Microincineration of Degenerating Anterior Horn Cells in Experimental Poliomyelitis.

Abstract

The literature concerned with poliomyelitis seems to be largely composed of results of studies on the more general and gross pathological aspects of the disease. Another line of investigation has been opened up by Marinesco, Policard and Cowdry which begins with the cell rather than the symptom. As yet, no such approach has been made toward the understanding- of poliomyelitis. The present paper deals with but a single phase of the cytopathology of the disease—the changes in inorganic constitution as determined by the microincineration method. The material was obtained from autopsies of 43 monkeys (Maeacus rhesus) experimentally infected with poliomyelitis by the intracerebral and intranasal routes. The tissues were fixed in absolute alcohol formalin and prepared for incineration according to the method described by Scott. Alternate serial sections were incinerated or were stained with hematoxylin and eosin in such a manner that colored and ashed preparations of the same cell were available for comparison. For controls, similarly prepared material from 10 normal monkeys or monkeys dying of diseases other than poliomyelitis was used. The normal anterior horn cell incinerated under optimum conditions leaves a characteristic and uniform ash. The cytoplasm is represented by a very finely divided, mist-like, bluish or whitish ash. Against this filmy background spots of somewhat denser whitish, powdery material may usually be seen, evidently representing the Nissl bodies. The nucleus appears as a hole in the cell, set here and there with refractile granules, sometimes yellowish, but more often white, which may be identified as the chromatin substance. The mineral residue of the nucleolus is seen as a flat white, finely granular material of varying intensity. In the spinal cord of a monkey inoculated with poliomyelitis virus, several forms of degenerating cells may be seen. Three typical pictures will be described here: 1. During the early stages of degeneration the cell becomes somewhat swollen, the Nissl bodies are lost and the cytoplasm tends to take a lighter stain. The nucleus is often enlarged and may occupy an excentric position in the cell body.