Faculty Profiles - HANAMOTO Katsumi

Papers - HANAMOTO Katsumi

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Studies on possibility for alleviation of lifestyle diseases by low-dose irradiation or radon inhalation. Reviewed

Kataoka T, Sakoda A, Yoshimoto M, Nakagawa S, Toyota T, Nishiyama Y, Yamato K, Ishimori Y, Kawabe A, Hanamoto K, Taguchi T, Yamaoka K

Radiation protection dosimetry 146 ( 1-3 ) 360 - 363 2011.7

Language：English Publishing type：Research paper (scientific journal) Publisher：OXFORD UNIV PRESS

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.

DOI： 10.1093/rpd/ncr189

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A comparative study on effect of continuous radon inhalation on several-time acute alcohol-induced oxidative damages of liver and brain in mouse

Takahiro Kataoka, Akihiro Sakoda, Masaaki Yoshimoto, Teruaki Toyota, Yuki Yamamoto, Yuu Ishimori, Katsumi Hanamoto, Atsushi Kawabe, Fumihiro Mitsunobu, Kiyonori Yamaoka

Radiation Safety Management 10 ( 1 ) 1 - 7 2011

Erratum to Differences of natural radioactivity and radon emanation fraction between constituent minerals of rock or soil [Appl. Radiat. Isot. 68, 6, (2010), 1180-1184] Reviewed

Akihiro Sakoda, Yuichi Nishiyama, Katsumi Hanamoto, Yuu Ishimori, Yuki Yamamoto, Takahiro Kataoka, Atsushi Kawabe, Kiyonori Yamaoka

Applied Radiation and Isotopes 68 ( 12 ) 2452 2010.12

Applicability and performance of an imaging plate at subzero temperatures Reviewed

Akihiro Sakoda, Yuu Ishimori, Katsumi Hanamoto, Atsushi Kawabe, Takahiro Kataoka, Tomohiro Nagamatsu, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 68 ( 10 ) 2013 - 2015 2010.10

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The performance of imaging plates (IPs) has not been studied at temperatures lower than 0 degrees C. In the present study, an IP was irradiated with gamma rays emitted from the mineral monazite at temperatures between -80 and 30 degrees C to determine its fundamental properties. The IP response as a function of irradiation time was found to be linear, suggesting that the IP works properly at low temperatures. Fading, an effect which should be considered at temperatures of more than 0 degrees C, was not observed at -30 and 80 degrees C. Furthermore, the fading-corrected PSL value of the IP irradiated at 80 degrees C was lower than at other temperatures (30.5 and -30 degrees C). This can be explained by thermostimulated luminescence (TSL). Since the only intensive TSL peak in the temperature range from -80 to 30 degrees C is present at about -43 degrees C, some of the electrons trapped at F centers recombine with holes through the process of TSL before the stored radiation image is read out at room temperature. This finding suggests that the apparent sensitivity of the IP is lower at -80 degrees C although it is similar to sensitivities between -30 and 30 degrees C. This low sensitivity should be corrected to perform quantitative measurements. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2010.03.020

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Physiologically Based Pharmacokinetic Modeling of Inhaled Radon to Calculate Absorbed Doses in Mice, Rats, and Humans Reviewed

Akihiro Sakoda, Yuu Ishimori, Atsushi Kawabe, Takahiro Kataoka, Katsumi Hanamoto, Kiyonori Yamaoka

JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY 47 ( 8 ) 731 - 738 2010.8

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

This is the first report to provide radiation doses, arising from inhalation of radon itself, in mice and rats. To quantify absorbed doses to organs and tissues in mice, rats, and humans, we computed the behavior of inhaled radon in their bodies on the basis of a physiologically based pharmacokinetic (PBPK) model. It was assumed that radon dissolved in blood entering the gas exchange compartment is transported to any tissue by the blood circulation to be instantaneously distributed according to a tissue/blood partition coefficient. The calculated concentrations of radon in the adipose tissue and red bone marrow following its inhalation were much higher than those in the others, because of the higher partition coefficients. Compared with a previous experimental data for rats and model calculation for humans, the present calculation was proved to be valid. Absorbed dose rates to organs and tissues were estimated to be within the range of 0.04-1.4 nGy (Bq m(-3))(-1) day(-1) for all the species. Although the dose rates are not so high, it may be better to pay attention to the dose to the red bone marrow from the perspective of radiation protection. For more accurate dose assessment, it is necessary to update tissue/blood partition coefficients of radon that strongly govern the result of the PBPK modeling.

DOI： 10.1080/18811248.2010.9711649

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First model of the effect of grain size on radon emanation Reviewed

Akihiro Sakoda, Katsumi Hanamoto, Yuu Ishimori, Takahiro Kataoka, Atsushi Kawabe, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 68 ( 6 ) 1169 - 1172 2010.6

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The present model represents an improvement on previous models of radon emanation from soil by incorporating soil grain size in addition to moisture. Monte Carlo simulation was employed in the calculation since it was difficult to mathematically express the radon emanation fraction for the present soil model. Grain size is one of the most important factors in describing the properties of soil. Grain size was demonstrated to affect the radon emanation fraction, depending on moisture content. Although the emanation fraction is generally considered to be proportional to grain size, the result of the model calculation suggested that the effect of grain size is not so simple. This study should serve as an initial step toward improving the modeling of this radon emanation. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2009.11.070

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Differences of natural radioactivity and radon emanation fraction among constituent minerals of rock or soil Reviewed

Akihiro Sakoda, Yuichi Nishiyama, Katsumi Hanamoto, Yuu Ishimori, Yuki Yamamoto, Takahiro Kataoka, Atsushi Kawabe, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 68 ( 6 ) 1180 - 1184 2010.6

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

We examined differences in the radioactive characteristics among the main minerals forming granite materials. Using a non-toxic high-density agent, minerals were separated from rock (granite-gneiss) and soil (weathered granite) samples. The natural radioactivity ((238)U and (226)Ra) and radon emanation fraction of the minerals were then studied by gamma-ray spectrometry. The radon emanation fractions (27-43%) of the minerals from the soil were much higher than those (0.6-4.6%) of the rock minerals. Additionally, the emanation fractions differed greatly among the minerals separated from both the bulk rock and soil. These results were discussed in terms of the differences of surface area and radium distribution in the mineral grains. It was noticeable that a higher emanation fraction than expected for quartz was commonly observed in the rock and soil samples. We then estimated the contribution of each constituent mineral to the total radon exhalation from the bulk samples. The result depended not only on the radon emanation fraction, but also on the (226)Ra activity and the mineral content. Furthermore, using the obtained data, we also discussed the effect of grain size on radon emanation and why this has been reported to vary markedly in previous studies. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2009.12.036

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Experimental and modeling studies of grain size and moisture content effects on radon emanation Reviewed

Akihiro Sakoda, Yuu Ishimori, Katsumi Hanamoto, Takahiro Kataoka, Atsushi Kawabe, Kiyonori Yamaoka

RADIATION MEASUREMENTS 45 ( 2 ) 204 - 210 2010.2

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Some models have already been developed to explain the effect of moisture content on the radon emanation fraction of soil. For this purpose, "microscopic" soil models, which are easy to deal with mathematically but cannot take grain size into consideration, have been designed. These previous models consist basically of two opposite grain surfaces and pores between the grains. In the present study, in order to study the effect of not only moisture content but also grain size, we present a simple modeling approach based on two "macroscopic" soil models: (1) a single-grain model and (2) a multiple-grain model. The latter model represents a configuration of spherical grains packed in a simple cubic structure. Based on these soil models and general assumptions, the radon emanation fraction was calculated as a function of grain size or moisture content by Monte Carlo simulation. The results for the multiple-grain model show that the radon emanation fraction is markedly increased with grain sizes ranging from 10 to 100 inn and reaches a constant value of 50% when moisture content is 0% and the radium is uniformly distributed on the grain surface. Moreover, a drastic increase is seen at smaller grain sizes with increasing moisture content. From these results, we concluded that the calculation of radon emanation depends greatly on the pore size between a Ra-bearing grain and a neighboring grain. The validity of the model was also evaluated by comparison to experimental data. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.radmeas.2010.01.010

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Estimation of Occupational Radiation Exposure in Veterinary Practice Reviewed

KAWABE Atsushi, YAMADA Kazutaka, HANAMOTO Katsumi, SAKODA Akihiro, KATAOKA Takahiro, YAMAOKA Kiyonori

Journal of Animal Clinical Medicine 19 ( 4 ) 113 - 117 2010

Language：Japanese Publisher：Japanese Society of Clinical Veterinary Medicine

The purpose of this study was to estimate the effective dose of radiation to which veterinary staff were exposed during general radiographic procedures. The Ordinance for Enforcement of Veterinary Practice Act has published dose limits of occupational exposure in accordance with the International Commission on Radiological Protection. According to the recommendation, exposure of any radiation worker must be maintained beneath a certain dose limit, that is, the dose must not exceed 20 mSv per year for 5 consecutive years. But there is danger that single dosimetry under a lead apron might lead to underestimation of the dose that a radiation worker actually received. Calculation by single dosimetry is done as if the whole body was radiated uniformly, although protective shielding such as a lead apron covers the body widely. The Act requires double dosimetry to estimate the effective dose of radiation more exactly, and requires that a radiation worker should wear an additional dosimeter at the location at which he or she receives the highest deep-dose equivalent. Experimentally, using a double dosimitry model, we tested and calculated the effective dose for veterinary staff: it was 2.4 micro Sv per one radiograph. By extrapolation, it is estimated that the limit of 20 mSv per year will be exceeded when, for example, one veterinary nurse is engaged in holding an animal down on the stand to take one radiograph, more than 160 times per week, excluding exposure of the hands.

DOI： 10.11252/dobutsurinshoigaku.19.113

CiNii Article

CiNii Books

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バドガスタイン産出岩石から分離した鉱石中の放射能特性

花元克巳, 迫田晃弘, 山本祐紀, 西山祐一, 石森有, 永松知洋, 山岡聖典

日本放射線影響学会大会講演要旨集 51回 151 - 151 2008.11

様々な単粒構造土壌モデルにおけるラドン散逸能の算出

迫田晃弘, 花元克巳, 石森有, 山岡聖典

日本放射線影響学会大会講演要旨集 51回 151 - 151 2008.11

Radioactivity and radon emanation fraction of the granites sampled at Misasa and Badgastein

Akihiro Sakoda, Katsumi Hanamoto, Yuu Ishimori, Tomohiro Nagamatsu, Kiyonori Yamaoka

APPLIED RADIATION AND ISOTOPES 66 ( 5 ) 648 - 652 2008.5

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

The chemical composition was analyzed and the radioactivity, radon exhalation rate and emanation fraction were measured to investigate the characteristics of the granites sampled at Misasa and Badgastein, world famous for radon therapy. The Misasa granite was probably composed of quartz, albite and microcline. The Badgastein granite was probably composed of quartz and muscovite. The radon exhalation rates and emanation fractions of the Misasa granite were much higher than those of the Badgastein granite, regardless of the (226)Ra activity concentrations. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.apradiso.2007.11.015

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小型MRI装置の作製エコー信号のフィッティングによる再構成画像の鮮鋭化

花元克巳, 加藤博和, 澁谷光一, 川崎祥二, 黒田昌宏, 金澤右, 岸幹二, 柳文修, 本多康聡, 大野誠一郎, 門久繁文, 高橋則雄, 青木雅昭

Radiation Medicine 26 ( Suppl.I ) 59 - 59 2008.4

MRI装置の作製

加藤博和, 花元克巳, 山本尚武, 黒田昌宏, 金澤右, 本多康聡, 柳文修, 高橋則雄, 岸幹二, 大塚裕太, 井上皓介, 真鍋英朗, 宮武匡義, 青木雅昭

Radiation Medicine 26 ( Suppl.I ) 58 - 58 2008.4

Effects of some physical conditions on leaching rate of radon from radioactive minerals originating from some hot springs

Akihiro Sakoda, Katsumi Hanamoto, Yuu Ishimori, Tomohiro Nagamatsu, Kiyonori Yamaoka

RADIATION MEASUREMENTS 43 ( 1 ) 106 - 110 2008.1

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

In order to determine the best physical conditions for leaching more radon from minerals into water, we measured the leaching rate of radon from radioactive minerals under the conditions of some different grain sizes and water temperatures. Water temperature affected the leaching rate of radon although the grain size did not significantly affect it. Furthermore, we proposed ultrasonic irradiation to the mixture of a mineral and water as the method of leaching more radon. Ultrasonic irradiation was efficient to leach more radon from the mineral soaked in water because of ultrasonic cavitation. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.radmeas.2007.07.009

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Basic Study on Activation of Antioxidation Function in Some Organs of Mice by Radon Inhalation Using New Radon Exposure Device

Shinya NAKAGAWA, Takahiro KATAOKA, Akihiro SAKODA, Yuu ISHIMORI, Katsumi HANAMOTO, Kiyonori YAMAOKA

RADIOISOTOPES 57 ( 4 ) 241 - 245 2008