المؤلفون: Kurihara, Osamu, Yamada, Takehisa, Kato, Katsuhito, Miyauchi, Yasushi

المصدر: Clinical & Experimental Nephrology; Mar2024, Vol. 28 Issue 3, p208-216, 9p

مصطلحات موضوعية: KIDNEY diseases, LOGISTIC regression analysis, GLOMERULAR filtration rate, CHRONIC kidney failure, EPIDERMAL growth factor receptors

مستخلص: Background: Although hyperuricemia is associated with the progression of chronic kidney disease (CKD), a reduction in CKD progression by uric acid (UA)-lowering therapy has been controversial. Recently, dotinurad, a uricosuric drug with selective urate reabsorption inhibitory properties, has been developed. However, its efficacy in lowering serum UA levels and its effects on renal function in patients with severe renal dysfunction are unclear. Thus, this study aimed to determine the effects of dotinurad on renal function in patients with severe renal dysfunction. Methods: Data from 53 outpatients with hyperuricemia who newly received dotinurad between December 2020 and October 2022 were retrospectively analyzed. The mean baseline estimated glomerular filtration rate (eGFR) was 38.7 ± 17.0 mL/min/1.73 m². The patients were divided into three groups based on their baseline eGFR: eGFR < 30 (n = 17), 30 ≤ eGFR < 45 (n = 17), and eGFR ≥ 45 (n = 19). Results: The mean follow-up period was 9.8 ± 4.5 (range, 3–21) months. Serum UA levels significantly decreased in all groups. Although eGFR did not significantly change in patients with 30 ≤ eGFR < 45 and eGFR ≥ 45 (P = 0.918 and P = 0.535, respectively), it improved significantly in patients with eGFR < 30 (P = 0.032). The proportion of patients with improved eGFR was significantly higher in patients with eGFR < 30 (P = 0.038) than in patients with 30 ≤ eGFR < 45 and eGFR ≥ 45. In the multivariate logistic regression analysis, baseline eGFR < 30 and achieving a serum UA level of ≤ 6.0 mg/dL were significantly associated with improved eGFR (P = 0.033 and P = 0.015, respectively). Conclusions: Dotinurad may have UA-lowering effects and the potential to improve kidney function in patients with severe renal dysfunction. [ABSTRACT FROM AUTHOR]

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المؤلفون: Tani, Kotaro, Kim, Eunjoo, Yajima, Kazuaki, Naito, Masayuki, Ishigure, Nobuhito, Beaumont, Tiffany, Broggio, David, Kurihara, Osamu

المصدر: Radiation Protection Dosimetry; Mar2024, Vol. 200 Issue 3, p315-321, 7p

مصطلحات موضوعية: NUCLEAR power plant shutdowns, THYROID gland, IODINE isotopes, NUCLEAR power plants

مصطلحات جغرافية: JAPAN

الشركة/الكيان: FUKUSHIMA Daiichi Nuclear Power Plant (Japan)

مستخلص: In a nuclear emergency, one of the actions taken for the sake of public is to monitor thyroid exposure to radioiodines. Japan's Nuclear Regulation Authority recently published a report on such monitoring and proposed direct thyroid measurements with conventional NaI(Tl) survey meters (e.g. Hitachi model TCS-172) as a primary screening method. A previous study proposed screening levels (SLs) used in these simplified measurements as the net reading values of the TCS-172 device. Age-specific SLs were derived from a thyroid equivalent dose of 100 mSv due to the inhalation intake of ¹³¹I. This study addressed the possible influence of short-lived iodine isotopes other than ¹³¹I on the simplified measurements. In preparation for such measurements, the responses of the device for ¹³²I as an ingrowth component from ¹³²Te, ¹³³I, ¹³⁴I and ¹³⁵I in the thyroid were evaluated by numerical simulations using age-specific stylized phantoms in addition to those obtained for ¹³¹I in the previous study. The radioactivity ratios of the relevant isotopes were taken from the inventory data of the Fukushima Daiichi Nuclear Power Plant. The results were used to predict the net readings of the device when ¹³²Te-¹³²I and ¹³³I as well as ¹³¹I were inhaled at 24 or 72 h after the shutdown of a nuclear power plant. In these cases, the signals from ¹³²Te-¹³²I and ¹³³I become undetectable a couple of days after intake, which could lead to underestimations of the thyroid dose. To estimate the thyroid dose accurately from the simplified measurements, it is necessary to identify the exact time of intake after the shutdown and the actual physiochemical property of ¹³²Te that affects the thyroid uptake of ¹³²I. [ABSTRACT FROM AUTHOR]

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المؤلفون: Yang, Guosheng, Tazoe, Hirofumi, Kim, Eunjoo, Zheng, Jian, Kowatari, Munehiko, Kurihara, Osamu

المصدر: JAAS (Journal of Analytical Atomic Spectrometry); Dec2023, Vol. 38 Issue 12, p2562-2570, 9p

مصطلحات موضوعية: URINE, BIOLOGICAL assay, NUCLEAR accidents, DETECTION limit, REFERENCE sources, QUALITY control

مصطلحات جغرافية: FRANCE

مستخلص: It is critical to perform dose assessment after internal contamination with beta-particle emitting ⁹⁰Sr due to its relatively long physical and biological half-lives, along with the higher specific activities of ⁹⁰Sr and its daughter ⁹⁰Y. For rapid public screening after a large-scale radiological/nuclear accident, we developed a novel ⁹⁰Sr bioassay for small-volume urine samples using triple-quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS). After organic matter decomposition of 10 mL urine using HNO3, stacked DGA and Sr resin cartridges were used directly for chromatographic separation and purification of Sr. Yields of Sr were measured as 94 ± 5% (n = 12) for the whole procedure, using stable ⁸⁸Sr originally in the urine sample as a yield tracer. CO2 proved to be a better reaction gas than O2, to overcome isobaric/polyatomic interferences, especially those caused by Zr and Ge. With a conventional introduction system + s lens + 75% CO2 flow rate in the 4^# cell gas line, the method detection limit (MDL) was estimated to be 0.978 pg L⁻¹ (5 Bq L⁻¹) in 10 mL urine, meeting the public screening requirement for judging ingestion/inhalation exposure beyond 1 mSv Committed Effective Dose Equivalent, with a reasonable throughput (∼6 h for 12 samples). For method validation, the standard reference materials provided by PROCORAD (Association for the PROmotion of Quality COntrol in RADiotoxicological Analysis), France, were analyzed and the results were all in good agreement with the assigned values. [ABSTRACT FROM AUTHOR]

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المؤلفون: Omori, Yasutaka, Sorimachi, Atsuyuki, Hosoda, Masahiro, Sahoo, Sarata Kumar, Kavasi, Norbert, Kurihara, Osamu, Tokonami, Shinji, Ishikawa, Tetsuo

المصدر: Radiation Protection Dosimetry; Nov2023, Vol. 199 Issue 18, p2233-2237, 5p

مصطلحات موضوعية: NUCLEAR power plant accidents, GAMMA ray spectrometry, RADIOISOTOPES, ABSORBED dose, SPECTROMETERS, PHOTON flux

الشركة/الكيان: FUKUSHIMA Daiichi Nuclear Power Plant (Japan)

مستخلص: In-situ measurements by gamma-ray spectrometry using a NaI(Tl) scintillation spectrometer are performed to discriminate primordial and artificial radionuclides contributing to ambient gamma dose rates in the living environment to quantify prolonged influence of nuclear accidents. However, low energy resolution of the spectrometer causes poor discrimination in the measurements at high-dose-rate points, which leads to overestimation of ambient gamma dose rate from the primordial radionuclides. The present study clarified that photon fluxes originating from ⁴⁰K and ²¹⁴Bi were affected by the presence of ¹³⁴Cs, whereas those from ²⁰⁸Tl were independent of it. In addition, the absorbed dose rates in air were strongly correlated with the ²⁰⁸Tl photon fluxes. These findings indicate that ²⁰⁸Tl photon fluxes can be used to evaluate absorbed dose rates in air from the primordial radionuclides. When estimated from the ²⁰⁸Tl photon fluxes only, the absorbed dose rates in air in Namie Town and Okuma Town, locations affected by the Fukushima Dai-ichi Nuclear Power Plant accident, were 19–71 and 20–47 nGy h⁻¹, respectively. [ABSTRACT FROM AUTHOR]

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المؤلفون: Naito, Masayuki, Tamakuma, Yuki, Yajima, Kazuaki, Kim, Eunjoo, Obara, Satoshi, Tani, Kotaro, Kurihara, Osamu

المصدر: Radiation Protection Dosimetry; Oct2023, Vol. 199 Issue 15, p2030-2034, 5p

مصطلحات موضوعية: FUKUSHIMA Nuclear Accident, Fukushima, Japan, 2011, NUCLEAR accidents, BODY size, IRRADIATION

مصطلحات جغرافية: FUKUSHIMA-shi (Japan)

مستخلص: We experimentally obtained the responses of two personal dosemeters (PDs, D-shuttle and Dose-i) attached on five age-specific phantoms under rotational irradiation geometry, which simulated an environment that was radiologically affected by the 2011 Fukushima nuclear accident using of a ¹³⁷Cs source. Although the PD responses showed an angular phase shift by the PD position on the phantoms, the angular dependence was small when the contamination was widely distributed. The PD responses decreased as much as ~10% with the increase in the phantoms' body size. Although there were ~17% variations in the PD/ADE (ambient dose equivalent) ratio depending on the different PDs, this variation was due to the fact that D-shuttle was calibrated with the inclusion of a safety margin. The PD/ADE ratios were similar to the effective dose to ADE ratios for corresponding age-specific phantoms. Our results suggest that these two PDs can provide reasonable estimates for age-dependent effective doses. [ABSTRACT FROM AUTHOR]

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المؤلفون: Kim, Eunjoo, Yajima, Kazuaki, Tani, Kotaro, Takashima, Yoshio, Ishigure, Nobuhito, Beaumont, Tiffany, Broggio, David, Kurihara, Osamu

المصدر: Radiation Protection Dosimetry; Oct2023, Vol. 199 Issue 15, p1989-1993, 5p

مصطلحات موضوعية: NUCLEAR accidents, AGE groups, FUKUSHIMA Nuclear Accident, Fukushima, Japan, 2011, THYROID gland

مستخلص: It is a challenging task to establish a feasible and robust method for the population monitoring of individuals' thyroid exposure following an accidental intake of radioiodines in a nuclear emergency, because of the time restriction. The authors previously proposed a method for such monitoring to obtain as many reliable human data as possible and one of the components is simplified measurements by conventional NaI(Tl) survey meters that are intended to be used for the initial triage to identify significantly exposed individuals and get an overall picture of the exposure levels in a target population in a timely manner. This study determined screening levels (SLs) for a conventional NaI(Tl) survey meter (model TCS-172, Hitachi, Japan) using the conversion factor (¹³¹I kBq in the thyroid per μSv h⁻¹) that were obtained from experiments and simulations with age-specific phantoms. The results demonstrated that the derived SLs for 100 mSv thyroid equivalent dose were as follows: 0.2 μSv h⁻¹ (SL1) for the age group ≤ 5-y-olds, 0.5 μSv h⁻¹ (SL2) for the 10- and 15-y-old age groups and 1.0 μSv h⁻¹ (SL3) for adults. These SLs would be reasonably available within 1 week after the intake of ¹³¹I on the safe side. [ABSTRACT FROM AUTHOR]

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المؤلفون: Yang, Guosheng, Kim, Eunjoo, Zheng, Jian, Kowatari, Munehiko, Kurihara, Osamu

المصدر: Radiation Protection Dosimetry; Oct2023, Vol. 199 Issue 15, p1994-1999, 6p

مصطلحات موضوعية: URANIUM isotopes, ACTINIDE elements, ION exchange resins, URINE, FERRIC hydroxides, QUALITY control

مستخلص: To provide timely information for prompting decision-making in emergency radiation therapy, we developed simple and rapid mass and alpha spectrometric methods for urinary bioassays to determine ultra-trace actinide isotopes. For the mass spectrometric method, after organic matter decomposition, LaF3/CaF2 co-precipitation and chromatographic purification using 2 ml of AG MP-1 M anion exchange resin, U and Pu isotopes were measured in a 20-ml urine sample by inductively coupled plasma-mass spectrometry. In the alpha spectrometric method, after organic matter decomposition, iron hydroxide co-precipitation and chromatographic purification using 2 ml of TEVA and 2 ml of DGA resin cartridges, Pu, U and Am/Cm isotopes were measured in a 500-ml urine sample by alpha spectrometry. These alpha and mass spectrometric methods were then applied for participation in the 2020 intercomparison organized by the Association for the PROmotion of Quality COntrol in RADiotoxicological Analysis (PROCORAD), France, for method validations. [ABSTRACT FROM AUTHOR]

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المؤلفون: Narita, Masato, Tani, Kotaro, Kunishima, Naoaki, Kim, Eunjoo, Kurihara, Osamu

المصدر: Radiation Protection Dosimetry; Oct2023, Vol. 199 Issue 15, p1802-1806, 5p

مصطلحات موضوعية: INDIVIDUAL differences, PHOTON detectors, MAGNETIC resonance imaging, UNITS of measurement, THYROID gland

مستخلص: Photon detectors utilised for direct thyroid measurements to determine the radioiodine content in the thyroid are normally calibrated using a phantom that mimics the human neck, including the thyroid. However, such measurements are necessarily subject to uncertainty because of the difference between the phantom and the real human subject and also the morphological differences among individuals. In this study, personal voxel phantoms were created from magnetic resonance images of the necks of 24 adult volunteers (15 males and 9 females), and numerical simulations using these phantoms were performed to examine the variation in a conversion factor (¹³¹I kBq in the thyroid per μSv h⁻¹) for a conventional NaI(Tl) survey meter among the individuals and also to confirm the suitability of reference Japanese voxel phantoms as a calibration standard for such measurements. As a result, it was found that the conversion factor obtained from the reference Japanese male (female) phantom was 1.29 (1.18) times larger than the average conversion factor for the male (female) subjects, suggesting that the conversion factors of the reference Japanese adult male and female phantoms would generally overestimate the ¹³¹I thyroidal contents and that the thyroid volume would be one of the factors influencing the conversion factor. This study also revealed a wide difference in the thyroid volume among individuals, which would be of concern when performing specific dose assessments for heavily exposed persons. [ABSTRACT FROM AUTHOR]

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المؤلفون: Tamakuma, Yuki, Naito, Masayuki, Yang, Guosheng, Tani, Kotaro, Yajima, Kazuaki, Kim, Eunjoo, Kowatari, Munehiko, Kurihara, Osamu

المصدر: Radiation Protection Dosimetry; Oct2023, Vol. 199 Issue 15, p1848-1852, 5p

مصطلحات موضوعية: LUNGS, GERMANIUM radiation detectors, MONTE Carlo method, COINCIDENCE, NUCLEAR research, NUCLEAR energy, IRON

مصطلحات جغرافية: JAPAN

الشركة/الكيان: LAWRENCE Livermore National Laboratory

مستخلص: A new in-vivo counting system that functions as both a whole-body counter (WBC) and a lung counter (LC) was developed at the QST to enhance its dose assessment capability. This paper presents an overview of this system and the results of its performance tests. For use of the system as a WBC, three high purity germanium (HPGe) detectors installed in a 20-cm-thick iron shielding chamber are linearly arrayed over a subject lying on the bed, whereas two of the three HPGe detectors are placed over the subject's chest from side to side when using the system as an LC. The new in-vivo system was calibrated using three de-facto phantoms owned by the QST: an adult-male BOttle Manikin ABsorption (BOMAB) phantom, a Lawrence Livermore National Laboratory (LLNL) phantom and a Japan Atomic Energy Research Institute (JAERI) phantom. Monte Carlo simulations were also performed to determine an optimum location for the three detector array in the WBC mode and revealed that the peak efficiency for the BOMAB phantom (662 keV) was little varied as long as the middle detector was placed above the thorax and abdomen parts of the phantom. The calculated peak efficiencies agreed well with the observed peak efficiencies for photons with energies over 100 keV. For lung counting, a tentative Minimum Detectable Activity of ²⁴¹Am was evaluated as 9.5 Bq for a counting time of 30 minutes, and a Japanese male subject with an average chest wall thinness (2.27 cm). The developed system is now ready for use. [ABSTRACT FROM AUTHOR]

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المؤلفون: Tani, Kotaro, Ishigure, Nobuhito, Kim, Eunjoo, Tominaga, Takako, Tatsuzaki, Hideo, Akashi, Makoto, Kurihara, Osamu

المصدر: Radiation Protection Dosimetry; Oct2023, Vol. 199 Issue 15, p2025-2029, 5p

مصطلحات موضوعية: ACTINIDE elements, PLUTONIUM isotopes, RADIATION dosimetry, NUMERICAL analysis, BIOLOGICAL assay, PLUTONIUM

مصطلحات جغرافية: JAPAN

مستخلص: Accidental inhalation intake of plutonium isotopes and ²⁴¹Am occurred at a Pu research facility in Japan in 2017, and the five workers involved in this accident were treated by the administration of Ca/Zn-diethylenetriaminepentaacetic acid (DTPA). For the worker who was most internally exposed, the therapy was continued over 1 y after the accident. Urinary samples collected before and after each administration were subject to bioassay to evaluate the efficacy of the dose reduction. This study performed numerical analyses using a biokinetic model dealing with ²⁴¹Am-DTPA with reference to the European Coordinated Network on Radiation Dosimetry approach, which assumes that the complex of actinides and Ca/Zn-DTPA is generated in the designated compartments in the biokinetic model. The results of the model prediction well captured the trend of the observed urinary excretion in the long-term bioassay and would be useful to evaluate the efficacy of the Ca/Zn-DTPA administration for the worker involved in the accident. [ABSTRACT FROM AUTHOR]

: Copyright of Radiation Protection Dosimetry is the property of Oxford University Press / USA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)