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Biomedical subjects

S Hase

Publications and source records attributed to S Hase.

At least 127 records · Page 7Linked to original sources

Studies on the sugar chains of interferon-gamma from human peripheral-blood lymphocytes.

Sugar chains of interferon-gamma (IFN-gamma) from human peripheral-blood lymphocytes (PBL) were liberated by hydrazinolysis. After N-acetylation, the reducing end residues of the sugar chains were tagged with 2-aminopyridine and the pyridylamino (PA-) derivatives were purified by gel filtration and reversed-phase HPLC. Five major PA-sugar chains were obtained. The structure of each PA-sugar chain was estimated by comparing its elution times on anion exchange, reversed-phase, and size-fractionation HPLC with those of PA-sugar chains of IFN-gamma from the human myelomonocyte cell line HBL-38 (Yamamoto, S. et al. (1989) J. Biochem. 105, 547-555) as standards, and also by comparison of their elution times after partial desialylation. The results showed that IFN-gamma (PBL) contained mono- and disialo-biantennary structures with 0 or 1 mol of fucose residue, as found for IFN-gamma (HBL-38), but the N-acetylneuraminyl alpha 2-6 linkage was dominant in IFN-gamma (PBL), unlike IFN-gamma (HBL-38), which contains both N-acetylneuraminyl alpha 2-3 and alpha 2-6 linkages.

Carbohydrates↗

Effects of prednisolone and human epidermal growth factor on angiogenesis in granulation tissue of gastric ulcer induced by acetic acid.

In an attempt to elucidate the role of granulation vessels in the healing of gastric ulcer, healing and angiogenesis in granulation tissue of acetic acid ulcers were studied in rats. In addition, the effects of prednisolone and synthetic human epidermal growth factor (EGF) on angiogenesis and ulcer healing were investigated. The newly formed granulation vessels in the ulcer base were measured by means of a carmine dye infusion method. Prednisolone, administered subcutaneously at 40 mg/kg/day, significantly decreased angiogenesis in the ulcer base on the 10th day after ulcer production, and on the 30th day ulcer healing was found to be significantly delayed. In contrast, angiogenesis was significantly increased, and ulcer healing was enhanced by intragastric administration of 100 micrograms/kg/day of EGF. With combined administration of prednisolone and EGF, angiogenesis was significantly increased compared to that observed with prednisolone treatment alone. The authors conclude that suppression of angiogenesis by prednisolone is a delaying factor in gastric ulcer healing and that exogenous EGF promotes ulcer healing, partly through restoration of angiogenesis.

Acetates↗

Fluctuation of the mucosal hydroxyproline content in compound 48/80-induced gastric lesions in rats.

Extensive gastric mucosal lesions were observed after i.p. administration of compound 48/80 (0.75 mg/kg) for 3 days to rats. The mucosal hydroxyproline content was significantly increased at 4 h after the last injection of compound 48/80 and subsequently decreased as the lesions were healed. Treatment with cimetidine (50 mg/kg, i.p.) did not prevent compound 48/80-induced gastric lesions. The increase in the mucosal hydroxyproline content was significantly reduced by treatment with cimetidine. This fact suggested that cimetidine might have an inhibitory effect on the regeneration of connective tissue.

Animals↗

The role of prostaglandin D2 in the genesis of indomethacin-induced gastric lesions in rats.

Four kinds of prostaglandins (PGs), 6-keto-PGF1 alpha, PGF2 alpha, PGE2 and PGD2, in rat gastric mucosa were decreased at 1 or 6 h after oral administration of indomethacin (2 or 12 mg/kg). With 2 mg/kg of indomethacin, the PG levels had slightly recovered 6 h later. Gastric lesions were observed 6 h after administration of indomethacin (12 mg/kg), but not with 2 mg/kg. Omeprazole (20 mg/kg, i.p.) prevented ulcer formation caused by indomethacin, without improvement of the reduced gastric mucosal PG levels. PGD2 (0.5 mg/kg, p.o.) reduced indomethacin-induced gastric lesions and considerable amounts of PGD2 existed in the gastric mucosa. We conclude that H+ is a determining factor in the genesis of indomethacin-induced gastric lesions and persistent decreases in tissue PG levels also participate in ulcer formation.

Animals↗

Endoscopic ultrasonography of gastric myogenic tumor. A comparative study between histology and ultrasonography.

In order to find a correspondence between the sonographic findings of endoscopic ultrasonography (EUS) and the histology of gastric myogenic tumors, histologic specimens (24 cases) and preoperative ultrasonograms (10 cases) were examined. Histologically, the incidence of necrosis within the tumor was more frequent and the area of necrosis was larger in leiomyosarcoma than in leiomyoma. Liquefaction necrosis was observed only in leiomyosarcoma. By EUS, myogenic tumors originating from the proper muscle were delineated as clearly demarcated hypoechoic tumors arising from the fourth layer. Irregularly shaped sonolucent areas within the tumor corresponded to liquefaction necrosis. Thus, sonolucent areas may be indicative of leiomyosarcoma.

Female↗

[A study on gastric and small intestinal aberrant pancreas by endoscopic ultrasonography--with special reference to comparison with histological appearance].

To obtain characteristic findings of gastrointestinal aberrant pancreas by endoscopic ultrasonography (EUS), we made comparison between endoscopic ultrasonograms and histological findings in 5 cases (6 lesions) of resected gastric aberrant pancreas and 1 case (1 lesion) of small intestinal one. By EUS, gastrointestinal aberrant pancreases were delineated as hypoechoic masses with blurred boundary containing fine scattered hyperechoic spots, and also there were thickening of the fourth layer below the mass. Occasionally, there were some duct-like structures within the mass or marginal lobular structures. Moreover, the ultrasonographic patterns of aberrant pancreases were classified into 2 types, that is, M and S types. On histological examination, M type cases, in which the mass attached to the thickened fourth layer by EUS, were corresponded to acinar type and the pancreatic acinar cells penetrated into the proper muscle layer of the gastrointestinal wall, whereas S type cases, in which the mass was separated from the fourth layer, to ductal or mixed type. We conclude, therefore, that not only making the accurate diagnosis of aberrant pancreas but also drawing an inference of its histological type might become possible by EUS.

Adolescent↗

Analysis of tissue glycoprotein sugar chains by two-dimensional high-performance liquid chromatographic mapping.

Excellent separation of 45 pyridylamino derivatives of oligosaccharides were achieved by the two-dimensional combination of reversed-phase and size-fractionation high-performance liquid chromatography. The sugar chains of brain glycoproteins were derivatized into a mixture of pyridylamino-oligosaccharides from lyophilized brain tissue without any purification steps, and they were well separated by the system used. The pattern obtained was reproducible, and inter-individual variation was negligible. This finding demonstrated the possibility that this method could be applied to the detection of differences in the structure of glycoprotein sugar chains in crude preparations.

Animals↗

The effect of a new gastric proton pump inhibitor on serotonin-induced gastric mucosal lesions in rats.

The anti-ulcer effect of NC-1300, a new proton pump inhibitor, and its effect on gastric mucosal blood flow were studied in rats. Acute gastric mucosal lesions were induced by the subcutaneous administration of serotonin, 20 mg/kg. Using the electrolytically generated hydrogen gas clearance technique, it was determined that such gastric ulceration resulted mainly from a decrease in gastric mucosal blood flow. These lesions could be inhibited to a statistically significant extent by the intravenous administration of NC-1300, 20 mg/kg, which markedly inhibited gastric acid secretion. However, the serotonin-induced decrease in gastric mucosal blood flow could not be prevented by pretreatment with 20 mg/kg of NC-1300. It was concluded that protection against serotonin-induced gastric ulceration can be achieved by markedly inhibiting gastric acid secretion.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Pyridylamino sugar chain as an acceptor for galactosyltransferase.

Pyridylamino asialo-agalacto-biantennary sugar chain (PA-acceptor), prepared from human alpha 1-acid glycoprotein, was incubated with bovine milk galactosyltransferase. Transfer of galactose residues to PA-acceptor was detected by HPLC analysis, and thus PA-acceptor was shown to be useful for galactosyltransferase assay. Moreover, three species of products, i.e. PA-acceptor monogalactosylated on the Man alpha 1-3 branch of the trimannosyl core, PA-acceptor monogalactosylated on the Man alpha 1-6 branch, and digalactosylated PA-acceptor, were separated and identified by reversed-phase HPLC, so we could simultaneously determine the branch specificity (the ratio of galactosylation on Man alpha 1-3 branch to that on Man alpha 1-6 branch) of the galactosyltransferase. We fractionated the bovine milk galactosyltransferase on a DEAE-5PW column and confirmed that there was a heterogeneity in this enzyme preparation. Each fraction was assayed for acceptor specificity (the ratio of the activity towards N-acetylglucosamine to that towards PA-acceptor) and branch specificity using the PA-acceptor. However, we could not detect differences in the specificities among the fractions. In addition, we found that alpha-lactalbumin stimulated the galactosyltransferase activity towards PA-acceptor.

Aminopyridines↗

Structures of the sugar chains of recombinant human granulocyte-colony-stimulating factor produced by Chinese hamster ovary cells.

Recombinant human granulocyte-colony-stimulating factor (G-CSF) was purified from Chinese hamster ovary cells transfected with human G-CSF cDNA. The recombinant human G-CSF was treated with alkaline borohydride and the oligosaccharide-alditols liberated were fractioned by gel filtration on a Bio-Gel P-4 column, followed by high-performance liquid chromatography by use of a strong anion exchanger. Two oligosaccharide-alditols were obtained and their structures were identified by component analysis and 500-MHz 1H-NMR spectroscopy. The structures of the sugar chains were NeuAc alpha 2-3Gal beta 1-3GalNAcol and NeuAc alpha 2-3Gal beta 1-3(NeuAc alpha 2-6)GalNAcol.

Animals↗

Structures of sugar chains of ricin D.

The toxic lectin, ricin D, contains mannose, fucose, xylose, and N-acetylglucosamine as sugar components. Sugar chains are linked to Asn-10 of the A-chain, and to Asn-95 and Asn-135 of the B-chain (Funatsu, G. et al. (1978) Agric. Biol. Chem. 42, 501-503; Araki, T. & Funatsu, G. (1985) FEBS Lett. 191, 121-124). Asparagine-linked sugar chains of each glycopeptide from ricin D were liberated by hydrazinolysis followed by N-acetylation. The reducing end residues of the sugar chains were coupled with 2-aminopyridine and the pyridylamino (PA-) derivatives obtained were purified by gel-filtration and reversed-phase HPLC. Eight main PA-sugar chains were obtained from three glycopeptides and the structures of these sugar chains were determined by component analysis, stepwise exoglycosidase digestions, partial acetolysis, and 500 MHz 1H-NMR spectroscopy. The results show that oligomannose type sugar chains (Man6-7GlcNAc2) are linked to Asn-95; Man5-7 GlcNAc2 and M4X (structure, see below) to Asn-135 of the B-chain, and M3FX and M3X to Asn-10 of the A-chain. (Formula: see text).

Acetylation↗

Structures of sugar chains of a p-nitrophenyl acetate-hydrolyzing esterase from the microsomes of rat liver.

The structures of sugar chains of a p-nitrophenyl acetate-hydrolyzing esterase from the microsomes of rat liver were established. The enzyme contained mannose and glucosamine as sugar components. Asparagine-linked sugar chains of the esterase were liberated by hydrazinolysis. After N-acetylation of the hydrazinolysate, the reducing ends of the sugar chains were coupled with 2-aminopyridine. Fluorescent pyridylamino (PA-) derivatives of sugar chains thus obtained were purified by gel filtration and reversed-phase HPLC. Eleven PA-sugar chains were obtained. The structures of the PA-sugar chains were first identified by HPLC using two series of separation systems by which 11 PA-oligomannose-type sugar chains with known structures could be separated. Further elucidation of the structures of each PA-sugar chain was performed by exoglycosidase digestions and partial acetolysis. The structures of two of the PA-sugar chains were further confirmed by 500 mHz 1H-NMR spectroscopy.

Animals↗

A new trisaccharide sugar chain linked to a serine residue in bovine blood coagulation factors VII and IX.

A new trisaccharide sugar chain was identified in bovine blood coagulation factors VII and IX. A pentapeptide isolated from factor VII contained Ser-52, which could not be identified with a gas-phase sequencer, suggesting an unknown substituent on the serine residue (Takeya, H. et al. (1988) J. Biol. Chem., in press). The same results were obtained for a pentapeptide containing Ser-53 of factor IX. Component sugar analysis revealed that the peptide contained 1 mol of glucose and 2 mol of xylose. This sugar component was also confirmed by high-resolution fast atom bombardment mass spectrometric analysis of the pentapeptide. The trisaccharide was released from the peptides by means of beta-elimination reaction and its reducing end was coupled with 2-aminopyridine. The fluorescent pyridylamino (PA-) derivative of the trisaccharide was purified by gel-filtration and reversed-phase HPLC. The sugar composition of the PA-trisaccharide was found to be 2 mol of xylose and 1 mol of PA-glucose. These results indicate the existence of a (Xyl2)Glc-Ser structure in factors VII and IX.

Amino Acids↗

Chronic alcohol abuse leads to gastric atrophy and decreased gastric secretory capacity: a histological and physiological study.

We performed morphological and physiological studies in 43 male patients with alcohol dependence (ALC) who had no other apparent lesions in the upper gastrointestinal tract except atrophic and erosive gastritis. A gastric secretory study in which tetragastrin was used as the stimulant revealed that acid and pepsin secretion was less in ALC patients than in hospital controls (p less than 0.001). Endoscopic biopsy specimens of gastric mucosa from ALC patients revealed that atrophy of the gastric mucosa advanced with age. A strong negative correlation was also found between the secretory capacity of the stomach and the degree of atrophy. Possibly, the interval between recurrent episodes of acute mucosal damage was too short to allow complete healing of mucosal lesions. Failure to regenerate denuded epithelium would result in a decrease in the gastric secretory area. Thus, chronic alcohol abuse seems to be an etiological factor in atrophic gastritis.

Adult↗

Fluorescence method for the structural analysis of oligomannose-type sugar chains by partial acetolysis.

Fluorescence labeling was used in the analysis of partial acetolysis products of oligomannose-type sugar chains with five to nine mannose residues. The principle of the method was the pyridylamination of fragments obtained by the partial acetolysis of pyridylamino sugar chains and the identification of the fragments with an HPLC apparatus equipped with a fluorescence spectrophotometer. The method was tested by analysis of eight oligomannose-type sugar chains with known chemical structures and was found to be effective for analysis of branching structures with samples of 0.5 nmol.

Carbohydrate Sequence↗

Effect of omeprazole on gastric acid secretion in rat: evaluation of dose, duration of effect, and route of administration.

The effect of omeprazole on gastric acid output was studied in rats before and during stimulation by continuous administration of tetragastrin at 50 micrograms/kg-hour. From 5 to 20 mg/kg of omeprazole was given to animals intraperitoneally, perorally and intravenously from 2 to 24 hours before the gastric secretory study was started, and the respective effects on acid secretion were compared. In each administration group, 20 mg/kg of omeprazole was the most potent among the groups receiving 5, 10 or 20 mg/kg, when the drug was given 2 hours before the study. There were statistically significant differences between the control group given tetragastrin only and each of the groups given 20 mg/kg of omeprazole perorally, intraperitoneally and intravenously. There was no significant difference among the groups given 20 mg/kg of omeprazole intraperitoneally, intravenously and perorally. The effect of 20 mg/kg of omeprazole continued at least 24 hours after the agent was administered perorally.

Administration, Oral↗