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Biomedical subjects

H Sugihara

Publications and source records attributed to H Sugihara.

At least 469 records · Page 26Linked to original sources
PubMed1982

Electron microscopic visualization of cathepsin D using mercury-labeled pepstatin as an enzyme inhibitor.

Pepstatin, a specific inhibitor of pepsin, cathepsin D (E), renin, etc., was used in a new method to demonstrate the sites of enzymes. Pepstatin (Pst) was covalently attached to glutathione (GSH), using a dicyclohexylcarbodiimide, and CH3Hg+ was then put in the residue of SH for electron microscopic observation. Pst-GS-HgCH3 thus obtained was nonisotopical, had a very low molecular weight (about 1,200 daltons), and still almost completely retained its inhibitory activity. Sections of rat liver (less than 1 mm3 thick), prefixed by glutaraldehyde, were incubated in the prepared reaction medium. Cathepsin D, located in the lysosomes, was demonstrated by this compound, but when the sections were preincubated with pepstatin, this was not the case. These results demonstrate that mercury-labeled pepstatin is a useful reagent for the histochemical staining of acid proteases for electron microscope.

Animals↗
PubMed1982

Relationship between colloid droplets of thyroid follicular cells and serum thyroglobulin concentration in neonatal rats after thyrotropin releasing hormone (TRH) injection.

Thyrotropin Releasing Hormone (TRH) shows the obvious and long-durated stimulation to the neonatal thyroid tissue through the pituitary. The sequential changes of serum thyroglobulin (Tg) levels and light and ultrastructural change in the cells of the thyroid gland were studied after TRH injection into neonatal rats. TRH injection induced a rapid increase of the colloid droplets in the thyroid follicular cells followed by a slow increase in serum Tg levels. Ultrastructurally, although marked surface activities consisting of formation of pseudopods and colloid droplets were observed after TRH injection, luminal colloid did not appear to go across the intercellular space between the thyroid follicular cells.

Animals↗
PubMed1982

The effect of alpha-melanocyte-stimulating hormone on the adrenal cortex of the fetal rat.

The effect of alpha-melanocyte-stimulating hormone (alpha-MSH) on the fetal adrenal cortex in rat was studied in vivo and in vitro. In vivo, an injection of alpha-MSH stimulated the adrenal cortex slightly. Treatment of the adrenal cortex with alpha-MSH in organ culture caused hyperfunctional change in the innermost layer of the cortex, the detection of which was done by electron microscope. This treatment caused at the same time an increase in corticosterone in the culture medium. Furthermore, comparison was made between alpha-MSH and ACTH with respect to their effect on the fetal adrenal cortex.

Adrenal Cortex↗
PubMed1982

[Analysis of end-systolic pressure-volume relation by gated radionuclide angiocardiography].

Left ventricular end-systolic pressure-volume relation has been proved experimentally to be an useful index of left ventricular contractility relatively independent of preload or afterload. But less clinical application has been reported because of its invasive nature, and we evaluated this relationship non-invasively using gated radionuclide angiocardiography as volume determination and cuff sphyngomanometer in the arm as pressure measurement. Gated equilibrium blood pool scintigrams were obtained at rest and during intravenous infusion of angiotensin or nitrate. Ventricular volumes were derived from ventricular activity and peripheral blood volume and activity. The peak systolic pressure (PSP) by cuff method to end-systolic volume index (ESVI) relations showed good linearity (r greater than .930 in 84% of consecutive 50 cases) and were gentler in the groups with more impaired left ventricular function. Emax was related exponentially to ejection fraction (EF) and hyperbolically to end-diastolic volume index. The dead volume (VoI) was unfixed and fell into positive or negative value, and was not related to EF under control condition. PSP/ESVI in each loading condition was less variable with the alteration of blood pressure than EF. The linear relation was found between PSP/ESVI under control condition and Emax (PSP/ESVI = 0.651 . Emax + 0.958, r = 0.841, p less than .001). Thus in measuring ventricular volume, gated radionuclide angiocardiography is a non-invasive method less affected by the geometry of the left ventricle. Non-invasive determination of end-systolic pressure-volume relation using the volume by radionuclide and the blood pressure by cuff method is clinically useful in the assessment of left ventricular contractility.

Angiocardiography↗
PubMed1981

Nonspecific therapy of asthma with gold preparation and insulin.

Nonspecific therapy of asthma with Solganal and insulin showed excellent results in more than 80% of the patients, in which 50% or more recovered from asthma completely. Over all, recovered condition lasted for a long period of time. Solganal-treated patients showed resistance to acetylcholine provocation tests, good results in Tromp's water bath tests, and decreases in intensity of itching and erythema of P. K. reaction and of those caused by intracutaneous histamine injection. Animal experiments investigating damage to the liver, kidney and heart with Solganal showed no serious findings.

Adolescent↗
PubMed1980

Ligand bindings of bovine carboxypeptidase B. III. Hydrophobic activators in dipeptide hydrolysis.

Several hydrophobic compounds acted as activators in dipeptide (Bz-Gly-L-Arg-OH, Z-Gly-L-Phe-OH) hydrolysis by bovine carboxypeptidase B. These hydrophobic compounds include Bz-Gly-OH, Z-Gly-OH, Z-L-Phe-OH, and Z-L-Phe-GLy-OH. These compounds were indicated to bind to the secondary substrate binding sites which is proposed to be responsible for substrate activation kinetics in dipeptide hydrolysis. Of the compounds Z-L-Phe-OH alone acted also as a inhibitor at higher concentrations, indicating that it binds to both primary and secondary sites as the dipeptide substrates do. Comparison of the activation effects of the compounds employed indicated that hydrophobic interaction played an important role in binding to the secondary site. Substrate and modifier binding constants were also determined and the results indicated that modifier binding increased both affinity and catalytic rate constant of the primary site. On the other hand, Z-Gly-OH and Z-L-Phe-Gly-OH inhibited the hydrolyses of tri and tetrapeptide substrates. This observation suggests that the secondary site is contained in the extended active center which the enzyme possibly has.

Alcohols↗
PubMed1980

Functional pathology of aldosterone-producing adenoma.

In addition to the morphological examination, the measurement of the content of corticosteroids was done in aldosterone-producing adenoma. Histologically, the adenoma consists of four types of cells. The major component of the adenoma was clear-type cells. In this type of cells, the activities of 3 beta-hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase showed weakly positive. The fine structure was characterized by numerous lipid vacuoles and poor organellae. On the contrary, intermediate- and compact-type cells revealed higher than moderate activities of these enzymes. Moreover, marked development of smooth endoplasmic reticulum and mitochondria was noted. Zona glomerulosa-type cells were observed only in a small part. The content of aldosterone and corticosterone in aldosterone-producing adenoma was significantly larger than those of the other type of adenoma. A tendency of positive correlation between the increase of compact-type cells and content of aldosterone was found. The cell origin of this aldosterone-producing adenoma and functional role of clear- and compact-type cells were also discussed.

3-Hydroxysteroid Dehydrogenases↗