Bone Abstracts

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Classical osteogenesis imperfecta (OI) is caused by mutations in the two genes encoding type I collagen. OI is associated with low bone mass and abnormally high bone matrix mineralization. The Brtl/+ OI mouse is a knock-in model caused by a glycine substitution in one COL1A1 allele. Brtl/+ pups display 30% perinatal lethality; survivors have small size and brittle bone. Unexpectedly, homozygous Brtl/Brtl pups, producing only mutant collagen, have normal survival rates...

Hypoparathyroidism results in low bone turnover and increased bone mineral density (BMD). Replacing deficient PTH with rhPTH(1–84) has the potential to correct these skeletal abnormalities. To investigate the effect of rhPTH(1–84) on BMD and bone turnover markers (BTMs), data from two studies were assessed.REPLACE, a double-blind, multicenter, placebo-controlled study, randomized 134 patients with hypoparathyroidism to receive once-daily rhPTH(...

Purpose: To test whether bisphosphonates for osteoporosis reduce the risk of breast cancer.Background: Observational studies and meta-analyses find that women taking bisphosphonates have about a 1/3rd reduction in risk of breast cancer as soon as 1 year of treatment. This is plausible because bisphosphonates have in vitro anti-tumor activity and high doses of zoledronate reduce recurrence in women with breast cancer. However, observational studi...

Background: Hypercalcaemia secondary to malignancy is rare in children and adolescents. Parathyroid hormone related peptide (PTH-rP) secreted by malignant cells increases bone resorption and renal calcium retention causing hypercalcaemia. We report two cases of hypercalcaemia of malignancy refractory to treatment with pamidronate and corticosteroids but responsive to treatment with Denosumab and Zoledronic acid.Case 1: Presenting problem: A 17-year-old b...

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An increasing number of biomaterials are in development, seeking to mimic the natural cascade of events during fracture repair. However, these biomaterials need to be rigorously tested prior to clinical application. In vitro testing lacks the physiological environment, while in vivo studies do not always predict the patient response. Here we hypothesize that the chorioallantoic membrane (CAM) assay can be used to culture human living bone and we aim to examin...

Background: Hypophosphatasia is generally regarded as a disease of bone and teeth. Lack of Tissue Non-Specific Alkaline Phosphatase (TNAP) leads to an accumulation of inorganic pyrophosphate and the Vitamin B6 metabolite pyridoxal 5′-phosphate (PLP), a reduction in pyridoxic acid (PA) and increased PLP/PA ratio. Vitamin B6 deficiency in the brain impairs synthesis of neurotransmitters, and is a well-recognised cause of neonatal seizures. We have found no previous reports...

Background: There is still limited information on changes in growth especially segmental growth and bone mass of glucocorticoid(GC) treated boys with Duchenne Muscular Dystrophy (DMD).Objectives: To evaluate changes in growth and bone mass in GC treated boys with DMD.Methods: Retrospective study of 15 boys with DMD treated with GC, median age 7.6 years (4.1, 15.5) who had repeated DXA scan for clinical monitoring of bone health, me...

Bone fractures may depend on Vitamin D Receptor Gene (VDR), bone mineral density, bone turnover markers.Patients and methods: About 161 patients were recruited and underwent: skeletal densitometry (DXA) method and bone turnover studies (Osteocalcin and Ntx).The study group was evaluated using restriction enzyme digestion at BsmI (rs1544410), FokI (rs2228570), ApaI (rs7975232) and TaqI (rs731236), polymorphic sites of t...