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Biomedical subjects

M Hata

Publications and source records attributed to M Hata.

At least 289 records · Page 16Linked to original sources
PubMed1981

Myelolipoma of the adrenal gland.

A case is reported of an adrenal myelolipoma producing a retroperitoneal hematoma. A right suprarenal mass with fatty density was detected by a computerized tomography scan. The mass had irregular vessels on the arteriogram. This is the youngest patient reported among those with surgically removed myelolipoma. There was no endocrine activity.

Adrenal Gland Neoplasms↗
PubMed1981

Influence of blood proteins on biomedical analysis. III. Pharmacokinetics and protein binding of gliclazide.

Both pharmacokinetics of total and free gliclazide, a potential hypoglycemic drug, were studied in the healthy (n = 12) and diabetic subjects (n = 11). The blood level of gliclazide was determined by a high-performance liquid chromatography, and the free gliclazide (unbound to proteins) in the serum separated by means of an ultrafiltration. The binding ratio of gliclazide to the blood proteins was about 96% during the periods of 24 hr after administration of the drug. Several pharmacokinetic parameters for the blood gliclazide were derived from the decay curves of the blood drug levels. Each pharmacokinetic parameter was not changed by differences between the healthy and diabetic subjects, the total and free drug levels, and method of administration of the drug; each mean parameter, the elimination rate (ke), the time to peak level (tmax), the elimination half-life (t1/2) and the volume of distribution (Vd beta) was 0.07 hr-1, 2.8 hr, 12.3 hr and 16.4 1 (total level), respectively. The serum from healthy subject receiving orally administered gliclazide was gel-filtered on a Sephadex G-150 column. Each fractionated serum protein of macroglobulin (IgM), gamma-globulin (IgG), albumin (A) and small molecular substances (F), contained gliclazide at average of 3.7, 0.7, 82.3 and 13.2%, respectively, during the periods of 24 hr after administration. In in vitro experiment, it was found that the ratio of gliclazide-albumin binding kept a constant level at 96.5% in the range of normal protein levels (3.3--4.8 g/100 ml). In conclusion, the present result shows that the pharmacokinetics of the total blood level of gliclazide reflect the free gliclazide level, moreover, gliclazide predominantly binds with albumin in the blood and its binding ratio is not constant, but variable according to the dose-relation between the drug and the serum protein.

Adult↗
PubMed1980

Determination of gliclazide in human serum by high-performance liquid chromatography using an anion-exchange resin.

A method for the routine clinical examination of serum gliclazide by high-performance liquid chromatography (HPLC) on a column packed with a macroporous anion-exchange resin, Diaion CDR-10, was developed. The elution was performed with acetonitrile-methyl alcohol-1.2 M ammonium perchlorate (4:3:7, v/v/v) at a flow-rate of 0.4 ml/min. The retention time of gliclazide was 15 min. It seems that the retention mechanism of gliclazide under the HPLC conditions described is not only ion-exchange mode but reversed-phase mode between the anion-exchange resin and the mobile phase. The detection limit of gliclazide was 0.2 microgram/ml in plasma. The coefficient of variation for the within-day assay was 5.0% (0.2 microgram/ml, n = 8). The decay curve of serum gliclazide in diabetic patients was determined.

Chromatography, Gas↗
PubMed1980

Insulin receptors in rabbit erythrocyte.

The existence of insulin receptors in rabbit erythrocytes was studied by evaluating the specific binding of 125I-insulin to erythrocyte membranes. The binding of 125I-insulin was pH, time and temperature dependent. Maximal binding was achieved by incubation for 20 hr at 0 degrees C. The optimum pH was 7.4. Treatment with cations and enzymes enhanced the specific binding except for with trypsin, the treatment which greatly reduced the binding. Unlabeled insulin over a wide range of concentrations competitively inhibited the binding of 125I-insulin, while the binding was little affected by structurally unrelated hormones. Scatchard plot was represented as a concave curve. Binding sites of relatively high affinity (K1 = 0.9 X 10(9) M-1) and low capacity (8.0 X 10(13)/g protein) could be distinguished from those of lower affinity (K2 = 0.8 X 10(7) M-1) and higher capacity (1.8 X 10(15)/g protein). Hill's analysis and dissociation of 125I-insulin from membranes demonstrated the characteristics of negative cooperation between receptor sites. Both incorporation of H3(32)PO4 to erythrocyte membranes and uptake of 45Ca were significantly reduced by the addition of unlabeled insulin. Unlabeled insulin produced no effect on uptake of 45Ca into trypsin-treated erythrocytes. On the basis of these results, it was suggested that rabbit erythrocytes might possess biologically significant insulin receptors located on the cell membranes.

Adenosine Triphosphatases↗
PubMed1978

Antiandrogenic effects of spironolactone: hormonal and ultrastructural studies in dogs and men.

A decrease in the level of plasma testosterone and an increase in the level of plasma progesterone were noted after spironolactone had been administered for 20 days in 5 patients with prostatic carcinoma, as well as in 8 male dogs. Electron microscopic observation disclosed myelin-like bodies in the cytoplasm of Leydig and adrenocortical cells in dogs, contributing to a resolution of the mode of antiandrogenic action of spironolactone.

Adrenal Glands↗