Bone Abstracts

see PP474....

Denosumab (DMAb) has a unique profile of bone resorption inhibition: CTX decreases rapidly by 3 days and inhibition is released at the end of the 6-month dosing interval, when DMAb serum levels decrease (McClung NEJM 2006). The dynamic CTX inhibition profile is not curtailed by continued treatment. In the 3-year FREEDOM study, CTX values at 6 months were influenced by baseline CTX values and days since the 1st injection (Eastell JBMR 2011). With 3 additional ...

Mutations in the PHEX gene cause X-linked familial hypophosphatemic rickets (XLH) with severe bone (osteomalacia) and tooth abnormalities being the distinguishing features of this disease. The PHEX mutations lead to an increase in ASARM peptides (acidic serine- and aspartate-rich motif) and osteopontin fragments which inhibit bone extracellular matrix mineralization. MEPE-derived ASARM has been shown to accumulate in tooth dentin of patients with XLH where it may impair dentin...

Autosomal dominant osteopetrosis type II (ADO2) is a rare osteosclerotic disease due heterozygous missense mutations of the CLC7 gene encoding the type seven chloride channel. Our two labs independently generated the first C57 black 6 (B6) mouse model of ADO2 by inserting the pG213R-clc7 mutation. Homozygous mice showed lack of tooth eruption and died within 30 days of age with severe osteopetrosis and central nervous system degenera...

Autosomal dominant type II osteopetrosis (ADO2) is a rare osteosclerotic disorder due to heterozygous missense mutations of CLC7 gene encoding the type 7 chloride channel. Our two labs (L’Aquila and Indianapolis) independently generated the first C57 black 6 (B6) mouse model of ADO2 by inserting the pG213R-clc7 mutation. We created pG213R-clc7 KI mice using a gene targeting approach. Homozygous mice showed lack of tooth eruption and died within ...

Objectives: Creation of reference curves for areal bone mineral density (aBMD) and bone mineral content (BMC) with consideration of relevant anthropometric variables.Methods: Analysis of the dual-energy X-ray absorptiometry (DXA) data collected as part of the Bone Mineral Density in Childhood Study1, including 2012 boys and girls, 5–22 years old, with a total of 10 525 visits, resulting in aBMD and BMC observations at the lumbar spine, hi...

Background: Low vitamin D concentrations among children and adolescents at northern latitudes are frequently observed. Also, inverse associations between 25-hydroxyvitamin D (25(OH)D) and PTH concentrations have been found in children of different ages. More studies on the link between vitamin D status and childhood bone health are needed.Objective: To evaluate the status of serum 25(OH)D in autumn and the association between 25(OH)D concentrations and b...

Objective: Evidence for further reduction of nonvertebral fracture (NVFX) beyond 3 years of antiresorptive therapy is limited. Since long-term denosumab (DMAb) treatment is associated with continuous increases in BMD and sustained fracture reduction, we analyzed the influence of femoral neck (FN) BMD after 3 years on NVFX rates.Methods: Long-term subjects received 7 continuous years of DMAb; cross-over subjects received 3 years of placebo (FREEDOM) and 4...

Background: Hypoxia induces mesenchymal stem cells (MSCs) proliferation but results in a population with impaired osteogenic differentiation potential. Bone healing of tibial lengthening is enhanced by hyperbaric oxygen therapy. However, little is known about the effects of HBO on the Wnt signaling pathway in MSCs.Materials and methods: MSCs were cultured in complete medium and the osteogenic groups were cultured in osteogenic induction medium. Control c...

Background: It is known that one of the features of rheumatoid arthritis (RA) is a generalized bone loss, therefore important tasks for the physician are timely evaluating of the risk of fractures and approving osteoporosis treatment in patients with RA.Objectives: Through the Programme of the Russian Association of Rheumatology for the diagnosis, prevention and treatment osteoporosis (OP) in patients with RA we evaluated the 10 year probability of major...