270. Charakterisierung und Behandlung von Abstossungskrisen nach Lebertransplantation

Zusammenfassung Klinische Merkmale von Abstossungskrisen sowie ihre Ansprechrate auf Behandlung wurden nach 34 Lebertransplantationen in 31 Patienten retrospektiv ausgewertet. 38 Abstossungskrisen wurden diagnostiziert, von denen 34 behandelt wurden. Transplantatfunktionsstörungen wurden durch klinisch-chemische Tests, Leberbiopsien und nuclearmedizinische Untersuchungen diagnostiziert. Durch Steroidbolustherapie (3 x 500 mg) konnten 19/24 (79%) akute Abstossungskrisen behandelt werden und 5/14 (36%) Wiederholungsabstossungen. Bei steroidresistenten Abstossungen konnte eine ALG-Therapie 4/5 erste und 5/8 Rezidivabstossungen kontrollieren. Transplantatverluste infolge irreversibler Abstossungen traten bei 5/34 Transplantaten auf (15%). Infolge der hohen Ansprechrate empfiehlt sich die Steroidbolusbehandlung als Initialtherapie. Polyklonale Antikörperbehandlung ( ALG-Präparate) empfiehlt sich bei steroidresistenten und Wiederholungsabstossungen. Transplantatverluste durch irreversible Abstossungen bleiben mit 15% Incidenz ein wesentliches Problem und rfordern frühe Entscheidung zur Retransplantation.     

Urinzytologische Charakterisierung von Patienten mit Urothelkarzinomen und Verbesserung und kombinierte Zytologie und Zytometrie zur Vermeidung von Fehlinterpretationen durch die Urinzytologie

Ohne Zusammenfassung     

Tissue Engineering von Sehnen- und Bandgewebe

Ohne Zusammenfassung     

Tissue Engineering von Sehnen- und Ligamentgewebe Eine neue Herausforderung

Injuries to ligaments and tendons heal by formation of inferior repair tissue. This may result in severe joint dysfunction. Because of an increased occurrence of sports-related injuries, musculoskeletal disorders may become one of the major burden of health care. Tissue engineering offers the potential to improve the quality of ligament and tendon tissues during the healing process and may provide a more effective approach to the treatment of injuries to ligaments and tendons than traditional methods. Application of growth factors, gene transfer techniques, cell therapy and cell-matrix composites have shown to affect the process of ligament and tendon healing. The benefits of using mesenchymal stem cells on a three dimensional biological matrix have been shown recently. Tissue engineering will also include mechanical manipulation of tissue environments to accelerate cell differentiation and to improve matrix formation. Fibroblast-seeded polymer scaffolds could be useful in ligament and tendon replacement in which autogenous fibroblasts would be obtained through biopsy, cultured and seeded onto a scaffold.     

Sonographische Charakterisierung von Narben nach thermischen Verletzungen beim Kind

So far, little is known about the acoustic phenomena of high-frequency sonography for the assessment of healing processes in thermal wounds. However, ex vivo investigations have shown clear age-dependent differences in the rate of sound propagation in thermal scars compared to healthy skin. In order to answer the question of whether measurable acoustic characteristics of burn or scald scars can be classified in a way which corresponds to the clinical severity of the injuries, age of scar or type of treatment, 92 thermal scars, with an average scar age of 3.1 years, in 55 children were investigated with regard to corium thickness and echogenicity. A control group of 25 non-injured children of similar age was studied for comparison. It was shown that measurable echogenicity differences can allow conclusions about clinical severity to be drawn. The comparison of different therapeutic strategies showed no therapeutic effect either for compression or for the application of silicone gel sheets. In contrast, a decrease in scar thickness and a loosening of scar structure could be seen after early application of a sterile, silicone-covered polyamide net bandage. The 20-MHz-Sonography is a suitable non-invasive procedure for the characterisation of burn scars.     

Tissue Engineering von Knochen

Tissue engineering opens up new ways for therapy of bone defects. Therefore, the aim of this study was to establish a mouse model to investigate local cell growth of human mesenchymal stem cells (hMSC) on the scaffold in vivo. Moreover, migration of cells to other organs should be excluded.hMSC (Cambrex, USA) were cultivated according to supplier's recommendations. After inoculation on cylindric scaffolds, one matrix cell construct and one scaffold without hMSC were implanted subcutaneously left and right paravertebrally in athymic nude mice. After 2, 4, 8, and 12 weeks constructs and organs were harvested for immunohistological evaluation and PCR.In conclusion, we found integration of scaffolds loaded with hMSC implanted ectopically. HMSC seeded on 3D scaffolds survived for a period of up to 12 weeks. In addition, we could not detect hMSC in any other organ of the host.     

Tissue Engineering von Herzklappen

With the introduction of heart valve prostheses cardiac valvular disease has become much more accessible to therapeutic options. However, currently available prostheses display significant limitations, such as limited long-term durability (biological prostheses) and a long-term necessity for anticoagulation therapy. Hence, alternative prosthesis types have been extensively explored in recent years particularly aiming at the development of vital and regenerative prostheses by means of tissue engineering. In the scientific field, different competing concepts have been introduced, including biological or synthetic scaffolds which can be further enhanced by cellular or extracellular components to promote further in vivo development of the prosthesis after implantation. Nowadays, decellularized donor heart valves are among the most advanced prosthesis types experiencing growing clinical attention and widespread use.     

Diagnostik und Therapie von Schulter- und Ellengelenkempyemen

Diagnosis of acute joint infections is based primarily on clinical alterations, laboratory tests, sonography and examination of aspirated joint fluid. Conventional X-rays should also always be done, to exclude other diseases. We use three criteria for classification: previous treatment, extent of infection, and extent of joint destruction (4 grades). Treatment has to take account of all three criteria: if the joint alone is infected treatment is exclusively, or preferentially, arthroscopic in stages I–III; while in stage IV disease, two-stage open surgery predominates. Local antibiotic substances (fleece or chains) are often used; in cases of far advanced joint destruction joint resections cannot be avoided. Even in the case of combined joint and bone infections of the upper extremity we prefer to do resections preserving partial function. The results of treating 32 elbow infections and 26 shoulder joint infections are presented. Both these populations reflected negative patient population, but in spite of this the functional results were predominantly good to satisfactory. On the basis of these results, we conclude that even when the initial situation seems desolate, a comprehensive surgical therapy is the treatment of choice and that in the upper extremity greater importance should be attached to restoration of function than to stability, which means that arthrodeses are seldom necessary.     

Tissue Engineering von vaskularisiertem Myokardersatzgewebe

Tissue engineering of bioartificial myocardial tissue will become an increasingly important therapeutic approach in the near future but supply of oxygen and nutrients as well as evacuation of metabolic products represent a critical obstacle in tissues with a thickness of 100???m and above. Viability of seeded cells in the myocardial patch is positively correlated with its function and thus early sufficient vascularization is mandatory. The choice of substrate, structure of matrices, specific cellular seeding and addition of growth factors contribute to this necessary vascularization process. This review article gives an overview of the current state of research on recent myocardial tissue engineering utilizing natural and solid substrates (urinary bladder, gall bladder, small intestine, stomach, peritoneum, omentum, uterus, skeletal muscle, diaphragm and cardiac muscle) with a special focus on the results of vascularization of bioartificial tissue for each approach.     

Zur instrumentellen Durchtrennung von Bronchien und von Lungengewebe

Ohne Zusammenfassung     

Operative und konservative Therapie von Acetabulumfrakturen-Indikation und Ergebnisse

Between 1975 and 1983 38 patients with a fracture of the acetabulum were treated-28 patients were operated upon, 10 patients were treated conservatively. 26 in 28 patients treated operatively and 8 in 10 patients treated conservatively could be checked up. 3 of the cases treated operatively could not be evaluated, as the operation had been realized less than two years before. Following an accurate indication for the operative treatment 14 in 23 patients proved an efficient osteosynthesis. In 5 in 8 cases treated conservatively good results were obtained. In aged patients and in certain types of fractures of the acetabulum, especially in comminuted fractures, conservative treatment is still justified.     

Aufnahme und Verteilung von Sevofluran

Sevoflurane is characterized by a low blood/ gas partition coefficient of 0.69, only desflurane and nitrous oxide have lower blood/gas solubilities. Alveolar equilibration is fast, a feature useful for rapid induction of anesthesia. Because of its pleasant smell, mask induction is feasible and routinely used in clinical settings. Formation of inorganic fluoride by metabolism and by compound A by degradation in CO₂-absorbent has not yet been shown to be nephrotoxic in humans. Pulmonal elimination of sevoflurane is rapid because of its low blood solubility. Clinical results showed that rapidity of recovery from sevoflurane anesthesia is equal to that of desflurane anesthesia. Physicochemical properties of sevoflurane allow its application in conventional vaporizers.     

Interaktion von Volumentherapie und Gerinnung

Apart from haemodilution many volume substitutes can additionally influence haemostasis through specific ways of action. Specific effects include decreased activity of factor VIII and von Willebrand factor (vWF), prolongation of bleeding time, inhibition of fibrin polymerisation and induction of platelet dysfunction. Crystalloids and albumin only initiate haemodilution. Hydroxyethyl starch (HES) with a high molecular weight (HMW) and dextran significantly impair coagulation by specific effects and thus should be avoided in patients with active bleeding or risk of bleeding. Gelatin and HES with low molecular weights (LMW) may impair fibrin polymerisation. In young patients with low serum fibrinogen levels timely substitution of fibrinogen must be considered. The haemostatic co-factors acidosis and hypothermia contribute to impairment of coagulation in a relevant manner and thus should be treated effectively. Balanced solutions reduce the incidence of hyperchloraemic acidosis and thereby also coagulopathic effects.     

Neurobiologie von Schmerz und Stress

In recent years the understanding of pain and in particular chronic pain has changed. It has been shown that there is a close link between the pain and stress processing systems. The latter is genetically determined but is, however, influenced by environmental conditions which also determine the linkage behavior. In the present article these connections will be presented in detail and the consequences for the diagnosis, differential diagnosis and therapy of chronic pain syndrome will be explained.     

Therapie von Glenoid- und Skapulafrakturen

Fractures of the scapula are caused by direct or indirect trauma and can be isolated or associated with multiple injuries. Most such fractures can be diagnosed in plain X-rays of the shoulder in the a-p plane. In the case of more complex injuries computer tomography is a great help in deciding whether or not surgery is indicated. As the shoulder blade is surrounded by powerful muscles, which give adequate stability in the case of bone fracture, conservative treatment of scapular fractures is usually possible. If dislocated fracture of the joint or shoulder instability with fracture of the clavicle is present or the movement in the thoracoscapular joint is impaired surgical stabilization is necessary. Anterior access is used mainly in the case of rim fractures. When a dorsal or combined access route to the shoulder is used the particular anatomical conditions in this region must be borne in mind to avoid iatrogenic vascular and/or neural injuries. The triangular bony structure of the shoulder blade with its almost paper-thin centre allows the fixation of devices for osteosynthesis only at the edges and in the glenoid region (Kirschner wires, fragment screws, plates). A wide variety of classification systems take account of anatomical and functional aspects and those suggesting what treatment is indicated. Carrier bags and the Gilchrist and Desault bandage are both suitable for the initial immobilization. Physiotherapy is started when posttraumatic or postoperative pain fades away.