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Biomedical subjects

S Hase

Publications and source records attributed to S Hase.

At least 109 records · Page 6Linked to original sources
PubMed1991

Studies on the substrate specificity of neutral alpha-mannosidase purified from Japanese quail oviduct by using sugar chains from glycoproteins.

The substrate specificity of neutral alpha-mannosidase purified from Japanese quail oviduct [Oku, H., Hase, S., & Ikenaka, T. (1991) J. Biochem. 110, 29-34] was analyzed by using 21 oligomannose-type sugar chains. The enzyme activated with Co2+ hydrolyzed the Man alpha 1-3 and Man alpha 1-6 bonds from the non-reducing termini of Man alpha 1-6(Man alpha 1-3)Man alpha 1-6(Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4GlcNAc (M5A), but hardly hydrolyzed the Man alpha 1-2 bonds of Man9GlcNAc2. The hydrolysis rate decreased as the reducing end of substrates became more bulky: the hydrolysis rate for the pyridylamino (PA) derivative of M5A as to that of M5A was 0.8; the values for M5A-Asn and Taka-amylase A having a M5A sugar chain being 0.5 and 0.04, respectively. The end product was Man beta 1-4GlcNAc2. For the substrates with the GlcNAc structure at their reducing ends (Man5GlcNAc, Man6GlcNAc and Man9GlcNAc), the hydrolysis rate was remarkably increased: Man5GlcNAc was hydrolyzed 16 times faster than M5A, and Man2GlcNAc 40 times faster than Man9GlcNAc2. The enzyme did not hydrolyze Man alpha 1-2 residue(s) linked to Man alpha 1-3Man beta 1-4GlcNAc. The end products were as follows: [formula; see text] These results suggest that oligomannose-type sugar chains with the GlcNAc structure at their reducing ends seem to be native substrates for neutral alpha-mannosidase and the enzyme seems to hydrolyze endo-beta-N-acetylgucosaminidase digests of oligomannose-type sugar chains in the cytosol.

Animals↗
PubMed1991

Serotonin-induced decrease of duodenal mucosal blood flow plus acid load produces duodenal mucosal lesion in rats.

To clarify the role of duodenal mucosal blood flow in the genesis of duodenal mucosal lesions, a single dose of serotonin, 20 mg/kg, was administered subcutaneously to rats. Serotonin significantly decreased both the duodenal mucosal blood flow and the output of gastric acid and pepsin. However, mild duodenal erosions were observed in only 2 of the 9 rats receiving that agent. The repeated intragastric administration of 1 ml of 0.1 N HCl hourly for 6 h failed to induce duodenal mucosal lesions. On the other hand, the administration of both serotonin and repeated doses of HCl produced marked duodenal mucosal lesions in all rats. It is concluded, therefore, that one of the factors responsible for the genesis of duodenal mucosal lesions is a decrease of duodenal mucosal blood flow combined with an acid load against the duodenal mucosa.

Animals↗
PubMed1991

A new method for evaluating gastric ulcer healing by endoscopic ultrasonography.

We observed the quantitative estimation of the transmural changes associated with gastric ulcer healing by using endoscopic ultrasonography (EUS). It was possible to diagnose the depth of ulcer by EUS. Forty-eight patients were divided into three treatment groups. Group A (n = 16) was treated with 800 mg cimetidine daily, group B (n = 22) with 20 mg omeprazole daily, and group C (n = 10) with 400 mg cimetidine + 300 mg gefarnate daily. EUS was performed before and after 2, 4, and 8 weeks of treatment. The groups were compared from the viewpoints of endoscopic findings and contraction rate of the length and the cross-sectional area of the ulcer in EUS pictures. The best healing of both the endoscopic and EUS findings was seen in group B. By estimating the changes inside the ulcer, EUS may provide useful information for choice of anti-ulcer agents.

Anti-Ulcer Agents↗
PubMed1991

Evaluation of acetic acid-induced gastric ulcers in rats by scanning acoustic microscopy.

To clarify the mechanism of gastric ulcer recurrence, we studied acetic acid-induced gastric ulcers. The healing of these gastric ulcers was then studied for 4-21 weeks after the injection. Forty-eight ulcers were examined by macroscopic observation and scanning acoustic microscopy (SAM) and by histologic study of the ulcers. SAM has a higher radio frequency and provides more detailed information about the gastric wall than endoscopic ultrasonography (EUS). Thirteen healed and 35 non-healed gastric ulcers were observed by macroscopic observation over 4-21 weeks. SAM enabled us to observe the normal gastric wall of the rat in five different layers. The SAM echo patterns of the healed ulcers were all one pattern. On the other hand, we were able to classify the echo patterns of the non-healed ulcers into two different patterns; one pattern consisted of a high-echogenic region in the first and second layers with an underlying relatively high echogenic region in a horizontal pattern. The other pattern showed a poorly defined and spotted low-echogenic region in the first and second layers which fanned out toward the fifth layer. However, these two different ulcers could not be distinguished macroscopically. Histologic findings supported the results of the SAM study which showed one pattern in healed ulcers and two patterns in non-healed ulcers. In the non-healed ulcers the two different patterns may be ascribed to the proliferation of collagen fibers. SAM makes it possible to image the proliferation of collagen fibers and identify the two different types with an accuracy of 97%.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1991

Effect of cimetidine on the mucosal hydroxyproline content of rat gastric lesions induced by compound 48/80.

Extensive gastric mucosal lesions developed in rats after the administration of compound 48/80 at a dose of 0.75 mg/kg daily for 3 days. The hydroxyproline content of gastric mucosa was significantly increased 4 h after the last injection of compound 48/80, and subsequently decreased as the lesions healed. Treatment with cimetidine (CAS 51481-61-9) at a dose of 50 mg/kg (twice a day for 3 days) did not affect either the development or the healing of the compound 48/80-induced gastric lesions. However, the increase in mucosal hydroxyproline content was significantly reduced by treatment with cimetidine. This fact suggests that cimetidine might have an inhibitory effect on the regeneration of collagen in gastric mucosa.

Animals↗
PubMed1991

[Examination of endoscopical ultrasonography (EUS) on carcinoid tumors of gastrointestinal tract].

In order to clarify the usefulness of EUS in the diagnosis of gastrointestinal carcinoid tumor, we examined 15 patients, who had carcinoid tumors of gastrointestinal tract (stomach: 5, duodenum: 2, rectum: 8), on the diagnosis in quality and depth by comparing endoscopical ultrasonography (EUS) with resected specimen. Carcinoid tumors of gastrointestinal tract were detected as homogenous hypoechoic tumors with sharp border in all site by EUS. Especially, it was characteristic that 14 of the 17 lesions (82%) which invaded into submucosa were mainly located in the third layer, and the second layer covered the tumor at the foot, and near the top, it touched the tumor and got indistinct. We decided the depth of invasion by comparing the hypoechoic tumor with normal structure of 5 layers. The accuracy rate was 88%. In conclusion, EUS was thought to be useful in the diagnosis and choice for treatment of carcinoid tumors of gastrointestinal tract.

Adult↗
PubMed1990

The structure of (xylose)2glucose-O-serine 53 found in the first epidermal growth factor-like domain of bovine blood clotting factor IX.

We reported the presence of a new trisaccharide composed of two xylose and reducing terminal glucose residues linked to serine residues of bovine blood clotting factors VII and IX (Hase, S., Kawabata, S., Nishimura, H., Takeya, H., Sueyoshi, T., Miyata, T., Iwanaga, S., Takao, T., Shimonishi, Y., and Ikenaka, T. (1988) J. Biochem. (Tokyo) 104, 867-868). The present paper describes the detailed structural analysis of the trisaccharide. Glycopeptides were prepared from bovine factor IX by digestion with Pronase followed by purification by column chromatography. The trisaccharide was released from the protein by the beta-elimination reaction with hydrazine, and the reducing end of the sugar chain was tagged with 2-aminopyridine. The fluorescent pyridylamino derivative of the trisaccharide was purified by gel filtration and reversed-phase high performance liquid chromatography. The glycopeptides and pyridylamino-trisaccharide thus obtained were subjected to methylation study, 500-MHz 1H nuclear magnetic resonance spectroscopy, and periodate oxidation. Glucose and xylose belong to the D series by high performance liquid chromatography on a chiral column. From the results, the structure of the trisaccharide is proposed as: D-Xyl p alpha 1-3-D-Xyl p alpha 1-3-D-Glcp beta 1-O-Ser-53.

Animals↗
PubMed1990

A new trisaccharide sugar chain linked to a serine residue in the first EGF-like domain of clotting factors VII and IX and protein Z.

Recently, we determined the complete amino acid sequence of bovine factor VII (Takeya, H. et al. (1988) J. Biol. Chem. 263, 14868-14877). In the course of the studies, we found an unknown serine derivative at position 52 in the first epidermal growth factor-like domain of factor VII. A pentapeptide isolated from the S-aminoethylated factor VII contained Ser-52, which could not be identified with a gas-phase sequencer. The same results were also obtained for a pentapeptide containing Ser-53 of factor IX and protein Z. 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 identified as pyridylamino-glucose. These results indicate the existence of a (Xyl2)Glc-Ser structure in factors VII, IX and protein Z. Similar results were obtained for human factors VII, IX and protein Z. This is the first report of a (Xyl2)-Glc-Ser structure in glycoproteins to our knowledge. The presence of the unique trisaccharide structure in factors VII, IX and protein Z leads us to anticipate its biological role in the tissue factor pathway.

Amino Acid Sequence↗
PubMed1990

Estimation of elution times on reverse-phase high-performance liquid chromatography of pyridylamino derivatives of sugar chains from glycoproteins.

Addition of a sugar residue to a pyridylamino (PA) sugar chain affects its elution time on reverse-phase HPLC and the contribution of the sugar residue is not influenced by the other sugar residues [S. Hase, S. Natsuka, H. Oku, and T. Ikenaka (1987) Anal. Biochem. 167, 321-326]. The partial relative elution times (Ei) of 22 sugar residues were calculated from the relative elution times (the elution time relative to Man5Glc-NAc2-PA) of three kinds of PA-sugar chain: the oligomannose and N-acetyllactosamine types and sugar chains with a xylose residue. The relative elution time of a PA-sugar chain can be calculated by summing the Ei values of all of the constituent sugar residues. The calculated relative elution times of 44 PA-sugar chains agreed well with the observed values. This method can be used to estimate the relative elution times of PA-sugar chains that are not yet available, and to estimate the structures of sugar chains in limited amounts of glycoproteins by a combination of sugar composition analysis and exoglycosidase digestion.

Aminopyridines↗
PubMed1990

Separation of oligomannose-type sugar chains having one to five mannose residues by high-performance liquid chromatography as their pyridylamino derivatives.

Ten oligomannose-type sugar chains (ManGlcNAc2-Man5GlcNAc2) were prepared from various glycoproteins and fluorescence labeled with 2-aminopyridine. The fluorescent pyridylamino (PA)-sugar chains were first separated into five fractions according to their molecular sizes by HPLC on a TSK gel Amide-80 column. Each fraction was then separated into the component PA-sugar chains by reversed-phase HPLC on a Capcell Pak C18 column according to their chemical structures. The method is useful for studying the substrate specificities of alpha-mannosidases with Man5GlcNAc2-PA as a substrate.

Aminopyridines↗
PubMed1990

Effects of cimetidine and omeprazole on angiogenesis in granulation tissue of acetic acid-induced gastric ulcers in rats.

We investigated the effects of cimetidine and omeprazole on angiogenesis in granulation tissue and on the healing of gastric ulcers induced by acetic acid in rats. Either cimetidine (50 or 100 mg/kg) or omeprazole (10 or 20 mg/kg) was orally administered once daily for 9 consecutive days from the day following ulcer production. The ulcer index on the 10th and 30th days after ulcer production, and the extent of angiogenesis on the 10th day were examined. Cimetidine dose-dependently decreased the extent of angiogenesis on the 10th day, whereas the ulcer index on the 10th days was not significantly different between cimetidine-treated and control rats. The ulcer index of the groups treated with cimetidine during the initial 9-day period was increased compared with the control group on the 30th day. In contrast, oral omeprazole did not affect angiogenesis on the 10th day and decreased the ulcer index on both the 10th and 30th days. These results suggest that oral cimetidine may inhibit angiogenesis in ulcer granulation tissue possibly via the blocking of histamine H2 receptors and this may be one cause of delayed ulcer healing.

Acetates↗
PubMed1990

[Endoscopic ultrasonography for assessing the horizontal spread of invasive gastric cancer].

The subjects were 64 cases of gastric cancer. In all 64 cases, resected specimens (formalin fixed) were subjected to endoscopic ultrasonographic examination by the water immersion method in order to assess the horizontal spread of the invasive gastric cancer. Ultrasonographic findings were compared with the histopathological findings of resected specimens. The tumor which invaded the submucosa or deeper layers was visualized as low echogenicity region in the third layer (corresponding to the submucosa) or deeper layers. The horizontal spread of the low echogenicity region represented that of the tumor or the associated fibrosis, but not the tumor itself. In the cases showing echo patterns which were characteristic of the peptic ulceration in the tumor focus (Type II-1, II-2, UL), the horizontal spread of cancer invasion in the submucosal layer or deeper layers (L Ca) was smaller than that of low echogenicity region depicted by ultrasonography (L U). In the other (Type II-3, III, A, B) cases, L Ca was almost comparable to L U.

Gastric Mucosa↗
PubMed1990

[Studies on 5-FU concentration and thymidine phosphorylase activity in tissues of patients with colorectal cancer after SF-SP administration].

5-fluorouracil (5-FU) concentrations in peripheral blood, portal blood, normal and cancer tissues were evaluated in 26 patients with colorectal cancer after SF-SP administration (800 mg/day for 10 days). Thymidine phosphorylase activity in cancer tissues was also evaluated. 5-FU concentration in cancer tissues was significantly higher than that in other three specimens, and much higher than 0.05 microgram/g which was reported to be the minimum effective concentration. 5-FU concentration in portal blood was lower than MEC (0.05 microgram/ml). As for the relationship with the pathological features of cancer, the protruding lesions showed a higher 5-FU concentration than the ulcerative ones, and the lesions invaded only to submucosa or proper muscle showed a higher concentration than others. 5-FU concentration ratio in cancer tissues per in peripheral blood (T/B ratio) was related to thymidine phosphorylase activity. The higher was the thymidine phosphorylase activity, the greater T/B ratio. The results suggest that the tumor with higher thymidine phosphorylase activity might have a more pronounced anticancer efficacy of 5-FU.

Colorectal Neoplasms↗
PubMed1989

Identification of a disaccharide (Xyl-Glc) and a trisaccharide (Xyl2-Glc) O-glycosidically linked to a serine residue in the first epidermal growth factor-like domain of human factors VII and IX and protein Z and bovine protein Z.

We have recently described a unique trisaccharide linked to a serine residue in the first epidermal growth factor-like domains of bovine blood coagulation factors VII (Ser-52) and IX (Ser-53) (Hase, S., Kawabata, S., Nishimura, H., Takeya, H., Sueyoshi, T., Miyata, T., Iwanaga, S., Takao, T., Shimonishi, Y., and Ikenaka, T. (1988) J. Biochem. (Tokyo) 104, 867-868). The sugar chain identified in these clotting factors consists of 1 mol of hexose (glucose (Glc] and 2 mol of pentose (xylose (Xyl]. We report here that human factors VII and IX and protein Z and bovine protein Z also contain such carbohydrate moieties linked to a serine residue at the same position found in bovine factors VII and IX. A glycopeptide derived from each of these proteins was subjected to amino acid sequence and component sugar analyses and fast atom bombardment mass spectrometric analysis. The results indicate that the glycopeptide derived from human factor IX contains 1 mol each of Glc and Xyl. The reducing end of this disaccharide was identified as Glc by analyzing the disaccharide generated by hydrazinolysis. In contrast, human factor VII and protein Z yielded two different glycopeptides which contained Glc and Xyl at molar ratios of 1:1 and 1:2, respectively, suggesting microheterogeneity of these O-linked sugar chains. Bovine protein Z glycopeptide contained 1 mol of Glc and 2 mol of Xyl. These sugar compositions were confirmed by analyses of the intact proteins. In relation to the trisaccharide sugar chain previously discovered in bovine factors VII and IX, these findings indicate the existence of a Xyl2-Glc-Ser and a Xyl-Glc-Ser structure in the first epidermal growth factor-like domains of human factors VII and IX and protein Z in addition to that of bovine protein Z. Whether these carbohydrate moieties contribute to the biological activities of these proteins is unknown.

Amino Acid Sequence↗
PubMed1989

Structures of the sugar chains of interferon-gamma produced by human myelomonocyte cell line HBL-38.

Interferon-gamma produced by the human myelomonocyte cell line HBL-38 contained galactose, mannose, fucose, N-acetylglucosamine, and N-acetylneuraminic acid as sugar components. Sugar chains were liberated from interferon-gamma by hydrazinolysis. Free amino groups of the sugar chains were acetylated and the reducing-end sugar residues were tagged with 2-aminopyridine under new reaction conditions in which no sialic acid residue was hydrolyzed. The pyridylamino (PA-) derivatives of the sugar chains thus obtained were purified by gel filtration and reversed-phase HPLC. Seven major PA-sugar chains were isolated and the structure of each purified PA-sugar chain was identified by stepwise exoglycosidase digestion and 500-mHz 1H-NMR spectroscopy. The results indicated that the structures of the major PA-sugar chains were of the biantennary type, to which 0 to 2 mol of fucose and 1 to 2 mol of N-acetylneuraminic acid were linked as shown below. (formula; see text)

Asialoglycoproteins↗