PubMed Health⌕ Search

Biomedical subjects

S Yazawa

Publications and source records attributed to S Yazawa.

At least 91 records · Page 5Linked to original sources
PubMed1993

A novel lectin in rabbit serum binds H type 1, H type 2 and N-acetyl lactosamine structures.

A novel lectin (RSL) which recognizes blood group H type 1 and type 2 (Fuc alpha 1-->2Gal beta 1-->3/4GlcNAc beta-R), and N-acetyllactosamine (Gal beta 1-->4GlcNAc beta-R) was purified from rabbit serum using affinity chromatography on Synsorb H type 2 beads, gel filtration and preparative polyacrylamide gel electrophoresis. The lectin agglutinated human O type red cells, and the hemagglutination reaction was inhibited by H type 1 and type 2 haptens, N-acetyllactosamine and human salivas from secretor individuals. The molecular weight of the lectin was estimated to be approximate 650,000 and 65,000 on Sephacryl S-400 gel filtration and SDS-polyacrylamide gel electrophoresis, respectively.

Amino Sugars↗
PubMed1993

Immunochemical characterization of anti-H monoclonal antibodies obtained from a mouse immunized with human saliva.

Three IgM class anti-H monoclonal antibodies (1E3, 1E5 and 3H1) were obtained from a BALB/c mouse immunized with human O type saliva. These antibodies were found to agglutinate red cells from O group and A and B subgroups but not from Bombay and para-Bombay individuals whose H antigen was barely detected by anti-H reagents. The agglutination reactions of these antibodies were inhibited by H antigens from human tissues. It was also demonstrated that both 1E3 and 3H1 reacted with H disaccharide (Fuc alpha 1-->2Gal beta), H type 1 (Fuc alpha 1-->2Gal beta 1-->3GlcNAc beta), H type 2 (Fuc alpha 1-->2Gal beta 1-->4GlcNAc beta), H type 3 (Fuc alpha 1-->2Gal beta 1-->3GalNAc alpha) and H type 4 (Fuc alpha 1-->2Gal beta 1-->3GalNAc beta) but not with Lea (Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta), Leb (Fuc alpha 1-->2Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta), X (Gal beta 1-->4[Fuc alpha-->3]GlcNAc beta) or Y (Fuc alpha 1-->2Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta). On the other hand, 1E5 was found to react with H type 1, H type 2, Leb and Y. Because of the unique reactivities against various fucosyl linkages these monoclonal antibodies could be useful not only as anti-H reagents but also as reagents for the structural analysis of fucosylated glycoconjugates.

ABO Blood-Group System↗
PubMed1993

Aberrant alpha 1-->2fucosyltransferases found in human colorectal carcinoma involved in the accumulation of Leb and Y antigens in colorectal tumors.

Evidence indicates that the presence of aberrant alpha 1-->2fucosylation pathways is responsible for the accumulation of large quantities of Le(b) and Y antigens in human colorectal carcinoma. Significantly higher activities of alpha 1-->2 as well as alpha 1-->3 and alpha 1-->4fucosyltransferases were found in most of the tissues from carcinoma than in the adjacent normal tissues and in healthy subjects. alpha 1-->2Fucosyltransferases associated with the synthesis of Le(b) (Fuc alpha 1-->2Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta) and Y (Fuc alpha 1-->2Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta) structures from Le(a) (Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta) and X (Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta) ones, respectively, were demonstrated in colorectal carcinomas and in colorectal carcinoma cell lines (COLO201, LS174T and SW1116). The activation of alpha 1-->2fucosyltransferase with such new substrate specificities in colorectal carcinoma might result in the preferential synthesis of Le(b) and Y structures from Le(a) and X rather than from H type 1 and H type 2 structures.

Blood Group Antigens↗
PubMed1993

Development and characterization of a novel anti-fucosylated antigen monoclonal antibody YB-2 and its usefulness in the immunohistochemical diagnosis of colorectal cancer.

A novel monoclonal antibody, YB-2 was obtained after immunization of mice with fucosylated antigens isolated from human saliva. The antibody was demonstrated to react with Y (Fuc alpha 1-->2Gal-beta 1-->4[Fuc alpha 1-->3]GlcNAc beta),Leb (Fuc alpha 1-->2Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta) and H type 2 (Fuc alpha 1-->2Gal-beta 1-->4GlcNAc beta) antigens, but not with H type 1 (Fuc alpha 1-->2Gal beta 1-->3GlcNAc beta), Lea (Gal beta 1-->3[Fuc alpha 1-->4]GlcNAc beta), X (Gal beta 1-->4[Fuc alpha 1-->3]GlcNAc beta) or with non-fucosylated antigens. Inhibition assays of YB-2 antibody with such reactive antigens showed that YB-2 antibody preferentially reacted with Y antigen. Formalin-fixed and paraffin-embedded sections prepared from normal and malignant colorectal tissues were examined immunohistochemically with YB-2. The positive rates of staining with YB-2 antibody were 88.6% in malignant and 12.0% in normal tissues. The expression of fucosylated antigens detected by YB-2 antibody seemed to be correlated with survival among patients with primary colorectal cancer. Therefore, YB-2 antibody could be useful as an immunochemical tool for diagnosis and evaluation of the prognosis of colorectal cancer.

Antibodies, Monoclonal↗
PubMed1993

Biosynthesis of the blood group P antigen-like GalNAc beta 1-->3Gal beta 1-->4GlcNAc/Glc structure: kinetic evidence for the responsibility of N-acetylglucosaminyl-transferase.

Previously we reported the occurrence of UDP-GalNAc:Gal beta 1-->4GlcNAc/Glc beta-1,3-N-acetylgalactosaminyltransferase activity in human plasma. Here, the donor substrate specificity of the enzyme partially purified from blood group O plasma was investigated by means of competition experiments with analogs of donor. The enzyme activity was found to be inhibited most strongly by UDP-GlcNAc among the nucleotide sugars tested, and UDP was the best inhibitor among test nucleotides. UDP-GlcNAc was much more inhibitory than UDP, whereas UDP-GalNAc was much less inhibitory than UDP. These results show that the donor-binding site of enzyme has a high affinity for UDP-GlcNAc, but not UDP-GalNAc, suggesting that the enzyme essentially functions in the transfer of N-acetylglucosamine. Indeed, UDP-GlcNAc:Gal beta 1-->4GlcNAc/Glc beta-1,3-N-acetylglucosaminyltransferase activity is known to occur in human plasma. The ratio of N-acetylgalactosamine to N-acetylglucosamine transferred to lactose with O or B plasma was 1:20 when assayed separately at 1 microM of donor, but increased to 1.2:1 at 5 mM. The nearly identical ratio was obtained with the partially purified enzyme preparation.

Binding, Competitive↗
PubMed1992

A simple and sensitive method for the determination of blood group antigens in secretions.

A simple method for the determination of ABH blood group antigens in secretions has been developed. Blood group ABH specific monoclonal antibodies were covalently bound to blue dyed microspheres of acryl polymer with a diameter of 2.2 microns. The dyed microspheres coated with anti-A, -B and -H antibodies were found to be agglutinated specifically on a plastic microtiter plate by the corresponding blood group antigens secreted in saliva. The agglutination reactions with saliva samples were also observed rapidly and conveniently in a glass capillary tube which contained the same antibody immobilized dyed microspheres. The procedure provides a simple and sensitive method for the determination of blood group antigens through the visible agglutination reaction of dyed microspheres despite the invisibility of the antigens.

ABO Blood-Group System↗
PubMed1992

Biosynthesis of the blood group P antigen-like GalNAc beta 1-->3Gal beta 1-->4GlcNAc/Glc structure: a novel N-acetylgalactosaminyltransferase in human blood plasma.

Human blood group O plasma was found to contain an N-acetylgalactosaminyltransferase which catalyzes the transfer of N-acetylgalactosamine from UDP-GalNAc to Gal beta 1-->4Glc, Gal beta 1-->4GlcNAc, asialo-alpha 1-acid glycoprotein, and Gal beta 1-->4GlcNAc beta 1-->3Gal beta 1-->4Glc-ceramide, but not to Gal beta 1-->3GlcNAc. The enzyme required Mn2+ for its activity and showed a pH optimum at 7.0. The reaction products were readily hydrolyzed by beta-N-acetylhexosaminidase and released N-acetylgalactosamine. Apparent Km values for UDP-GalNAc, Mn2+, lactose, N-acetyllactosamine, and terminal N-acetyllactosaminyl residues of asialo-alpha 1-acid glycoprotein were 0.64, 0.28, 69, 20, and 1.5 mM, respectively. Studies on acceptor substrate competition indicated that all the acceptor substrates mentioned above compete for one enzyme, whereas the enzyme can be distinguished from an NeuAc alpha 2-->3Gal beta-1,4-N-acetylgalactosaminyltransferase, which also occurs in human plasma. The methylation study of the product formed by the transfer of N-acetylgalactosamine to lactose revealed that N-acetylgalactosamine had been transferred to the carbon-3 position of the beta-galactosyl residue. Although the GalNAc beta 1-->3Gal structure is known to have the blood group P antigen activity, human plasma showed no detectable activity of Gal alpha 1-->4Gal beta-1,3-N-acetylgalactosaminyltransferase, which is involved in the synthesis of the major P antigen-active glycolipid, GalNAc beta 1-->3Gal alpha 1-->4Gal beta 1-->4Glc-ceramide. Hence, the GalNAc beta 1-->3Gal beta 1-->4GlcNAc/Glc structure is synthesized by the novel Gal beta 1-->4GlcNAc/Glc beta-1,3-N-acetylgalactosaminyltransferase.

Acetylgalactosamine↗
PubMed1992

Enhancing effect of cyclodextrins on nasal absorption of insulin and its duration in rabbits.

The absorption of insulin (from porcine pancreas) in rabbits after the nasal administration of aqueous preparations containing insulin and five kinds of cyclodextrins (CyDs) in phosphate buffer solution at pH 7.0 was investigated. Without CyD, the insulin and glucose levels in plasma were unchanged, whereas a marked increase in the plasma levels of insulin and a decrease in glucose concentrations were observed following the simultaneous administration of insulin and CyD such as alpha- and heptakis (2,6-di-O-methyl)-beta-CyD (DM-beta-CyD). The largest enhancing effect on the nasal absorption of insulin was obtained by DM-beta-CyD. To evaluate the duration of the absorption-enhancing effect of CyDs, preadministration (administration of CyD 0.5, 6, 12 and 24 h before insulin administration) was performed. The area under plasma concentration-time curve (AUC) and Cmax of insulin significantly decreased with the preadministration of DM-beta-CyD 6, 12 and 24 h before nasal administration. The absorption-enhancing effect disappeared 24h after the preadministration. These findings demonstrate that CyDs enhance the nasal absorption of insulin, and the recovery of the membrane transport barrier function in nasal mucosa is achieved, at the latest, 24 h after the administration of CyDs.

Absorption↗
PubMed1992

A novel method for blood group typing with the aid of monoclonal antibody immobilized dyed microspheres.

A novel and simple method for blood group typing has been developed. The procedure involves the use of type-specific monoclonal antibodies covalently linked to dyed microspheres of polyglycidyl methacrylate. The presence of ABH and Lewis blood group antigens in saliva and plasma could be determined easily and specifically with respective monoclonal antibodies bound to dyed microspheres. The present method could also be applicable for the determination of the presence of invisible antigens for the forensic and diagnostic purpose with visible agglutination reaction.

ABO Blood-Group System↗
PubMed1992

Use of synthetic H disaccharides as acceptors for detecting activities of UDP-GalNAc:Fuc alpha 1-->2Gal beta-R alpha 1-->3-N-acetylgalactosaminyltransferase in plasma samples from blood group A subgroups.

Concentrations of blood group A-specified alpha(1-->3)-N-acetylgalactosaminyltransferase (A enzyme) were measured in human plasma of blood groups A1, A2, and A3 by using chemically synthesized H disaccharides and H type 1 and type 2 trisaccharides attached to hydrophobic aglycones as acceptors. When the trisaccharides were used as acceptors, enzyme activities were reduced in samples from A2 and A3. However, the H disaccharides were shown to be good acceptors even for enzymes from A2 and A3, and no significant difference in enzyme concentration was detected in any of the plasma tested.

ABO Blood-Group System↗
PubMed1992

[Clinical significance of alpha(1----3)-L-fucosyltransferase activities in sera from patients with malignant diseases with a special reference to a potential tumor marker].

We measured alpha(1----3)-L-fucosyltransferase (alpha 13FT) activity in human plasma samples obtained from a group of 111 patients with malignant diseases, 86 patients with benign diseases, and 58 healthy controls using a newly developed assay method (Clin. Chem., 37: 2081-2086, 1991). The cutoff value was arbitrarily set at 73 units/ml (mean +/- 3SD of results for healthy controls). Forty-one of the 111 (36.9) plasma samples from patients with cancer showed high enzyme activity, and twelve of the 86 (13.6%) samples from patients with benign diseases were above the cutoff value. The levels of alpha 13FT were considerably high in samples obtained from the patients with esophagus, lung, liver and pancreatic and biliary cancer, and corresponding positive rates were 66.7, 64.7, 62.5 and 62.5%, respectively. The elevation of the enzyme activity was found in many samples from advanced cancer, whereas samples from patients with gastric and colon cancer in the clinical stage I showed high positive rates. No correlation was observed between the level of alpha 13FT and tumor--associated antigens such as carcinoembryonic antigen, CA19-9, and sialyl Tn (STN). These results suggest that alpha 13FT activity measured by the present assay method could have a potentiality for a new type of tumor marker.

Biomarkers, Tumor↗
PubMed1991

Carcinoembryonic antigen levels in peritoneal washings can predict peritoneal recurrence after curative resection of gastric cancer.

Carcinoembryonic antigen (CEA) levels were determined in the peritoneal washings from 120 patients with gastric cancer and 9 patients with benign diseases. Elevated values (greater than 100 ng/g of protein) were observed in 20 of 25 patients with gastric cancer with visible dissemination and 16 of 25 patients with serosal invasion but no dissemination. The same elevation was found in only 9 of 70 patients with no serosal invasion and none of the patients with benign disease. The 2-year survival rates after curative operation for the patients with and without elevation of CEA levels were 21% (19 patients) and 100% (66 patients), respectively (P less than 0.001). A negative correlation was found between CEA levels and survival times after noncurative operation. These results indicate that the CEA level in peritoneal washings could be a sensitive detector of invisible peritoneal dissemination and a new predictor for the postoperative prognosis of gastric cancer.

Carcinoembryonic Antigen↗
PubMed1991

Isolation and characterization of anti-H antibody from egg yolk or immunized hens.

An anti-H antibody was demonstrated to be produced in egg yolk as well as in serum of hens which were immunized with human type O red blood cells. The antibody in egg yolk was isolated with polyethylene glycol and ethanol and was purified by affinity chromatography using immunoadsorbant beads immobilized with H type 2 hapten (Fuca1----2Gal beta 1----4GlcNAc beta). Hemagglutination reaction of the antibody from egg yolk was inhibited by human saliva samples from secretor types irrespective of their ABO blood types, and by immunoadsorbant beads which contain Fuca1----2Gal beta structures.

ABO Blood-Group System↗
PubMed1991

Characterization of anti-Leb antibody purified from serum of immunized rabbits.

An anti-Le(b) antibody was produced in sera of rabbits by immunization with human saliva from blood group O Le(a-b+) secretor and purified by sequential use of silica beads immobilized with H type 1, Le(a) and Le(b). The purified antibody agglutinated only Le(a-b+) red cells irrespective of their ABO blood type. Hemagglutination reaction with the antibody of blood group O Le(a-b+) red cells was inhibited not only by saliva samples from blood group Le(a-b+) secretors and Synsorb beads immobilized with Le(b) hapten, but also weakly by Synsorb immobilized with Y and H type 2 haptens.

Animals↗
PubMed1991

Novel method for quantifying alpha(1----3)-L-fucosyltransferase activity in serum.

A novel method has been developed to quantify alpha(1----3)-L-fucosyltransferase activity in human sera by applying a sandwich-type immunoradiometric assay. H type 2 trisaccharide (6Fuc alpha 1----2Gal beta 1----4GlcNAc) covalently attached to bovine serum albumin (BSA) was used as an acceptor and incubated with serum samples in the presence of guanosine diphosphate-fucose. The resulting product, Y tetrasaccharide (Fuc alpha 1----2Gal beta 1----4[Fuc alpha 1----3] GlcNAc beta-BSA), was detected by a sequential use of anti-BSA antibody-coated bead and 125I-labeled anti-Y antibody. Inter- and intra-assay CVs for alpha(1----3)-L-fucosyltransferase were both less than 4%, and the results of the dilution linearity and analytical recovery studies were satisfactory. Using the present assay method, we measured alpha(1----3)-L-fucosyltransferase in serum from patients with benign and malignant gastric disorders and in healthy subjects. The detection rate of alpha(1----3)-L-fucosyltransferase for cancer was apparently higher than that of carcinoembryonic antigen measured in the same samples, particularly in the early clinical stage; indeed, no correlation was observed between the concentrations of the two potential markers. The results indicate that the present assay method seems to be excellent for the determination of serum alpha(1----3)-L-fucosyltransferase activity and useful for the detection of cancer-associated increases of the enzyme activity at the early stage of gastric cancer.

Carbohydrate Sequence↗
PubMed1990

Use of benzyl 2-acetamido-2-deoxy-3-O-(2-O-methyl-beta-D-galactosyl)-beta- D-glucopyranoside [2'-O-methyllacto-N-biose I beta Bn] as a specific acceptor for GDP-fucose: N-acetylglucosaminide alpha(1----4)-L-fucosyltransferase.

A synthetic substrate, benzyl 2-acetamido-2-deoxy-3-O-(2-O-methyl-beta-D- galactopyranosyl)-beta-D-glucopyranoside, was demonstrated to be a specific acceptor for the Lewis blood group-specified alpha(1----4)-L-fucosyltransferase from human saliva and stomach mucosa. The fucosyl linkage of the product resulting from the use of this substrate isolated by paper chromatography was characterized by hydrolysis with specific alpha(1----3)/(1----4)-L- fucosidase. The product can be separated by adsorption onto the reverse-phase cartridge and recovered by one-step elution with methanol. The enzymatic properties of alpha(1----4)-L-fucosyltransferase from saliva and stomach mucosa have also been examined using this substrate.

Chemical Phenomena↗