著者

永田 弘治 菅原 努 田中 富蔵

出版者

日本放射線影響学会

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.13, no.3, pp.163-166, 1972-09

被引用文献数

1 31

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A new sulfhydryl compound, 2-mercaptopropionylglycine, which is commercially available in Japan as a detoxicating agent, has been shown to be protective in mice against lethal doses of ionizing radiation at a very low dose of 20 mg/kg, far below its toxic dose of more than 2,000 mg/kg. The drug has an optimum dose for protection, 20 mg/kg, and its protection continues more than 3 hours, though with a less extent after 1 hour than within 1 hour. The results suggest a clue on the mechanism of sulfhydryl radioprotectors and give promise of clinical application.

著者

QUANFU SUN SUMINORI AKIBA ZUFAN TAO YONGLING YUAN JIANMING ZOU HIROSHIGE MORISHIMA HIROO KATO YONGRU ZHA TSUTOMU SUGAHARA LUXIN WEI

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.41, no.SUPPL, pp.S43-S52, 2000 (Released:2001-10-19)

参考文献数

18

被引用文献数

19

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A study was made on cancer mortality in the high-background radiation areas of Yangjiang, China. Based on hamlet-specific environmental doses and sex- and age-specific occupancy factors, cumulative doses were calculated for each subject. In this article, we describe how the indirect estimation was made on individual dose and the methodology used to estimate radiation risk. Then, assuming a linear dose response relationship and using cancer mortality data for the period 1979-1995, we estimate the excess relative risk per Sievert for solid cancer to be -0.11 (95% CI, -0.67, 0.69). Also, we estimate the excess relative risks of four leading cancers in the study areas, i.e., cancers of the liver, nasopharynx, lung and stomach. In addition, we evaluate the effects of possible bias on our risk estimation.

著者

Noboru TAKAMURA Yoshihiro NAKAMURA Katsu ISHIGAKI Jitsuro ISHIGAKI Mariko MINE Kiyoshi AOYAGI Shunichi YAMASHITA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.45, no.2, pp.201-204, 2004 (Released:2004-08-10)

参考文献数

16

被引用文献数

11

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We examined the effect of stable iodine on thyroid gland blockade in patients with hyperthyroidism in order to make a preliminary evaluation of the appropriate dose of iodine prophylaxis in the event of a radiation emergency in Japan in which radioiodine is released to the environment. Eight patients were orally given single doses of 50 mg or 100 mg of potassium iodide, which contained 38 mg and 76 mg of iodide, respectively. Both doses significantly suppressed a thyroid uptake of 123I for 24 h (p = 0.03). The protective effects at 24 h were 73.3% and 79.5%, respectively. No side effects were observed during the trial. The present study demonstrates that a single oral administration of 38 mg of iodide produces a thyroid-blocking effect equivalent to that of 76 mg of iodide, suggesting that a reevaluation of the stable iodine dosage during radiation emergencies in iodine-rich areas such as Japan is warranted.

著者

Manami MONOBE Akiko UZAWA Makiko HINO Koichi ANDO Shuji KOJIMA

出版者

Journal of Radiation Research 編集委員会

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.46, no.1, pp.117-121, 2005 (Released:2005-04-01)

参考文献数

23

被引用文献数

21

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Human whole-blood was exposed to 137Cs γ-rays or 50 keV/μm carbon ions in the presence or absence of glycine betaine, a beer component in vitro. The dicentrics of chromosome aberrations in human lymphocytes were significantly (p < 0.05) reduced by glycine betaine after irradiation with 4 Gy of either γ-rays or carbon ions. The maximum protection by glycine betaine for γ-rays or carbon ions was 37% and 20%, respectively. C3H/He female mice, aged 14 weeks, received an i.p. injection of glycine betaine 15 min before whole-body irradiation with γ-rays or 50 keV/μm carbon ions. Glycine betaine significantly (p < 0.05) increased the percent survival of irradiated mice with either γ-rays or carbon ions. In conclusion, glycine betaine is a potent protector against damages caused by low- and high-LET radiation.

著者

HIGO KEN-ICHI YAMAMOTO OSAMU

出版者

日本放射線影響学会

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.26, no.3, pp.353-359, 1985-09

被引用文献数

2

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In the presence of tritiated water (HTO), Escherichia coil 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 H_2O_2. 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 ^<60>Co 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.

著者

松田 日吉 増田 高広 近藤 正春

出版者

日本放射線影響学会

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.6, no.1, pp.45-53, 1965-03

被引用文献数

2

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Kinetic investigations for reduction of cytochrome c in aqueous solution induced by cobalt-60 gamma rays have been carried out. Initial reduction yield of cytochrome c is about 5 as limiting value. The decrease in initial reduction yield in presence of thallous ion as a radical scavenger with ferricytochrome c provides some evidences that OH radicals can contribute to reduction through some possible intermediate. The effects of concentration ratio in ferro-ferricytochrome c and thallous ion-ferricytochrome c systems on initial reduction yield were investigated. The results can be explained on the basis of some reaction scheme based on the contribution of OH radicals to reduction of ferricytochrome c. The following rate constants were determined by kinetic treatment of the results. k_<OH+RH2Fe1+>=5×10^<10>M^<-1>sec^<-1> k_<OH+RH2Fe2+>=4.1×10^<10>M^<-1>sec^<-1>.

著者

松坂 尚典 SAKAMOTO HIDEKI SATO ITARU SHINAGAWA KUNIHIRO KOBAYASHI HARUO NISHIMURA YOSHIKAZU

出版者

日本放射線影響学会

雑誌

Journal of radiation research (ISSN:04493060)

巻号頁・発行日

vol.36, no.3, pp.196-202, 1995-09

被引用文献数

2

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Whole-body retention and fetal uptake of ^<65>5Zn under a Zn-deficient diet were studied in pregnant mice in the late gestational stage after a single oral administration of ^<65>Zn. Whole-body retentions were much greater in mice given a Zn-deficient diet than in those given a Zn-normal diet. Accordingly, the amount of ^<65>Zn transmitted to the offspring in utero was greater in the Zn-deficient diet group. In another experiment, fetal uptake of ^<65>Zn in dams on gestation day 17 was examined over a period of 24 hr after a single intravenous administration of ^<65>Zn to the Zn-deficient and Zn-normal animals. There was no major difference in fetal uptake between the two groups, indicative that approximately a similar proportion of the ^<65>Zn retained in the maternal body was transmitted to the in utero offspring in both groups.

著者

AUDA H. KHALEF Z.

出版者

日本放射線影響学会

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.23, no.2, pp.141-149, 1982-06

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The kinetics of degradation and synthesis of DNA and the nature of radioactive substances released from M. radiodurans R_<11>5 labeled with thymidine-methyl-^3H after UV and gamma irradiations were investigated. The release of labeled material from the DNA began immediately upon incubation and terminated in due time 90 min and 180 min for UV and gamma irradiations, respectively. When acriflavine was added to the medium, post-irradiation degradation process did not terminate even after 9 h in the case of UV exposure. However, it terminated after 6 h in the case of gamma irradiation. In the presence of acriflavine, DNA synthesis resumed after termination of DNA degradation in the case of gamma irradiation and this was not observed in the case of UV irradiation. Degradation products were chromatographed and it was found that they were located in one major radioactive peak. However their locations were different for UV and gamma radiations. For UV irradiation, the peak fell in the thymine region, while for gamma irradiation it fell in the thymidine region.

著者

FUJIMOTO KENZO YONEHARA HIDENORI YAMAGUCHI YASUHIRO ENDO AKIRA

出版者

日本放射線影響学会

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.42, pp.85-93, 2001-12

被引用文献数

1 4

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The NIRS staff interviewed the residents in the evacuated zone around the JCO facility in Tokai-mura on 19 and 20 November, 1999, to obtain the following parameters every 30 minutes starting from 10:35 A.M. on 30 September to 6:15 A.M. on 1 October: the distance from the precipitation tank, the type of the house, positions in the house, wall materials and their thickness in order to estimate individual doses due to the accident. The ambient dose equivalents were obtained based on monitoring data during the accident. In addition, computer calculations were conducted to evaluate the conversion factor from ambient dose equivalent to effective dose equivalent as well as the shielding effect of the house or factory to estimate the effective dose equivalent to the residents. The estimated individual doses based on the behavior survey were in the range from zero to 21mSv. The individual doses were reported to the residents during the second visit to each house and factory at the end of January, 2000.

著者

Wang Bing

出版者

日本放射線影響学会

雑誌

Journal of radiation research (ISSN:04493060)

巻号頁・発行日

vol.42, no.1, pp.1-10, 2001-03

被引用文献数

17 37

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The irradiation of fetuses at the late period of organogenesis has been known to induce a dramatic increase in malformations. The mechanisms involved, however, have remained unclear for a long time. Using the mouse limb bud system, we first found that radiation-induced apoptosis is involved in the malformation, namely, radiation-induced apoptosis in the predigital regions of embryonic limb buds is responsible for digital defects in mice. An examination of embryonic C57BL/6J mice with different p53 (trp53) status enabled us to further find that susceptibility to radiation-induced apoptosis in the predigital regions and digital defects depend on both the p53 status and the radiation dose; p53 wild-type mice appeared to be the most sensitive, while p53 knockout mice were the most resistant. These results indicate that p53-dependent apoptosis mediates radiation-induced digital defects in the later organogenesis period. The existence of a radioadaptive response in embryonic mice, which has not been reported so far, was found by irradiating embryos with either 5 cGy or 30 cGy on embryonic day 11 prior to a challenging irradiation at 3 Gy on embryonic day 12. p53-heterozygous embryos did not show the radioadaptive response, indicating the involvement of p53 in the radioadaptive response in embryogenesis.

著者

Wang Bing

出版者

Journal of Radiation Research 編集委員会

雑誌

Journal of radiation research (ISSN:04493060)

巻号頁・発行日

vol.42, no.1, pp.1-10, 2001-03-15

参考文献数

44

被引用文献数

17 37

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The irradiation of fetuses at the late period of organogenesis has been known to induce a dramatic increase in malformations. The mechanisms involved, however, have remained unclear for a long time. Using the mouse limb bud system, we first found that radiation-induced apoptosis is involved in the malformation, namely, radiation-induced apoptosis in the predigital regions of embryonic limb buds is responsible for digital defects in mice. An examination of embryonic C57BL/6J mice with different <i>p53</i> (<i>trp53</i>) status enabled us to further find that susceptibility to radiation-induced apoptosis in the predigital regions and digital defects depend on both the <i>p53</i> status and the radiation dose; <i>p53</i> wild-type mice appeared to be the most sensitive, while <i>p53</i> knockout mice were the most resistant. These results indicate that p53-dependent apoptosis mediates radiation-induced digital defects in the later organogenesis period. The existence of a radioadaptive response in embryonic mice, which has not been reported so far, was found by irradiating embryos with either 5 cGy or 30 cGy on embryonic day 11 prior to a challenging irradiation at 3 Gy on embryonic day 12. <i>p53</i>-heterozygous embryos did not show the radioadaptive response, indicating the involvement of p53 in the radioadaptive response in embryogenesis.

著者

Nair Cherupally K.K. Parida Dillip K. Nomura Taisei

出版者

日本放射線影響学会

雑誌

Journal of radiation research (ISSN:04493060)

巻号頁・発行日

vol.42, no.1, pp.21-37, 2001-03

被引用文献数

38 321

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Radiotherapy is the most common modality for treating human cancers. Eighty percent of cancer patients need radiotherapy at some time or other, either for curative or palliative purpose. To obtain optimum results, a judicious balance between the total dose of radiotherapy delivered and the threshold limit of the surrounding normal critical tissues is required. In order to obtain better tumor control with a higher dose, the normal tissues should be protected against radiation injury. Thus, the role of radioprotective compounds is very important in clinical radiotherapy. Ionizing radiation causes damage to living tissues through a series of molecular events, such as photoelectric, Compton and Auger effects, depending on the radiation energy. Because human tissues contain 80% water, the major radiation damage is due to the aqueous free radicals, generated by the action of radiation on water. The major free radicals resulting from aqueous radiolysis are OH, H, e_<aq>^- , HO_2, H_ 3 O^+ , etc. These free radicals react with cellular macromolecules, such as DNA, RNA, proteins, membrane, etc, and cause cell dysfunction and mortality. These reactions take place in tumor as well as normal cells when exposed to radiation. The radiation damage to a cell is potentiated or mitigated depending on several factors, such as the presence of oxygen, sulfhydryl compounds and other molecules in the cellular milieu. In the presence of oxygen, hydrated electrons and H atoms react with molecular oxygen to produce radicals, such as HO_2 , O_2^- , apart from other aqueous free radicals. The increase in the sensitivity of cells to ionizing radiation in the presence of oxygen, compared to that in its absence, is called the oxygen effect. The ratio of the dose required to achieve a given cell survival in the absence of oxygen to the dose required for the same effect under fully oxygenated conditions is called the oxygen enhancement ratio (OER), the value of which varies between 2.5 - 3 for X- and gamma- radiation. The effect of oxygen is said to be dose modifying and is independent of the radiation dose. Oxidative damage to the cellular genetic material, i.e., DNA, plays a major role in mutagenesis and carcinogenesis. Highly reactive oxygen radicals produced by ionizing radiation cause lesions in DNA which lead to cell killing and mutations. Enzymes such as superoxide dismutase, glutathione peroxidase and catalase protect mammalian cells from oxidative radiation damage7). It was recently reported that a cell line derived from a mutant strain of mouse having low cellular levels of temperature sensitive catalase activity is more sensitive to radiation and hydrogen peroxide.

著者

小室 正人

出版者

日本放射線影響学会

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.17, no.2, pp.99-105, 1976-06

被引用文献数

1

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The process of ovarian tumorigenesis in ddY/F and C3H/TW mice was studied at various times until 18 months after whole body irradiation with a single dose of 130R or 260 R of X-rays. The first ovarian tumors were observed at 9 months after irradiation in ddY/F mice. In a total of 28 of 71 ddY/F mice, 33 ovarian tumors were developed, which were subdivided to 25 luteomas, 4 granulosa-cell tumors, one mixed cell tumor and 3 tubular adenomas. On the other hand, 21 of 29 C3H/TW mice had altogether 32 tubular adenomas and one mixed cell tumor. At older ages, small interstitial cells with eosinophilic cytoplasm were observed in irradiated ovaries. The cells resembled luteoma cells. Luteoma may be derived from the small interstitial cells. Since the earlier works by Parkes, Brambell et al. , it has been well documented that mammalian ovaries are very sensitive to radiation in all stages of postnatal life. Furth and Furth, Upton et al. reported that ovarian tumors developed in mice at more than 7-10 months after irradiation at 5-12 weeks of age.