No abstract available

[en] Low dose and low dose rate radiation effects on lifespan, pathological changes, hemopoiesis and cytokine production in mice have been investigated in our laboratory. In the intermediate period of the investigation, an expert committee on radiation biology was organized. The purposes of the committee were to assess previous studies and advise on a future research plan for the Advanced Molecular Bio-Sciences Research Center (AMBIC). The committee emphasized the necessity of molecular research in radiation biology, and proposed the following five subjects: 1) molecular carcinogenesis by low dose radiation; 2) radiation effects on the immune and hemopoietic systems; 3) molecular mechanisms of hereditary effect; 4) noncancer diseases of low dose radiation, and 5) cellular mechanisms by low dose radiation. (author)

[en] Low-dose and low-dose-rate radiation effects on life-span, pathological changes, hemopoiesis and cytokine production in experimental animals have been investigated in our laboratory. In the intermediate period of the investigation, an expert committee on radiation biology, which was composed of two task groups, was organized. The purposes of the committee were to assess of previous studies and plan future research for Advanced Molecular Bio-Sciences Research Center (AMBIC). In its report, the committee emphasized the necessity of molecular research in radiation biology and ecology, and proposed six subjects for the research: 1) Molecular carcinogenesis of low-dose radiation; 2) Radiation effects on the immune system and hemopoietic system; 3) Molecular mechanisms of hereditary effect; 4) Non cancer effect of low-dose radiation; 5) Gene targeting for ion transport system in plants; 6) Bioremediation with transgenic plant and bacteria. Exploration of the AMBIC project will continue under the committee's direction. (author)

[en] Monitoring and protecting of occupational eye doses in interventional radiology (IR) are very important matters. DOSIRIS™ is the useful solution to estimate the 3 mm dose-equivalent (Hp(3)), and it can be worn behind lead glasses. And DOSIRIS™, adjustable according to 3 axes, it is ideally placed as close to the eye and in contact with the skin. So, DOSIRIS™ will be suitable eye lens dosimeter. However, the fundamental characteristics of the DOSIRIS™ in the diagnostic x-ray energy domain (including that of IR x-ray systems) remain unclear. Here, we evaluated the performance of the dosimeter in that energy range. As a result, the DOSIRIS™ has good fundamental characteristics (batch uniformity, dose linearity, energy dependence, and angular dependence) in the diagnostic x-ray energy domain. We conclude that the DOSIRIS™ has satisfactory basic performance for occupational eye dosimetry in diagnostic x-ray energy settings (including IR x-ray systems). (note)

[en] Trans radial access for cardiac catheterization is associated with reduced complications and improved patient comfort. Pelvic lead shielding of the patient has been reported to reduce operator radiation exposure. We tested the hypothesis that the originally developed L-shaped lead drape would reduce operator exposure using the human phantom. Scatter radiation was measured at the operator's position with an ionization chamber survey meter, with and without the L-shaped lead drape. At the operator's standing position, scatter radiation was reduced by up to 87%, as compared with that without. Similarly, scatter radiation at the operator's hand position was reduced by up to 92%. The use of the L-shaped lead drape during radial approach reduced the operator exposure at multiple measurement sites. (author)

[en] In 2011, International Commission on Radiological Protection recommended a reduction in the lens equivalent dose limit. However, few studies have been conducted on nurses working with PET examinations. Therefore, we evaluated the annual dose to PET nurses from 6-month dose using a lens dosimeter. We also examined the relationship between lens dose and number of procedures or injected dose. In addition, we compared lens dosimeter and personal dosimeter. As a result, the annual dose for nurses was below the dose limit. There was a correlation between lens dose and number of procedures or injected dose. In addition, the possibility of underestimation of personal dosimeters was suggested. (author)

[en] Although the clinical value of fluoroscopically guided respiratory endoscopy (bronchoscopy) is clear, there have been very few studies on the radiation dose received by staff during fluoroscopically guided bronchoscopy. The International Commission on Radiological Protection (ICRP) is suggesting reducing the occupational lens dose limit markedly from 150 to 20 mSv/year, averaged over defined periods of five years. The purpose of this study was to clarify the current occupational eye dose of bronchoscopy staff conducting fluoroscopically guided procedures. We measured the occupational eye doses (3-mm-dose equivalent, Hp(3)) of bronchoscopy staff (physicians and nurses) over a 6-month period. The eye doses of eight physicians and three nurses were recorded using a direct eye dosimeter, the DOSIRIS. We also estimated eye doses using personal dosimeters worn at the neck. The mean ± SD radiation eye doses (DOSIRIS) to physicians and nurses were 7.68 ± 5.27 and 2.41 ± 1.94 mSv/6 months, respectively. The new lens dose limit, 20 mSv/year, may be exceeded among bronchoscopy staff, especially physicians. The eye dose of bronchoscopy staff (both physicians and nurses) was underestimated when measured using a neck dosimeter. Hence, the occupational eye dose of bronchoscopy staff should be monitored. To reduce the occupational eye dose, we recommend that staff performing fluoroscopically guided bronchoscopy wear Pb glasses. correct evaluation of the lens dose [Hp(3)] using an eye dosimeter such as the DOSIRIS is necessary for bronchoscopy staff.