Agglutinations

Polyagglutinability involving all the blood cells of one patient has been shown to be related to a partial deficiency of sialic acid residues at the surface of the erythrocyte (Lalezari and Al-Mondhiry, 1973). 

On the basis of a concentration of 2.4 x 10 molecules of sialic acid per cell, a high sialyltransferase activity, and a measurable neuraminidase activity at the surface of the human blood platelet, Bosmann (1972) proposed that platelet aggregation could result from an interaction, at the surface of the cell, between the sialyltransferases and the galactosyl residues liberated by the action of the neuraminidase. This application of Roseman s (1970) theory to platelet aggregation would require a dynamic equilibrium of transfers and removals of sialic acid residues, with continuous formation, degradation, and reformation of the enzyme-substrate complexes. 

Other Blood Cells. In their study of blood cells in cheek-pouch venules Atherton and Bom (1973) found that neuraminidase treatment caused near complete adhesion of the granulocytes to the vascular endothelium, but addition of A -acetylneuraminic acid had no effect, thus establishing a clear difference between the adhesion of platelets and that of granulocytes. Increase of sialic acid concentration in the plasma by neuraminidase treatment or addition of V-acetylneuraminic acid increased the time of the first appearance of thrombi in cheek-pouch venules, but neither neuraminidase nor V-acetylneuraminic acid modified the platelet count (Atherton and Born, 1973). 

Small lymphocytes leave the blood circulation through an endothelial cell that normally occurs only in the postcapillary venules of lymph nodes. Pretreatment of the small lymphocytes with neuraminidase or trypsin greatly diminished their rate of migration (Bom, 1974). 

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Turbidimetric Agglutination Immunoassays. Agglutination—precipitation immunoassays were among the first practical appHcations of the antigen—antibody reaction in diagnostic tests. These assays are not as widely used in the 1990s as EIA and FIA because they are either not quantitative enough or lack the sensitivity limits of RIA, EIA, and EIA. 

Latex agglutination immunoassays are easily formatted into simple kits which can provide yes/no and semiquantitative estimates of antigen (or antibody) in a sample. The first such assay was developed in 1957 for rheumatoid factor (15) and assays are on the market for the deterrnination of many species of bacteria, fungi. Mycoplasma, parasites, ckettsia, and vimses, as well as for the deterrnination of autoimmune disease, hormones (qv), dmgs (see Pharmaceuticals), and blood proteins (16). Latex agglutination is also the basis of many home pregnancy tests. 

Turbidimetry and Nephelometry. In contrast to classical absorbance methods, immunoassay reactions frequently involve agglutination in which the optical scatter signal of the agglutinated particles is measured by turbidimetric or nephelometric means. The principles of light scattering as it relates to analytical methods is discussed in reference 6. 

Lectins (proteins and/or glycoproteins of non-immune origin that agglutinate cells, from seeds of Robinia pseudoacacia), M 100,000. Purified by pptn with ammonium sulfate and dialysis then chromatographed on DE-52 DEAE-cellulose anion-exchanger, hydroxylapatite and Sephacryl S-200. [Wantyghem et al. Biochem J 237 483 1986.]... 

Zorbax PSM particles are made from small (80-2000 A), extremely uniform colloidal silica sol beads. In a patented polymerization process, these beads are agglutinated to form spherical particles. The size of the Zorbax PSM particles is controlled by the polymerization process, and the pore size is determined by the size of the silica sol beads. After polymerization, the silica is heated to remove the organic polymer and sinter the particles. The result is a spherical, porous, mechanically stable, pure silica particle that provides excellent chromatographic performance (Pig. 3.1). 

Agglomerat, n. agglomerate sinter cake, agglomerieren, v.t. i. agglomerate, agglutmleren, v.t. i. agglutinate. 

Kleb-kraft, /. adhesive power, -kraut, n. cleavers Galium). -lack, m. adhesive lacquer, -material, n. adhesive material, -mittel, n. adhesive, agglutinant binder, -pflaster, n. adhesive plaster, klebrig, klebricht, a. — kleberig. 

Lfltung,/. soldering sealing (of glass) agglutination adhesion. 

Zusammen-klebung, /. adhesion agglutination. -kunft, /. convention, assembly conference. -lagerung, /. assemblage. 

It has been known for more than a century that human blood can be classified into four blood-group types (A, B, AB, and 0) and that blood from a donor of one type can t be transfused into a recipient with another type unless the two types are compatible (Table 25.1). Should an incompatible mix be made, the red blood cells clump together, or agglutinate. 

The agglutination of incompatible red blood cells, which indicates that the body s immune system has recognized the presence of foreign cells in the body and has formed antibodies against them, results from the presence of polysaccharide markers on the surface of the cells. Types A, B, and O red blood cells... 

The suspension of influenza virus, strain A/X-53, was separated from the constituents of alantoic fluid by preparative size exclusion chromatography on a 10 x 120 cm column. The hemo-agglutination method revealed an elevated level (93%) of viral activity. The leakage of the bonded phases can be more efficiently minimized, however, with the use of positively charged polymers. 

Universal anti-Rh sera deprived of anti-A or B-antibodies were prepared by contacting A and B-immunoadsorbents with human blood sera. To achieve zero titer in the Coombs agglutination test a portion of immunoadsorbent (80-160 mg) proportional to the initial serum titer (1 8-1 64, 1 ml) is required. The incorporation of A-immunoadsorbent into anti-B sera did not interfere with their titer and vice versa, Under the same circumstances an anti-Rh serum titer is lowered by one step or remains unchanged [125], Properties of this composite sorbent are therefore promising for its use in extracorporal hemisorption processes. 

Several results are quite apparent from the data shown in Table II. It is evident from the pentapeptide model compounds that substitution of amino acid residues at positions 4 and 5 does not significantly affect the structure about the N-terminus. This observation corroborated earlier work from agglutination-inhibition assays, which demonstrated that the nature of the amino acid at position 4 of the peptide (or glycopeptide) is not a requirement for specificity. 

Agglutination. The aggregation of bacterial cells into agglutinates enabling phagocytes to eliminate these cells rapidly firm the body. 

Spherical microparticles are more difficult to manufacture and can be prepared by several methods. One method prepares silica hydrogel beads by emulsification of a silica sol in an immiscible organic liquid [20,21,24,25]. To promote gelling a silica hydrosol, prepared as before, is dispersed into small droplets in a iater immiscible liquid and the temperature, pH, and/or electrolyte concentration adjusted to promote solidification. Over time the liquid droplets become increasingly viscous and solidify as a coherent assembly of particles in bead form. The hydrogel beads are then dehydrated to porous, spherical, silica beads. An alternative approach is based on the agglutination of a silica sol by coacervation [25-27], Urea and formaldehyde are polymerized at low pH in the presence of colloidal silica. Coacervatec liquid... 

If CSF Gram stain and/or culture is negative, rapid diagnostic tests (such as latex agglutination) may be useful these tests are positive even if bacteria are dead. 

Lectins, glycoproteins known for their ability to agglutinate erythrocytes in vitro, are present in many types of plants, including beans. Some lectins are toxic. Lectins interact with certain carbohydrates in a specific way. Lectins are still being studied. It appears that lectins may be involved in recognition between... 

Serological methods (mostly requiring one day) Latex agglutination... 

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