Experimental studies on the biological effects of chronic low dose-rate radiation exposure in mice: overview of the studies at the Institute for Environmental Sciences

Braga-Tanaka, Ignacia; Tanaka, Satoshi; Kohda, Atsushi; Takai, Daiya; Nakamura, Shingo; Ono, Tetsuya; Tanaka, Kimio; Komura, Jun‐ichiro

doi:10.1080/09553002.2018.1451048

Cited by 56 publications

(32 citation statements)

References 48 publications

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“…Radyasyonun insan vücudu üzerine olan zararlı etkileri hem deneysel çalışmalar, hem de klinik araştırmalar ile gösterilmektedir (7)(8)(9). Bu etkiler düşük dozlarda halsizlik, yorgunluk, hemogram ve biyokimyasal değerlerde değişme şeklinde görülebilirken doz miktarında artışla birlikte kilo kaybı, gen mutasyonları, kromozom kırıkları, anti-kanser immünitesinde değişikliklikler ve kanser oluşumları, kısalmış yaşam süresi olarak karşımıza çıkabilir (7)(8)(9). Bunun yanında düşük doz radyasyonun, normal hücresel fonksiyonlar için gerekli olduğunu savunan yayınlar da bulunmaktadır (10).…”

Section: Discussionunclassified

Radyoterapi çalışanlarının maruz kaldığı radyasyon miktarının dozimetrik değerlendirilmesi

Göksel

Demircioğlu

2020

Journal of Health Sciences and Medicine

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Aim: Radiotherapy is one of the most commonly used cancer treatment methods and high dose ionizing radiation is used to provide therapeutic effect. Radiation exposure is the biggest occupational problem for radiotherapy personnel working in this radiation environment and serious protection measures must be taken. In this regard, the last 3 years of personal dosimeter values of all the staff working in our radiation oncology clinic were examined and radiation exposure rates were evaluated. Material and Method:Between 2015 and 2018, the data of TLD measurements of personal dosimeters of all personnel were recorded, the amount of doses exposed in the measurement periods, the average doses exposed in the measurement periods according to occupational groups, the annual total dose exposure and the differences between the groups were evaluated. Results:For measurements in a total of 18 periods, the average amount of dose each employee is 0.21 mSv per period. When evaluated according to profession groups they were; 0,20 mSv in physicians, 0,20 mSv in medical physicists and 0,21 mSv in technicians. There was no statistically significant difference between the groups. While evaluating the periods individually, the doses exposed by the occupational groups are similar, but there is a significant difference between the physicians and other workers in the 1st period of 2016 and the 5th period of 2017 and between the medical physicists and other workers in the 3rd period body doses of 2018 and the fourth period of 2018. Conclusion:Staff training, dosimetric measurements, and inspections are extremely important in a radiation oncology center. All of our measurement values performed in our clinic, where we have radiotherapy experience for nearly 30 years, were determined in accordance with international standards. In this direction, it is recommended that all centers working with radiation should make current evaluations meticulously.

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Section: Discussionunclassified

Radyoterapi çalışanlarının maruz kaldığı radyasyon miktarının dozimetrik değerlendirilmesi

Göksel

Demircioğlu

2020

Journal of Health Sciences and Medicine

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“…Chronic exposures of 0.05, 1.1 or 21 mGy/day continued for 400 days leading to total doses of 2, 40, or 800 cGy. Similar to the Janus experiments, many mice from the IES experiments were allowed to live out their entire lifespan, and each mouse was assigned a single cause of death (24, 40). These data were included in this study because of their similarity to the experiments carried out on B6CF1 mice during the NURA experiments.…”

Section: Methodsmentioning

confidence: 99%

Analyses of cancer incidence and other morbidities in gamma irradiated B6CF1 mice

Woloschak¹,

Zander²,

Paunesku³

2020

Preprint

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26With increasing medical radiation exposures, it is important to understand how 27 different modes of delivery of ionizing radiation as well as total doses of exposure impact 28 health outcomes. Our lab studied the risks associated with ionizing radiation by analyzing the 29 Northwestern University Radiation Archive for animals (NURA). NURA contains detailed data 30 from a series of 10 individual neutron and gamma irradiation experiments conducted on over 31 50,000 mice. Rigorous statistical testing on control mice from all Janus experiments enabled us 32 to select studies that could be compared to one another and uncover unexpected differences 33 among the controls as well as experimental animals. For controls, mice sham irradiated with 34 300 fractions died significantly earlier than those with fewer sham fractions. Using the 35 integrated dataset of gamma irradiated and control mice, we found that fractionation 36 significantly decreased the death hazard for animals dying of lymphomas, tumors, non-tumors, 37 and unknown causes. Gender differences in frequencies of causes of death were identified 38 irrespective of irradiation and dose fractionation, with female mice being at a greater risk for all 39 causes of death, except for lung tumors. Irradiated and control male mice were at a significantly 40 greater risk for lung tumors, the opposite from observations noted in humans. Additionally, we 41 discovered that lymphoma deaths can occur quickly after exposures to high doses of gamma 42 rays. This study systematically cross-compared outcomes of different modes of fractionation 43 across a wide span of total doses to demonstrate that protraction modulated survival and 44 disease status differently based on the total dose, cause of death, and sex of an animal. This 45 novel method for analyzing the Janus datasets will lead to insightful new mechanistic 46 hypotheses and research in the fields of radiation biology and protection.49 impacts is important for setting radiation protection standards. Approximately half of 50 humankind's cumulative annual radiation exposure comes from natural sources, such as cosmic 51 radiation and soil; the other half is derived from human-made sources including medical 52 procedures and nuclear medicine (1). Most of the general population receives low dose chronic 53 ionizing radiation exposures, accumulating to a few hundred mSv over a lifetime (2). 54Calculating the risks associated with these chronic exposures is challenging because of 55 the high background levels for the same diseases ionizing radiation can induce and the low 56 overall effect of these lower dose/dose-rate exposures. There are several helpful data sources 57 that researchers have utilized to help quantify these risks including radiation therapy studies, 58 atomic bomb survivor data, and other epidemiological studies from workers in the field and 59 nuclear disasters. The radiation doses given to patients for radiation therapy are much larger 60 than standard exposure and are only used on a small segmen...

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“…Understanding the health risks (mainly cancer) due to low doses of IR has been provided by epidemiological studies of atomic bomb survivors [45]; however, the risk or biological effects from chronic exposure to low dose rates of IR has only recently been more examined. To understand the molecular mechanisms following exposure to low dose rates of IR, irradiation instruments for chronic exposure to low dose rates of IR have been established in Japan and other countries [46]. The instruments in Japan use 137 Cs as a radiation source and can irradiate biological specimens with γ-rays.…”

Section: Irradiation Tests With Ground Facilitiesmentioning

confidence: 99%

“…Among them, the irradiation instrument for the Institute for Environmental Sciences (IES) can expose small animals such as mice with extremely low dose rates (about 0.05 mGy/day), and other instruments at IES can expose mice to different low dose rates (about 1 or 20 mGy/day). These instruments can perform chronic irradiation for a few years and have been supplying important information on the biological effects of chronic low dose rate irradiation to mice [46]. The instruments at the Research Institute for Radiation Biology and Medicine (RIRBM), Hiroshima University, Central Research Institute of Electric Power Industry (CRIEPI), University of Occupational and Environmental Health (UOEH), and National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST-NIRS), can also perform chronic irradiation with dose rates that are higher than the instruments at IES.…”

Section: Irradiation Tests With Ground Facilitiesmentioning

confidence: 99%

Space Radiation Biology for “Living in Space”

Furukawa

Nagamatsu

Nenoi

et al. 2020

BioMed Research International

100

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Space travel has advanced significantly over the last six decades with astronauts spending up to 6 months at the International Space Station. Nonetheless, the living environment while in outer space is extremely challenging to astronauts. In particular, exposure to space radiation represents a serious potential long-term threat to the health of astronauts because the amount of radiation exposure accumulates during their time in space. Therefore, health risks associated with exposure to space radiation are an important topic in space travel, and characterizing space radiation in detail is essential for improving the safety of space missions. In the first part of this review, we provide an overview of the space radiation environment and briefly present current and future endeavors that monitor different space radiation environments. We then present research evaluating adverse biological effects caused by exposure to various space radiation environments and how these can be reduced. We especially consider the deleterious effects on cellular DNA and how cells activate DNA repair mechanisms. The latest technologies being developed, e.g., a fluorescent ubiquitination-based cell cycle indicator, to measure real-time cell cycle progression and DNA damage caused by exposure to ultraviolet radiation are presented. Progress in examining the combined effects of microgravity and radiation to animals and plants are summarized, and our current understanding of the relationship between psychological stress and radiation is presented. Finally, we provide details about protective agents and the study of organisms that are highly resistant to radiation and how their biological mechanisms may aid developing novel technologies that alleviate biological damage caused by radiation. Future research that furthers our understanding of the effects of space radiation on human health will facilitate risk-mitigating strategies to enable long-term space and planetary exploration.

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Experimental studies on the biological effects of chronic low dose-rate radiation exposure in mice: overview of the studies at the Institute for Environmental Sciences

Cited by 56 publications

References 48 publications

Radyoterapi çalışanlarının maruz kaldığı radyasyon miktarının dozimetrik değerlendirilmesi

Radyoterapi çalışanlarının maruz kaldığı radyasyon miktarının dozimetrik değerlendirilmesi

Analyses of cancer incidence and other morbidities in gamma irradiated B6CF1 mice

Space Radiation Biology for “Living in Space”

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