Research Projects -
-
放射線と環境酸化ストレスに対する生体応答の相違性の解明
2024.04 - 2028.03
日本学術振興会 科学研究費補助事業 基盤研究(C)
片岡隆浩, 山岡聖典
Authorship：Coinvestigator(s)
-
放射線と複数ストレス曝露が及ぼす組織への影響とその予防効果の検証
Grant number：21K04943 2021.04 - 2024.03
日本学術振興会 科学研究費助成事業 基盤研究(C)
片岡隆浩, 山岡聖典
Authorship：Coinvestigator(s)
Grant amount：\4160000 （ Direct expense: \3200000 、 Indirect expense：\960000 ）
今まで，マウスへの低線量・低線量率（3.0mGy/h，総線量0.5Gy）のγ線照射が強制水泳試験（FST）に伴う酸化ストレスに及ぼす効果に関して検討してきた。その結果，抗酸化物質の活性・量の変化特性から，脳や腎臓はFSTに対して，肝臓は照射とFSTの相加に対して各々弱く，肺はこれらに対して強いなど，臓器に大きく依存していることが示唆してきた。そこで本研究課題では，低線量・高線量率X線照射（約1.2Gy/m，総線量0.5Gy）とFST後に，アルコール投与により肝臓に酸化ストレスを負荷した場合の肝障害の程度について検討した。BALB/cマウスに0.5GyのX線（線量率 約1.2Gy/m）を照射した。対照には擬似(sham)照射をした。その4時間後に，10分間のFST（直径10cm，高さ25cmの円筒形の筒に25±1℃の水を入れ，マウスを強制水泳させる。マウスを水の入った円筒に入れた際，足・尾が水底につかない程度の水深とする）をした。FSTは５回（１日１回）実施した。5回目のFST終了直後に50％エタノール（5g/kg体重）を腹腔投与した。その6時間または24時間後にマウスを安楽死させ，血液を採取した。なお，本実験は岡山大学動物実験委員会の承認を得て実施した。その結果，肝機能の指標であるglutamic oxaloacetic transaminase(GOT)や glutamic pyruvic transaminase(GPT)活性は，アルコール投与に伴い増加した。FSTとアルコールを投与した場合，0.5Gy照射のGOT活性とGPT活性はsham照射のそれに比べそれぞれ40％，25%高かったが有意な差はないことがわかった。
-
ラドン療法による新型コロナウイルス感染症の予防と症状改善に関する基礎的研究
2020.04 - 2026.03
岡山大学 学都基金研究助成事業
山岡聖典, 片岡隆浩
Authorship：Principal investigator
-
創造的健康増進プランによる三朝地区の地域再開発
2018.04 - 2022.03
岡山大学 理事裁量経費
山岡聖典, 片岡隆浩
Authorship：Principal investigator
-
Grant number：18K04994 2018.04 - 2021.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
Yamaoka Kiyonori
Authorship：Principal investigator
Grant amount：\4160000 （ Direct expense: \3200000 、 Indirect expense：\960000 ）
We evaluated the effects of low-dose X- or γ-irradiation on the forced swim test (FST)-immobility and oxidative stress in mouse organs. Results showed that 0.5 Gy X-irradiation after FST inhibits FST-induced immobility and oxidative stress in brain of mice. The superoxide dismutase (SOD) activity in the liver of the 3.0 mGy/h γ-irradiated mice were significantly lower than those of the non-FST-treated mice. The CAT activity in the lungs of mice exposed to 3.0 mGy/h γ-irradiation was higher than that of non-FST treated mice and mice treated with FST. These findings suggest that low-dose irradiation inhibits FST-induced immobility and that the effects of low-dose-irradiation on FST are highly organ-dependent.
-
Study on the health effects of low-dose irradiation in restricted area
Grant number：16K18349 2016.04 - 2019.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B) Grant-in-Aid for Young Scientists (B)
Kataoka Takahiro, YAMAOKA Kiyonori
Authorship：Coinvestigator(s)
Grant amount：\3770000 （ Direct expense: \2900000 、 Indirect expense：\870000 ）
The purpose of this study was to evaluate the oxidative stress in the brain after X-irradiation. Results showed that low-dose irradiation mostly showed decrease in lipid peroxide (LPO) levels, increase in superoxide dismutase (SOD) activities and heat shock protein (HSP) levels. In addition, the combined use of 0.5 Gy irradiation with ascorbic acid administration showed a significant decrease in lipid peroxide level, suggesting the combined effect of antioxidant.
-
原子力防災・危機管理のための安全技術者育成講座他
2016.04 - 2018.03
経済産業省 安全性向上原子力人材育成委託事業
鈴木和彦, 山岡聖典他
-
Grant number：26420872 2014.04 - 2017.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
Yamaoka Kiyonori
Authorship：Principal investigator
Grant amount：\4940000 （ Direct expense: \3800000 、 Indirect expense：\1140000 ）
We compared liver damage by radiation with by alcohol which is living environment factor to dispel the fear of low-dose radiation. We analyzed liver function and anti-oxidative function in liver using self-organizing maps. The results showed that the effects of radon inhalation at a concentration of up to 2000 Bq/m3 or X-irradiation at a dose of up to 2.0 Gy were comparable with the effect of alcohol administration at 0.5 g/kg bodyweight. According to our result of clustering, their different patterns of liver damage caused by different factors. We found that the effects of low-dose X-irradiation or radon inhalation was extremely small and highly individual.
-
Study on health concern about low-dose irradiation
Grant number：25820449 2013.04 - 2016.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B) Grant-in-Aid for Young Scientists (B)
Kataoka Takahiro, YAMAOKA Kiyonori
Authorship：Coinvestigator(s)
Grant amount：\4160000 （ Direct expense: \3200000 、 Indirect expense：\960000 ）
We have reported that radon inhalation increases antioxidative activity in many organs of mice. On the other hand, brain damage following ischemia-reperfusion injury involves reactive oxygen species. The purpose of this study was to compare the antioxidative effects of radon with the effects of ascorbic acid. Gerbils inhaled radon or administered ascorbic acid before induction of transient global cerebral ischemia. Results showed that radon inhalation or ascorbic acid administration inhibited global cerebral ischemia induced neuron damage. Radon inhalation activated superoxide dismutase activity. These results indicated that radon inhalation at a concentration of 2000 Bq/m3 has a protective antioxidative effect against transient global cerebral ischemic injury similar to 500 mg/kg ascorbic acid treatment.
-
三朝ラドン温泉を活用した未来型健康増進プランの構築
2012.04 - 2014.03
岡山大学 機能強化戦略経費大型研究推進支援
山岡聖典, 片岡隆浩
Authorship：Principal investigator
-
天然ラドン健康増進製品の試作と健康効果の基礎的検討
2009.04 - 2010.03
岡山県産業振興財団 研究補助金
山岡聖典
Authorship：Principal investigator
-
低線量放射線環境安全・安心工学の研究教育の推進
2008.04 - 2018.03
文部科学省 特別教育研究経費事業
鈴木和彦, 山岡聖典他
Authorship：Coinvestigator(s)
-
極微量ウラン影響効果試験
2007.04 - 2026.03
日本原子力研究開発機構 共同研究
山岡聖典, 片岡隆浩他
Authorship：Principal investigator
-
天然ラドンミスト発生装置開発事業
2006.04 - 2007.03
岡山県産業振興財団 研究補助金
山岡聖典
Authorship：Principal investigator
-
DEVELOPMENT OF RISK ASSESSMENT METHODS ON HAZARD IDENTIFICATION USING CATALASE MUTANT GENE AS A PREDICTIVE INDEX
Grant number：14570299 2002.04 - 2004.03
Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C) Grant-in-Aid for Scientific Research (C)
WANG Da-hong, YAMAOKA Kiyonori
Authorship：Coinvestigator(s)
Grant amount：\3500000 （ Direct expense: \3500000 ）
This research was aimed at developing a risk assessment method for potential hazards by using catalase mutant strains. At first, we successfully constructed catalase mutant E coli strains by transforming plasmids encoding the catalase cDNA from catalase mutant mice (Cs^b, Cs^c) and its corresponding wild type (Cs^a) into catalase-deficient Escherichia coli UM255. There was a significant difference in catalase activities among each catalase-deficient E. coli mutant. The level of catalase in Csa appeared higher than that in the others, the catalase level in Cs^c was 65.1% of Cs^a, Cs^b was 61.7%, and UM 255 was 8.8% of Cs^a. Susceptibility to H_2O_2 showed a clear dose dependency with negative correlation to catalase activity levels. The susceptibility order was UM255>Cs^b>Cs^c>Cs^a. To assess the cytotoxicity of the chemicals, we employed colony-forming efficiency test and zones of inhibition test, the results demonstrated that survival of catalase-deficient E. coli mutants was significantly reduced by treatment of hydroquinone, pyrogallol and L-Dopa in a dose-dependent manner and the cell viabilities underexposure to these chemicals were also different significantly among each catalase mutant strain, showing the following orders : Cs^a>Cs^c>Cs^b>UM255. The cytotoxicities induced by hydroquinone, pyrogallol and L-Dopa were also confirmed by zone of inhibition test, in which UM255 was the most susceptible, showing the largest zone of growth inhibition surrounding the paper disc, followed by Cs^b, Cs^c and Cs^a. The toxicities of these chemicals were completely blocked by catalase and ascorbic acid in a concentration-dependent relation. Treatment by some heavy metals (Hg, Cr, Cd, As, Ni, Fe, Cu) also significantly reduced the survival of these strains in a dose-dependent manner, suggesting H_2O_2 was increasingly produced in the process of hydroquinone cytotoxicity and catalase played a protective role in inhibiting the cell damage. The results support the usefulness of these newly established strains for hazard identification of oxidative chemicals in a risk assessment process.
-
低線量放射線の健康影響と医療応用に関する研究Ⅱ
2001.04 - 2027.03
12機関（24件） 奨学寄付金
山岡聖典
Authorship：Principal investigator
-
低線量放射線に応答する生体機能に関する研究
1999.04 - 2007.03
電力中央研究所 共同研究
山岡聖典
Authorship：Principal investigator
-
低線量放射線の健康影響と医療応用に関する研究Ⅰ
1984.04 - 1999.03
岡山大学,理化学研究所,東京大学他 共同研究
山岡聖典, 森昭胤, 二木鋭雄他
Authorship：Principal investigator
-
低レベル廃棄物の分別管理システムに関する検討
1983.04 - 1985.03
科学技術庁 依頼研究
山岡聖典, 根本和泰, 尾崎幸男, 讃井敏光
Authorship：Principal investigator
-
紫外部チェレンコフ光による使用済燃料集合体の確認法に関する検討
1982.04 - 1984.03
科学技術庁 依頼研究
中岡章, 山岡聖典, 栗原雅幸, 福島政法
Authorship：Coinvestigator(s)