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Biomedical subjects

F Sato

Publications and source records attributed to F Sato.

At least 433 records · Page 24Linked to original sources

Role of calcium in cholinergic and adrenergic mechanisms of eccrine sweat secretion.

The role of Ca2+ in eccrine sweat secretion was studied using isolated cannulated monkey palm eccrine sweat glands in vitro. Removal of Ca2+ from the incubation medium promptly abolished sweat secretion induced by methacholine or phenylephrine. In contrast, isoproterenol-induced sweat secretion lasted from 40 to 220 min in a Ca2+-free medium. The methacholine-induced maximal sweat rate was a hyperbolic function of the Ca2+ concentration in the bath and reached a plateau at 1 mM Ca2+. Higher Ca2+ concentrations rather suppressed the secretory rate. The Ca2+ ionophore A23187, but not X537A, at 3 X 10(-6) M induced copious prolonged sweat secretion after a latent period of 10 min. A23187-induced sweat secretion was not inhibited by either atropine or propranolol. D 600 (methoxyverapamil) at 10(-3) M inhibited sweat secretion induced by methacholine or by isoproterenol, although the latter lasted longer than methacholine sweating (20 vs. 5 min) in the presence of D 600. The data support the notion that Ca2+ influx into the cell plays a crucial role in cholinergic and alpha-adrenergic sweating, whereas a partial supply of Ca2+ for isoproterenol-induced sweating is derived from an intracellular store.

Animals↗

Pharmacologic responsiveness of isolated single eccrine sweat glands.

Pharmacologic responsiveness of the eccrine sweat gland has never been studied under well-defined in vitro experimental conditions. Using isolated cannulated single monkey palm eccrine sweat glands, the dose response to both cholinergic and alpha- and beta-adrenergic agents and the effects of various antagonists on agonists were studied. The maximal sweat rate was highest after stimulation with cholinergic agonists, was lower with the beta-adrenergic agonist, and was least with the alpha-adrenergic agonist. Each secretory response was inhibited by its specific antagonist. Attempts to demonstrate the spare receptor, if any, by means of preincubation of the glands with N-(2-chlorethyl)dibenzylamine (Dibenamine) were unsuccessful. From the hyperbolic dose-response curves the values for KA and KB, dissociation constants for agonists and antagonists, respectively, were thus tentatively estimated according to Clark's classical receptor theory. Schild plots for each agonist-antagonist interaction produced straight lines with slopes of near unity, indicating the adequacy of the methodology. It was concluded that the isolated eccrine sweat glands retain their pharmacologic viability in vitro and show responsiveness to cholinergic as well as both alpha- and beta-adrenergic stimulations.

Animals↗

A clinicopathological study of minute polypoid lesions of the colon based on magnifying fiber-colonoscopy and dissecting microscopy.

Magnifying fiber-colonoscopy reveals that adenoma, minute carcinomatous lesion in an adenoma (which is termed focal carcinoma), and mucosal carcinoma of the colon, each has its own characteristic pit pattern. Inspection by dissecting microscope of resected specimens obtained from subjects whose colonic mucosa had been considered normal, often reveals an abnormal pit pattern of less than 1 mm, and subsequent histologic examination confirms the frequent presence of incipient adenoma. Clinical magnification inspection of areas of colonic mucosa considered normal on the basis of ordinary observation, reveals pit patterns identical to those seen in resected specimens.

Adenoma↗

Determination of dose-plasma concentration relationship of phenobarbital in epileptic patients by a new specific radioimmunoassay.

A new phenobarbital hapten, 1-(4-carboxybutyl)-phenobarbital (CBP) was synthesized. Antiserum obtained from a rabbit immunized with CBP-bovine serum albumin conjugates is specific for phenobarbital and does not substantially cross-react with a major metabolite, p-hydroxyphenobarbital. The antiserum was used to develop a sensitive radioimmunoassay which could determine as little as 100 pg of phenobarbital. The radioimmunoassay was applied to the determination of plasma phenobarbital concentrations in epileptic patients and the results were compared with those obtained by a spectrophotometric technique (r = 0.950, P < 0.01). A significant dose-plasma concentration relationship for phenobarbital was observed in epileptic patients treated with phenobarbital for more than a month.

Animals↗

[Downward migration of the optic system after transsphenoidal approach of a giant eosinophilic adenoma (author's transl)].

Headache and visual impairment resulting from downward migration of the optic system in an acromegalic patient, occurred after one year postoperatively. A 25-year-old woman with eosinophilic adenoma was operated on via transsphenoidal approach and irradiated (5,000 rads) following the operation. After the operation, bitemporal hemianopia was thoroughly improved and serum HGH level was also markedly decreased after radiation therapy. One year later, headache and visual impairment recurred. Pneumoencephalogram revealed that the infundibular and optic recessus of the third ventricle were elongated and descended into the sella turcica. The second operation was performed by subfrontal approach and the optic system was found to be migrated into the sella, which we assumed to be the cause for the recurrence of the headache and visual field defect. In order to prevent this type of complication, it would be recommended to fill up the dead space in the sella with bone or cartilage fragments in addition to muscle pieces, as was suggested by Guiot et al.

Adenoma, Acidophil↗

[Chronic hepatitis--clinicopathological studies of 687 cases (author's transl)].

Chronic hepatitis is one of liver diseases with arguments from the clinical and histopathological aspects. Histopathological examinations were made on 687 biopsy cases clinically diagnosed as chronic hepatitis. Histopathological classification was based on our own criteria by referring to discussions in the series of Inuyama symposia on hepattis and others. The correlation between histological diagnosis and clinical data was also examined. Histopathological diagnoses made of the 687 cases were classified as follows; normal liver or liver with no pathognomonic changes of 77 cases (11.2%), non-specific reactive hepatitis of 56 cases (8.0%), viral hepatitis of 488 cases (71.0%), alcoholic hepatitis of 25 cases (3.6%), fatty liver of 23 cases (3.3%), massive liver necrosis of 3 cases, liver fibrosis of 2 cases, congestive liver of 1 case, and unclassified 12 cases due to inadequate specimens or other reasons. Among 488 viral hepatitis cases, histological stages were as follows; acute hepatitis (38 cases, 7.8%), persistent hepatitis (23 cases, 4.7%), chronic inactive hepatitis (142 cases, 29.1%), chronic active hepatitis (165 cases, 33.8%), chronic hepatitis with subloblar necrosis (33 cases, 6.8%), precirrhosis (51 cases, 10.5%), cirrhosis (27 cases, 5.5%). The relationship between histological aspects and clinical features was discussed by sex, age, and others. Of 41 follow up cases, significant values of histological type, presence of HB ag., or alcoholic were discussed as for the causative factors evolving liver cirrhosis.

Adolescent↗

Reconstruction of laryngeal function for recurrent laryngeal nerve paralysis: historical view, advancement of latest investigations and a preliminary experiment.

Historical investigations of the functional restoration for recurrent laryngeal nerve paralysis are reviewed and some advancement in recent studies are introduced. A preliminary experiment is reported in which the ansa hypoglossi and the sternothyroid muscle pedicle was implanted into the denervated posterior cricoarytenoid muscle in dogs. From these experiments we have concluded that the ansa hypoglossi and sternothyroid muscle pedicle, which has been shown to transmit efferent inspiratory bursts, is capable of restoring function to the paralyzed posterior cricoarytenoid muscle in some dogs.

Animals↗