Informa Healthcare Acta Medica Okayama 1525-6049 34 9 2012 Comparative Study on the Inhibitory Effects of α-Tocopherol and Radon on Carbon Tetrachloride-Induced Renal Damage 1181 1187 EN Takahiro Kataoka Keiko Yamato Yuichi Nishiyama Yuji Morii Reo Etani Yuji Takata Katsumi Hanamoto Atsuishi Kawabe Akihiro Sakoda Yuu Ishimori Takehito Taguchi Kiyonori Yamaoka Since the 2011 nuclear accident in Fukushima, the effects of low-dose irradiation, especially internal exposure, are at the forefront of everyone’s attention. However, low-dose radiation induced various stimulating effects such as activation of antioxidative and immune functions. In this study, we attempted to evaluate the quantitative effects of the activation of antioxidative activities in kidney induced by radon inhalation on carbon tetrachloride (CCl₄)-induced renal damage. Mice were subjected to intraperitoneal (i.p.) injection of CCl₄ after inhaling approximately 1000 or 2000 Bq/m³ radon for 24 h, or immediately after i.p. injection of α-tocopherol (100, 300, or 500 mg/kg bodyweight). In case of renal function, radon inhalation at a concentration of 2000 Bq/m³ has the inhibitory effects similar to α-tocopherol treatment at a dose of 300–500 mg/kg bodyweight. The activities of superoxide dismutase and catalase in kidneys were significantly higher in mice exposed to radon as compared to mice treated with CCl₄ alone. These findings suggest that radon inhalation has an antioxidative effect against CCl₄-induced renal damage similar to the antioxidative effects of α-tocopherol due to induction of antioxidative functions. No potential conflict of interest relevant to this article was reported.

Japan Radioisotope Association Acta Medica Okayama 0033-8303 61 1 2012 ラドン吸入がペットの健康改善に及ぼす効果に関する基礎的検討 1 8 EN Takahiro Kataoka Rikizo Tokunaga Akihiro Sakoda Atsushi Kawabe Katsumi Hanamoto Kiyonori Yamaoka 著者らは今までに，共同開発したラドン吸入装置を用いマウスにラドン吸入をさせた場合，諸臓器中の抗酸化機能が亢進する可能性などを明らかにしてきた。本研究では，ラドン吸入の獣医療への応用の可能性について新たに検討するため，健常なイヌ5頭(オス：2(1，9才)，メス：3(1〜5才))及び慢性腎不全症のネコ8頭(オス：3(2〜6才)，メス：5(5〜7才))を対象に基礎的な検討をした。すなわち，約5500Bq/m³のラドンを1回30分で隔日に30日間(計15回)それぞれ吸入させた。その結果，イヌにおいて，中性脂肪が減少する可能性が示された。また，その効果は吸入開始20〜30日後に現れることも示唆できた。他方，ネコにおいて，飲水量が改善し血清中クレアチニンが基準値内に減少する症例がみられるなど，慢性腎不全症に対し一定の効果が期待できる可能性が示唆された。 No potential conflict of interest relevant to this article was reported.

Oxford University Press Acta Medica Okayama 0144-8420 146 1-3 2011 Studies on possibility for alleviation of lifestyle diseases by low-dose irradiation or radon inhalation 360 363 EN Takahiro Kataoka Akihiro Sakoda Masaaki Yoshimoto Shinya Nakagawa Teruaki Toyota Yuichi Nishiyama Keiko Yamato Yuu Ishimori Atsushi Kawabe Katsumi Hanamoto Takehito Taguchi Kiyonori Yamaoka Our previous studies showed the possibility that activation of the antioxidative function alleviates various oxidative damages, which are related to lifestyle diseases. Results showed that, low-dose X-ray irradiation activated superoxide dismutase and inhibits oedema following ischaemia-reperfusion. To alleviate ischaemia-reperfusion injury with transplantation, the changes of the antioxidative function in liver graft using low-dose X-ray irradiation immediately after exenteration were examined. Results showed that liver grafts activate the antioxidative function as a result of irradiation. In addition, radon inhalation enhances the antioxidative function in some organs, and alleviates alcohol-induced oxidative damage of mouse liver. Moreover, in order to determine the most effective condition of radon inhalation, mice inhaled radon before or after carbon tetrachloride (CCl₄) administration. Results showed that radon inhalation alleviates CCl₄-induced hepatopathy, especially prior inhalation. It is highly possible that adequate activation of antioxidative functions induced by low-dose irradiation can contribute to preventing or reducing oxidative damages, which are related to lifestyle diseases. No potential conflict of interest relevant to this article was reported.

The Editorial Secretariat of JCBN Acta Medica Okayama 0912-0009 43 1 2008 No Different Sensitivity in Terms of Whole-Body Irradiation between Normal and Acatalasemic Mice 41 49 EN Shinya Nakagawa Takahiro Kataoka Yuko Mizuguchi Masaaki Yoshimoto Akihiro Sakoda Takaharu Nomura Da-Hong Wang Atsushi Kawabe Takehito Taguchi Kiyonori Yamaoka To elucidate the radiosensitivity of an acatalasemic mouse, we examined the time and dose-dependency in the survival rates, the lymphocytes and the intestinal epithelial cells, and the antioxidant function after 3.0 to 12.0 Gy whole body irradiation. Results showed that no significant differences between acatalasemic mice and normal mice were observed in the survival rates and the histological changes in spleens and small intestine after each irradiation. The catalase activities in livers and spleens of acatalasemic mice were significantly lower than those of normal mice and the glutathione peroxidase activity in livers of acatalasemic mice was significantly higher than that of normal mice. At 10 days after 6.0 Gy irradiation, the catalase activities in livers of acatalasemic and normal mice and that in spleens of normal mice significantly decreased compared with no-irradiation control, and there were no differences between those catalase activities. The total glutathione content in acatalasemic mice was significantly higher than that in normal mice at 10 days after 6.0 Gy irradiation. These findings suggested that the radiosensitivity of acatalasemic mice in terms of whole body irradiation doesn’t significantly differ from that of normal mice, probably due to compensated sufficient contents of glutathione peroxidase and total glutathione in acatalasemic mice. No potential conflict of interest relevant to this article was reported.

岡山大学医学部保健学科 Acta Medica Okayama 1345-0948 14 1 2003 放射線治療時の治療患部外散乱被曝線量に関する研究 15 22 EN Atsushi Kawabe Yoshitada Nakagiri Kazuki Kobashi Naoki Yasumura Takahiro Yamashita Sachiko Goto Toshinori Maruyama Kouichi Shibuya Katsuhiko Sugita 10.18926/15203 現代の医療のなかで癌治療において不可欠な存在となった放射線治療｡一方,放射線被曝はたとえわずかであってもリスクが伴い,厳しく規制されている｡ただし医療被曝はこの限りになく,過去においては癌患者に放射線治療をおこなう際の患部以外の被曝についてはあまり問題視されなかった｡これには癌の治療という前提に加え,長期生存の可能性が低く,存命中に晩発障害が発生することが低いと考えられていたからである｡しかし,集学的治療が確立した今後の放射線治療においては完治する放射線治療患者が多くなり,治癒後の余命が長くなることが予測される｡放射線被曝による確率的影響は閾値がなく,影響は当然現れるであろう｡そこで,放射線治療をおこなう際の患者の散乱線被曝線量,治療室内散乱線量,さらに高エネルギー放射線発生装置を取り扱うときに問題となっている中性子を測定した｡その結果,測定線量は治療患部外被曝,室内散乱線量ともに無視できない量であることがわかった｡中性子については,人体に影響がある線量は検出されなかったが,中性子の存在は室内物品の放射化の可能性を示唆するもので定期的な測定管理が必要である｡また,�]線撮影室用の防護衣による散乱線被曝の低減効果は放射線治療室では無意味であった｡ No potential conflict of interest relevant to this article was reported.

岡山大学医学部保健学科 Acta Medica Okayama 1345-0948 14 1 2003 化学発がんの非遺伝毒性的メカニズムの解明に関する最近の動向 1 14 EN Kiyonori Yamaoka Katsumi Hanamoto Yasuhiro Ina Takahiro Kataoka Atsusi Kawabe Masanobu Sano Ayako Ujifuku 10.18926/15202 本総説は,筆者らが進めている｢低線量放射線の健康への影響と医療への応用｣に関する研究に資するために調査した,化学発がんの非遺伝毒性的メカニズムの解明に関する最近の動向の概要についてまとめたものである｡即ち,非遺伝毒性的発がんにおける細胞増殖,シトクロムP450誘導,酸化的ストレス,および遺伝子発現のそれぞれの役割,並びに量的な応答性について言及した｡また,後成的発がんにおけるアポトーシス,およびギャップ結合による情報伝達のそれぞれの役割についても触れた｡その結果,非遺伝毒性的な発がん物質の作用の様式とメカニズムやこれによる後成的な影響などについては解明さ れつつあり,特に,これらの発がん物質がゲノムDNAに対し直接的な相互作用,突然変異,修飾などを行う発がん物質とは機能的に異なった作用をすることが明らかになった｡また,これらは放射線発がんなど低線量放射線の健康への影響などについて研究する上で,重要な知見となっていることもわかった。 No potential conflict of interest relevant to this article was reported.

Acta Medica Okayama 2008 Reduction in patient skin dose during Interventional Radiology with the use of an air-gap substitute EN Atsushi Kawabe No potential conflict of interest relevant to this article was reported.