Haemagglutination inhibition

Biological characterization of the nanoparticles was carried out by monitoring in vitro interactions with hepatocytes isolated from rat liver [12], Haemagglutination inhibition test of erythrocytes with ricine agglutinin (RCA120) was carried out [13]. The fluorescence of the hepatocytes incubated with the FlTC-labeled nanoparticles was determined by means of a FACS Star Becto-Dickinson instmment. 

Autoanalyser chemical ionization and electron impact m.s./ chromatography-colorimetry electron-capture g.c. fluorimetry g.l.c. " g.c.-chemical ionization m.s. g.c.-m.s. gravimetric, tit-rimetric analysis " haemagglutination inhibition " latex agglutination inhibition " liquid chromatography " mass fragmentography radioimmunoassay " spin-label immunoassayt.l.c. t.l.c.-g.l.c. T.l.c. ... 

CS 6-O-sulfate Esterification using inorganic acids Polyampholite soluble in water Anticoagulant Haemagglutination inhibition activities Anti sclerotic Antiviral Antihuman immunodeficiency virus Antibacterial Antioxidant Enzyme inhibition activities... 

Figure 3.4 Representative plot of of PCPP versus influenza haemagglutination-inhibition (HAI) antibody response. Reproduced w ith permission from L.G. Payne, S.A. Jenkins, A.L. Woods, E.M. Grund, WE. Geribo, J.R. Loebelenz, A.K. Andrianov and B.E. Roberts, Vaccine, 1998,16, 1, 92. 1998, Elsevier [43]...

Haemagglutination inhibition. This is based on the ability of certain antigens to inhibit haemagglutination of coated cells by antibody. 

Haemagglutination inhibition assays with guinea pig erythrocytes using the decavalent mannose derivative 60 (Fig. 22.19) gave low pM values for the minimum inhibitory concentration (5.91 pM), a 6.7-fold enhancement per mannose unit, compared to a monomeric control confirming the potential of multivalent ligands to aid binding even with monomeric lectins. 

The passive haemagglutination technique presents several disadvantages. For example, certain biological fluids contain spontaneous agglutinins which induce haemagglutination independently of the presence of antibodies. In addition, when the technique is applied to complex media such as human serum or urine, nonspecific haemagglutination inhibition is sometimes observed. 

Larin and Gallimore [86] have provided evidence to show that if viral protein is solubilized by surfactants this may result in loss or enhancement of specific viral antigenicity. Treatment of influenza virus with Triton X-100 significantly enhances the antigenicity of viral protein as judged by virus neutralization and haemagglutination inhibition tests similar treatment by Tween 80, NaDS and deoxycholate led to a partial or complete loss of immunogenicity. 

The most active metabolite was the novel cyclic undecapeptide, cyclosporin A (Figure 8). As an antibiotic, cyclosporin A exhibited only a very narrow spectrum of modest antifungal activity, but in 1972 its true potential was realised. Jean Borel and colleagues at Sandoz discovered that cyclosporin A also neutralised cytotoxic T-cell activity in vitro and prevented haemagglutination in mice immunised against sheep erythrocytes. Further studies revealed that cyclosporin A inhibits T-cell proliferation by blocking the synthesis of IL-2. ... 

Glycoproteins isolated from the erythrocytes of rhesus monkeys inhibit haemagglutination by measles virus. 

Sialic acid has been attached, as an a-glycoside, to a spacer arm terminating in an acrylamide unit. Polymerization of this material with excess acrylamide gave a material which inhibited haemagglutination induced by influenza virus. ... 

Phytohaemagglutinins.—pH-Acetyl]concanavalin A has been shown to bind to, and partially inhibit the enzymic activity of, proline 2-oxoglutaratedioxygenase. The products obtained when concanavalin A is labelled with 4-azidophenyl a-D-mannopyranoside under u.v.-irradiation have been separated by affinity chromatography on Sephadex G-lOO at pH 5. One of the products is a monovalent dimer at pH 5 and a divalent tetramer at pH 7, indicating that photo-affinity labelling did not alter the quaternary structure of concanavalin A, although the haemagglutinating activity of the derivatized lectin was reduced. 

The quantity of capsular polysaccharide is apparently of importance in a variety of pathogens. Klebsiella pneumoniae. Salmonella typhi, 5. typhi-murium, E. coli. Streptococcus pneumoniae and Staphylococcus aureus have all been reported to show a relationship between the amount of capsular material and virulence, resistance to phagocytosis, or resistance to humoral host defences. It has been suggested in the case of E. coli that the amount of K-antigen, as measured by its ability to coat red blood cells and inhibit their aggregation by haemagglutinating antiserum, is the most important factor determining resistance to the complement-mediated bactericidal activity of serum. Other studies have found evidence that the type of capsular polysaccharide may be more important. 

Rosenberg, A., and E. Chargaff Inhibition of influenza virus haemagglutination by a brain lipid fraction. Nature (Lond.) 177, 234 (1956). 

Both studies show that the duration of the illness can be reduced by 3 - 4 days with elderberry syrup compared with placebo. A possible mechanism of action of elderberry extract in the treatment of influenza is that the flavonoids stimulate the immune system by enhancing production of cytokines by monocytes [44], In addition, elderberry has been shown to inhibit the haemagglutination of the influenza virus and thus prevent the adhesion of the virus to the cell receptors [42]. 

Brunetti, P., Jourdian, G. W., and Roseman, S., 1%2, The sialic acids III. Distribution and properties of animal N-acetylneuraminic aldolase, J. Biol. Chem. 237 2447-2453. Burnet, F. M., 1948, Mucins and mucoids in relation to influenza virus action. III. Inhibition of virus haemagglutination by glandular mucins, Aust. J. Exp. Biol. Med. Sci. 26 371-329. 

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