Effect of the method of agitation on the accumulation of protective antigen in cultures of Bacillus anthracis.
Accumulation of protective antigen was essentially independent of culture volume, provided the organisms were kept in suspension by stirring. Agitation by orbited shaking was unsatisfactory.
Studies on immunity in anthrax. III. Elaboration of protective antigen in a chemically defined, non-protein medium.
Summary Elaboration of the protective antigen of Bacillus anthracis was obtained in a chemically-defined, non-protein medium composed of 17 amino acids, inorganic salts, adenine, guanine, uracil, thiamine, glutamine, glucose, and sodium bicarbonate. Sterile filtrates of static 20-hour cultures of a non-proteolytic mutant strain of B. anthracis , when injected in divided doses totaling 1 ml., were capable of immunizing rabbits so that they survived intracutaneous challenge with 10,000 spores of virulent B. anthracis , representing at least 100 lethal doses. The preparations immunized guinea pigs against a challenge of 1000 spores and, when precipitated with alum, produced detectable immunity in mice. A preliminary experiment suggested that the antigen also produced effective immunity in monkeys. Tentative indications as to some of the critical constituents and cultural conditions for production of antigen were obtained. Protective antigen activity of the crude culture filtrate was relatively unstable; the protective antigen could, however, be concentrated and stabilized by lyophilization or by alum precipitation. The meaning of the results is discussed.
ARRESTS AMONG HOMELESS AND RUNAWAY YOUTHS: THE EFFECTS OF RACE AND GENDER
ABSTRACT This study examined the contributions of race and gender to the likelihood of a first post-run arrest for a more serious and less serious offense in a sample of homeless and runaway youths from four Midwestern states. Event history analysis was used to test the hypothesis that race and gender would interact so that the likelihood of a first post-run arrest for a more serious and less serious offense would be highest for non-white males and non-white females, respectively. Potentially confounding factors—deviant subsistence strategies, substance use, gang involvement and membership, prior arrests, age, prior physical abuse, age on own, and spending time on the street—were controlled in the analyses. The hypotheses regarding the interaction of race and gender were not supported by the data. Non-whites were more likely than whites, and males were more likely than females, to be arrested for a more serious offense, and white females were more likely than non-white females to be arrested for a less serious offense.