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)

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

Human-type blood group activities on the red blood cells (RBCs) of three chimpanzees were individually examined with commercial mouse monoclonal antibodies (anti-A, -B, -H, -M, -N, -Lea, and -Leb) as well as lectins (UEA-I and VGA) and conventional polyclonal antisera for the systems ABO, MN, Lewis, Rh-Hr, P, Kell, Kidd, Duffy, and Lutheran. For further analysis of the MN antigens, treatment of the RBCs with sialidase, trypsin, and chymotrypsin were employed. The activities recognized among the three chimpanzees were A, H, M, N, Leb, c, S, k, and Jka. The RBCs of the three individuals possessed the A antigen which showed the same serologic activity as the human A1. Those chimpanzee RBCs showed higher H-activity than the human A1 RBCs. The Lewis b activity was revealed by the absorption-elution method. The RBCs of the three individuals showed a reactivity to the polyclonal anti-M reagents, which was affected by both the sialidase and trypsin treatment. The RBCs of two individuals were agglutinated with the monoclonal anti-N. The receptor was sensitive to sialidase and chymotrypsin. The RBCs of the three individuals, however, did not react with the monoclonal anti-M or with one of the polyclonal anti-N. These results indicate structural differences in the glycophorins and MN antigens between the human and chimpanzee.
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PMID:Human-type blood group activities on chimpanzee erythrocytes with special reference to M and N. 323 60

Specific antiserum of human red cells was prepared from rabbit anti-human red cell serum by absorption with red cells of horse, hog, dog and Japanese monkey. This antiserum proved specific for human red cells regardless of blood types ABO and MN as demonstrated by the hemagglutination test. Sialoglycoproteins were extracted with lithium diiodosalicylate and isolated through chromatographic procedures from human red cell membranes, and showed inhibitory activity for the specific antiserum as well as for anti-M and anti-N sera. The isolated glycoproteins corresponded to the sialoglycoproteins on the basis of SDS-PAG electrophoresis. The inhibitory activity of the sialoglycoproteins for the specific antiserum was lost after the substance was treated with sialidase for 24h. A moderate reduction of the inhibitory activity for anti-M and anti-N sera but not for the specific antiserum was seen after treatment for 1h. These results showed that the receptors for the species-specific antiserum were more resistant towards sialidase treatment.
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PMID:Species-specific glycoproteins of the human red cell membrane. 707 95

T activation of red cells results from the effects of microbial sialidase catalysing the cleavage of sialic acid from red cell membrane. Abnormal agglutination may be induced when human-derived antiA,B antibodies containing antiT are used. By the using of mouse-derived antiA,B monoclonal antibodies this type of polyagglutination as source of error could be overcome. Most common cause of ABO mismatch is due to more simple technical or clerical error resulting in transfusion of the wrong blood to the recipient. Three such cases with non-fatal hemolytic transfusion reaction are described.
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PMID:[Abnormal agglutination by reducing surface charge of red cell membrane as source of error in ABO typing and actual cases of incompatible ABO blood transfusion due to various factors]. 930 3

Whereas monoclonal reagents for ABO, Rhesus, Kell, Kidd, Lewis and MNS antigens are widely used in blood grouping laboratories and have been well evaluated, little attention has been given so far to monoclonal anti-P1 reagents. Therefore it was the aim of our study to examine the suitability of monoclonal anti-P1 reagents for routine use in comparison to polyclonal anti-P1 reagents. 10 polyclonal anti-P1 reagents (9 from goat, 1 from rabbit) and 5 monoclonal anti-P1 reagents (4 with clone 650, 1 with clone OSK17) were tested by the tube-spin-method at room temperature (incubation time as prescribed by the manufacturer) using untreated P1+ red blood cells (RBCs) for titration and untreated P1- RBCs as negative controls. P1- RBCs with a positive direct anti-globulin test (DAT+) (coated with incomplete anti-D) and sialidase-treated P1- RBCs (T+) were used to recognize false positive reactions. 3 monoclonal anti-P1 reagents had a titer of < or = 1 with P1+(weak) RBCs, but all polyclonal anti-P1 reagents showed a titer > or = 2. Negative controls (untreated P1- RBCs) were inconspicuous. 7 polyclonal and 1 monoclonal anti-P1 reagents showed false positive reactions with P1- DAT+ RBCs. All polyclonal and 1 monoclonal (containing clone OSK17) reagent showed false positive reactions with P1- T+ RBCs. As several monoclonal anti-P1 reagents are less suitable for routine use than polyclonal anti-P1 reagents, quality control of anti-P1 reagents should be intensified.
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PMID:Comparison of monoclonal and polyclonal anti-P1 reagents. 1140 3

The human coagulation factor VIII (FVIII) is essential in the intrinsic pathway of blood coagulation and circulates mainly as a non-covalently bound complex with the von Willebrand factor (VWF). This complex (FVIII/VWF) protects FVIII from degradation and cellular uptake, although no biological role has been identified yet for this complex. The FVIII/VWF complex was purified from a healthy donor's plasma by affinity chromatography on a Sepharose 4B-Concanavalin A column and was used to determine its capability to interact with erythrocytes and platelets. The purified FVIII/VWF complex at 6.0 and 12 microg/ml agglutinates rabbit and bovine erythrocytes, and showed negative agglutination with erythrocytes from other species including human ABO. Treatment of erythrocytes with Clostridium perfringens sialidase or trypsin increased four-fold the activity toward rabbit erythrocytes and positive agglutination for human A and B erythrocytes, suggesting the presence of FVIII/VWF-cryptic receptors in these erythrocytes. Goat, pig, or human O erythrocytes were not agglutinated even after enzymatic treatment. Fucose or N-acetyl-glucosamine (GlcNAc), at 10 mM, inhibited agglutinating activity of the complex with rabbit, human A and B erythrocytes, whereas galactose and N-acetyl-galactosamine, even at 200 mM, showed no effect on the complex activity. The FVIII/VWF complex, at 1.5 microg/200,000 platelets, significantly decreased platelet aggregation (p < 0.001) when compared with the effect of platelet-rich plasma; this effect was inhibited with 15 mM GlcNAc or fucose. ELISA assays on FVIII/VWF coated polystyrene plates confirmed specific binding to fucose- or biotinylated GlcNAc-dextran derivatives. We therefore propose that the FVIII/VWF complex possesses lectin activity.
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PMID:Lectin activity of the coagulation factor VIII/von Willebrand complex. 1928 56

Cross-reactivities of monoclonal reagents for red blood cell (RBC) typing are seen very rarely, e.g. in some reagents for testing of ABO or Lewis antigens. We report on two patients in whom we observed weak reactions using a monoclonal anti-c reagent containing clone MS35, but no reactions with anti-c reagents containing other monoclonal or polyclonal antibodies. To resolve this discrepancy, we studied RHCE exon 1 (Ex1) and 2 from genomic DNA of one patient and performed quality controls of the false-positive reacting anti-c reagent. RHCE Ex1 showed no abnormalities as well as RH Ex2 examined with primers specific for Ex2 D/C. No amplification product of RH Ex2 was received with primers specific for c. A titration study with untreated, papain-treated and sialidase-treated adult and newborn RBCs showed anti-i reactivity of the false-positive reacting reagent. This reactivity could not be removed by absorption with c-negative newborn RBCs without reducing the anti-c titre in the same way, indicating a cross-reactivity. Some manufacturers give a remark on a possible cold agglutinin activity of their monoclonal anti-c reagents in the instruction leaflet, but in order to avoid such irritation, we recommend to remove this cross-reactivity by dilution during the manufacturing process.
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PMID:False-positive reactions of some monoclonal anti-c reagents. 1956 72