1,3-Butadiene is a major monomer in the rubber and plastics industry and is one of the highest-production industrial chemicals in the United States. Although not highly acutely toxic to rodents, inhalation of concentrations as low as 6.25 ppm causes tumors in mice. Butadiene is oncogenic in rats, but much higher exposure concentrations are required than in mice. Chronic toxicity targets the gon...

There have been several suggestions of biomarkers that are specific to high LET radiation. Such a biomarker could significantly increase the power of epidemiological studies of individuals exposed to densely-ionising radiations such as alpha particles (e.g. radon, plutonium workers, individuals exposed to depleted uranium) or neutrons (e.g. radiation workers, airline personnel. We discuss here ...

The chromosomal composition of micronuclei (MN) induced by the model mutagens mitomycin (MMC) and colchicine (COL) as well as by acrylamide (AA) and the traditional Chinese medicine Tripterygium hypoglaucum (level) hutch (THH) in NIH 3T3 cells was analyzed by multicolor fluorescence in situ hybridization (FISH) using DNA probes for the centromere repeated minor satellite DNA and the telomeric h...

The multicopy λgt10-lacZ transgene shuttle vector of Muta™Mouse serves as an important tool for genotoxicity studies. Here, we describe a model for λgt10-lacZ transgene molecular structure, based on characterisation of transgenes recovered from animals of our intramural breeding colony. Unique nucleotide sequences of the 47 513 bp monomer are reported with GenBank® assigned accession numbers. B...

Largely on the basis of studies using the potent clastogen ionizing radiation, it has been widely assumed that up-regulation of the cyclin-dependent kinase inhibitor p21(waf1cip1) in cultured cells exposed to DNA-damaging agents is contingent upon the presence of functional p53 tumor suppressor protein. Nevertheless, we demonstrate here that the model mutagen 254-nm UV light induces p21(waf1cip...

From July 1965 until November 1971, New Zealand Defence Force Personnel fought in the Vietnam War. During this time the United States military forces sprayed more than 76,500,000 litres of phenoxylic herbicides over parts of Southern Vietnam and Laos. The most common herbicide sprayed was known as ‘Agent Orange’. All of the Agent Orange sprayed during the Vietnam War was contaminated with 2,3,7...

Clastogen induced chromosome breakage analysis is widely used for the differential diagnosis of Fanconi's anemia. Mitomycin-C (MMC) induced chromosome fragility test was performed on the cultured lymphocytes of 50 children with clinical suspicion of Fanconi's anemia. According to the results of the MMC test, the patients were divided into two subgroups: FA displaying typical sensitivity to MMC ...

A single-dose oral toxicity study was conducted to examine the qualitative and quantitative toxicity of a commercial-grade batch of dihydrocapsiate (4-hydroxy-3-methoxybenzyl 8-methylnonanoate; CAS No. 205687-03-2). Dihydrocapsiate was administered once by gavage to ICR mice at dose levels of 0 (vehicle) or 5000 mg/kg/day. No mortality was observed during the 14 day observation period following...

Cytogenetic biomarkers such as chromosomal aberrations (CAs), sister chromatid exchanges (SCEs) and micronuclei (MN) have been applied to the study of individuals exposed to known or potential genotoxic agents. Recent evidence also suggests the usefulness of MN tests for screening carriers of specific mutations that indicate cancer susceptibility . Nevertheless, these biomarkers have not demons...

The in vitro micronucleus (MN) assay is widely used to assess genotoxic potential of the test substances by measuring frequency of MN in cultured mammalian cells. Traditionally, MN frequency has been determined by microscopy. In recent years, a flow cytometric method for enumeration of MN has been developed, which significantly shortens analysis time and enhances assay throughput. However, a ma...