Searchable abstracts of presentations at key conferences on calcified tissues

ba0001pp205 | Cell biology: osteoblasts and bone formation | ECTS2013

Thrombin receptor deficiency leads to osteopetrosis by decreasing the RANKL/OPG ratio

van der Eerden BCJ , Tudpor K , Jongwattapapisan P , Woudenberg-Vrenken TE , Bindels RJM , Hoenderop JGJ , van Leeuwen JPTM

Communication between osteoblasts and osteoclasts is crucial for bone remodeling. Thrombin and its thrombin receptor (TR; PAR-1) are expressed in osteoclasts and osteoblasts, respectively. To date, the physiological roles of thrombin and TR in bone metabolism have not been elucidated. Therefore, we fully characterized the bone phenotype of mice lacking the thrombin receptor.We performed bone microarchitectural analyses of the femurs of 10–12 week ol...

ba0002p120 | (1) | ICCBH2013

Osteoblasts communicate with their neighbouring cells via extracellular vesicles

Morhayim Jess , Demmers Jeroen , de Jong Ton , Braakman Eric , de Peppel Jeroen van , Cornelissen Jan , van Leeuwen Hans

Objectives: Strong coordination between osteoblasts and bone marrow cells is fundamental for the regulation of healthy bone turnover and other (patho)physiological processes. Extracellular vesicles (EVs) mediate communication between cells via horizontal transfer of proteins and nucleic acids. Osteoblasts secrete EVs in the form of matrix vesicles involved in bone mineralization, however, information about a role in intercellular communication is still lacking. In this study, ...

ba0005p83 | Bone Matrix | ECTS2016

Cortical bone matrix mineralisation is decreased in TRPV4 deficient male, but not in female mice

Roschger Paul , Misof Barbara , Fratzl-Zelman Nadja , Hoenderop Joost , Bindels Rene , van Leeuwen Johannes , Klaushofer Klaus , van der Eerden Bram

Transient receptor potential vanilloid channels (TRPVs) have been implicated in Ca2+ homeostasis and bone metabolism. In particular, TRPV4 deficiency was shown to cause sexual dimorphism in bone metabolism and osteoporotic fracture risk. Cortical bone structure was reported to be altered in male TRPV4 knock-out (TRPV4−/−) mice but not in female TRPV−/− mice compared to sex-matched wildtype (TRPV4+/+) animals.To gain knowledge on t...

ba0003oc2.2 | Osteoporosis epidemiology | ECTS2014

Effect of daily vitamin B12 and folic acid supplementation on fracture incidence in elderly with an elevated plasma homocysteine level: B-PROOF, a randomized controlled trial

van Wijngaarden JP , Swart KMA , Enneman AW , Dhonukshe-Rutten RAM , van Dijk SC , Ham AC , Brouwer-Brolsma EM , van der Zwaluw NL , Sohl E , van Meurs JBJ , Zillikens MC , van Schoor NM , van der Velde N , Brug J , Uitterlinden AG , Lips P , de Groot CPGM

Background: Elevated plasma homocysteine levels are a risk factor for osteoporotic fractures. Supplementation with vitamin B12/folic acid lowers homocysteine levels. This study aimed to determine whether vitamin B12/folic acid supplementation reduces osteoporotic fracture incidence in hyperhomocysteinemic elderly.Methods: B-PROOF is a double-blind, randomized, placebo-controlled trial including 2 919 participants aged ≧65 years with elevated homocyste...

ba0001pp265 | Chondrocytes and cartilage | ECTS2013

Decrypting TGFβ signaling in age-induced osteoarthritis

de Vinuesa Amaya Garcia , Blaney-Davidson Esmeralda , Sanchez-Duffhues Gonzalo , van Caam Arjan , Vitters Elly , Meulenbelt Ingrid , Goumans Marie Jose , van der Kraan Peter , ten Dijke Peter

Destruction of the articular cartilage is the major feature of Osteoarthritis (OA). Ageing is the primary risk factor, but how ageing results in OA is still an enigma. In OA, articular chondrocytes degrade their own matrix, while in healthy articular cartilage they preserve it.Transforming growth factor β (TGFβ) is a central regulator of chondrocyte proliferation, differentiation and extracellular matrix production. Deregulation of TGFβ si...

ba0005oc1.5 | Clinical trials and osteoporosis treatment | ECTS2016

Secular trends in prescription incidence of different anti-osteoporotic drugs in the UK population aged 50 years or above from 1990 till 2012

van der Velde Robert , Wyers Caroline , Geusens Piet , van den Bergh Joop , de Vries Frank , Cooper Cyrus , vandeStaa Tjeerd-Pieter , Harvey Nicholas

Objective: To study the trends in prescription of different anti-osteoporotic drugs (AOD) in the UK population aged 50 years or above from 1990 till 2012.Methods: Retrospective observational study using the CPRD data link representative for the total UK population. The incidence of prescription of a specific AOD was calculated by dividing the number of prescriptions by the total person-years (py) of follow-up.Results: AOD prescript...

ba0001pp268 | Genetics | ECTS2013

No mutations in the serotonin related TPH1 and HTR1B genes in patients with monogenic sclerosing bone disorders

Boudin Eveline , Jennes Karen , de Freitas Fenna , Tegay David , Mortier Geert , Van Hul Wim

Since the identification of LRP5 as the causative gene for the osteoporosis pseudoglioma syndrome (OPPG) as well as the high bone mass (HBM) phenotype, LRP5 and the Wnt/β-catenin signalling have been extensively studied for their role in the differentiation and proliferation of osteoblasts, in the apoptosis of osteoblasts and osteocytes and in the response of bone to mechanical loading. However, more recently the direct effect of LRP5 on osteoblasts and bone formation has...

ba0001pp305 | Muscle, physical activity and bone | ECTS2013

Associations of 25-hydroxyvitamin D concentrations with quality of life and self-rated health

Rafiq Rachida , Swart Karin , van Schoor Natasja , Deeg Dorly , Lips Paul , de Jongh Renate

Introduction: Vitamin D deficiency has been associated with impaired physical functioning and several chronic diseases and might thereby affect quality of life and self-rated health. The aim of this study was to assess relationships of serum 25-hydroxyvitamin D (25(OH)D) with quality of life and self-rated health, and to examine whether physical performance and number of chronic diseases mediate these relationships.Methods: Data were obtained from the LA...

ba0002p48 | (1) | ICCBH2013

Pubertal induction with testosterone of a boy with bilateral anorchia guided by the development of his monozygotic twin brother

Van Caenegem Eva , Vandewalle Sara , Taes Youri , Kaufman Jean-Marc , Craen Margarita , Guy T'Sjoen

Introduction: We describe a monozygotic twin pair, of which one boy was diagnosed with anorchia. Both were followed-up till age 17.Case report: At birth, in one twin 46 XY boy (A), testes were not palpable while his brother (B) was unaffected. Stimulation with human chorionic gonadotrophin (hCG) and orchidopexia were unsuccessful at age 3. A second hCG-stimulation test was performed at age 8, where serum testosterone response failed to increase. No testi...