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in subjects: "Rbe"

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TRITOX: a multiple parameter evaluation of tritium toxicity

The increased use of nuclear reactors for power generation will lead to the introduction of tritium into the environment. The need for assessing possible immediate and long-term effects of exposure to this tritium led to the development of a broad program directed towards evaluating the possible somatic and genetic effects of continuous exposure to tritiated water (HTO). Among the parameters measured are the genetic, cytogenetic, reproductive efficiency, growth, nonspecific lifetime shortening,… more

Date: January 1, 1982

Creator: Carsten, A.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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BIOLOGICAL AND MEDICAL RESEARCH DIVISION ANNUAL REPORT, 1967

No Description Available.

Date: December 31, 1967

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Neutron-induced mutation experiments. Progress report, March 1, 1977--February 28, 1978. [Drosophila female gonial cell exposure]

Experiments have been carried out to study the relative mutagenic effectiveness for Drosophila female germ cells of neutrons of different energies employing X-linked recessive lethal and specific locus mutation tests. The energies and doses employed to date to study X-linked lethals are 0.43 MeV (500, 1000, 1500, 1900 R (in progress)), 0.68 MeV (250, 500, 1000, 1500 R), 2 MeV (250, 500, 1000, 1500, 2000 R), 6 MeV (250, 500, 1500, 3000 R) and 15 MeV (250, 500, 1000, 1500, 3000 R). 0.43-MeV neutr… more

Date: November 1, 1977

Creator: Abrahamson, S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Cancer risks and neutron RBE's from Hiroshima and Nagasaki

The new radiation dose estimates for Hiroshima and Nagasaki are here combined with epidemiologic data from the A-bomb survivors and examined radiobiologically for compatability with other human and experimental data. The new doses show certain improvements over the original T65 doses. However, they suggest for chronic granulocytic leukemia, total malignancies, and chromosome aberrations, at neutron doses of 1 rad, RBEs in excess of 100, higher than expected from other findings. This and other i… more

Date: April 30, 1982

Creator: Dobson, R.L. & Straume, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Gene conversion in yeast as a function of linear energy transfer (LET) for low-LET radiation

The relative biological effectiveness (RBE) for low-LET radiation is known to depend on such factors as LET and dose rate. Microdosimetric calculations indicate that the biological target size could also be an important parameter, and calculations predict that the RBE for effects produced by hits in target sizes below about 100 nm should be unity for all low LET radiation. We have measured that RBE for gene conversion in yeast (a small target) for five different low LET photon sources, and the … more

Date: May 1, 1992

Creator: Unrau, P.; Morrison, D.P. (Pacific Northwest Lab., Richland, WA (United States)) & Johnson, J.R. (Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Photon-activation therapy

Photon Activation Therapy (PAT) is a technique in which radiation dose to tumor is enhanced via introduction of stable /sup 127/I in the form of iodinated deoxyuridine (IdUrd). Stimulation of cytotoxic effects from IdUrd is accomplished by activation with external (or implanted) radiation sources. Thus, accumulations of this nucleoside in actively competing cellpools do not preclude therapy in so far as such tissues can be excluded from the radiation field. Calculations show that 5% replacement… more

Date: January 1, 1982

Creator: Fairchild, R.G. & Bond, V.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Workshop on radiobiological effectiveness of neutrons

The radiobiological effectiveness (RBE) of neutrons has become the subject of some heated discussions in both scientific and radiation-protection oriented communities. This has become especially so since the realization that neutron exposures of A-bomb survivors in Hiroshima were considerably lower than previously assumed, thus ''devaluating'' the importance of what we thought was a solid human data base. At the same time, more recent data from radiobiological research appeared to indicate that… more

Date: September 1, 1985

Creator: Stapleton, G. E.; Thomas, R. G. & Thiessen, J. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation enhancement with /sup 127/I-deoxyuridine

A technique for radiation enhancement of photon radiotherapy is outlined. High LET radiations in the form of Auger electron distributions are generated by photoactivation of stable iodine incorporated as iodinated deoxyuridine (IdUrd). Of the several halogenated deoxyribonucleosides evaluated, IdUrd was found to be the only thymidine analog providing effective photoactivation. This mechanism is combined with radiation sensitization to produce an overall radiation enhancement. Calculations show … more

Date: June 1, 1982

Creator: Fairchild, R.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Low-exposure tritium radiotoxicity in mammals

Studies of tritium radiotoxicity involving chronic /sup 3/H0H exposures in mammals demonstrate in both mice and monkeys that biological effects can be measured following remarkably low levels of exposure - levels in the range of serious practical interest to radiation protection. These studies demonstrate also that deleterious effects of /sup 3/H beta radiation do not differ significantly from those of gamma radiation at high exposures. In contrast, however, at low exposures tritium is signific… more

Date: February 11, 1982

Creator: Dobson, R.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiobiology of pions at LAMPF

Recent radiobiology data for pion beams used in therapy are presented. The biological systems used were cultured cells suspended in gelatin and intestinal crypt assay. The importance of fast neutrons from pion stars in large treatment volumes is discussed. The data for compensating the depth dose distribution to produce uniform cell killing across the peak region are presented. The changes in biological effectiveness with peak width for pion beams (unlike heavy ions) are small because of fast n… more

Date: January 1, 1982

Creator: Raju, M.R. & Tokita, N.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Characterization of ionizing radiation damage in DNA. Final report, February 1, 1977--September 30, 1977. [Gamma radiation, fast neutrons, uv radiation]

An experimental method for the measurement of covalent DNA-protein cross-links in bacteriophage T7 based on phenol-water countercurrent distribution has been developed and a statistical model for quantitative interpretation of these measurements has been devised. It has been found that DNA-protein cross links accumulate linearly with dose in response to exposure to /sup 60/Co gamma radiation at a rate .05 to .20 times the rate of accumulation of double strand breaks if phage are exposed in high… more

Date: January 1, 1977

Creator: Hawkins, R. B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Early and continuing effects of combined alpha and beta irradiation of the lung:

This report summarizes an inhalation exposure experiment that concerns early and continuing effects of combined alpha and beta irradiation of the lung of rats. Both morbidity at 18 months and mortality within 18 months after exposure were examined for rats exposed to the beta-emitter /sup 147/Pm, the alpha-emitter /sup 238/Pu, or both combined. The results were used to validate hazard-function models that were developed (1)for pulmonary functional morbidity at 18 months and (2) for lethality fr… more

Date: March 1, 1988

Creator: Scott, B. R.; Hahn, F. F.; Snipes, M. B.; Newton, G. J.; Eidson, A. F.; Mauderly, J. L. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Updating the tritium quality factor: the argument for conservatism

Estimated doses resulting from tritium releases to the environment are linearly dependent upon the quality factor (Q) chosen for tritium beta radiation. In 1969 the International Commission on Radiological Protection (ICRP) recommended using 1 as the Q for all low energy beta radiation. Considerable improvements have been made in evaluating exposures to tritium at very low dose rates and in refining physiological and biological endpoints since the 1969 ICRP recommendations. This study summarize… more

Date: January 1, 1980

Creator: Till, J. E.; Etnier, E. L. & Meyer, H. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Criteria for the selection of nuclides for radioimmunotherapy

This report describes many factors that need to be considered if radioimmunotherapy is to become a commonplace reality. For beta-emitting radionuclides, two physical features of importance are half-life and energy, with the latter determining the range. These features must be matched to the pharmacokinetics of the carrier and the distribution of the radionuclide, both macroscopically and microscopically. Alpha-particle emitters could be considered for cells that are readily accessible to the la… more

Date: January 1, 1986

Creator: Adelstein, S. J. & Kassis, A. I.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Genetic changes in Mammalian cells transformed by helium cells

Midterm Syrian Hamster embryo (SHE) cells were employed to study high LET-radiation induced tumorigenesis. Normal SHE cells (secondary passage) were irradiated with accelerated helium ions at an incident energy of 22 MeV/u (9--10 keV/{mu}m). Transformed clones were isolated after growth in soft agar of cells obtained from the foci of the initial monolayer plated postirradiation. To study the progression process of malignant transformation, the transformed clones were followed by monolayer subcu… more

Date: November 1, 1990

Creator: Durante, M.; Grossi, G. (Naples Univ. (Italy). Dipt. di Scienze Fisiche); Yang, T.C. & Roots, R. (Lawrence Berkeley Lab., CA (USA))

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

RBE (relative biological effectiveness) of tritium beta radiation to gamma radiation and x-rays analyzed by both molecular and genetic methods

The relative biological effectiveness (RBE) of tritium beta radiation to /sup 60/Co gamma radiation was determined using sex-linked recessive lethals (SLRL) induced in Drosophila melanogaster spermatozoa as the biological effect. The SLRL test, a measure of mutations induced in germ cells transmitted through successive generations, yields a linear dose-response curve in the range used in these experiments. From these ratios of the slopes of the /sup 3/H beta and the /sup 60/ Co gamma radiation … more

Date: January 1, 1988

Creator: Lee, W.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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New particles and their application in medicine

In recent years there has been increasing interest in the use of new particle beams for various medical applications. The particles being used, fast neutrons, protons, helium ions, negative pions, and heavy ions, have in fact been known and studied for over forty years. They are new only in the sense that, until recently, the medical community has had little experience with them in the clinic. The applications of these new particles to clinical medicine, primarily in the areas of tumor radiothe… more

Date: September 1, 1979

Creator: Curtis, S.B.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Cancer risks and neutron RBE's from Hiroshima and Nagasaki

The new radiation dose estimates for Hiroshima and Nagasaki are radiobiologically examined for compatability with other human and experimental data. The new doses show certain improvements over the original T65 doses. However, they suggest for chronic granulocytic leukemia, total malignancies, and chromosome aberrations, at neutron doses of 1 rad, RBEs in excess of 100, higher than expected from other findings. This and other indications suggest that either there are unrecognized systematic pro… more

Date: March 25, 1982

Creator: Dobson, R.L. & Straume, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tritium toxicity program in the Medical Department, Brookhaven National Laboratory

It is possible to detect somatic, cytogenetic and genetic effects resulting from exposures at 33 to 100 times the mpc's for tritiated water (HTO). The reduction in bone marrow cells in animals maintaining normal total cellularity demonstrate both the presence of an effect at the primitive cell level as well as the animal's ability to compensate for this effect by recruiting stem cells from the G/sub 0/ resting state. This evidence of damage together with the observed cytogenetic changes leads o… more

Date: January 1, 1983

Creator: Carsten, A.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation effects in space

The paper discusses the radiation environment in space that astronauts are likely to be exposed to. Emphasis is on proton and HZE particle effects. Recommendations for radiation protection guidelines are presented. (ACR)

Date: January 1, 1986

Creator: Fry, R.J.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Conceptual basis for evaluating risk from low-level radiation exposure

Serious or lethal injuries that may result from the exposure of animals or human beings to ionizing radiations can be divided into two distinctly different categories, on the basis of whether the injury results only from failure of an entire vital organ, or stems from impairment of the function of a single cell. These two categories of injury are termed here organ effects, normally induced by non-stochastic processes, and single cell effects, normally induced by stochastic processes. This prese… more

Date: January 1, 1981

Creator: Bond, V.P.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Summary and recommendations for research on tritium toxicity

Lengthy presentations on many aspects of /sup 3/H and its toxicity were given: /sup 3/H Decay - Anticipated Q, J. Booz; Influence of Dose and Dose Rate on RBE, L. Feinendegen; /sup 3/H Effects on Stem Cells and Dominant Lethals, A. Carsten; /sup 3/H Incorporation into Murine Molecular Species, S. Commerford; /sup 3/H and Hemopoietic Effects, T. Fliedner; Evidence for Site-Specific Genetic Transmutation Effects, M. Bender; /sup 3/H and Effect on Testes, A. Lambert; /sup 3/H and Oocytes, L. Dobso… more

Date: January 1, 1979

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dihydroxyboryldeoxyuridine (DBDU); can a borated nucleoside deceive the DNA molecule

The possibility of using a boronated analog of thymidine for Neutron Capture Therapy (NCT) is intriguing, as the boron is targeted to the cell's most sensitive location. Such an analog has been synthesized in the form of dihydroxyboryldeoxyuridine (DBDU). Data are presented indicating that DBDU is indeed incorporated in the nucleus, and that significant radiosensitization is produced in cell cultures as a consequence of this uptake. The results demonstrate that cells exposed to DBDU for 1 cell … more

Date: January 1, 1985

Creator: Laster, B. H.; Schinazi, R. F.; Fairchild, R. G.; Popenoe, E. A. & Sylvester, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Neutron Capture Therapy for Melanoma

The development of boron-containing compounds which localize selectively in tumor may require a tumor-by-tumor type of approach that exploits any metabolic pathways unique to the particular type of tumor. Melanin-producing melanomas actively transport and metabolize aromatic amino acids for use as precursors in the synthesis of the pigment melanin. It has been shown that the boron-containing amino acid analog p-borono-phenylalanine (BPA) is selectively accumulated in melanoma tissue, producing … more

Date: January 1, 1988

Creator: Coderre, Jeffrey A.; Glass, John D.; Micca, Peggy & Fairchild, Ralph G.

Item Type: Article

Partner: UNT Libraries Government Documents Department