Bone Abstracts

Extracellular nucleotides stimulate both the formation and resorptive activity of osteoclasts. Ecto-nucleotide pyrophosphatase/phosphodiesterases (NPPs) hydrolyse extracellular nucleotide triphosphates to their corresponding monophosphate and pyrophosphate (PPi). We investigated if osteoclasts express functional NPPs and whether Enpp1 gene deletion influenced osteoclast formation and activity. Osteoclasts were formed from the bone marrow of 8 and 15 week old knockou...

Background: The ‘adequate’ level of 25-hydroxyvitamin D (25OHD) in children remains unclear. For bone outcomes, parathyroid hormone (PTH) is an important functional biomarker. Prior studies have shown too weak a correlation between 25OHD and PTH levels to determine adequate 25OHD level.Objective: To determine adequate 25OHD level(s) in children using a normal PTH value of 65 pg/ml while adjusting for calcium intake.Design...

Fractures are very common and affect 2% of the population per annum. Fragility fractures represent the greatest unmet need and are associated with high rates of morbidity and mortality. Currently, there is no approved therapy for enhancing healing of fragility fractures. We previously reported that upregulation of the early inflammatory response following skeletal injury can promote fracture repair (Glass et al PNAS 2011). Inflammation represents the earliest response followin...

Melatonin is a neuro-hormone released primarily from the pineal gland, which has been shown to have bone anabolic effect, although it is still unclear whether its skeletal action is directly mediated by receptors expressed on bone cells or is indirect. In this study, we examined melatonin’s effects on bone cellular activities in vitro and tested whether it modifies angiogenesis and blood flow to bone, which are both essential for bone formation.<p class="abst...

Vascular calcification (VC) involves hydroxyapatite deposition in the arteries and cardiac muscle. VC is thought to share some outward similarities to skeletal mineralisation and has been associated with the transdifferentiation of vascular smooth muscle cells (VSMCs) to an osteoblast-like phenotype. We have previously shown that ATP, UTP and synthetic ATP-analogues (α, β-meATP, β, γ-meATP, Bz-ATP) (≥1 μM) act to potently inhibit both bone minera...

Objectives: Differential diagnosis vs. Osteogenesis Imperfecta (OI).Methods: The parents were Moroccan origin, consanguineous. The patient is an 8 year old girl, who was visited for a first time in our hospital in October 2016, presenting a fracture of the left femur, with dramatic bone deformations, with important disability, unable to walk and with growth retardation (weight 15 kg, length: 92 cm). The first registered fracture is at birth, consisting o...

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...

Introduction: Although systemic lupus erythematosus (SLE) has traditionally been considered a disease of women, men may also be afected. Male osteoporosis is increasingly recognised. Several studies have reported that mean bone mineral density is significantly reduced in SLE women patients and most of them have low levels of vitamin D. The aim of our study is to analize this situation in men.Objectives: Determine 25-hydroxyvitamin-D (25OHD) serum concent...

To point out common patterns of malalignment and deformity in hypophosphatemic rickets and describe treatment principles and techniques as well as common obstacles.Methods: Deformities of the lower limb in hypophosphatemic rickets do not resolve spontaneously under metabolic control of the disease. To prevent severe deformity and joint overload in the growing child guided growth has been shown to be effective in most cases. As recurrence of malalignment ...

Osteoporosis pseudoglioma syndrome (OPPGS) is a rare autosomal recessive disorder characterised by congenital or juvenile-onset blindness, severe juvenile-onset osteoporosis, and skeletal fragility. OPPGS is caused by loss-of-function mutations in the LRP5 gene, a member of the LDL receptor family. It activates the canonical Wnt/β-catenin pathway, regulating osteoblastic bone formation. We investigated a 40-year-old Caucasian male presenting with congenital blind...