Endostatin inhibits VEGF-A induced osteoclastic bone resorption in vitro

BACKGROUND: Endostatin is a C-terminal fragment of collagen XVIII which is a component of basement membranes with the structural properties of both collagens and proteoglycans. Endostatin has a major role in angiogenesis which is intimately associated with bone development and remodeling. Signaling between the endothelial cells and the bone cells, for example, may have a role in recruitment of osteoclastic precursor cells. Our study aims at exploring a possibility that endostatin, either as a part of basement membrane or as a soluble molecule, may control osteoclastogenesis and osteoclastic bone resorption in vitro. METHODS: Rat pit formation assay was employed in order to examine the effect of endostatin alone or in combination with vascular endothelial growth factor-A (VEGF-A) on bone resorption in vitro. Effect of these agents on osteoclast differentiation in vitro was also tested. Osteoclastogenesis and the number of osteoclasts were followed by tartrate resistant acid phosphatase (TRACP) staining and resorption was evaluated by measuring the area of excavated pits. RESULTS: Endostatin inhibited the VEGF-A stimulated osteoclastic bone resorption, whereas endostatin alone had no effect on the basal resorption level in the absence of VEGF-A. In addition, endostatin could inhibit osteoclast differentiation in vitro independent of VEGF-A. CONCLUSION: Our in vitro data indicate that collagen XVIII/endostatin can suppress VEGF-A induced osteoclastic bone resorption to the basal level. Osteoclastogenesis is also inhibited by endostatin. The regulatory effect of endostatin, however, is not critical since endostatin alone does not modify the basal bone resorption

Knowledge and skills needed to improve as preceptor: development of a continuous professional development course – a qualitative study part I

BACKGROUND: Preceptors are expected to have the skills to be able to form an effective learning environment and facilitate a constructive clinical learning experience for students and new employees. Internationally, access to education for preceptors varies, with preceptors worldwide requesting more education in preceptorship. This article is based on a two-part study focusing on both the development and evaluation of a continuous, credit-bearing professional development course. The aim of this part of the study was to investigate and include preceptors’ requests and educational needs when developing a continuous professional development course on an advanced level. METHODS: This study used a qualitative research approach. In total, 64 preceptors (62 women and two men) answered one single written, self-administered global question online. The participants were all interested in teaching and had completed an undergraduate training in preceptorship. The collected data was analysed by content analysis inspired by Burnard’s description of the method. RESULTS: The participating preceptors illuminated two main themes: ‘Tools for effective precepting of students and healthcare professionals’ and ‘in-depth knowledge and understanding of preceptorship in an academic setting’. The results suggest that vital components for preceptor preparation could be a) teaching and learning strategies, b) reflective and critical reasoning, c) communication models, d) the role of the preceptor, and e) preceptorship. CONCLUSION: Using the results from this study as a guide, a continuous professional development course was designed to assist preceptors in deepening their knowledge of preceptorship in regard to planning, leading and implementing educational activities directed at students, healthcare professionals, patients and their families. The course content focuses on skills needed for preceptorship and is based on adult learning principles. A continuous, credit-bearing professional development course must include an exam by which participants are formally assessed and graded; therefore, a written assignment was included as part of the course