Biomedical subjects
W Mann
Publications and source records attributed to W Mann.
Optic nerve decompression in trauma and tumor patients.
Optic nerve decompression is a procedure that is now receiving increasing clinical attention. However, there are currently no standardized treatment protocols in the therapy of traumatic or pressure insults to the nerve. The present retrospective study was designed to report our experience with microscopic endonasal transethmoid-sphenoid optic nerve decompression in 24 unilateral trauma cases and 11 unilateral skull base tumor patients. In general preoperative visual acuities in the trauma patients were worse than in the tumor patients. Following surgery, 9 of 11 tumor patients (82%) had at least some improvement of their vision, including 5 complete recoveries. In the group with traumatic visual impairment, 16 of the patients had no light perception preoperatively. Postoperatively, 13 patients (54%) had at least some improvement, with 4 patients regaining normal or near normal vision. Compared to other techniques and approaches, our technique is a minimally invasive procedure for optic nerve decompression, reducing unnecessary operative trauma to nasal structures, skin incisions or even craniotomy and frontal lobe retraction.
The exposure of healthy volunteers to 200 ppm 1,1,1-trichloroethane increases the concentration of proinflammatory cytokines in nasal secretions.
OBJECTIVES: Irritating effects of organic solvents have usually been measured by means of questionnaires. The aim of the present study was to evaluate the sensitivity of different methods of detecting subclinical irritating effects. METHODS: Twelve healthy, non-smoking students were exposed to 200 ppm and to 20 ppm 1,1,1-trichloroethane in an exposure chamber, using a crossover design. The amounts of interleukins (IL)-1beta, IL-6 and IL-8 and prostaglandin E(2) (PGE(2)) in nasal secretions were measured. Mucociliary transport time was determined with the saccharine test. Ciliary beat frequency of nasal epithelial cells was measured with video-interference contrast microscopy. Subjective symptoms were assessed by questionnaire. RESULTS: Concentrations of ILs were significantly elevated after exposure to 200 ppm 1,1,1-trichloroethane (IL-1beta 82.4 vs. 28.8 pg/ml (medians), P=0.003; IL-6 12.2 vs. 7.2 pg/ml, P=0. 01; IL-8 549 vs. 424 pg/ml, P=0.007), whereas the other parameters remained unchanged. CONCLUSION: The interleukins measured proved to be sensitive indicators of irritating effects of 1,1, 1-trichloroethane. The German threshold limit (MAK value) of 200 ppm 1,1,1-trichloroethane does not prevent the subclinical inflammation of nasal mucosa.
The effect of short-term immunotherapy with molecular standardized grass and rye allergens on eosinophil cationic protein and tryptase in nasal secretions.
BACKGROUND: Activation of mast cells and eosinophils under pollen exposure can be inhibited by specific immunotherapy. OBJECTIVE: The effect of short-term immunotherapy with 7 preseasonal injections of molecular standardized allergens from grass and rye pollen on eosinophil cationic protein (ECP) and tryptase levels in nasal secretions has been compared with symptomatic drug treatment in an open, randomized study with 48 patients. METHODS: Nasal reactivity and mediator levels in nasal secretions were measured at baseline, before season, in season, and after season. RESULTS: Symptom scores in the immunotherapy group were 134.5 (95% CI, 65 to 336) versus 386. 0 (95% CI, 185 to 563), significantly lower as in the drug-treated group. ECP and tryptase levels increased significantly during natural allergen exposition. The seasonal levels in the immunotherapy group were significantly lower than in the drug-treated group with 272.1 ng/mL (252.0 to 293.9 ng/mL; immunotherapy) versus 470.4 ng/mL (SEM, 435.6 to 508.0 ng/mL; drugs) for ECP and with 8.73 ng/mL (SEM, 8.20 to 9.29 ng/mL) versus 17.47 ng/mL (16.42 to 18.60 ng/mL) for tryptase (all, P <.001). The ECP level induced by nasal provocation was 105.6 ng/mL (99.0 to 112.6 ng/mL) versus 180.4 ng/mL (169.2 to 192.4 ng/mL), significantly lower (P <.001) in the immunotherapy group, as was the tryptase level with 12.12 ng/mL (11.53 to 12.75 ng/mL) versus 8.19 ng/mL (7. 79 to 8.62 ng/mL; P <.001) at the after-season visit. CONCLUSION: Short-term immunotherapy is able to reduce tryptase and ECP in nasal secretions more effectively than drug treatment in patients with allergic rhinitis.
Neuroradiological diagnosis in thyroid-associated orbitopathy.
No renunciation can be made of modern imaging techniques in primary diagnosis as well as in the course of endocrine orbitopathy. Even in times of cost reduction of the public health and although expansive CT and MR play a constant role in the interdisciplinary challenge, concerning the treatment of these patients. Both methods show the actual objective morphological findings, MR giving additional information concerning the acuteness (T2 relaxation time) or chronicity (fatty degeneration), which is of great importance for the chosen therapy. CT and MR is mandatory for the control of the clinical course after conservative, surgical and/or radiotherapeutic therapy.
Radiotherapy for thyroid-associated orbitopathy.
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[Anosmia caused by inhaled hazardous substances. Significance for expert assessment general practice].
BACKGROUND: Both environmental and occupational pollutants can affect the functional integrity of the olfactory epithelium or even destroy olfactory tissue. However, occupational hyposmia and anosmia have not been included into the list of occupational diseases. Therefore, compensation of occupationally induced smell disorders is difficult. OBJECTIVE: To evaluate patients with toxic hyposmia for the pollutants involved and to discuss consequences for occupational and environmental medicine. METHODS: A total of 19 patients were evaluated in our departments between 1993 and 1997 for olfactory disorders related to environmental or occupational pollutants. The charts of these patients were retrospectically analyzed and the causative pollutants compared with the literature. RESULTS: A chronical exposure to mixtures of metal dusts and steam, volatile organic substances, and anorganic gases were the most common pollutants involved in occupational dysosmia. Only one case of acute development of an anosmia due to exposure to CO and combustion gases was documented. CONCLUSIONS: Olfactory disorders are underestimated in occupational and environmental medicine. Relevance of olfactotoxic substances for occupational medicine can be postulated in metal and chemical workers, in welding and disinfection. The list of occupational diseases should be completed by olfactory hyposmia and anosmia.
[Experiences with using the Kozlov trocar for trans-facial removal of maxillary sinus pathology].
BACKGROUND: Pathologies of the maxillary sinus can be reached through a transfacial approach. METHODS AND PATIENTS: Therefore a new trocar designed by Kozlov was used to remove pathologic changes in 39 patients using a transcanin fossa puncture approach. A total of 52 procedures were performed and the long-term sequelae were evaluated over a period at least 12 months. RESULTS: This new trocar allowed in all cases for removal of pathologies within the maxillary sinus with various instruments and even powered instruments under microscopic control. Hypesthesia and numbness of the lip and individual teeth persisted after 11 of 52 procedures without major discomfort for the patient. CONCLUSION: This new instrument has proved to be a useful tool to perform limited sinus procedures under local anaesthesia or as an adjunct of endonasal surgery under general anaesthesia in our hands.
[Duplex ultrasonography-controlled Nd:Yag laser therapy of vascular malformations].
AIM: Vascular malformations can be studied in detail by colour Doppler sonography. These lesions are best treated by Nd:YAG laser therapy. The aim of the study was to improve the quality of therapy by the use of colour Doppler sonography guided Nd-YAG laser application. PATIENTS AND METHOD: 17 vascular malformations/haemangiomas in 16 patients were treated by colour Doppler sonography guided Nd:YAG laser therapy. 5 children were less than one year of age, 4 children were between one and five years of age, the other patients were adults (age 22-57 years). The size of the vascular malformations (largest diameter) were 1.5-3 cm (8 cases), all others were larger than 3 cm. RESULTS: When using laser therapy in combination with colour Doppler sonography it is possible to adjust the treatment variables (dose, duration and energy of the laser pulse as well as the precise intralesional positioning) individually. As a result more than 80% of cases can be treated successfully during a single session. Larger lesions may be divided into functional units which can be treated subsequently. CONCLUSION: Through colour Doppler sonography it is possible to monitor the effects of laser treatment in vascular malformations. The development of smaller ultrasound probes has facilitated the application of laser therapy guided by Doppler sonography in the region of the head and neck. Colour Doppler sonography guided laser therapy increases efficiency and selectivity of the laser treatment. Early interventions prevent growth of the lesions and reduce long-term disfigurement particularly in children.
[Tumor biologic prognostic parameters in T1N0M0 squamous cell carcinoma of the oral cavity].
BACKGROUND: Conventional prognostic factors in squamous cell carcinomas are tumor stage, tumor size, evidence of lymph node metastases, extracapsular spread of lymph node metastases, and Broder's grading. Unfortunately these parameters are only of limited value in predicting the biological behavior and ultimately the prognosis of a particular tumor. The present study was conducted for determining objective prognostic factors based on tumor biologic examinations in patients with squamous cell carcinomas of the oral cavity. These parameters were compared to the conventional prognostic factors. PATIENTS AND METHODS: Operative specimens of fourty-two patients who underwent surgery for a squamous cell carcinoma of the oral cavity with clinical TNM stage T1N0M0 were examined. All tumors were radically excised with histologic clear margins, which were confirmed by serial sections. The examinations included morphologic multifactorial tumor front grading, quantitative DNA analysis, and immunohistochemical assessment of proliferation markers (i.e. proliferating cell nuclear antigen [PCNA] and MIB1) and of oncogene products (i.e. p53; nm23). Prognostic significance of particular parameters was evaluated by univariate and multivariate Cox regression models. RESULTS: In clinical follow-up of 70 months on average, 6 patients developed local recurrences and 5 patients lymph node metastases. Three patients died of disease. Tumors which recurred had increased values for 2 c Deviation Index, 5 c Exceeding Rate along with high tumor front grading scores and proliferation scores. Using multivariate Cox regression analysis, parameters which were highly significant for prognosis were 5 c Exceeding Rate, tumor front grading score and PCNA score. None of the clinical parameters achieved statistical significance in the multivariate model. Tumors which recurred had also increased expression rates for p53 and nm23. Nevertheless this was statistically not significant. CONCLUSIONS: Tumor biologic examinations provide important informations about the clinical aggressiveness and ultimately about the prognosis of a particular tumor. Tumors with aggressive behavior can already be identified during initial diagnosis, which has consequences for the therapeutic management of the patients.
[Diagnostic procedure in primary ciliary dyskinesia].
BACKGROUND: Primary ciliary dyskinesia (PCD) is usually diagnosed by ultrastructural investigations of nasal or bronchial mucosa. Less invasive techniques for quick and cost-effective diagnosis of PCD should be evaluated. METHODS: In 32 patients with suspected PCD, saccharin transport time, ciliary beating of nasal respiratory epithelium, and ultrastructure of nasal mucosa biopsies were investigated. RESULTS: In 13 patients, PCD was excluded by a normal saccharin transport time (< 20 min). In 19 patients, respiratory cells were obtained by nasal brushing. Frequency, coordination, and amplitude of ciliary beating were examined using interference contrast microscopy and scored. PCD was excluded in 10 of 19 patients, who revealed normal ciliary activity. In the remaining 9 patients, nasal mucosa specimens for ultrastructural investigation were obtained. Ultrastructural alterations indicating PCD were found 4 of 9 specimens, in 2 specimens no cilia were found and in 3 specimens alterations indicating secondary inflammatory alterations were found. CONCLUSIONS: PCD may be efficiently excluded in several cases using cost-effective diagnostic techniques. The definite diagnosis in the remaining cases requires ultrastructural investigations which should be performed in specialized centers. In the present study, PCD in a carefully preselected group had a surprisingly high prevalence.
[Orientational evaluation of otolith function by eye counter-rolling in patients with various kinds of vertigo].
BACKGROUND: Measurement of ocular counterrolling (OCR) is well known as a simple method to evaluate the peripheral vestibular organ, especially the otolith organ. But it has rarely been used because of the difficulty in differentiating between pathologically reduced OCR and the wide physiological variation of this parameter. PATIENTS: In this study, the OCR of 55 patients with unclarified vertigo (n = 20), vestibular neuronitis (n = 15), Menière's disease (n = 10), and benign paroxysmal positional nystagmus (n = 10) were evaluated and compared to a control group (n = 30) with the intention of diagnosing peripheral vestibular dysfunction and establishing a differential diagnosis. The test sequence was carried out with Vesta goggles by Panares and included head tilts of 5 degrees, 15 degrees, and 30 degrees to the left and right. RESULTS: The results show a significantly reduced OCR in patients suffering from peripheral vestibular disorders when compared to the control group. CONCLUSION: There is no specific finding for a specific type of vestibular lesion, but otolith function is affected in several disorders as measured by ocular counterrolling.
A passive-marker-based optical system for computer-aided surgery in otorhinolaryngology: development and first clinical experiences.
OBJECTIVES: To develop a new type of optical computer-aided surgery (CAS) device that overcomes some of the restrictions of common systems and to examine its accuracy and usability under laboratory and intraoperative conditions. STUDY DESIGN: Prospective study using laboratory experiments and intraoperative data collection. METHODS: An optical CAS system applying passive optical markers for coordinate determination was developed. Laboratory accuracy measurements were obtained on a Plexiglas model with known coordinates of fiducial markers, before and after predefined table movements. Intraoperative accuracy measurements were recorded from 24 patients undergoing endonasal surgery of the paranasal sinuses with two different referencing techniques (fiducial markers and mouthpiece). RESULTS: The system demonstrated laboratory accuracy to within 0.86 mm (SD = 0.94 mm). After table movements, the accuracy decreased to 1.12 mm (SD = 0.99 mm), 1.05 mm (SD = 0.96 mm), 1.15 mm (SD = 1.04 mm), and 1.54 mm (SD = 1.25 mm), respectively, in four different positions. Intraoperative accuracy was within 1.14 mm (SD = 0.57 mm) (fiducial markers) and 2.66 mm (SD = 1.89 mm) (mouthpiece) (P < .05). One of the main advantages of the new technology was the possibility of using any common instrument or endoscope by adapting a marker array. CONCLUSIONS: Passive-marker technology has been demonstrated to be useful for optical position determination in computer-aided surgery.
Towards identification of individual homologous chromosomes: comparative genomic hybridization and spectral karyotyping discriminate between paternal and maternal euchromatin in Mus musculus x M. spretus interspecific hybrids.
We have developed an in situ technique to label individual euchromatic chromosome arms in interspecific crosses between Mus musculus (MMU) and M. spretus (MSP). The MMU and MSP genomes diverged 2-3 million years ago and show an overall sequence divergence of approximately 1%. Comparative hybridization of MMU versus MSP DNA and subsequent spectral analysis of the euchromatic hybridization profiles discriminated between maternal (MMU) and paternal (MSP) chromosomes in F(1) hybrids. Dispersed repetitive DNA elements were the preferred hybridization target of MMU DNA on maternal chromosomes and of MSP DNA on paternal chromosomes. Differences in centromeric satellite DNAs were detected by conventional fluorescence in situ hybridization and served as internal controls. Our experiments suggest that it is possible, in principle, to discriminate between paternal and maternal chromosomes on the basis of sequence differences.
[High-frequency jet ventilation for placing tracheal stents--a case report].
Stenoses of the larynx and trachea may cause acute life-threatening situations. Surgical procedures in patients presenting this type of problem are a real challenge for the surgeon and the anaesthesiologist. Depending on the extent and the nature of the stenosis, the insertion of a stent may be the best therapeutic option. In this case, the high frequency jet ventilation offers certain advantages for the surgeon. Thanks to modern jet ventilators with automatic pressure monitoring and jet ventilation tubes with a separate lumen for pressure monitoring, the danger of barotrauma is considerably reduced, even in patients with a high-degree stenosis of the larynx and trachea. During insertion of a tracheal stent during jet ventilation, the complete cross-section of the trachea must at least be temporarily available to the surgeon. In addition, at the end of the operation the newly implanted stent should not be altered by manipulations necessary for artificial respiration. We describe a new method which uses tracheal jet ventilation for implanting a stent with only short interruptions of artificial ventilation. During recovery from anaesthesia, there is no risk of dislocating the newly placed stent.
Is stapedectomy ever ethical?--Faulty premise, faulty conclusion.
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Virtual reality: preparation and execution of sinus surgery.
Endonasal sinus surgery requires a great deal of training before it can be performed adequately. Due to the complex and variable anatomy and the proximity of important structures, severe complications are possible, even for experienced surgeons. The nasal endoscopy simulator (NES) is an interactive training system for nasal endoscopy and endonasal sinus surgery that combines computer graphics and virtual reality (VR) techniques. This system consists of a graphics workstation, a tracking system for measuring the position of the endoscope and surgical instruments in space, a head model, image data sets of the nasal cavity and paranasal sinus area, and complementary software. The current NES is a visual and auditory VR system that provides both educational and planning options for sinus surgery. The usual resistance when touching relevant anatomical structures is not provided by this release. Therefore, a "force feedback system" is implemented that allows for such a response. VR simulation will become an important part of surgical education and planning for individual sinus surgery procedures. The ongoing development of the NES will lead to an improved educational environment for residents in training and practitioners.
Development of computer-aided surgery for otorhinolaryngology.
Computer-aided surgery (CAS) describes a method that allows intraoperative navigation in the surgical field based on digital image data such as computed tomography, magnetic resonance imaging, and others. A computer processes the image data in real time and is intraoperatively connected to a measuring system for coordinate determination. CAS has been used in ENT surgery since 1986, and we developed several generations of CAS systems. A passive robot arm was employed in the first approach. Then electromechanical and infrared optical coordinate-measuring devices followed. CAS was applied to several fields of otorhinolaryngologic surgery, including the paranasal sinuses, the orbit, the rhino- and otobasis, and others. CAS was found to be particularly useful for acoustic neuroma removal, paranasal sinus surgery in cases of massive disease or revision surgery, decompression of the orbit or optic nerve, extraction of deep-seated foreign bodies, stereotaxy-like biopsies, and educational purposes. CAS in its current state of development is a useful tool that can be applied routinely; however, further technical developments are necessary.