Histopathology of Experimental Vesicular Stomatitis of the Guinea Pig.

Abstract

In a previous article by one of the writers, the histopathology of the lesions of vesicular stomatitis was described and mention was made of further studies on this subject, which were in progress at the time. Additional facts have been secured from the later investigations and are herewith presented. The tissues examined consisted of pads from guinea pigs, 18 to 120 hours after inoculation with guinea-pig passage virus of vesicular stomatitis of horses. The pads were fixed in Zenker's fluid (with acetic acid) and stained with eosin-methylene blue. The cells which are most profoundly affected are those in the upper part of the epidermis, that is, just beneath the horny layer. The basal epithelial cells are not as much damaged by this virus as by the virus of herpes. The cells immediately beneath the horny layer are swollen and stain less intensely than normal ones. As degeneration proceeds vesicles form, containing a loose reticulum composed of collapsed degenerated cells. Later there is infiltration with polymorphonuclear and endothelial leucocytes. The cytoplasm of the affected epithelial cells becomes granular. The nuclei swell and finally appear as empty sacs with a dark blue-staining membrane. The nucleoli become first vacuolated and later fragmented. Often they are extruded and enter the cytoplasm, and frequently the staining is pink instead of blue.