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Aims: Different approaches to performance-oriented allocation of resources according to teaching quality are currently being discussed within German medical schools. The implementation of these programmes is impeded by a lack of valid criteria to measure teaching quality. An assessment of teaching quality should include structural and procedural aspects but focus on learning outcome itself. The aim of this study was to implement a novel, outcome-based evaluation tool within the clinical phase of a medical curriculum and address differences between the novel tool and traditional evaluation methods. Methods: Student self-assessments before and after completion of a teaching module were used to compute performance gains for specific learning objectives. Mean performance gains in each module were compared to student expectations before the module and data derived from a traditional evaluation tool using overall course ratings at the end of the module.Results: A ranking of the 21 modules according to computed performance gains yielded entirely different results than module rankings based on overall course ratings. There was no significant correlation between performance gain and overall ratings. However, the latter were significantly correlated to student expectations before entering the module as well as structural and procedural parameters (Pearson's r 0.7-0.9).Conclusion: Performance gain computed from comparative self-assessments adds an important new dimension to course evaluation in medical education. In contrast to overall course ratings, the novel tool is less heavily confounded by construct-irrelevant factors. Thus, it appears to be more appropriate than overall course ratings in determining teaching quality and developing algorithms to guide performance-oriented resource allocation in medical education., Zielsetzung: Aktuell werden an den deutschen medizinischen Fakultäten unterschiedliche Konzepte zur leistungsorientierten Mittelvergabe (LOM) in der Lehre diskutiert. Die Umsetzung scheitert mitunter am Mangel valider Messkriterien zur Beurteilung der Lehrqualität. Neben der Struktur und den Prozessen der Lehre sollte das Ergebnis der Lehre im Mittelpunkt der Qualitätsbewertung stehen. Ziele dieser Arbeit waren die Erprobung eines neuen, lernzielbezogenen Evaluationssystems im klinischen Abschnitt des Studiums der Humanmedizin und der Vergleich der Ergebnisse mit den Daten eines traditionellen Evaluationsverfahrens.Methodik: Aus studentischen Selbsteinschätzungen zu Beginn und Ende eines jeden Lehrmoduls wurde nach einer neu entwickelten Formel der lernzielbezogene, prozentuale Lernerfolg berechnet. Die Lernerfolgs-Mittelwerte pro Modul wurden mit traditionellen Evaluationsparametern, insbesondere mit Globalbewertungen, ins Verhältnis gesetzt.Ergebnisse: Der mittels vergleichender Selbsteinschätzungen berechnete Lernerfolg und die Globalbewertungen produzierten deutlich unterschiedliche Rangfolgen der 21 klinischen Module. Zwischen dem Lernerfolg und den Globalbewertungen fand sich keine statistisch signifikante Korrelation. Allerdings korrelierten die Globalbewertungen stark mit den studentischen Erwartungen vor Modulbeginn und mit strukturellen und prozeduralen Parametern der Lehre (Pearson's r zwischen 0,7 und 0,9). Schlussfolgerung: Die Messung des Lernzuwachses mittels vergleichender studentischer Selbsteinschätzungen kann die traditionelle Evaluation um eine wichtige Dimension erweitern. Im Unterschied zu studentischen Globalbewertungen ist das neue Instrument lernzielbezogen und unabhängiger vom Einfluss Konstrukt-irrelevanter Parameter. Hinsichtlich der Entwicklung eines LOM-Algorithmus eignet sich das neue Instrument gut zur Beurteilung der Lehrqualität.

Basal cell carcinoma (BCC) is the most common skin tumor in humans. Although BCCs rarely metastasize, they can cause significant morbidity due to local aggressiveness. Approximately 20% of BCCs show signs of spontaneous regression. The understanding of molecular events mediating spontaneous regression has the potential to reduce morbidity of BCC and, potentially, other tumors, if translated into tumor therapies. We show that BCCs induced in conditional Ptchr flox/floxERT2 +/- knockout mice regress with time and show a more differentiated phenotype. Differentiation is accompanied by Wnt5a expression in the tumor stroma, which is first detectable at the fully developed tumor stage. Coculture experiments revealed that Wnt5a is upregulated in tumor-adjacent macrophages by soluble signals derived from BCC cells. In turn, Wnt5a induces the expression of the differentiation marker K10 in tumor cells, which is mediated by Wnt/Ca 2+ signaling in a CaMKII-dependent manner. These data support a role of stromal Wnt5a in BCC differentiation and regression, which may have important implications for development of new treatment strategies for this tumor. Taken together, our results establish BCC as an easily accessible model of tumor regression. The regression of BCC despite sustained Hedgehog signaling activity seems to be mediated by tumor-stromal interactions via Wnt5a signaling.