Searchable abstracts of presentations at key conferences on calcified tissues

ba0004p64 | (1) | ICCBH2015

Peripubertal bone quality and density profile of Chinese adolescents in Hong Kong

Cheuk Ka Yee , Cheung Franco , Lee WayneY W , Hung Vivian , Tam Elisa , Lam Tsz Ping , Ng Bobby K W , Lee Simon K M , Cheng Jack C Y

Objectives: This study aimed to evaluate detailed bone profiles during puberty for Chinese adolescents in Hong Kong using high-resolution peripheral quantitative computed tomography (HR-pQCT) and dual-energy x-ray absorptiometry (DXA).Methods: 333 healthy girls and 231 healthy boys (12–16-years-old) were recruited from secondary schools. Areal bone mineral density (aBMD) of bilateral femoral necks were measured by DXA while bone quality parameters w...

ba0005p153 | Cell biology: osteoblasts and bone formation | ECTS2016

RhoA and ROCK regulate spreading of osteoblasts

Yang Seungwon , Kim Hyun-Man

When cells detach from or re-attach to the substrates, there is a drastic change in shape. Molecular mechanism by which controls shape upon cell attachment to the substrates was studied in osteoblastic MC3T3-E1 cells in vitro. Most striking feature found in the ovoid cells detached from the substrates was densely packed cortical actin bundles (CAB) encircling cells. Cells lost the CAB upon attachment and spreading on to the substrates. CABs were under control of small...

ba0004oc1 | (1) | ICCBH2015

Abnormal trabecular micro-architecture and bone mechanical properties in adolescent idiopathic scoliosis: a case–control study with high-resolution peripheral quantitative computed tomography and finite element analysis

Cheuk Ka Yee , Chen Huanxiong , Yu Fiona , Lam Tsz Ping , Lee Simon K M , Ng Bobby K W , Cheng Jack C Y

Adolescent idiopathic scoliosis (AIS) is associated with low bone mineral density (BMD) which has been reported to be an important prognostic factor for curve progression. In addition to BMD, high-resolution peripheral quantitative computed tomography (HR-pQCT) allows measurement of volumetric BMD, bone morphology, trabecular micro-architecture, and evaluation with structure model index (SMI) and finite element analysis (FEA) for mechanical property assessment. The aim of this...

ba0004op12 | (1) | ICCBH2015

A non-invasive method for screening vitamin D insufficiency for adolescents using skin colourimetry

Lam Tsz Ping , Lee Wayne Y W , Cheung Franco T F , Tsang Echo K L , Wong Lyn L N , Lee Simon K M , Ng Bobby K W , Cheng Jack C Y

Introduction: Effective screening for vitamin D (Vit-D) insufficiency is desirable. Pigmentation of unexposed (constitutive) skin and exposed (facultative) skin can be measured with skin colourimetry to assess dermal capability in synthesizing Vit-D and degree of sunlight exposure respectively. This study aimed at evaluating whether skin colourimetry could be used to screen Vit-D insufficiency among adolescents.Methods: 240 healthy adolescents (mean age=...

ba0004p76 | (1) | ICCBH2015

Bone quality in severe adolescent idiopathic scoliosis -- quantitative computed tomography of lumbar spine vs high-resolution peripheral quantitative computed tomography of the distal radius: a pilot study

Yu Fiona Wai Ping , Shi Lin , Wang Defeng , Hung Vivian Wing Yin , Choy Wing Yee , Hui Steve Cheuk Ngai , Lee Pak Yin , Tam Elisa Man Shan , Lam Tsz Ping , Qin Lin , Ng Bobby Kin Wah , Chu Winnie Chiu Wing , Griffith James , Cheng Jack Chun Yiu

Introduction and objective: Adolescent idiopathic scoliosis (AIS) is a structural spinal deformity characterized by 3D deformity with lateral curvature of ≧10° as measured by Cobb angle and is predominately seen in girlsaged between 10 and 16-years-old. Low bone mass has been found to be a significant prognostic factor for curve progression in AIS.In our hospital, computed assisted navigation is used for intraoperative pedicle screw placement...

ba0001pp32 | Bone biomechanics and quality | ECTS2013

Vitamin D levels of >85 nmol/l in the presence of adequate dietary Ca minimise bone turnover and improve bone strength

O'Loughlin Peter , Lee Alice , Anderson Paul , Steck Roland , Forwood Mark , Sawyer Rebecca , Morris Howard

We have reported femoral osteopenia in short term-vitamin D restricted rats without deterioration in tibial cortical bone volume (CBV), geometry or strength1. This study aimed to establish the effect of extended vitamin D deficiency in aged rat tibial volume and strength. Female Sprague-Dawley rats (9 m, n=6/group) were fed a diet containing varying vitamin D3 (D) levels (0, 2, 12, and 20 IU/day) with either low (0.1%, LCa) or high (1%, HCa) diet...

ba0002p22 | (1) | ICCBH2013

Association of volumetric bone mineral density, bone morphometry and trabecular bone micro-architecture with leptin and soluble leptin receptor in adolescent idiopathic scoliosis

Tam Elisa M S , Yu Fiona W P , Hung Vivian W Y , Liu Zhen , Lam Tsz-Ping , Liu King Lok , Ng Bobby K W , Lee Simon K M , Qiu Yong , Cheng Jack C Y

Objectives: Low bone mass in adolescent idiopathic scoliosis (AIS) has been well reported, however the etiologies of the disease and this abnormal phenotype were still unknown. Leptin have profound effects on bone metabolism and skeletal growth, and was speculated to play a role in the etiopathogenesis of AIS. The objective of this study was to investigate the bone quality in AIS and its association with leptin and soluble leptin receptor (sOB-R).Methods...

ba0004p60 | (1) | ICCBH2015

Comparing two scanning protocols for high-resolution peripheral quantitative computed tomography for bone quality assessment in young subjects

Cheuk Ka Yee , Zhang Jiajun , Tsang Echo , Yu Fiona , Hung Vivian , Tam Elisa M S , Lam Tsz Ping , Lee Simon K M , Ng Bobby K W , Cheng Jack C Y

Objectives: High resolution peripheral quantitative computed tomography (HR-pQCT) was used to evaluate bone quality and volumetric bone mineral density (vBMD). However, manufacturers only provide a standard protocol for adult but not for growing subjects. The aim of this study was to investigate the difference on measurement between two different HR-pQCT scanning protocols in adolescence with unfused growth plate.Methods: 27 boys and 26 girls aged 13&#15...

ba0003pp403 | Other diseases of bone and mineral metabolism | ECTS2014

Adsorption salivary proteins on dental materias

Lee Juhyun

The aim of this study was to evaluate the adsorption of salivary proteins on giomer (Beautifil II) and composite resin (Filtek Z350).Three discs (5 mm diameter and 1 mm height) were prepared for each material. Three discs were immersed in 1 ml? of human saliva within polyethylene tube and stored at room temperature. Evaluations were performed by Bradford method and SDS gel electrophoresis for analysis of salivary protein adsorbed on giomer and composite ...

ba0004is2 | (1) (1) | ICCBH2015

Bone and osteocyte biology: lessons from human genetic diseases

Lee Brendan

Human skeletal dysplasias consist of over 450 distinct conditions that affect the development and maintenance of bone and cartilage. Broadly they can be characterized by those that affect primarily bone, i.e., the osteodysplasias, vs those that affect cartilage, i.e., the chondrodysplasia. However, the lines dividing these two are increasingly blurred as we recognized them to be a spectrum of osteochondrodysplasias. Importantly, the advent of next generation sequencing has led...