Publications by authors named "Alan A Edwards"

The aim of this study was to apply the fluorescence in situ hybridization (FISH) translocation assay in combination with chromosome painting of peripheral blood lymphocytes for retrospective biological dosimetry of Mayak nuclear power plant workers exposed chronically to external gamma radiation. These data were compared with physical dose estimates based on monitoring with badge dosimeters throughout each person's working life. Chromosome translocation yields for 94 workers of the Mayak production association were measured in three laboratories: Southern Urals Biophysics Institute, Leiden University Medical Center and the former Health Protection Agency of the UK (hereinafter Public Health England).

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Purpose: To compare the development of intestinal adenomas following neutron and X-ray exposure of Apc(Min/+) mice (Apc - adenomatous polyposis coli; Min - multiple intestinal neoplasia).

Materials And Methods: Adult mice were exposed to acute doses of X-rays or fission neutrons. Tumour counting was undertaken 200 days later and samples were taken for Loss of Heterozygosity (LOH) analysis.

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Controversy regarding potential health risks from increased use of medical diagnostic radiologic examinations has come to public attention. We evaluated whether chromosome damage, specifically translocations, which are a potentially intermediate biomarker for cancer risk, was increased after exposure to diagnostic X-rays, with particular interest in the ionizing radiation dose-response below the level of approximately 50 mGy. Chromosome translocation frequency data from three separately conducted occupational studies of ionizing radiation were pooled together.

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The U.S. population has nearly one radiographic examination per person per year, and concern about cancer risks associated with medical radiation has increased.

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Informative studies of cancer risks associated with medical radiation are difficult to conduct owing to low radiation doses, poor recall of diagnostic X rays, and long intervals before cancers occur. Chromosome aberrations have been associated with increased cancer risk and translocations are a known radiation biomarker. Seventy-nine U.

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Chromosome translocations in peripheral blood lymphocytes of normal, healthy humans increase with age, but the effects of gender, race, and cigarette smoking on background translocation yields have not been examined systematically. Further, the shape of the relationship between age and translocation frequency (TF) has not been definitively determined. We collected existing data from 16 laboratories in North America, Europe, and Asia on TFs measured in peripheral blood lymphocytes by fluorescence in situ hybridization whole chromosome painting among 1933 individuals.

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Measurement of chromosome translocations in peripheral blood lymphocytes has been used to quantify prior exposure to ionizing radiation, including for workers exposed to low, chronic doses. We assessed translocation frequencies in a subset of U.S.

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Data on the induction of small intestinal tumors, predominantly adenomas, by X radiation in Apc(Min/+) mice are reported. Comparison of these incidences with estimates of radiation-induced direct single gene mutation frequencies taken from the literature support the hypothesis that direct mutational loss of Apc+ is the sole requirement for initiation of adenoma. Furthermore, estimates of radiation-induced initiation of adenoma per target stem cell in this animal model are similar to or less than radiation-induced direct somatic gene mutation frequencies.

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