Bone Abstracts

Objectives: Childhood osteoporosis can be treated with i.v. bisphosphonates in order to improve bone mass and density. The aims of this study were to evaluate the safety and efficacy of 6-monthly zoledronic acid (ZA) in children with osteoporosis.Methods: A retrospective cohort study of 27 patients (16 males and 11 females) were treated with 6-monthly ZA (0.05 mg/kg per dose) for a minimum of 1 year. Seventeen patients were immobile, 4 had steroid-induce...

Fibroblast growth factor-23 (FGF23) is a bone derived phosphate-regulating hormone which is elevated in hypophosphataemic rickets. Recent findings demonstrate iron deficiency as a potential mediator of FGF23 expression and murine studies have shown in utero effects of maternal iron deficiency leading to increased FGF23 concentration and disordered bone development (Clinkenbeard. JBMR 2013). Children with rickets in rural Gambia, West Africa, have high prevalences of i...

Multiple myeloma is usually incurable, the bone marrow niche providing a protective microenvironment for quiescent tumour cells. We hypothesised that manipulation of BMP activity, a regulator of cell differentiation in the bone marrow, might affect control of tumour growth by its niche and in addition alter the lytic bone disease of myeloma. Moreover BMP signalling contributes to the hepcidin upregulation and resultant inflammatory anaemia that is characteristic of myeloma. Re...

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...

Breast cancer is the most frequent malignancy in women and frequently results in osteolytic bone metastases. Amino-bisphosphonates are a standard bone protective therapy and, similarly to statins, inhibit the mevalonate pathway that is crucial for posttranslational protein modifications (farnesylation and geranylation). Direct anti-tumor effects of amino-bisphosphonates and statins have been suggested but high concentrations are necessary to achieve meaningful effects. Our stu...

Effects of whole bone scaling on isolated osteoblast behaviours are unknown. Exhibiting a huge range in size, inbred canines are an ideal species to determine such relationships. We have therefore undertaken initial studies in both male and female red foxes (Vulpes vulpes), the most abundant and accessible wild canid member in the United Kingdom.Femoral heads were removed from five fresh red fox cadavers (see details on table) and bone fragments...

Hip osteoarthritis is a cause of significant morbidity to people and their canine companions. Medical management is frequently insufficient, leading to surgery to relieve pain and regain mobility. Hip replacements are not without potential complications, including loosening and infection. Currently, there is a focus on uncemented implants to decrease these problems, however these rely on the biology of the femur for osseointegration and long-term stability. It has been previou...

Effects of whole bone scaling on isolated osteoblast behaviour are unknown. With two orders of magnitude range in body mass, dog breeds are well-suited to determine such relationships.Femoral heads from three canine hip replacement surgeries were collected. Bone fragments were washed in PBS+AB/AM, trypsin-digested and incubated in 0.2% collagenase. Cells from resultant supernatant were seeded in DMEM+10% FCS+AB/AM at 37 °C, 5% CO2, g...

Objectives: Murine studies have shown that iron deficiency during pregnancy can cause abnormal phosphate and bone metabolism in offspring by elevating concentrations of fibroblast growth factor-23 (FGF23). FGF23 exists in plasma as an intact phosphate- and vitamin D-regulating hormone and its C-terminal fragment, a cleavage product that possibly antagonises the intact hormone. These findings are pertinent to low-income countries, where the prevalence of iron deficiency in preg...