著者

三宅 泰雄 猿橋 勝子 葛城 幸雄 金沢 照子

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.2, no.1, pp.25-28, 1961-06-01 (Released:2006-08-29)

参考文献数

11

被引用文献数

14

---

Concentration of Cs-137 and Sr-90 in the western North Pacific was determined. The content of Cs-137 ranged from 0.8 to 4.8 μμc/l while Sr-90 of 0.6 to 3.1 μμc/l was observed. These values are much higher than those obtained in the Atlantic and the eastern part of the North Pacific. The cause of higher contamination is due to the direct flowout of the fission product from the proving grounds in the tropical region of the Pacific. The reason for the lower ratio of Cs-137/Sr-90 in sea water is also discussed.

著者

Qiang LIU Bo JIANG Li-Ping JIANG Ying WU Xiao-Guang WANG Feng-Ling ZHAO Bao-Hua FU Turai ISTVAN Enhai JIANG

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.49, no.1, pp.63-69, 2008 (Released:2008-02-01)

参考文献数

12

被引用文献数

47

---

On 26 April 1999, three persons were accidentally exposed by high dose 60Co irradiation. They suffered from severe (one case) or moderate (two cases) hemopoietic form of acute radiation sickness (ARS). As part of the comprehensive treatment, strict reverse isolation and granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy were applied. All the patients recovered after an appropriate treatment for 83 days. In our experience, the correct diagnosis and effective treatment at an early stage proved to be helpful to the patients in pulling out from the critical stage of acute radiation sickness. To avoid menstruation by the female patient just in the critical stage, we modified her menstruation cycle by testosterone. In our view, GM-CSF should be given as early as possible with enough dosage for promoting early hematological reconstruction. The experience obtained from the medical management of these patients is valuable for the treatment of such patients in the future.

著者

Gen SUZUKI Ichiro YAMAGUCHI Hiromitsu OGATA Hideo SUGIYAMA Hidenori YONEHARA Fumiyoshi KASAGI Saeko FUJIWARA Yoshimi TATSUKAWA Ippei MORI Shinzo KIMURA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.51, no.6, pp.683-689, 2010 (Released:2010-11-23)

参考文献数

23

被引用文献数

28

---

In two previous nation-wide surveys in the late 1980s and early 1990s, Japanese indoor radon concentrations increased in homes built after the mid 1970s. In order to ascertain whether this trend continued, a nation-wide survey was conducted from 2007 to 2010. In total 3,900 houses were allocated to 47 prefectures by the Neyman allocation method and 3,461 radon measurements were performed (88.7% success). The fraction of reinforced concrete / concrete block buildings was 32.4%, similar to the value from national statistics. Arithmetic mean (standard deviation, SD) and geometric mean (geometric SD) of radon concentration after adjusting for seasonal fluctuation were 14.3 (14.7) and 10.8 (2.1) Bq/m3. The corresponding population-weighted values were 13.7 (12.3) and 10.4 (2.0) Bq/m3, respectively. It was estimated that only 0.1% of dwellings exceed 100 Bq/m3, a new WHO reference level for indoor radon. Radon concentrations were highest in houses constructed in the mid 1980s and decreased thereafter. In conclusion, arithmetic mean indoor radon in the present survey was slightly lower than in previous surveys and significant reductions in indoor radon concentrations in both wooden and concrete houses can be attributed to alterations in Japanese housing styles in recent decades.

著者

井上 義和 岩倉 哲男

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.31, no.4, pp.311-323, 1990-12-15 (Released:2006-06-16)

参考文献数

15

被引用文献数

15

---

Polished rice samples harvested in 1985 were collected from 25 prefectures throughout Japan. Concentrations of both tissue free water tritium (TFWT) and organically bound tritium (OBT) were determined. Nearly uniform distribution of the TFWT and OBT concentrations was observed in Japan, taking into account a relatively large counting error. The average values for all Japanese polished rice were 2.69 ±0.74 Bq/L for the TFWT concentration, 2.01 ±0.78 Bq/L for the OBT concentration and 0.83 ±0.32 for the specific activity ratio. The TFWT concentration was within the range of tritium concentration of the land water reported by other researchers. The specific activity ratio below unity also confirmed by analyses of the 4 Chinese polished rice samples suggests that OBT in the rice is not equilibrated with TFWT or HTO in the environment because of isotope discrimination.

著者

KOBASHI ASAYA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of radiation research (ISSN:04493060)

巻号頁・発行日

vol.37, no.2, pp.81-95, 1996

参考文献数

27

被引用文献数

2 3

---

The radioactivities of the naturally occurring radionuclides (^<226>Ra, ^<228>Ra, ^<228>Th and ^<40>K) and a fallout nuclide (^<137>Cs) in books produced in Japan in the 20th century were measured by gamma-ray spectrometry to obtain information on radiation emitted from books. The respective concentration ranges of ^<226>Ra, ^<228>Ra, ^<228>Th ^<40>K, and ^<137>Cs were 0.2-6.4, 0.4-11. 2, 0.3-11.3, 1-112, and 0-3.6 Bq kg^<-1>. X-ray diffraction spectra of the papers used in book printing showed that pyrophyllite, talc, kaolinite, and calcium carbonate were contained as fillers. A comparison of the radioactivity contents of the pulp and filler indicated that most of ^<226>Ra, ^<228>Ra, and ^<228>Th in the books was present in the filler whereas ^<137>Cs was in the pulp. The pattern of the concentration of each nuclide vs. the year of issue of the book was investigated. Patterns for the naturally occurring radionuclides were similar and were explained by the kinds of filler used. The pattern for ^<137>Cs differed from the patterns of the naturally occurring radionuclides, having a marked peak in the mid-1960s.

著者

JAMES V. NEEL WILLIAM J. SCHULL AKIO A. AWA CHIYOKO SATOH HIROO KATO MASANORI OTAKE YASUHIKO YOSHIMOTO

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.32, no.SUPPLEMENT, pp.347-374, 1991 (Released:2006-05-31)

参考文献数

75

被引用文献数

5

---

The data collected in Hiroshima and Nagasaki during the past 40 years on the children of survivors of the atomic bombings and on the children of a suitable control population are analyzed on the basis of the newly revised estimates of radiation doses. No statistically significant effects emerge with respect to eight different indicators. Since, however, it may confidently be assumed some mutations were induced, we have taken the data at face value and calculated the minimal gametic doubling doses of acute radiation for the individual indicators at various probability levels. An effort has also been made to calculate the most probable doubling dose for the indicators combined. The latter value is between 1.7 and 2.2 Sv. It is suggested the appropriate figure for chronic radiation would be between 3.4 and 4.5 Sv. These estimates suggest humans are less sensitive to the genetic effects of radiation than has been assumed on the basis of past extrapolations from experiments with mice.

著者

Naoki HAYASHI Satoru MONZEN Koichi ITO Tsuyoshi FUJIOKA Yukio NAKAMURA Ikuo KASHIWAKURA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.53, no.2, pp.195-201, 2012 (Released:2012-04-17)

参考文献数

28

被引用文献数

8

---

The present study aimed to estimate the clonogenic and differentiation potential of induced pluripotent stem (iPS) cells exposed to ionizing radiation. Compared with mouse hematopoietic stem/progenitor cells, iPS cells were less sensitive to radiation. To examine the effect of ionizing radiation on the early differentiation pathway of iPS cells, we assessed embryoid body (EB) formation. Although EB formation was observed at all radiation doses, EB diameter decreased in a radiation dose-dependent manner. At the same time, we analyzed the expression of genes specific to differentiation in the initial iPS cells and cells of EB. The expression of the endoderm marker Afp increased remarkably in cells of EB derived from non-irradiated iPS cells; however, in irradiated cells, this expression significantly decreased in a radiation dose-dependent manner. Further, the expressions of the pluripotent stem cell markers Nanog and Oct-4 and the early mesoderm marker Brachyury significantly decreased. The results of the present study suggest that radiosensitivity with regard to gene expression differs at various stages in the early differentiation pathways of iPS cells that lead to the formation of the 3 germ layers; the sensitivity is the highest in the genes expressed during the differentiation pathways of iPS cells, leading to the formation of the endoderm.

著者

Megumi HADA Alexandros G. GEORGAKILAS

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.49, no.3, pp.203-210, 2008 (Released:2008-05-21)

参考文献数

79

被引用文献数

363

---

Radiation can cause as well as cure cancer. The risk of developing radiation-induced cancer has traditionally been estimated from cancer incidence among survivors of the atomic bombs in Hiroshima and Nagasaki.1) These data provide the best estimate of human cancer risk over the dose range for low linear energy transfer (LET) radiations, such as X- or γ-rays. The situation of estimating the real biological effects becomes even more difficult in the case of high LET particles encountered in space or as the result of domestic exposure to α-particles from radon gas emitters or other radioactive emitters like uranium-238.Complex DNA damage, i.e., the signature of high-LET radiations comprises of closely spaced DNA lesions forming a cluster of DNA damage. The two basic groups of complex DNA damage are double strand breaks (DSBs) and non-DSB oxidative clustered DNA lesions (OCDL). Theoretical analysis and experimental evidence suggest an increased complexity and severity of complex DNA damage with increasing LET (linear energy transfer) and a high mutagenic or carcinogenic potential. Data available on the formation of clustered DNA damage (DSBs and OCDL) by high-LET radiations are often controversial suggesting a variable response to dose and type of radiation. The chemical nature and cellular repair mechanisms of complex DNA damage have been much less characterized than those of isolated DNA lesions like an oxidized base or a single strand break especially in the case of high-LET radiation. This review will focus on the induction of clustered DNA damage by high-LET radiations presenting the earlier and recent relative data.

著者

Masao SUZUKI Chizuru TSURUOKA Yukio UCHIHORI Hisashi KITAMURA Cui Hua LIU

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.50, no.5, pp.395-399, 2009 (Released:2009-09-16)

参考文献数

23

被引用文献数

2

---

We studied cellular responses in normal human fibroblasts induced with low-dose (rate) or low-fluence irradiations of different radiation types, such as gamma rays, neutrons and high linear energy transfer (LET) heavy ions. The cells were pretreated with low-dose (rate) or low-fluence irradiations (~1 mGy/7-8 h) of 137Cs gamma rays, 241Am-Be neutrons, helium, carbon and iron ions before irradiations with an X-ray challenging dose (1.5 Gy). Helium (LET = 2.3 keV/μm), carbon (LET = 13.3 keV/μm) and iron (LET = 200 keV/μm) ions were produced by the Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. No difference in cell-killing effect, measured by a colony forming assay, was observed among the pretreatment with different radiation types. In mutation induction, which was detected in the hypoxanthine-guanine phosphoribosyltransferase (hprt) locus to measure 6-thioguanine resistant clones, there was no difference in mutation frequency induced by the X-ray challenging dose between unpretreated and gamma-ray pretreated cells. In the case of the pretreatment of heavy ions, X-ray-induced mutation was around 1.8 times higher in helium-ion pretreated and 4.0 times higher in carbon-ion pretreated cells than in unpretreated cells (X-ray challenging dose alone). However, the mutation frequency in cells pretreated with iron ions was the same level as either unpretreated or gamma-ray pretreated cells. In contrast, it was reduced at 0.15 times in cells pretreated with neutrons when compared to unpretreated cells. The results show that cellular responses caused by the influence of hprt mutation induced in cells pretreated with low-dose-rate or low-fluence irradiations of different radiation types were radiation-quality dependent manner.Translated and modified from Radiat. Biol. Res. Comm. Vol.43(4); 424-435, (2008, in Japanese).

著者

Nakashi SASANO Atsushi ENOMOTO Yoshio HOSOI Yosuke KATSUMURA Yoshihisa MATSUMOTO Kenshiro SHIRAISHI Kiyoshi MIYAGAWA Hiroshi IGAKI Keiichi NAKAGAWA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.48, no.6, pp.495-503, 2007 (Released:2007-11-21)

参考文献数

58

被引用文献数

20

---

Edaravone, a clinical drug used widely for the treatment of acute cerebral infarction, is reported to scavenge free radicals. In the present study, we investigated the radioprotective effect of edaravone on X-ray-induced apoptosis in MOLT-4 cells. Apoptosis was determined by the dye exclusion test, Annexin V binding assay, cleavage of caspase, and DNA fragmentation. We found that edaravone significantly suppressed the X-ray-induced apoptosis. The amount of intracellular ROS production was determined by the chloromethyl-2',7'-dichlorodihydro-fluorescein diacetate system. We found that the intracellular ROS production by X-irradiation was completely suppressed by the addition of edaravone. The accumulation and phosphorylation of p53 and the expression of p21WAF1, a target protein of p53, which were induced by X-irradiation, were also suppressed by adding edaravone. We conclude that the free radical scavenger edaravone suppresses X-ray-induced apoptosis in MOLT-4 cells by inhibiting p53.

著者

Yasuyuki TAIRA Naomi HAYASHIDA Gopalganapathi M. BRAHMANANDHAN Yuji NAGAYAMA Shunichi YAMASHITA Jumpei TAKAHASHI Alexander GUTEVITC Alexander KAZLOVSKY Marat URAZALIN Noboru TAKAMURA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.52, no.1, pp.88-95, 2011 (Released:2011-01-29)

参考文献数

24

被引用文献数

25

---

To evaluate current environmental contamination and contributions from internal and external exposure due to the accident at the Chernobyl Nuclear Power Plant (CNPP) and nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS), concentrations of artificial radionuclides in edible mushrooms, soils and stones from each area were analyzed by gamma spectrometry. Annual effective doses were calculated for each area from the cesium contamination. Calculated internal effective doses of 137Cs due to ingestion of mushrooms were 1.8 × 10–1 mSv/year (y) in Gomel city (around CNPP), 1.7 × 10–1 mSv/y in Korosten city (around CNPP), 2.8 × 10–4 mSv/y in Semipalatinsk city, and 1.3 × 10–4 mSv/y in Nagasaki. Calculated external effective doses of 137Cs were 3.4 × 10–2 mSv/y in Gomel city, 6.2 × 10–2 mSv/y in Korosten city, 2.0 × 10–4 mSv/y in Semipalatinsk city, and 1.3 × 10–4 mSv/y in Nagasaki. Distribution of radionuclides in stones collected beside Lake Balapan (in SNTS) were 241Am (49.4 ± 1.4 Bq/kg), 137Cs (406.3 ± 1.7 Bq/kg), 58Co (3.2 ± 0.5 Bq/kg), and 60Co (125.9 ± 1.1 and 126.1 ± 1.1 Bq/kg). The present study revealed that dose rates from internal and external exposure around CNPP were not sufficiently low and radiation exposure potency still exists even though current levels are below the public dose limit of 1 mSv/y (ICRP1991). Moreover, parts of the SNTS area may be still contaminated by artificial radionuclides derived from nuclear tests. Long-term follow-up of environmental monitoring around CNPP and SNTS, as well as evaluation of health effects in the population residing around these areas, may contribute to radiation safety with a reduction of unnecessary exposure of residents.

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

---

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

---

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.