Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.53 (sialidase)
 2,694 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Previous studies have shown that sialidase-treated mammalian erythrocytes were rapidly eliminated from circulation. In contrast, chicken asialoerythrocytes remained fully viable. This investigation was undertaken to ascertain the reason for this difference in behavior as well as to determine the extent of the similarity of the physiological mechanism for the elimination from circulation of asialoglycoproteins and mammalian asialoerythrocytes. To that end, erythrocytes from dogs, rabbits, and chickens were each subjected to the action of galactose oxidase (D-galactose:oxygen 6-oxidoreductase; EC 1.1.3.9) both before and after sialidase (acylneuraminyl hydrolase; EC 3.2.1.18) treatment. The viability of the autologously transfused erythrocytes in circulation was monitored by Na2-51CrO4 labeling. Galactose oxidase had no deleterious effect on the viability of dog or chicken erythrocytes, nor did it restore the viability of dog or rabbit asialoerythrocytes. On the other hand, desialated chicken erythrocytes, which were fully viable, were rendered nonviable upon treatment with galactose oxidase. It may be concluded therefore that (a) the physiological mechanism of elimination of mammalian asialoerythrocytes from circulation is not the same as that for plasma asialoglycoproteins and (b) the treatment of chicken asialoerythrocytes with galactose oxidase results in the oxidation at carbons 6 of the galactosyl- or N-acetylgalactosaminyl residues, thereby rendering the erythrocytes nonviable.
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PMID:Effect of galactose oxidase, with and without prior sialidase treatment, on the viability of erythrocytes in circulation. 27 Jun 64

Galactose oxidase interacts with immobilized D-galactosyl residues and related immobilized and free sugars under the conditions of affinity electrophoresis in polyacrylamide gel and agglutinates sialidase-treated human erythrocytes. The agglutination is also inhibited by D-galactose and its derivatives and is temperature dependent. The sugar binding and hemagglutinating activity are preserved after removal of Cu2+ essential for enzymic activity. These properties are very similar to those of some typical lectins; however, a number of D-galactose specific lectins do not possess any detectable galactose oxidase activity.
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PMID:Galactose oxidase. An enzyme with lectin properties. 45 53

The presence of sialic acid on the cell surface is crucial for the survival of mammalian erythrocytes in circulation. In contrast, sialidase-treated chicken erythrocytes retain their viability in circulation. Galactose oxidase treatment of chicken red blood cells has no effect on their viability. However, after sialidase treatment, galactose oxidase treatment results in the rapid elimination of the chicken erythrocytes from circulation. This is compatible with the interpretation that consecutive treatment with the 2 enzymes abolishes the ability of the chicken erythrocytes to regenerate the sialic acid on the cell surface. Mammalian asialo-erythrocytes are sequestered in the liver and spleen. We have shown that at the cellular level there is a preferential recognition of sialidase-treated as compared to normal erythrocytes by mononuclear spleen cells and Kupffer cells of the liver. This recognition manifests itself in both autologous and homologous systems by rosette-like adhesions. These adhesions may represent the normal physiological mechanism for the removal of senescent erythrocytes from circulation by liver and spleen since it has been previously reported that older erythrocytes contain decreased amounts of sialic acid. The mechanisms in mammals for the elimination from circulation of asialo-erythrocytes and asialo-glycoproteins, while analogous in many respects, are definitely not identical.
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PMID:Cell surface carbohydrate recognition and the viability of erythrocytes in circulation. 66 20

The histogenesis of human stomach cancer was assessed based on the determination of the differentiation of component cancer cells. Specimens of 229 surgically obtained primary gastric cancers were used. Histochemical staining of mucins [paradoxical concanavalin A, galactose oxidase-Schiff (GOS), and sialidase-GOS sequence] and immunohistochemical demonstration of pepsinogens (Pg) I and II allowed the differentiation of gastric elements including mucous neck cells, pyloric gland cells, and surface mucous cells as well as intestinal goblet and absorptive cell types. Of 122 papillary and tubular adenocarcinomas, the proportion consisting mainly of intestinal type cells increased with progression from 22.9% (early) to 41.9% (advanced). Similarly, intestinal features increased with progression from 8.3% (early) to 25.4% (advanced) in the 107 poorly differentiated adenocarcinomas, signet ring cell carcinomas, and mucinous adenocarcinomas studied. A phenotypic shift from gastric- to intestinal-type expression was thus observed with progression of each histologic type of gastric cancer. Furthermore, tumors consisting mainly of gastric-type cells were commonly found within intestinal metaplastic mucosa, suggesting that this latter is not a preneoplastic lesion for gastric cancers in humans.
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PMID:Histogenesis of human stomach cancers based on assessment of differentiation. 137 65

Human lung adenocarcinoma sub-cell lines HAL-8, HAL-24 and HAL-33, showing different lung colonization potential (LCP), were established from human lung adenocarcinoma cell line KUM-LK-2 using repeated cloning with limiting dilution technique. Cell lines HAL-8 and -33 were characterized by high and low LCP, respectively, while HAL-24 did not give rise to lung colonies. The cell surface protein and carbohydrate profiles were determined by cell surface labeling (with lactoperoxidase-dependent 125I-iodination and galactose oxidase-NaB3H4, respectively) followed by SDS-gel electrophoresis. Various carbohydrate epitopes expressed at the cell surface were analysed by cytofluorometry using various monoclonal antibodies (MAbs) directed to Le(x), sialosyl-Le(x), sialosyl dimeric Le(x), T, Tn and sialosyl-Tn structures, which are often reported as being highly expressed in a variety of human cancers, particularly adenocarcinoma. Expression of sialosyl dimeric Le(x) (defined by MAb FH6) was high on HAL-8, moderate on HAL-33, and relatively low on HAL-24. In contrast, each of the three lines showed essentially equal expression (as determined by MAb reactivity) of sialosyl-Tn (defined by MAb TKH2), Le(x) (defined by MAb SH1), and Tn (defined by MAb 1E3). The cell lines showed extremely weak expression of T (defined by MAb HH8). LCP of HAL-8 and -33 was completely inhibited by sialidase treatment of cells. It is suggested that higher expression of sialosyl dimeric Le(x) (defined by MAb FH6) in HAL-8 cells may play an important role in higher potential of blood-borne lung colonization.
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PMID:Human lung adenocarcinoma cell lines with different lung colonization potential (LCP), and a correlation between expression of sialosyl dimeric Le(x) (defined by MAb FH6) and LCP. 167 53

The gastric and intestinal phenotypic expressions of tumor cells in 18 adenomatous hyperplasias, 33 well-differentiated adenocarcinomas, and 16 undifferentiated adenocarcinomas (4 poorly differentiated adenocarcinomas, 10 signet-ring cell carcinomas and 2 mucinous adenocarcinomas) induced by N-methyl-N'-nitro-N-nitrosoguanidine or 4-nitroquinoline-1-oxide in the rat glandular stomach were studied by histochemical stainings for mucin and immunohistochemical staining for pepsinogen isozyme 1 (Pg 1). By histochemical staining for mucin [by the paradoxical concanavalin A method, the modified method with labeled peanut lectin, the galactose oxidase-Schiff (GOS) reaction, and the sialidase-GOS reaction] and immunohistochemical staining of Pg 1, gastric cancer cells of each histological group could be clearly classified into a gastric type, including mucous neck cell pyloric gland cell, and surface mucous cell subtypes, and an intestinal type, including goblet-cell, and intestinal absorptive cell subtypes. All tumors examined in this work consisted mainly of gastric-type cells but intestinal-type tumor cells were occasionally found among the gastric-type tumor cells. The incidences of intestinal-type cells in adenomatous hyperplasias (11.1%) and small well-differentiated adenocarcinomas (28.6%) were significantly less (P less than 0.05) than that in large well-differentiated adenocarcinomas (68.4%). The incidence of intestinal-type cells in small undifferentiated adenocarcinomas (25.0%) was also less than that in large ones (58.3%). The present results suggest the occurrence of change of phenotypic expression of tumor cells from the gastric type to the intestinal type during growth of tumors.
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PMID:Cellular differentiation and histogenesis of rat glandular stomach cancers. 169 50

A multi-coupled enzyme assay system for determining sialidase activity is described. Enzymes, substrates and chromogens are reacted in situ and determined spectrophotometrically in ELISA microtiter plates. Sialidase is assayed by the extent of desialylated galactose on an appropriate sialoglycoconjugate (fetuin), which is otherwise unavailable for oxidation by galactose oxidase. The oxidation is monitored by the coupling of H2O2 released to a third enzyme, peroxidase. The rate of change of absorbance at 405 nm, resulting from the oxidized chromogen is a measure of the reaction rate of the coupled enzyme system. A similar system can be used for determining galactose oxidase in solution, or on blots using galactose as substrate. Due to the small-scale single-step measurement, the described assay is a sensitive, convenient, and inexpensive alternative to the classic colorimetric determination.
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PMID:A coupled enzyme assay for measurement of sialidase activity. 170 71

Morphological and phenotypical patterns of proliferative epithelial lesions induced in the gastric stump mucosa by duodenal content reflux after Billroth II partial gastrectomy (BII) were evaluated in rats. Control animals were either sham-operated or submitted at different times after BII to Roux-en-Y (RY) surgical procedure which prevents duodenal reflux. The lesions were analysed using routine haematoxylin and eosin staining, immunohistochemical staining for pepsinogen isoenzyme 1 and histochemical procedures for mucins (paradoxical Concanavalin A, galactose oxidase Schiff and sialidase galactose oxidase Schiff reactions). Mucosal hyperplasia (H) was observed in the group submitted to BII procedure 6 weeks after surgery. Adenomatous hyperplasia (AH) also appeared 6 weeks after induction of the reflux and its incidence and size increased until the 54th week of the experiment. RY procedure performed in the normal animals at the beginning of the experiment or at the 24th week after BII gastrectomy led to a significantly lower incidence of AH which was related to the moment of surgery. Most of H was due to pyloric mucosal hyperplasia. AH consisted mainly of gastric type glands but in some animals glands of the intestinal type were present probably originating from the intestinal mucosa. Six mucinous adenocarcinomas were observed, all of them of intestinal type. This study demonstrates that AH induced by BII procedure is a reversible lesion and that the anomalous epithelial proliferation in the stoma may lead to adenocarcinomas.
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PMID:Reversibility of adenomatous hyperplasia in the gastric stump after diversion of bile reflux in rats. 186 Jan 64

Gastric and intestinal phenotypic expression in 223 surgically obtained primary gastric cancers and their histogenetic relationship to intestinal metaplasia in the surrounding gastric mucosa were studied by mucin histochemistry and pepsinogen (Pg) immunohistochemistry. Histochemical differentiation of mucins (paradoxical concanavalin A, the galactose oxidase-Schiff sequence and sialidase-galactose oxidase-Schiff) and immunohistochemical staining of Pgs I and II, allowed differentiation of gastric cancer cells from different histological categories into gastric elements including mucous neck cells, pyloric gland cells and surface mucous cells or intestinal elements including goblet cell and intestinal absorptive cell types. Of 122 papillary and tubular adenocarcinomas, 33 (27.1%) consisted mainly of gastric-type cells and 42 (34.4%) predominantly of intestinal-type cells. The remainder (38.5%) consisted of mixtures of gastric- and intestinal-type cells. Of 101 poorly differentiated adenocarcinomas, signet ring cell carcinomas and mucinous adenocarcinomas, 59 (58.4%) consisted mainly of gastric-type cells and 20 (19.8%) mainly of intestinal-type cells. Seven out of 35 papillary and tubular adenocarcinomas consisting mainly of gastric-type cancer cells were surrounded by mucosa with intestinal metaplasia. Conversely, 10 out of 40 papillary and tubular adenocarcinomas consisting mainly of intestinal-type cancer cells were observed in nonmetaplastic gastric mucosa. Thus no relationship as regards intestinal phenotypic expression was found between gastric cancers and surrounding gastric mucosa.
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PMID:Gastric and intestinal phenotypic expression of human stomach cancers as revealed by pepsinogen immunohistochemistry and mucin histochemistry. 222 Mar 96

Two monoclonal antibodies, NCC-LU-35 and NCC-LU-81, have been established after immunization of mice with membrane preparations of human lung cancer Lu65 tumor xenograft cells grown in vivo and intact cells cultured in vitro, respectively. These two antibodies react specifically with a majority of human adenocarcinomas, irrespective of the host's blood group ABO status, as well as with normal tissues and erythrocytes of blood group A individuals. The antigenicity is associated with a high molecular weight mucin-like glycoprotein separated by gel filtration of Lu65 tumor extracts. The epitope of the mucin-like glycoprotein has been identified as alpha-N-acetylgalactosaminyl residue directly linked O-glycosidically to serine or threonine residues of polypeptides. This epitope was serologically detected several years ago and given the name Tn. Our identification of the epitope is based on the following results: The antigen is sensitive to alpha-N-acetylgalactosaminidase, but not to sialidase or alpha-fucosidase. Various mono- and difucosyl A determinants, either type 1 or type 2 chain, cross-react with both antibodies. The reactivity with both antibodies can be created by treatment of glycophorin A of normal erythrocytes with sialidase followed by beta-galactosidase. N-[3H]acetylgalactosamine can be released by galactose oxidase/NaB3H4 treatment from the Lu65 mucin-like glycoprotein but not from the mucin-like glycoprotein of normal colonic mucosa upon reductive beta-elimination (alkaline borohydride treatment). The antigen may be one of the tumor-associated A cross-reacting antigens occurring in a wide variety of human adenocarcinomas of hosts belonging to all ABO blood groups.
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PMID:Blood group A cross-reacting epitope defined by monoclonal antibodies NCC-LU-35 and -81 expressed in cancer of blood group O or B individuals: its identification as Tn antigen. 241 56


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