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Biomedical subjects

S Otsuji

Publications and source records attributed to S Otsuji.

At least 55 records · Page 3Linked to original sources
PubMed1984

Changes in erythrocyte carbonic anhydrase activity due to physical exercise.

Changes in erythrocyte carbonic anhydrase (RBC-CA) activity due to physical exercise were investigated using a measuring apparatus based on the electrometric method. RBC-CA activities were slightly changed due to transient aerobic (20-min run) or anaerobic (200-m run) exercise in moderately trained subjects, but there were no fixed trends. In 3 weeks of weight training, there were no differences in RBC-CA activities between before training and after 1 day of recovery in both trained and untrained subjects. However, after 1 week of recovery, RBC-CA activities slightly decreased in both types of subjects. The trained subjects showed higher levels of RBC-CA activity than the untrained subjects before and after training. The rest values of RBC-CA activity were higher in trained subjects than in untrained subjects. It was evident that RBC-CA activities were higher in subjects (especially in long-distance runners, swimmers etc.) who had undergone long-term strenuous aerobic training.

Adolescent↗
PubMed1983

Metabolic dependence of the fluidity of intact erythrocyte membrane.

The motion of spin labeled phosphatidylcholine embedded in the lipid bilayer of erythrocyte membrane increased in association with metabolic ATP-depletion. The fluidity change was reversed by subsequent ATP-replenishment. However, levels of cellular 1,2-diacylglycerol, GSH or intracellular Ca2+ contributed little to the fluidity change. Temperature dependence of the fluidity indicated the disappearance of inflection points in ATP-depleted cells, thereby suggesting alterations in protein-lipid interactions. The fluidity change was also reproduced with oxidizing agents which cross-link spectrin. We suggest that the lipid phase state of membrane is maintained by protein-lipid interactions which depend on the metabolic state of the cells, particularly ATP levels.

Adenosine Triphosphate↗
PubMed1983

Lower levels of erythrocyte membrane fluidity in diabetic patients. A spin label study.

The dynamic properties of intact erythrocyte membrane in diabetic patients were investigated by means of electron spin resonance using three stearic acid spin labels (SAL): 5-, 12-, and 16-SAL. Significantly lower levels of erythrocyte membrane fluidity were revealed with 16-SAL as a probe in diabetic patients when compared with normal controls. However, there were no significant differences in fluidity values using 5- or 12-SAL between the two groups. Therefore, it became obvious that the decrease in fluidity was located in deeper sites (hydrophobic region) of the erythrocyte double membrane in diabetic patients. It was strongly suggested that changes in the membrane cholesterol to phospholipid molar ratios are not a principal factor contributing to the fluidity change. A significant increase of sphingomyelin and decrease of phosphatidylethanolamine were found in the erythrocyte membrane of diabetic patients and an alteration in membrane phospholipid classes and their acyl-chains could conceivably be related to the fluidity change. There were no significant correlations between change in membrane fluidity and most plasma lipids, plasma lecithin-cholesterol acyl-transferase activities, erythrocyte glycosylated hemoglobin, erythrocyte adenosine triphosphate, fasting blood glucose or duration of the disease. Plasma cholesterol of high-density lipoprotein showed a significant negative correlation with the membrane fluidity values. Some of the possible factors contributing to and the significance of the lower levels of erythrocyte membrane fluidity were discussed in conjunction with both metabolic and clinical aspects in diabetic patients.

Adenosine Triphosphate↗
PubMed1982

Turbidimetric immunoassay of serum C-reactive protein.

This rapid, reliable equilibrium turbidimetric immunoassay for serum C-reactive protein involves a potent monospecific antibody. Polyethylene glycol-6000 to accelerate and enhance the immunoprecipitation reaction, and Tween-20 surfactant to lower and stabilize the sample blank values. Grossly lipemic, icteric, or hemolyzed sera can be assayed. Values up to about 220 mg/L, for which the standard curve is linear, can be measured without sample dilution. Results by the proposed method and by radial immunodiffusion (r 0.989) or laser nephelometry (r = 0.957) correlated well. Analytical recovery averaged 101.3%. Within-, between-, and day-to-day CVs ranged from 0.9% to 3.5%, 0.8% to 5.5%, and 1.9% to 4.8%, respectively. The method is demonstrably superior to radial immunodiffusion or nephelometry. Any spectrophotometer that can measure turbidimetrically at 340 nm can be used.

C-Reactive Protein↗
PubMed1981

Erythrocyte membrane microviscosity in diabetes.

Decreased erythrocyte membrane fluidity was revealed by analyses with fluorescence depolarization using 1,6-diphenyl-1,3,5-hexatriene (DPH) and with electron paramagnetic resonance using spin-labelled stearates (EPR). The decreased membrane fluidity measured by DPH appeared to be related to the increase in membrane or plasam free cholesterol to phospholipid (C/PL) mol ratios. The decreased membrane fluidity observed by EPR appeared to be located, at least in part, in a deeper portion of membrane lipid core and the change may not be derived principally from the effect of cholesterol. Increases of membrane sphingomyelin (+ lysophosphatidylcholine) and decreases of phosphatidylethanolamine were found in erythrocytes of diabetic patients. The contributing factors to the decreased erythrocyte membrane fluidity in diabetic patients were suggested to be not only an increase in membrane C/PL mol ratios but also multifactorial changes involving membrane phospholipid fractions and other complex factors. It is considered that the determinant factors of membrane fluidity are so complex that the decreased membrane fluidity observed with diabetic erythrocytes cannot be closely correlated with any single constituent measured. The decreased membrane fluidity observed in this study appears to be related to poor metabolic control and is often associated with diabetic microangiopathy.

Blood Viscosity↗
PubMed1979

Higher levels of erythrocyte membrane microviscosity in diabetes.

Significantly higher levels of erythrocyte membrane microviscosity (MV) [n-: 5.22 +/- 0.17 (4.70--5.92), mean +/- SD (range), poise, N = 67, P less than 0.005] measured by fluorescence depolarization using 1,6-diphenyl-1,3,5-hexatriene as a fluorescent probe were found in diabetic patients when compared with normal controls [5.05 +/- 0.15 (4.70--5.29), N = 22]. No significant differences in MV existed between males and females, nor was MV significantly correlated with diabetic age, duration of diabetes, plasma cholesterol, cholesterol/phsopholipid ratios, and plasma lecithin:cholesterol acyltransferase activities. No significant difference in MV was observed between groups with or without diabetic retinopathy. There was, however, significantly higher MV [5.29 +/- 0.19 (5.00--5.92), N = 20, P less than 0.05] in the group with fasting blood glucose (FBG) greater than or equal to 140 mg/dl than that [5.19 +/- 0.15 (4.70--5.46), N = 47] in the group with FBG less than 140 mg/dl. The changes in erythrocyte membrane MV presented in this study appear to be related to the current metabolic control of diabetic patients and are considered to be one of the factors responsible for the reduced erythrocyte deformability in diabetes.

Diabetes Mellitus↗