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Biomedical subjects

Y Nagase

Publications and source records attributed to Y Nagase.

At least 91 records · Page 5Linked to original sources
PubMed1984

Somatostatin-like immunoreactivity in mammalian thyroid glands: contents and partial characterization.

Somatostatin (SRIF)-like immunoreactivity (SLI) in the thyroid glands of human and several animal species were compared, and the SLI peptides were characterized chromatographically and immunologically. All specimens were extracted with 2 M acetic acid, and the SLI content determined by RIA. The SLI concentrations in guinea pigs [34.3 +/- (SE) 4.8 ng/mg protein] and rabbits (9.4 +/- 0.8 ng/mg protein) were much greater than those in other mammals: dogs, rats, mice, and humans. On gel filtration of extracts of the guinea pig, rabbit and dog thyroids, the major peak of SLI (1.6 K SLI) coeluted with synthetic SRIF-14 (S-14). Two other forms of SLI ("big" SLI and 3 K SLI) were also detected, although their relative proportions to total SLI were small (2.3 to 8.2%). The 3 K SLI and 1.6 K SLI from guinea pig and rabbit thyroids contained peptides coeluting with synthetic SRIF-28 (S-28) and S-14, respectively, on reverse-phase high performance liquid chromatography. The dilution curves of the two molecular forms of SLI, i.e. 3 K SLI and 1.6 K SLI, were parallel to the displacement curves of S-28 and S-14 in the SRIF RIA. It is concluded 1) that the thyroid contents of SLI varied greatly from species to species, with the highest content being found in guinea pig thyroids; 2) that in guinea pigs, rabbits, and dogs, the predominant form of thyroid SLI is 1.6 K SLI; and 3) that the 3 K SLI and 1.6 K SLI peptides from guinea pig and rabbit thyroids are immunologically and chromatographically indistinguishable from S-28 and S-14, respectively.

Animals↗
PubMed1984

ACTH-mediated effect of metoclopramide on plasma pregnenolone in man.

Five healthy adult men were given metoclopramide (10 mg and 20 mg) iv and the effects of L-dopa and dexamethasone on metoclopramide-induced increases in the plasma pregnenolone concentration were determined. After an injection of 10 mg metoclopramide, the pregnenolone level rose slightly, though not significantly vs a control. After injecting 20 mg metoclopramide, the pregnenolone level rose significantly vs both the control and the basal level. The pregnenolone increase was not inhibited by L-dopa pretreatment, whereas pretreatment with dexamethasone did suppress it significantly. The data suggest that metoclopramide increases pregnenolone secretion through an ACTH-dependent effect and that dopamine does not modulate pregnenolone secretion in man. This means that dopaminergic modulation does not affect the early steps (cholesterol to pregnenolone) of steroid biosynthesis in man.

Adrenocorticotropic Hormone↗
PubMed1983

Stress-mediated effect of metoclopramide on cortisol secretion in man.

Five healthy adult men were given metoclopramide (10 and 20 mg) iv, and in repeated tests almost always developed transient restlessness lasting from 10-30 min. The effects of L-dopa and dexamethasone on metoclopramide-induced increases in cortisol concentration were determined. These response values were compared with those of a control. After an injection of 10 mg metoclopramide, the cortisol level increased significantly only at 40 min; the ACTH level did not change. The cortisol rise was suppressed by dexamethasone pretreatment. Pretreatment with 0.5 g L-dopa resulted in a decrease in the PRL level from -20 min to 20 min, and the increase in cortisol seen at 40 min was cancelled. The ACTH level did not change. After injecting 20 mg metoclopramide, the ACTH level increased significantly from 20 min to 60 min and the cortisol level showed a significant increase from 20 min to 120 min. Pretreatment with dexamethasone resulted in a decrease in these hormones. The L-dopa pretreatment did not reduce even the rise in the PRL level which resulted from the administration of 20 mg metoclopramide. These findings suggest that the ACTH and cortisol response to metoclopramide is a stress-mediated effect. Plasma cortisol responses to 20 mg metoclopramide and insulin-induced hypoglycemia were studied and compared in seven volunteers and found to be similar.

Adrenocorticotropic Hormone↗
PubMed1983

Adrenocorticotropin-mediated effect of metoclopramide on plasma aldosterone in man.

Five healthy adult men were given metoclopramide (10 and 20 mg) iv and the effects of L-dopa and dexamethasone on metoclopramide-induced increases in plasma aldosterone concentration were determined. Plasma PRL, ACTH, and cortisol levels were also measured and the results reported in a previous study. After an injection of 10 mg metoclopramide, aldosterone levels increased significantly. The aldosterone rise was inhibited by L-dopa, but not by dexamethasone. After injecting 20 mg metoclopramide, aldosterone levels increased significantly vs. both the control and the basal level. The aldosterone increase was not inhibited by L-dopa pretreatment, whereas pretreatment with dexamethasone did suppress it. The data suggest that metoclopramide increased aldosterone secretion through an ACTH-dependent (stress mediated) effect in addition to its antidopaminergic adrenal action, simultaneously. There were no significant differences between the ACTH-dependent and dopamine antagonist-mediated aldosterone increases in either the 10- or 20-mg tests. However, the ACTH-dependent aldosterone increase was statistically greater in the 20-mg test than in the 10-mg test, whereas there was only a slight and not statistically significant difference in the dopamine antagonist-mediated aldosterone increase between the tests. This means that the ACTH-dependent component of the aldosterone secretion is affected by the doubling of the metoclopramide dose, whereas the dopamine antagonist-mediated component is not.

Adrenocorticotropic Hormone↗
PubMed1983

Chemical synthesis of a human fibroblast interferon gene and its expression in Escherichia coli.

Using the solid phase phosphotriester method, a gene coding for human fibroblast interferon consisting of 166 amino acid residues was chemically synthesized. The gene obtained by ligation of 61 synthesized oligodeoxyribonucleotide fragments was inserted into the downstream of tryptophan promoter, and expressed in E. coli. Lysate of this E. coli showed the antiviral activity which was specifically neutralized by anti-fibroblast interferon antibody. No particular advantage was observed in the expression efficiency by the synthetic gene over that by the native gene.

Amino Acid Sequence↗
PubMed1981

[Measurement of cardiac volume by computed tomography (author's transl)].

Noninvasive cardiac volume measurement by computed tomography (CT) was attempted in this study. It was found that non-gated CT images were very close to the end-diastolic images by ECG-gated CT. Ten to fifteen non-gated scannings were obtained serially from the upper atria to the left diaphragm in 9 normal subjects and 72 patients (6 hypertensives, 7 aortic valvular diseases, 22 mitral valvular diseases, 5 shunt lesions and 33 ischemic heart diseases). To demarcate each chamber, contrast enhancement CT was performed by drip infusion in most cases, but it was done by 4-6 times bolus injections at the level of the left ventricle (LV) to visualize LV lumen in ischemic cardiac patients who had ventriculography. The volume was calculated by summing each slice's volume which was obtained from the area times slice thickness (Fig. 2). The total cardiac volume and the volume of each chamber (LA, RA, RV and LV) were calculated. The interventricular septum and LV wall were included into LV volume. There was a good relationship (r = 0.90) between the total cardiac volume by CT and that by chest X-ray (PA and lateral views) (Fig. 4). Each volume by CT in 9 normal subjects was: 353 +/- 30 ml/m2 in total, RA: 53 +/- 17 ml/m2, LA: 54 +/- 21 ml/m2, RV: 90 +/- 15 ml/m2, and LV: 123 +/- 15 ml/m2 (mean +/- SD), respectively, and an increment of each volume was shown according to the hemodynamic features of various heart diseases: the total volume was increased significantly in valvular disease (Fig. 5), RA and RV volumes in mitral valvular disease with tricuspid regurgitation and ASD (Figs. 6, 7) LA volume in mitral valvular disease and shunt lesion (Fig. 8) and LV volume in aortic valvular disease and mitral regurgitation (Fig. 9). Between the left ventricular lumen volume by Ct and its end-diastolic volume by ventriculography (area-length method), there was a good relationship (r - 0.81) in 17 cases without cardiac aneurysms out of 22 ischemic cardiac patients examined by ventriculography (RAO and LAO views) (Fig. 11). The cardiac CT was found very useful for measurements of cardiac volume, since it is noninvasive and quite simple yet reasonably accurate.

Adult↗
PubMed1980

Quantitative high-performance liquid chromatographic determinations of aminopyrine and its metabolites in man.

A quantitative high-performance liquid chromatographic method, using a polystyrene-divinyl benzene (Hitachi No. 3010 gel) column and aqueous methanol as the mobile phase, was employed for the determination of aminopyrine and its related compounds, 4-acetyl-aminoantipyrine, 4-aminoantipyrine and 4-monomethylaminoantipyrine. Baseline separation could be achieved within 25 min. The method was applied to the recovery of these materials from control urine and human urine. Before separation human urine was adjusted to pH 9 and extracted with ethyl acetate, chloroform and diethyl ether.

Adult↗
PubMed1978

Studies on drug metabolism by use of isotopes XX: Ion cluster technique for detection of urinary metabolites of 1-butyryl-4-cinnamylpiperazine by mass chromatography.

An ion cluster technique and mass chromatography were used for the structural elucidation of several unidentified urinary metabolites of 1-butyryl-4-cinnamylpiperazine (I) in mice and guinea pigs. The urinary metabolites in guinea pigs and mice receiving a single 100 mg/kg dose of an equimolar mixture of 1-butyryl-4-[aromatic-d(5)]-cinnamylpiperazine (I-d(5)) hydrochloride and I hydrochloride (I:I-d(5)) were purified and subjected to trimethylsilyl derivatization with bis(trimethylsilyl)acetamide, followed by GLC-mass spectrometry-computer analysis. Appropriate fragment and molecular ions of unidentified metabolites were selected based on the major mass fragment ions appearing in the mass spectra of the previously identified metabolites of I to provide the mass chromatograms. The presence of ion clusters as doublet peaks in the mass chromatograms indicated that the corresponding total ion peaks originated from the administered I:I-d(5). The mass spectra of selected scans from the total ion chromatogram were plotted, and the structures of unidentified metabolites were readily determined by the presence of ion clusters separated by 3-5 mass units and by the shift of the fragment ions. By using this technique, six previously unidentified metabolites were identified in the urine of guinea pigs and two were identified in the urine of mice.

Analgesics↗