Immunohistochemical study on proliferative activity of experimental cholesteatoma.
ABSTRACT In this study, we induced canal ligation cholesteatoma using Mongolian gerbils and investigated the hyperproliferative nature of canal ligation cholesteatoma by using an immunohistochemical technique with proliferation markers (cytokeratin 13/16, PCNA, EGFR, thrombomodulin). Canal ligation cholesteatoma using Mongolian gerbils had a hyperproliferative character in the suprabasal cell layer similar to human cholesteatomas. This result will provide a good morphological basis for future cholesteatoma animal research concerning the pathogenesis of cholesteatoma.
- [show abstract] [hide abstract]
ABSTRACT: Topical otic preparations now in clinical use contain a variety of antibiotics and solvents that may produce severe inflammation if they reach the middle ear cavity. This report describes the response of the chinchilla middle ear to direct application of one such preparation that appears to act as a nonspecific irritant. Cortisporin otic suspension (containing neomycin, polymyxin B, hydrocortisone, and propylene glycol) was introduced into the bullae of 32 chinchillas that were kept alive for four days to five months before histologic examination of their temporal bones. All the experimental animals had tissue damage and inflammation within the middle ear. The changes observed included proliferation of ciliated and secretory columnar cells, formation of granulation tissue, bone erosion, and osteoneogenesis. Some areas of the mucosa underwent metaplasia to stratified squamous epithelium; this metaplastic epithelium, however, did not produce keratin. In the majority of animals kept for two months or more, cholesteatoma was identified in the middle ear. The cholesteatomas appeared to develop as a result of penetration of external canal epidermis through intact tympanic membranes or as the result of migration of epidermis through perforations. The experimental cholesteatomas behaved like those seen clinically in humans, with extensive erosion of bony structures within the middle ear.American Journal of Otolaryngology 01/1985; 6(5):327-41. · 1.23 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: Cholesteatoma epithelium is characterized by a keratinocyte dysregulation accompanied by destruction of the ossicles and temporal bone. Immunohistochemical methods using antibodies to cell-cycle-related antigens can be used as a means for assessing various aspects of proliferation in cholesteatoma tissue. They also have the important advantage of preserving the spatial orientation of proliferating cells in histological sections. Proliferating cell nuclear antigen (PCNA) is a 36 kDa DNA-delta-polymerase-associated protein that is directly involved in the mechanisms of DNA synthesis. In the present study the expression of PCNA was investigated in formalin-fixed, paraffin-embedded biopsy specimens of cholesteatomas and normal skin. Normal skin revealed nuclear staining in a small number of keratinocytes (PCNA grade, 1.5) located in the basal cell layer. In contrast, an increased number of PCNA-labeled basal and suprabasal epidermal cells (PCNA grade, 9.3) were found in cholesteatoma samples. Our findings indicate that PCNA represents a reliable marker for epithelial proliferation, showing that cholesteatoma epithelium proliferates at a higher rate than normal epidermis. These findings also support the concept of keratinocyte dysregulation in middle ear cholesteatoma.Archiv für Klinische und Experimentelle Ohren- Nasen- und Kehlkopfheilkunde 02/1996; 253(1-2):21-4. · 1.46 Impact Factor
- Cell 12/1982; 31(1):11-24. · 31.96 Impact Factor