[Seeding metastases due to tracheotomy?].
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Biomedical subjects
Publications and source records attributed to A Koitschev.
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OBJECTIVES: Data on the prevalence of otorhinolaryngological (ORL) symptoms in patients with cystic fibrosis (CF) are limited. A standard annual examination would be useful for definition of risk factors and/or management alternatives for these symptoms. STUDY DESIGN: Prospective observational study of an unselected group of CF patients. PATIENTS AND METHODS: Between 1997 and 2004, 123 CF patients were routinely examined. The examinations included nasal endoscopy and audiological evaluation. RESULTS: All patients who were approached to take part in the study gave their consent and were extremely cooperative. In 40% of the patients nasal polyps were found endoscopically. In 22% rhinological surgery had already been performed. Of the 123 patients, 13 (12%) showed different grades of sensorineural hearing loss, and all of these patients had received aminoglycoside antibiotics. CONCLUSIONS: CF patients demonstrate a high prevalence of ORL symptoms. Therefore, an annual standard examination would provide data for identifying potential risk factors and for optimizing the management of these symptoms in CF patients.
We have previously reported cases of severe suprastomal stenosis after tracheostomy. In this observational study we investigated the occurrence of suprastomal stenosis as a late complication. Patients with persistent tracheostomy after intensive care underwent an endoscopic examination of tracheostoma, larynx and trachea. A percutaneous dilational tracheostomy was employed in 105 (71.9%) and surgical tracheostomy in 41 (28.1%) of the cases (n = 146). The incidence of severe suprastomal stenosis (grade II > 50% of the lumen) was 23.8% (25 of 105) after dilational tracheostomy and 7.3% (3 of 41) after surgical tracheostomy (p = 0.033). Age, gender, underlying disease, ventilation time, and swallowing ability were not significantly associated with the tracheal pathology. This study suggests that dilational tracheostomy is associated with an increased risk of severe suprastomal tracheal stenosis compared to the surgical technique.
Calcium pyrophosphate dihydrate deposition disease (CPPD) of the temporomandibular joint is rare. The disorder is characterized by the presence of crystal deposits within the affected joint. The deposition of crystals in adjacent soft tissue may lead to the formation of pseudotumors. This form of the disease is called tophaceous pseudogout and typically affects the temporomandibular joint. It is difficult to differentiate the disease, particularly from malignant tumors, on the clinical and radiographic findings alone. The diagnosis is based on histological identification of the calcium pyrophosphate crystals. We present an unusually advanced case of tophaceous pseudogout of the temporomandibular joint. The etiology, clinical and diagnostic criteria as well as treatment options are discussed on the basis of our own experience and a review of the literature.
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OBJECTIVES: Studies of the mechanoelectrical sensor system of the hair cell bundle in the cochlea require a manipulation device that enables controlled force application and movement of individual stereocilia in the nanometer range. METHODS: In our atomic force microscope (AFM) setup, the scan is directly controlled in an upright differential interference contrast (DIC) infrared video microscope with a water immersion objective and in the measured AFM image. Here we present studies on hair cells of the mammalian cochlea. RESULTS AND CONCLUSIONS: The resulting images revealed the tips of individual stereocilia of living sensory cells of the organ of Corti and the typical shape of the ciliary bundle. Scanning electron-microscopic (SEM) images of the identical hair bundles obtained after AFM investigation demonstrated that up to four AFM manipulations on the same cell did not cause obvious damage to the surface morphology of the stereocilia.
For the treatment of idiopathic sudden sensorineural hearing loss (ISSNHL), a variety of studies about intravenous drug administration with the beginning of treatment in the early period of less then one week after the onset of hearing loss have been performed. In contrast, very little information is available about the efficacy of intravenous drug therapy for ISSNHL with the beginning of treatment later than four weeks after the onset of hearing loss. In a retrospective chart review we studied the treatment results of 57 patients with ISSNHL with beginning of treatment later than four weeks after the onset of hearing loss with no spontaneous recovery of hearing. Patients received a treatment with intravenous administration of Dextran (concentration 40 g/l with NaCl 0.9%) and Procain-HCl (a derivative of the local anaesthetic lidocaine,400-800 mg in a 500 ml rheologic infusion of Dextran 40). 25% of the patients showed a significant improvement of 10 dB or more in hearing threshold at 1000 Hz measured in bone-conducted pure tone audiometry. In a subjective evaluation 53% of the patients noticed a subjective improvement of their individual hearing thresholds.
Movement or metal artefacts as well as the relatively high radiation exposure of both the axial and the coronal scan are disadvantages of computed tomography. A single spiral CT scan with a secondary reformation replacing the second CT scan might solve these problems. The goal of this project was to compare the diagnostic value of primary spiral CT scans of paranasal sinuses with secondary reformations. These were evaluated by ENT surgeons as well as radiologists. We performed axial and coronal spiral-CT's of paranasal sinuses in 80 patients. The secondary coronal and axial reformations were calculated with 2 mm image sections. Although a reduced resolution was observed in the secondary reformations, this did not compromise the detection of important anatomical features. Image deterioration due to artifacts was significantly reduced.
Massive osteolysis Gorham-Stout is a rare, benign but locally aggressive angiomatosis which results in destruction and resorption of bone. The etiology and pathogenesis are undefined. The occurrence of the disease in the skull base is uncommon. A 54-year-old female presented with isolated, one-sided surditas. Eight years before the patient underwent surgery and radiation therapy for treatment of hypopharyngeal cancer. A transtemporal biopsy was taken and a highly vascularized, cystic lesion with destruction of the right occipital and temporal bone and the atlas was found. Histopathology showed thin-walled capillaries with flattened endothelial lining cells. After exclusion of malignant and infectious components the diagnosis of Gorham's disease was established. Review of the literature suggests radiation therapy as the method of choice for stopping the disease's progress. The aim of this case report is to emphasize the Gorham-Stout-Syndrome as a rare differential diagnosis for skull base lesions.
The invasive phenotype of cancers critically depends on the expression of proteases such as the M(R) 92,000 type IV collagenase (MMP-9). Several growth factors and oncogenes were found to increase promoter activity and as a consequence protease expression. This frequently requires the activation of the transcription factor AP-1 by signal transduction cascades such as the ERK and JNK pathways. We have previously demonstrated that the tumor promoter TPA can induce MMP-9 expression via a third signaling cascade, the p38 pathway. Considering that TPA is a potent activator of AP-1, we hypothesized that this transcription factor might also be required for p38 pathway-dependent MMP-9 regulation. While dominant negative p38 and MKK-6 mutants reduced MMP-9 promoter activity in CAT assays, a construct encoding an activating mutation in the MKK-6 protein potently stimulated it. This was mediated via 144 bp of the 5'flanking region of the wild-type promoter, which contains an AP-1 site at -79. Both point mutations in this motif and the expression of a c-jun protein lacking its transactivation domain and therefore acting as a dominant negative AP-1 mutant abrogated MKK-6-dependent promoter stimulation. Finally SB 203580, a specific p38 pathway inhibitor, reduced MMP-9 expression/secretion and in vitro invasion of cancer cells. Thus, our results provide evidence that also the third SAPK/MAPK signaling cascade, the p38 signal transduction pathway, stimulates MMP-9 expression in an AP-1-dependent fashion.
For understanding the gating process of transduction channels in the inner ear it is essential to characterize and examine the functional properties of the ultrastructure of stereociliary bundles. There is strong evidence that transduction channels in hair cells are gated by directly pulling at the so-called tip links. In addition to these tip links a second class of filamentous structures was identified in the scanning and transmission electron microscope: the side-to-side links. These links laterally connect stereocilia of the same row of a hair bundle. This study concentrates on mechanical coupling of stereocilia of the tallest row connected by side-to-side links. Atomic Force microscopy (AFM) was used to investigate hair bundles of outer hair cells (OHCs) from postnatal rats (day 4). Although hair bundles of postnatal rats are still immature at day 4 and interconnecting cross-links do not show preferential direction yet, hair bundles of investigated OHCs already showed the characteristic V-shape of mature hair cells. In a first experiment, the stiffness of stereocilia was investigated scanning individual stereocilia with an AFM tip. The spring constant for the excitatory direction was 2.5 +/- 0.6 x 10(-3) N/m whereas a higher spring constant (3.1 +/- 1.5 x 10(-3) N/m) was observed in the inhibitory direction. In a second set of experiments, the force transmission between stereocilia of the tallest row was measured using AFM in combination with a thin glass fiber. This fiber locally displaced a stereocilium while the force laterally transmitted to the neighboring untouched taller stereocilia was measured by AFM. The results show a weak force interaction between tallest stereocilia of postnatal rats. The force exerted to an individual stereocilium declines to 36% at the nearest adjacent stereocilium of the same row not touched with the fiber. It is suggested that the amount of force transmitted from a taller stereocilium to an adjacent one of the same row depends on the orientation of links. Maximum force transmission is expected to appear along the axis of interconnecting side links. In our studies it is suggested that transmitted forces are small because connecting side links are oriented very close to an angle of 90 degrees with respect of the scan direction (excitatory-inhibitory direction).
Angiosarcomas are very rare but highly malignant soft tissue tumors derived from the vascular endothelium. The tumor is most commonly found in the skin. The cancer is known to cause early and widespread metastases leading to a very poor prognosis of less than 24 months. The therapy of choice is radical surgery followed by adjuvant radiation. In this case study, we report on a patient with a very unusual localization of angiosarcoma in the frontal sinus. Based on this case, we discuss important aspects of tumor biology, diagnostic procedures, and histologic features as well as therapeutic options. We conclude that angiosarcoma has to be considered by a differential diagnosis in all head and neck neoplasias with uncertain histology.
BACKGROUND: Cogan I syndrome is a rare, inflammatory, systemic disease that is typically characterized by severe audiovestibular dysfunction and various inflammatory eye changes. PATIENTS AND METHODS: Between 1978 and 1996 ten patients with Cogan I syndrome were treated at the eye hospital, ENT clinic and medical clinic of the University of Tübingen. Retrospectively, the clinical picture, course of the disease and outcome were investigated by reviewing the charts of these patients. RESULTS: Patient ages ranged from 18 to 78 years (mean 37 years) at the time of disease manifestation. Eight patients were female. Inflammatory ocular changes were observed in nine patients in both eyes. Uveitis was found in six patients, keratitis in five, episcleritis in three and scleritis in two patients. Both patients with scleritis showed a severe, partially sight-threatening course of the disease despite immunosuppressive therapy. Severe hearing loss was seen in all patients. Further manifestations of Cogan's syndrome included pericarditis associated with arthritis, and polyserositis in one patient, and fibromyalgia in two patients. CONCLUSION: In Cogan I syndrome, typically both eyes are affected by the disease process. Various ocular inflammatory changes may occur including uveitis, scleritis, keratitis and episcleritis. The visual prognosis is mostly good, although severe sight-threatening scleritis may occur.
This paper describes the investigation of elastical properties and imaging of living cochlear hair bundles of inner (IHC) and outer hair cells (OHC) on the level of individual stereocilia. A custom-made AFM-setup was used, allowing to scan the mechano-sensitive structures of the inner ear under direct control of an upright differential interference contrast (DIC) microscope with a water-immersion objective. Scanning electron microscopy (SEM) images of the identical hair bundles obtained after AFM investigation demonstrated that forces up to 1.5 nanonewton (nN) did not cause obvious damage of the surface morphology of the stereocilia. These are the first images of hair bundles of living sensory cells of the organ of Corti by AFM. They display the tips of individual stereocilia and the typical V-shape of ciliary bundles. Since line scans clearly show that slope and force interaction depend on the elastical properties of stereocilia, quantitative stiffness measurements and stimulation of single transduction channels are suggested.
PURPOSE: Determination of the radiation doses in spiral CT of the paranasal sinuses using a variety of mAs values and scan protocols. MATERIAL AND METHODS: CT examinations of the paranasal sinuses were performed using an Alderson-Rando phantom. Radiation dose was determined by LiF-TLD at the level of high risk organs in the head and neck region for combinations of different scan parameters (2/3, 3/3, 3/4 mm) and decreasing charges (200, 150, 100, 50, 25 mAs) on a spiral CT. Additional measurements were performed on three other CT scanners using the 2/3 mm protocol at 50 mAs, and a single slice technique (5/5 mm) on one scanner. RESULTS: The lowest dose values found were 1.88 mGy for the eye lenses, 1.35 mGy for the parotid gland, 0.03 mGy for the thyroid gland and 0.1 mGy for the medulla oblongata using 2 mm collimation and 3 mm table feed at 25 mAs. Maximal dose values resulted using the 3/3 mm protocol at 200 mAs (31.00 mGy for the eye lense, 0.65 mGy for the thyroid gland). There were no significant differences found between the different CT scanners. CONCLUSIONS: Using up-to-date CT scanners, radiation exposure may be reduced by a factor of 15-20 compared to that of conventional CT technique. Thus, the exposure of the eye lens comes to only a thousandth of the value supposedly inducing a cataract, as published by the ICRP.
Since the first description by Ciaglia in 1985, percutaneous dilatational tracheostomy (PDT) has emerged worldwide to be a favored and frequently used technique for airway control. Advantages are the rapidity, simplicity and independence of the physician. These characteristics tempt clinicians to perform the procedure uncritically and thus produce complications. Based on our experiences with the technique and on a critical analysis of the literature the indications and optimal operative technique are discussed. Operative steps are illustrated and potential pitfalls (anatomic variations, injury to vital structures and bleeding) are defined. In our experience endoscopic control plays a crucial role in preventing intraoperative complications. ENT colleagues should know the technique because of their experience with tracheotomized patients and should offer their services to other disciplines.
Isolated hair cell preparations have gained wide acceptance as a model for studying physiological and molecular properties of the sensory cells involved in the hearing process. Ultrastructural details, such as stereocilia links, lateral membrane substructure or synaptic links are of crucial importance for normal sensory transduction. For this reason, we developed a high-resolution scanning electron microscopy (SEM) procedure to study the surface of isolated hair cells. Cells were mechanically and/or enzymatically separated, isolated and immobilized on cover slips by alcian blue and fixed by 2% glutardialdehyde or 1% OsO4. After dehydration, preparations were critical point-dried and sputter-coated with gold-palladium (2-4 nm). Up to 5 nm resolution was achieved. Optimal fixation kept the cells in their typical cylindrical forms. Preservation of the stereocilia and the apical plates of the outer hair cells depended strongly on the fixation process. Tip- and side-links were observed only sporadically because of the aggressive preparation procedure. The lateral plasma membranes of the cell bodies showed regular granular structures of 5-7 nm diameter at maximal magnification. The granular structure of the cell membrane seemed to correspond to putative transmembrane proteins believed to generate membrane-based motility. The remnants of the nerve endings and/or supporting cells usually covered the cell base. The preservation of the cells was better when enzymatic isolation was omitted. The technique used allowed for high resolution ultrastructural examination of isolated hair cells and, when combined with immunological labeling, may permit the identification of proteins at a molecular level.