Biomedical subjects

Yasushi Honda

Publications and source records attributed to Yasushi Honda.

8 recordsLinked to original sources

PubMed2006

SAC and SAC-CI calculations of excitation and circular dichroism spectra of straight-chain and cyclic dichalcogens.

Accurate quantum-chemical calculations of the excitation energies and the rotatory strengths of dichalcogens R-Ch-Ch-R (Ch = S, Se, Te) were carried out with the symmetry adapted cluster (SAC) and SAC-configuration interaction (CI) methods. A series of straight-chain molecules (dihydrogen dichalcogenide, dimethyl dichalcogenide, and (+)-bis(2-methylbutyl) dichalcogenide) and one cyclic molecule (2,3-(R,R)-dichalcogenadecalin) were adopted for comparative analysis. The calculated excitation and circular dichroism (CD) spectra were in good agreement with experimental ones (Laur, P. H. A. In Proceedings of the Third International Symposium on Organic Selenium and Tellurium Compounds; Cagniant, D., Kirsch, G., Eds.; Universite de Metz: Metz, 1979; pp 219-299) within 0.3 eV. The fitting CD spectra also reasonably reproduced the experimental ones. In all the molecules adopted, the first and second lowest bands were assigned to the n-sigma(Ch-Ch) transition and the third and fourth lowest bands to the n-sigma(Ch-R) transition. The first and second lowest bands apparently depended on the R-Ch-Ch-R dihedral angle, suggesting that the orbital energies of two sigma(Ch-Ch) change with the R-Ch-Ch-R dihedral angle. This calculated trend agrees with two empirical rules: the C(2) rule and the quadrant rule.

Chalcogens↗

PubMed2006

Childhood leukemia and magnetic fields in Japan: a case-control study of childhood leukemia and residential power-frequency magnetic fields in Japan.

Residential power-frequency magnetic fields (MFs) were labeled as a possible human carcinogen by the International Agency for Research on Cancer panel. In response to great public concern, the World Health Organization urged that further epidemiologic studies be conducted in high-exposure areas such as Japan. We conducted a population-based case-control study, which covered areas inhabited by 54% of Japanese children. We analyzed 312 case children (0-15 years old) newly diagnosed with acute lymphoblastic leukemia (ALL) or acute myelocytic leukemia (AML) in 1999-2001 (2.3 years) and 603 controls matched for gender, age and residential area. Weekly mean MF level was determined for the child's bedroom. MF measurements in each set of a case and controls were carried out as closely in time as possible to control for seasonal variation. We evaluated the association using conditional logistic regression models. The odds ratios for children whose bedrooms had MF levels of 0.4 microT or higher compared with the reference category (MF levels below 0.1 microT) was 2.6 (95% CI=0.76-8.6) for AML+ALL and 4.7 (1.15-19.0) for ALL only. Controlling for some possible confounding factors did not alter the results appreciably. Even an analysis in which selection bias was maximized did not fully explain the association. Most of the leukemia cases in the highest exposure category had MF levels far above 0.4 microT. Our results provided additional evidence that high MF exposure was associated with a higher risk of childhood leukemia, particularly of ALL.

Acute Disease↗

PubMed2005

Relationship between ventilatory response and body temperature during prolonged submaximal exercise.

We examined whether an increase in skin temperature or the rate of increase in core body temperature influences the relationship between minute ventilation (Ve) and core temperature during prolonged exercise in the heat. Thirteen subjects exercised for 60 min on a cycle ergometer at 50% of peak oxygen uptake while wearing a suit perfused with water at 10 degrees C (T10), 35 degrees C (T35), or 45 degrees C (T45). During the exercise, esophageal temperature (Tes), skin temperature, heart rate (HR), Ve, tidal volume, respiratory frequency (f), respiratory gases, blood pressure (BP), and blood lactate were all measured. We found that oxygen uptake, carbon dioxide output, BP, and blood lactate did not differ among the sessions. Tes, HR, Ve, and f remained nearly constant from minute 10 onward in the T10 session, but all of these parameters progressively increased in the T35 and T45 sessions, and significantly higher levels were seen in the T45 than the T35 session. For all but two subjects in the T35 and T45 sessions, plotting Ve as a function of Tes revealed no threshold for hyperventilation; instead, increases in Ve were linearly related to Tes, and there were no significant differences in the slopes or intercepts between the T35 and T45 sessions. Thus, during prolonged submaximal exercise in the heat, Ve increases with core temperature, and the influences of skin temperature and the rate of increase in Tes on the relationship between Ve and Tes are apparently small.

Adult↗

PubMed2005

[Research on choices of people with mild symptoms of common cold between consulting physicians and taking OTC (over-the-counter) medicine using a hypothetical question method].

PURPOSE: This study was aimed at predicting the demand for medical services of people with mild symptoms of common cold. Three alternatives to cope with this condition were presented in questionnaires, which were: consulting physicians, taking OTC (over-the-counter) medicine, and doing nothing. Our prediction of employees' choices with these alternatives will contribute to cost-containment policies of health insurers. METHOD: We mailed questionnaires to 12,000 selected randomly employees, insured by "A" health insurance company. The questionnaires were designed a hypothetical question method, utilizing several criteria, including number of OTC medicines on hand, and socioeconomic status. A multinomial probit model was used for our estimation and analysis, with alternatives set as dependent variables. RESULTS: There were 3139 respondents, and the response rate was 26.2%. Gender, age, number of family members, and income level did not have any significant effect on the choice of any of the three alternaives. On the other hand, having a family doctor and a number of OTC medicines on hand had significant consequences. In males with a family doctor and without OTC medicine, the probabilities of choose to consult with a physicians, take on OTC medication, or doing nothing, were predicted to be 0.46, 0.32, and 0.22, respectively. People with three or more kinds of OTC medicine are more likely to choose OTC medication than physicians. CONCLUSION: The study suggests that more kinds of OTC medicine on hand of for individual with mild symptoms of common cold, the leaves the demand for medical services. To reduce medical expenses through consulting medical services, it might be effective for health insurers to provide insured employees with incentives to keep more OTC medicines on hand.

Common Cold↗

PubMed2005

[Comparative study of daily maximum exposure to temperatures during hot summer days in 3 Japanese cities].

OBJECTIVES: Health risk assessment and developing measures to deal with global warming (including increased heat waves) have become urgent global issues. In the present study, we measured the personally exposed temperature (Tp) during summer among residents in major Japanese cities to investigate the relation to daily maximum ambient temperature (Tmax), which is generally been used as an index of temperature exposure in epidemiological studies. METHODS: Personal exposures to temperature (Tp) were measured for a week with portable monitors (HOBO H8 Loggers, Onset Computer Corporation) for 194 subjects (101 males and 93 females, aged 21-82 years) in 3 cities, i.e., Sapporo, Tokyo and Naha (Okinawa), from July to September, 2003 (73 days). RESULTS AND DISCUSSION: Even on days with a Tmax of 30-35 degrees C, associated with significantly increased risk of mortality in Tokyo, neither average Tp for 7-19 o'clock nor the value for 13-15 o'clock appeared to rise beyond 30 degrees C in Tokyo and 31 degrees C in Naha. It was, thus, apparent that Tp's are generally controlled to not exceed these values at least during daytime, suggesting that they could be regarded as a threshold for heat stress tolerance. On the other hand, although average Tp's for night time (0-7 o'clock) were also found to be asymptomatic at 29 degrees C in Tokyo and 30 degrees C in Naha, they were generally too high to be free from heat stress including sleep disturbance in both cities as indicated in our questionnaire study. For both cities, in days with the Tmax above 30 degrees C, the average Tmin was 26 degrees C, while average and minimum Tp's during the night time were 28 degrees C and 27 degrees C, respectively. The correlation coefficients with Tmax were generally low; 0.35 for average Tp during daytime, 0.42 for Tmin and 0.27 and 0.19 for average and minimum night time Tp, respectively.

Adult↗

PubMed2004

Effects of brief leg cooling after moderate exercise on cardiorespiratory responses to subsequent exercise in the heat.

We investigated the effects of brief leg cooling after moderate exercise on the cardiorespiratory responses to subsequent exercise in the heat. Following 40 min of ergometer cycling [65% peak oxygen uptake (VO(2peak))] at 35 degrees C (Ex. 1), seven male subjects [21.9 (1.1) years of age; 170.9 (1.9) cm height; 66.0 (2.0) kg body mass; 46.7 (2.0) ml kg(-1) min(-1) VO(2peak)] immersed their legs in 35 degrees C (control condition, CONT) or 20 degrees C (cooling condition, COOL) water for 5 min and then repeated the cycling (as before, but for 10 min) (Ex. 2). Just before Ex. 2, esophageal temperature ( T(es)) was lower in COOL than in CONT [36.9 (0.2) vs 37.5 (0.1) degrees C] ( P<0.01), as also were both mean skin temperature [33.9 (0.2) vs 35.2 (0.2) degrees C] ( P<0.01), and heart rate (HR) [93.2 (6.0) vs 102.7 (4.9) beats min(-1)] ( P<0.05). During Ex. 2, no differences between CONT and COOL were observed in oxygen uptake, arterial blood pressure, blood lactate concentration, or ratings of perceived exertion; however, T(es), skin temperature, and HR were lower in COOL than in CONT. Further, during the first 5 min of Ex. 2, minute ventilation was significantly lower in COOL than in CONT [50.3 (2.0) vs 53.4 (2.6) l min(-1)] ( P<0.01). These results suggest that brief leg cooling during the recovery period may be effective at reducing thermal and cardiorespiratory strain during subsequent exercise in the heat.

Adult↗

PubMed2002

Mortality among workers at a talc mining and milling facility.

BACKGROUND: This study evaluated mortality among workers at a talc mining and milling facility. METHODS: Subjects were white men actively employed between 1948 and 1989 and known to have been alive in or after 1950. Analyses assessed cancer mortality during the period 1950-89 (809 subjects) and non-cancer mortality during 1960-89 (782 subjects). RESULTS: Comparisons with regional general population death rates for 1960-89 indicated that the workers had more than expected deaths from all causes combined [209 observed/160 expected, standardized mortality ratio (SMR) = 131, 95% confidence interval (CI) = 114-150], due mainly to increased mortality from lung cancer (31/13, SMR = 232, CI = 157-329) and non-malignant respiratory disease (NMRD) (28/13, SMR = 221, CI = 147-320). The lung cancer excess was concentrated in miners (18/4.6, SMR = 394, CI = 233-622); millers had only a small increase (7/5.5, SMR = 128, CI = 51-263). An excess of NMRD occurred both in miners (10/4.2, SMR = 241, CI = 116-444) and in millers (11/4.8, SMR = 227, CI = 113-407). The median estimated exposure to respirable dust was 511 mg/m(3)-days for all exposed employees, 739 mg/m(3)-days for mine workers and 683 mg/m(3)-days for mill workers. Employees with high, compared with low, estimated exposure to dust had a rate ratio of 0.5 (CI = 0.2-1.3) for lung cancer and of 11.8 (CI = 3.1-44.9) for pulmonary fibrosis. CONCLUSIONS: Exposure to talc ore dust may not have been responsible for the lung cancer excess among these workers but probably contributed to the elevated rate of NMRD, particularly pulmonary fibrosis.

Dust↗

PubMed2002

Assessment of historical exposures to talc at a mining and milling facility.

The purpose of this study was to develop an estimate of exposure to respirable dust for all job categories and all years in a retrospective follow-up study of worker mortality in a talc mining and milling facility. All jobs were assigned to work areas that were considered to have similar exposure profiles. Uniform exposure time periods during which non-random, deterministic variables were thought to be constant were identified and an experienced rater assigned categorical exposure scores to each work area/time period. These scores and measured baseline respirable dust concentrations were used to calculate the estimated job area/year concentrations for each work area/time period. Estimates were compared to available historical measurements. The estimated exposures ranged from 1.7 to 0.1 mg/m(3) and displayed a decreasing trend over time. When compared with measured exposures, the estimated exposures had a correlation coefficient of 0.55 with an average difference of 0.01 mg/m(3) and a range of 0.60 to -0.48 mg/m(3). The estimates were considered to be acceptable for determining relative ranking of subjects according to cumulative exposure.

Follow-Up Studies↗