„Lessons learned“ in der Revision von schriftlichen Prüfungs-Fragen

Fragestellung/Einleitung: Bisher existieren kaum Daten für den deutschsprachigen Raum, welche Fehler häufig bei der Erstellung von schriftlichen Prüfungsfragen gemacht werden. Diese Erkenntnisse könnten hilfreich sein, um Autoren in Schulungsworkshops mit dem Fokus auf die häufigsten Fehler zu schulen. Im vorliegenden Projekt wird der Frage nachgegangen, welche Fehler am häufigsten bei der Erstellung von schriftlichen Prüfungsfragen gemacht werden, und welche Schlussfolgerungen daraus für Autorenschulungen gezogen werden können. Methoden: Am Institut für Medizinische Lehre Bern werden die mit der inhaltlichen und/oder formalen Fragenrevision befassten MitarbeiterInnen (N=14) anhand von semi-strukturierten Interviews befragt, mit welcher Art von Mängeln sie bei den Fragen der von ihnen betreuten schriftlichen Prüfungen am häufigsten umgehen. Weiter wird erhoben, wie dem Revisionsbedarf aus ihrer Sicht in Schulungen am besten begegnet werden kann. Ergebnisse: Die vorläufigen Ergebnisse weisen darauf hin, dass in folgenden Bereichen am häufigsten Revisionsbedarf besteht: eindeutiger Focus auf ein konkretes Lernziel authentische und relevante Vignette für den Ausbildungsstand angemessener Schwierigkeitsgrad eindeutige Lösung formale und sprachliche Korrektheit Dementsprechend sollte auf diese Themenbereiche ein besonderer Schwerpunkt bei Schulungen gelegt werden. Diskussion/Schlussfolgerung: Die vorläufigen Ergebnisse weisen darauf hin, dass Mängel von schriftlichen Prüfungsfragen häufig in den Bereichen Focus, Vignette, Schwierigkeitsgrad, Eindeutigkeit und formal-sprachlichen Aspekten liegen. Autorenschulungen sollten diese Aspekte in den Vordergrund stellen. Unsere zum Zeitpunkt der GMA-Tagung vorliegenden definitiven Ergebnisse können dazu beitragen, Workshops zur Fragenerstellung noch besser am Schulungsbedarf auszurichten.

New findings on echinococcosis

The following new aspects of cystic and alveolar echinococcosis (= infections with the metacestode stages of Echinococcus granulosus and E. multilocularis respectively) are reported: identification of a Swiss E. granulosus isolate as "cattle strain" which differs from the "sheep strain"; new observations on proliferation and metastasis formation of larval E. multilocularis; information on chemotherapy of human echinococcosis; recent developments in immunoserology. The latter includes a new technique for serological differential diagnosis of cystic and alveolar echinococcosis, the determination of parasite-specific immunoglobulin classes (IgG, IgM, IgA and IgE) and circulating antigens in ELISA, and the introduction of arc-5 detection in routine serodiagnosis. A highly purified, species-specific antigen from E. multilocularis is now available for seroepidemiological studies.

Sectio caesarea: actual controversy

Caesarean section is one of the most frequently performed operations in human medicine. It has become a routine procedure with a very low morbidity and mortality. Over the centuries, it has emerged an essential achievement in obstetric medicine. In the presence of cephalo-pelvic-disproportion, cervical dystocia, malpresentation, preterm birth, macrosomia, placental insufficiency, placenta praevia or fetal distress it is crucial to improve the perinatal morbiditiy and mortality of mother and child. The procedure has become much more frequent over the past 20 years for multiple reasons. There is variety in incidence between countries but also regional differences. It's occurrence is being influenced by level of education and socio-economic status of the pregnant woman. In the meantime, also the longterm consequences of cesarean section are well known. The potential hazards for future pregnancies and deliveries are well described. Actual controversy addresses cesarean section on demand without any medical indication, which in fact is only seldom performed in Switzerland. The ethical justification of this procedure needs to be discussed in view of the current tendency towards autonomy and self-determination of the pregnant woman.

The effect of extracellular nucleotides on cytokine production and phagocytosis of macrophages

Bacterial sepsis is a severe clinical condition, leading to severe sepsis, septic shock, and death. The complex pathophysiology of sepsis is not yet fully understood. Cytokines, released by immune cells such as macrophages, play an important role in the pathophysiology of sepsis. Kupffer cells are the largest population of macrophages in the body. Purinergic signaling, mediated by different nucleosides and nucleotides, and purinergic receptors, has been shown to have various effects on cytokine release, inflammatory processes and the immune system. In our work with in vitro experiments we studied the effect of extracellular nucleotides on the release of TNFα by primary murine Kupffer cells, and the effect of extracellular nucleotides on the phagocytosis of murine RAW 264.7 and human U-937 cell culture macrophages. Secretion of TNFα was measured using ELISA, phagocytosis of bio particles was measured using a plate reader phagocytosis assay and flow cytometry. Our experiments show, that extracellular LPS stimulate release of TNFα in murine Kupffer cells and that extracellular nucleotides inhibit this effect in a dose dependent matter. Our other experiments show phagocytosis of fluorescence labeled bio particles by both macrophage cell lines RAW 264.7 and U-937 in a dose dependent manner. The experiments could not show an effect of extracellular nucleotides on phagocytosis of cell culture macrophages.

Patientensicherheit in der Shuntchirurgie

Zusammenfassung Hintergrund. Hämodialysepatienten, die operativ mit einem Gefäßzugang versorgt werden müssen, sind eine vulnerable Patientengruppe, die aufgrund von Multimorbidität, der intensiven und oft fragmentierten Behandlung und vieler Schnittstellen ein erhöhtes Risiko für vermeidbare unerwünschte Ereignisse tragen. Fragestellung. Aktuelle Entwicklungen und Maßnahmen zur Förderung der Patientensicherheit mit Fokus auf die Shuntchirurgie. Material und Methoden. Auswertung und Aufarbeitung aktueller Daten zur Patientensicherheit und Instrumenten zu ihrer Förderung. Ergebnisse. Fehler im nicht operativen Management verursachen einen wesentlichen Anteil der unerwünschten Ereignisse. Checklisten, präoperative Seitenmarkierung, Zählkontrollen und interprofessionelle Teamtrainings sind wichtige Instrumente der Patientensicherheit im OP. Standardisierungen von postoperativen Übergaben durch einfache Protokolle können erheblich zur Reduktion von Fehlern und Schädigungen beitragen. Die Sicherheitskultur einer Abteilung ist ein Umgebungsfaktor, der für die Effektivität dieser Sicherheitsbarrieren wesentlich ist. Schlussfolgerungen. Es existieren wirksame Instrumente, die die Patientensicherheit in der Shuntchirurgie fördern. Gerade an den Schnittstellen zur weiteren Versorgung können durch die konsequente Implementierung und Nutzung dieser Maßnahmen und ein aktives Sicherheitsmanagement unerwünschte Ereignisse vermieden werden. Die interprofessionelle und interdisziplinäre Zusammenarbeit und der Einbezug der Patienten sind wichtige Ressource für die Behandlungssicherheit, die stärker genutzt werden sollten.

Molecular and cellular basis of bone resorption.

Osteoclast research has an exciting history and a challenging future. More than 3 decades ago, it became evident that bone-resorbing osteoclasts are of hematopoietic origin and are ultimately linked to the "basic multicellular unit," where they team up with the other cell types, including bone-forming osteoblasts. Since 2 decades, we have learned about the signaling pathways controlling genes relevant for osteoclastogenesis and bone resorption. It took another decade until the hypothesized "osteoclast differentiation" factor was discovered and was translated into an approved pharmacologic strategy. Here, the focus is on another molecular target, cathepsin K, a cysteine protease being released by the osteoclast into the resorption compartment. Genetic deletion and pharmacological blocking of cathepsin K reduces bone resorption but with ongoing bone formation. This observation not only holds great promise to become a new pharmacologic strategy, but it also provides new insights into the coordinated work of cells in the "basic multicellular unit" and thus, bridges the history and future of osteoclast research. This article is a short primer on osteoclast biology for readers of the special issue on odanacatib, a cathepsin K inhibitor.

The new final Clinical Skills examination in human medicine in Switzerland: Essential steps of exam development, implementation and evaluation, and central insights from the perspective of the national Working Group

Objective: Since 2011, the new national final examination in human medicine has been implemented in Switzerland, with a structured clinical-practical part in the OSCE format. From the perspective of the national Working Group, the current article describes the essential steps in the development, implementation and evaluation of the Federal Licensing Examination Clinical Skills (FLE CS) as well as the applied quality assurance measures. Finally, central insights gained from the last years are presented. Methods: Based on the principles of action research, the FLE CS is in a constant state of further development. On the foundation of systematically documented experiences from previous years, in the Working Group, unresolved questions are discussed and resulting solution approaches are substantiated (planning), implemented in the examination (implementation) and subsequently evaluated (reflection). The presented results are the product of this iterative procedure. Results: The FLE CS is created by experts from all faculties and subject areas in a multistage process. The examination is administered in German and French on a decentralised basis and consists of twelve interdisciplinary stations per candidate. As important quality assurance measures, the national Review Board (content validation) and the meetings of the standardised patient trainers (standardisation) have proven worthwhile. The statistical analyses show good measurement reliability and support the construct validity of the examination. Among the central insights of the past years, it has been established that the consistent implementation of the principles of action research contributes to the successful further development of the examination. Conclusion: The centrally coordinated, collaborative-iterative process, incorporating experts from all faculties, makes a fundamental contribution to the quality of the FLE CS. The processes and insights presented here can be useful for others planning a similar undertaking. Keywords: national final examination, licensing examination, summative assessment, OSCE, action research

Exploring the emotional brain: Neural correlates of homeostatic and sensory-evoked emotions and their interaction in emotional rivalry

Human emotions are essential for survival. They are vital for the satisfaction of basic needs, the regulation of personal life and successful integration into social structures. Depending on which aspect of an emotion is used in its definition, many different theories offer possible answers to the questions of what emotions are and how they can be distinguished. The systematic investigation of emotions in cognitive neuroscience is relatively new, and neuroimaging studies specifically focussing on the neural correlates of different categories of emotions are still lacking. Therefore, the current thesis aimed at investigating the behavioural and neurophysiological correlates of different human emotional levels and their interaction in healthy subjects. We differentiated between emotions according to their cerebral entry site and neural processing pathways: homeostatic emotions, which are elicited by metabolic changes and processed by the interoceptive system (such as thirst, hunger, and need for air), and sensory-evoked emotions, which are evoked by external inputs via the eyes, ears or nose, or their corresponding mental representations and processed in the brain as sensory perception (e.g. fear, disgust, or pride). Using functional magnetic resonance imaging (fMRI) and behavioural parameters, we examined both the specific neural underpinnings of a homeostatic emotion (thirst) and a sensory-evoked emotion (disgust), and their interaction in a situation of emotional rivalry when both emotions were perceived simultaneously. This thesis comprises three research articles reporting the results of this research. The first paper presents disgust-related brain imaging data in a thirsty and a satiated condition. We found that disgust mainly activated the anterior insular cortex. In the thirsty condition, however, we observed an interaction effect between disgust and thirst: when thirsty, the subjects rated the disgusting stimulus as less repulsive. On the neurobiological level, this reduction of subjective disgust was accompanied by significantly reduced neural activity in the insular cortex. These results provide new neurophysiological evidence for a hierarchical organization among homeostatic and sensory-evoked emotions, revealing that in a situation of emotional conflict, homeostatic emotions are prioritized over sensory-evoked emotions. In the second paper, findings on brain perfusion over four different thirst stages are reported, with a special focus on the parametric progression of thirst. Cerebral perfusion differences over all thirst stages were found in the posterior insular cortex. Taking this result together with the findings of the first paper, the insular cortex seems to be a key player in human emotional processing, since it comprises specific representations of homeostatic and sensory-evoked emotions and also represents the site of cortical interaction between the two levels of emotions. Finally, although this thesis focussed on the homeostatic modulation of disgust, we were also interested in whether dehydration modulates taste perception. The results of this behavioural experiment are described in the third paper, where we show that dehydration alters the perception of neutral taste stimuli.

Improved VMAT planning for head and neck tumors with an advanced optimization algorithm

OBJECTIVE In this study, the "Progressive Resolution Optimizer PRO3" (Varian Medical Systems) is compared to the previous version "PRO2" with respect to its potential to improve dose sparing to the organs at risk (OAR) and dose coverage of the PTV for head and neck cancer patients. MATERIALS AND METHODS For eight head and neck cancer patients, volumetric modulated arc therapy (VMAT) treatment plans were generated in this study. All cases have 2-3 phases and the total prescribed dose (PD) was 60-72Gy in the PTV. The study is mainly focused on the phase 1 plans, which all have an identical PD of 54Gy, and complex PTV structures with an overlap to the parotids. Optimization was performed based on planning objectives for the PTV according to ICRU83, and with minimal dose to spinal cord, and parotids outside PTV. In order to assess the quality of the optimization algorithms, an identical set of constraints was used for both, PRO2 and PRO3. The resulting treatment plans were investigated with respect to dose distribution based on the analysis of the dose volume histograms. RESULTS For the phase 1 plans (PD=54Gy) the near maximum dose D2% of the spinal cord, could be minimized to 22±5 Gy with PRO3, as compared to 32±12Gy with PRO2, averaged for all patients. The mean dose to the parotids was also lower in PRO3 plans compared to PRO2, but the differences were less pronounced. A PTV coverage of V95%=97±1% could be reached with PRO3, as compared to 86±5% with PRO2. In clinical routine, these PRO2 plans would require modifications to obtain better PTV coverage at the cost of higher OAR doses. CONCLUSION A comparison between PRO3 and PRO2 optimization algorithms was performed for eight head and neck cancer patients. In general, the quality of VMAT plans for head and neck patients are improved with PRO3 as compared to PRO2. The dose to OARs can be reduced significantly, especially for the spinal cord. These reductions are achieved with better PTV coverage as compared to PRO2. The improved spinal cord sparing offers new opportunities for all types of paraspinal tumors and for re-irradiation of recurrent tumors or second malignancies.

Sicherheit und Zuverlässigkeit der Nebenschilddrüsenchirurgie bei Patienten mit Hyperparathyreoidismus und intraoperativ gemessenem intakten Parathormon

In der vorliegenden Arbeit wurde die Sicherheit und Zuverlässigkeit der Nebenschilddrüsenchirurgie beim Hyperparathyreoidismus mit intraoperativer Bestimmung des intakten Parathormons (Parathormonschnelltest) untersucht. Im Zeitrahmen zwischen 1/2004 und 12/2008 wurden an der universitären Klinik für viszerale Chirurgie und Medizin bei 194 operierten Patienten 150 Adenome, 39 Hyperplasien, sowie 5 Doppeladenome der Nebenschilddrüsen gefunden. Das intakte Parathormons (iPTH) im Serum wurde zu Beginn der Operation, nach Präparation der vergrösserten Nebenschilddrüse bei noch erhaltenem Gefässstiel, sowie 5, 10 und 15 Minuten nach der Parathyreoidektomie gemessen. Für den Erfolg der Operation wurde ein Abfall des iPTH um mehr als 50% vom Ausgangswert innerhalb der ersten 5 Minuten, sowie um mehr als 60% innerhalb der ersten 10 Minuten festgelegt. Bei solitären Adenomen der Nebenschilddrüse kam es bereits 5 Minuten nach der Parathyreoidektomie zu einem durchschnittlichen Abfall des iPTH um 61±19% vom Ausgangswert und nach 10 Minuten um 73±17%. Bei einer Hyperplasie der Nebenschilddrüse blieb dieser schnell eintretende steile Abfall des iPHT aus, der Rückgang des iPHT-Spiegels war zögerlich und erreichte erst nach subtotaler Parathyreoidektomie Normalwerte. In dem vorliegenden Patientengut wurden drei falsch-negative sowie ein falsch-positiver Befund beobachtet. Prognostisch ergibt sich für ein solitäres Adenom unserem Patientengut eine Sensitivität von 96% und eine Spezifität von 91% für den 10 Minuten-Wert. Der prädiktive Wert des positiven Tests beträgt 97%. Die vorliegende Arbeit zeigt, dass mit Hilfe der intraoperativen iPTH-Messung die Sicherheit in der Chirurgie des Parathyreoidismus gesteigert werden kann, vor allem beim Vorliegen eines Doppeladenoms oder bei schwierigen Rezidiveingriffen.