Potential inhibitory effects of low-dose thoron inhalation and ascorbic acid administration on alcohol-induced hepatopathy in mice

Kataoka, Takahiro*; Ishida, Tsuyoshi*; Naoe, Shota*; Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*

Journal of Radiation Research (Internet), 63(5), p.719 - 729, 2022/09

https://doi.org/10.1093/jrr/rrac046

Mechanisms of action of radon therapy on cytokine levels in normal mice and rheumatoid arthritis mouse model

Kataoka, Takahiro*; Naoe, Shota*; Murakami, Kaito*; Yukimine, Ryohei*; Fujimoto, Yuki*; Kanzaki, Norie; Sakoda, Akihiro; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*

Journal of Clinical Biochemistry and Nutrition, 70(2), p.154 - 159, 2022/03

https://doi.org/10.3164/jcbn.21-91

Dosimetry of radon progeny deposited on skin in air and thermal water

Sakoda, Akihiro; Ishimori, Yuu; Kanzaki, Norie; Tanaka, Hiroshi; Kataoka, Takahiro*; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*

Journal of Radiation Research (Internet), 62(4), p.634 - 644, 2021/07

https://doi.org/10.1093/jrr/rrab030

It is held that the skin dose from radon progeny is not negligibly small and that introducing cancer is a possible consequence under normal circumstances, while there are a number of uncertainties in terms of related parameters such as activity concentrations in air, target cells in skin, skin covering materials, and deposition velocities. Meanwhile, an interesting proposal emerged in that skin exposure to natural radon-rich thermal water as part of balneotherapy can produce an immune response to induce beneficial health effects. The goal of the present study was to obtain generic dose coefficients with a focus on the radon progeny deposited on the skin in air or water in relation to risk or therapeutic assessments. We thus first estimated the skin deposition velocities of radon progeny in the two media based on data from the latest human studies. Using the optimized velocities, skin dosimetry was then performed under different assumptions regarding alpha-emitting source position and target cell (i.e., basal cells or Langerhans cells). Furthermore, the impact of the radon progeny deposition on effective doses from all exposure pathways relating to "radon exposure" was assessed using various possible scenarios. It was found that in both exposure media, effective doses from radon progeny inhalation are one to four orders of magnitude higher than those from the other pathways. In addition, absorbed doses on the skin can be the highest among all pathways when the radon activity concentrations in water are two or more orders of magnitude higher than those in air.

Comparison of antioxidative effects between radon and thoron inhalation in mouse organs

Kobashi, Yusuke*; Kataoka, Takahiro*; Kanzaki, Norie; Ishida, Tsuyoshi*; Sakoda, Akihiro; Tanaka, Hiroshi; Ishimori, Yuu; Mitsunobu, Fumihiro*; Yamaoka, Kiyonori*

Radiation and Environmental Biophysics, 59(3), p.473 - 482, 2020/08

https://doi.org/10.1007/s00411-020-00843-0

Radon therapy has been traditionally performed globally for oxidative stress-related diseases. Many researchers have studied the beneficial effects of radon exposure in living organisms. However, the effects of thoron, a radioisotope of radon, have not been fully examined. In this study, we aimed to compare the biological effects of radon and thoron inhalation on mouse organs with a focus on oxidative stress. Male BALB/c mice were randomly divided into 15 groups: sham inhalation, radon inhalation at a dose of 500 Bq/m or 2000 Bq/m, and thoron inhalation at a dose of 500 Bq/m or 2000 Bq/m were carried out. Immediately after inhalation, mouse tissues were excised for biochemical assays. The results showed a significant increase in superoxide dismutase and total glutathione, and a significant decrease in lipid peroxide following thoron inhalation under several conditions. Additionally, similar effects were observed for different doses and inhalation times between radon and thoron. Our results suggest that thoron inhalation also exerts antioxidative effects against oxidative stress in organs. However, the inhalation conditions should be carefully analyzed because of the differences in physical characteristics between radon and thoron.

Comparative effects of radon inhalation according to mouse strain and cisplatin dose in a cisplatin-induced renal damage model

Sasaoka, Kaori*; Kataoka, Takahiro*; Kanzaki, Norie; Kobashi, Yusuke*; Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori*

Pakistan Journal of Zoology, 50(3), p.1157 - 1170, 2018/06

https://doi.org/10.17582/journal.pjz/2018.50.3.1157.1170

Cisplatin (CDDP) is widely used for treating solid cancers; however, it induces nephrotoxicity caused by oxidative stress. Here, we investigated whether radon inhalation has different effects against CDDP induced renal injury in two mouse strains differing in radiosensitivity, and determined the appropriate dose of CDDP combined with radon inhalation for highly radiosensitive mice. CDDP was administered at 20 mg/kg weight to C57BL/6J and BALB/c mice after radon inhalation at 1000 Bq/m and 2000 Bq/m for 24 h. Radon inhalation had a slight positive effect against CDDP toxicity in C57BL/6J mice with respect to improved hair condition, whereas radon inhalation exacerbated CDDP-induced toxicity in BALB/c mice. When BALB/c mice were treated with a lower dose of CDDP (15 mg/kg) after 1000 Bq/m radon inhalation, the creatinine level was reduced and the superoxide dismutase content was increased. The supportive effect of radon inhalation shows its good potential as a candidate treatment to alleviate CDDP-induced renal damage.

Protective effects of hot spring water drinking and radon inhalation on ethanol-induced gastric mucosal injury in mice

Etani, Reo*; Kataoka, Takahiro*; Kanzaki, Norie*; Sakoda, Akihiro; Tanaka, Hiroshi; Ishimori, Yuu; Mitsunobu, Fumihiro*; Taguchi, Takehito*; Yamaoka, Kiyonori*

Journal of Radiation Research, 58(5), p.614 - 625, 2017/05

https://doi.org/10.1093/jrr/rrx021

Radon therapy using radon (Rn) gas is classified into two types of treatment: inhalation of radon gas and drinking water containing radon. Although short- or long-term intake of spa water is effective in increasing gastric mucosal blood flow, and spa water therapy is useful for treating chronic gastritis and gastric ulcer, the underlying mechanisms for and precise effects of radon protection against mucosal injury are unclear. In the present study, we examined the protective effects of hot spring water drinking and radon inhalation on ethanol-induced gastric mucosal injury in mice. Mice inhaled radon at a concentration of 2000 Be/m for 24 h or were provided with hot spring water for 2 weeks. The activity density of Rn ranged from 663 Bq/l (start point of supplying) to 100 Bq/l (end point of supplying).Mice were then orally administered ethanol at three concentrations. The ulcer index (UI), an indicator of mucosal injury, increased in response to the administration of ethanol; however, treatment with either radon inhalation or hot spring water inhibited the elevation in the UI due to ethanol. Although no significant differences in antioxidative enzymes were observed between the radon-treated groups and the non-treated control groups, lipid peroxide levels were significantly lower in the stomachs of mice pre-treated with radon or hot spring water. These results suggest that hot spring water drinking and radon inhalation inhibit ethanol-induced gastric mucosal injury.

Comparative effect of C beam and -ray irradiation on callus growth and shoot formation from lavandin isolated cells

Tsuro, Masato*; Iwata, Chizuru*; Kataoka, Rie*; Yoshihara, Ryohei; Hase, Yoshihiro

JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 72, 2008/11

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2008-055.pdf

no abstracts in English

Comparative of suppressive effects by low-dose radiation and related-medicine using machine learning

Kanzaki, Norie; Kataoka, Takahiro*; Kobashi, Yusuke*; Ishida, Tsuyoshi*; Yunoki, Yuto*; Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori*

no journal, , 

We have suggested that low-dose radiation increases anti-oxidative function and inhibits various oxidative stress-related diseases. On the other hand, there are some reports about the extraction of some plants which inhibit similar diseases. In this research, we collected and analyzed the reports for comprehensive comparison. For example, we found that the effects of radon 2000 Bq/m inhalation for 24 hours (low-dose irradiation) or taraxeren-3-one (the extraction from diospyros maritima) 20 mg/kg bodyweight administration were similar with the effects of indomethacin 10 mg/kg bodyweight administration regarding carrageenan-induced paw edema. Our results have a limitation of small dataset but are useful for future research about oxidative stress.

Approach of machine-learning-based visualization for the evaluation of fuzzy effects of low-dose radiation

Kanzaki, Norie; Sakoda, Akihiro; Kataoka, Takahiro*; Yamaoka, Kiyonori*

no journal, , 

It is not easy to evaluate fuzzy effects of low-dose radiation by basic statistical analysis or basic machine learning. In the present study, the modification of self-organizing maps, which is a kind of machine learning, was made for the evaluation of such effects: namely many reference vectors which learned input dataset by self-organizing maps were reanalyzed with the same technique. Based on this procedure, we analyzed a dataset about low-dose radiation as well as a benchmark dataset, suggesting that the modified self-organizing maps can work even for input data with complex topology and data distribution.

Machine learning based metabolic analysis about the regulation of glutathione synthesis in mouse brain due to radon inhalation

Kanzaki, Norie; Sakoda, Akihiro; Tanaka, Hiroshi; Kataoka, Takahiro*; Ishida, Tsuyoshi; Yamaoka, Kiyonori*

no journal, , 

We found that glutathione was elevated by radon inhalation. However, the mechanism of production of glutathione has been known quite little. In the present study, the metabolic analysis focusing on the sulfur metabolites including anti-oxidative substances was performed to find the change in sulfur metabolites in mouse brain following radon inhalation. Brains taken from male BALB/c mice after radon exposure at background level, 1000 or 10000 Bq/m for 24 h were used for the exhaustive assay of sulfur metabolism-related substances. As a result, we detected 27 out of 55 metabolites in brain. We found the induction of glutathione precursor cysteine and cystathionine due to radon inhalation. This suggests that the increase of glutathione associated with radon inhalation could rely on the transsulfuration pathway. Moreover, the information on 27 sulfur metabolites detected in the present assay was comprehensively analyzed using self-organizing maps. Based on this clustering, a possibility of sulfur metabolites working as a biomarker for estimating radiation doses will be discussed.