to evaluate the effect of supplemental vitamin c (vc) levels on performance and immune response of broiler chicks, 300 day-old ross male broiler chicks were allocated to a completly randomized design of 5 treatments(500 and 1000 ppm in diet, 500 and 1000 ppm in drinking water and control). immunity was assessed as antibody production against infectious bronchitis virus (ibv) and newcastle disea...

Monovalent dimers of concanavalin A (Con A) have been prepared by a combination of succinylation and photoaffinity labeling. Partial derivatization of native Con A using the photoaffinity label, p-azidophenyl-alpha-D-mannopyranoside, followed by affinity chromatography yielded a fraction that consisted of dimers with a single saccharide-binding site at pH 5. These monovalent dimers formed dival...

The stimulation of granulocyte O2- production by concanavalin-A can be reversed with alpha-methylmannoside. Such cells can be reactivated to generate O2- by adding phorbol myristate acetate or N-formyl-methionyl-leucyl-phenylalanine. Opsonized zymosan, however, is not an effective stimulant to these cells. alpha-Methylmannoside prevents, but does not reverse, depolarization of granulocytes by c...

An increase in the free cytoplasmic Ca2+ concentration in thymocytes can be detected by the fluorescent indicator quin 2 within a few seconds of the addition of concanavalin A and the response is quantified from the increased proportion of quin 2 in the cells chelated by Ca2+ ('% Ca-quin 2'). The % Ca-quin 2 in untreated cells is 53 +/- 6%, increases to 64 +/- 7% immediately after the addition ...

The current use of concanavalin A, the phytohemagglutinin of the jack bean ~ , as a probe for investigating membranous glycoproteins and glycolipids requires a detailed knowledge of the protein's specificity. Extensive hapten inhibition studies employing monoand oligosaccharides and their simple derivatives demonstrated that the concanavalin A combining sites are complimentary to ct-D-mannopyra...

The inhibition of protein synthesis in Chinese hamster V79 cells by diphtheria toxin is antagonized by the lectins concanavalin A, succinylated concanavalin A, and wheat germ agglutinin but not by Proteus vulgaris phytohemagglutinin or abrus agglutinin. The effects of concanavalin A and wheat germ agglutinin are reversed by methyl alpha-mannoside and N-acetylglucosamine, respectively. The inhib...

1. Gastric juice, saliva and ovarian-cyst fluid were fractionated into glycoprotein components by centrifuging to equilibrium in a caesium chloride density gradient. 2. The glycoprotein fractions from the gastric juice of two group O non-secretors, two group O secretors and three group A secretors all formed insoluble complexes with concanavalin A. 3. Fractions showing maximum interaction with ...