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Biomedical subjects

K Nishimura

Publications and source records attributed to K Nishimura.

At least 1,171 records · Page 65Linked to original sources
PubMed1980

Differential diagnosis of hypoparathyroid disorders during childhood.

Changes in the plasma and urinary adenosine 3', 5' monophosphate (cyclic AMP) levels on infusion of parathyroid hormone were studied in 10 normal children, 5 children with idiopathic hypoparathyroidism, and 3 children with pseudohypoparathyroidism. In normal children the plasma concentration of cyclic AMP ranges from 18.0 to 68.0 pmoles/ml under basal conditions, and increases to a peak of about 10-fold the basal level 5 min after infusion of parathyroid hormone. Infusion of parathyroid hormone caused no increase in plasma cyclic AMP in patients with pseudohypoparathyroidism but about 18-fold increase in those with idiopathic hypoparathyroidism. The measurement of plasma cyclic AMP before and 5 min after infusion of parathyroid hormone is concluded to be a single and effective method for differential diagnosis of hypoparathyroid disorders.

Child↗
PubMed1980

High speed rotating scanner for transesophageal cross-sectional echocardiography.

In conventional cross-sectional echocardiography, the configuration of the chest or the presence of excessive chest wall tissue or air-containing lung often limits the resolution and field of view. To increase the diagnostic capability of cross-sectional echocardiography, a transesophageal ultrasonic high speed rotating scanner that can obtain cardiac images without hindrance from ribs, sternum and lung was developed. The scanner uses a single small transducer with a flexible shaft to permit easy swallowing by adults and mechanically scans ultrasonic beams within the esophagus. The small transducer in the esophagus is rotated through a full 360 degrees at a rate of 15 to 50 cycles/s, and cardiac images obtained through the esophageal wall are displayed on a cathode ray tube in real time. The transesophageal scanning technique was evaluated in more than 50 adult patients. Aside from some slight gagging, no serious complications were encountered. In all patients, high quality images of most portions of the heart were obtained. There was little difference in the image quality among various patients.

Adolescent↗
PubMed1980

Activation of membrane-bound kallikrein and renin in the kidney.

Rat kidney contains membrane-bound renin (EC 3.4.99.19) and kallikrein (EC 3.4.21.8). Kallikrein activity was measured by a spectrophotometric assay and renin by radioimmunoassay. Plasma membrane-bound kallikrein was activated by lysolecithin and by melittin, which was a more potent activator., This activation by mellitin was independent of calcium concentration. Mellitin was, however, a more potent activator of membrane-bound renin in the presence of calcium. Administration of aldosterone to rats for 6 days increased kallikrein activity in the renal homogenate and in the membrane-enriched fractions, whereas renin activity was not affected. It was proposed that kallikrein may also be located on the basal membrane of tubular epithelial cells, where aldosterone can enhance its activity.

Aldosterone↗
PubMed1980

pH-dependent association-dissociation of GM1-beta-galactosidase purified from porcine spleen.

A beta-galactosidase [EC 3.1.23] catalyzing the hydrolysis of GM1-ganglioside was purified from porcine spleen to a homogeneous form. By applying a hydrophobic chromatography procedure as the first purification step, the enzyme could be purified through subsequent purification steps as a dissociated form. The purified enzyme was a monomer with an apparent molecular weight of 70,000-74,000 at neutral pH and associated to a dimer with an apparent molecular weight of 158,000-160,000 at acidic pH, near optimal for its activity (pH 4.6). It had specific activities of 1,820 mumol/mg/h towards GM1 with an apparent Km of 3.18 X 10(-5) M, 1,880 mumol/mg/h towards lactosylceramide with an apparent Km of 1.99 X 10(-4) M, and 1,340 mumol/mg/h towards p-nitrophenyl-beta-galactopyranoside (pNp-beta galactoside) with an apparent Km of 2,14 X 10(-4) M. Kinetic studies suggested that common catalytic site(s) cleaved the two natural substrates mentioned above.

Animals↗
PubMed1980

Primary cerebral malignant lymphoma of the histiocytic type.

A 60-year-old house wife complained of anorexia, headaches and vomiting for several months. Later she developed disturbances in gait. At the terminal stage of her clinical course, 3 masses in the cerebrum and one in the cerebellum were detected by angiography and CT-scans. At autopsy, 3 masses in the frontal lobes, and one in each thalamus and still another in the cerebellum were found. They were accompanied with necrotic and haemorrhagic changes. Tumor cells were large irregular or round in shape, and showed metallophilia by the silver impregnations for reticlum cells and microglia. Some of them were multinucleated giant cells. Tumor cells showed occasionally phagocytic activity. Perivascular infiltration of tumor cells was marked around the tumor masses.

Brain↗