THE CARDIOTOXIC ACTION OF PREPARATIONS CONTAINING THE OXYGEN-LABILE HEMOLYSIN OF STREPTOCOCCUS PYOGENES : I. INCREASED SENSITIVITY OF THE ISOLATED FROG'S HEART TO REPEATED APPLICATION OF THE TOXIN.

1. A study has been made of the effect on the isolated frog's heart of a preparation derived from the supernatant fluid of cultures of hemolytic streptococcus. 2.

KINETICS OF LYSIS BY CLOSTRIDIUM SEPTICUM HEMOLYSIN.

The kinetics of the hemolytic reaction effected by the hemolysin of Clostridium septicum, strain 44, has been studied with regard to the effect of concentration, temperature, and hydrogen ion concentration on the rate of the hemolytic reaction. The kinetics of hemolysis was found to resemble in several respects that of enzyme-catalyzed reactions, but differed in the absence of a clearly defined pH optimum. Attention is drawn to differences between the hemolytic system studied and certain other hemolytic systems.

NUTRITIONAL REQUIREMENTS AND FACTORS AFFECTING THE PRODUCTION OF TOXIN OF CLOSTRIDIUM SEPTICUM.

A medium consisting of a complete acid hydrolysate of casein supplemented with cystine, tryptophan, growth accessory factors, glucose, and inorganic salts, has been developed for the cultivation of Clostridium septicum. Toxin equivalent to 400 to 700 L.D(50) per ml.

PARALLELISM IN THE LETHAL AND HEMOLYTIC ACTIVITY OF THE TOXIN OF CLOSTRIDIUM SEPTICUM.

The relation of the lethal toxin to the hemolysin produced by Clostridium septicum, strain 44, has been investigated. The following results suggest that the hemolytic and lethal actions of crude toxin are functions of a single substance or that they are functions of two substances which have similar physical, chemical, and antigenic properties. (1) Within the limits of experimental error, the lethal activity of cultures is directly proportional to their hemolytic activity.

THE SEROLOGICAL DIAGNOSIS OF RELAPSING FEVER.

1. Spirochetes of relapsing fever have been separated from the blood of heavily infected mice and rats by hemolysing with saponin, followed by repeated washing of the spirochetal suspension with physiological saline. 2.

THE CONTROL OF THE RENAL EXCRETION OF WATER : II. THE RATE OF LIBERATION OF THE POSTERIOR PITUITARY ANTIDIURETIC HORMONE IN THE DOG.

1. The administration of the posterior pituitary antidiuretic hormone by constant intravenous infusion has been used to examine the two characteristic actions of the hormone; namely, the facilitation of the active renal tubular reabsorption of water distally in the nephron and the inhibition of the renal tubular reabsorption of sodium proximally. 2.

THE CONTROL OF THE RENAL EXCRETION OF WATER : I. THE EFFECT OF VARIATIONS IN THE STATE OF HYDRATION ON WATER EXCRETION IN DOGS WITH DIABETES INSIPIDUS.

Water and electrolyte excretion has been studied in a series of dogs with diabetes insipidus, in which the extent of neurological damage was subsequently determined. The animals were studied before and after the introduction of variables which produce marked changes in the state of hydration,-administration and restriction of water and the substitution of 0.5 per cent sodium chloride for it as a drinking fluid.

THE INACTIVATING EFFECT OF SULFAPYRIDINE ON THE LEUKOTOXIC ACTION OF BENZENE.

1. In rabbits receiving subcutaneous injections of benzene, the simultaneous administration of sulfapyridine, per os, prevented the development of leukopenia. The sparing effect of sulfapyridine on the intoxication of the leukopoietic tissue by benzene was demonstrated not only by the range of daily leukocyte counts but also by microscopic examination of the bone marrow of treated animals.