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Biomedical subjects

T Oda

Publications and source records attributed to T Oda.

At least 937 records · Page 52Linked to original sources
PubMed1976

Alkaline phosphatase isoenzymes in intestinal metaplasia and carcinoma of the stomach.

The enzymological and immunological properties of alkaline phosphatase (ALP) isoenzymes in intestinal metaplasia and gastric carcinoma tissues were compared with those of purified human intestinal, placental, and hepatic ALP's to speculate the gene expression of gastric cancer cells. The results were as follows: Intestinal metaplasia was found in 21 of 23 cases (91%) of gastric cancer, whereas normal gastric mucosa had no ALP activity. ALP extracted from the mucosa of intestinal metaplasia was identical with intestinal ALP as to enzymological and immunological properties. ALP obtained from gastric carcinoma tissues of 23 patients was separated into 3 bands (ALPa, ALPb, and ALPc) by polyacrylamide-gel disc electrophoresis. Ten cases showed ALPa only, 4 cases showed ALPa and ALPb, 5 cases showed ALPa and ALPc, and the other 4 cases showed ALPa, ALPb, ALPc, respectively. It was concluded that ALPa was similar in its enzymological and immunological properties to hepatic-type ALP, ALPb was similar to placental-type ALP, and ALPc was similar to intestinal-type ALP, ALPb probably originates from the cancer cell itself. As for the other enzymes, ALPa and ALPc, further investigation should be made to determine whether they come from the cancer cell itself or not.

Alkaline Phosphatase↗
PubMed1975

Subfractionation of rat liver plasma membrane. Uneven distribution of plasma membrane-bound enzymes on the liver cell surface.

Plasma membranes were isolated from rat liver mainly under isotonic conditions. As marker enzymes for the plasma membrane, 5'-nucleotidase and (Na+ + K+)-ATPase were used. The yield of plasma membrane was 0.6-0.9 mg protein per g wet weight of liver. The recovery of 5'-nucleotidase and (Na+ +K+)-ATPase activity was 18 and 48% of the total activity of the whole-liver homogenate, respectively. Judged from the activity of glucose-6-phosphatase and succinate dehydrogenase in the plasma membrane, and from the electron microscopic observation of it, the contamination by microsomes and mitochondria was very low. A further homogenization of the plasma membrane yielded two fractions, the light and heavy fractions, in a discontinuous sucrose gradient centrifugation. The light fraction showed higher specific activities of 5'-nucleotidase, alkaline phosphatase, (Na+ +K+)-ATPase and Mg2+-ATPase, whereas the heavy one showed a higher specific activity of adenylate cyclase. Ligation of the bile duct for 48 h decreased the specific activities of (Na2+ +K+)-ATPase and Mg2+-ATPase in the light fraction, whereas it had no significant influence on the activities of these enzymes in the heavy fraction. The specific activity of alkaline phosphate was elevated in both fractions by the obstruction of the bile flow. Electron microscopy on sections of the plasma membrane subfractions showed that the light fraction consisted of vesicles of various sizes and that the heavy fractions contained membrane sheets and paired membrane strips connected by junctional complexes, as well as vesicles. The origin of these two fractions is discussed and it is suggested that the light fraction was derived from the bile front of the liver cell surface and the heavy one contained the blood front and the lateral surface of it.

Adenosine Triphosphatases↗
PubMed1975

Synthesis of alpha-fetoprotein by rat ascites hepatoma cells.

AH-66 rat ascites hepatoma cells incorporated [14C]leucine into the AFP fraction. In a cell-free system, hepatoma ribosomes were found to be active in AFP synthesis whereas the supernatant fraction from hepatoma had no specific effect on AFP production. The amount of [14C]leucine incorporated in AFP by membrane-bound polysomes was 20 to 90 times higher than that by free polysomes, suggesting that AFP is mainly synthesized on membrane-bound polysomes. DBcAMP inhibited the growth of hepatoma cells. However, the incorporation of [14C]leucine into the AFP fraction as well as into total proteins was stimulated by DBcAMP.

Animals↗
PubMed1975

Demonstration of C-peptide immunoreactivity in various body fluids and clinical evaluation of the determination of urinary C-peptide immunoreactivity.

C-peptide immunoreactivity (CPR) was demonstrated not only in plasma, but in urine, ascites, cerebrospinal fluid and pleural effusion. The concentration of CPR in urine was very high compared with that in the other body fluids and was easy to assay. CPR in urine after glucose administration or tolbutamide injection increased parallel to the change of CPR in plasma and also to that of IRI in normals or diabetics without renal disturbances. The result suggest that the determination of CPR in urine before and after stimulation of insulin secretion could serve as a simple indicator of insulin secretory function of pancreas.

Adult↗
PubMed1975

Effect of glucose on adenosine 3', 5'-monophosphate levels in rat pancreatic islets.

Time course of the changes in insulin release and cyclic AMP levels in isolated rat islets incubated in media containing 5 or 16.7 mM of glucose were followed. The higher glucose concentration caused a slight but significant increase of cyclic AMP levels after 10 min incubation, but not 5 min incubation, whereas the stimulation of insulin release by 16.7 mM of glucose was apparent in both incubation times. Theophylline increased cyclic AMP levels markedly but did not stimulate insulin release when the glucose concentration was 5 mM. A slight augmentation by theophylline of insulin release was observed in the incubation medium containing 16.7 mM glucose. All these findings suggest that the elevation of cyclic AMP in islets may not play a role for the initiation of the insulin release induced by glucose, though it may act to modulate the glucose effect.

Animals↗