Bone Abstracts

Osteoclasts are multinucleated giant cells derived from the monocyte/macrophage lineage in the presence of receptor activator of nuclear factor kappa-B ligand (RANKL) and colony-stimulating factor 1 (CSF1). The bone remodeling process in zebrafish is incompletely understood. Here we describe several methods to quantify bone formation and resorption using a zebrafish mutant that lacks functional colony stimulating factor 1a receptor (csf1ramh5/mh5). Mice deficient in...

Many disorders cause osteosclerosis, and many exclusively affect adults. Pediatricians are likely to encounter those that are Mendelian diseases, with most still classified as ‘dysplasias’ although now understood at the gene level. Thus, there is promise for defining their molecular and biochemical pathogeneses, and for developing targeted medical treatments. Sclerosing bone dysplasias too have become the ‘turf’ of the metabolic bone disease specialist. How...

Objectives: Different versions of the Childhood Health Questionnaire (CHAQ) have been used in Paediatric Rheumatology since 1994 to establish levels of functional disability. To date, use of the CHAQ has not been reported in Osteogenesis Imperfecta (OI). The aim of this study was to establish if disability scores generated from a modified CHAQ (MCHAQ) correlate with OI severity.Methods: The MCHAQ was developed to reflect the specific needs of children wi...

Hypoparathyroidism results in low bone turnover and increased bone mineral density (BMD). Replacing deficient PTH with rhPTH(1–84) has the potential to correct these skeletal abnormalities. To investigate the effect of rhPTH(1–84) on BMD and bone turnover markers (BTMs), data from two studies were assessed.REPLACE, a double-blind, multicenter, placebo-controlled study, randomized 134 patients with hypoparathyroidism to receive once-daily rhPTH(...

: In osteoporosis, poor adherence to bisphosphonate (BP) therapy is common, and is associated with poor outcomes and increased treatment costs (Siris 2006; Recker 2005). Although compliance is improved with monthly vs weekly dosing (Reginster 2008), no evidence suggests cycling through BP agents offers therapeutic benefit, assessed by bone mineral density (BMD). In two randomized, open-label studies in postmenopausal women aged ≥55 years previously treated with, but subo...

Objective: To evaluate musculoskeletal development using pQCT in children with coeliac disease (CD) on gluten free diet (GFD) compared with age and gender matched healthy controlsMethod: 38 children (18 males) with CD on GFD for a duration of 3.6 years (0.6, 12.5) underwent pQCT at 4%, 38 and 66% tibial sites. Bloods were collected in CD children only. Results reported as median (range).Result: Median TTG was 1.8 IU/l (0.1, 114) wi...

Objectives: To elucidate the incidence and risk factors of skeletal toxicity in children with ALL treated with the dexamethasone-based DCOG-ALL9 protocol.Methods: Prospectively, the cumulative incidence of fractures was assessed in 672 patients and compared between different subgroups using the log-rank test. Serial measurements of bone mineral density of the lumbar spine (BMDLS) were performed in 399 ALL patients using dual energy X-ray absor...

Background: Low vitamin D concentrations among children and adolescents at northern latitudes are frequently observed. Also, inverse associations between 25-hydroxyvitamin D (25(OH)D) and PTH concentrations have been found in children of different ages. More studies on the link between vitamin D status and childhood bone health are needed.Objective: To evaluate the status of serum 25(OH)D in autumn and the association between 25(OH)D concentrations and b...

Objectives: In XLH, musculoskeletal outcomes of current treatment with oral phosphate (Pi)/active vitamin D are suboptimal for many patients. In a Phase 2, open-label study, we tested the hypothesis that KRN23 improves rickets and functional outcomes in XLH children.Methods: Fifty-two children with XLH (ages 5–12 years at baseline) received KRN23 subcutaneously biweekly (Q2W) or monthly (Q4W). At study entry, most participants had received oral Pi/a...

Background: Proline and hydroxyproline account for ~25% of aminoacids in collagen., Prolidase (peptidase D (EC 3.4.14.9)), cleaves iminodipeptides with a C-terminal proline or hydroxyproline, playing a major role in collagen catabolism. Mice with prolidase deficiency (PD) present with varied phenotypes including reduced size compared to wild-type littermates. We measured structural and mechanical properties of bones in PD mice.Methods: Whole femurs from ...