PubMed Health⌕ Search

Biomedical subjects

D Boedts

Publications and source records attributed to D Boedts.

14 recordsLinked to original sources
PubMed1992

Immunohistochemical analysis of the cytokeratin expression in middle ear cholesteatoma and related epithelial tissues.

Immunohistochemical investigations were carried out to determine the pattern of cytokeratin (CK) expression in middle ear cholesteatoma and related epithelia. Using monoclonal antibodies specific for CK chains and the indirect immunoperoxidase technique, we examined 10 CK polypeptides for expression. The external stratified squamous epithelium of the tympanic membrane generally expressed CKs 5, 10, and 14. In addition, basal keratinocytes in the annular region of the pars tensa expressed CK 19 (a simple epithelium marker), while suprabasally the hyperproliferative marker CK 16 was expressed. These data reflect the unusual proliferative nature of this region. The unexpected appearance of CK 16 (known to have a limited distribution in healthy epidermis) clearly relates to its expression in the neighboring deep meatus. The medial simple epithelium of the eardrum revealed mucosal CKs 7, 8, 14, 18, and 19. Acquired cholesteatoma lesions, besides CKs 5, 10, and 14, consistently expressed CK 16 in suprabasal layers. These results constitute the first direct molecular evidence for the hyperproliferative nature of the cholesteatoma matrix. Overall, our CK data suggest that aural cholesteatoma lesions and epidermal tissue in this area are related. However, they do not explain the mechanism(s) by which the eardrum or meatal epithelia might invade the middle ear cavity. Congenital cholesteatomas expressed CKs 5, 10, 14, and 16 equally. These CK data do not support the idea of a metaplastic origin from middle ear mucosa; instead, they suggest activation of an ectodermal rest in the middle ear cavity.

Adult↗
PubMed1992

A hairy polyp of the middle ear and mastoid cavity.

A case of a 'hairy polyp', a dermoid tumor of the middle ear and the mastoid cavity is described, which is very unusual location. The radiological, surgical and histological features are discussed. Comment is made on the differentiation between dermoid cysts and teratomas and on the scarcity of both tumors in the area of the temporal bone.

Dermoid Cyst↗
PubMed1991

The keratinizing tympanic epithelium: an enigma.

Both the centrifugal keratin dispersion on the pars tensa as well as the centripetal proliferative properties at the inferior annular tympanic region are discussed. There is evidence, histological and clinical, that these features are two distinct and different phenomena which both have clinical implications. While the centrifugal keratin dispersion is a physiological cleaning mechanism, the cytokeratin expression demonstrates the unusual but for years clinically noticed proliferative nature of the lower annular epithelium and provides biochemical evidence for a relationship between this epithelium and cholesteatoma formation.

Cell Movement↗
PubMed1990

A scanning electron-microscopic study of different tympanic grafts.

The surface architecture of dried temporalis fascia autografts and preserved tympanic allografts was investigated by scanning electronmicroscopy. During the storage in formaldehyde-cialit solutions the outer epithelial as well as the inner mucosal layer of tympanic allografts are progressively detached, and finally the lamina propria with outer radial and inner circular fiber arrangement remains. Due to dehydration phenomena irregular "crater-like" defects, surrounded by an amorphous structure, appear in dried fascia autografts. While a real lamina propria graft may induce migration and differentiation of the host's canal wall epithelium into a specific tympanic epithelium, one may imagine epithelial spreading toward the middle ear along the observed defects in dried fascia grafts. This latter observation gives new evidence for the immigration cholesteatoma theory.

Fascia↗
PubMed1979

Adult rhabdomyoma of the larynx.

A case of rhabdomyoma of the larynx in a 76-year-old woman patient is reported. The tumor was localized on the left vocal cord. This case is, so far described, the seventh one of adult rhadbomyoma of the larynx. The differential histological and histochemical diagnosis with granular cell myoblastoma is discussed and tabulated. Both tumors can easily be confused. In accordance with previously reported cases no evidence of recurrence after more than two years could be observed.

Aged↗
PubMed1978

Tympanic epithelial migration.

The literature on tympanic epidermal migration is reviewed. From isotope experiments and whole-mount autoradiographs the tympanic mitotic activity appeared to be confined to an area close to the annulus typmpanicus. A very slow migratory activity was observed of labelled cells, situated in the basal cell layer. Perforation of the tympanic membrane showed no effect on the position of the labels. This slow migration is considered to differ from the rapid epithelial migration described by several authors. The latter migration is suggested to occur in the upper layers of the stratum corneum, and to represent a physiological mechanism taking care of the removal of keratin from the tympanic membrane. The extrusion and displacement of ear grommets might be at least partly attributable to this phenomenon.

Animals↗
PubMed1978

Styloid process syndrome or stylohyoid syndrome?

The literature on the syndromes related with the stylohyoid apparatus is reviewed and the embryology is discussed. Since the embryological, and symptomatical similarity, a "stylohyoid" syndrome can be defined including symptoms related to the styloid process, stylohyoid ligament, the hyoid bone and even the hyothyroid cartilage junction. Some possible aetiological factors are listed even as appropriate treatment which includes surgery.

Humans↗
PubMed1977

Histopathological research on eardrum perforations.

Basic information on the healing process of tympanic membrane perforations is scarce and sometimes contradictory. So the histological and histopathological course of the closure of tympanic membrane perforations was studied in experiments on mice and hamsters. From this investigations it seems evident that traumatic tympanic membrane perforations close nearly always spontaneously in animals. This fact must be kept in mind in the evaluation of techniques and results of tympanoplasties in animal experiments. Furthermore the squamous epithelium of the eardrum plays an important role in the regeneration of tympanic perforations. The closure of the connective tissue defect has always a tendency to lay behind the healing of the epithelial layer. This mechanism differs from the normal healing process of skin wounds where the squamous epithelium migrates over a newly formed granulation tissue layer. On the basis of these findings some practical considerations can be made on tympanoplasties in human.

Animals↗
PubMed1975

[Otology].

Explore the source record for details and available documents.

Ear, External↗
PubMed1975

Clinical trials of betahistine hydrochloride in the treatment of Ménière's disease.

Thirty Ménière patients were treated with betahistine hydrochlorid for an average period of 17 months. The majority of them had been resistent to every previous treatment. The results of this new treatment were very gratifying with respect to the attacks of vertigo and the accompanying neuro-vegetative symptoms. The tinnitus aurium proved to be resistent, whereas the auditory acuity was significantly improved in 7 patients. Early treatment with this product at the first signs of Ménière's disease is very likely to hold up the progressive degradation of auditory acuity, during the further spontaneous evolution of the disease.

Betahistine↗
PubMedDate not supplied

Epithelial migration on the tympanic membrane. An experimental study.

The existence of an epidermal migration pattern was studied in mice using a whole-mount autoradiographical technique. The mitotic activity appeared to be confined to an area close to the annulus tympanicus. A very slow migratory activity of the labelled cells, was observed, situated in the basal cell layer. Perforation of the tympanic membrane showed no effect on the position of the labelled cells. This slow migration described by several authors. The latter migration was suggested to represent a mechanism for cleaning the tympanic membrane.

Animals↗