Bone Abstracts

Extreme high bone mass (HBM) may be monogenic (e.g. due to mutations in SOST or LRP5) or polygenic, due to variants in the same genes determining bone mineral density (BMD) as found in the general population. We aimed to determine the genetic cause underlying HBM in an extreme HBM population.258 unexplained HBM cases (defined as L1 Z-score ≥+3.2 plus total hip Z-score ≥+1.2, or total hip Z-score ≥+3.2 and L1 <...

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...

Mineralized tissues like bone, articular calcified cartilage or mineralized turkey leg tendon (MTLT) are build by a composite of hydroxyapatite nano-particles and organic matrix. In bone and MTLT the matrix is formed by collagen type-I, but in contrast to bone in MTLT the collagen is uniaxial orientated, while in cartilage the matrix consists of collagen type-II and proteoglycans.Composition/orientation differences were investigated by a new scanning aco...

In order to examine metabolic and biophysical parameters arising from obesity, male rats were given to drinking 30% sucrose (p/v) for 8 weeks. During the experimental period, animals in the control group (C) consumed higher amounts of food and water, but the body mass was smaller than the group receiving sucrose (S). In this group, the caloric load given to the animals for eight weeks resulted in increased energy consumption, in glycemia and in plasma leptin and abdominal fat....

Bone is a tough composite material, comprised of a compliant collageneous matrix, brittle apatite mineral crystals and a suite of non-collageneous proteins (NCPs). Bone material properties depend on these components, and their interactions at the mineral-collagen interface. ‘Bone mineral density’ (BMD), a parameter used to predict fracture risk, is routinely quantified by DEXA. Previous studies used ex vivo emu tibiae as a model to test the effect of organic...

Study aim: Vertebral strength is determined by bone size, shape, bone mineral density, microarchitecture, and bone material properties. Despite its importance to vertebral mechanics, no studies have reported on the variation of bone microdamage present in the human vertebra. Thus, the aim of this study was to assess regional changes in trabecular bone microdamage in association with bone microarchitecture and resorption in whole human lumbar vertebrae.Me...

Study aim: The general assumption that changes in bone microstructure and material properties at the iliac crest are representative of skeletal sites that are susceptible to osteoporotic fracture has not yet been addressed. Therefore, our study aim was to perform a comparative analysis of bone microarchitecture, accumulated microdamage and osteocyte morphology between the iliac crest, proximal femur and vertebral body.Methods: Trabecular bone cores were ...

Bisphosphonates (BP) are used as anti-resorptive drugs in benign (osteoporosis) and malignant (myeloma, bone metastasis) bone diseases. Their high affinity for biominerals allows prolonged storage within bone. However information about molecular impact of BP on bone quality are missing. Better understanding of BP properties to optimize their clinical use is needed. The aim of this study was thus to investigate human bone physicochemical changes upon BP uptake.<p class="abs...

Objectives: Glucose-dependent insulinotropic polypeptide (GIP) is secreted by intestinal K-cells into the blood supply in response to nutrient ingestion and absorption. Although osteoblasts and osteoclasts express the GIP receptor (GIPR), the main action of the GIP/GIPR pathway in bone physiology and bone quality is unknown. The aim of the present study was to investigate bone quality in a mouse model of GIPR deficiency.Materials/methods: Eleven 16 weeks...

Multiple myeloma (MM) is associated with lytic bone destruction leading to high fracture incidence in the vertebrae. Accurate assessment of fracture risk is required for physicians to determine the necessity for surgery. This risk is currently determined by examining lesion size or number; however, this method does not consider the biomechanical attributes of the bone. Finite element (FE) modelling can simulate mechanical loading on vertebral bodies, and estimate mechanical in...

For a reliable assessment of bone’s material quality in a clinical environment, a fast way to measure the mechanical properties of bone is needed. The investigation of material heterogeneity and anisotropy resulting from bone remodeling and mineralization requires an imaging technique with micrometer resolution. Scanning acoustic microscopy (SAM) using high-frequency lenses allows measuring the stiffness of bone under wet conditions in a non-destructive way with this spat...

Background: Osteoporosis is a leading cause of morbidity in patients affected by β-thalassaemia major (TM) and intermediate thalassaemia (TI). Appropriate supportive care and identification of long-term sequels of therapy are important in thalassaemic patients. As low bone mineral quality (BMQ) in patients can be considered a marker of possible degeneration to osteopenia and osteoporosis in adulthood, we evaluated bone features in a young population followed at ‘A. P...

Bone damage is one of the main unfavourable health effects of chronic exposure to cadmium (Cd). This heavy metal stimulates osteoclastic bone resorption and inhibits osteoblastic bone formation resulting in decreased bone mineralization and as a result weakening of the bone biomechanical properties. Recently, using a rat model of chronic human exposure to cadmium, we have revealed that even low exposure to this metal may increase bone vulnerability to fracture. Taking into acc...

Synthetic glucocorticoids such as dexamethasone (Dex) are widely used for treatment of premature infants with chronic lung disease or respiratory distress syndrome or in allergic conditions such as asthma. Adverse effect of these treatments is glucocorticoids-induced osteoporosis. On the other hand there are functional foods, for instance 2-oxoglutaric acid (2-Ox) a precursor of hydroxyproline the prevailing amino acid in bone collagen, which reduce the risk of osteoporosis. T...

Purpose: The purpose of this study was to scan femoral heads from cadaveric donors and investigate the microarchitecture within each femoral head comprehensively.Material and methods: Ten proximal femora was harvested from eight human cadaveric donors and these specimens were scanned using micro-computed tomography. Reconstructed batches of images were aligned along the main trabecular direction (MTD). The upper hemisphere of each femoral head was includ...

Introduction: Low-magnitude, high-frequency (LMHF) mechanical stimuli lead to enhance bone formation and decrease resorption. This study aimed to investigate the effect of vibration on the bone loss induced by inflammatory cytokine, lipopolysaccharide (LPS).Methods and designs: Balb-C mice were administered to LPS (5 mg/kg) with two i.p. injections on days 0 and 4, while sham control group was injected with 400 μl of water for injection without LPS....

Purpose: The purpose of this study was to investigate the bony change of mandibular condyle when the originally less-loaded or unloaded surface was subjected to functional loading by the newly designed animal experiment, and to evaluate whether this experiment is adequate for the animal model of condylar resorption due to mechanical loading.Methods: Twelve adult male New Zealand white rabbits were used. Unilateral oblique vertical body osteotomy (UOVBO) ...

Apart from analyses of well-known correlates of age-related hip fracture risk, such as low BMD, impaired external geometry and deteriorated micro-architecture, there is increasing interest to elucidate nano-structural determinants of fracture risk at the bone mineralized matrix level.In this study we analyzed cortical bone specimens of the femoral neck region in five elderly women who sustained hip fracture and in four healthy women of corresponding age....

Tooth fracture is considered as a major problem in dentistry. As it is commonly observed in dental practice, one of the main factors that lead to increased tooth fragility is its devitalization. However, there is no definite mechanistic explanation for such phenomenon. We hypothesize that the possible response to this matter lies in the changes that occur in dentin due to altered microenvironment after endodontic procedure. Therefore, in this study we analyzed the structural a...

Bone remodeling is the key process in bone structural reorganization, and its alterations lead to changes in bone mechanical strength. Since osteons reflect different bone remodeling patterns, we hypothesize that the femoral cortex of females with miscellaneous age, disease, and treatment conditions will display distinct osteonal morphology and osteocyte lacunar numbers along with different mechanical properties.The specimens used in this study were coll...

Despite widely accepted classical mechanical theory of buttresses as a load bearing areas in the midfacial skeleton, the data related to its microstructural adaptation on functional demands are scarce. In this study we investigated microstructural features of the different regions in the facial bones in relation to the occlusal load dissipation using a combination of finite element analysis (FEA) and micro-CT analysis (μCT). The FEA was performed on the model of the dry h...

Peripheral quantitative computed tomography (pQCT) is receiving considerable attention in the diagnosis and monitoring of human bone diseases. It is well accepted that lower image resolution compared to micro-computed tomography (micro-CT) affects bone morphometry. With advances in micro-CT evaluation techniques such as sample-specific remodeling simulations or dynamic bone morphometry, there is the potential to also allow the application of such techniques to clinical pQCT sc...

Bone strength, hence fracture risk, is dependent on bone geometry, microstructure and bone material level properties. We have reported that microstructure and material level properties contribute independently to the increase in bone strength in rats treated with strontium ranelate for 2 years, as evaluated by μCT-based Finite Element analysis.We investigated the effects of strontium ranelate (SrRan) treatment on bone material level properties of tr...

Bone microarchitecture and material level properties independently contribute to the improvement of bone strength induced by strontium (Sr) ranelate treatment as evaluated by μCT-based finite element analysis. The influence of in vitro Sr exposure on material level properties and on bone mechanical properties is unknown.We investigated whether in vitro exposure of rat femurs to Sr is able to modify the bone mechanical properties in...

A micro-indentation technology potentially allows in vivo investigation of intrinsic bone tissue quality, a determinant of bone fragility. Thus the signification of the parameters investigated is still unclear.Since protein malnutrition affects bone material level properties – geometry and strength – rats were fed a normal or an isocaloric low-protein diet. Both femurs were collected and measurements of geometry using micro CT, materia...

Subchondral bone remodelling and osteophyte growth are widely recognised hallmarks of knee osteoarthritis (OA) although their contribution to disease is not fully understood. Murine models, with targeted genetic modifications, have become powerful tools for discovering disease pathophysiology. Our unpublished observations suggest that osteophyte formation is independent of cartilage loss thereby implying potentially independent molecular drivers. We have developed a novel imag...

Adaptive responses of the skeleton to loading changes architecture and physical properties in order to optimise strength for function. However, bone is subjected to many local and circulating osteotropic factors, most acting on G-protein coupled receptors. Receptor activity modifying protein-3 is a single trans-membrane domain receptor accessory protein, which aids in trafficking of calcitonin and calcitonin-like receptors to the cell surface and changes ligand selectivity. As...

Glucocorticoids inhibit osteoblast function and cause an increase in osteoblast and osteocyte apoptosis. Bone remodelling defects occur resulting in an increase in fracture risk that cannot be fully explained by decreases in bone mineral density (BMD). We propose that this may be due to alterations in bone quality. Trabecular bone score (TBS) correlates with 3D bone micro-architectural parameters and can be derived directly from grey-level variations within 2D DXA images.<...