[Squamous cell carcinoma developing in oral lichen planus]. / Plattenepithelkarzinom auf dem Boden eines Lichen ruber mucosae.

Oral lichen planus is a mucosal inflammatory disease whose pathogenesis is unclear. The chronic inflammation leads to development of a squamous cell carcinoma in 1-2% of the patients; we present an exemplary case.

Identification and analysis of murine pancreatic islet enhancers.

AIMS/HYPOTHESIS: The paucity of information on the epigenetic barriers that are blocking reprogramming protocols, and on what makes a beta cell unique, has hampered efforts to develop novel beta cell sources. Here, we aimed to identify enhancers in pancreatic islets, to understand their developmental ontologies, and to identify enhancers unique to islets to increase our understanding of islet-specific gene expression. METHODS: We combined H3K4me1-based nucleosome predictions with pancreatic and duodenal homeobox 1 (PDX1), neurogenic differentiation 1 (NEUROD1), v-Maf musculoaponeurotic fibrosarcoma oncogene family, protein A (MAFA) and forkhead box A2 (FOXA2) occupancy data to identify enhancers in mouse islets. RESULTS: We identified 22,223 putative enhancer loci in in vivo mouse islets. Our validation experiments suggest that nearly half of these loci are active in regulating islet gene expression, with the remaining regions probably poised for activity. We showed that these loci have at least nine developmental ontologies, and that islet enhancers predominately acquire H3K4me1 during differentiation. We next discriminated 1,799 enhancers unique to islets and showed that these islet-specific enhancers have reduced association with annotated genes, and identified a subset that are instead associated with novel islet-specific long non-coding RNAs (lncRNAs). CONCLUSIONS/INTERPRETATIONS: Our results indicate that genes with islet-specific expression and function tend to have enhancers devoid of histone methylation marks or, less often, that are bivalent or repressed, in embryonic stem cells and liver. Further, we identify a subset of enhancers unique to islets that are associated with novel islet-specific genes and lncRNAs. We anticipate that these data will facilitate the development of novel sources of functional beta cell mass.

[Student evaluation of anesthesiological teaching: steering instrument of a continuous improvement process]. / Studentische Evaluation der anästhesiologischen Lehre : Steuerinstrument eines kontinuierlichen Verbesserungsprozesses.

BACKGROUND: The amendment to the higher education act ("Hochschulrahmengesetz") of 1998 postulates an evaluation of teaching for quality assurance. Hence, in the winter semester of 2004 the University Medical Center of Bonn introduced a semester questionnaire for students to evaluate the quality of teaching (EVALON). This evaluation is designed to be an objective benchmarking tool which is used for the distribution of university funds. It is also a steering instrument for direct improvement of teaching in clinical subjects. The aim of this study was to investigate, whether EVALON improved the quality of teaching between 2006 and 2010 and whether the department of anesthesiology improved its ranking in comparison with the other participating institutes. MATERIALS AND METHODS: Data from the EVALON questionnaire from the years 2006-2010 were analyzed for improvements in the quality of teaching in anesthesiology. This study focused on three essential contents of the EVALON questionnaire (structural content and organizational procedure of lectures and seminars, course presentation), which were used for the generation of a ranking list of all participating medical institutes and departments. On the basis of these results, 12.5% of the funding was assigned for educational purposes. RESULTS: There was an average return rate of the questionnaires of 74.5%. A significant increase in the overall assessment score of 43.4% could be observed from 5.3 in the summer semester of 2006 to 7.6 in the winter semester of 2009/10. The evaluation score for the department of anesthesiology concerning structural content of seminars and lectures increased by 79% from 4.8 in 2006 to 8.6 in 2010. The quality of organizational procedure was evaluated with a score of 4.9 in 2006 and improved by 74% to 8.5 in 2010. The course presentation skills of the teachers as evaluated by EVALON improved by 61% from a score of 5.2 in 2006 to 8.4 in 2010. In comparison with all other participating medical institutes the department of anesthesiology improved its ranking from position 36 in the winter semester 2006 to position 2 in the summer semester 2010. CONCLUSIONS: The reorganization of teaching anesthesiology, directly controlled by the results of EVALON improved the ranking of the department of anesthesiology. There was also a concomitant increase of the performance-oriented allocation of funds assigned to the department of anesthesiology based on the EVALON results.

Class proximity measures--dissimilarity-based classification and display of high-dimensional data.

For two-class problems, we introduce and construct mappings of high-dimensional instances into dissimilarity (distance)-based Class-Proximity Planes. The Class Proximity Projections are extensions of our earlier relative distance plane mapping, and thus provide a more general and unified approach to the simultaneous classification and visualization of many-feature datasets. The mappings display all L-dimensional instances in two-dimensional coordinate systems, whose two axes represent the two distances of the instances to various pre-defined proximity measures of the two classes. The Class Proximity mappings provide a variety of different perspectives of the dataset to be classified and visualized. We report and compare the classification and visualization results obtained with various Class Proximity Projections and their combinations on four datasets from the UCI data base, as well as on a particular high-dimensional biomedical dataset.

Alpha particle spectroscopy in radon/thoron progeny measurements.

A comparison is made between the relative variances and counting time requirements for obtaining radon and thoron progeny air concentrations from total alpha count data and from spectroscopically resolved alpha count data collected from air sampling filters. Spectral resolution is shown to have significant advantages, especially in mixed radon/thoron atmospheres. Systematic biases resulting from imperfect energy peak resolution are shown to be subject to accurate mathematical compensation.