Bone Abstracts

Objectives: Conventional wisdom suggests that bone is most responsive to physical activity during the growing the years, especially the period just before puberty. Few studies have addressed the entire period of adolescence and even fewer have done so using bone imaging techniques to capture structural outcomes which contribute to bone strength. Using a well-defined cohort (The Iowa Bone Development Study, IBDS), this report examined the magnitude and consistency of the associ...

The relationship between vitamin D status and lean mass accretion in young children is not well understood.Objective: To explore vitamin D status in relation to lean mass outcomes over 12 mo in children 2–8 years.Methods: This was a secondary analysis of trial data (clinicaltrials.gov: NCT02097160, NCT02387892) in Montreal, Canada. Children consumed their normal vitamin D intake for 6 mo (Apr–Oct 2014, n=39) and ...

Survival of chronic diseases in childhood is often achieved utilizing glucocorticoids. However, the survival comes at a cost to the growing skeleton, resulting in impairment in the acquisition of peak bone mass and is the major etiology of secondary osteoporosis in children. We recently found that preosteoclasts secrete platelet derived growth factor type BB (PDGF-BB) to promote angiogenesis and osteogenesis during both modeling and remodeling. As glucocorticoid therapy affect...

Objectives: Early-onset osteoporosis is characterized by low bone mineral density (BMD) and reduced bone strength since childhood or young adulthood. Although several monogenic forms have already been identified, the spectrum of mutations and genes behind this condition remain inadequately characterized. Furthermore, it is not clear whether genetic factors determine susceptibility to bone fractures in children with normal BMD. In order to further explore the genetic background...

Hypophosphatasia (HPP) occurs when there is lack of the activity of the alkaline phosphatase protein (ALP). The principal clinical manifestations are seen in the skeleton, although some infants can develop convulsions due to the failure of pyridoxine, cleaved from pyridoxal-5-phosphate by ALP, to enter brain cells.HPP has traditionally been classified by age at presentation, with severe forms being diagnosed in utero or at birth because of fract...

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune disease that usually affects women during the childbearing ages. The disease can affect any organ system and varies in its clinical manifestations and severity between individuals. The disease course is characterized by relapses and remissions.Because survival of SLE patients has improved dramatically over the last decades, attention is now more focused on complications of the disease...

GH is an important anabolic hormone involved in the regulation of longitudinal bone growth. However, acromegaly patients have a higher prevalence of vertebral fractures despite normal bone mineral density (BMD), suggesting that GH overexpression has adverse effects on skeletal architecture and strength. We used giant bovine GH (bGH) transgenic mice to analyse the effects of high serum GH levels on BMD, architecture and mechanical strength. Five month-old hemizygous male bGH mi...

The endocannabinoid system has important effects on bone mass and bone turnover. Mice with targeted inactivation of type 1 (CB1) and type 2 (CB2) cannabinoid receptors develop osteoporosis with increasing age raising the possibility that cannabinoid receptor agonists might protect against age-related bone loss. Since cannabis is the most widely used illegal drug and its main psychotropic component -Δ9-tetrahydrocannabinol (THC)- is an agonist at CB1 and CB2 receptors, we ...

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...

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...