Bone Abstracts

The relationship between bone formation and blood flow is unclear. Recently, PTH was reported to activate production of nitric oxide (NO), a potent vasorelaxing agent, in endothelial cells and we and others have confirmed a strong vasorelaxing action of PTH in vivo in the mouse. Here, we tested the hypothesis that a potent NO synthase inhibitor (L-NAME: NG-nitro-L-arginine methyl ester) may alter the effect of intermittent PTH (iPTH) on b...

see PP27....

The re-initiation of developmental processes in osteoarthritis (OA) has emerged with similarities to endochondral ossification; responsible for long bone development. We aimed to establish the role of the Wnt inhibitor, sclerostin in endochondral ossification, and its relationship with MEPE, a calcification inhibitor with potential downstream functions. Knee joints from male Str/ort (spontaneous OA) and age-matched CBA control mice were analysed at 8, 18, and 40+ weeks of age ...

Successful long-term, cementless fixation of human shoulder components in osteoporotic (OP) and osteoarthritic (OA) patients poses major challenges. The possibility that enhanced osseointegration may rely on both the region of bone targeted and its relationship with the vasculature remains unexplored. We hypothesise that bone cells derived from subchondral (SC), cortical (C) and trabecular (Trb) bone regions exhibit differing osteogenic potential, which will be diminished in b...

Effects of whole bone scaling on isolated osteoblast behaviours are unknown. Exhibiting a huge range in size, inbred canines are an ideal species to determine such relationships. We have therefore undertaken initial studies in both male and female red foxes (Vulpes vulpes), the most abundant and accessible wild canid member in the United Kingdom.Femoral heads were removed from five fresh red fox cadavers (see details on table) and bone fragments...

Hip osteoarthritis is a cause of significant morbidity to people and their canine companions. Medical management is frequently insufficient, leading to surgery to relieve pain and regain mobility. Hip replacements are not without potential complications, including loosening and infection. Currently, there is a focus on uncemented implants to decrease these problems, however these rely on the biology of the femur for osseointegration and long-term stability. It has been previou...

Effects of whole bone scaling on isolated osteoblast behaviour are unknown. With two orders of magnitude range in body mass, dog breeds are well-suited to determine such relationships.Femoral heads from three canine hip replacement surgeries were collected. Bone fragments were washed in PBS+AB/AM, trypsin-digested and incubated in 0.2% collagenase. Cells from resultant supernatant were seeded in DMEM+10% FCS+AB/AM at 37 °C, 5% CO2, g...

see P208....

Analysis of osteocyte function often uses promoter elements of osteocyte-specific genes i.e. SOST or Dentin-matrix-protein 1 (Dmp1) to overexpress genes or the Cre-recombinase for conditional deletion studies. However, evidence suggests that these promoters may not be osteocyte-specific, which would be critical for subsequent data interpretation. To investigate the selectivity of supposedly osteocyte-specific in vivo models, we crossed the 8kb-Dmp1-Cre mice (i) with A...