Revealing the high-resolution three-dimensional network of chromatin and interchromatin space: a novel electron-microscopic approach to reconstructing nuclear architecture.

The nuclear architecture is considered an important contributor to genome function. Although the fine structural features of the cell nucleus have been investigated extensively by means of ultrastructural cytochemistry, mainly on ultrathin sections in two dimensions (2D), there was a of lack routine methods for a rapid reconstruction of three-dimensional (3D) distribution of different structural constituents throughout the nuclear volume. We have now filled this gap by the application of a novel approach associating a pre-embedding selective visualization of nuclear components with a method making use of ultramicrotomy combined with scanning electron microscopy (microtome serial block face scanning electron microscopy--'3View'). We have been able to apply this method to the study of DNA distribution within the nuclear volume and reconstruction of 3D chromatin arrangement in nuclei of rat hepatocytes and endothelial cells. Our observations demonstrate that while chromatin appears to occupy the interior of nuclei rather sparsely on 2D images, once reconstructed in 3D from a series of sequential 2D images it gives the impression of considerably filling the nuclear volume. However, quantitative evaluation of the nuclear volume occupied by DNA in the above two types of nuclei leaves a significant part to the interchromatin space (66.2% for hepatic cells and 41.7% for endothelial cells, including nuclear space occupied by nucleoli). Detailed analysis of the reconstructed nuclei reveals a high degree of superposition of chromatin domains, giving rise to a false impression that they fill a much larger part of the nuclear volume than they really do. Our results show the importance of the contribution of such reconstruction techniques to our understanding of the nuclear architecture.

[Workplace learning for final-year medical students: a comprehensive analysis of student's expectancies and experiences]. / Lernen am späteren Arbeitsplatz: Eine Analyse studentischer Erwartungen und Erfahrungen im "Praktischen Jahr".

BACKGROUND: The amended German license to practice medicine (AAppO) focuses on practically oriented, patient-centred medical education. After the cancellation of the former medical doctor traineeship "Arzt im Praktikum" (AiP) qualification period in October 2004, the final year of medical education, the so-called "practical year" (PJ), has become a key teaching module in realising the demands of the AAppO. So far no studies have been carried out in the German-speaking area to qualitatively assess the specific needs and central problems that PJ students are facing. The aim of this investigation was to representatively evaluate the expectancies and experiences of final-year medical students in a workplace learning environment. METHODS: 65 students (30 male, 35 female, age 25.4 +/- 2 years) of two German university hospitals participated in focus groups both prior and subsequent (n = 60; drop-out rate 7.7%) to a 4-month period of internal medicine traineeship during their final year. Focus group protocols were transcribed and subjected to content analysis. RESULTS: 1137 individual statements on relevant topics were identified from the transcriptions. Students widely reported lack of time on the part of supervising doctors and exorbitant assignment to routine jobs. This results in insufficient training of independent patient management, followed by feelings of uncertainty and the fear of making medical errors. CONCLUSIONS: Specific educational strategies and motivation of medical teachers are important factors to the workplace learning environment. A structured curriculum including cognitive, procedural and communicative learning objectives and the introduction of defined time slots for bedside teaching is considered a good first step in this process.

Undergraduate technical skills training guided by student tutors--analysis of tutors' attitudes, tutees' acceptance and learning progress in an innovative teaching model.

BACKGROUND: Skills labs provide a sheltered learning environment. As close supervision and individual feedback were proven to be important in ensuring effective skills training, we implemented a cross-year peer tutor system in our skills lab of internal medicine that allowed intense training sessions with small learning groups (3-4 students) taught by one student tutor. METHODS: The expectations, experiences and criticisms of peer tutors regarding the tutor system for undergraduate skills lab training were investigated in the context of a focus group. In addition, tutees' acceptance of this learning model and of their student tutors was evaluated by means of a pre/post web-based survey. RESULTS: 14 voluntary senior students were intensely prepared by consultants for their peer tutor activity. 127 students participated in the project, 66.9% of which responded to the web-based survey (23 topics with help of 6-point Likert scale + free comments). Acceptance was very high (5.69 +/- 0.07, mean +/- SEM), and self-confidence ratings increased significantly after the intervention for each of the trained skills (average 1.96 +/- 0.08, all p < 0.002). Tutors received high global ratings (5.50 +/- 0.07) and very positive anonymous individual feedback from participants. 82% of tutees considered the peer teaching model to be sufficient, and a mere 1% expressed the wish for skills training to be provided by faculty staff only. Focus group analyses with tutors revealed 18 different topics, including profit in personal knowledge and personal satisfaction through teaching activities. The ratio of 1:4 tutor/tutees was regarded to be very beneficial for effective feedback, and the personalized online evaluation by tutees to be a strong motivator and helpful for further improvements. The tutors ascribed great importance to the continuous availability of a contact doctor in case of uncertainties. CONCLUSION: This study demonstrates that peer teaching in undergraduate technical clinical skills training is feasible and widely accepted among tutees, provided that the tutors receive sufficient training and supervision.

[Working on the ward as part of the medical school curriculum: the influence of final year students on learning outcomes of medical students in their 7th semester and their feeling integrated]. / Einsatz auf Station innerhalb der Medizinischen Ausbildung: Einfluss von PJ-Studenten auf den Lernerfolg und das Integrationsgefühl von Medizinstudenten des 7. Semesters.

INTRODUCTION: Integrating medical students into their future working environment is of utmost importance in order to ensure a smooth transition from university life to clinical practice. In the German-speaking area, there has so far been no quantitative analysis of the extent or the quality of supervision received by medical students during their ward clerkship during their clinical studies in the specialist field of internal medicine. METHODS: In the summer of 2005, 161 medical students in their 6th and 7th semester undertook ward clerkships on internal wards at the University Clinic of Heidelberg and its academic hospitals. Using a questionnaire, a survey was conducted among these students about the intensity and quality of supervision received during their work on ward. RESULTS: Medical students working on the wards of academic hospitals were significantly more frequently co-supervised by senior physicians (p < 0.001), while a higher level of co-supervision by final year students was reported for the University Clinic (p < 0.001). Students supervised by final year students reported greater subjective learning outcomes (p < 0.001). However, this had no effect on the extent to which students felt integrated on the ward. DISCUSSION: Final year students play a central role in incorporating medical students into the ward routines of teaching hospitals. While they cannot replace instruction or supervision by a qualified physician, the promising potential of "peer-teaching" programmes should be utilized and junior physicians should be systematically prepared for and supervised in this important function.

[Communication training using "standardized parents" for paediatricians--structured competence-based training within the scope of continuing medical education]. / Kommunikationsschulung mittels "Standardi- sierter Eltern" für Arzte im Fachbereich der Pädiatrie--strukturierte Kompetenzvermittlung im Rahmen der arztlichen Weiterbildung.

INTRODUCTION: Following the recent amendment to the Medical Education Act in Germany (Approbationsordnung 2002) and the abolition of the preliminary approbation for early residency (AiP), the discussion increasingly focuses on the restructuring of German post-graduate medical training. The training should include well-defined learning objectives and an educational concept with a central emphasis on communication skills training. In the German-speaking countries there has as yet been no publication of a structured training course for the improvement of communication skills in the context of post-graduate education. METHODS: Jointly designed by the University of Heidelberg's Clinic of Internal Medicine and Clinic of Paediatrics, this study aimed to measure the effect of a training programme for handling problems and difficult situations arising in the communication with parents and patients. 28 paediatric residents took part in a randomised controlled trial using standardized patients and video-feedback (intervention group: N = 14; control group: N = 14). Upon completion of the study, the control group also received training and was subsequently evaluated. The training course consisted of four units, lasting 90 minutes each. Both the acceptance of the training units and the self-evaluation of communication skills in dealing with parents were subject to assessment. RESULTS: The participating residents acknowledged the training course to be an extremely useful tool for improving their communication skills and confidence in dealing with the parents of ill children. A pre-post comparison of self-assessed communication skills revealed a significant increase in the intervention group, but not in the control group. DISCUSSION: The structured training course presented in the current study proved highly effective and should serve as a model for a compulsory component of a post-graduate training.