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Biomedical subjects

H Ochiai

Publications and source records attributed to H Ochiai.

At least 235 records · Page 13Linked to original sources
PubMed1985

Analysis of N-linked oligosaccharide chains of glycoproteins on nitrocellulose sheets using lectin-peroxidase reagents.

A rapid and convenient method was established for analysis of the N-linked carbohydrate chains of glycoproteins on nitrocellulose sheets. Proteins were separated by polyacrylamide gel electrophoresis, transferred to nitrocellulose sheets, reacted with peroxidase-coupled lectins, and detected by color development of the enzyme reaction. Four glycoproteins having N-linked oligosaccharide chains were used as test materials: Taka-amylase A (which has a high-mannose-type chain), ovalbumin (high-mannose-type chains and hybrid-type chains), transferrin (biantennary chains of complex type), and fetuin (triantennary chains of complex type and O-linked-type chains). Concanavalin A interacted with Taka-amylase A, transferrin, and ovalbumin but barely interacted with fetuin. After treatment of the glycoproteins on a nitrocellulose sheet with endo-beta-N-acetylglucosaminidase H, transferrin reacted with concanavalin A but Taka-amylase A and ovalbumin did not. Wheat germ agglutinin interacted with Taka-amylase A but not ovalbumin; therefore, they were distinguishable from each other. Fetuin and transferrin were detected by Ricinus communis agglutinin or peanut agglutinin after removal of sialic acid by treatment with neuraminidase or by weak-acid hydrolysis. Erythroagglutinating Phaseolus vulgaris agglutinin detected fetuin and transferrin. Thus, the combined use of these procedures distinguished the four different types of N-linked glycoproteins. This method was also applied to the analysis of membrane glycoproteins from sheep red blood cells. The terminally positioned sugars of sialic acid, alpha-fucose, alpha-galactose, and alpha-N-acetylgalactosamine were also detected with lectins from Limulus polyphemus, Lotus tetragonolobus, Maclura pomifera, and Dolichos biflorus, respectively.

Binding Sites↗
PubMed1985

Coronary artery spasm immediately after percutaneous transluminal coronary recanalization.

A 55-year-old man developed acute inferior myocardial infarction. A coronary arteriogram performed within two hours later showed complete occlusion of the right coronary artery, which was not resolved by two doses of 300 micrograms of intracoronary nitroglycerin. It was recanalized with 50% luminal diameter narrowing after 600,000 units of urokinase. Immediately after this thrombolytic therapy, the patient experienced chest pain, and the coronary artery became completely obstructed again. The pain was promptly relieved by 300 micrograms of intracoronary nitroglycerin, with disappearance of the obstruction. The observations during the procedure indicate that coronary artery spasm can occur after successful thrombolytic therapy on an occluded artery, inducing postinfarction angina, and might culminate in a second complete occlusion after percutaneous transluminal coronary recanalization.

Angioplasty, Balloon↗
PubMed1985

[Fundamental and clinical studies on aspoxicillin in the field of pediatrics].

Fundamental and clinical studies were performed with aspoxicillin (ASPC), a new developed injectable broad penicillin, in pediatric infectious diseases, and the following results were obtained. Pharmacokinetics ASPC was administered to 2 cases at a dose of 20 mg/kg by one shot intravenous injection. The mean half-life (T 1/2) was 1.17 hours. The mean urinary excretion rate was 58.4% during 6 hours after ASPC treatment. In 3 cases of intravenous drip infusion with a period of 1 hour at a dose of 10 mg/kg (2 cases) and 20 mg/kg (1 case), the half-lives (T 1/2) were 1.7 hours, 3.5 hours and 1.0 hour, respectively. The urinary recovery rate during 6 hours after administration was 57.7%, 32.6% and 42.7%, respectively. At only one case treated with 10 mg/kg intravenous drip infusion, the half-life was prolonged and urinary excretion rate was lower than other 2 cases. Clinical study ASPC was administered 50-80 mg/kg/day for 4-8 days to 22 children comprising 6 tonsillitis, 2 bronchitis, 6 pneumonia and 8 urinary tract infections. Clinical efficacy was excellent in 13 cases, good in 8 cases and fair in 1 case, the total cure rate was 95%. As for the clinical response classified by diagnosis, the each efficacy rate of tonsillitis, bronchitis and pneumonia was 100%, and that of urinary tract infection was 87.5%. Clinical side effect and abnormal laboratory findings were not observed in any cases. From the above results, it was concluded that ASPC was one of the useful secure drug for treatment of infections in pediatric field.

Adolescent↗
PubMed1984

Ultrastructural and morphometric studies on the neurohypophysial nerve terminals of the rat following administration of angiotensin II.

The neurohypophysial nerve terminals of rats were studied by electron microscopy and morphometric analysis of vesicles and vacuoles labeled with horseradish peroxidase (HRP) after intraventricular injection of angiotensin II (AII). Exocytotic figures of neurosecretory granules from the nerve terminals were observed. The electron-dense materials resembling the contents of neurosecretory granules were occasionally observed in the extracellular spaces. A highly significant increase in the relative volume occupied by HRP-impregnated structures in the terminals occurred after administration of 500 ng AII. These findings provide morphological evidence for the stimulation of neurohypophysial hormone secretion following administration of 500 ng AII.

Angiotensin II↗
PubMed1984

[Study on human pituitary gonadotropin synthesis and release in amenorrhea and anovulation by LH-RH two step test].

The pituitary gonadotropin response of synthesis and release to two step stimulation at a 60 minute interval with 100 micrograms of luteinizing hormone-releasing hormone (LH-RH) was studied by radioimmunoassay of hLH and hFSH in the normal menstrual cycle, amenorrhea and anovulation. The definition of delta 1 and delta 2 was as follows: delta 1 = 30 (or 60) min. value-0 min. value. delta 2 = 90 (or 120, 180) min. value-60 min. value. delta 1, delta 2 ratio = delta 2/delta 1. Serum mean levels of hLH in follicular and luteal phase increased after the first injection of LH-RH. The second injection of the hormone induced an increase to above the first peak, indicating the priming effect of the first LH-RH on the second peak. The first peak is presumed to be the pituitary gonadotropin release due to the first injection of LH-RH, and the second peak can be composed in part of hLH newly synthesized by the first LH-RH stimulation. The response of hLH in the ovulatory phase increased after the first administration, but showed no significant peak after the second. The LH-RH two step test in normoestrogenic and PCO type amenorrhea produced two peaks of the mean levels of hLH. In ovarian anovulation, an hLH value higher than the others was detected before the first LH-RH stimulation. The first injection caused an increase in serum hLH but after the second there is no significant peak. In contrast, serum hLH and hFSH values were lower than in the normal menstrual cycle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Ultrastructural relationship between monoamine- and TRH-containing axons in the rat median eminence as revealed by combined autoradiography and immunocytochemistry in the same tissue section.

The correlation of dopamine (DA)-, noradrenaline (NA)- or serotonin (5HT)-containing neurons and thyrotropin releasing hormone (TRH)-containing neurons in the median eminence of the rat, as well as the coexistence of monoamines (MA) and TRH in the neurons, were examined by subjecting ultrathin sections to a technique that combines MA autoradiography and TRH immunocytochemistry. The distribution and localization of silver grains after 3H-MA injection were examined by application of circle analysis on the autoradiographs. TRH-like immunoreactive nerve terminals containing the immunoreactive dense granular vesicles were found to have an intimate contact with monoaminergic terminals labeled after 3H-DA, 3H-NA or 3H-5HT infusion in the vicinity of the primary portal capillaries in the median eminence. Synapses between TRH-like immunoreactive axons and MA axons labeled with silver grains, however, have not been observed to date. Findings suggesting the coexistence of TRH and MA in the same nerve terminals or the uptake of 3H-MA into TRH-like immunoreactive nerve terminals, where silver grains after 3H-MA injection were concurrently localized in TRH-like immunoreactive nerve terminals, were rarely observed in the median eminence. Percentages of the nerve terminals containing both immunoreactive granular vesicles and silver grains after 3H-MA injection to total nerve terminals labeled after 3H-MA infusion silver grains were equally very low in 3H-DA, 3H-NA or 3H-5HT, amounting to less than 6.1%.

Animals↗
PubMed1982

Monoclonal antibodies against contact sites A of Dictyostelium discoideum: detection of modifications of the glycoprotein in tunicamycin-treated cells.

Tunicamycin acts on cell aggregation in Dictyostelium discoideum by changing cell movement and by inhibiting the EDTA-stable type of intercellular adhesion. Tunicamycin-treated cells show unco-ordinated pseudopodial activity such that pseudopods are simultaneously extended from all parts of the cell surface, and the cells are unable to move in straight paths. Concurrent with the inhibition of formation of EDTA-stable contacts, N-glycosylation of a glycoprotein specific for aggregation-competent cells is inhibited. This glycoprotein, previously called contact site A, has an apparent mol. wt. of 80 kilodaltons (kd). In membranes of tunicamycin-treated cells, two components are detected that react with certain monoclonal antibodies against contact sites A: one component of 66 kd, the other of 53 kd apparent mol. wt. Another group of monoclonal antibodies reacts only with the 80-kd glycoprotein and the 66-kd component. These results are in accord with the assumption that the glycoprotein carries two carbohydrate chains, and that the antibodies differ in their requirement for glycosylation of the antigen. Despite the coincidence between blockage of EDTA-stable cell adhesion and inhibited glycosylation of contact sites A, direct involvement of the carbohydrate moieties of this glycoprotein in intercellular adhesion seems questionable. EDTA-stable cell adhesion has not been blocked by Fab fragments from antibodies that specifically react with the glycosylated protein.

Journal Article↗
PubMed1982

Stage-specific antigens reacting with monoclonal antibodies against contact site A, a cell-surface glycoprotein of Dictyostelium discoideum.

Monoclonal antibodies against a glycoprotein presumably involved in adhesion of aggregating Dictyostelium discoideum cells have been used for labeling of the antigen at the cell surface. The antigen is distributed over the whole surface of the cells, apparently in form of small clusters. The antigen appears concomitantly with the acquisition of EDTA-stable adhesiveness typical of aggregation competent cells. In contrast, discoidin I, a lectin whose accumulation during development parallels EDTA-stable adhesiveness in another strain (NC-4), is present in nearly the same amounts of growth phase and aggregating cells of AX2-214, the strain used by use. Thus, no correlation exists in this strain between the expression of discoidin I and the development of cell adhesiveness. The 80 kilodalton glycoprotein typical of aggregation competent cells has been purified by affinity chromatography on a monoclonal antibody column. The purified antigen absorbs adhesion-blocking Fab from rabbits. Another antigen strongly reacting with the same monoclonal antibodies has an apparent molecular weight of 106 000 and is not detectable before slugs are formed.

Animals↗