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Biomedical subjects

K Okano

Publications and source records attributed to K Okano.

At least 253 records · Page 14Linked to original sources

Comparative efficacy of various vitamin D metabolites in the treatment of various types of hypoparathyroidism.

Fourteen patients with pseudohypoparathyroidism, 17 with idiopathic hypoparathyroidism, and 12 with postoperative hypoparathyroidism were treated with vitamin D2, dihydrotachysterol, 1 alpha-hydroxyvitamin D3)1 alpha-OHD3), and 1,25-dihydroxyvitamin D3 for 6-18 months. The optimal maintenance dose or minimum daily dose of 1,25-dihydroxyvitamin D3 to maintain serum calcium at approximately 8.5 mg/100 ml and control all the clinical symptoms was 1.3 +/- 0.16 micrograms/day (mean +/- SE) in pseudohypoparathyroidism, 1.5 +/- 0.18 micrograms/day in idiopathic hypoparathyroidism, and 1.9 +/- 0.50 micrograms/day in postoperative hypoparathyroidism. There was no significant difference in the optimal maintenance dose among the 3 groups. The optimal maintenance dose of 1 alpha-OHD3, however, was 2.0 +/- 0.12 micrograms/day in pseudohypoparathyroidism, significantly lower than that in idiopathic hypoparathyroidism (3.5 +/-0.29 micrograms/day; P less than 0.001) and in postoperative hypoparathyroidism (4.89 +/- 0.54 micrograms/day; P less than 0.001). Significantly lower doses were required in the treatment of idiopathic hypoparathyroidism than in postoperative hypoparathyroidism (P less than 0.05). No significant difference was found in the optimal maintenance dose of dihydrotachysterol and vitamin D2 among the 3 groups. The average pretreatment serum calcium levels and clinical manifestations were indistinguishable among the 3 groups of patients. This suggests that such a difference in the optimal maintenance dose of 1 alpha-OHD3 is ascribed not to the difference in the severity of hypoparathyroidism, but most probably to differences in the pathophysiological processes in pseudohypoparathyroidism and idiopathic or postoperative hypoparathyroidism. The excess parathyroid hormone levels in blood of patients with pseudohypoparathyroidism (and not in other types of hypoparathyroidism) may explain such a difference.

Adolescent↗

Clinical evaluation of amylase-creatinine clearance ratio and amylase isoenzyme clearance in chronic renal failure.

Amylase-creatinine clearance ratio (ACCR) and amylase isoenzyme clearance were determined simultaneously in patients with chronic renal failure. ACCR in patients with compensated renal failure (3.5 +/- 0.4%) was not significantly different from normals (2.6 +/- 0.2%), while that in patients with non-compensated renal failure (6.7 +/- 0.4%) was significantly higher than that in normals. Clearance ratio of pancreatic isoamylase (Amylase-1) relative to creatinine clearance (CAmy . 1/Ccr) in patients with both compensated (5.9 +/- 1.0%) and non-compensated (6.8 +/- 0.4%) renal failure was as high as that in patients with acute pancreatitis (6.6 +/- 0.5%). On the other hand, clearance ratio of salivary isoamylase (Amylase-3) relative to creatinine clearance (CAmy . 3/CCr) in patients with compensated renal failure (1.5 +/- 0.3%) was almost the same as that in normals (2.1 +/- 0.1%), while that in patients with non-compensated renal failure was 5.9 +/- 0.7%, which was significantly higher than that in normals. The present study revealed that elevated ACCR in patients with severely impaired renal function was due to the increase of the clearance ratio for both pancreatic and salivary amylase. These facts suggested that glomerular permeability and tubular reabsorption for pancreatic and salivary amylase might play an important role on ACCR in patients with severely impaired renal function.

Amylases↗

Ultrasonic measurements of two-component lipid bilayer suspensions.

Two-component lipid bilayers of dipalmitoylphosphatidylcholine and dimyristoylphosphatidylcholine were studied by measuring ultrasonic velocity and absorption at 3 MHz. The phase diagram of the two-component lipid bilayers is discussed based upon the transition anomalies of the ultrasonic velocity as well as absorption, and it is suggested that this binary system has two critical points. The bulk modulus of lipid bilayers was determined from the ultrasonic velocity to be (2.2-3.0) x 10(10) dyne/cm2, whereas the bulk viscosity calculated from the absorption was 10-20 P except for the transition regions.

Dimyristoylphosphatidylcholine↗

Galactosyltransferase activities in human sera of various diseases.

Recently galactosyltransferase has been noted as a new tumor marker. In this report galactosyltransferase activity was measured in sera of various diseases including malignant tumors and the levels of the enzyme activities were compared. The levels of the enzyme were higher in sera of malignant tumors and liver diseases than those in sera of other diseases. In malignant tumors little organ specificity was found with respect to the levels of galactosyltransferase activities. The levels of the enzyme were considered to have no relation to carcinoembryonic antigen or alpha-feto protein. On the other hand, in liver diseases the levels of the enzyme were correlated to the severity of liver damage. Therefore, it is reasonable to presume that the elevation of serum galactosyltransferase activity is caused chiefly by malignant tumors and liver damage.

Galactosyltransferases↗

Dynamic properties of concentrated suspensions of charged polystyrene spheres.

Ordered structure formation of charged polystyrene spheres was studied by measuring the order-disorder phase diagrams as well as the mechanical properties. The phase diagrams indicate that the ordering of polystyrene spheres obeys Lindemann's law of crystal melting, in which the Lindemann's parameter is about 5%. The rigidity of about 10(3) dyn/cm(2) was observed in the ordered suspension of polystyrene spheres as measured by a torsional quartz crystal method. The steady flow properties of suspensions of polystyrene spheres showed a remarkable change from a Bingham body to a Newtonian liquid at the transition point. The limit of elasticity in the ordered phase was about 1 dyn/cm(2). The viscosity in the disordered phase was well explained by the free volume theory of liquids. It is concluded from these facts that the ordered phase of polystyrene spheres is a real "crystal" whereas the disordered phase is a "liquid". Properties of ordered structures in biological systems are also discussed.

Journal Article↗

Histopathological study on right endomyocardial biopsy of Kawasaki disease.

Fifty right ventricular endomyocardial biopsy specimens taken from patients with Kawasaki disease were studied. These were taken from 33 male and 17 female patients. Biopsies were examined for inflammatory cell infiltration, fibrosis, myocardial fibre disarrangement, and the cellular and nuclear changes of hypertrophy. A score of severity was prepared. The degree of abnormality was found to correlate with the duration of the disease, as did fibrosis found in 18 cases (36%), but inflammatory cell infiltration did not (13 cases, 26%). Coronary involvement was restricted to the male patients but the myocardial changes occurred in both sexes.

Cardiomegaly↗

Osseous changes and abnormalities of mineral metabolism in rats with glycopeptide-induced nephritis.

A laboratory model of renal osteodystrophy was developed in rats by a single injection of glycopeptide isolated from renal cortical tissues of rats according to the method used by Shibata et al. to induce glomerulonephritis. Approximately 60-70 days after injection, severe proteinuria appeared and continued for at least 170 days at a rate of more than 1 g/day. Morphological changes in the kidney were typical of chronic glomerulonephritis. The plasma calcium concentration was lowered transiently by the 96th day after injection, but was restored to the normal range thereafter. Plasma parathyroid hormone levels, however, continued to rise in parallel with the degree of proteinuria. Marked secondary hyperparathyroidism was induced which led to severe bone atrophy. Histological examinations showed a marked increase of resorbing cavities, with a quantitatively larger number of osteoclasts in cortical bone tissues compared with the control animals. No spontaneous remission was observed. It is emphasized that all of the biochemical and morphological changes reported here were induced by a single injection of homologous renal glycopeptide, and they were highly reproducible.

Animals↗

Comparative therapeutic effects of vitamin D3 and its derivatives on experimental renal osteodystrophy.

The comparative effectiveness of vitamin D3 and its derivatives in curing hyperparathyroidism and osteodystrophic bone lesions was examined in a laboratory model of renal osteodystrophy associated with marked secondary hyperparathyroidism in rats. The experimental model was prepared by a single injection of homologous glycopeptide. Plasma levels of 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] appeared to decrease in the rats receiving glycopeptide. Various doses of vitamin D3 derivatives [2 or 10 microgram/kg D3, 2 microgram/kg 25-hydroxyvitamin D3 (25OHD3), 0.1 microgram/kg 1 alpha,25(OH)2D3, and 0.1 or 0.2 microgram/kg 1 alpha-hydroxyvitamin D3 (1 alpha OHD3)] were daily administered orally to the nephritic rats for 23 days before sacrifice. 1 alpha,25(OH)2D3 and 1 alpha OHD3 were much more potent than 25OHD3 and D3 in reducing the hyperplasia of parathyroir glands. The potency of 1 alpha OHD3 in curing the histological changes of osteodystrophy appeared to be greater than that of 1 alpha,25(OH)2D3. The same dose level of 1 alpha OHD3 was more effective than 1 alpha,25(OH)2D3 in enhancing plasma 1 alpha,25(OH)2D3 levels.

Animals↗