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Biomedical subjects

T Ishida

Publications and source records attributed to T Ishida.

At least 1,243 records · Page 69Linked to original sources
PubMed1978

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↗
PubMed1978

Isolation of mouse hepatitis virus from infant mice with fatal diarrhea.

An epizootic of fatal diarrhea occurred in mice which were approximately 10 days of age. The enteric lesions were similar to those reported in lethal intestinal virus of infant mice, but many diseased mice also had necrotic hepatitis. Mouse hepatitis virus antigen was demonstrated in the affected intestine and liver, and a virus that produced syncitium formation in mouse brain tumor cell culture was isolated from the intestines, livers, and brains. The virus was capable of producing intestinal and hepatic lesions similar to the naturally occurring disease after inoculation into suckling mice. Electron microscopy revealed viral particles within affected intestinal epithelial cells of the inoculated mice.

Animals↗
PubMed1977

Lipid cell tumor of the ovary: an ultrastructural study.

An ovarian lipid cell tumor without Reinke's crystalloids in a woman with secondary amenorrhea, minimal hirsutism, and elevated 17-ketosteroid excretion was studied by light and electron microscopy. Tumor cells were found in small clumps or scattered singly within a collagenous matrix. The cytoplasm of the tumor cells contained abundant smooth endoplasmic reticula, numerous mitochondria with tubular cristae, lipid droplets, lysosomal dense bodies, and concentric membranous whorls, characteristic of steroidogenic cells. In addition, "peripheral canalicular systems" were found at the outer margins of the nests of the tumor cells. These "peripheral canalicular systems" were bordered by the cell membranes and the surrounding collagenous stroma into which microvilli projected. Since the intercellular canalicular system present between the tumor cells was continuous with the "peripheral canalicular system," both systems probably have a common function related to steroid metabolism. The intercellular and "peripheral" canalicular systems and cytoplasmic microfilaments found in this tumor suggest that this ovarian lipid cell tumor was derived from the ovarian stroma.

17-Ketosteroids↗
PubMed1977

N4-Behenoyl-1-beta-D-arabinofuranosylcytosine as a potential new antitumor agent.

N4-Acyl-1-beta-D-arabinofuranosylcytosines, which are lipophilic antitumor analogs of 1-beta-D-arabinofuranosylcytosine, were dissolved by the use of a detergent, HCO-60, and the differences in the antitumor activities when the drugs were administered in the forms of solution or suspension were compared. N4-Stearoyl-1-beta-D-arabinofuranosylcytosine (NSC 201290), which was the most active compound when administered as an aqueous suspension, diminished in its activities after it had been dissolved into a clear solution, whereas N4-behenoyl-1-beta-D-arabinofuranosylcytosine (NSC 239336) exhibited activities superior to those of the parent compound 1-beta-D-arabinofuranosylcytosine when administered as a solution. Moreover, the high efficacy of this compound was long lasting in the host animal, regardless of the treatment schedules or the presence of the 1-beta-D-arabinofuranosylcytosine-inactivating enzyme, cytidine deaminase.

Animals↗
PubMed1976

Gonadoblastoma: ultrastructural evidence for testicular origin.

A gonadoblastoma arising in the dysgenetic gonad of a virilized 17-year-old Caucasian with a female phenotype and with a 45,X0/46, X-ring-Y genotype was studied by light microscopic histochemistry, electron microscopy, and ultrastructural histochemistry. The gonadoblastoma was composed of nests of cells containg large germ cells and small "granulosa-Sertoli-like cells," and stromal tissue containing "Leydig-like cells." The germ cells were identical to those found in normal fetal gonads and in germ cell tumors. Charcot-Böttcher crystalloids present in the "granulosa-Sertoli-like cells" strongly suggest that they are, in fact, Sertoli cells. Multilayered basal laminae located in the periphery of the tumor nests and in "hyaline bodies" were identical to those surrounding the seminiferous tubules of the adult testis. The "Leydig-like cells" present in the stroma contained occasional dense bodies and crystalloids which characterize the Leydig cells of the fetal testis. Delta 5-3 beta hydroxysteroid dehydrogenase activity was demonstrated in the periphery of lipid droplets and lysosome-like dense bodies of the Leydig cells, and in some Sertoli cells. The findings support the theory that gonadoblastoma arises in a dysgenetic testis rather than in a dysgenetic ovary.

Adolescent↗
PubMed1976

A malignant tumor of the vagina resembling synovial sarcoma: a light and electron microscopic study.

A malignant tumor arising in the upper lateral vaginal mucosa in a 24-year-old white woman, hitherto undescribed in the literature, was studied by light and electron microscopy. The main part of the tumor was epithelioid, forming a tubular or acinar pattern. At the periphery, the tumor cells were more spindly and formed sheets resembling fibrosarcoma. The tumor cells contained occasional material positive for mucicarmine, alcian blue, and PAS stains, and the nests of the cells forming acini were surrounded by reticulin fibers. The tumor ultrastructure consisted of a single type of cell with large cytoplasmic vacuoles and occasional perinuclear intracytoplasmic filaments. Slender long microvilli projecting into the lumina were also characteristic. Basal laminae were occasionally present around the acini. The findings suggested that the tumor was of mesenchymal origin, closely related to synovial sarcoma.

Adult↗
PubMed1976

Direct inhibitions of basal and arginine-induced plasma gastrin secretion by somatostatin in anesthetized dogs.

Effect of somatostatin on plasma gastrin levels was investigated in anesthetized dogs. Somatostatin was infused into the right gastroepiploic artery and plasma gastrin levels in the right gastroepiploic, superior pancreaticoduodenal and peripheral veins were measured by radioimmnuoassay. Somatostatin suppressed basal gastrin level promptly in the right gastroepiploic vein and impaired the normal gastrin secretion in response to intravenous infusion of arginine. The inhibitory effect of somatostatin on the plasma gastrin secretion was quite clearly demonstrated in the right gastroepiploic vein. It appears likely that the inhibition of gastrin secretion by somatostatin resulted in direct action on the gastrin secretory cell.

Animals↗