Bone Abstracts

Background: Pseudohypoparathyroidism (PHP) is a group of heterogeneous endocrine disorders characterised by hormone resistance, primarily to parathyroid hormone (PTH). The resistance is caused by defects in the GNAS gene, which encodes the Gsα protein that activates the cAMP pathway. PHP patients demonstrate elevated plasma PTH, hypocalcaemia, hyperphosphataemia with normal renal function. PTH resistance can be confirmed by Ellsworth-Howard test (PTH s...

The PTH type 1 receptor (PTH1R) is an important modulator of bone remodeling. In mice, PTH1R ablation in osteocytes produces trabecular bone reduction and impaired calcium homeostasis; meanwhile, its overexpression in these cells promotes periosteal and endocortical bone formation. Osteocytes can translate mechanical stimuli into bone-forming signals. Skeletal unloading induces osteocyte apoptosis and bone loss, whereas mechanical stimuli prevent osteocyte apoptosis through in...

Objectives: Asfotase alfa (AA), an enzyme replacement therapy, is the only approved medical treatment for pediatric-onset hypophosphatasia (HPP), which is caused by deficient tissue-nonspecific alkaline phosphatase activity. We detail the long-term efficacy of AA observed from the pediatric clinical trial program.Methods: Efficacy data collected to study completion were pooled from 3 open-label, multicenter investigations of children who manifested HPP s...

In adults, majority of bone marrow (BM) space of long bones is filled with fat tissue. Adipocytes are also present within trabecular bone areas such as vertebral bodies. Despite its prevalence the roles of BM fat in energy and bone metabolism have been largely overlooked. To characterize bone marrow metabolic activity we measured regional glucose uptake in femoral and vertebral bone marrow during fasting and insulin stimulation in normal weight healthy subjects.<p class="a...

Background: Risk of fracture in chronic kidney disease (CKD) population is high and it is associated with increased mortality. CKD affects bone quality through changes in bone turnover, microarchitecture, and mineralization. Secondary hyperparathyroidism has different effects on cortical and trabecular bone but dual-energy X-ray absorptiometry (DXA) is unable to effectively differentiate these bone compartments. High resolution peripheral quantitative computed tomography (HRpQ...

Objective: Although there is adequate sunlight throughout the year, low serum 25OHD concentrations are being increasingly reported among Indian children (Gupta, 2014). Thus, quantifying individual sunlight exposure may be an important step in understanding hypovitaminosis D in sun-rich geographies. The objectives of our study were to quantify the sunlight exposure of school-children using a questionnaire and to use polysulphone film badges to validate the questionnaire adminis...

Objectives: Limited data exist on growth parameters in children with hypophosphatasia (HPP), a rare metabolic disease characterized by impaired bone mineralization. We aimed to describe growth characteristics in untreated children with HPP enrolled in the Global HPP Patient Registry.Methods: Children (<18 years old) with a diagnosis of HPP who were not receiving enzyme replacement therapy with asfotase alfa at the time of evaluation were identified f...

The relationship between bone formation and blood flow is unclear. Recently, PTH was reported to activate production of nitric oxide (NO), a potent vasorelaxing agent, in endothelial cells and we and others have confirmed a strong vasorelaxing action of PTH in vivo in the mouse. Here, we tested the hypothesis that a potent NO synthase inhibitor (L-NAME: NG-nitro-L-arginine methyl ester) may alter the effect of intermittent PTH (iPTH) on b...

The neuro-hypophiseal hormone oxytocin (OT) is a novel anabolic regulator of bone mass (Tamma et al. PNAS, 2009), upregulating expression of critical osteoblast transcription factors. These effects are mediated by oxytocin receptor, a GPCR expressed by osteoblasts. Recently an increasing number of reports indicates that GPCRs could be targeted to the nuclear membrane; prostaglandin receptors, endothelin receptors and β-adrenergic receptors among others (...

Introduction: The patients with rheumatoid arthritis (RA) are less physically active than the general population. The aim of the study is to assess the effect of two exercise programs on the functional status of patients with early RA.Methods: Fifteen patients with early RA underwent ten high-intensity dynamic exercises using Enraf-Nonius gym for 45–60 min, including aerobic part (En-Cardio) and 18–20 muscle-strengthening exercises (En-Dynamic ...