Bone Abstracts

Objectives: Glucose-dependent insulinotropic polypeptide (GIP) is secreted by intestinal K-cells into the blood supply in response to nutrient ingestion and absorption. Although osteoblasts and osteoclasts express the GIP receptor (GIPR), the main action of the GIP/GIPR pathway in bone physiology and bone quality is unknown. The aim of the present study was to investigate bone quality in a mouse model of GIPR deficiency.Materials/methods: Eleven 16 weeks...

For a reliable assessment of bone’s material quality in a clinical environment, a fast way to measure the mechanical properties of bone is needed. The investigation of material heterogeneity and anisotropy resulting from bone remodeling and mineralization requires an imaging technique with micrometer resolution. Scanning acoustic microscopy (SAM) using high-frequency lenses allows measuring the stiffness of bone under wet conditions in a non-destructive way with this spat...

Adaptive responses of the skeleton to loading changes architecture and physical properties in order to optimise strength for function. However, bone is subjected to many local and circulating osteotropic factors, most acting on G-protein coupled receptors. Receptor activity modifying protein-3 is a single trans-membrane domain receptor accessory protein, which aids in trafficking of calcitonin and calcitonin-like receptors to the cell surface and changes ligand selectivity. As...

Introduction: Loss in bone mineral density may occur soon after initiation of adjuvant therapy for hormone-receptor-positive (HR+), breast cancer (BC) and correlates with changes in hormone levels. Adding zoledronic acid (ZOL) to adjuvant treatment for BC can preserve/improve bone mineral density and delay disease recurrence; however, effects of ZOL on endocrine hormone levels are currently unclear.Methods: Probone II assessed the course of endocrine hor...

Introduction: Patients with multiple myeloma (MM) commonly present with devastating bone disease mediated by increased bone resorption and suppressed bone formation. We have previously shown that blocking activity of the Wnt antagonist Dkk-1 promotes osteoblastogenesis and inhibits development of bone lesions in experimental models of MM. In the 5T murine models of MM, tumour cells home to the bone marrow. Injection of 5T2MM cells into C57BLKalwRij mice results in bone disease...

Successful long-term, cementless fixation of human shoulder components in osteoporotic (OP) and osteoarthritic (OA) patients poses major challenges. The possibility that enhanced osseointegration may rely on both the region of bone targeted and its relationship with the vasculature remains unexplored. We hypothesise that bone cells derived from subchondral (SC), cortical (C) and trabecular (Trb) bone regions exhibit differing osteogenic potential, which will be diminished in b...

Several studies have shown a higher mortality after hip fracture but the reasons and the duration of the excess risk is not well understood. We aimed to determine whether there exists a higher mortality after hip fracture when controlling for genetic constitution, environmental and life-style risk factors, and comorbidity. All 286 identical Swedish twin pairs discordant for hip fracture (1972–2010) were identified by use of the National patient register and the Swedish tw...

Background: Proline and hydroxyproline account for ~25% of aminoacids in collagen., Prolidase (peptidase D (EC 3.4.14.9)), cleaves iminodipeptides with a C-terminal proline or hydroxyproline, playing a major role in collagen catabolism. Mice with prolidase deficiency (PD) present with varied phenotypes including reduced size compared to wild-type littermates. We measured structural and mechanical properties of bones in PD mice.Methods: Whole femurs from ...

Background: At present, clinical assessment of bone strength in children predominantly relies bone mass measurement using absorptiometry (DXA) or QCT densitometric approaches. However, bone strength is not only dependent on mass/density, but also structural and material mechanical properties. Currently no technique measures bone mechanical properties. Recently, a new micro-indentation device, the reference point indentation (RPI) instrument has been validated for the measure o...

Background: Idiopathic infantile hypercalcemia (IIH) is a rare disorder caused by CYP24A1 loss-of-function mutation, resulting in impaired degradation of 1,25-dihydroxyvitamin D3. Typical signs include muscle hypotonia, dehydration, failure to thrive, psychomotor retardation, constipation, nephrocalcinosis. IIH should be distinguished from other causes of hypercalcemia in infancy. Treatment includes low calcium diet, glucocorticoids, furosemide, calcitonin. Pamidron...