title: Experimental otitis media with effusion induced by lipopolysaccharide from Klebsiella pneumoniae. Mucociliary pathology of the eustachian tube.
abstract: Otitis media with effusion (OME) is generally benign and self-limiting but is often recurrent and can change into a chronic type. We have previously reported that intratympanic inoculation of lipopolysaccharide (LPS) from Klebsiella pneumoniae can develop experimental OME in the guinea pig. However, OME induced by 10 micrograms/ml of LPS was of a self-limiting type. Our hypothesis was that a higher concentration of LPS might develop a chronic OME because LPS reduces the ciliary activity in the tubotympanum in a dose related manner. In our present study we inoculated 100 micrograms/ml of LPS from K. pneumoniae into the tympanic cavity of the guinea pig, in the hope of illuminating a possible mechanism predisposing to the chronicity of the disease. A longer-term OME was observed after tympanic inoculation of 100 micrograms/ml of LPS. Ciliary activity in the Eustachian tube was depressed for a longer term by this dose than by the previous one. In addition to mucociliary pathologies and general inflammatory changes similar to those induced by 10 micrograms/ml of LPS, intracytoplasmic ciliary cysts were observed after inoculation of 100 micrograms/ml of LPS, which appeared to show disturbed ciliogenesis and chronic mucociliary lesions. In conclusion, intratympanic inoculation of a higher concentration of LPS developed a longer-term OME in the guinea pig, which was supported by functional as well as morphological examinations.
authors.affiliation: Department of Otolaryngology, Osaka City University Medical School, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ohashi
authors.forename: Y
authors.initials: Y
authors.lastname: Nakai
authors.forename: Y
authors.initials: Y
authors.lastname: Esaki
authors.forename: Y
authors.initials: Y
authors.lastname: Ohno
authors.forename: Y
authors.initials: Y
authors.lastname: Sugiura
authors.forename: H
authors.initials: H
authors.lastname: Okamoto
mesh_terms: D000818:Animals; D002908:Chronic Disease; D002923:Cilia / Q000648:ultrastructure; D005064:Eustachian Tube / Q000648:ultrastructure*; D006168:Guinea Pigs; D007711:Klebsiella pneumoniae / Q000276:immunology*; D008070:Lipopolysaccharides / Q000009:adverse effects*; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D010034:Otitis Media with Effusion / Q000209:etiology* / Q000473:pathology
chemical_list: D008070:Lipopolysaccharides