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Biomedical subjects

Y Motohashi

Publications and source records attributed to Y Motohashi.

84 records · Page 5Linked to original sources
PubMed1982

Erythrocyte changes in aqueous polyethylene glycol solutions containing sodium chloride.

The behavior of rabbit erythrocytes in aqueous solutions of polyethylene glycol 300 (I) and polyethylene glycol 400 (II) containing sodium chloride was investigated during 2-120 min incubation at 37 degrees. No hemolysis was found in I (0-10.1%) and II (0-12.9%) solutions in the presence of sodium chloride (0.45-1.35%), but prelytic potassium ion loss and changes in the appearance of the erythrocytes proceeded with the passage of time. The potassium ion loss increased with increasing concentration of polyethylene glycol and/or sodium chloride. The mean cellular volume of erythrocytes decreased temporarily (during the first 2 min) in both I (6.7%) and II (8.6%) solutions containing sodium chloride (0.68-1.35%), and then increased progressively to the same value as that determined by solution of sodium chloride at the same concentration but without polyethylene glycol (approximately 30 and 120 min in I and II solutions, respectively). Both I (10.1%) and II (12.9%) induced a stomatocytic transformation of erythrocytes, but at the higher concentrations (0.9-1.35%) of sodium chloride, II accelerated the progress of spontaneous transformation of erythrocytes, but at the higher concentrations (0.9-1.35%) of sodium chloride, II accelerated the progress of spontaneous transformation to echinocytes. The results indicate that these solutions were not isotonic with rabbit erythrocytes.

Animals↗
PubMedDate not supplied

Assessment of behavioral effects of tetrachloroethylene using a set of time-series analyses.

A systematic approach to the analysis of time-series data for spontaneous locomotor activity in the rat was developed to evaluate the behavioral effects of chemical substances. Chronogram, spectral analysis, analysis of the slope of fluctuation, and the cosinor method were used to analyze data obtained by continuously recording spontaneous locomotor activity in the rat. Under synchronized conditions, a circadian period of 24 h was observed and the 1/f fluctuation, in which the power spectral density is inversely proportional to frequency, was confirmed. The 1/f fluctuation was considered to reflect the fractal-like structure of ultradian components of spontaneous locomotor activity. IP administration of 1.0 g/kg body weight of tetrachloroethylene at 0900 h produced a remarkable phase-shift (4.0 +/- 0.9 h) in the activity rhythm and an increase in the slope of fluctuation (0.4 +/- 0.1) in contrast to a relatively smaller decrease in the total amount of spontaneous locomotor activity. These behavioral effects of tetrachloroethylene were dose-dependently lower at lower doses. The present study demonstrated the usefulness of our systematic approach in evaluating the behavioral effects of chemical substances.

Animals↗
PubMedDate not supplied

Physical performance tests after stroke: reliability and validity.

OBJECTIVE: To evaluate the reliability and validity of the modified physical performance tests for stroke survivors who live in a community. DESIGN: The subjects included 40 stroke survivors and 40 apparently healthy independent elderly persons. The physical performance tests for the stroke survivors comprised two physical capacity evaluation tasks that represented physical abilities necessary to perform the main activities of daily living, e.g., standing-up ability (time needed to stand up from bed rest) and walking ability (time needed to walk 10 m). RESULTS: Regarding the reliability of tests, significant correlations were confirmed between test and retest of physical performance tests with both short and long intervals in individuals after stroke. Regarding the validity of tests, the authors studied the significant correlations between the maximum isometric strength of the quardriceps muscle and the time needed to walk 10 m, centimeters reached while sitting and reaching, and the time needed to stand up from bed rest. CONCLUSIONS: The authors confirmed that there were significant correlations between the instrumental activity of daily living and the time needed to stand up from bed rest, along with the time needed to walk 10 m for the stroke survivors. These physical performance tests are useful guides for evaluating a level of activity of daily living and physical frailty of stroke survivors living in a community.

Activities of Daily Living↗
PubMedDate not supplied

Internal desynchronization of circadian rhythms and tolerance of shift work.

Fifteen male subjects including 12 shift workers (oil refinery operators) volunteered to document circadian rhythms in sleep-wake, grip strength of both hands, peak expiratory flow, heart rate, self-rated drowsiness, fatigue and attention. Each of these variables was measured 4 to 6 times/day for 2 to 3 weeks. In addition, both axillary temperature (with a shielded probe) and wrist activity were almost continuously recorded at 15 min intervals during the same time span. Individual time series were analyzed according to several statistical methods (power spectrum, cosinor, chi 2, etc.), in order to estimate the prominent circadian period tau and to evaluate both individual and subgroup differences with regard to tolerance of shift work, age, duration of shift work. The present study confirms for continuously recorded temperature and wrist activity, grip strength of both hands, heart rate and peak expiratory flow that intolerance of shift work is frequently associated with an internal desynchronization. However, this conclusion cannot be extended to circadian rhythms in self-rated drowsiness, fatigue and attention. The internal desynchronization among several circadian rhythms supports the hypothesis that these latter are driven by several oscillators, with presumable differences between right and left hemispheres as suggested by unequal values of tau in rhythms of both hand grip strength. Since an internal desynchronization can be observed in tolerant shift workers having no complaint, it is likely that symptoms of intolerance are related to the subject's sensitivity to internal desynchronization rather than to the desynchronization itself.

Adult↗
PubMedDate not supplied

Dosing time and sex-related differences in the pharmacokinetics of cefodizime and in the circadian cortisol rhythm.

Two g cefodizime i.v. administration at 00:00, 06:00, 12:00 and 18:00 respectively, to 8 male and 8 female, young healthy volunteers, has shown: 1. a sex-related difference in both plasma (AUC) and total cumulative excretion of the agent with larger values in females than in males; 2. a dosing time-related difference in plasma (AUC) with the largest values for Rx at 00:00 and lowest for Rx at 18:00 in both males and females; 3. a dosing time-related difference in urinary concentration of cefodizime with largest values for Rx at 06:00 and lowest for Rx at 12:00. These urinary changes were highly correlated with changes in AUC for each dosing time; 4. no dosing time-related changes were observed for plasma T1/2 as well as cumulative urinary excretion of cefodizime; 5. curve patterns of plasma cortisol had similar aspects for both control and Rx at 00:00 with no sex-related differences. Curve patterns differed from control for other dosing times (p less than 0.005 to p less than 0.001 with ANOVA tests).

Adult↗