Bone Abstracts

Background: Most patients with hypoparathyroidism are controlled under conventional treatment with calcium and vitamin D analogues. However, this treatment may be difficult to manage, especially in patients with ADHH who have an increased risk of nephrocalcinosis and chronic renal insufficiency. ADHH is caused by activating mutations in the calcium-sensing receptor (CaSR) resulting in suppressed PTH secretion and decreased calcium reabsorption within the thick ascending limb o...

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Introduction: QCT of the spine is typically restricted to the BMD analysis of the lumbar vertebrae. However, fractures frequently occur in the thoracolumbar region. Also the load distribution in the spine may depend on the intervertebral disc space (IDS), a good approximation of the intervertebral disc, which itself cannot be reliably assessed by X-ray based methods.Materials and methods: A QCT 3D acquisition and automated analysis technique (with option...

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...

Introduction: The quantification of cortical BMD and thickness in QCT images remains challenging due to the limited spatial resolution of CT scanners. We simulated the impact of longitudinal cortical BMD and thickness changes on accuracy of cortical measurements using three different segmentation algorithms.Methods: A step function of varying width d (cortical thickness) and height (cortical BMD) and an additional step representing trabecular BMD was con...

The local mechanical properties of bone are influenced not only by the material chemical composition but also by the spatial arrangement of the component’s e.g. orientation of collagen matrix. However, not much is known about local elastic modulus variations in cortical bone. Our goal was to use acoustic imaging to map elastic properties of murine bone with a several microns resolution. Rodent long bones exhibit a permanent growth with endosteal/periosteal bone formation ...

Menopause is accompanied by a decrease in bone mineral density which can be caused by a reduction in bone volume and/or degree of bone matrix mineralization. Both of them are suggested to contribute to the increased fracture risk in postmenopausal individuals. In the present work, we aimed for information whether a drop in bone matrix mineralization is occurring in the perimenopausal stage of women. For this purpose, we measured the bone mineralization density distribution (BM...

Background: Crohn’s disease (CD) is an inflammatory bowel disease which affects many organ systems including the skeleton. In children with CD, bone mineral density is frequently low. Bone metabolic abnormalities, including lower biochemical measures of bone turnover (NTX) as well as decreased bone formation indices at the tissue level have been reported. The aim of our study was to gain information on the bone matrix mineralization in CD.Methods: W...

Objective: To determine differences between osteoarthritic (OA) knees with normal knees for subchondral trabecular bone structure according to depth and location in the tibial plateau.Methods: In a population of 30 cadaveric left knees (18 women and 12 men, mean age: 79.1 years±8.2, range: 63–90) the Kellgren-Lawrence (KL) score was determined from post mortem radiographs: OA=KL≧2 (n=6 women, n=5 men) and controls=KL &#8804...

Tumor development occurs often by over-activation of members of the RAS-oncogene family (small GTPases (sGTPs)). By blocking the mevalonate pathway, aminobisphosphonates (BPs), and statines prevent activation of GTPs by inhibiting their post-translational prenylation. As we have shown, this induces apoptosis in U2OS osteosarcoma cells by re-activation of FAS expression via epigenetic DNA demethylation (1).The histone demethylase JHD...