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S Takasaki

Publications and source records attributed to S Takasaki.

At least 37 records · Page 2Linked to original sources
PubMed1998

Analysis of 2-aminobenzamide-labeled oligosaccharides by high-pH anion-exchange chromatography with fluorometric detection.

To establish high-pH anion-exchange chromatography with fluorometric detection (HPAEC-FD) for the sensitive oligosaccharide analysis, the system for HPAEC with pulsed amperometric detection (PAD) was modified by placing the anion micromembrane suppressor between PAD and fluoromonitor to neutralize the alkaline eluate and connecting the flow path. N-Linked oligosaccharides were released from various glycoproteins by hydrazinolysis followed by labeling with 2-aminobenzamide, and their asialooligosaccharides were analyzed by HPAEC-FD using an isocratic elution with 0.3 M NaOH solution. The results indicated that the new system using FD offers fine separation of oligosaccharides at the subpicomole level. Coinjection of reduced dextran oligomers as internal standards which are detected by PAD permits us to express elution positions of the fluorescent oligosaccharides as glucose units, resulting in a much more reliable analysis. The system was also effectively used for structural analysis of oligosaccharides by sequential glycosidase digestion. Thus, HPAEC-FD promises to be an alternative tool for the sensitive analysis of oligosaccharides.

Carbohydrate Conformation↗
PubMed1998

Occurrence of reducing terminal N-acetylglucosamine 3-sulfate and fucosylated outer chains in acidic N-glycans of porcine zona pellucida glycoproteins.

Structures of acidic N-glycans released from porcine zona pellucida glycoproteins by hydrazinolysis were studied. The results indicated that the acidic glycans are of mono- to tetraantennary complex-type with and without N-acetyllactosamine repeating units. Sulfated residues are not only located at the C-6 position of GlcNAc included in the N-acetyllactosamine repeating units, but also at the C-6 position of GlcNAc in the non-repeated antennae and at the C-3 position of reducing terminal GlcNAc residue. Analysis of the oligosaccharide fragments released by endo-beta-galactosidase digestion and by hydrazine/nitrous acid treatment also revealed that various sulfated and non-sulfated forms of fucosylated structures such as Fucalpha1 --> 2Galbeta1 --> 4(+/-SO3- --> 6)GlcNAc (type 2H), Galbeta1 --> 4(Fucalpha1 --> 3)(+/-SO3- --> 6)GlcNAc(Lex) and Fucalpha1 --> 3 or 4(+/-SO3- --> 6)GlcNAc, are expressed in the repeated outer chain moieties.

Acetylglucosamine↗
PubMed1998

Structural study of N-linked sugar chains of sheep erythrocyte membrane glycoproteins.

Our previous study showed that non-reducing terminal galactose residues of N-linked sugar chains present in sheep erythrocyte membrane glycoproteins are important for rosette formation with T lymphoblastic cells [Ogasawara et al. (1995) Immunol Lett 48: 35-38]. As a first step to elucidate the significant structures of sugar chains involved in rosette formation, we analysed N-linked sugar chains released from the membrane glycoproteins by hydrazinolysis. The oligosaccharides were labeled with NaB3H4 and fractionated using columns of Aleuria aurantia lectin-Sepharose, MonoQ and Bio-Gel P-4. Structural analyses of oligosaccharides by sequential exoglycosidase digestion in combination with methylation analysis revealed that the membrane glycoproteins contain bi- (19%), tri- (33%), and tetraantennary (44%) complex-type oligosaccharides and that the oligosaccharides having exposed galactose residues amount to 40% of the total.

Animals↗
PubMed1997

Analysis of O-linked oligosaccharide alditols by high-pH anion-exchange chromatography with pulsed amperometric detection.

To apply high-pH anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) to the accurate and sensitive analysis of O-linked oligosaccharide alditol, removal of glycopeptides and peptides from oligosaccharide samples obtained by beta-elimination was first investigated. The results obtained by using fetuin as a model glycoprotein indicated that (glyco)peptides derivatized by fluorescamine are easily removed from the beta-eliminated oligosaccharide sample by means of a Sep-Pak C18 cartridge due to their increased hydrophobicity. This clean-up procedure was also effectively applied to the beta-eliminated oligosaccharide sample obtained from delipidated sheep erythrocyte ghosts. Furthermore, structural analysis of the oligosaccharide alditols by HPAEC-PAD was successfully performed in combination with partial and complete desialylation, composition analysis, periodate oxidation, and glycosidase digestion and revealed that sheep erythrocyte membrane glycoproteins contain Gal beta 1-->3Gal-NAc and Gal beta 1-->4GlcNAc beta 1-->3Gal beta 1-->3GalNac, to which one or two residues of Neu5Ac and Neu5Gc are attached in different combinations.

Animals↗
PubMed1997

Binding of mouse sperm to beta-galactose residues on egg zona pellucida and asialofetuin-coupled beads.

Mouse eggs fixed with paraformaldehyde were incubated with various exoglycosidases and their sperm-binding activities were examined. The number of sperm bound per egg was increased by sialidase treatment and decreased by beta-galactosidase treatment. No prominent reduction of sperm-binding was observed after alpha-galactosidase treatment. Mouse sperm also bound to asialofetuin-coupled agarose beads but not to fetuin-coupled beads. The sperm-binding was abolished when asialofetuin-gel was treated with beta-galactosidase specific to the beta 1-->4 linkage or N-Glycanase. Furthermore asialofetuin, but not beta-galactosidase-treated asialofetuin, competitively inhibited the binding of sperm to the zona pellucida of live eggs. These results suggest that mouse sperm recognize beta-galactose residues of the zona pellucida at the initial stage of the binding.

Animals↗
PubMed1997

A novel monoantennary complex-type sugar chain found in octopus rhodopsin: occurrence of the Gal beta1-->4Fuc group linked to the proximal N-acetylglucosamine residue of the trimannosyl core.

The N-linked sugar chains were liberated as oligosaccharides from octopus rhodopsin by hydrazinolysis. Most of the oligosaccharides were neutral, and separated into two major components by column chromatography using immobilized lectins and Bio-Gel P-4. Structural analysis of the one major component by sequential exoglycosidase digestion, chemical fragmentation in combination with methylation analysis revealed that it is a nonasaccharide; Man alpha1-->6(Gal beta1-->3GlcNAc beta1-->2Man alpha1-->3)Man beta1--> 4GlcNAc beta1-->4(Gal beta1-->4Fuc alpha1-->6)GlcNAc. This structure is quite unique in that a novel galactosylated fucose residue is attached to the reducing terminal N-acetylglucosamine residue.

Acetylglucosamine↗
PubMed1997

[A case of colon cancer with local recurrence successfully treated by systemic and local intra-arterial chemotherapy using a combination of 5-fluorouracil, interferon-alpha 2A, leucovorin and carboplatin].

A 59-year-old man with colon cancer was diagnosed as having a local recurrence of the disease, forming a huge intra pelvic tumor, accompanied by pulmonary metastasis 16 months after hemicolectomy. He received alternate systemic and local chemotherapy consisting respectively of a 5-day course of continuous infusion of 5-FU 600 mg/m2/day, bolus injection of leucovorin (LV) 20 mg/m2/day, intramuscular injection of interferon (IFN)-alpha 2a 6 x 10(6) IU/day, and intra-arterial administration of 5-FU, LV and carboplatin using reservoir catheter through pudendal artery, each repeated every 3 weeks. After 6 systemic and 8 local treatments, metastatic lesions disappeared and the intra-pelvic tumor shrunk by 62%, indicating a partial response. The patient then underwent dissection of the intra-pelvic tumor. Pathological examination indicated a curative resection. Alternate systemic and local intra arterial chemotherapy using a combination of 5-FU, LV, IFN and and carboplatin is highly promising for metastatic colorectal cancer with local recurrence.

Adenocarcinoma↗
PubMed1996

Purification and structural analysis of extracellular matrix of a skin tumor from a patient with juvenile hyaline fibromatosis.

Juvenile hyaline fibromatosis is a rare mesenchymal dysplasia that is inherited in an autosomal recessive fashion. The histological features of the tumor-like lesions are characterized by the deposition of amorphous hyaline material in the extracellular spaces of the dermis and soft tissues. We have analyzed the hyaline substance in a specimen of a skin tumor obtained from a 4-year-old Japanese girl with juvenile hyaline fibromatosis. It was found to consist mainly of type VI collagen; a small amount of type I collagen was also present. These components were separated by DEAE-cellulose ion-exchange chromatography under reducing conditions. The ratio of the dry weights of type I and type VI collagen was 1:4. Of the three chains of type VI collagen (alpha 1(VI), alpha 2(VI) and alpha 3(VI)), alpha 3(VI) was the most abundant. Glycosaminoglycans in the tumor tissue comprised dermatan sulfate, chondroitin sulfate and hyaluronan, with dermatan sulfate predominating. In contrast, hyaluronan is the most abundant in normal skin.

Amino Acid Sequence↗
PubMed1995

Role of antennary structure of N-linked sugar chains in renal handling of recombinant human erythropoietin.

To elucidate the role of the branched structure of sugar chains of human erythropoietin (EPO) in the expression of in vivo activity, the pharmacokinetic profile of a less active recombinant human EPO sample (EPO-bi) enriched with biantennary sugar chains was compared with that of a highly active control EPO sample enriched with tetraantennary sugar chains. After an intravenous injection in rats, 125I-EPO-bi disappeared from the plasma with 3.2 times greater total body clearance (Cltot) than control 125I-EPO. Whole-body autoradiography after 20 minutes of administration indicated that the overall distribution of radioactivity is similar, but 125I-EPO-bi showed a higher level of radioactivity in the kidneys than control 125I-EPO. Quantitative determination of radioactivity in the tissues also indicated that radioactivity of 125I-EPO-bi in the kidneys was two times higher than that of control 125I-EPO. The difference in plasma disappearance between 125I-EPO-bi and control 125I-EPO was not observed in bilaterally nephrectomized rats. The distribution of 125I-EPO-bi to bone marrow and spleen was similarly inhibited by simultaneous injection of excess amounts of either the nonlabeled EPO-bi or control EPO. These results indicate that the low in vivo biologic activity of EPO-bi results from rapid clearance from the systemic circulation by renal handling. Thus, the well-branched structure of the N-linked sugar chain of EPO is suggested to play an important role in maintaining its higher plasma level, which guarantees an effective transfer to target organs and stimulation of erythroid progenitor cells.

Animals↗
PubMed1995

Surgically resected adrenal leiomyoma: report of a case.

This report describes the case of a 48-year-old woman found to have a leiomyoma of the left adrenal gland after presenting with anemia and hypertension. An upper gastrointestinal series revealed a mass in the posterior region of the body that distorted the stomach. A computed tomography (CT) scan showed a well-circumscribed mass with a high-density outline in the left adrenal gland, and magnetic resonance imaging (MRI) revealed a homogeneous mass. Multiple catheter samplings of vena cava blood revealed a slight elevation of epinephrine and norepinephrine in the left adrenal vein and the left renal vein. Thus, asymptomatic pheochromocytoma of the left adrenal gland was highly suspected as a preoperative diagnosis and a left adrenalectomy was performed. However, histologic examination subsequently revealed findings suggestive of leiomyoma of the adrenal gland, which was confirmed by electron microscopy. The patient's postoperative course was uneventful and she has remained free from any further symptoms.

Adrenal Gland Neoplasms↗
PubMed1995

Role of terminal galactose residues in N-linked sugar chains of sheep erythrocyte membrane glycoproteins in rosette formation with T lymphocytes.

In this study, we found that rosette formation of T lymphoblastic Molt-3 cells with sheep erythrocytes is inhibited by addition of membrane glycoproteins which were solubilized from sheep erythrocyte ghosts by the lithium diiodosalicylate extraction methods. Their rosetting inhibitory activity was markedly reduced by digestion with N-glycanase, but not with O-glycanase. The inhibitory activity was also reduced by beta-galactosidase digestion, while it was enhanced by desialylation. These observations indicate that nonreducing terminal galactose residues of N-linked sugar chains included in membrane glycoproteins on sheep erythrocytes are important for rosette formation with T lymphocytes.

Animals↗
PubMed1995

Human type VI collagen: purification from human subcutaneous fat tissue and an immunohistochemical study of morphea and systemic sclerosis.

Collagen was isolated from human placenta by pepsin digestion and salt precipitation. This collagen was similar in its electrophoretic mobility and immunological reactivity with monoclonal antibody to form B of type VI collagen in the literature (Trueb B, Schreier T, Bruckner P and Winterhalter K. 1987. Eur. J. Biochem. 166: 699-703). We prepared polyclonal rabbit antiserum against alpha 2 chain of type VI collagen and performed an immunohistochemical study using this polyclonal antibody. It reacted in fat tissue and around vessels and peripheral nerves in normal human skin. To confirm the presence of type VI collagen in fat tissue, we isolated collagen from human subcutaneous tissue. This collagen showed a similar pattern in polyacrylamide gel electrophoresis with that from human placenta and cross-reacted with monoclonal or polyclonal antibody against type VI collagen. By immunohistochemical staining, abundant type VI collagen was observed in the septum of subcutaneous fat tissue in morphea or systemic sclerosis. In the mild hyalinizing areas or after treatment with 6M urea or hyaluronidase in highly hyalinized areas, the staining of type VI collagen increased. These data suggest that the amount of type VI collagen in subcutaneous tissue is involved in the early phases of these fibrosing disorders and that type VI collagen accumulates even more in hyalinizing tissue in late phases of these diseases.

Adipose Tissue↗
PubMed1995

[Local chemotherapy by a sustained-release preparation with fibrin seal against the operative wound in head and neck cancer].

Fibrin seal has been used for hemostasis and sealing in operative field of tumors in the head and neck. The authors applied it for drug preparation and tried a local chemotherapy to treat residual and disseminated tumors of cellular level in the operative wound using 5-FU. The drug release rate in this therapy in vitro study was 50% after 24 hrs. When injected to rats bearing Yoshida sarcoma, it exhibited a marked antitumor effect compared to the control group given 5-FU alone. This therapy is easy to make the dosage adjustment and can apply drugs directly to the tumor residue at the high concentration. It will be clinically a useful adjuvant therapy for radiotherapy, surgery or chemotherapy.

Animals↗
PubMed1994

A case of Goltz syndrome presenting as congenital incomplete alopecia.

A 5-year-old Japanese girl had had localized, incomplete hair loss on the scalp, minimal distichia, and a small papillomatous eruption on the right upper eyelid since birth. The diagnosis of Goltz syndrome was made by histological findings such as upward extension of the subcutaneous tissue to the papillary dermis and marked diminution in the thickness of the dermis, although typical linear atrophy-like eruptions and other mesoectodermal dysplasia were absent.

Alopecia↗