Pathophysiology of intense physical conditioning in a hot climate. I. Mechanisms of potassium depletion.

Serial estimations of exchangeable (42)K showed that six volunteer subjects undergoing intensive physical conditioning in a hot climate sustained a mean deficit of 517 mEq. This deficit occurred despite a daily potassium intake of 100 mEq. Simultaneous values for lean body mass rose suggesting that potassium deficiency was not the result of catabolism.

Chloramphenicol-specific antibody. V. A method for the detection of anti-chloramphenicol antibody in human serum.

Chloramphenicol coupled to human serum albumin labelled with Iodine was used as the detecting antigen, in an improved method (modified Farr technique) for the measurement of anti-chloramphenicol antibody. By blocking with crystalline chloramphenicol to distinguish specific from non-specific binding, 10 ng/ml of antibody can be detected in human serum.

Chloramphenicol-specific antibody. II. Reactivity to analogues of chloramphenicol.

Using the classical hapten inhibition technique, antibody binding sites on the chloramphenicol molecule were explored. Sixteen compounds related to chloramphenicol, but with varying degrees of change in their structure, were examined for inhibiting ability at 1-, 10- and 100-μg levels. The removal of the two chlorine atoms accounted for the greatest loss of antibody binding capacity.

Chloramphenicol-specific antibody. IV. Neutralization of antibiotic effect on Escherichia coli.

While normal serum globulin is able to bind chloramphenicol, it does not interfere with chloramphenicol's inhibition of the growth of , whereas serum globulin containing antibody specific for chloramphenicol significantly inhibits the usual antibiotic activity.

Chloramphenicol-specific antibody. 3. Differential antibody decay rates to separate determinants on one antigen.

In rabbits, peak titres to repeated immunization with chloramphenicol bound to bovine γ-globulin (CAP—BGG) appear on the 4th to 7th day for the BGG part of the antigen, but not until the 9th to 12th day for CAP. Similarly the antibody to CAP declines in titre much more rapidly than the antibody to the BGG and 4–6 weeks later anti-CAP antibody is no longer detectable while the anti-BGG antibody is still found in high titre.

Chloramphenicol-specific antibody.

Antibody to the antibiotic chloramphenicol was obtained by immunizing rabbits with a chloramphenicol derivative coupled to bovine gamma globulin. Production of antibody was demonstrated by the precipitin and complement fixation reactions with "reduced chloramphenicol" coupled to rabbit serum albumin as the test antigen. Specificity of the antibody was confirmed in that crystalline chloramphenicol completely inhibited complement fixation and precipitin reactions.

Passive immune kill of cells in tissue culture.

Mammalian cells in tissue culture can bind foreign protein to the cell surface and be killed by antiserum with specificity directed to the foreign antigen. The reaction is complement-dependent and, by analogy to passive immune haemolysis, is termed passive immune kill. Passive immune kill is specifically inhibited by incorporation of the foreign protein, in antigen excess, into the reaction mixture.

ANTIGENIC SPECIFICITIES ACQUIRED FROM THE GROWTH MEDIUM BY CELLS IN TISSUE CULTURE.

Studies employing quantitative complement fixation have shown that HeLa and other mammalian cells grown in tissue culture adsorb serum protein components from the growth medium. The serum proteins are not completely removed by vigorous washing. Upon injection of extensively washed cells into rabbits the bound serum proteins give rise to specific antibodies detectable by gel diffusion and complement fixation.