MUCOSAL FINE-STRUCTURE IN EXPERIMENTAL SINUSITIS

Rabbit maxillary sinuses were inoculated with Streptococcus pneumoniae and Bacteroides fragilis, and the histologic response in the sinus mu cosa was observed over a 12-week period. An increased height of the cy lindric cells and hyperplasia of the basal cells were frequent finding s irrespective of the pathogen inoculated. The disease was found to in fluence the character of the secretory product from epithelial secreto ry cells and to degranulate the subepithelial glands. Ciliary loss was a transitional finding. A reduction in the number of mitochondria, th e occurrence of deformed short microvilli, and cytoplasmic blebbing we re seen in the cells devoid of normal cilia. It is inferred from this study that pneumococcal sinusitis in rabbits is a self-limiting proces s, and the mucosal sequelae of the acute infection are persisting gobl et cells, slight focal fibrosis, and edema. Inoculation with B fragili s produces a chronic inflammatory process with infiltration of mononuc lear cells, luminal dilatation of the glands exhibiting zymogen granul e depletion, and an increased thickness of the whole mucosal layer.