Journal of Radiation Research
Online ISSN : 1349-9157
Print ISSN : 0449-3060
Volume 29, Issue 1
Displaying 1-4 of 4 articles from this issue
  • MASAYUKI KITAZUME, MASANORI OKAMOTO, SAYAKA NAKAI
    1988 Volume 29 Issue 1 Pages 97-103
    Published: March 15, 1988
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    The sperm of crab-eating monkeys (Macaca fascicularis) were examined every two weeks after their testes were acutely irradiated with 1, 2 and 3 Gy using 137Cs γ-rays at a dose rate of 0.25 Gy/min. The spontaneous incidence of abnormal head shapes of their sperm was estimated to be 0.80%, with a range of 0.33% to 1.57%. The frequencies of abnormal sperm heads clearly increased with increasing dose and varied with time post irradiation. The maximum γ-ray effects were observed after 8 weeks in the 1 and 2-Gyirradiated animals and at 6 weeks in the animals exposed to 3 Gy. The results suggested that early spermatocytes and late spermatogonia are the cells most sensitive to radiation-induced abnormalities of the sperm heads. The peak yields were 5.4% at 1 Gy, 13.1% at 2 Gy and 14.9% at 3 Gy. The dose-response relationship for induction of sperm abnormalities fitted well to the linear equation, Y = 0.24 + 6.15D, when the testes of the crab-eating monkeys were irradiated with doses below 2 Gy. Above 2 Gy, the rates of induction of sperm abnormalities seemed to decrease.
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  • K.K WARY, R.N. SHARAN
    1988 Volume 29 Issue 1 Pages 104-109
    Published: March 15, 1988
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    Studies were performed to provide mechanistic insights into the action of the radioprotector drug, 2-mercaptopropionylglycine (MPG) following the radiolysis of catalase, a detoxifying enzyme. The enzyme solution was γ-irradiated in the presence and absence of MPG. The enzyme activity was monitored in vitro using H2O2 as a substrate. MPG behaved primarily as a radioprotective drug. However, due to the presence of Fe++/Fe+++, and the in homogeneity of catalase, under certain conditions there was circumstancial interaction of Fe++/Fe+++ with MPG, resulting in the formation of an unstable catalase Fe++/Fe+++-MPG chelate/complex. This resulted in the radiosensitizing effect of MPG on enzyme catalase.
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  • SHUN''ICHI HISAMATSU, YUKIO TAKIZAWA, TOURU ABE
    1988 Volume 29 Issue 1 Pages 110-118
    Published: March 15, 1988
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    Decontamination ratios of 103Ru 134Cs, and 137Cs were determined for leafy vegetable samples after they were cooked. Samples contaminated with radionuclides from the Soviet Chernobyl reactor accident were obtained in Akita City. The decontamination ratio of the 103Ru content of washed spinach samples to that of similar unwashed samples was 0.83 ± 0.21. The ratio of the 103Ru content of leafy vegetables and edible wild grass samples which were boiled in water to that of similar washed samples was, on the average, 0.72 ± 0.20. The overall decontamination ratio of 103Ru in boiled leafy vegetable samples to unwashed vegetable samples was 0.52 ± 0.20. The decontamination ratios of 134Cs and 137Cs after washing were 0.65 ± 0.42 and 0.64 ± 0.17, respectively. The reduction ratios of 134Cs and 137Cs by boiling were 0.50 0.15 and 0.53 ± 0.13. The overall decontamination ratios were 0.33 ± 0.24 for 134 Cs and 0.34 ± 0.12 for 137Cs. These results indicate that the decontamination ratio of 0.5 which is stipulated by the Nuclear Safety Commission, Japan, is a practical value.
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  • DI CHEN, SEIJI TAKEOKA, MASAHARU HOSHI, SHOZO SAWADA
    1988 Volume 29 Issue 1 Pages 119-129
    Published: March 15, 1988
    Released on J-STAGE: June 16, 2006
    JOURNAL FREE ACCESS
    Depth doses in rat and mouse phantoms from the 252Cf neutron beam were determined using a pair of gas flow type tissue equivalent, and magnesium ionization chambers, which were especially designed for measuring depth doses in phantoms. Depth dose distribution and neutron-to-gamma dose ratios in the central plane of a rat phantom are included. The dose distribution with a unilateral irradiation was found to be nonuniform, however, if significantly be improved by adopting bilateral or rotation irradiation. Kerma rates were determined using four types of tissue equivalent ionization chambers and two kinds of non-hydrogenous ionization chambers (aluminum and magnesium), employed in pairs. The best kerma rate value was estimated. Tissue-air ratios for both phantoms were calculated based on the results of kerma rate and absorbed dose data obtained at the centers of the rat and mouse phantoms.
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