著者

MARIA KOWALSKA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.26, no.1, pp.99-108, 1985-03-15 (Released:2006-06-16)

参考文献数

18

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Three generations of rats were long-term exposed to HTO in drinking water at activity of 37.0 kBq/ ml or to food containing OBT at activity of 48.1 kBq/g. The rats consumed tritiated water and tritiated food ad libitum. The parent females P0 were exposed for 64 days, the F1 and F2 generations were lifetime exposed and F3 generation during whole intrauterine life. It was found that the amount of tritium incorporated into rat brain protein amino acids after administration of tritiated food was higher than after administration of tritiated water and was the highest in rats exposed during their intrauterine life.

著者

Tadaaki BAN-NAI Yasuyuki MURAMATSU Satoshi YOSHIDA

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.325-332, 2004 (Released:2004-08-10)

参考文献数

58

被引用文献数

13

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Mushrooms are known to accumulate radiocesium. To estimate the intake of radiocesium through the eating of mushrooms, about 30 samples belonging to 4 commonly consumed species (Lentinula edodes, Hypsizigus marmoreus, Grifola frondosa, and Tricholoma matsutake), were analyzed for 137Cs and 40K. The concentration ranges were 0.060-29 Bq kg-1 (wet wt) for 137Cs and 38-300 Bq kg-1 (wet wt) for 40K. The geometric mean concentration for 137Cs was 0.56 Bq kg-1 (wet wt), and the mean concentration for 40K was 92 Bq kg-1 (wet wt). The 137Cs concentrations in L. edodes cultivated in mushroom beds (sawdust-rice bran media) were lower than those cultivated on bed logs (natural wood with bark). The annual intake of 137Cs per person through mushrooms was calculated, by using the current analytical results and food consumption data in Japan, to be 3.1 Bq for 137Cs, which is about 28% of the total dietary intake of this nuclide. The effective dose equivalent of 137Cs through mushrooms was estimated to be 4.0 ¤ 10-8 Sv, which is about the half the value obtained in our previous study. The decrease of the 137Cs intake through mushrooms is probably related to changes in cultivation methods in recent years, from the use of bed logs to mushroom beds.

著者

Naomi HAYASHIDA Yui SEKITANI Alexander KOZLOVSKY Ruslan RAFALSKY Alexander GUTEVICH Valery DANILIUK Shunichi YAMASHITA 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.5, pp.629-633, 2011 (Released:2011-09-27)

参考文献数

12

被引用文献数

13 4

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During the Chernobyl Nuclear Power Plant (CNPP) accident on 26 April 1986, large amounts of radionuclides were released and spread to vast areas. Inhabitants residing around CNPP have been exposed to external and internal irradiation due to the long half-life of 137Cs (30 years). In this study, we screened for internal whole-body 137Cs concentration using a whole-body counter in the Zhitomir state of Ukraine. The total number of participants was 144,972 (96,149 females and 48,823 males). The median body burden of 137Cs per body weight decreased from 1996 to 2008. In particular, after 2003, more than half of subjects had internal exposure doses below the detectable level. A weak seasonal effect was found in measurement data from 1997 to 1999, but no such effects were observed in later years. We also calculated annual dose for each year and confirmed that doses have been decreasing gradually. In particular, after 2003, the annual effective dose decreased to 0.1 mSv y–1 for 95% of the participants. Only two persons were found to have received more than 5 mSv y–1 since 2007. Although the health effects of 137Cs body burden due to the Chernobyl accident remain uncertain, further screening is needed to monitor the health status and to allay the anxiety of inhabitants in the contaminated areas around CNPP.

著者

Tetsuo YAMAMOTO Manabu KINOSHITA Nariyoshi SHINOMIYA Sadayuki HIROI Hidekazu SUGASAWA Yoshitaro MATSUSHITA Takashi MAJIMA Daizoh SAITOH Shuhji SEKI

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.2, pp.145-156, 2010 (Released:2010-03-25)

参考文献数

38

被引用文献数

38 28

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While bone marrow or stem cell transplantation can rescue bone marrow aplasia in patients accidentally exposed to a lethal radiation dose, radiation-induced irreversible gastrointestinal damage (GI syndrome) is fatal. We investigated the effects of ascorbic acid on radiation-induced GI syndrome in mice. Ascorbic acid (150 mg/kg/day) was orally administered to mice for 3 days, and then the mice underwent whole body irradiation (WBI). Bone marrow transplantation (BMT) 24 h after irradiation rescued mice receiving a WBI dose of less than 12 Gy. No mice receiving 14 Gy-WBI survived, because of radiation-induced GI syndrome, even if they received BMT. However, pretreatment with ascorbic acid significantly suppressed radiation-induced DNA damage in the crypt cells and prevented denudation of intestinal mucosa; therefore, ascorbic acid in combination with BMT rescued mice after 14 Gy-WBI. DNA microarray analysis demonstrated that irradiation up-regulated expressions of apoptosis-related genes in the small intestine, including those related to the caspase-9-mediated intrinsic pathway as well as the caspase-8-mediated extrinsic pathway, and down-regulated expressions of these genes in ascorbic acid-pretreated mice. Thus, pretreatment with ascorbic acid may effectively prevent radiation-induced GI syndrome.

著者

YUMIKO NITTA SATORU ENDO NARIAKI FUJIMOTO KENJI KAMIYA MASAHARU HOSHI

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.42, no.2, pp.143-155, 2001 (Released:2001-10-27)

参考文献数

28

被引用文献数

5 4

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Female rats of the Fischer 344 strain at ages of 1, 4 and 9 weeks were exposed to 131I intraperitoneally with activities of 0.38, 1.03 and 3.42 kBq per gram of body weight under the condition of iodine deficiency. The absorbed doses in the thyroid increased linearly depending on the injected activities. Irradiation at 1 week old caused heavier exposure than those at 4 and 9 weeks old by 7.5 and 7.7 times, respectively; however, damage of the thyroid tissue was more obvious in the 4-week-old groups than in the 1-week-old groups. The absorbed doses in the total body were proportional to the square root of the injected activities. The one-week-old groups were exposed more heavily than the 4- and 9-week-old groups by 3.6 and 4.7 times, respectively, shown by the slow excretion of 131I with the values of effective half-life of 131I activity (Teff). An IDD-treatment was not so effective to enhance the 131I absorption in the total body, as in the thyroid. No matter how the iodine concentration in the blood changed, the 1-week-old groups could not react to normalize the level. We drew standard curves, which enabled us to estimate the absorbed doses in the thyroid and the total body in the case of the injected activities of 131I for the newborn, pubertal and adult rats.

著者

Dusan SOKOLOVIC Boris DJINDJIC Jelenka NIKOLIC Gordana BJELAKOVIC Dusica PAVLOVIC Gordana KOCIC Dejan KRSTIC Tatjana CVETKOVIC Voja PAVLOVIC

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.6, pp.579-586, 2008 (Released:2008-11-28)

参考文献数

42

被引用文献数

80

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Purpose: The aim of the study was to evaluate the intensity of oxidative stress in the brain of animals chronically exposed to mobile phones and potential protective effects of melatonin in reducing oxidative stress and brain injury. Materials and methods: Experiments were performed on Wistar rats exposed to microwave radiation during 20, 40 and 60 days. Four groups were formed: I group (control)- animals treated by saline, intraperitoneally (i.p.) applied daily during follow up, II group (Mel)- rats treated daily with melatonin (2 mg kg-1 body weight i.p.), III group (MWs)- microwave exposed rats, IV group (MWs + Mel)- MWs exposed rats treated with melatonin (2 mg kg-1 body weight i.p.). The microwave radiation was produced by a mobile test phone (SAR = 0.043-0.135 W/kg). Results: A significant increase in the brain tissue malondialdehyde (MDA) and carbonyl group concentration was registered during exposure. Decreased activity of catalase (CAT) and increased activity of xanthine oxidase (XO) remained after 40 and 60 days of exposure to mobile phones. Melatonin treatment significantly prevented the increase in the MDA content and XO activity in the brain tissue after 40 days of exposure while it was unable to prevent the decrease of CAT activity and increase of carbonyl group contents. Conclusion: We demonstrated two important findings; that mobile phones caused oxidative damage biochemically by increasing the levels of MDA, carbonyl groups, XO activity and decreasing CAT activity; and that treatment with the melatonin significantly prevented oxidative damage in the brain.

著者

TOMOTAKA SOBUE VALERIE S. LEE WEIMIN YE HIROSHI TANOOKA MASAAKI MIFUNE AKIHIKO SUYAMA TAEKO KOGA HIROSHIGE MORISHIMA SOHEI KONDO

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.2, pp.81-92, 2000 (Released:2001-07-26)

参考文献数

23

被引用文献数

17

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In order to investigate an association between residential radon exposure and risk of lung cancer, a case-control study was conducted in Misasa Town, Tottori Prefecture, Japan. The case series consisted of 28 people who had died of lung cancer in the years 1976-96 and 36 controls chosen randomly from the residents in 1976, matched by sex and year of birth. Individual residential radon concentrations were measured for 1 year with alpha track detectors. The average radon concentration was 46 Bq/m3 for cases and 51 Bq/m3 for controls. Compared to the level of 24 or less Bq/m3, the adjusted odds ratios of lung cancer associated with radon levels of 25-49, 50-99 and 100 or more Bq/m3, were 1.13 (95% confidence interval; 0.29-4.40), 1.23 (0.16-9.39) and 0.25 (0.03-2.33), respectively. None of the estimates showed statistical significance, due to small sample size. When the subjects were limited to only include residents of more than 30 years, the estimates did not change substantially. This study did not find that the risk pattern of lung cancer, possibly associated with residential radon exposure, in Misasa Town differed from patterns observed in other countries.

著者

Stéphane GRISON Jean-Charles MARTIN Line GRANDCOLAS Nathalie BANZET Eric BLANCHARDON Elie TOURLONIAS Catherine DEFOORT Gaëlle FAVÉ Romain BOTT Isabelle DUBLINEAU Patrick GOURMELON Maâmar SOUIDI

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.1, pp.33-43, 2012 (Released:2012-02-02)

参考文献数

52

被引用文献数

20 9

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Reports have described apparent biological effects of 137Cs (the most persistent dispersed radionuclide) irradiation in people living in Chernobyl-contaminated territory. The sensitive analytical technology described here should now help assess the relation of this contamination to the observed effects. A rat model chronically exposed to 137Cs through drinking water was developed to identify biomarkers of radiation-induced metabolic disorders, and the biological impact was evaluated by a metabolomic approach that allowed us to detect several hundred metabolites in biofluids and assess their association with disease states. After collection of plasma and urine from contaminated and non-contaminated rats at the end of the 9-months contamination period, analysis with a LC-MS system detected 742 features in urine and 1309 in plasma. Biostatistical discriminant analysis extracted a subset of 26 metabolite signals (2 urinary, 4 plasma non-polar, and 19 plasma polar metabolites) that in combination were able to predict from 68 up to 94% of the contaminated rats, depending on the prediction method used, with a misclassification rate as low as 5.3%. The difference in this metabolic score between the contaminated and non-contaminated rats was highly significant (P = 0.019 after ANOVA cross-validation). In conclusion, our proof-of-principle study demonstrated for the first time the usefulness of a metabolomic approach for addressing biological effects of chronic low-dose contamination. We can conclude that a metabolomic signature discriminated 137Cs-contaminated from control animals in our model. Further validation is nevertheless required together with full annotation of the metabolic indicators.

著者

伊沢 正実 坪田 博行

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.3, no.2, pp.120-129, 1962 (Released:2006-08-29)

参考文献数

16

被引用文献数

5

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To evaluate hazards of environmental contamination due to fission products from nuclear weapon test explosions, determination of body burden of the radionuclides taken in human body is essential. Because urine analysis is one of the practical methods to estimate body burden, Cs-137 concentration in human urine has been surveyed in Osaka and Ishikawa Prefectures since the fall of 1959. From the results of analyses, time variation of Cs-137 concentration and difference between two sampling sites were discussed with respect to the fallout rate. Cs-137 body burden was estimated from the analytical results by assuming the exponential equation for continuous exposure : In November 1959 the values were 8.4 mμc in Ishikawa and 6.0 mμc in Osaka respectively. And they decreased to 3 mμc in October 1961 in both areas. These values were consistent with the results obtained by other methods. Cs-137 gonad dose could be calculated with these values assuming uniform distribution of Cs-137 in a human body. Gonad dose rate due to internally deposited Cs-137 at present is about 0.7 mrad/y, and gonad dose up to the present is in the range of 5 to 8 mrad.

著者

Miao-Fen CHEN Chun-Te WU Yu-Jen CHEN Peter C. KENG Wen-Cheng CHEN

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.253-260, 2004 (Released:2004-08-10)

参考文献数

47

被引用文献数

65

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Caffeic acid phenethyl ester (CAPE) is a biologically active ingredient of honeybee propoplis. The cytotoxicity and radiation sensitization effects of CAPE were evaluated in human lung cancer A549 cells and normal lung fibroblast WI-38 cells. A549 cells treated with 6 μg/ml CAPE showed marked growth inhibition (60%) at 48 hr after treatments. During the same time, the number of viable cells decreased to 46% of the control value. In contrast, WI-38 cells showed 20% growth inhibition with no change in the number of viable cells under the same treatment conditions. At 72 hr after CAPE treatment (6 μg/ml), the percentage of apoptotic cells in A549 cultures increased significantly to 67% and an S/G2 arrest was also detected in the culture. Furthermore, there was a significant decrease in the level of intracellular glutathione and hydrogen peroxide contents within one hr after CAPE treatment, and the expression of cyclin B1 was reduced 6 hr after treatment. The radiation sensitization effect of CAPE on A549 cells was determined from the clonogenic survival curves, and the results showed a small but significant difference in radiation survival between cells treated with or without CAPE. Taken together, our results suggest that the effects of CAPE on differential cytotoxicity, apoptosis, and radiosensitization are associated with glutathione depletion that occurred shortly after treatments.

著者

Minli WANG Megumi HADA Janice HUFF Janice M. PLUTH Jennifer ANDERSON Peter O'NEILL Francis A. CUCINOTTA

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.1, pp.51-57, 2012 (Released:2012-02-02)

参考文献数

27

被引用文献数

13

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TGFβ is a key modulator of the Epithelial–Mesenchymal Transition (EMT), a process important in cancer progression and metastasis, which leads to the suppression of epithelial genes and expression of mesenchymal proteins. Ionizing radiation was found to specifically induce expression of the TGF-β1 isoform, which can modulate late post-radiation changes and increase the risk of tumor development and metastasis. Interactions between TGFβ induced EMT and DNA damage responses have not been fully elucidated, particularly at low doses and following different radiation quality exposures. Further characterization of the relationship between radiation quality, EMT and cancer development is warranted. We investigated whether space radiation induced TGFβ dependent EMT, using hTERT immortalized human esophageal epithelial cells (EPC2-hTERT) and non-transformed mink lung epithelial cells (Mv1Lu). We have observed morphologic and molecular alterations in EPC2 and Mv1Lu cells consistent with EMT after pre-treatment with TGFβ1. This effect could be efficiently inhibited in both cell lines by the use of a TGFβRI inhibitor. High-energy silicon or iron nuclei were each able to cause a mild induction of EMT, with the inclusion of TGFβ1 inducing a greatly enhanced EMT phenotype even when cells were irradiated with doses as low as 0.1 Gy. A further enhancement of EMT was achieved at a higher dose of 2 Gy. TGFβRI inhibitor was able to reverse the EMT induced by the combination of TGFβ1 and radiation. These studies indicate that heavy ions, even at a low dose, may trigger the process of TGFβ1–induced EMT, and suggest further studies are needed to determine whether the chronic exposures received in space may potentiate this process in astronauts, leading to an increased risk of cancer.

著者

Kazunori ANZAI Nobuo IKOTA Megumi UENO Minako NYUI Tsutomu V. KAGIYA

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.4, pp.425-430, 2008 (Released:2008-07-17)

参考文献数

17

被引用文献数

12

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In vivo radioprotection of C3H mice by i.p. administration of Zn-, Mn-, Cu-, or Se-containing heat-treated Saccharomyces serevisiae yeast sample was examined. The 30-day survival of the group treated 30 min before 7.5 Gy whole-body X-irradiation with mineral-containing yeast powders suspended in 0.5% methylcellulose was significantly higher than that of control group. When mineral-yeast was administered immediately after irradiation, the survival rate was even higher and Zn- or Cu-yeast showed the highest rate (more than 90%). Although treatment with simple yeast showed a high survival rate (73%), it was significantly lower than that obtained by the Zn-yeast treatment. The effects of Zn-yeast were studied further. When the interval between irradiation and administration was varied, the protective activity of Zn-yeast decreased gradually by increasing the interval but was still significantly high for the administration at 10 h post-irradiation. The dose reduction factor of Zn-yeast (100 mg/kg, i.p. administration immediately after irradiation) was about 1.2. When the suspension of Zn-yeast was fractionated by centrifugation, the insoluble fraction showed a potent effect, while the soluble fraction had only a moderate effect. In conclusion, mineral-yeast, especially Zn-yeast, provides remarkable post-irradiation protection against lethal whole body X-irradiation. The activity is mainly attributable to the insoluble fraction, whereas some soluble components might contribute to the additional protective activity.

著者

MARIA KOWALSKA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.26, no.4, pp.385-394, 1985-12-15 (Released:2006-06-16)

参考文献数

15

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Three generations of rats were long-term exposed to HTO in drinking water at activity of 37.0 kBq/ml or to food containing OBT at activity of 48.1 kBq/g. The rats consumed tritiated water and tritiated food ad libitum. In the experiment the F1 and F2 generation of rats were exposed continuously from conception to the 21-st or 120-th day of age and rats of F3 generation during 22 days of their intrauterine life. It was found that the amount of tritium incorporated into the major rat brain phospholipids and gangliosides after administration of tritiated food was higher than after administration of tritiated water. Tritium activity in all studied phospholipids and gangliosides was the highest in 21-day-old rats exposed during both-pregnancy and lactation.

著者

大北 威

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.16, no.SUPPLEMENT, pp.49-66, 1975-09-16 (Released:2006-07-14)

参考文献数

132

被引用文献数

26

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An outline of the acute effects of the Hiroshima and Nagasaki atomic bombs are summarized, based on documentary records. Acute injuries caused by the atomic bombs have been classified as thermal, mechanical, and radiation injuries. Combinations of these were most common. Many died from the immediate effects of blast and burns, but individuals often succumbed to trauma or burns before the radiation syndrome developed. Many more would have died from irradiation, had they been saved from the effects of trauma or burns. Nearly all who died within 10 weeks had signs suggestive of radiation injuries. Remarkable variation in sensitivity of body tissues to ionizing radiation was apparent. Radiation-induced bone marrow depletion was the most critical damage leading to death. In these instances, leukopenia and thrombocytopenia, and subsequent infections and hemorrhagic tendencies were the main causes of death. The clinical symptoms and signs of radiation injuries; the RBE of the atomic bomb neutrons for acute effects; and the effects of irradiation on spermatogenesis are also discussed.

著者

武田 洋 樫田 義彦

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.20, no.2, pp.174-185, 1979-05-15 (Released:2006-07-14)

参考文献数

18

被引用文献数

17

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Distribution and retention of tritium in various tissue of a rat after administration of tritiated water (HTO) was investigated during about 100 days. Tritium incorporated into the body was rapidly and uniformly distribution in the whole body and excreted immediately with a biological half-life of 3.5 days for almost all the tissues. However, excretion of tritium incorporated into the tissue constituents was relatively slow and the retention curves were considerably different from tissue to tissue. At the end of this experiment, the highest concentration of total tritium was observed in the fat tissue, followed by brain and muscle. These results suggested that the intake of tritium from HTO into organic compounds and the excretion of tissue-bound tritium would be related to metabolic activity of the tissue. This prediction was reinforced by the experiment on age dependence. The radiation dose to each tissue after the administration of 6.0 μCi/g body weight of HTO ranged from 2.0 to 9.5 rem, which was the highest in blood and the lowest in fat tissue. Contribution from tissue-bound tritium was within 10% of the dose from total tritium for each tissue, except for fat tissue which was 64%.

著者

Yamamoto Tetsuo Kinoshita Manabu Shinomiya Nariyoshi HIROI Sadayuki SUGASAWA Hidekazu MATSUSHITA Yoshitaro MAJIMA Takashi SAITOH Daizoh SEKI Shuhji

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.2, pp.145-156, 2010-03-16

被引用文献数

38

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While bone marrow or stem cell transplantation can rescue bone marrow aplasia in patients accidentally exposed to a lethal radiation dose, radiation-induced irreversible gastrointestinal damage (GI syndrome) is fatal. We investigated the effects of ascorbic acid on radiation-induced GI syndrome in mice. Ascorbic acid (150 mg/kg/day) was orally administered to mice for 3 days, and then the mice underwent whole body irradiation (WBI). Bone marrow transplantation (BMT) 24 h after irradiation rescued mice receiving a WBI dose of less than 12 Gy. No mice receiving 14 Gy-WBI survived, because of radiation-induced GI syndrome, even if they received BMT. However, pretreatment with ascorbic acid significantly suppressed radiation-induced DNA damage in the crypt cells and prevented denudation of intestinal mucosa; therefore, ascorbic acid in combination with BMT rescued mice after 14 Gy-WBI. DNA microarray analysis demonstrated that irradiation up-regulated expressions of apoptosis-related genes in the small intestine, including those related to the caspase-9-mediated intrinsic pathway as well as the caspase-8-mediated extrinsic pathway, and down-regulated expressions of these genes in ascorbic acid-pretreated mice. Thus, pretreatment with ascorbic acid may effectively prevent radiation-induced GI syndrome.

著者

Shiga Takeki Suzuki Hiroyuki Yamamoto Ayumi YAMAMOTO Hiroaki YAMAMOTO Kazuo

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.4, pp.405-415, 2010-07-16

被引用文献数

1 12

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Previously, we have shown that phenyl hydroquinone, a hepatic metabolite of the Ames test-negative carcinogen <i>o</i>-phenylphenol, efficiently induced aneuploidy in <i>Saccharomyces cerevisiae</i> by arresting the cell cycle at the G2/M transition as a result of the activation of the Hog1 (p38 MAPK homolog)-Swe1 (Wee1 homolog) pathway. In this experiment, we examined the aneuploidy forming effects of hydroquinone, a benzene metabolite, since both phenyl hydroquinone and hydroquinone are Ames-test negative carcinogens and share similar molecular structures. As was seen in phenyl hydroquinone, hydroquinone induced aneuploidy in yeast by delaying the cell cycle at the G2/M transition. Deficiencies in <i>SWE1</i> and <i>HOG1</i> abolished the hydroquinone-induced delay at the G2/M transition and aneuploidy formation. Furthermore, Hog1 was phosphorylated by hydroquinone, which may stabilize Swe1. These data indicate that the hydroquinone-induced G2/M transition checkpoint, which is activated by the Hog1-Swe1 pathway, plays a role in the formation of aneuploidy.

著者

小松 賢志 樋口 昌孝 粟冠 正利

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.22, no.2, pp.226-241, 1981-07-15 (Released:2006-06-16)

参考文献数

38

被引用文献数

11

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Accumulation of tritium in aquatic organisms was estimated through a model food chain such as; tritiated water (THO) → diatoms → brine shrimps → Japanese killifish. Tritium accumulations in each organism as organic bound form are expressed as the R value which is defined as the ratio of tritium specific activity in lyophilized organisms (μCi/gH) to that in water (μCi/gH). The maximum R values were 0.5 in diatoms, Chaetoceros gracilis, 0.5 in brine shrimps, Artamia salina, and 0.32 in Japanese killifish, Oryzias latipes under the growing condition where tritium accumulation took place from tritiated water without tritiated diets. Brine shrimps and Japanese killifish, which grew from larvae to adult in tritiated sea water with feeding on tritiated diets (model food chain), had the R value at 0.70 and 0.67 respectively, indicating that more tritium accumulation in consumer populations with tritiated diets than those without tritiated diets. In addition, the R values of each organ of Japanese killifish, of DNA and the nucleotides purified rfom brine shrimps growing under the condition with or without our model food chain were measured to estimate the tritium distribution in the body or various components of the organism. These results did not indicate the seeking characteristic of tritium to some specific organs of compounds.

著者

TAKEO OHNISHI KEN OHNISHI AKIHISA TAKAHASHI YOSHITAKA TANIGUCHI MASARU SATO TAMOTSU NAKANO SHUNJI NAGAOKA

出版者

Journal of Radiation Research Editorial Committee

雑誌

Journal of Radiation Research (ISSN:04493060)

巻号頁・発行日

vol.43, no.S, pp.S133-S136, 2002 (Released:2003-05-02)

参考文献数

7

被引用文献数

20

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Although physical monitoring of space radiation has been accomplished, we aim to measure exact DNA damage as caused by space radiation. If DNA damage is caused by space radiation, we can detect DNA damage dependent on the length of the space flight periods by using post-labeling methods. To detect DNA damage caused by space radiation, we placed fixed human cervical carcinoma (HeLa) cells in the Russian Mir space station for 40 days and in an American space shuttle for 9 days. After landing, we labeled space-radiation-induced DNA strand breaks by enzymatic incorporation of [3H]-dATP with terminal deoxyribo-nucleotidyl transferase (TdT). We detected DNA damage as many grains on fixed silver emulsion resulting from β-rays emitted from 3H-atoms in the nuclei of the cells placed in the Mir-station (J/Mir mission, STS-89), but detected hardly any in the ground control sample. In the space shuttle samples (S/MM-8), the number of cells having many grains was lower than that in the J/Mir mission samples. These results suggest that DNA damage is caused by space radiation and that it is dependent on the length of the space flight.

著者

Muzahir Ali BALOCH Aziz Ahmed QURESHI Abdul WAHEED Muhammad ALI Nawab ALI Muhammad TUFAIL Saima BATOOL Muhammad AKRAM Poonam IFTIKHAR Hamza QAYYUM Shahid MANZOOR Hameed Ahmed KHAN

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.3, pp.411-421, 2012 (Released:2012-06-01)

参考文献数

55

被引用文献数

20

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The Khewra Salt Mines, the second largest salt mines in the world, are located 160 km south of Islamabad, the capital of Pakistan. Around 1000 workers are involved in the removal of salt from these mines. More than 40,000 visitors come annually to see the mines. The visitors and workers are directly exposed to the internal and external radiological hazards of radon and gamma rays in these mines. The general public is affected by the intake of the salt containing the naturally occurring radionuclides. Therefore the concentration of radon (222Rn) in the Khewra Salt Mines and activity concentrations of the naturally occurring radionuclides in the salt samples from these mines were measured. Both active and passive techniques were employed for the measurement of radon with Radon Alpha Detector (RAD-7) and SSNTD respectively. The concentration of 222Rn was 26 ± 4 Bq m–3 measured by the active method while 43 ± 8 Bq m–3 was measured by the passive method. The activity concentration of the radionuclides was measured using gamma ray spectrometry with HPGe detector. The mean activity of 40K in salt samples was found to be 36 ± 20 Bq kg–1 and the concentration of 226Ra and 232Th in the salt samples was below the detection limits. Gamma radiation hazard was assessed in terms of the external gamma dose from salt slabs and the rooms made of salt and the annual effective dose due to gamma radiation. The exposure to radon daughters, annual effective dose and excessive lifetime cancer risk due to radon in the mines were estimated. The mean annual effective dose due to an intake of 40K from the salt was calculated as 20.0 ± 11.1 μSv, which is lower than the average annual effective dose rate of 0.29 mSv, received by the ingestion of natural radionuclides. Due to the low concentration values of primordial radionuclides in the salt and radon (222Rn) in the mines, a ‘low level activity measurement laboratory' is suggested to be established in these mines.