Biomedical subjects

Toshiaki Miyamoto

Publications and source records attributed to Toshiaki Miyamoto.

5 recordsLinked to original sources

PubMed2006

In situ x-ray diffraction measurements of the capillary fountain jet produced via ultrasonic atomization.

In situ x-ray diffraction measurements were carried out for investigating the liquid structure in the ultrasonic fountain jet to consider the mechanism of the "ultrasonic ethanol separation" reported by Sato et al. [J. Chem. Phys. 114, 2382 (2001)]. For pure liquids (water and ethanol), it was found that the high frequency ultrasound does not affect the liquid structure microscopically. For the 20 mol % ethanol-water mixture, the estimated ethanol mole fraction in the ultrasonic fountain jet by using the position of the main maximum in the x-ray diffraction profile coincided with that in the reservoir. This result suggests that the ethanol separation is not caused by any distorted liquid structure under the ultrasound irradiation and occurs when or after the generation of the liquid droplet mist.

Journal Article↗

PubMed2006

Health status of workers in small and medium-sized companies as compared to large companies in Japan.

The health status of workers in small companies has been noted to be relatively poor, but no actual comparisons of groups of variously sized companies within the same region based on the same methodology have ever been conducted. We undertook this study to clarify differences in health status according to company size. The subjects comprised workers of a Japanese steel company and various subcontractors who received health checkups in 2003. We obtained answers from 83 companies employing 11,844 workers and analyzed the data for 6,480 men aged 40 yr or more, comparing results of the health checkups, health management practices, and number of occupational health personnel according to company size (number of employees). Mean worker age in the various groups ranged from 49.7 to 54.0 yr. Drinking and smoking habits did not differ between them. There was a significant trend to higher prevalences of diabetes and hypertension, and lower prevalences of renal disease and hypercholesterolemia in smaller companies. Mean body mass index and diastolic blood pressure were significantly higher in companies with 1,000-2,999 workers. Health management practices satisfied the legal requirements of the respective company size. Occupational physicians devoted more time per worker in companies with 1,000-2,999 and 50-299 workers. No consistent differences were apparent between small and large companies in worker health status. Inter-company activities for occupational safety and health were undertaken and labor regulations almost equally adhered to. Endeavors to maintain a certain level of hygiene and health management play an important role in maintaining worker health in small companies.

Adult↗

PubMed2004

Possible association between heavy computer users and glaucomatous visual field abnormalities: a cross sectional study in Japanese workers.

STUDY OBJECTIVE: To study the association between computer use and visual field abnormalities (VFA) and to assess whether heavy computer users have an increased risk of glaucoma. DESIGN: Cross sectional multicentre study. Subjects and observation procedures: A total of 10 202 randomly selected Japanese workers (mean (SD) age 43.2 (9.8) years) were screened for VFA using the frequency doubling technology perimetry (FDT-VFA), in addition to undergoing a general medical check up, and then ophthalmologically examined. Information about their computer use and refractive errors was obtained from a questionnaire and interview, respectively. MAIN RESULTS: As a result of FDT test, 522 and 8602 subjects were positive and negative for FDT-VFA, respectively. A significant (p = 0.004) interaction was found between computer use and refractive errors regarding the risk of FDT-VFA. In stratified analysis, heavy computer users with refractive errors showed a significant positive association with FDT-VFA (odds ratio (OR) = 1.74, 95% confidence interval (CI) 1.28 to 2.37), while those without refractive errors did not. Comparison of 165 subjects with an ophthalmological diagnosis of glaucoma and 2918 controls showed that the OR for glaucoma of heavy computer users with refractive errors was 1.82 (95% CI 1.06 to 3.12). Of 165 subjects with glaucoma, 141 had refractive errors, especially myopia (96.4%, 136 of 141). CONCLUSIONS: Although there are limitations to this study, such as its cross sectional design, heavy computer users with refractive errors seem to have an increased risk of FDT-VFA. Glaucoma might be involved in an underlying disease and myopia in a risk factor for FDT-VFA.

Adult↗

PubMed2003

Laterality of the performance of glaucoma mass screening using frequency-doubling technology.

PURPOSE: This study investigated laterality during the performance of glaucoma mass screening with a frequency-doubling technology perimetry test. MATERIALS AND METHODS: A frequency-doubling technology screening mode (C-20-1, version 2.6) test was performed on both eyes of 14,784 persons. Subjects with visual field abnormalities detected by the frequency-doubling technology test or with fixation error underwent retesting without a specified interval for rest. Consequently, 206 subjects who fulfilled the screening criteria of the frequency-doubling technology-based glaucoma screening protocol [FDT-GSP(+)] were further investigated using the Humphrey visual field analyzer (30-2). As a result, 74 right eyes and 57 left eyes were shown to have definite glaucoma. RESULTS: Frequency-doubling technology data for the left eye demonstrated a significantly (P<0.001) higher rate of artifacts, such as no reproducibility of results between the first and second tests (left/right: 2.4%/1.7%) as well as fixation errors (left/right: 2.8%/1.0%). The false-positive rate of the FDT-GSP for glaucoma was more than 1.5-fold higher in the left eye than in the right eye (16.3%/9.8%). In the case that either eye exhibited FDT-GSP(+), the positive predictive value of the FDT-GSP for definite glaucoma in the left eye was almost half of that in the right eye (28.4% vs. 53.8%). Specificity of the FDT-GSP for detection of definite glaucoma also exhibited a lower trend (P = 0.097) in the left eye (44.6%) than in the right eye (55.3%), but the sensitivity of the test was similar in both eyes (91.2% vs. 90.5%, respectively). CONCLUSIONS: When frequency-doubling technology-based mass screening is performed on the general population, performance is lower for the left eye than for the right eye. This performance disparity is likely to be primarily associated with a difference in specificity.

Adult↗

PubMed2002

Performance of glaucoma mass screening with only a visual field test using frequency-doubling technology perimetry.

PURPOSE: To report the performance of glaucoma mass screening with only a visual field test utilizing frequency- doubling technology (FDT) perimetry in general populations. DESIGN: Hospital and population-based cross-sectional study. METHODS: This study took place in a multicenter setting. One hundred three consecutive glaucomatous patients and 14,814 persons were randomly selected. We had created a glaucoma screening protocol (GSP) using FDT perimetry (FDT-GSP). Frequency-doubling technology-glaucoma screening protocol was tested on consecutive glaucoma patients diagnosed with Humphrey visual field analyzer (30-2 SITA standard), and then FDT-GSP was applied to general populations. Frequency-doubling technology-glaucoma screening protocol positive subjects were ophthalmologically diagnosed. Detection ability of FDT-GSP was determined in consecutive patients, and the positive predictive value (PPV) of FDT-GSP to detect definitive glaucoma was estimated in general populations. RESULTS: Frequency-doubling technique-glaucoma screening protocol detected 83.3% and 100% of definitive glaucoma patients with an early (mean deviation [MD] > -6 dB) and more advanced stage (MD < or = -6 dB), respectively. In the population-based screening, there were 660 (4.5%) subjects who had positive FDT-GSP, including 512 in whom no visual field abnormalities (VFA) had been pointed out previously. Of them, 370 subjects underwent ophthalmologic diagnosis. Then, 266 (71.9%, 266/370) subjects had a glaucomatous disk and 167 had definitive glaucomatous VFA. Fifty-five (14.9%) and 39 (10.5%) subjects were diagnosed as having other diseases and as normal, respectively. The PPV of FDT-GSP ranged from 32.6% (167/512)-45.1% (167/370). CONCLUSIONS: Frequency-doubling technology-based screening with only a visual field test showed reasonable performance on mass screening for detection of definitive glaucoma in this study population, considering the glaucoma prevalence.

Aged↗