Akademik

That which is more than the usual or specified amount.

- antibody e. in a precipitation test, the presence of antibody in an amount greater than that required to combine with all of the antigen present. See prozone.

- antigen e. 1. in a precipitation test, the presence of uncombined antigen above that required to combine with all of the antibody; precipitation may be inhibited because the presence of e. antigen gives rise to soluble antigen-antibody complexes; 2. in vivo the resultant antigen-antibody interaction in such an antigen e. may give rise to immune complexes, which have a potential to induce cellular damage; could be tolerogenic.

- base e. a measure of metabolic alkalosis, usually predicted from the Siggaard-Andersen nomogram; the amount of strong acid that would have to be added per unit volume of whole blood to titrate it to pH 7.4 while at 37°C and at a carbon dioxide pressure of 40 mm Hg.

- convergence e. that condition in which an esophoria or esotropia is greater for near vision than for far vision.

- negative base e. a measure of metabolic acidosis, usually predicted from the Siggaard-Andersen nomogram; the amount of strong alkali that would have to be added per unit volume of whole blood to titrate it to pH 7.4 while at 37°C and at a carbon dioxide pressure of 40 mm Hg.