THE SPIROCHETICIDAL ACTIVITY OF THE HUMAN SYPHILITIC SERUM AND THE IMMUNOLOGIC SIGNIFICANCE OF THE WASSERMANN REACTION

Abstract

EXPERIMENTAL WORK Rabbits were inoculated intratesticularly with the Nichols-Hough strain of Spirochaeta pallida; when acute syphilomas developed, showing numerous actively motile organisms by dark-field examination, the animals were castrated, and finely divided suspensions of the infected tissues were prepared in warm saline solution. These were so diluted that each microscopic field showed ten or more actively motile spirochetes, and the intratesticular injection of 0.5 cc. amounts into suitable rabbits gave 100 per cent "takes." Amounts of 1.0 cc. were placed in small sterile test tubes along with amounts of 2 cc. of unheated sterile serums from healthy nonsyphilitic and syphilitic persons. These mixtures were kept in a water bath at 37 C. for two hours; then 0.5 or 1.5 cc. of each was injected intratesticularly into selected rabbits. Controls were included in each experiment, in which 2 cc. amounts of saline solution were employed instead of serum. The serums were