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Biomedical subjects

S Machida

Publications and source records attributed to S Machida.

At least 109 records · Page 6Linked to original sources

The effects of xenopsin of endocrine pancreas and gastric antrum in dogs.

Effects of synthetic xenopsin on endocrine pancreas and gastric antrum in anesthetized dogs were studied. Synthetic xenopsin was administered into the superior pancreaticoduodenal artery and plasma insulin, glucagon and gastrin in the superior pancreaticoduodenal vein and gastrin in the right gastroepiploic vein were measured radioimmunologically. Administration of 10 microgram of xenopsin per kg of body weight brought about a hyperglycemic response and rapid and sharp elevations of the hormones in the pancreatic vein. Plasma gastrin level in the gastric vein also showed an immediate and sharp increase following xenopsin administration. Xenopsin appeared more potent inducer of the glucagon. It is concluded that xenopsin acts directly on endocrine pancreas and gastric antrum to secrete their hormones.

Animals↗

Potential endocrine effects of hypothalamic peptide "neurotensin" on pancreas in dogs.

Effects of synthetic neurotensin on the endocrine pancreas were studied in nine normal and six hypophysectomized (10th to 14th day post-hypophysectomy) dogs. Synthetic neurotensin was administered into the superior pancreaticoduodenal artery, and plasma insulin and glucagon concentrations were measured radioimmunologically. In normal dogs, ten microgram/kg neurotensin administration brought about a mild hyperglycemic response and sharp and rapid increase of plasma insulin and glucagon concentrations in the superior pancreaticoduodenal vein. A biphasic insulin response was noted in the pancreatic vein. The results suggest that a large dose of neurotensin acts directly on the endocrine pancreas causing secretion of these hormones. In hypophysectomized dogs, basal levels of plasma insulin and glucagon were decreased and neurotensin had little effect on the endocrine pancreas even with the administration of a large dose.

Animals↗

Establishment of a human rectal cancer cell line producing carcinoembryonic antigen.

A permanent cell line (S-7512) was established by cell culture from the subcutaneous metastatic tumor of a human rectal cancer and has been maintained for 18 months. Cultured cells grew as isolated and piled-up colonies of epithelial cells, each with a scanty cytoplasm and a large nucleus containing several nucleoli. The average doubling time of this cell line was 57 hr and plating efficiency was 30.1 approximately 45.2% in a liquid medium. The modal chromosome number was 115 but a marker chromosome was not evident. Electron microscopic examination revealed many microvilli, free ribosomes, and abundant glycogen granules. Heterotransplantation of the cultured cells produced a large tumor and its microscopic examination showed the same histological appearance as the original tumor (carcinoma simplex). Carcinoembryonic antigen level of the spent medium of the confluent culture was 235.50 ng/3.2 X 10(6) cells.

Adenocarcinoma↗

Isolation of a new polyether antibiotic, lonomycin.

A new polyether antibiotic, lonomycin, was isolated from the culture of Streptomyces ribosidifcus strain TM-481. The antibiotic obtained as a sodium salt is a colorless prism having a molecular formula of C44H75O14Na(M.W. 850), m.p. 188 approximately 189 degrees C, and has no absorption maxima in the ultraviolet region. The infrared and NMR spectra of the antibiotic suggest the presence of a carboxyl and four methoxyl groups. Lonomycin shows antimicrobial activity against gram-positive bacteria.

Animals↗