Bone Abstracts

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Chronic obstructive pulmonary disease (COPD) has been found associated with low areal bone mineral density and an increase in fracture rate. Previous histomorphometric findings revealed abnormally low cancellous bone volume and thin cortices. In the present work, we studied the same transiliac bone biopsy samples from n=19 COPD patients for cancellous (Cn.) and cortical (Ct.) bone mineralization density distribution (BMDD) based on quantitative backscatter electron im...

In type 2 diabetes mellitus (T2DM) patients, an increased fracture risk is observed, although the bone mineral density is even higher than in non-diabetic patients. This raises the question of the quality of the organic and inorganic matrix in bone1–3. T2DM is also known to forward dysfunctions in the development of soft tissues such as brittle skin due to cross-linking of the collagen or inflammation of the gingiva. For the latter, a possible influence of diab...

Bisphosphonates (BPs) including alendronate (ALN) are the most widely prescribed therapy for post-menopausal osteoporosis. Despite their overall excellent safety record and efficacy in reducing fractures, concerns have been expressed lately regarding potential detrimental effects due to prolonged bone turnover reduction, although no definite cause–effect relationship has been established to date. The purpose of the present study was to determine bone material quality by R...

Duchenne muscular dystrophy (DMD) causes progressive muscle weakness and loss of ambulation. While glucocorticoid (GC) therapy improves motor function, many boys sustain fractures due to osteoporosis. Recently, i.v. bisphosphonate (i.v.BP) therapy has shown promise in the treatment of DMD-related osteoporosis. At the same time, bone histomorphometry revealed lowered bone volume and significant reductions in bone formation pre-i.v.BP treatment, and a further drop after 2 years&...

Spatial distributions of major and minor chemical elements are supposed to change during tissue maturation and due to bone diseases. Previous studies suggested that osteocytes have the ability to interact with the bone matrix of their environment. For this interaction osteocytes make use of the big inner surface of the osteocyte lacuno-canalicular network (OLCN) in which they are accommodated. The aim of this study was to quantify spatial correlations between the elemental com...

Deficiency of Cyclophilin B (CyPB) causes recessively inherited Type IX osteogenesis imperfecta, a moderately severe to lethal bone dysplasia. CyPB, encoded by PPIB, is an ER-resident peptidyl-prolyl cis-trans isomerase (PPIase) that catalyzes the rate-limiting step in collagen folding, and also functions as a component of the collagen prolyl 3-hydroxylation complex. We previously demonstrated in a Ppib−/− mouse model that CyPB PPIase activity r...

Objectives: Osteocytes play a major role in bone metabolism as mechanosensors, key regulators of osteoblast and osteoclast activity and of the mineral homeostasis. Therefore the assessment of osteocytes characteristics is important to understand bone pathology. We propose to study indirectly the osteocytes by performing quantitative backscattered electron imaging to quantify the sectioned osteocyte lacunae density and size in 2D on bone samples.Methods: ...

Objectives: FGF23 is expressed in clusters of osteocytes at the trabecular periphery suggesting that FGF23-expressing osteocytes are confined to specific basic multicellular units (BMUs) at the trabecular surface. Higher numbers of FGF23-expressing osteocytes are found in chronic kidney disease (CKD) patients with preserved skeletal mineralization indices. We thus combined immunohistochemistry and quantitative backscattered electron imaging (qBEI) to explore the hypothesis tha...

Objectives: Mice with a non-functioning vitamin D receptor (VDR mutants) develop severe secondary hyperparathyroidism, which can be rescued by a diet enriched with calcium, phosphate and lactose. In this work, we studied the effects of a low calcium challenge (CD), normal calcium (ND) and a calcium enriched rescue diet (RD) on the bone mineralization density distribution (BMDD) and osteocyte lacunae sections (OLS) in these mice.Methods: BMDD and OLS were...