Bone Abstracts

Background: Primary de Toni-Debré-Fanconi syndrome is a metabolic disorder characterized by hypophosphatemic rickets or osteomalacia, renal tubular acidosis, renal glycosuria, generalized aminoaciduria. It is a non-FGF23-mediated hypophosphatemic disorder, with primary defect in proximal tubular dysfunction. The orthopaedic sequela of this rare disorder in the literature is scarce.Presenting problem: We present a clinical case of a 10-year-old femal...

Introduction: In 1979 Sillence described Type II OI as perinatal lethal. We report two children whose features were consistent with Type II OI who survived beyond infancy. Both have mutations previously reported in cases of lethal OI.Case 1: This girl was born full term, small for gestational age (SGA) following antenatal detection of short bowed femora. Skeletal survey showed multiple long bone fractures and a small chest with beaded ribs. A COL1A2 gene...

Objective: GH through IGF1 plays an important role in both bone growth and mineralization. This cross-sectional study was carried out to evaluate the relationship between serum IGF1 concentrations and dual energy X-ray (DXA) measured total body less head (TB) bone area (BA), lean body mass (LBM) and bone mineral content (BMC).Methods: One hundred and nineteen children (B=70, age =7.3–15.6 years) were studied for their anthropometric paramet...

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...

Objectives: Bone mineral density (BMD) in children is generally measured with dual energy X-ray absorptiometry (DXA). Digital X-ray Radiogrammetry (DXR) is a promising alternative technique, that uses BoneXpert software to measure cortical BMD on hand radiographs, expressed as bone health index (BHI). DXR is a cheap method, is easy to apply in every hospital and involves less ionizing radiation compared to DXA. We aim to compare DXR and DXA measurements for determining bone de...

Bone remodeling is a crucial process to maintain a healthy bone structure in order to avoid diseases like osteoporosis or osteopetrosis. Osteoclasts contribute to this process by resorbing old and brittle bone allowing osteoblasts to renew the bone substance. During resorption osteoclasts rearrange their actin cytoskeleton by forming an F-actin ring generating a resorptive cavity on the bone surface. Recently, we reported that the F-actin binding protein SWAP-70 regulates oste...

Recent studies have demonstrated that the global or osteoblast-specific deletion of neuropeptide Y Y1 receptor (Y1R), as well as the pharmacological blockade of Y1R, leads to pronounced anabolic effects in bone metabolism. This suggests that anti-Y1R drug therapy might have clinical applications for the prevention/recovery of bone loss occurring in osteoporosis. Given the high fracture incidence in this target population, it remained...

Aim: Lean mass is a strong determinant of bone structure, particularly during growth and development. We sought to determine if there are sex differences in bone acquisition in pre-pubertal children and the potential relation with skeletal loading.Methods: This study included 3602 children (50.7% girls) whose total body BMD and hip scans were measured on the same iDXA devise (GE-Lunar) at 6 years of age. Hip scans underwent hip structural analysis (HSA) ...

Multiple myeloma (MM) bone disease is characterized by lytic bone lesions that contribute to patient morbidity and mortality after patients are in complete remission. The mechanisms mediating this long-term osteoblast (OB) suppression are poorly understood. We hypothesized that MM cells induce epigenetic changes at the Runx2 promoter in preOB bone marrow stromal cells (BMSC). We demonstrated that Gfi1, a transcriptional repressor of Runx2 that is induced in B...

Background: Low total body BMD (TB-BMD) is an established risk factor for fractures in healthy children. However, bone strength depends not only on bone mass and density, but also on the structural geometry of bones. Hip structural analysis (HSA) is a technique applied on hip DXA scans to calculate several bone geometry parameters. The aim of our study was to evaluate other bone geometrical parameters that can constitute determinants of fracture risk. Specifically, we examined...