STEPWISE INTRATYPE TRANSFORMATION OF PNEUMOCOCCUS FROM R TO S BY WAY OF A VARIANT INTERMEDIATE IN CAPSULAR POLYSACCHARIDE PRODUCTION.

1. A variant intermediate between the classical R and S forms has been isolated by selective procedures from a rough strain of pneumococcus originally derived from Type II S. 2.

THE TOXIC ACTION OF PREPARATIONS CONTAINING THE OXYGEN-LABILE HEMOLYSIN OF STREPTOCOCCUS PYOGENES : III. INDUCTION IN MICE OF TEMPORARY RESISTANCE TO THE LETHAL EFFECT OF THE TOXIN.

1. The susceptibility of mice to the lethal effect of preparations containing the oxygen-labile hemolysin (streptolysin O) of group A hemolytic streptococci has been studied. Injection of a single sublethal dose of the streptococcal preparation causes the development of resistance to the effect of a lethal dose injected subsequently.

PROTAMINE PURIFICATION OF STREPTOKINASE AND EFFECT OF pH AND TEMPERATURE ON REVERSIBLE INACTIVATION.

1. Treatment of crude concentrates of streptokinase with protamine results in removal of about 90 per cent of the nitrogenous material, including nucleic acid and protease inhibitor, with little or no loss of activity. 2.

RELATION OF IRON SALTS TO INHIBITION OF GLYCOLYSIS BY THEILER FA VIRUS OF MOUSE ENCEPHALOMYELITIS.

1. Brain homogenates of mice infected with the Theiler FA strain of mouse encephalomyelitis virus show marked inhibition of glucose phosphorylation. 2.

FACTORS INVOLVED IN PRODUCTION OF CLOSTRIDIUM WELCHII ALPHA TOXIN.

Maximum production of the alpha toxin by Cl. welchii is dependent on the inclusion in the medium of several substances in addition to those required for growth. These factors include: 1.

COMPARATIVE KINETICS OF HEMOLYSIS INDUCED BY BACTERIAL AND OTHER HEMOLYSINS.

A study has been made of the kinetics of lysis induced by various hemolytic agents. The course of bemolysis was followed by mixing lysin with washed human erythrocytes, removing samples from the mixture, and estimating colorimetrically the hemoglobin in the supernatant fluid of the centrifuged samples. Most of the curves (but not all of them, e.

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 ACTIVATION OF PLASMINOGEN BY CHLOROFORM.

1. Treatment of serum with chloroform results in immediate inactivation of the protease inhibitor present. 2.

INHIBITION OF PHOSPHORYLATION OF GLUCOSE IN MOUSE BRAINS BY VIRUSES AND ITS PREVENTION BY PREPARATIONS OF DIPHOSPHOPYRIDINE NUCLEOTIDE.

1. Inhibition of glucose utilization in homogenates of brains of mice infected with poliomyelitis virus (Lansing strain) is reported. The inhibition occurs with glucose, or fructose-6-phosphate as substrate.

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.

PREVENTION OF PNEUMOCOCCAL PNEUMONIA BY IMMUNIZATION WITH SPECIFIC CAPSULAR POLYSACCHARIDES.

1. Immunization of man with 0.03 to 0.

A PROTEOLYTIC ENZYME OF SERUM: CHARACTERIZATION, ACTIVATION, AND REACTION WITH INHIBITORS.

1. Fibrinolysin-activated lysin factor and chloroform-activated serum protease of serum and plasma are one and the same enzyme, differing only in their mode of activation. 2.

STREPTOCOCCAL FIBRINOLYSIS: A PROTEOLYTIC REACTION DUE TO A SERUM ENZYME ACTIVATED BY STREPTOCOCCAL FIBRINOLYSIN.

1. Methods for the preparation and partial purification of streptococcal fibrinolysin are described. 2.

THE CARDIOTOXIC ACTION OF PREPARATIONS CONTAINING THE OXYGEN-LABILE HEMOLYSIN OF STREPTOCOCCUS PYOGENES : II. INHIBITION OF CARDIOTOXIC EFFECT BY A SUBSTANCE RELEASED FROM THE FROG'S HEART.

1. The mechanism of sensitization of the isolated frog' heart to a product of the hemolytic streptococcus has been investigated. The sensitization depends upon the release from the isolated heart of a substance which inhibits the action of the cardiotoxin.