catechol, was examined in groups of male F344 rats treated continuously with 0.8% catechol in the diet for 12, 24, 48, 72, or 96 weeks. After a return to basal diet for 84, 72, 48, 24, and 0 weeks, respectively, the animals were killed for histopathological examination. Incidences of submucosal hyperplasia, adeno...

The Benchmark Dose (BMD) method is the favored approach for quantitative dose–response analysis where uncertainty measurements are delineated between upper (BMDU) and lower (BMDL) confidence bounds, or intervals (CIs). Little has been published on accurate interpretation of potency comparative analyses different test conditions. We highlight this by revisiting a previously in vitro genotoxicity...