Search PubMed⌕ Search

Biomedical subjects

E Kastenbauer

Publications and source records attributed to E Kastenbauer.

At least 55 records · Page 3Linked to original sources
PubMed1996

Immunobiological peculiarities of cholesteatoma in children: quantification of epithelial proliferation by MIB1.

Cholesteatoma in children is characterized by a more extensive and rapid growth in the middle ear and mastoid cavities. The growth characteristics of the cholesteatoma in 20 children were studied using the monoclonal antibody MIB 1, which recognizes a nuclear antigen expressed by cells in the G1, S, and G2/M phases. Specimens of normal adult auditory meatal skin (n = 15) and adult cholesteatoma (n = 15) served as controls. The tissue specimens were prepared for immunohistochemical examination using the alkaline phosphatase-antialkaline phosphatase method and an automatic image analyzer. Specimens of normal skin revealed an average MIB 1 score of 9.2 +/- 3.10%. Child and adult cholesteatomas showed higher values. The average MIB 1 score was higher in child cholesteatoma (42 +/- 9.4%) than in adult cholesteatoma (28.2 +/- 6%). This difference was statistically significant (P<.01). Our results confirm a significant increase of the proliferative rate of cholesteatoma keratinocytes in children, giving an explanation for the more aggressive clinical behavior observed in these patients.

Adult↗
PubMed1996

Functional morphology of nasal blood vessels in humans.

"Secretion" and "obstruction" as predominant clinical symptoms in rhinology affect a great number of patients with disorders of the nose. According to clinical experience as well as morphological investigations, the endonasal vascular system is most likely to be involved in these functional mechanisms. In the present study, we report morphological findings on the angioarchitecture of human nasal mucosa. Meticulous investigation of the structure and ultrastructure of nasal mucosal capillaries revealed differences in the appearance of the endothelial lining. Especially the morphological feature of attenuated fenestrated endothelia in these vessels might be correlated with the functional behaviour under various physiological and pathological conditions. Inspection of the vascular wall of nasal swell bodies revealed differences in the orientation as well as the shape of muscle cells in different parts of this vascular system. The functional role of special morphological features known as muscular bolsters and intervascular muscle fibres for the swelling mechanism of the nasal mucosa is emphasized. Our results enabled us to define the muscular structures that are most probably responsible for constriction and dilatation of nasal swell bodies.

Blood Vessels↗
PubMed1996

Epidermal growth factor receptor (EGF-R) in human middle ear cholesteatoma: an analysis of protein production and gene expression.

Previous studies have shown an altered epithelial cell proliferation in middle ear cholesteatoma, reporting an aberrant expression of epidermal growth factor receptor (EGF-R) glycoprotein by immunohistochemistry. In this study, we quantified the presence of EGF-R using enzyme-linked immunosorbent assays (ELISAs) on tissue extracts, as well as the EGF-R gene expression by in situ hybridization on frozen sections. Human skin obtained from the external ear canal was used as control. The amounts of EGF-R glycoprotein in cholesteatoma were very similar to those in human skin. Human skin showed EGF-R messenger RNA (mRNA) only in the basal layer. A higher percentage of cells hybridized for the anti-sense probes EGF-R was found in cholesteatoma epithelium. Furthermore, we could find suprabasal cells with EGF-R mRNA. Our results confirm that the abnormal growth of cholesteatoma epithelium is reflected in an aberrant expression of EGF receptor.

Binding Sites↗
PubMed1995

[In vitro studies of the effect of papain on isolated chondrocytes: clinical relevance for correction of structural abnormalities of the ear].

A permanent change of shape of the auricle can be achieved by local application of papain to the elastic cartilage. To assess possible clinical use of papain, we investigated its effect on isolated and cultured chondrocytes derived from human cartilage of the auricle. We determined cellular vitality using the trypan blue method. The release of the cytokines IL-1 alpha and IL-6 measured by ELISA and HLA-DR antigen expression evaluated by histological procedures was used as a parameter of the state of activation of chondrocytes. Cell proliferation was also determined by the number of Ki-67 positive cells. A papain concentration above 160 micrograms/ml led to decreasing vitality and number of proliferating cells. A papain concentration above 160 micrograms/ml solvent led to expression of HLA-class-II-antigen on the surface of the chondrocytes. The release of IL-6 was reduced depending on the concentration of papain. However, IL-1 alpha was detected in low concentration with and without application of papain. These investigations show for the first time that papain not only leads to direct destruction of the matrix as described in literature, but also influences the integrity of the matrix by the function and state of activation of chondrocytes. A concentration of papain above 160 micrograms/ml should not be exceeded in clinical application.

Cartilage↗
PubMed1995

[Allogeneic transplantation and HIV infection: studies of HIV-infected tissue].

BACKGROUND: Because of the limited availability of autologous tissue, stored allograft is commonly used. Before grafting, bank tissue is subjected to chemical preservation procedures. This procedure is important to diminish antigenicity and to inactivate possible inherent viruses. The aim of this study was to determine the influence of different chemical preservation procedures like Cialit, Merthiolate, and formaldehyde on the presence of HIV DNA. METHODS: HIV-infected tissues were obtained from eight HIV-positive patients and examined using the polymerase chain reaction (PCR). RESULTS: After chemical treatment, we could observe the presence of HIV DNA in all examined tissues. CONCLUSIONS: The findings indicate the importance of the mandatory serological screening and selection in donor patients.

Adult↗
PubMed1995

Surgery of the internal nasal valve.

Over the past 25 years external rhinoplasty has become increasingly popular. Some rhinosurgeons recommend its use widely, even in routine cases. In our view, however, the classical endonasal approaches remain the first choice. Open rhinoplasty offers an excellent visualization and therefore facility of precise correction, but causes a larger area of wound and scarring. It should, therefore, be restricted to cases of particular difficulties. In the era of minimal invasive surgery, external rhinoplasty advocated as a standard procedure seems to be a drawback, particularly if the aesthetic problem is the leading one. Every facial plastic surgeon should master closed and external rhinoplasty to be able to decide which approach is the most suitable in each situation from the patient's point of view.

Airway Resistance↗
PubMed1995

Engineering of cartilage tissue using bioresorbable polymer fleeces and perfusion culture.

Replacement of injured or diseased skeletal tissues by either autograft or allograft cartilage has increased steadily during recent decades. The ideal method is to use autologous cartilage; however, this is extremely limited due to the scarcity of donor sites. We present a new approach to the in vitro formation of cartilage grafts for autologous grafting in reconstructive surgery. Bioresorbable polymer fleeces of polylactic acid were used as temporary cell carrier matrices to establish three-dimensional cultures of human chondrocytes. The polymer surface was coated with poly-L-lysine before cell integration. These cell-polymer tissue constructs were encapsulated with low melting point agarose and then placed in perfusion culture chambers to provide a constant supply of nutrients into the cultures. The culture medium consisted of Ham's F12 supplemented with 2% fetal calf serum and 50 micrograms/ml ascorbic acid. The cell-polymer tissues were harvested and frozen for toloudine and alcian blue staining as well as electron microscopic examination after different periods of time in culture. A monoclonal antibody specific for collagen type II was used to characterize the cell phenotype. With this culture procedure chondrocytes maintained a differentiated phenotype with synthesis of collagen and proteoglycan. Collagen fibrils with clear cross-striation were evident in electron microscopic images. The results show that our organotypic cell culture method allows the in vitro production of bioartificial cartilage for transplantation.

Biomedical Engineering↗
PubMed1995

Alteration of epidermal differentiation in middle ear cholesteatoma.

This immunohistologic study was undertaken to compare the localization of markers of epidermal differentiation in cholesteatoma and normal external ear canal skin. Both basal cells and suprabasal cell layers of cholesteatoma exhibit an abnormal distribution of differentiation markers (involucrin, filaggrin, glycoproteins detected by monoclonal antibodies J143 [alpha3 integrin chain] and T16 [Trop-2]). The immunostaining intensity of filaggrin and involucrin was higher in cholesteatoma than in external ear canal skin. In cholesteatoma, involucrin was localized in the cytoplasm of the suprabasal cells, and particularly in spinous cells, it appeared earlier than in ear canal skin. Filaggrin was noted in the cytoplasm of the granular and cornified cells in both tissues. The J143 reactive integrin, very late antigen 3 (VLA-3), which in normal epidermis is confined to the basal cells, was also seen in spinous and granular cell layers of cholesteatoma. Furthermore, the immunostaining for VLA-3 in the basal cell layer of cholesteatoma was stronger than in normal epidermis. In contrast to this, expression of Trop-2, which is preferentially found in the suprabasal cell layers, particularly in granular cells of normal epidermis, was clearly reduced in cholesteatoma. These results demonstrate complex alterations in the differentiation of the keratinocytes in cholesteatoma.

Antigens, Neoplasm↗
PubMed1994

Isolation and characterization of trypsin-like and chymotrypsin-like proteinases from human cholesteatoma.

The mast-cell-specific proteolytic enzymes tryptase and chymase were identified in and isolated from cholesteatoma in a ratio similar to that found in human skin. We assume that this ratio reflects a similar distribution of tryptase-containing and tryptase/chymase-containing mast cells in both these tissues. It seems conceivable that mechanisms able to trigger excessive and/or continuous mast cell degranulation in the middle ear might be causative for the formation of cholesteatoma either directly or via primed chronic inflammatory reactions. By their ability to amplify degranulation of mast cells, mast cell proteinases, in particular chymase, may contribute to the chain of events leading to the formation of cholesteatoma.

Cell Degranulation↗
PubMed1994

Profile of anti-stratum corneum autoantibodies in patients with aural cholesteatoma.

The stratum corneum (SC) antibodies are present in high titers in the sera of patients who have diseases in which cells containing keratin intermediate filaments have been damaged. Aural cholesteatoma is a skin-related disease of the temporal bone with an extensive production and accumulation of keratinizing epithelium in the middle ear. The aim of the present investigation was to study the humoral immune response to SC in these patients. Sera were obtained from patients with aural cholesteatoma (n = 10) and from normal donors (n = 8) of about the same sex and age distribution. All sera were analyzed for the existence of autoantibodies (IgG and IgM) against SC by both direct and indirect immunofluorescence, using skin and cholesteatoma frozen tissue sections as antigen substrate. The direct immunofluorescence showed a low level of staining intensity for nearly all of the cholesteatoma patients, indicating the in vivo absence of deposits of anti-SC autoantibodies. The indirect immunofluorescence demonstrated positive staining of the SC in both cholesteatoma and skin tissue sections. Furthermore, some patients showed for IgG anti-SC-autoantibodies a positive staining of the highest suprabasal layers of the epithelium of cholesteatoma. IgM anti-SC autoantibodies were always weaker in titer than IgG autoantibodies. Results show that cholesteatoma patients do not have particularly high levels of anti-SC autoantibodies. A humoral response against SC seems not to be a significant event in the pathogenesis of cholesteatoma disease.

Adolescent↗
PubMed1993

Interaction of human mast cell tryptase and chymase with low-molecular-mass serine proteinase inhibitors from the human respiratory tract.

Mast cell degranulation results in the release of serine class proteinases with trypsin- and chymotrypsin-like specificity. While looking for natural protein inhibitors of these enzymes, we studied their reactions with the double-headed Kunitz-type inhibitor, bikunin, and the human bronchial secretion inhibitor (BSI), which are the only known low-molecular-mass proteinase inhibitors of the human respiratory tract. Both trypsin and chymotrypsin can be inhibited by these inhibitors. However, human BSI is unable to inhibit human tryptase and is the physiological counterpart of chymase in the upper respiratory tract. Human bikunin is unable to inhibit human chymase and human tryptase. Furthermore, human tryptase is also not inhibited by a fragment that consists only of the trypsin-specific C-terminal inhibitor domain of human bikunin. This finding contradicts reports that claim the occurrence of a tryptase-specific proteinase inhibitor in rat mast cells.

Bronchoalveolar Lavage Fluid↗
PubMed1993

[Reconstruction of a malformed external ear by an endoprosthesis of porous polyethylene with an integrated suction system].

Complete reconstruction of the external ear is one of the most difficult tasks in plastic and reconstructive surgery. The risk of frame protrusion inherent in all alloplastic materials is reduced by using a new premoulded endoprosthesis with an integrated suction system. It consists of tissue-compatible porous polyethylene. A conventional suction drainage can be attached to a hollow canal system within the endoprosthesis that empties from defined spaces corresponding to the natural concavities of the external ear. In combination with a preceding expansion the overlying skin is then adapted evenly and completely to the frame by suction. As a result of this vacuum seromas and haematomas can be prevented. Furthermore, infections and pressure necroses due to matress sutures cannot develop. The use of this endoprosthesis obviates the removal of autogenous cartilage and all the complications and scars that are connected with this procedure. The frame itself is stable and has a relief that is largely similar to the natural form of the auricle. Thus, an aesthetically satisfying result can be achieved also in the hand of the surgeon who is not often engaged in this field of plastic surgery.

Adolescent↗
PubMed1993

Hyperproliferation-associated keratin expression in human middle ear cholesteatoma.

Cholesteatoma is characterized by the presence of a squamous epithelium invading the middle ear altering its growth properties. This epithelium is believed to have hyperproliferative properties. Keratin 16 is accepted as a molecular marker for hyperproliferative epithelia. Two monoclonal antibodies K8.12 (directed against keratin 13) and KS.1A3 (directed against keratin 13 and 16) were used in an alkaline phosphatase anti-alkaline-phosphatase (APAAP)-technique to compare the expression of both keratin 13 and keratin 16 in normal human skin and aural cholesteatoma. Furthermore, the cytokeratin expression was compared to that of normal skin and palatine tonsil using one-dimensional gel electrophoresis. For both monoclonal antibodies, normal ear skin was stained only in the basal layer. In contrast, in the cholesteatoma samples the immunostaining of the antibody KS-1A3 was done not only in the basal cell layer but also in the suprabasal cells of the stratum spinosum and stratum granulosum. Using gel-electrophoresis, the presence of cytokeratin 16 was demonstrated in the cholesteatoma samples only. These results support the hyperproliferative character of cholesteatoma epithelium.

Cell Division↗