Search results for "Hemagglutination Tests"
showing 10 items of 10 documents
Determination of lectin-cell-binding parameters by a new agglutination technique.
1992
We applied a recently described technique which is based on a light transmission/scattering method to determine the association characteristics of the Geodia lectin to sheep erythrocytes. The agglutination assays were performed in a total volume of 3 ml with 5.4 x 10(6) erythrocytes/ml. At a concentration of 360 ng/ml 50% of the lectin molecules were bound to the cells within the first 10 s of incubation. Scatchard analyses revealed an association constant (K(a)) of 0.9 +/- 0.1 x 10(8) M-1 and a number of 3.8 +/- 0.6 x 10(6) lectin binding sites on one erythrocyte. The method was also successfully applied to determine quantitatively the inhibitory potential of sugars competing with cell sur…
Cytotoxic activity of Ciona intestinalis (Tunicata) hemocytes: Properties of the in vitro reaction against erythrocyte targets
1993
Hemocytes (effectors) of Ciona intestinalis showed a natural cytotoxic capacity (HCA) when assayed in vitro against erythrocytes (targets). Cytotoxic cells lysed, to a variable extent, rabbit (RE), human (A, B, O), guinea pig, and sheep (SE) erythrocytes. Hemocyte cytotoxic activity (HCA) assayed against SE is a calcium-dependent reaction, occurs rapidly (15-30 min), at 25-37 degrees C over a wide range of pH (5.4-8.0). Assays were carried out using: 1) the medium in which hemocytes were maintained, 2) the soluble portion of hemocyte lysates, and 3) debris prepared from hemocyte lysates. Results suggest that HCA is a cell-mediated process that requires effector-target cell contacts. Anti-SE…
Carbohydrate binding specificity and purification by biospecific affinity chromatography of Ascidiamalaca traust. Hemagglutinins
1982
The carbohydrate specificities of Ascidia malaca serum hemagglutinins were determined by hemagglutination inhibition tests. Analysis of agglutinins against rabbit and human A, B, O erythrocytes suggests that the size of the combining site corresponds to a disaccharide with a specificity for saccharides containing a D-galacto configuration (D-melibiose, D-raffinose, D-galactose, alpha-lactose, lactulose, L-arabinose). No anomeric specificity was observed with oligosaccharides. Hydroxyl groups probably involved in hydrogen-bond formation with agglutinin binding site, were identified as carbons C2, C4, C5 and C6 of D-galactose. Absorption experiments showed that two distinct agglutinins with s…
The Specificity of Hemagglutinating Bean and Seed Extracts (Lectins)
1969
Circulating diphtheria antitoxin levels in children aged 11-14 years in relation to the vaccinal history.
1991
Diphtheria antitoxin level in serum samples obtained from 204 healthy children aged 11-14 years was determined by means of an indirect haemagglutination technique and related to the vaccinal history of the subjects. Irrespective of the time since the last toxoid inoculation, the mean antitoxin titre per ml of serum in the individuals who had received incomplete/irregular anti-diphtheria vaccination in childhood was significantly higher when the number of toxoid doses was higher (from two to more than four doses); the same was not observed for individuals given primary vaccination (three toxoid doses) according to the schedule for childhood vaccination in Italy (regular vaccinees) and one or…
A novel galactose- and arabinose-specific lectin from the sponge Pellina semitubulosa: isolation, characterization and immunobiological properties.
1992
A new lectin from the sponge Pellina semitubulosa is derived which was extracted and purified to homogeneity. The purified lectin is probably a hexamer of polypeptide chains (each M(r) 34,000) which are covalently linked via disulfide linkages; the isoelectric point is 6.1. The lectin displays the following specificities: D-galactose (50% inhibition of hemagglutination at 0.2 mM) = L-arabinose (0.2 mM) greater than D-fucose (1.5 mM) greater than D-glucose (3.0 mM). It precipitates human erythrocytes (A1, A2, A1B, B, and O) with a titer between 2(8) and 2(11) and erythrocytes from sheep and rabbits with a titer between 2(5) and 2(10). The Pellina lectin displays a strong mitogenic effect on …
Immune activation rapidly mirrored in a secondary sexual trait.
2003
A crucial assumption underlying most models of sexual selection is that sexual advertisements honestly reflect the phenotypic and/or genetic quality of their bearers ([1][1]). Here we show that experimental activation of the immune system is rapidly mirrored in the expression of a carotenoid-based
Arthus type inflammation with rat immunoglobulins.
1971
Etude comparative des proprietes biologiques des anticorps IgM, IgG1 et IgG2 du rat. Les resultats montrent que le pouvoir agglutinant et lytique des anticorps IgM est respectivement 37 et 100 fois superieur a celui des deux classes d'anticorps IgG. Par contre, en ce qui concerne le phenomene d'Arthus, les anticorps IgM sont moins actifs que les anticorps IgG, si les rapports sont exprimes en poids. Si l'on calcule les rapports par nombre de molecules, les anticorps IgM sont aussi, dans ce cas, plus actifs que les IgG.
A serum fucolectin isolated and characterized from sea bass Dicentrarchus labrax
2001
A lectin specific for fucose and galactose was isolated by affinity chromatography on Sepharose CL-6B from the serum of Dicentrarchus labrax. The hemagglutinating activity against rabbit erythrocytes was calcium-independent, and reached its maximum at 37 degrees C. Two protein components were found in the hemagglutinating fractions eluted from the Sepharose column. Only the 34 kDa component (DLL2) eluted from the polyacrylamide gels (SDS-PAGE) showed agglutinating activity against rabbit erythrocytes. SDS-PAGE, in non-reducing conditions, revealed a single 66 kDa protein that reacted with antibodies to the 34 kDa component. Therefore, a dimeric structure stabilized by disulfide bonds can be…