Bone Abstracts

Introduction: Lymphoblastic leukemia is the predominant form of childhood malignancies with survival rates of >80%. Late effects of cancer and treatment can affect endocrine function and may account for acute and chronic impairment of bone health.Aim and design: To assess bone health in pediatric patients after therapy for lymphoblastic leukemia we initiated a clinical trial investigating clinical and biochemical parameters of growth, puberty, bone t...

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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...

Mutations in LRP5 cause a variety of phenotypes, including high bone mass and low bone mass disorders. In patients with high bone mass, different heterozygous mutations have been described, all of them clustering in a region including the binding pocket for DKK1 and sclerostin. The pathogenic mechanism is thought to be a gain-of-function mediated by an impaired inhibition of the canonical Wnt signalling pathway, thereby leading to increased bone modelling.<p class="abstext...

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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...