Bone Abstracts

Communication between osteoblasts and osteoclasts is crucial for bone remodeling. Thrombin and its thrombin receptor (TR; PAR-1) are expressed in osteoclasts and osteoblasts, respectively. To date, the physiological roles of thrombin and TR in bone metabolism have not been elucidated. Therefore, we fully characterized the bone phenotype of mice lacking the thrombin receptor.We performed bone microarchitectural analyses of the femurs of 10–12 week ol...

Objectives: Strong coordination between osteoblasts and bone marrow cells is fundamental for the regulation of healthy bone turnover and other (patho)physiological processes. Extracellular vesicles (EVs) mediate communication between cells via horizontal transfer of proteins and nucleic acids. Osteoblasts secrete EVs in the form of matrix vesicles involved in bone mineralization, however, information about a role in intercellular communication is still lacking. In this study, ...

Transient receptor potential vanilloid channels (TRPVs) have been implicated in Ca2+ homeostasis and bone metabolism. In particular, TRPV4 deficiency was shown to cause sexual dimorphism in bone metabolism and osteoporotic fracture risk. Cortical bone structure was reported to be altered in male TRPV4 knock-out (TRPV4−/−) mice but not in female TRPV−/− mice compared to sex-matched wildtype (TRPV4+/+) animals.To gain knowledge on t...

Background: Elevated plasma homocysteine levels are a risk factor for osteoporotic fractures. Supplementation with vitamin B12/folic acid lowers homocysteine levels. This study aimed to determine whether vitamin B12/folic acid supplementation reduces osteoporotic fracture incidence in hyperhomocysteinemic elderly.Methods: B-PROOF is a double-blind, randomized, placebo-controlled trial including 2 919 participants aged ≧65 years with elevated homocyste...

Destruction of the articular cartilage is the major feature of Osteoarthritis (OA). Ageing is the primary risk factor, but how ageing results in OA is still an enigma. In OA, articular chondrocytes degrade their own matrix, while in healthy articular cartilage they preserve it.Transforming growth factor β (TGFβ) is a central regulator of chondrocyte proliferation, differentiation and extracellular matrix production. Deregulation of TGFβ si...

Objective: To study the trends in prescription of different anti-osteoporotic drugs (AOD) in the UK population aged 50 years or above from 1990 till 2012.Methods: Retrospective observational study using the CPRD data link representative for the total UK population. The incidence of prescription of a specific AOD was calculated by dividing the number of prescriptions by the total person-years (py) of follow-up.Results: AOD prescript...

Since the identification of LRP5 as the causative gene for the osteoporosis pseudoglioma syndrome (OPPG) as well as the high bone mass (HBM) phenotype, LRP5 and the Wnt/β-catenin signalling have been extensively studied for their role in the differentiation and proliferation of osteoblasts, in the apoptosis of osteoblasts and osteocytes and in the response of bone to mechanical loading. However, more recently the direct effect of LRP5 on osteoblasts and bone formation has...

Introduction: Vitamin D deficiency has been associated with impaired physical functioning and several chronic diseases and might thereby affect quality of life and self-rated health. The aim of this study was to assess relationships of serum 25-hydroxyvitamin D (25(OH)D) with quality of life and self-rated health, and to examine whether physical performance and number of chronic diseases mediate these relationships.Methods: Data were obtained from the LA...

Introduction: We describe a monozygotic twin pair, of which one boy was diagnosed with anorchia. Both were followed-up till age 17.Case report: At birth, in one twin 46 XY boy (A), testes were not palpable while his brother (B) was unaffected. Stimulation with human chorionic gonadotrophin (hCG) and orchidopexia were unsuccessful at age 3. A second hCG-stimulation test was performed at age 8, where serum testosterone response failed to increase. No testi...

Background: This case illustrates the longitudinal improvements quantified by serial bone mineral density scans in an adolescent female with juvenile idiopathic osteoporosis treated with pamidronate.Presenting problem: The girl in question presented at 11 years and 10 months with a 5-month history of increasing back pain. A MRI scan prior to referral had indicated vertebral collapse and osteopenia. She had no medical, social or developmental history of n...