Searchable abstracts of presentations at key conferences on calcified tissues

ba0003pp355 | Osteoporosis: treatment | ECTS2014

Continuous modelling-based bone formation could explain sustained increases in hip bone mineral density with denosumab treatment

Ominsky Michael S , Libanati Cesar , Boyce Rogely , Kostenuik Paul J , Baron Roland , Wagman Rachel B , Dempster David W

In clinical studies, denosumab (DMAb) administration up to 8 years is associated with continued increases in bone mineral density (BMD) and low fracture incidence despite persistently low bone turnover markers and limited iliac crest tetracycline labelling (Papapoulos 2013). We tested the hypothesis that, with persistently low bone remodelling, BMD increases may result from a non-remodelling dependent mechanism to accrue bone matrix. We examined the fluorochrome labelling patt...

ba0003pp364 | Other diseases of bone and mineral metabolism | ECTS2014

Hypophosphatasia: a retrospective natural history study of the severe perinatal and infantile forms

Whyte Michael , Leung Edward , Wilcox William , Liese Johannes , Reeves Amy , Melian Agustin , Odrljin Tatjana , Zhang Hui , Hofmann Christine

Background: Hypophosphatasia (HPP) is caused by inactivating mutation(s) in the gene for tissue non-specific alkaline phosphatase. Extracellular accumulation of inorganic pyrophosphate can lead to profound hypomineralization resulting in limb and chest deformity, respiratory complications and vitamin B6-dependent seizures in the severe forms of HPP. The natural history of HPP is poorly understood, but the perinatal and infantile forms are often considered lethal.<p class="...

ba0004p103 | (1) | ICCBH2015

Gait assessment in children with childhood hypophosphatasia: impairments in muscle strength and physical function

Phillips Dawn , Griffin Donna , Przybylski Tracy , Morrison Erica , Reeves Amy , Vallee Marc , Fujita Kenji , Madson Katherine , Whyte Michael

Objectives: Hypophosphatasia (HPP) is the rare inherited metabolic disease caused by low tissue nonspecific alkaline phosphatase activity. HPP manifests a wide spectrum of complications, which may include HPP-related rickets and compromised physical function in children.Methods: We report on clinical gait assessments based on archival video recordings of six children with onset of HPP symptoms at ≧6 months and documented HPP-related skeletal abnor...

ba0004p136 | (1) | ICCBH2015

A modified performance-oriented mobility assessment tool for assessing clinically relevant gait impairments and change in children with hypophosphatasia: development and validation

Phillips Dawn , Griffin Donna , Przybylski Tracy , Morrison Erica , Reeves Amy , Vallee Marc , Fujita Kenji , Madson Katherine , Whyte Michael

Objective: Mobility is an important endpoint in patient care with implications for activities of daily living, community participation, and quality of life. We adapted the performance-oriented mobility assessment (POMA-G),1 a widely used and validated clinical gait assessment tool for adults, to use in children with hypophosphatasia (HPP). HPP is the rare metabolic disease caused by loss-of-function mutation(s) in the gene encoding tissue non-specific alkaline phosp...

ba0005p59 | Bone development/growth and fracture repair | ECTS2016

Midkine is involved in the pathogenesis of delayed osteoporotic fracture healing after ovariectomy in mice

Haffner-Luntzer Melanie , Kemmler Julia , Heidler Verena , Prystaz Katja , Schinke Thorsten , Amling Michael , Ignatius Anita , Liedert Astrid

Previous studies demonstrated a negative influence of the growth- and differentiation factor midkine (MDK) on bone formation during bone remodeling and fracture healing. Additionally, MDK-deficiency protected mice from a loss of trabecular bone mass after ovariectomy (OVX). Therefore, we hypothesized that MDK may also be involved in the pathogenesis of delayed, osteoporotic fracture healing after OVX in mice. Thus, we analyzed the expression of MDK during bone regeneration and...

ba0005p88 | Calciotropic and phosphotropic hormones and mineral metabolism | ECTS2016

Trabecular (Spine) bone density increases significantly in the first 6 months after weaning (Factors Affecting Bone Formation After Breastfeeding Pilot Study (FABB-Pilot))

Cooke-Hubley Sandra , Mugford Gerry , Valcour James , Wahl Michael , Woodrow Janine , Adachi J D , Kovacs Christopher S

Breastfeeding women resorb trabecular bone to supply much of the calcium content of milk. Few studies have examined the speed and extent of BMD recovery after weaning, or the factors that predict a greater post-lactation increase in BMD. We hypothesize that weight-bearing, nutrition, hormones, and other factors facilitate bone formation after lactation.The aims of the Factors Affecting Bone Formation After Breastfeeding Pilot Study (FABB-Pilot) were to d...

ba0005p337 | Osteoporosis: pathophysiology and epidemiology | ECTS2016

Longitudinal increase in vitamin D binding protein levels after initiation of tenofovir/lamivudine/efavirenz therapy among HIV-infected individuals

Hsieh Evelyn , Fraenkel Liana , Han Yang , Xia Weibo , Insogna Karl , Yin Michael , Zhu Ting , Cheng Xinqi , Li Taisheng

Tenofovir disoproxil fumarate (TDF) is a critical component of first-line antiretroviral regimens for HIV worldwide. However, TDF-containing regimens have been associated with decreased bone mineral density and increased fracture risk, which may in part be mediated through secondary elevations in parathyroid hormone (PTH). Prior cross-sectional data suggest vitamin D binding protein (DBP) levels may increase with TDF exposure leading to a functional vitamin D deficiency, which...

ba0006oc24 | (1) | ICCBH2017

KRN23 effects on phosphate and vitamin D dysregulation in children <5 years old with X-Linked Hypophosphatemia (XLH)

Imel Erik , Carpenter Thomas , Gottesman Gary S , Martin Javier San , Mao Meng , Skrinar Alison , Whyte Michael P

Objectives: XLH features renal phosphate (Pi) wasting, hypophosphatemia, rickets, and skeletal deformities from elevated circulating levels of fibroblast growth factor 23 (FGF23). KRN23, an investigational fully human monoclonal antibody, binds FGF23 and inhibits its action. Our Phase 2 study of KRN23 in XLH children (ages 5–12 years) is demonstrating improvements in serum Pi and rickets. Here we present our Phase 2 trial evaluating the efficacy and safety of KRN23 in you...