Search

[english] In the past, the ministry of science of North Rhine-Westphalia distributed part of its funding of the medical faculties based on exam results of their graduates. Due to legal and curricular changes, this procedere appeared to be no longer tenable. Therefore, the Deans for Medical Education convened to elaborate and agree upon a new algorithm, to be presented and proposed to the ministry. The new algorithm incorporated outcome parameters of the graduates (grades, duration, loss), together with process- and structure-related parameters (evaluation-based internal fund redistribution, teacher training, funding of peer-reviewed teaching projects, etc.) of the respective universities and their curricula. We describe the consented proposal and discuss the general risks and potential benefits of performance-based funding for medical faculties. [german] In Nordrhein-Westfalen wurde bislang der auf die Lehre bezogene Anteil leistungsbezogener Landesmittel auf Grundlage der jeweiligen Staatsexamensergebnisse vergeben. Durch die Änderung der Approbationsordnung sowie die Einführung mehrerer Modellstudiengänge im Land wurde diese Bemessungsgrundlage erheblich geschmälert. Eine Arbeitsgruppe der Studiendekane entwarf daher als Diskussionsvorlage für das Ministerium einen neuen Bemessungs- und Verteilungsalgorithmus, der neben Studienverlaufs-bezogenen Ergebnisparametern (Examensergebnis, Studiendauer, Schwund) auch Studiengangs-bezogene Prozess- und Strukturparameter (Evaluationsbezogene interne Mittelvergabe, Lehrpersonalentwicklung, Finanzierung begutachteter Lehrprojekte, usw.) berücksichtigt. Der Artikel beschreibt diesen konsensuell erarbeiteten Entwurf und diskutiert dabei die generellen Chancen und Risiken einer auf die Lehre angewandten leistungsbezogenen Mittelvergabe.

[english] Because of the missing relevance of graded examinations at the German medical faculties, there was no need to reflect the question quality in written examinations consistently. Through the new national legislation for medical education certification-relevant, faculty-internal examinations are prescribed. Until now, there is a lack of structures and processes which could lead to an improvement of the question quality. To reflect the different performance of the students, a different severity and a good selectivity of the test questions are necessary. For a interdisciplinary examination for fourth year undergraduate students at the University Hospital Duesseldorf, new Multiple choice (MC)- questions which are application-orientated, clearly formulated and to a large extent free from formal errors should be developed. The implementation took place in the conception and performance of Workshops for the construction of MC-questions and the appointment of an interdisciplinary review-committee. It could be shown that an author training facilitates and accelerates the review-process for the committee and that a review process reflects itself in a high practise-orientation of the items. Prospectively, high-quality questions which are created in a review-process and metrological analysed could be read into inter-university databases. Therewith the initial expenditure of time could be reduced. The interdisciplinary constitution of the review-committee offers the possibility of an intensified discussion over content and relevance of the questions. [german] Wegen fehlender notenrelevanter Prüfungen an den Medizinischen Fakultäten in Deutschland bestand bisher keine Notwendigkeit, die Fragenqualität in schriftlichen Prüfungen konsequent zu reflektieren. Erst durch die neue Approbationsordnung sind zeugnisrelevante, fakultätsinterne Prüfungen vorgeschrieben. Es fehlen somit oftmals Strukturen und Prozesse, die zu einer Verbesserung der Fragenqualität führen. Damit die Klausuren das unterschiedliche Leistungsspektrum der Studierenden widerspiegeln, sind u.a. unterschiedliches Schwierigkeitsniveau und eine gute Trennschärfe der Prüfungsfragen notwendig. Für eine fachübergreifende Klausur des vierten Studienjahres an der Universität Düsseldorf sollten neue MC -Fragen entwickelt werden, die anwendungsorientiert prüfen, eindeutig formuliert und weitgehend frei von formalen Fehlern sind. Die Umsetzung erfolgte in der Konzeption und Durchführung von Workshops zur Erstellung von MC-Fragen für Fragenautoren und die Einrichtung eines interdisziplinären Reviewkomitees. Es konnte gezeigt werden, dass eine Autorenschulung den Reviewprozess für das Reviewkomitee erleichtert und beschleunigt. Der Nutzen des Reviewprozesses spiegelt sich in einer hohen Anwendungsorientierung der einzelnen Items wider. Hochwertige, in einem Reviewverfahren erstellte und messtechnisch analysierte Prüfungsfragen könnten künftig in interuniversitäre Datenbanken eingegeben werden und damit den anfänglich erforderlichen Zeitaufwand relativieren. Durch die interdisziplinäre Zusammensetzung des Reviewkomitees bietet sich außerdem die Möglichkeit einer verstärkten Diskussion über die Inhalte der Prüfungsfragen.

The purpose of this study was to develop, test, evaluate and finally implement effective state-of-the-art Teacher Trainings in didactic skills and methods. The training concept should be designed and beneficial for medical teachers in under- and postgraduate Medical Education.Methods: A 5-day workshop with 12 theoretical and 9 „hands-on" modules has been designed and stepwise improved, according to trainees' feedback. All trainees were educated in small groups (6 to 10 participants per workshop). The workshops consisted of mini-lectures, repeated microteaching exercises and video-supported feedback concerning the following key-competencies: Communication of goals, methods to trigger interactivity, design of slides in ppt-presentations, effective feedback-techniques and use of media, time-management, skills teaching, assessment methods (e.g. OSCE and others), evaluation and general presentation skills. The evaluation was based on two components: A) Trainees' scores in two OSTEs (objecitve structured teaching exercises) at the beginning and end of workshop: the ratings of 15 to 20 external oberservers were checked for significant trends (X2 -Test Pearson) in 17 pregiven criteria for high teaching effectiveness. B) The trainees rated 20 teaching competencies in a retrospective „pre-post-analysis" (self-assessment questionaire) at the end of each workshop and after 6 to 12 months later. The results revealed highly significant improvements (p < 0.01) in 15 of 17 OSTE-criteria and in 19 of 20 items of the pre-post-analysis, predominantly estimated to be „persistent". Overall, trainees' feedback has been highly encouraging to continue and broaden the program. The discussion covers potential factors for the training success as well as pitfalls and controverse issues of time and costs.In conclusion, the designed 5-day training workshops to enhance didactic skills and teaching methods turned out to be highly effective and can be attended by all medical teachers with different teaching backgrounds and specialities (http://www.medidak-pilotprojekt.de/). The training has been CME-certified for 21 credits (category „C") by the Academy of the Physicians' State Association North-Rhine-Westfalia (LÄK Nordrhein).

1. Glutamine uptake is decreased in isolated perfused rat liver when the extracellular pH is lowered. This is also observed in the presence of ammonia concentrations nearly 20-fold above that required for half-maximal stimulation of glutaminase, indicating that the effect is not explained by a submaximal ammonium activation of the enzyme. 2. In livers perfused with a physiological glutamine concentration (0.6 mM), the tissue glutamine but not glutamate content is strongly dependent on the extracellular pH and increases from 2.9 µmol/g to 4.7 µmol/g liver when the extracellular pH is increased from 7.3 to 7.5. 3. Subfractionation of the livers revealed that the mitochondrial glutamine concentration increases from about 15 mM to 50 mM, when the extracellular pH is raised from 7.3 to 7.7, whereas the cytosolic glutamine concentration increases only slightly. Simultaneously the cytosolic and mitochondrial pH values are largely unaffected, being 7.25 and 7.7 respectively. Thus, the pH gradient between mitochondria and cytosol remains unchanged when the extracellular pH varies. 4. Amiloride (2 mM) inhibits glutamine uptake by the liver and abolishes the extra/intracellular pH gradient. With amiloride present, tissue glutamine levels are no longer dependent on extracellular pH and are only about 2 µmol/g liver. 5. It is concluded that pH control of glutaminase flux is also mediated by variations of the mitochondrial glutamine concentration pointing to a regulatory role of the glutamine carrier in the mitochondrial membrane for hepatic glutamine breakdown. [ABSTRACT FROM AUTHOR]

Examines free cystosolic adenylates in relation to adenosine plus inosine released from perfused working guinea pig hearts. Measurement of adenosine and inosine in venous cardiac effluents by high-performance liquid chromatography; Suggestions that concentrations of free ADP and AMP in the cytosol are major determinants of the production of inosine and coronary vasodilator adenosine.

1. In livers of fed rats and in perfused livers supplied with a physiological portal glutamine concentration of 0.6 mM, the mitochondrial and cytosolic glutamine concentations are 20 mM and 7 mM, respectively, thus, the mitochondrial/cytosolic glutamine concentration gradient is 2-3. 2. Uptake and release of glutamine by periportal and perivenous hepatocytes occurs predominantly by an Na+-dependent transport system (so-called system 'N'). 3. Histidine in near-physiological concentrations inhibits both glutamine uptake by periportal hepatocyts and its release by perivenous hepatocytes. This is not due to an inhibtion of glutamine-metabolizing enzymes by histidine or its metabolites. with polysiological portal glutamine concentrations (0.6 mM), simulation of glutaminase flux or of glutamine transaminase flux is followed by a decrease of hepatic glutamine levels to about 80% or 30% respectively, glutamine levels are further decreased to 50% or 20% in the presence of histidine. 4. When glutamine is synthesized endogeneously (no glutamine added), the histidine-induced inhibition of glutamine release is paralleled by a 210% increase of the hepatic tissue level of glutamine. 5. In experiments with and without methionine sulfoximine and in the absence of added glutamine, the glutamine content in the small perivenous hepatocyte population containing glutamine synthetase is estimated to be about 3.5 µmol/g wet weight and that in the periportal hepatocytes as low as 0.1 µmol/g wet weight. 6. In contrast to the prevailing view, it is concluded that glutamine transport across the plasma membrane of hepatocytes is a potential regulatory site in glutamine degradation and synthesis, especially under the influence of effectors like histidine. [ABSTRACT FROM AUTHOR]

The uncoupling-like effect of fatty acids [Scholz. R., Schwabe. U., and Soboll. S. (1984) Eur . J. Biochem. 141, 223-230] was further substantiated in experiments with perfused rat livers by two ways firstly the kinetics of changes in metabolic rates (oxygen consumption, ketogenesis, fatty acid oxidation) were analysed: secondly subcellular contents of adenine nucleotides and pH gradients across the mitochondrial membrane were determined following fractionation of freeze-fixed and dried tissues in non-aqueous solvents. The following results were obtained. 1. The relaxation kinetics of the increase in oxygen consumption following fatty acid infusion revealed two components, a rapid one with a half-time around 10s and a slow one with a half-time of more than 100s. 2. The rapid component was similar to the kinetics of fatty acid oxidation (ketogenesis and 14CO2 production from labelled fatty acids) whereas the half-time of the slow component was in the range of half-times observed with the increase in oxygen consumption following addition of carbonylcyanide p-trifluoromethoxyphenylhydrazone. 3. In the presence of fatty acids, the cytosolic ATP concentrations and ATP ADP ratios decreased, whereas the corresponding parameters for the mitochondrial space were either increased (oleate) or decreased (octanoate). The effects of oleate were dependent on the albumin concentrations in the perfusate. The normally large difference between cytosolic and mitochondrial ATP/ADP ratios became smaller. Similar observations were obtained with uncoupling agents. 4. The pH gradient across the mitochondrial membrane as calculated from the subcellular distribution of 5,5 di- methyl[2-14C]oxazolidine-2,4-dione was inversed following the addition of both carbonylcyanide p-trifluoromethoxyphenylhydrazone and fatty acids, i.e. the mitochondrial matrix became more acidic than the cytosol. The pH gradient was not affected when oleate was added in the presence of high albumin concentrations. The data support the hypothesis that the increase in hepatic oxygen consumption due to octanoate or oleate is, in part, caused by a mechanism similar to uncoupling of oxidative phosphorylation. This mechanism seems not to be an artifact of isolated systems; it may be of physiological importance for processes in which reducing equivalents are removed independently of the ATP demand of the hepatocyte. [ABSTRACT FROM AUTHOR]

Mitochondrial and cytosolic contents of adenine nucleotides and phosphate were measured in perfused rat livers employing a technique of fractionation of freeze-fixated tissue in non-aqueous solvents. From the subcellular contents the mitochondrial and cytosolic concentrations of ATP, ADP. AMP and phosphale and the phosphorylation potentials of the subcellular ATP systems were calculated. An attempt was made to elucidate the relationship between mitochondrial and cytosolic adenine nucleotide systems and the dependency on the metabolic state of the liver. The following results were obtained; 1. Under all metabolic conditions studied the mitochondrial ATP/ADP ratios were considerably lower than the cytosolic ratios (mitochondria: 0.1–0.7); cytosol: 2 –11). 2. The ATP/ADP ratios calculated from overall tissue contents reflect mainly the cytosolic ratios, 3. An inverse relationship was found between mitochondrial and cytosolic ATP/ADP ratios, i.e. when the mitochondrial ratios tended to increase, the cytosolic ratios decreased and vice versa. 4. The phosphorylation potentials calculated from the subcellular concentrations were higher in the cytosol than in the mitochondria. The potential difference varied between 11 and 3 kJ/mol in livers from fed and starved rats, respectively. 5. In the presence of mitochondrial inhibitors, i.e. amytal, dinitrophenol and carboxyatractyloside, the potential difference between the subcellular ATP systems decreased predominantly due to an increase in the mitochondria] ATP/ADP ratios. 6. A correlation between mitochondrial ATP/ADP ratios and the respiratory rates was not observed, but the subcellular ratios appeared to correlate with the rate of glycolysis. When the rate of lactate + pyruvate production was increased, the cytosolic ATP/ADP ratios were increased, too, whereas the mitochondrial ratios tended to decrease. 7. The adenme nucleotides in the cytosol appear to be in near equilibrium catalysed by the adenylate kinase. In the mitochondria, the AMP concentration is much lower than to be expected under equilibrium conditions. These results were discussed with respect to rate control of processes involved in ATP generation, i.e. oxidative phosphorylation, adenine nucleotide translocation and glycolysis. [ABSTRACT FROM AUTHOR]

Changes in metabolic rates (oxygen consumption, ketogenesis, 14CO2 production from labelled fatty acids, glycolysis) following the addition of octanoate or oleate were studied in isolated livers from fed and starved rats perfused with Krebs-Henseleit bicarbonate buffer in a non-recirculating system. The following results were obtained. 1. The infusion of fatty acids caused a large increase in the rate of oxygen consumption. The effect was greater with octanoate than with oleate and was half-maximal with fatty acid concentrations (free plus albumin bound) around 0.1 mM. 2. The effects of oleate were only partially suppressed when the perfusate contained albumin concentrations near the physiological range. 3. When fatty acids were oxidized at high rates, the glycolytic rate was diminished by 50%. 4. The increase in oxygen consumption could not be explained fully by the increased ATP demand for fatty acid metabolism or by a compensation for the diminished extramitochondrial ATP generation. 5. In the presence of phenylalkyl oxirane carboxylic acid, an inhibitor of the transport of long-chain acyl-CoA derivates into the mitochondria, ketogenesis and 14CO2 production from labelled oleate were strongly inhibited, whereas the increase in oxygen consumption was only slightly affected. 6. In the presence of antimycin A, the increase in oxygen consumption due to fatty acids was totally abolished. 7. Following pretreatment of rats with ciprofibrate (induction of enzymes for peroxisomal β-oxidation of long- chain fatty acids), ketogenesis (but not 14CO2 production) from oleate was enhanced threefold. The increase in oxygen consumption, however, was not affected. In conclusion, the increase in hepatic oxygen consumption due to addition of fatty acids reflects a mitochondrial process; it is, in part, independent of the ATP demand of the cell. An uncoupling-like effect of fatty acids on the respiratory chain and its possible physiological significance in ketogenesis are discussed. [ABSTRACT FROM AUTHOR]