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Biomedical subjects

S Matsuda

Publications and source records attributed to S Matsuda.

At least 757 records · Page 42Linked to original sources
PubMed1980

A specific competitive protein binding assay for serum 24,25-dihydroxyvitamin D in normal children and patients with nephrotic syndrome.

A specific competitive protein binding assay for 24,25-dihydroxyvitamin D by Sephadex LH-20 column chromatography, followed by high pressure liquid chromatography with normal rat kidney cytosol as the binding protein, was developed. The mean concentrations of serum 24,25-dihydroxyvitamin D of the cord, in newborn infants and in infants under 12 months of age were 0.90 +/- 0.40 (S.D.) ng/ml, 0.52 +/- 0.21 (S.D.) ng/ml and 1.20 +/- 0.38 (S.D.) ng/ml, respectively. These concentrations were significantly lower than those in children aged 1-15 years (1.96 +/- 0.83 (S.D.) ng/ml). The serum levels in the acute stage of the nephrotic syndrome were significantly reduced, and they increased in remission. These results show that patients wioth nephrotic syndrome have low levels of serum 24,25-dihydroxyvitamin D. This is probably due to its loss in the urine.

24,25-Dihydroxyvitamin D 3↗
PubMed1980

Plasma 1,25-dihydroxyvitamin D concentrations in cords, newborns, infants, and children.

Plasma 1,25-dihydroxyvitamin D [1,25-(OH)2-D] was measured in cord serum, newborns, infants, and children. The mean for the values obtained from the six cords was significantly higher than the mean for the older children (6-15 years). The mean for the six newborns (0-1 week) was significantly higher than that for the older children. The mean for the nine infants (1 week-6 months) and the 14 younger children (6 months-6 years) was significantly higher than that for older children. The present study suggests that the perinatal period is associated with a marked increase in 1,25-(OH)2-D.

Adolescent↗
PubMed1980

The apparent binding constants of Ca2+ to EGTA and heavy meromyosin.

The apparent binding constant (K E app) of EGTA to Ca2+ was determined using a color indicator, murexide, or a Ca2+-selective electrode in the pH range between 6.5 and 7.5, at 5 degrees C and at 20 degrees C. K E app values obtained at two different temperatures (5 degrees C and 20 degrees C) were essentially the same when measured at the same pH. However, K E app depended markedly on pH. In the presence of 0.1 M KCl and 20 mM MOPS-KOH buffer (pH 6.8), K E app was 6.3 X 10(5) M-1. The absolute binding constant (K) was calculated as 10(10.48). Addition of 10 mM MgCl2 did not change the K E app. The binding of Ca2+ to heavy meromyosin was studied in 0.1 M KCl and 20 mM MOPS-KOH buffer (pH 7.2), at 5 degrees C. The binding constant and maximum binding number (mol/mol) were obtained as 1.8 X 10(6) M-1 and 1.4, respectively.

Animals↗
PubMed1979

Role of reduced glutathione on platelet functions.

The role of reduced glutathione (GSH) on platelet functions was investigated utilizing thiol oxidizing agent, "diamide". Diamide reacted rapidly with GSH in platelets, but not with protein thiols. Platelets treated with diamide showed inhibition of platelet aggregation induced by ADP, epinephrine and collagen in a concentration dependent manner. Clot retraction was grossly inhibited by diamide. Platelet interaction with polymerizing fibrin was examined by the method of Niewiarowski et al. (1972). There was no interaction obeserved between diamide-treated platelets and polymerizing fibrin. Ultrastructural observation of clots formed in the presence of diamide also showed no direct contact between platelets and fibrin strands. Platelets retained their granular contents, but showed loss of microtubules and dilatation of open canalicular system. Our findings may further support the idea that GSH plays an important role on platelet functions.

Adenosine Diphosphate↗