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Biomedical subjects

Y Oshida

Publications and source records attributed to Y Oshida.

At least 91 records · Page 5Linked to original sources
PubMed1989

Long-term mild jogging increases insulin action despite no influence on body mass index or VO2 max.

Physical training has been shown to improve glucose tolerance and insulin sensitivity. In the present study, insulin action was determined using the euglycemic clamp technique in six untrained nonobese subjects before, during, and after long-term mild regular jogging. After 1 yr of jogging, steady-state plasma insulin levels (I) decreased significantly, and the metabolic clearance rate of insulin was increased by 87%, although insulin infusion rate during the clamp was constant for each individual. The amount of glucose infused (glucose metabolism, M) tended to increase from 6.16 +/- 0.94 to 8.15 +/- 1.94 mg.kg-1.min-1 after regular jogging for 1 yr, although that was not statistically significant. However, M/I increases significantly from 0.060 +/- 0.012 to 0.184 +/- 0.056 (P less than 0.05) after 1 yr. The concentrations of plasma free fatty acids during the hyperinsulinemic clamp decreased more significantly after 1 yr of jogging (P less than 0.05). The concentrations of plasma glycerol decreased gradually before and after long-term regular jogging, showing only a 50-60% reduction in 120 min. Therefore, long-term mild regular jogging, which did not influence either body mass index or maximal O2 uptake, appears to improve insulin action in both carbohydrate and lipid metabolism and to increase the metabolic clearance rate of insulin.

Adult↗
PubMed1989

Experimental atherosclerosis-like lesions induced by hyperinsulinism in Wistar rats.

To elucidate the possible role of hyperinsulinism in the etiology of diabetic macroangiopathy, we studied the long-term effects of insulin injection on the arterial wall of the rat both biochemically and histologically. Fifty male Wistar rats were divided into two groups. One group was subjected to daily injection of insulin-zinc suspension (20 U/kg), and the other group was treated with saline. After 1 yr, all the animals were killed, and the lipid contents in the intimal media of their aortas were determined. Parts of the ascending aortic tissues were further examined by use of either light or electron microscopy. The triglyceride content of the insulin-treated rat aortas was significantly (P less than .05) increased compared with that of the saline-treated rat aortas. As determined by light microscopy, the intimas of the aortas from the insulin-treated rats were significantly (P less than .001) thickened, and the subendothelial tissues consisted of eosinophilic fiber bundles, amorphous ground substances, and irregularly arranged cells. These cells were identified by electron microscopy as having smooth muscle cell origin. All these findings suggest that atherosclerosis-like lesions could be induced by long-term insulin injection in the aortas of the rat and that hyperinsulinism plays a certain role in the development of diabetic macroangiopathy.

Animals↗
PubMed1988

Effect of acute physical exercise on lymphocyte subpopulations in trained and untrained subjects.

To clarify the difference in immunity between untrained subjects and well-trained athletes, the number of total leukocytes (WBC), lymphocytes, and neutrophils, percentages of various lymphocyte subpopulations (OKT3, OKT4, OKT8, Leu7, OKla1), and the levels of lymphocyte transformation response to phytohemagglutinin (PHA) were determined in five untrained male subjects and six male athletes before, immediately after, and 24 and 72 h after acute physical exercise at 60% of VO2max for 2 h. Exercise produced a significant rise in the number of WBC, lymphocytes, and neutrophils in both groups. Immediately after exercise, the percentage of OKT3 or OKT4 positive cells had significantly decreased in both groups, whereas that of OKT8 positive cells had markedly increased only in the athletes. Neither group showed any change in the percentage of OKla1 positive cells. In both groups, the response of lymphocytes to PHA immediately after exercise was significantly lower than before, 24 h and 72 h after exercise. The level of Leu7 positive cells rose remarkably immediately after exercise in the athletes, but not significantly in the untrained subjects. These results suggest that an increase in Leu7 positive cells provides added host defense capacity in trained athletes during periods of stress which impair T-lymphocyte function.

Adolescent↗
PubMed1987

Studies on glucose intolerance in chronic renal failure: estimation of insulin sensitivity before and after initiation of hemodialysis.

Using the euglycemic insulin clamp technique, we quantified insulin resistance in the genesis of the glucose intolerance observed in patients with CRF. Tissue sensitivity to insulin was evaluated in 11 patients with CRF (just before, and at one and four weeks after initiation of hemodialysis). The glucose infusion rate in patients with CRF (4.38 +/- 0.28 mg/kg/min) was significantly lower than in 28 controls (7.40 +/- 0.21 mg/kg/min) (p less than 0.001). The decreased glucose infusion rate in patients with CRF increased to 5.63 +/- 0.44 mg/kg/min (p less than 0.02) one week after starting hemodialysis and further improved to 7.46 +/- 0.90 mg/kg/min (p less than 0.02) after four weeks of hemodialysis. During the insulin clamp study, free fatty acid (FFA) decreased more rapidly in patients with CRF (both before and after initiation of hemodialysis) than in the controls (p less than 0.05-0.001). Glycerol decreased gradually in both groups, showing only a 50-60% reduction in 120 min. These results confirm that glucose intolerance in patients with CRF can be improved by the initiation of hemodialysis.

Adult↗
PubMed1986

Increased serum IgE antibodies in institutionalized asthmatic children after a transient return home. The role of house dust mite allergens in the home as a trigger of asthmatic attacks in mite-sensitive patients.

Increased serum IgE antibodies to Dermatophagoides pteronyssinus, a house dust mite, were observed in 12 of 13 institutionalized mite-sensitive asthmatic children after returning for four days to their own homes. These results implicate the house dust mite as a trigger of asthmatic attacks in these patients.

Adolescent↗
PubMed1982

Effect of sustained-release theophylline administration on pituitary-thyroid axis.

The effect of therapeutic doses of theophylline on the pituitary-thyroid axis was studied in four normal adults and in 15 asthmatic children on theophylline treatment. In the four normal adults, sustained-release theophylline was administered every 12 hr for 60 hr, and serial determinations of serum theophylline, thyroxine (T4), triiodothyronine (T3), reverse triiodothyronine (rT3), thyrotropin (TSH), and cyclic AMP (cAMP) were done. In all four cases, serum T4 increased significantly (134% +/- 4% vs basal level) with significant correlation to plasma cAMP level (r = 0.67, p less than 0.05). Changes in T3 and rT3 showed a marked individuality; an increase in T3 occurred in a subject with severe side effects, while the increase in rT3 was observed in a subject with mild side effects. Of the 15 children on theophylline treatment, a higher T4 level was found in 12 and a lower T3 level in nine at 1 wk, but these values returned to the previous level after 4 wk. These results indicate that the therapeutic doses of theophylline significantly but transiently increased the serum T4 level. In most cases, T4 is metabolized to rT3, an inactive metabolite of T4, but in a few cases it is metabolized to T3, which might double the side effects of theophylline.

Adolescent↗
PubMed1981

Lymphocyte responsiveness to Dermatophagoides farinae extract in mite-sensitive patients: effect of immunotherapy on cellular proliferative response and specific immunoglobulin E antibody (RAST score).

Lymphocyte responsiveness in vitro and serum levels of specific IgE antibody to mite extracts (Dermatophagoides farinae) were evaluated in mite-sensitive asthmatic patients and in nonatopic individuals. Lymphocytes from untreated mite-sensitive patients (n = 16) responded to mite extracts with greater 3H-thymidine uptake than those from nonatopic individuals (n = 20; p less than 0.01). Specific IgE antibody and total IgE levels were significantly higher in mite-sensitive patients than those in nonatopic individuals. These results suggest that mite-sensitive patients respond to mite allergen with exaggerated lymphocyte proliferation as well as with enhanced specific IgE antibody production. Lymphocyte response to mite extracts was significantly lower in the patients with long-term dust immunotherapy than that in the untreated patients (p less than 0.05), but there was no significant difference in the total IgE and the specific IgE antibody levels between them. Lymphocyte response to Candida albicans was not significantly affected in these patients. These results suggest that as far as mite allergy is concerned, there is some difference in the effect of immunotherapy between lymphocyte proliferative response and specific IgE antibody to mite allergen.

Animals↗