Maintenance of Nucleolar Homeostasis by CBX4 Alleviates Senescence and Osteoarthritis. Abstract CBX4, a component of polycomb repressive complex 1 (PRC1), plays important roles in the maintenance of cell identity and organ development through gene silencing. However, whether CBX4 regulates human stem cell homeostasis remains unclear. Here, we demonstrate that CBX4 counteracts human mesenchymal stem cell (hMSC) aging via the maintenance of nucleolar homeostasis. CBX4 protein is downregulated in aged hMSCs, whereas CBX4 knockout in hMSCs results in destabilized nucleolar heterochromatin, enhanced ribosome biogenesis, increased protein translation, and accelerated cellular senescence. CBX4 maintains nucleolar homeostasis by recruiting nucleolar protein fibrillarin (FBL) and heterochromatin protein KRAB-associated protein 1 (KAP1) at nucleolar rDNA, limiting the excessive expression of rRNAs. Overexpression of CBX4 alleviates physiological hMSC aging and attenuates the development of...
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Fostering novice students' diagnostic ability: the value of guiding deliberate reflection. Abstract BACKGROUND: Deliberate reflection when practising the diagnosis of clinical cases has been shown to develop medical students' diagnostic competence. Adding guidance by cueing reflection or providing modelling of reflection increased the benefits of reflection for advanced (Years 5-6) students. The present study investigated whether we could replicate and extend these findings by comparing the effects of free, cued and modelled reflection on novice students' diagnostic competence. METHODS: A total of 80 third-year medical students participated in a two-phase experiment. In the learning phase, students diagnosed nine clinical cases under one of three conditions: free reflection; cued reflection, and modelled reflection. Two weeks later, all students diagnosed four new examples of the diseases studied in the learning phase and four cases of non-studied related diseas...
A Novel Braided Biodegradable Stent for Use in Congenital Heart Disease: Short-Term Results in Porcine Iliac Artery. Abstract BACKGROUND: To evaluate the properties and efficacy of a novel braided biodegradable stent (BBS) consisting of poly (p-dioxanone) (PPDO) and polycaprolactone (PCL) for usage in children with congenital cardiovascular diseases. METHODS: PCL/PPDO composite filaments were fabricated by coating PCL layers onto PPDO filaments, which were fused with PPDO monofilaments to form the BBS. Physical properties of BBSs including elastic recovery rate, deformation rate and mechanical characteristics with adjunctive post-dilation were evaluated by radial force-tests. 10 BBS stents and 10 metallic wall stents (WS) as controls were implanted into the common carotid arteries of 10 pigs and angiography as well as histological examinations were performed 4 and 8 weeks after implantation. RESULTS: An 8 mm BBS with adjunctive post-dilation had the best morpholo...
