Objective: To obtain clues on the anatomical features of the eustachian tube (ET) related to the susceptibility to otitis media with effusion (OME) in children. Methods:The angle and length of the ET in children with (54 ears, OME children) and without OME (50 ears, normal children), as well as those of normal adults were measured on the CT using the multiplanar reconstruction technique Results:The angles of ET in OME children group, normal children group, and normal adult group were 20.4±3.5 degree (°) and 21.2±4.8°, 19.9±3.4°and 20.0±3.6°, and 27.3±2.7° and 27.3±2.8° in the right and left sides, respectively. There was no significant difference between the right and left sides in any group (p=0.541, p=0.952, p=0.978). The lengths of the ET in the OME children group, normal children group, and normal adult group were 37.2±3.0 mm (mean±standard deviation) and 37.6±3.2 mm, 37.5±3.3 mm and 38.0±3.2 mm, and 42.5±2.8 mm and 42.9±2.9 mm in the right and the left side, respectively. There was no significant difference between in the right and left sides in any groups (p=0.670, p=0.597, and p=0.545).Both the angles and lengths were significantly greater in the normal adult group than in either the OME children group or normal children group (one-way ANOVA and Fisher's PLSD tests, p<0.05), but there was no significant difference either in the angle or length of the ET between the OME group and normal children group (p>0.05). In the OME and normal children groups, the angle was observed to constantly increase with age, and the values were found to be within the range of the adult size in all the cases older than 2737 days and 2818 days in the OME children group and in normal children group, respectively. In addition to the angle, the lengths were observed to constantly increase with age, but the increase appeared to be greater in younger age until around 1000 to 1500 days (3 to 4 year old) than in the older age, and the values were found to be within the range of the adult size in all the cases older than 2470 days and 2818 days in OME children group and in normal children group, respectively. Conclusion:The angle and length of ET are more horizontal and shorter in infants than in adults. However, there is no statistical difference between the angle and length of ET in infants with and without OME. These results suggest that short and horizontal ET may be one of the predisposing factors related to the high susceptibility of OME in infants and children rather than etiological factors.

SUMMARY:Middle-ear cholesteatoma is characterized by enhanced proliferation of epithelial cells and granular tissue formation. However, the molecular mechanism underlying these pathological changes is largely unknown. Keratinocyte growth factor (KGF) is a mesenchymal cell-derived paracrine growth factor that specifically stimulates epithelial cell proliferation. In the present study, we investigated the possible involvement of KGF and its receptor, KGFR, in the pathogenesis of cholesteatoma using in situ hybridization and immunohistochemistry, respectively. We examined 56 cholesteatoma specimens, and 8 normal skin areas as control. KGF and KGFR expression was examined by immunohistochemistry using rabbit anti-human KGF and anti-human KGFR polyclonal antisera raised in our laboratories against synthetic peptides corresponding to parts of human KGF and KGFR, respectively. KGF protein and mRNA were detected exclusively in stromal fibroblasts and infiltrating T lymphocytes in 80% of cholesteatoma cases, whereas KGFR protein and mRNA were localized in the epithelium in 72% of cases. Assessment of the proliferative activity of cholesteatoma using the labeling index for Ki-67 showed a significantly higher Ki-67 labeling index (66%) in KGFϩ/KGFRϩ cases than other cases. There was a significant correlation between KGFϩ/KGFRϩ expression and recurrence. Our results indicate the possible involvement of both KGF and KGFR in enhanced epithelial cell proliferative activity and recurrence of cholesteatoma. (Lab Invest 2003, 83:123-136).

Middle-ear mucosa maintains middle-ear pressure. However, the majority of surgical cases exhibit inadequate middle-ear mucosal regeneration, and mucosal transplantation is necessary in such cases. The aim of the present study was to assess the feasibility of transplantation of isolated mucosal cells encapsulated within synthetic self-assembling peptide nanofiber scaffolds using PuraMatrix, which has been successfully used as scaffolding in tissue engineering, for the repair of damaged middle-ear. Middle-ear bullae with mucosa were removed from Sprague Dawley (SD) transgenic rats, transfected with enhanced green fluorescent protein (EGFP) transgene and excised into small pieces, then cultured up to the third passage. After surgical elimination of middle-ear mucosa in SD recipient rats, donor cells were encapsulated within PuraMatrix and transplanted into these immunosuppressed rats. Primary cultured cells were positive for pancytokeratin but not for vimentin, and retained the character of middle-ear epithelial cells. A high proportion of EGFP-expressing cells were found in the recipient middle-ear after transplantation with PuraMatrix, but not without PuraMatrix. These cells retained normal morphology and function, as confirmed by histological examination, immunohistochemistry, and electron microscopy, and multiplied to form new epithelial and subepithelial layers together with basement membrane. The present study demonstrated the feasibility of transplantation of cultured middle-ear mucosal epithelial cells encapsulated within PuraMatrix for regeneration of surgically eliminated mucosa of the middle-ear in SD rats.

Objective. To investigate whether human T lymphotropic virus type I (HTLV-I) directly infects salivary gland epithelial cells (SGECs

Middle ear acquired cholesteatoma is a pathological condition associated with otitis media, which may be associated with temporal bone resorption, otorrhea and hearing loss, and occasionally various other complications. Cholesteatoma is characterized by the enhanced proliferation of epithelial cells with aberrant morphologic characteristics. Unfortunately, our understanding of the mechanism underlying its pathogenesis is limited. To investigate its pathogenesis, different animal models have been used. This paper provides a brief overview of the current status of research in the field of pathogenesis of middle ear acquired cholesteatoma, four types of animal models previously reported on, up-to-date cholesteatoma research using these animal models, our current studies of the local hybrid ear model, and the future prospect of new animal models of middle ear cholesteatoma.