Bone Abstracts

Background: Genetic disorders of mineral metabolism causing nephrolithiasis and bone abnormalities are uncommon and have a varied clinical spectrum. Hypophosphataemic rickets with hypercalciuria (HHRH) is a rare autosomal-recessive condition, typically presenting with severe rickets and hypophosphataemia. Milder forms can present with hypercalciuria and nephrolithiasis without bone disease. The underlying pathophysiology is due to mutations in the SLC34A3 gene, which encodes t...

Extracellular nucleotides, signalling through P2 receptors, play a significant role in bone biology. ATP and ADP act via the P2Y1 or P2Y12 receptors to promote osteoclast formation and activity. Bone cells express the P2Y2 receptor and, in osteoblasts, it plays a role in regulating bone mineralisation. This investigation examined the role of the P2Y2 receptor in osteoclasts. Primary osteoclasts were isolated from the bone ma...

Vitamin D deficiency is common in older persons and non-western immigrants. Vitamin D is often started in loading doses of 50 000 IU/ml solution. Though, generally considered safe, this highly concentrated solution carries some risks as is illustrated by the following cases. A woman of >80 years old was admitted with hypercalcemia, calcium 3.27 mmol/l. She complained of nausea, thirst and polyuria for 3 months. History included cholecystitis, atrial fibrillation, myocardia...

Introduction: Osteoblast lineage cells express glutamate receptors and secrete glutamate, which acts as an autocrine factor to promote cellular differentiation and activation. However, the mechanisms by which glutamate regulates these functions, remain unclear.Methods: Primary osteoblasts were isolated from calvaria of 2–3 days old mice. The cells were treated with inhibitors of glutamate transporters, namely the Scl1a1 and Scl1a3 inhibitor L...

The in vitro culture of calvarial osteoblasts from neonatal rodents remains an important method for studying the regulation of osteoblast function. Widespread use of transgenics has created a particular need for a reliable, simple method that allows the differentiation and bone-forming activity of mouse osteoblasts to be studied directly. We have established such a method and have identified key differences in optimal culture conditions between mouse and rat osteoblas...

Strontium ranelate (SrR) is now widely used for the prevention of osteoporotic fractures. The mechanisms by which this occurs, however, remain unclear. We investigated the actions of Sr2+ salts in bone-forming cultures of primary osteoblasts from rat calvariae. Osteoblasts were treated continuously with either SrR or SrCl2 for 14 days. Abundant, discretely mineralised ‘trabecular’ bone structures formed in alizarin red-stained control cultures. ...

Background: Defects in 1-α-hydroxylase enzyme activity result in reduced activity of 1,25(OH)2D causing vitamin D dependent rickets. Physiologically FGF23 levels are stimulated by a rise in 1,25(OH)2D which in turn suppresses 1-α-hydroxylase expression to complete the feedback loop.Presenting problem: A 15-month-old Irish Caucasian girl was referred by her GP for failure to weight bear. She was born at term via elective se...

Type 2 diabetes mellitus prevalence increases with age and the disease predisposes to increased risk of fractures and skeletal complications. One possible contributor to skeletal weakening in diabetes is a decline in blood supply. We hypothesised that bone blood flow is impaired in diabetic mice and that chronic administration of glucagon-like peptide-1 receptor agonists (GLP-1RA) can increase blood flow to bone, thereby stimulating bone formation and improving bone architectu...

Objectives: To ascertain if parents and consultants at secondary care level hospitals felt there were areas that the Clinical Nurse Specialists (CNS), working with children and families with Osteogenesis Imperfecta (OI) could improve upon within their service, and to gain feedback on the current service provided.Methods: A SurveyMonkey© questionnaire was created through the audit team at Great Ormond Street Hospital and the Paediatric Ost...

Parathyroid hormone (PTH) is used to stimulate bone formation in osteoporotic patients, however concerns have been raised about the quality of the matrix produced since lower levels of total matrix mineral have been reported in osteoporotic and fracture patients treated with PTH. High resolution synchrotron-based Fourier Transform Infrared Microscopy (sFTIRM) was used to determine mineral content in age-matched bone during anabolic PTH treatment, using the simplified lamellar ...