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Biomedical subjects

M Miyamura

Publications and source records attributed to M Miyamura.

At least 91 records · Page 5Linked to original sources
PubMed1982

Peak blood lactate after short periods of maximal treadmill running.

Blood lactate was determined in 19 untrained subjects after maximal treadmill exercise lasting for about 1 min. It was found that blood lactate increases after exercise, reaching a maximum level 6-9 min after the cessation of exercise, and the average time for the appearance of the peak blood lactate concentration was 7.65 min. Peak blood lactate concentration at 7.65 min (CLA7.65), which was calculated by substituting t (7.65) into the equation for the lactate recovery curve for each subject, agreed well with the observed peak blood lactate concentration (r = 0.98, p less than 0.001). In addition, correlations of r = -0.65, r = -0.78, r = -0.79 were found between CLA7.65 and the running times of 100 m, 200 m, and 400 m sprints, respectively. These results suggest that CLA7.65 may be used as a valid indicator of anaerobic work capacity in man.

Adult↗
PubMed1981

Ventilatory response to CO2 rebreathing at rest in the ama.

Ventilatory response to CO2 in the Ama (Kachido) was determined by the CO2 rebreathing method in the beginning (March) and during (September) harvest season. It was found that mean slopes of the ventilatory response curve in March and September were 0.76 and 0.73 liters/(min.m2.mmHg), respectively, this difference being insignificant.

Acclimatization↗
PubMed1980

Ventilatory response to hypercapnia in sprint and long-distance swimmers.

Ventilatory response lines to carbon dioxide at rest were determined by the rebreathing method in 10 untrained subjects, 17 sprint swimmers, and 11 long-distance swimmers. It was found that the mean slope of the ventilatory response line of the swimmer was lower than that of untrained group, and the mean slope of the long distance swimmer was lower as compared with the sprint swimmer, though these differences were statistically not significant. The differences in the hypercapnic drive between untrained subjects and swimmers obtained here is discussed in connection with their maximum oxygen uptake.

Adolescent↗
PubMed1980

Controlled trial of D-penicillamine with low dosis in the treatment of chronic liver diseases.

Controlled trial of D-penicillamine was carried out with low dosis in 10 patients with chronic persistent hepatitis, 11 patients with chronic aggressive hepatitis and 7 patients with liver cirrhosis. After 6 weeks and 6 months treatment mean values of transaminases improved in patients with chronic persistent hepatitis. The mean serum transaminases levels of the patients with chronic aggressive hepatitis were statistically decreased after 6 weeks treatment but not significantly lower after 6 months treatment than on entry. D-penicillamine is not effective for the treatment of patients with liver cirrhosis. Eight of 36 patients treated were withdrawn from the trial because of adverse drug toxicity side effects.

Alanine Transaminase↗
PubMed1980

Blood flow of the ipsilateral and contralateral lower limbs after isometric contraction.

Calf and thigh blood flows in both of right and left legs were measured simultaneously after isometric contraction of the right thigh muscle. Isometric contraction was performed at a force of about 50% of maximal voluntary contraction for 15 sec. The thigh blood flow of the right leg increased immediately after voluntary contraction in all subjects, while the calf blood flow of right leg decreased conversely in spite of exercised ipsilateral leg.

Adult↗
PubMed1980

Blood lactate after strenuous exercise with and without breath-holding.

Lactic acid concentration of venous blood was determined in healthy male subjects after strenuous exercise with and without breath-holding. It was found that in all subjects the peak and total values of lactate during recovery was higher in the breathing run than in the breath-holding run, though the running time was the same.

Adult↗
PubMed1980

Ventilatory response to hypercapnia by rebreathing in successive trials.

The ventilatory response to carbon dioxide at rest was determined repeatedly by the rebreathing method; three successive CO2 response lines, with 30-min intervals, were examined in 12 healthy male subjects. Overall mean slopes obtained at 30, 60 and 90 min were 2.95, 2.47 and 2.28 liters/min . mmHg, respectively, the difference being statistically not significant. However, the slopes of four high responders, who were subjects with higher slopes than that of the mean values obtained here, decreased significantly (p less than 0.05) at 60 min as compared with the 30 min test, but this did not occur in the other subjects. Better reproducibility in obtaining the CO2 response slopes in the high responders was observed in the first rather than the 60 or 90 min trails, suggesting incomplete recovery in the humoral agents released during the CO2 test. These results indicated that the CO2 response curve by rebreathing should be determined carefully, especially in the high responder, taking into consideration its individual variability and and interval in consecutive measurements.

Adolescent↗
PubMed1980

Effects of physical training on the calf and thigh blood flows.

Blood flows of the calf and thigh at rest and after submaximal and maximal exercise were determined by the venous occlusion method in 6 healthy subjects before and after physical training for 5 weeks. It was found that the magnitude of the flow after training was significantly (p less than 0.05) decreased when measured immediately after submaximal exercise, while there were no significant differences found with respect to both calf and thigh blood flows measured immediately after maximal exercise before and after training.

Adolescent↗
PubMed1978

Oxygen uptake and blood flow of the lower limb in maximal treadmill and bicycle exercise.

The present study was undertaken to compare the effects of maximal treadmill and bicycle exercise on maximum oxygen uptake and blood flow in the lower extremity. Mean maximum oxygen uptake in maximal treadmill exercise was higher than that in bicycle exercise (p less than 0.001). Mean values and standard errors of blood flow measured immediately after maximal treadmill and bicycle exercise in the thigh were 39.1 +/- 4.0 and 44.2 +/- 2.8 ml/100 ml . min, the difference not being significant. However, a significant difference in blood flow in the calf measured immediately after both types of exercise was observed (p less than 0.001). Blood flow in the thigh immediately after bicycle exercise was significantly higher than that in the calf (p less than 0.001), whereas the difference between thigh and calf in treadmill exercise was small and statistically not significant. Leg blood flow, the average value of blood flow of the thigh and calf added together, was used as an index of blood flow in the lower extremity. It was found that the leg blood flow was significantly higher on the treadmill than with bicycle exercise (p less than 0.05). From these results, it is suggested that the lower maximum oxygen uptake observed during bicycle exercise as compared with treadmill exercise seems to be due to a lower blood flow in the lower limb.

Adult↗
PubMed1978

CO2 dissociation curves of oxygenated whole blood obtained at rest and in exercise.

In vitro CO2 dissociation curves for oxygenated whole blood were determined in 19 healthy male subjects at rest and during submaximal and maximal bicycle work. Hemoglobin concentration and blood lactate increased with increasing work load and accordingly buffer value of the whole blood increased while bicarbonate and Base Excess (BE) decreased, resulting in a downward shift of the CO2 dissociation curve during exercise. Despite the marked increase in buffer values of the blood, the slopes of the CO2 dissociation curves during exercise were found to be about the same as those obtained at rest. It was inferred that the increasing effect of increased buffer value, on the dissociation slope, was essentially compensated by the decreasing effect of diminished bicarbonate content. The advantages of this relatively constant CO2 dissociation slope for the indirect measurement of cardiac output by the Fick principle are discussed.

Adult↗
PubMed1976

Ventilatory response to CO2 at rest and during positive and negative work in normoxia and hyperoxia.

Ventilation versus alveolar PCO2 relationships were determined by the steady-state method in 6 normal male subjects at rest and during positive and negative work at one load in both normoxic and hyperoxic condition. In 5 subjects the slopes of the VE-PACO2 lines during positive and negative work increased in normoxia as compared with rest. This effect was less evident in hyperoxia. It was also found that the slopes of the VE-PACO2 lines in positive and in negative work were about the same in both normoxic and hyperoxic conditions. Oxygen uptake and CO2 production during positive work is higher than during negative work. These results suggest that: 1) the disagreement between various authors on the change of the slope of the VE-PACO2 line may be due to the differences in the method of calculation of the slope or the method of the determination of VE-PACO2 lines; 2) the stimuli from the muscle spindles in the working muscle during exercise probably do not contribute to the increase in ventilatory response to CO2; 3) the increased slope of the normoxic VE-PACO2 line during exercise may be due to the interaction of several factors such as impulses from working muscles, chemosensitivity of central or peripheral chemoreceptors, adrenal-sympathetic pathways or temperature; 4) respiratory oscilations of PAO2 or PACO2 do not seem to influence the respiratory response to CO2.

Adult↗
PubMed1976

Ventilatory responses to CO2 rebreathing at rest and during exercise in untrained subjects and athletes.

Ventilatory responses to CO2 during rest and exercise were studied in 10 marathon runners and 14 untrained subjects by the rebreathing method. The average responses of the untrained subjects and athletes at rest as meausred by the slope of VE-PACO2 curves were 1.86 and 1.12 liters/min-mmHg, the difference being statistically significant (p less than 0.05). During exercise the slope of VE-PACO2 decreased from 1.86 to 0.62 in the controls, and from 1.12 to 0.62 in the athletes (p less than 0.01). The mean slope obtained in the athletes, at rest and during exercise, was about 50-60% of that in untrained subjects (p less than 0.05). The difference in the VE-PACO2 curves between the athlete and the untrained group may be due to a reduced exitability of the respiratory center and/or by a reduced input signal.

Adult↗