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Biomedical subjects

T Tsuchiya

Publications and source records attributed to T Tsuchiya.

At least 667 records · Page 37Linked to original sources
PubMed1985

Distribution pattern of liver matrix proteins, fibronectin and type I collagen, in DAB-induced hepatoma of rat.

Specific antibodies to fibronectin and type I collagen in rat livers were used to demonstrate these matrix proteins with direct immunoperoxidase method in paraffin sections of normal liver, DAB-induced hepatoma and CCl4-induced fibrotic liver. In normal livers, the immunoreactive products of both matrix proteins were found in the periportal regions, while the hepatocytes and most of the interstitial matrix remained unstained. The specimens obtained from DAB-treated liver showed a more intense reaction with fibronectin antibody in the perisinusoidal space including proliferated cholangiolar cells, as compared to no reaction with type I collagen antibody. In CCl4-fibrotic liver, apparent reactions were also found for both matrix proteins in the periportal interstitium and in progressing fibrotic area with severe fatty metamorphosis. These findings suggest that these matrix proteins have an advantage in the attempt to distinguish different patterns of neoplastic alteration in experimental rat livers.

Animals↗
PubMed1985

Role of vagus nerve in secretion of gastric inhibitory polypeptide in dogs.

In order to clarify the role of the vagus nerve in the secretion of gastric inhibitory polypeptide (GIP), experiments were performed on dogs. Response of plasma GIP to intraduodenal instillation of glucose was slightly lower in a group which received atropine, than in a group of normal dogs. The response of plasma GIP to intraduodenal glucose load was not different between vagotomized dogs and normal dogs. Electric stimulation of the vagus nerve did not produce any significant changes in plasma GIP in anesthetized dogs. In conclusion, the present study indicates that the role of the vagus nerve on GIP secretion is tiny, if any, and that the nervous influence does not overcome the effect of intraluminal administration of glucose.

Animals↗
PubMed1985

Effects of intragastric ethanol administration on gastric acid secretion and gastrointestinal hormone release in dogs.

Dogs with a vagally denervated (Heidenhain) pouch and a gastric fistula were used to investigate the humoral mechanism which would affect the gastric acid secretion following acute intragastric ethanol administration. Ethanol solutions induced a dose-related secretion of gastric acid. Although plasma gastrin levels increased after the loading of both 20% and 30% ethanol solutions, there was a discrepancy between total acid output and the integrated gastrin response. Plasma secretin levels also augmented after the administration of ethanol solutions, with a delay of about one hour after the onset of acid secretion. The response of gastric inhibitory polypeptide (GIP) to ethanol was very slight, similar to that of insulin. There was a significant rise in plasma glucose levels after the instillation of 30% ethanol solution as in the case of liquid meal. It is concluded that gastrin may be merely one of the factors which stimulate acid secretion after ethanol administration, and that gastric acid would have a close relationship with secretin release. It is also probable that acid is not an effective stimulant to the release of GIP.

Animals↗
PubMed1985

Electron microscopy of fat-storing cells in liver diseases with special reference to cilia and cytoplasmic cholesterol crystals.

Two hundred and ten fat-storing cells in the liver of patients with liver diseases were examined electron microscopically, and 5 of them were found to project a single cilium from the perinuclear region to the space of Disse. Three cilia were in the space between a hepatocyte and their own cell body, and 2 were between a sinusoidal endothelial cell and their own cell body. In cross sections of the cilium, the axoneme consisted of 9 pairs of microtubules arranged in a cylinder and lacked a central pair of microtubules ("9 + 0" pattern). Arms and spokes were also absent in the axoneme. Therefore, the single cilium of fat-storing cells was considered to be immotile. Some fat-storing cells from a patients with alcoholic liver cirrhosis contained an angular electron lucid inclusion, which was identical to cholesterol ester crystals, suggesting the presence of disturbed cholesterol metabolism.

Cholesterol↗
PubMed1985

Force-velocity relation in paired frog sartorius muscles attached to opposite lever arms.

To study the mechanism of the longitudinal stability at the level of whole muscles, paired frog sartorius muscles were attached to the opposite lever arms at unequal distances from the pivot. The lever was initially fixed in position, and when the full isometric forces were developed in both muscles, it was released to move, the result being that the advantaged muscle shortened by stretching the disadvantaged one with a nearly constant velocity depending on the ratio between their points of attachment from the pivot. The force-velocity relation of the advantaged muscle was virtually identical with the ordinary force-velocity relation obtained from the isotonic release experiments, while the force-velocity relation of the disadvantaged muscle was found to be entirely different from the ordinary one because of a marked increase in the load-bearing ability. These results are discussed in connection with the enhancement of mechanical performance in lengthening muscle.

Animals↗
PubMed1985

Reconstitution of the melibiose carrier of Escherichia coli.

Different conditions were studied for optimal solubilization and reconstitution of the melibiose carrier of Escherichia coli. Several alpha- and beta-galactosides, known to be substrates for the melibiose carrier, were found to inhibit [3H]-melibiose uptake by proteoliposomes. In the presence of 10 mM Na+ the Km for melibiose counterflow was 0.42 mM. Melibiose and raffinose were good substrates for counterflow, while thiomethyl-beta-galactoside and p-nitrophenyl-alpha-galactoside were accumulated very poorly. Although the latter two sugars are known to be substrates for the carrier, they showed a very rapid rate of passive diffusion across the liposome membrane. The proton ionophore carbonylcyanidechlorophenylhydrazone had no effect on uptake, suggesting that a proton motive force is not essential for the counterflow phenomenon.

Biological Transport, Active↗
PubMed1985

N-Substituted derivatives of 23-amino-4',23-dideoxymycaminosyl tylonolide. Synthesis and antibacterial activity.

23-Amino-4',23-dideoxymycaminosyl tylonolide diethyl acetal (5) has been prepared from 4',23-dideoxy-23-iodomycaminosyl tylonolide diethyl acetal (3) by treatment with sodium azide followed by selective reduction of the resulting azide (4). 23-Acylamino-23-deoxy (6 approximately 8) and 23-deoxy-23-urethane-type compounds (12 approximately 15) were further prepared. Treatment of the 23-alkylamino-4',23-dideoxymycaminosyl tylonolides (9, 10) with chloroformates gave 23-N-alkyl-23-deoxy-23-urethane-type compounds (16 approximately 21, 29, 30). 23-N-Alkyl-23-deoxy-23-(2-hydroxyethalamino and 2-methoxyethylamino)-4',23-dideoxymycaminosyl tylonolides (22 approximately 25, 27, 28) were prepared from 3 and the corresponding amines. Antibacterial activities and toxicities (for 23 and 27) of these compounds are described. toxicities (for 23 and 27) of these compounds are described.

Bacteria↗
PubMed1985

Repair of potentially lethal and sublethal radiation damage in x-irradiated ascites tumor cells.

The ability of cells to repair cellular radiation damage during the growth of TMT-3 ascites tumor and the effect of host reaction on the repair ability were examined by using an in vitro assay of cell clonogenicity after in situ irradiation of tumor cells. In single-dose experiments, the repair of potentially lethal radiation damage (PLD) was observed in stationary phase cells (12-day tumor) of the unirradiated host, but not in exponential phase cells (3-day tumor) of the unirradiated host animals. However, if previously irradiated host animals were used, even the exponentially growing tumor cells showed repair of PLD. In two-dose experiments, the ability to repair sublethal radiation damage (SLD) in exponential phase tumor cells was less than that of stationary phase cells in the unirradiated host. In the pre-irradiated host, the extent of the repair in exponential phase cells was somewhat enhanced. These results suggest that irradiation of host animals might suppress a factor that inhibits repair, resulting in enhancement of the repair capability of tumor cells.

Animals↗