epidermal-growth-factor and Otitis-Media-with-Effusion

Epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) promote the differentiation and proliferation of epithelia as well as the proliferation and chemotaxis of fibroblasts. Additionally, EGF promotes wound healing in tissues composed largely of epithelial cells and fibroblasts. We hypothesized that EGF and TGF-alpha regulate the differentiation and proliferation of the epithelial lining and the migration and proliferation of fibroblasts in the subepithelial space of the middle ear mucosa in children with otitis media. As an initial test of this hypothesis, EGF and TGF-alpha concentrations were measured in 82 middle ear effusions of children undergoing tympanostomy tube placement. EGF was present in 45% of these effusions, and TGF-alpha was present in 6%. The mean concentration +/- SEM values for EGF and TGF-alpha were 19+/-7.6 and 3.7+/-7.9 pg/mL, respectively. In addition, neutrophils, macrophages, and lymphocytes in middle ear effusions stained for EGF by immunocytochemistry. We conclude that growth factors are frequently present in middle ear effusions of children with otitis media.

Topics: Adolescent; Child; Child, Preschool; Epidermal Growth Factor; Female; Humans; Immunohistochemistry; Infant; Male; Otitis Media with Effusion; Transforming Growth Factor alpha

To study the process of aural cholesteatoma formation, we used gerbilline temporal bones to examine histologically the early stages of spontaneous cholesteatomas associated with experimentally induced otitis media with effusion (OME) following electric cauterizations of the eustachian tube. Epidermal growth factor (EGF) was then localized immunohistochemically in the pars flaccida of normal ears and the forming spontaneous cholesteatomas. Findings in the ears with the early spontaneous cholesteatomas were effusion inside the pars flaccida and hypertrophy and hyperkeratosis of the pars flaccida. Findings in the ears with experimental OME involved an effusion in the whole middle ear cavity as well as hypertrophy and hyperkeratosis in both the pars flaccida and pars tensa. The incidence of ear drum changes was higher in the experimental OME group than in control animals without cauterization. EGF was localized in the mucous layer of normal drums, the mucous layer and lamina propria of drums with hypertrophy alone, and all layers in drums with hypertrophy and hyperkeratosis. EGF was especially positive in the cytoplasms of transformed cuboidal cells. These findings suggest that EGF within the transformed mucous layer may play an important role as a biochemical factor in developing cholesteatomas.

Topics: Animals; Cautery; Cholesteatoma, Middle Ear; Cytoplasm; Disease Models, Animal; Epidermal Growth Factor; Epithelium; Eustachian Tube; Gerbillinae; Hypertrophy; Immunohistochemistry; Keratosis; Mucous Membrane; Otitis Media with Effusion; Temporal Bone; Tympanic Membrane