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Biomedical subjects

M Miyamura

Publications and source records attributed to M Miyamura.

At least 73 records · Page 4Linked to original sources
PubMed1986

Small hepatocellular carcinomas in chronic liver disease: detection with SPECT.

Single-photon emission computed tomography (SPECT) performed using a rotating gamma camera was compared with alpha 1-fetoprotein (AFP) assay, conventional liver scintigraphy, ultrasound (US) imaging, computed tomography (CT), and selective celiac angiography in 40 patients with a total of 50 small hepatocellular carcinomas (HCCs; less than 5 cm). The detection rates of US and CT were determined on an initial screening study and on a second, more precisely focused study. The detection rate of small HCCs by the various modalities was as follows: AFP, 13%; liver scintigraphy, 36%; SPECT, 72%; initial screening US, 80%; second, more precise US studies, 94%; initial screening CT, 64%; second, more precise CT study, 82%; angiography, 88%. Although SPECT was inferior to the initial screening US examination in detecting HCCs less than 2 cm in size, its sensitivity was identical to that of the initial screening US study for detecting HCCs of 2-5 cm. The combination of SPECT and US was an excellent method for the early detection of HCCs, yielding a detection rate of 94%.

Aged↗
PubMed1986

Concept of the clinical stages of acute hepatic failure.

Serial medical diagnostic imagings were performed on 15 patients with acute hepatic failure to compare liver size and clinical picture. In patients showing hepatatrophy at the onset of coma, the interval between the onsets of disease and coma was long, ascites and edema supervened, high total bilirubin and low glutamic pyrubic transaminase levels tended to be found, and prothrombin time did not respond to treatment. All of these patients died. Based on liver size changes in patients who survived acute hepatic failure, acute hepatic failure was assumed to be classified into swelling, reduction, and recovery stages. The shorter the interval between the onsets of disease and coma, the earlier coma and prolonged prothrombin time occurred before hepatatrophy. In acute hepatic failure, signs of hepatic failure develop with various histological pictures and it is very important to institute the treatment before the liver is atrophied.

Acute Disease↗
PubMed1985

Lymphocyte-mediated enhancement of hepatic fibrosis in chronic active hepatitis.

The effect of the supernatant from a culture of liver specific protein-stimulated lymphocytes on collagen production by cultured fibroblasts was examined. The supernatant from the culture of unstimulated lymphocytes was used as a control. Both supernatants were added to the culture medium of L929 fibroblast monolayer. After incubation for 72 hours, 1 microCi of tritium-labelled proline was added to the culture medium of the monolayer. The radioactivity of tritium labelled hydroxyproline incorporated into collagen was measured. The results demonstrated that the supernatant from the culture of stimulated lymphocytes enhanced collagen production in 5 of 6 cases of chronic active hepatitis and in 2 of 14 cases of chronic inactive hepatitis. These findings suggest that cellular immune regulation may play an important role in the development of hepatic fibrosis in chronic active hepatitis.

Adult↗
PubMed1985

The influence of body size on the ventilatory response to hypercapnia.

The slope of ventilatory response to hypercapnia at rest was determined in 77 healthy male students by means of the CO2 rebreathing method. It was found that the hypercapnic ventilatory response slope (S) was significantly lower in the lean group with BMI (body mass index) below 19 than that in the normal group, while there were no significant correlation between S and body weight or height. These results indicate that sensitivity of hypercapnia in the lean subjects differed from that of normal and overweight subjects.

Adolescent↗
PubMed1984

Blood lactate and glycerol after 400-m and 3,000-m runs in sprint and long distance runners.

Lactate, glycerol, and catecholamine in the venous blood after 400-m and 3,000-m runs were determined in eight sprint runners, eight long distance runners, and seven untrained students. In 400-m sprinting, average values of velocity, peak blood lactate, and adrenaline were significantly higher in the sprint group than in the long distance and untrained groups. The mean velocity of 400-m sprinting was significantly correlated with peak blood lactate in the untrained (r = 0.76, P less than 0.05) and long distance (r = 0.71, P less than 0.05) groups, but not in the sprint group. In the 3,000-m run, on the other hand, average values of velocity and glycerol were significantly higher in the long distance group than in the sprint and untrained groups, but there are no significant differences in lactate levels between the three groups. These results suggest that 1) performance in 400-m sprinting may depend mainly upon an energy supply from glycolysis in the long distance and untrained group, but in the sprinters is influenced not only by glycolysis, but also by other factors such as content of ATP or force per unit muscle cross-sectional area; 2) peak blood lactate obtained after 400-m sprinting may be used as a useful indication of anaerobic work capacity in the long distance and untrained groups, but not in the sprinters. 3) high speed in the 3,000-m run could be maintained in the long distance runners by means of a greater energy supply from lipid metabolism as compared with sprinters or untrained subjects.

Adult↗
PubMed1984

Plasma LDH and CK activities after 400 m sprinting by well-trained sprint runners.

Blood lactate concentration and the activities of plasma LDH and CK were determined in 13 well-trained middle distance runners after a 400-m sprint. It was found that there is a significant relationship between mean velocity in the 400-m sprint and plasma CK activity (r = -0.56, P less than 0.05), but the mean sprint velocity did not correlate with peak blood lactate concentration (r = -0.09) or plasma LDH activity (r = -0.40). There was a significant negative correlation between mean sprint velocity and H type LDH isozyme activity (r = -0.66, P less than 0.05), and a significant positive correlation with M type LDH isozyme activity (r = 0.66, P less than 0.05). These results suggest that the magnitude of enzyme efflux from tissue into blood may be depressed by training, and that in well-trained sprinters plasma CK and LDH isozyme activities may be better indicators of physical training and/or physical performance than peak blood lactate or plasma LDH activities.

Adolescent↗
PubMed1984

Peak blood lactate after 400 m sprinting in sprinters and long-distance runners.

Peak blood lactate following 400 m sprinting was determined in 8 sprinters and 8 long-distance runners. The mean velocity of 400 m run and peak blood lactate were significantly higher in the sprinters than in the long-distance runners. It was suggested that peak blood lactate may be a useful indication of anaerobic work capacity in long-distance runners, but not in sprinters.

Adolescent↗
PubMed1984

Influence of body posture on maximum calf blood flow in reactive hyperemia.

Reactive hyperemia in the calf after arresting femoral blood flow for 3 min was measured by means of strain gauge plethysmography in different postures, i.e. supine, sitting with legs resting horizontally (sitting I), and sitting with the feet on the ground (sitting II). Blood flow in the calf at rest and hyperemia decreased more in the sitting I and II positions than in the supine position. However, the peak flow of the reactive hyperemia was higher in the sitting I and II positions than in the supine position.

Adult↗
PubMed1983

Cross transfer effects of muscular training on blood flow in the ipsilateral and contralateral forearms.

Blood flow in the right and left forearms was determined by venous occlusion plethysmography in ten healthy male subjects before and after training with a hand ergometer. The subjects in group A and B were trained using work loads of 1/3 and 1/2, respectively, of maximum grip strength 6 days/week for 6 weeks. It was found that the blood flow in the left (untrained or contralateral) forearm during exhaustive training of the right hand increased gradually with increasing training periods, and that after 6 weeks of training, grip strength, endurance and peak blood flow of the forearm increased significantly not only in the trained forearm, but also in the untrained forearm. From these results, it is suggested that the increase of blood flow in the contralateral limb after training may, at least in part, be related to the cross transfer effect of muscular endurance.

Adult↗
PubMed1983

Thigh and calf blood flows after isometric contraction in untrained and trained subjects.

The present study was undertaken to examine whether or not there were any differences between untrained and trained subjects in the changes of blood flow in the ipsilateral and contralateral lower limbs after isometric exercise. Blood flow of the thigh and calf in both right and left legs were measured simultaneously before and after isometric contraction with mercury-in-silastic strain gauge venous occlusion plethysmography. In the present study, the main pattern of blood flow responses in the active and non-active limbs was strikingly similar in all subjects: a significant fall in blood flow immediately after isometric contraction at a force of about 50% of maximal muscle strength for 15 sec was observed in the non-active lower limbs. Peak blood flow of the exercised thigh in the trained group was significantly higher than that in the untrained ones. From these results, it was suggested that higher blood flow after isometric exercise in the trained subjects may be due to the improvement of degree of vasodilation in the lower limb as a result of physical training.

Adult↗