Bone Abstracts

Objectives: Examine the effects of a ramped dosage schedule of pamidronate on BMD, fracture rate and location compared to a uniform 5-course regimen. The ramping regimen is intended to alter the tendency for post-treatment fractures to occur at the juncture of pamidronate bands where stress-riser related fractures have been described.Methods: Ten non-ambulatory children (seven females) with neuromuscular disabilities who received IV pamidronate with a ta...

Objectives: To assess the effects of short-term vitamin D supplementation on bone metabolism, glycaemic status and immune function in vitamin D deficient children.Method: Treatment with daily 5000 IU cholecalciferol supplementation for 6 weeks. At baseline and end of treatment serum 25 hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), alkaline phosphatase (ALP), serum collagen type 1 cross-linked C-telopeptide (CTX), serum calcium, HbA1c, sex hormon...

Bone damage is one of the main unfavourable health effects of chronic exposure to cadmium (Cd). This heavy metal stimulates osteoclastic bone resorption and inhibits osteoblastic bone formation resulting in decreased bone mineralization and as a result weakening of the bone biomechanical properties. Recently, using a rat model of chronic human exposure to cadmium, we have revealed that even low exposure to this metal may increase bone vulnerability to fracture. Taking into acc...

The Runt-domain transcription factors Runx2 and Runx3 are known to drive chondrocyte maturation from prehypertrophic to the terminal stage. The RUNX family proteins form dimers with CBFb, and bind to consensus sequences of 5′-PuACCPuCa-3′ upstream of target genes to activate or repress transcription.To address the role of Runx3 transcription factor in zebrafish, we have isolated the different splice variants encoding distinct runx3 p...

Background: Recently, the prevalence of osteoporosis and sarcopenia in the elderly has dramatically increased. However the relationship between theses disease is not clear.Object: We aimed to determine the independent relations of muscle mass to osteoporosis (femur neck) in relation to body weight, fat mass, and other confounders.Design: We analyzed body composition and BMD data of 570 males and 734 females who are older than 65 ye...

Background: Genetic disorders of mineral metabolism causing nephrolithiasis and bone abnormalities are uncommon and have a varied clinical spectrum. Hypophosphataemic rickets with hypercalciuria (HHRH) is a rare autosomal-recessive condition, typically presenting with severe rickets and hypophosphataemia. Milder forms can present with hypercalciuria and nephrolithiasis without bone disease. The underlying pathophysiology is due to mutations in the SLC34A3 gene, which encodes t...

Background: Children with special needs may be greater risk of vitamin D deficiency due to decreased mobility and outdoor play, concomitant medications that increase catabolism of vitamin D, reduced nutritional intake and low body weight. Gastrostomy-fed children receiving a nutritionally complete formula may still be at risk of vitamin D deficiency due to the above factors.Objective: The objective of this study is to assess the vitamin D status of speci...

Background: Fibrodysplasia ossificans progressiva (FOP) is a rare condition characterised by congenital malformation of the great toes and progressive heterotopic endochondral ossification. The disease progresses with episodic flare-ups, resulting in disabling cumulative immobility. The discovery of the ACVR1 gene as the cause of FOP has allowed identification of therapeutic targets. Palovarotene, a retinoic acid receptor gamma agonist, is in phase 2 clinical trials.<...

Delta-like 1/fetal antigen-1 (DLK1/FA1) is a negative regulator of bone mass in vivo as it inhibits osteoblast (OB) and stimulates osteoclast differentiation. However, the molecular mechanisms underlying these effects are not known. Thus, we studied the effect of DLK1/FA1 on different signaling pathways known to regulate OB differentiation. We identified DLK1/FA1 as an inhibitor of BMP2-induced OB differentiation. Stable overexpression of DLK1/FA1 in C2C12 cells or th...

Background: Infantile hypercalcemia occurs in ~15% of patients with Williams Syndrome (WS) and is typically mild. Severe hypercalcemia has been reported in infants/toddlers with WS, requiring treatment with intravenous (IV) saline hydration, furosemide, calcitonin, calcium and vitamin D restriction, and in some cases IV bisphosphonates.Presenting problem: Three cases of infants with WS age 9–13 months presented with severe hypercalcemia, failure to ...