Bone Abstracts

Objectives: To describe the incidence of vertebral fractures in steroid-treated children.Methods: Fractures were assessed prospectively each year for 3 years according to the Genant semi-quantitative method. Proportions of children with incident fractures were determined annually over the study period. To examine associations with baseline clinical factors, the 3-year total number of incident fractures was analyzed using multivariable Poisson regression....

Preterm infants develop reduced bone mass and fragility fractures. Nevertheless, normal ranges in preterm infants are poorly defined for concentrations of vitamin D; its isomers (C3α-epimer of 25(OH)D3) and metabolites (24, 25(OH)2D3, 1, 24(OH)2D); and other mineral-regulating hormones, including FGF23 in both intact (iFRG23) and inactive (C- terminal) forms.Objective: To clarify normal concentrations of minerals and hormones in healthy, preterm inf...

Mutations in the C-propeptide cleavage site of both COL1A1 and COL1A2 cause dominant high bone mass (HBM) osteogenesis imperfecta (OI), characterized by bone hypermineralization. To elucidate the role of C-propeptide processing in bone formation, we generated heterozygous HBM mice in which both residues of the COL1A1 cleavage site were mutated to prevent cleavage by BMP1. HBM mice are smaller than WT in both weight and length and have extremely brittle bones....

The c-Myb transcription factor is associated with proliferation of undifferentiated cells in number of tissues, but recent data suggests its role also in differentiation. c-Myb is important in formation of the cartilage, bone and apparently also in hard tissue mineralization (Matalova et al. 2011).Embryonic micromasses were established from mouse front limbs at the embryonic day E12. Micromass cultures represent an effective tool for experimenta...

Introduction: Osteogenesis imperfecta (OI) is a genetically heterogeneous disorder characterized by bone fragility. OI type V, with autosomal dominant inheritance, is characterized by ossification of the forearm interosseus membrane, radiodense metaphyseal bands, propensity for hyperplastic callus formation, and mesh-like lamellation on bone histology. Type V OI probands are reported to have white sclerae and normal teeth. Recent reports identified the cause of type V OI as a ...

Background: The incidence and prevalence of gout have markedly increased over the last few decades in keeping with the rise in prevalence of obesity and metabolic syndrome. The management of gout in patients with associated metabolic syndrome and comorbid illnesses such as renal impairment was difficult because of limited treatment options. Recent efficacy and safety data favour lower over higher doses of colchicine, and oral corticosteroids over non-steroidal anti-inflammator...

In bone marrow, bone marrow stromal cells (BMSCs) have the capacity to differentiate into osteoblasts and adipocytes. Onset of osteoporosis with age stems in part from the enhanced bone marrow adipogenesis that represses osteogenesis. In this study, we demonstrate that disruption of nuclear factor I-C (NFI-C) impairs osteoblast differentiation and bone formation, and increases bone marrow adipocytes. Interestingly, NFI-C controls postnatal bone formation but does not influence...

C-C chemokine receptor 5 (CCR5) is a co-receptor of macrophage-tropic viruses including HIV. Epidemiological and pathological findings have reported that functional changes in CCR5 correlate with HIV transmission bone destruction disease. However, the roles of CCR5 in bone pathophysiology have not been well documented.Ccr5-deficient osteoclasts showed decreased bone resorption activity accompanied with disorganized cellular architecture and impa...

Introduction: Activated protein C (APC) plays an important role in the cutaneous healing of chronic wounds arising from orthopaedic surgery and has cytoprotective and anti-inflammatory properties which may also assist bone repair. The aim of this study was to examine whether APC could directly influence osteoblasts and increase bone formation in a rodent model.Methods: Proliferation of MG-63 osteoblast-like cells was quantified by MTT assay and direct co...

Over 80% of Quebec woman initiate breastfeeding, and rates of exclusive breastfeeding at 6 months doubled from 2003 (9.7%) to 2009 (19.0%). To prevent deficiency, current recommendations for these infants include 400 IU/day of vitamin D. For 20 years, Quebec has offered a program of free vitamin D supplements through its public medication insurance plan (RAMQ).Objective: Program evaluation over the last decade.Methods: This is a re...