Bone Abstracts

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...

Introduction: Using transgenic mice ectopically expressing Hoxa2 all along chondrogenesis, we previously associated the resulting animal phenotype to human idiopathic proportionate short stature. Our analysis showed that this overall size reduction was due to a negative influence of Hoxa2 in the very first step of endochondral ossification. As the molecular pathways underlying this pathogenesis are still unknown, we here tried to identify the impact of Hoxa2 overexpression on ...

Denosumab (DMAb) significantly improves bone strength at the hip, estimated by FEA from QCT scans, from baseline (B/L) and vs placebo (Pbo) (Keaveny ASBMR 2010). We determined the extent and distribution of mass and thickness changes at the proximal femur, a key skeletal site for fracture risk, using a novel cortical bone mapping technique on the same serial QCT scans. A FREEDOM substudy included 80 women who underwent hip QCT scanning at B/L and months 12, 24 and 36 during DM...

Aim: Differences in fracture risk between ethnic groups have been documented. The basis for these differences is yet incomplete and the age at what ethnic differences appear is uncertain. Assessment of bone health in pediatric populations could bring insights on factors compromising bone accrual. We describe here differences in total body bone mineral density (TB-BMD) in a unique setting of children of the same age, measured with the same device (iDXA) different ethnic backgro...

Lack of Klotho, the co-receptor for the bone-derived hormone fibroblast growth factor-23 (FGF23), leads to a severe impairment in bone mineralization in mice. However, the mechanisms underlying the Klotho deficiency-associated defects in bone mineralization are still poorly understood. Here, we sought to elucidate the vitamin D independent role of Klotho in bone mineralization. To ablate increased vitamin D signaling in Klotho knockout mice (Kl−/−), we c...

Osteoporosis pseudoglioma syndrome (OPPGS) is a rare autosomal recessive disorder characterised by congenital or juvenile-onset blindness, severe juvenile-onset osteoporosis, and skeletal fragility. OPPGS is caused by loss-of-function mutations in the LRP5 gene, a member of the LDL receptor family. It activates the canonical Wnt/β-catenin pathway, regulating osteoblastic bone formation. We investigated a 40-year-old Caucasian male presenting with congenital blind...

It is well known that the epidermal growth factor receptor (EGFR), its ligands, and the structurally related receptor ERBB2/neu are expressed in skeletal cells. However, the functions of EGFR ligands in bone cells remain poorly defined. In this study, we employed a transgenic mouse line overexpressing the EGFR ligand amphiregulin (AREG) specifically in osteoblasts under the α1(I)-collagen promoter. AREG-tg mice did not show changes in body weight or gross phenotype. Compa...

Calcium (Ca) and vitamin D nutritional status effects on oral health were evaluated in 85 healthy women aged between 20 and 30 years (24.6±0.4). They attended the first year of the Nutrition Carrier at the Private University (ISALUD, Buenos Aires, Argentine). Usual Ca intake (CaI) was determined by a food-frequency questionnaire that included consumption of dairy products and calcium-enriched foods. Blood samples were obtained in a fasting state in winter: the end of Augu...

Background: The tyrosine kinase inhibitor (TKI) imatinib is applied as front-line treatment in adult and pediatric patients with chronic myeloid leukemia (CML) in order to selectively inhibit the causative oncogenic BCR-ABL1 tyrosine kinase. However, TKIs exhibit off-target effects on further kinases involved in the regulation of bone metabolism. As consequence, pediatric patients display longitudinal growth retardation while on imatinib treatment. As CML is a rare disease in ...

Objective: Bone metabolism was studied in patients with phosphate diabetes before and after medication.Methods: 39 patients with phosphate diabetes age 2–18 years (7.8±4 years, 64% male) and multiplanar deformities of the lower extremities were treated with monthly vitamin D (2000 IU/day), alfacalcidol (0.25 mg/every other day) and calcium glycerophosphate (600 mg/day) for 6 months.Biochemical indices were evaluated befor...