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Biomedical subjects

F Bootz

Publications and source records attributed to F Bootz.

At least 55 records · Page 3Linked to original sources
PubMed2001

Magnetic resonance imaging--guided biopsies of the petrous apex and petroclival region.

OBJECTIVE: To analyze the advantages in safety and precision of biopsies of the petrous apex and petroclival region using open magnetic resonance imaging (MRI). SETTING: The University of Leipzig Medical Center. PATIENTS: Biopsies were taken in 13 patients with tumors of the petrous apex and petroclival region. INTERVENTION: With the patient in the 0.5-T intraoperative MRI system (Signa SP; General Electric Medical Systems, Boston, MA, U.S.A.), biopsies were taken from the petrous apex and the petroclival region under imaging control by transseptal, transsphenoidal access. The region of interest was approached with a virtual pointer (Flashpoint Position Encoder; Image Guided Technologies, U.S.A.) and marked with a gadolinium-filled pointer. RESULTS: In all patients, the authors obtained enough tissue for histologic study, which also proved to be the suspected tumor. One patient had a bone cyst, another had a malignant lymphoma, and another two a cholesterol granuloma originating from the petrous apex. Three other patients had metastases (carcinoma of the breast, bronchial carcinoma, and unknown origin). Three patients had a meningioma, and another three a chordoma. The authors did not see any postoperative complications. CONCLUSIONS: In the authors' experience, the transsphenoidal access is favorable for approaching and sampling lesions of the petrous apex and the petroclival region. This route, however, is disadvantageous because the course of the internal carotid artery and the brainstem narrow the surgical space to the petrous apex. Open MRI in these cases is very useful because it allows a safe approach to the tumor by navigation and by visualizing the anatomic structures in real-time imaging.

Adult↗
PubMed2001

CUP (carcinoma of unknown primary) syndrome in head and neck: clinic, diagnostic, and therapy.

BACKGROUND: Up to 10% of all cervical lymph node metastases present without a known primary site. Between 70 and 80% of the found primary tumors are located in the head and neck region, because cervical lymph nodes represent the lymph drainage of the head and neck. PATIENTS AND METHODS: We demonstrate the clinic, diagnostic management and therapy of carcinoma of unknown primary (CUP) in this retrospective study of 75 patients who primarily presented cervical metastases with unknown primary tumor at the Otorhinolaryngological Department of the University of Leipzig, Germany. RESULTS: A primary tumor was found in 44% of the patients, and 76% of the primary tumors were localized in the head and neck region. The overall 5-year survival rate was 13.3%. The 34 patients with pretherapeutically detected primary tumors showed a tendency towards better survival, with a 5-year survival rate of 21% compared to 10% in patients with undetected primary. CONCLUSIONS: Following a thorough physical examination, radiologic imaging, i.e., computed tomography and/or magnetic resonance imaging, of the head and neck region as well a chest X ray, panendoscopy with biopsy of the most probable tumor sites, and diagnostic tonsillectomy should be performed. Further diagnostic procedures as gastroenterologic, urogenital and gynecological examinations should be performed, depending on histology and location of the node and under consideration of cost-benefit analysis. Curative treatment should at least include ipsilateral neck dissection and adjuvant irradiation of the complete cervical lymph drainage. In the literature, radiation of the laryngopharyngeal mucosa is still discussed controversially: some authors recommend the irradation of the pharyngeal mucosa extending from the nasopharynx to the upper esophagus, whereas others regard the resulting side effects as too high compared to the expected benefit.

Biopsy↗
PubMed2000

Immunophenotyping of peripheral blood leukocytes by laser scanning cytometry.

Many clinical situations demand repeated analyses of blood parameters but permit only minimal amounts of peripheral blood to be taken, e.g., in neonates with low birth weight, during extensive operations of young children, or in patients with restricted bone marrow function. In these cases laser scanning cytometry is the ideal tool to determine the distribution of different leukocyte-subsets. The purpose of this protocol is to describe stepwise a new method of immunophenotyping by laser scanning cytometry. In this assay nuclear DNA is stained by 7-aminoactinomycin-D (7-AAD) and surface antigens are detected by direct three-colour immunofluorescence. For data acquisition, measurements are triggered on the 7-AAD-fluorescence. Data are obtained for forward scatter, green, orange, and long red fluorescence by excitation with the argon-laser, and for far red fluorescence by excitation with the helium-neon-laser. Using this protocol the amount of peripheral blood needed is minimised to 10 microl. Specimens can be stained a second time in a different way and analysed repeatedly and archived.

Antigens, CD↗
PubMed2000

Immune deficiency in mouse models for inherited peripheral neuropathies leads to improved myelin maintenance.

The adhesive cell surface molecule P(0) is the most abundant glycoprotein in peripheral nerve myelin and fulfills pivotal functions during myelin formation and maintenance. Mutations in the corresponding gene cause hereditary demyelinating neuropathies. In mice heterozygously deficient in P(0) (P(0)(+/-) mice), an established animal model for a subtype of hereditary neuropathies, T-lymphocytes are present in the demyelinating nerves. To monitor the possible involvement of the immune system in myelin pathology, we cross-bred P(0)(+/-) mice with null mutants for the recombination activating gene 1 (RAG-1) or with mice deficient in the T-cell receptor alpha-subunit. We found that in P(0)(+/-) mice myelin degeneration and impairment of nerve conduction properties is less severe when the immune system is deficient. Moreover, isolated T-lymphocytes from P(0)(+/-) mice show enhanced reactivity to myelin components of the peripheral nerve, such as P(0), P(2), and myelin basic protein. We hypothesize that autoreactive immune cells can significantly foster the demyelinating phenotype of mice with a primarily genetically based peripheral neuropathy.

Animals↗
PubMed2000

[Axonotmesis].

Explore the source record for details and available documents.

Bell Palsy↗
PubMed2000

[Neuromuscular reinnervation of mimetic muscles. A histomorphologic study of the zygomatic muscle of the rabbit].

To evaluate occurrences of reinnervation and degeneration, the portio auricularis of the zygomatic muscle was reinnervated (either primary or secondary reinnervation) with an interval of 6 weeks, using a neuromuscular transplant of the sternohyoid muscle, which was left at the ansa hypoglossi. Histological examination was performed 6 and 12 weeks later. Enzymatic stains for myofibrillar ATPase were used for differentiation of muscle fibre types. Histomorphological features of denervation and reinnervation were analysed. Six weeks after denervation and primary neuromuscular transplantation, type grouping in regions close to the transplanted muscle were detectable as signs of reinnervation. After a period of 12 weeks, the progressing reinnervation was proved by type grouping in distal areas of the muscle far from the area of transplantation. At the same time, differentiation of fibre typing in the type grouping areas increased. All denervated and reinnervated muscles had pathological variations of fibre diameter. Primary reinnervated muscles showed tendency of normalization in variation of diameter. Compared with primary reinnervated muscles, secondary reinnervated muscles with an interval of 6 weeks showed pronounced polymorphology of fibres and a high pathological increase of the variation of fibre diameters. The interfascicular space was significantly spread. The tendency of reinnervation with incidence of fibre type grouping was comparable to primary reinnervated muscles and also occurred 6 weeks after transplantation.

Animals↗
PubMed2000

[Quality assurance in ENT tumor surgery].

BACKGROUND AND OBJECTIVE: Quality control is of special importance in head and neck oncology since the quality of medical care constitutes a vital parameter for the diseased patient. In contrast to other medical specialties, no quality assurance program for head and neck cancer patients has yet been established in Germany. Therefore, a survey was conducted to assess the quality assurance instruments that are in use today in otorhinolaryngology-head and neck (ORL-HNS) centers. PATIENTS AND METHODS: In a nationwide survey, questionnaires were sent out to 146 German ORL-HNS departments (the return rate was 75%). RESULTS: 56% of all departments apply dedicated quality assurance processes, and 38% have appointed a formal quality assurance officer. Interdisciplinary oncological conferences are held in the vast majority of all departments with the participation of radiation oncologists in 86 (78%), medical oncologists in 84 (76%), diagnostic radiologists in 82 (74%), and pathologists in 73 (66%). Morbidity-mortality conferences are held in seven departments (6%). A standardized follow-up of oncological patients is carried out in 95 units (86%), and 53 departments use computer-assisted data bases to organize their follow-up data (48%). A wide variety of documentation systems is in use throughout the country: 78 units (71%) offer formal follow-up to their oncological patients. CONCLUSIONS: This survey documents a wide-spread interest in quality assurance procedures. Many individual efforts are being undertaken. However, no uniform quality assurance or auditing system is currently in use in Germany nor is a commonly accepted data base available. The ability to offer oncological follow-up within the national social security system is generally considered indispensable for the maintenance of high-quality oncological care in ORL-HNS departments.

Germany↗
PubMed2000

[Institutionalization of skull base surgery. Development, concept and initial experiences of the interdisciplinary center for skull base surgery of the Leipzig University].

The treatment of complex tumorous, inflammatory, traumatic, vascular processes, or developmental disorders of the skull base increasingly needs the interdisciplinary cooperation of specialties involved in diagnostics or treatment. Due to this inevitable cooperation of different hospital specialties, institutionalization of skull base surgery, organized as a center or working group, seems recommendable. Moreover, such a center may have additional effects on the external representation of skull base surgery, which is also important. On the initiative of 11 departments and institutes of the university hospital of Leipzing, the Interdisciplinary Center of Skull Base Surgery (IZSL) was founded in March 1997. The following aims were proclaimed: improvement of the interdisciplinary clinical treatment of patients with skull base diseases, evaluation of the patient's data, advancement of clinical and experimental research on the field of skull base surgery, as well as the organization of meetings for training and teaching and scientific meetings. Structure, concept, and first experiences of the interdisciplinary center of skull base surgery are discussed.

Germany↗
PubMed2000

[Growth of human respiratory epithelium on collagen foil].

BACKGROUND: Clinical application of bioartificial tracheal prosthesis must still be regarded as an experimental concept because restoration of a functional respiratory epithelium outlining the prosthesis is still not possible. Tissue engineering as a relatively new biotechnological discipline may offer new methods in expanding differentiated respiratory epithelium in vitro. In this study we compare two different cell and tissue culture procedures for growing human nasal mucosa on commercially available collagen foil. MATERIAL AND METHODS: Harvested specimens of human nasal mucosa (n = 6, 4 x 4 cm) were placed on collagen foil and incubated as tissue cultures for 4, 6 and 8 weeks. A suspension of enzymatically dispersed nasal epithelium seeded on collagen foil (5 x 10(5) cells) served as control. Cell growth and ciliary beat were monitored through an inverted microscope with Hoffman's modulation contrast and video set-up. Histological examination was performed after 4, 6 and 8 weeks. RESULTS: In the tissue cultures, the collagen foil was initially covered with fibroblasts growing from the mucosa specimen before epithelial cells spread out. The epithelial layer showed mostly ciliated cells which developed metachronous ciliary beat after 4 weeks in vitro. Ciliary activity was observed until the end of the experiments in 8 weeks. New cells on the suspension cultures were mesenchymal and did not exhibit any ciliary activity. CONCLUSIONS: Mucosa specimens seem to be more appropriate for tissue engineering of respiratory epithelium than cell suspensions from nasal epithelium. Collagen foil as tissue scaffold initiates epithelial-mesenchymal interaction and may play an important role in epithelial differentiation of new respiratory epithelium.

Biomedical Engineering↗
PubMed2000

Influence of age and presbyacusis on DPOAE.

The influence of presbyacusis on distortion-product otoacoustic emissions (DPOAEs) was studied on 180 ears of 96 normal-hearing subjects. The subjects' ages were distributed equally and ranged from 14 to 82 years. It was shown that there is a highly significant decrease in DPOAE amplitudes during the ageing process. By means of special statistical procedures, such as partial correlation and multiple regression, it was proved that the main reason for this is deterioration in pure-tone thresholds. However, other age-related effects were determined and were also found to lead to a further decrease in DPOAE amplitudes. The latter might be due to middle ear alterations in elderly people. Knowledge of the influence of presbyacusis on DPOAE is important if DPOAEs are to be used in expert assessment of inner ear disorders, for example, occupational noise-induced hearing loss.

Acoustic Impedance Tests↗
PubMed1999

[Use of open MRI in head-neck surgery].

The vertical open MRI (Signa SP, 0, 5 Tesla) is ideal for interventional diagnosis and therapy. From our point of view indications in Otorhinolaryngology are biopsies of tumours which are difficult to access such as the petrous apex and the petroclival region, the parapharyngeal space and neck and the orbit. Furthermore the open MRI is useful in the surgery of paranasal sinuses, in the evaluation of tissue-resection and helpful in detection of the anatomy of delicate structures as the internal carotid artery, the skull-base and the orbit. Also navigation in open MRI is possible for example with a flash-point-system. The advantage to conventional navigation systems is the possibility of real-time-imaging, which allows detection of tissue shift occurring during the procedure. We report about our experience with ten biopsies of the petrous apex and the petroclival junction and two biopsy of the parapharyngeal space and the neck. Further experience was gained with MR guided placement of afterloading tubes into large neck metastases in three cases and microscopic surgery of paranasal sinuses in five cases. In all operative procedures an excellent resolution was found especially for soft tissue structures as for example blood vessels. With the aid of special pointer systems or artefacts by surgical instruments all relevant anatomical structures could be detected intraoperatively, concerning normal and pathologic tissue. Thus open MRI proved to be a helpful instrument in these operative procedures.

Adult↗
PubMed1999

Open MRI-guided neurosurgery.

OBJECTIVES: A number of different image-guided surgical techniques have been developed during the past decade. None of these methods can provide the surgeon with information about the dynamic changes that occur intra-operatively. MATERIAL AND METHOD: The first vertical open 0.5T MRI-scanner for intra-operative MRI-guided neurosurgery in Germany was installed at the University of Leipzig during the summer 1996. Since autumn 1996 a number of surgical procedures including biopsies (n = 31), craniotomies (n = 32), transsphenoidal procedures (n = 8) and interstitial lasertherapies (n = 3) have been performed using intra-operative MR image guidance. RESULTS: The development of MR-compatible and MR-safe non-magnetic instruments and components had to be solved. Specific surgical instruments were developed to perform biopsies, craniotomies, microsurgical tumour resections and transsphenoidal procedures in the 0.5-T open MRI. Several components required adaptation including the head holder the stereotactic navigation device, the high speed drill, the suction unit, the ultrasonic aspirator, the bipolar coagulation, the laser probe and the surgical microscope. All these newly developed technical features enable the neurosurgeon to perform a large number of surgical procedures under direct control and guidance of intra-operative MR imaging. In contrast to frame-based for framless navigation systems, intra-operative MRI provides accurate and immediate information during the progress of surgery. These intra-operative images allow definitive localization and targeting of the lesions and accommodate anatomical changes that may occur during surgery. CONCLUSION: Intra-operative MRI is helpful for navigation as well as determining of tumour margins to achieve a complete and safe resection of intracranial lesions. Complications related to the surgical procedure are reduced and the risk of neurological deterioration due to tumour removal and postoperative complications is minimized. It can be concluded that the intra-operative application of interventional MRI technology may represent a major step forward in the field of neurosurgery.

Biopsy↗