IMPROVED METHODS FOR THE PREPARATION OF THE SPECIFIC POLYSACCHARIDES OF PNEUMOCOCCUS.

The specific polysaccharides of Types I and V pneumococcus give sharp equivalence zones and show maximal precipitation with homologous rabbit antisera only when carefully prepared from cultures which have not been neutralized with alkali. The precipitating power of S V toward homologous rabbit antiserum falls off in 0.1 N NaOH even more rapidly than that of S I, dropping to 7 per cent of the original value in 6 days at room temperature.

ANTIPROTEINS IN HORSE SERA : IV. ANTIBODIES TO RABBIT SERUM GLOBULIN AND THEIR INTERACTION WITH ANTIGEN.

1. The intravenous injection of two horses with alum-precipitated rabbit serum globulin resulted in the production of antibody which gave a typical precipitin reaction without a prezone in the region of antibody excess. 2.

ANTIPROTEINS IN HORSE SERA : III. ANTIBODIES TO RABBIT SERUM ALBUMIN AND THEIR REACTION WITH ANTIGEN.

1. Two horses were injected subcutaneously with alum-precipitated rabbit serum albumin. 2.

ANTIPROTEINS IN HORSE SERA : II. ANTIBODIES TO PNEUMOCOCCUS NUCLEOPROTEIN AND THEIR REACTION WITH ANTIGEN.

The antiprotein in an antipneumococcus horse serum resulting from intravenous injections of infected pleural exudate showed a precipitin type of reaction with pneumococcus nucleoprotein rather than the antitoxin type of response.

ANTIBODY FORMATION IN MEN FOLLOWING INJECTION OF FOUR TYPE-SPECIFIC POLYSACCHARIDES OF PNEUMOCOCCUS.

1. Random selections of the sera of trainees injected 2 months previously with the specific polysaccharides of Types I, II, V, and VII pneumococci contained quantities of antibody to Types I, II, and VII sufficient to account for the favorable results of the immunization procedure. 2.

THE ACTIVATING EFFECT OF MAGNESIUM AND OTHER CATIONS ON THE HEMOLYTIC FUNCTION OF COMPLEMENT.

1. The evidence presented indicates that Mg(++), or other cation such as Ca(++), Ni(++), or Co(++), is essential for the hemolytic action of C'. Ca(++), Ni(++), and Co(++) are less effective than Mg(++).

ANTIBODY FORMATION IN VOLUNTEERS FOLLOWING INJECTION OF PNEUMOCOCCI OR THEIR TYPE-SPECIFIC POLYSACCHARIDES.

1. A modification of the microanalytical quantitative precipitin method, five to ten times as sensitive as the older procedure, has been used to measure the type-specific antibody response in human beings. Injections of type-specific pneumococci or equivalent amounts of their type-specific polysaccharides led to comparable antibody production.

A COMPARISON OF HUMAN AND GUINEA PIG COMPLEMENTS AND THEIR COMPONENT FRACTIONS.

1. Defects in methods previously proposed for the estimation of complement components are: failure to ensure an excess of the desired components and failure to ensure absence of anticomplementary effects in the dilution ranges used. Existing data are therefore subject to these uncertainties.

THE EFFECT OF SALICYLATES ON THE PRECIPITATION OF ANTIGEN WITH ANTIBODY.

1. Sodium salicylate modifies the precipitation of normal rabbit serum protein by sodium tungstate, and partially inhibits the precipitation of horse serum euglobulin by rabbit antiserum. Sodium salicylate added to a system containing crystalline egg albumin and its antibody partly prevents the formation of precipitate, the degree of inhibition being related to the concentration of salicylate.

QUANTITATIVE CHEMICAL STUDIES ON HEMOLYSINS : I. THE ESTIMATION OF TOTAL ANTIBODY IN ANTISERA TO SHEEP ERYTHROCYTES AND STROMATA.

1. Total antibody in hemolysins may be estimated from the nitrogen added to sheep stromata suspensions. 2.

QUANTITATIVE CHEMICAL STUDIES ON COMPLEMENT OR ALEXIN : IV. ADDITION OF HUMAN COMPLEMENT TO SPECIFIC PRECIPITATES.

1. A modified method is given for the titration of human complement so that C'1 titers are measured, as in guinea pig serum, instead of the C'2 titers yielded by the usual titration. 2.

QUANTITATIVE EXPERIMENTS WITH ANTIBODIES TO A SPECIFIC PRECIPITATE : III. ANTIGENIC PROPERTIES OF HORSE SERUM FRACTIONS ISOLATED BY ELECTROPHORESIS AND BY ULTRACENTRIFUGATION.

1. Rabbit antisera to a Type II pneumococcus specific precipitate from horse serum were tested with fractions prepared by ultracentrifugation and electrophoresis of normal and immune horse serum. 2.

A FURTHER STUDY OF THE CROSS REACTION BETWEEN THE SPECIFIC POLYSACCHARIDES OF TYPES III AND VIII PNEUMOCOCCI IN HORSE ANTISERA.

1. The cross reaction of the specific polysaccharide of Type VIII pneumococcus with Type III antipneumococcus horse serum has been studied quantitatively and found similar to the S III-anti-S VIII reaction. 2.

QUANTITATIVE CHEMICAL STUDIES ON COMPLEMENT OR ALEXIN : III. UPTAKE OF COMPLEMENT NITROGEN UNDER VARYING EXPERIMENTAL CONDITIONS.

1. Quantitative data are given on the effect of variations in the time of contact and the proportions of the reactants on the quantity of complement combining component nitrogen (C'1 N) found in active guinea pig serum. 2.

CHEMICAL STUDIES ON BACTERIAL AGGLUTINATION : VI. THE AGGLUTININ CONTENT OF ANTISERA TO HEMOLYTIC STREPTOCOCCI.

1. Application of the quantitative agglutination procedure to hemolytic streptococci and their antisera is shown to yield values indicative of the antibody content of the antisera in weight units. 2.

QUANTITATIVE CHEMICAL STUDIES ON COMPLEMENT OR ALEXIN : II. THE INTERRELATION OF COMPLEMENT WITH ANTIGEN-ANTIBODY COMPOUNDS AND WITH SENSITIZED RED CELLS.

1. The molecular quantities of hemolysin and complement combining component or components (C'1) involved in hemolysis have been calculated on the basis of new, quantitative, absolute methods of analysis. 2.

QUANTITATIVE CHEMICAL STUDIES ON COMPLEMENT OR ALEXIN : I. A METHOD.

1. A quantitative micro method, conforming to the criteria of analytical chemistry, is proposed for the estimation of complement, or its combining component or components, in milligrams per milliliter instead of in the customary relative and variable volume units. 2.