1,720,971 research outputs found
Extracorporeal Shock Waves Stimulate Osteoblast Activities
No full textThe extracorporeal shock wave therapy (ESWT) is an extensively applied treatment for musculoskeletal disorders because it promotes bone repair. The aim of this study was to evaluate the direct effect of ESWT on murine osteoblasts to clarify the cellular mechanism that leads to the induction of osteogenesis. Osteoblasts in culture flasks were treated with ESWT pulses (500 impulses of 0.05 mJ/mm(2)) generated by an electromagnetic device. Using western blot analysis 3 h after ESWT, an increased expression of Bax was found, indicating a fast pro-apoptotic effect of treatment on some of the osteoblasts. Activation of the cyclin E2/CDK2 is the complex that regulates the G1-S transition and is essential for cell proliferation. It was evident 24 to 72 h after treatment, indicating a proliferative stimulus. A decreased expression of osteoprotegerin (OPG) and receptor activator NF kappa B ligand (RANKL) 24 and 48 h after ESW, followed by a later increase of OPG, paired with a much smaller increase of RANKL, was evident by real-time polymerase chain reaction (PCR). The decreased RANKL/OPG ratio suggests inhibition of osteoclastogenesis. We can conclude that ESWT induces bone repair through the proliferation and differentiation of osteoblasts and the reduction of their secretion of pro-osteoclastogenic factors. (E-mail: [email protected]) (C) 2009 World Federation for Ultrasound in Medicine & Biology
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
