Abstract
Purpose: This is a paper based on a talk given in the BER2018 conference by M. Bando. We first emphasize the importance of collaborations among scientists in various fields for the low dose/dose-rate effects on biological body. We make comparisons of quantitative estimations of mutation caused by the radiation exposure on various animals and plants using one mathematical model. We derive the importance of the spontaneous mutation at the DNA level, which provides the key to understand the biological evolution. We try to make a guide map to solve this problem and find that the mutation is an important stage of the pathway from the DNA damage to the macroscopic biological evolution.
Materials and methods: We construct a mathematical model for the mutation, named as ‘WAM’ model, which takes into account the recovery effect. The model setting is regarded as an extension of the survival and the hazard functions. The WAM model is used to reproduce accumulated data of mutation frequency of animals and plants. Especially the model analysis shows that the dose-rate dependence is important to understand various mutation data.
Results and conclusions: The WAM model is successful in reproducing various mutation data of animals and plants. We find that the inclusion of the dose rate is important to understand all the mutation data. Hence, we are able to develop the ‘scaling law’ to make the cross-species comparison of mutation frequency data. With this finding, we can extract the dominant effect on the mutation to be caused by the spontaneous mutation, and quantify this amount. We are able to write then the artificial radiation frequency by subtracting the spontaneous mutation. With this success, we estimate the origin of the spontaneous mutation as due to ROS, the order of which agrees to the spontaneous mutation.
Acknowledgments
The authors are greatly encouraged by many scientists who kindly gave valuable information and fruitful discussions. In particular, Drs. L. Russell and Prof. H. Maki kindly took time for us and introduced the latest valuable knowledge. We would like to thank all those people for their encouragement and valuable discussions.
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Funding
Notes on contributors
Masako Bando
Masako Bando, Ph.D. in Physics, is a researcher of Research Center for Nuclear Physics, Osaka University, and of Yukawa Institute for Fundamental Physics, Kyoto University. Her speciality is physics (elementary particle theory; Grand Unified theory), and she extended her research to traffic flow theory and economic physics. She started to contract mathematical model of the biological effects of radiation after the Fukushima accident and is now devoted in bridging their mathematical model, WAM, to radiation therapy by corroborating with scientists in different fields.
Tetsuhiro Kinugawa
Tetsuhiro Kinugawa is a master’s course student in Graduate School of Engineering, Osaka University. His research topic is mathematical analysis of biological effects caused by radiation.
Yuichiro Manabe
Yuichiro Manabe, Assistant Professor, Doctor of Sciences (theoretical nuclear physics), is representative of interdisciplinary platform for biological effect of radiation, Collaborative Research Projects, Graduate School of Engineering, Osaka University. His research topics are simple mathematical model which give account to biological effects caused by radiation.
Miwako Masugi
Miwako Masugi-Tokita, M.D., Ph.D., is researcher in Department of Urology, Shiga University of Medical Science. Her research topics are neuroscience and andrology.
Hiroo Nakajima
Hiroo Nakajima, Doctor of Medical Science, is an Assistant professor at Institute for Radiation Sciences, and Medical Imaging Center for Translational Research, Graduate School of Medicine, Osaka University. His research interests are carcinogenicity and transgenerational effects of low dose-rate internal radiation exposure.
Kazuyo Suzuki
Kazuyo Suzuki, M.D., Ph.D., is program-specific assistant professor of Preemptive Medicine and Lifestyle-Related Disease Research Center, Kyoto University. Her research interests lie in nutrition science, metabolism, and preventive medicine.
Yuichi Tsunoyama
Yuichi Tsunoyama, Ph.D., is an Assistant Professor of Radioisotope Research Center, Agency for Health, Safety and Environment, Kyoto University. His research topic is biological effect of radiation at the molecular and cellular level.
Takahiro Wada
Takahiro Wada, Ph.D., is a Professor of Faculty of Engineering Science, Kansai University. His research interests lie in theoretical nuclear physics, especially the synthesis of superheavy elements and in mathematical model analysis of the biological effects of radiation.
Hiroshi Toki
Hiroshi Toki, Ph.D., Physics, is an Emeritus Professor of Osaka University, and a Special Professor of Engineering Science. His research field is theoretical nuclear physics, where a special interest lies on the effect of the pion on nuclear structure. His recent interest is the electric circuit theory and biophysics.