Biomedical subjects

Karl Hörmann

Publications and source records attributed to Karl Hörmann.

At least 19 recordsLinked to original sources

PubMed2007

Radiofrequency surgery of the tongue base in the treatment of snoring--a pilot study.

In a previously published study, a significant reduction of snoring was reported after treatment with radiofrequency surgery of the tongue base in patients suffering from obstructive sleep apnea syndrome. The aim of this study was to investigate the efficacy of radiofrequency surgery of the tongue base in the treatment of primary snoring. Twenty patients suffering from primary snoring (AHI < 10/h, body mass index < 32 kg/m(2)) and an isolated hypertrophic tongue base at clinical examination were enrolled in this clinical trial. The patients underwent bipolar radiofrequency surgery of the tongue base under local anaesthesia. Pre- and post-operative body weight, daytime sleepiness (Epworth sleepiness scale) and snoring scores (visual analogue scales) were evaluated by the patients and their bed partners, respectively. Postoperative follow-up data was collected 6-8 weeks after treatment. A statistically significant reduction of the preoperative snoring levels from 7.5 +/- 2.4 to 6.1 +/- 2.8 was seen after treatment (p < 0.001). Body weight and daytime sleepiness remained unaffected. Only 3 out of 20 patients were satisfied with the result as defined by VAS < 3. Despite statistically significant reduction of the subjective snoring scores after radiofrequency of the tongue base, only minimal clinical improvement was achieved. Only 3 out of 20 patients were satisfied with the results. With regard to the clearly beneficial effect seen in patients with obstructive sleep apnea, this result indicates different pathophysiological principles in the generation of snoring.

Adult↗

PubMed2007

A three-step purification method of large quantities of human recombinant alpha endothelial cellular growth factor for clinical use.

The endothelial cellular growth factor alpha-ECGF is a candidate drug for the induction of therapeutic neoangiogenesis. Its use in extensive experimental and clinical trials is hampered by the fact that currently published purification procedures allow only small yields, and the absence of pyrogenic impurities is not demonstrated. The rh alpha-ECGF was expressed in E. coli. Isolation of rh alpha-ECGF from E. coli lysates to apparent homogenicity was achieved by a three step purification procedure involving ionic exchange, heparin-sepharose and polymyxin B chromatography. By this method, 200 mg of rh alpha-ECGF was purified from 15 g wet weight E. coli bacteria. The isolated protein of 18 kDa appeared as a single band after SDS gel electrophoresis and subsequent silver-staining. The biological activity was expressed in the chorion-allantois-membrane assay and in the 3H-thymidine proliferation in baby hamster kidney cells. Drug trials with rabbits revealed no increase in body temperature after intravenous injections with 1 mg rh-ECGF.

Animals↗

PubMed2006

Chemosensory event-related potentials during sleep--a pilot study.

Aim of the present pilot study was to investigate whether cortically generated chemosensory event-related potentials (ERPs) can be recorded during sleep. Chemosensory function during sleep was assessed in 14 healthy female volunteers. An overnight polysomnography was performed to assess nocturnal sleep and to classify sleep stages. Chemosensory ERPs were recorded using air-dilution olfactometry. H2S (4ppm) was used for olfactory and CO2 (40%, v/v) for trigeminal stimulation. Chemosensory ERPs could be recorded during sleep for both olfactory and trigeminal stimuli in some but not all subjects. Compared to baseline, latencies of olfactory ERPs were longer and amplitudes were larger during light sleep and slow wave sleep (SWS). For trigeminal stimulation N1 latencies were longest during REM sleep. These results indicate that both trigeminal and olfactory ERPs can be recorded during sleep suggesting that chemosensory stimuli are processed on a cortical level during sleep.

Adult↗

PubMed2006

Ossifying fibromyxoid tumor of the nasal septum.

The fibromyxoid tumor is quite a rare soft tissue tumor and typically presents as an ossifying fibromyxoid tumor (OFMT) in the subcutis of the extremities of adults. Most authors favour schwannian or chondroid origin of this lesion with somehow uncertain biologic dignity. Local recurrence is seen in 27% of patients after primary excision. We present a case of a fibromyxoid tumor of the nasal septum in a 49-year-old female who complained of nasal airway obstruction and enlargement of the right contour of the nose. Endonasal, endoscopic tumor excision was performed. The tumor contained spindle-shaped and polygonal cells, mucoid pseudocysts and a fibromyxoid stroma with local calcifications. The clinical behaviour of OFMT in general is benign but some reports have documented atypical tumors with histologic signs of malignancy. Complete local resection is the treatment of choice. Because of the high rate of local recurrence, clinical follow-up examinations are necessary.

Airway Obstruction↗

PubMed2006

Hereditary hemorrhagic telangiectasia: an update on clinical manifestations and diagnostic measures.

Hereditary hemorrhagic telangiectasia (HHT), also known as Rendu-Osler-Weber disease, is an autosomal dominant disorder of the fibrovascular tissue. It is characterized by the classic triad of (muco-)cutaneous telangiectases, arteriovenous malformations with recurrent epistaxis and hemorrhages, and inheritance. A wide variety of clinical manifestations in HHT have been described. In more than 90% of the patients, nosebleeds are the first predominant symptom, therefore ENT physicians often play a key role as far as diagnosis and management of the disease are concerned. In spite of recent diagnostic and therapeutic progress, a cure for this often burdening and handicapping disease is still not available. Apart from affecting the nose, arteriovenous malformations (AVMs) may also affect the skin, lungs, brain, liver and gastrointestinal tract. The two known genes that are implicated in HHT are endoglin (ENG) located on chromosome 9q33-q34 and activin-receptor-like kinase (ALK1) located on chromosome 12q13. Mutations of ENG are observed in HHT type 1 with an incidence up to 40% for pulmonary AVMs, whereas mutations of ALK1 are observed in HHT type 2 with an incidence of only 14% for pulmonary AVMs, which clinically distinguishes these two types of mutation. The emphasis of this paper is mainly on the clinical manifestation, molecular genetics and diagnosis of HHT, taking account of current literature on HHT in order to better understand the complexity of the disease. Recent therapeutic options in the treatment of HHT have been omitted from this paper as they are subject of a following paper. HHT is more common than previously thought and shows a broad range of different clinical organ manifestations that can be sources of substantial morbidity and mortality, making HHT a continuing challenge for many sub-specialties where interdisciplinary diagnostic screening is mandatory in the management of the disease.

Activin Receptors, Type I↗

PubMed2006

Multilevel surgery for obstructive sleep apnea: short-term results.

OBJECTIVE: To determine the efficacy of a new multilevel surgical protocol for obstructive sleep apnea (OSA). STUDY DESIGN AND SETTING: Sixty patients with moderate to severe OSA because of multilevel pharyngeal obstruction were enrolled into this prospective, controlled clinical trial after clinical examination, endoscopy, and polysomnography. Surgery included uvulaflap, tonsillectomy, hyoid suspension, and radiofrequency treatment of the tongue base (group A). A second group did not receive hyoid suspension (group B). In both groups, nasal surgery was performed if necessary. Polysomnography and Epworth Sleepines Scale (ESS) were recorded at baseline and 2 to 15 months after surgery. RESULTS: In group A, the mean apnea-hypopnea index (AHI) decreased significantly after surgery (38.9 +/- 20.0 vs 20.7 +/- 20.6, P < 0.0001), whereas in group B the AHI did not. All secondary variables (minimal oxygen saturation, mean oxygen saturation, arousal index), and the ESS significantly improved in group A with only changes in arousal index and ESS reaching levels of significance in group B. CONCLUSION: The presented protocol including the hyoid suspension proved to be effective in the treatment of OSA, whereas surgery without hyoid suspension was less successful. EBM RATING: B-2b.

Adult↗

PubMed2006

The effect of hyoid suspension in a multilevel surgery concept for obstructive sleep apnea.

OBJECTIVE: This study investigated the outcome of the hyoid suspension as a part of a multilevel surgery protocol. STUDY DESIGN AND SETTING: Eighty-three patients with obstructive sleep apnea (OSA) underwent a multilevel surgical treatment because of continuous positive-airway pressure intolerance, 67 with the hyoid suspension and 16 without the hyoid suspension. All patients underwent a pre- and postoperative polysomnography in the sleep laboratory. RESULTS: The mean preoperative apnea hypopnea index (AHI) was 36.4+/-21.2 and 19.4+/-19.7 postoperatively for all patients (P<0.0001). Further statistically significant changes were found for the arousal index, the oxygen saturation, and the daytime sleepiness. No statistically significant change was found for body mass index. In the group of patients treated without the hyoid suspension, the AHI did not decrease statistically significant. After surgery, 59.7% of the subjects with the hyoid suspension were regarded as cured. CONCLUSION: Multilevel surgery including the hyoid suspension is an effective treatment in subgroup of OSA patients. EBM RATING: C-4.

Adult↗

PubMed2006

Axonemal localization of the dynein component DNAH5 is not altered in secondary ciliary dyskinesia.

Primary ciliary dyskinesia (PCD) is a heterogeneous genetic disorder characterized by recurrent airway infections and situs inversus in half of affected individuals. Diagnosis currently relies on demonstration of abnormal ciliary ultrastructure or altered ciliary beat. Alterations encountered in secondary ciliary dyskinesia (SCD) caused by inflammation often complicate the diagnostic workup. We have recently shown that in respiratory epithelial cells from PCD patients with outer dynein arm defects the dynein protein DNAH5 is mislocalized and either completely or partially absent from the ciliary axoneme. In this study, we addressed the question whether SCD might affect axonemal DNAH5 localization in respiratory cells. To induce SCD in vitro, we treated primary human respiratory epithelial cell cultures with interleukin-13 (IL-13). Ciliary function and ultrastructure were assessed by high-speed videomicroscopy and transmission electron microscopy, respectively. For in vivo localization of DNAH5, we performed nasal brushing biopsies in patients with evidence of SCD. Expression of DNAH5 was analyzed by immunofluorescence microscopy. IL-13-treated cells showed evidence of SCD. Ciliary beat frequency was significantly reduced and ultrastructural analyses showed axonemal disorganization compared with control cells. High-resolution immunofluorescence studies of respiratory epithelial cells with SCD identified in vitro and in vivo normal axonemal DNAH5 localization. DNAH5 localization is not altered by SCD, indicating a high potential for immunofluorescence analysis as a novel diagnostic tool in PCD.

Axonemal Dyneins↗

PubMed2006

In vitro analysis of integrin expression during chondrogenic differentiation of mesenchymal stem cells and chondrocytes upon dedifferentiation in cell culture.

Tissue engineering represents a promising method for generating chondrogenic grafts for reconstructive surgery. In cultured chondrocytes, the dedifferentiation of cells seems unavoidable for multiplication. Stem cells, however, displaying unlimited self-renewal and the capacity to differentiate towards chondrocytes, might be usable after further characterization. As the interactions between the extracellular matrix and the cellular compartment can alter the cellular behaviour, we investigated the expression of integrins using microarray analysis during chondrogenic differentiation of human mesenchymal stem cells (MSC) in comparison with de-differentiating human chondrocytes (HC) harvested during septoplasty. During chondrogenic differentiation of MSC, the fibronectin-receptor (Integrin beta1alpha5), fibronectin and the GPIIb/IIIa-receptor were downregulated. The components of the vitronectin-receptor (Integrin alphavbeta3) and CD47 were constantly expressed and ILK was downregulated. Vitronectin and osteopontin were not expressed by the cells. In HC, Integrin beta1alpha5 in conjunction with the ligand fibronectin were upregulated during dedifferentiation, Integrin alphavbeta3 as well as the GBIIb/IIIa-receptor were activated on day 21 but neither vitronectin nor osteopontin were expressed by the cells. The integrins, beta2, beta4, beta6, beta8 and alpha2, alpha4, alpha6, alpha7, alpha11, were not expressed at any time. ILK, CD47, and ICAP were activated with ongoing dedifferentiation. In conclusion, a candidate for signal-transmission is the fibronectin receptor (integrin alpha5beta1) in conjunction with its ligand fibronectin. Other receptors, e.g. for vitronectin and osteopontin (alphavbeta3), or their ligands do not seem to be involved in signal transmission for dedifferentiation. The GPIIb/IIIa-receptor might assist the process of dedifferentiation. Intracellularly, ILK, ICAP1 and CD47 might be involved in the transduction of integrin-dependent signals.

Cell Differentiation↗

PubMed2005

Management of radiation-induced tracheocutaneous tissue defects by transplantation of an ear cartilage graft and deltopectoral flap.

Patients suffering from head and neck cancer often require temporary tracheostomy during therapy. The tracheostomy can usually be closed when postoperative swelling decreases and swallowing ability recovers. However, some patients, especially after adjuvant radiotherapy, may develop severe chronic wounds resulting in persistent tracheocutaneous fistula. Local wound care and plastic reconstruction strategies are required in such cases. We present two patients with head and neck cancer treated with primary surgical regimen including temporary tracheostomy and adjuvant radiotherapy. Both patients developed a persistent, poorly healing wound with persistent tracheocutaneous tissue defect. After local debridement and wound care, the peristomal necrotic tissue was excised down to the level of the trachea. The defect of the anterior tracheal wall was closed with a autogenous ear cartilage graft. The graft was harvested from the cavum conchae and sutured to the tracheal defect. The soft tissue defect was covered by transposition of a well-vascularized, fasciocutaneous deltopectoral flap. In both cases, the flaps healed satisfactorily. The donor defect was closed primarily. Complications were not observed in these two cases. A flexible tracheo-bronchoscopy showed no stenosis of the trachea at the site of cartilage graft transplantation. In conclusion, treatment of persistent radiated tracheocutaneous defects by cartilage graft and deltopectoral flap turned out to be a safe and reliable procedure which can be performed as a one-stage method with low morbidity at the donor site.

Cutaneous Fistula↗

PubMed2005

Cross-sectional imaging combined with 3D-MR angiography (3D-MRA): diagnostic tool for preoperative vascular assessment of head and neck tumors.

BACKGROUND: Head and neck cancer accounts for 5% of all malignancies worldwide. The presence of lymph node metastases and vascular infiltration influence patient outcome. This prospective study describes the preoperative morphologic assessment of the vascular status of patients with head and neck tumors by means of high spatial resolution and extended coverage of the arterial and venous system reaching from the supra-aortic region to the skull base. PATIENTS AND METHODS: Cross-sectional imaging combined with contrast-enhanced 3D-maximum intensity projection MR angiography (3D-MRA) was applied using a dedicated head and neck coil with a 4-channel panorama array system interface to assess vascular involvement in patients with suspected head and neck cancer. 32 patients underwent preoperative assessment by magnetic resonance imaging (MRI). The results were then correlated with surgical and histological findings. RESULTS: 3 of the 32 patients (9%) demonstrated involvement of the arterial system. In 2 of these 3 cases, MRA correctly predicted the arterial status, while in 1 case it gave a false negative result. 11 of the 32 patients (34%) presented with involvement of the venous system. 10 cases showed complete concordance between the findings of the MR venography and the intraoperative status, while in 1 case a false negative result was produced. CONCLUSION: In patients with suspected head and neck tumors, 3D-MRA in combination with cross sectional imaging is a valuable diagnostic tool for the detection of vascular involvement.

Adult↗

PubMed2005

Diagnostic evaluation of magnetic resonance imaging with turbo inversion recovery sequence in head and neck tumors.

The clinical outcome of patients with head and neck cancer depends on many factors such as tumor size, metastatic involvement and angioarchitecture of the tumor. The correct staging of tumor extension, presence of cervical lymph node metastases and evaluation of vascular infiltration are essential diagnostic steps before treatment. The aim of this study was to evaluate the accuracy of turbo inversion recovery magnitude (TIRM) magnetic resonance imaging (MRI) in the diagnosis of head and neck tumors with special attention to tumor size and tumor spread according to the current TNM classification. TIRM sequence with short T1 relaxation and long TE (echo time) improves imaging contrast because of the increased T1-weighting and the inherent fat suppression. In a prospective clinical study, 32 patients underwent preoperative MRI. Diagnosis was confirmed histologically in all cases. Scanning was performed on a 1.0-T unit applying TIRM as well as T1- and T2-weighted turbo spin echo (TSE) sequences. In all sequences, tumor size was overestimated due to reactive inflammatory changes surrounding the tumor tissue. The least overestimation was documented on TIRM and post-contrast T1 TSE. The highest values of relative tumor signal intensities were obtained in TIRM (3.5+/-0.9) and T2 TSE (3.5+/-0.8) followed by post-contrast T1 TSE (1.6+/-0.7) and pre-contrast T1 TSE (1.2+/-0.3). Due to the inherent fat suppression, tumor delineation was most obvious in TIRM. In patients with suspected cancer of the head and neck, TIRM should be considered as a standard and a diagnostically relevant sequence in the MRI staging protocol.

Adult↗

PubMed2005

[Is imaging possible for otosclerosis? Characteristics of the disease and a survey of the clinical relevance of imaging].

Otosclerosis is a localized progressive disease of bone remodeling within the otic capsule of the human temporal bone. Histomorphologically, active cochlea otosclerosis (otospongiosis) is diagnosed in the presence of foci of demineralization in the otic capsule. The clinical symptoms of otosclerosis are associated with mixed and sensorineural hearing loss. With recent technological advances, diagnostic imaging of the inner ear is becoming more and more important in the evaluation of diseases affecting the cochlea. Studies could demonstrate that otosclerosis has a characteristic appearance on high-resolution computed tomography (HRCT), producing a distinctive pericochlear hypodense double ring. Its appearance on MRI is not as readily appreciated, producing a ring of intermediate signals in the pericochlear and perilabyrinthine regions on T1-weighted images, demonstrating mild to moderate enhancement after gadolinium administration. The ethiology and pathophysiology of otosclerosis are described and a review of the literature is given to illustrate the clinical relevance of imaging in otosclerosis.

Diagnosis, Differential↗

PubMed2005

Volumetric tissue reduction in radiofrequency surgery of the tongue base.

OBJECTIVES: Radiofrequency surgery is a minimally invasive technique for the treatment of the tongue base in sleep-disordered breathing. The aim of this study was to evaluate the changes in upper airway anatomy induced by radiofrequency surgery with MRI. STUDY DESIGN AND SETTING: 10 patients with sleep-disordered breathing were treated with radiofrequency surgery at tongue base. MRI measurements were performed before and after surgery with the help of a recently published protocol. RESULTS: The mean total number of energy delivered per patient was 4750 +/- 1641 Joule. Relevant changes could be observed neither for tongue volume or dimension nor for retrolingual space. CONCLUSIONS: Changes in upper airway anatomy could not be demonstrated. The effects of radiofrequency surgery of the tongue base may more likely be a result of changes in upper airway collapsibility. SIGNIFICANCE: Functional effects of surgical interventions in sleep-disordered breathing should be considered in addition to mechanistic concepts alone.

Adult↗

PubMed2005

Palatal implants for primary snoring: short-term results of a new minimally invasive surgical technique.

OBJECTIVE: To determine the safety and efficacy of a new soft palate implant procedure for the reduction of snoring. STUDY DESIGN AND SETTING: Fifteen healthy patients with primary snoring due to palatal flutter were enrolled into this prospective study after clinical and endoscopic examination and polysomnography. The average age of the patients was 41.2 +/- 8.6 years with a body mass index of 26.2 +/- 2.5 kg/m2. The Anti-Snoring Device consists of a delivery tool with a cylindrical implant of braided polyester filaments. Under local anesthesia, three implants intended for permanent implantation were placed into the soft palate. Snoring-related symptoms were assessed by visual analogue scales (VAS), polysomnography, and the SNAP system at baseline and 90 days postoperatively. RESULTS: All implants were placed without complications. Only minor discomfort was reported in four cases within the first three days postprocedure. At the 90-day follow-up snoring was reduced from 7.3 +/- 1.6 to 2.5 +/- 2.1 (VAS, P < 0.01) and from 347 +/- 239 to 264 +/- 168 snoring sounds/hour (SNAP, P > 0.05). Polysomnography did not show any deterioration of sleep or breathing. Speech, swallowing, and taste were unchanged. CONCLUSION: The Anti-Snoring Device is a new surgical tool offering a simple and minimally invasive procedure. Our data demonstrate that the treatment is safe and effective with good patient acceptance. Further patient follow-ups are needed to evaluate the long-term results.

Adult↗

PubMed2005

Anatomic changes after hyoid suspension for obstructive sleep apnea: an MRI study.

OBJECTIVE: To assess the effects of isolated hyoid suspension on subjective and objective parameters of obstructive sleep apnea and to evaluate changes in upper airway anatomy with the help of standardized magnetic resonance imaging. STUDY DESIGN AND SETTING: Fifteen patients received isolated hyoid suspension. Changes in respiratory disturbance index were assessed with polysomnography, and anatomical changes with standardized magnetic resonance imaging. Snoring, daytime sleepiness, and functional parameters were assessed with questionnaires. Lateral x-ray cephalometry was performed preoperatively. RESULTS: Mean respiratory disturbance index was reduced from 35.2 +/- 19.1 to 27.4 +/- 26.2. Forty percent of the patients were classified as responders. Daytime sleepiness improved significantly. Relevant changes in upper airway anatomy could not be detected. There were no remarkable differences between responders and nonresponders in regard to imaging. CONCLUSIONS: Hyoid suspension is effective only in a subgroup of patients and does not lead to relevant changes in airway diameters in the awake patient. Magnetic resonance imaging and x-ray cephalometry do not add additional information for patient selection. SIGNIFICANCE: The reported clinical effects of hyoid suspension are more likely due to functional changes in airway collapsibility than to an enlargement of the upper airway.

Adult↗

PubMed2005

Long-term results of palatal implants for primary snoring.

OBJECTIVE: To determine the safety and efficacy of the Pillar Palatal Implant System over a 1-year follow-up period. STUDY DESIGN AND SETTING: In this prospective study, 40 healthy adult patients with primary snoring due to palatal flutter were treated after clinical, polysomnographic, and endoscopic examination. Under local anesthesia 3 implants were placed into the soft palate. Postoperative morbidity and functional parameters were assessed. Snoring and daytime sleepiness were assessed before and 90, 180, and 360 days after surgery. Objective data were obtained by polysomnography and SNAP-recording before and 90 days after treatment. RESULTS: All implants were placed without complications. A total of 13 implants partially extruded uneventfully in 10 patients. Functional parameters remained unchanged. After 1 year, snoring was reduced from 7.1 +/- 1.9 to 4.8 +/- 2.5 (Visual-Analogue-Scale, P < 0.05) and daytime sleepiness from 6.1 +/- 3.2 to 4.9 +/- 3.1 (Epworth-Sleepiness-Scale, P < 0.05). SNAP data and polysomnography parameters showed clinically irrelevant changes. CONCLUSION: Our data demonstrate a significant decrease in snoring and daytime sleepiness over a period of one year.

Adult↗

PubMed2005

In vitro analysis of matrix proteins and growth factors in dedifferentiating human chondrocytes for tissue-engineered cartilage.

CONCLUSIONS: With ongoing culture and dedifferentiation of chondrocytes, significant changes in the expression patterns of various collagens and the insulin-like growth factor (IGF) receptor were detected. The latter could play an important role in the differentiation of human chondrocytes. OBJECTIVE: Tissue engineering represents a promising method for the construction of autologous chondrogenic grafts for reconstructive surgery. So far, little is known about the expression of markers for cell proliferation and differentiation in cultured chondrocytes. MATERIAL AND METHODS: Human chondrocytes were isolated from septal cartilage (n=5) and held in primary cell culture. Cells were harvested after 24 h and 6 days. Proliferation was analyzed using an Alamar Blue assay. The differentiation of the cells was investigated using bright field microscopy, the expression patterns of various proteins using immunohistochemistry and the expression of distinct genes using a microarray technique. RESULTS: The chondrocytes showed strong proliferation (Day 0: 16.7+/-0.7 fluorescent units; Day 5: 52.4+/-2.2 fluorescent units) from the third day of cell culture in medium without growth factors. From this point onwards, a dedifferentiation of the chondrocytes could be observed. In cell culture, the chondrocytes expressed collagen 1 and 10 without expression of collagen 3. After 6 days of cell culture, they expressed collagen 2. The chondrocytes showed constant low expression of the fibroblast growth factor-2 receptor, but constant high expression of vascular endothelial growth factor, matrix metalloproteinase (MMP)2 and MMP9. The cells never expressed the epidermal growth factor receptor. The proportion of IGF receptor-expressing cells diminished significantly during cell culture.

Cartilage↗