Michael D. Shelby

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In order to assess the potential of cytogenetic determinations on peripheral blood lymphocytes as a means of monitoring human populations subject to low level occupational and environmental exposures to chemical mutagens and carcinogens, accurate baseline data are required. Accordingly, we have determined mean frequencies of chromosomal aberrations and of(More)
Four widely used in vitro assays for genetic toxicity were evaluated for their ability to predict the carcinogenicity of selected chemicals in rodents. These assays were mutagenesis in Salmonella and mouse lymphoma cells and chromosome aberrations and sister chromatid exchanges in Chinese hamster ovary cells. Seventy-three chemicals recently tested in(More)
Forty-nine chemicals were tested in a mouse bone marrow micronucleus test that employed three daily exposures by intraperitoneal injection. Bone marrow samples were obtained 24 hr following the final exposure. Twenty-five rodent carcinogens and 24 noncarcinogens were selected randomly from the 44 carcinogens and 29 noncarcinogens used by Tennant et al.(More)
Because of rampant concern that estrogenic chemicals in the environment may be adversely affecting the health of humans and wildlife, reliable methods for detecting and characterizing estrogenic chemicals are needed. It is important that general agreement be reached on which tests to use and that these tests then be applied to the testing of both man-made(More)
Acrylamide is an animal carcinogen and probable human carcinogen present in appreciable amounts in heated carbohydrate-rich foodstuffs. It is also a germ cell mutagen, inducing dominant lethal mutations and heritable chromosomal translocations in postmeiotic sperm of treated mice. Acrylamide's affinity for male germ cells has sometimes been overlooked in(More)
The highly conserved nature of the thyroid gland and the thyroid system among mammalian species suggests it is critical to species survival. Studies show the thyroid system plays a critical role in the development of several organ systems, including the reproductive tract. Despite its highly conserved nature, the thyroid system can have widely different(More)
Forty-two chemicals were tested for their ability to induce cytogenetic change in Chinese hamster ovary cells using assays for chromosome aberrations (ABS) and sister chromatid exchanges (SCE). These chemicals were included in the National Toxicology Program's evaluation of the ability of four in vitro short-term genetic toxicity assays to distinguish(More)