Journal of Radiation Research
Online ISSN : 1349-9157
Print ISSN : 0449-3060
Volume 26, Issue 3
Displaying 1-10 of 10 articles from this issue
  • OSAMU YAMAMOTO, IZUMI FUJI
    1985 Volume 26 Issue 3 Pages 257-268
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    Thymine aqueous solutions were prepared at a concentration of 5 × 10-4 M (contained 14C-thymine and buffered at pH 7.0) and were irradiated with 60Co gamma-rays and 3H beta-rays from 3HHO, in the presence of N2, 02, N20 or t-BuOH-N2. Thin-layer chromatography was carried out bidimensionally and autoradiography was performed. Considerable difference in the dose-yield curves was observed between beta-irradiation and gamma-irradiation. Oxygen enhancement ratio, 1.35 and 1.06 at a dose of 1.5 × 103 Gy, were obtained by gamma-rays and by beta-rays, respectively, for thymine degradation. Oxygen effect on product formation was very low in beta-irradiation. The yield of 5-hydroxy-5-methylbarbituric acid + 5-hydroxy-5-methylhydantoin was much higher in beta-irradiation than in gamma-irradiation under N2 and N2O. These results lead to the conclusion that in beta-irradiation there could be a progression of oxidation of materials with some species differed from OH radicals.
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  • RICHARD C. MILLER, TOSHIO HIRAOKA, NORI NAKAMURA, HIROMI TENOU, KENNET ...
    1985 Volume 26 Issue 3 Pages 269-282
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    Procedures for establishing primary cultures of human thyroid tissue are described. Tissues removed surgically from patients with papillary carcinoma (PC), follicular adenoma (FA), or hyperthyroidism were grown in culture. In addition, normal cells were separated from the margins of excised tumors and were also cultured. For each gram of thyroid tissue cultured, more than 1 × 105 cells attached to culture dishes. A mixture of 2.5% fetal bovine serum supplemented with insulin, hydrocortisone, transferrin, glycl-l-histidylL-lysine acetate, somatostatin and epidermal growth factor was added to nutrient media containing equal parts of Ham''s F-12 and minimum essential medium (αMEM). Complete medium selectively supported epithelial cell growth while restricting fibroblast cell growth, especially during the first two weeks of the primary culture. Cells were stimulated with thyroid stimulating hormone (TSH) and produced raised levels of cAMP and thyroid hormone (T3).
    Culture conditions that affected the response of cells to X-rays were identified. During the culture period, first and second passage cells were compared for differences in their radiosensitivities. In all cases, cells showed differences in their responses to radiation depending on the cell passage number. However, results of replicate experiments of first passage cells that were exposed to X-rays showed good agreement between experiments. This technique makes it possible to quantitate the effects of chemical and physical cytotoxic agents on proliferating human thyroid epithelial cells.
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  • HIROSHIGE MORISHIMA, HIROSHI KAWAI, TAEKO KOGA, TAKEO NIWA
    1985 Volume 26 Issue 3 Pages 283-312
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    The trends of global tritium precipitation from 1953 to 1979 were estimated based on the tritium data published in seven volumes of Environmental Isotope Data by the International Atomic Energy Agency (IAEA). Tritium precipitation samples were collected from 342 stations in the world and tritium concentrations were measured by IAEA and 27 laboratories. Due to repeated atomospheric nuclear explosions, tritium precipitations showed maximum peak in 1963. After the agreement of the Partial Test Ban Treaty in 1964, they have gradually decreased until now showing seasonal variations. To obtain clear trends of tritium precipitations, seasonal and irregular factors were eliminated from the original time-series data using a code developed by the Japanese Economic Planning Agency.
    Results of analyses were as follows; a) Peak concentrations and precipitations of tritium were observed every year around the period of late spring to summer. b) The maximum annual tritium concentration and precipitation were observed in 1963 for northern hemisphere stations. c) A latitude effect was observed in the northern hemisphere. The maximum concentrations and precipitations were seen at the latitude of approximately 50°N. d) Continental stations always showed higher tritium concentrations and precipitations than comparable maritime stations.
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  • T. UEDA, M. NAKAHARA, R. NAKAMURA, Y. SUZUKI, C. SHIMIZU
    1985 Volume 26 Issue 3 Pages 313-320
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    In order to aim the prevention of the radiation hazard to human beings through sea food, the accumulation and excretion of 65Zn by octopus Octopus vulgaris was examined by the radioisotope tracer experiment. The concentration factor of 65Zn for whole body of the octopus that take up the nuclide from sea water and food was estimated as 9, 900, by assuming that the octopus feeds on clams alone. In that case the contribution of food was about twenty times greater than that of sea water on the accumulation of the nuclide. The biological half-life of 65Zn accumulated through sea water was 74 days. High accumulation of 65Zn in the branchial heart of the octopus, as in the case of Co, was not observed. In the liver, 65Zn combined with three constituents which have a molecular weight of more than 80, 000, 7, 000-8, 000 and less than 5, 000. In the kidney, 65Zn combined with three constituents of a molecular weight of more than 80, 000, 10, 000-20, 000 and less than 5, 000.
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  • AHMAD S. ANSARI, ISRAR A. KHAN, RASHID ALI
    1985 Volume 26 Issue 3 Pages 321-329
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    The synergistic action of ultraviolet radiation (254 nm) and hydrogen peroxide on arginine resulted in the formation of a number of different amino acids, ammonia and urea. The amino acids were tentatively identified as aspartic acid, serine, norvaline and ornithine. When tested individually, both ultraviolet radiation and hydrogen peroxide were found incapable of degrading arginine. The photodegradation of arginine, formation of amino acids, ammonia and urea followed first order rate kinetics with respect to radiation dose. The formation of reaction products was inhibited by hydroxyl radical scavengers indicating a definite involvement of OH· species in the UV degradation of arginine.
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  • YOSHIFUMI HOMMA, YOICHIRO OHMOMO
    1985 Volume 26 Issue 3 Pages 330-333
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    The amount of stable Zn and the specific activity (S.A.) of 65Zn in DTPA extract were pursued as a function of time after the administration of 65Zn to Tanashi volcanic ash soil and Naka-gawa alluvial soil to investigate chemical states of Zn in the soils and also aging effect of 65Zn introduced to the soils.
    There were at least 3 kinds of Zn pools, i.e., rapid exchange pool (pool A; possibly soil solution), exchange pool (pool B; several tens of days are needed to attain in isotopic exchange equilibrium), and very slow exchange pool (pool C; several thousand days are needed to reach isotopic exchange equilibrium).
    The aging effect was not clearly observed because 65Zn introduced into the soil remained in an available fraction (in pool A and B) for relatively long days.
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  • KUNIO SHINOHARA, HIROSHI OHARA, KATSUMI KOBAYASHI, HIROSHI MAEZAWA, KO ...
    1985 Volume 26 Issue 3 Pages 334-338
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    The HeLa cells labeled with 5-bromodeoxyuridine were irradiated with monochromatic synchrotron radiation at 0.90 Å or 1.00 Å, below or above the wavelength of the K absorption edge (0.92 Å) of bromine. Although non-specific sensitization of labeled cells to the radiation was observed irrespective of the wavelengths, the labeled cells were killed at a higher rate by the irradiation at 0.90 Å than at 1.00 Å. The nonlabeled cells showed no difference in the sensitivity to the radiation at the two wavelengths. The enhanced lethality of labeled cells at 0.90 Å may be inferred to be due to the induction of Auger effect in bromine atom of the DNA selectively absorbed the photon at 0.90 Å. Implications of this finding for the photon activation therapy was discussed.
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  • RICHARD C. MILLER, MASUMI ENNO, MOTOI YAMANE, MASAYUKI NISHIKI
    1985 Volume 26 Issue 3 Pages 339-345
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    Human skin fibroblast cells from six patients were obtained during surgical operations and grown in culture. Dose response survival curves from single dose exposures of X-rays were developed for the six cell strains. Individual D0 values varied in the six strains from 61 to 83 cGy. The shouldered survival curves had extrapolation numbers (n) ranging from 2.2 to 4.8. To assess repair of sublethal damage, cells were exposed to a total dose of 304 cGy split into two equal fractions separated by varying time intervals. Maximal increase in cell survival was observed when the time interval was at least three hours. Dose-response curves were generated for the six cell strains by first irradiating cells with 152 cGy X-rays and then allowing four hours for recovery from sublethal damage before exposing them to second graded doses. The fractionated dose-response survival curves were distinctly different from the single dose exposure curves and confirmed the ability of these cells to recover from X-ray-induced damage.
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  • RICHARD C. MILLER, TOSHIO HIRAOKA, MASUMI ENNO, NOBUO TAKEICHI
    1985 Volume 26 Issue 3 Pages 346-352
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    Human thyroid epithelial tissues from 23 individuals were obtained from surgical tissue, and cultured in vitro. Dose response survival curves showed thyroid cells, when compared to mammary epithelial and skin fibroblast cells of human origin, to be only slightly more radiosensitive to X-rays. Cell survival curves from the cell strains showed wide variability in radiation sensitivity. Of the 23 cell strains tested, 21 strains displayed significant shoulders (nonzero quasi-threshold (Dq) values and extrapolation number (n) values greater than 1) at low dose exposures. The ability of human cells to recover from radiation damage was further studied by dose fractionation. Two cell strains were given a total X-ray dose of 304 cGy in two equal fractions separated by varying time intervals. Maximal cell survival was observed when the time interval exceeded two hours. When the two cell strains were exposed to 152 cGy of X-rays followed four hours later by second graded doses, cell survival was enhanced as compared to survival after single dose exposures. However, no benefit of dose splitting was observed when cells were exposed to low second doses. These results support previous studies showing that human cells are capable of repair but require relatively large doses to elicit a repair response.
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  • KEN-ICHI HIGO, OSAMU YAMAMOTO
    1985 Volume 26 Issue 3 Pages 353-359
    Published: September 15, 1985
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    In the presence of tritiated water (HTO), Escherichia coli NG30 was grown in sealed test tubes containing synthetic medium (M9-0.4% glucose-0.005% arginine), and cell growth was monitored by measuring medium turbidity. Catalase (60 μg/ml) was added to the medium to reduce HTO associated accumulation of H202. A positive correlation between increasing concentration of HTO in the medium and the growth suppression was seen. A similar trend was observed when cells were grown under continuous irradiation of 60Co gamma-rays. The RBE of HTO beta-rays relative to gamma-rays was calculated from the accumulated doses to the cultures. It was found to be 1.7 when the growth was inhibited to 60% of the control, and increased with decreasing dose.
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