M. Schwaab

Cytokeratin expression pattern in congenital and acquired pediatric cholesteatoma

Pediatric cholesteatoma can be classified as congenital or acquired based on clinical criteria. We studied the expression patterns of five distinctive cytokeratins in both types of cholesteatoma in order to improve understanding of their pathogenesis and origin. A comparable expression pattern for CK10, CK14, CK18, CK19 and 34βE12 antigens was found in the matrix of congenital and acquired pediatric cholesteatoma. Our results demonstrate that congenital and acquired pediatric cholesteatoma exhibit an identical cytokeratin distribution pattern, suggesting that they share a common origin. Therefore, it seems possible that a portion of the so-called “acquired” cholesteatoma may actually originate from advanced congenital cholesteatoma with secondary destruction of the tympanic membrane in the pediatric patient population.

Human β-Defensins in different states of diseases of the tonsilla palatina

Tonsils are believed to play an important role during the development of the immune system. Although diseases of the tonsils like hypertrophy of the tonsil, acute tonsillitis, chronic tonsillitis or peritonsillar abscess are common, little is known about the underlying pathophysiology. Little is known about antimicrobial peptides produced by the tonsils. The human β-Defensins 1-3 (hBD1-3) are naturally produced “antibiotics” with antimicrobial activity against different bacteria, fungi, and viruses. The objective of the study was to determine the concentrations for hBD1-3 in different states of diseases of the tonsilla palatina. After tonsillectomy and tissue fixation in formalin, total proteins were isolated from 38 samples (11 hypertrophy of the tonsil, 8 acute tonsillitis, 11 chronic tonsillitis, 8 peritonsillar abscesses). The protein concentration was determined and ELISA for hBD1-3 were performed. We also conducted immunofluorescence double stainings for the co-expression of streptococcus group A and hBD1-3. We could verify a significant difference for the mean hBD1 score of the acute tonsillitis in comparison to the hyperplastic tonsil, the chronic tonsillitis, and the peritonsillar abscess. There was no statistically significant difference in the hBD2 and hBD3 concentrations between the four groups. The immunofluorescence stainings showed that hBD1-3 and the streptococcus group A in the same place. We conclude that in the hyperplastic tonsilla palatina hBD1-3 play an important role. The mouth is constantly faced with a high bacterial load. During a tonsillitis, the hBD1 concentration is lower than in the non-acute infected tonsil because hBD1 is being consumed for fighting the bacterial infection. But, the existence of hBD1-3 in the tonsil cannot prevent the tonsillitis to become chronic.

Human β-defensins—at the front line of the peritonsillar abscess

Antimicrobial proteins like human β-defensins 1-4 (hBD1-4) protect the surface of organs against different bacteria. Little is still known about these proteins within an abscess formation. The purpose of this study was to analyse and describe the distribution of the antimicrobial proteins hBD 1-4 within the peritonsillar abscess. A total of 17 peritonsillar abscesses were analysed. Immunhistochemical stainings were performed, characteristic pictures were taken, and the mean colour intensity was measured using a specific imaging software. A statistical analysis compared the areas of interest of the specific protein staining with the one of the control staining. A total of 4,573 areas of interests were measured. A significantly stronger expression was detected for hBD1 in the surface epithelium, crypt, epithelium of the crypt, lymphocytic cap, and abscess formation in the hBD1 staining in comparison to the control samples. But there was no significance in the specific hBD1-protein expression in comparison to the control samples in the lymphoid follicle and in the germinal centre. There was a significantly stronger hBD2, hBD3, and hBD4 expression in all areas of interest for the specifics stainings in comparison to the control samples. In conclusion, we developed different scenarios which could lead to a peritonsillar abscess formation.

Human antimicrobial proteins in ear wax

The external auditory canal is vulnerable to bacterial infections, but little is known about thechemical compositions of ear wax regarding antimicrobial peptides. We, therefore, studied the proteinconcentrations of ten well-known human antimicrobial peptides from ear wax.Twenty ear wax samples from healthy individuals were analysed using enzyme-linked immunosorbent assay (ELISA) to determine theprotein concentrations of the antimicrobial peptides hBD1-3, lactoferrin, LL-37, BPI, hSLPI and HNP1-3. All ten antimicrobial peptides are present in ear wax. Some of these proteins seem to be merelycell-bound in ear wax. Antimicrobial peptides in ear wax prevent bacteria and fungi from causing infections inthe external auditory canal. The role and importance of these proteins for the blind-ending ear externalcanal is discussed. If this local defence system fails, infections of the external auditory canal may result.The knowledge about the presence of antimicrobial peptides in cerumen may lead to new concepts ofthe local treatment of external auditory canal diseases in the future.

Growth behavior of spiral ganglion explants on cochlear implant electrodes and their materials

BACKGROUND With the increasing use of cochlear implants (CIs), the insertion of alloplastic material into the inner ear is nowadays an established treatment for severe to profound hearing loss in children and adults. Beyond its widespread use, the biocompatibility of the CI electrode and its interaction with the neural structures of the cochlea is not yet established. METHODS To investigate the survival and growth behavior of spiral ganglion neurons on different CI materials, spiral ganglion explants from newborn rats were cultured on silicone and platinum, on a surface combination of silicone and platinum, and, finally, on a CI electrode. RESULTS The results of this study indicate that the growth of spiral ganglion neurons in vitro is strongly influenced by the different materials and their arrangement, with platinum exhibiting the highest degree of biocompatibility with respect to neurite extension. Level differences in the surface structure between silicone and platinum lead to inhibition of neurite outgrowth. Furthermore, the culturing of spiral ganglion explants on a CI electrode leads to neurite sprouting toward the electrodes made of platinum. CONCLUSION The biocompatibility of CI materials with spiral ganglion neurons was shown in this study, but it differs with different CI materials. Besides the material itself, the arrangement of the materials can affect the neurite extension.

Wachstumsanalyse von Spiralganglienexplantaten auf Kochleaimplantat-Elektroden und deren Materialkomponenten

BACKGROUND With the increasing use of cochlear implants (CIs), the insertion of alloplastic material into the inner ear is nowadays an established treatment for severe to profound hearing loss in children and adults. Beyond its widespread use, the biocompatibility of the CI electrode and its interaction with the neural structures of the cochlea is not yet established. METHODS To investigate the survival and growth behavior of spiral ganglion neurons on different CI materials, spiral ganglion explants from newborn rats were cultured on silicone and platinum, on a surface combination of silicone and platinum, and, finally, on a CI electrode. RESULTS The results of this study indicate that the growth of spiral ganglion neurons in vitro is strongly influenced by the different materials and their arrangement, with platinum exhibiting the highest degree of biocompatibility with respect to neurite extension. Level differences in the surface structure between silicone and platinum lead to inhibition of neurite outgrowth. Furthermore, the culturing of spiral ganglion explants on a CI electrode leads to neurite sprouting toward the electrodes made of platinum. CONCLUSION The biocompatibility of CI materials with spiral ganglion neurons was shown in this study, but it differs with different CI materials. Besides the material itself, the arrangement of the materials can affect the neurite extension.

Protein isolation from ear wax made easy.

Cerumen is a waxy substance with a mixture of different lipids and and not yet identified proteins. Analysing ear wax can be quite laborious because of the different and sometimes interfering components. Therefore, time-consuming techniques such as chromatography or spectrometry were used to gain informations about the components of ear wax. Conclusions were drawn from immunohistochemical detections of special proteins within the skin or the glands of the external ear canal about the existence of these proteins within the ear wax. But directly analysing the proteins within the ear wax was difficult. We, therefore, worked out a method to isolate proteins from ear wax. Ear wax was collected from 16 adults with no infections of the external ear canal. The protein isolation was conducted using the Qproteome™ Mammalian Protein Prep Kit by Qiagen in two different kind of ways (cell and lysat fraction). Afterwards, we performed a quantification of the total protein concentration using the BCA method. There was a statistical significant difference in the total protein concentration between the two different (cell and lysat fraction) described ways. Furthermore, it is a fast and easy method to extract proteins from ear wax. The benefit of the described method and the field of application will be discussed.

Wachstumsanalyse von Spiralganglienexplantaten auf Kochleaimplantat-Elektroden und deren Materialkomponenten@@@Growth behavior of spiral ganglion explants on cochlear implant electrodes and their materials

BACKGROUND With the increasing use of cochlear implants (CIs), the insertion of alloplastic material into the inner ear is nowadays an established treatment for severe to profound hearing loss in children and adults. Beyond its widespread use, the biocompatibility of the CI electrode and its interaction with the neural structures of the cochlea is not yet established. METHODS To investigate the survival and growth behavior of spiral ganglion neurons on different CI materials, spiral ganglion explants from newborn rats were cultured on silicone and platinum, on a surface combination of silicone and platinum, and, finally, on a CI electrode. RESULTS The results of this study indicate that the growth of spiral ganglion neurons in vitro is strongly influenced by the different materials and their arrangement, with platinum exhibiting the highest degree of biocompatibility with respect to neurite extension. Level differences in the surface structure between silicone and platinum lead to inhibition of neurite outgrowth. Furthermore, the culturing of spiral ganglion explants on a CI electrode leads to neurite sprouting toward the electrodes made of platinum. CONCLUSION The biocompatibility of CI materials with spiral ganglion neurons was shown in this study, but it differs with different CI materials. Besides the material itself, the arrangement of the materials can affect the neurite extension.