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Quantitative cytologic and histologic changes in the middle ear after the injection of nontypable Hemophilus
T F DeMaria1, T Yamaguchi, D J Lim
1Department of Otolaryngology, Ohio State University College of Medicine, Columbus.
Abstract:
This study was undertaken to investigate and quantify the morphologic changes in the middle ear mucosa and connective tissue after the inoculation of graded doses (0.001 to 100 micrograms) of endotoxin prepared from Hemophilus influenzae. Histopathologic changes were observed in the middle ear mucosa in all animals. Marked bleeding and new bone formation in the submucosa were prominent at days 4 through 14. These findings indicate that the endotoxin from nontypable H influenzae is capable of inducing inflammation or pathologic changes in the middle ear mucosa and may play an important role in the pathogenesis of otitis media with effusion and its sequelae.
Insights
Endotoxin from nontypable Haemophilus influenzae causes middle ear inflammation and bone changes. This suggests a key role in otitis media with effusion and its complications.
Area of Science:
- Otolaryngology
- Pathology
- Microbiology
Background:
- Otitis media with effusion (OME) is a common pediatric condition.
- The role of bacterial endotoxins in OME pathogenesis requires further elucidation.
Purpose of the Study:
- To investigate and quantify morphologic changes in middle ear mucosa and connective tissue.
- To assess the effects of graded doses of endotoxin from nontypable *Haemophilus influenzae*.
Main Methods:
- Inoculation of graded doses of *Haemophilus influenzae* endotoxin in animal models.
- Histopathologic examination of middle ear mucosa and submucosa.
Main Results:
- All animals exhibited histopathologic changes in the middle ear mucosa.
- Significant bleeding and new bone formation in the submucosa were observed between days 4 and 14 post-inoculation.
Conclusions:
- Endotoxin from nontypable *H. influenzae* induces inflammation and pathologic changes in the middle ear mucosa.
- This endotoxin may be a significant factor in the pathogenesis of OME and its sequelae.