Deep Meatal Skin Research Articles

Localisation of basic fibroblast growth factor in cholesteatoma matrix: an immunochemical study

To investigate the expression of basic fibroblast growth factor in the matrix of human acquired cholesteatoma compared to the deep meatal skin. This topic does not appear to have been fully investigated before. An immunochemical study was conducted. Cholesteatoma tissues from adult patients were collected during surgery (n = 19). Control specimens were taken from the deep meatal skin (n = 8) and compared. A highly significant difference in basic fibroblast growth factor expression was identified between cholesteatoma and skin (mean ± standard error = 58.53 ± 3.6 per cent in cholesteatoma vs 40.6 ± 3.5 per cent in skin; p = 0.005). Both basal and parabasal keratinocytes were stained positive with basic fibroblast growth factor. Additionally, there was specific staining in the basal columnar middle-ear epithelium and mast cell membrane. Basic fibroblast growth factor plays an active role in proliferative activity of cholesteatoma through its overexpression in basal and parabasal layers of cholesteatoma matrix. Moreover, its expression in the mast cell membrane supports its role in bone resorption activity.

Cytokeratin 13, Cytokeratin 17, and Ki-67 Expression in Human Acquired Cholesteatoma and Their Correlation With Its Destructive Capacity.

Objectives Cholesteatoma is a nonneoplastic destructive lesion of the temporal bone with debated pathogenesis and bone resorptive mechanism. Both molecular and cellular events chiefly master its activity. Continued research is necessary to clarify factors related to its aggressiveness. We aimed to investigate the expression of Ki-67, cytokeratin 13 (CK13) and cytokeratin 17 (CK17) in acquired nonrecurrent human cholesteatoma and correlate them with its bone destructive capacity.Methods A prospective quantitative immunohistochemical study was carried out using fresh acquired cholesteatoma tissues (n=19), collected during cholesteatoma surgery. Deep meatal skin tissues from the same patients were used as control (n=8). Cholesteatoma patients were divided into 2 groups and compared (invasive and noninvasive) according to a grading score for bone resorption based upon clinical, radiologic and intraoperative findings. To our knowledge, the role of CK17 in cholesteatoma aggressiveness was first investigated in this paper.Results Both Ki-67 and CK17 were significantly overexpressed in cholesteatoma than control tissues (P<0.001 for both Ki-67 and CK17). In addition, Ki-67 and CK17 were significantly higher in the invasive group than noninvasive group of cholesteatoma (P=0.029, P=0.033, respectively). Furthermore, Ki-67 and CK17 showed a moderate positive correlation with bone erosion scores (r=0.547, P=0.015 and r=0.588, P=0.008, respectively). In terms of CK13, no significant difference was found between cholesteatoma and skin (P=0.766).Conclusion Both Ki-67 and CK17 were overexpressed in cholesteatoma tissue and positively correlated with bone resorption activity. The concept that Ki-67 can be a predictor for aggressiveness of cholesteatoma was supported. In addition, this is the first study demonstrating CK17 as a favoring marker in the aggressiveness of acquired cholesteatoma.

Repair of Big Drum‐Head Defect by Underlay Fascia and STSG

Objective: 1) Describe the technique of grafting total and near-total tympanic membrane perforations using underlay temporalis- fascia graft augmented by split-thickness skin graft from the ear lobule. 2) Evaluate the procedure in terms of graft take, hearing outcomes, and complications. Method: This clinical study was conducted on 91 patients (93 perforations) having total (6) or near-total (87) tympanic-membrane perforation from January 2005 till December 2010 in a teaching university hospital. Myringoplasty utilizing temporalis-fascia graft underlay supported externally by split-thickness lobular-skin graft. Graft take, early and late PTA changes, and complications were evaluated. Results: Graft take was achieved in 86 out of 93 operations (92%), with 7 cases of graft failure (8%). PTA improvement was 16.3 dB at 3-month postoperative versus 15.5 dB at 1 year. Other complications noticed were prolonged graft swelling with discharge (3 cases), 2 of them ended by graft breakdown and the third improved. Bleeding from the jugular bulb during abrasion of middle-ear floor mucosa occurred twice, and in one of them bleeding stopped with surgicel. In the other extraluminal packing of the sigmoid sinus was necessary. The procedure was completed. No blunting or donor site complications were noticed. Conclusion: Large TM perforations can be managed successfully by underlay temporalis-fascia graft supported externally by STSG from the ear lobule laid in part over the deep meatal skin and in the other part over the graft. One can expect &gt;90% graft take, &gt;15 dB PTA improvement, and a limited number of complications.

The localization of matrix metalloproteinases-8 and -13 in cholesteatoma, deep-meatal and post-auricular skin: a comparative analysis

Conclusion. The presence of matrix metalloproteinase (MMP)-8 and MMP-13 was found to be significantly higher in cholesteatoma compared with post-auricular skin. The results show that the control group used has implications for further studies. Objectives. To compare the presence of MMP-8 and MMP-13 in cholesteatoma, deep meatal and post-auricular skin. Our null hypothesis was that there was no difference in expressions of MMP-8 and MMP-13 in the three groups. Materials and methods. The study was carried out in a secondary care specialist centre and used prospective retrieval of specimens for immunohistological localization of MMP-8 and MMP-13. Eleven patients undergoing cholesteatoma surgery were recruited for the study. Eleven cholesteatoma specimens, 10 deep meatal skin specimens and 10 post-auricular skin specimens were analysed. Specimens were analysed by immunohistochemistry using monoclonal antibodies to MMP-8 and MMP-13. Two observers scored the slides independently in a blind fashion. Results. The presence of MMP-8 and MMP-13 was found to be significantly higher in cholesteatoma compared to post-auricular skin (p=0.02, p=0.03, respectively). There were no significant differences in expression of MMP-8 and MMP-13 between cholesteatoma and deep meatal skin (p=0.08, p=0.09, respectively). There were no significant differences in the control groups.

Epidermal hyperplasia of the tympanic membrane and deep external ear canal: novel histo‐pathological features, embryological and clinical correlates

Objectives. To study the histology and developmental biology of epidermis of tympanic membrane and deep ear canal and to correlate the histo‐pathological features with clinical conditions.Method. Histo‐pathological and electron microscopic examination was performed of deep meatal skin, keratosis, keratosis obturans, external canal cholesteatoma, retraction pockets, acquired cholesteatoma and tympanic membrane perforations.Results. In some mature ears, a marked change in the normal flat thin epidermis to one resembling that of the fetus is seen in the presence of local inflammation. This hyperplastic epidermis is present in varying lengths on the tympanic membrane and deep ear canal and displayed as hyperplastic bands growing down into sub‐epidermal tissue and sometimes penetrated the collagen layer of the tympanic membrane to enter the middle ear. Keratosis was frequent on the surfaces of the tympanic membrane and deep ear canal, which may also be found in the invading bands, where they produced small keratin cysts.Conclusions. Severe chronic otitis media, with inflammatory exudates, glandular metaplasia or tympanosclerosis, may be associated with hyperplasia. This type of epidermal hyperplasia appeared to be pathogenic and was observed in several structurally distinct entities such as keratosis, keratosis obturans, retraction pockets, and cholesteatoma of the deep external canal. Invading epidermis in the middle ear, in some cases, is indistinguishable from acquired cholesteatoma. This reverse differentiation highlights a primordial property of auditory epithelium, which was not previously recognised. Furthermore, hyperplastic epidermis appears to be pathogenic and may be the cause of some specific conditions or their complications.References 1 Johnson A., Hawke M., Berger G. (1984) Hodge memorial Award‐surface wrinkles, cell ridges, and desquamation in the external auditory canal. J Otolaryngol.13, 345–3542 Johnson A., Hawke M. (1985) Cell shape in the migratory epidermis of the external auditory canal. J Otolaryngol.14, 273–281

P53 Expression and keratinocyte hyperproliferation in middle ear cholesteatoma.

Keratinocytes in middle ear cholesteatoma have hyperproliferative properties. There is controversy regarding the role of p53 and its effect on cellular proliferation in cholesteatoma. This study was instituted to examine this. Cholesteatoma and deep meatal skin control specimens were analysed for MIB-1 (n = 7, controls = 7), a marker of cellular proliferation, and p53 (n = 17, controls = 17) expression by immunocytochemistry. Expression of p53 was minimal or absent in both cholesteatoma and controls (P = 0.2). MIB-1 expression was higher, but not significantly so, in cholesteatoma than in controls (P = 0.09). Our study has shown no significant p53 expression in cholesteatoma epithelium. This suggests that there is no dysfunction in the p53-mediated cell cycle control mechanisms in cholesteatoma.

Localization of matrix metalloproteinase 1 in cholesteatoma and deep meatal skin.

Matrix metalloproteinase 1 (MMP-1) is overexpressed in cholesteatoma. Cholesteatoma destroys bone, whereas deep meatal skin does not. MMP-1 is a type I collagenase that may be responsible for this destruction. This prospective study was designed to identify overexpression of MMP-1 by cholesteatoma in comparison with deep meatal skin. Ten cholesteatoma specimens and nine deep meatal skin specimens were removed during otologic surgery and then fixed in formalin and embedded in paraffin. Immunocytochemistry studies were performed using a monoclonal antibody to MMP-1. A pathologist assessed the slides in a blinded fashion. Expression of MMP-1 protein in epidermis and in stroma was scored from 0 to 10. Five further cholesteatoma specimens and three deep meatal skin specimens underwent reverse transcriptase polymerase chain reactions to assess messenger ribonucleic acid production. Paired and unpaired Student's t tests were used to assess the difference in expression levels. Cholesteatoma stroma expressed significantly more MMP-1 protein than did deep meatal skin stroma (p = 0.04). MMP-1 was localized to stromal fibroblasts. There was no difference in the epidermal expression levels of the two tissue types (p = 0.42). The reverse transcriptase polymerase chain reaction showed expression at the messenger ribonucleic acid size of MMP-1 (262 base pair) in all cholesteatoma specimens examined. One deep meatal skin specimen showed a weak signal; no signal was seen in the other specimens. MMP-1 is overexpressed by the stromal fibroblasts present in cholesteatoma as compared with deep meatal skin. It is possible that these cells rather than the keratinocytes are responsible for bone destruction in this disease.

Expression of Phospholipase C-?1 in Experimental Cholesteatoma Using Mongolian Gerbils

Phospholipase C (PLC)-gamma1 is known to play a central role in ligand-mediated signal transduction for cell proliferation. The purpose of this study was to elucidate the distribution of PLC-gamma1 in deep meatal skin, retroauricular skin and cholesteatoma matrix of experimental animals. We induced canal ligation cholesteatoma using Mongolian gerbils and investigated the expression of PLC-gamma1 in this model by using Western blot analysis and immunohistochemistry. By Western blot analysis, considerably higher levels of PLC-gamma1 protein were detectable in experimental cholesteatoma. On immunohistochemistry, experimental cholesteatoma showed more intense immunolabeling of PLC-gamma1 protein than deep meatal skin and retroauricular skin. In conclusion, overexpression of PLC-gamma1 may in part contribute to abnormal proliferation and differentiation of experimental cholesteatoma in Mongolian gerbils.

Are p53 and MIB-1 overexpressed in cholesteatoma?

INTRODUCTION: There is controversy regarding the expression of p53 and MIB-1 in cholesteatoma.1 This study was instituted to study this. p53 is an intracellular protein which plays a critical role in control of the cell cycle at the G1 check point. MIB-1 is recognized as a marker of cellular proliferation. Using deep meatal skin controls, the question addressed was, 'are p52 and MIB-1 overexpressed in cholesteatoma'? METHOD: Immunocytochemistry using the avidin-biotin technique on frozen tissue sections with primary antibody to p53 (n = 17, controls = 17) and MIB (n = 17, controls = 7) was performed on cholesteatoma and deep meatal skin control specimens. Appropriate positive and negative controls were employed for each antibody. Slides were analysed in a blind fashion by two independent observers. Statistical analysis was performed using the Mann-Whitney test. RESULTS: Expression of p53 was minimal or absent in both cholesteatoma and controls. No significant difference in p53 expression was found between the two groups (P = 0.02). MIB-1 expression was higher in cholesteatoma than in controls, although this was not statistically significant (P = 0.09). CONCLUSION: This study did not demonstrate an increased expression of p53 cholesteatoma, indicating no evidence of a dysfunctional cell cycle. MIB-1 results showed a possible trend towards significance, which requires a more powerful study to evaluate this further. The probability that there is an increased rate of cellular proliferation in cholesteatoma, when compared to deep meatal skin controls, cannot be excluded.

Myringoplasty: update on onlay pedicle skin flap and temporalis fascia sandwich graft.

The technique of onlay sandwich grafting of tympanic membrane perforations fashioned by the use of pedicle flap raised from the posterior deep meatal skin and autologous temporalis fascia is described. The results of a series of 124 ears operated between 1987 and 1999 are the basis of this report. Of these 106 patients had myringoplasty for the first time. The operation was successful in 102 (96.23 per cent) patients. Eighteen patients had revision myringoplasty, with a successful result in 14 (77.78 per cent). None of the patients developed complications usually associated with onlay grafting. A preliminary report of this work was presented at the XVI World Congress of Otolaryngology Head and Neck Surgery at Sydney in 1997.

An immunocytochemical comparison of MMP-1, TIMP-2 and TIMP-3 expression in cholesteatoma and deep meatal skin

An immunocytochemical comparison of MMP-1, TIMP-2 and TIMP-3 expression in cholesteatoma and deep meatal skin

Signal transduction pathway in human middle ear cholesteatoma

Phospholipase C-γ1 plays a central role in signal transduction, and it is important in cellular growth, differentiation, and proliferation. Human cholesteatoma in the middle ear is characterized by the presence of a keratinizing epithelium that is believed to have hyperproliferative properties. The purpose of this study is to elucidate the distribution of phospholipase C-γ1 in cholesteatoma matrix and deep meatal skin with Western blot analysis and immunohistochemistry. In conclusion, overexpression of phospholipase C-γ1 in cholesteatoma matrix suggests a possible derangement of enhanced growth signal transduction in keratinocytes. (Otolaryngol Head Neck Surg 1999;120:899-904.)

Immunohistochemical Study of Cell Proliferation using BrdU Labelling on Tympanic Membrane, External Auditory Canal and Induced Cholesteatoma in Mongolian Gerbils

The Mongolian gerbil is a well-known animal model for induction of aural cholesteatomas. This animal model is useful for studying changes in the keratinizing epithelium. It is not known whether keratin accumulation can increase the proliferative activity of the keratinizing epithelium in tympanic membrane and meatal skin. In this study, we investigated the proliferative activity of the epidermis in induced aural cholesteatoma at various stages and in different areas of the tympanic membrane and meatal skin in normal gerbils. Anti-5-bromo-2- deoxyuridine (BrdU) was injected intraperitoneally to detect the proliferative activity of keratinizing epithelium. Immunohistochemistry with monoclonal BrdU antibody in the normal gerbil showed intense immunolabelled keratinocytes at the handle of malleus, and the superior parts of pars tensa and pars flaccida. Also, mitotic activity in the deep meatal skin was more active than in the lateral meatal skin. The induced aural cholesteatoma showed more active proliferation centre of the epithelial cell than eardrum and external ear canal of the normal gerbil. These observations suggest that the accumulation of the keratin debris might induce changes of the cellular proliferation in the external auditory meatus.

Matrix metalloproteinase-2 and matrix metalloproteinase-9 in cholesteatoma and deep meatal skin.

A qualitative and quantitative study of the presence of Matrix metalloproteinase-2 (MMP-2) and Matrix metalloproteinase-9 (MMP-9) in cholesteatoma was performed. Ten cholesteatoma and four deep meatal skin specimens were analysed for gelatinase activity at molecular weights corresponding to MMP-2 and MMP-9 using Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS PAGE) Zymography. Gelatinase activity at 72 kDa and 92 kDa was investigated. Western blotting was employed using primary monoclonal antibodies to provide a qualitative assessment of MMP-2 and MMP-9. Non-parametric data analysis using the Mann-Whitney U test did not show a significant difference in expression of MMP-2 (P = 0.51) or MMP-9 (P = 0.14) between the two tissue types. Western blotting showed the presence of both MMP-2 and MMP-9 in the majority of specimens, both cholesteatoma and deep meatal skin.

An immunocytochemical study of Matrixmetalloproteinase 1 in cholesteatoma and deep meatal skin

The means by which cholesteatoma destroys bone is not understood. The release of Matrixmetalloproteinase 1 (MMP-1), a bone collagenase, into the supernatants of cultured explants of cholesteatoma and deep meatal skin has previously been studied.1[1 BAnerjee, A.R., CRowther, M., BHangoo, R. ] This prospective study sought to identify any localization differences in MMP-1 distribution between these tissues. Two cholesteatoma, nine deep meatal skin, and two granulation specimens were studied. Immunocytochemical analysis was performed using a monoclonal antibody to MMP-1 (Oncogene Science) on formalin fixed paraffin-embedded tissue sections using the avidin biotin technique. Slides were then assessed in a blind fashion by a pathologist (JLJ). Expression in epidermis and stroma respectively was subjectively scored from 0 to 10. The Shapiro–Wilk test and the F (variance ratio) test was used to assess data suitability for parametric statistical analysis (see Table 1). Mastoid granulations expressed moderate amounts of MMP-1 but the specimen number was too small for comparison. In this pilot study MMP-1 protein was expressed at a significantly higher level in cholesteatoma stroma than in deep meatal skin stroma (P = 0.04). In addition cholesteatoma stroma showed a trend towards a significantly higher level of MMP-1 protein expression than cholesteatoma epidermis (P = 0.06).

Epidermal Differentiation in the Human External Auditory Meatus

The differentiation of epidermis in the various parts of the human ear canal was documented on the basis of cytokeratin (Ck) expression patterns. Immunohistochemistry was performed on cryostat sections of normal meatal skin using a comprehensive panel of monospecific Ck antibodies representing the main lines of epithelial differentiation. The epidermis of the cartilaginous part showed a Ck profile characteristic of normal skin type differentiation. The deep meatal skin, including the tympanic membrane, showed a peculiar type of differentiation: in addition to epidermal Cks, hyperproliferation-associated Cks 6, 16, and 17 were expressed in the suprabasal cells, while the simple epithelia cell marker Ck 19 was found in the basal cells. The presence of hyperproliferative Cks in the deep meatal skin could only partly be related to areas of proliferative activity. Keratinocytes, which express markers of hyperproliferation, are migratory. Therefore, their presence in the meatal skin is likely to be related to the peculiar pattern of keratinocyte migration, the purpose of which is to keep the meatus free from desquamation products.

Totally implantable hearing aids: The effects of skin thickness on microphone function

With the advent of totally implantable hearing aids, the question of the impact of the choice of implantation site on microphone function has yet to be fully addressed. We investigated the effects of skin thickness on microphone function over a 2-week period in a porcine model. Sound attenuation was found to be directly proportional to skin thickness within the range of 0.5 to 3.0 mm. A decrease in resonant frequency of 500 Hz was noted after implantation under a skin thickness of 3.0 mm. The general shape of the frequency response curves was maintained across all thicknesses tested. Attenuation (dB loss) across the range of 500 to 8,000 Hz appeared to be linear over the various skin thicknesses measured, with a regression coefficient ( r = .99 at 1 kHz and r = .99 at 3 kHz). To minimize attenuation and exploit the sound-collecting qualities of the external ear, the deep meatal skin appears to be a favorable position for implantation.

The nature and behaviour of the deep meatal skin.

The nature and behaviour of the deep meatal skin.