Studies of the Affinity of Rickettsia mooseri for Tunica vaginalis I: Affinity for Tunica vaginalis of Guinea-pig

It is said that Neill-Mooser reaction in the scrotum of the male guinea-pig is specific to R. mooseri, but R. prowazeki also sometimes causes the non-specific reaction, so-called false Neil-Mooser reaction. The author studied on the substance of Neill-Mooser reaction by investigation of the figures of cells in the exudate of the tunica vaginalis of scrotum. The results are summarized as follows: 1) In every case, the tunica reaction by R. mooseri was markedly positive and lasted for a long time. The reaction by R. prowazeki was accidental and not specific. 2) Even inthe cases of inoculation of R. mooseri into male guineapigs, the reaction did not always appear typically in those weighing under 400 g. 3) In the positive phase of the scrotal reaction in guinea-pigs inoculated with R. mooseri, activation of fibrohistiocyte system appeared in the tunica vaginalis, and the great majority of rickettsiae became visible in the serous cells. In short, the affinity of R. mooseri for the tunica vaginalis of the guinea-pig was specific, while that of R. prowazeki was not specific.