Search PubMed⌕ Search

Biomedical subjects

H Tsuchiya

Publications and source records attributed to H Tsuchiya.

At least 253 records · Page 14Linked to original sources

Effects of prostaglandins on the cytosolic free calcium concentration in vascular smooth muscle cells.

The effects of prostaglandin (PG) F2 alpha and 9,11-epithio-11,12-methanothromboxane A2 (STA2), a stable analogue of thromboxane A2, on the cytosolic free calcium concentration ([Ca2+]i) in vascular smooth muscle cells were studied with a new fluorescent Ca2+ indicator fura 2. PGF2 alpha and STA2, which are strong vasoconstrictors, caused rapid phasic and subsequent tonic increases in [Ca2+]i. PGF2 alpha caused dose-dependent elevation of [Ca2+]i not only in control solution but also in the calcium-free solution. A first stimulation with PGF2 alpha caused dose-dependent decrease in the response of [Ca2+]i to a second stimulation with PGF2 alpha. Pretreatment with 13-Azaprostanoic acid, a receptor level antagonist of thromboxane A2 inhibited the increase of [Ca2+]i induced by STA2. These results suggest that PGF2 alpha induces calcium mobilization followed by smooth muscle contraction through its specific receptors.

Angiotensin II↗

Unusual case of diffuse connective tissue disease with nodule formations in muscle, lung, kidney and brain.

A 9-year-old boy had nodular masses in the left gastrocnemius muscle and lung, right kidney and right frontal area of the brain. Laboratory examinations, including positive anti-nuclear antibody, anti-RNP antibody, RA and CRP, hyper-gamma-globulinemia and accelerated ESR, showed characteristic of diffuse connective tissue disease (DCTD). Biopsy specimens were obtained from the thymus and from masses in the left lung and gastrocnemius muscle. The thymus showed hyperplasia, and a mass in the lung showed nonspecific inflammatory reactions such as connective tissue proliferation and cellular infiltration. Biopsied muscle also showed severe connective tissue proliferation, cellular infiltration, variation in fiber size and thickened blood vessel walls. In addition, abnormalities, including thickening of the basement membrane and an almost occluded narrow lumen of capillaries, were found on electron microscopy examination. Steroid administration led to remarkable improvement of the symptoms. These results suggested that DCTD is responsible for these symptoms.

Biopsy↗

Eel calcitonin suppresses plasma human calcitonin levels in medullary carcinoma of the thyroid.

The effects of synthetic [Asu1,7]-eel calcitonin (0.5 MRC unit/kg body weight intravenously for 30 min) on circulating levels of human calcitonin, calcium and gastrin were investigated in five patients with medullary carcinoma of the thyroid. Blood samples were obtained before and 15, 30, 60, 90, 120 and 180 min after commencement of infusion of [Asu1,7]-eel calcitonin. Plasma levels of human calcitonin were measured by radioimmunoassay. Cross-reactivity with [Asu1,7]-eel calcitonin in this assay was negligible. On infusion of [Asu1,7]-eel calcitonin, the mean plasma level of human calcitonin decreased significantly to 71.0 +/- 8.7% of the basal level (mean +/- SEM, P less than 0.05) after 30 min and 68.4 +/- 25.4% of the basal level (P less than 0.05) after 60 min. The serum calcium level also decreased significantly, but lagged behind the decrease of human calcitonin, being 95.1 +/- 0.7% of the basal level (P less than 0.01) at 120 min and 94.8 +/- 0.6% of the basal level (P less than 0.02) at 180 min. The mean plasma gastrin level did not change significantly on infusion of [Asu1,7]-eel calcitonin. In pooled data for all times, the percentage change in human calcitonin was not significantly correlated with either the percentage change in calcium (r = -0.25, P greater than 0.1) or the percentage change in gastrin (r = -0.38, P greater than 0.1).

Adolescent↗

High-performance liquid chromatographic analysis of bacterial fatty acid composition for chemotaxonomic characterization of oral streptococci.

A high-performance liquid chromatographic method was developed to analyze the fatty acid composition of bacterial lipids. After saponification of lipids extracted from bacteria, the liberated fatty acids were labeled with a fluorescence reagent, 4-bromomethyl-7-acetoxycoumarin, followed by reversed-phase high-performance liquid chromatographic separation and fluorescence detection. All bacterial fatty acids were simultaneously separated within 30 min and sensitively determined. This method was applied to the chemotaxonomic characterization of oral streptococci. The fatty acid composition of phospholipids and total lipids distinguished Streptococcus mutans from any other species examined and showed that Streptococcus sanguis had a close taxonomic relationship with Streptococcus salivarius.

Cardiolipins↗

Simplified procedure for specific determination of imino acids in human blood plasma by high-performance liquid chromatography.

After deproteinization with 70% aqueous ethanol and evaporation to dryness, a plasma sample was subjected to the formol reaction. Then Dns derivatization of imino acids was carried out for 20 min at 37 degrees C. An aliquot of the resulting solution was subjected to reversed-phase chromatography using continuous gradient elution with acetonitrile-50 mM acetate buffer (pH 4.0) as solvent system. This method is selective for imino acids. Hydroxyproline and proline levels could be determined using 30 microliter of plasma.

Chromatography, High Pressure Liquid↗

A new type of laryngotracheoesophageal cleft with extended bronchoesophageal cleft.

A case of total laryngotracheoesophageal cleft with extended fronchoesophageal cleft is reported. The baby had a long cleft not only on the whole length of the laryngotracheoesophagus but it also extended to the right lower bronchus and esophagus. It was associated with right upper bronchial stenosis, sequestration of right lower lobe, and a complex cardiovascular anomaly. There have been no reports of this extended type of cleft in the 59 reported cases.

Abnormalities, Multiple↗

Serum phosphate, parathyroid hormone and vitamin D metabolites in patients with chronic renal failure: effect of aluminum hydroxide administration.

Patients with chronic renal failure showed the existence of phosphate retention, secondary hyperparathyroidism, and reduced production of 1,25-(OH)2D. In order to determine the effect of correction of hyperphosphatemia on secondary hyperparathyroidism and vitamin D metabolism in those patients, 7 nondialyzed patients with chronic renal failure were treated with large doses of A1(OH)3 (15-18 g/day) to correct their high levels of serum phosphate. After treatment with A1(OH)3, serum phosphate fell significantly (p less than 0.005) from 6.3 +/- 1.3 (mean +/- SD) to 3.7 +/- 0.5 mg/dl. Serum parathyroid hormone decreased significantly (p less than 0.02) from 2.87 +/- 1.64 to 1.85 +/- 1.26 ngEq/ml. Serum 1,25-(OH)2D was low compared to the normal mean level before A1(OH)3 administration and decreased significantly (p greater than 0.02) from 19.4 +/- 6.1 to 11.4 +/- 4.3 pg/ml after the treatment. Aluminum levels increased significantly (p greater than 0.02) from 1.7 +/- 1.0 to 3.6 +/- 1.5 micrograms/dl. Serum calcium, calcitonin, and 25-(OH)D showed no significant change. Our data suggested that the suppression of secondary hyperparathyroidism by A1(OH)3 treatment results in a decrease of the 1,25-(OH)2D level in patients with chronic renal failure, even though their hyperphosphatemia has been corrected. We speculate that aluminum loading might play a role in diminishing the secretion of parathyroid hormone and the production of 1,25-(OH)2D in humans.

Adult↗

Prolactin secretion in acromegalic patients before and after selective adenomectomy.

PRL secretion before and after transsphenoidal adenomectomy was studied in 13 patients with acromegaly. Six patient had elevated basal serum PRL levels before surgery, while 7 patients had normal levels. In every patient, the basal serum GH level decreased to less than 5.0 ng/ml after surgery. In the group (group A) with high basal serum PRL levels (mean +/- SD, 41.3 +/- 5.8 ng/ml) before surgery, the PRL levels decreased significantly (P less than 0.0002) to less than 10.0 ng/ml (4.8 +/- 3.6 ng/ml) after the operation. However, in the group (group B) with normal levels (10.8 +/- 4.4 ng/ml) before surgery, PRL levels changed little (7.8 +/- 3.1 ng/ml) after the operation. In group A, the increment of PRL after TRH injection decreased or disappeared (P less than 0.02; 4.1 +/- 2.4 ng/ml) after surgery compared with that before surgery (39.2 +/- 25.9 ng/ml). On the other hand, in group B, the increment of PRL after TRH injection was nearly unchanged (17.1 +/- 7.0 ng/ml) after surgery compared with that before surgery (19.3 +/- 8.0 ng/ml). The results indicate that PRL is secreted from the pituitary adenoma in acromegalic patients with hyperprolactinemia, while PRL secretion from the normal part of the pituitary gland is decreased.

Acromegaly↗

Changes in calcium homeostasis in acromegaly treated by pituitary adenomectomy.

Patients with acromegaly have alterations in mineral metabolism. To determine the effect of correction of excess GH secretion on calcium metabolism, we studied 12 acromegalic patients before and 3-4 weeks after pituitary adenomectomy. Treatment of acromegaly resulted in significant decreases in both serum calcium [from 9.3 +/- 0.2 to 8.7 +/- 0.1 mg/dl (mean +/- SEM); P less than 0.01] and urinary calcium excretion (from 200 +/- 24 to 88 +/- 12 mg/24 h; P less than 0.0002). Serum phosphate also decreased significantly (P less than 0.01) from 4.8 +/- 0.2 to 4.3 +/- 0.2 mg/dl. Both serum immunoreactive PTH and calcitonin levels were normal initially and did not change after surgery. The mean serum 25-hydroxyvitamin D (25OHD) level was significantly (P less than 0.01) lower and the 1,25-dihydroxyvitamin D [1,25-(OH)2D] level was significantly (P less than 0.0001) higher in acromegaly compared with measurements in 25 normal subjects. After surgery, the serum 25OHD level did not change; however, the serum 1,25-(OH)2D concentration fell significantly (P less than 0.0001) from 60 +/- 4 to 43 +/- 2 pg/ml. A positive correlation was found between the decrements in urinary calcium excretion and the serum 1,25-(OH)2D level when the comparison was made between the decrements as percentages of pretreatment values (r = 0.64; P less than 0.05). The accumulated data suggest that the hypercalciuria in acromegaly might be due to intestinal calcium hyperabsorption, which could be attributed to the elevated circulating 1,25-(OH)2D level. Excessive GH secretion might stimulate the production of 1,25-(OH)2D and might also directly stimulate calcium absorption.

Acromegaly↗

[Effect of Saiboku-to, a blended Chinese traditional medicine, on Type I hypersensitivity reactions, particularly on experimentally-caused asthma].

Effect of Saiboku-to, which has been used for the therapy of bronchial asthma, on Type I hypersensitivity reactions was investigated. Forty eight-hr homologous PCA and antigen-induced histamine release in peritoneal cavities of rats passively sensitized with anti-DNP-As . IgE serum tended to be inhibited by the oral administration of Saiboku-to. On the other hand, 7-day homologous PCA in guinea pigs mediated by anti-BPO-BGG . IgE serum was significantly inhibited with 200 and 500 mg/kg of Saiboku-to given orally 2 hr prior to challenge. In experimentally caused asthma in guinea pigs, 200 mg/kg of Saiboku-to dramatically inhibited decreases in the rate and volume of respiration, and 500 mg/kg of the drug inhibited even an increase in the ratio of expiration time to inspiration time. The Schultz-Dale reaction in guinea pig tracheal muscle was significantly inhibited by the pretreatment with 10(-4) g/ml of Saiboku-to. The antigen-induced histamine release from sensitized guinea pig lung tissue was inhibited by 10(-6) to 10(-4) g/ml of Saiboku-to in a dose-dependent fashion, though the release of SRS-A was not affected. Saiboku-to did not show an antagonistic effect on allergic mediator-induced contraction in guinea pig ileum. From these results, it is considered that Saiboku-to shows an inhibitory activity on the Type I hypersensitivity reaction through the suppression of histamine release.

Anaphylaxis↗

An acromegalic patient with recurrent urolithiasis.

A 52-year-old man with an acromegalic appearance of prolonged duration suffered abdominal colic attacks and hematuria during the middle of the course of the disease. The patient was diagnosed as having urolithiasis caused by increased urinary calcium. The calcium metabolic disorder was not considered to be due to hyperparathyroidism because serum calcium and PTH levels were within the normal range and no abnormality was observed in a parathyroidal scintigraph. The serum 1,25-dihydroxyvitamin D (1,25-(OH)2D) levels (55.0 and 73.0 pg/ml) were higher than the normal range (27.2-53.8 pg/ml). A selective adenomectomy by the transsphenoidal route (Hardy's method) was performed, resulting in an improvement in the hypercalciuria and urolithiasis, and a decrease in the levels of serum 1,25-(OH)2D (23.0 and 23.0 pg/ml). These findings suggest that GH may promote the activation of vitamin D in the kidney in acromegaly, resulting in an acceleration of calcium absorption in the intestine through the action of activated vitamin D and the induction of increased urinary calcium excretion by the urinary excretion of excessive blood calcium.

Acromegaly↗