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Radiation induced micrencephaly in guinea pigs

Description: A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely rela… more
Date: January 1, 1991
Creator: Wagner, L.K.; Johnston, D.A. & Felleman, D.J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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DNA repair in spermatocytes and spermatids of the mouse

Description: When male mice are exposed to chemical agents that reach the germ cells several outcomes are possible in terms of the germ cell unscheduled DNA synthesis (UDS) response and removal of DNA adducts. It is possible that: the chemical binds to the DNA and induces a UDS response with concomittant removal of DNA adducts; the chemical binds to the DNA but no UDS response is induced; or the chemical does not bind to DNA and no UDS is induced. Many mutagens have been shown to induce a UDS response in po… more
Date: January 1, 1982
Creator: Sega, G.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Qualitative analysis of mouse specific-locus mutations: information on genetic organization, gene expression, and the chromosomal nature of induced lesions

Description: Analysis of mouse specific-locus (SL) mutations at three loci has identified over 33 distinct complementation groups - most of which are probably overlapping deficiencies - and 13 to 14 new functional units. The complementation maps that have been generated for the d-se and c regions include numerous vital functions; however, some of the genes in these regions are non-vital. At such loci, hypomorphic mutants must represent intragenic alterations, and some viable nulls could conceivably be intra… more
Date: January 1, 1982
Creator: Russell, L.B.
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Partner: UNT Libraries Government Documents Department
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Low-level x-irradiation of the brain during development morphological, physiological, and behavioral consequences. Final report, September 1, 1976--August 31, 1977

Description: Morphological research was continued in the following areas: glial recovery patterns in the rat corpus callosum after x-irradiation during infancy; the prenatal development of the deep nuclei and cortex of the cerebellum; the prenatal development of the inferior olive, pontine gray and the precerebellar reticular nuclei; and the postnatal development of the olfactory bulb. In these studies autoradiography and x-irradiation were among the experimental techniques utilized. The behavioral studies,… more
Date: January 1, 1977
Creator: Altman, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Delayed radiation injury of gut-exposed and gut-shielded mice. II. The decrement in life span

Description: Two mouse strains (RF/J and C57B1/6J) were exposed to x-ray doses totaling 400, 800, and 1200 rad. Total doses were given in 200-rad fractions at 7-day intervals to the whole body, gut only, or bone tissue with the gut shielded. Animals were anesthetized during exposure. Two control groups were used. A sham control group was anesthetized but not exposed to x rays, and another control group received neither anesthesia nor x-radiation. All mice were retained in a standard laboratory environment f… more
Date: January 1, 1978
Creator: Spalding, J.F.; Archuleta, R.F. & Prine, J.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Mammary carcinogenesis in rats: basic facts and recent results in Brookhaven

Description: Some research results from experiments investigating neutron-induced mammary carcinogenesis in rats are presented. The additive effects of neutrons and 3-methylcholanthrene on mammary adenocarcinoma were determined. Synergism between diethylstilbestrol and neutrons was likewise studied. Differences in mammary neoplastic response between strains of laboratory rats was also investigated. (ACR)
Date: January 1, 1982
Creator: Shellabarger, C.J.; Stone, J.P. & Holtzman, s.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Late biological effects of ionizing radiation as influenced by dose, dose rate, age at exposure, and genetic sensitivity to neoplastic transformation. [Gamma radiation, mice]

Description: A most comprehensive investigation is in progress at the Los Alamos Scientific Laboratory to study the late biological effects of whole-body exposure to gamma irradiation as they may be influenced by total dose, dose rate, age at exposure, and genetic background. Strain C57B1/6J mice of four age groups (newborn, 2, 6, and 15 months) were given five doses (20, 60, 180, 540, and 1620 rad) of gamma rays, with each dose being delivered at six dose rates (0.7, 2.1, 6.3, 18.9, 56.7 rad/day and 25 rad… more
Date: January 1, 1978
Creator: Spalding, J.F.; Prine, J.R. & Tietjen, G.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Problems and solutions in the estimation of genetic risks from radiation and chemicals

Description: Extensive investigations with mice on the effects of various physical and biological factors, such as dose rate, sex and cell stage, on radiation-induced mutation have provided an evaluation of the genetics hazards of radiation in man. The mutational results obtained in both sexes with progressive lowering of the radiation dose rate have permitted estimation of the mutation frequency expected under the low-level radiation conditions of most human exposure. Supplementing the studies on mutation … more
Date: January 1, 1980
Creator: Russell, W.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Damage and repair of irradiated mammalian brain

Description: We have demonstrated that focal charged particle irradiation of the rabbit brain can create well-defined lesions which are observable by nuclear magnetic resonance imaging (NMR) and positron emission tomography (PET) imaging techniques. These are similar, in terms of location and characteristic NMR and PET features, to those that occur in the brain of about 10% of clinical research human subjects, who have been treated for intracranial vascular malformations with stereotactic radiosurgery. Thes… more
Date: July 1, 1989
Creator: Frankel, K.; Lo, E.; Phillips, M.; Fabrikant, J.; Brennan, K.; Valk, P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spermatogonial stem cell renewal following irradiation

Description: The spermatogonial cell renewal system can maintain function and a steady level of cell population for relatively long periods of continuous low-level irradiation indicating that there does not appear to be a serious accumulation, over many generations, of damage affecting proliferation. Provided the dose-rate is quite low, there is an effective selective removal of damaged cells with almost complete repair of cellular nonlethal damage. At dose-rates greater than 2 rad/day, spermatogonia are ve… more
Date: May 1, 1979
Creator: Fabrikant, Jacob I.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Metabolism and biological effects of alpha-emitting radionuclides

Description: The emphasis of much of the current and planned research on the toxicity of alpha-emitting radionuclides is directed toward the complexities of actual and potential conditions of occupational environmental exposures of human beings. These, as well as the more limited studies on mechanisms of biological transport and effects, should increase our ability to predict health risks more accurately and to deal more confidently with human exposures, if and when they occur.
Date: May 1, 1979
Creator: Bair, W. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Cytometric analysis of shape and DNA content in mammalian sperm

Description: Male germ cells respond dramatically to a variety of insults and are important reproductive dosimeters. Semen analyses are very useful in studies on the effects of drugs, chemicals, and environmental hazards on testicular function, male fertility and heritable germinal mutations. Sperm were analyzed by flow cytometry and slit-scan flow analysis for injury following the exposure of testes to mutagens. The utility of flow cytometry in genotoxin screening and monitoring of occupational exposure wa… more
Date: October 10, 1983
Creator: Gledhill, B.L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Radiogenic neoplasia in thyroid and mammary clonogens

Description: We have developed rat thyroid and mammary clonogen transplantation systems for the study of radiogenic cancer induction at the target cell level in vivo. The epithelial cell populations of both glands contain small subpopulations of cells which are capable of giving rise to monoclonal glandular structures when transplanted and stimulated with appropriate hormones. During the end of the last grant year and the first half of the current grant year, we have completed analyses and summarized for pu… more
Date: May 31, 1991
Creator: Clifton, K.H.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effects of low-level radiation upon the hematopoietic steam cell: implications for leukemogenesis

Description: These studies have addressed firstly the effect of single small doses of x-ray upon murine hematopoietic stem cells to obtain a better estimate of the D/sub q/. It is small, of the order of 20 rads. Secondly, a dose fractionation schedule tht does not kill or perturb the kinetics of hemopoietic cell proliferation was sought in order to investigate the leukemogenic potential of low level radiation upon an unperturbed hemopoietic system. The studies reported herein show tht 1.25 rads every other … more
Date: January 1, 1983
Creator: Cronkite, E. P.; Bond, V. P.; Carsten, A. L.; Miller, M. E. & Bullis, J. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Hematopoietic cell crisis: An early stage of evolving myeloid leukemia following radiation exposure

Description: Under select radiological conditions, chronic radiation exposure elicits a high incidence of myeloproliferative disease, principally myeloid leukemia (ML), in beagles. Previously we demonstrated that for full ML expression, a four-stage preclinical sequence is required, namely (1) suppression, (2) recovery, (3) accommodation, and (4) preleukemic transition. Within this pathological sequence, a critical early event has been identified as the acquisition of radioresistance by hematopoietic progen… more
Date: January 1, 1990
Creator: Seed, T.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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NMR imaging and spectroscopy of the mammalian central nervous system after heavy ion radiation

Description: NMR imaging, NMR spectroscopic, and histopathologic techniques were used to study the proton relaxation time and related biochemical changes in the central nervous system after helium beam in vivo irradiation of the rodent brain. The spectroscopic observations reported in this dissertation were made possible by development of methods for measuring the NMR parameters of the rodent brain in vivo and in vitro. The methods include (1) depth selective spectroscopy using an optimization of rf pulse e… more
Date: September 1, 1984
Creator: Richards, T.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Cytometric analysis of mammalian sperm for induced morphologic and DNA content errors

Description: Some flow-cytometric and image analysis procedures under development for quantitative analysis of sperm morphology are reviewed. The results of flow-cytometric DNA-content measurements on sperm from radiation exposed mice are also summarized, the results related to the available cytological information, and their potential dosimetric sensitivity discussed. (ACR)
Date: June 27, 1983
Creator: Pinkel, D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Division of Biological and Medical Research research summary 1984-1985

Description: The Division of Biological and Medical Research at Argonne National Laboratory conducts multidisciplinary research aimed at defining the biological and medical hazards to man from energy technologies and new energy options. These technically oriented studies have a strong base in fundamental research in a variety of scientific disciplines, including molecular and cellular biology, biophysics, genetics, radiobiology, pharmacology, biochemistry, chemistry, environmental toxicology, and epidemiolo… more
Date: August 1, 1985
Creator: Barr, S.H. (ed.)
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Study on the induction of thyroid tumors in rats using x irradiation in conjunction with a goitrogen. [1 methyl--2 mercaptoimidazole (methimazole)]

Description: The influence of acute localized thyroid x irradiation and chronic goitrogen administration, separately or combined, on thyroid tumor formation in mature female rats was studied. In the first experiment, the radiation doses were 0, 80, 160, 320, or 640 rads, and the dosages of goitrogen were 0, 4, or 40 parts per million (ppM) of 1 methyl - 2 mercaptoimidazole (MMI). The incidence of rats with thyroid tumors in any treated group receiving 0 or 4 ppM MMI was not significantly greater than the in… more
Date: January 1, 1979
Creator: Mahler, P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Low dose neutron late effects: Cataractogenesis

Description: The work is formulated to resolve the uncertainty regarding the relative biological effectiveness (RBE) of low dose neutron radiation. The study exploits the fact that cataractogenesis is sensitive to the inverse dose-rate effect as has been observed with heavy ions and was an endpoint considered in the follow-up of the A-bomb survivors. The neutron radiations were initiated at the Radiological Research Accelerator facility (RARAF) of the Nevis Laboratory of Columbia University. Four week old (… more
Date: December 1, 1991
Creator: Worgul, B. V.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Relationship between unscheduled DNA synthesis and mutation induction in male mice

Description: Unscheduled DNA synthesis (UDS) induced in the germ cells of male mice by chemical and physical agents can be studied in vivo by making use of the timing of spermatogenesis and spermiogenesis. In meiotic and post-meiotic germ-cell stages UDS occurs from leptotene through mid-spermatid stages but is not detected in later stages. No consistent correlation has been seen between the occurrence of UDS in the germ cells and reduced dominant-lethal frequencies or reduced specific-locus mutation freque… more
Date: January 1, 1979
Creator: Sega, G. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Radiation-induced dominant skeletal mutations in mice: mutation rate, characteristics, and usefulness in estimating genetic hazard to humans from radiation

Description: The work discussed in this paper represents a major advance in the difficult task of trying to estimate the effects that an increase in mutation frequency would have on human health. Male mice were bred to three females prior to being killed and skeleton studies made. Guidelines were instituted for checking progeny mutations. Surprising results showed a mutation frequency of 1.4% per gamete where none would have been expected. It is now clear that mice can be greatly deformed without showing ex… more
Date: May 1, 1979
Creator: Selby, P. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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