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Generator-produced alpha-emitters

Description: This review briefly describes the nuclear characteristics and production parameters for 7.2-h {sup 211}At, 60.6-min {sup 212}Bi, 45.6-min {sup 213}Bi, 11-d {sup 233}Ra, and 20-h {sup 255}Fm. These a-emitting radioisotopes are the subject of current interest for a-particle-mediated radioimmunotherapy.
Date: December 31, 1996
Creator: Mirzadeh, S.
Partner: UNT Libraries Government Documents Department

RFNC-VNIIEF Capabilities to Production High Pure Isotopes for Scientific and Medical Applications

Description: In the technical paper there is presented the information on the basic equipment and more than thirty-year experience of RFNC-VNIIEF activities in the sphere of producing highly enriched isotopes of actinide elements--thorium, uranium, neptunium, plutonium, americium and curium--for scientific researches and practical applications. Electromagnetic separator and radiochemical methods provide obtaining of superpure isotope samples for nuclear-physical radiometric and mass-spectrometric equipment, and also as tracers when analyzing environmental contamination. There are presented the structure of the laboratory occupied with these isotopes electromagnetic separation as well as the nomenclature and characteristics of the specimens supplied. There are stated science and engineering elaborations of technologies aimed at producing alpha-ray radiating radionuclides--thorium-229, thorium-228, actinium-225, radium-224--for the purpose of anti-cancer therapy using bismuth-212 and bismuth-213 produced by the specially developed generators. There are presented the basic directions of cooperation with other Russian Institutes in developing this promising line of conversion.
Date: February 26, 2002
Creator: Vesnovskii, S. P.
Partner: UNT Libraries Government Documents Department

Production of Endohedral Fullerenes by Ion Implantation

Description: The empty interior cavity of fullerenes has long been touted for containment of radionuclides during in vivo transport, during radioimmunotherapy (RIT) and radioimaging for example. As the chemistry required to open a hole in fullerene is complex and exceedingly unlikely to occur in vivo, and conformational stability of the fullerene cage is absolute, atoms trapped within fullerenes can only be released during extremely energetic events. Encapsulating radionuclides in fullerenes could therefore potentially eliminate undesired toxicity resulting from leakage and catabolism of radionuclides administered with other techniques. At the start of this project however, methods for production of transition metal and p-electron metal endohedral fullerenes were completely unknown, and only one method for production of endohedral radiofullerenes was known. They therefore investigated three different methods for the production of therapeutically useful endohedral metallofullerenes: (1) implantation of ions using the high intensity ion beam at the Oak Ridge National Laboratory (ORNL) Surface Modification and Characterization Research Center (SMAC) and fullerenes as the target; (2) implantation of ions using the recoil energy following alpha decay; and (3) implantation of ions using the recoil energy following neutron capture, using ORNL's High Flux Isotope Reactor (HFIR) as a thermal neutron source. While they were unable to obtain evidence of successful implantation using the ion beam at SMAC, recoil following alpha decay and neutron capture were both found to be economically viable methods for the production of therapeutically useful radiofullerenes. In this report, the procedures for preparing fullerenes containing the isotopes {sup 212}Pb, {sup 212}Bi, {sup 213}Bi, and {sup 177}Lu are described. None of these endohedral fullerenes had ever previously been prepared, and all of these radioisotopes are actively under investigation for RIT. Additionally, the chemistry for derivatizing the radiofullerenes for water-solubility and a method for removing exohedral radionuclides are reported. The methods and chemistry developed ...
Date: May 31, 2007
Creator: Diener, M.D.; Alford, J. M. & Mirzadeh, S.
Partner: UNT Libraries Government Documents Department

Human radiation studies: Remembering the early years: Oral history of medical physicist Katherine L. Lathrop and physician Paul V. Harper, conducted January 26, 1995

Description: This report provides a transcript of an interview with Ms. Katherine L. Lathrop and Dr. Paul V. Hopper by representatives of the DOE Office of Human Radiation Research. Ms. Lathrop and Dr. Hopper were chosen for this interview because of their long-standing interest and research experience in the development of nuclear medicine. After brief biographical sketches the researchers provide a broad and interesting description of their roles in the initial uses of many radiopharmaceuticals, their experiences in human experimentation, and interactions with many other pioneers in nuclear medicine.
Date: September 1, 1995
Partner: UNT Libraries Government Documents Department

[Analysis of DNA damage and mutations induced by radon daughter products]. [Final report]

Description: In order to understand the genetic and somatic risks associated with exposure to radon and its daughter products, it is important to characterize those lesions that lead to mutation induction and carcinogenesis. The effect of exposure to the radon daughter (212)Bi has been analyzed in 4 CHO cell lines, CHO-KL, xrs-5, AA8 and EM9. These cell lines have different radiation sensitivities and different abilities to rejoin radiation-induced DNA strand breaks. Three endpoints have been examined in these cells; cell killing, chromosome aberration induction and mutation induction. We find RBEs for AA8, EM9 and CHO-KL of about 2.5-4 for cell killing and around 2 for G2-induced aberrations. The RBEs for xrs-5 cells are much smaller for cell killing and chromosome aberration induction, suggesting that the principle lethal lesion resulting from [212]Bi exposure is a non-repaired DNA double-strand break. (The CHO cell line xrs-5 is defective in the rejoining of DNA double-strand breaks.) The survival curves suggest that a portion of the cell killing is probably derived from the low LET beta component of the radiation. Mutation studies suggest that while the lethal and pre-mutagenic lesions might overlap, they are not exactly the same. RBEs for gene mutation induction in AA8 and EM9 cells are higher than the RBEs for killing and chromosome aberration induction. Interestingly, CHO-KL is not more sensitive to mutation induction than killing or chromosome aberration induction by [212]Bi suggesting that this cell line differs from AA8 and EM9 in its ability to repair a premutagenic lesion induced by [212]Bi. These studies should help define the nature of the lesions induced by radon exposure and thereby help understand the carcinogenic risk from radon exposure and how it differs from low LET radiation exposure.
Date: December 31, 1992
Partner: UNT Libraries Government Documents Department

Estimating population sizes in a mixture of two radioactive populations

Description: The event times are observed of a mixture of two kinds of radioactive atoms, each producing alpha particles. The probability of observing an event is p, 0 < p < 1, and of missing the observation is 1 - p. A maximum likelihood statistical method is given for estimating the size of the two populations. A second discussion assumes that the populations themselves are samples from parent populations. Bayesian methods are given for estimating parameters of the parent populations. An example is presented of an experiment involving the search for particle-bound polyneutron systems. 2 figures, 3 tables.
Date: April 1, 1978
Creator: Beyer, W.A. & Qualls, C.
Partner: UNT Libraries Government Documents Department

Alpha particle emitters in medicine

Description: Radiation-induced cancer of bone, liver and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High dose rates at high LET, effectiveness under hypoxic conditions, and minimal expectancy of repair are additional advantages of alpha emitters over antibodies labeled with beta emitting radionuclides for cancer therapy. Cyclotron-produced astatine-211 ({sup 211}At) and natural bismuth-212 ({sup 212}Bi) have been proposed and are under extensive study in the United States and Europe. Radium-223 ({sup 223}Ra) also has favorable properties as a potential alpha emitting label, including a short-lived daughter chain with four alpha emissions. The radiation dosimetry of internal alpha emitters is complex due to nonuniformly distributed sources, short particle tracks, and high relative specific ionization. The variations in dose at the cellular level may be extreme. Alpha-particle radiation dosimetry, therefore, must involve analysis of statistical energy deposition probabilities for cellular level targets. It must also account fully for nonuniform distributions of sources in tissues, source-target geometries, and particle-track physics. 18 refs., 4 figs.
Date: September 1, 1989
Creator: Fisher, D.R.
Partner: UNT Libraries Government Documents Department

[Analysis of DNA damage and mutations induced by radon daughter products]

Description: In order to understand the genetic and somatic risks associated with exposure to radon and its daughter products, it is important to characterize those lesions that lead to mutation induction and carcinogenesis. The effect of exposure to the radon daughter (212)Bi has been analyzed in 4 CHO cell lines, CHO-KL, xrs-5, AA8 and EM9. These cell lines have different radiation sensitivities and different abilities to rejoin radiation-induced DNA strand breaks. Three endpoints have been examined in these cells; cell killing, chromosome aberration induction and mutation induction. We find RBEs for AA8, EM9 and CHO-KL of about 2.5-4 for cell killing and around 2 for G2-induced aberrations. The RBEs for xrs-5 cells are much smaller for cell killing and chromosome aberration induction, suggesting that the principle lethal lesion resulting from [212]Bi exposure is a non-repaired DNA double-strand break. (The CHO cell line xrs-5 is defective in the rejoining of DNA double-strand breaks.) The survival curves suggest that a portion of the cell killing is probably derived from the low LET beta component of the radiation. Mutation studies suggest that while the lethal and pre-mutagenic lesions might overlap, they are not exactly the same. RBEs for gene mutation induction in AA8 and EM9 cells are higher than the RBEs for killing and chromosome aberration induction. Interestingly, CHO-KL is not more sensitive to mutation induction than killing or chromosome aberration induction by [212]Bi suggesting that this cell line differs from AA8 and EM9 in its ability to repair a premutagenic lesion induced by [212]Bi. These studies should help define the nature of the lesions induced by radon exposure and thereby help understand the carcinogenic risk from radon exposure and how it differs from low LET radiation exposure.
Date: January 1, 1992
Partner: UNT Libraries Government Documents Department

Radon and thoron emanation measurements and the effect of ground water

Description: In the past, corrections for annual dose rate calculations have used a qualitative approach to the effect of ground water saturation and radon and thoron loss. An example is presented of how this correction can now be precisely determined using natural gamma-ray activities to determine the amount of emanation from ceramic sherds and soil, both in a dry state and saturated with ground water. The experimental data also provide information concerning disequilibria in /sup 234/Th and /sup 226/Ra regions of the decay series. Additionally, approximate values of uranium and thorium concentrations (sufficiently accurate for authenticity work) are provided.
Date: January 1, 1980
Creator: Carriveau, G.W. & Harbottle, G.
Partner: UNT Libraries Government Documents Department

Activity ratios of thorium daughters in vivo

Description: A computerized method of least squares has been used to analyze the /sup 228/Ac and /sup 212/Pb-/sup 212/Bi and daughter ..gamma..-ray spectra obtained in vivo from 133 former workers at a thorium refinery. In addition, the exhalation rate of /sup 220/Rn was determined for each subject and expressed as pCi of emanating /sup 224/Ra. This value was added to the /sup 212/Pb value determined from the ..gamma..-ray measurements to obtain the total /sup 224/Ra present, and the ratio of /sup 224/Ra to /sup 228/Ac was calculated. Values of the ratio ranged from 0.52 +- 0.32 to 2.1 +- 1.7, with a weighted mean of 0.92 +- 0.17. However, it appears that the ratio observed in a given case is characteristic for that case alone; the computed mean value may not be meaningful. The least squares fitting procedure and the overall calibration of the counting system were validated by measurements of /sup 224/Ra in the lungs of one subject postmortem, compared with results obtained from the same subject in vivo. 6 references, 5 figures.
Date: January 1, 1984
Creator: Toohey, R.E.; Rundo, J.; Sha, J.Y.; Essling, M.A.; Pedersen, J.C. & Slane, J.M.
Partner: UNT Libraries Government Documents Department

Criteria for the selection of nuclides for radioimmunotherapy

Description: 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 labeled antibody and for populations that uniformly and constantly display the targeted antigen or idiotype, e.g., trafficking cells such as T or B lymphocytes. For cells that concentrate the radioactive label, the use of low-energy electrons should be examined. If the radionuclide is translocated to the nucleus, the Auger effect can be particularly lethal because of the high LET-like biological response. 15 refs., 3 figs., 2 tabs.
Date: January 1, 1986
Creator: Adelstein, S.J. & Kassis, A.I.
Partner: UNT Libraries Government Documents Department

On-Line Measurement of Stack-Gas Particulate Radionuclides

Description: This paper describes an advanced process-monitoring system for the automatic sample collection, analysis, reporting, and alarming of the concentration of long-lived radionuclides in nuclear process stack-gas effluents. This system, the Moving Filter Radioactive Aerosol Monitor, collects particulates in a conditioned sampling chamber, under computer control, for subsequent and separate alpha and beta counting and analysis. The alpha measurement is performed with a solid-state surface-barrier detector. Beta analysis is performed with a phoswich scintillation detector. A unique alpha-energy analysis program that provides automatic energy calibration and lowered detection limits for plutonium in the presence of high quantities of interfering /sup 212/Bi/Po is described. The /sup 212/Bi/Po alpha results are further used to monitor system quality and to compensate for the radon daughter beta components in the beta system. Results of the system calibration and detection limits are also presented. 8 refs., 6 figs.
Date: November 1987
Creator: Stong, F. S.; Troyer, G. L. & Criddle, J. D., Jr.
Partner: UNT Libraries Government Documents Department