Bone Abstracts

Vitamin D deficiency is common in aging people and is associated with secondary hyperparathyroidism, bone loss, osteoporosis and fractures in epidemiological studies. Vitamin D3 is produced in the skin through u.v. irradiation of the sun in spring and summer, and it can also be obtained from food, especially fatty fish, such as herring or mackerel. Vitamin D is activated by liver and kidney. Its main action is stimulation of calcium absorption from the gut. Vitamin ...

Biographical DetailsDr A Linglart is a Paediatric Endocrinologist working at the Hôpital St Vincent de Paul in Parism, France. She has a special interest in rare diseases....

Objectives and method: We retrospectively reviewed records of current patients with osteogenesis imperfecta (OI) to identify those on risedronate, doses used and effects of treatment. BMD changes over time were calculated as difference between measurement before risedronate and at one year (including measurements −3–0 m and 10–14 m after starting risedronate respectively).Results: 219/296 (74%) patients with OI had received bisphosphonate...

Osteoclasts are highly specialized cell types, responsible for the resorption of bone matrix. Coordinated with osteoblasts they contribute to a proper bone turnover. An impaired or reduced function of the osteoclast leads to a pathogenic increase of the bone mass and finally osteopetrosis. Lysosomal hydrolases, as exemplied by CTSK and Acp5 (TRAP), are known to play an important role in the function of osteoclasts, and knockout mouse models of these proteins develop a bone res...

Background: Magnetic resonance imaging (MRI) is used clinically to assess bone marrow, muscle and joints. The assessment of cortical and trabecular structure using MRI may provide further insight into the muscle–bone–bone marrow unit. Previous studies using MRI to evaluate microarchitecture are confined to research due to the need for specially adapted coils and navigator software to limit motion artifact. We present a novel statistical method using HRpQCT to determi...

Objectives: The clinical assessment of bone mass in children with osteogenesis imperfecta (OI) is normally assessed by DXA. Further information about bone microarchitecture is obtained from bone biopsy which is invasive and requires anaesthetic. High-resolution peripheral quantitative computer tomography (HRpQCT) is an in-vivo imaging modality capable of assessing skeletal microstructure and integrity to a resolution of 80 μm. To date, no HRpQCT studies have incl...

Mineralized tissues like bone, articular calcified cartilage or mineralized turkey leg tendon (MTLT) are build by a composite of hydroxyapatite nano-particles and organic matrix. In bone and MTLT the matrix is formed by collagen type-I, but in contrast to bone in MTLT the collagen is uniaxial orientated, while in cartilage the matrix consists of collagen type-II and proteoglycans.Composition/orientation differences were investigated by a new scanning aco...

Vitamin D deficiency is common in older persons and non-western immigrants. Vitamin D is often started in loading doses of 50 000 IU/ml solution. Though, generally considered safe, this highly concentrated solution carries some risks as is illustrated by the following cases. A woman of >80 years old was admitted with hypercalcemia, calcium 3.27 mmol/l. She complained of nausea, thirst and polyuria for 3 months. History included cholecystitis, atrial fibrillation, myocardia...

The co-chaperone protein, Bcl-2-associated athanogene 1 (BAG-1) is expressed ubiquitously in bone including cells of the osteoblast-lineage and, plays an important role in cell proliferation, apoptosis and differentiation by regulating signalling and transcription. The study aims to elucidate the function of BAG-1 in osteoblast development by examining differences in osteogenic differentiation of bone marrow stromal cells (BMSCs) from Bag-1+/−</sup...

The process of vascular calcification shares many similarities with that of skeletal mineralisation, and involves the phenotypic trans-differentiation of vascular smooth muscle cells (VSMCs) to osteoblastic and chondrocytic cells within a calcified environment. Various microRNAs (miRs) are known to regulate cell differentiation, however their role in mediating VSMC calcification has yet to be fully understood.Murine VSMCs were cultured for up to 28 days ...