Bone Abstracts

Elevated levels of circulating serotonin have been reported to decrease bone mineral density1. Conversely, reduced serotonin (5HT) in mice lacking TPH1, the rate limiting enzyme for 5HT synthesis, was reported to be anabolic to the skeleton with high osteoblastic activity2. However, in other studies TPH1 deletion led to either an initial increase in BMD due to inhibition of osteoclastic bone resorption3, or had no bone effect4</su...

Introduction: The calcium sensing receptor presence (CaSR) at the surface of the osteocytes has never been clearly investigated. The CaSR are known to be express on osteoblasts. Osteocytes being old osteoblasts embedded in the matrix, this expression of CaSR is likely, and could constitute a key role to calcium signalling.Strontium ranelate (SrRan) has shown to activate osteoblasts by fixation on CaSR (Chattopadhyay N 2007, Biochem Pharmacol; Hu...

Objective: Idiopathic hypercalciuria (IH) is defined as excessive 24 h urinary calcium excretion (>4 mg/kg per 24 h), that persists after correction of dietary imbalances in the absence of secondary causes. Recent studies with DXA in children with IH provide evidence of decreased areal BMD. We used peripheral quantitative computed tomography (pQCT) of the tibia, to test the hypothesis that IH results in decreases of volumetric (mg/cm3) BMD of the trabecular and/...

RANKL, the receptor activator of nuclear factor kappa B ligand, is an essential factor for the formation of mature osteoclasts. Together with its receptor RANK and its antagonist Osteoprotegerin (OPG) RANKL is a key regulator in bone metabolism1. RANKL is a membrane-bound protein that can be segregated to a soluble form (sRANKL), whereas only the latter has been reported to be bioactive2. Due to its low circulating levels and the nature of the analyte bin...

We have shown previously that TSG–6 acts as an autocrine regulator of osteoclast activity in vitro, capable of inhibiting RANKL-mediated osteoclastic bone resorption with a similar potency to OPG1,2. Thus, the TSG–6 protein has the potential to be developed as a novel treatment for osteoporosis, which is associated with excessive bone loss3.The aim of this study was to determine the therapeutic potential of the is...

Objectives: We recently identified a heterozygous missense mutation c.652T→G (p. C218G) in WNT1 as the cause of severe primary osteoporosis (Laine et al. New Engl J Med 2013). The mutated WNT1 reduces activation of the canonical WNT1/β-catenin-signaling, resulting in decreased osteoblastic function. The mutation was originally identified in a large Finnish family presenting with dominantly inherited, early-onset osteoporosis, with affected...

Background: Prader Willi syndrome (PWS) is a genetic disorder characterized by severe hypotonia in infancy, hypogonadism, dysmorphic features, early onset obesity and mild mental retardation.Although hip dysplasia occurs in 10–20% in patients with PWS, hip dislocation requiring surgery is seen rarely. To our knowledge, surgical treatment of hip dislocation in PWS has not been reported before.We present a case with PWS and hip ...

Introduction: Vascularised fibula autograft combined with a massive bone allograft (Capanna 2007) is used in skeletal reconstructions in children. If vascularisation is successful a clear remodelling of the reconstruction can be observed. This study aims to define a protocol to characterise bone’s structural evolution in skeletal reconstructions through a computer-aided analysis, and attempts a biomechanical interpretation of the observed phenomena through a multiscale mo...

Calcium supplements are associated with increased cardiovascular risk, but the mechanism by which this occurs is presently uncertain. In a secondary analysis of a trial examining the acute effects of calcium supplements, we found that blood pressure declined over 8 h in the control group, consistent with its diurnal rhythm, and that this decline was smaller in the calcium group [1]. To investigate these effects further, we carried out a randomised controlled cross-over trial o...

Paget’s disease of bone (PDB) is a common disorder of bone metabolism characterized by focal areas of excessive and rapid bone resorption and formation, leading to bone pain, deformity and fractures. Despite the well documented increase in the risk of primary bone tumors due to neoplastic degeneration of pagetic tissue, a large retrospective analysis suggested that patients with prostate cancer and PDB have delayed time to bone metastases and improved overall survival tha...