Bone Abstracts

Objectives: Osteocytes play a major role in bone metabolism as mechanosensors, key regulators of osteoblast and osteoclast activity and of the mineral homeostasis. Therefore the assessment of osteocytes characteristics is important to understand bone pathology. We propose to study indirectly the osteocytes by performing quantitative backscattered electron imaging to quantify the sectioned osteocyte lacunae density and size in 2D on bone samples.Methods: ...

Objectives: Intravenous cyclical bisphosphonates are widely used to treat children with moderate to severe osteogenesis imperfecta (OI). They increase bone mineral density (BMD), diminish fracture rates and improve mobility. Bisphosphonates are often discontinued when growth is completed. We aimed to determine if the skeletal gains achieved with bisphosphonates persist after their discontinuation in patients with OI.Methods: We assessed patients with OI ...

Objective: Rett syndrome (RTT) is an X-linked neurodevelopment disorder. More than 95% of RTT female have mutations in methyl-CpG-binding protein 2 (MECP2), whose protein product modulates gene transcription. Specific MECP2 mutations may lead phenotypic variability and different degrees of disease severity. It is known that low bone mass is a frequent complication of subjects with Rett syndrome. This study aimed to investigate if specific MECP2 mutations may affects the degree...

see PP292....

Osteoporosis is common in rheumatoid arthritis (RA). Since osteoblasts express receptors for CXCL8 and CCL20, which are produced by inflammatory cells around the inflamed joints in RA, we hypothesized that CXCL8 and CCL20 contribute to osteoporosis in RA by affecting osteoblast proliferation, differentiation, and osteoblast-osteoclast communication.Primary human osteoblasts were cultured±CXCL8 (2–200 pg/ml) and CCL20 (5–500 pg/ml) for 14 d...

Delayed fracture healing is frequently experienced in patients with systemic inflammation such as during rheumatoid arthritis (RA). The reasons for this are diverse, but could also be caused by inflammatory cytokines and/or growth factors in serum from patients with active disease. We hypothesized that serum from patients with active RA contains circulating inflammatory factors that inhibit differentiation of osteochondrogenic precursors.Serum was obtain...

We recently established a large animal model of osteoporosis in sheep using hypothalamic–pituitary disconnection (HPD). As central regulation is important for bone metabolism, HPD-sheep developed severe osteoporosis because of low bone turnover. In this study we investigated metaphyseal fracture healing in HPD-sheep. To elucidate potential pathomechanisms, we included a treatment group receiving thyroxine (T4) and 17β-estradiol. Because clinically osteopor...

Osteogenesis imperfecta (OI) type V is caused by a unique dominant mutation (c.−14C>T) in IFITM5, which encodes BRIL, a transmembrane ifitm-like protein most strongly expressed in osteoblasts, while type VI OI is caused by recessive null mutations in SERPINF1, encoding pigment epithelium-derived factor (PEDF). We identified a 25-year-old woman with severe OI, whose dermal fibroblasts and cultured osteoblasts displayed minimal secretion of PEDF, but ...

Background and methods: Pigment epithelium-derived factor (PEDF) is a potent antiangiogenic factor, ubiquitously expressed and secreted in human tissues. Hypertrophic cartilage and osteoblasts express PEDF that binds to type I collagen and glycosaminoglycans in the extracellular matrix. Two rare forms of osteogenesis imperfecta (OI) with intact collagen synthesis are associated with PEDF deficiency. Histological observations revealed excessive osteoid formation and prolonged m...

Objective: To study the trends in prescription of different anti-osteoporotic drugs (AOD) in the UK population aged 50 years or above from 1990 till 2012.Methods: Retrospective observational study using the CPRD data link representative for the total UK population. The incidence of prescription of a specific AOD was calculated by dividing the number of prescriptions by the total person-years (py) of follow-up.Results: AOD prescript...