Takashi Moritake

Dr. Takashi Moritake

Radiation Regulatory Science Research, National Institutes for Quantum Science and Technology, Chiba, Japan
orcid
Director, Institute for Radiological Science, Nationl Instit...

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2021 in European Journal of Radiology
Verified
Journal Article
Open access
SMSatoru Matsuzaki
Satoru Matsuzaki
TMTakashi Moritake
Takashi Moritake
KMKoichi Morota
Koichi Morota
KNKeisuke Nagamoto
Keisuke Nagamoto
KNKoichi Nakagami
Koichi Nakagami
NKNaoki Kunugita
Naoki Kunugita
An augmented reality (AR) application to help medical staff involved in interventional radiology (IR) learn how to properly use ceiling-suspended radiation shielding screens was created, and its utility was tested from the perspective of learner motivation. The distribution of scattered radiation in an angiography room was visualized with an AR application in three settings: when a ceiling-suspended radiation shielding screen is not used (incorrect); when there is a gap between the bottom edge of the shielding screen and the patient's torso (incorrect); and when there is no gap between the bottom edge of the shielding screen and the patient's torso (correct). This AR application was used by 33 medical staff, after which an Instructional Materials Motivation Survey (IMMS) based on the John Keller's ARCS (four categories of Attention, Relevance, Confidence, and Satisfaction) Motivation Model, consisting of 36-items with responses on a 5-point (1-5) Likert scale, was conducted. The overall score was a high 4.67 ± 0.30 (mean ± standard deviation). Physician's scores tended to be lower than those of other medical staff in the categories of Attention, Relevance, and Satisfaction (not statistically significant). The AR application to learn how to properly use ceiling-suspended radiation shielding screens was highly rated from the perspective of learner motivation.

24 March 2021 in Scientific Reports
Verified
Journal Article
Open access
PDF file
LSLue Sun
Lue Sun
YIYohei Inaba
Yohei Inaba
YSYu Sogo
Yu Sogo
AIAtsuo Ito
Atsuo Ito
MBMahesh Bekal
Mahesh Bekal
TMTakashi Moritake
Takashi Moritake
Ionizing radiation exposure may not only cause acute radiation syndrome, but also an increased risk of late effects. It has been hypothesized that induction of chronic oxidative stress mediates the late effects of ionizing radiation. However, only a few reports have analyzed changes in long-term antioxidant capacity after irradiation in vivo. Our previous study demonstrated changes in whole-blood antioxidant capacity and red blood cell (RBC) glutathione levels within 50 days after total body irradiation (TBI). In this study, seven-week-old, male, C57BL/6J mice exposed to total body irradiation by X-ray and changes in whole-blood antioxidant capacity and RBC glutathione levels at ≥ 100 days after TBI were investigated. Whole-blood antioxidant capacity was chronically decreased in the 5-Gy group. The RBC reduced glutathione (GSH) level and the GSH/oxidative glutathione (GSSG) ratio were chronically decreased after ≥ 1 Gy of TBI. Interestingly, the complete blood counts (CBC) changed less with 1-Gy exposure, suggesting that GSH and the GSH/GSSG ratio were more sensitive radiation exposure markers than whole-blood antioxidant capacity and CBC counts. It has been reported that GSH depletion is one of the triggers leading to cataracts, hypertension, and atherosclerosis, and these diseases are also known as radiation-induced late effects. The present findings further suggest that chronic antioxidant reduction may contribute to the pathogenesis of late radiation effects.

13 May 2021 in Journal of Radiation Research
Verified
Journal Article
Open access
PDF file
MBMahesh Bekal
Mahesh Bekal
LSLue Sun
Lue Sun
SUSusumu Ueno
Susumu Ueno
TMTakashi Moritake
Takashi Moritake
Radiation exposure has multiple effects on the brain, behavior and cognitive functions. It has been reported that high-dose (>20 Gy) radiation-induced behavior and cognitive aberration partly associated with severe tissue destruction. Low-dose (<3 Gy) exposure can occur in radiological disasters and cerebral endovascular treatment. However, only a few reports analyzed behavior and cognitive functions after low-dose irradiation. This study was undertaken to assess the relationship between brain neurochemistry and behavioral disruption in irradiated mice. The irradiated mice (0.5 Gy, 1 Gy and 3 Gy) were tested for alteration in their normal behavior over 10 days. A serotonin (5-HT), Dopamine, gamma-Aminobutyric acid (GABA) and cortisol analysis was carried out in blood, hippocampus, amygdala and whole brain tissue. There was a significant decline in the exploratory activity of mice exposed to 3 Gy and 1 Gy radiation in an open field test. We observed a significant short-term memory loss in 3 Gy and 1 Gy irradiated mice in Y-Maze. Mice exposed to 1 Gy and 3 Gy radiation exhibited increased anxiety in an elevated plus maze (EPM). The increased anxiety and memory loss patterns were also seen in 0.5 Gy irradiated mice, but the results were not statistically significant. In this study we observed that neurotransmitters are significantly altered after irradiation, but the neuronal cells in the hippocampus were not significantly affected. This study suggests that the low-dose radiation-induced cognitive impairment may be associated with the neurochemical in low-dose irradiation and unlike the high-dose scenario might not be directly related to the morphological changes in the brain.

1 July 2010 in Clinical Neurology and Neurosurgery
Verified
Journal Article
Closed access
MHMikito Hayakawa
Mikito Hayakawa
TMTakashi Moritake
Takashi Moritake
FKFumikatsu Kataoka
Fumikatsu Kataoka
TTTomoji Takigawa
Tomoji Takigawa
YKYasuhiro Koguchi
Yasuhiro Koguchi
YMYuji Matsumaru
Yuji Matsumaru

9 May 2018 in Scientific Reports
Verified
Journal Article
Open access
PDF file
LSLue Sun
Lue Sun
YIYohei Inaba
Yohei Inaba
KSKeizo Sato
Keizo Sato
Aki HirayamaAki Hirayama
Aki Hirayama
KTKoji Tsuboi
Koji Tsuboi
TMTakashi Moritake
Takashi Moritake
Many reports have demonstrated that radiation stimulates reactive oxygen species (ROS) production by mitochondria for a few hours to a few days after irradiation. However, these studies were performed using cell lines, and there is a lack of information about redox homeostasis in irradiated animals and humans. Blood redox homeostasis reflects the body condition well and can be used as a diagnostic marker. However, most redox homeostasis studies have focused on plasma or serum, and the anti-oxidant capacity of whole blood has scarcely been investigated. Here, we report changes in the anti-oxidant capacity of whole blood after X-ray irradiation using C57BL/6 J mice. Whole-blood anti-oxidant capacity was measured by electron spin resonance (ESR) spin trapping using a novel spin-trapping agent, 2-diphenylphosphinoyl-2-methyl-3,4-dihydro-2H-pyrrole N-oxide (DPhPMPO). We found that whole-blood anti-oxidant capacity decreased in a dose-dependent manner (correlation factor, r > 0.9; P < 0.05) from 2 to 24 days after irradiation with 0.5–3 Gy. We further found that the red blood cell (RBC) glutathione level decreased and lipid peroxidation level increased in a dose-dependent manner from 2 to 6 days after irradiation. These findings suggest that blood redox state may be a useful biomarker for estimating exposure doses during nuclear and/or radiation accidents.

18 February 2025 in Journal of Bone and Joint Surgery
Verified
Journal Article
Open access
YHYasukazu Hijikata
Yasukazu Hijikata
KYKazuta Yamashita
Kazuta Yamashita
NHNatsuko Hatsusaka
Natsuko Hatsusaka
TNTatsuo Nagata
Tatsuo Nagata
HKHiroko Kitamura
Hiroko Kitamura
TMTakashi Moritake
Takashi Moritake
Background: The impact of radiation exposure on cataracts and hand skin cancer in orthopaedic and spine surgeons remains understudied. This study aimed to investigate the prevalence of cataracts and chronic hand inflammation in orthopaedic and spine surgeons and to assess their association with radiation exposure. Methods: A cross-sectional analysis was conducted on orthopaedic and spine surgeons attending the 38th Annual Meeting of the Neurospinal Society of Japan or the 31st Annual Meeting of the Japanese Society for the Study of Low Back Pain. Cataractous changes were categorized into none, lens micro-opacity, or cataracts and were detailed alongside the prevalence of chronic hand inflammation, which included longitudinal melanonychia and hand eczema. Participants were divided into quartiles according to hand-exposure opportunities in the operating and fluoroscopy rooms in 2022. Prevalence ratios and 95% confidence intervals (CIs) of chronic hand inflammation in the upper quartiles relative to the first quartile were calculated using modified Poisson regression adjusted for potential confounders. Results: The median work experience of the 162 participants was 23 years, and the median number of hand-exposure opportunities was 70 (interquartile range [IQR], 20 to 123) in the operating room and 20 (IQR, 0 to 60) in the fluoroscopy room. The prevalence of cataracts was 20% (32 participants), and the prevalence of cataractous changes, including lens micro-opacity, was 40% (64 participants). Chronic hand inflammation was present in 62 participants (38%), of whom 52 had longitudinal melanonychia and 23 had hand eczema. The adjusted prevalence ratios of chronic hand inflammation relative to the lowest quartile of hand-exposure opportunities in the operating room were 0.91 (0.50, 1.66) for quartile 2, 0.72 (0.41, 1.25) for quartile 3, and 1.56 (0.97, 2.50) for quartile 4. For fluoroscopy room exposure, the adjusted prevalence ratios were 2.31 (1.16, 4.58) for quartile 2, 2.03 (1.00, 4.09) for quartile 3, and 2.94 (1.51, 5.75) for quartile 4. Conclusions: This study highlighted substantial cataractous and chronic hand inflammatory changes in spine surgeons, indicating indirect and direct radiation exposure effects. Therefore, radiation safety and protective measures must be emphasized. Comparative studies with other populations and longitudinal observations are required to better understand the effects of radiation on health. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.