Common bile duct calculi: updated experience with dissolution with methyl tertiary butyl ether

The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control.     

Disposition of oral and intravenous pravastatin in MRP2-deficient TR- rats.

The aim of this study was to characterize the role of the efflux transporter Mrp2 (Abcc2) in the pharmacokinetics of orally and intravenously administered pravastatin in rats. Eight Mrp2-deficient TR- rats and eight wild-type rats were given an oral dose of 20 mg/kg pravastatin. Four TR- animals and four wild-type animals were studied after intravenous administration of pravastatin (5 mg/kg). The TR(-) rats showed a 6.1-fold higher mean area under the plasma concentration-time curve (AUC) of pravastatin (p < 0.001) after oral administration and a 4.7-fold higher AUC (p < 0.01) after intravenous administration of pravastatin as compared with the wild-type animals. The mean systemic (total) clearance of pravastatin was 4.6-fold higher (39.2 versus 8.50 l/h/kg, p < 0.001) and the mean V 4.3-fold higher (14.1 versus 3.29 l/kg, p < 0.01) in the wild-type rats. The mean renal clearance of pravastatin in the TR(-) rats was 16.5-fold increased as compared with the wild-type animals (0.695 versus 0.042 l/h/kg, p < 0.05). The increased systemic exposure to oral pravastatin in the TR- rats was associated with a greater inhibitory effect on 3-hydroxy-3-methylglutaryl CoA reductase, as shown by smaller lathosterol to cholesterol concentration ratios. These results suggest that the reduced biliary pravastatin excretion in the Mrp2-deficient TR- rats is partly compensated for by increased urinary excretion of pravastatin. Furthermore, intestinal Mrp2 does not appear to play a major role in the oral absorption of pravastatin in normal rats.     

Knochenersatz durch Kallusdistraktion an der unteren Extremität

Successful treatment of posttraumatic chronic osteitis is often only achieved at the cost of some degree of bone loss. Various procedures for segmental transfer based on Ilizarov’s callus distraction technique have become established for reconstruction of extensive bony substance defects in recent years. Technically, both extramedullary and intramedullary procedures are available for the achievement of such a segmental transfer. Various factors must be taken into account when it is necessary to decide whether segmental transfer by means of a ring fixator, a unilateral fixateur externe or an intramedullary force carrier in combination with a fixateur externe or tension wires as the transfer system is indicated. These include how long the history of osteitis already is, how extensive it is, time taken for successful treatment of infection, soft tissue situation, resulting length of the defect following resection, and the patient’s age, together whether there are any patient-specific risk factors or comorbidities. In this paper an algorithm for deciding on the specific situations in which the different techniques of segmental transfer are indicated is discussed on the basis of many years of clinical experience in postinfectious defects on the lower extremities.     

Development of cholinergic retinal neurons from embryonic chicken in monolayer cultures: stimulation by glial cell-derived factors

In recent years evidence has indicated that, like the PNS, the development of the CNS is influenced by neuronotrophic polypeptide factors. In the present study, cultures of dissociated retinal neurons from 8-d-old chicken embryos were used to investigate the role of neuronotrophic factors (NTF) in the development of the neural retina. CAT, which in vivo is located in amacrine cells of the retina, served as a marker for studying the in vitro development of cholinergic retinal neurons. Differentiation of cholinergic cells under control conditions was indicated by a 10-fold increase of enzyme activity during a 7-d culture period. Addition of media conditioned by high-density retinal cultures resulted in a further stimulation of CAT activity by 100-400%. The CAT-stimulating activity was associated with a high-molecular-weight component of the retina conditioned medium (RCM) and was sensitive to protease treatment, but was not affected by other hydrolytic enzymes. The putative cholinergic factor was secreted by retinal cultures virtually free of neurons, suggesting that it is mainly produced by Müller cells. CAT-stimulating activity was also present in extracts from embryonic chicken retinae and medium conditioned by rat retinal cultures. NGF, anti-NGF antiserum, extracts from chicken brain tissues, and a number of other extracts and conditioned media, all known to contain neuronotrophic activities, were found to have no influence on cholinergic development in chicken retinal cultures. An extract from non-retinal eye tissue containing ciliary neuronotrophic factor (CNTF) stimulated CAT activity to the same extent as did RCM.(ABSTRACT TRUNCATED AT 250 WORDS)     

Behandlung der Pseudarthrosen des Beckens

Malunion is rare after pelvic fractures. The cardinal symptom is chronic stress-related pain in the pelvic girdle. It is necessary to investigate whether the symptom cluster is caused by malunion, posttraumatic malalignment or a combination of both. The diagnostic workup must include a physical examination with the patient undressed, provocation tests, X-ray investigations (general X-ray view of pelvis, plus views of inlet, outlet, ala, and obturator), and also computer tomography with 2D and 3D reconstructions, which is essential for the analysis of any malalignments, instabilities and malunions in the pelvic girdle. Conservative treatment is not usually adequate for chronic instabilities in the pelvic girdle. The operative procedure selected depends on the localization of the primary injury, malunion and/or malalignment. The basic principle of operative treatment is that all instabilities and/or maluinions in any region must be stabilized. Late operations for reconstruction of the pelvic girdle are challenging and technically difficult interventions, with a complication rate that is anything but negligible. Some of the complications possible are haemorrhage, wound haematomas, vascular and neural lesions, infections, incomplete correction, loss of correction, persisting malunion or symptoms and premature loosening or failure of implants.     

Sekundär- und Späteingriffe nach Beckenring- und Azetabulumfrakturen

Secondary or delayed reconstructions following mal- or nonunited fractures of the pelvic ring and acetabulum are challenging procedures. Three different healing problems have to be distinguished: malunion, nonunion, and fractures and/or dislocations that have healed incompletely. Combinations of these three pathologies are also possible. Delayed reconstructions have no chance of success unless the patient’s signs and symptoms are clearly attributable to the malunion or nonunion. This means that extensive clinical and radiological evaluation is mandatory preoperatively. Risks involved and the results that can be expected must be discussed thoroughly with the patient once the surgery has been planned in detail. For the treatment of nonunion or delayed union, the unstable zone must be debrided, and autologous bone grafting with cancellous bone and stable internal fixation are then required. Malunion requires careful mobilization of the malunited fracture fragments, which is often a very demanding procedure. If there is already advanced damage to the acetabulum little functional improvement can be expected after a corrective osteotomy. Viable treatment alternatives are hip fusion and endoprosthetic joint replacement. Possible complications include damage to neurovascular structures, impaired wound healing, infections and implant failure. Extensive experience in the management of acute fractures of the pelvic ring and acetabulum is essential if delayed reconstruction is to be successful.     

Ruptur der langen Bizepssehne und operative Therapiestrategien

Zusammenfassung Die Ruptur der langen Bizepssehne beruht auf ihrer anatomischen Disposition und, bedingt durch die biomechanische Belastung, zu 90% auf degenerativen Veränderungen. In der Regel finden sich begleitende Verschleißschäden anderer Strukturen des Schultergelenks wie der Rotatorenmanschette. Es wird ein Überblick über die Häufigkeit und den Entstehungsmechanismus von Rupturen der langen Bizepssehne sowie gängige operative Behandlungskonzepte gegeben. Die Rolle und das anatomisch-funktionelle Prinzip der Sehne des Caput longum im komplexen dynamischen System des Schultergelenks werden erläutert. Eingang finden die klinische Symptomatik, Beschreibungen sowie Wertungen apparativer diagnostischer Verfahren. Der Stand derzeit etablierter Operationstechniken wird unter Darstellung von Vor- und Nachteilen beleuchtet und diskutiert. Des Weiteren werden die selbst favorisierte Methode und die gesammelten Erfahrungen dargestellt.