Rapid detection of plutonium contamination with and without uranium contamination in wounds by x-ray fluorescence.

In the event of an accident at a nuclear fuel handling facility, the wounds of affected workers may be contaminated with plutonium. The current approach for identifying plutonium contamination is by detecting α-particles in the blood stream. However, the applicability of this approach is impeded due to the α-particles being easily shielded by the bodily fluid components.

Pseudo-inflammatory manifestations of choroidal lymphoma resembling Vogt-Koyanagi-Harada disease: case report based on multimodal imaging.

Background: Hematologic malignancies occasionally cause serous retinal detachment (SRD); however, its pathogenesis remains unclear. Here we present the imaging characteristics of metastatic choroidal lymphoma masquerading as Vogt-Koyanagi-Harada (VKH) disease.

Case Presentation: A 45-year-old Japanese woman was referred to our clinic because of bilateral SRD with blurred vision.

The clinical features of radiation cataract in patients with ocular adnexal mucosa-associated lymphoid tissue lymphoma.

Background: To examine the clinical features of radiation cataract in patients with ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma.

Methods: Twenty-one patients with 26 eyes diagnosed with ocular adnexal MALT lymphoma (26 eyes), who were treated in Hokkaido University Hospital, were retrospectively reviewed based on medical records.

Results: Out of the 21 patients, 16 patients (21 eyes) received radiation therapy (RT) with a total dose of 30 Gy.

Intake ratio of 131I to 137Cs derived from thyroid and whole-body doses to Fukushima residents.

This study deals with the intake ratio of (131)I to (137)Cs that allows for the utilisation of late whole-body measurements to reconstruct the internal thyroid doses to Fukushima residents. The ratio was derived from the thyroid dose distribution of children and the effective dose distribution of adults based on the assumption that various age groups of persons inhaled the two nuclides at the same activity ratio and at around the same time, while taking into account age-dependent ventilation rates. The two dose distributions were obtained from residents of Iitate village and Kawamata town, located northwest of Fukushima Daiichi nuclear power plant (FDNPP).

Development of radon sources with a high stability and a wide range.

A solid (222)Rn (radon) source using a fibrous and porous SiC ceramic disk was developed. The emission rate of radon emanated from the disk depended on the content of (226)Ra and the sintering temperature. A (226)Ra sulfate ((226)RaSO4) solution was dropped on a fibrous SiC ceramic disk (33 mmφ) of 1 mm in thickness, and sintered at 400 °C.

Rapid estimation of inhaled particle size for internal dose during nuclear emergency medicine.

Information on particle size is one of the important factors for internal dose estimation at accidents with airborne radioactive materials. An autoradiography method has been investigated as a technique for the sizing of alpha-emitting particles. Concerning nuclear emergency medicine, the waiting time for dose estimation is limited.

Contamination control by a greenhouse for emergency medical treatment of the contaminated patient.

In emergency medical treatment of patients contaminated with radioactivity, air contamination control is very important to prevent the secondary contamination of medical staff. In order to optimize design of a greenhouse, a numerical analysis was made by using the Flow Designer software. As a scenario of air contamination, the breathing air of the patient was assumed to be highly contaminated with radioactive gaseous or particulate matter.

Loss-of-heterozygosity analysis of 6-thioguanine-resistant mutants induced by radon exposure in mouse FM3A cells.

Radon is an inert gas that can migrate from soils and rocks and accumulate in enclosed areas such as buildings and underground mines. The ubiquitous occurrence of radon in the environment is the primary cause of harmful radiation exposure to the public. To investigate the mutagenic effect of radon, mouse FM3A cells growing on soft agarose plates were exposed to alpha particles disintegrated from radon-222 and daughter elements.

Identification of mouse mutant cells exhibiting plastic mutant phenotype II; ionizing radiation-induced mutant phenotype plasticity is not dependent on DNA methylation of the hypoxanthine phosphoribosyl transferase gene in mouse FM3A cells.

As we previously reported, we isolated and examined mouse mutant cells exhibiting phenotypic plasticity. Approximately 10% of 6-thioguanine resistant (6TG(R)) cells derived from the irradiated cell population exhibited phenotypic plasticity and reverted to wild type HAT resistance (HAT(R)). Similar mutant cells were also identified in an un-irradiated wild type cell population, but at a lower frequency.

Identification of mouse mutant cells exhibiting the plastic mutant phenotype.

The initial processes involved in radiation carcinogenesis have not been clearly elucidated. We isolated mouse mutant cells exhibiting plasticity in their mutation phenotypes. These mutant cells were originally isolated from an irradiated cell population as 6-thioguanine resistant (6TGR) mutants that were deficient in hypoxanthine phosphoribosyl transferase (Hprt, E.

Characterisation of nasal swab samples by alpha spectrometry.

A positive nasal swab taken at a radiation emergency, when properly collected and analysed, is a good indication of a potential inhalation intake. It may be expected to be a useful method for early dose assessment in cases of accidental inhalation of an alpha emitter. To improve the first estimation of intake activity, the quality of a nasal swab measurement was experimentally investigated.

Air contamination analysis during emergency medical treatment.

After radiological emergencies, patients contaminated with radioactivity are taken to radiation emergency hospitals for treatment. Numerical simulations using the computer software 'Flow Designer((R))' were made in order to evaluate indoor air contamination caused by the breathing out of contaminated air. The National Institute of Radiological Sciences facility was used for the numerical evaluation.

Radon-thoron discriminative measurements in Gansu Province, China, and their implication for dose estimates.

Indoor radon measurements were carried out in cave dwellings of the Chinese loess plateau in Gansu province, where previously the Laboratory of Industrial Hygiene (LIH), China, and the U.S. National Cancer Institute (NCI) had conducted an international collaborative epidemiological study.

Deposition and clearance for radon progeny in the human respiratory tract.

In vivo counting of 214Pb was conducted to estimate the deposition and retention of radon progeny in the human respiratory tract. Two volunteer subjects were exposed to high radon concentrations. After the exposures, activity deposited in the extrathoracic (ET) region for each subject was measured using a NaI(Tl) detector.

Repair of DNA double-strand breaks and cell killing by charged particles.

It has been suggested that it is not simple double-strand breaks (dsb) but the non-reparable breaks which correlate well with the high biological effectiveness of high LET radiations for cell killing (Kelland et al., 1988; Radford, 1986). We have compared the effects of charged particles on cell death in 3 pairs of cell lines which are normal or defective in the repair of DNA dsbs.

Inactivation of aerobic and hypoxic cells from three different cell lines by accelerated (3)He-, (12)C- and (20)Ne-ion beams.

The LET-RBE spectra for cell killing for cultured mammalian cells exposed to accelerated heavy ions were investigated to design a spread-out Bragg peak beam for cancer therapy at HIMAC, National Institute of Radiological Sciences, Chiba, prior to clinical trials. Cells that originated from a human salivary gland tumor (HSG cells) as well as V79 and T1 cells were exposed to (3)He-, (12)C- and (20)Ne-ion beams with an LET ranging from approximately 20-600 keV/micrometer under both aerobic and hypoxic conditions. Cell survival curves were fitted by equations from the linear-quadratic model and the target model to obtain survival parameters.

Response of mouse intestine after single and fractionated irradiation with accelerated carbon ions with a spread-out Bragg peak.

The responses of mouse intestine were examined after irradiation with accelerated carbon ions with a spread-out Bragg peak. The carbon-ion beam (135 MeV/nucleon), accelerated by the RIKEN ring cyclotron facility, was modulated to have a spread-out Bragg peak (SOBP) 3 cm wide. In the SOBP the biological dose (relative physical dose x RBE) was designed in earlier studies to be flat at the 10% survival level of Chinese hamster V79 cells.

Effects of reoxygenation on repair of potentially lethal radiation damage in cultured MG-63 osteosarcoma cells.

The effects of reoxygenation on repair of potentially lethal radiation damage were investigated using MG-63 human osteosarcoma cells in vitro. When exponentially growing MG-63 cells were cultured under hypoxic conditions for 24 h, cells stopped growing and remained at a low density. The hypoxic cells were then reoxygenated by exposure to air and irradiated with a single dose of 3 Gy X rays.

Characterization and application of UV detector spore films: the sensitivity curve of a new detector system provides good similarity to the action spectrum for UV-induced erythema in human skin.

The UV action spectra of two different biologically weighting UV photofilms (spore films), produced with Bacillus subtilis spores (wild-type and DNA repair-deficient strains), were determined at the Okasaki large spectrograph (OLS) within the level of wavelength range 254-400 nm. The action spectrum of the mutant strain film was modified with a cut-off filter, yielding a sensitivity curve similar to the action spectrum for erythemal induction in human skin. The detector system was tested in a field study and in a study using lamps with different UV spectral compositions.