Hannover, Germany
Hannover, Germany

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Lautermann J.,Hals Nasen Ohren Klinik | Schock E.-J.,Hals Nasen Ohren Klinik | Zacher S.,Hals Nasen Ohren Klinik | Wagler E.,Klinik fur Allgemein und Visceralchirurgie
HNO | Year: 2010

Operations of the thyroid gland belong to the most frequent surgical procedures in Germany. Ultrasound is used for examination of the morphology and scintigraphy for examination of the function of the thyroid gland. Cytology can be used to examine scintigraphically cold nodules. Nodules represent the most frequent indication for thyroid surgery. In differentiated thyroid carcinoma postoperative radioactive iodine therapy plays an important role. Operations of the thyroid gland should be performed with optical magnification to identify the recurrent laryngeal nerve with the help of neuromonitoring. A missing electric signal after stimulation of the nerve with intact morphology is indicative of temporary paresis of the vocal cord and operation of the contralateral side should be postponed. Thus, a bilateral paresis can be safely avoided. © Springer Medizin Verlag 2009.


PubMed | Universitats Klinik, Universitatsklinik Und Poliklinik For Hals Nasen Ohren Heilkunde, University of Duisburg - Essen, Hals Nasen Ohren Klinik and 2 more.
Type: Comparative Study | Journal: Laryngo- rhino- otologie | Year: 2015

The stimulation of the upper airway represents an effective treatment option in case of CPAP failure in patients with moderate to severe obstructive sleep apnea. The stimulation with respiratory sensing (Inspire Medical Systems) has shown a high level of evidence in larger cohorts and longer follow-up studies. Whether the results of the stimulation without respiratory sensing (ImThera Medical) can be compared with the therapy with sensing, remains open up to now. Additional data are awaited after the planned phase III study THN#2. To optimize both procedure and to provide long term results, more studies are needed. The workgroup sleep medicine of the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery supports theses activities with the help of the newly founded task force Neurostimulation in Sleep Apnea.


Ehlert N.,Leibniz University of Hanover | Muller P.P.,Helmholtz Center for Infection Research | Stieve M.,Hals Nasen Ohren Klinik | Behrens P.,Leibniz University of Hanover
Microporous and Mesoporous Materials | Year: 2010

The immobilization of a model enzyme, alkaline phosphatase (ALP), onto differently modified silica surfaces and coatings was investigated as a test case for the biofunctionalization of implant surfaces. In this context, the influence of silica surface structures and various silane linker molecules on the capacity to bind active proteins were studied. For this purpose, microscope glass slides were coated with unstructured or mesoporous silica films. The binding of the protein to the surface was mediated by trialkoxysilanes with different functional groups like amino, epoxy, and urea functions. The model protein ALP was chosen due to its robustness and the availability of a simple activity assay. This assay showed that all the functionalized trialkoxysilanes tested were able to immobilize active ALP on silica surfaces. Using the 3-aminopropylsilyl modification resulted in the highest activity of bound ALP, especially in combination with a mesoporous surface coating. Interestingly, unstructured silica sol-gel films had only low capacity to immobilize active enzyme whereas both mesoporous silica coatings and plain glass bound higher amounts of active ALP. By using mesoporous coatings functionalized with 3-aminopropylsilyl residues, maximal binding capacities for active ALP were achieved. This combination appears most promising for the further development of bioactive surfaces for practical applications such as surgical implant functionalization. © 2009 Elsevier Inc. All rights reserved.


Ehlert N.,Leibniz University of Hanover | Mueller P.P.,Helmholtz Center for Infection Research | Stieve M.,Hals Nasen Ohren Klinik | Lenarz T.,Hals Nasen Ohren Klinik | Behrens P.,Leibniz University of Hanover
Chemical Society Reviews | Year: 2013

In this tutorial review we present the process of the development of functional implants using mesoporous silica. The different steps from chemical synthesis and physicochemical characterization followed by in vitro testing in cell culture assays to clinically relevant in vivo animal studies are examined. Since the end of the 1990s, mesoporous silicas have been considered as biomaterials. Numerous investigations have demonstrated their non-toxic and biocompatible properties. These qualities in combination with the unique properties of high surface area and pore volume, uniform and tunable pore sizes and chemical modifiability are the reasons for the great scientific interest in this field. Here we show that besides bulk materials or mesoporous silica nanoparticles, mesoporous silica films are highly promising as coatings on medical prostheses or implants. We report on the development of functionalized mesoporous silica materials specifically for middle ear applications. Middle ear prostheses are used to restore the sound transmission through this air-filled cavity when the small bones of the middle air (the ossicular chain) have been destroyed by disease or by accidents. In addition to optimal restoration of sound transmission, this technique bears several challenges, e.g. an ongoing bacterial infection or the displacement of the prosthesis due to insufficient fixation. To improve the healing process, a mesoporous silica coating was established on ceramic middle ear prostheses, which then served as a base for further functionalizations. For example, the bone growth factor BMP2 was locally attached to the coating in order to improve the fixation of the prosthesis by forming a bony connection to the remainder of the ear bones. Further, an implant-based local drug delivery system for the antibiotic ciprofloxacin was developed with the aim of fighting bacterial infections. Further possibilities using mesoporous silica nanoparticles as part of a composite on an implant are briefly discussed. © The Royal Society of Chemistry 2013.


Ehlert N.,Leibniz University of Hanover | Hoffmann A.,Helmholtz Center for Infection Research | Luessenhop T.,Leibniz University of Hanover | Gross G.,Helmholtz Center for Infection Research | And 4 more authors.
Acta Biomaterialia | Year: 2011

Due to its ability to induce de novo bone formation the differentiation factor bone morphogenetic protein 2 (BMP2) is often used to enhance the integration of bone implants. With the aim of reducing possible high dose side-effects and to lower the costs, in order to produce affordable implants, we developed a simple and fast method for the immobilization of BMP2 on silica-based surfaces using silane linkers which carry amino or epoxy functions. We put an especial emphasis on the influence of the nanoscale surface topography of the silica layer. Therefore, we chose glass (for control experiments) and Bioverit® II (as a typical implant base material) as support materials and coated these substrates with unstructured or nanoporous amorphous silica layers for comparison. Immobilized BMP2 was quantified by two different methods: by ELISA and by a cell-based assay for active BMP2. These tests probe for immunologically and biologically active BMP2, respectively. The results show that the amino functionalization is better suited for immobilizing the protein. Strikingly, a considerably higher amount of BMP2 could be immobilized on coated Bioverit® II surfaces compared with coated glass substrates, which was presumably due to the macroscopic roughness of the Bioverit® II substrates. In addition, it was found that the nanoporous silica coatings on Bioverit® II substrates were able to bind more BMP2 than the unstructured ones. © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


Ehlert N.,Leibniz University of Hanover | Badar M.,Helmholtz Center for Infection Research | Christel A.,Leibniz University of Hanover | Lohmeier S.J.,Leibniz University of Hanover | And 5 more authors.
Journal of Materials Chemistry | Year: 2011

To generate bioactive coatings for medical implants, a novel procedure has been developed using a coating of mesoporous silica for controlled drug delivery. Plain glass slides were used as substrates. The mesoporous coatings were then loaded with the antibacterial drug ciprofloxacin. The drug release kinetics were investigated in a physiological buffered solution. The drug loading capacity of the unmodified mesoporous coatings was low but could be increased nearly ten-fold (to about 2 g cm-2 of the macroscopic surface) by functionalizing the mesoporous surface with sulfonic acid groups. To achieve a controlled drug release over an extended time period, further coatings were added. Covering the surface of the drug loaded mesoporous silica layer by dip-coating with bis(trimethoxysilyl)hexane resulted in an organosiloxane layer which retarded the release for up to 30 days. By an additional evaporation coating with dioctyltetramethyldisilazane, the release of ciprofloxacin was prolonged for up to 60 days. The biocompatibility of the different coatings was tested in cell culture assays. The presence of the additional silane-derived hydrophobic coatings somewhat reduced the biocompatibility. The antibacterial efficacy of the materials was demonstrated by using clinically relevant biofilm-forming pathogenic bacteria. A test where the sequential release of ciprofloxacin (in 2 days intervals) and the bacterial viability were tested in parallel showed good concordance in the results. The material where a sulfonate-functionalized mesoporous silica layer is loaded with ciprofloxacin and then coated by an organosiloxane layer derived from bis(trimethoxysilyl)hexane showed the best results with regard to antibacterial efficacy and will further be tested in animal experiments.


PubMed | Hals Nasen Ohren Klinik
Type: Journal Article | Journal: HNO | Year: 2010

Over the last two decades, the use of the external approach for primary and secondary rhinoplasties has become increasingly popular. This article illustrates the versatility of endonasal techniques for the correction of nasal tip deformities on the basis of four cases.The approach to the nasal tip and the chosen technique as used in 100 consecutive rhinoplasties were reviewed.For primary and revision tip plasty, endonasal approaches were used in 81% of cases. Preferred incisions were the infracartilaginous approach and the transfixion incision. Using these approaches, correction of the tip was achieved by using sutures to reposition and reshape the alar cartilages and the columella without grafts to the nasal tip in most cases.Nasal tip plasty via endonasal approaches using sutures is technically more challenging compared to the external approach with its superior exposure. This drawback is outweighed by less operating time and faster patient recovery. Contrary to the general trend, the authors believe that endonasal tip plasty techniques using sutures can obviate the external approach and grafts in many cases and should form an integral part of the rhino-surgeons repertoire.


Tasman A.-J.,Hals Nasen Ohren Klinik | Palma P.,Universitatsklinik Varese
HNO | Year: 2010

Background: Over the last two decades, the use of the external approach for primary and secondary rhinoplasties has become increasingly popular. This article illustrates the versatility of endonasal techniques for the correction of nasal tip deformities on the basis of four cases. Patients and Methods: The approach to the nasal tip and the chosen technique as used in 100 consecutive rhinoplasties were reviewed. Results: For primary and revision tip plasty, endonasal approaches were used in 81% of cases. Preferred incisions were the infracartilaginous approach and the transfixion incision. Using these approaches, correction of the tip was achieved by using sutures to reposition and reshape the alar cartilages and the columella without grafts to the nasal tip in most cases. Conclusion: Nasal tip plasty via endonasal approaches using sutures is technically more challenging compared to the external approach with its superior exposure. This drawback is outweighed by less operating time and faster patient recovery. Contrary to the general trend, the authors believe that endonasal tip plasty techniques using sutures can obviate the external approach and grafts in many cases and should form an integral part of the rhino-surgeon's repertoire. © 2010 Springer-Verlag.


PubMed | Hals Nasen Ohren Klinik
Type: Journal Article | Journal: HNO | Year: 2010

Operations of the thyroid gland belong to the most frequent surgical procedures in Germany. Ultrasound is used for examination of the morphology and scintigraphy for examination of the function of the thyroid gland. Cytology can be used to examine scintigraphically cold nodules. Nodules represent the most frequent indication for thyroid surgery. In differentiated thyroid carcinoma postoperative radioactive iodine therapy plays an important role. Operations of the thyroid gland should be performed with optical magnification to identify the recurrent laryngeal nerve with the help of neuromonitoring. A missing electric signal after stimulation of the nerve with intact morphology is indicative of temporary paresis of the vocal cord and operation of the contralateral side should be postponed. Thus, a bilateral paresis can be safely avoided.


PubMed | Hals Nasen Ohren Klinik
Type: Case Reports | Journal: HNO | Year: 2010

A 54-year-old cattle farmer presented with crusty purulent plaques in the neck area. The clinical picture and microscopical proof of hyphae in the skin smear combined with Woods lamp testing led to the diagnosis of Tinea barbae, a mycological infection of the skin transmitted by cattle (typically Trichophyton verrucosum). Therapy with itraconazole 200 mg q.d. p.o. and miconazole ointment 1/day over 2 weeks was successful. This case report and its image are designed to bring attention to this rarely diagnosed pathology.

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