Bone Abstracts

Several environmental and genetic factors are determinant, also including sex, hormonal, ethnics, nutritional and lifestyle, may interferer on bone mass of children. However, the pediatric studies that approach the socioeconomic status and the quantitative ultrasound parameters (QUS) are scarce. The aim of this study was to compare the socioeconomic status on bone mass assessed by QUS in boys from 7 to 15 years old. In this cross-sectional study, were evaluated 520 Brazilian b...

Osteocytes make up >90% of bone cells, are embedded in mineralised matrix where they form a communication network. Osteocytes differentiate from osteoblasts, and are mechano-sensitive. They are very difficult to isolate with a dependence on cell lines for in vitro studies of osteocyte biology. Therefore new methods to study these cells are essential. Recent publications indicate that osteoblasts maintained in in vitro 3D collagen gels may differentiate to...

Objectives: XLH features renal phosphate (Pi) wasting, hypophosphatemia, rickets, and skeletal deformities from elevated circulating levels of fibroblast growth factor 23 (FGF23). KRN23, an investigational fully human monoclonal antibody, binds FGF23 and inhibits its action. Our Phase 2 study of KRN23 in XLH children (ages 5–12 years) is demonstrating improvements in serum Pi and rickets. Here we present our Phase 2 trial evaluating the efficacy and safety of KRN23 in you...

Objectives: Vitamin D deficiency is of current interest especially in high risk patients for reduced bone mineral density as in pediatric hematologic oncologic patients.Methods: During a 4 year period 194 pediatric hematologic oncologic patients were screened for serological vitamin D deficiency (defined as 25 (OH)D levels <30 ng/ml and accordingly <75 nmol/l). 61 patients were in the prospective group 1 defined as screening at time of diagnosis,...

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Background: Morquio disease was described by the Uruguayan pediatrician Luis Morquio. It’s a congenital disease caused by a deficiency of the N-acetilgalactosamine 6 sulfatase (MPS IV A) or B galactosidase (MPS IV B) and his frequency is 1/100 000 live births Accumulation of mucopolysacharides in tissues results in short stature, skeletal anomalies (vertebral column deformities), loss of hearing, visual anomalies (corneal opacities), cardiac, hepatic and respirat...

Background: Achondroplasia is a genetic disorder wich affects bone growth leading to short stature. It occurs in 1 of every 25 000 live births and it is characteristized by short extremities, hyperlordosis, small hands and macrocephaly, with high forehead and saddle nose. Neurologic complications are due to narrowing of the vertebral foramen. Is transmitted as autosomal dominant and it is due to mutations of the FGFR3 gene witch codifies the fibroblastic receptor of G...

Background: Pseudohypoparathyroidism is characterized by a resistance to parathormone, with variable phenotypical and biochemical manifestations. With genetic disorder caused by heterozygous inactivating mutations in GNAS1, the gene encoding the alpha-chain of G(s), and is associated with short stature, obesity, brachydactyly, and sc ossifications. AHO patients with GNAS1 mutations on maternally inherited alleles also manifest resistance to multiple hormones (e.g. PTH, TSH, LH...

Introduction: Albright-McCune Sternberg syndrome (SAMS) is a rare disorder which originates in a germinal mutation of gene GNAS1, which codifies the alpha subunit of protein G (Gsa). It is characterized by a typical phenotype which includes polyostotic fibrodysplasia, precocious puberty independent from gonadotropins, cafe-au-lait spots and a series of endocrine abnormalities. The most common mutations include a cysteine or histidine for arginine substitution in codon 201 of e...

Osteosarcoma is the most frequent primary bone tumor that develops mainly in young adults. The survival rate at 5 years is below 30% for patients with poor response to treatment or with metastasis.The histones modifications are of critical importance in maintaining the transcription program of both normal and tumor cells. The bromodomain and extra-terminal domain (BET) protein family is an important class of ‘histone reading protein’ capable to...