Bone Abstracts

Bruck syndrome, a disorder caused by bi-allelic mutations in either PLOD2 or FKBP10, is characterized by flexion contractures and bone fractures and shows strong clinical overlap with the brittle bone disease Osteogenesis Imperfecta. PLOD2 encodes the Lysyl hydroxylase 2 (LH2) enzyme, which is responsible for the hydroxylation of lysine residues in the type-I collagen telopeptides. This hydroxylation directs cross-linking of the collagen fibrils in t...

A mixture of Galacto-oligosaccharides (GOS) and Fructooligosaccharides (FOS) are added to commercial infant formula to promote an intestinal microbiota similar to that prevalent in breast-fed infants to improve Ca bioavailability and general health, but their mechanisms are under debate.Our objective was to evaluate the beneficial effects of the mixture of GOS/FOS added to infant formulae, on the absorption of Ca, Mg and P of a low Ca diet. Changes in in...

Autosomal dominant hypophosphatemic rickets (ADHR) is a hereditary disorder characterized by isolate renal phosphate wasting, hypophosphatemia, and inappropriately normal 1,25(OH)2D3 levels. ADHR is caused by mutations in FGF23 protein that actively regulates phosphate homeostasis. In contrast to X-linked dominant hypophosphatemic rickets, ADHR shows incomplete penetrance, variable age at onset, and in rare cases resolution of the phosphate-wasting defect...

The effects of prolactin on bone metabolism have been the subjects of several studies. It is believed that prolactin acts directly influencing the synthesis of bone matrix by stimulating the osteoblastic activity, since receptors for this hormone have been identified in osteoblasts and human mesenchymal stem cells (MSCs). However, no study on the effects of prolactin on the osteogenic differentiation of MSCs was found in the literature. The objective of this study was to verif...

Objective: To analyze the effects of statins on bone mineral density (BMD), in participants from a large population-based cohort.Subjects and methods: We studied 2315 subjects (1422 women and 893 men) from the Camargo Cohort, and analyzed the differences in BMD between statin or non-statin users. We also studied the effect of the type of statin, dose, pharmacokinetic properties, and length of treatment, on BMD.Results: Four hundred...

Objectives: Erythropoietic protoporphyria (EPP) is a rare disease with cutaneous photosensitivity, in which patients avoid sun exposure and use sunscreen. Our purpose was to study bone mineral density (BMD), serum 25-OHD levels and other mineral parameters, to evaluate the impact of these measures in the follow-up of EPP patients.Patients and methods: A ten EPP patients (median age 25; range 22–55, four males and six females), were study for clinica...

Introduction: Osteopenia is a well-known complication of anorexia nervosa (AN) in older adolescents and adults, especially in those with a long duration of the disease and a severe underweight.Aim: We investigated whether young premenarchal girls with AN have similar risk factors for a disturbed bone growth and mineralization.Methods: Twenty-four female premenarchal AN patients as well as 24 age and height matched female controls u...

Introduction: Umbilical cord blood (UCB) is increasingly used in hematopoietic stem cell (HSC) transplantations; however, the low cell numbers are still remaining as a limiting factor for proper engraftment. Osteoblasts are major constituents of HSC niche and play important roles in regulating HSC self-renewal and differentiation. Recently, extracellular vesicles (EVs) have been implicated in stem cell fate regulation via horizontal transfer of proteins and nucleic acids betwe...

IGF1 is an osteo-anabolic factor that stimulates osteogenic precursor cell differentiation. IGF1 is produced in bone in response to mechanical stimulation, but also in mechanically-stimulated muscle cells. IGF1 enhances the rate of mRNA translation in muscle cells via activation of the PI3K/AKT/mTOR pathway, thereby increasing in muscle mass. Therefore we hypothesized that IGF1 not just enhances osteogenic differentiation of precursors, but also stimulates protein syn...

Background: Patients with differentiated thyroid cancer (DTC) are treated with L-thyroxine (L-T4) in relatively hight doses to suppress endogenous TSH levels. Very long-term effect of thyroid hormones supplementation on bone are controversial.Objetive: To study the possible negative effects on bone mineral density (BMD) and bone markers in DTC patients followed in our center.Methods: A 46 po...