Brain Reactions to Bacterial Filtrates Potent in Eliciting Local Tissue Reactivity. ∗

Abstract

The effects of bacterial toxins upon neuraxis have received the attention of many investigators. Studies of Claude 1 (tetanus toxin); Putnam, McKenna and Evans 2 (tetanus toxin): Lotmar 3 (Shigella dysenteriac), and Branham and Lillie 4 (experimental meningitis) are of direct interest.

In the work described below bacterial principles potent in the elicitation of the phenomenon of local tissue reactivity were used. All injections were given only intravenously, thus avoiding the possible mechanical injury to the brain. It was shown previously that, while in its usual form the phenomenon requires for elicitation the combined local preparatory and intravenous provocative injections, in some organs 2 intravenous injections 24 hours apart are capable of producing severe lesions (kidneys, intestines, etc.) (Apitz, 5 Gerber, 6 and Shwartzman. 7 ) In the latter modification the first intravenous injection takes the place of the local preparatory injection of the former. The report deals with histological examinations of the brain of 11 rabbits. Each intravenous injection was given in a dose of 1 cc per kilo of body weight of bacterial filtrates variously diluted. One rabbit received one intravenous injection of meningococcus “agar washings” filtrate diluted 1:5 and died 24 hours later. In this animal there was found an acute meningococcus encephalitis. In addition to severe perivascular infiltration there were some independent foci beyond the vascular site in the tissues. They predominated in the cerebrum, were less conspicuous in the brain stem, were absent from the cerebellum and contained leuco-, lymphocytes and many tissue cells showing marked disintegration of the nuclei (Fig. 1). Myelin-stained sections of the frontal brain disclosed small foci of demyelinization around the bolld vessels (Fig. 2). The axons were swollen or destroyed. Another animal received 2 intravenous injections of meningococcus filtrate each dilution 1:40 and died 24 hours after the second injection.