MUCOSAL PATHOLOGY OF THE NOSE AND SINUSES - A STUDY IN EXPERIMENTAL MAXILLARY SINUSITIS IN RABBITS INDUCED BY STREPTOCOCCUS-PNEUMONIAE, BACTEROIDES-FRAGILIS, AND STAPHYLOCOCCUS-AUREUS

Unilateral maxillary sinusitis was experimentally induced in New Zeala nd White rabbits with Streptococcus pneumoniae serotype 3, Bacteroides fragilis NCTC 9343, and Staphylococcus aureus V8 in order to study po ssible differences in the inflammatory response of the sinus and nasal mucosa at different time-intervals during a 12-week period of infecti on. The initial sinus mucosal response, most pronounced in pneumococca l sinusitis, was characterized by leukocytosis, epithelial desquamatio n, and squamous cell metaplasia. Tissue reactions at later intervals i ncluded fibrosis of lamina propria, gland involution, polyp formation, and bone remodelling, and were most pronounced in S. aureus and B. fr agilis sinusitis. The nasal mucosa was altered with a redistribution o f goblet cells, development of polyps in the ethmoidal region, involut ion of Bowman's glands and locally, areas of degenerated olfactory sen sory epithelium. These findings endorse that the degree of local patho logy depends on the infecting microorganism's specific pathogenetic fa ctors. However, local tissue factors guiding the cellular inflammatory proliferative and regenerative processes are also of fundamental impo rtance for the type of pathological changes occurring in an infected n asal or sinus mucosa.