Interlaboratory comparison of electron paramagnetic resonance tooth enamel dosimetry with investigations of the dose responses of the standard samples.

A total of seven Japanese laboratories participated in an intercomparison study to estimate the dose given to tooth enamel samples, using the electron spin resonance method. Each of four of the participating laboratories prepared a set of tooth enamel samples, using the electron spin resonance method. Four of the participating laboratories each prepared a set of tooth enamel samples, consisting of seven standard aliquots irradiated from 100 to 2000 mGy and three samples with an 'unknown' dose between 140 and 960 mGy, were intended to eliminate bias from sample preparation. Although not all seven laboratories measured all four sets of samples, the major finding was that systematic biases in estimating doses may be caused by differences in laboratory measurements rather than by the enamel extracting procedures. When doses were averaged by measurements made by multiple laboratories, the averaged values were close to the actual values. Scattering in the intercepts in the standard dose response would be a serious problem in actual dosimetry where no background sample is available.

Real-world treatment and health care resource use among severe asthma patients in Japan.

BACKGROUND: There are limited studies on healthcare resource use (HCRU) among adult asthma patients in Japan using real-world evidence, and analysis on acute treatment and associated costs stratified by disease severity is further limited. This study aimed to characterize the disease burden of severe asthma patients in Japan in terms of HCRU and comorbid medical conditions, with particular interest in oral corticosteroid (OCS) dependency. METHODS: This retrospective cohort study of asthma patients used data from a claims database of diagnosis procedure combination hospitals in Japan. The severe asthma cohort included patients treated with OCS for more than 180 days in one year before the index date, with at least one asthma diagnosis claim. Comorbidity and drug use in the look-back period, HCRU, assumed OCS-related adverse events, and asthma exacerbations in the follow-up period were analyzed. RESULTS: Costs associated with the treatment of severe asthma were approximately twice that of mild/moderate asthma, and the annual median cost of patients hospitalized due to asthma reached ¥448,000 (USD $4073). Annual asthma exacerbation rate was higher in the severe asthma cohort than in the mild/moderate cohort. Patients with longer OCS use in the previous year had higher risks of secondary adrenal insufficiency, osteoporosis, and pneumonia in the following year. CONCLUSIONS: OCS use among asthma patients in Japan incurred greater medical and economic burden. Better understanding of the disease characteristics including the severity of asthma and appropriate management of disease burden will lead to more optimal use of healthcare resources in Japan.

Measurement of residual 60Co activity induced by atomic-bomb neutrons in Nagasaki and background contribution by environmental neutrons.

Residual 60Co activity in five steel samples induced by neutrons from the Nagasaki atomic bomb has been measured within about 1000 m from the hypocenter. The chemical separation of cobalt and nickel from steel samples was performed, and cobalt-enriched samples were prepared for all samples. Gamma-ray measurements were carried out with a low-background well-type germanium detector. The gamma-ray spectra for five samples were compared with the spectrum of a control sample to ensure that the observed 60Co was actually induced by A-bomb neutrons. The activation of cobalt by environmental neutrons was also investigated. It has been shown that the present 60Co data are consistent with earlier Hashizume's data.