Bone Abstracts

Osteoclasts secrete acid and cathepsin K to dissolve the mineral and digest the organic matrix of bone, cartilage and dentine. The secretions are by necessity destructive and potentially harmful to the cell itself and are therefore trafficked through the cell in membrane bound vesicles. Secretion takes place over a specialised membrane compartment, the ruffled border, which is only present in resorbing osteoclasts. The ruffled border membrane and the vesicles in its vicinity h...

Osteoclasts are the only cell type capable of resorption of mineralised matrix such as bone or dentine. Resorbing osteoclasts form distinct membrane domains: the functional secretory, the basolateral and the ruffled border (RB) domains. The RB allows acidification of the resorption lacuna, exocytosis of osteolytic enzymes and uptake of degraded bone material, processes that require directed vesicular transport. Few studies have tried to classify the vesicles near the RB into s...

Introduction: Intracellular fat within muscle and visceral tissue has been suggested to adversely influence bone development.Design: We aimed to compare associations between intramuscular and subcutaneous fat and cortical bone outcomes in young adults, in cross-sectional analyses based on the Avon Longitudinal Study of Parents and Children.Method: Data were collected from a research clinic conducted at 17 years of age. Intramuscula...

Objective: The protein kinases, PKR, and PERK have been implicated in pro-inflammatory cytokine-mediated cartilage degradation in vitro and endoplasmic reticulum stress-induced arthritis respectively. The objective of this study was to establish whether loss of P58IPK, an inhibitor of PKR and PERK, results in a degenerative joint phenotype in vivo.Methods: Sections of knee joints from P58IPK-null and wild-type mice...

Objectives: Studies indicate that later puberty is associated with lower bone mineral density (BMD) in childhood. Less is known about effects of puberty timing on long-term bone accrual. We examined association between age at puberty and BMD accrual rate from 10 to 25 years.Methods: This was a prospective birth cohort of healthy largely European people born in southwest England in 1991–1992 and regularly follow-up from birth to mean age 25 years. Ag...

Hip development is influenced by mechanical loading during fetal movement by joint and reaction forces equivalent to several times bodyweight. These forces increase with fetal size and gestation length, and are lower in oligohydramnios and breech presentation which are both risk factors for developmental hip disorders. However, associations between indicators of prenatal mechanical loading and hip shape in later life remain unexplored. We therefore examined associations betwee...

Background and Objectives: The relations among cortical volumetric bone mineral density (CortBMD) and comprehensive measures of mineral metabolism have not been addressed in chronic kidney disease (CKD). The aim was to identify determinants of CortBMD in childhood CKD. A secondary objective was to assess if CortBMD was associated with subsequent fracture.Design/participants: This prospective cohort study in children, adolescents and young adults (ages 5&...

Objective: The main aim was to evaluate associations between muscular fitness indices and bone outcomes, including hip geometry estimates in young males.Methods: One hundred twenty one males (13.1±0.1 years) were included: 41 swimmers, 37 footballers, 29 cyclists and 14 non-athletes. Lean mass, areal bone mineral density (aBMD) and hip structural estimates were measured using dual-energy X-ray absorptiometry. Relationships of physical fitness tests ...

Objective: The main aim was to evaluate associations between cardiorespiratory fitness and bone outcomes, including hip geometry estimates in young males.Methods: One hundred twenty one males (13.1±0.1 years) were included: 41 swimmers, 37 footballers, 29 cyclists and 14 non-athletes. Lean mass, areal bone mineral density (aBMD) and hip structural estimates were measured using dual-energy X-ray absorptiometry. Relationships of physical fitness test ...

Objectives: Soft tissues, such as fat mass (FM) and lean mass (LM), play an important role in bone development but this is poorly understood in highly active youths. The objective of this study was to determine whether FM or LM is a stronger predictor of areal bone mineral density (aBMD) and hip geometry estimates in a group of physically active boys after adjusting for height, chronological age, moderate-to-vigorous physical activity (MVPA), FM, and LM....