Capturing microscopic features of bone remodeling into a macroscopic model based on biological rationales of bone adaptation.

Science.gov (United States)

Kim, Young Kwan; Kameo, Yoshitaka; Tanaka, Sakae; Adachi, Taiji

2017-10-01

To understand Wolff's law, bone adaptation by remodeling at the cellular and tissue levels has been discussed extensively through experimental and simulation studies. For the clinical application of a bone remodeling simulation, it is significant to establish a macroscopic model that incorporates clarified microscopic mechanisms. In this study, we proposed novel macroscopic models based on the microscopic mechanism of osteocytic mechanosensing, in which the flow of fluid in the lacuno-canalicular porosity generated by fluid pressure gradients plays an important role, and theoretically evaluated the proposed models, taking biological rationales of bone adaptation into account. The proposed models were categorized into two groups according to whether the remodeling equilibrium state was defined globally or locally, i.e., the global or local uniformity models. Each remodeling stimulus in the proposed models was quantitatively evaluated through image-based finite element analyses of a swine cancellous bone, according to two introduced criteria associated with the trabecular volume and orientation at remodeling equilibrium based on biological rationales. The evaluation suggested that nonuniformity of the mean stress gradient in the local uniformity model, one of the proposed stimuli, has high validity. Furthermore, the adaptive potential of each stimulus was discussed based on spatial distribution of a remodeling stimulus on the trabecular surface. The theoretical consideration of a remodeling stimulus based on biological rationales of bone adaptation would contribute to the establishment of a clinically applicable and reliable simulation model of bone remodeling.

Adaptive growth factor delivery from a polyelectrolyte coating promotes synergistic bone tissue repair and reconstruction

Science.gov (United States)

Shah, Nisarg J.; Hyder, Md. Nasim; Quadir, Mohiuddin A.; Dorval Courchesne, Noémie-Manuelle; Seeherman, Howard J.; Nevins, Myron; Spector, Myron; Hammond, Paula T.

2014-01-01

Traumatic wounds and congenital defects that require large-scale bone tissue repair have few successful clinical therapies, particularly for craniomaxillofacial defects. Although bioactive materials have demonstrated alternative approaches to tissue repair, an optimized materials system for reproducible, safe, and targeted repair remains elusive. We hypothesized that controlled, rapid bone formation in large, critical-size defects could be induced by simultaneously delivering multiple biological growth factors to the site of the wound. Here, we report an approach for bone repair using a polyelectrolye multilayer coating carrying as little as 200 ng of bone morphogenetic protein-2 and platelet-derived growth factor-BB that were eluted over readily adapted time scales to induce rapid bone repair. Based on electrostatic interactions between the polymer multilayers and growth factors alone, we sustained mitogenic and osteogenic signals with these growth factors in an easily tunable and controlled manner to direct endogenous cell function. To prove the role of this adaptive release system, we applied the polyelectrolyte coating on a well-studied biodegradable poly(lactic-co-glycolic acid) support membrane. The released growth factors directed cellular processes to induce bone repair in a critical-size rat calvaria model. The released growth factors promoted local bone formation that bridged a critical-size defect in the calvaria as early as 2 wk after implantation. Mature, mechanically competent bone regenerated the native calvaria form. Such an approach could be clinically useful and has significant benefits as a synthetic, off-the-shelf, cell-free option for bone tissue repair and restoration. PMID:25136093

[Bone Cell Biology Assessed by Microscopic Approach. A mathematical approach to understand bone remodeling].

Science.gov (United States)

Kameo, Yoshitaka; Adachi, Taiji

2015-10-01

It is well known that bone tissue can change its outer shape and internal structure by remodeling according to a changing mechanical environment. However, the mechanism of bone functional adaptation induced by the collaborative metabolic activities of bone cells in response to mechanical stimuli remains elusive. In this article, we focus on the hierarchy of bone structure and function from the microscopic cellular level to the macroscopic tissue level. We provide an overview of a mathematical approach to understand the adaptive changes in trabecular morphology under the application of mechanical stress.

Correlation between pre-operative periprosthetic bone density and post-operative bone loss in THA can be explained by strain-adaptive remodelling

NARCIS (Netherlands)

Kerner, J.; Huiskes, H.W.J.; Lenthe, van G.H.; Weinans, H.; Rietbergen, van B.; Engh, C.A.; Amis, A.A.

1999-01-01

Periprosthetic adaptive bone remodelling after total hip arthroplasty can be simulated in computer models, combining bone remodelling theory with finite element analysis. Patient specific three-dimensional finite element models of retrieved bone specimens from an earlier bone densitometry (DEXA)

Radiographic evaluation of bone adaptation adjacent to percutaneous osseointegrated prostheses in a sheep model.

Science.gov (United States)

Jeyapalina, Sujee; Beck, James Peter; Bachus, Kent N; Chalayon, Ornusa; Bloebaum, Roy D

2014-10-01

Percutaneous osseointegrated prostheses (POPs) are being investigated as an alternative to conventional socket suspension and require a radiographic followup in translational studies to confirm that design objectives are being met. In this 12-month animal study, we determined (1) radiographic signs of osseointegration and (2) radiographic signs of periprosthetic bone hypertrophy and resorption (adaptation) and (3) confirmed them with the histologic evidence of host bone osseointegration and adaptation around a novel, distally porous-coated titanium POP with a collar. A POP device was designed to fit the right metacarpal bone of sheep. Amputation and implantation surgeries (n = 14) were performed, and plane-film radiographs were collected quarterly for 12 months. Radiographs were assessed for osseointegration (fixation) and bone adaptation (resorption and hypertrophy). The cortical wall and medullary canal widths were used to compute the cortical index and expressed as a percentage. Based on the cortical index changes and histologic evaluations, bone adaptation was quantified. Radiographic data showed signs of osseointegration including those with incomplete seating against the collar attachment. Cortical index data indicated distal cortical wall thinning if the collar was not seated distally. When implants were bound proximally, bone resorbed distally and the diaphyseal cortex hypertrophied. Histopathologic evidence and cortical index measurements confirmed the radiographic indications of adaptation and osseointegration. Distal bone loading, through collar attachment and porous coating, limited the distal bone resorption. Serial radiographic studies, in either animal models or preclinical trials for new POP devices, will help to determine which designs are likely to be safe over time and avoid implant failures.

The contribution of experimental in vivo models to understanding the mechanisms of adaptation to mechanical loading in bone

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Lee B Meakin

2014-10-01

Full Text Available Changing loading regimens by natural means such as exercise, with or without interference such as osteotomy, has provided useful information on the structure:function relationship in bone tissue. However, the greatest precision in defining those aspects of the overall strain environment that influence modeling and remodeling behavior has been achieved by relating quantified changes in bone architecture to quantified changes in bones’ strain environment produced by direct, controlled artificial bone loading.Jiri Heřt introduced the technique of artificial loading of bones in vivo with external devices in the 1960s using an electromechanical device to load rabbit tibiae through transfixing stainless steel pins. Quantifying natural bone strains during locomotion by attaching electrical resistance strain gauges to bone surfaces was introduced by Lanyon, also in the 1960s. These studies in a variety of bones in a number of species demonstrated remarkable uniformity in the peak strains and maximum strain rates experienced.Experiments combining strain gauge instrumentation with artificial loading in sheep, pigs, roosters, turkeys, rats and mice has yielded significant insight into the control of strain-related adaptive (remodeling. This diversity of approach has been largely superseded by non-invasive transcutaneous loading in rats and mice which is now the model of choice for many studies. Together such studies have demonstrated that; over the physiological strain range, bone’s mechanically-adaptive processes are responsive to dynamic but not static strains; the size and nature of the adaptive response controlling bone mass is linearly related to the peak loads encountered; the strain-related response is preferentially sensitive to high strain rates and unresponsive to static ones; is most responsive to unusual strain distributions; is maximized by remarkably few strain cycles and that these are most effective when interrupted by short periods of

The Contribution of Experimental in vivo Models to Understanding the Mechanisms of Adaptation to Mechanical Loading in Bone

Science.gov (United States)

Meakin, Lee B.; Price, Joanna S.; Lanyon, Lance E.

2014-01-01

Changing loading regimens by natural means such as exercise, with or without interference such as osteotomy, has provided useful information on the structure:function relationship in bone tissue. However, the greatest precision in defining those aspects of the overall strain environment that influence modeling and remodeling behavior has been achieved by relating quantified changes in bone architecture to quantified changes in bones’ strain environment produced by direct, controlled artificial bone loading. Jiri Hert introduced the technique of artificial loading of bones in vivo with external devices in the 1960s using an electromechanical device to load rabbit tibiae through transfixing stainless steel pins. Quantifying natural bone strains during locomotion by attaching electrical resistance strain gages to bone surfaces was introduced by Lanyon, also in the 1960s. These studies in a variety of bones in a number of species demonstrated remarkable uniformity in the peak strains and maximum strain rates experienced. Experiments combining strain gage instrumentation with artificial loading in sheep, pigs, roosters, turkeys, rats, and mice has yielded significant insight into the control of strain-related adaptive (re)modeling. This diversity of approach has been largely superseded by non-invasive transcutaneous loading in rats and mice, which is now the model of choice for many studies. Together such studies have demonstrated that over the physiological strain range, bone’s mechanically adaptive processes are responsive to dynamic but not static strains; the size and nature of the adaptive response controlling bone mass is linearly related to the peak loads encountered; the strain-related response is preferentially sensitive to high strain rates and unresponsive to static ones; is most responsive to unusual strain distributions; is maximized by remarkably few strain cycles, and that these are most effective when interrupted by short periods of rest between them

Adapted preparation technique for screw-type implants: explorative in vitro pilot study in a porcine bone model.

Science.gov (United States)

Beer, Andreas; Gahleitner, André; Holm, Anders; Birkfellner, Wolfgang; Homolka, Peter

2007-02-01

The aim of this study was to quantify the effect of adapted preparation on the insertion torque of self-tapping implants in cancellous bone. In adapted preparation, bone condensation - and thus, insertion torque - is controlled by changing the diameter of the drilling. After preparation of cancellous porcine vertebral bone with drills of 2.85, 3, 3.15 or 3.35 mm final diameters, Brånemark sytem Mk III implants (3.75 x 11.5 mm) were inserted in 141 sites. During implantation, the insertion torque was recorded. Prior to implant insertion, bone mineralization (bone mineral density (BMD)) was measured with dental quantative computed tomography. The BMD values measured at the implant position were correlated with insertion torque for varying bone condensation. Based on the average torque recorded during implant insertion into the pre-drilled canals with a diameter of 3 mm, torque increased by approximately 17% on reducing the diameter of the drill by 5% (to 2.85 mm). On increasing the diameter of the osteotomy to 3.15 mm (5%) or 3.35 mm (12%), torque values decreased by approximately 21% and 50%, respectively. The results demonstrate a correlation between primary stability (average insertion torque) and the diameter of the implant bed on using a screw-shaped implant. Thus, using an individualized bone mineralization-dependent drilling technique, optimized torque values could be achieved in all tested bone qualities with BMDs ranging from 330 to 500 mg/cm(3). The results indicate that using a bone-dependent drilling technique, higher torque values can also be achieved in poor bone using an individualized drilling resulting in higher bone condensation. As immediate function is dependent on primary stability (high insertion torque), this indicates that primary stability can be increased using a modified drilling technique in lesser mineralized bone.

Functional bone marrow scintigraphy in psoriatics

International Nuclear Information System (INIS)

Munz, D.; Altmeyer, P.; Chilf, G.; Schlesinger, G.; Holzmann, H.; Hoer, G.

1982-01-01

24 psoriatics as well as 24 normal healthy adults were studied by functional bone marrow scintigraphy using Tc-99m-labeled human serum albumin millimicrospheres (Tc-99m-HSA-MM). Functional bone marrow scintigraphy is an in vivo test system for the assessment of various functional properties of fixed macrophages. 58% of psoriatics who had no systemic drug treatment demonstrated peripheral extension of the bone marrow space indicating hyperplasia of bone marrow macrophages. This phenomenon could be observed only in one normal subject who was a high-performance sportsman. 83% (n=6) of psoriatics with cirrhosis of liver demonstrated bone marrow extension. The 'capacity' of bone marrow macrophages to engulf Tc-99m-HSA-MM ('uptake ratio') was diminished in 42% of non-treated as well as 66% of psoriatics treated with aromatic retinoid. The phagocytic and proteolytic turnover of Tc-99m-HSA-MM in bone marrow, spleen, and liver was found to be accelerated in 66% of non-treated psoriatics, normal, accelerated or delayed in psoriatics treated with aromatic retinoid as well as considerably delayed in all of the psoriatics with cirrhosis of liver. Functional bone marrow scintigraphy proved to be an appropriate in vivo test system to reveal abnormalities of fixed macrophages in psoriatics. Furthermore, theratpeutic effects as well as influences of pre-existing disorders on different macrophage populations can be assessed. (Author)

Adaptive Bone Remodeling of the Femoral Bone After Tumor Resection Arthroplasty With an Uncemented Proximally Hydroxyapatite-Coated Stem

DEFF Research Database (Denmark)

Andersen, Mikkel R.; Petersen, Michael M.

2016-01-01

-fluted 125-mm uncemented press-fit titanium alloy stem with hydroxyapatite coating of the proximal part of the stem. Measurements of bone mineral density (BMD; g/cm2) were done postoperatively and after 3, 6, and 12 mo in the part of the femur bone containing the Global Modular Replacement System stem using...... of 8%-9% during the first postoperative year was seen along the femoral stem, but in the bone containing the hydroxyapatite-coated part of the stem, the decrease in BMD was 14%, thus indicating that stress shielding of this part of the bone may play a role for the adaptive bone remodeling....

Biology of Bone Tissue: Structure, Function, and Factors That Influence Bone Cells.

Science.gov (United States)

Florencio-Silva, Rinaldo; Sasso, Gisela Rodrigues da Silva; Sasso-Cerri, Estela; Simões, Manuel Jesus; Cerri, Paulo Sérgio

2015-01-01

Bone tissue is continuously remodeled through the concerted actions of bone cells, which include bone resorption by osteoclasts and bone formation by osteoblasts, whereas osteocytes act as mechanosensors and orchestrators of the bone remodeling process. This process is under the control of local (e.g., growth factors and cytokines) and systemic (e.g., calcitonin and estrogens) factors that all together contribute for bone homeostasis. An imbalance between bone resorption and formation can result in bone diseases including osteoporosis. Recently, it has been recognized that, during bone remodeling, there are an intricate communication among bone cells. For instance, the coupling from bone resorption to bone formation is achieved by interaction between osteoclasts and osteoblasts. Moreover, osteocytes produce factors that influence osteoblast and osteoclast activities, whereas osteocyte apoptosis is followed by osteoclastic bone resorption. The increasing knowledge about the structure and functions of bone cells contributed to a better understanding of bone biology. It has been suggested that there is a complex communication between bone cells and other organs, indicating the dynamic nature of bone tissue. In this review, we discuss the current data about the structure and functions of bone cells and the factors that influence bone remodeling.

The Adaptive Nature of the Bone-Periodontal Ligament-Cementum Complex in a Ligature-Induced Periodontitis Rat Model

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Ji-Hyun Lee

2013-01-01

Full Text Available The novel aspect of this study involves illustrating significant adaptation of a functionally loaded bone-PDL-cementum complex in a ligature-induced periodontitis rat model. Following 4, 8, and 15 days of ligation, proinflammatory cytokines (TNF-α and RANKL, a mineral resorption indicator (TRAP, and a cell migration and adhesion molecule for tissue regeneration (fibronectin within the complex were localized and correlated with changes in PDL-space (functional space. At 4 days of ligation, the functional space of the distal complex was widened compared to controls and was positively correlated with an increased expression of TNF-α. At 8 and 15 days, the number of RANKL(+ cells decreased near the mesial alveolar bone crest (ABC but increased at the distal ABC. TRAP(+ cells on both sides of the complex significantly increased at 8 days. A gradual change in fibronectin expression from the distal PDL-secondary cementum interfaces through precementum layers was observed when compared to increased and abrupt changes at the mesial PDL-cementum and PDL-bone interfaces in ligated and control groups. Based on our results, we hypothesize that compromised strain fields can be created in a diseased periodontium, which in response to prolonged function can significantly alter the original bone and apical cementum formations.

Biology of Bone Tissue: Structure, Function, and Factors That Influence Bone Cells

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Rinaldo Florencio-Silva

2015-01-01

Full Text Available Bone tissue is continuously remodeled through the concerted actions of bone cells, which include bone resorption by osteoclasts and bone formation by osteoblasts, whereas osteocytes act as mechanosensors and orchestrators of the bone remodeling process. This process is under the control of local (e.g., growth factors and cytokines and systemic (e.g., calcitonin and estrogens factors that all together contribute for bone homeostasis. An imbalance between bone resorption and formation can result in bone diseases including osteoporosis. Recently, it has been recognized that, during bone remodeling, there are an intricate communication among bone cells. For instance, the coupling from bone resorption to bone formation is achieved by interaction between osteoclasts and osteoblasts. Moreover, osteocytes produce factors that influence osteoblast and osteoclast activities, whereas osteocyte apoptosis is followed by osteoclastic bone resorption. The increasing knowledge about the structure and functions of bone cells contributed to a better understanding of bone biology. It has been suggested that there is a complex communication between bone cells and other organs, indicating the dynamic nature of bone tissue. In this review, we discuss the current data about the structure and functions of bone cells and the factors that influence bone remodeling.

Does subchondral bone of the equine proximal phalanx adapt to race training?

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Noble, Phillipa; Singer, Ellen R; Jeffery, Nathan S

2016-07-01

Sagittal fractures of the first phalanx are a common, potentially catastrophic injury in racehorses. These fractures are often linked to an acute, one time, biomechanical event; however, recent evidence implies that chronic exposure to stress can lead to the accumulation of bony changes that affect the structural integrity of the bone and increase the likelihood of fracture. The aim of the study was to compare variations of two common metrics of bone adaptation - subchondral bone density and thickness across the proximal articular surface of the first phalanx in Thoroughbred horses that (1) raced but never experienced a first phalanx fracture (Raced Control); (2) raced and had experienced fracture of the contralateral first phalanx (Contralateral to Fracture); (3) had never raced or experienced a first phalanx fracture (Unraced Control). A total of 22 first phalangeal bones were sampled post-mortem and imaged using micro-computed tomography calibrated for mineral density measures. Measurements of volumetric subchondral bone mineral density and thickness were taken from images at five sites from medial to lateral, in three coronal planes (25, 50 and 75% dorsal-palmar). At each of the 15 sites, measurements were repeated and averaged across 10 adjacent micro-computed tomography slices of bone, spanning 0.75 mm. The magnitude and variance of these measurements were compared between sites and between cohorts with non-parametric statistical tests. Across the proximal osteochondral surface of the first phalanx, the pattern of subchondral bone volumetric bone mineral density and thickness varied with each coronal section studied. The subchondral bone thickness was greater for the central and dorsal coronal sections, compared with the palmar section. For the race-fit groups (Raced Control and Contralateral to Fracture), the highest volumetric bone mineral density was in the central sagittal groove. The volumetric bone mineral density was significantly greater in the

The G-factor as a tool to learn more about bone structure and function.

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Zerath, E

1999-07-01

In normal life on earth, the locomotor system is exposed to two types of stimulation: gravity (passive stimulation) and motion (active stimulation). Both permanently combine, and the interactions between locomotion and gravity induce an overall recruitment which is repeated daily and maintains the bone tissue structure within the range of constraints to which it is adapted. This range is one of the basic hypotheses underlying the mechanical concepts of bone structure control, and it has been considered as logical to assume that weightlessness of spaceflight should produce bone loss since astronauts are outside of the terrestrial gravitational field of forces, no longer relying on muscular work to change positions or move. But, thirty years after the first changes in phospho-calcium metabolism were observed in astronauts after spaceflight, current knowledge does not provide a full understanding of this pathogeny, and prove the G-factor is now considered as an essential component of the experimental tools available to study bone physiology. The study of the physiology of bone tissue usually consists in the investigation of its two fundamental roles, i.e. reservoir of inorganic elements (calcium, phosphorus, magnesium) and mechanical support for soft tissues. Together with the combined action of muscles, tendons, and ligaments, this support permits motion and locomotion. These two functions rely on a sophisticated bone tissue architecture, and on the adaptability of this structure, with modeling and remodeling processes, themselves associated with the coupled activity of specialized bone cell populations.

Biomechanical stability of novel mechanically adapted open-porous titanium scaffolds in metatarsal bone defects of sheep.

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Wieding, Jan; Lindner, Tobias; Bergschmidt, Philipp; Bader, Rainer

2015-04-01

Open-porous titanium scaffolds for large segmental bone defects offer advantages like early weight-bearing and limited risk of implant failure. The objective of this experimental study was to determine the biomechanical behavior of novel open-porous titanium scaffolds with mechanical-adapted properties in vivo. Two types of the custom-made, open-porous scaffolds made of Ti6Al4V (Young's modulus: 6-8 GPa and different pore sizes) were implanted into a 20 mm segmental defect in the mid-diaphysis of the metatarsus of sheep, and were stabilized with an osteosynthesis plate. After 12 and 24 weeks postoperatively, torsional testing was performed on the implanted bone and compared to the contralateral non-treated side. Maximum torque, maximum angle, torsional stiffness, fracture energy, shear modulus and shear stress were investigated. Furthermore, bone mineral density (BMD) of the newly formed bone was determined. Mechanical loading capabilities for both scaffolds were similar and about 50% after 12 weeks (e.g., max. torque of approximately 20 Nm). A further increase after 24 weeks was found for most of the investigated parameters. Results for torsional stiffness and shear modulus as well as bone formation depended on the type of scaffold. Increased BMD after 24 weeks was found for one scaffold type but remained constant for the other one. The present data showed the capability of mechanically adapted open-porous titanium scaffolds to function as bone scaffolds for large segmental defects and the influence of the scaffold's stiffness. A further increase in the biomechanical stability can be assumed for longer observation periods of greater than six months. Copyright © 2014 Elsevier Ltd. All rights reserved.

Functional adaptation in female rats: the role of estrogen signaling.

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Susannah J Sample

Full Text Available Sex steroids have direct effects on the skeleton. Estrogen acts on the skeleton via the classical genomic estrogen receptors alpha and beta (ERα and ERβ, a membrane ER, and the non-genomic G-protein coupled estrogen receptor (GPER. GPER is distributed throughout the nervous system, but little is known about its effects on bone. In male rats, adaptation to loading is neuronally regulated, but this has not been studied in females.We used the rat ulna end-loading model to induce an adaptive modeling response in ovariectomized (OVX female Sprague-Dawley rats. Rats were treated with a placebo, estrogen (17β-estradiol, or G-1, a GPER-specific agonist. Fourteen days after OVX, rats underwent unilateral cyclic loading of the right ulna; half of the rats in each group had brachial plexus anesthesia (BPA of the loaded limb before loading. Ten days after loading, serum estrogen concentrations, dorsal root ganglion (DRG gene expression of ERα, ERβ, GPER, CGRPα, TRPV1, TRPV4 and TRPA1, and load-induced skeletal responses were quantified. We hypothesized that estrogen and G-1 treatment would influence skeletal responses to cyclic loading through a neuronal mechanism. We found that estrogen suppresses periosteal bone formation in female rats. This physiological effect is not GPER-mediated. We also found that absolute mechanosensitivity in female rats was decreased, when compared with male rats. Blocking of adaptive bone formation by BPA in Placebo OVX females was reduced.Estrogen acts to decrease periosteal bone formation in female rats in vivo. This effect is not GPER-mediated. Gender differences in absolute bone mechanosensitivity exist in young Sprague-Dawley rats with reduced mechanosensitivity in females, although underlying bone formation rate associated with growth likely influences this observation. In contrast to female and male rats, central neuronal signals had a diminished effect on adaptive bone formation in estrogen-deficient female rats.

Pilot Study: Unique Response of Bone Tissue During an Investigation of Radio-Adaptive Effects in Mice

Science.gov (United States)

Sibonga, J. D.; Iwaniec, U.; Wu, H.

2011-01-01

PURPOSE: We obtained bone tissue to evaluate the collateral effects of experiments designed to investigate molecular mechanisms of radio-adaptation in a mouse model. Radio-adaptation describes a process by which the prior exposure to low dose radiation can protect against the toxic effect of a subsequent high dose exposure. In the radio-adaptation experiments, C57Bl/6 mice were exposed to either a Sham or a priming Low Dose (5 cGy) of Cs-137 gamma rays before being exposed to either a Sham or High Dose (6 Gy) 24 hours later. ANALYSIS: Bone tissue were obtained from two experiments where mice were sacrificed at 3 days (n=3/group, 12 total) and at 14 days (n=6/group, 24 total) following high dose exposure. Tissues were analyzed to 1) evaluate a radio-adaptive response in bone tissue and 2) describe cellular and microstructural effects for two skeletal sites with different rates of bone turnover. One tibia and one lumbar vertebrae (LV2), collected at the 3-day time-point, were analyzed by bone histomorphometry and micro-CT to evaluate the cellular response and any evidence of microarchitectural impact. Likewise, tibia and LV2, collected at the 14-day time-point, were analyzed by micro-CT alone to evaluate resulting changes to bone structure and microarchitecture. The data were analyzed by 2-way ANOVA to evaluate the effects of the priming low dose radiation, of the high dose radiation, and of any interaction between the priming low and high doses of radiation. Bone histomorphometry was performed in the cancellous bone (aka trabecular bone) compartments of the proximal tibial metaphysis and of LV2. RESULTS: Cellular Response @ 3 Days The priming Low Dose radiation decreased osteoblast-covered bone perimeter in the proximal tibia and the total cell density in the bone marrow in the LV2. High Dose radiation, regardless of prior exposure to priming dose, dramatically reduced total cell density in bone marrow of both the long bone and vertebra. However, in the proximal

Adaptations in tibial cortical thickness and total volumetric bone density in postmenopausal South Asian women with small bone size.

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Darling, Andrea L; Hakim, Ohood A; Horton, Khim; Gibbs, Michelle A; Cui, Liang; Berry, Jacqueline L; Lanham-New, Susan A; Hart, Kathryn H

2013-07-01

There is some evidence that South Asian women may have an increased risk of osteoporosis compared with Caucasian women, although whether South Asians are at increased risk of fracture is not clear. It is unknown whether older South Asian women differ from Caucasian women in bone geometry. This is the first study, to the authors' knowledge, to use peripheral Quantitative Computed Tomography (pQCT) to measure radial and tibial bone geometry in postmenopausal South Asian women. In comparison to Caucasian women, Asian women had smaller bone size at the 4% (-18% pAsians had increased cortical thickness (-17% p=0.04) at the 38% tibia, (in proportion to bone size (-30% p=0.003)). Furthermore, at the 4% and 14% tibia there were increased total densities (+12% to +29% pAsians. These differences at the 14% and 38% (but not 4%) remained statistically significant after adjustment for Body Mass Index (BMI). These adaptations are similar to those seen previously in Chinese women. Asian women had reduced strength at the radius and tibia, evidenced by the 20-40% reduction in both polar Strength Strain Index (SSIp) and fracture load (under bending). Overall, the smaller bone size in South Asians is likely to be detrimental to bone strength, despite some adaptations in tibial cortical thickness and tibial and radial density which may partially compensate for this. Copyright © 2013 Elsevier Inc. All rights reserved.

Temporal mechanically-induced signaling events in bone and dorsal root ganglion neurons after in vivo bone loading.

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Jason A Bleedorn

Full Text Available Mechanical signals play an integral role in the regulation of bone mass and functional adaptation to bone loading. The osteocyte has long been considered the principle mechanosensory cell type in bone, although recent evidence suggests the sensory nervous system may play a role in mechanosensing. The specific signaling pathways responsible for functional adaptation of the skeleton through modeling and remodeling are not clearly defined. In vitro studies suggest involvement of intracellular signaling through mitogen-activated protein kinase (MAPK, phosphatidylinositol 3-kinase (PI3K/protein kinase B (Akt, and mammalian target of rapamycin (mTOR. However, anabolic signaling responses to bone loading using a whole animal in vivo model have not been studied in detail. Therefore, we examined mechanically-induced signaling events at five time points from 0 to 24 hours after loading using the rat in vivo ulna end-loading model. Western blot analysis of bone for MAPK's, PI3K/Akt, and mTOR signaling, and quantitative reverse transcription polymerase chain reaction (qRT-PCR to estimate gene expression of calcitonin gene-related protein alpha (CGRP-α, brain-derived neurotrophic factor (BDNF, nerve growth factor (NGF, c-jun, and c-fos in dorsal root ganglion (DRG of the brachial intumescence were performed. There was a significant increase in signaling through MAPK's including extracellular signal-related kinase (ERK and c-Jun N-terminal kinase (JNK in loaded limbs at 15 minutes after mechanical loading. Ulna loading did not significantly influence expression of the genes of interest in DRG neurons. Bone signaling and DRG gene expression from the loaded and contralateral limbs was correlated (SR>0.40, P<0.05. However, bone signaling did not correlate with expression of the genes of interest in DRG neurons. These results suggest that signaling through the MAPK pathway may be involved in load-induced bone formation in vivo. Further characterization of the

First Reported Cases of Biomechanically Adaptive Bone Modeling in Non-Avian Dinosaurs.

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Jorge Cubo

Full Text Available Predator confrontation or predator evasion frequently produces bone fractures in potential prey in the wild. Although there are reports of healed bone injuries and pathologies in non-avian dinosaurs, no previously published instances of biomechanically adaptive bone modeling exist. Two tibiae from an ontogenetic sample of fifty specimens of the herbivorous dinosaur Maiasaura peeblesorum (Ornithopoda: Hadrosaurinae exhibit exostoses. We show that these outgrowths are cases of biomechanically adaptive periosteal bone modeling resulting from overstrain on the tibia after a fibula fracture. Histological and biomechanical results are congruent with predictions derived from this hypothesis. Histologically, the outgrowths are constituted by radial fibrolamellar periosteal bone tissue formed at very high growth rates, as expected in a process of rapid strain equilibration response. These outgrowths show greater compactness at the periphery, where tensile and compressive biomechanical constraints are higher. Moreover, these outgrowths increase the maximum bending strength in the direction of the stresses derived from locomotion. They are located on the antero-lateral side of the tibia, as expected in a presumably bipedal one year old individual, and in the posterior position of the tibia, as expected in a presumably quadrupedal individual at least four years of age. These results reinforce myological evidence suggesting that Maiasaura underwent an ontogenetic shift from the primitive ornithischian bipedal condition when young to a derived quadrupedal posture when older.

First Reported Cases of Biomechanically Adaptive Bone Modeling in Non-Avian Dinosaurs.

Science.gov (United States)

Cubo, Jorge; Woodward, Holly; Wolff, Ewan; Horner, John R

2015-01-01

Predator confrontation or predator evasion frequently produces bone fractures in potential prey in the wild. Although there are reports of healed bone injuries and pathologies in non-avian dinosaurs, no previously published instances of biomechanically adaptive bone modeling exist. Two tibiae from an ontogenetic sample of fifty specimens of the herbivorous dinosaur Maiasaura peeblesorum (Ornithopoda: Hadrosaurinae) exhibit exostoses. We show that these outgrowths are cases of biomechanically adaptive periosteal bone modeling resulting from overstrain on the tibia after a fibula fracture. Histological and biomechanical results are congruent with predictions derived from this hypothesis. Histologically, the outgrowths are constituted by radial fibrolamellar periosteal bone tissue formed at very high growth rates, as expected in a process of rapid strain equilibration response. These outgrowths show greater compactness at the periphery, where tensile and compressive biomechanical constraints are higher. Moreover, these outgrowths increase the maximum bending strength in the direction of the stresses derived from locomotion. They are located on the antero-lateral side of the tibia, as expected in a presumably bipedal one year old individual, and in the posterior position of the tibia, as expected in a presumably quadrupedal individual at least four years of age. These results reinforce myological evidence suggesting that Maiasaura underwent an ontogenetic shift from the primitive ornithischian bipedal condition when young to a derived quadrupedal posture when older.

Architectural and biochemical adaptations in skeletal muscle and bone following rotator cuff injury in a rat model.

Science.gov (United States)

Sato, Eugene J; Killian, Megan L; Choi, Anthony J; Lin, Evie; Choo, Alexander D; Rodriguez-Soto, Ana E; Lim, Chanteak T; Thomopoulos, Stavros; Galatz, Leesa M; Ward, Samuel R

2015-04-01

Injury to the rotator cuff can cause irreversible changes to the structure and function of the associated muscles and bones. The temporal progression and pathomechanisms associated with these adaptations are unclear. The purpose of this study was to investigate the time course of structural muscle and osseous changes in a rat model of a massive rotator cuff tear. Supraspinatus and infraspinatus muscle architecture and biochemistry and humeral and scapular morphological parameters were measured three days, eight weeks, and sixteen weeks after dual tenotomy with and without chemical paralysis via botulinum toxin A (BTX). Muscle mass and physiological cross-sectional area increased over time in the age-matched control animals, decreased over time in the tenotomy+BTX group, and remained nearly the same in the tenotomy-alone group. Tenotomy+BTX led to increased extracellular collagen in the muscle. Changes in scapular bone morphology were observed in both experimental groups, consistent with reductions in load transmission across the joint. These data suggest that tenotomy alone interferes with normal age-related muscle growth. The addition of chemical paralysis yielded profound structural changes to the muscle and bone, potentially leading to impaired muscle function, increased muscle stiffness, and decreased bone strength. Structural musculoskeletal changes occur after tendon injury, and these changes are severely exacerbated with the addition of neuromuscular compromise. Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.

Finite element analysis of functionally graded bone plate at femur bone fracture site

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Satapathy, Pravat Kumar; Sahoo, Bamadev; Panda, L. N.; Das, S.

2018-03-01

This paper focuses on the analysis of fractured Femur bone with functionally graded bone plate. The Femur bone is modeled by using the data from the CT (Computerized Tomography) scan and the material properties are assigned using Mimics software. The fracture fixation plate used here is composed of Functionally Graded Material (FGM). The functionally graded bone plate is considered to be composed of different layers of homogeneous materials. Finite element method approach is adopted for analysis. The volume fraction of the material is calculated by considering its variation along the thickness direction (z) according to a power law and the effective properties of the homogeneous layers are estimated. The model developed is validated by comparing numerical results available in the literature. Static analysis has been performed for the bone plate system by considering both axial compressive load and torsional load. The investigation shows that by introducing FG bone plate instead of titanium, the stress at the fracture site increases by 63 percentage and the deformation decreases by 15 percentage, especially when torsional load is taken into consideration. The present model yields better results in comparison with the commercially available bone plates.

The Role of Peripheral Nerve Function in Age-Related Bone Loss and Changes in Bone Adaptation

Science.gov (United States)

2015-12-01

E Production of Osteoblasts, and Attenuates the Inflammatory Bone Loss Induced by Lipopolysaccharide. ISRN Pharmacol, 2012. 2012: p. 439860. 17...Kobayashi M, Watanabe K, Yokoyama S, et al. Capsaicin, a TRPV1 Ligand, Suppresses Bone Resorption by Inhibit- ing the Prostaglandin E Production of...example, mechanoreceptors in the skin respond to bending and stretching and can provide information about touch. Pacini’s corpuscle consists of onion like

The law of adaptive bone remodeling : a case for crying Newton?

NARCIS (Netherlands)

Huiskes, R.; Odgaard, A.; Weinans, H.

1995-01-01

The biological mechanisms of strain-adaptive bone remodeling are largely unknown. Yet, several authors published algorithms to mimic this process, without prior validation of its premises. Biologists are sometimes confused by this seemingly irresponsible behavior. However, this kind of inductive

Intractable Diseases Treated with Intra-Bone Marrow-Bone Marrow Transplantation

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Ming eLi

2014-09-01

Full Text Available Bone marrow transplantation (BMT is used to treat hematological disorders, autoimmune diseases and lymphoid cancers. Intra bone marrow-BMT (IBM-BMT has been proven to be a powerful strategy for allogeneic BMT due to the rapid hematopoietic recovery and the complete restoration of T cell functions. IBM-BMT not only replaces hematopoietic stem cells but also mesenchymal stem cells (MSMCs. MSMCs are multi-potent stem cells that can be isolated from bone marrow, umbilical cord blood, and adipose tissue. MSMCs play an important role in the support of hematopoiesis, and modify and influence the innate and adaptive immune systems. MSMCs also differentiate into mesodermal, endodermal and ectodermal lineage cells to repair tissues. This review aims to summarize the functions of bone marrow-derived- MSMCs, and the treatment of intractable diseases such as rheumatoid arthritis and malignant tumors with IBM-BMT.

Bone inner structure suggests increasing aquatic adaptations in Desmostylia (Mammalia, Afrotheria.

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Shoji Hayashi

Full Text Available The paleoecology of desmostylians has been discussed controversially with a general consensus that desmostylians were aquatic or semi-aquatic to some extent. Bone microanatomy can be used as a powerful tool to infer habitat preference of extinct animals. However, bone microanatomical studies of desmostylians are extremely scarce.We analyzed the histology and microanatomy of several desmostylians using thin-sections and CT scans of ribs, humeri, femora and vertebrae. Comparisons with extant mammals allowed us to better understand the mode of life and evolutionary history of these taxa. Desmostylian ribs and long bones generally lack a medullary cavity. This trait has been interpreted as an aquatic adaptation among amniotes. Behemotops and Paleoparadoxia show osteosclerosis (i.e. increase in bone compactness, and Ashoroa pachyosteosclerosis (i.e. combined increase in bone volume and compactness. Conversely, Desmostylus differs from these desmostylians in displaying an osteoporotic-like pattern.In living taxa, bone mass increase provides hydrostatic buoyancy and body trim control suitable for poorly efficient swimmers, while wholly spongy bones are associated with hydrodynamic buoyancy control in active swimmers. Our study suggests that all desmostylians had achieved an essentially, if not exclusively, aquatic lifestyle. Behemotops, Paleoparadoxia and Ashoroa are interpreted as shallow water swimmers, either hovering slowly at a preferred depth, or walking on the bottom, and Desmostylus as a more active swimmer with a peculiar habitat and feeding strategy within Desmostylia. Therefore, desmostylians are, with cetaceans, the second mammal group showing a shift from bone mass increase to a spongy inner organization of bones in their evolutionary history.

Bone and bone marrow function of reconstructed chest wall after surgical correction of pectus excavatum

International Nuclear Information System (INIS)

Watanabe, Yoh; Magara, Tatsuo; Kobayashi, Hiroaki; Ichihashi, Takumi; Hikishima, Hiroshi

1984-01-01

Bone and Bone marrow functions of the reconstructed chest wall after surgical correction of the funnel chest deformities were evaluated by scanning method. In our series, three kinds of operative procedures were employed; strut method for adult cases, sternal turnover method with and without muscle pedicle for infant cases. Bone function was scanned by sup(99m)Tc-methylene-diphosphonate and bone marrow function was evaluated by sup(99m)Tc-sulfur-colloid. For the cases undergone each surgical procedure, bone and bone marrow scan were done at short term after surgery (within 30 days), at intermediate stage (one month to 12 months), and at long term stage (beyond one year). The results were as follows: By the evaluation at the long term stage of the cases undergoing strut method, bone as well as bone marrow scan visualized normal view of the reconstructed sternum. Regarding the cases undergone sternal turnover method without muscle pedicle, or free graft implantation of the plastron, the bone scan at the long term follow-up stage showed abnormal finding, i.e. hypo-, or defect-visualization of the inverted sternum, in 11.5% of the cases. Furthermore, bone marrow scan showed abnormality in 33.3% of the cases. On the other hand, the cases undergone sternal turnover method with muscle pedicle, in which blood supply to the plastron were preserved by the connection from superior epigastric artery to internal mammary artery, showed no abnormality as far as at the long term follow-up study neither in bone scan nor bone marrow scan. However, in the evaluation at short term after surgery, 50% of the cases undergoing bone scan showed abnormality. In addition, in this stage 85.7% of the bone marrow scan showed abnormal finding. These abnormality, however, normalized within 6 months for bone scan and 12 months for bone marrow scan, in contrast to the results of the cases undergone sternal turnover without pedicle. (J.P.N.)

Comparative functional anatomy of hindlimb muscles and bones with reference to aquatic adaptation of the sea otter.

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Mori, Kent; Suzuki, Satoshi; Koyabu, Daisuke; Kimura, Junpei; Han, Sung-Yong; Endo, Hideki

2015-05-01

Although the sea otter (Enhydra lutris) is a complete aquatic species, spending its entire life in the ocean, it has been considered morphologically to be a semi-aquatic animal. This study aimed to clarify the unique hindlimb morphology and functional adaptations of E. lutris in comparison to other Mustelidae species. We compared muscle mass and bone measurements of five Mustelidae species: the sea otter, Eurasian river otter (Lutra lutra), American mink (Neovison vison), Japanese weasel (Mustela itatsi) and Siberian weasel (M. sibirica). In comparison with the other 4 species, E. lutris possessed significantly larger gluteus, popliteus and peroneus muscles, but smaller adductor and ischiopubic muscles. The popliteus muscle may act as a medial rotator of the crus, and the peroneus muscle may act as an abductor of the fifth toe and/or the pronator of the foot. The bundles of the gluteus superficialis muscle of E. lutris were fused with those of the tensor fasciae latae muscle and gluteofemoralis muscles, and they may play a role in femur abduction. These results suggest that E. lutris uses the abducted femur, medially rotated crus, eversion of the ankle and abducted fifth digit or extended interdigital web as a powerful propulsion generator. Therefore, we conclude that E. lutris is a complete aquatic animal, possessing differences in the proportions of the hindlimb muscles compared with those in other semi-aquatic and terrestrial mustelids.

Bone mineral density and menstrual function in adolescent female ...

African Journals Online (AJOL)

Bone mineral density and menstrual function in adolescent female long-distance runners - A prospective comparative study of bone structure and menstrual function in adolescent female endurance athletes from five secondary schools in Pretoria.

Influence of Body Weight on Bone Mass, Architecture, and Turnover

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Iwaniec, Urszula T.; Turner, Russell T.

2016-01-01

Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. While the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size. PMID:27352896

Functional Diversity of Fibroblast Growth Factors in Bone Formation

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Yuichiro Takei

2015-01-01

Full Text Available The functional significance of fibroblast growth factor (FGF signaling in bone formation has been demonstrated through genetic loss-of-function and gain-of-function approaches. FGFs, comprising 22 family members, are classified into three subfamilies: canonical, hormone-like, and intracellular. The former two subfamilies activate their signaling pathways through FGF receptors (FGFRs. Currently, intracellular FGFs appear to be primarily involved in the nervous system. Canonical FGFs such as FGF2 play significant roles in bone formation, and precise spatiotemporal control of FGFs and FGFRs at the transcriptional and posttranscriptional levels may allow for the functional diversity of FGFs during bone formation. Recently, several research groups, including ours, have shown that FGF23, a member of the hormone-like FGF subfamily, is primarily expressed in osteocytes/osteoblasts. This polypeptide decreases serum phosphate levels by inhibiting renal phosphate reabsorption and vitamin D3 activation, resulting in mineralization defects in the bone. Thus, FGFs are involved in the positive and negative regulation of bone formation. In this review, we focus on the reciprocal roles of FGFs in bone formation in relation to their local versus systemic effects.

Microanatomical and histological features in the long bones of Mosasaurine mosasaurs (Reptilia, Squamata)--implications for aquatic adaptation and growth rates.

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Houssaye, Alexandra; Lindgren, Johan; Pellegrini, Rodrigo; Lee, Andrew H; Germain, Damien; Polcyn, Michael J

2013-01-01

During their evolution in the Late Cretaceous, mosasauroids attained a worldwide distribution, accompanied by a marked increase in body size and open ocean adaptations. This transition from land-dwellers to highly marine-adapted forms is readily apparent not only at the gross anatomic level but also in their inner bone architecture, which underwent profound modifications. The present contribution describes, both qualitatively and quantitatively, the internal organization (microanatomy) and tissue types and characteristics (histology) of propodial and epipodial bones in one lineage of mosasauroids; i.e., the subfamily Mosasaurinae. By using microanatomical and histological data from limb bones in combination with recently acquired knowledge on the inner structure of ribs and vertebrae, and through comparisons with extant squamates and semi-aquatic to fully marine amniotes, we infer possible implications on mosasaurine evolution, aquatic adaptation, growth rates, and basal metabolic rates. Notably, we observe the occurrence of an unusual type of parallel-fibered bone, with large and randomly shaped osteocyte lacunae (otherwise typical of fibrous bone) and particular microanatomical features in Dallasaurus, which displays, rather than a spongious inner organization, bone mass increase in its humeri and a tubular organization in its femora and ribs. The dominance of an unusual type of parallel-fibered bone suggests growth rates and, by extension, basal metabolic rates intermediate between that of the extant leatherback turtle, Dermochelys, and those suggested for plesiosaur and ichthyosaur reptiles. Moreover, the microanatomical features of the relatively primitive genus Dallasaurus differ from those of more derived mosasaurines, indicating an intermediate stage of adaptation for a marine existence. The more complete image of the various microanatomical trends observed in mosasaurine skeletal elements supports the evolutionary convergence between this lineage of

Microanatomical and histological features in the long bones of Mosasaurine mosasaurs (Reptilia, Squamata--implications for aquatic adaptation and growth rates.

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Alexandra Houssaye

Full Text Available BACKGROUND: During their evolution in the Late Cretaceous, mosasauroids attained a worldwide distribution, accompanied by a marked increase in body size and open ocean adaptations. This transition from land-dwellers to highly marine-adapted forms is readily apparent not only at the gross anatomic level but also in their inner bone architecture, which underwent profound modifications. METHODOLOGY/PRINCIPAL FINDINGS: The present contribution describes, both qualitatively and quantitatively, the internal organization (microanatomy and tissue types and characteristics (histology of propodial and epipodial bones in one lineage of mosasauroids; i.e., the subfamily Mosasaurinae. By using microanatomical and histological data from limb bones in combination with recently acquired knowledge on the inner structure of ribs and vertebrae, and through comparisons with extant squamates and semi-aquatic to fully marine amniotes, we infer possible implications on mosasaurine evolution, aquatic adaptation, growth rates, and basal metabolic rates. Notably, we observe the occurrence of an unusual type of parallel-fibered bone, with large and randomly shaped osteocyte lacunae (otherwise typical of fibrous bone and particular microanatomical features in Dallasaurus, which displays, rather than a spongious inner organization, bone mass increase in its humeri and a tubular organization in its femora and ribs. CONCLUSIONS/SIGNIFICANCE: The dominance of an unusual type of parallel-fibered bone suggests growth rates and, by extension, basal metabolic rates intermediate between that of the extant leatherback turtle, Dermochelys, and those suggested for plesiosaur and ichthyosaur reptiles. Moreover, the microanatomical features of the relatively primitive genus Dallasaurus differ from those of more derived mosasaurines, indicating an intermediate stage of adaptation for a marine existence. The more complete image of the various microanatomical trends observed in mosasaurine

Sex-specific functional adaptation of the femoral diaphysis to body composition.

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Lacoste Jeanson, Alizé; Santos, Frédéric; Dupej, Ján; Velemínská, Jana; Brůžek, Jaroslav

2018-03-24

The human femoral diaphysis is often used to reconstruct loading histories (mobility, activity, body mass). The proximal femur is known to be differentially affected by changes in total fat-mass (FM), fat-free mass (FFM), and body fat percentage (BF%), but the adaptation of the entire diaphysis to body composition has not been thoroughly characterized to date. Understanding how the femoral diaphysis adapts to body components would benefit biomechanical interpretations of the femoral variation and nutrition-related studies. Combining various methods from clinical nutrition, biological anthropology, and geometric morphometrics, we evaluated the correlation of measures taken on the entire femoral diaphysis with estimated FM, FFM, and BF% from 61 CT scans (17 females, 44 males). The sample was predominantly composed of people with obesity. Cortical area of the cross-sections and local cortical thickness showed high correlation with BF% in particular, in females only. The curvature significantly decreased with FM and BF% in both sexes. The lowest correlations are found with FFM. The observed sexual dimorphism is consistent with differing aging processes; cortical bone decreases in females through endosteal resorption while it remains almost constant in males who compensate for endosteal resorption by periosteal apposition on the diaphyseal surface. The functional adaptation to compressive forces indicates a systemic endosteal apposition of bone material with increased BF% and FM in females only. FM and BF% are linked to a straighter femur in both sexes, suggesting an optimization of the resistance to compressive loads by distributing them more linearly along the entire diaphysis. © 2018 Wiley Periodicals, Inc.

Maxillary Bone Regeneration Based on Nanoreservoirs Functionalized ε-Polycaprolactone Biomembranes in a Mouse Model of Jaw Bone Lesion

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Marion Strub

2018-01-01

Full Text Available Current approaches of regenerative therapies constitute strategies for bone tissue reparation and engineering, especially in the context of genetical diseases with skeletal defects. Bone regeneration using electrospun nanofibers’ implant has the following objectives: bone neoformation induction with rapid healing, reduced postoperative complications, and improvement of bone tissue quality. In vivo implantation of polycaprolactone (PCL biomembrane functionalized with BMP-2/Ibuprofen in mouse maxillary defects was followed by bone neoformation kinetics evaluation using microcomputed tomography. Wild-Type (WT and Tabby (Ta mice were used to compare effects on a normal phenotype and on a mutant model of ectodermal dysplasia (ED. After 21 days, no effect on bone neoformation was observed in Ta treated lesion (4% neoformation compared to 13% in the control lesion. Between the 21st and the 30th days, the use of biomembrane functionalized with BMP-2/Ibuprofen in maxillary bone lesions allowed a significant increase in bone neoformation peaks (resp., +8% in mutant Ta and +13% in WT. Histological analyses revealed a neoformed bone with regular trabecular structure, areas of mineralized bone inside the membrane, and an improved neovascularization in the treated lesion with bifunctionalized membrane. In conclusion, PCL functionalized biomembrane promoted bone neoformation, this effect being modulated by the Ta bone phenotype responsible for an alteration of bone response.

Functional microimaging. A hierarchical investigation of bone failure behavior

International Nuclear Information System (INIS)

Voide, Romain; Lenthe, G.Harry van; Stauber, Martin; Schneider, Philipp; Thurner, Philipp J.; Mueller, Ralph; Wyss, Peter; Stampanoni, Marco

2008-01-01

Biomechanical testing is the gold standard to determine bone competence, and has been used extensively. Direct mechanical testing provides detailed information on overall bone mechanical and material properties, but fails in revealing local properties such as local deformations and strains and does not permit quantification of fracture progression. Therefore, we incorporated several imaging methods in our mechanical setups to get a better insight into bone deformation and failure characteristics on various levels of structural organization. Our aim was to develop an integrative approach for hierarchical investigation of bone, working at different scales of resolution ranging from the whole bone to its ultrastructure. Inbred strains of mice make useful models to study bone properties. In this study, we concentrated on C57BL/6 (B6) and in C3H/He (C3H) mice, two strains known for their differences in bone phenotype. At the macroscopic level, we used high-resolution and high-speed cameras which allowed to visualize global failure behavior and fracture initiation with high temporal resolution. This image data proved especially important when dealing with small bones such as murine femora. At the microscopic level, bone microstructure, i.e. trabecular architecture and cortical porosity, are known to influence bone strength and failure mechanisms significantly. For this reason, we developed an image-guided failure assessment technique, also referred to as functional microimaging, allowing direct time-lapsed three-dimensional visualization and computation of local displacements and strains for better quantification of fracture initiation and progression. While the resolution of conventional desktop micro-computed tomography is typically around a few micrometers, computer tomography systems based on highly brilliant synchrotron radiation X-ray sources permit to explore the sub-micrometer world. This allowed, for the first time, to uncover fully nondestructively the 3D

Expression and Function of Myostatin in Obesity, Diabetes, and Exercise Adaptation

Science.gov (United States)

Allen, David L.; Hittel, Dustin S.; McPherron, Alexandra C.

2011-01-01

Myostatin is a member of the transforming growth factor-beta/bone morphogenetic protein (TGF-β/BMP) super-family of secreted factors that functions as a potent inhibitor of skeletal muscle growth. Moreover, considerable evidence has accumulated that myostatin also regulates metabolism and that its inhibition can significantly attenuate the progression of obesity and diabetes. While at least part of these effects on metabolism can be attributable to myostatin’s influence over skeletal muscle growth and therefore on the total volume of metabolically active lean body mass, there is mounting evidence that myostatin affects the growth and metabolic state of other tissues, including the adipose and the liver. In addition, recent work has explored the role of myostatin in substrate mobilization, uptake and/or utilization of muscle independent of its effects on body composition. Finally, the effects of both endurance and resistance exercise on myostatin expression, as well as the potential role of myostatin in the beneficial metabolic adaptations occurring in response to exercise, have also begun to be delineated in greater detail. The purpose of this review is to summarize the work to date on the expression and function of myostatin in obesity, diabetes, and exercise adaptation. PMID:21364474

The role of vasculature in bone development, regeneration and proper systemic functioning.

Science.gov (United States)

Filipowska, Joanna; Tomaszewski, Krzysztof A; Niedźwiedzki, Łukasz; Walocha, Jerzy A; Niedźwiedzki, Tadeusz

2017-08-01

Bone is a richly vascularized connective tissue. As the main source of oxygen, nutrients, hormones, neurotransmitters and growth factors delivered to the bone cells, vasculature is indispensable for appropriate bone development, regeneration and remodeling. Bone vasculature also orchestrates the process of hematopoiesis. Blood supply to the skeletal system is provided by the networks of arteries and arterioles, having distinct molecular characteristics and localizations within the bone structures. Blood vessels of the bone develop through the process of angiogenesis, taking place through different, bone-specific mechanisms. Impaired functioning of the bone blood vessels may be associated with the occurrence of some skeletal and systemic diseases, i.e., osteonecrosis, osteoporosis, atherosclerosis or diabetes mellitus. When a disease or trauma-related large bone defects appear, bone grafting or bone tissue engineering-based strategies are required. However, a successful bone regeneration in both approaches largely depends on a proper blood supply. In this paper, we review the most recent data on the functions, molecular characteristics and significance of the bone blood vessels, with a particular emphasis on the role of angiogenesis and blood vessel functioning in bone development and regeneration, as well as the consequences of its impairment in the course of different skeletal and systemic diseases.

Alertness function of thalamus in conflict adaptation.

Science.gov (United States)

Wang, Xiangpeng; Zhao, Xiaoyue; Xue, Gui; Chen, Antao

2016-05-15

Conflict adaptation reflects the ability to improve current conflict resolution based on previously experienced conflict, which is crucial for our goal-directed behaviors. In recent years, the roles of alertness are attracting increasing attention when discussing the generation of conflict adaptation. However, due to the difficulty of manipulating alertness, very limited progress has been made in this line. Inspired by that color may affect alertness, we manipulated background color of experimental task and found that conflict adaptation significantly presented in gray and red backgrounds but did not in blue background. Furthermore, behavioral and functional magnetic resonance imaging results revealed that the modulation of color on conflict adaptation was implemented through changing alertness level. In particular, blue background eliminated conflict adaptation by damping the alertness regulating function of thalamus and the functional connectivity between thalamus and inferior frontal gyrus (IFG). In contrast, in gray and red backgrounds where alertness levels are typically high, the thalamus and the right IFG functioned normally and conflict adaptations were significant. Therefore, the alertness function of thalamus is determinant to conflict adaptation, and thalamus and right IFG are crucial nodes of the neural circuit subserving this ability. Present findings provide new insights into the neural mechanisms of conflict adaptation. Copyright © 2016 Elsevier Inc. All rights reserved.

Cytogenetic adaptive response of mouse bone marrow cells to low level HTO

International Nuclear Information System (INIS)

Chen Deqing; Zhang Zhaoyang; Zhou Xiangyan

1993-01-01

Mice were abdominally injected with a adaptive dose of 3.7 x 10 2 -3.7 x 10 5 Bq/gbw HTO, and then exposed to a challenge dose of 1.5 Gy of 6 '0Co γ-rays. In bone marrow cells that received both the adaptive and challenge doses, the chromatid breaks are lower than expected on the basis of additivity of the effects of the individual treatment. The adaptive response induced with 3.7 x 10 3 Bq/gbw HTO is the most remarkable, but at 3.7 x 10 5 Bq/gbw the adaptive response seems to disappear. The adaptive response can be observed by exposing to 1.5 Gy γ-rays from 1 to 5 days after injection of 3.7 x 10 3 Bq/gbw HTO, which is the most obvious one to reduce chromatid breaks to 50% of expected at the 5th day, but at the 7th day to equate to expected. The frequency of chromatid breaks is gradually reduced with time after challenge dose, the maximum index number of adaptive response is 0.50 and appears at 24 hr after challenge dose

The emerging role of bone marrow adipose tissue in bone health and dysfunction.

Science.gov (United States)

Ambrosi, Thomas H; Schulz, Tim J

2017-12-01

Replacement of red hematopoietic bone marrow with yellow adipocyte-rich marrow is a conserved physiological process among mammals. The extent of this conversion is influenced by a wide array of pathological and non-pathological conditions. Of particular interest is the observation that some marrow adipocyte-inducing factors seem to oppose each other, for instance obesity and caloric restriction. Intriguingly, several important molecular characteristics of bone marrow adipose tissue (BMAT) are distinct from the classical depots of white and brown fat tissue. This depot of fat has recently emerged as an active part of the bone marrow niche that exerts paracrine and endocrine functions thereby controlling osteogenesis and hematopoiesis. While some functions of BMAT may be beneficial for metabolic adaptation and bone homeostasis, respectively, most findings assign bone fat a detrimental role during regenerative processes, such as hematopoiesis and osteogenesis. Thus, an improved understanding of the biological mechanisms leading to formation of BMAT, its molecular characteristics, and its physiological role in the bone marrow niche is warranted. Here we review the current understanding of BMAT biology and its potential implications for health and the development of pathological conditions.

Adaptation of BAp crystal orientation to stress distribution in rat mandible during bone growth

Energy Technology Data Exchange (ETDEWEB)

Nakano, T; Fujitani, W; Ishimoto, T [Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1, Yamada-oka, Suita, Osaka 565-0871 (Japan); Umakoshi, Y [National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaragi, 305-0471 (Japan)], E-mail: nakano@mat.eng.osaka-u.ac.jp

2009-05-01

Biological apatite (BAp) c-axis orientation strongly depends on stress distribution in vivo and tends to align along the principal stress direction in bones. Dentulous mandible is subjected to a complicated stress condition in vivo during chewing but few studies have been carried out on the BAp c-axis orientation; so the adaptation of BAp crystal orientation to stress distribution was examined in rat dentulous mandible during bone growth and mastication. Female SD rats 4 to 14 weeks old were prepared, and the bone mineral density (BMD) and BAp crystal orientation were analyzed in a cross-section of mandible across the first molar focusing on two positions: separated from and just under the tooth root on the same cross-section perpendicular to the mesiodistal axis. The degree of BAp orientation was analyzed by a microbeam X-ray diffractometer using Cu-K{alpha} radiation equipped with a detector of curved one-dimensional PSPC and two-dimensional PSPC in the reflection and transmission optics, respectively. BMD quickly increased during bone growth up to 14 weeks, although it was independent of the position from the tooth root. In contrast, BAp crystal orientation strongly depended on the age and the position from the tooth root, even in the same cross-section and direction, especially along the mesiodistal and the biting axes. With increased biting stress during bone growth, the degree of BAp orientation increased along the mesiodistal axis in a position separated from the tooth root more than that near the tooth root. In contrast, BAp preferential alignment clearly appeared along the biting axis near the tooth root. We conclude that BAp orientation rather than BMD sensitively adapts to local stress distribution, especially from the chewing stress in vivo in the mandible.

IL-6 and IGF-1 signaling within and between muscle and bone: how important is the mTOR pathway for bone metabolism?

NARCIS (Netherlands)

Bakker, A.D.; Jaspers, R.T.

2015-01-01

Insulin-like growth factor 1 (IGF-1) and interleukin 6 (IL-6) play an important role in the adaptation of both muscle and bone to mechanical stimuli. Here, we provide an overview of the functions of IL-6 and IGF-1 in bone and muscle metabolism, and the intracellular signaling pathways that are well

IL-6 and IGF-1 Signaling within, and between, Muscle and Bone: How Important is the mTOR Pathway for Bone Metabolism?

NARCIS (Netherlands)

Bakker, A.D.; Jaspers, R.T.

2015-01-01

Insulin-like growth factor 1 (IGF-1) and interleukin 6 (IL-6) play an important role in the adaptation of both muscle and bone to mechanical stimuli. Here, we provide an overview of the functions of IL-6 and IGF-1 in bone and muscle metabolism, and the intracellular signaling pathways that are well

Edentulation alters material properties of cortical bone in the human craniofacial skeleton: functional implications for craniofacial structure in primate evolution

Science.gov (United States)

Dechow, Paul C.; Wang, Qian; Peterson, Jill

2011-01-01

Skeletal adaptations to reduced function are an important source of skeletal variation and may be indicative of environmental pressures that lead to evolutionary changes. Humans serve as a model animal to investigate the effects of loss of craniofacial function through edentulation. In the human maxilla, it is known that edentulation leads to significant changes in skeletal structure such as residual ridge resorption and loss of cortical thickness. However, little is known about changes in bone tissue structure and material properties, which are also important for understanding skeletal mechanics but are often ignored. The aims of this study were to determine cortical material properties in edentulous crania and to evaluate differences with dentate crania and thus examine the effects of loss of function on craniofacial structure. Cortical bone samples from fifteen edentulous human skulls were measured for thickness and density. Elastic properties and directions of maximum stiffness were determined by using ultrasonic techniques. These data were compared to those from dentate crania reported in a previous investigation. Cortical bone from all regions of the facial skeleton of edentulous individuals is thinner than in dentate skulls. Elastic and shear moduli, and density are similar or greater in the zygoma and cranial vault of edentulous individuals, while these properties are less in the maxilla. Most cortical bone, especially in edentulous maxillae, has reduced directional orientation. The loss of significant occlusal loads following edentulation may contribute to the change in material properties and the loss of orientation over time during the normal process of bone remodeling. These results suggest that area-specific cortical microstructural changes accompany bone resorption following edentulation. They also suggest that functional forces are important for maintaining bone mass throughout the craniofacial skeleton, even in areas such as the browridges, which

In vivo engineering of bone tissues with hematopoietic functions and mixed chimerism.

Science.gov (United States)

Shih, Yu-Ru; Kang, Heemin; Rao, Vikram; Chiu, Yu-Jui; Kwon, Seong Keun; Varghese, Shyni

2017-05-23

Synthetic biomimetic matrices with osteoconductivity and osteoinductivity have been developed to regenerate bone tissues. However, whether such systems harbor donor marrow in vivo and support mixed chimerism remains unknown. We devised a strategy to engineer bone tissues with a functional bone marrow (BM) compartment in vivo by using a synthetic biomaterial with spatially differing cues. Specifically, we have developed a synthetic matrix recapitulating the dual-compartment structures by modular assembly of mineralized and nonmineralized macroporous structures. Our results show that these matrices incorporated with BM cells or BM flush transplanted into recipient mice matured into functional bone displaying the cardinal features of both skeletal and hematopoietic compartments similar to native bone tissue. The hematopoietic function of bone tissues was demonstrated by its support for a higher percentage of mixed chimerism compared with i.v. injection and donor hematopoietic cell mobilization in the circulation of nonirradiated recipients. Furthermore, hematopoietic cells sorted from the engineered bone tissues reconstituted the hematopoietic system when transplanted into lethally irradiated secondary recipients. Such engineered bone tissues could potentially be used as ectopic BM surrogates for treatment of nonmalignant BM diseases and as a tool to study hematopoiesis, donor-host cell dynamics, tumor tropism, and hematopoietic cell transplantation.

Changes of thyroid function, autoantibodies, bone mineral density and bone metabolism indexes in patients with hyperthyroidism

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Yan Wang

2016-07-01

Full Text Available Objective: To investigate the changes of thyroid function, autoantibodies, bone mineral density and bone metabolism in patients with hyperthyroidism. Methods: A total of 216 cases of hyperthyroidism in our hospital from December 2015 to January 2015 were selected as the case group, 216 cases of healthy people selected the same period in our hospital physical examination center as the control group, detected thyroid function, autoantibodies, bone mineral density and bone metabolism indexes of all the studied subjects and compared with each other. Results: In this study, it was found that diastolic blood pressure, BMI, triglyceride, total cholesterol, HDL-C, VLDL-C, TSH were all significantly lower than the control group (P<0.05, systolic blood pressure, LDL-C, GLU, T3, T4, FT3, FT4, HTG, TG-Ab, TPO-Ab in case group were significantly higher than the control group (P<0.05. Right calcaneal speed of sound (SOS in case group was significantly lower than the control group (P<0.05, BGP, PTH in case group were significantly higher than the control group (P<0.05. Conclusions: Hyperthyroidism can cause thyroid hormone levels abnormal, abnormal increase autoantibodies, decrease bone density, bone metabolism actively, easy to form osteoporosis, clinical treatment of hyperthyroidism in the same time, should actively prevent the occurrence of osteoporosis

Function of Matrix IGF-1 in Coupling Bone Resorption and Formation

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Crane, Janet L.; Cao, Xu

2013-01-01

Balancing bone resorption and formation is the quintessential component for the prevention of osteoporosis. Signals that determine the recruitment, replication, differentiation, function, and apoptosis of osteoblasts and osteoclasts direct bone remodeling and determine whether bone tissue is gained, lost, or balanced. Therefore understanding the signaling pathways involved in the coupling process will help develop further targets for osteoporosis therapy, by blocking bone resorption or enhancing bone formation in a space and time dependent manner. Insulin-like growth factor type 1 (IGF-1) has long been known to play a role in bone strength. It is one of the most abundant substances in the bone matrix, circulates systemically and is secreted locally, and has a direct relationship with bone mineral density. Recent data has helped further our understanding of the direct role of IGF-1 signaling in coupling bone remodeling which will be discussed in this review. The bone marrow microenvironment plays a critical role in the fate of MSCs and HSCs and thus how IGF-1 interacts with other factors in the microenvironment are equally important. While previous clinical trials with IGF-1 administration have been unsuccessful at enhancing bone formation, advances in basic science studies have provided insight into further mechanisms that should be considered for future trials. Additional basic science studies dissecting the regulation and the function of matrix IGF-1 in modeling and remodeling will continue to provide further insight for future directions for anabolic therapies for osteoporosis. PMID:24068256

Function of matrix IGF-1 in coupling bone resorption and formation.

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Crane, Janet L; Cao, Xu

2014-02-01

Balancing bone resorption and formation is the quintessential component for the prevention of osteoporosis. Signals that determine the recruitment, replication, differentiation, function, and apoptosis of osteoblasts and osteoclasts direct bone remodeling and determine whether bone tissue is gained, lost, or balanced. Therefore, understanding the signaling pathways involved in the coupling process will help develop further targets for osteoporosis therapy, by blocking bone resorption or enhancing bone formation in a space- and time-dependent manner. Insulin-like growth factor type 1 (IGF-1) has long been known to play a role in bone strength. It is one of the most abundant substances in the bone matrix, circulates systemically and is secreted locally, and has a direct relationship with bone mineral density. Recent data has helped further our understanding of the direct role of IGF-1 signaling in coupling bone remodeling which will be discussed in this review. The bone marrow microenvironment plays a critical role in the fate of mesenchymal stem cells and hematopoietic stem cells and thus how IGF-1 interacts with other factors in the microenvironment are equally important. While previous clinical trials with IGF-1 administration have been unsuccessful at enhancing bone formation, advances in basic science studies have provided insight into further mechanisms that should be considered for future trials. Additional basic science studies dissecting the regulation and the function of matrix IGF-1 in modeling and remodeling will continue to provide further insight for future directions for anabolic therapies for osteoporosis.

Receptor tyrosine kinase inhibition causes simultaneous bone loss and excess bone formation within growing bone in rats

International Nuclear Information System (INIS)

Nurmio, Mirja; Joki, Henna; Kallio, Jenny; Maeaettae, Jorma A.; Vaeaenaenen, H. Kalervo; Toppari, Jorma; Jahnukainen, Kirsi; Laitala-Leinonen, Tiina

2011-01-01

During postnatal skeletal growth, adaptation to mechanical loading leads to cellular activities at the growth plate. It has recently become evident that bone forming and bone resorbing cells are affected by the receptor tyrosine kinase (RTK) inhibitor imatinib mesylate (STI571, Gleevec (registered) ). Imatinib targets PDGF, ABL-related gene, c-Abl, c-Kit and c-Fms receptors, many of which have multiple functions in the bone microenvironment. We therefore studied the effects of imatinib in growing bone. Young rats were exposed to imatinib (150 mg/kg on postnatal days 5-7, or 100 mg/kg on postnatal days 5-13), and the effects of RTK inhibition on bone physiology were studied after 8 and 70 days (3-day treatment), or after 14 days (9-day treatment). X-ray imaging, computer tomography, histomorphometry, RNA analysis and immunohistochemistry were used to evaluate bone modeling and remodeling in vivo. Imatinib treatment eliminated osteoclasts from the metaphyseal osteochondral junction at 8 and 14 days. This led to a resorption arrest at the growth plate, but also increased bone apposition by osteoblasts, thus resulting in local osteopetrosis at the osteochondral junction. The impaired bone remodelation observed on day 8 remained significant until adulthood. Within the same bone, increased osteoclast activity, leading to bone loss, was observed at distal bone trabeculae on days 8 and 14. Peripheral quantitative computer tomography (pQCT) and micro-CT analysis confirmed that, at the osteochondral junction, imatinib shifted the balance from bone resorption towards bone formation, thereby altering bone modeling. At distal trabecular bone, in turn, the balance was turned towards bone resorption, leading to bone loss. - Research highlights: → 3-Day imatinib treatment. → Causes growth plate anomalies in young rats. → Causes biomechanical changes and significant bone loss at distal trabecular bone. → Results in loss of osteoclasts at osteochondral junction.

Adaptations in the Microarchitecture and Load Distribution of Maternal Cortical and Trabecular Bone in Response to Multiple Reproductive Cycles in Rats

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de Bakker, Chantal M. J.; Altman-Singles, Allison R.; Li, Yihan; Tseng, Wei-Ju; Li, Connie; Liu, X. Sherry

2017-01-01

Pregnancy, lactation, and weaning result in dramatic changes in maternal calcium metabolism. In particular, the increased calcium demand during lactation causes a substantial degree of maternal bone loss. This reproductive bone loss has been suggested to be largely reversible, as multiple clinical studies have found that parity and lactation history have no adverse effect on post-menopausal fracture risk. However, the precise effects of pregnancy, lactation, and post-weaning recovery on maternal bone structure are not well understood. Our study aimed to address this question by longitudinally tracking changes in trabecular and cortical bone microarchitecture at the proximal tibia in rats throughout three cycles of pregnancy, lactation, and post-weaning using in vivo μCT. We found that the trabecular thickness underwent a reversible deterioration during pregnancy and lactation, which was fully recovered after weaning, while other parameters of trabecular microarchitecture (including trabecular number, spacing, connectivity density, and structure model index) underwent a more permanent deterioration which recovered minimally. Thus, pregnancy and lactation resulted in both transient and long-lasting alterations in trabecular microstructure. In the meantime, multiple reproductive cycles appeared to improve the robustness of cortical bone (resulting in an elevated cortical area and polar moment of inertia), as well as increase the proportion of the total load carried by the cortical bone at the proximal tibia. Taken together, changes in the cortical and trabecular compartments suggest that while rat tibial trabecular bone appears to be highly involved in maintaining calcium homeostasis during female reproduction, cortical bone adapts to increase its load-bearing capacity, allowing the overall mechanical function of the tibia to be maintained. PMID:28109138

The role of P2X receptors in bone biology.

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Jørgensen, N R; Syberg, S; Ellegaard, M

2015-01-01

Bone is a highly dynamic organ, being constantly modeled and remodeled in order to adapt to the changing need throughout life. Bone turnover involves the coordinated actions of bone formation and bone degradation. Over the past decade great effort has been put into the examination of how P2X receptors regulate bone metabolism and especially for the P2X7 receptor an impressive amount of evidence has now documented its expression in osteoblasts, osteoclasts, and osteocytes as well as important functional roles in proliferation, differentiation, and function of the cells of bone. Key evidence has come from studies on murine knockout models and from pharmacologic studies on cells and animals. More recently, the role of P2X receptors in human bone diseases has been documented. Loss-of-functions polymorphisms in the P2X7 receptorare associated with bone loss and increased fracture risk. Very recently a report from a genetic study in multiple myeloma demonstrated that decreased P2X7 receptor function was associated with increased risk of developing multiple myeloma. In contrast, the risk of developing myeloma bone disease and subsequent vertebral fractures was increased in subjects carrying P2X7 receptor gain-of-function alleles as compared to subjects only carrying loss-of-function or normal functioning alleles. It is evident that P2X receptors are important in regulating bone turnover and maintaining bone mass, and thereby holding great potential as novel drug targets for treatment of bone diseases. However, further research is needed before we fully understand the roles and effects of P2X receptors in bone.

Functions and Epigenetic Regulation of Wwox in Bone Metastasis from Breast Carcinoma: Comparison with Primary Tumors

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Paola Maroni

2017-01-01

Full Text Available Epigenetic mechanisms influence molecular patterns important for the bone-metastatic process, and here we highlight the role of WW-domain containing oxidoreductase (Wwox. The tumor-suppressor Wwox lacks in almost all cancer types; the variable expression in osteosarcomas is related to lung-metastasis formation, and exogenous Wwox destabilizes HIF-1α (subunit of Hypoxia inducible Factor-1, HIF-1 affecting aerobic glycolysis. Our recent studies show critical functions of Wwox present in 1833-osteotropic clone, in the corresponding xenograft model, and in human bone metastasis from breast carcinoma. In hypoxic-bone metastatic cells, Wwox enhances HIF-1α stabilization, phosphorylation, and nuclear translocation. Consistently, in bone-metastasis specimens Wwox localizes in cytosolic/perinuclear area, while TAZ (transcriptional co-activator with PDZ-binding motif and HIF-1α co-localize in nuclei, playing specific regulatory mechanisms: TAZ is a co-factor of HIF-1, and Wwox regulates HIF-1 activity by controlling HIF-1α. In vitro, DNA methylation affects Wwox-protein synthesis; hypoxia decreases Wwox-protein level; hepatocyte growth factor (HGF phosphorylates Wwox driving its nuclear shuttle, and counteracting a Twist program important for the epithelial phenotype and metastasis colonization. In agreement, in 1833-xenograft mice under DNA-methyltransferase blockade with decitabine, Wwox increases in nuclei/cytosol counteracting bone metastasis with prolongation of the survival. However, Wwox seems relevant for the autophagic process which sustains metastasis, enhancing more Beclin-1 than p62 protein levels, and p62 accumulates under decitabine consistent with adaptability of metastasis to therapy. In conclusion, Wwox methylation as a bone-metastasis therapeutic target would depend on autophagy conditions, and epigenetic mechanisms regulating Wwox may influence the phenotype of bone metastasis.

The functional muscle-bone unit in children with cerebral palsy.

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Duran, I; Schütz, F; Hamacher, S; Semler, O; Stark, C; Schulze, J; Rittweger, J; Schoenau, E

2017-07-01

Our results suggest that the prevalence of bone health deficits in children with CP was overestimated, when using only age- and height-adjusted bone mineral content (BMC) and areal bone mineral density (aBMD). When applying the functional muscle-bone unit diagnostic algorithm (FMBU-A), the prevalence of positive results decreased significantly. We recommend applying the FMBU-A when assessing bone health in children with CP. The prevalence of bone health deficits in children with cerebral palsy (CP) might be overestimated because age- and height-adjusted reference percentiles for bone mineral content (BMC) and areal bone mineral density (aBMD) assessed by dual-energy X-ray absorptiometry (DXA) do not consider reduced muscle activity. The aim of this study was to compare the prevalence of positive DXA-based indicators for bone health deficits in children with CP to the prevalence of positive findings after applying a functional muscle-bone unit diagnostic algorithm (FMBU-A) considering reduced muscle activity. The present study was a monocentric retrospective analysis of 297 whole body DXA scans of children with CP. The prevalence of positive results of age- and height-adjusted BMC and aBMD defined as BMC and aBMD below the P3 percentile and of the FMBU-A was calculated. In children with CP, the prevalence of positive results of age-adjusted BMC were 33.3% and of aBMD 50.8%. Height-adjusted results for BMC and aBMD were positive in 16.8 and 36.0% of cases. The prevalence of positive results applying the FMBU-A regarding BMC and aBMD were significantly (p BMC and aBMD (8.8 and 14.8%). Our results suggest that the prevalence of bone health deficits in children with CP was overestimated, when using age- and height-adjusted BMC and aBMD. When applying the FMBU-A, the prevalence decreased significantly. We recommend applying the FMBU-A when assessing bone health in children with CP.

Bone remodelling: its local regulation and the emergence of bone fragility.

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Martin, T John; Seeman, Ego

2008-10-01

Bone modelling prevents the occurrence of damage by adapting bone structure - and hence bone strength - to its loading circumstances. Bone remodelling removes damage, when it inevitably occurs, in order to maintain bone strength. This cellular machinery is successful during growth, but fails during advancing age because of the development of a negative balance between the volumes of bone resorbed and formed during remodelling by the basic multicellular unit (BMU), high rates of remodelling during midlife in women and late in life in both sexes, and a decline in periosteal bone formation. together resulting in bone loss and structural decay each time a remodelling event occurs. The two steps in remodelling - resorption of a volume of bone by osteoclasts and formation of a comparable volume by osteoblasts - are sequential, but the regulatory events leading to these two fully differentiated functions are not. Reparative remodelling is initiated by damage producing osteocyte apoptosis, which signals the location of damage via the osteocyte canalicular system to endosteal lining cells which forms the canopy of a bone-remodelling compartment (BRC). Within the BRC, local recruitment of osteoblast precursors from the lining cells, the marrow and circulation, direct contact with osteoclast precursors, osteoclastogenesis and molecular cross-talk between precursors, mature cells, cells of the immune system, and products of the resorbed matrix, titrate the birth, work and lifespan of the cells of this multicellular remodelling machinery to either remove or form a net volume of bone appropriate to the mechanical requirements.

Exploring bone dynamics using in-vivo micro-CT imaging

NARCIS (Netherlands)

J.H. Waarsing (Jan)

2006-01-01

textabstractBone is an active organ that adapts its shape to the (mechanical) environment. The general mechanisms behind bone adaptation remain largely unknown. In this thesis a new imaging modality for bone research is introduced and used to investigate various aspects of bone adaptation. The

Exercise Preserves Physical Function in Prostate Cancer Patients with Bone Metastases.

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Galvão, Daniel A; Taaffe, Dennis R; Spry, Nigel; Cormie, Prue; Joseph, David; Chambers, Suzanne K; Chee, Raphael; Peddle-McIntyre, Carolyn J; Hart, Nicolas H; Baumann, Freerk T; Denham, James; Baker, Michael; Newton, Robert U

2018-03-01

The presence of bone metastases has excluded participation of cancer patients in exercise interventions and is a relative contraindication to supervised exercise in the community setting because of concerns of fragility fracture. We examined the efficacy and safety of a modular multimodal exercise program in prostate cancer patients with bone metastases. Between 2012 and 2015, 57 prostate cancer patients (70.0 ± 8.4 yr; body mass index, 28.7 ± 4.0 kg·m) with bone metastases (pelvis, 75.4%; femur, 40.4%; rib/thoracic spine, 66.7%; lumbar spine, 43.9%; humerus, 24.6%; other sites, 70.2%) were randomized to multimodal supervised aerobic, resistance, and flexibility exercises undertaken thrice weekly (EX; n = 28) or usual care (CON; n = 29) for 3 months. Physical function subscale of the Medical Outcomes Study Short-Form 36 was the primary end point as an indicator of patient-rated physical functioning. Secondary end points included objective measures of physical function, lower body muscle strength, body composition, and fatigue. Safety was assessed by recording the incidence and severity of any adverse events, skeletal complications, and bone pain throughout the intervention. There was a significant difference between groups for self-reported physical functioning (3.2 points; 95% confidence interval, 0.4-6.0 points; P = 0.028) and lower body muscle strength (6.6 kg; 95% confidence interval, 0.6-12.7; P = 0.033) at 3 months favoring EX. However, there was no difference between groups for lean mass (P = 0.584), fat mass (P = 0.598), or fatigue (P = 0.964). There were no exercise-related adverse events or skeletal fractures and no differences in bone pain between EX and CON (P = 0.507). Multimodal modular exercise in prostate cancer patients with bone metastases led to self-reported improvements in physical function and objectively measured lower body muscle strength with no skeletal complications or increased bone pain. ACTRN12611001158954.

Shoe adaptation after amputation of the II - V phalangeal bones of the foot.

Science.gov (United States)

Rommers, G M; Diepstraten, H J M; Bakker, E; Lindeman, E

2006-12-01

In The Netherlands, about 50% of all amputations of the lower limb are toes and forefoot amputations. Traumata of toes and mid-foot are rare. Preservation of the foot is the primary goal for treatment. Crush injuries of the foot may be associated with prolonged morbidity. This case study presents an insole solution for the solitary first phalangeal bone after amputation of the phalangeal bones II - V. The normal adaptation for forefoot amputations is stiffening of the sole of the shoe and a rocker bar to improve the toe off phase with load reduction of the forefoot. Because the patient had to do excessive stair climbing during work another solution was chosen. As a foot orthosis, a metal soleplate was made in order to have free movement during loading and toe-off during walking. The soleplate gives safety and provides self-adjusting properties after toe off. This enables the shoe technician to make a shoe without a rocker bar or an extra stiff insole. The 0.5 mm custom-made spring-steel plate is also used as a protective in industrial safety shoes. To improve shoe adaptation more research and case reports have to be published in order to inform doctors and shoe technicians about everyday solutions to partial foot amputations.

Bone marrow transplantations to study gene function in hematopoietic cells

NARCIS (Netherlands)

de Winther, Menno P. J.; Heeringa, Peter

2011-01-01

Immune cells are derived from hematopoietic stem cells in the bone marrow. Experimental replacement of bone marrow offers the unique possibility to replace immune cells, to study gene function in mouse models of disease. Over the past decades, this technique has been used extensively to study, for

Alterations to the subchondral bone architecture during osteoarthritis : bone adaptation versus endochondral bone formation

NARCIS (Netherlands)

Cox, L.G.E.; Donkelaar, van C.C.; Rietbergen, van B.; Emans, P.J.; Ito, K.

2013-01-01

Objective Osteoarthritis (OA) is characterized by loss of cartilage and alterations in subchondral bone architecture. Changes in cartilage and bone tissue occur simultaneously and are spatially correlated, indicating that they are probably related. We investigated two hypotheses regarding this

Mechanistic aspects of fracture and R-curve behavior in elk antler bone

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Launey, Maximilien E.; Chen, Po-Yu; McKittrick, Joanna; Ritchie, Robert O.

2009-11-23

Bone is an adaptative material that is designed for different functional requirements; indeed, bones have a variety of properties depending on their role in the body. To understand the mechanical response of bone requires the elucidation of its structure-function relationships. Here, we examine the fracture toughness of compact bone of elk antler which is an extremely fast growing primary bone designed for a totally different function than human (secondary) bone. We find that antler in the transverse (breaking) orientation is one of the toughest biological materials known. Its resistance to fracture is achieved during crack growth (extrinsically) by a combination of gross crack deflection/twisting and crack bridging via uncracked 'ligaments' in the crack wake, both mechanisms activated by microcracking primarily at lamellar boundaries. We present an assessment of the toughening mechanisms acting in antler as compared to human cortical bone, and identify an enhanced role of inelastic deformation in antler which further contributes to its (intrinsic) toughness.

Curved bones: An adaptation to habitual loading.

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Milne, Nick

2016-10-21

Why are long bones curved? It has long been considered a paradox that many long bones supporting mammalian bodies are curved, since this curvature results in the bone undergoing greater bending, with higher strains and so greater fracture risk under load. This study develops a theoretical model wherein the curvature is a response to bending strains imposed by the requirements of locomotion. In particular the radioulna of obligate quadrupeds is a lever operated by the triceps muscle, and the bending strains induced by the triceps muscle counter the bending resulting from longitudinal loads acting on the curved bone. Indeed the theoretical model reverses this logic and suggests that the curvature is itself a response to the predictable bending strains induced by the triceps muscle. This, in turn, results in anatomical arrangements of bone, muscle and tendon that create a simple physiological mechanism whereby the bone can resist the bending due to the action of triceps in supporting and moving the body. The model is illustrated by contrasting the behaviour of a finite element model of a llama radioulna to that of a straightened version of the same bone. The results show that longitudinal and flexor muscle forces produce bending strains that effectively counter strains due to the pull of the triceps muscle in the curved but not in the straightened model. It is concluded that the curvature of these and other curved bones adds resilience to the skeleton by acting as pre-stressed beams or strainable pre-buckled struts. It is also proposed that the cranial bending strains that result from triceps, acting on the lever that is the radioulna, can explain the development of the curvature of such bones. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Translation into Portuguese, cross-cultural adaptation and validation of "The European Organization for Research and Treatment of Cancer-Quality of Life Questionnaire-Bone Metastases-22".

Science.gov (United States)

Miki-Rosário, Natália; Garcia Filho, Reynaldo Jesus; Garcia, Jairo Greco; Dini, Gal Moreira; Bottomley, Andrew; Chow, Edward; Sabino Neto, Miguel

2016-07-01

The aim of the present study was to conduct a cross-cultural adaptation (with translation into Brazilian Portuguese) and validation of the European Organization for Research and Treatment of Cancer-Quality of Life Questionnaire-Bone Metastases-22 (EORTC QLQ-BM22). Ninety-five bone metastasis patients (31 men and 64 women, mean age 58.36±8.90 years) took part in the investigation. The translation guide of the EORTC was used to translate from English into Brazilian Portuguese and adapt the instrument culturally. The reliability and the face, content and construct validities were tested. Internal consistency was estimated using Cronbach's alpha for the total score, pain and functional subscales of the EORTC QLQ-BM22 (0.93, 0.86, 0.90). Reliability was analyzed by Pearson's correlation and intraclass correlation coefficients (ICCs). The correlations were higher than the recommended value of 0.75, which indicated good test-retest reliability. Construct validity was demonstrated by correlation with the questionnaire medical outcome study questionnaire 36-Item Short Form Survey (SF-36). It showed significant correlation between the fields of QLQ-BM22 and the SF-36 (P≤0.001). The EORTC QLQ-BM22 was translated into Brazilian Portuguese, was culturally adapted and was proven to be reliable, with face, content and construct validity.

Estimation of bone Calcium-to-Phosphorous mass ratio using dual-energy nonlinear polynomial functions

International Nuclear Information System (INIS)

Sotiropoulou, P; Koukou, V; Martini, N; Nikiforidis, G; Michail, C; Kandarakis, I; Fountos, G; Kounadi, E

2015-01-01

In this study an analytical approximation of dual-energy inverse functions is presented for the estimation of the calcium-to-phosphorous (Ca/P) mass ratio, which is a crucial parameter in bone health. Bone quality could be examined by the X-ray dual-energy method (XDEM), in terms of bone tissue material properties. Low- and high-energy, log- intensity measurements were combined by using a nonlinear function, to cancel out the soft tissue structures and generate the dual energy bone Ca/P mass ratio. The dual-energy simulated data were obtained using variable Ca and PO 4 thicknesses on a fixed total tissue thickness. The XDEM simulations were based on a bone phantom. Inverse fitting functions with least-squares estimation were used to obtain the fitting coefficients and to calculate the thickness of each material. The examined inverse mapping functions were linear, quadratic, and cubic. For every thickness, the nonlinear quadratic function provided the optimal fitting accuracy while requiring relative few terms. The dual-energy method, simulated in this work could be used to quantify bone Ca/P mass ratio with photon-counting detectors. (paper)

A candidate multimodal functional genetic network for thermal adaptation

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Katharina C. Wollenberg Valero

2014-09-01

Full Text Available Vertebrate ectotherms such as reptiles provide ideal organisms for the study of adaptation to environmental thermal change. Comparative genomic and exomic studies can recover markers that diverge between warm and cold adapted lineages, but the genes that are functionally related to thermal adaptation may be difficult to identify. We here used a bioinformatics genome-mining approach to predict and identify functions for suitable candidate markers for thermal adaptation in the chicken. We first established a framework of candidate functions for such markers, and then compiled the literature on genes known to adapt to the thermal environment in different lineages of vertebrates. We then identified them in the genomes of human, chicken, and the lizard Anolis carolinensis, and established a functional genetic interaction network in the chicken. Surprisingly, markers initially identified from diverse lineages of vertebrates such as human and fish were all in close functional relationship with each other and more associated than expected by chance. This indicates that the general genetic functional network for thermoregulation and/or thermal adaptation to the environment might be regulated via similar evolutionarily conserved pathways in different vertebrate lineages. We were able to identify seven functions that were statistically overrepresented in this network, corresponding to four of our originally predicted functions plus three unpredicted functions. We describe this network as multimodal: central regulator genes with the function of relaying thermal signal (1, affect genes with different cellular functions, namely (2 lipoprotein metabolism, (3 membrane channels, (4 stress response, (5 response to oxidative stress, (6 muscle contraction and relaxation, and (7 vasodilation, vasoconstriction and regulation of blood pressure. This network constitutes a novel resource for the study of thermal adaptation in the closely related nonavian reptiles and

Executive Function and Adaptive Behavior in Muenke Syndrome.

Science.gov (United States)

Yarnell, Colin M P; Addissie, Yonit A; Hadley, Donald W; Guillen Sacoto, Maria J; Agochukwu, Nneamaka B; Hart, Rachel A; Wiggs, Edythe A; Platte, Petra; Paelecke, Yvonne; Collmann, Hartmut; Schweitzer, Tilmann; Kruszka, Paul; Muenke, Maximilian

2015-08-01

To investigate executive function and adaptive behavior in individuals with Muenke syndrome using validated instruments with a normative population and unaffected siblings as controls. Participants in this cross-sectional study included individuals with Muenke syndrome (P250R mutation in FGFR3) and their mutation-negative siblings. Participants completed validated assessments of executive functioning (Behavior Rating Inventory of Executive Function [BRIEF]) and adaptive behavior skills (Adaptive Behavior Assessment System, Second Edition [ABAS-II]). Forty-four with a positive FGFR3 mutation, median age 9 years, range 7 months to 52 years were enrolled. In addition, 10 unaffected siblings served as controls (5 males, 5 females; median age, 13 years; range, 3-18 years). For the General Executive Composite scale of the BRIEF, 32.1% of the cohort had scores greater than +1.5 SD, signifying potential clinical significance. For the General Adaptive Composite of the ABAS-II, 28.2% of affected individuals scored in the 3rd-8th percentile of the normative population, and 56.4% were below the average category (General Executive Composite and the ABAS-II General Adaptive Composite. Individuals with Muenke syndrome are at an increased risk for developing adaptive and executive function behavioral changes compared with a normative population and unaffected siblings. Published by Elsevier Inc.

Non-Hematopoietic Essential Functions of Bone Marrow Cells: A Review of Scientific and Clinical Literature and Rationale for Treating Bone Defects.

Science.gov (United States)

Harrell, David B; Caradonna, Eugenio; Mazzucco, Laura; Gudenus, Rosmarie; Amann, Berthold; Prochazka, Vaclav; Giannoudis, Peter V; Hendrich, Christian; Jäger, Marcus; Krauspe, Rüdiger; Hernigou, Philippe

2015-12-28

Hematopoiesis as the only essential function of bone marrow cells has been challenged for several decades through basic science (in vitro and in vivo) and clinical data. Such work has shed light on two other essential functions of bone marrow cells: osteopoiesis and angio-genesis/vasculogenesis. Clinical utility of autologous concentrated bone marrow aspirate (CBMA) has demonstrated both safety and efficacy in treating bone defects. Moreover, CBMA has been shown to be comparable to the gold standard of iliac crest bone graft (ICBG), or autograft, with regard to being osteogenic and osteoinductive. ICBG is not considered an advanced therapy medicinal product (ATMP), but CBMA may become regulated as an ATMP. The European Medicines Agency Committee for Advanced Therapies (EMA:CAT) has issued a reflection paper (20 June 2014) in which reversal of the 2013 ruling that CBMA is a non-ATMP has been proposed. We review bone marrow cell involvement in osteopoiesis and angiogenesis/vasculogenesis to examine EMA:CAT 2013 decision to use CBMA for treatment of osteonecrosis (e.g, of the femoral head) should be considered a non-ATMP. This paper is intended to provide discussion on the 20 June 2014 reflection paper by reviewing two non-hematopoietic essential functions of bone marrow cells. Additionally, we provide clinical and scientific rationale for treating osteonecrosis with CBMA.

Non-hematopoietic essential functions of bone marrow cells: a review of scientific and clinical literature and rationale for treating bone defects

Directory of Open Access Journals (Sweden)

David B. Harrell

2015-12-01

Full Text Available Hematopoiesis as the only essential function of bone marrow cells has been challenged for several decades through basic science (in vitro and in vivo and clinical data. Such work has shed light on two other essential functions of bone marrow cells: osteopoiesis and angiogenesis/vasculogenesis. Clinical utility of autologous concentrated bone marrow aspirate (CBMA has demonstrated both safety and efficacy in treating bone defects. Moreover, CBMA has been shown to be comparable to the gold standard of iliac crest bone graft (ICBG, or autograft, with regard to being osteogenic and osteoinductive. ICBG is not considered an advanced therapy medicinal product (ATMP, but CBMA may become regulated as an ATMP. The European Medicines Agency Committee for Advanced Therapies (EMA:CAT has issued a reflection paper (20 June 2014 in which reversal of the 2013 ruling that CBMA is a non-ATMP has been proposed. We review bone marrow cell involvement in osteopoiesis and angiogenesis/vasculogenesis to examine EMA:CAT 2013 decision to use CBMA for treatment of osteonecrosis (e.g, of the femoral head should be considered a non-ATMP. This paper is intended to provide discussion on the 20 June 2014 reflection paper by reviewing two non-hematopoietic essential functions of bone marrow cells. Additionally, we provide clinical and scientific rationale for treating osteonecrosis with CBMA.

Carbon nanotubes functionalized with fibroblast growth factor accelerate proliferation of bone marrow-derived stromal cells and bone formation

International Nuclear Information System (INIS)

Hirata, Eri; Takita, Hiroko; Watari, Fumio; Yokoyama, Atsuro; Ménard-Moyon, Cécilia; Venturelli, Enrica; Bianco, Alberto

2013-01-01

Multi-walled carbon nanotubes (MWCNTs) were functionalized with fibroblast growth factor (FGF) and the advantages of their use as scaffolds for bone augmentation were evaluated in vitro and in vivo. The activity of FGF was assessed by measuring the effect on the proliferation of rat bone marrow stromal cells (RBMSCs). The presence of FGF enhanced the proliferation of RBMSCs and the FGF covalently conjugated to the nanotubes (FGF–CNT) showed the same effect as FGF alone. In addition, FGF–CNT coated sponges were implanted between the parietal bone and the periosteum of rats and the formation of new bone was investigated. At day 14 after implantation, a larger amount of newly formed bone was clearly observed in most pores of FGF–CNT coated sponges. These findings indicated that MWCNTs accelerated new bone formation in response to FGF, as well as the integration of particles into new bone during its formation. Scaffolds coated with FGF–CNT could be considered as promising novel substituting materials for bone regeneration in future tissue engineering applications. (paper)

Carbon nanotubes functionalized with fibroblast growth factor accelerate proliferation of bone marrow-derived stromal cells and bone formation

Science.gov (United States)

Hirata, Eri; Ménard-Moyon, Cécilia; Venturelli, Enrica; Takita, Hiroko; Watari, Fumio; Bianco, Alberto; Yokoyama, Atsuro

2013-11-01

Multi-walled carbon nanotubes (MWCNTs) were functionalized with fibroblast growth factor (FGF) and the advantages of their use as scaffolds for bone augmentation were evaluated in vitro and in vivo. The activity of FGF was assessed by measuring the effect on the proliferation of rat bone marrow stromal cells (RBMSCs). The presence of FGF enhanced the proliferation of RBMSCs and the FGF covalently conjugated to the nanotubes (FGF-CNT) showed the same effect as FGF alone. In addition, FGF-CNT coated sponges were implanted between the parietal bone and the periosteum of rats and the formation of new bone was investigated. At day 14 after implantation, a larger amount of newly formed bone was clearly observed in most pores of FGF-CNT coated sponges. These findings indicated that MWCNTs accelerated new bone formation in response to FGF, as well as the integration of particles into new bone during its formation. Scaffolds coated with FGF-CNT could be considered as promising novel substituting materials for bone regeneration in future tissue engineering applications.

Toward mechanical systems biology in bone.

Science.gov (United States)

Trüssel, Andreas; Müller, Ralph; Webster, Duncan

2012-11-01

Cyclic mechanical loading is perhaps the most important physiological factor regulating bone mass and shape in a way which balances optimal strength with minimal weight. This bone adaptation process spans multiple length and time scales. Forces resulting from physiological exercise at the organ scale are sensed at the cellular scale by osteocytes, which reside inside the bone matrix. Via biochemical pathways, osteocytes orchestrate the local remodeling action of osteoblasts (bone formation) and osteoclasts (bone resorption). Together these local adaptive remodeling activities sum up to strengthen bone globally at the organ scale. To resolve the underlying mechanisms it is required to identify and quantify both cause and effect across the different scales. Progress has been made at the different scales experimentally. Computational models of bone adaptation have been developed to piece together various experimental observations at the different scales into coherent and plausible mechanisms. However additional quantitative experimental validation is still required to build upon the insights which have already been achieved. In this review we discuss emerging as well as state of the art experimental and computational techniques and how they might be used in a mechanical systems biology approach to further our understanding of the mechanisms governing load induced bone adaptation, i.e., ways are outlined in which experimental and computational approaches could be coupled, in a quantitative manner to create more reliable multiscale models of bone.

CHONDROSARCOMA OF BONE - ONCOLOGIC AND FUNCTIONAL RESULTS

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VANLOON, CJM; VETH, RPH; PRUSZCZYNSKI, M; WOBBES, T; LEMMENS, JAM; VANHORN, J

1994-01-01

A retrospective review of 27 patients (21 males and 6 females) with chondrosarcoma of bone was performed to evaluate the oncologic and functional results. The average age of the patients was 48 years (range: 17-76). The tumor sites were pelvis in 10 cases, distal femur in 2, proximal tibia in 3, rib

Why does starvation make bones fat?

Science.gov (United States)

Devlin, Maureen J

2011-01-01

Body fat, or adipose tissue, is a crucial energetic buffer against starvation in humans and other mammals, and reserves of white adipose tissue (WAT) rise and fall in parallel with food intake. Much less is known about the function of bone marrow adipose tissue (BMAT), which are fat cells found in bone marrow. BMAT mass actually increases during starvation, even as other fat depots are being mobilized for energy. This review considers several possible reasons for this poorly understood phenomenon. Is BMAT a passive filler that occupies spaces left by dying bone cells, a pathological consequence of suppressed bone formation, or potentially an adaptation for surviving starvation? These possibilities are evaluated in terms of the effects of starvation on the body, particularly the skeleton, and the mechanisms involved in storing and metabolizing BMAT during negative energy balance. Copyright © 2011 Wiley-Liss, Inc.

A theoretical framework for strain-related trabecular bone maintenance and adaptation

NARCIS (Netherlands)

Ruimerman, R.; Hilbers, P.A.J.; Rietbergen, van B.; Huiskes, R.

2005-01-01

It is assumed that density and morphology of trabecular bone is partially controlled by mechanical forces. How these effects are expressed in the local metabolic functions of osteoclast resorption and osteoblast formation is not known. In order to investigate possible mechano-biological pathways for

Adaptive response to ionizing radiation in bone marrow mouse cells (CFU-s) in vivo. Oxygen effect

Energy Technology Data Exchange (ETDEWEB)

Saenko, A.S.; Semina, O.V.; Semenets, T.N.; Smirnova, S.G.; Orlova, N.V. [Russian Academy of Medical Sciences, Kaluga Region (Russian Federation). Medical Radiological Research Centre

1997-03-01

An acute gamma-irradiation of mice in small doses of 0.003-0.05 Gy results in elevated radioresistance of bone marrow CFU-s to challenge dose of 1.5 Gy. Hypoxia during exposure to conditioning dose abolishes or strongly decreases AR in CFU-s of mice marrow. Ascorbic acid and menadione induce cross-adaptation of mouse bone marrow CFU-s to action of gamma-radiation. The increase radioresistance was observed during 4 days after orally administration of vitamins C and K in doses of 1 mg and 0.06 mg/animal, accordingly, AR in Lewis lung carcinoma cells did not be observed in two independent experiments. (authors)

Adaptive response to ionizing radiation in bone marrow mouse cells (CFU-s) in vivo. Oxygen effect

International Nuclear Information System (INIS)

Saenko, A.S.; Semina, O.V.; Semenets, T.N.; Smirnova, S.G.; Orlova, N.V.

1997-01-01

An acute gamma-irradiation of mice in small doses of 0.003-0.05 Gy results in elevated radioresistance of bone marrow CFU-s to challenge dose of 1.5 Gy. Hypoxia during exposure to conditioning dose abolishes or strongly decreases AR in CFU-s of mice marrow. Ascorbic acid and menadione induce cross-adaptation of mouse bone marrow CFU-s to action of gamma-radiation. The increase radioresistance was observed during 4 days after orally administration of vitamins C and K in doses of 1 mg and 0.06 mg/animal, accordingly, AR in Lewis lung carcinoma cells did not be observed in two independent experiments. (authors)

Functional assessment of endoprosthesis in the treatment of bone tumors

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Denis Kiyoshi Fukumothi

Full Text Available ABSTRACT OBJECTIVES: Evaluate the functional grade of these patients and to identify the types of complications found that influenced the average life span of endoprostheses the functions of the operated limb. METHODS: We analyzed 14 post-operative cases of endoprosthesis, patients with malignant bone tumors and aggressive benign bone tumors submitted to surgery between 2004 and 2014. The evaluation system used was proposed by Enneking, recommended by the Musculoskeletal Tumor Society (MSTS, in addition to the radiologic evaluation. RESULTS: Endoprosthesis are excellent choices for the treatment of bone tumors with limb preservation in relation to pain, strength, and patient's emotional acceptance. Another factor for good results is the immediate weight-bearing capacity, generating a greater independence. CONCLUSION: The authors conclude that all patients classified the therapy as excellent/good, regardless of the type of prosthesis used, extent of injury, and/or type of tumor resection performed.

On the mechanistic origins of toughness in bone

Energy Technology Data Exchange (ETDEWEB)

Launey, Maximilien E.; Buehler, Markus J.; Ritchie, Robert O.

2009-10-07

One of the most intriguing protein materials found in Nature is bone, a material composed out of assemblies of tropocollagen molecules and tiny hydroxyapatite mineral crystals, forming an extremely tough, yet lightweight, adaptive and multi-functional material. Bone has evolved to provide structural support to organisms, and therefore, its mechanical properties are of great physiological relevance. In this article, we review the structure and properties of bone, focusing on mechanical deformation and fracture behavior from the perspective of the multi-dimensional hierarchical nature of its structure. In fact, bone derives its resistance to fracture with a multitude of deformation and toughening mechanisms at many of these size-scales, ranging from the nanoscale structure of its protein molecules to its macroscopic physiological scale.

Redefining "Critical" Bone Loss in Shoulder Instability: Functional Outcomes Worsen With "Subcritical" Bone Loss.

Science.gov (United States)

Shaha, James S; Cook, Jay B; Song, Daniel J; Rowles, Douglas J; Bottoni, Craig R; Shaha, Steven H; Tokish, John M

2015-07-01

Glenoid bone loss is a common finding in association with anterior shoulder instability. This loss has been identified as a predictor of failure after operative stabilization procedures. Historically, 20% to 25% has been accepted as the "critical" cutoff where glenoid bone loss should be addressed in a primary procedure. Few data are available, however, on lesser, "subcritical" amounts of bone loss (below the 20%-25% range) on functional outcomes and failure rates after primary arthroscopic stabilization for shoulder instability. To evaluate the effect of glenoid bone loss, especially in subcritical bone loss (below the 20%-25% range), on outcomes assessments and redislocation rates after an isolated arthroscopic Bankart repair for anterior shoulder instability. Cohort study; Level of evidence, 3. Subjects were 72 consecutive anterior instability patients (73 shoulders) who underwent isolated anterior arthroscopic labral repair at a single military institution by 1 of 3 sports medicine fellowship-trained orthopaedic surgeons. Data were collected on demographics, the Western Ontario Shoulder Instability (WOSI) score, Single Assessment Numeric Evaluation (SANE) score, and failure rates. Failure was defined as recurrent dislocation. Glenoid bone loss was calculated via a standardized technique on preoperative imaging. The average bone loss across the group was calculated, and patients were divided into quartiles based on the percentage of glenoid bone loss. Outcomes were analyzed for the entire cohort, between the quartiles, and within each quartile. Outcomes were then further stratified between those sustaining a recurrence versus those who remained stable. The mean age at surgery was 26.3 years (range, 20-42 years), and the mean follow-up was 48.3 months (range, 23-58 months). The cohort was divided into quartiles based on bone loss. Quartile 1 (n = 18) had a mean bone loss of 2.8% (range, 0%-7.1%), quartile 2 (n = 19) had 10.4% (range, 7.3%-13.5%), quartile 3 (n

[Ecological executive function characteristics and effects of executive function on social adaptive function in school-aged children with epilepsy].

Science.gov (United States)

Xu, X J; Wang, L L; Zhou, N

2016-02-23

To explore the characteristics of ecological executive function in school-aged children with idiopathic or probably symptomatic epilepsy and examine the effects of executive function on social adaptive function. A total of 51 school-aged children with idiopathic or probably symptomatic epilepsy aged 5-12 years at our hospital and 37 normal ones of the same gender, age and educational level were included. The differences in ecological executive function and social adaptive function were compared between the two groups with the Behavior Rating Inventory of Executive Function (BRIEF) and Child Adaptive Behavior Scale, the Pearson's correlation test and multiple stepwise linear regression were used to explore the impact of executive function on social adaptive function. The scores of school-aged children with idiopathic or probably symptomatic epilepsy in global executive composite (GEC), behavioral regulation index (BRI) and metacognition index (MI) of BRIEF ((62±12), (58±13) and (63±12), respectively) were significantly higher than those of the control group ((47±7), (44±6) and (48±8), respectively))(Pchildren with idiopathic or probably symptomatic epilepsy in adaptive behavior quotient (ADQ), independence, cognition, self-control ((86±22), (32±17), (49±14), (41±16), respectively) were significantly lower than those of the control group ((120±12), (59±14), (59±7) and (68±10), respectively))(Pchildren with idiopathic or probably symptomatic epilepsy. School-aged children with idiopathic or probably symptomatic epilepsy may have significantly ecological executive function impairment and social adaptive function reduction. The aspects of BRI, inhibition and working memory in ecological executive function are significantly related with social adaptive function in school-aged children with epilepsy.

Stress and Alterations in Bones: An Interdisciplinary Perspective

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Pia-Maria Wippert

2017-05-01

Full Text Available Decades of research have demonstrated that physical stress (PS stimulates bone remodeling and affects bone structure and function through complex mechanotransduction mechanisms. Recent research has laid ground to the hypothesis that mental stress (MS also influences bone biology, eventually leading to osteoporosis and increased bone fracture risk. These effects are likely exerted by modulation of hypothalamic–pituitary–adrenal axis activity, resulting in an altered release of growth hormones, glucocorticoids and cytokines, as demonstrated in human and animal studies. Furthermore, molecular cross talk between mental and PS is thought to exist, with either synergistic or preventative effects on bone disease progression depending on the characteristics of the applied stressor. This mini review will explain the emerging concept of MS as an important player in bone adaptation and its potential cross talk with PS by summarizing the current state of knowledge, highlighting newly evolving notions (such as intergenerational transmission of stress and its epigenetic modifications affecting bone and proposing new research directions.

Assessment of the influence of body composition on bone mass in children and adolescents based on a functional analysis of the muscle-bone relationship.

Science.gov (United States)

Golec, Joanna; Chlebna-Sokół, Danuta

2014-01-01

The functional model of skeletal development considers the mechanical factor to be the most important skeletal modulant. The aim of the study was a functional analysis of the bone-muscle relationship in children with low and normal bone mass. The study involved 149 children with low and 99 children with normal bone mass (control group). All patients underwent a densitometry examination (DXA). Low bone mass was diagnosed if the Z-score was below values of Z-scores for all parameters in children with low bone mass as compared to the control group. Children with low bone mass had lower content of adipose and muscle tissue and a marked deficit of muscle tissue with regard to height (which according to mechanostat theory leads to lower muscle-generated strain on bones). This group of children had also lower TBBMC/LBM Z-scores, which indicates greater fracture susceptibility. 1. Functional analysis, which showed associations between bone and muscle tissues, can be useful for diagnosing and monitoring skeletal system disorders as well as making therapeutic decisions.2. The study emphasizes the role of proper nutrition and physical activities, which contribute to proper body composition, in the prevention of bone mineralization disorders in childhood and adolescence. 3. The study showed the inadequacy of the classic reference ranges used in interpreting DXA data in children and demonstrated the usefulness of continuous variables for that purpose.

Locomotor adaptations in Plio-Pleistocene large carnivores from the Italian Peninsula: Palaeoecological implications

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Carlo MELORO

2011-06-01

Full Text Available Mammalian carnivores are rarely considered for environmental reconstructions because they are extremely adaptable and their geographic range is usually large. However, the functional morphology of carnivore long bones can be indicative of locomotor behaviour as well as adaptation to specific kind of habitats. Here, different long bone ratios belonging to a subsample of extant large carnivores are used to infer palaeoecology of a comparative sample of Plio-Pleistocene fossils belonging to Italian paleo-communities. A multivariate long bone shape space reveals similarities between extant and fossil carnivores and multiple logistic regression models suggest that specific indices (the brachial and the Mt/F can be applied to predict adaptations to grassland and tropical biomes. These functional indices exhibit also a phylogenetic signal to different degree. The brachial index is a significant predictor of adaptations to tropical biomes when phylogeny is taken into account, while Mt/F is not correlated anymore to habitat adaptations. However, the proportion of grassland-adapted carnivores in Italian paleo-communities exhibits a negative relationship with mean oxygen isotopic values, which are indicative of past climatic oscillations. As climate became more unstable during the Ice Ages, large carnivore guilds from the Italian peninsula were invaded by tropical/closed-adapted species. These species take advantage of the temperate forest cover that was more spread after 1.0 Ma than in the initial phase of the Quaternary (2.0 Ma when the climate was more arid [Current Zoology 57 (3: 269–283, 2011].

Development, regulation, metabolism and function of bone marrow adipose tissues.

Science.gov (United States)

Li, Ziru; Hardij, Julie; Bagchi, Devika P; Scheller, Erica L; MacDougald, Ormond A

2018-05-01

Most adipocytes exist in discrete depots throughout the body, notably in well-defined white and brown adipose tissues. However, adipocytes also reside within specialized niches, of which the most abundant is within bone marrow. Whereas bone marrow adipose tissue (BMAT) shares many properties in common with white adipose tissue, the distinct functions of BMAT are reflected by its development, regulation, protein secretion, and lipid composition. In addition to its potential role as a local energy reservoir, BMAT also secretes proteins, including adiponectin, RANK ligand, dipeptidyl peptidase-4, and stem cell factor, which contribute to local marrow niche functions and which may also influence global metabolism. The characteristics of BMAT are also distinct depending on whether marrow adipocytes are contained within yellow or red marrow, as these can be thought of as 'constitutive' and 'regulated', respectively. The rBMAT for instance can be expanded or depleted by myriad factors, including age, nutrition, endocrine status and pharmaceuticals. Herein we review the site specificity, age-related development, regulation and metabolic characteristics of BMAT under various metabolic conditions, including the functional interactions with bone and hematopoietic cells. Copyright © 2018 Elsevier Inc. All rights reserved.

Bone Cells Dynamics during Peri-Implantitis: a Theoretical Analysis

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Maria Helena Fernandes

2016-09-01

Full Text Available Objectives: The present manuscript aims a detailed characterization of the bone cells dynamics during physiological bone remodelling and, subsequently, to address the cellular and molecular mechanisms that play a fundamental role in the immune-inflammatory-induced uncoupled bone remodelling observed in peri-implantitis. Results: An intimate relationship between the immune system and bone is acknowledged to be determinant for bone tissue remodelling and integrity. Due to the close interaction of immune and bone cells, the two systems share a number of surface receptors, cytokines, signalling pathways and transcription factors that are involved in mutual regulatory mechanisms. This physiological equilibrium is disturbed in pathological conditions, as verified in peri-implantitis establishment and development. Activation of the innate and adaptive immune response, challenged by the local bacterial infection, induces the synthesis of high levels of a variety of pro- and anti-inflammatory cytokines that disturb the normal functioning of the bone cells, by uncoupling bone resorption and formation, ending up with a net alveolar bone loss and subsequent implant failure. Most data points to an immune-inflammatory induced osteoclast differentiation and function, as the major underlying mechanism to the uncoupled bone resorption to bone formation. Further, the disturbed functioning of osteoblasts, reflected by the possible expression of a fibro-osteoblastic phenotype, may also play a role. Conclusions: Alveolar bone loss is a hallmark of peri-implantitis. A great deal of data is still needed on the cellular and humoral crosstalk in the context of an integrated view of the osteoimmunologic interplay occurring in the peri-implantitis environment subjacent to the bone loss outcome.

Enhancing Functional Performance using Sensorimotor Adaptability Training Programs

Science.gov (United States)

Bloomberg, J. J.; Mulavara, A. P.; Peters, B. T.; Brady, R.; Audas, C.; Ruttley, T. M.; Cohen, H. S.

2009-01-01

During the acute phase of adaptation to novel gravitational environments, sensorimotor disturbances have the potential to disrupt the ability of astronauts to perform functional tasks. The goal of this project is to develop a sensorimotor adaptability (SA) training program designed to facilitate recovery of functional capabilities when astronauts transition to different gravitational environments. The project conducted a series of studies that investigated the efficacy of treadmill training combined with a variety of sensory challenges designed to increase adaptability including alterations in visual flow, body loading, and support surface stability.

Adaptive responses induced in bone marrow and blood of the rats by tritium contamination

International Nuclear Information System (INIS)

Savu, D.I.; Ionescu, M.A.; Petcu, I.

2000-01-01

It has been more than a decade since the initial report on the phenomenon termed 'adaptive response to ionizing radiation'. Although a number of reports have appeared since then, the understanding of this response is still incomplete. Our group intended to investigate whether the adaptive response could be induced in vivo by low level internal tritium contamination of rats and subsequently exposed to challenging irradiations with fast neutrons or gamma rays. Two experiments were performed and analysed comparatively. In the first experiment the rats have been pre-contaminated for 3 weeks to total doses of 7 cGy and 35 cGy and subsequently irradiated to 1 Gy by fast neutrons (d(13.5)+Be). They were sacrificed after 24 hours. In the second experiment rats were exposed to high gamma irradiation (1.4 Gy) after prior contamination with tritium for 20 days to total doses of 4.4 cGy and 5.1 cGy. We followed up the modifications of two biochemical parameters: (i) the in vitro tritiated thymidine incorporation in the bone marrow cells and (ii) the reduced glutathione level in the blood cells. The thymidine incorporation assay revealed a putative adaptive reaction only for the rats preirradiated with tritiated water to 35 cGy and post-irradiated with fast neutrons. The glutathione content was found to be increased (back to the normal level) for the tritium pre-contaminated and neutron irradiated animals as compared to those exposed only to fast neutrons. The adaptive response is believed to be a protective mechanism that confers resistance to the detrimental effects of ionizing radiation. Our studies suggest that the irradiation with low conditioning doses of tritium (7; 35 cGy) is more efficient in conferring radioresistance to bone marrow and blood cells at the treatment with fast neutrons (1 Gy) than the irradiation with tritium doses of 4.4 and 5.1 cGy followed by gamma rays (1.4 Gy). (authors)

Beyond the functional matrix hypothesis: a network null model of human skull growth for the formation of bone articulations.

Science.gov (United States)

Esteve-Altava, Borja; Rasskin-Gutman, Diego

2014-09-01

Craniofacial sutures and synchondroses form the boundaries among bones in the human skull, providing functional, developmental and evolutionary information. Bone articulations in the skull arise due to interactions between genetic regulatory mechanisms and epigenetic factors such as functional matrices (soft tissues and cranial cavities), which mediate bone growth. These matrices are largely acknowledged for their influence on shaping the bones of the skull; however, it is not fully understood to what extent functional matrices mediate the formation of bone articulations. Aiming to identify whether or not functional matrices are key developmental factors guiding the formation of bone articulations, we have built a network null model of the skull that simulates unconstrained bone growth. This null model predicts bone articulations that arise due to a process of bone growth that is uniform in rate, direction and timing. By comparing predicted articulations with the actual bone articulations of the human skull, we have identified which boundaries specifically need the presence of functional matrices for their formation. We show that functional matrices are necessary to connect facial bones, whereas an unconstrained bone growth is sufficient to connect non-facial bones. This finding challenges the role of the brain in the formation of boundaries between bones in the braincase without neglecting its effect on skull shape. Ultimately, our null model suggests where to look for modified developmental mechanisms promoting changes in bone growth patterns that could affect the development and evolution of the head skeleton. © 2014 Anatomical Society.

Lung function after allogeneic bone marrow transplantation for leukaemia or lymphoma

DEFF Research Database (Denmark)

Nysom, K; Holm, K; Hesse, B

1996-01-01

Longitudinal data were analysed on the lung function of 25 of 29 survivors of childhood leukaemia or lymphoma, who had been conditioned with cyclophosphamide and total body irradiation before allogeneic bone marrow transplantation, to test whether children are particularly vulnerable to pulmonary...... damage after transplantation. None developed chronic graft-versus-host disease. Transfer factor and lung volumes were reduced immediately after bone marrow transplantation, but increased during the following years. However, at the last follow up, 4-13 years (median 8) after transplantation, patients had...... to their age at bone marrow transplantation. In conclusion, patients had subclinical restrictive pulmonary disease at a median of eight years after total body irradiation and allogeneic bone marrow transplantation....

Role of inflammation in the aging bones.

Science.gov (United States)

Abdelmagid, Samir M; Barbe, Mary F; Safadi, Fayez F

2015-02-15

Chronic inflammation in aging is characterized by increased inflammatory cytokines, bone loss, decreased adaptation, and defective tissue repair in response to injury. Aging leads to inherent changes in mesenchymal stem cell (MSC) differentiation, resulting in impaired osteoblastogenesis. Also, the pro-inflammatory cytokines increase with aging, leading to enhanced myelopoiesis and osteoclastogenesis. Bone marrow macrophages (BMMs) play pivotal roles in osteoblast differentiation, the maintenance of hematopoietic stem cells (HSCs), and subsequent bone repair. However, during aging, little is known about the role of macrophages in the differentiation and function of MSC and HSC. Aged mammals have higher circulating pro-inflammatory cytokines than young adults, supporting the hypothesis of increased inflammation with aging. This review will aid in the understanding of the potential role(s) of pro-inflammatory (M1) and anti-inflammatory (M2) macrophages in differentiation and function of osteoblasts and osteoclasts in relation to aging. Copyright © 2014 Elsevier Inc. All rights reserved.

Normal Parathyroid Function with Decreased Bone Mineral Density in Treated Celiac Disease

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Bernard Lemieux

2001-01-01

, an important determinant of the actual bone mass of patients. Normal parathyroid function in treated patients suggests a lack of previous severe secondary hyperparathyroidism and/or complete adaptation to prior changes in parathyroid function.

Evaluation-Function-based Model-free Adaptive Fuzzy Control

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Agus Naba

2016-12-01

Full Text Available Designs of adaptive fuzzy controllers (AFC are commonly based on the Lyapunov approach, which requires a known model of the controlled plant. They need to consider a Lyapunov function candidate as an evaluation function to be minimized. In this study these drawbacks were handled by designing a model-free adaptive fuzzy controller (MFAFC using an approximate evaluation function defined in terms of the current state, the next state, and the control action. MFAFC considers the approximate evaluation function as an evaluative control performance measure similar to the state-action value function in reinforcement learning. The simulation results of applying MFAFC to the inverted pendulum benchmark verified the proposed scheme’s efficacy.

Unique biochemical and mineral composition of whale ear bones.

Science.gov (United States)

Kim, Sora L; Thewissen, J G M; Churchill, Morgan M; Suydam, Robert S; Ketten, Darlene R; Clementz, Mark T

2014-01-01

Abstract Cetaceans are obligate aquatic mammals derived from terrestrial artiodactyls. The defining characteristic of cetaceans is a thick and dense lip (pachyosteosclerotic involucrum) of an ear bone (the tympanic). This unique feature is absent in modern terrestrial artiodactyls and is suggested to be important in underwater hearing. Here, we investigate the mineralogical and biochemical properties of the involucrum, as these may hold clues to the aquatic adaptations of cetaceans. We compared bioapatites (enamel, dentine, cementum, and skeletal bone) of cetaceans with those of terrestrial artiodactyls and pachyosteosclerotic ribs of manatees (Sirenia). We investigated organic, carbonate, and mineral composition as well as crystal size and crystallinity index. In all studied variables, bioapatites of the cetacean involucrum were intermediate in composition and structure between those of tooth enamel on the one hand and those of dentine, cementum, and skeletal bone on the other. We also studied the amino acid composition of the cetacean involucrum relative to that of other skeletal bone. The central involucrum had low glycine and hydroxyproline concentrations but high concentrations of nonessential amino acids, unlike most bone samples but similar to the tympanic of hippos and the (pachyosteosclerotic) ribs of manatees. These amino acid results are evidence of rapid bone development. We hypothesize that the mineralogical and amino acid composition of cetacean bullae differs from that of other bone because of (1) functional modifications for underwater sound reception and (2) structural adaptations related to rapid ossification.

Estimation of bone perfusion as a function of intramedullary pressure in sheep

International Nuclear Information System (INIS)

Rosenthal, M.S.; Lehner, C.E.; Pearson, D.W.; Kanikula, T.M.; Adler, G.G.; Venci, R.; Lanphier, E.H.; De Luca, P.M.

1985-01-01

It has been reported previously that following decompression (i.e. diving ascents) the intramedullary pressure (IMP) in bone can rise dramatically and possibly by the mechanism which can induce dysbaric osteonecrosis or the ''silent bends''. If the blood supply for the bone transverses the marrow compartment, than an increase in IMP could cause a temporary decrease in perfusion or hemostasis and hence ischemia leading to bone necrosis. To test this hypothesis, the authors measured the perfusion of bone in sheep as a function of IMP. The bone perfusion was estimated by measuring the perfusion-limited clearance of Ar-41 (Eγ=1293 keV, T/sub 1/2/=1.83 h) from the bone mineral matrix of sheep's tibia. The argon gas was formed in vivo by the fast neutron activation of Ca-44 to Ar-41 following the Ca-44(n,α) reaction. Clearance of Ar-41 was measured by time gated gamma-ray spectroscopy. These results indicate that an elevation of intramedullary pressure can decrease perfusion in bone and may cause bone necrosis

The draft genome of blunt snout bream (Megalobrama amblycephala) reveals the development of intermuscular bone and adaptation to herbivorous diet

Science.gov (United States)

Liu, Han; Chen, Chunhai; Gao, Zexia; Min, Jiumeng; Gu, Yongming; Jian, Jianbo; Jiang, Xiewu; Cai, Huimin; Ebersberger, Ingo; Xu, Meng; Zhang, Xinhui; Chen, Jianwei; Luo, Wei; Chen, Boxiang; Chen, Junhui; Liu, Hong; Li, Jiang; Lai, Ruifang; Bai, Mingzhou; Wei, Jin; Yi, Shaokui; Wang, Huanling; Cao, Xiaojuan; Zhou, Xiaoyun; Zhao, Yuhua; Wei, Kaijian; Yang, Ruibin; Liu, Bingnan; Zhao, Shancen; Fang, Xiaodong

2017-01-01

Abstract The blunt snout bream Megalobrama amblycephala is the economically most important cyprinid fish species. As an herbivore, it can be grown by eco-friendly and resource-conserving aquaculture. However, the large number of intermuscular bones in the trunk musculature is adverse to fish meat processing and consumption. As a first towards optimizing this aquatic livestock, we present a 1.116-Gb draft genome of M. amblycephala, with 779.54 Mb anchored on 24 linkage groups. Integrating spatiotemporal transcriptome analyses, we show that intermuscular bone is formed in the more basal teleosts by intramembranous ossification and may be involved in muscle contractibility and coordinating cellular events. Comparative analysis revealed that olfactory receptor genes, especially of the beta type, underwent an extensive expansion in herbivorous cyprinids, whereas the gene for the umami receptor T1R1 was specifically lost in M. amblycephala. The composition of gut microflora, which contributes to the herbivorous adaptation of M. amblycephala, was found to be similar to that of other herbivores. As a valuable resource for the improvement of M. amblycephala livestock, the draft genome sequence offers new insights into the development of intermuscular bone and herbivorous adaptation. PMID:28535200

Three-dimensional geometric analysis of felid limb bone allometry.

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Michael Doube

Full Text Available Studies of bone allometry typically use simple measurements taken in a small number of locations per bone; often the midshaft diameter or joint surface area is compared to body mass or bone length. However, bones must fulfil multiple roles simultaneously with minimum cost to the animal while meeting the structural requirements imposed by behaviour and locomotion, and not exceeding its capacity for adaptation and repair. We use entire bone volumes from the forelimbs and hindlimbs of Felidae (cats to investigate regional complexities in bone allometry.Computed tomographic (CT images (16435 slices in 116 stacks were made of 9 limb bones from each of 13 individuals of 9 feline species ranging in size from domestic cat (Felis catus to tiger (Panthera tigris. Eleven geometric parameters were calculated for every CT slice and scaling exponents calculated at 5% increments along the entire length of each bone. Three-dimensional moments of inertia were calculated for each bone volume, and spherical radii were measured in the glenoid cavity, humeral head and femoral head. Allometry of the midshaft, moments of inertia and joint radii were determined. Allometry was highly variable and related to local bone function, with joint surfaces and muscle attachment sites generally showing stronger positive allometry than the midshaft.Examining whole bones revealed that bone allometry is strongly affected by regional variations in bone function, presumably through mechanical effects on bone modelling. Bone's phenotypic plasticity may be an advantage during rapid evolutionary divergence by allowing exploitation of the full size range that a morphotype can occupy. Felids show bone allometry rather than postural change across their size range, unlike similar-sized animals.

Functionalized D-form self-assembling peptide hydrogels for bone regeneration

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He B

2016-04-01

Full Text Available Bin He,1 Yunsheng Ou,1 Ao Zhou,1 Shuo Chen,1 Weikang Zhao,1 Jinqiu Zhao,2 Hong Li,3 Yong Zhu,1 Zenghui Zhao,1 Dianming Jiang1 1Department of Orthopedics, 2Department of Infectious Diseases, The First Affiliated Hospital of Chongqing Medical University, Chongqing, People’s Republic of China; 3School of Physical Science and Technology, Sichuan University, Chengdu, People’s Republic of China Abstract: Bone defects are very common in orthopedics, and there is great need to develop suitable bone grafts for transplantation in vivo. However, current bone grafts still encounter some limitations, including limited availability, immune rejection, poor osteoinduction and osteoconduction, poor biocompatibility and degradation properties, etc. Self-assembling peptide nanofiber scaffolds have emerged as an important substrate for cell culture and bone regeneration. We report on the structural features (eg, Congo red staining, circular dichroism spectroscopy, transmission electron microscopy, and rheometry assays and osteogenic ability of D-RADA16-RGD peptide hydrogels (with or without basic fibroblast growth factor due to the better stability of peptide bonds formed by these peptides compared with those formed by L-form peptides, and use them to fill the femoral condyle defect of Sprague Dawley rat model. The bone morphology change, two-dimensional reconstructions using microcomputed tomography, quantification of the microcomputed tomography analyses as well as histological analyses have demonstrated that RGD-modified D-form peptide scaffolds are able to enhance extensive bone regeneration. Keywords: bone defect, functionalized D-form self-assembling peptide, D-RADA16-RGD, peptide hydrogel, bone regeneration

Biology of bone and how it orchestrates the form and function of the skeleton

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Sommerfeldt, D. W.; Rubin, C. T.

2001-01-01

The principal role of the skeleton is to provide structural support for the body. While the skeleton also serves as the body's mineral reservoir, the mineralized structure is the very basis of posture, opposes muscular contraction resulting in motion, withstands functional load bearing, and protects internal organs. Although the mass and morphology of the skeleton is defined, to some extent, by genetic determinants, it is the tissue's ability to remodel--the local resorption and formation of bone--which is responsible for achieving this intricate balance between competing responsibilities. The aim of this review is to address bone's form-function relationship, beginning with extensive research in the musculoskeletal disciplines, and focusing on several recent cellular and molecular discoveries which help understand the complex interdependence of bone cells, growth factors, physical stimuli, metabolic demands, and structural responsibilities. With a clinical and spine-oriented audience in mind, the principles of bone cell and molecular biology and physiology are presented, and an attempt has been made to incorporate epidemiologic data and therapeutic implications. Bone research remains interdisciplinary by nature, and a deeper understanding of bone biology will ultimately lead to advances in the treatment of diseases and injuries to bone itself.

A theoretical framework for strain-related trabecular bone maintenance and adaptation.

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Ruimerman, R; Hilbers, P; van Rietbergen, B; Huiskes, R

2005-04-01

It is assumed that density and morphology of trabecular bone is partially controlled by mechanical forces. How these effects are expressed in the local metabolic functions of osteoclast resorption and osteoblast formation is not known. In order to investigate possible mechano-biological pathways for these mechanisms we have proposed a mathematical theory (Nature 405 (2000) 704). This theory is based on hypothetical osteocyte stimulation of osteoblast bone formation, as an effect of elevated strain in the bone matrix, and a role for microcracks and disuse in promoting osteoclast resorption. Applied in a 2-D Finite Element Analysis model, the theory explained the formation of trabecular patterns. In this article we present a 3-D FEA model based on the same theory and investigated its potential morphological predictability of metabolic reactions to mechanical loads. The computations simulated the development of trabecular morphological details during growth, relative to measurements in growing pigs, reasonably realistic. They confirmed that the proposed mechanisms also inherently lead to optimal stress transfer. Alternative loading directions produced new trabecular orientations. Reduction of load reduced trabecular thickness, connectivity and mass in the simulation, as is seen in disuse osteoporosis. Simulating the effects of estrogen deficiency through increased osteoclast resorption frequencies produced osteoporotic morphologies as well, as seen in post-menopausal osteoporosis. We conclude that the theory provides a suitable computational framework to investigate hypothetical relationships between bone loading and metabolic expressions.

Functional evaluation of bone marrow derived DC of tumor bearing mice after immunotherapy

International Nuclear Information System (INIS)

Li Min; Chen Cheng; Gu Tao; Zhou Huan; Zhang Feng; Zhu Yibei; Yu Gehua; Zhang Xueguang; Gu Zongjiang

2006-01-01

Objective: To evaluate the function of bone marrow derived DC of tumor bearing mice after immunotherapy. Methods: Tumor bearing mice were immunized with DC vaccine plus injection of agonistic anti-4-1BB monoclonal antibody. The proliferation of T cells primed with bone marrow derived DC of tumor bearing mice after immunotherapy was tested by 3 H-TdR incorporation. ELISA was employed to determine the levels of IL-2, IFN-γ and IL-10 secreted by DC primed T cells. Results: Bone marrow derived DC of tumor bearing mice was less efficient in stimulating the proliferation of T cells and IL-2 and IFN-γ secretion made by T cells. After immunotherapy, the proliferation of cells and IL-2 and IFN-γ secretionmade by T cells were enhanced. Conclusion: The function of bone marrow derived DC of tumor bearing mice after immunotherapy was ameliorated. (authors)

Bifurcation into functional niches in adaptation.

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White, Justin S; Adami, Christoph

2004-01-01

One of the central questions in evolutionary biology concerns the dynamics of adaptation and diversification. This issue can be addressed experimentally if replicate populations adapting to identical environments can be investigated in detail. We have studied 501 such replicas using digital organisms adapting to at least two fundamentally different functional niches (survival strategies) present in the same environment: one in which fast replication is the way to live, and another where exploitation of the environment's complexity leads to complex organisms with longer life spans and smaller replication rates. While these two modes of survival are closely analogous to those expected to emerge in so-called r and K selection scenarios respectively, the bifurcation of evolutionary histories according to these functional niches occurs in identical environments, under identical selective pressures. We find that the branching occurs early, and leads to drastic phenotypic differences (in fitness, sequence length, and gestation time) that are permanent and irreversible. This study confirms an earlier experimental effort using microorganisms, in that diversification can be understood at least in part in terms of bifurcations on saddle points leading to peak shifts, as in the picture drawn by Sewall Wright.

Adaptive Functional-Based Neuro-Fuzzy-PID Incremental Controller Structure

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Ashraf Ahmed Fahmy

2014-03-01

Full Text Available This paper presents an adaptive functional-based Neuro-fuzzy-PID incremental (NFPID controller structure that can be tuned either offline or online according to required controller performance. First, differential membership functions are used to represent the fuzzy membership functions of the input-output space of the three term controller. Second, controller rules are generated based on the discrete proportional, derivative, and integral function for the fuzzy space. Finally, a fully differentiable fuzzy neural network is constructed to represent the developed controller for either offline or online controller parameter adaptation.  Two different adaptation methods are used for controller tuning, offline method based on controller transient performance cost function optimization using Bees Algorithm, and online method based on tracking error minimization using back-propagation with momentum algorithm. The proposed control system was tested to show the validity of the controller structure over a fixed PID controller gains to control SCARA type robot arm.

Bio-functionalized MWCNT/hyperbranched polyurethane bionanocomposite for bone regeneration

International Nuclear Information System (INIS)

Das, Beauty; Karak, Niranjan; Chattopadhyay, Pronobesh; Upadhyay, Aadesh; Maji, Somnath; Maity, Tapas Kumar; Purkayastha, Manashi Das; Mohanta, Charu lata

2015-01-01

The proper fabrication of biomaterials, particularly for purposes like bone regeneration, is of the utmost importance for the clinical success of materials that fulfill the design criteria at bio-interfacial milieu. Building on this aspect, a polyurethane nanocomposite (PNC) was fabricated by the combination of rapeseed protein functionalized multi-walled carbon nanotubes (MWCNTs) and vegetable-oil-based hyperbranched polyurethane. Biofunctionalized MWCNTs showed incredible biocompatibility compared to pristine MWCNTs as ascertained via in vitro and in vivo studies. PNC showed enhanced MG63 cell differentiation ability compared to the control and carboxyl functionalized MWCNT-based nanocomposite, as postulated by alkaline phosphatase activity together with better cellular adhesion, spreading and proliferation. Consequently, a critical-sized fracture gap (6 mm) bridged by the sticky PNC scaffold illustrated rapid bone neoformation within 30–45 d, with 90–93% of the defect area filling up. Histopathological studies demonstrated the reorganization of the normal tibial architecture and biodegradation of the implant. The subsequent toxicological study through cytokine expression, biochemical analysis and hematological studies suggested non-immunogenic and non-toxic effects of PNCs and their degraded/leached products. Their excellent bio-physiological features with high load-bearing ability (49–55.5 Mpa), ductility (675–790%) and biodegradability promote them as the best alternative biomaterials for bone regeneration in a comprehensive manner. (paper)

Genomic islands predict functional adaptation in marine actinobacteria

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Penn, Kevin; Jenkins, Caroline; Nett, Markus; Udwary, Daniel; Gontang, Erin; McGlinchey, Ryan; Foster, Brian; Lapidus, Alla; Podell, Sheila; Allen, Eric; Moore, Bradley; Jensen, Paul

2009-04-01

Linking functional traits to bacterial phylogeny remains a fundamental but elusive goal of microbial ecology 1. Without this information, it becomes impossible to resolve meaningful units of diversity and the mechanisms by which bacteria interact with each other and adapt to environmental change. Ecological adaptations among bacterial populations have been linked to genomic islands, strain-specific regions of DNA that house functionally adaptive traits 2. In the case of environmental bacteria, these traits are largely inferred from bioinformatic or gene expression analyses 2, thus leaving few examples in which the functions of island genes have been experimentally characterized. Here we report the complete genome sequences of Salinispora tropica and S. arenicola, the first cultured, obligate marine Actinobacteria 3. These two species inhabit benthic marine environments and dedicate 8-10percent of their genomes to the biosynthesis of secondary metabolites. Despite a close phylogenetic relationship, 25 of 37 secondary metabolic pathways are species-specific and located within 21 genomic islands, thus providing new evidence linking secondary metabolism to ecological adaptation. Species-specific differences are also observed in CRISPR sequences, suggesting that variations in phage immunity provide fitness advantages that contribute to the cosmopolitan distribution of S. arenicola 4. The two Salinispora genomes have evolved by complex processes that include the duplication and acquisition of secondary metabolite genes, the products of which provide immediate opportunities for molecular diversification and ecological adaptation. Evidence that secondary metabolic pathways are exchanged by Horizontal Gene Transfer (HGT) yet are fixed among globally distributed populations 5 supports a functional role for their products and suggests that pathway acquisition represents a previously unrecognized force driving bacterial diversification

Assessing Adaptive Functioning in Death Penalty Cases after Hall and DSM-5.

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Hagan, Leigh D; Drogin, Eric Y; Guilmette, Thomas J

2016-03-01

DSM-5 and Hall v. Florida (2014) have dramatically refocused attention on the assessment of adaptive functioning in death penalty cases. In this article, we address strategies for assessing the adaptive functioning of defendants who seek exemption from capital punishment pursuant to Atkins v. Virginia (2002). In particular, we assert that evaluations of adaptive functioning should address assets as well as deficits; seek to identify credible and reliable evidence concerning the developmental period and across the lifespan; distinguish incapacity from the mere absence of adaptive behavior; adhere faithfully to test manual instructions for using standardized measures of adaptive functioning; and account for potential bias on the part of informants. We conclude with brief caveats regarding the standard error of measurement (SEM) in light of Hall, with reference to examples of ordinary life activities that directly illuminate adaptive functioning relevant to capital cases. © 2016 American Academy of Psychiatry and the Law.

Low-dose radiation-induced adaptive response in bone marrow cells of mice

International Nuclear Information System (INIS)

Farooqi, Zeba; Kesavan, P.C.

1993-01-01

Using bone marrow cells of whole body irradiated mice, the cytogenetic adaptive response induced by low conditioning doses of gamma-rays was investigated. The conditioning doses (0.025 and 0.05 Gy) were given at a dose-rate of 1.67 Gy/min. The challenging dose of 1 Gy was given at a dose-rate of 0.045 Gy/s. The challenging dose was given at different time intervals after the conditioning dose. The time intervals between the conditioning dose and challenging dose were 2, 7.5, 13, 18.5 and 24 h. When the time interval between the conditioning dose and the challenging dose was 2 h, both conditioning doses (0.025 and 0.05 Gy) reduced the frequency of MNPCEs and chromosomal aberrations in the bone marrow cells. The data collected at different time intervals (7.5, 13, 18.5 h) reveal that the radioadaptive response persisted for a longer time when the lower conditioning dose (0.025 Gy) was given. With the higher conditioning dose (0.05 Gy), the radioadaptive response disappeared after a time interval of 13 h. When the time interval between the conditioning dose and the challenging doses was 18.5 or 24 h, only the lower conditioning dose appeared effective in inducing the radioadaptive response

P2X7 Receptor Function in Bone-Related Cancer

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Elena Adinolfi

2012-01-01

Full Text Available Modulation of tumor microenvironment by different mediators is central in determining neoplastic formation and progression. Among these molecules extracellular ATP is emerging as a good candidate in promoting cell growth, neovascularization, tumor-host interactions, and metastatization. This paper summarizes recent findings on expression and function of P2X7 receptor for extracellular ATP in primary and metastatic bone cancers. Search of mRNA expression microchip databases and literature analysis demonstrate a high expression of P2X7 in primary bone tumors as well as in other malignancies such as multiple myeloma, neuroblastoma, breast, and prostate cancer. Evidence that P2X7 triggers NFATc1, PI3K/Akt, ROCK, and VEGF pathways in osteoblasts promoting either primary tumor development or osteoblastic lesions is also reported. Moreover, P2X7 receptor is involved in osteoclast differentiation, RANKL expression, matrix metalloproteases and cathepsin secretion thus promoting bone resorption and osteolytic lesions. Taken together these data point to a pivotal role for the P2X7 receptor in bone cancer biology.

Bone fatigue and its implications for injuries in racehorses.

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Martig, S; Chen, W; Lee, P V S; Whitton, R C

2014-07-01

Musculoskeletal injuries are a common cause of lost training days and wastage in racehorses. Many bone injuries are a consequence of repeated high loading during fast work, resulting in chronic damage accumulation and material fatigue of bone. The highest joint loads occur in the fetlock, which is also the most common site of subchondral bone injury in racehorses. Microcracks in the subchondral bone at sites where intra-articular fractures and palmar osteochondral disease occur are similar to the fatigue damage detected experimentally after repeated loading of bone. Fatigue is a process that has undergone much study in material science in order to avoid catastrophic failure of engineering structures. The term 'fatigue life' refers to the numbers of cycles of loading that can be sustained before failure occurs. Fatigue life decreases exponentially with increasing load. This is important in horses as loads within the limb increase with increasing speed. Bone adapts to increased loading by modelling to maintain the strains within the bone at a safe level. Bone also repairs fatigued matrix through remodelling. Fatigue injuries develop when microdamage accumulates faster than remodelling can repair. Remodelling of the equine metacarpus is reduced during race training and accelerated during rest periods. The first phase of remodelling is bone resorption, which weakens the bone through increased porosity. A bone that is porous following a rest period may fail earlier than a fully adapted bone. Maximising bone adaptation is an important part of training young racehorses. However, even well-adapted bones accumulate microdamage and require ongoing remodelling. If remodelling inhibition at the extremes of training is unavoidable then the duration of exposure to high-speed work needs to be limited and appropriate rest periods instituted. Further research is warranted to elucidate the effect of fast-speed work and rest on bone damage accumulation and repair. © 2014 EVJ Ltd.

Nitric oxide signaling in mechanical adaptation of bone

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Klein Nulend, J.; van Oers, R.F.M.; Bakker, A.D.; Bacabac, R.G.

2014-01-01

One of the most serious healthcare problems in the world is bone loss and fractures due to a lack of physical activity in elderly people as well as in bedridden patients or otherwise inactive youth. Crucial here are the osteocytes. Buried within our bones, these cells are believed to be the

Adaptive plasticity in mammalian masticatory joints

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Ravosa, Matthew J.; Kunwar, Ravinder; Nicholson, Elisabeth K.; Klopp, Emily B.; Pinchoff, Jessie; Stock, Stuart R.; Stack, M. Sharon; Hamrick, Mark W.

2006-08-01

Genetically similar white rabbits raised on diets of different mechanical properties, as well as wild-type and myostatin-deficient mice raised on similar diets, were compared to assess the postweaning effects of elevated masticatory loads due to increased jaw-adductor muscle and bite forces on the proportions and properties of the mandibular symphysis and temporomandibular joint (TMJ). Microcomputed tomography (microCT) was used to quantify bone structure at a series of equidistant external and internal sites in coronal sections for a series of joint locations. Discriminant function analyses and non-parametric ANOVAs were used to characterize variation in biomineralization within and between loading cohorts. In both species, long-term excessive loading results in larger joint proportions, thicker articular and cortical bone, and increased biomineralization of hard tissues. Such adaptive plasticity appears designed to maintain the postnatal integrity of masticatory joint systems for a primary loading environment(s). This behavioral signal may be increasingly mitigated in older organisms by the interplay between adaptive and degradative joint tissue responses.

On the relationship between the dynamic behavior and nanoscale staggered structure of the bone

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Qwamizadeh, Mahan; Zhang, Zuoqi; Zhou, Kun; Zhang, Yong Wei

2015-05-01

Bone, a typical load-bearing biological material, composed of ordinary base materials such as organic protein and inorganic mineral arranged in a hierarchical architecture, exhibits extraordinary mechanical properties. Up to now, most of previous studies focused on its mechanical properties under static loading. However, failure of the bone occurs often under dynamic loading. An interesting question is: Are the structural sizes and layouts of the bone related or even adapted to the functionalities demanded by its dynamic performance? In the present work, systematic finite element analysis was performed on the dynamic response of nanoscale bone structures under dynamic loading. It was found that for a fixed mineral volume fraction and unit cell area, there exists a nanoscale staggered structure at some specific feature size and layout which exhibits the fastest attenuation of stress waves. Remarkably, these specific feature sizes and layouts are in excellent agreement with those experimentally observed in the bone at the same scale, indicating that the structural size and layout of the bone at the nanoscale are evolutionarily adapted to its dynamic behavior. The present work points out the importance of dynamic effect on the biological evolution of load-bearing biological materials.

Mechanical and biological properties of the micro-/nano-grain functionally graded hydroxyapatite bioceramics for bone tissue engineering.

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Zhou, Changchun; Deng, Congying; Chen, Xuening; Zhao, Xiufen; Chen, Ying; Fan, Yujiang; Zhang, Xingdong

2015-08-01

Functionally graded materials (FGM) open the promising approach for bone tissue repair. In this study, a novel functionally graded hydroxyapatite (HA) bioceramic with micrograin and nanograin structure was fabricated. Its mechanical properties were tailored by composition of micrograin and nanograin. The dynamic mechanical analysis (DMA) indicated that the graded HA ceramics had similar mechanical property compared to natural bones. Their cytocompatibility was evaluated via fluorescent microscopy and MTT colorimetric assay. The viability and proliferation of rabbit bone marrow mesenchymal stem cells (BMSCs) on ceramics indicated that this functionally graded HA ceramic had better cytocompatibility than conventional HA ceramic. This study demonstrated that functionally graded HA ceramics create suitable structures to satisfy both the mechanical and biological requirements of bone tissues. Copyright © 2015 Elsevier Ltd. All rights reserved.

Changes of hyoid bone position following treatment of class II div1 malocclusion with Farmand functional appliance

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Yassaei S

2007-01-01

Full Text Available Background and Aim: Unlike other bones of the head and neck, hyoid bone has no bony articulations. It is connected to mandible, cranium and pharynx through muscles and ligaments. During treatment with functional appliance in patients with class II div1 malocclusion, mandible is positioned in inferior and anterior direction. Regarding the relation between hyoid and mandibular bone, alterations of hyoid bone position can be a result of functional appliance therapy. The aim of this study was to evaluate the changes of hyoid bone position following treatment with Farmand functional appliance in patients with class II div 1 malocclusion. Materials and Methods: In this before-after clinical trial, 28 patients with class II div 1 malocclusion which were under treatment with Farmand functional appliance for 11 months were selected. Facial growth in vertical, normal or horizontal direction was determined by cephalometric measurement. Data were analyzed with Paired-t test to compare the differences of mean values pre and post treatment. Variance analysis was used to compare the three growth patterns. P<0.05 was considered as the limit of significance. Results: Hyoid bone shifted significantly forward in horizontal dimension (P<0.01 and non-significantly upward in vertical dimension. There was no significant difference among the three studied groups with respect to hyoid bone position alterations in horizontal dimension but significant difference was observed between horizontal and vertical growth pattern in vertical dimension (P<0.05. There was significant correlation between decrease of ANB angle and forward movement of hyoid bone. Conclusion: Based on the results of this study, treatment with Farmand functional appliance (Fa II leads to significant alterations in the position and anterior displacement of the hyoid bone.

Feasibility of the adaptive and automatic presentation of tasks (ADAPT system for rehabilitation of upper extremity function post-stroke

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Choi Younggeun

2011-08-01

Full Text Available Abstract Background Current guidelines for rehabilitation of arm and hand function after stroke recommend that motor training focus on realistic tasks that require reaching and manipulation and engage the patient intensively, actively, and adaptively. Here, we investigated the feasibility of a novel robotic task-practice system, ADAPT, designed in accordance with such guidelines. At each trial, ADAPT selects a functional task according to a training schedule and with difficulty based on previous performance. Once the task is selected, the robot picks up and presents the corresponding tool, simulates the dynamics of the tasks, and the patient interacts with the tool to perform the task. Methods Five participants with chronic stroke with mild to moderate impairments (> 9 months post-stroke; Fugl-Meyer arm score 49.2 ± 5.6 practiced four functional tasks (selected out of six in a pre-test with ADAPT for about one and half hour and 144 trials in a pseudo-random schedule of 3-trial blocks per task. Results No adverse events occurred and ADAPT successfully presented the six functional tasks without human intervention for a total of 900 trials. Qualitative analysis of trajectories showed that ADAPT simulated the desired task dynamics adequately, and participants reported good, although not excellent, task fidelity. During training, the adaptive difficulty algorithm progressively increased task difficulty leading towards an optimal challenge point based on performance; difficulty was then continuously adjusted to keep performance around the challenge point. Furthermore, the time to complete all trained tasks decreased significantly from pretest to one-hour post-test. Finally, post-training questionnaires demonstrated positive patient acceptance of ADAPT. Conclusions ADAPT successfully provided adaptive progressive training for multiple functional tasks based on participant's performance. Our encouraging results establish the feasibility of ADAPT; its

Maintenance of exercise-induced benefits in physical functioning and bone among elderly women.

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Karinkanta, S; Heinonen, A; Sievänen, H; Uusi-Rasi, K; Fogelholm, M; Kannus, P

2009-04-01

This study showed that about a half of the exercise-induced gain in dynamic balance and bone strength was maintained one year after cessation of the supervised high-intensity training of home-dwelling elderly women. However, to maintain exercise-induced gains in lower limb muscle force and physical functioning, continued training seems necessary. Maintenance of exercise-induced benefits in physical functioning and bone structure was assessed one year after cessation of 12-month randomized controlled exercise intervention. Originally 149 healthy women 70-78 years of age participated in the 12-month exercise RCT and 120 (81%) of them completed the follow-up study. Self-rated physical functioning, dynamic balance, leg extensor force, and bone structure were assessed. During the intervention, exercise increased dynamic balance by 7% in the combination resistance and balance-jumping training group (COMB). At the follow-up, a 4% (95% CI: 1-8%) gain compared with the controls was still seen, while the exercise-induced isometric leg extension force and self-rated physical functioning benefits had disappeared. During the intervention, at least twice a week trained COMB subjects obtained a significant 2% benefit in tibial shaft bone strength index compared to the controls. A half of this benefit seemed to be maintained at the follow-up. Exercise-induced benefits in dynamic balance and rigidity in the tibial shaft may partly be maintained one year after cessation of a supervised 12-month multi-component training in initially healthy elderly women. However, to maintain the achieved gains in muscle force and physical functioning, continued training seems necessary.

Bone-like apatite coating on functionalized poly(etheretherketone) surface via tailored silanization layers technique

International Nuclear Information System (INIS)

Zheng, Yanyan; Xiong, Chengdong; Zhang, Shenglan; Li, Xiaoyu; Zhang, Lifang

2015-01-01

Poly(etheretherketone) (PEEK) is a rigid semi-crystalline polymer with outstanding mechanical properties, bone-like stiffness and suitable biocompatibility that has attracted much interest as a biomaterial for orthopedic and dental implants. However, the bio-inert surface of PEEK limits its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, –PO 4 H 2 , –COOH and –OH groups were introduced on the PEEK surface by further chemical treatments of the vinyl-terminated silanization layers formed on the hydroxylation-pretreated PEEK surface. Both the surface-functionalized and pristine specimens were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and water contact angle measurements. When placed in 1.5 strength simulated body fluid (SBF) solution, apatite was observed to form uniformly on the functionalized PEEK surface and firmly attach to the substrate. The characterized results demonstrated that the coating was constituted by poorly crystallized bone-like apatite and the effect of surface functional groups on coating formation was also discussed in detail. In addition, in vitro biocompatibility of PEEK, in terms of pre-osteoblast cell (MC3T3-E1) attachment, spreading and proliferation, was remarkably enhanced by the bone-like apatite coating. Thus, this study provides a method to enhance the bioactivity of PEEK and expand its applications in orthopedic and dental implants. - Highlights: • –PO 4 H 2 , –COOH and –OH groups were successfully introduced onto PEEK surface via tailored silanization layer technique. • Bone-like apatite formed uniformly on surface-functionalized PEEK after immersion in SBF, and tightly adhered to the PEEK. • SEM, EDS, FTIR, XPS and XRD results showed that apatite layer is composed of low-crystalline bone-like apatite. • Bone-like apatite coating remarkably enhanced pre

Functional Attachment of Soft Tissues to Bone: Development, Healing, and Tissue Engineering

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Lu, Helen H.; Thomopoulos, Stavros

2014-01-01

Connective tissues such as tendons or ligaments attach to bone across a multitissue interface with spatial gradients in composition, structure, and mechanical properties. These gradients minimize stress concentrations and mediate load transfer between the soft and hard tissues. Given the high incidence of tendon and ligament injuries and the lack of integrative solutions for their repair, interface regeneration remains a significant clinical challenge. This review begins with a description of the developmental processes and the resultant structure-function relationships that translate into the functional grading necessary for stress transfer between soft tissue and bone. It then discusses the interface healing response, with a focus on the influence of mechanical loading and the role of cell-cell interactions. The review continues with a description of current efforts in interface tissue engineering, highlighting key strategies for the regeneration of the soft tissue–to-bone interface, and concludes with a summary of challenges and future directions. PMID:23642244

Age and Adaptive Functioning in Children and Adolescents with ASD: The Effects of Intellectual Functioning and ASD Symptom Severity.

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Hill, Trenesha L; Gray, Sarah A O; Kamps, Jodi L; Enrique Varela, R

2015-12-01

The present study examined the moderating effects of intellectual functioning and ASD symptom severity on the relation between age and adaptive functioning in 220 youth with autism spectrum disorder (ASD). Regression analysis indicated that intellectual functioning and ASD symptom severity moderated the relation between age and adaptive functioning. For younger children with lower intellectual functioning, higher ASD symptom severity was associated with better adaptive functioning than that of those with lower ASD symptom severity. Similarly, for older children with higher intellectual functioning, higher ASD symptom severity was associated with better adaptive functioning than that of those with lower ASD symptom severity. Analyses by subscales suggest that this pattern is driven by the Conceptual subscale. Clinical and research implications are discussed.

Evolutionary medicine and bone loss in chronic inflammatory diseases--A theory of inflammation-related osteopenia.

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Straub, Rainer H; Cutolo, Maurizio; Pacifici, Roberto

2015-10-01

Bone loss is typical in chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel diseases, pemphigus vulgaris, and others. It is also typical in transplantation-related inflammation and during the process of aging. While we recognized that bone loss is tightly linked to immune system activation or inflamm-aging in the form of acute, chronic active, or chronic smoldering inflammation, bone loss is typically discussed to be an "accident of inflammation." Extensive literature search in PubMed central. Using elements of evolutionary medicine, energy regulation, and neuroendocrine regulation of homeostasis and immune function, we work out that bone waste is an adaptive, evolutionarily positively selected program that is absolutely necessary during acute inflammation. However, when acute inflammation enters a chronic state due to the inability to terminate inflammation (e.g., in autoimmunity or in continuous immunity against microbes), the acute program of bone loss is a misguided adaptive program. The article highlights the complexity of interwoven pathways of osteopenia. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Relative binding affinity of carboxylate-, phosphonate-, and bisphosphonate-functionalized gold nanoparticles targeted to damaged bone tissue

Energy Technology Data Exchange (ETDEWEB)

Ross, Ryan D. [Rush University Medical Center, Department of Anatomy and Cell Biology (United States); Cole, Lisa E.; Roeder, Ryan K., E-mail: rroeder@nd.edu [University of Notre Dame, Department of Aerospace and Mechanical Engineering Bioengineering Graduate Program (United States)

2012-10-15

Functionalized Au NPs have received considerable recent interest for targeting and labeling cells and tissues. Damaged bone tissue can be targeted by functionalizing Au NPs with molecules exhibiting affinity for calcium. Therefore, the relative binding affinity of Au NPs surface functionalized with either carboxylate (l-glutamic acid), phosphonate (2-aminoethylphosphonic acid), or bisphosphonate (alendronate) was investigated for targeted labeling of damaged bone tissue in vitro. Targeted labeling of damaged bone tissue was qualitatively verified by visual observation and backscattered electron microscopy, and quantitatively measured by the surface density of Au NPs using field-emission scanning electron microscopy. The surface density of functionalized Au NPs was significantly greater within damaged tissue compared to undamaged tissue for each functional group. Bisphosphonate-functionalized Au NPs exhibited a greater surface density labeling damaged tissue compared to glutamic acid- and phosphonic acid-functionalized Au NPs, which was consistent with the results of previous work comparing the binding affinity of the same functionalized Au NPs to synthetic hydroxyapatite crystals. Targeted labeling was enabled not only by the functional groups but also by the colloidal stability in solution. Functionalized Au NPs were stabilized by the presence of the functional groups, and were shown to remain well dispersed in ionic (phosphate buffered saline) and serum (fetal bovine serum) solutions for up to 1 week. Therefore, the results of this study suggest that bisphosphonate-functionalized Au NPs have potential for targeted delivery to damaged bone tissue in vitro and provide motivation for in vivo investigation.

Splenic concentration of bone imaging agents in functional asplenia

International Nuclear Information System (INIS)

Dhekne, R.D.

1981-01-01

Three cases of sickle cell disease associated with functional asplenia are described. The spleen was not visualized on routine Tc-99m-sulfur colloid scan. The bone scan performed with Tc-99m-phosphate compounds revealed abnormal splenic activity in all three cases. The previous case reports and the literature on this subject are reviewed

Everyday executive functioning influences adaptive skills in autism spectrum disorders

Directory of Open Access Journals (Sweden)

Rachel K. Peterson

2015-11-01

Full Text Available Adaptive skills are often defined as a set of behaviors or constellation of skills that allow for an individual to function independently and meet environmental demands. Adaptive skills have been linked with an array of social and academic outcomes. Executive functions (EF have been defined as a set of “capacities that enable a person to engage successfully in independent, purposive, self-serving behavior”. While the literature has demonstrated some overlap in the definitions of adaptive skills and the purpose of executive functions, little has been done to investigate the relationship between the two. The current study sought to investigate this relationship within Autistic Spectrum Disorders (ASD, a clinical grouping that has demonstrated a predisposition towards deficits within both of these functional domains. ASD are oftentimes associated with EF deficits, especially in the domains of cognitive flexibility, planning, and working memory. Deficits in adaptive skills have also been commonly reported in relation to ASD, with a wide range of abilities being noted across previous studies. The purpose of this study was to examine relationships between adaptive skills and EF in individuals with ASD with the idea that an understanding of such relationships may offer insight into possible focus for intervention.

Functional grading of mineral and collagen in the attachment of tendon to bone.

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Genin, Guy M; Kent, Alistair; Birman, Victor; Wopenka, Brigitte; Pasteris, Jill D; Marquez, Pablo J; Thomopoulos, Stavros

2009-08-19

Attachment of dissimilar materials is a major challenge because high levels of localized stress may develop at their interfaces. An effective biologic solution to this problem exists at one of nature's most extreme interfaces: the attachment of tendon (a compliant, structural "soft tissue") to bone (a stiff, structural "hard tissue"). The goal of our study was to develop biomechanical models to describe how the tendon-to-bone insertion derives its mechanical properties. We examined the tendon-to-bone insertion and found two factors that give the tendon-to-bone transition a unique grading in mechanical properties: 1), a gradation in mineral concentration, measured by Raman spectroscopy; and 2), a gradation in collagen fiber orientation, measured by polarized light microscopy. Our measurements motivate a new physiological picture of the tissue that achieves this transition, the tendon-to-bone insertion, as a continuous, functionally graded material. Our biomechanical model suggests that the experimentally observed increase in mineral accumulation within collagen fibers can provide significant stiffening of the partially mineralized fibers, but only for concentrations of mineral above a "percolation threshold" corresponding to formation of a mechanically continuous mineral network within each collagen fiber (e.g., the case of mineral connectivity extending from one end of the fiber to the other). Increasing dispersion in the orientation distribution of collagen fibers from tendon to bone is a second major determinant of tissue stiffness. The combination of these two factors may explain the nonmonotonic variation of stiffness over the length of the tendon-to-bone insertion reported previously. Our models explain how tendon-to-bone attachment is achieved through a functionally graded material composition, and provide targets for tissue engineered surgical interventions and biomimetic material interfaces.

Galloping exercise induces regional changes in bone density within the third and radial carpal bones of Thoroughbred horses

International Nuclear Information System (INIS)

Firth, E.C.; Delahunt, J.; Wichtel, J.W.; Birch, H.L.; Goodship, A.E.

1999-01-01

This study was performed to test the hypothesis that a localised bone hypertrophy could occur within the subchondral cancellous architecture of the third and radial carpal bones. Using 2 levels of controlled and defined exercise, it was observed that a high intensity treadmill exercise protocol resulted in functional adaptation of the carpal bones. The increase in trabecular thickening and density was seen to be localised to those regions underlying common sites of cartilage degradation, the interface of the thickened trabeculae with the normal architecture in the third carpal hone was coincident with a common site of clinical fractures. The bone changes were determined both qualitatively on examination of slab radiographs and quantified by dual energy x-ray absorptiometry. The findings from this study are relevant to mechanical factors involved in the pathophysiology of joint degeneration. The potential clinical implications of this study are in relation to changes in the type and duration of exercise regimens used in training of equine athletes. The rapid response of bone to mechanical stimulation has implications in the longer term for localised cartilage degradation. Imaging techniques could be developed to monitor these early bone changes in the specific areas identified in this study and thus allow appropriate changes in training intensity to minimise subsequent damage to the articular surface

Structural and Biomechanical Adaptations to Free-Fall Landing in Hindlimb Cortical Bone of Growing Female Rats

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Hsin-Shih Lin, Ho-Seng Wang, Hung-Ta Chiu, Kuang-You B. Cheng, Ar-Tyan Hsu, Tsang-Hai Huang

2018-06-01

Full Text Available The purpose of the study was to investigate the adaptation process of hindlimb cortical bone subjected to free-fall landing training. Female Wistar rats (7 weeks old were randomly assigned to four landing (L groups and four age-matched control (C groups (n = 12 per group: L1, L2, L4 L8, C1, C2, C4 and C8. Animals in the L1, L2, L4 and L8 groups were respectively subjected to 1, 2, 4 and 8 weeks of free-fall-landing training (40 cm height, 30 times/day and 5 days/week while the C1, C2, C4 and C8 groups served as age-matched control groups. The tibiae of the L8 group were higher in cortical bone mineral content (BMC than those in the C8 group (p < 0.05. Except for the higher bone mineralization over bone surface ratio (MS/BS, % shown in the tibiae of the L1 group (p < 0.05, dynamic histomorphometry in the tibial and femoral cortical bone showed no difference between landing groups and their age-matched control groups. In the femora, the L1 group was lower than the C1 group in cortical bone area (Ct.Ar and cortical thickness (Ct.Th (p < 0.05; however, the L4 group was higher than the C4 group in Ct.Ar and Ct.Th (p <0 .05. In the tibiae, the moment of inertia about the antero-posterior axis (Iap, Ct.Ar and Ct.Th was significantly higher in the L8 group than in the C8 group (p < 0.05. In biomechanical testing, fracture load (FL of femora was lower in the L1 group than in the C1 group (p < 0.05. Conversely, yield load (YL, FL and yield load energy (YE of femora, as well as FL of tibiae were all significantly higher in the L8 group than in the C8 group (p < 0.05. Free-fall landing training may initially compromise bone material. However, over time, the current free-fall landing training induced improvements in biomechanical properties and/or the structure of growing bones.

Structural and Biomechanical Adaptations to Free-Fall Landing in Hindlimb Cortical Bone of Growing Female Rats.

Science.gov (United States)

Lin, Hsin-Shih; Wang, Ho-Seng; Chiu, Hung-Ta; Cheng, Kuang-You B; Hsu, Ar-Tyan; Huang, Tsang-Hai

2018-06-01

The purpose of the study was to investigate the adaptation process of hindlimb cortical bone subjected to free-fall landing training. Female Wistar rats (7 weeks old) were randomly assigned to four landing (L) groups and four age-matched control (C) groups (n = 12 per group): L1, L2, L4 L8, C1, C2, C4 and C8. Animals in the L1, L2, L4 and L8 groups were respectively subjected to 1, 2, 4 and 8 weeks of free-fall-landing training (40 cm height, 30 times/day and 5 days/week) while the C1, C2, C4 and C8 groups served as age-matched control groups. The tibiae of the L8 group were higher in cortical bone mineral content (BMC) than those in the C8 group (p < 0.05). Except for the higher bone mineralization over bone surface ratio (MS/BS, %) shown in the tibiae of the L1 group (p < 0.05), dynamic histomorphometry in the tibial and femoral cortical bone showed no difference between landing groups and their age-matched control groups. In the femora, the L1 group was lower than the C1 group in cortical bone area (Ct.Ar) and cortical thickness (Ct.Th) (p < 0.05); however, the L4 group was higher than the C4 group in Ct.Ar and Ct.Th (p <0 .05). In the tibiae, the moment of inertia about the antero-posterior axis ( I ap ), Ct.Ar and Ct.Th was significantly higher in the L8 group than in the C8 group (p < 0.05). In biomechanical testing, fracture load (FL) of femora was lower in the L1 group than in the C1 group (p < 0.05). Conversely, yield load (YL), FL and yield load energy (YE) of femora, as well as FL of tibiae were all significantly higher in the L8 group than in the C8 group (p < 0.05). Free-fall landing training may initially compromise bone material. However, over time, the current free-fall landing training induced improvements in biomechanical properties and/or the structure of growing bones.

Bone loss in rheumatoid arthritis. Influence of disease activity, duration of the disease, functional capacity, and corticosteroid treatment

DEFF Research Database (Denmark)

Hansen, M; Florescu, A; Stoltenberg, M

1996-01-01

Axial and appendicular bone mass were studied in 95 patients with rheumatoid arthritis. The aims were to quantify bone mineral density (BMD) and to evaluate the importance of disease activity, duration of disease, functional capacity, and corticosteroid treatment for bone loss in patients...... after the start of the disease. The overall functional capacity in terms of physical activity increased BMD in the axial skeleton. The local functional capacity in terms of grip strength was positively related to BMD in the appendicular skeleton. Patients with severe functional impairment had the lowest...

Adapting SMME business functions during economic turmoil

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Chantal Rootman

2010-12-01

Full Text Available Purpose: The purpose of this study is to investigate how SMMEs should adapt their business functions to improve business performance during times of economic turmoil. Problem investigated: SMMEs are important contributors to the economy as these firms provide employment opportunities and create economic wealth. However, many SMMEs fail due to reasons such as the influence of economic factors (low sales and growth prospects as well as the lack of finance, managerial skills and expertise. SMMEs could possibly increase their chances of success if they adjust aspects in their firms which the owners and managers of the SMMEs can control. Business functions are regarded as internal forces influencing a firm and SMME owners and managers can control these functions. These business functions include general and strategic management, purchasing management, production management, marketing management, financial management, human resources management, business communication management and information management. It is important to investigate how SMMEs can adapt their business functions, during difficult economic times, to improve their business performance. Methodology: A self-developed, self-administered and structured questionnaire was distributed to 300 SMMEs in the Eastern Cape and the Garden Route area. A total of 250 usable questionnaires were received, therefore a response rate of 83% was obtained. Findings and implications: The findings of this study revealed that all eight of the business functions require adjustments during difficult economic times to improve the business performance of SMMEs. Respondents regarded the financial management function as the area in SMMEs that needs the most focus and adjustments, during challenging economic times to improve business performance. Following financial management is the purchasing- and information management business functions. Originality and value of the research: This study specifically focussed on

A Copolymer Scaffold Functionalized with Nanodiamond Particles Enhances Osteogenic Metabolic Activity and Bone Regeneration.

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Yassin, Mohammed A; Mustafa, Kamal; Xing, Zhe; Sun, Yang; Fasmer, Kristine Eldevik; Waag, Thilo; Krueger, Anke; Steinmüller-Nethl, Doris; Finne-Wistrand, Anna; Leknes, Knut N

2017-06-01

Functionalizing polymer scaffolds with nanodiamond particles (nDPs) has pronounced effect on the surface properties, such as improved wettability, an increased active area and binding sites for cellular attachment and adhesion, and increased ability to immobilize biomolecules by physical adsorption. This study aims to evaluate the effect of poly(l-lactide-co-ε-caprolactone) (poly(LLA-co-CL)) scaffolds, functionalized with nDPs, on bone regeneration in a rat calvarial critical size defect. Poly(LLA-co-CL) scaffolds functionalized with nDPs are also compared with pristine scaffolds with reference to albumin adsorption and seeding efficiency of bone marrow stromal cells (BMSCs). Compared with pristine scaffolds, the experimental scaffolds exhibit a reduction in albumin adsorption and a significant increase in the seeding efficiency of BMSCs (p = 0.027). In the calvarial defects implanted with BMSC-seeded poly(LLA-co-CL)/nDPs scaffolds, live imaging at 12 weeks discloses a significant increase in osteogenic metabolic activity (p = 0.016). Microcomputed tomography, confirmed by histological data, reveals a substantial increase in bone volume (p = 0.021). The results show that compared with conventional poly(LLA-co-CL) scaffolds those functionalized with nDPs promote osteogenic metabolic activity and mineralization capacity. It is concluded that poly(LLA-co-CL) composite matrices functionalized with nDPs enhance osteoconductivity and therefore warrant further study as potential scaffolding material for bone tissue engineering. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydroxyapatite nanorod and microsphere functionalized with bioactive lactoferrin as a new biomaterial for enhancement bone regeneration.

Science.gov (United States)

Shi, Pujie; Wang, Qun; Yu, Cuiping; Fan, Fengjiao; Liu, Meng; Tu, Maolin; Lu, Weihong; Du, Ming

2017-07-01

Lactoferrin (LF) has been recently recognized as a promising new novel bone growth factor for the beneficial effects on bone cells and promotion of bone growth. Currently, it has been attracted wide attention in bone regeneration as functional food additives or a potential bioactive protein in bone tissue engineering. The present study investigated the possibility that hydroxyapatite (HAP) particles, a widely used bone substitute material for high biocompatibility and osteoconductivity, functionalized with lactoferrin as a composite material are applied to bone tissue engineering. Two kinds of hydroxyapatite samples with different sizes, including nanorods and microspheres particles, were functionalized with lactoferrin molecules, respectively. A detailed characterization of as-prepared HAP-LF complex is presented, combining thermal gravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FT-IR). Zeta potential and the analysis of electrostatic surface potential of lactoferrin were carried to reveal the mechanism of adsorption. The effects of HAP-LF complex on MC3T3-E1 osteoblast proliferation and morphology were systematically evaluated at different culture time. Interestingly, results showed that cell viability of HAP-LF group was significantly higher than HAP group indicating that the HAP-LF can improve the biocompatibility of HAP, which mainly originated from a combination of HAP-LF interaction. These results indicated that hydroxyapatite particles can work as a controlled releasing carrier of lactoferrin successfully, and lactoferrin showed better potentiality on using in the field of bone regeneration by coupling with hydroxyapatite. This study would provide a new biomaterial and might offer a new insight for enhancement of bone regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

A paradigm shift for bone quality in dentistry: A literature review.

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Kuroshima, Shinichiro; Kaku, Masaru; Ishimoto, Takuya; Sasaki, Muneteru; Nakano, Takayoshi; Sawase, Takashi

2017-10-01

The aim of this study was to present the current concept of bone quality based on the proposal by the National Institutes of Health (NIH) and some of the cellular and molecular factors that affect bone quality. This is a literature review which focuses on collagen, biological apatite (BAp), and bone cells such as osteoblasts and osteocytes. In dentistry, the term "bone quality" has long been considered to be synonymous with bone mineral density (BMD) based on radiographic and sensible evaluations. In 2000, the NIH proposed the concept of bone quality as "the sum of all characteristics of bone that influence the bone's resistance to fracture," which is completely independent of BMD. The NIH defines bone quality as comprising bone architecture, bone turnover, bone mineralization, and micro-damage accumulation. Moreover, our investigations have demonstrated that BAp, collagen, and bone cells such as osteoblasts and osteocytes play essential roles in controlling the current concept of bone quality in bone around hip and dental implants. The current concept of bone quality is crucial for understanding bone mechanical functions. BAp, collagen and osteocytes are the main factors affecting bone quality. Moreover, mechanical loading dynamically adapts bone quality. Understanding the current concept of bone quality is required in dentistry. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Clopidogrel (Plavix®), a P2Y(12) receptor antagonist, inhibits bone cell function in vitro and decreases trabecular bone in vivo

DEFF Research Database (Denmark)

Syberg, Susanne; Brandao-Burch, Andrea; Patel, Jessal J

2012-01-01

Clopidogrel (Plavix®), a selective P2Y(12) receptor antagonist, is widely prescribed to reduce the risk of heart attack and stroke and acts via the inhibition of platelet aggregation. Accumulating evidence now suggests that extracellular nucleotides, signalling through P2 receptors, play...... a significant role in bone, modulating both osteoblast and osteoclast function. In this study, we investigated the effects of clopidogrel treatment on (1) bone cell formation, differentiation and activity in vitro; and, (2) trabecular and cortical bone parameters in vivo. P2Y(12) receptor expression...

Deproteinized bovine bone functionalized with the slow delivery of BMP-2 for the repair of critical-sized bone defects in sheep.

Science.gov (United States)

Liu, Tie; Wu, Gang; Wismeijer, Daniel; Gu, Zhiyuan; Liu, Yuelian

2013-09-01

As an alternative to an autologous bone graft, deproteinized bovine bone (DBB) is widely used in the clinical dentistry. Although DBB provides an osteoconductive scaffold, it is not capable of enhancing bone regeneration because it is not osteoinductive. In order to render DBB osteoinductive, bone morphogenetic protein 2 (BMP-2) has previously been incorporated into a three dimensional reservoir (a biomimetic calcium phosphate coating) on DBB, which effectively promoted the osteogenic response by the slow delivery of BMP-2. The aim of this study was to investigate the therapeutic effectiveness of such coating on the DBB granules in repairing a large cylindrical bone defect (8 mm diameter, 13 mm depth) in sheep. Eight groups were randomly assigned to the bone defects: (i) no graft material; (ii) autologous bone; (iii) DBB only; (iv) DBB mixed with autologous bone; (v) DBB bearing adsorbed BMP-2; (vi) DBB bearing a coating but no BMP-2; (vii) DBB bearing a coating with adsorbed BMP-2; and (viii) DBB bearing a coating-incorporated depot of BMP-2. 4 and 8 weeks after implantation, samples were withdrawn for a histological and a histomorphometric analysis. Histological results confirmed the excellent biocompatibility and osteoconductivity of all the grafts tested. At 4 weeks, DBB mixed with autologous bone or functionalized with coating-incorporated BMP-2 showed more newly-formed bone than the other groups with DBB. At 8 weeks, the volume of newly-formed bone around DBB that bore a coating-incorporated depot of BMP-2 was greatest among the groups with DBB, and was comparable to the autologous bone group. The use of autologous bone and BMP-2 resulted in more bone marrow formation. Multinucleated giant cells were observed in the resorption process around DBB, whereas histomorphometric analysis revealed no significant degradation of DBB. In conclusion, it was shown that incorporating BMP-2 into the calcium phosphate coating of DBB induced strong bone formation around DBB

Nano-material aspects of shock absorption in bone joints.

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Tributsch, H; Copf, F; Copf, P; Hindenlang, U; Niethard, F U; Schneider, R

2010-01-01

This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three-dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones.

The Predentary Bone and Its Significance in the Evolution of Feeding Mechanisms in Ornithischian Dinosaurs.

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Nabavizadeh, Ali; Weishampel, David B

2016-10-01

The characteristic predentary bone in ornithischian dinosaurs is a unique, unpaired element located at the midline of the mandibular symphysis. Although traditionally thought to only be a plant "nipping" bone, the true functional significance of this bone among feeding mechanisms of ornithischian dinosaurs is poorly known. Recent studies of a select few ornithischian genera have suggested rotation of the mandibular corpora around their long axes relative to their midline joint articulation with the predentary bone. This study aims to re-evaluate these hypotheses as well as provide in-depth qualitative comparative descriptions of predentary bone morphology in ornithischian genera throughout all subclades, including heterodontosaurids, thyreophorans, ornithopods, and marginocephalians. Descriptions evaluate overall shape of the predentary, its articular surfaces contacting the rostral ends of the dentaries, and the morphology of the rostral extent of the dentaries and their midline symphysis. Functionally relevant morphologies in each predentary morphotype are accentuated for further speculation of feeding mechanisms. Three predentary morphotypes are described throughout ornithischian subclades and each plays a unique role in feeding adaptations. Most notably, the predentary likely evolved as a midline axial point of the mandibular symphysis for simultaneous variable movement or rotation of the mandibular corpora in many, but not all, taxa. This simultaneous movement of the hemimandibles would have aided in feeding on both sides of the jaw at once. The function of the predentary as well as other jaw adaptations is discussed for genera throughout all subclades, focusing on both general shape and joint morphology. Anat Rec, 299:1358-1388, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Report on Adaptive Force, a specific neuromuscular function

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Marko Hoff

2015-08-01

Full Text Available In real life motions, as well as in sports, the adaptation of the neuromuscular systems to externally applied forces plays an important role. The term Adaptive Force (AF shall characterize the ability of the nerve-muscle-system to adapt to impacting external forces during isometric and eccentric muscle action. The focus in this paper is on the concept of this neuromuscular action, which is not yet described in this way. A measuring system was constructed and evaluated for this specific neuromuscular function, but only the main information of the evaluation of the measuring system and the preliminary reference values are mentioned here, while an article with detailed description will be published separately. This paper concentrates on the three following points: 1 What is the peculiarity of this neuromuscular function, introduced as AF? 2 Is the measuring system able to capture its specific characteristics and which phases of measurement occur? 3 It seems reasonable to discuss if AF can be distinguished and classified among the known force concepts. The article describes the measuring system and how it is able to capture special features of real life motions like submaximal intensities and the subjects’ option to react adequately on external varying forces. Furthermore, within one measurement the system records three different force qualities: the isometric submaximal Adaptive Force (AFiso, the maximal isometric Adaptive Force (AFisomax and the maximal eccentric Adaptive Force (AFeccmax. Each of these phases provide different and unique information on the nerve-muscle-system that are discussed in detail. Important, in terms of the Adaptive Force, seems to be the combination of conditional and coordinative abilities.

Adaptation of subchondral bone in osteoarthritis

DEFF Research Database (Denmark)

Ding, Ming

2004-01-01

Osteoarthritis is a chronic joint disease with pathological changes in the articulating cartilage and all other tissues that occupy the joint. Radin and coworkers have suggested the involvement of subchondral bone in the disease process. However, evidence for an essential role in the etiology has...

Age-related mechanical strength evolution of trabecular bone under fatigue damage for both genders: Fracture risk evaluation.

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Ben Kahla, Rabeb; Barkaoui, Abdelwahed; Merzouki, Tarek

2018-05-04

Bone tissue is a living composite material, providing mechanical and homeostatic functions, and able to constantly adapt its microstructure to changes in long term loading. This adaptation is conducted by a physiological process, known as "bone remodeling". This latter is manifested by interactions between osteoclasts and osteoblasts, and can be influenced by many local factors, via effects on bone cell differentiation and proliferation. In the current work, age and gender effects on damage rate evolution, throughout life, have been investigated using a mechanobiological finite element modeling. To achieve the aim, a mathematical model has been developed, coupling both cell activities and mechanical behavior of trabecular bone, under cyclic loadings. A series of computational simulations (ABAQUS/UMAT) has been performed on a 3D human proximal femur, allowing to investigate the effects of mechanical and biological parameters on mechanical strength of trabecular bone, in order to evaluate the fracture risk resulting from fatigue damage. The obtained results revealed that mechanical stimulus amplitude affects bone resorption and formation rates, and indicated that age and gender are major factors in bone response to the applied loadings. Copyright © 2018 Elsevier Ltd. All rights reserved.

Systematic evaluation of skeletal mechanical function.

Science.gov (United States)

Smith, Lauren; Bigelow, Erin M R; Jepsen, Karl J

2013-06-01

Many genetic and environmental perturbations lead to measurable changes in bone morphology, matrix composition, and matrix organization. The skeletal system is highly adaptive, such that genetic and environmental perturbations affecting one trait are often accompanied by compensatory changes in other traits. This adaptation should be considered when attempting to draw meaningful conclusions about the role of a gene, for example. The challenge is to figure out which alterations can be attributed to the perturbation and which result from adaptive changes associated with establishing mechanical function. The goal of this chapter is to describe straight-forward biomechanical methods that can be used to determine whether a genetic or environmental perturbation affected bone strength. We introduce a systematic method for evaluating how bone strength was altered in the context of morphology and tissue-level mechanical properties, which are determined in large part from matrix composition, matrix organization, and porosity. We present this work as a first step toward screening mice for a phenotypic effect and for establishing the associated biomechanical mechanism by which function was altered. The outcome of these analyses generally provides insight into the next set of experiments required to further connect the cellular perturbation with the functional changes. The protocols were written to enable researchers without a background in engineering to conduct the assays or to enable researchers to better understand the outcomes of similar assays conducted by colleagues knowledgeable in engineering.

Functionalized Surface Geometries Induce: “Bone: Formation by Autoinduction”

Directory of Open Access Journals (Sweden)

Ugo Ripamonti

2018-02-01

Full Text Available The induction of tissue formation, and the allied disciplines of tissue engineering and regenerative medicine, have flooded the twenty-first century tissue biology scenario and morphed into high expectations of a fulfilling regenerative dream of molecularly generated tissues and organs in assembling human tissue factories. The grand conceptualization of deploying soluble molecular signals, first defined by Turing as forms generating substances, or morphogens, stemmed from classic last century studies that hypothesized the presence of morphogens in several mineralized and non-mineralized mammalian matrices. The realization of morphogens within mammalian matrices devised dissociative extractions and chromatographic procedures to isolate, purify, and finally reconstitute the cloned morphogens, found to be members of the transforming growth factor-β (TGF-β supergene family, with insoluble signals or substrata to induce de novo tissue induction and morphogenesis. Can we however construct macroporous bioreactors per se capable of inducing bone formation even without the exogenous applications of the osteogenic soluble molecular signals of the TGF-β supergene family? This review describes original research on coral-derived calcium phosphate-based macroporous constructs showing that the formation of bone is independent of the exogenous application of the osteogenic soluble signals of the TGF-β supergene family. Such signals are the molecular bases of the induction of bone formation. The aim of this review is to primarily describe today's hottest topic of biomaterials' science, i.e., to construct and define osteogenetic biomaterials' surfaces that per se, in its own right, do initiate the induction of bone formation. Biomaterials are often used to reconstruct osseous defects particularly in the craniofacial skeleton. Edentulism did spring titanium implants as tooth replacement strategies. No were else that titanium surfaces require functionalized

Bone architecture adaptations after spinal cord injury: impact of long-term vibration of a constrained lower limb.

Science.gov (United States)

Dudley-Javoroski, S; Petrie, M A; McHenry, C L; Amelon, R E; Saha, P K; Shields, R K

2016-03-01

This study examined the effect of a controlled dose of vibration upon bone density and architecture in people with spinal cord injury (who eventually develop severe osteoporosis). Very sensitive computed tomography (CT) imaging revealed no effect of vibration after 12 months, but other doses of vibration may still be useful to test. The purposes of this report were to determine the effect of a controlled dose of vibratory mechanical input upon individual trabecular bone regions in people with chronic spinal cord injury (SCI) and to examine the longitudinal bone architecture changes in both the acute and chronic state of SCI. Participants with SCI received unilateral vibration of the constrained lower limb segment while sitting in a wheelchair (0.6g, 30 Hz, 20 min, three times weekly). The opposite limb served as a control. Bone mineral density (BMD) and trabecular micro-architecture were measured with high-resolution multi-detector CT. For comparison, one participant was studied from the acute (0.14 year) to the chronic state (2.7 years). Twelve months of vibration training did not yield adaptations of BMD or trabecular micro-architecture for the distal tibia or the distal femur. BMD and trabecular network length continued to decline at several distal femur sub-regions, contrary to previous reports suggesting a "steady state" of bone in chronic SCI. In the participant followed from acute to chronic SCI, BMD and architecture decline varied systematically across different anatomical segments of the tibia and femur. This study supports that vibration training, using this study's dose parameters, is not an effective anti-osteoporosis intervention for people with chronic SCI. Using a high-spatial-resolution CT methodology and segmental analysis, we illustrate novel longitudinal changes in bone that occur after spinal cord injury.

CD146/MCAM defines functionality of human bone marrow stromal stem cell populations

DEFF Research Database (Denmark)

Harkness, Linda; Zaher, Walid; Ditzel, Nicholas

2016-01-01

BACKGROUND: Identification of surface markers for prospective isolation of functionally homogenous populations of human skeletal (stromal, mesenchymal) stem cells (hMSCs) is highly relevant for cell therapy protocols. Thus, we examined the possible use of CD146 to subtype a heterogeneous hMSC...... population. METHODS: Using flow cytometry and cell sorting, we isolated two distinct hMSC-CD146(+) and hMSC-CD146(-) cell populations from the telomerized human bone marrow-derived stromal cell line (hMSC-TERT). Cells were examined for differences in their size, shape and texture by using high...... and adipocytes on the basis of gene expression and protein production of lineage-specific markers. In vivo, hMSC-CD146(+) and hMSC-CD146(-) cells formed bone and bone marrow organ when implanted subcutaneously in immune-deficient mice. Bone was enriched in hMSC-CD146(-) cells (12.6 % versus 8.1 %) and bone...

A new look at ichthyosaur long bone microanatomy and histology: implications for their adaptation to an aquatic life.

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Alexandra Houssaye

Full Text Available BACKGROUND: Ichthyosaurs are Mesozoic reptiles considered as active swimmers highly adapted to a fully open-marine life. They display a wide range of morphologies illustrating diverse ecological grades. Data concerning their bone microanatomical and histological features are rather limited and suggest that ichthyosaurs display a spongious, "osteoporotic-like" bone inner structure, like extant cetaceans. However, some taxa exhibit peculiar features, suggesting that the analysis of the microanatomical and histological characteristics of various ichthyosaur long bones should match the anatomical diversity and provide information about their diverse locomotor abilities and physiology. METHODOLOGY/PRINCIPAL FINDINGS: The material analyzed for this study essentially consists of mid-diaphyseal transverse sections from stylopod bones of various ichthyosaurs and of a few microtomographic (both conventional and synchrotron data. The present contribution discusses the histological and microanatomical variation observed within ichthyosaurs and the peculiarities of some taxa (Mixosaurus, Pessopteryx. Four microanatomical types are described. If Mixosaurus sections differ from those of the other taxa analyzed, the other microanatomical types, characterized by the relative proportion of compact and loose spongiosa of periosteal and endochondral origin respectively, seem to rather especially illustrate variation along the diaphysis in taxa with similar microanatomical features. Our analysis also reveals that primary bone in all the ichthyosaur taxa sampled (to the possible exception of Mixosaurus is spongy in origin, that cyclical growth is a common pattern among ichthyosaurs, and confirms the previous assumptions of high growth rates in ichthyosaurs. CONCLUSIONS/SIGNIFICANCE: The occurrence of two types of remodelling patterns along the diaphysis, characterized by bone mass decrease and increase respectively is described for the first time. It raises questions

THE STRUCTURAL AND MECHANICAL PROPERTIES OF THE BONE

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Robert Karpiński

2017-06-01

Full Text Available The work contains basic information on the anatomy and physiology of bone tissue. Basic concepts related to the structure of bone tissue are presented. General issues related to bone reconstruction processes and biomechanical structural adaptations processes were described. Mechanical parameters of bone tissue were presented.

Bone-like apatite coating on functionalized poly(etheretherketone) surface via tailored silanization layers technique

Energy Technology Data Exchange (ETDEWEB)

Zheng, Yanyan [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Xiong, Chengdong; Zhang, Shenglan [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Li, Xiaoyu [State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041 (China); Zhang, Lifang, E-mail: zhanglfcioc@163.com [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China)

2015-10-01

Poly(etheretherketone) (PEEK) is a rigid semi-crystalline polymer with outstanding mechanical properties, bone-like stiffness and suitable biocompatibility that has attracted much interest as a biomaterial for orthopedic and dental implants. However, the bio-inert surface of PEEK limits its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, –PO{sub 4}H{sub 2}, –COOH and –OH groups were introduced on the PEEK surface by further chemical treatments of the vinyl-terminated silanization layers formed on the hydroxylation-pretreated PEEK surface. Both the surface-functionalized and pristine specimens were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and water contact angle measurements. When placed in 1.5 strength simulated body fluid (SBF) solution, apatite was observed to form uniformly on the functionalized PEEK surface and firmly attach to the substrate. The characterized results demonstrated that the coating was constituted by poorly crystallized bone-like apatite and the effect of surface functional groups on coating formation was also discussed in detail. In addition, in vitro biocompatibility of PEEK, in terms of pre-osteoblast cell (MC3T3-E1) attachment, spreading and proliferation, was remarkably enhanced by the bone-like apatite coating. Thus, this study provides a method to enhance the bioactivity of PEEK and expand its applications in orthopedic and dental implants. - Highlights: • –PO{sub 4}H{sub 2}, –COOH and –OH groups were successfully introduced onto PEEK surface via tailored silanization layer technique. • Bone-like apatite formed uniformly on surface-functionalized PEEK after immersion in SBF, and tightly adhered to the PEEK. • SEM, EDS, FTIR, XPS and XRD results showed that apatite layer is composed of low-crystalline bone-like apatite. • Bone-like apatite coating

Physical exercise and osteoporosis: effects of different types of exercises on bone and physical function of postmenopausal women.

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Moreira, Linda Denise Fernandes; Oliveira, Mônica Longo de; Lirani-Galvão, Ana Paula; Marin-Mio, Rosângela Villa; Santos, Rodrigo Nolasco dos; Lazaretti-Castro, Marise

2014-07-01

Physical exercise is an important stimulus for osteoporosis prevention and treatment. However, it is not clear yet which modality would be better to stimulate bone metabolism and enhance physical function of postmenopausal women. This review paper aims to summarize and update present knowledge on the effects of different kinds of aquatic and ground physical exercises on bone metabolism and physical function of postmenopausal women. Moderate to intense exercises, performed in a high speed during short intervals of time, in water or on the ground, can be part of a program to prevent and treat postmenopausal osteoporosis. Mechanical vibration has proven to be beneficial for bone microarchitecture, improving bone density and bone strength, as well as increasing physical function. Although impact exercises are recognized as beneficial for the stimulation of bone tissue, other variables such as muscle strength, type of muscle contraction, duration and intensity of exercises are also determinants to induce changes in bone metabolism of postmenopausal women. Not only osteoanabolic exercises should be recommended; activities aimed to develop muscle strength and body balance and improve the proprioception should be encouraged to prevent falls and fractures.

Adaptive Analysis of Functional MRI Data

International Nuclear Information System (INIS)

Friman, Ola

2003-01-01

Functional Magnetic Resonance Imaging (fMRI) is a recently developed neuro-imaging technique with capacity to map neural activity with high spatial precision. To locate active brain areas, the method utilizes local blood oxygenation changes which are reflected as small intensity changes in a special type of MR images. The ability to non-invasively map brain functions provides new opportunities to unravel the mysteries and advance the understanding of the human brain, as well as to perform pre-surgical examinations in order to optimize surgical interventions. This dissertation introduces new approaches for the analysis of fMRI data. The detection of active brain areas is a challenging problem due to high noise levels and artifacts present in the data. A fundamental tool in the developed methods is Canonical Correlation Analysis (CCA). CCA is used in two novel ways. First as a method with the ability to fully exploit the spatio-temporal nature of fMRI data for detecting active brain areas. Established analysis approaches mainly focus on the temporal dimension of the data and they are for this reason commonly referred to as being mass-univariate. The new CCA detection method encompasses and generalizes the traditional mass-univariate methods and can in this terminology be viewed as a mass-multivariate approach. The concept of spatial basis functions is introduced as a spatial counterpart of the temporal basis functions already in use in fMRI analysis. The spatial basis functions implicitly perform an adaptive spatial filtering of the fMRI images, which significantly improves detection performance. It is also shown how prior information can be incorporated into the analysis by imposing constraints on the temporal and spatial models and a constrained version of CCA is devised to this end. A general Principal Component Analysis technique for generating and constraining temporal and spatial subspace models is proposed to be used in combination with the constrained CCA

Role of intensity transformation function for enhancement of bone scintigraphic images.

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Pandey, Anil Kumar; Dhiman, Vishali; Sharma, Akshima; ArunRaj, Sreedharan Thankarajan; Baghel, Vivek; Patel, Chetan; Sharma, Param Dev; Bal, Chandrasekhar; Kumar, Rakesh

2018-03-29

The bone scintigraphic image might exceed the dynamic range (the ratio between the highest and the lowest brightness a monitor is capable of displaying) of display monitor. In this case, a high intensity area, and loss of the details of other structures in the displayed image makes the clinical interpretation a challenging task. We have investigated the role of intensity transformation function for enhancement of these types of images. Methods: Forty high dynamic range bone scintigraphic images were processed using intensity transformation (IT) function. The IT function has two parameters: threshold and slope. Keeping the threshold equal to mean counts of the image, the value of slope was varied from 1 to 20. In-house application program written in MATLAB R2013b was used to process images. Twenty output images corresponding to one input image were visually inspected by two experienced nuclear medicine (NM) physicians to select diagnostic quality images, and from their selection the standardized slope (value of slope parameter) that produced maximum numbers of diagnostic images was determined. They also rated the image quality of input and output images (at standardized slope) on scale 1 to 5 [where 1 is for poor and 5 if for the excellent diagnostic quality]. Student's t-test was used to test the significance of difference between the mean image quality score assigned to input and processed images at significance level α = 0.05. Results: The application of IT functions with standardized parameters significantly improved the quality of high dynamic range bone scintigraphic images ( P enhancement. Copyright © 2018 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Trabecular bone in the calcaneus of runners.

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Best, Andrew; Holt, Brigitte; Troy, Karen; Hamill, Joseph

2017-01-01

Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6), rearfoot-striking runners (n = 6), and non-runners (n = 6), all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the posterior calcaneus.

Adaptive Functioning in Williams Syndrome: A Systematic Review

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Brawn, Gabrielle; Porter, Melanie

2018-01-01

Literature on the level of adaptive functioning and relative strengths and weaknesses in functioning of individuals with Williams syndrome (WS) was reviewed. The electronic databases PsycINFO, PubMed, Expanded Academic, Web of Science, Scopus and ProQuest were searched electronically for relevant articles and dissertations using the search terms…

Bone structural changes in osteoarthritis as a result of mechanoregulated bone adaptation: a modeling approach

NARCIS (Netherlands)

Cox, L.G.E.; Rietbergen, van B.; Donkelaar, van C.C.; Ito, K.

2011-01-01

Objective There are strong indications that subchondral bone may play an important role in osteoarthritis (OA), making it an interesting target for medical therapies. The subchondral bone structure changes markedly during OA, and it has long been assumed that this occurs secondary to cartilage

Effects of different loading patterns on the trabecular bone morphology of the proximal femur using adaptive bone remodeling.

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Banijamali, S Mohammad Ali; Oftadeh, Ramin; Nazarian, Ara; Goebel, Ruben; Vaziri, Ashkan; Nayeb-Hashemi, Hamid

2015-01-01

In this study, the changes in the bone density of human femur model as a result of different loadings were investigated. The model initially consisted of a solid shell representing cortical bone encompassing a cubical network of interconnected rods representing trabecular bone. A computationally efficient program was developed that iteratively changed the structure of trabecular bone by keeping the local stress in the structure within a defined stress range. The stress was controlled by either enhancing existing beam elements or removing beams from the initial trabecular frame structure. Analyses were performed for two cases of homogenous isotropic and transversely isotropic beams.Trabecular bone structure was obtained for three load cases: walking, stair climbing and stumbling without falling. The results indicate that trabecular bone tissue material properties do not have a significant effect on the converged structure of trabecular bone. In addition, as the magnitude of the loads increase, the internal structure becomes denser in critical zones. Loading associated with the stumbling results in the highest density;whereas walking, considered as a routine daily activity, results in the least internal density in different regions. Furthermore, bone volume fraction at the critical regions of the converged structure is in good agreement with previously measured data obtained from combinations of dual X-ray absorptiometry (DXA) and computed tomography (CT). The results indicate that the converged bone architecture consisting of rods and plates are consistent with the natural bone morphology of the femur. The proposed model shows a promising means to understand the effects of different individual loading patterns on the bone density.

Nutrition and human physiological adaptations to space flight

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Lane, H. W.; LeBlanc, A. D.; Putcha, L.; Whitson, P. A.

1993-01-01

Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements. Changes in muscle mass and function may affect requirements for energy, protein and amino acids. Changes in bone mass lead to increased urinary calcium concentrations, which may increase the risk of forming renal stones. Space motion sickness may influence putative changes in gastro-intestinal-hepatic function; neurosensory alterations may affect smell and taste. Some or all of these effects may be ameliorated through the use of specially designed dietary countermeasures.

Functional profiling of cyanobacterial genomes and its role in ecological adaptations

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Ratna Prabha

2016-09-01

Full Text Available With the availability of complete genome sequences of many cyanobacterial species, it is becoming feasible to study the broad prospective of the environmental adaptation and the overall changes at transcriptional and translational level in these organisms. In the evolutionary phase, niche-specific competitive forces have resulted in specific features of the cyanobacterial genomes. In this study, functional composition of the 84 different cyanobacterial genomes and their adaptations to different environments was examined by identifying the genomic composition for specific cellular processes, which reflect their genomic functional profile and ecological adaptation. It was identified that among cyanobacterial genomes, metabolic genes have major share over other categories and differentiation of genomic functional profile was observed for the species inhabiting different habitats. The cyanobacteria of freshwater and other habitats accumulate large number of poorly characterized genes. Strain specific functions were also reported in many cyanobacterial members, of which an important feature was the occurrence of phage-related sequences. From this study, it can be speculated that habitat is one of the major factors in giving the shape of functional composition of cyanobacterial genomes towards their ecological adaptations.

Functional Interference Clusters in Cancer Patients With Bone Metastases: A Secondary Analysis of RTOG 9714

International Nuclear Information System (INIS)

Chow, Edward; James, Jennifer; Barsevick, Andrea; Hartsell, William; Ratcliffe, Sarah; Scarantino, Charles; Ivker, Robert; Roach, Mack; Suh, John; Petersen, Ivy; Konski, Andre; Demas, William; Bruner, Deborah

2010-01-01

Purpose: To explore the relationships (clusters) among the functional interference items in the Brief Pain Inventory (BPI) in patients with bone metastases. Methods: Patients enrolled in the Radiation Therapy Oncology Group (RTOG) 9714 bone metastases study were eligible. Patients were assessed at baseline and 4, 8, and 12 weeks after randomization for the palliative radiotherapy with the BPI, which consists of seven functional items: general activity, mood, walking ability, normal work, relations with others, sleep, and enjoyment of life. Principal component analysis with varimax rotation was used to determine the clusters between the functional items at baseline and the follow-up. Cronbach's alpha was used to determine the consistency and reliability of each cluster at baseline and follow-up. Results: There were 448 male and 461 female patients, with a median age of 67 years. There were two functional interference clusters at baseline, which accounted for 71% of the total variance. The first cluster (physical interference) included normal work and walking ability, which accounted for 58% of the total variance. The second cluster (psychosocial interference) included relations with others and sleep, which accounted for 13% of the total variance. The Cronbach's alpha statistics were 0.83 and 0.80, respectively. The functional clusters changed at week 12 in responders but persisted through week 12 in nonresponders. Conclusion: Palliative radiotherapy is effective in reducing bone pain. Functional interference component clusters exist in patients treated for bone metastases. These clusters changed over time in this study, possibly attributable to treatment. Further research is needed to examine these effects.

Bone Metabolism in Anorexia Nervosa

Science.gov (United States)

Fazeli, Pouneh K.; Klibanski, Anne

2014-01-01

Anorexia nervosa (AN), a psychiatric disorder predominantly affecting young women, is characterized by self-imposed chronic nutritional deprivation and distorted body image. AN is associated with a number of medical co-morbidities including low bone mass. The low bone mass in AN is due to an uncoupling of bone formation and bone resorption, which is the result of hormonal adaptations aimed at decreasing energy expenditure during periods of low energy intake. Importantly, the low bone mass in AN is associated with a significant risk of fractures and therefore treatments to prevent bone loss are critical. In this review, we discuss the hormonal determinants of low bone mass in AN and treatments that have been investigated in this population. PMID:24419863

Exercise-induced metacarpophalangeal joint adaptation in the Thoroughbred racehorse

Science.gov (United States)

Muir, P; Peterson, A L; Sample, S J; Scollay, M C; Markel, M D; Kalscheur, V L

2008-01-01

between groups. We conclude that differences in site-specific microdamage accumulation and associated targeted remodeling between athletic and non-athletic horses are much greater than differences in subchondral osteocyte morphology. However, the presence of atypical subchondral bone matrix in athletic horses was associated with extensive osteocyte loss. Although osteocyte mechanotransduction is considered important for functional adaptation, in this model, adaptation is likely regulated by multiple mechanotransduction pathways. PMID:19094186

[CHARACTERISTICS OF OSTEOCYTE CELL LINES FROM BONES FORMED AS A RESULT OF MEMBRANOUS (SKULL BONES) AND CHONDRAL (LONG BONES) OSSIFICATION].

Science.gov (United States)

Avrunin, A S; Doktorov, A A

2016-01-01

The aim of this work was to analyze the literature data and the results of authors' own research, to answer the question--if the osteocytes of bone tissues resulting from membranous and chondral ossification, belong to one or to different cell lines. The differences between the cells of osteocyte lines derived from bones resulting from membranous and chondral ossification were established in: 1) the magnitude of the mechanical signal, initiating the development of the process of mechanotransduction; 2) the nature of the relationship between the magnitude of the mechanical signal that initiates the reorganization of the architecture of bone structures and the resource of their strength; in membranous bones significantly lower mechanical signal caused a substantially greater increment of bone strength resource; 3) the biological activity of bone structures, bone fragments formed from membranous tissue were more optimal for transplantation; 4) the characteristics of expression of functional markers of bone cells at different stages of their differentiation; 5) the nature of the reaction of bone cells to mechanical stress; 6) the sensitivity of bone cells to one of the factors controlling the process of mechanotransduction (PGI2); 7) the functioning of osteocytes during lactation. These differences reflect the functional requirements to the bones of the skeleton--the supporting function in the bones of the limbs and the shaping and protection in the bones of the cranial vault. These data suggest that the results of research conducted on the bones of the skull, should not be transferred to the entire skeleton as a whole.

Body composition and reproductive function exert unique influences on indices of bone health in exercising women.

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Mallinson, Rebecca J; Williams, Nancy I; Hill, Brenna R; De Souza, Mary Jane

2013-09-01

Reproductive function, metabolic hormones, and lean mass have been observed to influence bone metabolism and bone mass. It is unclear, however, if reproductive, metabolic and body composition factors play unique roles in the clinical measures of areal bone mineral density (aBMD) and bone geometry in exercising women. This study compares lumbar spine bone mineral apparent density (BMAD) and estimates of femoral neck cross-sectional moment of inertia (CSMI) and cross-sectional area (CSA) between exercising ovulatory (Ov) and amenorrheic (Amen) women. It also explores the respective roles of reproductive function, metabolic status, and body composition on aBMD, lumbar spine BMAD and femoral neck CSMI and CSA, which are surrogate measures of bone strength. Among exercising women aged 18-30 years, body composition, aBMD, and estimates of femoral neck CSMI and CSA were assessed by dual-energy x-ray absorptiometry. Lumbar spine BMAD was calculated from bone mineral content and area. Estrone-1-glucuronide (E1G) and pregnanediol glucuronide were measured in daily urine samples collected for one cycle or monitoring period. Fasting blood samples were collected for measurement of leptin and total triiodothyronine. Ov (n = 37) and Amen (n = 45) women aged 22.3 ± 0.5 years did not differ in body mass, body mass index, and lean mass; however, Ov women had significantly higher percent body fat than Amen women. Lumbar spine aBMD and BMAD were significantly lower in Amen women compared to Ov women (p < 0.001); however, femoral neck CSA and CSMI were not different between groups. E1G cycle mean and age of menarche were the strongest predictors of lumbar spine aBMD and BMAD, together explaining 25.5% and 22.7% of the variance, respectively. Lean mass was the strongest predictor of total hip and femoral neck aBMD as well as femoral neck CSMI and CSA, explaining 8.5-34.8% of the variance. Upon consideration of several potential osteogenic stimuli, reproductive function appears to play

Cytokines and growth factors which regulate bone cell function

Science.gov (United States)

Seino, Yoshiki

Everybody knows that growth factors are most important in making bone. Hormones enhance bone formation from a long distance. Growth factors promote bone formation as an autocrine or paracrine factor in nearby bone. BMP-2 through BMP-8 are in the TGF-β family. BMP makes bone by enchondral ossification. In bone, IGF-II is most abundant, second, TGF-β, and third IGF-I. TGF-β enhances bone formation mainly by intramembranous ossification in vivo. TGF-β affects both cell proliferation and differentiation, however, TGF-β mainly enhances bone formation by intramembranous ossification. Interestingly, TGF-β is increased by estrogen(E 2), androgen, vitamin D, TGF-β and FGF. IGF-I and IGF-II also enhance bone formation. At present it remains unclear why IGF-I is more active in bone formation than IGF-II, although IGF-II is more abundant in bone compared to IGF-I. However, if only type I receptor signal transduction promotes bone formation, the strong activity of IGF-I in bone formation is understandable. GH, PTH and E 2 promotes IGF-I production. Recent data suggest that hormones containing vitamin D or E 2 enhance bone formation through growth factors. Therefore, growth factors are the key to clarifying the mechanism of bone formation.

Adaptive Shape Functions and Internal Mesh Adaptation for Modelling Progressive Failure in Adhesively Bonded Joints

Science.gov (United States)

Stapleton, Scott; Gries, Thomas; Waas, Anthony M.; Pineda, Evan J.

2014-01-01

Enhanced finite elements are elements with an embedded analytical solution that can capture detailed local fields, enabling more efficient, mesh independent finite element analysis. The shape functions are determined based on the analytical model rather than prescribed. This method was applied to adhesively bonded joints to model joint behavior with one element through the thickness. This study demonstrates two methods of maintaining the fidelity of such elements during adhesive non-linearity and cracking without increasing the mesh needed for an accurate solution. The first method uses adaptive shape functions, where the shape functions are recalculated at each load step based on the softening of the adhesive. The second method is internal mesh adaption, where cracking of the adhesive within an element is captured by further discretizing the element internally to represent the partially cracked geometry. By keeping mesh adaptations within an element, a finer mesh can be used during the analysis without affecting the global finite element model mesh. Examples are shown which highlight when each method is most effective in reducing the number of elements needed to capture adhesive nonlinearity and cracking. These methods are validated against analogous finite element models utilizing cohesive zone elements.

[Bone metabolism and cardiovascular function update. Estrogen and its therapeutic potential for bone and vascular health].

Science.gov (United States)

Ohta, Hiroaki

2014-07-01

Despite its long-standing role as a "guardian angel" for the female body, estrogen has recently been dethroned from its status as an "elixir" and its use has been restricted due to its oncogenic potential as well as its coagulation system-associated risk. However, it is recognized that estrogen not only works against bone resorption but also improves vascular function. In this regard, it is suggested that estrogen may have a role in improving deteriorated bone quality through its antioxidant action, while this same effect with the SERMs, which may be accounted for by the presence of estrogen, remains yet to be established. Not only evidence needs to be accumulated to support the vascular effects of the SERMs, but their pleiotropic, rather than extra-skeletal, effects, as likely mediated by the estrogen receptors distributed throughout the body, remain to be elucidated.

The Relation Between Intellectual Functioning and Adaptive Behavior in the Diagnosis of Intellectual Disability.

Science.gov (United States)

Tassé, Marc J; Luckasson, Ruth; Schalock, Robert L

2016-12-01

Intellectual disability originates during the developmental period and is characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills. In this article, we present a brief history of the diagnostic criteria of intellectual disability for both the DSM-5 and AAIDD. The article also (a) provides an update of the understanding of adaptive behavior, (b) dispels two thinking errors regarding mistaken temporal or causal link between intellectual functioning and adaptive behavior, (c) explains that there is a strong correlational, but no causative, relation between intellectual functioning and adaptive behavior, and (d) asserts that once a question of determining intellectual disability is raised, both intellectual functioning and adaptive behavior are assessed and considered jointly and weighed equally in the diagnosis of intellectual disability. We discuss the problems created by an inaccurate statement that appears in the DSM-5 regarding a causal link between deficits in intellectual functioning and adaptive behavior and propose an immediate revision to remove this erroneous and confounding statement.

Incorporation of bone marrow cells in pancreatic pseudoislets improves posttransplant vascularization and endocrine function.

Directory of Open Access Journals (Sweden)

Christine Wittig

Full Text Available Failure of revascularization is known to be the major reason for the poor outcome of pancreatic islet transplantation. In this study, we analyzed whether pseudoislets composed of islet cells and bone marrow cells can improve vascularization and function of islet transplants. Pancreatic islets isolated from Syrian golden hamsters were dispersed into single cells for the generation of pseudoislets containing 4×10(3 cells. To create bone marrow cell-enriched pseudoislets 2×10(3 islet cells were co-cultured with 2×10(3 bone marrow cells. Pseudoislets and bone marrow cell-enriched pseudoislets were transplanted syngeneically into skinfold chambers to study graft vascularization by intravital fluorescence microscopy. Native islet transplants served as controls. Bone marrow cell-enriched pseudoislets showed a significantly improved vascularization compared to native islets and pseudoislets. Moreover, bone marrow cell-enriched pseudoislets but not pseudoislets normalized blood glucose levels after transplantation of 1000 islet equivalents under the kidney capsule of streptozotocin-induced diabetic animals, although the bone marrow cell-enriched pseudoislets contained only 50% of islet cells compared to pseudoislets and native islets. Fluorescence microscopy of bone marrow cell-enriched pseudoislets composed of bone marrow cells from GFP-expressing mice showed a distinct fraction of cells expressing both GFP and insulin, indicating a differentiation of bone marrow-derived cells to an insulin-producing cell-type. Thus, enrichment of pseudoislets by bone marrow cells enhances vascularization after transplantation and increases the amount of insulin-producing tissue. Accordingly, bone marrow cell-enriched pseudoislets may represent a novel approach to increase the success rate of islet transplantation.

Amount of smoking, pulmonary function, and bone mineral density in middle-aged Korean men: KNHANES 2008-2011.

Science.gov (United States)

Lee, Ji Hyun; Hong, A Ram; Kim, Jung Hee; Kim, Kyoung Min; Koo, Bo Kyung; Shin, Chan Soo; Kim, Sang Wan

2018-01-01

Smoking induces bone loss; however, data on the relationship between smoking history and bone mineral density (BMD) are lacking. Age and pulmonary function can affect BMD. We investigated the relationships among pack-years (PYs) of smoking, pulmonary function, and BMD in middle-aged Korean men (50-64 years old). This cross-sectional study used data from the Korean National Health and Nutrition Examination Survey, 2008-2011. All participants underwent BMD measurements using dual energy X-ray absorptiometry and pulmonary function tests using standardized spirometry. In total, 388 never-smokers and 1088 ever-smokers were analyzed. The number of PYs of smoking was negatively correlated with total hip BMD (r = -0.088; P = 0.004) after adjusting for age, height, and weight. Ever-smokers were classified into 3 groups according to PYs of smoking. The highest tertile (n = 482) exhibited significantly lower total hip bone mass than the lowest tertile (n = 214) after adjusting for confounding factors (age, height, weight, forced expiratory volume in 1 s (FEV 1 ), alcohol consumption, physical activity, and vitamin D levels) that could affect bone metabolism (P = 0.003). In conclusion, smoking for >30 PYs was significantly associated with low hip BMD after adjusting for pulmonary function in middle-aged Korean men. Long-term smoking may be a risk factor for bone loss in middle-aged men independent of age, height, weight, and pulmonary function.

A visco-poroelastic model of functional adaptation in bones reconstructed with bio-resorbable materials.

Science.gov (United States)

Giorgio, Ivan; Andreaus, Ugo; Scerrato, Daria; dell'Isola, Francesco

2016-10-01

In this paper, the phenomena of resorption and growth of bone tissue and resorption of the biomaterial inside a bicomponent system are studied by means of a numerical method based on finite elements. The material behavior is described by a poro-viscoelastic model with infiltrated voids. The mechanical stimulus that drives these processes is a linear combination of density of strain energy and viscous dissipation. The external excitation is represented by a bending load slowly variable with sinusoidal law characterized by different frequencies. Investigated aspects are the influence of the load frequency, of type of the stimulus and of the effective porosity on the time evolution of the mass densities of considered system.

The Role of Nutrition in the Changes in Bone and Calcium Metabolism During Space Flight

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Morey-Holton, Emily R.; Arnaud, Sara B.

1995-01-01

On Earth, the primary purpose of the skeleton is provide structural support for the body. In space, the support function of the skeleton is reduced since, without gravity, structures have only mass and no weight. The adaptation to space flight is manifested by shifts in mineral distribution, altered bone turnover, and regional mineral deficits in weight-bearing bones. The shifts in mineral distribution appear to be related to the cephalic fluid shift. The redistribution of mineral from one bone to another or to and from areas in the same bone in response to alterations in gravitational loads is more likely to affect skeletal function than quantitative whole body losses and gains. The changes in bone turnover appear dependent upon changes in body weight with weight loss tending to increase bone resorption as well as decrease bone formation. During bedrest, the bone response to unloading varies depending upon the routine activity level of the subjects with more active subjects showing a greater suppression of bone formation in the iliac crest with inactivity. Changes in body composition during space flight are predicted by bedrest studies on Earth which show loss of lean body mass and increase tn body fat in adult males after one month. In ambulatory studies on Earth, exercising adult males of the same age, height, g weight, body mass index, and shoe size show significantly higher whole body mineral and lean body mass. than non-exercising subjects. Nutritional preference appears to change with activity level. Diet histories in exercisers and nonexercisers who maintain identical body weights show no differences in nutrients except for slightly higher carbohydrate intake in the exercisers. The absence of differences in dietary calcium in men with higher total body calcium is noteworthy. In this situation, the increased bone mineral content was facilitated by the calcium endocrine system. This regulatory system can be by-passed by raising dietary calcium. Increased

Profiling Osteogenic microRNAs For RNAi-Functionalization Of Scaffolds In Bone Tissue Engineering

DEFF Research Database (Denmark)

Chang, Chi-Chih (Clare); Chen, Li; Venø, Morten Trillingsgaard

is limited and grafts are required to assist in bone repair. The use of allografts can cause immunological complications, whilst autografts subject the patient to two surgeries. Bone tissue engineering is a multidisciplinary field encompassing material science, medicine, chemistry and molecular biology aimed...... both miRNAs that have been reported previously and many novel miRNAs with potent osteogenic capabilities. For tissue engineering applications, we then functionalized scaffolds with the miRNAs we identified and observed an increase in osteogenic capabilities in our 3D cultures. Our findings depicted...... the miRNA expression landscape as mesenchymal stem cells underwent osteogenic differentiation. We also highlight the potency of miRNAs as biological therapeutics in bone tissue engineering....

Radiographic evaluation of marginal bone level around implants with different neck designs after 1 year.

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Shin, Young-Kyu; Han, Chong-Hyun; Heo, Seong-Joo; Kim, Sunjai; Chun, Heoung-Jae

2006-01-01

To evaluate the influence of macro- and microstructure of the implant surface at the marginal bone level after functional loading. Sixty-eight patients were randomly assigned to 1 of 3 groups. The first group received 35 implants with a machined neck (Ankylos); the second group, 34 implants with a rough-surfaced neck (Stage 1); and the third, 38 implants with a rough-surfaced neck with microthreads (Oneplant). Clinical and radiographic examinations were conducted at baseline (implant loading) and 3, 6, and 12 months postloading. Two-way repeated analysis of variance (ANOVA) was used to test the significance of marginal bone change of each tested group at baseline, 3, 6, and 12 month follow-ups and 1-way ANOVA was also used to compare the bone loss of each time interval within the same implant group (P implant neck not only reduce crestal bone loss but also help with early biomechanical adaptation against loading in comparison to the machined neck design. A rough surface with microthreads at the implant neck was the most effective design to maintain the marginal bone level against functional loading.

Bone and muscular anatomy of the forearm and hand in Tapirus terrestris (Perissodactyla, Tapiridae

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Saulo Gonçalves Pereira

2017-05-01

Full Text Available In Brazil, there are two species of tapirs, the largest land mammals in Brazil, which belong to the order Perissodactyla, as do horses. Our aim was to describe the bone and muscular anatomy of the forearm and hand in T. terrestris and to propose adaptive functions. We used five anatomical specimens donated from a breeder to the Laboratory for Teaching and Research on Wild Animals of the Federal University of Uberlandia after death with no trauma. The bones were analyzed, the muscles dissected, and both described. The bones of the forearm and hand of the tapir are the ulna, radius, Os. metacarpalia, Os. carpi, phalanx and Os. sesamoideum. The muscles are M. extensor carpi radialis, M. ulnaris lateralis; M. flexor carpi radialis; M. extensor radialis communis; M. extensor digitorum longus II, III, IV and V, M. extensor digitorum lateralis; M. extensor digitorum; M. abductor longus; M. flexor digiti superficialis; M. flexor digitalis; M. flexor carpi ulnaris; M. flexor carpi obliquus; and M. interossei and M. lumbricales. Characteristics of bone and muscle structure are adapted to the development of the animal’s niche.

Skeletal Geometry and Indices of Bone Strength in Artistic Gymnasts

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Dowthwaite, Jodi N.; Scerpella, Tamara A.

2010-01-01

This review addresses bone geometry and indices of skeletal strength associated with exposure to gymnastic loading during growth. A brief background characterizes artistic gymnastics as a mechanical loading model and outlines densitometric techniques, skeletal outcomes and challenges in assessment of skeletal adaptation. The literature on bone geometric adaptation to gymnastic loading is sparse and consists of results for disparate skeletal sites, maturity phases, gender compositions and assessment methods, complicating synthesis of an overriding view. Furthermore, most studies assess only females, with little information on males and adults. Nonetheless, gymnastic loading during growth appears to yield significant enlargement of total and cortical bone geometry (+10 to 30%) and elevation of trabecular density (+20%) in the forearm, yielding elevated indices of skeletal strength (+20 to +50%). Other sites exhibit more moderate geometric and densitometric adaptations (5 to 15%). Mode of adaptation appears to be site-specific; some sites demonstrate marked periosteal and endosteal expansion, whereas other sites exhibit negligible or moderate periosteal expansion coupled with endocortical contraction. Further research is necessary to address sex-, maturity- and bone tissue-specific adaptation, as well as maintenance of benefits beyond loading cessation. PMID:19949278

Cognitive function in relation with bone mass and nutrition: cross-sectional association in postmenopausal women

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Brownbill Rhonda A

2004-05-01

Full Text Available Abstract Background It has been suggested that bone loss and cognitive decline are co-occurring conditions, possibly due to their relationship with estrogen. Cognitive decline has been associated with various nutritional deficiencies as well. The purpose of this study was to determine if cognitive function is related to bone mineral density of various skeletal sites as well as to various dietary components. Methods Cross-sectional study with 97 healthy, Caucasian, postmenopausal women (59.4–85.0 years enrolled in a larger longitudinal study, investigating the effects of sodium on bone mass. The subjects were divided into two groups based on cognition scores. Group 1 represented lower and Group 2 higher scores on cognitive function. Bone mineral density from the whole body, lumbar spine, femur and forearm were measured with the Lunar DPX-MD instrument. Anthropometry was measured by standard methods. Cognition was assessed using the Mini Mental State Examination. Cumulative (over 2 years dietary intake from 3-day records was analyzed by Food Processor® (ESHA Research, Salem, OR and cumulative physical activity was assessed using Allied Dunbar National Fitness Survey for older adults. Results Subjects' cognition scores ranged from 22–30 (normal, 27–30, indicating all subjects had either mild or no cognitive impairment. Multiple Analysis of Covariance adjusted for age, height, weight, physical activity, alcohol, calcium, sodium and energy intake, showed a statistically significant association between cognition and bone mineral density of all measurable sites (η2 = 0.21, P 2 = 0.07, P = 0.050. Group 2 did have a significantly higher potassium intake (P = 0.023. In multiple regression, saturated fat had a significant negative relationship with cognitive function. Conclusions It appears mild degree of cognitive impairment may be a marker for lower bone mineral density as well as for a diet lower in carbohydrate and potassium intake, and higher

Water extract of Acer tegmentosum reduces bone destruction by inhibiting osteoclast differentiation and function.

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Ha, Hyunil; Shim, Ki-Shuk; Kim, Taesoo; An, Hyosun; Lee, Chung-Jo; Lee, Kwang Jin; Ma, Jin Yeul

2014-04-01

The stem of Acer tegmentosum has been widely used in Korea for the treatment of hepatic disorders. In this study, we investigated the bone protective effect of water extract of the stem of Acer tegmentosum (WEAT). We found that WEAT inhibits osteoclast differentiation induced by receptor activator of nuclear factor-κB ligand (RANKL), an essential cytokine for osteoclast differentiation. In osteoclast precursor cells, WEAT inhibited RANKL-induced activation of JNK, NF-κB, and cAMP response element-binding protein, leading to suppression of the induction of c-Fos and nuclear factor of activated T cells cytoplasmic 1, key transcription factors for osteoclast differentiation. In addition, WEAT inhibited bone resorbing activity of mature osteoclasts. Furthermore, the oral administration of WEAT reduced RANKL-induced bone resorption and trabecular bone loss in mice. Taken together, our study demonstrates that WEAT possesses a protective effect on bone destruction by inhibiting osteoclast differentiation and function.

Psychometric evaluation of the Polish adaptation of the Hill-Bone Compliance to High Blood Pressure Therapy Scale.

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Uchmanowicz, Izabella; Jankowska-Polańska, Beata; Chudiak, Anna; Szymańska-Chabowska, Anna; Mazur, Grzegorz

2016-05-10

Development of simple instruments for the determination of the level of adherence in patients with high blood pressure is the subject of ongoing research. One such instrument, gaining growing popularity worldwide, is the Hill-Bone Compliance to High Blood Pressure Therapy. The aim of this study was to adapt and to test the reliability of the Polish version of Hill-Bone Compliance to High Blood Pressure Therapy Scale. A standard guideline was used for the translation and cultural adaptation of the English version of the Hill-Bone Compliance to High Blood Pressure Therapy Scale into Polish. The study included 117 Polish patients with hypertension aged between 27 and 90 years, among them 53 men and 64 women. Cronbach's alpha was used for analysing the internal consistency of the scale. The mean score in the reduced sodium intake subscale was M = 5.7 points (standard deviation SD = 1.6 points). The mean score in the appointment-keeping subscale was M = 3.4 points (standard deviation SD = 1.4 points). The mean score in the medication-taking subscale was M = 11.6 points (standard deviation SD = 3.3 points). In the principal component analysis, the three-factor system (1 - medication-taking, 2 - appointment-keeping, 3 - reduced sodium intake) accounted for 53 % of total variance. All questions had factor loadings > 0.4. The medication-taking subscale: most questions (6 out of 9) had the highest loadings with Factor 1. The appointment-keeping subscale: all questions (2 out of 2) had the highest loadings with Factor 2. The reduced sodium intake subscale: most questions (2 out of 3) had the highest loadings with Factor 3. Goodness of fit was tested at chi(2) = 248.87; p High Blood Pressure Therapy Scale proved to be suitable for use in the Polish population. Use of this screening tool for the assessment of adherence to BP treatment is recommended.

Geometry Design Optimization of Functionally Graded Scaffolds for Bone Tissue Engineering: A Mechanobiological Approach.

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Antonio Boccaccio

Full Text Available Functionally Graded Scaffolds (FGSs are porous biomaterials where porosity changes in space with a specific gradient. In spite of their wide use in bone tissue engineering, possible models that relate the scaffold gradient to the mechanical and biological requirements for the regeneration of the bony tissue are currently missing. In this study we attempt to bridge the gap by developing a mechanobiology-based optimization algorithm aimed to determine the optimal graded porosity distribution in FGSs. The algorithm combines the parametric finite element model of a FGS, a computational mechano-regulation model and a numerical optimization routine. For assigned boundary and loading conditions, the algorithm builds iteratively different scaffold geometry configurations with different porosity distributions until the best microstructure geometry is reached, i.e. the geometry that allows the amount of bone formation to be maximized. We tested different porosity distribution laws, loading conditions and scaffold Young's modulus values. For each combination of these variables, the explicit equation of the porosity distribution law-i.e the law that describes the pore dimensions in function of the spatial coordinates-was determined that allows the highest amounts of bone to be generated. The results show that the loading conditions affect significantly the optimal porosity distribution. For a pure compression loading, it was found that the pore dimensions are almost constant throughout the entire scaffold and using a FGS allows the formation of amounts of bone slightly larger than those obtainable with a homogeneous porosity scaffold. For a pure shear loading, instead, FGSs allow to significantly increase the bone formation compared to a homogeneous porosity scaffolds. Although experimental data is still necessary to properly relate the mechanical/biological environment to the scaffold microstructure, this model represents an important step towards

Laparoscopic sacrocolpopexy with bone anchor fixation: short-term anatomic and functional results.

NARCIS (Netherlands)

Withagen, M.I.J.; Vierhout, M.E.; Mannaerts, G.H.; Weiden, R.M.F. van der

2012-01-01

INTRODUCTION AND HYPOTHESIS: The aim of this study was to evaluate short-term anatomic and functional outcomes and safety of laparoscopic sacrocolpopexy with bone anchor fixation. METHODS: A prospective cohort study of women undergoing laparoscopic sacrocolpopexy between 2004 and 2009. Anatomic

Urokinase plasminogen activator receptor affects bone homeostasis by regulating osteoblast and osteoclast function

DEFF Research Database (Denmark)

Furlan, Federico; Galbiati, Clara; Jørgensen, Niklas R

2007-01-01

PAR and produce urokinase (uPA). The purpose of this study was to investigate the role of uPAR in bone remodeling. MATERIALS AND METHODS: In vivo studies were performed in uPAR knockout (KO) and wildtype (WT) mice on a C57Bl6/SV129 (75:25) background. Bone mass was analyzed by pQCT. Excised tibias were subjected......The uPAR and its ligand uPA are expressed by both osteoblasts and osteoclasts. Their function in bone remodeling is unknown. We report that uPAR-lacking mice display increased BMD, increased osteogenic potential of osteoblasts, decreased osteoclasts formation, and altered cytoskeletal...... of macrophage-colony stimulating factor (M-CSF) and RANKL. Phalloidin staining in osteoclasts served to study actin ring and podosome formation. RESULTS: pQCT revealed increased bone mass in uPAR-null mice. Mechanical tests showed reduced load-sustaining capability in uPAR KO tibias. uPAR KO osteoblasts showed...

Bone-associated gene evolution and the origin of flight in birds.

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Machado, João Paulo; Johnson, Warren E; Gilbert, M Thomas P; Zhang, Guojie; Jarvis, Erich D; O'Brien, Stephen J; Antunes, Agostinho

2016-05-18

Bones have been subjected to considerable selective pressure throughout vertebrate evolution, such as occurred during the adaptations associated with the development of powered flight. Powered flight evolved independently in two extant clades of vertebrates, birds and bats. While this trait provided advantages such as in aerial foraging habits, escape from predators or long-distance travels, it also imposed great challenges, namely in the bone structure. We performed comparative genomic analyses of 89 bone-associated genes from 47 avian genomes (including 45 new), 39 mammalian, and 20 reptilian genomes, and demonstrate that birds, after correcting for multiple testing, have an almost two-fold increase in the number of bone-associated genes with evidence of positive selection (~52.8 %) compared with mammals (~30.3 %). Most of the positive-selected genes in birds are linked with bone regulation and remodeling and thirteen have been linked with functional pathways relevant to powered flight, including bone metabolism, bone fusion, muscle development and hyperglycemia levels. Genes encoding proteins involved in bone resorption, such as TPP1, had a high number of sites under Darwinian selection in birds. Patterns of positive selection observed in bird ossification genes suggest that there was a period of intense selective pressure to improve flight efficiency that was closely linked with constraints on body size.

Effect of occlusal (mechanical) stimulus on bone remodelling in rat mandibular condyle.

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Gazit, D; Ehrlich, J; Kohen, Y; Bab, I

1987-09-01

Mechanical load influences the remodelling of skeletal tissues. In the mandibular condyle, occlusal alterations and the consequent mechanical stimulus induce changes in chondrocytes and cartilage mineralization. In the present study we quantified in the mandibular condyle the effect of occlusal interference on remodelling of the subchondral bone. Computerized histomorphometry after 5-21-day exposure to the influence of a unilateral occlusal splint revealed an increased rate of trabecular remodelling, consisting of enhancement in osteoblast and osteoclast numbers and activities. The bone formation parameters reached their high values on Days 5 or 9 and remained stable thereafter. Bone resorption showed a gradual increase throughout the experimental period. These results further characterize the temporomandibular joint reaction to occlusal alterations. It is suggested that the present increase in bone turnover together with the known enhancement in chondrogenesis are part of a process of functional adaptation in response to mechanical stimulus.

[Bone remodeling and modeling/mini-modeling.

Science.gov (United States)

Hasegawa, Tomoka; Amizuka, Norio

Modeling, adapting structures to loading by changing bone size and shapes, often takes place in bone of the fetal and developmental stages, while bone remodeling-replacement of old bone into new bone-is predominant in the adult stage. Modeling can be divided into macro-modeling(macroscopic modeling)and mini-modeling(microscopic modeling). In the cellular process of mini-modeling, unlike bone remodeling, bone lining cells, i.e., resting flattened osteoblasts covering bone surfaces will become active form of osteoblasts, and then, deposit new bone onto the old bone without mediating osteoclastic bone resorption. Among the drugs for osteoporotic treatment, eldecalcitol(a vitamin D3 analog)and teriparatide(human PTH[1-34])could show mini-modeling based bone formation. Histologically, mature, active form of osteoblasts are localized on the new bone induced by mini-modeling, however, only a few cell layer of preosteoblasts are formed over the newly-formed bone, and accordingly, few osteoclasts are present in the region of mini-modeling. In this review, histological characteristics of bone remodeling and modeling including mini-modeling will be introduced.

Biomaterials and bone mechanotransduction

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Sikavitsas, V. I.; Temenoff, J. S.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

2001-01-01

Bone is an extremely complex tissue that provides many essential functions in the body. Bone tissue engineering holds great promise in providing strategies that will result in complete regeneration of bone and restoration of its function. Currently, such strategies include the transplantation of highly porous scaffolds seeded with cells. Prior to transplantation the seeded cells are cultured in vitro in order for the cells to proliferate, differentiate and generate extracellular matrix. Factors that can affect cellular function include the cell-biomaterial interaction, as well as the biochemical and the mechanical environment. To optimize culture conditions, good understanding of these parameters is necessary. The new developments in bone biology, bone cell mechanotransduction, and cell-surface interactions are reviewed here to demonstrate that bone mechanotransduction is strongly influenced by the biomaterial properties.

Adaptive and non-adaptive data hiding methods for grayscale images based on modulus function

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Najme Maleki

2014-07-01

Full Text Available This paper presents two adaptive and non-adaptive data hiding methods for grayscale images based on modulus function. Our adaptive scheme is based on the concept of human vision sensitivity, so the pixels in edge areas than to smooth areas can tolerate much more changes without making visible distortion for human eyes. In our adaptive scheme, the average differencing value of four neighborhood pixels into a block via a threshold secret key determines whether current block is located in edge or smooth area. Pixels in the edge areas are embedded by Q-bit of secret data with a larger value of Q than that of pixels placed in smooth areas. Also in this scholar, we represent one non-adaptive data hiding algorithm. Our non-adaptive scheme, via an error reduction procedure, produces a high visual quality for stego-image. The proposed schemes present several advantages. 1-of aspects the embedding capacity and visual quality of stego-image are scalable. In other words, the embedding rate as well as the image quality can be scaled for practical applications 2-the high embedding capacity with minimal visual distortion can be achieved, 3-our methods require little memory space for secret data embedding and extracting phases, 4-secret keys have used to protect of the embedded secret data. Thus, level of security is high, 5-the problem of overflow or underflow does not occur. Experimental results indicated that the proposed adaptive scheme significantly is superior to the currently existing scheme, in terms of stego-image visual quality, embedding capacity and level of security and also our non-adaptive method is better than other non-adaptive methods, in view of stego-image quality. Results show which our adaptive algorithm can resist against the RS steganalysis attack.

Bone and fat connection in aging bone.

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Duque, Gustavo

2008-07-01

The fat and bone connection plays an important role in the pathophysiology of age-related bone loss. This review will focus on the age-induced mechanisms regulating the predominant differentiation of mesenchymal stem cells into adipocytes. Additionally, bone marrow fat will be considered as a diagnostic and therapeutic approach to osteoporosis. There are two types of bone and fat connection. The 'systemic connection', usually seen in obese patients, is hormonally regulated and associated with high bone mass and strength. The 'local connection' happens inside the bone marrow. Increasing amounts of bone marrow fat affect bone turnover through the inhibition of osteoblast function and survival and the promotion of osteoclast differentiation and activation. This interaction is regulated by paracrine secretion of fatty acids and adipokines. Additionally, bone marrow fat could be quantified using noninvasive methods and could be used as a therapeutic approach due to its capacity to transdifferentiate into bone without affecting other types of fat in the body. The bone and fat connection within the bone marrow constitutes a typical example of lipotoxicity. Additionally, bone marrow fat could be used as a new diagnostic and therapeutic approach for osteoporosis in older persons.

Interrelations between psychosocial functioning and adaptive- and maladaptive-range personality traits.

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Ro, Eunyoe; Clark, Lee Anna

2013-08-01

Decrements in one or more domains of psychosocial functioning (e.g., poor job performance, poor interpersonal relations) are commonly observed in psychiatric patients. The purpose of this study is to increase understanding of psychosocial functioning as a broad, multifaceted construct as well as its associations with both adaptive- and maladaptive-range personality traits in both nonclinical and psychiatric outpatient samples. The study was conducted in two phases. In Study 1, a nonclinical sample (N = 429) was administered seven psychosocial functioning and adaptive-range personality trait measures. In Study 2, psychiatric outpatients (N = 181) were administered the same psychosocial functioning measures, and maladaptive- as well as adaptive-range personality trait measures. Exploratory (both studies) and confirmatory (Study 2) factor analyses indicated a common three-factor, hierarchical structure of psychosocial functioning-Well Being, Social/Interpersonal Functioning, and Basic Functioning. These psychosocial functioning domains were closely--and differentially--linked with personality traits, especially strongly so in patients. Across samples, Well Being was associated with both Neuroticism/Negative Affectivity and Extraversion/Positive Affectivity, Social/Interpersonal Functioning was associated with both Agreeableness and Conscientiousness/Disinhibition, and Basic Functioning was associated with Conscientiousness/Disinhibition, although only modestly in the nonclinical sample. These relations generally were maintained even after partialing out current general dysphoric symptoms. These findings have implications for considering psychosocial functioning as an important third domain in a tripartite model together with personality and psychopathology. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Methods and theory in bone modeling drift: comparing spatial analyses of primary bone distributions in the human humerus.

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Maggiano, Corey M; Maggiano, Isabel S; Tiesler, Vera G; Chi-Keb, Julio R; Stout, Sam D

2016-01-01

This study compares two novel methods quantifying bone shaft tissue distributions, and relates observations on human humeral growth patterns for applications in anthropological and anatomical research. Microstructural variation in compact bone occurs due to developmental and mechanically adaptive circumstances that are 'recorded' by forming bone and are important for interpretations of growth, health, physical activity, adaptation, and identity in the past and present. Those interpretations hinge on a detailed understanding of the modeling process by which bones achieve their diametric shape, diaphyseal curvature, and general position relative to other elements. Bone modeling is a complex aspect of growth, potentially causing the shaft to drift transversely through formation and resorption on opposing cortices. Unfortunately, the specifics of modeling drift are largely unknown for most skeletal elements. Moreover, bone modeling has seen little quantitative methodological development compared with secondary bone processes, such as intracortical remodeling. The techniques proposed here, starburst point-count and 45° cross-polarization hand-drawn histomorphometry, permit the statistical and populational analysis of human primary tissue distributions and provide similar results despite being suitable for different applications. This analysis of a pooled archaeological and modern skeletal sample confirms the importance of extreme asymmetry in bone modeling as a major determinant of microstructural variation in diaphyses. Specifically, humeral drift is posteromedial in the human humerus, accompanied by a significant rotational trend. In general, results encourage the usage of endocortical primary bone distributions as an indicator and summary of bone modeling drift, enabling quantitative analysis by direction and proportion in other elements and populations. © 2015 Anatomical Society.

Adaptation of brain functional and structural networks in aging.

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Annie Lee

Full Text Available The human brain, especially the prefrontal cortex (PFC, is functionally and anatomically reorganized in order to adapt to neuronal challenges in aging. This study employed structural MRI, resting-state fMRI (rs-fMRI, and high angular resolution diffusion imaging (HARDI, and examined the functional and structural reorganization of the PFC in aging using a Chinese sample of 173 subjects aged from 21 years and above. We found age-related increases in the structural connectivity between the PFC and posterior brain regions. Such findings were partially mediated by age-related increases in the structural connectivity of the occipital lobe within the posterior brain. Based on our findings, it is thought that the PFC reorganization in aging could be partly due to the adaptation to age-related changes in the structural reorganization of the posterior brain. This thus supports the idea derived from task-based fMRI that the PFC reorganization in aging may be adapted to the need of compensation for resolving less distinctive stimulus information from the posterior brain regions. In addition, we found that the structural connectivity of the PFC with the temporal lobe was fully mediated by the temporal cortical thickness, suggesting that the brain morphology plays an important role in the functional and structural reorganization with aging.

Adaptation of brain functional and structural networks in aging.

Science.gov (United States)

Lee, Annie; Ratnarajah, Nagulan; Tuan, Ta Anh; Chen, Shen-Hsing Annabel; Qiu, Anqi

2015-01-01

The human brain, especially the prefrontal cortex (PFC), is functionally and anatomically reorganized in order to adapt to neuronal challenges in aging. This study employed structural MRI, resting-state fMRI (rs-fMRI), and high angular resolution diffusion imaging (HARDI), and examined the functional and structural reorganization of the PFC in aging using a Chinese sample of 173 subjects aged from 21 years and above. We found age-related increases in the structural connectivity between the PFC and posterior brain regions. Such findings were partially mediated by age-related increases in the structural connectivity of the occipital lobe within the posterior brain. Based on our findings, it is thought that the PFC reorganization in aging could be partly due to the adaptation to age-related changes in the structural reorganization of the posterior brain. This thus supports the idea derived from task-based fMRI that the PFC reorganization in aging may be adapted to the need of compensation for resolving less distinctive stimulus information from the posterior brain regions. In addition, we found that the structural connectivity of the PFC with the temporal lobe was fully mediated by the temporal cortical thickness, suggesting that the brain morphology plays an important role in the functional and structural reorganization with aging.

Adaptive modified function projective synchronization of multiple time-delayed chaotic Rossler system

International Nuclear Information System (INIS)

Sudheer, K. Sebastian; Sabir, M.

2011-01-01

In this Letter we consider modified function projective synchronization of unidirectionally coupled multiple time-delayed Rossler chaotic systems using adaptive controls. Recently, delay differential equations have attracted much attention in the field of nonlinear dynamics. The high complexity of the multiple time-delayed systems can provide a new architecture for enhancing message security in chaos based encryption systems. Adaptive control can be used for synchronization when the parameters of the system are unknown. Based on Lyapunov stability theory, the adaptive control law and the parameter update law are derived to make the state of two chaotic systems are function projective synchronized. Numerical simulations are presented to demonstrate the effectiveness of the proposed adaptive controllers.

[Psychological commitment: adaptive functions, paradoxes, modalities and components].

Science.gov (United States)

Brault-Labbé, Anne

2017-12-01

The process of psychological commitment, its adaptive functions and some of the difficulties that go along with it are specific. A description of the multimodal model of commitment provides an illustration of how motivational, affective, cognitive and behavioural mechanisms can be combined. These lead to different ways of entering into the commitment, with differing consequences on how the individual functions. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

FOXO1 orchestrates the bone-suppressing function of gut-derived serotonin

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Kode, Aruna; Mosialou, Ioanna; Silva, Barbara C.; Rached, Marie-Therese; Zhou, Bin; Wang, Ji; Townes, Tim M.; Hen, Rene; DePinho, Ronald A.; Guo, X. Edward; Kousteni, Stavroula

2012-01-01

Serotonin is a critical regulator of bone mass, fulfilling different functions depending on its site of synthesis. Brain-derived serotonin promotes osteoblast proliferation, whereas duodenal-derived serotonin suppresses it. To understand the molecular mechanisms of duodenal-derived serotonin action on osteoblasts, we explored its transcriptional mediation in mice. We found that the transcription factor FOXO1 is a crucial determinant of the effects of duodenum-derived serotonin on bone formation We identified two key FOXO1 complexes in osteoblasts, one with the transcription factor cAMP-responsive element–binding protein 1 (CREB) and another with activating transcription factor 4 (ATF4). Under normal levels of circulating serotonin, the proliferative activity of FOXO1 was promoted by a balance between its interaction with CREB and ATF4. However, high circulating serotonin levels prevented the association of FOXO1 with CREB, resulting in suppressed osteoblast proliferation. These observations identify FOXO1 as the molecular node of an intricate transcriptional machinery that confers the signal of duodenal-derived serotonin to inhibit bone formation. PMID:22945629

Sex assessment from carpals bones: discriminant function analysis in a contemporary Mexican sample.

Science.gov (United States)

Mastrangelo, Paola; De Luca, Stefano; Sánchez-Mejorada, Gabriela

2011-06-15

Sex assessment is one of the first essential steps in human identification, in both medico-legal cases and bio-archaeological contexts. Fragmentary human remains compromised by different types of burial or physical insults may frustrate the use of the traditional sex estimation methods, such as the analysis of the skull and pelvis. Currently, the application of discriminant functions to sex unidentified skeletal remains is steadily increasing. However, several studies have demonstrated that, due to variation in size and patterns of sexual dimorphism, discriminant functions are population-specific. In this study, in order to improve sex assessment from skeletal remains and to establish population-specific discriminant functions, the diagnostic values of the carpal bones were considered. A sample of 136 individuals (78 males, 58 females) of known sex and age was analyzed. They belong to a contemporary identified collection from the Laboratory of Physical Anthropology, Faculty of Medicine, UNAM (Universidad Nacional Autónoma de México, Mexico City). The age of the individuals ranged between 25 and 85 years. Between four and nine measurements of each carpal bone were taken. Independent t-tests confirm that all carpals are sexually dimorphic. Univariate measurements produce accuracy levels that range from 61.8% to 90.8%. Classification accuracies ranged between 81.3% and 92.3% in the multivariate stepwise discriminant analysis. In addition, intra- and inter-observer error tests were performed. These indicated that replication of measurements was satisfactory for the same observer over time and between observers. These results suggest that carpal bones can be used for assessing sex in both forensic and bio-archaeological identification procedures and that bone dimensions are population specific. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Osteoinductive peptide-functionalized nanofibers with highly ordered structure as biomimetic scaffolds for bone tissue engineering.

Science.gov (United States)

Gao, Xiang; Zhang, Xiaohong; Song, Jinlin; Xu, Xiao; Xu, Anxiu; Wang, Mengke; Xie, Bingwu; Huang, Enyi; Deng, Feng; Wei, Shicheng

2015-01-01

The construction of functional biomimetic scaffolds that recapitulate the topographical and biochemical features of bone tissue extracellular matrix is now of topical interest in bone tissue engineering. In this study, a novel surface-functionalized electrospun polycaprolactone (PCL) nanofiber scaffold with highly ordered structure was developed to simulate the critical features of native bone tissue via a single step of catechol chemistry. Specially, under slightly alkaline aqueous solution, polydopamine (pDA) was coated on the surface of aligned PCL nanofibers after electrospinning, followed by covalent immobilization of bone morphogenetic protein-7-derived peptides onto the pDA-coated nanofiber surface. Contact angle measurement, Raman spectroscopy, and X-ray photoelectron spectroscopy confirmed the presence of pDA and peptides on PCL nanofiber surface. Our results demonstrated that surface modification with osteoinductive peptides could improve cytocompatibility of nanofibers in terms of cell adhesion, spreading, and proliferation. Most importantly, Alizarin Red S staining, quantitative real-time polymerase chain reaction, immunostaining, and Western blot revealed that human mesenchymal stem cells cultured on aligned nanofibers with osteoinductive peptides exhibited enhanced osteogenic differentiation potential than cells on randomly oriented nanofibers. Furthermore, the aligned nanofibers with osteoinductive peptides could direct osteogenic differentiation of human mesenchymal stem cells even in the absence of osteoinducting factors, suggesting superior osteogenic efficacy of biomimetic design that combines the advantages of osteoinductive peptide signal and highly ordered nanofibers on cell fate decision. The presented peptide-decorated bone-mimic nanofiber scaffolds hold a promising potential in the context of bone tissue engineering.

How B cells influence bone biology in health and disease.

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Horowitz, Mark C; Fretz, Jackie A; Lorenzo, Joseph A

2010-09-01

It is now well established that important regulatory interactions occur between the cells in the hematopoietic, immune and skeletal systems (osteoimmunology). B lymphocytes (B cells) are responsible for the generation and production of antibodies or immunoglobulins in the body. Together with T cells these lymphocytes comprise the adaptive immune system, which allows an individual to develop specific responses to an infection and retain memory of that infection, allowing for a faster and more robust response if that same infection occurs again. In addition to this immune function, B cells have a close and multifaceted relationship with bone cells. B cells differentiate from hematopoietic stem cells (HSCs) in supportive niches found on endosteal bone surfaces. Cells in the osteoblast lineage support HSC and B cell differentiation in these niches. B cell differentiation is regulated, at least in part, by a series of transcription factors that function in a temporal manner. While these transcription factors are required for B cell differentiation, their loss causes profound changes in the bone phenotype. This is due, in part, to the close relationship between macrophage/osteoclast and B cell differentiation. Cross talk between B cells and bone cells is reciprocal with defects in the RANKL-RANK, OPG signaling axis resulting in altered bone phenotypes. While the role of B cells during normal bone remodeling appears minimal, activated B cells play an important role in many inflammatory diseases with associated bony changes. This review examines the relationship between B cells and bone cells and how that relationship affects the skeleton and hematopoiesis during health and disease. Copyright 2010 Elsevier Inc. All rights reserved.

Functionalization of PCL-3D Electrospun Nanofibrous Scaffolds for Improved BMP2-Induced Bone Formation.

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Miszuk, Jacob M; Xu, Tao; Yao, Qingqing; Fang, Fang; Childs, Josh D; Hong, Zhongkui; Tao, Jianning; Fong, Hao; Sun, Hongli

2018-03-01

Bone morphogenic protein 2 (BMP2) is a key growth factor for bone regeneration, possessing FDA approval for orthopedic applications. BMP2 is often required in supratherapeutic doses clinically, yielding adverse side effects and substantial treatment costs. Considering the crucial role of materials for BMPs delivery and cell osteogenic differentiation, we devote to engineering an innovative bone-matrix mimicking niche to improve low dose of BMP2-induced bone formation. Our previous work describes a novel technique, named thermally induced nanofiber self-agglomeration (TISA), for generating 3D electrospun nanofibrous (NF) polycaprolactone (PCL) scaffolds. TISA process could readily blend PCL with PLA, leading to increased osteogenic capabilities in vitro , however, these bio-inert synthetic polymers produced limited BMP2-induced bone formation in vivo. We therefore hypothesize that functionalization of NF 3D PCL scaffolds with bone-like hydroxyapatite (HA) and BMP2 signaling activator phenamil will provide a favorable osteogenic niche for bone formation at low doses of BMP2. Compared to PCL-3D scaffolds, PCL/HA-3D scaffolds demonstrated synergistically enhanced osteogenic differentiation capabilities of C2C12 cells with phenamil. Importantly, in vivo studies showed this synergism was able to generate significantly increased new bone in an ectopic mouse model, suggesting PCL/HA-3D scaffolds act as a favorable synthetic extracellular matrix for bone regeneration.

Trabecular bone in the calcaneus of runners.

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Andrew Best

Full Text Available Trabecular bone of the human calcaneus is subjected to extreme repetitive forces during endurance running and should adapt in response to this strain. To assess possible bone functional adaptation in the posterior region of the calcaneus, we recruited forefoot-striking runners (n = 6, rearfoot-striking runners (n = 6, and non-runners (n = 6, all males aged 20-41 for this institutionally approved study. Foot strike pattern was confirmed for each runner using a motion capture system. We obtained high resolution peripheral computed tomography scans of the posterior calcaneus for both runners and non-runners. No statistically significant differences were found between runners and nonrunners or forefoot strikers and rearfoot strikers. Mean trabecular thickness and mineral density were greatest in forefoot runners with strong effect sizes (<0.80. Trabecular thickness was positively correlated with weekly running distance (r2 = 0.417, p<0.05 and years running (r2 = 0.339, p<0.05 and negatively correlated with age at onset of running (r2 = 0.515, p<0.01 Trabecular thickness, mineral density and bone volume ratio of nonrunners were highly correlated with body mass (r2 = 0.824, p<0.05 and nonrunners were significantly heavier than runners (p<0.05. Adjusting for body mass revealed significantly thicker trabeculae in the posterior calcaneus of forefoot strikers, likely an artifact of greater running volume and earlier onset of running in this subgroup; thus, individuals with the greatest summative loading stimulus had, after body mass adjustment, the thickest trabeculae. Further study with larger sample sizes is necessary to elucidate the role of footstrike on calcaneal trabecular structure. To our knowledge, intraspecific body mass correlations with measures of trabecular robusticity have not been reported elsewhere. We hypothesize that early adoption of running and years of sustained moderate volume running stimulate bone modeling in trabeculae of the

Small animals bone density and morphometry analysis with a dual energy X-rays absorptiometry bone densitometer using a 2D digital radiographic detector

International Nuclear Information System (INIS)

Boudousq, V.; Bordy, T.; Gonon, G.; Dinten, J.M.

2004-01-01

LEXXOS (DMS, Montpellier, France) is the first axial and total body cone beam bone densitometer using a 2D digital radiographic detector. In previous papers, technical principles and patients' Bone Mineral Density (BMD) measurement performances were presented. Bone densitometers are also used on small animals for drug development. In this presentation, we show how LEXXOS can be adapted for small animals' examinations and evaluate its performances. At first, in order to take advantage of the whole area of the 20 x 20 cm 2 digital radiographic detector, it has been made profit of X-Rays magnification by adapting the geometrical configuration. Secondly, as small animals present low BMD, a specific dual energy calibration has been defined. This adapted system has then been evaluated on two sets of mice: six reference mice and six ovariectomized mice. Each month, these two populations have been examined and the averaged total body BMD has been measured. This evaluation shows that the right order of BMD magnitude is obtained and, as expected, BMD increases on two sets until a period around puberty and the ovariectomized set presents a significant decrease after. Moreover, the bone image obtained by dual energy processing on LEXXOS presents a radiographic image quality providing useful complementary information on bone morphometry and architecture. This study shows that LEXXOS cone beam bone densitometer provides simultaneously useful quantitative and qualitative information for analysis of bone evolution on small animals. In the future, same system architecture and processing methodology can be used with higher resolution detectors in order to refine information on bone architecture. (authors)

Behavior and adaptive functioning in adolescents with Down syndrome: specifying targets for intervention.

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Jacola, Lisa M; Hickey, Francis; Howe, Steven R; Esbensen, Anna; Shear, Paula K

2014-01-01

Research suggests that adolescents with Down syndrome experience increased behavior problems as compared to age matched peers; however, few studies have examined how these problems relate to adaptive functioning. The primary aim of this study was to characterize behavior in a sample of adolescents with Down syndrome using two widely-used caregiver reports: the Behavioral Assessment System for Children, 2 nd Edition (BASC-2) and Child Behavioral Checklist (CBCL). The clinical utility of the BASC-2 as a measure of behavior and adaptive functioning in adolescents with Down syndrome was also examined. Fifty-two adolescents with Down syndrome between the ages of 12 and 18 (24 males) completed the Peabody Picture Vocabulary Test, 4 th Edition (PPVT-IV) as an estimate of cognitive ability. Caregivers completed the BASC-2 and the CBCL for each participant. A significant proportion of the sample was reported to demonstrate behavior problems, particularly related to attention and social participation. The profile of adaptive function was variable, with caregivers most frequently rating impairment in skills related to activities of daily living and functional communication. Caregiver ratings did not differ by gender and were not related to age or estimated cognitive ability. Caregiver ratings of attention problems on the BASC-2 accounted for a significant proportion of variance in Activities of Daily Living ( Adj R 2 = 0.30) , Leadership ( Adj R 2 = 0.30) Functional Communication ( Adj R 2 = 0.28, Adaptability ( Adj R 2 = 0.29), and Social Skills ( Adj R 2 = 0.17). Higher frequencies of symptoms related to social withdrawal added incremental predictive validity for Functional Communication, Leadership, and Social Skills. Convergent validity between the CBCL and BASC-2 was poor when compared with expectations based on the normative sample. Our results confirm and extend previous findings by describing relationships between specific behavior problems and targeted areas of

Behavior and adaptive functioning in adolescents with Down syndrome: specifying targets for intervention

Science.gov (United States)

Jacola, Lisa M.; Hickey, Francis; Howe, Steven R.; Esbensen, Anna; Shear, Paula K.

2016-01-01

Background Research suggests that adolescents with Down syndrome experience increased behavior problems as compared to age matched peers; however, few studies have examined how these problems relate to adaptive functioning. The primary aim of this study was to characterize behavior in a sample of adolescents with Down syndrome using two widely-used caregiver reports: the Behavioral Assessment System for Children, 2nd Edition (BASC-2) and Child Behavioral Checklist (CBCL). The clinical utility of the BASC-2 as a measure of behavior and adaptive functioning in adolescents with Down syndrome was also examined. Methods Fifty-two adolescents with Down syndrome between the ages of 12 and 18 (24 males) completed the Peabody Picture Vocabulary Test, 4th Edition (PPVT-IV) as an estimate of cognitive ability. Caregivers completed the BASC-2 and the CBCL for each participant. Results A significant proportion of the sample was reported to demonstrate behavior problems, particularly related to attention and social participation. The profile of adaptive function was variable, with caregivers most frequently rating impairment in skills related to activities of daily living and functional communication. Caregiver ratings did not differ by gender and were not related to age or estimated cognitive ability. Caregiver ratings of attention problems on the BASC-2 accounted for a significant proportion of variance in Activities of Daily Living (Adj R2 = 0.30), Leadership (Adj R2 = 0.30) Functional Communication (Adj R2 = 0.28, Adaptability (Adj R2 = 0.29), and Social Skills (Adj R2 = 0.17). Higher frequencies of symptoms related to social withdrawal added incremental predictive validity for Functional Communication, Leadership, and Social Skills. Convergent validity between the CBCL and BASC-2 was poor when compared with expectations based on the normative sample. Conclusion Our results confirm and extend previous findings by describing relationships between specific behavior problems

Functional paralysis of GM-CSF-derived bone marrow cells productively infected with ectromelia virus.

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Lidia Szulc-Dąbrowska

Full Text Available Ectromelia virus (ECTV is an orthopoxvirus responsible for mousepox, a lethal disease of certain strains of mice that is similar to smallpox in humans, caused by variola virus (VARV. ECTV, similar to VARV, exhibits a narrow host range and has co-evolved with its natural host. Consequently, ECTV employs sophisticated and host-specific strategies to control the immune cells that are important for induction of antiviral immune response. In the present study we investigated the influence of ECTV infection on immune functions of murine GM-CSF-derived bone marrow cells (GM-BM, comprised of conventional dendritic cells (cDCs and macrophages. Our results showed for the first time that ECTV is able to replicate productively in GM-BM and severely impaired their innate and adaptive immune functions. Infected GM-BM exhibited dramatic changes in morphology and increased apoptosis during the late stages of infection. Moreover, GM-BM cells were unable to uptake and process antigen, reach full maturity and mount a proinflammatory response. Inhibition of cytokine/chemokine response may result from the alteration of nuclear translocation of NF-κB, IRF3 and IRF7 transcription factors and down-regulation of many genes involved in TLR, RLR, NLR and type I IFN signaling pathways. Consequently, GM-BM show inability to stimulate proliferation of purified allogeneic CD4+ T cells in a primary mixed leukocyte reaction (MLR. Taken together, our data clearly indicate that ECTV induces immunosuppressive mechanisms in GM-BM leading to their functional paralysis, thus compromising their ability to initiate downstream T-cell activation events.

Creatine supplementation in the aging population: effects on skeletal muscle, bone and brain.

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Gualano, Bruno; Rawson, Eric S; Candow, Darren G; Chilibeck, Philip D

2016-08-01

This narrative review aims to summarize the recent findings on the adjuvant application of creatine supplementation in the management of age-related deficits in skeletal muscle, bone and brain metabolism in older individuals. Most studies suggest that creatine supplementation can improve lean mass and muscle function in older populations. Importantly, creatine in conjunction with resistance training can result in greater adaptations in skeletal muscle than training alone. The beneficial effect of creatine upon lean mass and muscle function appears to be applicable to older individuals regardless of sex, fitness or health status, although studies with very old (>90 years old) and severely frail individuals remain scarce. Furthermore, there is evidence that creatine may affect the bone remodeling process; however, the effects of creatine on bone accretion are inconsistent. Additional human clinical trials are needed using larger sample sizes, longer durations of resistance training (>52 weeks), and further evaluation of bone mineral, bone geometry and microarchitecture properties. Finally, a number of studies suggest that creatine supplementation improves cognitive processing under resting and various stressed conditions. However, few data are available on older adults, and the findings are discordant. Future studies should focus on older adults and possibly frail elders or those who have already experienced an age-associated cognitive decline.

Functions of Tenascin-C and Integrin alpha9beta1 in Mediating Prostate Cancer Bone Metastasis

Science.gov (United States)

2017-10-01

AWARD  NUMBER:          W81XWH-16-1-0523 TITLE:  Functions of Tenascin- C and Integrin alpha9beta1 in Mediating Prostate Cancer Bone Metastasis...Prostat Prostate Cancer  Bone Metastasis   5a.  CONTRACT  NUMBER   Functions of Tenascin- C and Integrin alpha9beta1 in Mediating Prostate Cancer...SUPPLEMENTARY  NOTES 14. ABSTRACT The purpose of this work is to dissect mechanisms responsible for interactions between integrin a9b1 and tenascin- C that are

The EORTC emotional functioning computerized adaptive test

DEFF Research Database (Denmark)

Gamper, Eva-Maria; Grønvold, Mogens; Petersen, Morten Aa

2014-01-01

The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is currently developing computerized adaptive testing measures for the Quality of Life Questionnaire Core-30 (QLQ-C30) scales. The work presented here describes the development of an EORTC item bank for e...... for emotional functioning (EF), which is one of the core domains of the QLQ-C30....

Bone and muscular anatomy of the forearm and hand in Tapirus terrestris (Perissodactyla, Tapiridae

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Saulo Gonçalves Pereira

2017-05-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2017v30n2p35 In Brazil, there are two species of tapirs, the largest land mammals in Brazil, which belong to the order Perissodactyla, as do horses. Our aim was to describe the bone and muscular anatomy of the forearm and hand in T. terrestris and to propose adaptive functions. We used five anatomical specimens donated from a breeder to the Laboratory for Teaching and Research on Wild Animals of the Federal University of Uberlandia after death with no trauma. The bones were analyzed, the muscles dissected, and both described. The bones of the forearm and hand of the tapir are the ulna, radius, Os. metacarpalia, Os. carpi, phalanx and Os. sesamoideum. The muscles are M. extensor carpi radialis, M. ulnaris lateralis; M. flexor carpi radialis; M. extensor radialis communis; M. extensor digitorum longus II, III, IV and V, M. extensor digitorum lateralis; M. extensor digitorum; M. abductor longus; M. flexor digiti superficialis; M. flexor digitalis; M. flexor carpi ulnaris; M. flexor carpi obliquus; and M. interossei and M. lumbricales. Characteristics of bone and muscle structure are adapted to the development of the animal’s niche.

Biomechanical and biophysical environment of bone from the macroscopic to the pericellular and molecular level.

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Ren, Li; Yang, Pengfei; Wang, Zhe; Zhang, Jian; Ding, Chong; Shang, Peng

2015-10-01

Bones with complicated hierarchical configuration and microstructures constitute the load-bearing system. Mechanical loading plays an essential role in maintaining bone health and regulating bone mechanical adaptation (modeling and remodeling). The whole-bone or sub-region (macroscopic) mechanical signals, including locomotion-induced loading and external actuator-generated vibration, ultrasound, oscillatory skeletal muscle stimulation, etc., give rise to sophisticated and distinct biomechanical and biophysical environments at the pericellular (microscopic) and collagen/mineral molecular (nanoscopic) levels, which are the direct stimulations that positively influence bone adaptation. While under microgravity, the stimulations decrease or even disappear, which exerts a negative influence on bone adaptation. A full understanding of the biomechanical and biophysical environment at different levels is necessary for exploring bone biomechanical properties and mechanical adaptation. In this review, the mechanical transferring theories from the macroscopic to the microscopic and nanoscopic levels are elucidated. First, detailed information of the hierarchical structures and biochemical composition of bone, which are the foundations for mechanical signal propagation, are presented. Second, the deformation feature of load-bearing bone during locomotion is clarified as a combination of bending and torsion rather than simplex bending. The bone matrix strains at microscopic and nanoscopic levels directly induced by bone deformation are critically discussed, and the strain concentration mechanism due to the complicated microstructures is highlighted. Third, the biomechanical and biophysical environments at microscopic and nanoscopic levels positively generated during bone matrix deformation or by dynamic mechanical loadings induced by external actuators, as well as those negatively affected under microgravity, are systematically discussed, including the interstitial fluid flow

The Structure and Function of Non-Collagenous Bone Proteins

Science.gov (United States)

Hook, Magnus

1997-01-01

The long-term goal for this program is to determine the structural and functional relationships of bone proteins and proteins that interact with bone. This information will used to design useful pharmacological compounds that will have a beneficial effect in osteoporotic patients and in the osteoporotic-like effects experienced on long duration space missions. The first phase of this program, funded under a cooperative research agreement with NASA through the Texas Medical Center, aimed to develop powerful recombinant expression systems and purification methods for production of large amounts of target proteins. Proteins expressed in sufficient'amount and purity would be characterized by a variety of structural methods, and made available for crystallization studies. In order to increase the likelihood of crystallization and subsequent high resolution solution of structures, we undertook to develop expression of normal and mutant forms of proteins by bacterial and mammalian cells. In addition to the main goals of this program, we would also be able to provide reagents for other related studies, including development of anti-fibrotic and anti-metastatic therapeutics.

Motor ability and adaptive function in children with attention deficit hyperactivity disorder

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Hui-Yi Wang

2011-10-01

Full Text Available Attention deficit hyperactivity disorder (ADHD is a common neuropsychiatric disorder. Previous studies have reported that children with ADHD exhibit deficits of adaptive function and insufficient motor ability. The objective of this study was to investigate the association between adaptive function and motor ability in children with ADHD compared with a group of normal children. The study group included 25 children with ADHD (19 boys and 6 girls, aged from 4.6 years to 8.6 years (mean±standard deviation, 6.5±1.2. A group of 24 children without ADHD (normal children were selected to match the children with ADHD on age and gender. The Movement Assessment Battery for Children, which includes three subtests, was used to assess the motor ability of the children of both groups. The Chinese version of Adaptive Behavior Scales, which consists of 12 life domains, was used to assess adaptive function of the children with ADHD. Compared with the normal children, children with ADHD exhibited poorer motor ability on all the three subtests of motor assessment. In the ADHD group, nine (36% children had significant motor impairments and seven (28% were borderline cases. A total of 10 (40% children with ADHD had definite adaptive problems in one or more adaptive domains. With statistically controlling of IQ for the ADHD group, those children with impaired motor ability had significantly poorer behaviors in the adaptive domain of home living (p=0.035. Moreover, children with ADHD who had severely impaired manual dexterity performed worse than the control group in the adaptive domains of home living (r=−0.47, p=0.018, socialization (r=−0.49, p=0.013, and self-direction (r=−0.41, p=0.040. In addition, children with poorer ball skills had worse home living behavior (r=−0.56, p=0.003. Children who had more impaired balance exhibited poorer performance in social behavior (r=−0.41, p=0.040. This study found significant correlation between motor ability and

Assessment of bone mineral content in the internal bone volume

International Nuclear Information System (INIS)

Hoeiseth, A.; Alho, A.; Husby, T.; Ullevaal Sykehus, Oslo

1991-01-01

A method for assessing values related to bone density and mass is described. Mean attenuation and pixel area are measured in pixels selected on the basis of CT units. The method is to a large extent computerized and not dependent on manual positioning or outlining of a region of interest. Because it is not dependent on a comparatively large volume of homogeneous bone it can be used to make assessments even in very heterogeneous bones including cortical bone. The method is adaptable for measurement in all parts of the skeleton and values related to both bone density (DRV) and bone mass (MRV) are derived. The measurements in the femoral condyles were shown to have a precision of approximately 0.25 to 0.30 Z-score units (standard deviation of the measurements expressed in Z-score units). The agreement between chemically analyzed calcium density (weight of calcium per volume) and DRV was little less than 0.50 Z-scores and 0.30 Z-scores for the chemically determined calcium mass and the MRV. The agreement with mechanical bone strength was 0.78 Z-scores for DRV and 0.64 for the MRV. Altering scan parameters or measuring approaches gave systematic differences in the measurements. There were, however, good linear correlations between the measurements which show that these different measuring approaches essentially gave identical measurements. (orig.)

Uranium incorporation biokinetics in poultry bones as function of phytase doses

International Nuclear Information System (INIS)

Arruda-Neto, J.D.T.; Cestari, A.C.; Zamboni, C.B.; Saiki, M.; Nogueira, G.P.; Fonseca, L.E.C.; Manso-Guevara, M.V.; Deppman, A.; Likhachev, V.P.; Mesa, J.

2005-01-01

Neutron activation analysis has been used to study uranium incorporation in poultry bones as function of chow doped with: (a) uranium (20 ppm); (b) U-doped food (20 ppm) plus phytase (120 ppm) and (c) U-doped food (20 ppm) plus phytase (180 ppm). To investigate this situation experiments involving several groups of Cobb broilers was performed. Two animals per group were sacrificed weekly up to their adultness and uranium concentration in the tibia was measured. It was observed that the concentration of uranium (μg U/g bone) is decreasing all along the animal life spanning period of 14-42 days. This behavior suggests that the skeleton mass is growing faster than the corresponding accumulation of uranium. The administration of phytase seems not to alter this scenario. (author)

Adaptive function projective synchronization of two-cell Quantum-CNN chaotic oscillators with uncertain parameters

International Nuclear Information System (INIS)

Sudheer, K. Sebastian; Sabir, M.

2009-01-01

This work investigates function projective synchronization of two-cell Quantum-CNN chaotic oscillators using adaptive method. Quantum-CNN oscillators produce nano scale chaotic oscillations under certain conditions. By Lyapunove stability theory, the adaptive control law and the parameter update law are derived to make the state of two chaotic systems function projective synchronized. Numerical simulations are presented to demonstrate the effectiveness of the proposed adaptive controllers.

Continuous functionally graded porous titanium scaffolds manufactured by selective laser melting for bone implants.

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Han, Changjun; Li, Yan; Wang, Qian; Wen, Shifeng; Wei, Qingsong; Yan, Chunze; Hao, Liang; Liu, Jie; Shi, Yusheng

2018-04-01

A significant requirement for a bone implant is to replicate the functional gradient across the bone to mimic the localization change in stiffness. In this work, continuous functionally graded porous scaffolds (FGPSs) based on the Schwartz diamond unit cell with a wide range of graded volume fraction were manufactured by selective laser melting (SLM). The micro-topology, strut dimension characterization and effect of graded volume fraction on the mechanical properties of SLM-processed FGPSs were systematically investigated. The micro-topology observations indicate that diamond FGPSs with a wide range of graded volume fraction from 7.97% to 19.99% were fabricated without any defects, showing a good geometric reproduction of the original designs. The dimensional characterization demonstrates the capability of SLM in manufacturing titanium diamond FGPSs with the strut size of 483-905µm. The elastic modulus and yield strength of the titanium diamond FGPSs can be tailored in the range of 0.28-0.59GPa and 3.79-17.75MPa respectively by adjusting the graded volume fraction, which are comparable to those of the cancellous bone. The mathematical relationship between the graded porosity and compression properties of a FGPS was revealed. Furthermore, two equations based on the Gibson and Ashby model have been established to predict the modulus and yield strength of SLM-processed diamond FGPSs. Compared to homogeneous diamond porous scaffolds, FGPSs provide a wide range of mutative pore size and porosity, which are potential to be tailored to optimize the pore space for bone tissue growth. The findings provide a basis of new methodologies to design and manufacture superior graded scaffolds for bone implant applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Self-adaptive numerical integrator for analytic functions

International Nuclear Information System (INIS)

Garribba, S.; Quartapelle, L.; Reina, G.

1978-01-01

A new adaptive algorithm for the integration of analytical functions is presented. The algorithm processes the integration interval by generating local subintervals whose length is controlled through a feedback loop. The control is obtained by means of a relation derived on an analytical basis and valid for an arbitrary integration rule: two different estimates of an integral are used to compute the interval length necessary to obtain an integral estimate with accuracy within the assigned error bounds. The implied method for local generation of subintervals and an effective assumption of error partition among subintervals give rise to an adaptive algorithm provided with a highly accurate and very efficient integration procedure. The particular algorithm obtained by choosing the 6-point Gauss-Legendre integration rule is considered and extensive comparisons are made with other outstanding integration algorithms

Bone Adaptation as an Evolutionary Process

DEFF Research Database (Denmark)

Bagge, Mette

1998-01-01

. The memory of past loadings is included in themodel to account for the delay in the bone response from the loadchanges. The remodeling rate equation is derived from the structuraloptimization task of maximizing the stiffness in each time step. Additional informationscan be extracted from the optimization...... process; the remodelingequilibrium parameter where no apposition or resorption takes place is defined asthe element optimality conditions and the optimal design is used as aninitial design for the onset ofthe remodeling simulation. Some examples of boneadaptation resulting from load changes is given....

Possible mechanisms of retinal function recovery with the use of cell therapy with bone marrow-derived stem cells

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Rubens Camargo Siqueira

2010-10-01

Full Text Available Bone marrow has been proposed as a potential source of stem cells for regenerative medicine. In the eye, degeneration of neural cells in the retina is a hallmark of such widespread ocular diseases as age-related macular degeneration (AMD and retinitis pigmentosa. Bone marrow is an ideal tissue for studying stem cells mainly because of its accessibility. Furthermore, there are a number of well-defined mouse models and cell surface markers that allow effective study of hematopoiesis in healthy and injured mice. Because of these characteristics and the experience of bone marrow transplantation in the treatment of hematological disease such as leukemia, bone marrow-derived stem cells have also become a major tool in regenerative medicine. Those cells may be able to restore the retina function through different mechanisms: A cellular differentiation, B paracrine effect, and C retinal pigment epithelium repair. In this review, we described these possible mechanisms of recovery of retinal function with the use of cell therapy with bone marrow-derived stem cells.

Evolution of bone biomechanical properties at the micrometer scale around titanium implant as a function of healing time

International Nuclear Information System (INIS)

Vayron, Romain; Mathieu, Vincent; Haiat, Guillaume; Matsukawa, Mami; Tsubota, Ryo; Barthel, Etienne

2014-01-01

The characterization of the biomechanical properties of newly formed bone tissue around implants is important to understand the osseointegration process. The objective of this study is to investigate the evolution of elastic properties of newly formed bone tissue as a function of healing time. To do so, nanoindentation and micro-Brillouin scattering techniques are coupled following a multimodality approach using histological analysis. Coin-shaped implants were placed in vivo at a distance of 200 µm from the cortical bone surface, leading to an initially empty cavity. Two rabbits were sacrificed after 7 and 13 weeks of healing time. The histological analyses allow us to distinguish mature and newly formed bone tissue. The bone mechanical properties were measured in mature and newly formed bone tissue. Analysis of variance and Tukey–Kramer tests reveals a significant effect of healing time on the indentation modulus and ultrasonic velocities of bone tissue. The results show that bone mass density increases by 12.2% (2.2% respectively) between newly formed bone at 7 weeks (13 weeks respectively) and mature bone. The dependence of bone properties on healing time may be explained by the evolution of bone microstructure and mineralization. (paper)

[Research advances of fluid bio-mechanics in bone].

Science.gov (United States)

Chen, Zebin; Huo, Bo

2017-04-01

It has been found for more than one century that when experiencing mechanical loading, the structure of bone will adapt to the changing mechanical environment, which is called bone remodeling. Bone remodeling is charaterized as two processes of bone formation and bone resorption. A large number of studies have confirmed that the shear stress is resulted from interstitial fluid flow within bone cavities under mechanical loading and it is the key factor of stimulating the biological responses of bone cells. This review summarizes the major research progress during the past years, including the biological response of bone cells under fluid flow, the pressure within bone cavities, the theoretical modeling, numerical simulation and experiments about fluid flow within bone, and finally analyzes and predicts the possible tendency in this field in the future.

Monitoring renal function during biphosphonate treatment in patients with bone metastases - role of dynamic kidney scintigraphy

International Nuclear Information System (INIS)

Chavdarova, L.; Tzonevska, A.

2015-01-01

Full text: Biphosphonates (BP) are very effective in treatment of bone metastatic disease. Their renal excretion defines one of the major side effects - nephrotoxicity. Glomerular filtration rate (GFR) is a basic parameter for its early detection but clinical practice often uses only serum creatinine. Aim of our retrospective study is to assess the role of dynamic kidney scintigraphy (DKS) and the estimated during it GFR in BP-treated patients with bone metastatic disease. 61 patients (53 female, 8 male), aged 33-82, with biphosphonate-treated bone metastases from breast (n53), lung (n1) and prostate (n7) cancer were enrolled for the period 27.04.2012-14.04.2015. Overall 77 studies were made, in 13 patients more than one. GFR was assessed in 57 studies. Results were compared with serum creatinine. All patients with elevated creatinine showed low GFR and decreased renal function at DKS. With normal creatinine and decreased GFR: in 31 studies kidney function was reduced, in 14 function was normal but kidney scintigraphic appearance was disturbed- mostly as in diffuse parenchymal disease. In 5 studies GFR was normal and renal function decreased. In 3 studies both parameters were normal. Zoledronic acid was changed with denosumab in 2 patients because of worsened function and strongly reduced GFR, in one patient BP was stopped after DKS. In 3 patients the interval between BP was extended because of affected renal function. GFR is more sensitive than serum creatinine levels and changes in nephrographic curves. Dynamic kidney scintigraphy is a functional method directing clinical reaction to preserve renal function

Exercise does not enhance aged bone's impaired response to artificial loading in C57Bl/6 mice.

Science.gov (United States)

Meakin, Lee B; Udeh, Chinedu; Galea, Gabriel L; Lanyon, Lance E; Price, Joanna S

2015-12-01

Bones adapt their structure to their loading environment and so ensure that they become, and are maintained, sufficiently strong to withstand the loads to which they are habituated. The effectiveness of this process declines with age and bones become fragile fracturing with less force. This effect in humans also occurs in mice which experience age-related bone loss and reduced adaptation to loading. Exercise engenders many systemic and local muscular physiological responses as well as engendering local bone strain. To investigate whether these physiological responses influence bones' adaptive responses to mechanical strain we examined whether a period of treadmill exercise influenced the adaptive response to an associated period of artificial loading in young adult (17-week) and old (19-month) mice. After treadmill acclimatization, mice were exercised for 30 min three times per week for two weeks. Three hours after each exercise period, right tibiae were subjected to 40 cycles of non-invasive axial loading engendering peak strain of 2250 με. In both young and aged mice exercise increased cross-sectional muscle area and serum sclerostin concentration. In young mice it also increased serum IGF1. Exercise did not affect bone's adaptation to loading in any measured parameter in young or aged bone. These data demonstrate that a level of exercise sufficient to cause systemic changes in serum, and adaptive changes in local musculature, has no effect on bone's response to loading 3h later. This study provides no support for the beneficial effects of exercise on bone in the elderly being mediated by systemic or local muscle-derived effects rather than local adaptation to altered mechanical strain. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Surface Functionalization of Orthopedic Titanium Implants with Bone Sialoprotein.

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Andreas Baranowski

Full Text Available Orthopedic implant failure due to aseptic loosening and mechanical instability remains a major problem in total joint replacement. Improving osseointegration at the bone-implant interface may reduce micromotion and loosening. Bone sialoprotein (BSP has been shown to enhance bone formation when coated onto titanium femoral implants and in rat calvarial defect models. However, the most appropriate method of BSP coating, the necessary level of BSP coating, and the effect of BSP coating on cell behavior remain largely unknown. In this study, BSP was covalently coupled to titanium surfaces via an aminosilane linker (APTES, and its properties were compared to BSP applied to titanium via physisorption and untreated titanium. Cell functions were examined using primary human osteoblasts (hOBs and L929 mouse fibroblasts. Gene expression of specific bone turnover markers at the RNA level was detected at different intervals. Cell adhesion to titanium surfaces treated with BSP via physisorption was not significantly different from that of untreated titanium at any time point, whereas BSP application via covalent coupling caused reduced cell adhesion during the first few hours in culture. Cell migration was increased on titanium disks that were treated with higher concentrations of BSP solution, independent of the coating method. During the early phases of hOB proliferation, a suppressive effect of BSP was observed independent of its concentration, particularly when BSP was applied to the titanium surface via physisorption. Although alkaline phosphatase activity was reduced in the BSP-coated titanium groups after 4 days in culture, increased calcium deposition was observed after 21 days. In particular, the gene expression level of RUNX2 was upregulated by BSP. The increase in calcium deposition and the stimulation of cell differentiation induced by BSP highlight its potential as a surface modifier that could enhance the osseointegration of orthopedic implants

Clonidine reduces norepinephrine and improves bone marrow function in a rodent model of lung contusion, hemorrhagic shock, and chronic stress.

Science.gov (United States)

Alamo, Ines G; Kannan, Kolenkode B; Ramos, Harry; Loftus, Tyler J; Efron, Philip A; Mohr, Alicia M

2017-03-01

Propranolol has been shown previously to restore bone marrow function and improve anemia after lung contusion/hemorrhagic shock. We hypothesized that daily clonidine administration would inhibit central sympathetic outflow and restore bone marrow function in our rodent model of lung contusion/hemorrhagic shock with chronic stress. Male Sprague-Dawley rats underwent 6 days of restraint stress after lung contusion/hemorrhagic shock during which the animals received clonidine (75 μg/kg) after the restraint stress. On postinjury day 7, we assessed urine norepinephrine, blood hemoglobin, plasma granulocyte colony stimulating factor, and peripheral blood mobilization of hematopoietic progenitor cells, as well as bone marrow cellularity and erythroid progenitor cell growth. The addition of clonidine to lung contusion/hemorrhagic shock with chronic restraint stress significantly decreased urine norepinephrine levels, improved bone marrow cellularity, restored erythroid progenitor colony growth, and improved hemoglobin (14.1 ± 0.6 vs 10.8 ± 0.6 g/dL). The addition of clonidine to lung contusion/hemorrhagic shock with chronic restraint stress significantly decreased hematopoietic progenitor cells mobilization and restored granulocyte colony stimulating factor levels. After lung contusion/hemorrhagic shock with chronic restraint stress, daily administration of clonidine restored bone marrow function and improved anemia. Alleviating chronic stress and decreasing norepinephrine is a key therapeutic target to improve bone marrow function after severe injury. Copyright © 2016 Elsevier Inc. All rights reserved.

[Mechanical behavior of the subchondral bone in the experimentally induced osteoarthritis].

Science.gov (United States)

Miyanaga, Y

1979-06-01

In order to evaluate the role of the subchondral bone (cancellous bone) in the development and progression of the joint degeneration, osteoarthritis of the knee joint was produced experimentally in the rabbits and viscoelasticity and strength of the subchondral bone from the femoral medial condyle have been investigated along with the pathological, histological study of the joint. The viscoelastic spectrometer and the Instron type testing machine were used. As the first change after operation, osteophyte formation around the joint margin has been observed before the initiation of the degeneration of articular cartilage and there is a possibility that mechanical properties of subchondral bone such as high deformability and low elasticity to the mechanism of osteophyte formation. Subchondral bone softening with marked increase of ultimate strain and phase lag, marked decrease of compressive elastic modulus and ultimate stress precedes or occurs concurrently with the degeneration of the articular cartilage. These facts indicate the relationship between the mechanical properties of the subchondral bone and joint degeneration. Once the joint degeneration starts, degeneration continues progressively while the subchondral bone tends to become brittle. These changes may be considered as a kind of functional adaptation to the damage or denudation of articular cartilage. It is postulated that some architectural changes of the subchondral bone may provide alterations of the mechanical properties. Biomechanical roles of the subchondral bone is suggested as one of the factors in the joint degeneration.

Sodium and bone health

DEFF Research Database (Denmark)

Teucher, B.; Dainty, J. R.; Spinks, C. A.

2008-01-01

High salt intake is a well-recognized risk factor for osteoporosis because it induces calciuria, but the effects of salt on calcium metabolism and the potential impact on bone health in postmenopausal women have not been fully characterized. This study investigated adaptive mechanisms in response.......9 Versus 11.2 g) diets, reflecting lower and upper intakes in post men opausal women consuming a Western-style diet, were provided. Stable isotope labeling techniques were used to measure calcium absorption and excretion, compartmental modeling was undertaken to estimate bone calcium balance......, and biomarkers of bone formation and resorption were measured in blood and urine. Moderately high salt intake (11.2 g/d) elicited a significant increase in urinary calcium excretion (p = 0.0008) and significantly affected bone calcium balance with the high calcium diet 0.024). Efficiency of calcium absorption...

The exploration of the changes in bone metabolism in patients with abnormal thyroid function

International Nuclear Information System (INIS)

Chu Shaolin; Li Xiaohong; Lei Qiufang; Ye Peihong; Chai Luhua

2001-01-01

To explore the changes in bone metabolism with abnormal thyroid function, BGP and PTH in 91 patients with hyperthyroidism, 37 patients with hypothyroidism, 51 controls, were measured by means of IRMA, calcaneus heel bone density (BMD) was measured by means of 241 Am single photon absorptiometry. BGP levels in hyperthyroidism were significantly higher than those in controls (P < 0.001). BGP levels in hypothyroidism were significantly lower than those in controls (P < 0.001). PTH levels in hyperthyroidism were a little lower than those in controls (P < 0.05). PTH levels in hypothyroidism were significantly higher than those in controls (P < 0.001). The measurement of BMD showed that the prevalence rates of osteoporosis (OP) in hyperthyroidism and hypothyroidism were significantly higher than those in controls. In hyperthyroidism and hypothyroidism groups the age of OP tends to be younger. The patients with hyperthyroidism over 55 years of age were all suffered from OP. The changes in BGP and PTH were earlier than BMD, so BGP and PTH can be used as sensitive indicator of the changes in bone metabolism with abnormal thyroid function, especially for curative effect observations

A locally adapted functional outcome measurement score for total ...

African Journals Online (AJOL)

... in Europe or North America and seem not optimally suited for a general West ... We introduce a cross-cultural adaptation of the Lequesne index as a new score. ... Keywords: THR, Hip, Africa, Functional score, Hip replacement, Arthroscopy ...

Bone development

DEFF Research Database (Denmark)

Tatara, M.R.; Tygesen, Malin Plumhoff; Sawa-Wojtanowicz, B.

2007-01-01

The objective of this study was to determine the long-term effect of alpha-ketoglutarate (AKG) administration during early neonatal life on skeletal development and function, with emphasis on bone exposed to regular stress and used to serve for systemic changes monitoring, the rib. Shropshire ram.......01). Furthermore, AKG administration induced significantly higher bone mineral density of the cortical bone by 7.1% (P

Adaptive Control and Function Projective Synchronization in 2D Discrete-Time Chaotic Systems

International Nuclear Information System (INIS)

Li Yin; Chen Yong; Li Biao

2009-01-01

This study addresses the adaptive control and function projective synchronization problems between 2D Rulkov discrete-time system and Network discrete-time system. Based on backstepping design with three controllers, a systematic, concrete and automatic scheme is developed to investigate the function projective synchronization of discrete-time chaotic systems. In addition, the adaptive control function is applied to achieve the state synchronization of two discrete-time systems. Numerical results demonstrate the effectiveness of the proposed control scheme.

Assessment of functional displacement of bone marrow by osteoplastic metastases from prostatic carcinoma with bone marrow scintigraphy

International Nuclear Information System (INIS)

Venz, S.; Cordes, M.; Friedrichs, R.; Hosten, N.; Neumann, K.; Langer, R.; Nagel, R.; Felix, R.

1993-01-01

The detailed examination of the skeleton in prostate cancer has become more critical since surgical treatment requires the non-evidence of bone metastases. The data of 30 patients have been evaluated. All patients had a bone scan and a bone marrow scintigraphy with [ 99m Tc[-anti-NCA95. In this study we compared the degree of bone marrow displacement with the extent of metastatic deposits identified on the bone scan. Six patients showing the criterias of a superscan (maximal avidity of the osteotrope radiatracer) had as a correlate a complete displacement of the hematopoesis in the bone marrow scintigraphy and an increased activity in liver and spleen. The degree of the peripheral extension correlated strongly with the decrease of the haemoglobin in blood samples. The grading was based upon the number of metastatic deposits identified on the scan (0=no metastases; 1≤6 metastases; 2=multiple metastases; 3=superscan). In 28 of 30 patients (93%) we found corresponding results in both the bone scan and the bone marrow scintigraphy. The bone marrow scintigraphy is a sensitive method in the detection of metastatic disease and gives additional information about the extent of bone marrow displacement by osteoplastic metastases. (orig.) [de

Cartilage damage and bone erosion are more prominent determinants of functional impairment in longstanding experimental arthritis than synovial inflammation

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Silvia Hayer

2016-11-01

Full Text Available Chronic inflammation of articular joints causing bone and cartilage destruction consequently leads to functional impairment or loss of mobility in affected joints from individuals affected by rheumatoid arthritis (RA. Even successful treatment with complete resolution of synovial inflammatory processes does not lead to full reversal of joint functionality, pointing to the crucial contribution of irreversibly damaged structural components, such as bone and cartilage, to restricted joint mobility. In this context, we investigated the impact of the distinct components, including synovial inflammation, bone erosion or cartilage damage, as well as the effect of blocking tumor necrosis factor (TNF on functional impairment in human-TNF transgenic (hTNFtg mice, a chronic inflammatory erosive animal model of RA. We determined CatWalk-assisted gait profiles as objective quantitative measurements of functional impairment. We first determined body-weight-independent gait parameters, including maximum intensity, print length, print width and print area in wild-type mice. We observed early changes in those gait parameters in hTNFtg mice at week 5 – the first clinical signs of arthritis. Moreover, we found further gait changes during chronic disease development, indicating progressive functional impairment in hTNFtg mice. By investigating the association of gait parameters with inflammation-mediated joint pathologies at different time points of the disease course, we found a relationship between gait parameters and the extent of cartilage damage and bone erosions, but not with the extent of synovitis in this chronic model. Next, we observed a significant improvement of functional impairment upon blocking TNF, even at progressed stages of disease. However, blocking TNF did not restore full functionality owing to remaining subclinical inflammation and structural microdamage. In conclusion, CatWalk gait analysis provides a useful tool for quantitative

Adaptive Linear and Normalized Combination of Radial Basis Function Networks for Function Approximation and Regression

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Yunfeng Wu

2014-01-01

Full Text Available This paper presents a novel adaptive linear and normalized combination (ALNC method that can be used to combine the component radial basis function networks (RBFNs to implement better function approximation and regression tasks. The optimization of the fusion weights is obtained by solving a constrained quadratic programming problem. According to the instantaneous errors generated by the component RBFNs, the ALNC is able to perform the selective ensemble of multiple leaners by adaptively adjusting the fusion weights from one instance to another. The results of the experiments on eight synthetic function approximation and six benchmark regression data sets show that the ALNC method can effectively help the ensemble system achieve a higher accuracy (measured in terms of mean-squared error and the better fidelity (characterized by normalized correlation coefficient of approximation, in relation to the popular simple average, weighted average, and the Bagging methods.

Bone disease in primary hyperparathyroidism

Science.gov (United States)

Bandeira, Francisco; Cusano, Natalie E.; Silva, Barbara C.; Cassibba, Sara; Almeida, Clarissa Beatriz; Machado, Vanessa Caroline Costa; Bilezikian, John P.

2015-01-01

Bone disease in severe primary hyperparathyroidism (PHPT) is described classically as osteitis fibrosa cystica (OFC). Bone pain, skeletal deformities and pathological fractures are features of OFC. Bone mineral density is usually extremely low in OFC, but it is reversible after surgical cure. The signs and symptoms of severe bone disease include bone pain, pathologic fractures, proximal muscle weakness with hyperreflexia. Bone involvement is typically characterized as salt-and-pepper appearance in the skull, bone erosions and bone resorption of the phalanges, brown tumors and cysts. In the radiography, diffuse demineralization is observed, along with pathological fractures, particularly in the long bones of the extremities. In severe, symptomatic PHPT, marked elevation of the serum calcium and PTH concentrations are seen and renal involvement is manifested by nephrolithiasis and nephrocalcinosis. A new technology, recently approved for clinical use in the United States and Europe, is likely to become more widely available because it is an adaptation of the lumbar spine DXA image. Trabecular bone score (TBS) is a gray-level textural analysis that provides an indirect index of trabecular microarchitecture. Newer technologies, such as high-resolution peripheral quantitative computed tomography (HR-pQCT), have provided further understanding of the microstructural skeletal features in PHPT. PMID:25166047

Association between bone mass as assessed by quantitative ultrasound and physical function in elderly women: The Fujiwara-kyo study

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Akira Minematsu

2017-06-01

Conclusions: Measurements of physical function can effectively identify elderly women with low bone mass at an early stage without the need for bone mass measurements. In particular, one-leg standing time and 10-m gait time were good predictors of low bone mass, and is easy to measure, low-cost, and can be self-measured. These findings will be helpful in the prevention and treatment of osteoporosis.

Use of Calcium and Alendronic Acid Preparations in Correction of Structural and Functional Disorders of Bone Tissue in Thyrotoxicosis

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O.B. Oliynyk

2012-02-01

Full Text Available Impact of calcium and alendronic acid preparations on disorders of structural and functional state of bone tissue in experimental animals at exogenic thyrotoxicosis was studied. It was defined that introduction of calcium preparations reduces bone mineral density loss in female rats with drug thyrotoxicosis, and combined use of calcium and alendronic acid prevents bone tissue loss regardless of thyrotoxicosis duration and presence of ovariectomy.

A Prospective Study to Compare the Functional and Aesthetic Outcomes with and without Primary Bone Grafting in Facial Fractures

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Narayanamurthy Sundaramurthy

2017-10-01

Full Text Available Introduction: Open Reduction and Internal Fixation (ORIF has been the gold standard in treatment of facial fractures. Bone grafts have been used to correct bone defects in face. Many studies assessing outcomes of ORIF and primary bone grafting separately have been published in literature. Aim: A prospective study to compare the functional and aesthetic outcomes with and without primary bone grafting in facial fractures. Materials and Methods: Thirty patients, admitted between January 2012 and December 2013, were divided into two groups. Group 1 patients underwent ORIF with primary bone grafting and in group 2, only ORIF was done. Clinical and functional, photographic and radiological assessments were done after one month and three months. Results: Mean value of vertical dystopia in groups 1 and 2 after three months postoperatively were 1.25mm and 0.67mm. Mean value of enophthalmos in groups 1 and 2 after three months postoperatively were 0.5mm and 1mm. Thus, vertical dystopia was corrected better without bone grafts and enophthalmos corrected better with bone grafts. Photographic assessment revealed no statistical difference between the two groups. Postoperatively, in upper face fractures, both groups had similar number of patients in grades 1 and 2. Only one patient from group 2 of midface fractures ended up with grade 3 asymmetry. Radiologically, in upper face fractures, group 2 had more mean projection, height and breadth deficits (1.28mm, 2.57mm and 2.42mm when compared to group 1 (0.67mm, 1.50mm and 0.50mm. The mean projection and height deficits were statistically better in group 1. In midface fractures, mean zygomatic complex projection and height deficits were more in group 2 (1.88mm and 0.63mm than group 1 (0.78mm and 0.44mm. The mean zygomatic complex projection was statistically better in group1. Postoperative complications were lesser with the bone graft group. Conclusion: Judicious use of bone grafts in comminuted facial and orbital

Bone grafting: An overview

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D. O. Joshi

2010-08-01

Full Text Available Bone grafting is the process by which bone is transferred from a source (donor to site (recipient. Due to trauma from accidents by speedy vehicles, falling down from height or gunshot injury particularly in human being, acquired or developmental diseases like rickets, congenital defects like abnormal bone development, wearing out because of age and overuse; lead to bone loss and to replace the loss we need the bone grafting. Osteogenesis, osteoinduction, osteoconduction, mechanical supports are the four basic mechanisms of bone graft. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. An ideal bone graft material is biologically inert, source of osteogenic, act as a mechanical support, readily available, easily adaptable in terms of size, shape, length and replaced by the host bone. Except blood, bone is grafted with greater frequency. Bone graft indicated for variety of orthopedic abnormalities, comminuted fractures, delayed unions, non-unions, arthrodesis and osteomyelitis. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. By adopting different procedure of graft preservation its antigenicity can be minimized. The concept of bone banking for obtaining bone grafts and implants is very useful for clinical application. Absolute stability require for successful incorporation. Ideal bone graft must possess osteogenic, osteoinductive and osteocon-ductive properties. Cancellous bone graft is superior to cortical bone graft. Usually autologous cancellous bone graft are used as fresh grafts where as allografts are employed as an alloimplant. None of the available type of bone grafts possesses all these properties therefore, a single type of graft cannot be recomm-ended for all types of orthopedic abnormalities. Bone grafts and implants can be selected as per clinical problems, the equipments available and preference of

Cognitive functions in drivers with brain injury : Anticipation and adaption

OpenAIRE

Lundqvist, Anna

2001-01-01

The purpose of this thesis was to improve the understanding of what cognitive functions are important for driving performance, investigate the impact of impaired cognitive functions on drivers with brain injury, and study adaptation strategies relevant for driving performance after brain injury. Finally, the predictive value of a neuropsychological test battery was evaluated for driving performance. Main results can be summarized in the following conclusions: (a) Cognitive functions in terms ...

A methodology for incorporating functional bone marrow sparing in IMRT planning for pelvic radiation therapy

International Nuclear Information System (INIS)

McGuire, Sarah M.; Menda, Yusuf; Boles Ponto, Laura L.; Gross, Brandie; Juweid, Malik; Bayouth, John E.

2011-01-01

Background and purpose: The purpose of this study was to design a radiation therapy treatment planning approach that would spare hematopoietically active bone marrow using [ 18 F]FLT PET imaging. Materials and methods: We have developed an IMRT planning methodology to incorporate functional PET imaging using [ 18 F]FLT scans. Plans were generated for two simulated cervical cancer patients, where pelvic active bone marrow regions were incorporated as avoidance regions based on the ranges: SUV4 ≥ 4; 4 > SUV3 ≥ 3; and 3 > SUV2 ≥ 2. Dose objectives were set to reduce bone marrow volume that received 10 (V 10 ) and 20 (V 20 ) Gy. Results: Active bone marrow regions identified by [ 18 F]FLT with an SUV ≥ 2, SUV ≥ 3, and SUV ≥ 4 represented an average of 43.0%, 15.3%, and 5.8%, respectively of the total osseous pelvis for the two cases studied. Improved dose-volume histograms for all identified bone marrow SUV volumes and decreases in V 10 , and V 20 were achieved without clinically significant changes to PTV or OAR doses. Conclusions: Incorporation of [ 18 F]FLT PET in IMRT planning provides a methodology to reduce radiation dose to active bone marrow without compromising PTV or OAR dose objectives in pelvic malignancies.

Inhibitory control as a factor of adaptive functioning of children with mild intellectual disability

Directory of Open Access Journals (Sweden)

Gligorović Milica

2012-01-01

Full Text Available Bearing in mind that the adaptive behaviour is one of the defining parameters of intellectual disability, determining of the influence of inhibitory control on adaptive functioning in children with mild intellectual disability was defined as a basic aim of this research. The sample covered 95 children with mild intellectual disability (MID, of both genders, from 10 to 14 years of age. By analysis of the data of schools' pedagogical-psychological departments, data on age and intellectual abilities of participants were collected. Inhibitory control was estimated by Go no Go task, consisted of Conflict Response and Response Delay sets. Adaptive skills data were gained on the basis of a standardized interview with special education teachers, by applying of AAMR Scale of adaptive functioning. On the basis of factor analysis, Scale scores were grouped in five factors: Personal independence, Social Independence, Personal and Social Responsibility, Social Adaptability and Personal Adaptability. Significance of relations among the observed variables was established by Pearson's correlation coefficient, by partial correlation coefficient and multifactorial variance analysis. Based on the analysis of results a statistically significant relationship between errors in the execution of tasks that belong to the set of conflict motor responses and adaptive functioning (p≤0.000 was established. The relationship between errors that belong to the set of the response delay, and adaptive functioning is not statistically significant (p=0.324. Inhibition of the interference response is a significant factor of practical (partial η2=0.227, conceptual (partial η2=0.341 and social (partial η2=0.131 adaptive skills, while the response delay is significantly associated with the conceptual skills (p=0.029 only. Inhibitory control did not prove itself a significant factor in behaviour problems of externalizing and internalized type.

Bone-like apatite coating on functionalized poly(etheretherketone) surface via tailored silanization layers technique.

Science.gov (United States)

Zheng, Yanyan; Xiong, Chengdong; Zhang, Shenglan; Li, Xiaoyu; Zhang, Lifang

2015-10-01

Poly(etheretherketone) (PEEK) is a rigid semi-crystalline polymer with outstanding mechanical properties, bone-like stiffness and suitable biocompatibility that has attracted much interest as a biomaterial for orthopedic and dental implants. However, the bio-inert surface of PEEK limits its biomedical applications when direct osteointegration between the implants and the host tissue is desired. In this work, -PO4H2, -COOH and -OH groups were introduced on the PEEK surface by further chemical treatments of the vinyl-terminated silanization layers formed on the hydroxylation-pretreated PEEK surface. Both the surface-functionalized and pristine specimens were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and water contact angle measurements. When placed in 1.5 strength simulated body fluid (SBF) solution, apatite was observed to form uniformly on the functionalized PEEK surface and firmly attach to the substrate. The characterized results demonstrated that the coating was constituted by poorly crystallized bone-like apatite and the effect of surface functional groups on coating formation was also discussed in detail. In addition, in vitro biocompatibility of PEEK, in terms of pre-osteoblast cell (MC3T3-E1) attachment, spreading and proliferation, was remarkably enhanced by the bone-like apatite coating. Thus, this study provides a method to enhance the bioactivity of PEEK and expand its applications in orthopedic and dental implants. Copyright © 2015 Elsevier B.V. All rights reserved.

Connection of functional quality of partial removable dentures and the degree of patients' phonetic adaptation.

Science.gov (United States)

Artjomenko, Victoria; Vidzis, Aldis; Zigurs, Guntis

2015-01-01

Phonetic adaptation is a complex biological phenomenon with a highly individual course, depending on the patient's motivation to use prosthesis, on the functional quality of removable dentures. The aim of the study was to estimate phonetic adaptation in patients with partial dentures, connecting it to alteration in speech quality and dentures functional value. We examined some peculiarities of phonetic adaptation in 50 patients with removable dentures (50 patients with natural dentition were invited for the control group). The standardized evaluation protocols (12 speech quality determining parameters) were developed separately for Latvian and Russian native speakers. 500 speech video samples were recorded and analysed according to pre-established guidelines. The connection of speech quality and the functional quality of the dentures was assessed. Statistical analysis was performed using SPSS 20.0. P values equal to or less than 0.05 were considered to be statistically significant. In patients with appropriate functional quality of removable dentures distorted speech production was detected in 25% (pk=0.008) cases and in patients with inappropriate functional quality of the prosthesis - in 40% (pkdentures functional value were satisfied with their speech performance in 96% (pk=0.674), in the group with inappropriate dentures functional value only 59% (premovable dentures depends on the patient's individual adaptation capacity, prosthetic design and functional value. Thus statistically significant correlation between removable partial dentures functional value, duration of usage and the degree of patients' phonetic adaptation (p<0.001) may be considered to be confirmed.

Computational bone remodelling simulations and comparisons with DEXA results.

Science.gov (United States)

Turner, A W L; Gillies, R M; Sekel, R; Morris, P; Bruce, W; Walsh, W R

2005-07-01

Femoral periprosthetic bone loss following total hip replacement is often associated with stress shielding. Extensive bone resorption may lead to implant or bone failure and complicate revision surgery. In this study, an existing strain-adaptive bone remodelling theory was modified and combined with anatomic three-dimensional finite element models to predict alterations in periprosthetic apparent density. The theory incorporated an equivalent strain stimulus and joint and muscle forces from 45% of the gait cycle. Remodelling was simulated for three femoral components with different design philosophies: cobalt-chrome alloy, two-thirds proximally coated; titanium alloy, one-third proximally coated; and a composite of cobalt-chrome surrounded by polyaryletherketone, fully coated. Theoretical bone density changes correlated significantly with clinical densitometry measurements (DEXA) after 2 years across the Gruen zones (R2>0.67, p<0.02), with average differences of less than 5.4%. The results suggest that a large proportion of adaptive bone remodelling changes seen clinically with these implants may be explained by a consistent theory incorporating a purely mechanical stimulus. This theory could be applied to pre-clinical testing of new implants, investigation of design modifications, and patient-specific implant selection.

Shared human-chimpanzee pattern of perinatal femoral shaft morphology and its implications for the evolution of hominin locomotor adaptations.

Directory of Open Access Journals (Sweden)

Naoki Morimoto

Full Text Available Acquisition of bipedality is a hallmark of human evolution. How bipedality evolved from great ape-like locomotor behaviors, however, is still highly debated. This is mainly because it is difficult to infer locomotor function, and even more so locomotor kinematics, from fossil hominin long bones. Structure-function relationships are complex, as long bone morphology reflects phyletic history, developmental programs, and loading history during an individual's lifetime. Here we discriminate between these factors by investigating the morphology of long bones in fetal and neonate great apes and humans, before the onset of locomotion.Comparative morphometric analysis of the femoral diaphysis indicates that its morphology reflects phyletic relationships between hominoid taxa to a greater extent than taxon-specific locomotor adaptations. Diaphyseal morphology in humans and chimpanzees exhibits several shared-derived features, despite substantial differences in locomotor adaptations. Orangutan and gorilla morphologies are largely similar, and likely represent the primitive hominoid state.These findings are compatible with two possible evolutionary scenarios. Diaphyseal morphology may reflect retained adaptive traits of ancestral taxa, hence human-chimpanzee shared-derived features may be indicative of the locomotor behavior of our last common ancestor. Alternatively, diaphyseal morphology might reflect evolution by genetic drift (neutral evolution rather than selection, and might thus be more informative about phyletic relationships between taxa than about locomotor adaptations. Both scenarios are consistent with the hypothesis that knuckle-walking in chimpanzees and gorillas resulted from convergent evolution, and that the evolution of human bipedality is unrelated to extant great ape locomotor specializations.

A coupled mechano-biochemical model for bone adaptation

Czech Academy of Sciences Publication Activity Database

Klika, Václav; Pérez, M. A.; García-Aznar, J. M.; Maršík, F.; Doblaré, M.

2014-01-01

Roč. 69, 6-7 (2014), s. 1383-1429 ISSN 0303-6812 Institutional support: RVO:61388998 Keywords : mechano-biochemical model * bone remodelling * BMU Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2014 http://link.springer.com/article/10.1007%2Fs00285-013-0736-9

[Adapted physical activity in the prevention and therapy of osteoporosis].

Science.gov (United States)

Bosković, Ksenija; Gava, Branka Protić; Grajić, Mirko; Madić, Dejan; Obradović, Borislav; Todorović, Snezana Tomasević

2013-01-01

Osteoporosis, a disease characterized by the progressive loss of bone tissue, is one of the most common complications of aging. According to some calculations, there were 25% of women and 4% of men older than 50 years with osteoporosis in the world in 2010. It is assumed that the number of patients with osteoporosis will increase by 30% in every 10 years in the 21st century. There are many reasons for that: the world's population is growing older, diet is getting poorer in vitamins and minerals and physical activity is decreasing. THE QUALITY AND QUANTITY OF BONE TISSUE: Developing bones are much more responsive to mechanical loading and physical activity than mature bones. This suggests that training in early childhood may be an important factor in the prevention of osteoporosis in later life. It is important to note that the quality of bone achieved by training at younger age cannot be maintained permanently if it is not supported by physical activity later in life. Adapted physical activity represents physical activity individually tailored according to the psychosomatic capabilities of a person and the goal to be achieved. It can be applied at any age in order to maintain strong bones and reduce the risk of fracture. Adapted physical activity is different for men and women, for different age, as well as for the individuals. Aerobic exercises, which lead to an acceleration of breathing, increased heart rate and mild perspiration, as well as resistance exercises and exercises against resistance done by stretching elastic bands, for hands, legs and torso have been proven to increase bone density and improve bone strength. Coordination and balance exercises are important in an individual workout program. An explanation of the action of adapted physical activity is the basis for the theory of control and modulation of bone loss, muscle strength, coordination and balance. Physical activity is very effective in reducing sclerostin, which is known to inhibit bone

Bone indicators of grasping hands in lizards

Directory of Open Access Journals (Sweden)

Gabriela Fontanarrosa

2016-05-01

Full Text Available Grasping is one of a few adaptive mechanisms that, in conjunction with clinging, hooking, arm swinging, adhering, and flying, allowed for incursion into the arboreal eco-space. Little research has been done that addresses grasping as an enhanced manual ability in non-mammalian tetrapods, with the exception of studies comparing the anatomy of muscle and tendon structure. Previous studies showed that grasping abilities allow exploitation for narrow branch habitats and that this adaptation has clear osteological consequences. The objective of this work is to ascertain the existence of morphometric descriptors in the hand skeleton of lizards related to grasping functionality. A morphological matrix was constructed using 51 morphometric variables in 278 specimens, from 24 genera and 13 families of Squamata. To reduce the dimensions of the dataset and to organize the original variables into a simpler system, three PCAs (Principal Component Analyses were performed using the subsets of (1 carpal variables, (2 metacarpal variables, and (3 phalanges variables. The variables that demonstrated the most significant contributions to the construction of the PCA synthetic variables were then used in subsequent analyses. To explore which morphological variables better explain the variations in the functional setting, we ran Generalized Linear Models for the three different sets. This method allows us to model the morphology that enables a particular functional trait. Grasping was considered the only response variable, taking the value of 0 or 1, while the original variables retained by the PCAs were considered predictor variables. Our analyses yielded six variables associated with grasping abilities: two belong to the carpal bones, two belong to the metacarpals and two belong to the phalanges. Grasping in lizards can be performed with hands exhibiting at least two different independently originated combinations of bones. The first is a combination of a highly

Cosmetic and functional reconstruction achieved using a split myofascial bone flap for pterional craniotomy. Technical note.

Science.gov (United States)

Matsumoto, K; Akagi, K; Abekura, M; Ohkawa, M; Tasaki, O; Tomishima, T

2001-04-01

Cosmetic deformities that appear following pterional craniotomy are usually caused by temporal muscle atrophy, injury to the frontotemporal branch of the facial nerve, or bone pits in the craniotomy line. To resolve these problems during pterional craniotomy, an alternative method was developed in which a split myofascial bone flap and a free bone flap are used. The authors have used this method in the treatment of 40 patients over the last 3 years. Excellent cosmetic and functional results have been obtained. This method can provide wide exposure similar to that achieved using Yaşargil's interfascial pterional craniotomy, without limiting the operative field with a bulky temporal muscle flap.

Extracting neuronal functional network dynamics via adaptive Granger causality analysis.

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Sheikhattar, Alireza; Miran, Sina; Liu, Ji; Fritz, Jonathan B; Shamma, Shihab A; Kanold, Patrick O; Babadi, Behtash

2018-04-24

Quantifying the functional relations between the nodes in a network based on local observations is a key challenge in studying complex systems. Most existing time series analysis techniques for this purpose provide static estimates of the network properties, pertain to stationary Gaussian data, or do not take into account the ubiquitous sparsity in the underlying functional networks. When applied to spike recordings from neuronal ensembles undergoing rapid task-dependent dynamics, they thus hinder a precise statistical characterization of the dynamic neuronal functional networks underlying adaptive behavior. We develop a dynamic estimation and inference paradigm for extracting functional neuronal network dynamics in the sense of Granger, by integrating techniques from adaptive filtering, compressed sensing, point process theory, and high-dimensional statistics. We demonstrate the utility of our proposed paradigm through theoretical analysis, algorithm development, and application to synthetic and real data. Application of our techniques to two-photon Ca 2+ imaging experiments from the mouse auditory cortex reveals unique features of the functional neuronal network structures underlying spontaneous activity at unprecedented spatiotemporal resolution. Our analysis of simultaneous recordings from the ferret auditory and prefrontal cortical areas suggests evidence for the role of rapid top-down and bottom-up functional dynamics across these areas involved in robust attentive behavior.

Adaptive filters and internal models: multilevel description of cerebellar function.

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Porrill, John; Dean, Paul; Anderson, Sean R

2013-11-01

Cerebellar function is increasingly discussed in terms of engineering schemes for motor control and signal processing that involve internal models. To address the relation between the cerebellum and internal models, we adopt the chip metaphor that has been used to represent the combination of a homogeneous cerebellar cortical microcircuit with individual microzones having unique external connections. This metaphor indicates that identifying the function of a particular cerebellar chip requires knowledge of both the general microcircuit algorithm and the chip's individual connections. Here we use a popular candidate algorithm as embodied in the adaptive filter, which learns to decorrelate its inputs from a reference ('teaching', 'error') signal. This algorithm is computationally powerful enough to be used in a very wide variety of engineering applications. However, the crucial issue is whether the external connectivity required by such applications can be implemented biologically. We argue that some applications appear to be in principle biologically implausible: these include the Smith predictor and Kalman filter (for state estimation), and the feedback-error-learning scheme for adaptive inverse control. However, even for plausible schemes, such as forward models for noise cancellation and novelty-detection, and the recurrent architecture for adaptive inverse control, there is unlikely to be a simple mapping between microzone function and internal model structure. This initial analysis suggests that cerebellar involvement in particular behaviours is therefore unlikely to have a neat classification into categories such as 'forward model'. It is more likely that cerebellar microzones learn a task-specific adaptive-filter operation which combines a number of signal-processing roles. Copyright © 2012 Elsevier Ltd. All rights reserved.

Free Software Development. 4. Client-Server Implementation of Bone Age Assessment Calculations

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Sorana Daniela BOLBOACĂ

2003-03-01

Full Text Available In pediatrics, bone age also called skeletal maturity, an expression of biological maturity of a child, is an important quantitative measure for the clinical diagnosis of endocrinological problems and growth disorders. The present paper discusses a Java script implementation of Tanner-Whitehouse Method on computer, with complete graphical interface that include pictures and explanations for every bone. The program allows to select a stage (from a set of 7 or 8 stages for every bone (from a set of 20 bones, and also allow user to input some specific data such as natural age, sex, place of residence. Based on TW2 reported values, selected and input data, the program compute the bone age. Java script functions and objects were used in order to make an efficient and adaptive program. Note that in classic way, the program implementation it requires more than 160 groups of instructions only for user interface design. Using of dynamic creation of page, the program became smaller and efficient. The program was tested and put on a web server to serve for directly testing via http service and from where can also be download and runes from a personal computer without internet connection: http://vl.academicdirect.ro/medical_informatics/bone_age/v1.0/

Graft-versus-host reaction and immune function. III. Functional pre-T cells in the bone marrow of graft-versus-host-reactive mice displaying T cell immunodeficiency

International Nuclear Information System (INIS)

Seddik, M.; Seemayer, T.A.; Lapp, W.S.

1986-01-01

Studies were performed to determine whether pre-T cells develop normally in the bone marrow of mice displaying thymic dysplasia and T cell immunodeficiency as a consequence of a graft-versus-host (GVH) reaction. GVH reactions were induced in CBAxAF1 mice by the injection of A strain lymphoid cells. To test for the presence of pre-T cells in GVH-reactive mice, bone marrow from GVH-reactive mice (GVHBM) was injected into irradiated syngeneic F1 mice and 30-40 days later thymic morphology and function were studied. Morphology studies showed nearly normal thymic architectural restoration; moreover, such glands contained normal numbers of Thy-1-positive cells. Functional pre-T cells were evaluated by transferring thymocytes from the irradiated GVHBM-reconstituted mice into T-cell-deprived mice. These thymocytes reconstituted allograft reactivity, T helper cell function and Con A and PHA mitogen responses of T-cell-deprived mice. These results suggest that the pre-T cell population in the bone marrow is not affected by the GVH reaction. Therefore, the T cell immunodeficiency associated with the GVH reaction is not due to a deficiency of pre-T cells in the bone marrow but is more likely associated with GVH-induced thymic dysplasia

Carbon nanotubes functionalized with sodium hyaluronate restore bone repair in diabetic rat sockets.

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Sá, M A; Andrade, V B; Mendes, R M; Caliari, M V; Ladeira, L O; Silva, E E; Silva, G A B; Corrêa-Júnior, J D; Ferreira, A J

2013-07-01

We evaluated the effects of sodium hyaluronate (HY) and carbon nanotubes functionalized with HY (HY-CNT) on bone repair in the tooth sockets of diabetic rats. Diabetes was induced by streptozotocin (50 mg kg(-1) i.v.), and the sockets were divided into normal control, diabetic control, diabetic treated with HY (1%), and diabetic treated with HY-CNT (100 μg ml(-1)) groups. The sockets were analyzed according to the percentage of bone formation and the number of cell nuclei. The percentage of bone trabeculae was lower in diabetic control animals (11.16 ± 5.10% vs 41.92 ± 6.34% in normal animals) after 14 days. Treating diabetic animals with HY or HY-CNT significantly increased the percentage of neoformed trabeculae (HY: 29.43 ± 3.29%; HY-CNT: 36.90 ± 3.07%). Moreover, the sockets of diabetic animals had an increased number of cell nuclei and HY or HY-CNT reduced this parameter. Our results indicate that HY and HY-CNT restore bone repair in the tooth sockets of diabetic rats, suggesting that these biomaterials are potential adjuvant therapies for the management of diabetes. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Suppressed bone remodeling in black bears conserves energy and bone mass during hibernation.

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McGee-Lawrence, Meghan; Buckendahl, Patricia; Carpenter, Caren; Henriksen, Kim; Vaughan, Michael; Donahue, Seth

2015-07-01

Decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. Black bears, however, are physically inactive for up to 6 months annually during hibernation without losing cortical or trabecular bone mass. Bears have been shown to preserve trabecular bone volume and architectural parameters and cortical bone strength, porosity and geometrical properties during hibernation. The mechanisms that prevent disuse osteoporosis in bears are unclear as previous studies using histological and serum markers of bone remodeling show conflicting results. However, previous studies used serum markers of bone remodeling that are known to accumulate with decreased renal function, which bears have during hibernation. Therefore, we measured serum bone remodeling markers (BSALP and TRACP) that do not accumulate with decreased renal function, in addition to the concentrations of serum calcium and hormones involved in regulating bone remodeling in hibernating and active bears. Bone resorption and formation markers were decreased during hibernation compared with when bears were physically active, and these findings were supported by histomorphometric analyses of bone biopsies. The serum concentration of cocaine and amphetamine regulated transcript (CART), a hormone known to reduce bone resorption, was 15-fold higher during hibernation. Serum calcium concentration was unchanged between hibernation and non-hibernation seasons. Suppressed and balanced bone resorption and formation in hibernating bears contributes to energy conservation, eucalcemia and the preservation of bone mass and strength, allowing bears to survive prolonged periods of extreme environmental conditions, nutritional deprivation and anuria. © 2015. Published by The Company of Biologists Ltd.

Brazilian Portuguese transcultural adaptation of Barkley Deficits in Executive Functioning Scale (BDEFS

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Victor Polignano Godoy

2015-12-01

Full Text Available Abstract Background Considering the importance of Executive Functions to clinical and nonclinical situations, Barkley proposed a new theory of executive functioning based on an evolutionary neuropsychological perspective and clinical research using large samples of clinical and community identified adults and children as well as children with ADHD followed to adulthood. Objective The present study aims to adapt the Barkley Deficits in Executive Functions Scales (BDEFS to Brazilian Portuguese and also assess its construct validity in a sample of normal Brazilian adults. Methods The original version of scale was adapted to Brazilian Portuguese according to the guideline from the ISPOR Task Force. To assess the semantic equivalence between the original and adapted version, both of them were applied into a sample of 25 Brazilian bilingual adults. Finally, 60 Brazilian adults completed the BDEFS and the Brazilian versions of Barratt Impulsiveness Scale (BIS-11 and Adult Self-Report Scale (ASRS-18 to assess convergent validity. Results The BDEFS Brazilian Portuguese version has semantic correspondence with the original version indicating that the adaptation procedure was successful. The BDEFS correlated significantly with the impulsivity and attention scores from the BIS-11 and ASRS-18 supporting its construct validity. Cronbach’s alpha (α = 0.961 indicated that the BDEFS translated version has satisfactory internal consistency. Discussion Together, these findings indicate the successful adaptation of the BDEFS to Brazilian Portuguese and support its utility in that population.

Beyond Emotion Regulation: Emotion Utilization and Adaptive Functioning

OpenAIRE

Izard, Carroll; Stark, Kevin; Trentacosta, Christopher; Schultz, David

2008-01-01

Recent research indicates that emotionality, emotion information processing, emotion knowledge, and discrete emotion experiences may influence and interact with emotion utilization, that is, the effective use of the inherently adaptive and motivational functions of emotions. Strategies individuals learn for emotion modulation and emotion utilization become stabilized in emerging affective-cognitive structures, or emotion schemas. In these emotion schemas, the feeling/motivational component of...

P2X7 receptor regulates osteoclast function and bone loss in a mouse model of osteoporosis.

Science.gov (United States)

Wang, Ning; Agrawal, Ankita; Jørgensen, Niklas Rye; Gartland, Alison

2018-02-22

Post-menopausal osteoporosis is a condition that affects millions worldwide and places a huge socio-economic burden on society. Previous research has shown an association of loss of function SNPs in the gene for the purinergic receptor P2X7R with low bone mineral density, increased rates of bone loss and vertebral fractures in post-menopausal women. In this study we use a mouse model of oestrogen deficiency-induced bone loss and the BALB/cJ P2X7R -/- to show that absence of the P2X7R resulted in increased bone loss. Osteoclast precursors were isolated from both BALB/cJ P2X7R -/- and BALB/cJ P2X7R +/+ mice and then cultured in vitro to form mature resorbing osteoclasts. The BALB/cJ P2X7R -/- derived precursors generated slightly more osteoclasts but with a significant reduction in the amount of resorption per osteoclast. Furthermore, when using modified culture conditions osteoclast activity was additionally increased in the absence of the P2X7R suggest that P2X7R may regulate the lifespan and activity of osteoclasts. Finally using mechanical loading as an anabolic stimulus for bone formation, we demonstrated that the increased oestrogen-deficient bone loss could be rescued, even in the absence of P2X7R. This study paves the way for clinical intervention for women with post-menopausal osteoporosis and P2XR7 loss of function polymorphisms.

Cultural adaptation of a pediatric functional assessment for rehabilitation outcomes research.

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Arestad, Kristen E; MacPhee, David; Lim, Chun Y; Khetani, Mary A

2017-09-15

Significant racial and ethnic health care disparities experienced by Hispanic children with special health care needs (CSHCN) create barriers to enacting culturally competent rehabilitation services. One way to minimize the impact of disparities in rehabilitation is to equip practitioners with culturally relevant functional assessments to accurately determine service needs. Current approaches to culturally adapting assessments have three major limitations: use of inconsistent translation processes; current processes assess for some, but not all, elements of cultural equivalence; and limited evidence to guide decision making about whether to undertake cultural adaptation with and without language translation. The aims of this observational study are (a) to examine similarities and differences of culturally adapting a pediatric functional assessment with and without language translation, and (b) to examine the feasibility of cultural adaptation processes. The Young Children's Participation and Environment Measure (YC-PEM), a pediatric functional assessment, underwent cultural adaptation (i.e., language translation and cognitive testing) to establish Spanish and English pilot versions for use by caregivers of young CSHCN of Mexican descent. Following language translation to develop a Spanish YC-PEM pilot version, 7 caregivers (4 Spanish-speaking; 3 English-speaking) completed cognitive testing to inform decisions regarding content revisions to English and Spanish YC-PEM versions. Participant responses were content coded to established cultural equivalencies. Coded data were summed to draw comparisons on the number of revisions needed to achieve cultural equivalence between the two versions. Feasibility was assessed according to process data and data quality. Results suggest more revisions are required to achieve cultural equivalence for the translated (Spanish) version of the YC-PEM. However, issues around how the participation outcome is conceptualized were

Osteoinductive peptide-functionalized nanofibers with highly ordered structure as biomimetic scaffolds for bone tissue engineering

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Gao X

2015-11-01

Full Text Available Xiang Gao,1,2,* Xiaohong Zhang,3,* Jinlin Song,1,2 Xiao Xu,4 Anxiu Xu,1 Mengke Wang,4 Bingwu Xie,1 Enyi Huang,2 Feng Deng,1,2 Shicheng Wei2–41College of Stomatology, 2Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing Medical University, Chongqing, 3Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, 4Department of Oral and Maxillofacial Surgery, Laboratory of Interdisciplinary Studies, Peking University School and Hospital of Stomatology, Beijing, People’s Republic of China*These authors contributed equally to this workAbstract: The construction of functional biomimetic scaffolds that recapitulate the topographical and biochemical features of bone tissue extracellular matrix is now of topical interest in bone tissue engineering. In this study, a novel surface-functionalized electrospun polycaprolactone (PCL nanofiber scaffold with highly ordered structure was developed to simulate the critical features of native bone tissue via a single step of catechol chemistry. Specially, under slightly alkaline aqueous solution, polydopamine (pDA was coated on the surface of aligned PCL nanofibers after electrospinning, followed by covalent immobilization of bone morphogenetic protein-7-derived peptides onto the pDA-coated nanofiber surface. Contact angle measurement, Raman spectroscopy, and X-ray photoelectron spectroscopy confirmed the presence of pDA and peptides on PCL nanofiber surface. Our results demonstrated that surface modification with osteoinductive peptides could improve cytocompatibility of nanofibers in terms of cell adhesion, spreading, and proliferation. Most importantly, Alizarin Red S staining, quantitative real-time polymerase chain reaction, immunostaining, and Western blot revealed that human mesenchymal stem cells cultured on aligned nanofibers with osteoinductive peptides exhibited enhanced osteogenic differentiation potential than

Biochemical Interaction Between Muscle and Bone: A Physiological Reality?

NARCIS (Netherlands)

Jaspers, R.T.; Bravenboer, N.

2014-01-01

In elderly with a sedentary lifestyle, often suffering from sarcopenia to osteopenia, a training intervention could be an effective countermeasure for bone as well as muscle. Both bone and muscle adapt their mass and strength in response to mechanical loading in part via similar signaling pathways.

Craniovascular traits in anthropology and evolution: from bones to vessels.

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Píšová, Hana; Rangel de Lázaro, Gizéh; Velemínský, Petr; Bruner, Emiliano

2017-12-30

Many aspects of human biology can be reconstructed from skeletal and fossil remains. The endocranial vasculature runs through cerebral, connective, and bone elements, where it is influenced by the functional and structural relationships among these different components of the endocranial system. The imprints and traces of these vessels can be used to analyze the craniovascular features of extinct species or historical samples. These traits can supply information about evolutionary adaptation, the mutual relationships between and within populations, and individual life history. In particular, bioarchaeology considers individual morphological variants as indicators of temporal and spatial relatedness and population structure, whereas paleoanthropology studies functional aspects to consider evolutionary changes and phylogenetic processes. Forensic science can investigate the cause of death associated with craniovascular pathologies by relying on morphological variations for individual identification. In this review, we consider the imprints of middle meningeal vessels, dural venous sinuses, emissary veins, and diploic veins. We summarize the most relevant morphological and functional information about craniovascular features and their applications in retrospective anthropological and medical fields, as well as describing the methodological issues associated with the sampling and quantitative evaluation of these elusive vascular remnants imprinted in the cranial bones.

In vivo functional and morphological characterization of bone and striated muscle microcirculation in NSG mice.

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Haider Mussawy

Full Text Available Organ-specific microcirculation plays a central role in tumor growth, tumor cell homing, tissue engineering, and wound healing. Mouse models are widely used to study these processes; however, these mouse strains often possess unique microhemodynamic parameters, making it difficult to directly compare experiments. The full functional characterization of bone and striated muscle microcirculatory parameters in non-obese diabetic-severe combined immunodeficiency/y-chain; NOD-Prkds IL2rg (NSG mice has not yet been reported. Here, we established either a dorsal skinfold chamber or femur window in NSG mice (n = 23, allowing direct analysis of microcirculatory parameters in vivo by intravital fluorescence microscopy at 7, 14, 21, and 28 days after chamber preparation. Organ-specific differences were observed. Bone had a significantly lower vessel density but a higher vessel diameter than striated muscle. Bone also showed higher effective vascular permeability than striated muscle. The centerline velocity values were similar in the femur window and dorsal skinfold chamber, with a higher volumetric blood flow in bone. Interestingly, bone and striated muscle showed similar tissue perfusion rates. Knowledge of physiological microhemodynamic values of bone and striated muscle in NSG mice makes it possible to analyze pathophysiological processes at these anatomic sites, such as tumor growth, tumor metastasis, and tumor microcirculation, as well as the response to therapeutic agents.

Amine-Functionalized Mesoporous Silica Nanoparticles: A New Nanoantibiotic for Bone Infection Treatment

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Pedraza Daniel

2018-01-01

Full Text Available This manuscript reports an effective new alternative for the management of bone infection by the development of an antibiotic nanocarrier able to penetrate bacterial biofilm, thus enhancing antimicrobial effectiveness. This nanosystem, also denoted as “nanoantibiotic”, consists in mesoporous silica nanoparticles (MSNs loaded with an antimicrobial agent (levofloxacin, LEVO and externally functionalized with N-(2-aminoethyl-3- aminopropyltrimethoxysilane (DAMO as targeting agent. This amine functionalization provides MSNs of positive charges, which improves the affinity towards the negatively charged bacteria wall and biofilm. Physical and chemical properties of the nanoantibiotic were studied using different characterization techniques, including Xray diffraction (XRD, transmission electron microscopy (TEM, N2 adsorption porosimetry, elemental chemical analysis, dynamic light scattering (DLS, zeta (ζ-potential and solid-state nuclear magnetic resonance (NMR. “In vial” LEVO release profiles and the in vitro antimicrobial effectiveness of the different released doses were investigated. The efficacy of the nanoantibiotic against a S. aureus biofilm was also determined, showing the practically total destruction of the biofilm due to the high penetration ability of the developed nanosystem. These findings open up promising expectations in the field of bone infection treatment.

Amine-Functionalized Mesoporous Silica Nanoparticles: A New Nanoantibiotic for Bone Infection Treatment

Directory of Open Access Journals (Sweden)

Pedraza Daniel

2017-12-01

Full Text Available This manuscript reports an effective new alternative for the management of bone infection by the development of an antibiotic nanocarrier able to penetrate bacterial biofilm, thus enhancing antimicrobial effectiveness. This nanosystem, also denoted as “nanoantibiotic”, consists in mesoporous silica nanoparticles (MSNs loaded with an antimicrobial agent (levofloxacin, LEVO and externally functionalized with N-(2-aminoethyl-3-aminopropyltrimethoxysilane (DAMO as targeting agent. This amine functionalization provides MSNs of positive charges, which improves the affinity towards the negatively charged bacteria wall and biofilm. Physical and chemical properties of the nanoantibiotic were studied using different characterization techniques, including Xray diffraction (XRD, transmission electron microscopy (TEM, N2 adsorption porosimetry, elemental chemical analysis, dynamic light scattering (DLS, zeta (ζ -potential and solid-state nuclear magnetic resonance (NMR. “In vial” LEVO release profiles and the in vitro antimicrobial effectiveness of the different released doses were investigated. The efficacy of the nanoantibiotic against a S. aureus biofilm was also determined, showing the practically total destruction of the biofilm due to the high penetration ability of the developed nanosystem. These findings open up promising expectations in the field of bone infection treatment.

Longitudinal trajectories of intellectual and adaptive functioning in adolescents and adults with Williams syndrome.

Science.gov (United States)

Fisher, M H; Lense, M D; Dykens, E M

2016-10-01

Williams syndrome (WS) is associated with a distinct cognitive-behavioural phenotype including mild to moderate intellectual disability, visual-spatial deficits, hypersociability, inattention and anxiety. Researchers typically characterise samples of individuals with WS by their intellectual functioning and adaptive behaviour. Because of the low prevalence of the syndrome, researchers often include participants with WS across a broad age range throughout childhood and adulthood and assume participants demonstrate consistent cognitive development across ages. Indeed, IQ scores are generally stable for children and adolescents with WS, although there are significant individual differences. It is less clear whether this pattern of stable intellectual ability persists into adulthood. Furthermore, while adaptive behaviour is an important indicator of an individual's ability to apply their conceptual skills to everyday functioning, conflicting findings on the trajectories of adaptive behaviour in adolescents and adults with WS have been reported. The current study examined longitudinal profiles of cognitive and adaptive functioning in adolescents and adults with WS. To examine cognitive functioning, participants included 52 individuals with WS (51.9% men) who were assessed with the Kaufman Brief Intelligence Test, 2nd edition (KBIT-2) between two and seven times. At their first assessment, participants had a mean age of 25.4 years (SD = 8.4), ranging in age from 14.2 to 48.9 years. To assess adaptive behaviour, participants included a subset of 28 individuals with WS whose parents completed the Vineland Adaptive Behavior Scale, 2nd edition (VABS-II) between two and five times. At their initial administration, participants ranged from 17.1-40.2 years of age, with a mean age of 26.5 years (SD = 7.3). A series of multilevel models were used to examine changes in KBIT-2 Composite IQ, Verbal IQ and Nonverbal IQ standard scores over time, as well as the

Survival, Function, and Complications of Oral Implants Placed in Bone Flaps in Jaw Rehabilitation: A Systematic Review.

Science.gov (United States)

Zhang, Lei; Ding, Qian; Liu, Cunrui; Sun, Yannan; Xie, Qiufei; Zhou, Yongsheng

2016-01-01

This systematic review attempted to determine the survival rate of implants placed in bone flaps in jaw rehabilitation and the functional gains and the most common complications related to these implants. An electronic search was undertaken of PubMed, EMBASE, and CNKI records from 1990 through July 2014. Two independent examiners read the titles and abstracts of the results to identify studies that met the inclusion criteria. Subsequently, the reference lists of the selected publications were hand searched. Descriptive statistics were used to report all data related to the survival rate of implants placed in bone flaps in jaw rehabilitation, the functional gains, and complications. A total of 20 studies were included for systematic review without repetition. The mean follow-up time after implant placement ranged from 1.75 to 9.5 years. Within the limitations of available studies, the survival rate of implants placed in bone flaps in jaw rehabilitation ranged from 82.4% to 100%. Of the 20 included studies, 15 reported a survival rate higher than 90%. The cumulative survival rate was 93.2%, with the longest follow-up time being 12.9 years. The most common complications related to these implants were peri-implant bone resorption or peri-implant inflammation, and peri-implant soft tissue proliferation. The main factors associated with the survival rate of implants in bone flaps were reported as time of implant placement and radiotherapy. Despite some persistent soft tissue problems and implant loss, most patients reached a satisfactory functional and esthetic outcome, as evaluated by clinical examination and subjectively by the patients at interview. Implant-supported dental prosthetic rehabilitation in reconstructed jaws improved the quality of life in terms of speech, nutrition, oral competence, and facial appearance. Placement of implants in bone flaps in jaw rehabilitation was demonstrated to be a reliable technique with a high survival rate. Multicentered

Towards a cell-based mechanostat theory of bone: the need to account for osteocyte desensitisation and osteocyte replacement.

Science.gov (United States)

Lerebours, Chloé; Buenzli, Pascal R

2016-09-06

Bone׳s mechanostat theory describes the adaptation of bone tissues to their mechanical environment. Many experiments have investigated and observed such structural adaptation. However, there is still much uncertainty about how to define the reference mechanical state at which bone structure is adapted and stable. Clinical and experimental observations show that this reference state varies both in space and in time, over a wide range of timescales. We propose here an osteocyte-based mechanostat theory that encodes the mechanical reference state in osteocyte properties. This theory assumes that osteocytes are initially formed adapted to their current local mechanical environment through modulation of their properties. We distinguish two main types of physiological processes by which osteocytes subsequently modify the reference mechanical state at different timescales. One is cell desensitisation, which occurs rapidly and reversibly during an osteocyte׳s lifetime. The other is the replacement of osteocytes during bone remodelling, which occurs over the long timescales of bone turnover. The novelty of this theory is to propose that long-lasting morphological and genotypic osteocyte properties provide a material basis for a long-term mechanical memory of bone that is gradually reset by bone remodelling. We test this theory by simulating long-term mechanical disuse (modelling spinal cord injury), and short-term mechanical loadings (modelling daily exercises) with a mathematical model. The consideration of osteocyte desensitisation and of osteocyte replacement by remodelling is able to capture a number of phenomena and timescales observed during the mechanical adaptation of bone tissues, lending support to this theory. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preschooler Sleep Patterns Related to Cognitive and Adaptive Functioning

Science.gov (United States)

Keefe-Cooperman, Kathleen; Brady-Amoon, Peggy

2014-01-01

Research Findings: Preschoolers' sleep patterns were examined related to cognitive and adaptive functioning. The sample consisted of 874 typically developing preschool children with a mean age of 40.01 months. Parent/caregiver reports of children's sleep pattern factors, Stanford-Binet 5 intelligence scale scores, and Behavior Assessment System…

Functional Competencies for Adapting to the World of Work.

Science.gov (United States)

Selz, Nina; And Others

A study was conducted to determine who has the responsibility for teaching general occupational and consumer competencies--the home, the school, or the workplace. To answer this question, two national surveys on functional competencies in occupational adaptability and consumer economics were conducted. Competencies were first identified and then…

What expects orthopedic surgeon from bone scan?

International Nuclear Information System (INIS)

Sutter, B.; Cazenave, A.

2003-01-01

The isotope bone scan continues to be one of the 'lost widely performed nuclear medicine investigations. Beyond the common clinical indication like detection of skeletal metastases, bone scan use is increasing in benign orthopedic conditions, and after orthopedic surgery, despite development of new investigations modalities (US, MRI). Three (or two) phase bone scintigraphy, Single Photon Emission Computer Tomography have increased its value and provided new clinical roles. This review emphasizes through some practical clinical examples how to increase diagnostic value of the method and to offer an adapted response to the orthopedic surgeon's attempts. (author)

The feasibility of utilizing pseudo CT-data for online MRI based treatment plan adaptation for a stereotactic radiotherapy treatment of spinal bone metastases

International Nuclear Information System (INIS)

Hoogcarspel, Stan J; Van der Velden, Joanne M; Lagendijk, Jan J W; Van Vulpen, Marco; Raaymakers, Bas W

2014-01-01

The purpose of this study was to investigate what pseudo-CT (pCT) strategy is sufficient for online MRI based treatment plan adaptation of a stereotactic treatment for spinal bone metastases. For this purpose, the dosimetric accuracy of five increasingly complex pCT strategies was evaluated using the planning CT data of 20 patients suffering from spinal metastases. For each pCT, a treatment plan was developed and simulated on both the pCT and the original CT data of the patient. The two resulting dose distributions were compared using gamma analysis of 2%/2 mm. In this paper, a Gamma Pass Rate (GPR) of ⩾95% within the Target Volume (TV) was considered clinically acceptable. We additionally demonstrated in this paper the automatic generation of each investigated pCT strategy with the use of dedicated MRI data complemented with pre-treatment CT data of a patient in treatment position. The dosimetric accuracy of a pCT increases when additional bulk densities are utilized for a pCT. However, the dosimetric accuracy of even the most complex ‘bulk density’ pCT strategy used in this study had an average GPR of only 78% within the TV. However, if information on the heterogeneous electron density distribution within the affected vertebral body was available, a clinically acceptable 99% mean GPR was observed. All pCTs could successfully be generated using the MRI data in combination with the CT data of a patient in treatment position. The results presented in this study show that a simple ‘bulk density’ pseudo-CT strategy is not feasible for online MRI based treatment plan adaptation for spinal bone metastases. However, a clinically acceptable result is generated if the information on the heterogeneous electron density (ED) distribution within the affected vertebral bone is available. Therefore, any pCT strategy for this tumor site should include a method which can estimate the heterogeneous ED of the affected vertebral bone. (paper)

A comparative analysis of functional outcomes in adolescents and young adults with lower-extremity bone sarcoma.

Science.gov (United States)

Ginsberg, Jill P; Rai, Shesh N; Carlson, Claire A; Meadows, Anna T; Hinds, Pamela S; Spearing, Elena M; Zhang, Lijun; Callaway, Lulie; Neel, Michael D; Rao, Bhaskar N; Marchese, Victoria G

2007-12-01

Comparison of functional mobility and quality of life is performed in patients with lower-extremity bone sarcoma following either amputation, limb-sparing surgery, or rotationplasty with four different types of outcome measures: (1) an objective functional mobility measure that requires patients to physically perform specific tasks, functional mobility assessment (FMA); (2) a clinician administered tool, Musculoskeletal Tumor Society Scale (MSTS); (3) a patient questionnaire, Toronto Extremity Salvage Scale (TESS); and (4) a health-related quality of life (HRQL) measure, Short Form-36 version 2 (SF-36v.2). This is a prospective multi-site study including 91 patients with lower-extremity bone sarcoma following amputation, limb-sparing surgery, or rotationplasty. One of three physical therapists administered the quality of life measure (SF-36v.2) as well as a battery of functional measures (FMA, MSTS, and TESS). Differences between patients who had amputation, limb-sparing surgery, or rotationplasty were consistently demonstrated by the FMA. Patients with limb sparing femur surgery performed better than those patients with an above the knee amputation but similarly to a small number of rotationplasty patients. Several of the more conventional self-report measures were shown to not have the discriminative capabilities of the FMA in these cohorts. In adolescents with lower-extremity bone sarcoma, it may be advantageous to consider the use of a combination of outcome measures, including the FMA, for objective functional mobility assessment along with the TESS for a subjective measure of disability and the SF-36v.2 for a quality-of-life measure. 2007 Wiley-Liss, Inc

Gender-specific associations between physical functioning, bone quality and fracture risk in older people

NARCIS (Netherlands)

Furrer, R.; van Schoor, N.M.; de Haan, A.; Lips, P.; de Jongh, R.T.

2014-01-01

The aim of this study was to investigate which parameters of physical functioning are associated with bone quality and fracture risk and whether gender-specific differences exist within these associations. We studied 1,486 participants of the Longitudinal Aging Study Amsterdam. As measures of

Bone substitute biomaterials

CERN Document Server

Mallick, K

2014-01-01

Bone substitute biomaterials are fundamental to the biomedical sector, and have recently benefitted from extensive research and technological advances aimed at minimizing failure rates and reducing the need for further surgery. This book reviews these developments, with a particular focus on the desirable properties for bone substitute materials and their potential to encourage bone repair and regeneration. Part I covers the principles of bone substitute biomaterials for medical applications. One chapter reviews the quantification of bone mechanics at the whole-bone, micro-scale, and non-scale levels, while others discuss biomineralization, osteoductivization, materials to fill bone defects, and bioresorbable materials. Part II focuses on biomaterials as scaffolds and implants, including multi-functional scaffolds, bioceramics, and titanium-based foams. Finally, Part III reviews further materials with the potential to encourage bone repair and regeneration, including cartilage grafts, chitosan, inorganic poly...

Preservation of bone structure and function by Lithothamnion sp. derived minerals.

Science.gov (United States)

Aslam, Muhammad Nadeem; Bergin, Ingrid; Jepsen, Karl; Kreider, Jaclynn M; Graf, Kristin H; Naik, Madhav; Goldstein, Steven A; Varani, James

2013-12-01

Progressive bone mineral loss and increasing bone fragility are hallmarks of osteoporosis. A combination of minerals isolated from the red marine algae, Lithothamnion sp. was examined for ability to inhibit bone mineral loss in female mice maintained on either a standard rodent chow (control) diet or a high-fat western diet (HFWD) for 5, 12, and 18 months. At each time point, femora were subjected to μ-CT analysis and biomechanical testing. A subset of caudal vertebrae was also analyzed. Following this, individual elements were assessed in bones. Serum levels of the 5b isoform of tartrate-resistant acid phosphatase (TRAP) and procollagen type I propeptide (P1NP) were also measured. Trabecular bone loss occurred in both diets (evident as early as 5 months). Cortical bone increased through month 5 and then declined. Cortical bone loss was primarily in mice on the HFWD. Inclusion of the minerals in the diet reduced bone mineral loss in both diets and improved bone strength. Bone mineral density was also enhanced by these minerals. Of several cationic minerals known to be important to bone health, only strontium was significantly increased in bone tissue from animals fed the mineral diets, but the increase was large (5-10 fold). Serum levels of TRAP were consistently higher in mice receiving the minerals, but levels of P1NP were not. These data suggest that trace minerals derived from marine red algae may be used to prevent progressive bone mineral loss in conjunction with calcium. Mineral supplementation could find use as part of an osteoporosis-prevention strategy.

Adaptive radial basis function mesh deformation using data reduction

Science.gov (United States)

Gillebaart, T.; Blom, D. S.; van Zuijlen, A. H.; Bijl, H.

2016-09-01

Radial Basis Function (RBF) mesh deformation is one of the most robust mesh deformation methods available. Using the greedy (data reduction) method in combination with an explicit boundary correction, results in an efficient method as shown in literature. However, to ensure the method remains robust, two issues are addressed: 1) how to ensure that the set of control points remains an accurate representation of the geometry in time and 2) how to use/automate the explicit boundary correction, while ensuring a high mesh quality. In this paper, we propose an adaptive RBF mesh deformation method, which ensures the set of control points always represents the geometry/displacement up to a certain (user-specified) criteria, by keeping track of the boundary error throughout the simulation and re-selecting when needed. Opposed to the unit displacement and prescribed displacement selection methods, the adaptive method is more robust, user-independent and efficient, for the cases considered. Secondly, the analysis of a single high aspect ratio cell is used to formulate an equation for the correction radius needed, depending on the characteristics of the correction function used, maximum aspect ratio, minimum first cell height and boundary error. Based on the analysis two new radial basis correction functions are derived and proposed. This proposed automated procedure is verified while varying the correction function, Reynolds number (and thus first cell height and aspect ratio) and boundary error. Finally, the parallel efficiency is studied for the two adaptive methods, unit displacement and prescribed displacement for both the CPU as well as the memory formulation with a 2D oscillating and translating airfoil with oscillating flap, a 3D flexible locally deforming tube and deforming wind turbine blade. Generally, the memory formulation requires less work (due to the large amount of work required for evaluating RBF's), but the parallel efficiency reduces due to the limited

Optimizing Segmental Bone Regeneration Using Functionally Graded Scaffolds

Science.gov (United States)

2012-10-01

mechanical strength (130– 190 MPa).4 Cancellous bone accounts for the other 20% of the total bone mass and is highly porous (50%–90%), with *10% of the...bionanotechnology. Adv Mater 18, 1345, 2006. 96. Drury , J.L., and Mooney, D.J. Hydrogels for tissue engi- neering: scaffold design variables and applications. Bio

Neuropsychological presentation and adaptive skills in high-functioning adolescents with visual impairment: A preliminary investigation.

Science.gov (United States)

Greenaway, R; Pring, L; Schepers, A; Isaacs, D P; Dale, N J

2017-01-01

Studies in infants and young children with congenital visual impairment (VI) have indicated early developmental vulnerabilities, conversely research with older children and adults have highlighted areas of cognitive strength. A minimal amount is known, however, about the possible combination of strengths and weaknesses in adolescence, and this present study therefore aims to explore the neuropsychological presentation and adaptive behavior profile in high-functioning adolescents with congenital VI. Participants completed a battery of commonly used neuropsychological measures assessing memory, executive function, and attention. The measures utilized focused on auditory neuropsychological function, because only subtests that could be completed with auditory administration were suitable for this sample. Parents completed standardized measures of adaptive behavior, executive function, and social communication. Compared to aged-based norms for normal sight, adolescents with VI demonstrated strengths in aspects of working memory and verbal memory. Furthermore, performance across the neuropsychological battery was within or above the average range for the majority of the sample. In contrast, parent-report measures indicated areas of weakness in adaptive functioning, social communication, and behavioral executive functioning. Overall, this study provides preliminary evidence that relative to fully sighted peers, high-functioning adolescents with VI present with an uneven profile of cognitive and adaptive skills, which has important implications for assessment and intervention.

Monosodium urate monohydrate crystals inhibit osteoblast viability and function: implications for development of bone erosion in gout.

Science.gov (United States)

Chhana, Ashika; Callon, Karen E; Pool, Bregina; Naot, Dorit; Watson, Maureen; Gamble, Greg D; McQueen, Fiona M; Cornish, Jillian; Dalbeth, Nicola

2011-09-01

Bone erosion is a common manifestation of chronic tophaceous gout. To investigate the effects of monosodium urate monohydrate (MSU) crystals on osteoblast viability and function. The MTT assay and flow cytometry were used to assess osteoblast cell viability in the MC3T3-E1 and ST2 osteoblast-like cell lines, and primary rat and primary human osteoblasts cultured with MSU crystals. Quantitative real-time PCR and von Kossa stained mineralised bone formation assays were used to assess the effects of MSU crystals on osteoblast differentiation using MC3T3-E1 cells. The numbers of osteoblasts and bone lining cells were quantified in bone samples from patients with gout. MSU crystals rapidly reduced viability in all cell types in a dose-dependent manner. The inhibitory effect on cell viability was independent of crystal phagocytosis and was not influenced by differing crystal length or addition of serum. Long-term culture of MC3T3-E1 cells with MSU crystals showed a reduction in mineralisation and decreased mRNA expression of genes related to osteoblast differentiation such as Runx2, Sp7 (osterix), Ibsp (bone sialoprotein), and Bglap (osteocalcin). Fewer osteoblast and lining cells were present on bone directly adjacent to gouty tophus than bone unaffected by tophus in patients with gout. MSU crystals have profound inhibitory effects on osteoblast viability and differentiation. These data suggest that bone erosion in gout occurs at the tophus-bone interface through alteration of physiological bone turnover, with both excessive osteoclast formation, and reduced osteoblast differentiation from mesenchymal stem cells.

Anomalous brain functional connectivity contributing to poor adaptive behavior in Down syndrome.

Science.gov (United States)

Pujol, Jesus; del Hoyo, Laura; Blanco-Hinojo, Laura; de Sola, Susana; Macià, Dídac; Martínez-Vilavella, Gerard; Amor, Marta; Deus, Joan; Rodríguez, Joan; Farré, Magí; Dierssen, Mara; de la Torre, Rafael

2015-03-01

Research in Down syndrome has substantially progressed in the understanding of the effect of gene overexpression at the molecular level, but there is a paucity of information on the ultimate consequences on overall brain functional organization. We have assessed the brain functional status in Down syndrome using functional connectivity MRI. Resting-state whole-brain connectivity degree maps were generated in 20 Down syndrome individuals and 20 control subjects to identify sites showing anomalous synchrony with other areas. A subsequent region-of-interest mapping served to detail the anomalies and to assess their potential contribution to poor adaptive behavior. Down syndrome individuals showed higher regional connectivity in a ventral brain system involving the amygdala/anterior temporal region and the ventral aspect of both the anterior cingulate and frontal cortices. By contrast, lower functional connectivity was identified in dorsal executive networks involving dorsal prefrontal and anterior cingulate cortices and posterior insula. Both functional connectivity increases and decreases contributed to account for patient scoring on adaptive behavior related to communication skills. The data overall suggest a distinctive functional organization with system-specific anomalies associated with reduced adaptive efficiency. Opposite effects were identified on distinct frontal and anterior temporal structures and relative sparing of posterior brain areas, which is generally consistent with Down syndrome cognitive profile. Relevantly, measurable connectivity changes, as a marker of the brain functional anomaly, could have a role in the development of therapeutic strategies addressed to improve the quality of life in Down syndrome individuals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Functional Dual Adaptive Control with Recursive Gaussian Process Model

International Nuclear Information System (INIS)

Prüher, Jakub; Král, Ladislav

2015-01-01

The paper deals with dual adaptive control problem, where the functional uncertainties in the system description are modelled by a non-parametric Gaussian process regression model. Current approaches to adaptive control based on Gaussian process models are severely limited in their practical applicability, because the model is re-adjusted using all the currently available data, which keeps growing with every time step. We propose the use of recursive Gaussian process regression algorithm for significant reduction in computational requirements, thus bringing the Gaussian process-based adaptive controllers closer to their practical applicability. In this work, we design a bi-criterial dual controller based on recursive Gaussian process model for discrete-time stochastic dynamic systems given in an affine-in-control form. Using Monte Carlo simulations, we show that the proposed controller achieves comparable performance with the full Gaussian process-based controller in terms of control quality while keeping the computational demands bounded. (paper)

Nck adapter proteins: functional versatility in T cells

Directory of Open Access Journals (Sweden)

Janssen Ottmar

2009-02-01

Full Text Available Abstract Nck is a ubiquitously expressed adapter protein that is almost exclusively built of one SH2 domain and three SH3 domains. The two isoproteins of Nck are functionally redundant in many aspects and differ in only few amino acids that are mostly located in the linker regions between the interaction modules. Nck proteins connect receptor and non-receptor tyrosine kinases to the machinery of actin reorganisation. Thereby, Nck regulates activation-dependent processes during cell polarisation and migration and plays a crucial role in the signal transduction of a variety of receptors including for instance PDGF-, HGF-, VEGF- and Ephrin receptors. In most cases, the SH2 domain mediates binding to the phosphorylated receptor or associated phosphoproteins, while SH3 domain interactions lead to the formation of larger protein complexes. In T lymphocytes, Nck plays a pivotal role in the T cell receptor (TCR-induced reorganisation of the actin cytoskeleton and the formation of the immunological synapse. However, in this context, two different mechanisms and adapter complexes are discussed. In the first scenario, dependent on an activation-induced conformational change in the CD3ε subunits, a direct binding of Nck to components of the TCR/CD3 complex was shown. In the second scenario, Nck is recruited to the TCR complex via phosphorylated Slp76, another central constituent of the membrane proximal activation complex. Over the past years, a large number of putative Nck interactors have been identified in different cellular systems that point to diverse additional functions of the adapter protein, e.g. in the control of gene expression and proliferation.

Different evolutionary pathways underlie the morphology of wrist bones in hominoids.

Science.gov (United States)

Kivell, Tracy L; Barros, Anna P; Smaers, Jeroen B

2013-10-23

The hominoid wrist has been a focus of numerous morphological analyses that aim to better understand long-standing questions about the evolution of human and hominoid hand use. However, these same analyses also suggest various scenarios of complex and mosaic patterns of morphological evolution within the wrist and potentially multiple instances of homoplasy that would benefit from require formal analysis within a phylogenetic context.We identify morphological features that principally characterize primate - and, in particular, hominoid (apes, including humans) - wrist evolution and reveal the rate, process and evolutionary timing of patterns of morphological change on individual branches of the primate tree of life. Linear morphological variables of five wrist bones - the scaphoid, lunate, triquetrum, capitate and hamate - are analyzed in a diverse sample of extant hominoids (12 species, 332 specimens), Old World (8 species, 43 specimens) and New World (4 species, 26 specimens) monkeys, fossil Miocene apes (8 species, 20 specimens) and Plio-Pleistocene hominins (8 species, 18 specimens). Results reveal a combination of parallel and synapomorphic morphology within haplorrhines, and especially within hominoids, across individual wrist bones. Similar morphology of some wrist bones reflects locomotor behaviour shared between clades (scaphoid, triquetrum and capitate) while others (lunate and hamate) indicate clade-specific synapomorphic morphology. Overall, hominoids show increased variation in wrist bone morphology compared with other primate clades, supporting previous analyses, and demonstrate several occurrences of parallel evolution, particularly between orangutans and hylobatids, and among hominines (extant African apes, humans and fossil hominins). Our analyses indicate that different evolutionary processes can underlie the evolution of a single anatomical unit (the wrist) to produce diversity in functional and morphological adaptations across individual wrist

Motor functions and adaptive behaviour in children with childhood apraxia of speech.

Science.gov (United States)

Tükel, Şermin; Björelius, Helena; Henningsson, Gunilla; McAllister, Anita; Eliasson, Ann Christin

2015-01-01

Undiagnosed motor and behavioural problems have been reported for children with childhood apraxia of speech (CAS). This study aims to understand the extent of these problems by determining the profile of and relationships between speech/non-speech oral, manual and overall body motor functions and adaptive behaviours in CAS. Eighteen children (five girls and 13 boys) with CAS, 4 years 4 months to 10 years 6 months old, participated in this study. The assessments used were the Verbal Motor Production Assessment for Children (VMPAC), Bruininks-Oseretsky Test of Motor Proficiency (BOT-2) and Adaptive Behaviour Assessment System (ABAS-II). Median result of speech/non-speech oral motor function was between -1 and -2 SD of the mean VMPAC norms. For BOT-2 and ABAS-II, the median result was between the mean and -1 SD of test norms. However, on an individual level, many children had co-occurring difficulties (below -1 SD of the mean) in overall and manual motor functions and in adaptive behaviour, despite few correlations between sub-tests. In addition to the impaired speech motor output, children displayed heterogeneous motor problems suggesting the presence of a global motor deficit. The complex relationship between motor functions and behaviour may partly explain the undiagnosed developmental difficulties in CAS.

Load-adaptive bone remodeling simulations reveal osteoporotic microstructural and mechanical changes in whole human vertebrae.

Science.gov (United States)

Badilatti, Sandro D; Christen, Patrik; Parkinson, Ian; Müller, Ralph

2016-12-08

Osteoporosis is a major medical burden and its impact is expected to increase in our aging society. It is associated with low bone density and microstructural deterioration. Treatments are available, but the critical factor is to define individuals at risk from osteoporotic fractures. Computational simulations investigating not only changes in net bone tissue volume, but also changes in its microstructure where osteoporotic deterioration occur might help to better predict the risk of fractures. In this study, bone remodeling simulations with a mechanical feedback loop were used to predict microstructural changes due to osteoporosis and their impact on bone fragility from 50 to 80 years of age. Starting from homeostatic bone remodeling of a group of seven, mixed sex whole vertebrae, five mechanostat models mimicking different biological alterations associated with osteoporosis were developed, leading to imbalanced bone formation and resorption with a total net loss of bone tissue. A model with reduced bone formation rate and cell sensitivity led to the best match of morphometric indices compared to literature data and was chosen to predict postmenopausal osteoporotic bone loss in the whole group. Thirty years of osteoporotic bone loss were predicted with changes in morphometric indices in agreement with experimental measurements, and only showing major deviations in trabecular number and trabecular separation. In particular, although being optimized to match to the morphometric indices alone, the predicted bone loss revealed realistic changes on the organ level and on biomechanical competence. While the osteoporotic bone was able to maintain the mechanical stability to a great extent, higher fragility towards error loads was found for the osteoporotic bones. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rescuing loading induced bone formation at senescence.

Directory of Open Access Journals (Sweden)

Sundar Srinivasan

2010-09-01

Full Text Available The increasing incidence of osteoporosis worldwide requires anabolic treatments that are safe, effective, and, critically, inexpensive given the prevailing overburdened health care systems. While vigorous skeletal loading is anabolic and holds promise, deficits in mechanotransduction accrued with age markedly diminish the efficacy of readily complied, exercise-based strategies to combat osteoporosis in the elderly. Our approach to explore and counteract these age-related deficits was guided by cellular signaling patterns across hierarchical scales and by the insight that cell responses initiated during transient, rare events hold potential to exert high-fidelity control over temporally and spatially distant tissue adaptation. Here, we present an agent-based model of real-time Ca(2+/NFAT signaling amongst bone cells that fully described periosteal bone formation induced by a wide variety of loading stimuli in young and aged animals. The model predicted age-related pathway alterations underlying the diminished bone formation at senescence, and hence identified critical deficits that were promising targets for therapy. Based upon model predictions, we implemented an in vivo intervention and show for the first time that supplementing mechanical stimuli with low-dose Cyclosporin A can completely rescue loading induced bone formation in the senescent skeleton. These pre-clinical data provide the rationale to consider this approved pharmaceutical alongside mild physical exercise as an inexpensive, yet potent therapy to augment bone mass in the elderly. Our analyses suggested that real-time cellular signaling strongly influences downstream bone adaptation to mechanical stimuli, and quantification of these otherwise inaccessible, transient events in silico yielded a novel intervention with clinical potential.

Adaptive Importance Sampling with a Rapidly Varying Importance Function

International Nuclear Information System (INIS)

Booth, Thomas E.

2000-01-01

It is known well that zero-variance Monte Carlo solutions are possible if an exact importance function is available to bias the random walks. Monte Carlo can be used to estimate the importance function. This estimated importance function then can be used to bias a subsequent Monte Carlo calculation that estimates an even better importance function; this iterative process is called adaptive importance sampling.To obtain the importance function, one can expand the importance function in a basis such as the Legendre polynomials and make Monte Carlo estimates of the expansion coefficients. For simple problems, Legendre expansions of order 10 to 15 are able to represent the importance function well enough to reduce the error geometrically by ten orders of magnitude or more. The more complicated problems are addressed in which the importance function cannot be represented well by Legendre expansions of order 10 to 15. In particular, a problem with a cross-section notch and a problem with a discontinuous cross section are considered

Adaptive functioning in pediatric epilepsy: contributions of seizure-related variables and parental anxiety.

Science.gov (United States)

Kerne, Valerie; Chapieski, Lynn

2015-02-01

Young people with epilepsy are less likely to achieve the level of independence attained by their peers. We examined the seizure-related variables that placed a group of 97 pediatric patients with intractable seizures at risk for poor adaptive functioning. Analyses evaluated both the direct effects of the medical variables and indirect effects that were mediated through increased parental anxiety about their child's epilepsy. Higher numbers of anticonvulsants, presence of seizures that secondarily generalize, longer duration of seizure disorder, and younger age at onset were all identified as risk factors for poor adaptive functioning. Depending on the specific behavioral domain of adaptive functioning, the effects were sometimes direct and sometimes indirect. Lower levels of parental education and positive family history of seizures were associated with higher levels of parental anxiety. Interventions that target parental anxiety about seizures may mitigate the deleterious effects of epilepsy on social development. Copyright © 2014 Elsevier Inc. All rights reserved.

Peri-implant bone strains and micro-motion following in vivo service: a postmortem retrieval study of 22 tibial components from total knee replacements.

Science.gov (United States)

Mann, Kenneth A; Miller, Mark A; Goodheart, Jacklyn R; Izant, Timothy H; Cleary, Richard J

2014-03-01

Biological adaptation following placement of a total knee replacements (TKRs) affects peri-implant bone mineral density (BMD) and implant fixation. We quantified the proximal tibial bone strain and implant-bone micro-motion for functioning postmortem retrieved TKRs and assessed the strain/micro-motion relationships with chronological (donor age and time in service) and patient (body weight and BMD) factors. Twenty-two tibial constructs were functionally loaded to one body weight (60% medial/40% lateral), and the bone strains and tray/bone micro-motions were measured using a digital image correlation system. Donors with more time in service had higher bone strains (p = 0.044), but there was not a significant (p = 0.333) contribution from donor age. Donors with lower peri-implant BMD (p = 0.0039) and higher body weight (p = 0.0286) had higher bone strains. Long term implants (>11 years) had proximal bone strains 900 µϵ that were almost twice as high as short term (implants 570 µϵ. Micro-motion was greater for younger donors (p = 0.0161) and longer time in service (p = 0.0008). Increased bone strain with long term in vivo service could contribute to loosening of TKRs by failure of the tibial peri-implant bone. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Bioactive lipid coating of bone allografts directs engraftment and fate determination of bone marrow-derived cells in rat GFP chimeras

OpenAIRE

Das, Anusuya; Segar, Claire E.; Chu, Yihsuan; Wang, Tiffany W.; Lin, Yong; Yang, Chunxi; Du, Xeujun; Ogle, Roy C.; Cui, Quanjun; Botchwey, Edward A.

2015-01-01

Bone grafting procedures are performed to treat wounds incurred during wartime trauma, accidents, and tumor resections. Endogenous mechanisms of repair are often insufficient to ensure integration between host and donor bone and subsequent restoration of function. We investigated the role that bone marrow-derived cells play in bone regeneration and sought to increase their contributions by functionalizing bone allografts with bioactive lipid coatings. Polymer-coated allografts were used to lo...

Impact of clinical factors on the long-term functional and anatomic outcomes of osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis.

Science.gov (United States)

De La Paz, María Fideliz; De Toledo, Juan Álvarez; Charoenrook, Victor; Sel, Saadettin; Temprano, José; Barraquer, Rafael I; Michael, Ralph

2011-05-01

To report the long-term functional and anatomic outcomes of osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis; to analyze the influence of clinical factors, such as surgical technique, primary diagnosis, age, and postoperative complications, on the final outcome. Retrospective cohort study. setting: Centro de Oftalmología Barraquer, between 1974 and 2005. Two hundred twenty-seven patients. intervention: Biological keratoprosthesis using osteo-odonto-keratoprosthesis or tibial bone keratoprosthesis. main outcome measures: Functional survival with success defined as best-corrected visual acuity ≥0.05; anatomic survival with success defined as retention of the keratoprosthesis lamina. Osteo-odonto-keratoprosthesis and tibial bone keratoprosthesis have comparable anatomic survival at 5 and 10 years of follow-up, but osteo-odonto-keratoprosthesis has a significantly better functional success than tibial bone keratoprosthesis at the same time periods. Among the primary diagnoses, Stevens-Johnson syndrome, chemical burn, and trachoma have generally good functional and anatomic outcomes and the least favorable prognosis is for ocular cicatricial pemphigoid. Younger patients fared better than those in older age groups. The most frequent complications were extrusion (28%), retinal detachment (16%), and uncontrolled glaucoma (11%). The glaucoma group had the best anatomic success but the worst functional results, only exceeded by the retinal detachment group in terms of functional outcome. Clinical factors, such as surgical technique, primary diagnosis, age, and postoperative complications, can affect the long-term anatomic and functional successes of biological keratoprosthesis. Knowledge about the impact of each of these factors on survival can help surgeons determine the best approach in every particular case. Copyright © 2011 Elsevier Inc. All rights reserved.

The use of bone turnover markers in chronic kidney disease-mineral and bone disorders.

Science.gov (United States)

Chiang, Cherie

2017-03-01

Bone turnover markers assist in fracture risk prediction, management and monitoring of osteoporosis in patients without chronic kidney disease (CKD). The use in CKD-mineral bone disorder (MBD) has been limited as many of these markers and breakdown products are renally excreted, including the most commonly used and well standardized procollagen type I N propeptide and C-terminal cross-linking telopeptide of type I collagen. Of the markers unaffected by renal function, bone specific alkaline phosphatase is associated with mortality and fracture rate in CKD subjects and is now available on several automated analysers. When used in combination with PTH, bone specific alkaline phosphatase as a bone formation marker correlated well with bone biopsy histomorphometry in predicting adynamic bone disease. Tartrate-resistant acid phosphatase 5b is a resorption marker that is under development for automation. Both high and low bone turnover in CKD-MBD patients are associated with increased fracture and mortality risk. Bone biopsy as the gold standard to differentiate between adynamic bone disease and osteitis fibrosa is limited by availability and cost. Appropriate use of bone turnover markers is vital in the decision to commence anti-resorptive agents, and to monitor efficacy in order to avoid over suppression of bone turnover, which may lead to stress fractures. Further efforts are required to develop markers unaffected by renal function with standardized cut-off values and fracture as well as vascular calcification end-points. © 2017 Asian Pacific Society of Nephrology.

Outcome of bone recycling using liquid nitrogen as bone reconstruction procedure in malignant and recurrent benign aggressive bone tumour of distal tibia: A report of four cases.

Science.gov (United States)

Gede, Eka Wiratnaya I; Ida Ayu, Arrisna Artha; Setiawan I Gn, Yudhi; Aryana Ign, Wien; I Ketut, Suyasa; I Ketut, Siki Kawiyana; Putu, Astawa

2017-01-01

Amputation still considered as primary choice of malignancy treatment in distal tibia. Bone recycling with liquid nitrogen for reconstruction following resection of malignant bone tumours offers many advantages. We presented four patients with osteosarcoma, Ewing sarcoma, adamantinoma and recurrent giant cell tumour over distal tibia. All of the patients underwent wide excision and bone recycling using liquid nitrogen as bone reconstruction. The mean functional Musculoskeletal Tumor Society (MSTS) score was 75% with no infection and local recurrent. The reconstruction provides good local control and functional outcome.

Pedagogical Content Knowledge of Experienced Teachers in Physical Education: Functional Analysis of Adaptations

Science.gov (United States)

Ayvazo, Shiri; Ward, Phillip

2011-01-01

Pedagogical content knowledge (PCK) is the teacher's ability to pedagogically adapt content to students of diverse abilities. In this study, we investigated how teachers' adaptations of instruction for individual students differed when teaching stronger and weaker instructional units. We used functional analysis (Hanley, Iwata, & McCord, 2003) of…

Functional genetic divergence in high CO2 adapted Emiliania huxleyi populations.

Science.gov (United States)

Lohbeck, Kai T; Riebesell, Ulf; Collins, Sinéad; Reusch, Thorsten B H

2013-07-01

Predicting the impacts of environmental change on marine organisms, food webs, and biogeochemical cycles presently relies almost exclusively on short-term physiological studies, while the possibility of adaptive evolution is often ignored. Here, we assess adaptive evolution in the coccolithophore Emiliania huxleyi, a well-established model species in biological oceanography, in response to ocean acidification. We previously demonstrated that this globally important marine phytoplankton species adapts within 500 generations to elevated CO2 . After 750 and 1000 generations, no further fitness increase occurred, and we observed phenotypic convergence between replicate populations. We then exposed adapted populations to two novel environments to investigate whether or not the underlying basis for high CO2 -adaptation involves functional genetic divergence, assuming that different novel mutations become apparent via divergent pleiotropic effects. The novel environment "high light" did not reveal such genetic divergence whereas growth in a low-salinity environment revealed strong pleiotropic effects in high CO2 adapted populations, indicating divergent genetic bases for adaptation to high CO2 . This suggests that pleiotropy plays an important role in adaptation of natural E. huxleyi populations to ocean acidification. Our study highlights the potential mutual benefits for oceanography and evolutionary biology of using ecologically important marine phytoplankton for microbial evolution experiments. © 2012 The Author(s). Evolution © 2012 The Society for the Study of Evolution.

Intratrabecular distribution of tissue stiffness and mineralization in developing trabecular bone

NARCIS (Netherlands)

Mulder, L.; Koolstra, J.H.; Toonder, den J.M.J.; Eijden, van T.M.G.J.

2007-01-01

The purpose of this study was to investigate the relation between bone tissue stiffness and degree of mineralization distribution and to examine possible changes during prenatal development. Understanding this may provide insight into adaptation processes and into deformation mechanisms of the bone

Engineering an in vitro model of a functional ligament from bone to bone.

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Paxton, Jennifer Z; Grover, Liam M; Baar, Keith

2010-11-01

For musculoskeletal tissues that transmit loads during movement, the interfaces between tissues are essential to minimizing injury. Therefore, the reproduction of functional interfaces within engineered musculoskeletal tissues is critical to the successful transfer of the technology to the clinic. The goal of this work was to rapidly engineer ligament equivalents in vitro that contained both the soft tissue sinew and a hard tissue bone mimetic. This goal was achieved using cast brushite (CaHPO(4)·2H(2)O) anchors to mimic bone and a fibrin gel embedded with fibroblasts to create the sinew. The constructs formed within 7 days. Fourteen days after seeding, the interface between the brushite and sinew could withstand a stress of 9.51 ± 1.7  kPa before failure and the sinew reached a Young's modulus value of 0.16 ± 0.03  MPa. Treatment with ascorbic acid and proline increased the collagen content of the sinew (from 1.34% ± 0.2% to 8.34% ± 0.37%), strength of the interface (29.24 ± 6  kPa), and modulus of the sinew (2.69 ± 0.25  MPa). Adding transforming growth factor-β resulted in a further increase in collagen (11.25% ± 0.39%), interface strength (42 ± 8  kPa), and sinew modulus (5.46 ± 0.68  MPa). Both scanning electron and Raman microscopy suggested that the interface between the brushite and sinew mimics the in vivo tidemark at the enthesis. This work describes a major step toward the development of tissue-engineered ligaments for the repair of ligament ruptures in humans.

Longitudinal Investigation of Adaptive Functioning following Conformal Irradiation for Pediatric Craniopharyngioma and Low-Grade Glioma

Science.gov (United States)

Netson, Kelli L.; Conklin, Heather M.; Wu, Shengjie; Xiong, Xiaoping; Merchant, Thomas E.

2013-01-01

Purpose Children treated for brain tumors with conformal radiation therapy experience preserved cognitive outcomes. Early evidence suggests that adaptive functions or independent living skills may be spared. This longitudinal investigation prospectively examined intellectual and adaptive functioning during the first 5 years following irradiation for childhood craniopharyngioma and low-grade glioma (LGG). The effect of visual impairment on adaptive outcomes was investigated. Methods and Materials Children with craniopharyngioma (n=62) and LGG (n=77) were treated using conformal or intensity-modulated radiation therapy. The median age was 8.05 years (3.21 years –17.64 years) and 8.09 years (2.20 years–19.27 years), respectively. Serial cognitive evaluations including measures of intelligence quotient (IQ) and the Vineland Adaptive Behavior Scales (VABS) were conducted at pre-irradiation baseline, 6 months after treatment, and annually through 5 years. A total of 588 evaluations were completed during the follow-up period. Results Baseline assessment revealed no deficits in IQ and VABS indices for children with craniopharyngioma, with significant (p craniopharyngioma. Children with LGG performed below population norms (p < .05) at baseline on VABS Communication, Daily Living Indices, and the Adaptive Behavior Composite, with significant (p < .05) longitudinal decline limited to VABS Communication. Older age at irradiation was a protective factor against longitudinal decline. Severe visual impairment did not independently correlate with poorer adaptive outcomes for either tumor group. Conclusions There was relative sparing of post-irradiation functional outcomes over time in this sample. Baseline differences in functional abilities prior to the initiation of irradiation suggested that other factors influence functional outcomes above and beyond the effects of irradiation. PMID:23245284

[Bone graft reconstruction for posterior mandibular segment using the formwork technique].

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Pascual, D; Roig, R; Chossegros, C

2014-04-01

Pre-implant bone graft in posterior mandibular segments is difficult because of masticatory and lingual mechanical constraints, because of the limited bone vascularization, and because of the difficulty to cover it with the mucosa. The formwork technique is especially well adapted to this topography. The recipient site is abraded with a drill. Grooves are created to receive and stabilize the grafts. The bone grafts were harvested from the ramus. The thinned cortices are assembled in a formwork and synthesized by mini-plates. The gaps are filled by bone powder collected during bone harvesting. The bone volume reconstructed with the formwork technique allows anchoring implants more than 8mm long. The proximity of the inferior alveolar nerve does not contra indicate this technique. The formwork size and its positioning on the alveolar crest can be adapted to prosthetic requirements by using osteosynthesis plates. The lateral implant walls are supported by the formwork cortices; the implant apex is anchored on the native alveolar crest. The primary stability of implants is high, and the torque is important. The ramus harvesting decreases operative risks. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

3D Architecture of Trabecular Bone in the Pig Mandible and Femur: Inter-Trabecular Angle Distributions.

Science.gov (United States)

Ben-Zvi, Yehonatan; Reznikov, Natalie; Shahar, Ron; Weiner, Steve

2017-09-01

Cancellous bone is an intricate network of interconnected trabeculae, to which analysis of network topology can be applied. The inter-trabecular angle (ITA) analysis - an analysis of network topological parameters and regularity of network-forming nodes, was previously carried out on human proximal femora and showed that trabecular bone follows two main principles: sparsity of the network connectedness (prevalence of nodes with low connectivity in the network) and maximal space spanning (angular offset of connected elements is maximal for their number and approximates the values of geometrically symmetric shapes). These observations suggest that 3D organization of trabecular bone, irrespective of size and shape of individual elements, reflects a tradeoff between minimal metabolic cost of maintenance and maximal network stability under conditions of multidirectional loading. In this study we validate the ITA application using additional 3D structures (cork and 3D-printed metal lattices), analyze the ITA parameters in porcine proximal femora and mandibles and carry out a spatial analysis of the most common node type in the porcine mandibular condyle. The validation shows that the ITA application reliably detects designed or evolved topological parameters. The ITA parameters of porcine trabecular bones are similar to those of human bones. We demonstrate functional adaptation in the pig mandibular condyle by showing that the planar nodes with 3 edges are preferentially aligned in relation to the muscle forces that are applied to the condyle. We conclude that the ITA topological parameters are remarkable conserved, but locally do adapt to applied stresses.

3D Architecture of Trabecular Bone in the Pig Mandible and Femur: Inter-Trabecular Angle Distributions

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Yehonatan Ben-Zvi

2017-09-01

Full Text Available Cancellous bone is an intricate network of interconnected trabeculae, to which analysis of network topology can be applied. The inter-trabecular angle (ITA analysis—an analysis of network topological parameters and regularity of network-forming nodes—was previously carried out on human proximal femora and showed that trabecular bone follows two main principles: sparsity of the network connectedness (prevalence of nodes with low connectivity in the network and maximal space spanning (angular offset of connected elements is maximal for their number and approximates the values of geometrically symmetric shapes. These observations suggest that 3D organization of trabecular bone, irrespective of size and shape of individual elements, reflects a tradeoff between minimal metabolic cost of maintenance and maximal network stability under conditions of multidirectional loading. In this study, we validate the ITA application using additional 3D structures (cork and 3D-printed metal lattices, analyze the ITA parameters in porcine proximal femora and mandibles, and carry out a spatial analysis of the most common node type in the porcine mandibular condyle. The validation shows that the ITA application reliably detects designed or evolved topological parameters. The ITA parameters of porcine trabecular bones are similar to those of human bones. We demonstrate functional adaptation in the pig mandibular condyle by showing that the planar nodes with three edges are preferentially aligned in relation to the muscle forces that are applied to the condyle. We conclude that the ITA topological parameters are remarkably conserved, but locally do adapt to applied stresses.

Strategies to reverse bone loss in women with functional hypothalamic amenorrhea: a systematic review of the literature.

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Vescovi, J D; Jamal, S A; De Souza, M J

2008-04-01

Functional hypothalamic amenorrhea (FHA) impairs the attainment of peak bone mass and as such can increase the risk of fractures later in life. To document available treatment strategies, we conducted a systematic review of the literature. We report that hormonal therapies have limited effectiveness in increasing bone mass, whereas increased caloric intake resulting in weight gain and/or resumption of menses is an essential strategy for restoring bone mass in women with FHA. Women with functional hypothalamic amenorrhea (FHA) may not achieve peak bone mass (PBM), which increases the risk of stress fractures, and may increase the risk of osteoporotic fractures in later life. To identify effective treatment strategies for women with FHA, we conducted a systematic review of the literature. We included randomized controlled trials (RCTs), cross-sectional studies, and case studies that reported on the effects of pharmacological and non-pharmacological interventions on bone mineral density (BMD) or bone turnover in women with FHA. Most published studies (n=26) were designed to treat the hormonal abnormalities observed in women with FHA (such as low estrogen, leptin, insulin-like growth factor-1, and DHEA); however none of these treatments demonstrated consistent improvements in BMD. Therapies containing an estrogen given for 8-24 months resulted in variable improvements (1.0-19.0%) in BMD, but failed to restore bone mass to that of age-matched controls. Three studies reported on the use of bisphosphonates (3-12 months) in anorexic women, which appear to have limited effectiveness to improve BMD compared to nutritional treatments. Another three investigations showed no improvements in BMD after androgen therapy (DHEA and testosterone) in anorexic women. In contrast, reports (n=9) describing an increase in caloric intake that results in weight gain and/or the resumption of menses reported a 1.1-16.9% increase in BMD concomitant with an improvement in bone formation and

In vivo, noninvasive functional measurements of bone sarcoma using diffuse optical spectroscopic imaging

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Peterson, Hannah M.; Hoang, Bang H.; Geller, David; Yang, Rui; Gorlick, Richard; Berger, Jeremy; Tingling, Janet; Roth, Michael; Gill, Jonathon; Roblyer, Darren

2017-12-01

Diffuse optical spectroscopic imaging (DOSI) is an emerging near-infrared imaging technique that noninvasively measures quantitative functional information in thick tissue. This study aimed to assess the feasibility of using DOSI to measure optical contrast from bone sarcomas. These tumors are rare and pose technical and practical challenges for DOSI measurements due to the varied anatomic locations and tissue depths of presentation. Six subjects were enrolled in the study. One subject was unable to be measured due to tissue contact sensitivity. For the five remaining subjects, the signal-to-noise ratio, imaging depth, optical properties, and quantitative tissue concentrations of oxyhemoglobin, deoxyhemoglobin, water, and lipids from tumor and contralateral normal tissues were assessed. Statistical differences between tumor and contralateral normal tissue were found in chromophore concentrations and optical properties for four subjects. Low signal-to-noise was encountered during several subject's measurements, suggesting increased detector sensitivity will help to optimize DOSI for this patient population going forward. This study demonstrates that DOSI is capable of measuring optical properties and obtaining functional information in bone sarcomas. In the future, DOSI may provide a means to stratify treatment groups and monitor chemotherapy response for this disease.

Nonlinear pattern formation in bone growth and architecture

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Phil eSalmon

2015-01-01

Full Text Available The 3D morphology of bone arises through adaptation to its required engineering performance. Genetically and adaptively bone travels along a complex spatio-temporal trajectory to acquire optimal architecture. On a cellular, micro-anatomical scale, what mechanisms coordinate the activity of osteoblasts and osteoclasts to produce complex and efficient bone architectures? One mechanism is examined here – chaotic nonlinear pattern formation (NPF – which underlies in a unifying way natural structures as disparate as trabecular bone, swarms of birds flying, island formation, fluid turbulence and others. At the heart of NPF is the fact that simple rules operating between interacting elements, and Turing-like interaction between global and local signals, lead to complex and structured patterns. The study of group intelligence exhibited by swarming birds or shoaling fish has led to an embodiment of NPF called particle swarm optimization (PSO. This theoretical model could be applicable to the behavior of osteoblasts osteoclasts and osteocytes, seeing them operating socially in response simultaneously to both global and local signals (endocrine, cytokine, mechanical resulting in their clustered activity at formation and resorption sites. This represents problem-solving by social intelligence, and could potentially add further realism to in-silico simulation of bone modeling.What insights has NPF provided to bone biology? One example concerns the genetic disorder Juvenile Pagets Disease (JPD or Idiopathic Hyperphosphatasia, where the anomalous parallel trabecular architecture characteristic of this pathology is consistent with an NPF paradigm by analogy with known experimental NPF systems. Here coupling or feedback between osteoblasts and osteoclasts is the critical element.This NPF paradigm implies a profound link between bone regulation and its architecture: in bone the architecture is the regulation. The former is the emergent consequence of the

Calcium and bone metabolism disorders during pregnancy and lactation.

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Kovacs, Christopher S

2011-12-01

Pregnancy and lactation cause a substantial increase in demand for calcium that is met by different maternal adaptations within each period. Intestinal calcium absorption more than doubles during pregnancy, whereas the maternal skeleton resorbs to provide most of the calcium content of breast milk during lactation. These maternal adaptations also affect the presentation, diagnosis, and management of disorders of calcium and bone metabolism. Although some women may experience fragility fractures as a consequence of pregnancy or lactation, for most women, parity and lactation do not affect the long-term risks of low bone density, osteoporosis, or fracture. Copyright © 2011 Elsevier Inc. All rights reserved.

Is fatty acid composition of human bone marrow significant to bone health?

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Pino, Ana María; Rodríguez, J Pablo

2017-12-16

The bone marrow adipose tissue (BMAT) is a conserved component of the marrow microenvironment, providing storage and release of energy and stabilizing the marrow extent. Also, it is recognized both the amount and quality of BMAT are relevant to preserve the functional relationships between BMAT, bone, and blood cell production. In this article we ponder the information supporting the tenet that the quality of BMAT is relevant to bone health. In the human adult the distribution of BMAT is heterogeneous over the entire skeleton, and both BMAT accumulation and bone loss come about with aging in healthy populations. But some pathological conditions which increase BMAT formation lead to bone impairment and fragility. Analysis in vivo of the relative content of saturated and unsaturated fatty acids (FA) in BMAT indicates site-related bone marrow fat composition and an association between increased unsaturation index (UI) and bone health. With aging some impairment ensues in the regulation of bone marrow cells and systemic signals leading to local chronic inflammation. Most of the bone loss diseases which evolve altered BMAT composition have as common factors aging and/or chronic inflammation. Both saturated and unsaturated FAs originate lipid species which are active mediators in the inflammation process. Increased free saturated FAs may lead to lipotoxicity of bone marrow cells. The pro-inflammatory, anti-inflammatory or resolving actions of compounds derived from long chain poly unsaturated FAs (PUFA) on bone cells is varied, and depending on the metabolism of the parent n:3 or n:6 PUFAs series. Taking together the evidence substantiate that marrow adipocyte function is fundamental for an efficient link between systemic and marrow fatty acids to accomplish specific energy or regulatory needs of skeletal and marrow cells. Further, they reveal marrow requirements of PUFAs. Copyright © 2017 Elsevier Inc. All rights reserved.

Phenotypic characterization of Grm1crv4 mice reveals a functional role for the type 1 metabotropic glutamate receptor in bone mineralization.

Science.gov (United States)

Musante, Ilaria; Mattinzoli, Deborah; Otescu, Lavinia Alexandra; Bossi, Simone; Ikehata, Masami; Gentili, Chiara; Cangemi, Giuliana; Gatti, Cinzia; Emionite, Laura; Messa, Piergiorgio; Ravazzolo, Roberto; Rastaldi, Maria Pia; Riccardi, Daniela; Puliti, Aldamaria

2017-01-01

Recent increasing evidence supports a role for neuronal type signaling in bone. Specifically glutamate receptors have been found in cells responsible for bone remodeling, namely the osteoblasts and the osteoclasts. While most studies have focused on ionotropic glutamate receptors, the relevance of the metabotropic glutamate signaling in bone is poorly understood. Specifically type 1 metabotropic glutamate (mGlu1) receptors are expressed in bone, but the effect of its ablation on skeletal development has never been investigated. Here we report that Grm1 crv4/crv4 mice, homozygous for an inactivating mutation of the mGlu1 receptor, and mainly characterized by ataxia and renal dysfunction, exhibit decreased body weight, bone length and bone mineral density compared to wild type (WT) animals. Blood analyses of the affected mice demonstrate the absence of changes in circulating factors, such as vitamin D and PTH, suggesting renal damage is not the main culprit of the skeletal phenotype. Cultures of osteoblasts lacking functional mGlu1 receptors exhibit less homogeneous collagen deposition than WT cells, and present increased expression of osteocalcin, a marker of osteoblast maturation. These data suggest that the skeletal damage is directly linked to the absence of the receptor, which in turn leads to osteoblasts dysfunction and earlier maturation. Accordingly, skeletal histomorphology suggests that Grm1 crv4/crv4 mice exhibit enhanced bone maturation, resulting in premature fusion of the growth plate and shortened long bones, and further slowdown of bone apposition rate compared to the WT animals. In summary, this work reveals novel functions of mGlu1 receptors in the bone and indicates that in osteoblasts mGlu1 receptors are necessary for production of normal bone matrix, longitudinal bone growth, and normal skeletal development. Copyright © 2016 Elsevier Inc. All rights reserved.

Reconstruction of segmental bone defect of long bones after tumor resection by devitalized tumor-bearing bone.

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Qu, Huayi; Guo, Wei; Yang, Rongli; Li, Dasen; Tang, Shun; Yang, Yi; Dong, Sen; Zang, Jie

2015-09-24

The reconstruction of an intercalary bone defect after a tumor resection of a long bone remains a challenge to orthopedic surgeons. Though several methods have been adopted to enhance the union of long segmental allografts or retrieved segmental autografts to the host bones, still more progresses are required to achieve a better union rate. Several methods have been adopted to devitalize tumor bone for recycling usage, and the results varied. We describe our experiences of using devitalized tumor-bearing bones for the repairing of segmental defects after tumor resection. Twenty-seven eligible patients treated from February 2004 to May 2012 were included. The segmental tumor bone (mean length, 14 cm) was resected, and then devitalized in 20% sterile saline at 65 °C for 30 min after the tumor tissue was removed. The devitalized bone was implanted back into the defect by using nails or plates. Complete healing of 50 osteotomy ends was achieved at a median time of 11 months (interquartile range (IQR) 9-13 months). Major complications included bone nonunion in four bone junctions (7.4%), devitalized bone fracture in one patient (3.7%), deep infection in three patients (11.1%), and fixation failure in two patients (7.4%). The bone union rates at 1 and 2 years were 74.1 and 92.6%, respectively. The average functional score according to the Musculoskeletal Tumor Society (MSTS) 93 scoring system was 93 % (IQR 80-96.7%). Incubation in 20% sterile saline at 65 °C for 30 min is an effective method of devitalization of tumor-bearing bone. The retrieved bone graft may provide as a less expensive alternative for limb salvage. The structural bone and the preserved osteoinductivity of protein may improve bone union.

Morphology of the thoracic limb bones in the giant anteater

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Fabrício Singaretti de Oliveira

2013-11-01

Full Text Available The giant anteater has a grayish-brown pelage with white and black tones, its skull is elongated, cylindrical, and there are no teeth. Its tail is long, with thick and long bristles, resembling a flag. This is an endangered species, due to the constant degradation of its habitat, in addition to deaths caused by fires and roadkills. Thus, this paper aimed to describe the morphology of the thoracic limb bones in Myrmecophaga tridactyla, focusing on its main bone accidents. We used two specimens of giant anteater collected on highways in the state of Minas Gerais, Brazil, after death due to being run over. The scapula, humerus, radius, ulna, and the hand bones showed particular characteristics adapted to the species’ lifestyle and habits. In general, the scapula resembles that in human beings and the humerus is similar to that in armadillo, the radius and ulna exhibit articular surfaces which enable a wide range of rotational movements in the forearm, the carpal bones are also similar in number and shape to those in human beings, and the fingers are well developed in the giant anteater, having long, strong and sharp claws, especially in the third finger. Thus, the anatomical description of the thoracic limb bones in the giant anteater showed to be important, providing a deeper understanding both of the functional aspects of the thoracic limb and the comparative anatomy of wild animals.

Translation and adaptation of functional auditory performance indicators (FAPI

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Karina Ferreira

2011-12-01

Full Text Available Work with deaf children has gained new attention since the expectation and goal of therapy has expanded to language development and subsequent language learning. Many clinical tests were developed for evaluation of speech sound perception in young children in response to the need for accurate assessment of hearing skills that developed from the use of individual hearing aids or cochlear implants. These tests also allow the evaluation of the rehabilitation program. However, few of these tests are available in Portuguese. Evaluation with the Functional Auditory Performance Indicators (FAPI generates a child's functional auditory skills profile, which lists auditory skills in an integrated and hierarchical order. It has seven hierarchical categories, including sound awareness, meaningful sound, auditory feedback, sound source localizing, auditory discrimination, short-term auditory memory, and linguistic auditory processing. FAPI evaluation allows the therapist to map the child's hearing profile performance, determine the target for increasing the hearing abilities, and develop an effective therapeutic plan. Objective: Since the FAPI is an American test, the inventory was adapted for application in the Brazilian population. Material and Methods: The translation was done following the steps of translation and back translation, and reproducibility was evaluated. Four translated versions (two originals and two back-translated were compared, and revisions were done to ensure language adaptation and grammatical and idiomatic equivalence. Results: The inventory was duly translated and adapted. Conclusion: Further studies about the application of the translated FAPI are necessary to make the test practicable in Brazilian clinical use.

Hydroxyapatite nanocrystals functionalized with alendronate as bioactive components for bone implant coatings to decrease osteoclastic activity

Science.gov (United States)

Bosco, Ruggero; Iafisco, Michele; Tampieri, Anna; Jansen, John A.; Leeuwenburgh, Sander C. G.; van den Beucken, Jeroen J. J. P.

2015-02-01

The integration of bone implants within native bone tissue depends on periprosthetic bone quality, which is severely decreased in osteoporotic patients. In this work, we have synthesized bone-like hydroxyapatite nanocrystals (nHA) using an acid-base neutralization reaction and analysed their physicochemical properties. Subsequently, we have functionalized the nHA with alendronate (nHAALE), a well-known bisphosphonate drug used for the treatment of osteoporosis. An in vitro osteoclastogenesis test was carried out to evaluate the effect of nHAALE on the formation of osteoclast-like cells from monocytic precursor cells (i.e. RAW264.7 cell line) showing that nHAALE significantly promoted apoptosis of osteoclast-like cells. Subsequently, nHA and nHAALE were deposited on titanium disks using electrospray deposition (ESD), for which characterisation of the deposited coatings confirmed the presence of alendronate in nHAALE coatings with nanoscale thickness of about 700 nm. These results indicate that alendronate linked to hydroxyapatite nanocrystals has therapeutic potential and nHAALE can be considered as an appealing coating constituent material for orthopaedic and oral implants for application in osteoporotic patients.

Bone loss in rheumatoid arthritis

International Nuclear Information System (INIS)

Gotfredsen, A.; Als, O.S.; Hassager, C.; Christiansen, C.

1986-01-01

The authors studied 159 patients with rheumatoid arthritis (RA) treated with a variety of drugs. Stratification of the patients was done according to treatment, sex, menopausal state, duration of the disease, and functional impairment. Forearm bone mineral content (BMC) and total body bone mineral (TBBM) were measured by single and dual photon absorptiometry. Bone turnover was estimated by biochemical markers. All patients had significantly decreased BMC and TBBM compared to normals. Comparing glucocorticoid and penicillamine treatment in premenopausal patients, they found significantly lower BMC and TBBM values in the glucocorticoid treated group. However, no differences in BMC and TBBM values were found in the corresponding postmenopausal groups. In the premenopausal glucocorticoid group with the duration of treatment and cumulated dose correlated with BMC, whereas no such correlations were found in the postmenopausal women. In the patients who did not receive glucocorticoids they found significant relationships between BMC and functional impairment as well as duration of the disease. Indices of bone turnover rose with increasing functional, impairment, particularly those of bone resorption

Longitudinal Investigation of Adaptive Functioning Following Conformal Irradiation for Pediatric Craniopharyngioma and Low-Grade Glioma

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Netson, Kelli L. [Department of Psychiatry and Behavioral Sciences, Kansas University School of Medicine—Wichita, Kansas (United States); Conklin, Heather M. [Department of Psychology, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu, Shengjie; Xiong, Xiaoping [Department of Biostatistics, St Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St Jude Children' s Research Hospital, Memphis, Tennessee (United States)

2013-04-01

Purpose: Children treated for brain tumors with conformal radiation therapy experience preserved cognitive outcomes. Early evidence suggests that adaptive functions or independent-living skills may be spared. This longitudinal investigation prospectively examined intellectual and adaptive functioning during the first 5 years following irradiation for childhood craniopharyngioma and low-grade glioma (LGG). The effect of visual impairment on adaptive outcomes was investigated. Methods and Materials: Children with craniopharyngioma (n=62) and LGG (n=77) were treated using conformal or intensity modulated radiation therapy. The median age was 8.05 years (3.21-17.64 years) and 8.09 years (2.20-19.27 years), respectively. Serial cognitive evaluations including measures of intelligence quotient (IQ) and the Vineland Adaptive Behavior Scales (VABS) were conducted at preirradiation baseline, 6 months after treatment, and annually through 5 years. Five hundred eighty-eight evaluations were completed during the follow-up period. Results: Baseline assessment revealed no deficits in IQ and VABS indices for children with craniopharyngioma, with significant (P<.05) longitudinal decline in VABS Communication and Socialization indices. Clinical factors associated with more rapid decline included females and preirradiation chemotherapy (interferon). The only change in VABS Daily Living Skills correlated with IQ change (r=0.34; P=.01) in children with craniopharyngioma. Children with LGG performed below population norms (P<.05) at baseline on VABS Communication, Daily Living Indices, and the Adaptive Behavior Composite, with significant (P<.05) longitudinal decline limited to VABS Communication. Older age at irradiation was a protective factor against longitudinal decline. Severe visual impairment did not independently correlate with poorer adaptive outcomes for either tumor group. Conclusions: There was relative sparing of postirradiation functional outcomes over time in this sample

Longitudinal Investigation of Adaptive Functioning Following Conformal Irradiation for Pediatric Craniopharyngioma and Low-Grade Glioma

International Nuclear Information System (INIS)

Netson, Kelli L.; Conklin, Heather M.; Wu, Shengjie; Xiong, Xiaoping; Merchant, Thomas E.

2013-01-01

Purpose: Children treated for brain tumors with conformal radiation therapy experience preserved cognitive outcomes. Early evidence suggests that adaptive functions or independent-living skills may be spared. This longitudinal investigation prospectively examined intellectual and adaptive functioning during the first 5 years following irradiation for childhood craniopharyngioma and low-grade glioma (LGG). The effect of visual impairment on adaptive outcomes was investigated. Methods and Materials: Children with craniopharyngioma (n=62) and LGG (n=77) were treated using conformal or intensity modulated radiation therapy. The median age was 8.05 years (3.21-17.64 years) and 8.09 years (2.20-19.27 years), respectively. Serial cognitive evaluations including measures of intelligence quotient (IQ) and the Vineland Adaptive Behavior Scales (VABS) were conducted at preirradiation baseline, 6 months after treatment, and annually through 5 years. Five hundred eighty-eight evaluations were completed during the follow-up period. Results: Baseline assessment revealed no deficits in IQ and VABS indices for children with craniopharyngioma, with significant (P<.05) longitudinal decline in VABS Communication and Socialization indices. Clinical factors associated with more rapid decline included females and preirradiation chemotherapy (interferon). The only change in VABS Daily Living Skills correlated with IQ change (r=0.34; P=.01) in children with craniopharyngioma. Children with LGG performed below population norms (P<.05) at baseline on VABS Communication, Daily Living Indices, and the Adaptive Behavior Composite, with significant (P<.05) longitudinal decline limited to VABS Communication. Older age at irradiation was a protective factor against longitudinal decline. Severe visual impairment did not independently correlate with poorer adaptive outcomes for either tumor group. Conclusions: There was relative sparing of postirradiation functional outcomes over time in this sample

Predicting Adaptive Functioning of Mentally Retarded Persons in Community Settings.

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Hull, John T.; Thompson, Joy C.

1980-01-01

The impact of a variety of individual, residential, and community variables on adaptive functioning of 369 retarded persons (18 to 73 years old) was examined using a multiple regression analysis. Individual characteristics (especially IQ) accounted for 21 percent of the variance, while environmental variables, primarily those related to…

[Bone Cell Biology Assessed by Microscopic Approach. The effect of parathyroid hormone and teriparatide on bone].

Science.gov (United States)

Takahata, Masahiko

2015-10-01

Continuous exposure to parathyroid hormone (PTH) leads to hypercalcemia and a decrease in bone volume, which is referred to as its catabolic effect, while intermittent exogenously administered PTH leads to an anabolic effect on bone. Intermittent administration of PTH dramatically increases bone remodeling and modeling through their direct and indirect effects on the functional cells of bone remodeling units and their precursors. These effects on bone metabolism differ according to dosing frequency of PTH. Therefore, different dosing frequency of PTH shows different therapeutic effects on bone in terms of bone volume and bone quality in patients with osteoporosis.

Brief Report: Adaptive Functioning in Children with ASD, ADHD and ASD + ADHD

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Ashwood, Karen L.; Tye, Charlotte; Azadi, Bahare; Cartwright, Sally; Asherson, Philip; Bolton, Patrick

2015-01-01

Autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) often co-occur. Children with ASD and ADHD demonstrate deficits in adaptive functioning, yet pure and comorbid groups have not been directly compared. Vineland Adaptive Behaviour Scales (VABS-II) data were examined in boys with ASD (n = 17), ADHD (n = 31) and…

The Effect of Spaceflight on Bone Cell Cultures

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Landis, William J.

1999-01-01

Understanding the response of bone to mechanical loading (unloading) is extremely important in defining the means of adaptation of the body to a variety of environmental conditions such as during heightened physical activity or in extended explorations of space or the sea floor. The mechanisms of the adaptive response of bone are not well defined, but undoubtedly they involve changes occurring at the cellular level of bone structure. This proposal has intended to examine the hypothesis that the loading (unloading) response of bone is mediated by specific cells through modifications of their activity cytoskeletal elements, and/or elaboration of their extracellular matrices. For this purpose, this laboratory has utilized the results of a number of previous studies defining molecular biological, biochemical, morphological, and ultrastructural events of the reproducible mineralization of a primary bone cell (osteoblast) culture system under normal loading (1G gravity level). These data and the culture system then were examined following the use of the cultures in two NASA shuttle flights, STS-59 and STS-63. The cells collected from each of the flights were compared to respective synchronous ground (1G) control cells examined as the flight samples were simultaneously analyzed and to other control cells maintained at 1G until the time of shuttle launch, at which point they were terminated and studied (defined as basal cells). Each of the cell cultures was assayed in terms of metabolic markers- gene expression; synthesis and secretion of collagen and non-collagenous proteins, including certain cytoskeletal components; assembly of collagen into macrostructural arrays- formation of mineral; and interaction of collagen and mineral crystals during calcification of the cultures. The work has utilized a combination of biochemical techniques (radiolabeling, electrophoresis, fluorography, Western and Northern Blotting, and light microscopic immunofluorescence) and structural

Spatial relationship between bone formation and mechanical stimulus within cortical bone: Combining 3D fluorochrome mapping and poroelastic finite element modelling.

Science.gov (United States)

Carrieroa, A; Pereirab, A F; Wilson, A J; Castagno, S; Javaheri, B; Pitsillides, A A; Marenzana, M; Shefelbine, S J

2018-06-01

Bone is a dynamic tissue and adapts its architecture in response to biological and mechanical factors. Here we investigate how cortical bone formation is spatially controlled by the local mechanical environment in the murine tibia axial loading model (C57BL/6). We obtained 3D locations of new bone formation by performing 'slice and view' 3D fluorochrome mapping of the entire bone and compared these sites with the regions of high fluid velocity or strain energy density estimated using a finite element model, validated with ex-vivo bone surface strain map acquired ex-vivo using digital image correlation. For the comparison, 2D maps of the average bone formation and peak mechanical stimulus on the tibial endosteal and periosteal surface across the entire cortical surface were created. Results showed that bone formed on the periosteal and endosteal surface in regions of high fluid flow. Peak strain energy density predicted only the formation of bone periosteally. Understanding how the mechanical stimuli spatially relates with regions of cortical bone formation in response to loading will eventually guide loading regime therapies to maintain or restore bone mass in specific sites in skeletal pathologies.

Preservation of bone structure and function by Lithothamnion sp. – derived minerals

Science.gov (United States)

Aslam, Muhammad Nadeem; Bergin, Ingrid; Jepsen, Karl; Kreider, Jaclynn M.; Graf, Kristin H.; Naik, Madhav; Goldstein, Steven A.; Varani, James

2013-01-01

Progressive bone mineral loss and increasing bone fragility are hallmarks of osteoporosis. A combination of minerals isolated from the red marine algae, Lithothamnion sp. was examined for ability to inhibit bone mineral loss in female mice maintained on either a standard rodent chow (control) diet or a high-fat western diet (HFWD) for 5-, 12- and 18-months. At each time-point, femora were subjected to μ-CT analysis and biomechanical testing. A subset of caudal vertebrae was also analyzed. Following this, individual elements were assessed in bones. Serum levels of the 5b isoform of tartrate-resistant acid phosphatase (TRAP) and procollagen type I propeptide (P1NP) were also measured. Trabecular bone loss occurred in both diets (evident as early as 5-months). Cortical bone increased through month-5 and then declined. Cortical bone loss was primarily in mice on the HFWD. Inclusion of the minerals in the diet reduced bone mineral loss in both diets and improved bone strength. Bone mineral density (BMD) was also enhanced by these minerals. Of several cationic minerals known to be important to bone health, only strontium was significantly increased in bone tissue from animals fed the mineral diets, but the increase was large (5–10 fold). Serum levels of TRAP were consistently higher in mice receiving the minerals but levels of P1NP were not. These data suggest that trace minerals derived from marine red algae may be used to prevent progressive bone mineral loss in conjunction with calcium. Mineral supplementation could find use as part of an osteoporosis - prevention strategy. PMID:24096551

Treatment of active unicameral bone cysts with percutaneous injection of demineralized bone matrix and autogenous bone marrow.

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Rougraff, Bruce T; Kling, Thomas J

2002-06-01

The treatment of unicameral bone cysts varies from open bone-grafting procedures to percutaneous injection of corticosteroids or bone marrow. The purpose of this study was to evaluate the feasibility and effectiveness of percutaneous injection of a mixture of demineralized bone matrix and autogenous bone marrow for the treatment of simple bone cysts. Twenty-three patients with an active unicameral bone cyst were treated with trephination and injection of allogeneic demineralized bone matrix and autogenous bone marrow. The patients were followed for an average of fifty months (range, thirty to eighty-one months), at which time pain, function, and radiographic signs of resolution of the cyst were assessed. The average time until the patients had pain relief was five weeks, and the average time until the patients returned to full, unrestricted activities was six weeks. Bone-healing at the site of the injection was first seen radiographically at three to six months. No patient had a pathologic fracture during this early bone-healing stage. Cortical remodeling was seen radiographically by six to nine months, and after one year the response was usually complete, changing very little from then on. Five patients required a second injection because of recurrence of the cyst, and all five had a clinically and radiographically quiescent cyst after an average of thirty-six additional months of follow-up. Seven of the twenty-three patients had incomplete healing manifested by small, persistent radiolucent areas within the original cyst. None of these cysts increased in size or resulted in pain or fracture. Percutaneous injection of allogeneic demineralized bone matrix and autogenous bone marrow is an effective treatment for unicameral bone cysts.

Skeletal nutrient vascular adaptation induced by external oscillatory intramedullary fluid pressure intervention

Directory of Open Access Journals (Sweden)

Qin Yi-Xian

2010-03-01

Full Text Available Abstract Background Interstitial fluid flow induced by loading has demonstrated to be an important mediator for regulating bone mass and morphology. It is shown that the fluid movement generated by the intramedullary pressure (ImP provides a source for pressure gradient in bone. Such dynamic ImP may alter the blood flow within nutrient vessel adjacent to bone and directly connected to the marrow cavity, further initiating nutrient vessel adaptation. It is hypothesized that oscillatory ImP can mediate the blood flow in the skeletal nutrient vessels and trigger vasculature remodeling. The objective of this study was then to evaluate the vasculature remodeling induced by dynamic ImP stimulation as a function of ImP frequency. Methods Using an avian model, dynamics physiological fluid ImP (70 mmHg, peak-peak was applied in the marrow cavity of the left ulna at either 3 Hz or 30 Hz, 10 minutes/day, 5 days/week for 3 or 4 weeks. The histomorphometric measurements of the principal nutrient arteries were done to quantify the arterial wall area, lumen area, wall thickness, and smooth muscle cell layer numbers for comparison. Results The preliminary results indicated that the acute cyclic ImP stimuli can significantly enlarge the nutrient arterial wall area up to 50%, wall thickness up to 20%, and smooth muscle cell layer numbers up to 37%. In addition, 3-week of acute stimulation was sufficient to alter the arterial structural properties, i.e., increase of arterial wall area, whereas 4-week of loading showed only minimal changes regardless of the loading frequency. Conclusions These data indicate a potential mechanism in the interrelationship between vasculature adaptation and applied ImP alteration. Acute ImP could possibly initiate the remodeling in the bone nutrient vasculature, which may ultimately alter blood supply to bone.

Biomechanical adaptations of mice cortical bone submitted to three different exercise modalities

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Frajacomo, Fernando Tadeu Trevisan; Falcai, Maurício José; Fernandes, Cleverson Rodrigues; Shimano, Antonio Carlos; Garcia, Sérgio Britto

2013-01-01

Objective To compare the adaptive effects of three non-weight bearing exercise on bone mechanical properties. Methods 24 male Balb/c mice (22-25g), were randomly divided into four groups (n=6): sedentary group (S); swimming group (N) which performed sessions five times per week for 60 min progressively; resistance group (R), which performed climbing exercise with progressive load, three times per week; and combined group (C), which performed the same protocols aforementioned being three times a week according to N protocol and two times a week the R protocol during eight weeks. Biomechanical tests, load until failure and stiffness evaluation of shinbone was performed after animals have been sacrificed. Results Stiffness values were statistically higher only in the isolated modalities groups (N and R, 41.68 ± 10.43 and 41.21 ± 11.38 N/mm, respectively) compared with the S group (28.48 ± 7.34 N/mm). However, taking into consideration the final body mass, relative values, there was no difference in the biomechanical tests among the groups. Conclusion Data from the present investigation demonstrated a favorable influence of muscle contraction in lower impact isolated exercise modalities on absolute stiffness values, i.e.groups N and R, whereas the combined group (C) did not present any statistical significant difference compared to sedentary group. Level of Evidence II, Prospective Comparative Study. PMID:24453691

Instructive function of surface structure of calcium phosphate ceramics in bone regeneration

NARCIS (Netherlands)

Zhang, Jingwei

2016-01-01

The incidence of patients which require spinal fusion or bone regeneration in large bone defects caused by trauma, tumors, tumor resection, infections or abnormal skeletal development, is on the rise. Traditionally, in both spinal fusion surgery and other bone regeneration approaches, bone grafts

Natural killer function following allogeneic bone marrow transplantation. Very early reemergence but strong dependence of cytomegalovirus infection

DEFF Research Database (Denmark)

Hokland, M; Jacobsen, N; Ellegaard, J

1988-01-01

Natural killer (NK) cell function was followed sequentially after allogeneic bone marrow transplantation (BMT) using three approaches: (1) chromium-release assay with purified mononuclear effector cells, (2) chromium-release assay with whole blood effectors, and 3) enumeration of lymphocytes......) infections (primary or reactivated). In contrast, the presence of graft-versus-host (GVH) disease did not associate with consistent changes in the NK parameters measured here. After the first month of increase, NK declined reaching levels near those observed in their respective bone marrow donors at day 90...

[Metabolic status and bone mineral density in patients with pseudarthrosis of long bones in hyperhomocysteinemia].

Science.gov (United States)

Bezsmertnyĭ, Iu O

2013-06-01

In article described research of the metabolic status and bone mineral density in 153 patients with with pseudarthrosis of long bones, in individuals with consolidated fractures and healthy people. The violations of reparative osteogenesis at hyperhomocysteinemia are accompanied by disturbances of the functional state of bone tissue, inhibition of biosynthetic and increased destruction processes, reduced bone mineral density in the formation of osteopenia and osteoporosis. The degree and direction of change of bone depends on the type of violation of reparative osteogenesis.

An energetic orphan in an endocrine tissue: a revised perspective of the function of estrogen receptor-related receptor alpha in bone and cartilage.

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Bonnelye, Edith; Aubin, Jane E

2013-02-01

Estrogen receptor-related receptor alpha (ERRα) is an orphan nuclear receptor with sequence homology to the estrogen receptors, ERα/β, but it does not bind estrogen. ERRα not only plays a functional role in osteoblasts but also in osteoclasts and chondrocytes. In addition, the ERRs, including ERRα, can be activated by coactivators such as peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC1α and β) and are implicated in adipogenesis, fatty acid oxidation, and oxidative stress defense, suggesting that ERRα-through its activity in bone resorption and adipogenesis--may regulate the insulin and leptin pathways and contribute to aging-related changes in bone and cartilage. In this review, we discuss data on ERRα and its cellular and molecular modes of action, which have broad implications for considering the potential role of this orphan receptor in cartilage and bone endocrine function, on whole-organism physiology, and in the bone aging process. Copyright © 2013 American Society for Bone and Mineral Research.

Preservation of bone mass and structure in hibernating black bears (Ursus americanus) through elevated expression of anabolic genes.

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Fedorov, Vadim B; Goropashnaya, Anna V; Tøien, Øivind; Stewart, Nathan C; Chang, Celia; Wang, Haifang; Yan, Jun; Showe, Louise C; Showe, Michael K; Donahue, Seth W; Barnes, Brian M

2012-06-01

Physical inactivity reduces mechanical load on the skeleton, which leads to losses of bone mass and strength in non-hibernating mammalian species. Although bears are largely inactive during hibernation, they show no loss in bone mass and strength. To obtain insight into molecular mechanisms preventing disuse bone loss, we conducted a large-scale screen of transcriptional changes in trabecular bone comparing winter hibernating and summer non-hibernating black bears using a custom 12,800 probe cDNA microarray. A total of 241 genes were differentially expressed (P 1.4) in the ilium bone of bears between winter and summer. The Gene Ontology and Gene Set Enrichment Analysis showed an elevated proportion in hibernating bears of overexpressed genes in six functional sets of genes involved in anabolic processes of tissue morphogenesis and development including skeletal development, cartilage development, and bone biosynthesis. Apoptosis genes demonstrated a tendency for downregulation during hibernation. No coordinated directional changes were detected for genes involved in bone resorption, although some genes responsible for osteoclast formation and differentiation (Ostf1, Rab9a, and c-Fos) were significantly underexpressed in bone of hibernating bears. Elevated expression of multiple anabolic genes without induction of bone resorption genes, and the down regulation of apoptosis-related genes, likely contribute to the adaptive mechanism that preserves bone mass and structure through prolonged periods of immobility during hibernation.

The Role of Emotion Perception in Adaptive Functioning of People with Autism Spectrum Disorders

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Hudepohl, Margaret B.; Robins, Diana L.; King, Tricia Z.; Henrich, Christopher C.

2015-01-01

Cognitive functioning has historically been used to predict adaptive outcomes of people with autism spectrum disorders; however, research shows that it is not a complete predictor. The current study explored whether emotion perception was a predictor of adaptive outcomes, and more specifically, hypothesized that emotion perception (Diagnostic…

The Relation between Intellectual Functioning and Adaptive Behavior in the Diagnosis of Intellectual Disability

Science.gov (United States)

Tassé, Marc J.; Luckasson, Ruth; Schalock, Robert L.

2016-01-01

Intellectual disability originates during the developmental period and is characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills. In this article, we present a brief history of the diagnostic criteria of intellectual disability for both…

Effect of a new physiotherapy concept on bone mineral density, muscle force and gross motor function in children with bilateral cerebral palsy.

Science.gov (United States)

Stark, C; Nikopoulou-Smyrni, P; Stabrey, A; Semler, O; Schoenau, E

2010-06-01

The purpose of this study was to determine the effect of a new physiotherapy concept on bone density, muscle force and motor function in bilateral spastic cerebral palsy children. In a retrospective data analysis 78 children were analysed. The concept included whole body vibration, physiotherapy, resistance training and treadmill training. The concept is structured in two in-patient stays and two periods of three months home-based vibration training. Outcome measures were dual-energy x-ray absorption (DXA), Leonardo Tilt Table and a modified Gross Motor Function Measure before and after six months of training. Percent changes were highly significant for bone mineral density, -content, muscle mass and significant for angle of verticalisation, muscle force and modified Gross Motor Function Measure after six months training. The new physiotherapy concept had a significant effect on bone mineral density, muscle force and gross motor function in bilateral spastic cerebral palsy children. This implicates an amelioration in all International Classification of Functioning, Disability and Health levels. The study serves as a basis for future research on evidence based paediatric physiotherapy taking into account developmental implications.

ADAPTATION OF DASH OUTCOME MEASURES TO SLOVENIAN POPULATION - FUNCTIONALITY OF ARM, SHOULDER AND HAND

Directory of Open Access Journals (Sweden)

Katja Semprimožnik

2015-04-01

Full Text Available  ABSTRACT BackgroundIn Slovenia, there is no test for upper limb function, which would be uniform for all institutions and would allow comparison of results of the therapy and upper limb rehabilitation with medical centers. MethodsAfter reviewing the existing hand function tests and current literature we decided to translate the DASH test - Disabilities of arm, shoulder and hand. Adaptation was tested on patient population in outpatient hand clinic, General hospital Celje and showed good validity, reliability and responsiveness. Results and discussionAdaptation of DASH test to Slovene population is a procedure, where language and cultural differences must be considered. Testing the adapted DASH in the general population shows good validity, reliability and responsiveness of adapted test. ConclusionTranslations DASH test, QuickDASH test and instructions for scoring the DASH outcome measures are approved by the Institute for Work and Health. Translations are published on their site and available for use.

Brazilian Portuguese transcultural adaptation of Barkley Deficits in Executive Functioning Scale (BDEFS)

OpenAIRE

Godoy, Victor Polignano; Mata, Fernanda Gomes Da; Conde, Bárbara Romaneli; Souza, Caroline Antunes de Oliveira e; Martins, Ana Luiza Guimarães; Mattos, Paulo; Miranda, Débora Marques de; Malloy-Diniz, Leandro Fernandes

2015-01-01

Abstract Background Considering the importance of Executive Functions to clinical and nonclinical situations, Barkley proposed a new theory of executive functioning based on an evolutionary neuropsychological perspective and clinical research using large samples of clinical and community identified adults and children as well as children with ADHD followed to adulthood. Objective The present study aims to adapt the Barkley Deficits in Executive Functions Scales (BDEFS) to Brazilian Portug...

Are bi-axial proximal sesamoid bone fractures in the British Thoroughbred racehorse a bone fatigue related fracture? A histological study.

Science.gov (United States)

Kristoffersen, M; Hetzel, U; Parkin, T D H; Singer, E R

2010-01-01

To investigate whether microfractures and alterations in the trabecular bone area are associated with catastrophic bi-axial proximal sesamoid bone fractures (PSBF). Proximal sesamoid bones (PSB) from 10 racehorses with PSBF and from 10 control racehorses without musculoskeletal injury were examined using the bulk basic fuchsin method. Bone histomorphometric and microfracture analysis was performed, and cases and controls compared using two-sample t-test, paired t-test, and Mann-Whitney U test. There was no significant difference in the microfracture density and the trabecular bone area between bones from case and control horses, and between fractured and non-fractured bones in case horses. Microfracture density was low in the areas of the PSB examined. Microfracture density was not significantly different between groups, indicating that propagation of micro-cracks is an unlikely predisposing pathologic alteration in PSBF in British racehorses. There was no significant difference in the bone surface area between groups, which one would expect if modelling, adaptation and an increase in bone density were associated with PSBF fracture in the case horses. Therefore, PSBF in the British racehorse does not appear to be associated with microfractures of the trabecular bone of the PSB. The PSB fractures might represent an acute monotonic fracture; however, the aetiology of the fractures remains unknown with additional research required.

Adaptive landscape and functional diversity of Neotropical cichlids: implications for the ecology and evolution of Cichlinae (Cichlidae; Cichliformes).

Science.gov (United States)

Arbour, J H; López-Fernández, H

2014-11-01

Morphological, lineage and ecological diversity can vary substantially even among closely related lineages. Factors that influence morphological diversification, especially in functionally relevant traits, can help to explain the modern distribution of disparity across phylogenies and communities. Multivariate axes of feeding functional morphology from 75 species of Neotropical cichlid and a stepwise-AIC algorithm were used to estimate the adaptive landscape of functional morphospace in Cichlinae. Adaptive landscape complexity and convergence, as well as the functional diversity of Cichlinae, were compared with expectations under null evolutionary models. Neotropical cichlid feeding function varied primarily between traits associated with ram feeding vs. suction feeding/biting and secondarily with oral jaw muscle size and pharyngeal crushing capacity. The number of changes in selective regimes and the amount of convergence between lineages was higher than expected under a null model of evolution, but convergence was not higher than expected under a similarly complex adaptive landscape. Functional disparity was compatible with an adaptive landscape model, whereas the distribution of evolutionary change through morphospace corresponded with a process of evolution towards a single adaptive peak. The continentally distributed Neotropical cichlids have evolved relatively rapidly towards a number of adaptive peaks in functional trait space. Selection in Cichlinae functional morphospace is more complex than expected under null evolutionary models. The complexity of selective constraints in feeding morphology has likely been a significant contributor to the diversity of feeding ecology in this clade. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

A potential mechanism for allometric trabecular bone scaling in terrestrial mammals.

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Christen, Patrik; Ito, Keita; van Rietbergen, Bert

2015-03-01

Trabecular bone microstructural parameters, including trabecular thickness, spacing, and number, have been reported to scale with animal size with negative allometry, whereas bone volume fraction is animal size-invariant in terrestrial mammals. As for the majority of scaling patterns described in animals, its underlying mechanism is unknown. However, it has also been found that osteocyte density is inversely related to animal size, possibly adapted to metabolic rate, which shows a negative relationship as well. In addition, the signalling reach of osteocytes is limited by the extent of the lacuno-canalicular network, depending on trabecular dimensions and thus also on animal size. Here we propose animal size-dependent variations in osteocyte density and their signalling influence distance as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. Using an established and tested computational model of bone modelling and remodelling, we run simulations with different osteocyte densities and influence distances mimicking six terrestrial mammals covering a large range of body masses. Simulated trabecular structures revealed negative allometric scaling for trabecular thickness, spacing, and number, constant bone volume fraction, and bone turnover rates inversely related to animal size. These results are in agreement with previous observations supporting our proposal of osteocyte density and influence distance variation as a potential mechanism for negative allometric trabecular bone scaling in terrestrial mammals. The inverse relationship between bone turnover rates and animal size further indicates that trabecular bone scaling may be linked to metabolic rather than mechanical adaptations. © 2015 Anatomical Society.

Ultrasonic wave propagation in viscoelastic cortical bone plate coupled with fluids: a spectral finite element study.

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Nguyen, Vu-Hieu; Naili, Salah

2013-01-01

This work deals with the ultrasonic wave propagation in the cortical layer of long bones which is known as being a functionally graded anisotropic material coupled with fluids. The viscous effects are taken into account. The geometrical configuration mimics the one of axial transmission technique used for evaluating the bone quality. We present a numerical procedure adapted for this purpose which is based on the spectral finite element method (FEM). By using a combined Laplace-Fourier transform, the vibroacoustic problem may be transformed into the frequency-wavenumber domain in which, as radiation conditions may be exactly introduced in the infinite fluid halfspaces, only the heterogeneous solid layer needs to be analysed using FEM. Several numerical tests are presented showing very good performance of the proposed approach. We present some results to study the influence of the frequency on the first arriving signal velocity in (visco)elastic bone plate.

Association of Parameters of Mineral Bone Disorder with Mortality in Patients on Hemodialysis according to Level of Residual Kidney Function.

Science.gov (United States)

Wang, Mengjing; Obi, Yoshitsugu; Streja, Elani; Rhee, Connie M; Lau, Wei Ling; Chen, Jing; Hao, Chuanming; Hamano, Takayuki; Kovesdy, Csaba P; Kalantar-Zadeh, Kamyar

2017-07-07

The relationship between mineral and bone disorders and survival according to residual kidney function status has not been previously studied in patients on hemodialysis. We hypothesized that residual kidney function, defined by renal urea clearance, modifies the association between mineral and bone disorder parameters and mortality. The associations of serum phosphorus, albumin-corrected calcium, intact parathyroid hormone, and alkaline phosphatase with all-cause mortality were examined across three strata (kidney function modified the mortality risk associated with serum phosphorus and intact parathyroid hormone among incident hemodialysis patients. Future studies are needed to examine whether taking account for residual kidney function into the assessment of mortality risk associated with serum phosphorus and intact parathyroid hormone improves patient management and clinical outcomes in the hemodialysis population. Copyright © 2017 by the American Society of Nephrology.

Adaptive generalized function projective lag synchronization of different chaotic systems with fully uncertain parameters

International Nuclear Information System (INIS)

Wu Xiangjun; Lu Hongtao

2011-01-01

Highlights: → Adaptive generalized function projective lag synchronization (AGFPLS) is proposed. → Two uncertain chaos systems are lag synchronized up to a scaling function matrix. → The synchronization speed is sensitively influenced by the control gains. → The AGFPLS scheme is robust against noise perturbation. - Abstract: In this paper, a novel projective synchronization scheme called adaptive generalized function projective lag synchronization (AGFPLS) is proposed. In the AGFPLS method, the states of two different chaotic systems with fully uncertain parameters are asymptotically lag synchronized up to a desired scaling function matrix. By means of the Lyapunov stability theory, an adaptive controller with corresponding parameter update rule is designed for achieving AGFPLS between two diverse chaotic systems and estimating the unknown parameters. This technique is employed to realize AGFPLS between uncertain Lue chaotic system and uncertain Liu chaotic system, and between Chen hyperchaotic system and Lorenz hyperchaotic system with fully uncertain parameters, respectively. Furthermore, AGFPLS between two different uncertain chaotic systems can still be achieved effectively with the existence of noise perturbation. The corresponding numerical simulations are performed to demonstrate the validity and robustness of the presented synchronization method.

MicroRNA function and dysregulation in bone tumors: the evidence to date

International Nuclear Information System (INIS)

Nugent, Mary

2014-01-01

Micro ribonucleic acids (miRNAs) are small non-coding RNA segments that have a role in the regulation of normal cellular development and proliferation including normal osteogenesis. They exert their effects through inhibition of specific target genes at the post-transcriptional level. Many miRNAs have altered expression levels in cancer (either increased or decreased depending on the specific miRNA). Altered miRNA expression profiles have been identified in several malignancies including primary bone tumors such as osteosarcoma and Ewing’s sarcoma. It is thought that they may function as tumor suppressor genes or oncogenes and hence when dysregulated contribute to the initiation and progression of malignancy. miRNAs are also thought to have a role in the development of bone metastases in other malignancies. In addition, evidence increasingly suggests that miRNAs may play a part in determining the response to chemotherapy in the treatment of osteosarcoma. These molecules are readily detectable in tissues, both fresh and formalin fixed paraffin embedded and, more recently, in blood. Although there are fewer published studies regarding circulating miRNA profiles, they appear to reflect changes in tissue expression. Thus miRNAs may serve as potential indicators of disease presence but more importantly, may have a role in disease characterization or as potential therapeutic targets. This review gives a brief overview of miRNA biochemistry and explores the evidence to date implicating these small molecules in the pathogenesis of bone tumors

MicroRNA function and dysregulation in bone tumors: the evidence to date.

LENUS (Irish Health Repository)

Nugent, Mary

2014-01-01

Micro ribonucleic acids (miRNAs) are small non-coding RNA segments that have a role in the regulation of normal cellular development and proliferation including normal osteogenesis. They exert their effects through inhibition of specific target genes at the post-transcriptional level. Many miRNAs have altered expression levels in cancer (either increased or decreased depending on the specific miRNA). Altered miRNA expression profiles have been identified in several malignancies including primary bone tumors such as osteosarcoma and Ewing\\'s sarcoma. It is thought that they may function as tumor suppressor genes or oncogenes and hence when dysregulated contribute to the initiation and progression of malignancy. miRNAs are also thought to have a role in the development of bone metastases in other malignancies. In addition, evidence increasingly suggests that miRNAs may play a part in determining the response to chemotherapy in the treatment of osteosarcoma. These molecules are readily detectable in tissues, both fresh and formalin fixed paraffin embedded and, more recently, in blood. Although there are fewer published studies regarding circulating miRNA profiles, they appear to reflect changes in tissue expression. Thus miRNAs may serve as potential indicators of disease presence but more importantly, may have a role in disease characterization or as potential therapeutic targets. This review gives a brief overview of miRNA biochemistry and explores the evidence to date implicating these small molecules in the pathogenesis of bone tumors.

Non-linear pattern formation in bone growth and architecture.

Science.gov (United States)

Salmon, Phil

2014-01-01

The three-dimensional morphology of bone arises through adaptation to its required engineering performance. Genetically and adaptively bone travels along a complex spatiotemporal trajectory to acquire optimal architecture. On a cellular, micro-anatomical scale, what mechanisms coordinate the activity of osteoblasts and osteoclasts to produce complex and efficient bone architectures? One mechanism is examined here - chaotic non-linear pattern formation (NPF) - which underlies in a unifying way natural structures as disparate as trabecular bone, swarms of birds flying, island formation, fluid turbulence, and others. At the heart of NPF is the fact that simple rules operating between interacting elements, and Turing-like interaction between global and local signals, lead to complex and structured patterns. The study of "group intelligence" exhibited by swarming birds or shoaling fish has led to an embodiment of NPF called "particle swarm optimization" (PSO). This theoretical model could be applicable to the behavior of osteoblasts, osteoclasts, and osteocytes, seeing them operating "socially" in response simultaneously to both global and local signals (endocrine, cytokine, mechanical), resulting in their clustered activity at formation and resorption sites. This represents problem-solving by social intelligence, and could potentially add further realism to in silico computer simulation of bone modeling. What insights has NPF provided to bone biology? One example concerns the genetic disorder juvenile Pagets disease or idiopathic hyperphosphatasia, where the anomalous parallel trabecular architecture characteristic of this pathology is consistent with an NPF paradigm by analogy with known experimental NPF systems. Here, coupling or "feedback" between osteoblasts and osteoclasts is the critical element. This NPF paradigm implies a profound link between bone regulation and its architecture: in bone the architecture is the regulation. The former is the emergent

Adaptive responses of cardiac function to fetal postural change as gestational age increases

Science.gov (United States)

Kim, Woo Jin; Choi, Hye Jin; Yang, Sun Young; Koo, Boo Hae; Ahn, Ki Hoon; Hong, Soon Cheol; Oh, Min-Jeong; Kim, Hai-Joong

2016-01-01

Objective The cardiovascular system maintains homeostasis through a series of adaptive responses to physiological requirements. However, little is known about the adaptation of fetal cardiac function to gravity, according to gestational age. In the present study, we aimed to evaluate the adaptive responses of cardiac function to postural changes, using Tei index measurements. Methods Fetal echocardiography and Doppler examination were performed on 114 women with vertex singleton pregnancies at 19 to 40 weeks' gestation. Participants were placed in an upright seated position, and the Tei index for fetal left ventricular cardiac function was measured. The women were then moved into a supine position and the Tei index was re-measured. Results The mean Tei index when measured in an upright seated position was significantly lower than that measured in a supine positioning for all fetuses (0.528±0.103 vs. 0.555±0.106, P=0.014, respectively). This difference was also noted in fetuses with a gestational age of 28–40 weeks (0.539±0.107 vs. 0.574±0.102, P=0.011, respectively). However, there was no difference in the Tei index between an upright seated and a supine position among fetuses with a gestational age of Postural changes from an upright seated to a supine position result in an increased Tei index after a gestational age of 28 weeks. This appears to reflect maturation in the adaptive responses of the fetal cardiovascular system to postural changes. PMID:27896244

Role of Osteal Macrophages in Bone Metabolism

Directory of Open Access Journals (Sweden)

Sun Wook Cho

2015-03-01

Full Text Available Macrophages have been shown to have pleiotropic functions in various pathophysiologies, especially in terms of anti-inflammatory and regenerative activity. Recently, the novel functions of bone marrow resident macrophages (called osteal macrophages were intensively studied in bone development, remodeling and tissue repair processes. This review discusses the current evidence for a role of osteal macrophages in bone modeling, remodeling, and fracture healing processes.

Three-dimensional Microarchitecture of Adolescent Cancellous Bone

DEFF Research Database (Denmark)

Ding, Ming; Hvid, I; Overgaard, Søren

regarding three-dimensional (3-D) microarchitecture of normal adolescent cancellous bone. The objective of this study was to investigate 3-D microarchitecture of normal adolescent cancellous bone, and compared them with adult cancellous bone, thus seeking more insight into the subchondral bone adaptations...... of lateral condyle in the young adult. There were no statistical significances in the mechanical properties apart from the Young’s modulus of adolescent in anterior-posterior direction was significantly lower than the other groups. DISCUSSION: This is the first study on the 3-D microarchitecture of human......, Switzerland) resulting in cubic voxel sizes of 10*10*10 m3. Microarchitectural properties were calculated, and the mean values for either tibia, medial or lateral condyle were used in analyses. Furthermore, the samples were first tested non-destructively in compression in antero-posterior (AP) and medial...

Functional Task Test: 3. Skeletal Muscle Performance Adaptations to Space Flight

Science.gov (United States)

Ryder, Jeffrey W.; Wickwire, P. J.; Buxton, R. E.; Bloomberg, J. J.; Ploutz-Snyder, L.

2011-01-01

The functional task test is a multi-disciplinary study investigating how space-flight induced changes to physiological systems impacts functional task performance. Impairment of neuromuscular function would be expected to negatively affect functional performance of crewmembers following exposure to microgravity. This presentation reports the results for muscle performance testing in crewmembers. Functional task performance will be presented in the abstract "Functional Task Test 1: sensory motor adaptations associated with postflight alternations in astronaut functional task performance." METHODS: Muscle performance measures were obtained in crewmembers before and after short-duration space flight aboard the Space Shuttle and long-duration International Space Station (ISS) missions. The battery of muscle performance tests included leg press and bench press measures of isometric force, isotonic power and total work. Knee extension was used for the measurement of central activation and maximal isometric force. Upper and lower body force steadiness control were measured on the bench press and knee extension machine, respectively. Tests were implemented 60 and 30 days before launch, on landing day (Shuttle crew only), and 6, 10 and 30 days after landing. Seven Space Shuttle crew and four ISS crew have completed the muscle performance testing to date. RESULTS: Preliminary results for Space Shuttle crew reveal significant reductions in the leg press performance metrics of maximal isometric force, power and total work on R+0 (pperformance metrics were observed in returning Shuttle crew and these adaptations are likely contributors to impaired functional tasks that are ambulatory in nature (See abstract Functional Task Test: 1). Interestingly, no significant changes in central activation capacity were detected. Therefore, impairments in muscle function in response to short-duration space flight are likely myocellular rather than neuromotor in nature.

The relationships of personal and cultural identity to adaptive and maladaptive psychosocial functioning in emerging adults.

Science.gov (United States)

Schwartz, Seth J; Zamboanga, Byron L; Weisskirch, Robert S; Wang, Sherry C

2010-01-01

The present study examined the extent to which cultural identity would be associated with adaptive and maladaptive psychosocial functioning, both directly and indirectly through a personal identity consolidation. A sample of 773 White, Black, and Hispanic university students completed measures of cultural identity, personal identity consolidation, adaptive psychosocial functioning, internalizing symptoms, and proclivity toward externalizing symptoms. Both heritage and American cultural identity were positively related to adaptive psychosocial functioning; American-culture identity was negatively associated with internalizing symptoms; and heritage-culture identity was negatively related to proclivity toward externalizing symptoms. All of these findings were mediated by personal identity consolidation and were fully consistent across ethnic groups. We discuss implications in terms of broadening the study of identity to include both personal and cultural dimensions of self.

Cognitive plasticity as a moderator of functional dependency in elderly patients hospitalized for bone fractures.

Science.gov (United States)

Calero-García, M J; Calero, M D; Navarro, E; Ortega, A R

2015-01-01

Bone fractures in older adults involve hospitalization and surgical intervention, aspects that have been related to loss of autonomy and independence. Several variables have been studied as moderators of how these patients recover. However, the implications of cognitive plasticity for functional recovery have not been studied to date. The present study analyzes the relationship between cognitive plasticity--defined as the capacity for learning or improved performance under conditions of training or performance optimization--and functional recovery in older adults hospitalized following a bone fracture. The study comprised 165 older adults who underwent surgery for bone fractures at a hospital in southern Spain. Participants were evaluated at different time points thereafter, with instruments that measure activities of daily life (ADL), namely the Barthel Index (BI) and the Lawton Index, as well as with a learning potential (cognitive plasticity) assessment test (Auditory Verbal Learning Test of Learning Potential, AVLT-LP). Results show that most of the participants have improved their level of independence 3 months after the intervention. However, some patients continue to have medium to high levels of dependency and this dependency is related to cognitive plasticity. The results of this study reveal the importance of the cognitive plasticity variable for evaluating older adults hospitalized for a fracture. They indicate a possible benefit to be obtained by implementing programs that reduce the degree of long-term dependency or decrease the likelihood of it arising.

Preliminary functional results and quality of life after implantation of a new bone conduction hearing device in patients with conductive and mixed hearing loss.

Science.gov (United States)

Ihler, Friedrich; Volbers, Laura; Blum, Jenny; Matthias, Christoph; Canis, Martin

2014-02-01

To review functional results and quality of life of the first patients implanted with a newly introduced bone conduction implant system. Retrospective chart analysis of 6 patients (6 ears) implanted for conductive hearing loss (CHL) and mixed hearing loss (MHL) in 1 tertiary referral center between July 2012 and February 2013. Implantation of a new bone conduction hearing device. Pure tone audiometry (air conduction and bone conduction thresholds, pure tone average, air-bone gap, and functional gain), speech audiometry (Freiburg Monosyllabic Test), intraoperative and postoperative complication rate, and patient satisfaction (Glasgow benefit inventory [GBI]) were assessed. Air-conduction pure tone average (PTA) was 58.8 ± 8.2 dB HL. Unaided average air-bone gap (ABG) was 33.3 ± 6.2 dB. Aided air-conduction PTA in sound field was 25.2 ± 5.1 dB HL. Aided average ABG was -0.3 ± 7.3 dB. Average functional gain was 33.6 ± 7.2 dB. Mean improvement of GBI was +36.1. No intraoperative complications occurred. During a follow-up period of 8.5 ± 2.2 months, no device failure and no need for revision surgery occurred. Audiometric results of the new bone conduction hearing system are satisfying and comparable to the results of devices that have been applied previously for CHL and MHL. Intraoperatively and postoperatively, no complications were noted.

Bone scintigraphy in the diagnosis of fracture and infection of the temporal bone

International Nuclear Information System (INIS)

Djupesland, G.; Nakken, K.F.; Mueller, C.; Skjoerten, F.; Roehrt, T.; Eldevik, P.

1983-01-01

The sensivit of Tc99m-MDP-bone-scintiscanning in the diagnosis of temporal bone fracture was found to that of conventional radiography if the patients were examined 10 days after the trauma. Temporal bone osteomyelitis with concomitant moderate osteosclerosis was demonstrated by bone scintigraphy in 5 cases of mastoiditis with atypical symptoms. A case of apicitis was for the first time demonstrated by scintigraphy. A low sensivity of 67 Ga-scintigraphy was demonstrated by positive Tc99m-bone-scintigraphy and negative 67 Ga-scintigraphy in a patient with atypical mastoiditis. Tc99m-scintigraphy was negative in 5 cases of otitis media suppurative and in 3 cases of otitis media chronica cum cholesteatoma, all with slight degree of osteosclerosis in the mastoid. The sensitivity of Tc99m-bone-scintigraphy in fracture and osteomyelitis of the temporal bone seems to be a function of the amount of reactive new bone formed. (Authors)

P2X7 receptor regulates osteoclast function and bone loss in a mouse model of osteoporosis

DEFF Research Database (Denmark)

Wang, Ning; Agrawal, Ankita; Jørgensen, Niklas Rye

2018-01-01

Post-menopausal osteoporosis is a condition that affects millions worldwide and places a huge socio-economic burden on society. Previous research has shown an association of loss of function SNPs in the gene for the purinergic receptor P2X7R with low bone mineral density, increased rates of bone...... loss and vertebral fractures in post-menopausal women. In this study we use a mouse model of oestrogen deficiency-induced bone loss and the BALB/cJ P2X7R-/- to show that absence of the P2X7R resulted in increased bone loss. Osteoclast precursors were isolated from both BALB/cJ P2X7R-/- and BALB/cJ P2X7......R+/+ mice and then cultured in vitro to form mature resorbing osteoclasts. The BALB/cJ P2X7R-/- derived precursors generated slightly more osteoclasts but with a significant reduction in the amount of resorption per osteoclast. Furthermore, when using modified culture conditions osteoclast activity...

Bioactive lipid coating of bone allografts directs engraftment and fate determination of bone marrow-derived cells in rat GFP chimeras.

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Das, Anusuya; Segar, Claire E; Chu, Yihsuan; Wang, Tiffany W; Lin, Yong; Yang, Chunxi; Du, Xeujun; Ogle, Roy C; Cui, Quanjun; Botchwey, Edward A

2015-09-01

Bone grafting procedures are performed to treat wounds incurred during wartime trauma, accidents, and tumor resections. Endogenous mechanisms of repair are often insufficient to ensure integration between host and donor bone and subsequent restoration of function. We investigated the role that bone marrow-derived cells play in bone regeneration and sought to increase their contributions by functionalizing bone allografts with bioactive lipid coatings. Polymer-coated allografts were used to locally deliver the immunomodulatory small molecule FTY720 in tibial defects created in rat bone marrow chimeras containing genetically-labeled bone marrow for monitoring cell origin and fate. Donor bone marrow contributed significantly to both myeloid and osteogenic cells in remodeling tissue surrounding allografts. FTY720 coatings altered the phenotype of immune cells two weeks post-injury, which was associated with increased vascularization and bone formation surrounding allografts. Consequently, degradable polymer coating strategies that deliver small molecule growth factors such as FTY720 represent a novel therapeutic strategy for harnessing endogenous bone marrow-derived progenitors and enhancing healing in load-bearing bone defects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Deproteinized bovine bone functionalized with the slow delivery of BMP-2 for the repair of critical-sized bone defects in sheep

NARCIS (Netherlands)

Liu, T.; Wu, G.; Wismeijer, D.; Gu, Z.; Liu, Y.

2013-01-01

As an alternative to an autologous bone graft, deproteinized bovine bone (DBB) is widely used in the clinical dentistry. Although DBB provides an osteoconductive scaffold, it is not capable of enhancing bone regeneration because it is not osteoinductive. In order to render DBB osteoinductive, bone

Acute hypothalamic suppression significantly affects trabecular bone but not cortical bone following recovery and ovariectomy surgery in a rat model

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Vanessa R. Yingling

2016-01-01

Full Text Available Background. Osteoporosis is “a pediatric disease with geriatric consequences.” Bone morphology and tissue quality co-adapt during ontogeny for sufficient bone stiffness. Altered bone morphology from hypothalamic amenorrhea, a risk factor for low bone mass in women, may affect bone strength later in life. Our purpose was to determine if altered morphology following hypothalamic suppression during development affects cortical bone strength and trabecular bone volume (BV/TV at maturity.Methods. Female rats (25 days old were assigned to a control (C group (n = 45 that received saline injections (.2 cc or an experimental group (GnRH-a (n = 45 that received gonadotropin releasing hormone antagonist injections (.24 mg per dose for 25 days. Fifteen animals from each group were sacrificed immediately after the injection protocol at Day 50 (C, GnRH-a. The remaining animals recovered for 135 days and a subset of each group was sacrificed at Day 185 ((C-R (n = 15 and (G-R (n = 15. The remaining animals had an ovariectomy surgery (OVX at 185 days of age and were sacrificed 40 days later (C-OVX (n = 15 and (G-OVX (n = 15. After sacrifice femurs were mechanically tested and scanned using micro CT. Serum C-terminal telopeptides (CTX and insulin-like growth factor 1 (IGF-1 were measured. Two-way ANOVA (2 groups (GnRH-a and Control X 3 time points (Injection Protocol, Recovery, post-OVX was computed.Results. GnRH-a injections suppressed uterine weights (72% and increased CTX levels by 59%. Bone stiffness was greater in the GnRH-a groups compared to C. Ash content and cortical bone area were similar between groups at all time points. Polar moment of inertia, a measure of bone architecture, was 15% larger in the GnRH-a group and remained larger than C (19% following recovery. Both the polar moment of inertia and cortical area increased linearly with the increases in body weight. Following the injection protocol, trabecular BV/TV was 31% lower in the Gn

Adaptation gap hypothesis: How differences between users’ expected and perceived agent functions affect their subjective impression

Directory of Open Access Journals (Sweden)

Takanori Komatsu

2011-02-01

Full Text Available We describe an “adaptation gap” that indicates the differences between the functions of artificial agents that users expect before starting their interactions and the functions they perceive after their interactions. We investigated the effect of this adaptation gap on users’ impressions of artificial agents because any variations in impression before and after the start of an interaction determines whether the user feels that this agent is worth interacting with. The results showed that positive or negative signs of the adaptation gap and subjective impression scores of agents before the experiment significantly affected the users’ final impressions of the agents.

Automatic Detection of Cortical Bones Haversian Osteonal Boundaries

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Ilige Hage

2015-10-01

Full Text Available This work aims to automatically detect cement lines in decalcified cortical bone sections stained with H&E. Employed is a methodology developed previously by the authors and proven to successfully count and disambiguate the micro-architectural features (namely Haversian canals, canaliculi, and osteocyte lacunae present in the secondary osteons/Haversian system (osteon of cortical bone. This methodology combines methods typically considered separately, namely pulse coupled neural networks (PCNN, particle swarm optimization (PSO, and adaptive threshold (AT. In lieu of human bone, slides (at 20× magnification from bovid cortical bone are used in this study as proxy of human bone. Having been characterized, features with same orientation are used to detect the cement line viewed as the next coaxial layer adjacent to the outermost lamella of the osteon. Employed for this purpose are three attributes for each and every micro-sized feature identified in the osteon lamellar system: (1 orientation, (2 size (ellipse perimeter and (3 Euler number (a topological measure. From a training image, automated parameters for the PCNN network are obtained by forming fitness functions extracted from these attributes. It is found that a 3-way combination of these features attributes yields good representations of the overall osteon boundary (cement line. Near-unity values of classical metrics of quality (precision, sensitivity, specificity, accuracy, and dice suggest that the segments obtained automatically by the optimized artificial intelligent methodology are of high fidelity as compared with manual tracing. For bench marking, cement lines segmented by k-means did not fare as well. An analysis based on the modified Hausdorff distance (MHD of the segmented cement lines also testified to the quality of the detected cement lines vis-a-vis the k-means method.

Direct Reprogramming of Human Bone Marrow Stromal Cells into Functional Renal Cells Using Cell-free Extracts

Directory of Open Access Journals (Sweden)

Evangelia Papadimou

2015-04-01

Full Text Available The application of cell-based therapies in regenerative medicine is gaining recognition. Here, we show that human bone marrow stromal cells (BMSCs, also known as bone-marrow-derived mesenchymal cells, can be reprogrammed into renal proximal tubular-like epithelial cells using cell-free extracts. Streptolysin-O-permeabilized BMSCs exposed to HK2-cell extracts underwent morphological changes—formation of “domes” and tubule-like structures—and acquired epithelial functional properties such as transepithelial-resistance, albumin-binding, and uptake and specific markers E-cadherin and aquaporin-1. Transmission electron microscopy revealed the presence of brush border microvilli and tight intercellular contacts. RNA sequencing showed tubular epithelial transcript abundance and revealed the upregulation of components of the EGFR pathway. Reprogrammed BMSCs integrated into self-forming kidney tissue and formed tubular structures. Reprogrammed BMSCs infused in immunodeficient mice with cisplatin-induced acute kidney injury engrafted into proximal tubuli, reduced renal injury and improved function. Thus, reprogrammed BMSCs are a promising cell resource for future cell therapy.