Bone Abstracts

Fractures in infancy raise the spectre of child abuse; it has been suggested that lack of vitamin D could result in bone abnormalities that could predispose to fractures. We utilised a mouse model system to investigate whether vitamin D deficiency in utero alters early bone growth and development.C57BL/6 female mice received vitamin D deficient or replete diet for 6 weeks, then mated and continued on their respective diets until weaning. Pups were culled...

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...

Cancer-associated muscle weakness is an important paraneoplastic syndrome for which there is currently no treatment. Human breast cancer bone metastases (MDA-MB-231 cells in immune deficient mice) induce extensive bone destruction, leading to the release of TGF-β from the bone matrix. We have previously shown that bone-derived TGF-β is responsible for muscle weakness in this model. Mechanistically, TGF-β signaling increases the expression of NADPH oxidase 4 (Nox...

Up to half of women treated with an aromatase inhibitor (AI) for breast cancer develop muscle weakness, bone loss, and joint pain. Moreover, an elevated state of osteoclastic bone resorption has been shown to prime the bone microenvironment in ways that accelerate metastatic growth. We hypothesized that AI-induced bone loss could increase breast cancer progression in bone and exacerbate muscle weakness associated with bone metastases. Four-week female athymic nude mice underwe...

Loss of the gene encoding the secreted Wnt antagonist sclerostin results in increased bone mass in humans and mice. Administration of antibodies to sclerostin (Scl-Ab) has been shown to increase bone mineral density (BMD) by increasing bone formation and decreasing bone resorption, in both animal studies and human clinical trials. In these studies, the magnitude and rate of increase in bone formation markers, and the rate of increase of BMD, diminishes upon repeat dosing with ...

see P162....

Epigenetic mechanisms regulating osteoblast differentiation are still inadequately described. In a genome wide transcriptional profiling of MC3T3-E1 osteoblastic cell line, we identified RCOR2 as a significantly upregulated gene during a differentiation time-course from proliferative to mature osteoblasts. Similar expression profile of RCOR2 was found in mouse calvarial osteoblasts. RCOR2 belongs to CoREST/RCOR family of proteins that regulate action of lysine-specific histone...

We have shown that the bisphosphonate pamidronate (P) given to children <10d post-burn prevents resorptive bone loss and muscle protein breakdown. We have also shown in vitro that Ca modulates the inflammatory response by altering mononuclear cell chemokine production. We hypothesized that P affects muscle protein breakdown by altering cytokine or chemokine concentration directly or indirectly by lowering blood ionized (i) Ca. We retrospectively analysed biomarker...

FDA guidelines recommend the sheep as large animal model for osteoporosis. Studies of osteoporosis induction use dual energy x-ray absorptiometry (DEXA) to evaluate bone status. Experimentally, the T-score is calculated based on reference bone mineral density (BMD) values of animals before treatment (0 M). Whereas clinically the reference BMD represents values of an independent group of patients around 30 years old. The study hypothesize that the use of additional ind...

Goal: The use of intramedullary telescopic constructs for osteosynthesis in surgical correction of bone deformities in children with systemic skeletal disease can be complicated by delayed bony union, and the structural and functional pathology of bone in patients with these disorders do not always make it possible to avoid displacement of bone fragments and effectively correct the deformity.Methods: Analysis of treatment of 11 patients of femoral and ti...