ANTIGENIC PROPERTIES OF THE TYPE-SPECIFIC SUBSTANCE DERIVED FROM GROUP A HEMOLYTIC STREPTOCOCCI.

1. A substance extracted from group A hemolytic streptococcus is described, which induces active immunity in mice, and in rabbits gives rise to precipitins and to protective antibodies passively transferable to mice. 2.

STUDIES ON ANTIBACTERIAL IMMUNITY INDUCED BY ARTIFICIAL ANTIGENS : I. IMMUNITY TO EXPERIMENTAL PNEUMOCOCCAL INFECTION WITH AN ANTIGEN CONTAINING CELLOBIURONIC ACID.

1. An artificial antigen containing the azobenzyl glycoside of cellobiuronic acid gives rise in rabbits to antibodies which: (a) give the Neufeld reaction and agglutinate Type III pneumococci, (b) confer passive protection on mice against infection with Types II, III, and VIII pneumococci. 2.

INFECTIOUS MYXOMATOSIS OF RABBITS : STUDIES OF A SOLUBLE ANTIGEN ASSOCIATED WITH THE DISEASE.

The soluble antigen of myxoma is a heat-labile protein which has an isoelectric point near pH 4.5 and is precipitated from half saturated solutions of ammonium sulfate. It can be partially purified by methods of differential precipitation based on variations in the pH and electrolyte concentration.

ULTRACENTRIFUGATION STUDIES ON THE ELEMENTARY BODIES OF VACCINE VIRUS : I. GENERAL METHODS AND DETERMINATION OF PARTICLE SIZE.

Ultracentrifugal studies on the CL dermal strain of vaccine virus indicate the following characteristics of the elementary bodies:- 1. A stable suspension of Paschen bodies in a dilute buffer solution of pH 6.2 to 8 sediments with the formation of a characteristic primary boundary which consistently shows a spread of approximately 14 per cent.

CHEMO-IMMUNOLOGICAL STUDIES ON CONJUGATED CARBOHYDRATE-PROTEINS : XII. THE IMMUNOLOGICAL PROPERTIES OF AN ARTIFICIAL ANTIGEN CONTAINING CELLOBIURONIC ACID.

1. Artificial antigens containing the azobenzyl glycosides of the disaccharide cellobiose and the aldobionic acid, cellobiuronic acid, give rise in rabbits to antibodies which are specific and characteristic of the saccharide constituent. The antiserum to cellobiuronic acid shows broader serological cross reactions than does that to cellobiose.

THE ISOLATION OF THE BLOOD GROUP A SPECIFIC SUBSTANCE FROM COMMERCIAL PEPTONE.

The isolation of the blood group A specific substance from commercial peptone has been described. The chemical and serological properties of the material from that source have been defined.

PRODUCTION OF EXPERIMENTAL OSTEOMYELITIS IN RABBITS BY INTRAVENOUS INJECTION OF STAPHYLOCOCCUS AUREUS.

1. The conditions under which a certain strain of staphylococcus (OH 172) causes in rabbits the development of bone inflammation have been described. 2.

IMMUNIZATION OF EXPERIMENTAL ANIMALS WITH A SOLUBLE ANTIGEN EXTRACTED FROM PNEUMOCOCCI.

Pneumococci killed by acetic acid at pH 4.2, then allowed to become Gram-negative at pH 7.0, under conditions such that no cellular disintegration takes place, release in solution small amounts of a substance which is precipitable by acetic acid, and soluble at neutral reaction.

THE EFFECT OF A TISSUE ENZYME UPON PNEUMOCOCCI.

Polymorphonuclear leucocytes contain an enzyme which destroys the basophilic character of beat-killed pneumococci (R and S variants) and inactivates the type specific polysaccharide antigen of encapsulated cells. The same enzyme, however, fails to cause a disintegration of the bacterial cells, or to decompose the capsular polysaccharide itself. The enzyme has been extracted from a number of animal tissues; it appears identical with a purified enzyme extracted from pancreatin and which decomposes yeast nucleic acid.

THE ABSENCE FROM THE URINE OF PERNICIOUS ANEMIA PATIENTS OF A MOSQUITO GROWTH FACTOR PRESENT IN NORMAL URINE.

Extracts prepared from the urine of normal persons or patients with aplastic anemia or leukemia contain a substance, possibly flavine or a flavine compound, which under suitable conditions of test enhances the growth of larvae of the mosquito, Aëdes aegypti. This substance is lacking, or is present in much smaller amount, in extracts from the urine of pernicious anemia patients showing symptoms of the disease. Extracts from the urine of the same patients after adequate treatment contain as much of the substance as normal urine extracts.

HEPATIC DYSFUNCTION IN DOGS FED DIETS CAUSATIVE OF BLACK TONGUE.

1. The feeding to dogs of a diet lacking the vitamin B(2) (G) complex results in a lowered capacity of the liver to excrete intravenously injected bilirubin. 2.

THE EFFECT OF FORMALDEHYDE ON PNEUMOCOCCI.

When used in low concentration, formaldehyde increases the rate of autolytic disintegration of pneumococci whereas in large concentrations it completely inhibits autolysis and preserves both the morphological and staining characteristics of the cells. Pneumococci treated with large concentrations of formaldehyde, then washed free of the antiseptic and resuspended in physiological solutions, rapidly undergo a change which renders them Gram-negative and smaller. The lysis is only partial, however, and is not accompanied by an actual disintegration of the cell.

THE INCREASED SUSCEPTIBILITY TO HEMOLYSIS BY INDOL IN DOGS FED DEFICIENT DIETS.

1. Indol is more hemolytic in the presence of a deficiency complex than when a normal diet is fed. 2.

INDUCED SUSCEPTIBILITY OF THE BLOOD TO INDOL.

1. Indol, orally administered, causes anemia when certain deficient diets are fed. 2.

THE HEMOLYTIC EFFECT OF INDOL IN DOGS FED NORMAL DIETS.

Indol is mildly hemolytic when fed to dogs taking normal diets.

TWO SEROLOGICAL TYPES OF GROUP B HEMOLYTIC STREPTOCOCCI WITH RELATED, BUT NOT IDENTICAL, TYPE-SPECIFIC SUBSTANCES.

1. Among group B hemolytic streptococci one serological type previously described as homogeneous has been shown, instead, to contain two closely related types, distinguishable by reciprocal absorption experiments. These streptococci are designated Types Ia and Ib.

PROPERTIES OF THE TYPE SPECIFIC PROTEINS OF ANTIPNEUMOCOCCUS SERA : III. IMMUNOCHEMICAL FRACTIONATION OF TYPE I ANTIPNEUMOCOCCUS HORSE AND RABBIT SERA.

Immunological and immunochemical fractionation of Type I antipneumococcus horse and rabbit sera have demonstrated the existence of several forms of immune protein, each fraction behaving as a type specific antibody, but differing from the others in chemical and immunological properties.

PROPERTIES OF THE TYPE SPECIFIC PROTEINS OF ANTIPNEUMOCOCCUS SERA : II. IMMUNOLOGICAL FRACTIONATION OF TYPE I ANTIPNEUMOCOCCUS HORSE AND RABBIT SERA.

The generally held view has been that in any immune serum only a single antibody would be induced by and react with a single antigen. Were this true the various manifestations of antibody activity should show a quantitative parallelism. It has already been shown (1), however, that with antipneumococcus horse serum the mouse protective potency does not parallel the maximum amount of specifically precipitable protein except within certain well defined groups of antisera.

PROPERTIES OF THE TYPE SPECIFIC PROTEINS OF ANTIPNEUMOCOCCUS SERA : I. THE MOUSE PROTECTIVE VALUE OF TYPE I SERA WITH REFERENCE TO THE PRECIPITIN CONTENT.

The ability to carry out with some measure of precision mouse protection tests for the estimation of potency of antipneumococcus sera has made possible the correlation of the protective potency with the amount of specifically precipitable protein. With antipneumococcus rabbit sera these protective ratios are relatively constant and higher than those with immune horse serum. Type I antipneumococcus horse sera, on the other hand, show no such constancy but fall into two groups; and there is as yet no simple method for determining to which group a serum belongs.