WorldWideScience

Sample records for endochondral bone development

  1. Chondrocytes transdifferentiate into osteoblasts in endochondral bone during development, postnatal growth and fracture healing in mice.

    Directory of Open Access Journals (Sweden)

    Xin Zhou

    2014-12-01

    Full Text Available One of the crucial steps in endochondral bone formation is the replacement of a cartilage matrix produced by chondrocytes with bone trabeculae made by osteoblasts. However, the precise sources of osteoblasts responsible for trabecular bone formation have not been fully defined. To investigate whether cells derived from hypertrophic chondrocytes contribute to the osteoblast pool in trabecular bones, we genetically labeled either hypertrophic chondrocytes by Col10a1-Cre or chondrocytes by tamoxifen-induced Agc1-CreERT2 using EGFP, LacZ or Tomato expression. Both Cre drivers were specifically active in chondrocytic cells and not in perichondrium, in periosteum or in any of the osteoblast lineage cells. These in vivo experiments allowed us to follow the fate of cells labeled in Col10a1-Cre or Agc1-CreERT2 -expressing chondrocytes. After the labeling of chondrocytes, both during prenatal development and after birth, abundant labeled non-chondrocytic cells were present in the primary spongiosa. These cells were distributed throughout trabeculae surfaces and later were present in the endosteum, and embedded within the bone matrix. Co-expression studies using osteoblast markers indicated that a proportion of the non-chondrocytic cells derived from chondrocytes labeled by Col10a1-Cre or by Agc1-CreERT2 were functional osteoblasts. Hence, our results show that both chondrocytes prior to initial ossification and growth plate chondrocytes before or after birth have the capacity to undergo transdifferentiation to become osteoblasts. The osteoblasts derived from Col10a1-expressing hypertrophic chondrocytes represent about sixty percent of all mature osteoblasts in endochondral bones of one month old mice. A similar process of chondrocyte to osteoblast transdifferentiation was involved during bone fracture healing in adult mice. Thus, in addition to cells in the periosteum chondrocytes represent a major source of osteoblasts contributing to endochondral bone

  2. Roles of Chondrocytes in Endochondral Bone Formation and Fracture Repair

    Science.gov (United States)

    Hinton, R.J.; Jing, Y.; Jing, J.; Feng, J.Q.

    2016-01-01

    The formation of the mandibular condylar cartilage (MCC) and its subchondral bone is an important but understudied topic in dental research. The current concept regarding endochondral bone formation postulates that most hypertrophic chondrocytes undergo programmed cell death prior to bone formation. Under this paradigm, the MCC and its underlying bone are thought to result from 2 closely linked but separate processes: chondrogenesis and osteogenesis. However, recent investigations using cell lineage tracing techniques have demonstrated that many, perhaps the majority, of bone cells are derived via direct transformation from chondrocytes. In this review, the authors will briefly discuss the history of this idea and describe recent studies that clearly demonstrate that the direct transformation of chondrocytes into bone cells is common in both long bone and mandibular condyle development and during bone fracture repair. The authors will also provide new evidence of a distinct difference in ossification orientation in the condylar ramus (1 ossification center) versus long bone ossification formation (2 ossification centers). Based on our recent findings and those of other laboratories, we propose a new model that contrasts the mode of bone formation in much of the mandibular ramus (chondrocyte-derived) with intramembranous bone formation of the mandibular body (non-chondrocyte-derived). PMID:27664203

  3. Loss of ephrinB1 in osteogenic progenitor cells impedes endochondral ossification and compromises bone strength integrity during skeletal development.

    Science.gov (United States)

    Nguyen, Thao M; Arthur, Agnieszka; Paton, Sharon; Hemming, Sarah; Panagopoulos, Romana; Codrington, John; Walkley, Carl R; Zannettino, Andrew C W; Gronthos, Stan

    2016-12-01

    The EphB receptor tyrosine kinase family and their ephrinB ligands have been implicated as mediators of skeletal development and bone homeostasis in humans, where mutations in ephrinB1 contribute to frontonasal dysplasia and coronal craniosynostosis. In mouse models, ephrinB1 has been shown to be a critical factor mediating osteoblast function. The present study examined the functional importance of ephrinB1 during endochondral ossification using the Cre recombination system with targeted deletion of ephrinB1 (EfnB1 fl/fl ) in osteogenic progenitor cells, under the control of the osterix (Osx:Cre) promoter. The Osx:EfnB1 -/- mice displayed aberrant bone growth during embryonic and postnatal skeletal development up to 4weeks of age, when compared to the Osx:Cre controls. Furthermore, compared to the Osx:Cre control mice, the Osx:EfnB1 -/- mice exhibited significantly weaker and less rigid bones, with a reduction in trabecular/ cortical bone formation, reduced trabecular architecture and a reduction in the size of the growth plates at the distal end of the femora from newborn through to 4weeks of age. The aberrant bone formation correlated with increased numbers of tartrate resistant acid phosphatase positive osteoclasts and decreased numbers of bone lining osteoblasts in 4week old Osx:EfnB1 -/- mice, compared to Osx:Cre control mice. Taken together, these observations demonstrate the importance of ephrinB1 signalling between cells of the skeleton required for endochondral ossification. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Engineering Small-Scale and Scaffold-Based Bone Organs via Endochondral Ossification Using Adult Progenitor Cells.

    Science.gov (United States)

    Scotti, Celeste; Tonnarelli, Beatrice; Papadimitropoulos, Adam; Piccinini, Elia; Todorov, Atanas; Centola, Matteo; Barbero, Andrea; Martin, Ivan

    2016-01-01

    Bone development, growth, and repair predominantly occur through the process of endochondral ossification, characterized by remodelling of cartilaginous templates. The same route efficiently supports engineering of bone marrow as a niche for hematopoietic stem cells (HSC). Here we describe a combined in vitro/in vivo system based on bone marrow-derived Mesenchymal Stem/Stromal Cells (MSC) that duplicates the hallmark cellular and molecular events of endochondral ossification during development. The model requires MSC culture with instructive molecules to generate hypertrophic cartilage tissues. The resulting constructs complete the endochondral route upon in vivo implantation, in the timeframe of up to 12 weeks. The described protocol is clearly distinct from the direct ossification approach typically used to drive MSC towards osteogenesis. Recapitulation of endochondral ossification allows modelling of stromal-HSC interactions in physiology and pathology and allows engineering processes underlying bone regeneration.

  5. Recapitulation of endochondral bone formation using human adult mesenchymal stem cells as a paradigm for developmental engineering.

    Science.gov (United States)

    Scotti, Celeste; Tonnarelli, Beatrice; Papadimitropoulos, Adam; Scherberich, Arnaud; Schaeren, Stefan; Schauerte, Alexandra; Lopez-Rios, Javier; Zeller, Rolf; Barbero, Andrea; Martin, Ivan

    2010-04-20

    Mesenchymal stem/stromal cells (MSC) are typically used to generate bone tissue by a process resembling intramembranous ossification, i.e., by direct osteoblastic differentiation. However, most bones develop by endochondral ossification, i.e., via remodeling of hypertrophic cartilaginous templates. To date, endochondral bone formation has not been reproduced using human, clinically compliant cell sources. Here, we aimed at engineering tissues from bone marrow-derived, adult human MSC with an intrinsic capacity to undergo endochondral ossification. By analogy to embryonic limb development, we hypothesized that successful execution of the endochondral program depends on the initial formation of hypertrophic cartilaginous templates. Human MSC, subcutaneously implanted into nude mice at various stages of chondrogenic differentiation, formed bone trabeculae only when they had developed in vitro hypertrophic tissue structures. Advanced maturation in vitro resulted in accelerated formation of larger bony tissues. The underlying morphogenetic process was structurally and molecularly similar to the temporal and spatial progression of limb bone development in embryos. In particular, Indian hedgehog signaling was activated at early stages and required for the in vitro formation of hypertrophic cartilage. Subsequent development of a bony collar in vivo was followed by vascularization, osteoclastic resorption of the cartilage template, and appearance of hematopoietic foci. This study reveals the capacity of human MSC to generate bone tissue via an endochondral program and provides a valid model to study mechanisms governing bone development. Most importantly, this process could generate advanced grafts for bone regeneration by invoking a "developmental engineering" paradigm.

  6. Palmitoyl acyltransferase, Zdhhc13, facilitates bone mass acquisition by regulating postnatal epiphyseal development and endochondral ossification: a mouse model.

    Directory of Open Access Journals (Sweden)

    I-Wen Song

    Full Text Available ZDHHC13 is a member of DHHC-containing palmitoyl acyltransferases (PATs family of enzymes. It functions by post-translationally adding 16-carbon palmitate to proteins through a thioester linkage. We have previously shown that mice carrying a recessive Zdhhc13 nonsense mutation causing a Zdhcc13 deficiency develop alopecia, amyloidosis and osteoporosis. Our goal was to investigate the pathogenic mechanism of osteoporosis in the context of this mutation in mice. Body size, skeletal structure and trabecular bone were similar in Zdhhc13 WT and mutant mice at birth. Growth retardation and delayed secondary ossification center formation were first observed at day 10 and at 4 weeks of age, disorganization in growth plate structure and osteoporosis became evident in mutant mice. Serial microCT from 4-20 week-olds revealed that Zdhhc13 mutant mice had reduced bone mineral density. Through co-immunoprecipitation and acyl-biotin exchange, MT1-MMP was identified as a direct substrate of ZDHHC13. In cells, reduction of MT1-MMP palmitoylation affected its subcellular distribution and was associated with decreased VEGF and osteocalcin expression in chondrocytes and osteoblasts. In Zdhhc13 mutant mice epiphysis where MT1-MMP was under palmitoylated, VEGF in hypertrophic chondrocytes and osteocalcin at the cartilage-bone interface were reduced based on immunohistochemical analyses. Our results suggest that Zdhhc13 is a novel regulator of postnatal skeletal development and bone mass acquisition. To our knowledge, these are the first data to suggest that ZDHHC13-mediated MT1-MMP palmitoylation is a key modulator of bone homeostasis. These data may provide novel insights into the role of palmitoylation in the pathogenesis of human osteoporosis.

  7. Loss of transcription factor early growth response gene 1 results in impaired endochondral bone repair.

    Science.gov (United States)

    Reumann, Marie K; Strachna, Olga; Yagerman, Sarah; Torrecilla, Daniel; Kim, Jihye; Doty, Stephen B; Lukashova, Lyudmila; Boskey, Adele L; Mayer-Kuckuk, Philipp

    2011-10-01

    Transcription factors that play a role in ossification during development are expected to participate in postnatal fracture repair since the endochondral bone formation that occurs in embryos is recapitulated during fracture repair. However, inherent differences exist between bone development and fracture repair, including a sudden disruption of tissue integrity followed by an inflammatory response. This raises the possibility that repair-specific transcription factors participate in bone healing. Here, we assessed the consequence of loss of early growth response gene 1 (EGR-1) on endochondral bone healing because this transcription factor has been shown to modulate repair in vascularized tissues. Model fractures were created in ribs of wild type (wt) and EGR-1(-/-) mice. Differences in tissue morphology and composition between these two animal groups were followed over 28 post fracture days (PFDs). In wt mice, bone healing occurred in healing phases characteristic of endochondral bone repair. A similar healing sequence was observed in EGR-1(-/-) mice but was impaired by alterations. A persistent accumulation of fibrin between the disconnected bones was observed on PFD7 and remained pronounced in the callus on PFD14. Additionally, the PFD14 callus was abnormally enlarged and showed increased deposition of mineralized tissue. Cartilage ossification in the callus was associated with hyper-vascularity and -proliferation. Moreover, cell deposits located in proximity to the callus within skeletal muscle were detected on PFD14. Despite these impairments, repair in EGR-1(-/-) callus advanced on PFD28, suggesting EGR-1 is not essential for healing. Together, this study provides genetic evidence that EGR-1 is a pleiotropic regulator of endochondral fracture repair. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. NGF-TrkA Signaling by Sensory Nerves Coordinates the Vascularization and Ossification of Developing Endochondral Bone

    Directory of Open Access Journals (Sweden)

    Ryan E. Tomlinson

    2016-09-01

    Full Text Available Developing tissues dictate the amount and type of innervation they require by secreting neurotrophins, which promote neuronal survival by activating distinct tyrosine kinase receptors. Here, we show that nerve growth factor (NGF signaling through neurotrophic tyrosine kinase receptor type 1 (TrkA directs innervation of the developing mouse femur to promote vascularization and osteoprogenitor lineage progression. At the start of primary ossification, TrkA-positive axons were observed at perichondrial bone surfaces, coincident with NGF expression in cells adjacent to centers of incipient ossification. Inactivation of TrkA signaling during embryogenesis in TrkAF592A mice impaired innervation, delayed vascular invasion of the primary and secondary ossification centers, decreased numbers of Osx-expressing osteoprogenitors, and decreased femoral length and volume. These same phenotypic abnormalities were observed in mice following tamoxifen-induced disruption of NGF in Col2-expressing perichondrial osteochondral progenitors. We conclude that NGF serves as a skeletal neurotrophin to promote sensory innervation of developing long bones, a process critical for normal primary and secondary ossification.

  9. NGF-TrkA Signaling by Sensory Nerves Coordinates the Vascularization and Ossification of Developing Endochondral Bone.

    Science.gov (United States)

    Tomlinson, Ryan E; Li, Zhi; Zhang, Qian; Goh, Brian C; Li, Zhu; Thorek, Daniel L J; Rajbhandari, Labchan; Brushart, Thomas M; Minichiello, Liliana; Zhou, Fengquan; Venkatesan, Arun; Clemens, Thomas L

    2016-09-06

    Developing tissues dictate the amount and type of innervation they require by secreting neurotrophins, which promote neuronal survival by activating distinct tyrosine kinase receptors. Here, we show that nerve growth factor (NGF) signaling through neurotrophic tyrosine kinase receptor type 1 (TrkA) directs innervation of the developing mouse femur to promote vascularization and osteoprogenitor lineage progression. At the start of primary ossification, TrkA-positive axons were observed at perichondrial bone surfaces, coincident with NGF expression in cells adjacent to centers of incipient ossification. Inactivation of TrkA signaling during embryogenesis in TrkA(F592A) mice impaired innervation, delayed vascular invasion of the primary and secondary ossification centers, decreased numbers of Osx-expressing osteoprogenitors, and decreased femoral length and volume. These same phenotypic abnormalities were observed in mice following tamoxifen-induced disruption of NGF in Col2-expressing perichondrial osteochondral progenitors. We conclude that NGF serves as a skeletal neurotrophin to promote sensory innervation of developing long bones, a process critical for normal primary and secondary ossification. Published by Elsevier Inc.

  10. Constitutive E2F1 Overexpression Delays Endochondral Bone Formation by Inhibiting Chondrocyte Differentiation

    NARCIS (Netherlands)

    Scheijen, B.; Bronk, M.; Meer, T. van der; Bernards, R.A.

    2003-01-01

    Longitudinal bone growth results from endochondral ossification, a process that requires proliferation and differentiation of chondrocytes. It has been shown that proper endochondral bone formation is critically dependent on the retinoblastoma family members p107 and p130. However, the precise

  11. The PI3K pathway regulates endochondral bone growth through control of hypertrophic chondrocyte differentiation

    Directory of Open Access Journals (Sweden)

    Beier Frank

    2008-04-01

    Full Text Available Abstract Background The majority of our bones develop through the process of endochondral ossification that involves chondrocyte proliferation and hypertrophic differentiation in the cartilage growth plate. A large number of growth factors and hormones have been implicated in the regulation of growth plate biology, however, less is known about the intracellular signaling pathways involved. PI3K/Akt has been identified as a major regulator of cellular proliferation, differentiation and death in multiple cell types. Results and Discussion Employing an organ culture system of embryonic mouse tibiae and LY294002, a pharmacological inhibitor of PI3K, we show that inhibition of the pathway results in significant growth reduction, demonstrating that PI3K is required for normal endochondral bone growth in vitro. PI3K inhibition reduces the length of the proliferating and particularly of the hypertrophic zone. Studies with organ cultures and primary chondrocytes in micromass culture show delayed hypertrophic differentiation of chondrocytes and increased apoptosis in the presence of LY294002. Surprisingly, PI3K inhibition had no strong effect on IGF1-induced bone growth, but partially blocked the anabolic effects of C-type natriuretic peptide. Conclusion Our data demonstrate an essential role of PI3K signaling in chondrocyte differentiation and as a consequence of this, in the endochondral bone growth process.

  12. Endochondral bone formation in gelatin methacrylamide hydrogel with embedded cartilage-derived matrix particles

    NARCIS (Netherlands)

    Visser, Jetze; Gawlitta, Debby; Benders, Kim E. M.; Toma, Selynda M. H.; Pouran, Behdad; van Weeren, P. Rene; Dhert, Wouter J. A.; Malda, J

    The natural process of endochondral bone formation in the growing skeletal system is increasingly inspiring the field of bone tissue engineering. However, in order to create relevant-size bone grafts, a cell carrier is required that ensures a high diffusion rate and facilitates matrix formation,

  13. Recapitulating endochondral ossification: a promising route to in vivo bone regeneration.

    Science.gov (United States)

    Thompson, Emmet M; Matsiko, Amos; Farrell, Eric; Kelly, Daniel J; O'Brien, Fergal J

    2015-08-01

    Despite its natural healing potential, bone is unable to regenerate sufficient tissue within critical-sized defects, resulting in a non-union of bone ends. As a consequence, interventions are required to replace missing, damaged or diseased bone. Bone grafts have been widely employed for the repair of such critical-sized defects. However, the well-documented drawbacks associated with autografts, allografts and xenografts have motivated the development of alternative treatment options. Traditional tissue engineering strategies have typically attempted to direct in vitro bone-like matrix formation within scaffolds prior to implantation into bone defects, mimicking the embryological process of intramembranous ossification (IMO). Tissue-engineered constructs developed using this approach often fail once implanted, due to poor perfusion, leading to avascular necrosis and core degradation. As a result of such drawbacks, an alternative tissue engineering strategy, based on endochondral ossification (ECO), has begun to emerge, involving the use of in vitro tissue-engineered cartilage as a transient biomimetic template to facilitate bone formation within large defects. This is driven by the hypothesis that hypertrophic chondrocytes can secrete angiogenic and osteogenic factors, which play pivotal roles in both the vascularization of constructs in vivo and the deposition of a mineralized extracellular matrix, with resulting bone deposition. In this context, this review focuses on current strategies taken to recapitulate ECO, using a range of distinct cells, biomaterials and biochemical stimuli, in order to facilitate in vivo bone formation. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Impaired angiogenesis and endochondral bone formation in mice lacking the vascular endothelial growth factor isoforms VEGF164 and VEGF188.

    Science.gov (United States)

    Maes, Christa; Carmeliet, Peter; Moermans, Karen; Stockmans, Ingrid; Smets, Nico; Collen, Désiré; Bouillon, Roger; Carmeliet, Geert

    2002-02-01

    Vascular endothelial growth factor (VEGF)-mediated angiogenesis is an important part of bone formation. To clarify the role of VEGF isoforms in endochondral bone formation, we examined long bone development in mice expressing exclusively the VEGF120 isoform (VEGF120/120 mice). Neonatal VEGF120/120 long bones showed a completely disturbed vascular pattern, concomitant with a 35% decrease in trabecular bone volume, reduced bone growth and a 34% enlargement of the hypertrophic chondrocyte zone of the growth plate. Surprisingly, embryonic hindlimbs at a stage preceding capillary invasion exhibited a delay in bone collar formation and hypertrophic cartilage calcification. Expression levels of marker genes of osteoblast and hypertrophic chondrocyte differentiation were significantly decreased in VEGF120/120 bones. Furthermore, inhibition of all VEGF isoforms in cultures of embryonic cartilaginous metatarsals, through the administration of a soluble receptor chimeric protein (mFlt-1/Fc), retarded the onset and progression of ossification, suggesting that osteoblast and/or hypertrophic chondrocyte development were impaired. The initial invasion by osteoclasts and endothelial cells into VEGF120/120 bones was retarded, associated with decreased expression of matrix metalloproteinase-9. Our findings indicate that expression of VEGF164 and/or VEGF188 is important for normal endochondral bone development, not only to mediate bone vascularization but also to allow normal differentiation of hypertrophic chondrocytes, osteoblasts, endothelial cells and osteoclasts.

  15. Controlled Dual Growth Factor Delivery From Microparticles Incorporated Within Human Bone Marrow-Derived Mesenchymal Stem Cell Aggregates for Enhanced Bone Tissue Engineering via Endochondral Ossification.

    Science.gov (United States)

    Dang, Phuong N; Dwivedi, Neha; Phillips, Lauren M; Yu, Xiaohua; Herberg, Samuel; Bowerman, Caitlin; Solorio, Loran D; Murphy, William L; Alsberg, Eben

    2016-02-01

    Bone tissue engineering via endochondral ossification has been explored by chondrogenically priming cells using soluble mediators for at least 3 weeks to produce a hypertrophic cartilage template. Although recapitulation of endochondral ossification has been achieved, long-term in vitro culture is required for priming cells through repeated supplementation of inductive factors in the media. To address this challenge, a microparticle-based growth factor delivery system was engineered to drive endochondral ossification within human bone marrow-derived mesenchymal stem cell (hMSC) aggregates. Sequential exogenous presentation of soluble transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2) at various defined time courses resulted in varying degrees of chondrogenesis and osteogenesis as demonstrated by glycosaminoglycan and calcium content. The time course that best induced endochondral ossification was used to guide the development of the microparticle-based controlled delivery system for TGF-β1 and BMP-2. Gelatin microparticles capable of relatively rapid release of TGF-β1 and mineral-coated hydroxyapatite microparticles permitting more sustained release of BMP-2 were then incorporated within hMSC aggregates and cultured for 5 weeks following the predetermined time course for sequential presentation of bioactive signals. Compared with cell-only aggregates treated with exogenous growth factors, aggregates with incorporated TGF-β1- and BMP-2-loaded microparticles exhibited enhanced chondrogenesis and alkaline phosphatase activity at week 2 and a greater degree of mineralization by week 5. Staining for types I and II collagen, osteopontin, and osteocalcin revealed the presence of cartilage and bone. This microparticle-incorporated system has potential as a readily implantable therapy for healing bone defects without the need for long-term in vitro chondrogenic priming. Significance: This study demonstrates the regulation of chondrogenesis

  16. Endochondral vs. intramembranous demineralized bone matrices as implants for osseous defects.

    Science.gov (United States)

    Nidoli, M C; Nielsen, F F; Melsen, B

    1999-05-01

    This study focuses on the difference in regenerative capacity between endochondral and intramembranous demineralized bone matrices (DBMs) when implanted into bony defects. It also focuses on the possible influence of the type of skeletal recipient site (orthotopic or heterotopic). Of 34 Wistar rats, 10 served as a source of DBM, and 24 were divided into two groups of 12 animals. In group A identical defects were produced in the parietal bones, whereas in group B the defects were produced in each radius. The right defects were implanted with endochondral DBM and the left defects were implanted with intramembranous DBM. Descriptive and/or histomorphometric analyses were performed by means of light and polarized microscopy, and radiography (group B). Right and left data were compared to disclose differences in bone-healing capacity. The quantitative results demonstrated that endochondral DBM displays a greater regenerative capacity than intramembranous DBM when implanted heterotopically. The different clinical performances of endochondral and intramembranous bone grafts might be explained on the basis of the mechanical rather than the osteoinductive principle. The qualitative results suggest that the type of bone deposition induced by the DBMs is not related to the type of implanted DBM. Recipient site characteristics and/or environmental factors seem decisive in the occurrence of either types of ossification.

  17. Endochondral bone formation in gelatin methacrylamide hydrogel with embedded cartilage-derived matrix particles.

    Science.gov (United States)

    Visser, Jetze; Gawlitta, Debby; Benders, Kim E M; Toma, Selynda M H; Pouran, Behdad; van Weeren, P René; Dhert, Wouter J A; Malda, Jos

    2015-01-01

    The natural process of endochondral bone formation in the growing skeletal system is increasingly inspiring the field of bone tissue engineering. However, in order to create relevant-size bone grafts, a cell carrier is required that ensures a high diffusion rate and facilitates matrix formation, balanced by its degradation. Therefore, we set out to engineer endochondral bone in gelatin methacrylamide (GelMA) hydrogels with embedded multipotent stromal cells (MSCs) and cartilage-derived matrix (CDM) particles. CDM particles were found to stimulate the formation of a cartilage template by MSCs in the GelMA hydrogel in vitro. In a subcutaneous rat model, this template was subsequently remodeled into mineralized bone tissue, including bone-marrow cavities. The GelMA was almost fully degraded during this process. There was no significant difference in the degree of calcification in GelMA with or without CDM particles: 42.5 ± 2.5% vs. 39.5 ± 8.3% (mean ± standard deviation), respectively. Interestingly, in an osteochondral setting, the presence of chondrocytes in one half of the constructs fully impeded bone formation in the other half by MSCs. This work offers a new avenue for the engineering of relevant-size bone grafts, by the formation of endochondral bone within a degradable hydrogel. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Synergistic Inhibition of Endochondral Bone Formation by Silencing Hif1α and Runx2 in Trauma-induced Heterotopic Ossification

    Science.gov (United States)

    Lin, Lin; Shen, Qi; Leng, Huijie; Duan, Xiaoning; Fu, Xin; Yu, Changlong

    2011-01-01

    Angiogenesis and osteogenesis are tightly coupled during bone development. We studied the effect of inhibition of Hif1α and Runt-related protein 2 (Runx2) on the formation of heterotopic ossification (HO). We constructed lentivirus vectors expressing Hif1α small interfering RNA (siRNA) and Runx2 siRNA. The inhibition of Hif1α function impaired osteoblast proliferation while osteoblasts differentiated normally. Osteoblasts lacking Runx2 proliferated normally while the differentiation was impaired. The osteoblast differentiation was significantly inhibited by co-Runx2 and Hif1α siRNA treatment. The formation of HO by inhibiting Runx2 and Hif1α in an animal model induced by Achilles tenotomy was investigated. The results showed that lacking of Runx2 and Hif1α could inhibit HO formation. Inhibition of Hif1α prevented HO formation only at the initial step and inhibition of Runx2 worked both at the initial step and after chondrogenesis. Angiogenesis and the expressions of osteogenic genes were downregulated in the Hif1α siRNA group. We found synergistic inhibition of endochondral bone formation by silencing Hif1α and Runx2. Our study provided new insight into the roles of Hif1α and Runx2 during the processes of endochondral bone formation, and had important implications for the new therapeutic methods to inhibit HO or to enhance bone formation. PMID:21629226

  19. Activated FGFR3 promotes bone formation via accelerating endochondral ossification in mouse model of distraction osteogenesis.

    Science.gov (United States)

    Osawa, Yusuke; Matsushita, Masaki; Hasegawa, Sachi; Esaki, Ryusaku; Fujio, Masahito; Ohkawara, Bisei; Ishiguro, Naoki; Ohno, Kinji; Kitoh, Hiroshi

    2017-12-01

    Achondroplasia (ACH) is one of the most common short-limbed skeletal dysplasias caused by gain-of-function mutations in the fibroblast growth factor receptors 3 (FGFR3) gene. Distraction osteogenesis (DO) is a treatment option for short stature in ACH in some countries. Although the patients with ACH usually show faster healing in DO, details of the newly formed bone have not been examined. We have developed a mouse model of DO and analyzed new bone regenerates of the transgenic mice with ACH (Fgfr3 ach mice) histologically and morphologically. We established two kinds of DO protocols, the short-DO consisted of 5days of latency period followed by 5days of distraction with a rate of 0.4mm per 24h, and the long-DO consisted of the same latency period followed by 7days of distraction with a rate of 0.3mm per 12h. The callus formation was evaluated radiologically by bone fill score and quantified by micro-CT scan in both protocols. The histomorphometric analysis was performed in the short-DO protocol by various stainings, including Villanueva Goldner, Safranin-O/Fast green, tartrate-resistant acid phosphatase, and type X collagen. Bone fill scores were significantly higher in Fgfr3 ach mice than in wild-type mice in both protocols. The individual bone parameters, including bone volume and bone volume/tissue volume, were also significantly higher in Fgfr3 ach mice than in wild-type mice in both protocols. The numbers of osteoblasts, as well as osteoclasts, around the trabecular bone were increased in Fgfr3 ach mice. Cartilaginous tissues of the distraction region rapidly disappeared in Fgfr3 ach mice compared to wild-type mice during the consolidation phase. Similarly, type X collagen-positive cells were markedly decreased in Fgfr3 ach mice during the same period. Fgfr3 ach mice exhibited accelerated bone regeneration after DO. Accelerated endochondral ossification could contribute to faster healing in Fgfr3 ach mice. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Cellular Therapy to Obtain Rapid Endochondral Bone Formation

    Science.gov (United States)

    2008-02-01

    length from the tibial fusion site, and then stop which would be consistent with the resorption being associated with the lack of weight bearing load. In...Defect in the Rat Femur with Use of a Vascularized Periosteal Flap, a Biodegradable Matric, and Bone Morphogenetic Protein. J Bone Joint Surg 87-A(6

  1. Forkhead box O transcription factors in chondrocytes regulate endochondral bone formation.

    Science.gov (United States)

    Eelen, G; Verlinden, L; Maes, C; Beullens, I; Gysemans, C; Paik, J-H; DePinho, R A; Bouillon, R; Carmeliet, G; Verstuyf, A

    2016-11-01

    The differentiation of embryonic mesenchymal cells into chondrocytes and the subsequent formation of a cartilaginous scaffold that enables the formation of long bones are hallmarks of endochondral ossification. During this process, chondrocytes undergo a remarkable sequence of events involving proliferation, differentiation, hypertrophy and eventually apoptosis. Forkhead Box O (FoxO) transcription factors (TFs) are well-known regulators of such cellular processes. Although FoxO3a was previously shown to be regulated by 1,25-dihydroxyvitamin D3 in osteoblasts, a possible role for this family of TFs in chondrocytes during endochondral ossification remains largely unstudied. By crossing Collagen2-Cre mice with FoxO1(lox/lox);FoxO3a(lox/lox);FoxO4(lox/lox) mice, we generated mice in which the three main FoxO isoforms were deleted in growth plate chondrocytes (chondrocyte triple knock-out; CTKO). Intriguingly, CTKO neonates showed a distinct elongation of the hypertrophic zone of the growth plate. CTKO mice had increased overall body and tail length at eight weeks of age and suffered from severe skeletal deformities at older ages. CTKO chondrocytes displayed decreased expression of genes involved in redox homeostasis. These observations illustrate the importance of FoxO signaling in chondrocytes during endochondral ossification. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Cellular Therapy to Obtain Rapid Endochondral Bone Formation

    Science.gov (United States)

    2012-03-01

    osteoinductive components that could be seeded into the osteoconductive materials to generate normal bone which this study will explore. The central...without a scaffold, by using cells transduced with adenovirus vectors to express an osteoinductive factor (BMP2), which have been encapsulated in...minimally invasive percutaneous techniques and without a scaffold, by using cells transduced with adenovirus vectors to express an osteoinductive factor

  3. Hedgehog Signaling in Endochondral Ossification

    Directory of Open Access Journals (Sweden)

    Shinsuke Ohba

    2016-06-01

    Full Text Available Hedgehog (Hh signaling plays crucial roles in the patterning and morphogenesis of various organs within the bodies of vertebrates and insects. Endochondral ossification is one of the notable developmental events in which Hh signaling acts as a master regulator. Among three Hh proteins in mammals, Indian hedgehog (Ihh is known to work as a major Hh input that induces biological impact of Hh signaling on the endochondral ossification. Ihh is expressed in prehypertrophic and hypertrophic chondrocytes of developing endochondral bones. Genetic studies so far have demonstrated that the Ihh-mediated activation of Hh signaling synchronizes chondrogenesis and osteogenesis during endochondral ossification by regulating the following processes: (1 chondrocyte differentiation; (2 chondrocyte proliferation; and (3 specification of bone-forming osteoblasts. Ihh not only forms a negative feedback loop with parathyroid hormone-related protein (PTHrP to maintain the growth plate length, but also directly promotes chondrocyte propagation. Ihh input is required for the specification of progenitors into osteoblast precursors. The combinatorial approaches of genome-wide analyses and mouse genetics will facilitate understanding of the regulatory mechanisms underlying the roles of Hh signaling in endochondral ossification, providing genome-level evidence of the potential of Hh signaling for the treatment of skeletal disorders.

  4. Effect of therapeutic ultrasound on endochondral ossification

    NARCIS (Netherlands)

    Wiltink, A.; Nijweide, P.J.; Oosterbaan, W.A.; Hekkenberg, R.T.; Helders, P.J.M.

    1995-01-01

    The effect of therapeutic doses of ultrasound was tested on endochondral ossification of in vitro developing metatarsal long bone rudiments of 16- and 17-day-old fetal mice. Bone growth, calcification and resorption following exposure to several doses of pulse-wave (PW) or continuous-wave (CW)

  5. Endochondral ossification for enhancing bone regeneration: converging native extracellular matrix biomaterials and developmental engineering in vivo.

    Science.gov (United States)

    Dennis, S Connor; Berkland, Cory J; Bonewald, Lynda F; Detamore, Michael S

    2015-06-01

    Autologous bone grafting (ABG) remains entrenched as the gold standard of treatment in bone regenerative surgery. Consequently, many marginally successful bone tissue engineering strategies have focused on mimicking portions of ABG's "ideal" osteoconductive, osteoinductive, and osteogenic composition resembling the late reparative stage extracellular matrix (ECM) in bone fracture repair, also known as the "hard" or "bony" callus. An alternative, less common approach that has emerged in the last decade harnesses endochondral (EC) ossification through developmental engineering principles, which acknowledges that the molecular and cellular mechanisms involved in developmental skeletogenesis, specifically EC ossification, are closely paralleled during native bone healing. EC ossification naturally occurs during the majority of bone fractures and, thus, can potentially be utilized to enhance bone regeneration for nearly any orthopedic indication, especially in avascular critical-sized defects where hypoxic conditions favor initial chondrogenesis instead of direct intramembranous ossification. The body's native EC ossification response, however, is not capable of regenerating critical-sized defects without intervention. We propose that an underexplored potential exists to regenerate bone through the native EC ossification response by utilizing strategies which mimic the initial inflammatory or fibrocartilaginous ECM (i.e., "pro-" or "soft" callus) observed in the early reparative stage of bone fracture repair. To date, the majority of strategies utilizing this approach rely on clinically burdensome in vitro cell expansion protocols. This review will focus on the confluence of two evolving areas, (1) native ECM biomaterials and (2) developmental engineering, which will attempt to overcome the technical, business, and regulatory challenges that persist in the area of bone regeneration. Significant attention will be given to native "raw" materials and ECM-based designs that

  6. Differential actions of VEGF-A isoforms on perichondrial angiogenesis during endochondral bone formation.

    Science.gov (United States)

    Takimoto, Aki; Nishizaki, Yuriko; Hiraki, Yuji; Shukunami, Chisa

    2009-08-15

    During endochondral bone formation, vascular invasion initiates the replacement of avascular cartilage by bone. We demonstrate herein that the cartilage-specific overexpression of VEGF-A(164) in mice results in the hypervascularization of soft connective tissues away from cartilage. Unexpectedly, perichondrial tissue remained avascular in addition to cartilage. Hypervascularization of tissues similarly occurred when various VEGF-A isoforms were overexpressed in the chick forelimb, but also in this case perichondrial tissue and cartilage were completely devoid of vasculature. However, following bony collar formation, anti-angiogenic properties in perichondrial tissue were lost and perichondrial angiogenesis was accelerated by VEGF-A(146), VEGF-A(166), or VEGF-A(190). Once the perichondrium was vascularized, osteoclast precursors were recruited from the circulation and the induction of MMP9 and MMP13 can be observed in parallel with the activation of TGF-beta signaling. Neither perichondrial angiogenesis nor the subsequent cartilage vascularization was found to be accelerated by the non-heparin-binding VEGF-A(122) or by the VEGF-A(166)DeltaE(162)-R(166) mutant lacking a neuropilin-binding motif. Hence, perichondrial angiogenesis is a prerequisite for subsequent cartilage vascularization and is differentially regulated by VEGF-A isoforms.

  7. Chondrogenically differentiated mesenchymal stromal cell pellets stimulate endochondral bone regeneration in critical-sized bone defects

    NARCIS (Netherlands)

    J. van der Stok (Johan); M.K.E. Koolen; H. Jahr (Holger); N. Kops (Nicole); J.H. Waarsing (Jan); H.H. Weinans (Harrie); O.P. van der Jagt (Olav)

    2014-01-01

    markdownabstractAbstract: Grafting bone defects or atrophic non-unions with mesenchymal stromal cells (MSCs)-based grafts is not yet successful. MSC-based grafts typically use undifferentiated or osteogenically differentiated MSCs and regenerate bone through intramembranous ossification.

  8. Recapitulating endochondral ossification: a promising route to in vivo bone regeneration.

    OpenAIRE

    Thompson, Emmet M; Matsiko, Amos; Farrell, Eric; Kelly, Daniel J; O'Brien, Fergal

    2015-01-01

    Despite its natural healing potential, bone is unable to regenerate sufficient tissue within critical-sized defects, resulting in a non-union of bone ends. As a consequence, interventions are required to replace missing, damaged or diseased bone. Bone grafts have been widely employed for the repair of such critical-sized defects. However, the well-documented drawbacks associated with autografts, allografts and xenografts have motivated the development of alternative treatment options. Traditi...

  9. Functional bone histology of zebrafish reveals two types of endochondral ossification, different types of osteoblast clusters and a new bone type.

    Science.gov (United States)

    Weigele, Jochen; Franz-Odendaal, Tamara A

    2016-07-01

    The zebrafish is as an important vertebrate animal model system for studying developmental processes, gene functions and signalling pathways. It is also used as a model system for the understanding of human developmental diseases including those related to the skeleton. However, surprisingly little is known about normal zebrafish skeletogenesis and osteogenesis. As in most vertebrates, it is commonly known that the bones of adult zebrafish are cellular unlike that of some other teleosts. After careful histological analyses of each zebrafish adult bone, we identified several acellular bones, with no entrapped osteocytes in addition to several cellular bones. We show that both cellular and acellular bones can even occur within the same skeletal element and transitions between these two cell types can be found. Furthermore, we describe two types of osteoblast clusters during skeletogenesis and two different types of endochondral ossification. The epiphyseal plate, for example, lacks a zone of calcification and a degradation zone with osteoblasts. A new bone type that we term tubular bone was also identified. This bone is completely filled with adipose tissue, unlike spongy bones. This study provides important insight on how osteogenesis takes place in zebrafish, and especially on the transition from cellular to acellular bones. Overall, this study leads to a deeper understanding of the functional histological composition of adult zebrafish bones. © 2016 Anatomical Society.

  10. Endochondral ossification in vitro is influenced by mechanical bending.

    Science.gov (United States)

    Trepczik, Britta; Lienau, Jasmin; Schell, Hanna; Epari, Devakara R; Thompson, Mark S; Hoffmann, Jan-Erik; Kadow-Romacker, Anke; Mundlos, Stefan; Duda, Georg N

    2007-03-01

    Bone development is influenced by the local mechanical environment. Experimental evidence suggests that altered loading can change cell proliferation and differentiation in chondro- and osteogenesis during endochondral ossification. This study investigated the effects of three-point bending of murine fetal metatarsal bone anlagen in vitro on cartilage differentiation, matrix mineralization and bone collar formation. This is of special interest because endochondral ossification is also an important process in bone healing and regeneration. Metatarsal preparations of 15 mouse fetuses stage 17.5 dpc were dissected en bloc and cultured for 7 days. After 3 days in culture to allow adherence they were stimulated 4 days for 20 min twice daily by a controlled bending of approximately 1000-1500 microstrain at 1 Hz. The paraffin-embedded bone sections were analyzed using histological and histomorphometrical techniques. The stimulated group showed an elongated periosteal bone collar while the total bone length was not different from controls. The region of interest (ROI), comprising the two hypertrophic zones and the intermediate calcifying diaphyseal zone, was greater in the stimulated group. The mineralized fraction of the ROI was smaller in the stimulated group, while the absolute amount of mineralized area was not different. These results demonstrate that a new device developed to apply three-point bending to a mouse metatarsal bone culture model caused an elongation of the periosteal bone collar, but did not lead to a modification in cartilage differentiation and matrix mineralization. The results corroborate the influence of biophysical stimulation during endochondral bone development in vitro. Further experiments with an altered loading regime may lead to more pronounced effects on the process of endochondral ossification and may provide further insights into the underlying mechanisms of mechanoregulation which also play a role in bone regeneration.

  11. Osteoblast-Specific Loss of IGF1R Signaling Results in Impaired Endochondral Bone Formation During Fracture Healing

    Science.gov (United States)

    Wang, Tao; Wang, Yongmei; Menendez, Alicia; Fong, Chak; Babey, Muriel; Tahimic, Candice GT; Cheng, Zhiqiang; Li, Alfred; Chang, Wenhan; Bikle, Daniel D.

    2017-01-01

    during fracture repair, but it plays an important role in coordinating chondrocyte, osteoclast, and endothelial responses that all contribute to the endochondral bone formation required for normal fracture repair. PMID:25801198

  12. Endochondral fracture healing with external fixation in the Sost knockout mouse results in earlier fibrocartilage callus removal and increased bone volume fraction and strength.

    Science.gov (United States)

    Morse, A; Yu, N Y C; Peacock, L; Mikulec, K; Kramer, I; Kneissel, M; McDonald, M M; Little, D G

    2015-02-01

    Sclerostin deficiency, via genetic knockout or anti-Sclerostin antibody treatment, has been shown to cause increased bone volume, density and strength of calluses following endochondral bone healing. However, there is limited data on the effect of Sclerostin deficiency on the formative early stage of fibrocartilage (non-bony tissue) formation and removal. In this study we extensively investigate the early fibrocartilage callus. Closed tibial fractures were performed on Sost(-/-) mice and age-matched wild type (C57Bl/6J) controls and assessed at multiple early time points (7, 10 and 14days), as well as at 28days post-fracture after bony union. External fixation was utilized, avoiding internal pinning and minimizing differences in stability stiffness, a variable that has confounded previous research in this area. Normal endochondral ossification progressed in wild type and Sost(-/-) mice with equivalent volumes of fibrocartilage formed at early day 7 and day 10 time points, and bony union in both genotypes by day 28. There were no significant differences in rate of bony union; however there were significant increases in fibrocartilage removal from the Sost(-/-) fracture calluses at day 14 suggesting earlier progression of endochondral healing. Earlier bone formation was seen in Sost(-/-) calluses over wild type with greater bone volume at day 10 (221%, pfractured Sost(-/-) tibiae was greater than that that of wild type fractured tibiae. In summary, bony union was not altered by Sclerostin deficiency in externally-fixed closed tibial fractures, but fibrocartilage removal was enhanced and the resultant united bony calluses had increased bone fraction and increased strength. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

  13. Control of chondrocyte gene expression by actin dynamics: a novel role of cholesterol/Ror-alpha signalling in endochondral bone growth.

    Science.gov (United States)

    Woods, Anita; James, Claudine G; Wang, Guoyan; Dupuis, Holly; Beier, Frank

    2009-09-01

    Elucidating the signalling pathways that regulate chondrocyte differentiation, such as the actin cytoskeleton and Rho GTPases, during development is essential for understanding of pathological conditions of cartilage, such as chondrodysplasias and osteoarthritis. Manipulation of actin dynamics in tibia organ cultures isolated from E15.5 mice results in pronounced enhancement of endochondral bone growth and specific changes in growth plate architecture. Global changes in gene expression were examined of primary chondrocytes isolated from embryonic tibia, treated with the compounds cytochalasin D, jasplakinolide (actin modifiers) and the ROCK inhibitor Y27632. Cytochalasin D elicited the most pronounced response and induced many features of hypertrophic chondrocyte differentiation. Bioinformatics analyses of microarray data and expression validation by real-time PCR and immunohistochemistry resulted in the identification of the nuclear receptor retinoid related orphan receptor-alpha (Ror-alpha) as a novel putative regulator of chondrocyte hypertrophy. Expression of Ror-alpha target genes, (Lpl, fatty acid binding protein 4 [Fabp4], Cd36 and kruppel-like factor 5 [Klf15]) were induced during chondrocyte hypertrophy and by cytochalasin D and are cholesterol dependent. Stimulation of Ror-alpha by cholesterol results in increased bone growth and enlarged, rounded cells, a phenotype similar to chondrocyte hypertrophy and to the changes induced by cytochalasin D, while inhibition of cholesterol synthesis by lovastatin inhibits cytochalasin D induced bone growth. Additionally, we show that in a mouse model of cartilage specific (Col2-Cre) Rac1, inactivation results in increased Hif-1alpha (a regulator of Rora gene expression) and Ror-alpha(+) cells within hypertrophic growth plates. We provide evidence that cholesterol signalling through increased Ror-alpha expression stimulates chondrocyte hypertrophy and partially mediates responses of cartilage to actin dynamics.

  14. Chondrocyte-specific ablation of Osterix leads to impaired endochondral ossification

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jung-Hoon [Department of Molecular Medicine, Cell and Matrix Research Institute, BK21 Medical Education Program for Human Resources, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Park, Seung-Yoon [Department of Biochemistry, School of Medicine, Dongguk University, Gyeongju 780-714 (Korea, Republic of); Crombrugghe, Benoit de [Department of Genetics, University of Texas, M.D. Anderson Cancer Center, Houston (United States); Kim, Jung-Eun, E-mail: kjeun@knu.ac.kr [Department of Molecular Medicine, Cell and Matrix Research Institute, BK21 Medical Education Program for Human Resources, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer Conditional ablation of Osterix (Osx) in chondrocytes leads to skeletal defects. Black-Right-Pointing-Pointer Osx regulates chondrocyte differentiation and bone growth in growth plate chondrocytes. Black-Right-Pointing-Pointer Osx has an autonomous function in chondrocytes during endochondral ossification. -- Abstract: Osterix (Osx) is an essential transcription factor required for osteoblast differentiation during both intramembranous and endochondral ossification. Endochondral ossification, a process in which bone formation initiates from a cartilage intermediate, is crucial for skeletal development and growth. Osx is expressed in differentiating chondrocytes as well as osteoblasts during mouse development, but its role in chondrocytes has not been well studied. Here, the in vivo function of Osx in chondrocytes was examined in a chondrocyte-specific Osx conditional knockout model using Col2a1-Cre. Chondrocyte-specific Osx deficiency resulted in a weak and bent skeleton which was evident in newborn by radiographic analysis and skeletal preparation. To further understand the skeletal deformity of the chondrocyte-specific Osx conditional knockout, histological analysis was performed on developing long bones during embryogenesis. Hypertrophic chondrocytes were expanded, the formation of bone trabeculae and marrow cavities was remarkably delayed, and subsequent skeletal growth was reduced. The expression of several chondrocyte differentiation markers was reduced, indicating the impairment of chondrocyte differentiation and endochondral ossification in the chondrocyte-specific Osx conditional knockout. Taken together, Osx regulates chondrocyte differentiation and bone growth in growth plate chondrocytes, suggesting an autonomous function of Osx in chondrocytes during endochondral ossification.

  15. In-vivo generation of bone via endochondral ossification by in-vitro chondrogenic priming of adult human and rat mesenchymal stem cells

    LENUS (Irish Health Repository)

    Farrell, Eric

    2011-01-31

    Abstract Background Bone grafts are required to repair large bone defects after tumour resection or large trauma. The availability of patients\\' own bone tissue that can be used for these procedures is limited. Thus far bone tissue engineering has not lead to an implant which could be used as alternative in bone replacement surgery. This is mainly due to problems of vascularisation of the implanted tissues leading to core necrosis and implant failure. Recently it was discovered that embryonic stem cells can form bone via the endochondral pathway, thereby turning in-vitro created cartilage into bone in-vivo. In this study we investigated the potential of human adult mesenchymal stem cells to form bone via the endochondral pathway. Methods MSCs were cultured for 28 days in chondrogenic, osteogenic or control medium prior to implantation. To further optimise this process we induced mineralisation in the chondrogenic constructs before implantation by changing to osteogenic medium during the last 7 days of culture. Results After 8 weeks of subcutaneous implantation in mice, bone and bone marrow formation was observed in 8 of 9 constructs cultured in chondrogenic medium. No bone was observed in any samples cultured in osteogenic medium. Switch to osteogenic medium for 7 days prevented formation of bone in-vivo. Addition of β-glycerophosphate to chondrogenic medium during the last 7 days in culture induced mineralisation of the matrix and still enabled formation of bone and marrow in both human and rat MSC cultures. To determine whether bone was formed by the host or by the implanted tissue we used an immunocompetent transgenic rat model. Thereby we found that osteoblasts in the bone were almost entirely of host origin but the osteocytes are of both host and donor origin. Conclusions The preliminary data presented in this manuscript demonstrates that chondrogenic priming of MSCs leads to bone formation in vivo using both human and rat cells. Furthermore, addition of

  16. Facial development disorders due to inhibition to endochondral ossification of mandibular condyle process caused by malnutrition.

    Science.gov (United States)

    Martín, Adrián E; del R Pani, Maria; Holgado, Nora Ruiz; López Miranda, Laura I; Meheris, Héctor E; Garat, Juan A

    2014-05-01

    To analyze the effect of protein restriction on histomorphometric parameters of bone remodeling in mandibular condyle process and its possible influence in facial development in growing rats. Wistar rats weaned at the age of 21 days were assigned to one of the following groups: control (fed a regular hard diet ad libitum) and protein restricted (PR) (fed a hard diet lacking in protein ad libitum). The animals were euthanized on day 35 after the onset of the experiment. Mandibles were resected, fixed in 10% formalin, hemisected at the symphysis, and then radiographed in order to perform cephalometric studies of the condylar process length and the height of the lower alveolar process. Mandibles were then processed for light microscopy, and histomorphometric determinations were performed on histologic sections of the condylar process subchondral bone. The PR group showed a significantly lower body weight than control group at the end of the experiment. The length of the condylar process was lower in the PR group; however, the diet used in this study did not affect the height of the lower alveolar process. The histomorphometric analysis showed that the PR group exhibited a statistically significant decrease in bone formation and bone volume in condylar process subchondral bone. Protein restriction inhibits bone formation and longitudinal growth in the mandibular condylar process. This result suggest that protein restriction can alter normal facial development.

  17. 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...... has a long-term effect on skeletal development when given early in neonatal life, and that changes in rib properties serve to improve chest mechanics and functioning in young animals. Moreover, neonatal administration of AKG may be considered as an effective factor enhancing proper development...... at 146 days of life and five left and right ribs (fourth to eighth) were removed for analysis. The influence of AKG on skeletal system development was evaluated in relation to both geometrical and mechanical properties, as well as quantitative computed tomography (QCT). No significant differences between...

  18. Col11a1 Regulates Bone Microarchitecture during Embryonic Development

    Directory of Open Access Journals (Sweden)

    Anthony Hafez

    2015-12-01

    Full Text Available Collagen XI alpha 1 (Col11a1 is an extracellular matrix molecule required for embryonic development with a role in both nucleating the formation of fibrils and regulating the diameter of heterotypic fibrils during collagen fibrillar assembly. Although found in many different tissues throughout the vertebrate body, Col11a1 plays an essential role in endochondral ossification. To further understand the function of Col11a1 in the process of bone formation, we compared skeletal mineralization in wild-type (WT mice and Col11a1-deficient mice using X-ray microtomography (micro-CT and histology. Changes in trabecular bone microstructure were observed and are presented here. Additionally, changes to the periosteal bone collar of developing long bones were observed and resulted in an increase in thickness in the case of Col11a1-deficient mice compared to WT littermates. Vertebral bodies were incompletely formed in the absence of Col11a1. The data demonstrate that Col11a1 depletion results in alteration to newly-formed bone and is consistent with a role for Col11a1 in mineralization. These findings indicate that expression of Col11a1 in the growth plate and perichondrium is essential for trabecular bone and bone collar formation during endochondral ossification. The observed changes to mineralized tissues further define the function of Col11a1.

  19. Col11a1 Regulates Bone Microarchitecture during Embryonic Development.

    Science.gov (United States)

    Hafez, Anthony; Squires, Ryan; Pedracini, Amber; Joshi, Alark; Seegmiller, Robert E; Oxford, Julia Thom

    Collagen XI alpha 1 (Col11a1) is an extracellular matrix molecule required for embryonic development with a role in both nucleating the formation of fibrils and regulating the diameter of heterotypic fibrils during collagen fibrillar assembly. Although found in many different tissues throughout the vertebrate body, Col11a1 plays an essential role in endochondral ossification. To further understand the function of Col11a1 in the process of bone formation, we compared skeletal mineralization in wild-type (WT) mice and Col11a1-deficient mice using X-ray microtomography (micro-CT) and histology. Changes in trabecular bone microstructure were observed and are presented here. Additionally, changes to the periosteal bone collar of developing long bones were observed and resulted in an increase in thickness in the case of Col11a1-deficient mice compared to WT littermates. Vertebral bodies were incompletely formed in the absence of Col11a1. The data demonstrate that Col11a1 depletion results in alteration to newly-formed bone and is consistent with a role for Col11a1 in mineralization. These findings indicate that expression of Col11a1 in the growth plate and perichondrium is essential for trabecular bone and bone collar formation during endochondral ossification. The observed changes to mineralized tissues further define the function of Col11a1.

  20. Role of matrix metalloproteinase 13 in both endochondral and intramembranous ossification during skeletal regeneration.

    Directory of Open Access Journals (Sweden)

    Danielle J Behonick

    Full Text Available Extracellular matrix (ECM remodeling is important during bone development and repair. Because matrix metalloproteinase 13 (MMP13, collagenase-3 plays a role in long bone development, we have examined its role during adult skeletal repair. In this study we find that MMP13 is expressed by hypertrophic chondrocytes and osteoblasts in the fracture callus. We demonstrate that MMP13 is required for proper resorption of hypertrophic cartilage and for normal bone remodeling during non-stabilized fracture healing, which occurs via endochondral ossification. However, no difference in callus strength was detected in the absence of MMP13. Transplant of wild-type bone marrow, which reconstitutes cells only of the hematopoietic lineage, did not rescue the endochondral repair defect, indicating that impaired healing in Mmp13-/- mice is intrinsic to cartilage and bone. Mmp13-/- mice also exhibited altered bone remodeling during healing of stabilized fractures and cortical defects via intramembranous ossification. This indicates that the bone phenotype occurs independently from the cartilage phenotype. Taken together, our findings demonstrate that MMP13 is involved in normal remodeling of bone and cartilage during adult skeletal repair, and that MMP13 may act directly in the initial stages of ECM degradation in these tissues prior to invasion of blood vessels and osteoclasts.

  1. Skeletal development of mice lacking bone sialoprotein (BSP--impairment of long bone growth and progressive establishment of high trabecular bone mass.

    Directory of Open Access Journals (Sweden)

    Wafa Bouleftour

    Full Text Available Adult Ibsp-knockout mice (BSP-/- display shorter stature, lower bone turnover and higher trabecular bone mass than wild type, the latter resulting from impaired bone resorption. Unexpectedly, BSP knockout also affects reproductive behavior, as female mice do not construct a proper "nest" for their offsprings. Multiple crossing experiments nonetheless indicated that the shorter stature and lower weight of BSP-/- mice, since birth and throughout life, as well as their shorter femur and tibia bones are independent of the genotype of the mothers, and thus reflect genetic inheritance. In BSP-/- newborns, µCT analysis revealed a delay in membranous primary ossification, with wider cranial sutures, as well as thinner femoral cortical bone and lower tissue mineral density, reflected in lower expression of bone formation markers. However, trabecular bone volume and osteoclast parameters of long bones do not differ between genotypes. Three weeks after birth, osteoclast number and surface drop in the mutants, concomitant with trabecular bone accumulation. The growth plates present a thinner hypertrophic zone in newborns with lower whole bone expression of IGF-1 and higher IHH in 6 days old BSP-/- mice. At 3 weeks the proliferating zone is thinner and the hypertrophic zone thicker in BSP-/- than in BSP+/+ mice of either sex, maybe reflecting a combination of lower chondrocyte proliferation and impaired cartilage resorption. Six days old BSP-/- mice display lower osteoblast marker expression but higher MEPE and higher osteopontin(Opn/Runx2 ratio. Serum Opn is higher in mutants at day 6 and in adults. Thus, lack of BSP alters long bone growth and membranous/cortical primary bone formation and mineralization. Endochondral development is however normal in mutant mice and the accumulation of trabecular bone observed in adults develops progressively in the weeks following birth. Compensatory high Opn may allow normal endochondral development in BSP-/- mice

  2. Effect of alendronate on endochondral ossification in mandibular condyles of growing rats

    Directory of Open Access Journals (Sweden)

    V. Bradaschia-Correa

    2012-05-01

    Full Text Available The replacement of the calcified cartilage by bone tissue during the endochondral ossification of the mandibular condyle is dependent of the resorbing activity of osteoclats. After partial resorption, calcified cartilage septa are covered by a primary bone matrix secreted by osteoblasts. Osteoadherin (OSAD is a small proteoglycan present in bone matrix but absent in cartilage during the endochondral ossification. The aim of this study was to analyze the effect of alendronate, a drug known to inhibit bone resorption by osteoclasts, on the endochondral ossification of the mandibular condyle of young rats, by evaluating the distribution of osteoclasts and the presence of OSAD in the bone matrix deposited. Wistar newborn rats (n=45 received daily injections of alendronate (n=27 or sterile saline solution as control (n=18 from the day of birth until the ages of 4, 14 and 30 days. At the days mentioned, the mandibular condyles were collected and processed for transmission electron microscopy analysis. Specimens were also submitted to tartrate resistant acid phosphatase (TRAP histochemistry and ultrastructural immunodetection of OSAD. Alendronate treatment did not impede the recruitment and fusion of osteoclasts at the ossification zone during condyle growth, but they presented inactivated phenotype. The trabeculae at the ossification area consisted of cartilage matrix covered by a layer of primary bone matrix that was immunopositive to OSAD at all time points studied. Apparently, alendronate impeded the removal of calcified cartilage and maturation of bone trabeculae in the mandibular ramus, while in controls they occurred normally. These findings highlight for giving attention to the potential side-effects of bisphosphonates administered to young patients once it may represent a risk of disturbing maxillofacial development.

  3. Genome-wide analyses of gene expression during mouse endochondral ossification.

    Directory of Open Access Journals (Sweden)

    Claudine G James

    2010-01-01

    Full Text Available Endochondral ossification is a complex process involving a series of events that are initiated by the establishment of a chondrogenic template and culminate in its replacement through the coordinated activity of osteoblasts, osteoclasts and endothelial cells. Comprehensive analyses of in vivo gene expression profiles during these processes are essential to obtain a complete understanding of the regulatory mechanisms involved.To address these issues, we completed a microarray screen of three zones derived from manually segmented embryonic mouse tibiae. Classification of genes differentially expressed between each respective zone, functional categorization as well as characterization of gene expression patterns, cytogenetic loci, signaling pathways and functional motifs both confirmed reported data and provided novel insights into endochondral ossification. Parallel comparisons of the microdissected tibiae data set with our previously completed micromass culture screen further corroborated the suitability of micromass cultures for modeling gene expression in chondrocyte development. The micromass culture system demonstrated striking similarities to the in vivo microdissected tibiae screen; however, the micromass system was unable to accurately distinguish gene expression differences in the hypertrophic and mineralized zones of the tibia.These studies allow us to better understand gene expression patterns in the growth plate and endochondral bones and provide an important technical resource for comparison of gene expression in diseased or experimentally-manipulated cartilages. Ultimately, this work will help to define the genomic context in which genes are expressed in long bones and to understand physiological and pathological ossification.

  4. The Transcription Factor Hand1 Is Involved In Runx2-Ihh-Regulated Endochondral Ossification.

    Directory of Open Access Journals (Sweden)

    Lindsay E Laurie

    Full Text Available The developing long bone is a model of endochondral ossification that displays the morphological layers of chondrocytes toward the ossification center of the diaphysis. Indian hedgehog (Ihh, a member of the hedgehog family of secreted molecules, regulates chondrocyte proliferation and differentiation, as well as osteoblast differentiation, through the process of endochondral ossification. Here, we report that the basic helix-loop-helix transcription factor Hand1, which is expressed in the cartilage primordia, is involved in proper osteogenesis of the bone collar via its control of Ihh production. Genetic overexpression of Hand1 in the osteochondral progenitors resulted in prenatal hypoplastic or aplastic ossification in the diaphyses, mimicking an Ihh loss-of-function phenotype. Ihh expression was downregulated in femur epiphyses of Hand1-overexpressing mice. We also confirmed that Hand1 downregulated Ihh gene expression in vitro by inhibiting Runx2 transactivation of the Ihh proximal promoter. These results demonstrate that Hand1 in chondrocytes regulates endochondral ossification, at least in part through the Runx2-Ihh axis.

  5. The Transcription Factor Hand1 Is Involved In Runx2-Ihh-Regulated Endochondral Ossification.

    Science.gov (United States)

    Laurie, Lindsay E; Kokubo, Hiroki; Nakamura, Masataka; Saga, Yumiko; Funato, Noriko

    2016-01-01

    The developing long bone is a model of endochondral ossification that displays the morphological layers of chondrocytes toward the ossification center of the diaphysis. Indian hedgehog (Ihh), a member of the hedgehog family of secreted molecules, regulates chondrocyte proliferation and differentiation, as well as osteoblast differentiation, through the process of endochondral ossification. Here, we report that the basic helix-loop-helix transcription factor Hand1, which is expressed in the cartilage primordia, is involved in proper osteogenesis of the bone collar via its control of Ihh production. Genetic overexpression of Hand1 in the osteochondral progenitors resulted in prenatal hypoplastic or aplastic ossification in the diaphyses, mimicking an Ihh loss-of-function phenotype. Ihh expression was downregulated in femur epiphyses of Hand1-overexpressing mice. We also confirmed that Hand1 downregulated Ihh gene expression in vitro by inhibiting Runx2 transactivation of the Ihh proximal promoter. These results demonstrate that Hand1 in chondrocytes regulates endochondral ossification, at least in part through the Runx2-Ihh axis.

  6. MEMO1 drives cranial endochondral ossification and palatogenesis.

    Science.gov (United States)

    Van Otterloo, Eric; Feng, Weiguo; Jones, Kenneth L; Hynes, Nancy E; Clouthier, David E; Niswander, Lee; Williams, Trevor

    2016-07-15

    The cranial base is a component of the neurocranium and has a central role in the structural integration of the face, brain and vertebral column. Consequently, alteration in the shape of the human cranial base has been intimately linked with primate evolution and defective development is associated with numerous human facial abnormalities. Here we describe a novel recessive mutant mouse strain that presented with a domed head and fully penetrant cleft secondary palate coupled with defects in the formation of the underlying cranial base. Mapping and non-complementation studies revealed a specific mutation in Memo1 - a gene originally associated with cell migration. Expression analysis of Memo1 identified robust expression in the perichondrium and periosteum of the developing cranial base, but only modest expression in the palatal shelves. Fittingly, although the palatal shelves failed to elevate in Memo1 mutants, expression changes were modest within the shelves themselves. In contrast, the cranial base, which forms via endochondral ossification had major reductions in the expression of genes responsible for bone formation, notably matrix metalloproteinases and markers of the osteoblast lineage, mirrored by an increase in markers of cartilage and extracellular matrix development. Concomitant with these changes, mutant cranial bases showed an increased zone of hypertrophic chondrocytes accompanied by a reduction in both vascular invasion and mineralization. Finally, neural crest cell-specific deletion of Memo1 caused a failure of anterior cranial base ossification indicating a cell autonomous role for MEMO1 in the development of these neural crest cell derived structures. However, palate formation was largely normal in these conditional mutants, suggesting a non-autonomous role for MEMO1 in palatal closure. Overall, these findings assign a new function to MEMO1 in driving endochondral ossification in the cranium, and also link abnormal development of the cranial base

  7. HIF-1α as a Regulator of BMP2-Induced Chondrogenic Differentiation, Osteogenic Differentiation, and Endochondral Ossification in Stem Cells

    Directory of Open Access Journals (Sweden)

    Nian Zhou

    2015-04-01

    Full Text Available Background/Aims: Joint cartilage defects are difficult to treat due to the limited self-repair capacities of cartilage. Cartilage tissue engineering based on stem cells and gene enhancement is a potential alternative for cartilage repair. Bone morphogenetic protein 2 (BMP2 has been shown to induce chondrogenic differentiation in mesenchymal stem cells (MSCs; however, maintaining the phenotypes of MSCs during cartilage repair since differentiation occurs along the endochondral ossification pathway. In this study, hypoxia inducible factor, or (HIF-1α, was determined to be a regulator of BMP2-induced chondrogenic differentiation, osteogenic differentiation, and endochondral bone formation. Methods: BMP2 was used to induce chondrogenic and osteogenic differentiation in stem cells and fetal limb development. After HIF-1α was added to the inducing system, any changes in the differentiation markers were assessed. Results: HIF-1α was found to potentiate BMP2-induced Sox9 and the expression of chondrogenesis by downstream markers, and inhibit Runx2 and the expression of osteogenesis by downstream markers in vitro. In subcutaneous stem cell implantation studies, HIF-1α was shown to potentiate BMP2-induced cartilage formation and inhibit endochondral ossification during ectopic bone/cartilage formation. In the fetal limb culture, HIF-1α and BMP2 synergistically promoted the expansion of the proliferating chondrocyte zone and inhibited chondrocyte hypertrophy and endochondral ossification. Conclusion: The results of this study indicated that, when combined with BMP2, HIF-1α induced MSC differentiation could become a new method of maintaining cartilage phenotypes during cartilage tissue engineering.

  8. Indomethacin induces differential effects on in vitro endochondral ossification depending on the chondrocyte's differentiation stage.

    Science.gov (United States)

    Caron, Marjolein M J; Emans, Pieter J; Cremers, Andy; Surtel, Don A M; van Rhijn, Lodewijk W; Welting, Tim J M

    2017-04-01

    Heterotopic ossification (HO) is the abnormal formation of bone in soft tissues and is a frequent complication of hip replacement surgery. Heterotopic ossifications are described to develop via endochondral ossification and standard treatment is administration of indomethacin. It is currently unknown how indomethacin influences heterotopic ossification on a molecular level; therefore, we aimed to determine whether indomethacin might influence heterotopic ossification via impairing the chondrogenic phase of endochondral ossification. Progenitor cell models differentiating in the chondrogenic lineage (ATDC5, primary human bone marrow stem cells and ex vivo periosteal agarose cultures) were treated with increasing concentrations of indomethacin and a decrease in gene- and protein expression of chondrogenic and hypertrophic markers (measured by RT-qPCR and immunoblotting) as well as decreased glycosamino-glycan content (by alcian blue histochemistry) was observed. Even when hypertrophic differentiation was provoked, the addition of indomethacin resulted in decreased hypertrophic marker expression. Interestingly, when mature chondrocytes were treated with indomethacin, a clear increase in collagen type 2 expression was observed. Similarly, when ATDC5 cells and bone marrow stem cells were pre-differentiated to obtain a chondrocyte phenotype and indomethacin was added from this time point onward, low concentrations of indomethacin also resulted in increased chondrogenic differentiation. Indomethacin induces differential effects on in vitro endochondral ossification, depending on the chondrocyte's differentiation stage, with complete inhibition of chondrogenic differentiation as the most pronounced action. This observation may provide a rational behind the elusive mode of action of indomethacin in the treatment of heterotopic ossifications. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:847-857, 2017. © 2016 Orthopaedic Research

  9. Foxp1/2/4 regulate endochondral ossification as a suppresser complex.

    Science.gov (United States)

    Zhao, Haixia; Zhou, Wenrong; Yao, Zhengju; Wan, Yong; Cao, Jingjing; Zhang, Lingling; Zhao, Jianzhi; Li, Hanjun; Zhou, Rujiang; Li, Baojie; Wei, Gang; Zhang, Zhenlin; French, Catherine A; Dekker, Joseph D; Yang, Yingzi; Fisher, Simon E; Tucker, Haley O; Guo, Xizhi

    2015-02-15

    Osteoblast induction and differentiation in developing long bones is dynamically controlled by the opposing action of transcriptional activators and repressors. In contrast to the long list of activators that have been discovered over past decades, the network of repressors is not well-defined. Here we identify the expression of Foxp1/2/4 proteins, comprised of Forkhead-box (Fox) transcription factors of the Foxp subfamily, in both perichondrial skeletal progenitors and proliferating chondrocytes during endochondral ossification. Mice carrying loss-of-function and gain-of-function Foxp mutations had gross defects in appendicular skeleton formation. At the cellular level, over-expression of Foxp1/2/4 in chondroctyes abrogated osteoblast formation and chondrocyte hypertrophy. Conversely, single or compound deficiency of Foxp1/2/4 in skeletal progenitors or chondrocytes resulted in premature osteoblast differentiation in the perichondrium, coupled with impaired proliferation, survival, and hypertrophy of chondrocytes in the growth plate. Foxp1/2/4 and Runx2 proteins interacted in vitro and in vivo, and Foxp1/2/4 repressed Runx2 transactivation function in heterologous cells. This study establishes Foxp1/2/4 proteins as coordinators of osteogenesis and chondrocyte hypertrophy in developing long bones and suggests that a novel transcriptional repressor network involving Foxp1/2/4 may regulate Runx2 during endochondral ossification. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Perspectives: applications of a biomechanical model of the endochondral ossification mechanism.

    Science.gov (United States)

    Frost, H M; Jee, W S

    1994-12-01

    A biomechanical model of endochondral ossification (Frost and Jee, 1994. Anat. Rec., 240:435-446) can help to explain: (1) some differences in fracture patterns in children and adults, (2) increased fractures during the human adolescent growth spurt, (3) localization of stress fractures and pseudofractures to cortical instead of trabecular bone, (4) increased bone mass in adult-acquired and childhood obesity, (5) subchondral bone densification and osteopenia in some arthroses, (6) why and where mammals lose spongiosa with aging, (7) why, as percents of the original bone stock, metaphyseal trabecular bone losses with aging usually exceed cortical bone losses, (8) why osteochondritis dissecans and aseptic necroses of bone localize in epiphyses instead of metaphyses, (9) some features of growth plate histology in rickets and the chondrodystrophies, (10) why spontaneous fractures in osteoporotic patients affect vertebral more than metaphyseal spongiosa, (11) why osteopenias develop in most chronic, debilitating diseases, and (12) why histomorphometric values can differ in iliac bone biopsies obtained by the "vertical" Jamshidi and "horizontal" Bordier-Meunier techniques.

  11. Incomplete endochondral ossification of the otic capsule, a variation in children: evaluation of its prevalence and extent in children with and without sensorineural hearing loss.

    Science.gov (United States)

    Sanverdi, S E; Ozgen, B; Dolgun, A; Sarac, S

    2015-01-01

    Endochondral ossification of the otic capsule is a process that continues postnatally; hence, incomplete endochondral ossification is seen as pericochlear hypoattenuation on temporal bone CT scans of children. We determined the prevalence and extent of this entity in a large series and assessed its relation to age and underlying sensorineural hearing loss. Initially, temporal bone CTs of 40 children with sensorineural hearing loss were retrospectively assessed and compared with those of a control group scanned for non-sensorineural hearing loss reasons to assess any difference in the prevalence or extent of incomplete endochondral ossification. Then the CT scans of 510 children (age range, 17 days to 17 years) were retrospectively reviewed, and any observed endochondral ossification areas were classified as mild, moderate, or extensive, according to their extent. Neither the presence nor degree of incomplete endochondral ossification had any significant correlation with the presence of sensorineural hearing loss (P = .08 and P = .1, respectively). Incomplete endochondral ossification was more frequently seen (62% of cases) than complete ossification. There was no statistically significant correlation between incomplete endochondral ossification and sex (P = .8), but an inverse correlation was found between the presence of incomplete endochondral ossification and increasing age (P ossification was the most frequent involvement pattern (44.4%). The pericochlear hypoattenuation in the otic capsule representing incomplete endochondral ossification is a normal finding in children and can be seen as a marked curvilinear hypoattenuation at younger ages in the absence of any clinical disorder. © 2015 by American Journal of Neuroradiology.

  12. Mice Lacking Pten in Osteoblasts Have Improved Intramembranous and Late Endochondral Fracture Healing

    Science.gov (United States)

    Burgers, Travis A.; Hoffmann, Martin F.; Collins, Caitlyn J.; Zahatnansky, Juraj; Alvarado, Martin A.; Morris, Michael R.; Sietsema, Debra L.; Mason, James J.; Jones, Clifford B.; Ploeg, Heidi L.; Williams, Bart O.

    2013-01-01

    The failure of an osseous fracture to heal (development of a non-union) is a common and debilitating clinical problem. Mice lacking the tumor suppressor Pten in osteoblasts have dramatic and progressive increases in bone volume and density throughout life. Since fracture healing is a recapitulation of bone development, we investigated the process of fracture healing in mice lacking Pten in osteoblasts (Ocn-cretg/+;Ptenflox/flox). Mid-diaphyseal femoral fractures induced in wild-type and Ocn-cretg/+;Ptenflox/flox mice were studied via micro-computed tomography (µCT) scans, biomechanical testing, histological and histomorphometric analysis, and protein expression analysis. Ocn-cretg/+;Ptenflox/flox mice had significantly stiffer and stronger intact bones relative to controls in all cohorts. They also had significantly stiffer healing bones at day 28 post-fracture (PF) and significantly stronger healing bones at days 14, 21, and 28 PF. At day 7 PF, the proximal and distal ends of the Pten mutant calluses were more ossified. By day 28 PF, Pten mutants had larger and more mineralized calluses. Pten mutants had improved intramembranous bone formation during healing originating from the periosteum. They also had improved endochondral bone formation later in the healing process, after mature osteoblasts are present in the callus. Our results indicate that the inhibition of Pten can improve fracture healing and that the local or short-term use of commercially available Pten-inhibiting agents may have clinical application for enhancing fracture healing. PMID:23675511

  13. A review of the actual knowledge of the processes governing growth and development of long bones.

    Science.gov (United States)

    Pazzaglia, Ugo Ernesto; Beluffi, Giampiero; Benetti, Anna; Bondioni, Maria Pia; Zarattini, Guido

    2011-01-01

    Autoptic samples of human bones (from 8 weeks of gestation to 12 years of age) and a second group of serial, skeletal x-rays (required for pathologies not related to bone dysplasia in children from 4 months to 17 years of age) provided the material for the analysis of the physes normal growth mechanism presented in this review. Before the appearance of the ossification centers epiphyseal growth rests exclusively on chondrocytes proliferation (interstitial growth), without any detectable differentiated cellular organization. When endochondral ossification starts a defined spatial disposition of chondrocytes and a corresponding organization of the intercellular matrix is set up, so that it is possible to identify a growth vector corresponding to the columns of piled chondrocytes with direction from hypertrophic toward the proliferative cell layers. The complexity of the tubular bones growth process is well represented by the spatial arrangement of the growth vectors. In the late epiphyseal growth another mechanism is active in addition to endochondral ossification, namely, articular cartilage interstitial growth and subchondral remodelling. The knowledge of the normal mode of organization of the physis and its temporal sequence can help to better understand of the deviaton from the normal development of metaphyseal and epiphyseal dysplasias.

  14. A computational model to explore the role of angiogenic impairment on endochondral ossification during fracture healing.

    Science.gov (United States)

    OReilly, Adam; Hankenson, Kurt D; Kelly, Daniel J

    2016-10-01

    While it is well established that an adequate blood supply is critical to successful bone regeneration, it remains poorly understood how progenitor cell fate is affected by the altered conditions present in fractures with disrupted vasculature. In this study, computational models were used to explore how angiogenic impairment impacts oxygen availability within a fracture callus and hence regulates mesenchymal stem cell (MSC) differentiation and bone regeneration. Tissue differentiation was predicted using a previously developed algorithm which assumed that MSC fate is governed by oxygen tension and substrate stiffness. This model was updated based on the hypothesis that cell death, chondrocyte hypertrophy and endochondral ossification are regulated by oxygen availability. To test this, the updated model was used to simulate the time course of normal fracture healing, where it successfully predicted the observed quantity and spatial distribution of bone and cartilage at 10 and 20 days post-fracture (dpf). It also predicted the ratio of cartilage which had become hypertrophic at 10 dpf. Following this, three models of fracture healing with increasing levels of angiogenic impairment were developed. Under mild impairment, the model predicted experimentally observed reductions in hypertrophic cartilage at 10 dpf as well as the persistence of cartilage at 20 dpf. Models of more severe impairment predicted apoptosis and the development of fibrous tissue. These results provide insight into how factors specific to an ischemic callus regulate tissue regeneration and provide support for the hypothesis that chondrocyte hypertrophy and endochondral ossification during tissue regeneration are inhibited by low oxygen.

  15. Atmospheric pressure as a force that fills developing bones with marrow and air.

    Science.gov (United States)

    Kurbel, Sven; Radić, Radivoje; Kristek, Branka; Ivezić, Zdravko; Selthofer, Robert; Kotromanović, Zeljko

    2004-01-01

    Many theories try to explain the existence and function of paranasal sinuses. This paper is an attempt to correlate process of paranasal sinus development in human with bone pneumatization processes in animals. It is here proposed that this mechanism starts in utero and continues after birth. During endochondral development, a solid hyaline cartilage model transforms into long bones. Central chondrocytes hypertrophy and their lacunae become confluent. Dissolving of the cartilage intercellular matrix forms a primitive marrow cavity. It is soon invaded by the periostal bud. Once circulation is established in the developing bone, the dissolved hyaline matrix can be slowly washed away from the bone cavity. Circulation in the bone cavity can develop slight subatmospheric pressures, similar to negative interstitial pressures in subcutaneous tissues. The amniotic fluid conducts atmospheric pressure to the fetal body. The pressure is trying to fill enlarging bone cavities through the existing vascular openings, or to create new openings. Bone walls of developing paranasal bones are to weak to resist the pressure gradient on their walls. New openings form on the weakest spots allowing airway mucosa to form initial paranasal sinuses. The enlarging cavities of long bones that are remote from the body surface and airway also develop a slightly subatmospheric pressure that fills them with cellular elements. These elements enter bone through the feeding vessels and form bone marrow. During after birth skeletal growth, bone remodeling shapes paranasal sinuses in a process of slow evolution that do not require measurable pressure gradients. When two sinuses come in vicinity, their growth rate declines, since the remaining thin and fragile bone lamella between them does not retract anymore.

  16. Distinct requirements of wls, wnt9a, wnt5b and gpc4 in regulating chondrocyte maturation and timing of endochondral ossification.

    Science.gov (United States)

    Ling, Irving Tc; Rochard, Lucie; Liao, Eric C

    2017-01-15

    Formation of the mandible requires progressive morphologic change, proliferation, differentiation and organization of chondrocytes preceding osteogenesis. The Wnt signaling pathway is involved in regulating bone development and maintenance. Chondrocytes that are fated to become bone require Wnt to polarize and orientate appropriately to initiate the endochondral ossification program. Although the canonical Wnt signaling has been well studied in the context of bone development, the effects of non-canonical Wnt signaling in regulating the timing of cartilage maturation and subsequent bone formation in shaping ventral craniofacial structure is not fully understood.. Here we examined the role of the non-canonical Wnt signaling pathway (wls, gpc4, wnt5b and wnt9a) in regulating zebrafish Meckel's cartilage maturation to the onset of osteogenic differentiation. We found that disruption of wls resulted in a significant loss of craniofacial bone, whereas lack of gpc4, wnt5b and wnt9a resulted in severely delayed endochondral ossification. This study demonstrates the importance of the non-canonical Wnt pathway in regulating coordinated ventral cartilage morphogenesis and ossification. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Gelatin device for the delivery of growth factors involved in endochondral ossification.

    Directory of Open Access Journals (Sweden)

    Lucas A J Ahrens

    Full Text Available Controlled release drug delivery systems are well established as oral and implantable dosage forms. However, the controlled release paradigm can also be used to present complex soluble signals responsible for cellular organization during development. Endochondral ossification (EO, the developmental process of bone formation from a cartilage matrix is controlled by several soluble signals with distinct functions that vary in structure, molecular weight and stability. This makes delivering them from a single vehicle rather challenging. Herein, a gelatin-based delivery system suitable for the delivery of small molecules as well as recombinant human (rh proteins (rhWNT3A, rhFGF2, rhVEGF, rhBMP4 is reported. The release behavior and biological activity of the released molecules was validated using analytical and biological assays, including cell reporter systems. The simplicity of fabrication of the gelatin device should foster its adaptation by the diverse scientific community interested in interrogating developmental processes, in vivo.

  18. Stimulation of experimental endochondral ossification by low-energy pulsing electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, R.K.; Ciombor, D.M.; Jolly, G.

    1989-04-01

    Pulsed electromagnetic fields (PEMFs) of certain configuration have been shown to be effective clinically in promoting the healing of fracture nonunions and are believed to enhance calcification of extracellular matrix. In vitro studies have suggested that PEMFs may also have the effect of modifying the extracellular matrix by promoting the synthesis of matrix molecules. This study examines the effect of one PEMF upon the extracellular matrix and calcification of endochondral ossification in vivo. The synthesis of cartilage molecules is enhanced by PEMF, and subsequent endochondral calcification is stimulated. Histomorphometric studies indicate that the maturation of bone trabeculae is also promoted by PEMF stimulation. These results indicate that a specific PEMF can change the composition of cartilage extracellular matrix in vivo and raises the possibility that the effects on other processes of endochondral ossification (e.g., fracture healing and growth plates) may occur through a similar mechanism.

  19. Fibromodulin is expressed by both chondrocytes and osteoblasts during fetal bone development.

    Science.gov (United States)

    Gori, F; Schipani, E; Demay, M B

    Fibromodulin, a keratan-sulfate proteoglycan, was first isolated in articular cartilage and tendons. We have identified fibromodulin as a gene regulated during BMP-2-induced differentiation of a mouse prechondroblastic cell line. Because expression of fibromodulin during endochondral bone formation has not been studied, we examined whether selected cells of the chondrocytic and osteoblastic lineage expressed fibromodulin. Fibromodulin mRNA was detected in conditionally immortalized murine bone marrow stromal cells, osteoblasts, and growth plate chondrocytes, as well as in primary murine calvarial osteoblasts. We, therefore, investigated the temporo-spatial expression of fibromodulin in vivo during endochondral bone formation by in situ hybridization. Fibromodulin was first detected at 15.5 days post coitus (dpc) in the perichondrium and proliferating chondrocytes. Fibromodulin mRNA was also detected at 15.5 dpc in the bone collar and periosteum. At later time points fibromodulin was expressed in the primary spongiosa and the endosteum. To determine whether fibromodulin was expressed during intramembranous bone formation as well, in situ hybridization was performed on calvariae. Fibromodulin mRNA was present in calvarial osteoblasts from 15.5 dpc. These results demonstrate that fibromodulin is developmentally expressed in cartilage and bone cells during endochondral and intramembranous ossification. These findings suggest that this extracellular matrix protein plays a role in both endochondral and intramembranous bone formation. Copyright 2001 Wiley-Liss, Inc.

  20. Dlx5 Is a cell autonomous regulator of chondrocyte hypertrophy in mice and functionally substitutes for Dlx6 during endochondral ossification.

    Directory of Open Access Journals (Sweden)

    Hui Zhu

    Full Text Available The axial and appendicular skeleton of vertebrates develops by endochondral ossification, in which skeletogenic tissue is initially cartilaginous and the differentiation of chondrocytes via the hypertrophic pathway precedes the differentiation of osteoblasts and the deposition of a definitive bone matrix. Results from both loss-of-function and misexpression studies have implicated the related homeobox genes Dlx5 and Dlx6 as partially redundant positive regulators of chondrocyte hypertrophy. However, experimental perturbations of Dlx expression have either not been cell type specific or have been done in the context of endogenous Dlx5 expression. Thus, it has not been possible to conclude whether the effects on chondrocyte differentiation are cell autonomous or whether they are mediated by Dlx expression in adjacent tissues, notably the perichondrium. To address this question we first engineered transgenic mice in which Dlx5 expression was specifically restricted to immature and differentiating chondrocytes and not the perichondrium. Col2a1-Dlx5 transgenic embryos and neonates displayed accelerated chondrocyte hypertrophy and mineralization throughout the endochondral skeleton. Furthermore, this transgene specifically rescued defects of chondrocyte differentiation characteristic of the Dlx5/6 null phenotype. Based on these results, we conclude that the role of Dlx5 in the hypertrophic pathway is cell autonomous. We further conclude that Dlx5 and Dlx6 are functionally equivalent in the endochondral skeleton, in that the requirement for Dlx5 and Dlx6 function during chondrocyte hypertrophy can be satisfied with Dlx5 alone.

  1. The role of muscle loading on bone (Remodeling at the developing enthesis.

    Directory of Open Access Journals (Sweden)

    Alexander M Tatara

    Full Text Available Muscle forces are necessary for the development and maintenance of a mineralized skeleton. Removal of loads leads to malformed bones and impaired musculoskeletal function due to changes in bone (remodeling. In the current study, the development of a mineralized junction at the interface between muscle and bone was examined under normal and impaired loading conditions. Unilateral mouse rotator cuff muscles were paralyzed using botulinum toxin A at birth. Control groups consisted of contralateral shoulders injected with saline and a separate group of normal mice. It was hypothesized that muscle unloading would suppress bone formation and enhance bone resorption at the enthesis, and that the unloading-induced bony defects could be rescued by suppressing osteoclast activity. In order to modulate osteoclast activity, mice were injected with the bisphosphonate alendronate. Bone formation was measured at the tendon enthesis using alizarin and calcein fluorescent labeling of bone surfaces followed by quantitative histomorphometry of histologic sections. Bone volume and architecture was measured using micro computed tomography. Osteoclast surface was determined via quantitative histomorphometry of tartrate resistant acid phosphatase stained histologic sections. Muscle unloading resulted in delayed initiation of endochondral ossification at the enthesis, but did not impair bone formation rate. Unloading led to severe defects in bone volume and trabecular bone architecture. These defects were partially rescued by suppression of osteoclast activity through alendronate treatment, and the effect of alendronate was dose dependent. Similarly, bone formation rate was increased with increasing alendronate dose across loading groups. The bony defects caused by unloading were therefore likely due to maintained high osteoclast activity, which normally decreases from neonatal through mature timepoints. These results have important implications for the treatment of

  2. BMP2 induces chondrogenic differentiation, osteogenic differentiation and endochondral ossification in stem cells.

    Science.gov (United States)

    Zhou, Nian; Li, Qi; Lin, Xin; Hu, Ning; Liao, Jun-Yi; Lin, Liang-Bo; Zhao, Chen; Hu, Zhen-Ming; Liang, Xi; Xu, Wei; Chen, Hong; Huang, Wei

    2016-10-01

    Bone morphogenetic protein 2 (BMP2), a member of the transforming growth factor-β (TGF-β) super-family, is one of the main chondrogenic growth factors involved in cartilage regeneration. BMP2 is known to induce chondrogenic differentiation in various types of stem cells in vitro. However, BMP2 also induces osteogenic differentiation and endochondral ossification in mesenchymal stem cells (MSCs). Although information regarding BMP2-induced chondrogenic and osteogenic differentiation within the same system might be essential for cartilage tissue engineering, few studies concerning these issues have been conducted. In this study, BMP2 was identified as a regulator of chondrogenic differentiation, osteogenic differentiation and endochondral bone formation within the same system. BMP2 was used to regulate chondrogenic and osteogenic differentiation in stem cells within the same culture system in vitro and in vivo. Any changes in the differentiation markers were assessed. BMP2 was found to induce chondrogenesis and osteogenesis in vitro via the expression of Sox9, Runx2 and its downstream markers. According to the results of the subcutaneous stem cell implantation studies, BMP2 not only induced cartilage formation but also promoted endochondral ossification during ectopic bone/cartilage formation. In fetal limb cultures, BMP2 promoted chondrocyte hypertrophy and endochondral ossification. Our data reveal that BMP2 can spontaneously induce chondrogenic differentiation, osteogenic differentiation and endochondral bone formation within the same system. Thus, BMP2 can be used in cartilage tissue engineering to regulate cartilage formation but has to be properly regulated for cartilage tissue engineering in order to retain the cartilage phenotype.

  3. Does static precede dynamic osteogenesis in endochondral ossification as occurs in intramembranous ossification?

    Science.gov (United States)

    Ferretti, Marzia; Palumbo, Carla; Bertoni, Laura; Cavani, Francesco; Marotti, Gastone

    2006-11-01

    Endochondral ossification takes place with calcified cartilage cores providing a rigid scaffold for new bone formation. Intramembranous ossification begins in connective tissue and new bone formed by a process of static ossification (SO) followed by dynamic ossification (DO) as previously described. The aim of the present study was to determine if the process of endochondral ossification is similar to that of intramembranous ossification with both a static and a dynamic phase of osteogenesis. Endochondral ossification centers of the tibiae and humeri of newborn and young growing rabbits were studied by light and transmission electron microscopy. The observations clearly showed that in endochondral ossification, the calcified trabeculae appeared to be lined first by osteoclasts. The osteoclasts were then replaced by flattened cells (likely cells of the reversal phase) and finally by irregularly arranged osteoblastic laminae, typical of DO. This cellular sequence did not include osteoblasts seen in the phase of SO. These findings clearly support our working hypothesis that SO only forms in soft tissues to provide a rigid framework for DO, and that DO requires a rigid mineralized surface. The presence of osteocytes in contact with the calcified cartilage also suggests the existence of stationary osteoblasts in endochondral ossification. Stationary osteoblasts did not appear to be a unique feature of SO. The presence of stationary osteoblasts may appear to provide the initial osteocytes during osteogenesis that may function as mechanosensors throughout the bone tissue. If this is the case, then bone would be capable of sensing mechanical strains from its inception. (c) 2006 Wiley-Liss, Inc.

  4. Optimal Treatment of Malignant Long Bone Fracture: Influence of Method of Repair and External Beam Irradiation on the Pathway and Efficacy of Fracture Healing

    Science.gov (United States)

    2015-10-01

    healing, bone healing, endochondral ossification , intramembranous ossification , irradiation, radiotherapy, pathologic fractures, bony metastasis...pathways, endochondral or intramembranous ossification , and clinically the pathway followed is determined by the nature of fracture stabilization...Endochondral ossification (EO), “secondary bone healing”, is characterized by a cartilaginous callus intermediary induced by interfragmentary motion

  5. Special pattern of endochondral ossification in human laryngeal cartilages: X-ray and light-microscopic studies on thyroid cartilage.

    Science.gov (United States)

    Claassen, Horst; Schicht, Martin; Sel, Saadettin; Paulsen, Friedrich

    2014-04-01

    Endochondral ossification is a process that also occurs in the skeleton of the larynx. Differences in the ossification mechanism in comparison to growth plates are not understood until now. To get deeper insights into this process, human thyroid cartilage was investigated by the use of X-rays and a series of light-microscopic stainings. A statistical analysis of mineralization was done by scanning areas of mineralized cartilage and of ossification. We detected a special mode of endochondral ossification which differs from the processes in growth plates. Thyroid cartilage ossifies very slowly and in a gender-specific manner. Compared with age-matched women, bone formation in thyroid cartilage of men is significantly higher in the age group 41-60 years. Endochondral ossification is prepared by internal changes of extracellular matrix leading to areas of asbestoid fibers with ingrowing cartilage canals. In contrast to growth plates, bone is deposited on large areas of mineralized cartilage, which appear at the rims of cartilage canals. Furthermore, primary parallel fibered bone was observed which was deposited on woven bone. The predominant bone type is cancellous bone with trabeculae, whereas compact bone with Haversian systems was seldom found. Trabeculae contain a great number of reversal and arresting lines meaning that the former were often reconstructed and that bone formation was arrested and resumed again with advancing age. It is hypothesized that throughout life trabeculae of ossified thyroid cartilage undergo adaptation to different loads due to the use of voice. Copyright © 2014 Wiley Periodicals, Inc.

  6. Development of Bone Remodeling Model for Spaceflight Bone Physiology Analysis

    Science.gov (United States)

    Pennline, James A.; Werner, Christopher R.; Lewandowski, Beth; Thompson, Bill; Sibonga, Jean; Mulugeta, Lealem

    2015-01-01

    Current spaceflight exercise countermeasures do not eliminate bone loss. Astronauts lose bone mass at a rate of 1-2% a month (Lang et al. 2004, Buckey 2006, LeBlanc et al. 2007). This may lead to early onset osteoporosis and place the astronauts at greater risk of fracture later in their lives. NASA seeks to improve understanding of the mechanisms of bone remodeling and demineralization in 1g in order to appropriately quantify long term risks to astronauts and improve countermeasures. NASA's Digital Astronaut Project (DAP) is working with NASA's bone discipline to develop a validated computational model to augment research efforts aimed at achieving this goal.

  7. Effects of bisphosphonates on osteogenesis and osteoclastogenesis signaling during the endochondral ossification of growing rats.

    Science.gov (United States)

    Rezende, Eloiza; Bradaschia-Correa, Vivian; Siviero, Fabio; Ambrosio, Lucas M B; Arana-Chavez, Victor E

    2017-05-01

    Osteoclasts and chondroclasts are necessary, during endochondral ossification, for the resorption of primary bone and calcified cartilage septa, respectively. The bisphosphonates inhibit mineralized tissue resorption by various mechanisms according to the different types of this drug, which can affect bone remodeling during skeletal growth. The objective of the present study is to analyze the way that alendronate (ALN) and etidronate (ETN) can affect osteoclastogenesis and bone formation during endochondral ossification of the long bones of growing rats. Newborn Wistar rats were treated daily with ETN, ALN, or sterile saline solution (control) for 21 days. Their femur and tibiae epiphyses were radiographed and analyzed by light, scanning and transmission electron microscopy. The expression of genes related to osteogenesis and to osteoclast differentiation and activity were analyzed by real-time quantitative polymerase chain reaction. The ETN group presented reduced body weight, disorganized growth plate and an extended area of cartilage in the ossification zone with little bone matrix; in the ALN group, this area was not altered. The ALN presented latent TRAP-positive cells, whereas in the ETN group, they were activated. The expression of NFκB1 and 2, OPG, Spp1 and Runx2 in the ossification zone was reduced by both bisphosphonates. RANKL expression was reduced by ETN, whereas ALN decreased the expression of RANK. The results also indicated that, in addition to the anti-resorptive effect of the drugs, disturbances in bone deposition occurred concomitantly with the reduced expression of osteogenesis-related genes.

  8. Tranilast stimulates endochondral ossification by upregulating SOX9 and RUNX2 promoters.

    Science.gov (United States)

    Hasegawa, Sachi; Kitoh, Hiroshi; Ohkawara, Bisei; Mishima, Kenichi; Matsushita, Masaki; Masuda, Akio; Ishiguro, Naoki; Ohno, Kinji

    2016-02-05

    Endochondral ossification is an essential process for reparative phase of fracture healing, which starts with the differentiation of mesenchymal cells into chondrocytes followed by substitution of bone tissue. It is strictly controlled by the expression of crucial transcriptional factors: SOX9 in the early phase and RUNX2 in the late phase. Screening of FDA-approved compounds revealed that an anti-allergic drug, tranilast, that has been used for more than 30 years in clinical practice, enhanced the SOX9 promoter in chondrogenic cells and the RUNX2 promoter in osteoblastic cells. We observed that tranilast increased mRNA expression of both Sox9 and Runx2 in differentiating ATDC5 chondrogenic progenitor cells. Tranilast upregulated mRNA expression of chondrogenic marker genes (Col2a1, Acan, Col10a1, and Mmp13) in differentiating ATDC5 cells. Moreover, tranilast upregulated mRNA expression of essential signaling molecules involved in endochondral ossification (Pthrp, Ihh, and Axin2). In the later phase of differentiation of ATDC5 cells, tranilast increased synthesis of matrix proteoglycans, induced the alkaline phosphatase activity, and tended to accelerate mineralization. Tranilast is a potential agent that accelerates fracture repair by promoting the regulatory steps of endochondral ossification. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Chondrocytic ephrin B2 promotes cartilage destruction by osteoclasts in endochondral ossification.

    Science.gov (United States)

    Tonna, Stephen; Poulton, Ingrid J; Taykar, Farzin; Ho, Patricia W M; Tonkin, Brett; Crimeen-Irwin, Blessing; Tatarczuch, Liliana; McGregor, Narelle E; Mackie, Eleanor J; Martin, T John; Sims, Natalie A

    2016-02-15

    The majority of the skeleton arises by endochondral ossification, whereby cartilaginous templates expand and are resorbed by osteoclasts then replaced by osteoblastic bone formation. Ephrin B2 is a receptor tyrosine kinase expressed by osteoblasts and growth plate chondrocytes that promotes osteoblast differentiation and inhibits osteoclast formation. We investigated the role of ephrin B2 in endochondral ossification using Osx1Cre-targeted gene deletion. Neonatal Osx1Cre.Efnb2(Δ/Δ) mice exhibited a transient osteopetrosis demonstrated by increased trabecular bone volume with a high content of growth plate cartilage remnants and increased cortical thickness, but normal osteoclast numbers within the primary spongiosa. Osteoclasts at the growth plate had an abnormal morphology and expressed low levels of tartrate-resistant acid phosphatase; this was not observed in more mature bone. Electron microscopy revealed a lack of sealing zones and poor attachment of Osx1Cre.Efnb2(Δ/Δ) osteoclasts to growth plate cartilage. Osteoblasts at the growth plate were also poorly attached and impaired in their ability to deposit osteoid. By 6 months of age, trabecular bone mass, osteoclast morphology and osteoid deposition by Osx1Cre.Efnb2(Δ/Δ) osteoblasts were normal. Cultured chondrocytes from Osx1Cre.Efnb2(Δ/Δ) neonates showed impaired support of osteoclastogenesis but no significant change in Rankl (Tnfsf11) levels, whereas Adamts4 levels were significantly reduced. A population of ADAMTS4(+) early hypertrophic chondrocytes seen in controls was absent from Osx1Cre.Efnb2(Δ/Δ) neonates. This suggests that Osx1Cre-expressing cells, including hypertrophic chondrocytes, are dependent on ephrin B2 for their production of cartilage-degrading enzymes, including ADAMTS4, and this might be required for attachment of osteoclasts and osteoblasts to the cartilage surface during endochondral ossification. © 2016. Published by The Company of Biologists Ltd.

  10. Absence of endochondral ossification and craniosynostosis in posterior frontal cranial sutures of Axin2(-/- mice.

    Directory of Open Access Journals (Sweden)

    Björn Behr

    Full Text Available During the first month of life, the murine posterior-frontal suture (PF of the cranial vault closes through endochondral ossification, while other sutures remain patent. These processes are tightly regulated by canonical Wnt signaling. Low levels of active canonical Wnt signaling enable endochondral ossification and therefore PF-suture closure, whereas constitutive activation of canonical Wnt causes PF-suture patency. We therefore sought to test this concept with a knockout mouse model. PF-sutures of Axin2(-/- mice, which resemble a state of constantly activated canonical Wnt signaling, were investigated during the physiological time course of PF-suture closure and compared in detail with wild type littermates. Histological analysis revealed that the architecture in Axin2(-/- PF-sutures was significantly altered in comparison to wild type. The distance between the endocranial layers was dramatically increased and suture closure was significantly delayed. Moreover, physiological endochondral ossification did not occur, rather an ectopic cartilage appeared between the endocranial and ectocranial bone layers at P7 which eventually involutes at P13. Quantitative PCR analysis showed the lack of Col10α1 upregulation in Axin2(-/- PF-suture. Immunohistochemistry and gene expression analysis also revealed high levels of type II collagen as compared to type I collagen and absence of Mmp-9 in the cartilage of Axin2(-/- PF-suture. Moreover, TUNEL staining showed a high percentage of apoptotic chondrocytes in Axin2(-/- PF-sutures at P9 and P11 as compared to wild type. These data indicated that Axin2(-/- PF-sutures lack physiological endochondral ossification, contain ectopic cartilage and display delayed suture closure.

  11. Optimizing Soft Tissue Management and Spacer Design in Segmental Bone Defects

    Science.gov (United States)

    2014-10-01

    abundant in bone, cornea , dermis and tendon. COL2A1 Encodes the alpha-1 chain of type II collagen , a fibrillar collagen found in cartilage...growth. This gene has a proposed role in early bone development. COL1A1 Encodes a fibril-forming collagen that is found in most connective tissues and is...COL10A1 Encodes the alpha chain of type X collagen , a short chain collagen expressed by hypertrophic chondrocytes during endochondral ossification. GLA

  12. Skeletal dysplasia in perinatal lethal osteogenesis imperfecta. A complex disorder of endochondral and intramembranous ossification.

    Science.gov (United States)

    Marion, M J; Gannon, F H; Fallon, M D; Mennuti, M T; Lodato, R F; Kaplan, F S

    1993-08-01

    Osteogenesis imperfecta (OI) Type II is a rare heritable disorder of bone matrix that results in catastrophic congenital skeletal dysplasia. Two cases of OI Type II had symmetric rhizomelic skeletal dysplasia apparent on ultrasound at 16 and 20 weeks' gestation. Histologic and histochemical studies performed on skeletal tissue from fetal autopsies showed the following: (1) abnormal growth plate tissue characterized by failure of formation of primary bony spongiosa; (2) persistence of calcified cartilage bars in the diaphysis; (3) metaphyseal microfractures; (4) abundant cartilaginous fracture callus; (5) absence of bony callus; (6) failure of formation of intramembranous cortical diaphyseal bone; (7) angulation of long bones in portions of the metadiaphyses bordered by fracture callus; and (8) mechanical failure of the perichondral ring of LaCroix with a normal fibrous ossification groove of Ranvier. These findings suggest that skeletal dysplasia in OI Type II results from the action of muscular forces on a skeleton weakened by a complex disorder of endochondral and intramembranous ossification. The paucity of primary metaphyseal trabeculae and subperiosteal cortical bone leads to pathologic fractures of the immature fiber bone and an imperfect attempt at fracture repair. Angulation and shortening of long bones occurs between numerous sites of focal endochondral fracture callus. Mechanical failure of the fibrous perichondral ring leads to further collapse and shortening without obvious functional impairment of the fibrous ossification groove. Perinatal lethal OI provides insight into how a molecular disorder predominantly of Type I collagen metabolism results in pathology of numerous tissues, leading to severe skeletal dysplasia without primarily affecting chondrogenesis.

  13. Polyhydramnios and bone development: an unexplored relationship.

    Science.gov (United States)

    Sekulić, S R; Ilić, D; Novakov-Mikić, A

    2010-09-01

    Immersion of a humans and Macaca mulatta into a pool with fluid whose specific weight is equal to their specific weight cause bone demineralization. Also, in professional scuba divers, bone mineral density is reduced. Because of water immersion, the apparent weight of scuba divers represents 10% of their actual weight. The aim of this paper was to point out a previously unexplored aspect of fetal bone development in an environment lacking adequate mechanical stress on fetal bone, such as polyhydramnios. In the first part of gestation, the human fetus develops under conditions similar to neutral floating and has an apparent weight which is approximately 5% of its actual weight. During the last trimester of gestation, the fetus overgrows the intrauterine cavity and its apparent body weight is 60-80% of its actual weight. Polyhydramnios represents an excess of amniotic fluid in the uterus during gestation and it can reduce the apparent weight of the fetus to 10-20% of its actual weight. Reduction of the mechanical stress on fetal bone caused by polyhydramnios may significantly affect bone development and ossification during the last trimester of gestation. It is necessary to direct further studies towards examining bone development and mineralization in newborns from gestations complicated by polyhydramnios. A complete lack of data and studies on fetal bone development and bone mineralization in pregnancies complicated by polyhydramnios is not surprising. There is still a misleading opinion that the fetus is in weightlessness condition in the intrauterine environment throughout the second half of gestation regardless of the amount of amniotic fluid. (c) 2010 Elsevier Ltd. All rights reserved.

  14. Regulation of Bone Metabolism

    Directory of Open Access Journals (Sweden)

    Maryam Shahi

    2017-05-01

    Full Text Available Bone is formed through the processes of endochondral and intramembranous ossification. In endochondral ossification primary mesenchymal cells differentiate to chondrocytes and then are progressively substituted by bone, while in intramembranous ossification mesenchymal stem cells (MSCs differentiate directly into osteoblasts to form bone. The steps of osteogenic proliferation, differentiation, and bone homeostasis are controlled by various markers and signaling pathways. Bone needs to be remodeled to maintain integrity with osteoblasts, which are bone-forming cells, and osteoclasts, which are bone-degrading cells. In this review we considered the major factors and signaling pathways in bone formation; these include fibroblast growth factors (FGFs, bone morphogenetic proteins (BMPs, wingless-type (Wnt genes, runt-related transcription factor 2 (RUNX2 and osteoblast-specific transcription factor (osterix or OSX.

  15. Relationship between the chondrocyte maturation cycle and the endochondral ossification in the diaphyseal and epiphyseal ossification centers.

    Science.gov (United States)

    Pazzaglia, Ugo E; Congiu, Terenzio; Sibilia, Valeria; Pagani, Francesca; Benetti, Anna; Zarattini, Guido

    2016-09-01

    The chondrocyte maturation cycle and endochondral ossification were studied in human, fetal cartilage Anlagen and in postnatal meta-epiphyses. The relationship between the lacunar area, the inter-territorial fibril network variations, and calcium phosphorus nucleation in primary and secondary ossification centers were assessed using light microscopy and scanning electron microscopy (SEM) morphometry. The Anlage topographic, zonal classification was derived from the anatomical nomenclature of the completely developed long bone (diaphysis, metaphyses and epiphyses). A significant increase in the chondrocyte lacunar area was documented in the Anlage of epiphyseal zones 4 and 3 to zone 2 (metaphysis) and zone 1 (diaphysis), with the highest variation from zone 2 to zone 1. An inverse reduction in the intercellular matrix area and matrix interfibrillar empty space was also documented. These findings are consistent with the osmotic passage of free cartilage water from the interfibrillar space into the swelling chondrocytes, which increased the ion concentrations to a critical threshold for mineral precipitation in the matrix. The mineralized cartilage served as a scaffold for osteoblast apposition both in primary and secondary ossification centers and in the metaphyseal growth plate cartilage, though at different periods of bone Anlage development and with distinct patterns for each zone. All developmental processes shared a common initial pathway but progressed at different rates, modes and organization in diaphysis, metaphysis and epiphysis. In the ossification phase the developing vascular supply appeared to play a key role in determining the cortical or trabecular structure of the long bones. J. Morphol. 277:1187-1198, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  16. Delayed endochondral ossification in early medial coronoid disease (MCD): a morphological and immunohistochemical evaluation in growing Labrador retrievers.

    Science.gov (United States)

    Lau, S F; Hazewinkel, H A W; Grinwis, G C M; Wolschrijn, C F; Siebelt, M; Vernooij, J C M; Voorhout, G; Tryfonidou, M A

    2013-09-01

    Medial coronoid disease (MCD) is a common joint disease of dogs. It has a multifactorial aetiology, but the relationship between known causal factors and the disease has yet to be elucidated. As most of the published literature is clinical and it reports changes associated with advanced disease, it is not known whether the changes reflect the cause or consequences of the condition. The aim of this study was to investigate early micromorphological changes occurring in articular cartilage and to describe the postnatal development of the medial coronoid process (MCP) before MCD develops. Three litters of MCD-prone young Labrador retrievers were purpose-bred from a dam and two sires with MCD. Comparisons of the micromorphological appearance of the MCP in MCD-negative and MCD-positive joints demonstrated that MCD was initially associated with a disturbance of endochondral ossification, namely a delay in the calcification of the calcifying zone, without concurrent abnormalities in the superficial layers of the joint cartilage. Cartilage canals containing patent blood vessels were only detected in dogs <12 weeks old, but the role of these channels in impaired ossification requires further investigation. Retained hyaline cartilage might ossify as the disease progresses, but weak areas can develop into cracks between the retained cartilage and the subchondral bone, leading to cleft formation and fragmentation of the MCP. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Dietary Vitamin D Supplementation during Early Growth is not Protective for Medial Coronoid Disease Development in Labradors

    NARCIS (Netherlands)

    Corbee, R.J.|info:eu-repo/dai/nl/314838066; Tryfonidou, M.A.|info:eu-repo/dai/nl/24306599X; Grinwis, G.C.M.|info:eu-repo/dai/nl/141470909; Wolschrijn, Claudia F.; Lau, Seng Fong; Gorissen, Ben|info:eu-repo/dai/nl/372825788; Heuven, Henri C.M.; Vaandrager, Arie B.; Hazewinkel, Herman A.W.

    2015-01-01

    Introduction: Medial coronoid disease (MCD) is a common heritable disease in young large-breed dogs and is characterized by fissures and/or fragmentation of the medial coronoid process (MCP), cartilage, and/or subchondral bone. MCD development has also been attributed to disturbed endochondral

  18. Recent research on the growth plate: Advances in fibroblast growth factor signaling in growth plate development and disorders.

    Science.gov (United States)

    Xie, Yangli; Zhou, Siru; Chen, Hangang; Du, Xiaolan; Chen, Lin

    2014-08-01

    Skeletons are formed through two distinct developmental actions, intramembranous ossification and endochondral ossification. During embryonic development, most bone is formed by endochondral ossification. The growth plate is the developmental center for endochondral ossification. Multiple signaling pathways participate in the regulation of endochondral ossification. Fibroblast growth factor (FGF)/FGF receptor (FGFR) signaling has been found to play a vital role in the development and maintenance of growth plates. Missense mutations in FGFs and FGFRs can cause multiple genetic skeletal diseases with disordered endochondral ossification. Clarifying the molecular mechanisms of FGFs/FGFRs signaling in skeletal development and genetic skeletal diseases will have implications for the development of therapies for FGF-signaling-related skeletal dysplasias and growth plate injuries. In this review, we summarize the recent advances in elucidating the role of FGFs/FGFRs signaling in growth plate development, genetic skeletal disorders, and the promising therapies for those genetic skeletal diseases resulting from FGFs/FGFRs dysfunction. Finally, we also examine the potential important research in this field in the future. © 2014 Society for Endocrinology.

  19. Cellular Therapy to Obtain Rapid Endochondral Bone Formation

    Science.gov (United States)

    2010-02-01

    2001 Mar;22(5):439-444. 20. Sawhney AS, Pathak CP, Hubbell JA. Modification of islet of langerhans surfaces with immunoprotective poly(ethylene...vertebrae. Biomechanical Testing Prior to sectioning, formaldehyde fixed spines were encased in alginate in order to obtain flexion and extension...radiographs. Spines were suspended in an in-house mold. Alginate powder was combined in an equal volume to water (30 ml of each) and mixed until smooth

  20. Cellular Therapy to Obtain Rapid Endochondral Bone Formation

    Science.gov (United States)

    2009-02-01

    delivery of either the Ad5BMP2 transduced MRC5 cells or those encapsulated in hydrogel. As can be seen in figure 6, we still observe some signal...arrow: cell inoculation site White arrow: scar region Figure 4: Live animal optical imaging of nude mice which received 5 x 106 MRC5 cells transduced...Animal #1 Animal #2 Animal #1 Animal #2 031707 Figure 5: Live animal optical imaging of nude mice which received 5 x 106 MRC5 cells transduced with

  1. Development of polyurethanes for bone repair.

    Science.gov (United States)

    Marzec, M; Kucińska-Lipka, J; Kalaszczyńska, I; Janik, H

    2017-11-01

    The purpose of this paper is to review recent developments on polyurethanes aimed at the design, synthesis, modifications, and biological properties in the field of bone tissue engineering. Different polyurethane systems are presented and discussed in terms of biodegradation, biocompatibility and bioactivity. A comprehensive discussion is provided of the influence of hard to soft segments ratio, catalysts, stiffness and hydrophilicity of polyurethanes. Interaction with various cells, behavior in vivo and current strategies in enhancing bioactivity of polyurethanes are described. The discussion on the incorporation of biomolecules and growth factors, surface modifications, and obtaining polyurethane-ceramics composites strategies is held. The main emphasis is placed on the progress of polyurethane applications in bone regeneration, including bone void fillers, shape memory scaffolds, and drug carrier. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Nutrition and bone growth and development.

    Science.gov (United States)

    Prentice, Ann; Schoenmakers, Inez; Laskey, M Ann; de Bono, Stephanie; Ginty, Fiona; Goldberg, Gail R

    2006-11-01

    The growth and development of the human skeleton requires an adequate supply of many different nutritional factors. Classical nutrient deficiencies are associated with stunting (e.g. energy, protein, Zn), rickets (e.g. vitamin D) and other bone abnormalities (e.g. Cu, Zn, vitamin C). In recent years there has been interest in the role nutrition may play in bone growth at intakes above those required to prevent classical deficiencies, particularly in relation to optimising peak bone mass and minimising osteoporosis risk. There is evidence to suggest that peak bone mass and later fracture risk are influenced by the pattern of growth in childhood and by nutritional exposures in utero, in infancy and during childhood and adolescence. Of the individual nutrients, particular attention has been paid to Ca, vitamin D, protein and P. There has also been interest in several food groups, particularly dairy products, fruit and vegetables and foods contributing to acid-base balance. However, it is not possible at the present time to define dietary reference values using bone health as a criterion, and the question of what type of diet constitutes the best support for optimal bone growth and development remains open. Prudent recommendations (Department of Health, 1998; World Health Organization/Food and Agriculture Organization, 2003) are the same as those for adults, i.e. to consume a Ca intake close to the reference nutrient intake, optimise vitamin D status through adequate summer sunshine exposure (and diet supplementation where appropriate), be physically active, have a body weight in the healthy range, restrict salt intake and consume plenty of fruit and vegetables.

  3. Localization of Thy-1-positive cells in the perichondrium during endochondral ossification.

    Science.gov (United States)

    Nakamura, Hiroaki; Yukita, Akira; Ninomiya, Tadashi; Hosoya, Akihiro; Hiraga, Toru; Ozawa, Hidehiro

    2010-05-01

    We elucidated the localization of Thy-1-positive cells in the perichondrium of fetal rat limb bones to clarify the distribution of osteogenic cells in the process of endochondral ossification. We also examined the formation of calcified bone-like matrices by isolated perichondrial cells in vitro. At embryonic day (E) 15.5, when the cartilage primodia were formed, immunoreactivity for Thy-1 was detected in cells of the perichondrium adjacent to the zone of hypertrophic chondrocytes. At E17.5, when the bone collar formation and the vascular invasion were initiated, fibroblast-like cells at the sites of vascular invasion, as well as in the perichondrium, showed Thy-1 labeling. Double immunostaining for Thy-1 and osterix revealed that Thy-1 was not expressed in the osterix-positive osteoblasts. Electron microscopic analysis revealed that Thy-1-positive cells in the zone of hypertrophic chondrocytes came in contact with blood vessels. Perichondrial cells isolated from limb bones showed alkaline phosphatase activity and formed calcified bone-like matrices after 4 weeks in osteogenic medium. RT-PCR demonstrated that Thy-1 expression decreased as calcified nodules formed. Conversely, the expression of osteogenic marker genes Runx2, osterix, and osteocalcin increased. These results indicate that Thy-1 is a good marker for characterizing osteoprogenitor cells.

  4. Endochondral Growth Defect and Deployment of Transient Chondrocyte Behaviors Underlie Osteoarthritis Onset in a Natural Murine Model.

    Science.gov (United States)

    Staines, K A; Madi, K; Mirczuk, S M; Parker, S; Burleigh, A; Poulet, B; Hopkinson, M; Bodey, A J; Fowkes, R C; Farquharson, C; Lee, P D; Pitsillides, A A

    2016-04-01

    To explore whether aberrant transient chondrocyte behaviors occur in the joints of STR/Ort mice (which spontaneously develop osteoarthritis [OA]) and whether they are attributable to an endochondral growth defect. Knee joints from STR/Ort mice with advanced OA and age-matched CBA (control) mice were examined by Affymetrix microarray profiling, multiplex polymerase chain reaction (PCR) analysis, and immunohistochemical labeling of endochondral markers, including sclerostin and MEPE. The endochondral phenotype of STR/Ort mice was analyzed by histologic examination, micro-computed tomography, and ex vivo organ culture. A novel protocol for quantifying bony bridges across the murine epiphysis (growth plate fusion) using synchrotron x-ray computed microtomography was developed and applied. Meta-analysis of transcription profiles showed significant elevation in functions linked with endochondral ossification in STR/Ort mice (compared to CBA mice; P < 0.05). Consistent with this, immunolabeling revealed increased matrix metalloproteinase 13 (MMP-13) and type X collagen expression in STR/Ort mouse joints, and multiplex quantitative reverse transcriptase-PCR showed differential expression of known mineralization regulators, suggesting an inherent chondrocyte defect. Support for the notion of an endochondral defect included accelerated growth, increased zone of growth plate proliferative chondrocytes (P < 0.05), and widespread type X collagen/MMP-13 labeling beyond the expected hypertrophic zone distribution. OA development involved concomitant focal suppression of sclerostin/MEPE in STR/Ort mice. Our novel synchrotron radiation microtomography method showed increased numbers (P < 0.001) and mean areal growth plate bridge densities (P < 0.01) in young and aged STR/Ort mice compared to age-matched CBA mice. Taken together, our data support the notion of an inherent endochondral defect that is linked to growth dynamics and subject to regulation by the MEPE/sclerostin axis and

  5. Safety and morbidity of intra-oral zygomatic bone graft harvesting:development of a novel bone harvesting technique

    OpenAIRE

    Kainulainen, V.

    2004-01-01

    Abstract This study focuses on the development of a bone collecting device for intra-oral bone harvesting and on the introduction of a new bone graft donor site, zygomatic bone. A bone collector was constructed and tested in vitro. This bone collector is suitable and efficient in dental implant related bone grafting surgery. It was also found to be more efficient and with a larger capacity in bone harvesting when compared to the two commercially available bone collectors. A zygoma...

  6. Influence of gain-of-function mutation (Ser252Trp in fibroblast growth factor receptor 2 gene on long bone development

    Directory of Open Access Journals (Sweden)

    Peng CHEN

    2013-07-01

    Full Text Available Objective To observe the early postnatal long bone development in Fgfr2+/S252W mutant mice and littermate wild-type (WT mice, and explore the effect of continued function enhancement of fibroblast growth factor receptor 2 (FGFR2 gene on endochondral ossification. Methods A mouse model of Fgfr2+/S252W simulated human Apert syndrome was reproduced by knock-in technique, and then the gain-of-function mutation Fgfr2+/S252W mice and littermate WT mice were obtained after breeding and identification. Three Fgfr2+/S252W and same number of WT mice were sacrificed at 7, 10, 14 and 28 postnatal days respectively, and the morphology of long bone was examined with X-ray and Micro CT, the structure of bone and cartilage was observed by HE staining, and the expression of gene in growth plate was observed by immunohistochemical analysis. Results Fgfr2+/S252W mouse model exhibited typical craniosynostosis and brachycephalium of Apert syndrome, accompanied by short stature, growth retardation of long bone, delayed appearance of secondary ossification center, decrease of bone density and trabecula number. HE staining showed noticeable shortened zones of proliferation and hypertrophic chondrocytes, irregularity of cell arrangement, and small hypertrophic chondrocytes in the growth plates of the mutant mice. Immunohistochemical analysis revealed that the expression of genes related to chondrocytes proliferation and differentiation was decreased in mutant mice. Conclusions Gain-of-function mutation in FGFR2 may lead to abnormal development of long bone in mice. FGFR2 may have the function of regulating the development both of osteoblast and chondrocyte lineages, and play an important role in the process of skeletal development.

  7. Bone formation in cranial, mandibular, tibial and iliac bone grafts in rats

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Talsnes, O

    1995-01-01

    Several studies have suggested that grafts from membranous derived bone (e.g., calvarial grafts) retain their volume better than those from endochondral derived bone (e.g., iliac bone grafts). Increased osteogenesis in grafts of the former type has been offered as the explanation. However, simple...

  8. Strategies Developed to Induce, Direct, and Potentiate Bone Healing

    Directory of Open Access Journals (Sweden)

    Anne-Margaux Collignon

    2017-11-01

    Full Text Available Bone exhibits a great ability for endogenous self-healing. Nevertheless, impaired bone regeneration and healing is on the rise due to population aging, increasing incidence of bone trauma and the clinical need for the development of alternative options to autologous bone grafts. Current strategies, including several biomolecules, cellular therapies, biomaterials, and different permutations of these, are now developed to facilitate the vascularization and the engraftment of the constructs, to recreate ultimately a bone tissue with the same properties and characteristics of the native bone. In this review, we browse the existing strategies that are currently developed, using biomolecules, cells and biomaterials, to induce, direct and potentiate bone healing after injury and further discuss the biological processes associated with this repair.

  9. Inhibition of CaMKK2 Enhances Fracture Healing by Stimulating Indian Hedgehog Signaling and Accelerating Endochondral Ossification.

    Science.gov (United States)

    Williams, Justin N; Kambrath, Anuradha Valiya; Patel, Roshni B; Kang, Kyung Shin; Mével, Elsa; Li, Yong; Cheng, Ying-Hua; Pucylowski, Austin J; Hassert, Mariah A; Voor, Michael J; Kacena, Melissa A; Thompson, William R; Warden, Stuart J; Burr, David B; Allen, Matthew R; Robling, Alexander G; Sankar, Uma

    2018-01-03

    Approximately ten percent of all bone fractures do not heal, resulting in patient morbidity and healthcare costs. However, no pharmacological treatments are currently available to promote efficient bone healing. Inhibition of Ca2+ /calmodulin (CaM)-dependent protein kinase kinase 2 (CaMKK2) reverses age-associated loss of trabecular and cortical bone volume and strength in mice. In the current study, we investigated the role of CaMKK2 in bone fracture healing and show that its pharmacological inhibition using STO-609 accelerates early cellular and molecular events associated with endochondral ossification, resulting in a more rapid and efficient healing of the fracture. Within 7 days post-fracture, treatment with STO-609 resulted in enhanced Indian hedgehog signaling, paired-related homeobox (PRX1)-positive mesenchymal stem cell recruitment, chondrocyte differentiation and hypertrophy, along with elevated expression of osterix, vascular endothelial growth factor and type 1 collagen at the fracture callus. Early deposition of primary bone by osteoblasts resulted in STO-609 treated mice possessing significantly higher callus bone volume by 14 days following fracture. Subsequent rapid maturation of the bone matrix bestowed fractured bones in STO-609 treated animals with significantly higher torsional strength and stiffness by 28 days post-injury, indicating accelerated healing of the fracture. Previous studies indicate that fixed and closed femoral fractures in the mice take 35 days to fully heal without treatment. Therefore, our data suggest that STO-609 potentiates a 20% acceleration of the bone healing process. Moreover, inhibiting CaMKK2 also imparted higher mechanical strength and stiffness at the contralateral cortical bone within 4 weeks of treatment. Taken together, the data presented here underscore the therapeutic potential of targeting CaMKK2 to promote efficacious and rapid healing of bone fractures and as a mechanism to strengthen normal bones. This

  10. Bone Adaptation and Regeneration - New Developments

    Science.gov (United States)

    Klein-Nulend, Jenneke; Bacabac, Rommel Gaud

    Bone is a dynamic tissue that is constantly renewed and adapts to its local loading environment. Mechanical loading results in adaptive changes in bone size and shape that strengthen bone structure. The mechanisms for adaptation involve a multistep process called mechanotransduction, which is the ability of resident bone cells to perceive and translate mechanical energy into a cascade of structural and biochemical changes within the cells. The transduction of a mechanical signal to a biochemical response involves pathways within the cell membrane and cytoskeleton of the osteocytes, the professional mechansensor cells of bone. During the last decade the role of mechanosensitive osteocytes in bone metabolism and turnover, and the lacuno-canalicular porosity as the structure that mediates mechanosensing, is likely to reveal a new paradigm for understanding the bone formation response to mechanical loading, and the bone resorption response to disuse. Strain-derived fluid flow of interstitial fluid through the lacuno-canalicular porosity seems to mechanically activate the osteocytes, as well as ensures transport of cell signaling molecules, nutrients and waste products. Cell-cell signaling from the osteocyte sensor cells to the effector cells (osteoblasts or osteoclasts), and the effector cell response - either bone formation or resorption, allow an explanation of local bone gain and loss as well as remodeling in response to fatigue damage as processes supervised by mechanosensitive osteocytes. The osteogenic activity of cultured bone cells has been quantitatively correlated with varying stress stimulations highlighting the importance of the rate of loading. Theoretically a possible mechanism for the stress response by osteocytes is due to strain amplification at the pericellular matrix. Single cell studies on molecular responses of osteocytes provide insight on local architectural alignment in bone during remodeling. Alignment seems to occur as a result of the

  11. Interactions of the tooth and bone during development.

    Science.gov (United States)

    Alfaqeeh, S A; Gaete, M; Tucker, A S

    2013-12-01

    The tooth works as a functional unit with its surrounding bony socket, the alveolar bone. The growth of the tooth and alveolar bone is co-ordinated so that a studied distance always separates the 2, known as the tooth-bone interface (TBI). Lack of mineralization, a crucial feature of the TBI, creates the space for the developing tooth to grow and the soft tissues of the periodontium to develop. We have investigated the interactions between the tooth and its surrounding bone during development, focusing on the impact of the developing alveolar bone on the development of the mouse first molar (M1). During development, TRAP-positive osteoclasts are found to line the TBI as bone starts to be deposited around the tooth, removing the bone as the tooth expands. An enhancement of osteoclastogenesis through RANK-RANKL signaling results in an expansion of the TBI, showing that osteoclasts are essential for defining the size of this region. Isolation of the M1 from the surrounding mesenchyme and alveolar bone leads to an expansion of the tooth germ, driven by increased proliferation, indicating that, during normal development, the growth of the tooth germ is constrained by the surrounding tissues.

  12. Development of electrospun bone-mimetic matrices for bone regenerative applications

    Science.gov (United States)

    Phipps, Matthew Christopher

    Although bone has a dramatic capacity for regeneration, certain injuries and procedures present defects that are unable to heal properly, requiring surgical intervention to induce and support osteoregeneration. Our research group has hypothesized that the development of a biodegradable material that mimics the natural composition and architecture of bone extracellular matrix has the potential to provide therapeutic benefit to these patients. Utilizing a process known as electrospinning, our lab has developed a bone-mimetic matrix (BMM) consisting of composite nanofibers of the mechanically sta-ble polymer polycaprolactone (PCL), and the natural bone matrix molecules type-I colla-gen and hydroxyapatite nanocrystals (HA). We herein show that BMMs supported great-er adhesion, proliferation, and integrin activation of mesenchymal stem cells (MSCs), the multipotent bone-progenitor cells within bone marrow and the periosteum, in comparison to electrospun PCL alone. These cellular responses, which are essential early steps in the process of bone regeneration, highlight the benefits of presenting cells with natural bone molecules. Subsequently, evaluation of new bone formation in a rat cortical tibia defect showed that BMMs are highly osteoconductive. However, these studies also revealed the inability of endogenous cells to migrate within electrospun matrices due to the inherently small pore sizes. To address this limitation, which will negatively impact the rate of scaf-fold-to-bone turnover and inhibit vascularization, sacrificial fibers were added to the ma-trix. The removal of these fibers after fabrication resulted in BMMs with larger pores, leading to increased infiltration of MSCs and endogenous bone cells. Lastly, we evaluat-ed the potential of our matrices to stimulate the recruitment of MSCs, a vital step in bone healing, through the sustained delivery of platelet derived growth factor-BB (PDGF-BB). BMMs were found to adsorb and subsequently release greater

  13. Bone characteristics of late-term embryonic and hatchling broilers: bone development under extreme growth rate.

    Science.gov (United States)

    Yair, R; Uni, Z; Shahar, R

    2012-10-01

    The development of broilers is an extreme example of rapid growth, increasing in weight from 40 g at hatch to 2,000 g 5 to 6 wk later. Such rapid growth requires a correspondingly fast development of the skeleton. Bone development is a genetically programmed process that is modified by epigenetic factors, mainly muscle-induced stresses and strains. In this study, we describe the temporal changes in bone morphology and material properties during the prehatch period [embryonic day (E) 14, E17, E19, E21] and posthatch d 3 and 7. The bones were examined for their weight, length, ash content, mechanical properties, and cortical structure. We show that the cross-sectional shape of the tibia and femur changes during the examination period from circular to elliptical. Additionally, the changes in bone properties are time-dependent and nonuniform: from E14 to E17 and from d 3 to 7, fast bone growth was noted, with major increases in both mechanical properties (stiffness, ultimate load, and energy to fracture) and geometric properties (cross-sectional area and thickness, medullary area, and moment of inertia). On the other hand, during the last days of incubation, most mechanical and geometric properties remain unchanged or even decrease. The reasons for this finding may relate to the hatching process but also to mineral shortage during the last days of incubation. This study leads to better understanding of bone development in ovo and posthatch in fast-growing broilers.

  14. A newly developed snack effective for enhancing bone volume

    Directory of Open Access Journals (Sweden)

    Hayashi Hidetaka

    2009-07-01

    Full Text Available Abstract Background The incidence of primary osteoporosis is higher in Japan than in USA and European countries. Recently, the importance of preventive medicine has been gradually recognized in the field of orthopaedic surgery with a concept that peak bone mass should be increased in childhood as much as possible for the prevention of osteoporosis. Under such background, we have developed a new bean snack with an aim to improve bone volume loss. In this study, we examined the effects of a newly developed snack on bone volume and density in osteoporosis model mice. Methods Orchiectomy (ORX and ovariectomy (OVX were performed for C57BL/6J mice of twelve-week-old (Jackson Laboratory, Bar Harbar, ME, USA were used in this experiment. We prepared and given three types of powder diet e.g.: normal calcium diet (NCD, Ca: 0.9%, Clea Japan Co., Tokyo, Japan, low calcium diet (LCD, Ca: 0.63%, Clea Japan Co., and special diet (SCD, Ca: 0.9%. Eighteen weeks after surgery, all the animals were sacrified and prepared for histomorphometric analysis to quantify bone density and bone mineral content. Results As a result of histomorphometric examination, SCD was revealed to enhance bone volume irrespective of age and sex. The bone density was increased significantly in osteoporosis model mice fed the newly developmental snack as compared with the control mice. The bone mineral content was also enhanced significantly. These phenomena were revealed in both sexes. Conclusion It is shown that the newly developed bean snack is highly effective for the improvement of bone volume loss irrespective of sex. We demonstrated that newly developmental snack supplements may be a useful preventive measure for Japanese whose bone mineral density values are less than the ideal condition.

  15. Recent developments in trabecular bone characterization using ultrasound.

    Science.gov (United States)

    Padilla, Frédéric; Laugier, Pascal

    2005-06-01

    Currently available quantitative ultrasound technologies to assess cancellous bone are based on the measurements in transmission of speed of sound or slope of frequency-dependent attenuation (so called broadband ultrasonic attenuation). These two parameters are now considered as surrogate markers of site-matched bone mineral density. The ability of ultrasound techniques to provide non-bone mineral density-related bone properties (eg, microstructure) has not been clearly demonstrated yet. This is mainly because of two factors: a lack of understanding of ultrasound propagation with clear identification of the different underlying physical interactions; and the difficulty of performing experiments because of the limited sample size, the large number of statistical relationships to be tested with multiple variables, and the usual strong covariance observed between bone quantity and microarchitecture. The aim of this paper is to review the most recent development in the field of ultrasound characterization of trabecular bone. We present research work on ultrasound backscatter and how it could be used to estimate microarchitectural properties independently of bone quantity, and the first promising results obtained for the estimation of trabecular thickness. We then introduce numeric simulations of wave propagation through trabecular microarchitecture and show how it could contribute to elucidate and better characterize the physical underlying physics and result in more predictive models. These innovative acquisition schemes and the possibility of virtual experiments should altogether contribute to rapid advancement of ultrasonic bone characterization.

  16. Gli1 haploinsufficiency leads to decreased bone mass with an uncoupling of bone metabolism in adult mice.

    Directory of Open Access Journals (Sweden)

    Yoshiaki Kitaura

    Full Text Available Hedgehog (Hh signaling plays important roles in various development processes. This signaling is necessary for osteoblast formation during endochondral ossification. In contrast to the established roles of Hh signaling in embryonic bone formation, evidence of its roles in adult bone homeostasis is not complete. Here we report the involvement of Gli1, a transcriptional activator induced by Hh signaling activation, in postnatal bone homeostasis under physiological and pathological conditions. Skeletal analyses of Gli1+/- adult mice revealed that Gli1 haploinsufficiency caused decreased bone mass with reduced bone formation and accelerated bone resorption, suggesting an uncoupling of bone metabolism. Hh-mediated osteoblast differentiation was largely impaired in cultures of Gli1+/- precursors, and the impairment was rescued by Gli1 expression via adenoviral transduction. In addition, Gli1+/- precursors showed premature differentiation into osteocytes and increased ability to support osteoclastogenesis. When we compared fracture healing between wild-type and Gli1+/- adult mice, we found that the Gli1+/- mice exhibited impaired fracture healing with insufficient soft callus formation. These data suggest that Gli1, acting downstream of Hh signaling, contributes to adult bone metabolism, in which this molecule not only promotes osteoblast differentiation but also represses osteoblast maturation toward osteocytes to maintain normal bone homeostasis.

  17. Fetal Bone Marrow-Derived Mesenchymal Stem/Stromal Cells Enhance Humanization and Bone Formation of BMP7 Loaded Scaffolds.

    Science.gov (United States)

    Shafiee, Abbas; Baldwin, Jeremy G; Patel, Jatin; Holzapfel, Boris M; Fisk, Nicholas M; Khosrotehrani, Kiarash; Hutmacher, Dietmar W

    2017-09-01

    Tissue engineered constructs built with human cells capable of generating a bone-like organ within the mouse have attracted considerable interest over the past decade. Here, we aimed to compare the utility of human mesenchymal stem/stromal cells (MSC) isolated from fetal term placenta (fPL-MSC) and fetal first trimester bone marrow (fBM-MSC) in a polycaprolactone scaffold/BMP7-based model in nude mice. Furthermore, fPL-MSC were co-seeded with fetal placenta-derived endothelial colony forming cells (ECFC) to assess the impact of ECFC on fPL-MSC osteogenesis. X-ray radiography and micro computed tomography analyses showed enhanced bone formation in all BMP7 groups; however there was no difference after 2 months in bone formation between scaffolds seeded with fPL-MSC alone or combination of ECFC and fPL-MSC. Of interest, fBM-MSC showed the highest level of bone formation. Additionally, endochondral ossification contributed in generation of bone in fBM-MSC. Histological analysis showed the primary role of BMP in generation of cortical and trabecular bone, and the recruitment of hematopoietic cells to the scaffolds. Current in vivo engineered bone organs can potentially be used for drug screening or as models to study bone tissue development in combination with haematopoiesis. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A gain-of-function mutation in Tnni2 impeded bone development through increasing Hif3a expression in DA2B mice.

    Directory of Open Access Journals (Sweden)

    Xiaoquan Zhu

    2014-10-01

    Full Text Available Distal arthrogryposis type 2B (DA2B is an important genetic disorder in humans. However, the mechanisms governing this disease are not clearly understood. In this study, we generated knock-in mice carrying a DA2B mutation (K175del in troponin I type 2 (skeletal, fast (TNNI2, which encodes a fast-twitch skeletal muscle protein. Tnni2K175del mice (referred to as DA2B mice showed typical DA2B phenotypes, including limb abnormality and small body size. However, the current knowledge concerning TNNI2 could not explain the small body phenotype of DA2B mice. We found that Tnni2 was expressed in the osteoblasts and chondrocytes of long bone growth plates. Expression profile analysis using radii and ulnae demonstrated that Hif3a expression was significantly increased in the Tnni2K175del mice. Chromatin immunoprecipitation assays indicated that both wild-type and mutant tnni2 protein can bind to the Hif3a promoter using mouse primary osteoblasts. Moreover, we showed that the mutant tnni2 protein had a higher capacity to transactivate Hif3a than the wild-type protein. The increased amount of hif3a resulted in impairment of angiogenesis, delay in endochondral ossification, and decrease in chondrocyte differentiation and osteoblast proliferation, suggesting that hif3a counteracted hif1a-induced Vegf expression in DA2B mice. Together, our data indicated that Tnni2K175del mutation led to abnormally increased hif3a and decreased vegf in bone, which explain, at least in part, the small body size of Tnni2K175del mice. Furthermore, our findings revealed a new function of tnni2 in the regulation of bone development, and the study of gain-of-function mutation in Tnni2 in transgenic mice opens a new avenue to understand the pathological mechanism of human DA2B disorder.

  19. Osteoma of the Pharynx That Developed from the Hyoid Bone

    Directory of Open Access Journals (Sweden)

    Akira Hagiwara

    2014-01-01

    Full Text Available This paper reports on apparently the first case of a pharyngeal osteoma that developed from the hyoid bone. An 84-year-old man’s, presenting symptom was a slight throat pain. Endoscopic examination revealed a huge mass occluding the pharyngeal space. CT scan of the neck showed a large osseous mass adjacent to the hyoid bone. Transoral resection with tracheostomy was performed. Histopathologically, the tumor consisted of mature lamellar bone without a fibrous component. For two years postoperatively, the patient has been free from throat symptoms and signs of recurrence. Osteomas are benign, slow-growing tumors. They rarely develop symptoms or cause functional disturbance. We performed total resection to avoid further functional disturbance as the osteoma was huge. To the best of our knowledge, this is the first report on an osteoma that occupied the pharyngeal space and developed from the hyoid bone.

  20. Development of a piezoelectric bone substitute material

    CERN Document Server

    Al-Bader, Y A

    2000-01-01

    The thesis deals with the preparation and testing of ceramic compositions to be used as bone substitute. The proposed composition consisted of calcium enriched calcium phosphate, kaolin and barium titanate in different ratios. The homogeneous powder mixture was dry pressed at different pressures and fired at temperatures up to 1350 degC for different soaking times. The physical properties of the fired compacts that were tested are bulk density and porosity. These were determined as function of pressing pressure, firing temperature and soaking time for different compositions. The mechanical properties investigated were the ultimate compressive strength and Young's modulus, which were determined for different compositions and forming pressures. The electrical properties investigated were D.C. characteristics (resistivity) and A.C. characteristics (A.C. resistivity, dielectric constant, dielectric loss and loss tangent). The piezoelectric behaviour of the fired compacts was investigated and the piezoelectric coe...

  1. Loss of PiT-2 results in abnormal bone development and decreased bone mineral density and length in mice.

    Science.gov (United States)

    Yamada, Shunsuke; Wallingford, Mary C; Borgeia, Suhaib; Cox, Timothy C; Giachelli, Cecilia M

    2018-01-01

    Normal bone mineralization requires phosphate oversaturation in bone matrix vesicles, as well as normal regulation of phosphate metabolism via the interplay among bone, intestine, and kidney. In turn, derangement of phosphate metabolism greatly affects bone function and structure. The type III sodium-dependent phosphate transporters, PiT-1 and PiT-2, are believed to be important in tissue phosphate metabolism and physiological bone formation, but their requirement and molecular roles in bone remain poorly investigated. In order to decipher the role of PiT-2 in bone, we examined normal bone development, growth, and mineralization in global PiT-2 homozygous knockout mice. PiT-2 deficiency resulted in reduced vertebral column, femur, and tibia length as well as mandibular dimensions. Micro-computed tomography analysis revealed that bone mineral density in the mandible, femur, and tibia were decreased, indicating that maintenance of bone function and structure is impaired in both craniofacial and long bones of PiT-2 deficient mice. Both cortical and trabecular thickness and mineral density were reduced in PiT-2 homozygous knockout mice compared with wild-type mice. These results suggest that PiT-2 is involved in normal bone development and growth and plays roles in cortical and trabecular bone metabolism feasibly by regulating local phosphate transport and mineralization processes in the bone. Further studies that evaluate bone cell-specific loss of PiT-2 are now warranted and may yield insight into complex mechanisms of bone development and growth, leading to identification of new therapeutic options for patients with bone diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. MicroRNAs Regulate Bone Development and Regeneration

    Directory of Open Access Journals (Sweden)

    Sijie Fang

    2015-04-01

    Full Text Available MicroRNAs (miRNAs are endogenous small noncoding ~22-nt RNAs, which have been reported to play a crucial role in maintaining bone development and metabolism. Osteogenesis originates from mesenchymal stem cells (MSCs differentiating into mature osteoblasts and each period of bone formation is inseparable from the delicate regulation of various miRNAs. Of note, apprehending the sophisticated circuit between miRNAs and osteogenic homeostasis is of great value for artificial skeletal regeneration for severe bone defects. In this review, we highlight how different miRNAs interact with diverse osteo-related genes and endeavor to sketch the contours of potential manipulations of miRNA-modulated bone repair.

  3. Animal models of maternal nutrition and altered offspring bone structure – Bone development across the lifecourse

    OpenAIRE

    SA Lanham; C Bertram; C Cooper; ROC Oreffo

    2011-01-01

    It is widely accepted that the likelihood of offspring developing heart disease, stroke, or diabetes in later life, is influenced by the their in utero environment and maternal nutrition. There is increasing epidemiological evidence that osteoporosis in the offspring may also be influenced by the mother’s nutrition during pregnancy. This review provides evidence from a range of animal models that supports the epidemiological data; suggesting that lifelong bone development and growth in offspr...

  4. Assessing mechanical integrity of spinal fusion by in situ endochondral osteoinduction in the murine model.

    Science.gov (United States)

    Dewan, Ashvin K; Dewan, Rahul A; Calderon, Nathan; Fuentes, Angie; Lazard, Zawaunyka; Davis, Alan R; Heggeness, Michael; Hipp, John A; Olmsted-Davis, Elizabeth A

    2010-08-21

    Historically, radiographs, micro-computed tomography (micro-CT) exams, palpation and histology have been used to assess fusions in a mouse spine. The objective of this study was to develop a faster, cheaper, reproducible test to directly quantify the mechanical integrity of spinal fusions in mice. Fusions were induced in ten mice spine using a previously described technique of in situ endochondral ossification, harvested with soft tissue, and cast in radiolucent alginate material for handling. Using a validated software package and a customized mechanical apparatus that flexed and extended the spinal column, the amount of intervertebral motion between adjacent vertebral discs was determined with static flexed and extended lateral spine radiographs. Micro-CT images of the same were also blindly reviewed for fusion. Mean intervertebral motion between control, non-fused, spinal vertebral discs was 6.1 +/- 0.2 degrees during spine flexion/extension. In fusion samples, adjacent vertebrae with less than 3.5 degrees intervertebral motion had fusions documented by micro-CT inspection. Measuring the amount of intervertebral rotation between vertebrae during spine flexion/extension is a relatively simple, cheap (<$100), clinically relevant, and fast test for assessing the mechanical success of spinal fusion in mice that compared favorably to the standard, micro-CT.

  5. Assessing mechanical integrity of spinal fusion by in situ endochondral osteoinduction in the murine model

    Directory of Open Access Journals (Sweden)

    Dewan Ashvin K

    2010-08-01

    Full Text Available Abstract Background Historically, radiographs, micro-computed tomography (micro-CT exams, palpation and histology have been used to assess fusions in a mouse spine. The objective of this study was to develop a faster, cheaper, reproducible test to directly quantify the mechanical integrity of spinal fusions in mice. Methods Fusions were induced in ten mice spine using a previously described technique of in situ endochondral ossification, harvested with soft tissue, and cast in radiolucent alginate material for handling. Using a validated software package and a customized mechanical apparatus that flexed and extended the spinal column, the amount of intervertebral motion between adjacent vertebral discs was determined with static flexed and extended lateral spine radiographs. Micro-CT images of the same were also blindly reviewed for fusion. Results Mean intervertebral motion between control, non-fused, spinal vertebral discs was 6.1 ± 0.2° during spine flexion/extension. In fusion samples, adjacent vertebrae with less than 3.5° intervertebral motion had fusions documented by micro-CT inspection. Conclusions Measuring the amount of intervertebral rotation between vertebrae during spine flexion/extension is a relatively simple, cheap (

  6. Late sarcoma development after curettage and bone grafting of benign bone tumors

    Energy Technology Data Exchange (ETDEWEB)

    Picci, Piero, E-mail: piero.picci@ior.it [Bone Tumor Center, Istituto Ortopedico Rizzoli, Bologna (Italy); Sieberova, Gabriela [Dept. of Pathology, National Cancer Institute, Bratislava (Slovakia); Alberghini, Marco; Balladelli, Alba; Vanel, Daniel [Bone Tumor Center, Istituto Ortopedico Rizzoli, Bologna (Italy); Hogendoorn, Pancras C.W. [Dept. of Pathology, Leiden University Medical Center, Leiden (Netherlands); Mercuri, Mario [Bone Tumor Center, Istituto Ortopedico Rizzoli, Bologna (Italy)

    2011-01-15

    Background and aim: Rarely sarcomas develop in previous benign lesions, after a long term disease free interval. We report the experience on these rare cases observed at a single Institution. Patients and methods: 12 cases curetted and grafted, without radiotherapy developed sarcomas, between 1970 and 2005, 6.5-28 years from curettage (median 18, average 19). Age ranged from 13 to 55 years (median 30, average 32) at first diagnosis; tumors were located in the extremities (9 GCT, benign fibrous histiocytoma, ABC, and solitary bone cyst). Radiographic and clinic documentation, for the benign and malignant lesions, were available. Histology was available for 7 benign and all malignant lesions. Results: To fill cavities, autogenous bone was used in 4 cases, allograft in 2, allograft and tricalcium-phosphate/hydroxyapatite in 1, autogenous/allograft in 1, heterogenous in 1. For 3 cases the origin was not reported. Secondary sarcomas, all high grade, were 8 osteosarcoma, 3 malignant fibrous histiocytoma, and 1 fibrosarcoma. Conclusions: Recurrences with progression from benign tumors are possible, but the very long intervals here reported suggest a different cancerogenesis for these sarcomas. This condition is extremely rare accounting for only 0.26% of all malignant bone sarcomas treated in the years 1970-2005 and represents only 8.76% of all secondary bone sarcomas treated in the same years. This incidence is the same as that of sarcomas arising on fibrous dysplasia, and is lower than those arising on bone infarcts or on Paget's disease. This possible event must be considered during follow-up of benign lesions.

  7. Fibrocartilage Stem Cells Engraft and Self-Organize into Vascularized Bone.

    Science.gov (United States)

    Nathan, J; Ruscitto, A; Pylawka, S; Sohraby, A; Shawber, C J; Embree, M C

    2017-10-01

    Angiogenesis is a complex, multicellular process that is critical for bone development and generation. Endochondral ossification depends on an avascular cartilage template that completely remodels into vascularized bone and involves a dynamic interplay among chondrocytes, osteoblasts, and endothelial cells. We have discovered fibrocartilage stem cells (FCSCs) derived from the temporomandibular joint (TMJ) mandibular condyle that generates cartilage anlagen, which is subsequently remodeled into vascularized bone using an ectopic transplantation model. Here we explore FCSC and endothelial cell interactions during vascularized bone formation. We found that a single FCSC colony formed transient cartilage and host endothelial cells may participate in bone angiogenesis upon subcutaneous transplantation in a nude mouse. FCSCs produced an abundance of the proangiogenic growth factor vascular endothelial growth factor A and promoted the proliferation of human umbilical vein endothelial cells (HUVECs). Using a fibrinogen gel bead angiogenesis assay experiment, FCSC cell feeder layer induced HUVECs to form significantly shorter and less sprouts than D551 fibroblast controls, suggesting that FCSCs may initially inhibit angiogenesis to allow for avascular cartilage formation. Conversely, direct FCSC-HUVEC contact significantly enhanced the osteogenic differentiation of FCSCs. To corroborate this idea, upon transplantation of FCSCs into a bone defect microenvironment, FCSCs engrafted and regenerated intramembranous bone. Taken together, we demonstrate that the interactions between FCSCs and endothelial cells are essential for FCSC-derived vascularized bone formation. A comprehensive understanding of the environmental cues that regulate FCSC fate decisions may contribute to deciphering the mechanisms underlying the role of FCSCs in regulating bone formation.

  8. Dietary 135-fold cholecalciferol supplementation severely disturbs the endochondral ossification in growing dogs

    NARCIS (Netherlands)

    Tryfonidou, M.A.; Holl, M.S.; Stevenhagen, J.J.; Buurman, C.J.; Deluca, H.F.; Oosterlaken-Dijksterhuis, M.A.; Brom, W.E. van den; Leeuwen, J.P.T.M. van; Hazewinkel, H.A.W.

    2003-01-01

    The effects of excessive non-toxic dietary Vitamin D3 supplementation on Ca homeostasis with specific effects on endochondral ossification and skeletal remodeling were investigated in a group of growing Great Dane dogs supplemented with cholecalciferol (Vitamin D3; HVitD) versus a control group

  9. Cyclin‑dependent kinase inhibitor p21 does not impact embryonic endochondral ossification in mice.

    Science.gov (United States)

    Chinzei, Nobuaki; Hayashi, Shinya; Hashimoto, Shingo; Kanzaki, Noriyuki; Iwasa, Kenjiro; Sakata, Shuhei; Kihara, Shinsuke; Fujishiro, Takaaki; Kuroda, Ryosuke; Kurosaka, Masahiro

    2015-03-01

    Endochondral ossification at the growth plate is regulated by a number of factors and hormones. The cyclin‑dependent kinase inhibitor p21 has been identified as a cell cycle regulator and its expression has been reported to be essential for endochondral ossification in vitro. However, to the best of our knowledge, the function of p21 in endochondral ossification has not been evaluated in vivo. Therefore, the aim of this study was to investigate the function of p21 in embryonic endochondral ossification in vivo. Wild‑type (WT) and p21 knockout (KO) pregnant heterozygous mice were sacrificed on embryonic days E13.5, E15.5 and E18.5. Sagittal histological sections of the forearms of the embryos were collected and stained with Safranin O and 5‑bromo‑2'‑deoxyuridine (BrdU). Additionally, the expression levels of cyclin D1, type II collagen, type X collagen, Sox9, and p16 were examined using immunohistochemistry, and the expression levels of p27 were examined using immunofluorescence. Safranin O staining revealed no structural change between the cartilage tissues of the WT and p21KO mice at any time point. Type II collagen was expressed ubiquitously, while type X collagen was only expressed in the hypertrophic zone of the cartilage tissues. No differences in the levels of Sox9 expression were observed between the two groups at any time point. The levels of cyclin D1 expression and BrdU uptake were higher in the E13.5 cartilage tissue compared with those observed in the embryonic cartilage tissue at subsequent time points. Expression of p16 and p27 was ubiquitous throughout the tissue sections. These results indicate that p21 may not be essential for embryonic endochondral ossification in articular cartilage of mice and that other signaling networks may compensate for p21 deletion.

  10. The bone-anchored hearing aid for children: recent developments.

    Science.gov (United States)

    Snik, Ad; Leijendeckers, Joop; Hol, Myrthe; Mylanus, Emmanuel; Cremers, Cor

    2008-09-01

    In 1984 the Bone-Anchored Hearing Aid, or BAHA, system was introduced. Its transducer is coupled directly to the skull percutaneously to form a highly effective bone-conduction hearing device. Clinical studies on adults with conductive hearing loss have shown that the BAHA system outperforms conventional bone-conduction hearing aids. Therefore, the next step was to apply the BAHA system in children with congenital or acquired conductive hearing loss. Reviewed data showed that, on average, such children benefited significantly more from the BAHA than from reconstructive surgery. Thus, BAHA application appears to be the best option to achieve normal communication and speech and language development in children with bilateral conductive hearing loss. However, in children under the age of three to four years, a conventional solution must be applied, e.g. a bone conductor with a transcutaneous coupling, because they are too young to undergo BAHA implant surgery. In the case of unilateral congenital conductive hearing loss, there is no convincing evidence in the clinical literature for early intervention. In summary, the BAHA system can be considered a new, indispensable tool for children with bilateral conductive hearing loss.

  11. Revascularization of calvarial, mandibular, tibial, and iliac bone grafts in rats

    DEFF Research Database (Denmark)

    Pinholt, E M; Solheim, E; Talsnes, O

    1994-01-01

    Some studies have suggested that membranous bone grafts undergo less resorption than endochondral grafts, and faster revascularization of the former has been proposed as the explanation. We studied fresh syngeneic full-thickness bone grafts from calvaria, mandibula, tibia diaphysis, and iliac bon...

  12. Hypoxia inhibits hypertrophic differentiation and endochondral ossification in explanted tibiae.

    Directory of Open Access Journals (Sweden)

    Jeroen C H Leijten

    Full Text Available Hypertrophic differentiation of growth plate chondrocytes induces angiogenesis which alleviates hypoxia normally present in cartilage. In the current study, we aim to determine whether alleviation of hypoxia is merely a downstream effect of hypertrophic differentiation as previously described or whether alleviation of hypoxia and consequent changes in oxygen tension mediated signaling events also plays an active role in regulating the hypertrophic differentiation process itself.Fetal mouse tibiae (E17.5 explants were cultured up to 21 days under normoxic or hypoxic conditions (21% and 2.5% oxygen respectively. Tibiae were analyzed on growth kinetics, histology, gene expression and protein secretion.The oxygen level had a strong influence on the development of explanted fetal tibiae. Compared to hypoxia, normoxia increased the length of the tibiae, length of the hypertrophic zone, calcification of the cartilage and mRNA levels of hypertrophic differentiation-related genes e.g. MMP9, MMP13, RUNX2, COL10A1 and ALPL. Compared to normoxia, hypoxia increased the size of the cartilaginous epiphysis, length of the resting zone, calcification of the bone and mRNA levels of hyaline cartilage-related genes e.g. ACAN, COL2A1 and SOX9. Additionally, hypoxia enhanced the mRNA and protein expression of the secreted articular cartilage markers GREM1, FRZB and DKK1, which are able to inhibit hypertrophic differentiation.Collectively our data suggests that oxygen levels play an active role in the regulation of hypertrophic differentiation of hyaline chondrocytes. Normoxia stimulates hypertrophic differentiation evidenced by the expression of hypertrophic differentiation related genes. In contrast, hypoxia suppresses hypertrophic differentiation of chondrocytes, which might be at least partially explained by the induction of GREM1, FRZB and DKK1 expression.

  13. Risk factors for developing mineral bone disease in phenylketonuric patients.

    Science.gov (United States)

    Mirás, Alicia; Bóveda, M Dolores; Leis, María R; Mera, Antonio; Aldámiz-Echevarría, Luís; Fernández-Lorenzo, José R; Fraga, José M; Couce, María L

    2013-03-01

    There is a compromised bone mass in phenylketonuria patients compared with normal population, but the mechanisms responsible are still a matter of investigation. In addition, tetrahydrobiopterin therapy is a new option for a significant proportion of these patients and the prevalence of mineral bone disease (MBD) in these patients is unknown. We conducted a cross-sectional observational study including 43 phenylketonuric patients. Bone densitometry, nutritional assessment, physical activity questionnaire, biochemical parameters, and molecular study were performed in all patients. Patients were stratified by phenotype, age and type of treatment. The MBD prevalence in phenylketonuria was 14%. Osteopenic and osteoporotic (n=6 patients) had an average daily natural protein intake significantly lower than the remaining (n=37) patients with PKU (14.33 ± 8.95 g vs 21.25 ± 20.85 g). Besides, a lower body mass index was found. There were no statistical differences in physical activity level, calcium, phosphorus and fat intake, and in phenylalanine, vitamin D, paratohormone, docosahexaenoic and eicosapentaenoic acid blood levels. Mutational spectrum was found in up to 30 different PAH genotypes and no relationship was established among genotype and development of MBD. None of the twelve phenylketonuric patients treated with tetrahydrobiopterin (27.9%), for an average of 7.1 years, developed MBD. Natural protein intake and blood levels of eicosapentaenoic acid were significantly higher while calcium intake was lower in these patients. This study shows that the decrease in natural protein intake can play an important role in MBD development in phenylketonuric patients. Therapy with tetrahydrobiopterin allows a more relaxed protein diet, which is associated with better bone mass. Copyright © 2012 Elsevier Inc. All rights reserved.

  14. Histone deacetylase 3 depletion in osteo/chondroprogenitor cells decreases bone density and increases marrow fat.

    Directory of Open Access Journals (Sweden)

    David F Razidlo

    2010-07-01

    Full Text Available Histone deacetylase (Hdac3 is a nuclear enzyme that contributes to epigenetic programming and is required for embryonic development. To determine the role of Hdac3 in bone formation, we crossed mice harboring loxP sites around exon 7 of Hdac3 with mice expressing Cre recombinase under the control of the osterix promoter. The resulting Hdac3 conditional knockout (CKO mice were runted and had severe deficits in intramembranous and endochondral bone formation. Calvarial bones were significantly thinner and trabecular bone volume in the distal femur was decreased 75% in the Hdac3 CKO mice due to a substantial reduction in trabecular number. Hdac3-CKO mice had fewer osteoblasts and more bone marrow adipocytes as a proportion of tissue area than their wildtype or heterozygous littermates. Bone formation rates were depressed in both the cortical and trabecular regions of Hdac3 CKO femurs. Microarray analyses revealed that numerous developmental signaling pathways were affected by Hdac3-deficiency. Thus, Hdac3 depletion in osterix-expressing progenitor cells interferes with bone formation and promotes bone marrow adipocyte differentiation. These results demonstrate that Hdac3 inhibition is detrimental to skeletal health.

  15. Functions of nuclear factor kappaB in bone.

    Science.gov (United States)

    Boyce, Brendan F; Yao, Zhenqiang; Xing, Lianping

    2010-03-01

    Nuclear factor kappaB (NF-kappaB) is a set of multifunctional transcription factors that regulate expression of genes involved in numerous normal cellular activities. They also are activated in many inflammatory and neoplastic conditions in which their expression may be stimulated by proinflammatory cytokines. NF-kappaB, in turn, regulates the expression of cytokines and so can mediate autocrine self-amplifying cycles of cytokine release and NF-kappaB activation, leading to maintenance of inflammatory reactions beyond the initial stimulus, as seen in rheumatoid arthritis and asthma. Since discovery of the requirement of NF-kappaB for basal and cytokine-induced osteoclast formation in the mid-1990s, much has been learned about the role of NF-kappaB in bone. NF-kappaB has roles in skeletal development, endochondral ossification, osteoclast and osteoblast functions, and common bone diseases. NF-kappaB inhibitors have been developed, but none have made it to clinical trials for the treatment of common bone diseases. Here we review the roles for NF-kappaB in bone and in common bone diseases.

  16. Biofabrication of soft tissue templates for engineering the bone-ligament interface.

    Science.gov (United States)

    Harris, Ella; Liu, Yurong; Cunniffe, Grainne; Morrissey, David; Carroll, Simon; Mulhall, Kevin; Kelly, Daniel J

    2017-10-01

    Regenerating damaged tissue interfaces remains a significant clinical challenge, requiring recapitulation of the structure, composition, and function of the native enthesis. In the ligament-to-bone interface, this region transitions from ligament to fibrocartilage, to calcified cartilage and then to bone. This gradation in tissue types facilitates the transfer of load between soft and hard structures while minimizing stress concentrations at the interface. Previous attempts to engineer the ligament-bone interface have utilized various scaffold materials with an array of various cell types and/or biological cues. The primary goal of this study was to engineer a multiphased construct mimicking the ligament-bone interface by driving differentiation of a single population of mesenchymal stem cells (MSCs), seeded within blended fibrin-alginate hydrogels, down an endochondral, fibrocartilaginous, or ligamentous pathway through spatial presentation of growth factors along the length of the construct within a custom-developed, dual-chamber culture system. MSCs within these engineered constructs demonstrated spatially distinct regions of differentiation, adopting either a cartilaginous or ligamentous phenotype depending on their local environment. Furthermore, there was also evidence of spatially defined progression toward an endochondral phenotype when chondrogenically primed MSCs within this construct were additionally exposed to hypertrophic cues. The study demonstrates the feasibility of engineering spatially complex soft tissues within a single MSC laden hydrogel through the defined presentation of biochemical cues. This novel approach represents a new strategy for engineering the ligament-bone interface. Biotechnol. Bioeng. 2017;114: 2400-2411. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Development of an injectable pseudo-bone thermo-gel for application in small bone fractures.

    Science.gov (United States)

    Kondiah, Pariksha J; Choonara, Yahya E; Kondiah, Pierre P D; Kumar, Pradeep; Marimuthu, Thashree; du Toit, Lisa C; Pillay, Viness

    2017-03-30

    A pseudo-bone thermo-gel was synthesized and evaluated for its physicochemical, mechanical and rheological properties, with its application to treat small bone fractures. The pseudo-bone thermo-gel was proven to have thermo-responsive properties, behaving as a solution in temperatures below 25°C, and forming a gelling technology when maintained at physiological conditions. Poly propylene fumerate (PPF), Pluronic F127 and PEG-PCL-PEG were strategically blended, obtaining a thermo-responsive delivery system, to mimic the mechanical properties of bone with sufficient matrix hardness and resilience. A Biopharmaceutics Classification System (BCS) class II drug, simvastatin, was loaded in the pseudo-bone thermo-gel, selected for its bone healing properties. In vitro release analysis was undertaken on a series of experimental formulations, with the ideal formulations obtaining its maximum controlled drug release profile up to 14days. Ex vivo studies were undertaken on an induced 4mm diameter butterfly-fractured osteoporotic human clavicle bone samples. X-ray, ultrasound as well as textural analysis, undertaken on the fractured bones before and after treatment displayed significant bone filling, matrix hardening and matrix resilience properties. These characteristics of the pseudo-bone thermo-gel thus proved significant potential for application in small bone fractures. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Long bone development in the Japanese quail (Coturnix coturnixjaponica) embryos.

    Science.gov (United States)

    Ahmed, Yasser A; Soliman, Soha A

    2013-09-15

    The current study was undertaken to describe the main histological development stages of long bones (tibia and femur) from Japanese quail (Coturnix coturnix japonica) embryos. Whole Limbs or just tibia and femur of fifty Japanese quail embryos of different ages were fixed and embedded in paraffin or Spurr's resin. Paraffin and semi-thin, respectively, were undertaken and examined with light microscopy. Limb bud was established at day 5 of incubation. Mesenchymal cells differentiated into chondrocytes forming a cartilage template in the position of the future tibia and femur at day 6 of incubation. At day 7 of incubation, the cartilage template enlarged and had the shape and position of the future tibia and femur. At day 8, central chondrocytes underwent hypertrophy and were surrounded by a periosteal bone collar. Cellular and vascular invasion from the bone collar into the central zone of the cartilage template, cartilage resorption and formation of marrow tunnel and finally peripheral calcification was seen. Vascular cartilage canals penetrating the epiphysis were observed at day 9 and the canals gradually increased in thickness and number toward the hatching day. Articular epiphyseal growth cartilage with resting, proliferative and hypertrophic zones was clearly established by day 10 of incubation. After 17 days of incubation, the zonation of the articular epiphyseal cartilage were much clear, many cartilage canals were present within the epiphyses. In epiphyses of tibia but not femur, foci of chondrocytes hypertrophy were noticed close to the cartilage canals. The current study timed the main histological sequences of development of tibia and femur of embryonic quail.

  19. Cortical bone development under the growth plate is regulated by mechanical load transfer

    Science.gov (United States)

    Tanck, E; Hannink, G; Ruimerman, R; Buma, P; Burger, E H; Huiskes, R

    2006-01-01

    Longitudinal growth of long bones takes place at the growth plates. The growth plate produces new bone trabeculae, which are later resorbed or merged into the cortical shell. This process implies transition of trabecular metaphyseal sections into diaphyseal sections. We hypothesize that the development of cortical bone is governed by mechanical stimuli. We also hypothesize that trabecular and cortical bone share the same regulatory mechanisms for adaptation to mechanical loads. To test these hypotheses, we monitored the development of the tibial cortex in growing pigs, using micro-computer tomography and histology. We then tested the concept that regulatory mechanisms for trabecular bone adaptation can also explain cortical bone development using our mechanical stimulation theory, which could explain trabecular bone (re)modelling. The main results showed that, from the growth plate towards the diaphysis, the pores of the trabecular structure were gradually filled in with bone, which resulted in increased density and cortical bone. The computer model largely predicted this morphological development. We conclude that merging of metaphyseal trabeculae into cortex is likely to be governed by mechanical stimuli. Furthermore, cortex development of growing long bones can be explained as a form of trabecular bone adaptation, without the need for different regulatory mechanisms for cortical and trabecular bone. PMID:16420380

  20. R-spondin 2 facilitates differentiation of proliferating chondrocytes into hypertrophic chondrocytes by enhancing Wnt/β-catenin signaling in endochondral ossification

    Energy Technology Data Exchange (ETDEWEB)

    Takegami, Yasuhiko [Division of Neurogenetics, Center of Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, Nagoya (Japan); Department of Orthopaedic Surgery, Nagoya University School of Medicine, Nagoya (Japan); Ohkawara, Bisei; Ito, Mikako; Masuda, Akio [Division of Neurogenetics, Center of Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, Nagoya (Japan); Nakashima, Hiroaki; Ishiguro, Naoki [Department of Orthopaedic Surgery, Nagoya University School of Medicine, Nagoya (Japan); Ohno, Kinji, E-mail: ohnok@med.nagoya-u.ac.jp [Division of Neurogenetics, Center of Neurological Disease and Cancer, Nagoya University Graduate School of Medicine, Nagoya (Japan)

    2016-04-22

    Endochondral ossification is a crucial process for longitudinal growth of bones. Differentiating chondrocytes in growth cartilage form four sequential zones of proliferation, alignment into column, hypertrophy, and substitution of chondrocytes with osteoblasts. Wnt/β-catenin signaling is essential for differentiation of proliferating chondrocytes into hypertrophic chondrocytes in growth cartilage. R-spondin 2 (Rspo2), a member of R-spondin family, is an agonist for Wnt signaling, but its role in chondrocyte differentiation remains unknown. Here we report that growth cartilage of Rspo2-knockout mice shows a decreased amount of β-catenin and increased amounts collagen type II (CII) and Sox9 in the abnormally extended proliferating zone. In contrast, expression of collagen type X (CX) in the hypertrophic zone remains unchanged. Differentiating chondrogenic ATDC5 cells, mimicking proliferating chondrocytes, upregulate Rspo2 and its putative receptor, Lgr5, in parallel. Addition of recombinant human Rspo2 to differentiating ATDC5 cells decreases expressions of Col2a1, Sox9, and Acan, as well as production of proteoglycans. In contrast, lentivirus-mediated knockdown of Rspo2 has the opposite effect. The effect of Rspo2 on chondrogenic differentiation is mediated by Wnt/β-catenin signaling, and not by Wnt/PCP or Wnt/Ca{sup 2+} signaling. We propose that Rspo2 activates Wnt/β-catenin signaling to reduce Col2a1 and Sox9 and to facilitate differentiation of proliferating chondrocytes into hypertrophic chondrocytes in growth cartilage. - Highlights: • Rspo2 is a secreted activator of Wnt, and its knockout shows extended proliferating chondrocytes in endochondral ossification. • In proliferating chondrocytes of Rspo2-knockout mice, Sox9 and collagen type 2 are increased and β-catenin is decreased. • Rspo2 and its receptor Lgr5, as well as Sox9 and collagen type 2, are expressed in differentiating ATDC5 chondrogenic cells. • In ATDC5 cells, Rspo2 decreases

  1. ADAM10 is essential for cranial neural crest-derived maxillofacial bone development

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Yu, E-mail: tanyu2048@163.com; Fu, Runqing, E-mail: furunqing@sjtu.edu.cn; Liu, Jiaqiang, E-mail: liujqmj@163.com; Wu, Yong, E-mail: wyonger@gmail.com; Wang, Bo, E-mail: wb228@126.com; Jiang, Ning, E-mail: 179639060@qq.com; Nie, Ping, E-mail: nieping1011@sina.com; Cao, Haifeng, E-mail: 0412chf@163.com; Yang, Zhi, E-mail: wcums1981@163.com; Fang, Bing, E-mail: fangbing@sjtu.edu.cn

    2016-07-08

    Growth disorders of the craniofacial bones may lead to craniofacial deformities. The majority of maxillofacial bones are derived from cranial neural crest cells via intramembranous bone formation. Any interruption of the craniofacial skeleton development process might lead to craniofacial malformation. A disintegrin and metalloprotease (ADAM)10 plays an essential role in organ development and tissue integrity in different organs. However, little is known about its function in craniofacial bone formation. Therefore, we investigated the role of ADAM10 in the developing craniofacial skeleton, particularly during typical mandibular bone development. First, we showed that ADAM10 was expressed in a specific area of the craniofacial bone and that the expression pattern dynamically changed during normal mouse craniofacial development. Then, we crossed wnt1-cre transgenic mice with adam10-flox mice to generate ADAM10 conditional knockout mice. The stereomicroscopic, radiographic, and von Kossa staining results showed that conditional knockout of ADAM10 in cranial neural crest cells led to embryonic death, craniofacial dysmorphia and bone defects. Furthermore, we demonstrated that impaired mineralization could be triggered by decreased osteoblast differentiation, increased cell death. Overall, these findings show that ADAM10 plays an essential role in craniofacial bone development. -- Highlights: •We firstly reported that ADAM10 was essentially involved in maxillofacial bone development. •ADAM10 cKO mice present craniofacial dysmorphia and bone defects. •Impaired osteoblast differentiation,proliferation and apoptosis underlie the bone deformity.

  2. Role of Thyroid Hormones in Skeletal Development and Bone Maintenance

    Science.gov (United States)

    Bassett, J. H. Duncan

    2016-01-01

    The skeleton is an exquisitely sensitive and archetypal T3-target tissue that demonstrates the critical role for thyroid hormones during development, linear growth, and adult bone turnover and maintenance. Thyrotoxicosis is an established cause of secondary osteoporosis, and abnormal thyroid hormone signaling has recently been identified as a novel risk factor for osteoarthritis. Skeletal phenotypes in genetically modified mice have faithfully reproduced genetic disorders in humans, revealing the complex physiological relationship between centrally regulated thyroid status and the peripheral actions of thyroid hormones. Studies in mutant mice also established the paradigm that T3 exerts anabolic actions during growth and catabolic effects on adult bone. Thus, the skeleton represents an ideal physiological system in which to characterize thyroid hormone transport, metabolism, and action during development and adulthood and in response to injury. Future analysis of T3 action in individual skeletal cell lineages will provide new insights into cell-specific molecular mechanisms and may ultimately identify novel therapeutic targets for chronic degenerative diseases such as osteoporosis and osteoarthritis. This review provides a comprehensive analysis of the current state of the art. PMID:26862888

  3. The chorioallantoic membrane (CAM) assay for the study of human bone regeneration: a refinement animal model for tissue engineering

    Science.gov (United States)

    Moreno-Jiménez, Inés; Hulsart-Billstrom, Gry; Lanham, Stuart A.; Janeczek, Agnieszka A.; Kontouli, Nasia; Kanczler, Janos M.; Evans, Nicholas D.; Oreffo, Richard Oc

    2016-08-01

    Biomaterial development for tissue engineering applications is rapidly increasing but necessitates efficacy and safety testing prior to clinical application. Current in vitro and in vivo models hold a number of limitations, including expense, lack of correlation between animal models and human outcomes and the need to perform invasive procedures on animals; hence requiring new predictive screening methods. In the present study we tested the hypothesis that the chick embryo chorioallantoic membrane (CAM) can be used as a bioreactor to culture and study the regeneration of human living bone. We extracted bone cylinders from human femoral heads, simulated an injury using a drill-hole defect, and implanted the bone on CAM or in vitro control-culture. Micro-computed tomography (μCT) was used to quantify the magnitude and location of bone volume changes followed by histological analyses to assess bone repair. CAM blood vessels were observed to infiltrate the human bone cylinder and maintain human cell viability. Histological evaluation revealed extensive extracellular matrix deposition in proximity to endochondral condensations (Sox9+) on the CAM-implanted bone cylinders, correlating with a significant increase in bone volume by μCT analysis (p animal research and a step towards a humanized in vivo model for tissue engineering.

  4. Evaluation of high-resolution In Vivo MRI for longitudinal analysis of endochondral fracture healing in mice

    Science.gov (United States)

    Müller-Graf, Fabian; Matthys, Romano; Hägele, Yvonne; Fischer, Verena; Jonas, René; Abaei, Alireza; Gebhard, Florian; Rasche, Volker; Ignatius, Anita

    2017-01-01

    Mice are extensively used for experimental bone-healing studies. However, there are few established nondestructive in vivo techniques for longitudinal fracture-healing analysis in mice, including in vivo micro-computed tomography (μCT) and radiography. Importantly, none of the established methods can discriminate between non-mineralized fibrous tissue and cartilage in the soft fracture callus. Therefore, the objective was to establish high-resolution in vivo magnetic resonance imaging (MRI) for the longitudinal assessment of soft callus formation during bone healing in mice. C57BL/6J mice received a femur osteotomy stabilized using an external fixator and were randomly assigned to five groups. Group 1 mice were scanned three times longitudinally during fracture healing using an optimized MRI scanning protocol to establish an algorithm to characterize the different fracture-callus tissues. Mice of groups 2–4 were scanned once on day 10, 14 or 21, respectively, euthanized after scanning and their femurs subjected to ex vivo μCT and histomorphometric analysis to compare the data assessed by MRI with μCT and histology. Control group 5 mice were not scanned. After 28 days, mice of groups 1 and 5 were euthanized and the fracture-healing outcome was evaluated by bending-test, μCT and histology to determine whether the repeated anesthesia, handling and the MRI measurements themselves influenced fracture healing. The callus-tissue values determined by MRI were mostly comparable to those obtained by μCT and histomorphometric analysis. However, at time points characterized by small relative bone or cartilage areas, MRI measurements were weakly comparable to histomorphometric data, possibly due to the inferior spatial resolution. Importantly, at the early and intermediate phases of healing, cartilage and fibrous-tissue values obtained by MRI were highly accurate. Furthermore, repeated anesthesia, handling and MRI scans did not impact bone healing. Therefore, we

  5. Cranial bone histology of Metoposaurus krasiejowensis (Amphibia, Temnospondyli from the Late Triassic of Poland

    Directory of Open Access Journals (Sweden)

    Kamil Gruntmejer

    2016-11-01

    Full Text Available In this study, 21 skull bones of Metoposaurus krasiejowensis from the Late Triassic of Poland were investigated histologically. Dermal bones show a diploë structure, with an ornamented external surface. The ridges consist of mostly well vascularized parallel-fibered bone; the valleys are built of an avascular layer of lamellar bone. The thick middle region consists of cancellous bone, with varying porosity. The thin and less vascularized internal cortex consists of parallel-fibered bone. The numerous Sharpey’s fibers and ISF are present in all bones. The cyclicity of growth is manifested as an alternation of thick, avascular annuli and high vascularized zones as well as a sequence of resting lines. The detailed histological framework of dermal bones varies even within a single bone; this seems to be related to the local biomechanical loading of the particular part of the skull. The dynamic processes observed during the ornamentation creation indicate that the positions of the ridges and grooves change during growth and could be a specific adaptation to changing biomechanical conditions and stress distribution during bone development. In the supratemporal, the cementing lines show that the remodeling process could be involved in the creations of sculpture. The common occurrence of ISF suggests that metaplastic ossification plays an important role during cranial development. Endochondral bones preserved the numerous remains of calcified cartilage. This indicates that ossification follows a pattern known for stereospondyl intercentra, with relatively slow ossification of the trabecular part and late development of the periosteal cortex. The large accumulation of Sharpey’s fibers in the occipital condyles indicates the presence of strong muscles and ligaments connecting the skull to the vertebral column.

  6. Cranial bone histology of Metoposaurus krasiejowensis (Amphibia, Temnospondyli) from the Late Triassic of Poland

    Science.gov (United States)

    Konietzko-Meier, Dorota; Bodzioch, Adam

    2016-01-01

    In this study, 21 skull bones of Metoposaurus krasiejowensis from the Late Triassic of Poland were investigated histologically. Dermal bones show a diploë structure, with an ornamented external surface. The ridges consist of mostly well vascularized parallel-fibered bone; the valleys are built of an avascular layer of lamellar bone. The thick middle region consists of cancellous bone, with varying porosity. The thin and less vascularized internal cortex consists of parallel-fibered bone. The numerous Sharpey’s fibers and ISF are present in all bones. The cyclicity of growth is manifested as an alternation of thick, avascular annuli and high vascularized zones as well as a sequence of resting lines. The detailed histological framework of dermal bones varies even within a single bone; this seems to be related to the local biomechanical loading of the particular part of the skull. The dynamic processes observed during the ornamentation creation indicate that the positions of the ridges and grooves change during growth and could be a specific adaptation to changing biomechanical conditions and stress distribution during bone development. In the supratemporal, the cementing lines show that the remodeling process could be involved in the creations of sculpture. The common occurrence of ISF suggests that metaplastic ossification plays an important role during cranial development. Endochondral bones preserved the numerous remains of calcified cartilage. This indicates that ossification follows a pattern known for stereospondyl intercentra, with relatively slow ossification of the trabecular part and late development of the periosteal cortex. The large accumulation of Sharpey’s fibers in the occipital condyles indicates the presence of strong muscles and ligaments connecting the skull to the vertebral column. PMID:27843719

  7. Effect of ethane-1-hydroxy-1,1-bisphosphonate (EHBP) on endochondral ossification lesions induced by a lethal oral dose of uranyl nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Bozal, C.B.; Ubios, A.M. [University of Buenos Aires, Department of Histology and Embryology, Buenos Aires (Argentina); Martinez, A.B. [National University of Rosario, Department of Pharmacology (Argentina); Cabrini, R.L. [National Atomic Energy Commission, Department of Radiobiology (Argentina)

    2005-08-01

    A 350 mg/kg body weight (b.w.) oral dose of uranyl nitrate (UN) caused 100% mortality in mice three days after administration, due to resulting kidney lesions. Mortality decreased 50% after an oral (o) or subcutaneous (sc) dose of bisodic etidronate (EHBP). Given that bone is also a target organ for uranium (U) in acute intoxication, the aim of this work was to study the effect of exposure to a lethal oral dose of UN on endochondral ossification, and the latter's response to EHBP treatment. One hundred male Balb/c mice weighing 25 g were assigned to one of ten groups. Group I served as control. Group II received a lethal 350 mg/kg b.w. oral dose of UN by gavage. Groups III, IV, VII, and VIII received an equal dose of UN immediately followed by a single 500 mg/kg oral dose of EHBP in groups III and VII and a single 50 mg/kg subcutaneous dose of EHBP in groups IV and VIII. Groups V and IX only received a single 500 mg/kg oral dose of EHBP, and groups VI and X received a single 50 mg/kg subcutaneous dose of EHBP. The animals in groups II, III, IV, V, and VI were sacrificed 48 h after the onset of the experiment, whereas those in groups VII, VIII, IX, and X were killed at 14 days. Histologic and histomorphometric studies were performed on the femurs to determine growth cartilage width, bone volume, and metaphyseal bone activity. Our results showed that all growth cartilage and metaphyseal bone histomorphometric parameters were significantly lower in animals exposed to UN at 48 h than in controls. EHPB administration was found to prevent this condition at 48 h reaching similar values to those of controls. Although histomorphometric values did not reach control values at 14 days, they were higher than those of animals exposed to UN at 48 h not treated with EHBP. It is noteworthy that these values also decreased in animals only receiving EHBP at 14 days. Our results show that EHBP effectively ameliorates the adverse effects of a lethal dose of UN on endochondral

  8. Increased physical activity is associated with enhanced development of peak bone mass in men: A five‐year longitudinal study

    National Research Council Canada - National Science Library

    Nilsson, Martin; Ohlsson, Claes; Odén, Anders; Mellström, Dan; Lorentzon, Mattias

    2012-01-01

    ...‐year period was associated with increased bone mineral content (BMC), areal (aBMD) and volumetric (vBMD) bone mineral density, and a favorable development of cortical bone size in young adult men...

  9. Decalcified allograft in repair of lytic lesions of bone: A study to evolve bone bank in developing countries

    Directory of Open Access Journals (Sweden)

    Anil Kumar Gupta

    2016-01-01

    Full Text Available Background: The quest for ideal bone graft substitutes still haunts orthopedic researchers. The impetus for this search of newer bone substitutes is provided by mismatch between the demand and supply of autogenous bone grafts. Bone banking facilities such as deep frozen and freeze-dried allografts are not so widely available in most of the developing countries. To overcome the problem, we have used partially decalcified, ethanol preserved, and domestic refrigerator stored allografts which are economical and needs simple technology for procurement, preparation, and preservation. The aim of the study was to assess the radiological and functional outcome of the partially decalcified allograft (by weak hydrochloric acid in patients of benign lytic lesions of bone. Through this study, we have also tried to evolve, establish, and disseminate the concept of the bone bank. Materials and Methods: 42 cases of lytic lesions of bone who were treated by decalcified (by weak hydrochloric acid, ethanol preserved, allografts were included in this prospective study. The allograft was obtained from freshly amputated limbs or excised femoral heads during hip arthroplasties under strict aseptic conditions. The causes of lytic lesions were unicameral bone cyst ( n = 3, aneurysmal bone cyst ( n = 3, giant cell tumor ( n = 9, fibrous dysplasia ( n = 12, chondromyxoid fibroma, chondroma, nonossifying fibroma ( n = 1 each, tubercular osteomyelitis ( n = 7, and chronic pyogenic osteomyelitis ( n = 5. The cavity of the lesion was thoroughly curetted and compactly filled with matchstick sized allografts. Results: Quantitative assessment based on the criteria of Sethi et al. (1993 was done. There was complete assimilation in 27 cases, partial healing in 12 cases, and failure in 3 cases. Functional assessment was also done according to which there were 29 excellent results, 6 good, and 7 cases of failure (infection, recurrence, and nonunion of pathological fracture. We

  10. Decalcified allograft in repair of lytic lesions of bone: A study to evolve bone bank in developing countries.

    Science.gov (United States)

    Gupta, Anil Kumar; Keshav, Kumar; Kumar, Praganesh

    2016-01-01

    The quest for ideal bone graft substitutes still haunts orthopedic researchers. The impetus for this search of newer bone substitutes is provided by mismatch between the demand and supply of autogenous bone grafts. Bone banking facilities such as deep frozen and freeze-dried allografts are not so widely available in most of the developing countries. To overcome the problem, we have used partially decalcified, ethanol preserved, and domestic refrigerator stored allografts which are economical and needs simple technology for procurement, preparation, and preservation. The aim of the study was to assess the radiological and functional outcome of the partially decalcified allograft (by weak hydrochloric acid) in patients of benign lytic lesions of bone. Through this study, we have also tried to evolve, establish, and disseminate the concept of the bone bank. 42 cases of lytic lesions of bone who were treated by decalcified (by weak hydrochloric acid), ethanol preserved, allografts were included in this prospective study. The allograft was obtained from freshly amputated limbs or excised femoral heads during hip arthroplasties under strict aseptic conditions. The causes of lytic lesions were unicameral bone cyst (n = 3), aneurysmal bone cyst (n = 3), giant cell tumor (n = 9), fibrous dysplasia (n = 12), chondromyxoid fibroma, chondroma, nonossifying fibroma (n = 1 each), tubercular osteomyelitis (n = 7), and chronic pyogenic osteomyelitis (n = 5). The cavity of the lesion was thoroughly curetted and compactly filled with matchstick sized allografts. Quantitative assessment based on the criteria of Sethi et al. (1993) was done. There was complete assimilation in 27 cases, partial healing in 12 cases, and failure in 3 cases. Functional assessment was also done according to which there were 29 excellent results, 6 good, and 7 cases of failure (infection, recurrence, and nonunion of pathological fracture). We observed that after biological incorporation, the graft

  11. The Influence of Primary Microenvironment on Prostate Cancer Osteoblastic Bone Lesion Development

    Science.gov (United States)

    2015-09-01

    AWARD NUMBER: W81XWH-12-1-0271 TITLE: The Influence of Primary Microenvironment on Prostate Cancer Osteoblastic Bone Lesion Development PRINCIPAL...31Aug 2015 4. TITLE AND SUBTITLE The Influence of Primary Microenvironment on Prostate Cancer Osteoblastic Bone Lesion Development 5a. CONTRACT NUMBER...initiate prostate cancer (PCa), promote PCa progression, and facilitate the development of mixed osteoblastic/osteolytic bone lesions . However, the

  12. Evaluation of the effects of gastrectomy on the development of metabolic bone disease.

    Science.gov (United States)

    Higashi, Yuki; Fujimura, Takashi; Oyama, Katsunobu; Kinoshita, Jun; Miyashita, Tomoharu; Tajima, Hidehiro; Fushida, Sachio; Ohta, Tetsuo

    2017-05-15

    Metabolic bone disease after gastrectomy is one of the complications leading to deterioration in quality of life. The exact mechanism of the metabolic bone disease remains unclear. To clarify the cause of metabolic bone disease after gastrectomy, we evaluated the associations between the method of gastrectomy and the development of metabolic bone disease in a rat model. Rats were assigned to four groups as follows: (1) sham operation (control group); (2) resection of the glandular stomach with Billroth I reconstruction (RGBI group); (3) Roux-en-Y anastomosis preserving the secretory function of the whole stomach (PSRY group); and (4) total gastrectomy with Roux-en-Y reconstruction (TGRY group). In all groups, body weight, serum biochemistry (total protein, albumin, calcium, phosphorus, tartrate-resistant acid phosphatase, and bone alkaline phosphatase), bone density, and bone breaking strength were measured. Body weights and serum calcium levels were significantly lower in the three operation groups compared with the control group. Bone density was significantly lower in the PSRY and TGRY groups compared with the control group. Bone breaking strength was significantly lower in the three operation groups compared with the control group. Surgical methods led to metabolic bone disease. However, exclusion of the duodenum from food passage had major influence to reduction in bone density and breaking strength. A stomach-preserving procedure and physiological reconstruction which enable food passage through duodenum and proximal jejunum contribute to mitigation of metabolic bone disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Development of hydroxyapatite bone cement for controlled drug ...

    Indian Academy of Sciences (India)

    The results of this study demonstrate the potential of using HA cement as a carrier for drug delivery. Keywords. Calcium phosphate; bone cement; tetracycline hydrochloride; drug delivery. 1. Introduction. Calcium phosphates are becoming increasingly popular in the field of biomedical, in particular, dentistry, bone substi-.

  14. The bone-anchored hearing aid for children: recent developments.

    NARCIS (Netherlands)

    Snik, A.F.M.; Leijendeckers, J.M.; Hol, M.K.S.; Mylanus, E.A.M.; Cremers, C.

    2008-01-01

    In 1984 the Bone-Anchored Hearing Aid, or BAHA, system was introduced. Its transducer is coupled directly to the skull percutaneously to form a highly effective bone-conduction hearing device. Clinical studies on adults with conductive hearing loss have shown that the BAHA system outperforms

  15. Bone mineral density in developing children with osteogenesis imperfecta

    NARCIS (Netherlands)

    Kok, Dieke H. J.; Sakkers, Ralph J. B.; Pruijs, Hans E. H.; Joosse, Pieter; Castelein, René M.

    2013-01-01

    Background and purpose - Osteogenesis imperfecta (OI) is a heritable disorder of connective tissue caused by a defect in collagen type I synthesis. For bone, this includes fragility, low bone mass, and progressive skeletal deformities, which can result in various degrees of short stature. The

  16. Development of Composite Scaffolds for Load Bearing Segmental Bone Defects

    Science.gov (United States)

    2013-07-01

    REFERENCES [1] Xu HHK, Weir MD, Simon CG. Injectable and strong nano-apatite scaffolds for cell/growth factor delivery and bone regeneration. Dental ...scaffolds. Biomaterials 2010;31: 3429-3438. [60] Asefnejad A. Polyurethane/ fluor -hydroxyapatite nanocomposite scaffolds for bone tissue engineering

  17. [Development of computer aided forming techniques in manufacturing scaffolds for bone tissue engineering].

    Science.gov (United States)

    Wei, Xuelei; Dong, Fuhui

    2011-12-01

    To review recent advance in the research and application of computer aided forming techniques for constructing bone tissue engineering scaffolds. The literature concerning computer aided forming techniques for constructing bone tissue engineering scaffolds in recent years was reviewed extensively and summarized. Several studies over last decade have focused on computer aided forming techniques for bone scaffold construction using various scaffold materials, which is based on computer aided design (CAD) and bone scaffold rapid prototyping (RP). CAD include medical CAD, STL, and reverse design. Reverse design can fully simulate normal bone tissue and could be very useful for the CAD. RP techniques include fused deposition modeling, three dimensional printing, selected laser sintering, three dimensional bioplotting, and low-temperature deposition manufacturing. These techniques provide a new way to construct bone tissue engineering scaffolds with complex internal structures. With rapid development of molding and forming techniques, computer aided forming techniques are expected to provide ideal bone tissue engineering scaffolds.

  18. Postnatal Changes in Humerus Cortical Bone Thickness Reflect the Development of Metabolic Bone Disease in Preterm Infants

    Directory of Open Access Journals (Sweden)

    Shuko Tokuriki

    2016-01-01

    Full Text Available Objective. To use cortical bone thickness (CBT of the humerus to identify risk factors for the development of metabolic bone disease in preterm infants. Methods. Twenty-seven infants born at <32 weeks of gestational age, with a birth weight of <1,500 g, were enrolled. Humeral CBT was measured from chest radiographs at birth and at 27-28, 31-32, and 36–44 weeks of postmenstrual age (PMA. The risk factors for the development of osteomalacia were statistically analyzed. Results. The humeral CBT at 36–44 weeks of PMA was positively correlated with gestational age and birth weight and negatively correlated with the duration of mechanical ventilation. CBT increased with PMA, except in six very early preterm infants in whom it decreased. Based on logistic regression analysis, gestational age and duration of mechanical ventilation were identified as risk factors for cortical bone thinning. Conclusions. Humeral CBT may serve as a radiologic marker of metabolic bone disease at 36–44 weeks of PMA in preterm infants. Cortical bones of extremely preterm infants are fragile, even when age is corrected for term, and require extreme care to lower the risk of fractures.

  19. Bone cements for percutaneous vertebroplasty and balloon kyphoplasty: Current status and future developments

    Directory of Open Access Journals (Sweden)

    Zhiwei He

    2015-01-01

    Full Text Available Osteoporotic vertebral compression fractures (OVCFs have gradually evolved into a serious health care problem globally. In order to reduce the morbidity of OVCF patients and improve their life quality, two minimally invasive surgery procedures, vertebroplasty (VP and balloon kyphoplasty (BKP, have been developed. Both VP and BKP require the injection of bone cement into the vertebrae of patients to stabilize fractured vertebra. As such, bone cement as the filling material plays an essential role in the effectiveness of these treatments. In this review article, we summarize the bone cements that are currently available in the market and those still under development. Two major categories of bone cements, nondegradable acrylic bone cements (ABCs and degradable calcium phosphate cements (CPCs, are introduced in detail. We also provide our perspectives on the future development of bone cements for VP and BKP.

  20. EFFECTS OF RUN TRAINING ON BONE DEVELOPMENT AND BONE MINERALIZATION IN GROWING MICE

    Directory of Open Access Journals (Sweden)

    B Gönül

    2011-06-01

    Full Text Available We planned to study the body weights, bone sizes and bone mineral (Ca, Mg, Zn contents of growing mice subjected to treadmill training. Twelve 4-week-old male Swiss Albino mice were divided into sedentary and exercise groups. The mice were trained by running exercise on a flat bed treadmill with 15 m/min, 30 min/day motion, throughout 5 days per week, for 12 weeks. The body weight of animals, and length, fat-free dry weight and Ca, Mg, and Zn contents of bones were measured in both groups. Body weights of animals, and lengths and wet and dry weights of the femur and the tibia were significantly higher in the exercised group. Also, the Zn, Mg and Ca mineral contents of bones in the group that underwent exercise were higher than in the other group. Running exercise with a flat bed treadmill performed by the growing mice is an effective exercise mode, especially for bone morphology.

  1. New bone formation at the site of autotransplanted developing mandibular canines: a case report.

    Science.gov (United States)

    Plakwicz, Pawel; Wojtaszek, Julita; Zadurska, Malgorzata

    2013-01-01

    Until recently, adequate bone at the recipient site has been a determinant for tooth autotransplantation. This article presents the transplantation of developing mandibular canines to a suboptimal position because of inadequate bone at the recipient sites. Five years later, after eruption and orthodontic alignment, all criteria for successful healing were fulfilled. In addition, new bone that was not present at the time of surgery was identified at the roots of the transplanted teeth, implying that transplanted developing teeth can stimulate bone to grow along their roots.

  2. DEVELOPMENT AND TEST OF AN EXTENDIBLE ENDOPROSTHESIS FOR BONE RECONSTRUCTION IN THE LEG

    NARCIS (Netherlands)

    VERKERKE, GJ; KOOPS, HS; VETH, RPH; GROOTENBOER, HJ; DEBOER, LJ; OLDHOFF, J; POSTMA, A

    A malignant bone tumour may develop in the femur of a child. In the majority of cases it will be necessary to resect the bone involved, growth plate and adjacent tissues. A modular endoprosthetic system has been developed which can be extended noninvasively to bridge the defect resulting from such a

  3. Epiphyseal abnormalities, trabecular bone loss and articular chondrocyte hypertrophy develop in the long bones of postnatal Ext1-deficient mice.

    Science.gov (United States)

    Sgariglia, Federica; Candela, Maria Elena; Huegel, Julianne; Jacenko, Olena; Koyama, Eiki; Yamaguchi, Yu; Pacifici, Maurizio; Enomoto-Iwamoto, Motomi

    2013-11-01

    Long bones are integral components of the limb skeleton. Recent studies have indicated that embryonic long bone development is altered by mutations in Ext genes and consequent heparan sulfate (HS) deficiency, possibly due to changes in activity and distribution of HS-binding/growth plate-associated signaling proteins. Here we asked whether Ext function is continuously required after birth to sustain growth plate function and long bone growth and organization. Compound transgenic Ext1(f/f);Col2CreERT mice were injected with tamoxifen at postnatal day 5 (P5) to ablate Ext1 in cartilage and monitored over time. The Ext1-deficient mice exhibited growth retardation already by 2weeks post-injection, as did their long bones. Mutant growth plates displayed a severe disorganization of chondrocyte columnar organization, a shortened hypertrophic zone with low expression of collagen X and MMP-13, and reduced primary spongiosa accompanied, however, by increased numbers of TRAP-positive osteoclasts at the chondro-osseous border. The mutant epiphyses were abnormal as well. Formation of a secondary ossification center was significantly delayed but interestingly, hypertrophic-like chondrocytes emerged within articular cartilage, similar to those often seen in osteoarthritic joints. Indeed, the cells displayed a large size and round shape, expressed collagen X and MMP-13 and were surrounded by an abundant Perlecan-rich pericellular matrix not seen in control articular chondrocytes. In addition, ectopic cartilaginous outgrowths developed on the lateral side of mutant growth plates over time that resembled exostotic characteristic of children with Hereditary Multiple Exostoses, a syndrome caused by Ext mutations and HS deficiency. In sum, the data do show that Ext1 is continuously required for postnatal growth and organization of long bones as well as their adjacent joints. Ext1 deficiency elicits defects that can occur in human skeletal conditions including trabecular bone loss

  4. Development of Raman spectral markers to assess metastatic bone in breast cancer

    Science.gov (United States)

    Ding, Hao; Nyman, Jeffry S.; Sterling, Julie A.; Perrien, Daniel S.; Mahadevan-Jansen, Anita; Bi, Xiaohong

    2014-11-01

    Bone is the most common site for breast cancer metastases. One of the major complications of bone metastasis is pathological bone fracture caused by chronic bone loss and degeneration. Current guidelines for the prediction of pathological fracture mainly rely on radiographs or computed tomography, which are limited in their ability to predict fracture risk. The present study explored the feasibility of using Raman spectroscopy to estimate pathological fracture risk by characterizing the alterations in the compositional properties of metastatic bones. Tibiae with evident bone destruction were investigated using Raman spectroscopy. The carbonation level calculated by the ratio of carbonate/phosphate ν1 significantly increased in the tumor-bearing bone at all the sampling regions at the proximal metaphysis and diaphysis, while tumor-induced elevation in mineralization and crystallinity was more pronounced in the metaphysis. Furthermore, the increased carbonation level is positively correlated to bone lesion size, indicating that this parameter could serve as a unique spectral marker for tumor progression and bone loss. With the promising advances in the development of spatially offset Raman spectroscopy for deep tissue measurement, this spectral marker can potentially be used for future noninvasive evaluation of metastatic bone and prediction of pathological fracture risk.

  5. Regulation of bone morphogenetic proteins in early embryonic development

    Science.gov (United States)

    Yamamoto, Yukiyo; Oelgeschläger, Michael

    2004-11-01

    Bone morphogenetic proteins (BMPs), a large subgroup of the TGF-β family of secreted growth factors, control fundamental events in early embryonic development, organogenesis and adult tissue homeostasis. The plethora of dose-dependent cellular processes regulated by BMP signalling demand a tight regulation of BMP activity. Over the last decade, a number of proteins have been identified that bind BMPs in the extracellular space and regulate the interaction of BMPs with their cognate receptors, including the secreted BMP antagonist Chordin. In the early vertebrate embryo, the localized secretion of BMP antagonists from the dorsal blastopore lip establishes a functional BMP signalling gradient that is required for the determination of the dorsoventral or back to belly body axis. In particular, inhibition of BMP activity is essential for the formation of neural tissue in the development of vertebrate and invertebrate embryos. Here we review recent studies that have provided new insight into the regulation of BMP signalling in the extracellular space. In particular, we discuss the recently identified Twisted gastrulation protein that modulates, in concert with metalloproteinases of the Tolloid family, the interaction of Chordin with BMP and a family of proteins that share structural similarities with Chordin in the respective BMP binding domains. In addition, genetic and functional studies in zebrafish and frog provide compelling evidence that the secreted protein Sizzled functionally interacts with the Chd BMP pathway, despite being expressed ventrally in the early gastrula-stage embryo. These intriguing discoveries may have important implications, not only for our current concept of early embryonic patterning, but also for the regulation of BMP activity at later developmental stages and tissue homeostasis in the adult.

  6. Development of an experimental model of infected bone void in the ulna of rabbits

    Science.gov (United States)

    Lemos Azi, Matheus; Kfuri Junior, Mauricio; Martinez, Roberto; Salata, Luis Antonio; Paccola, Cleber Antonio Jansen

    2012-01-01

    Objective Develop a model that allowed the study of bone regeneration in infection conditions. Method A 15 mm defect was surgically created in the rabbit ulna and inoculated with 5x108 colony-forming units (CFU) of S. aureus. Surgical debridement was performed two weeks after and systemic gentamicin was administered for four weeks. Animals were followed up to 12 weeks to evaluate infection control and bone regeneration. Result Bone regeneration was inferior to 25% of the defect in radiological and histological analysis. Conclusion Infected bone defect of 15 mm in the rabbit ulna was unable to achieve full regeneration without further treatment. Level of Evidence V, Experimental Study. PMID:24453593

  7. Long bone histology of the stem salamander Kokartus honorarius (Amphibia: Caudata) from the Middle Jurassic of Kyrgyzstan.

    Science.gov (United States)

    Skutschas, Pavel; Stein, Koen

    2015-04-01

    Kokartus honorarius from the Middle Jurassic (Bathonian) of Kyrgyzstan is one of the oldest salamanders in the fossil record, characterized by a mixture of plesiomorphic morphological features and characters shared with crown-group salamanders. Here we present a detailed histological analysis of its long bones. The analysis of a growth series demonstrates a significant histological maturation during ontogeny, expressed by the progressive appearance of longitudinally oriented primary vascular canals, primary osteons, growth marks, remodelling features in primary bone tissues, as well as progressive resorption of the calcified cartilage, formation of endochondral bone and development of cartilaginous to bony trabeculae in the epiphyses. Apart from the presence of secondary osteons, the long bone histology of Kokartus is very similar to that of miniaturized temnospondyls, other Jurassic stem salamanders, miniaturized seymouriamorphs and modern crown-group salamanders. We propose that the presence of secondary osteons in Kokartus honorarius is a plesiomorphic feature, and the loss of secondary osteons in the long bones of crown-group salamanders as well as in those of miniaturized temnospondyls is the result of miniaturization processes. Hitherto, all stem salamander long bong histology (Kokartus, Marmorerpeton and 'salamander A') has been generally described as having paedomorphic features (i.e. the presence of Katschenko's Line and a layer of calcified cartilage), these taxa were thus most likely neotenic forms. The absence of clear lines of arrested growth and annuli in long bones of Kokartus honorarius suggests that the animals lived in an environment with stable local conditions. © 2015 Anatomical Society.

  8. Ellis Van Creveld2 is Required for Postnatal Craniofacial Bone Development.

    Science.gov (United States)

    Badri, Mohammed K; Zhang, Honghao; Ohyama, Yoshio; Venkitapathi, Sundharamani; Kamiya, Nobuhiro; Takeda, Haruko; Ray, Manas; Scott, Greg; Tsuji, Takehito; Kunieda, Tetsuo; Mishina, Yuji; Mochida, Yoshiyuki

    2016-08-01

    Ellis-van Creveld (EvC) syndrome is a genetic disorder with mutations in either EVC or EVC2 gene. Previous case studies reported that EvC patients underwent orthodontic treatment, suggesting the presence of craniofacial bone phenotypes. To investigate whether a mutation in EVC2 gene causes a craniofacial bone phenotype, Evc2 knockout (KO) mice were generated and cephalometric analysis was performed. The heads of wild type (WT), heterozygous (Het) and homozygous Evc2 KO mice (1-, 3-, and 6-week-old) were prepared and cephalometric analysis based on the selected reference points on lateral X-ray radiographs was performed. The linear and angular bone measurements were then calculated, compared between WT, Het and KO and statistically analyzed at each time point. Our data showed that length of craniofacial bones in KO was significantly lowered by ∼20% to that of WT and Het, the growth of certain bones, including nasal bone, palatal length, and premaxilla was more affected in KO, and the reduction in these bone length was more significantly enhanced at later postnatal time points (3 and 6 weeks) than early time point (1 week). Furthermore, bone-to-bone relationship to cranial base and cranial vault in KO was remarkably changed, i.e. cranial vault and nasal bone were depressed and premaxilla and mandible were developed in a more ventral direction. Our study was the first to show the cause-effect relationship between Evc2 deficiency and craniofacial defects in EvC syndrome, demonstrating that Evc2 is required for craniofacial bone development and its deficiency leads to specific facial bone growth defect. Anat Rec, 299:1110-1120, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Two populations of endochondral osteoblasts with differential sensitivity to Hedgehog signalling

    NARCIS (Netherlands)

    Hammond, Christina Lindsey; Schulte-Merker, Stefan

    2009-01-01

    Hedgehog (Hh) signalling has been implicated in the development of osteoblasts and osteoclasts whose balanced activities are critical for proper bone formation. As many mouse mutants in the Hh pathway are embryonic lethal, questions on the exact effects of Hh signalling on osteogenesis remain. Using

  10. Two populations of endochondral osteoblasts with differential sensitivity to Hedgehog signalling.

    NARCIS (Netherlands)

    Hammond, C.L.; Schulte-Merker, S.

    2009-01-01

    Hedgehog (Hh) signalling has been implicated in the development of osteoblasts and osteoclasts whose balanced activities are critical for proper bone formation. As many mouse mutants in the Hh pathway are embryonic lethal, questions on the exact effects of Hh signalling on osteogenesis remain. Using

  11. Craniosynostosis of coronal suture in Twist1+/- mice occurs through endochondral ossification recapitulating the physiological closure of posterior frontal suture

    Directory of Open Access Journals (Sweden)

    Bjorn eBehr

    2011-07-01

    Full Text Available Craniosynostosis, the premature closure of cranial suture, is a pathologic condition that affects 1/2000 live births. Saethre-Chotzen syndrome is a genetic condition characterized by craniosynostosis. The Saethre-Chotzen syndrome, which is defined by loss-of-function mutations in the TWIST gene, is the second most prevalent craniosynostosis. Although much of the genetics and phenotypes in craniosynostosis syndromes is understood, less is known about the underlying ossification mechanism during suture closure. We have previously demonstrated that physiological closure of the posterior frontal (PF suture occurs through endochondral ossification. Moreover, we revealed that antagonizing canonical Wnt signaling in the sagittal suture leads to endochondral ossification of the suture mesenchyme and sagittal synostosis, presumably by inhibiting Twist1. Classic Saethre-Chotzen syndrome is characterized by coronal synostosis, and the haploinsufficient Twist1+/- mice represents a suitable model for studying this syndrome. Thus, we seeked to understand the underlying ossification process in coronal craniosynostosis in Twist1+/- mice. Our data indicate that coronal suture closure in Twist1+/- mice occurs between postnatal day 9 to 13 by endochondral ossification, as shown by histology, gene expression analysis and immunohistochemistry. In conclusion, this study reveals that coronal craniosynostosis in Twist1+/- mice occurs through endochondral ossification. Moreover, it suggests that haploinsufficency of Twist1 gene, a target of canonical Wnt-signaling, and inhibitor of chondrogenesis, mimics conditions of inactive canonical Wnt-signaling leading to craniosynostosis.

  12. Radiographic aluminum equivalent value of bone : the development of a registration method and some clinical applications

    NARCIS (Netherlands)

    W.T. Trouerbach (Willem)

    1982-01-01

    textabstractThe aim of this thesis is to establish and develop a method suitable for obtaining an objective analysis of bone as registered on a radiographic image. This analysis concerns determination of the quantity of bone mineral present. The system has been tested in-vitro and in a clinical

  13. LRP4 in neuromuscular junction and bone development and diseases.

    Science.gov (United States)

    Shen, Chengyong; Xiong, Wen-Cheng; Mei, Lin

    2015-11-01

    Low-density lipoprotein receptor-related protein 4 (LRP4) is a member of the low-density lipoprotein receptor (LDLR) family. Recent studies have revealed multiple functions and complex signaling mechanisms of LRP4 in different organs and tissues. LPR4 mutation or malfunction has been implicated in neurological disorders including congenital myasthenic syndrome, myasthenia gravis, and diseases of bone or kidney. This article is part of a Special Issue entitled "Muscle Bone Interactions". Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Bone morphogenetic proteins: from structure to clinical use

    Directory of Open Access Journals (Sweden)

    Granjeiro J.M.

    2005-01-01

    Full Text Available Bone morphogenetic proteins (BMPs are multi-functional growth factors belonging to the transforming growth factor ß superfamily. Family members are expressed during limb development, endochondral ossification, early fracture, and cartilage repair. The activity of BMPs was first identified in the 1960s but the proteins responsible for bone induction were unknown until the purification and cloning of human BMPs in the 1980s. To date, about 15 BMP family members have been identified and characterized. The signal triggered by BMPs is transduced through serine/threonine kinase receptors, type I and II subtypes. Three type I receptors have been shown to bind BMP ligands, namely: type IA and IB BMP receptors and type IA activin receptors. BMPs seem to be involved in the regulation of cell proliferation, survival, differentiation and apoptosis, but their hallmark is their ability to induce bone, cartilage, ligament, and tendon formation at both heterotopic and orthotopic sites. This suggests that, in the future, they may play a major role in the treatment of bone diseases. Several animal studies have illustrated the potential of BMPs to enhance spinal fusion, repair critical-size defects, accelerate union, and heal articular cartilage lesions. Difficulties in producing and purifying BMPs from bone tissue have prompted the attempts made by several laboratories, including ours, to express these proteins in the recombinant form in heterologous systems. This review focuses on BMP structure, molecular mechanisms of action and significance and potential applications in medical, dental and veterinary practice for the treatment of cartilage and bone-related diseases.

  15. The effect of 12-month participation in osteogenic and non-osteogenic sports on bone development in adolescent male athletes. The PRO-BONE study.

    Science.gov (United States)

    Vlachopoulos, Dimitris; Barker, Alan R; Ubago-Guisado, Esther; Ortega, Francisco B; Krustrup, Peter; Metcalf, Brad; Castro Pinero, Jose; Ruiz, Jonatan R; Knapp, Karen M; Williams, Craig A; Moreno, Luis A; Gracia-Marco, Luis

    2017-09-01

    Research investigating the longitudinal effects of the most popular sports on bone development in adolescent males is scarce. The aim is to investigate the effect of 12-month participation in osteogenic and non-osteogenic sports on bone development. A 12-month study was conducted in adolescent males involved in football, swimming and cycling and compared with an active control group. 116 adolescent males (13.1±0.1years at baseline): 37 footballers, 37 swimmers, 28 cyclists and 14 active controls were followed for 12 months. Bone mineral content (BMC) was measured by dual-energy X-ray absorptiometry, and bone stiffness was measured by quantitative ultrasound. Bone outcomes at 12 months were adjusted for baseline bone status, age, height, lean mass and moderate to vigorous physical activity. Footballers had higher improvement in adjusted BMC at the total body, total hip, shaft, Ward's triangle, legs and bone stiffness compared to cyclists (6.3-8.0%). Footballers had significantly higher adjusted BMC at total body, shaft and legs compared to swimmers (5.4-5.6%). There was no significant difference between swimmers and cyclists for any bone outcomes. Swimming and cycling participation resulted in non-significant lower bone development at most sites of the skeleton compared to controls (-4.3 to -0.6%). Football participation induces significantly greater improvements in BMC and bone stiffness over 12 months compared to cycling and swimming. ISRCTN17982776. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. Development of Cranial Bone Surrogate Structures Using Stereolithographic Additive Manufacturing

    Science.gov (United States)

    2017-09-29

    public release; distribution is unlimited. vi Acknowledgments We would like to acknowledge Jacob Schimelman for assistance with the tensile...print anatomical surrogates. However, limitations in printing resolution precludes the reproduction of micronscale features while the random, organic...trabecular bone requires high-resolution manufacturing methods, which makes SLA one of the best suited compared to other AM techniques at present. In our

  17. The morphometric development and clinical importance of the hyoid bone during the fetal period.

    Science.gov (United States)

    Kadir, Desdicioglu; Osman, Sulak; Mehmet Ali, Malas

    2015-01-01

    It was aimed that the morphometric development of the hyoid bone throughout the fetal period be anatomically researched and its clinical importance be evaluated. A total of 90 human fetuses (44 male, 46 female) whose ages varied between 18 and 40 gestational weeks and without an external pathology or anomaly were involved in the study. The fetuses were divided into groups according to gestational weeks and trimesters. In the wake of making the general external measurements of fetuses, the neck dissection was performed. Following the localization of the hyoid bone, the morphometric parameters pertaining to the hyoid bone were measured. The averages of the measured parameters according to the gestational weeks, trimesters and months, and their standard deviations were determined. There was a significant correlation between the measured parameters and the gestational age (p columna vertebralis, the hyoid bone corpus length, the hyoid bone right cornu majus initial width, the hyoid bone left cornu majus initial width, and the upper distance between the hyoid bone cornu majus (es) (p > 0.001). We are of the opinion that the data obtained during our study will be of use to forensic physicians and the involved clinicians in the evaluation of the development of the hyoid bone area during the fetal period, and in clinical studies and practices.

  18. Disruption of bone development and homeostasis by trisomy in Ts65Dn Down syndrome mice.

    Science.gov (United States)

    Blazek, Joshua D; Gaddy, Anna; Meyer, Rachel; Roper, Randall J; Li, Jiliang

    2011-02-01

    Down syndrome (DS) is a genetic disorder resulting from trisomy 21 that causes cognitive impairment, low muscle tone and craniofacial alterations. Morphometric studies of the craniofacial and appendicular skeleton in individuals with DS suggest that bone development and homeostasis are affected by trisomy. The Ts65Dn mouse model has three copies of approximately half the genes found on human chromosome 21 and exhibits craniofacial skeletal and size differences similar to those observed in humans with DS. We hypothesized that Ts65Dn and euploid mice have distinct differences in bone development and homeostasis influencing both the craniofacial and appendicular skeletal phenotypes. Quantitative assessment of structural and mechanical properties of the femur in Ts65Dn and control mice at 6 and 16 weeks of age revealed significant deficiencies in trabecular and cortical bone architecture, bone mineral density, bone formation, and bone strength in trisomic bone. Furthermore, bone mineral density and dynamic dentin formation rate of the skull and incisor, respectively, were also reduced in Ts65Dn mice, demonstrating that trisomy significantly affects both the craniofacial and appendicular skeleton. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. The effect of 12-month participation in osteogenic and non-osteogenic sports on bone development in adolescent male athletes. The PRO-BONE study

    DEFF Research Database (Denmark)

    Vlachopoulos, Dimitris; Barker, Alan R; Ubago-Guisado, Esther

    2018-01-01

    OBJECTIVES: Research investigating the longitudinal effects of the most popular sports on bone development in adolescent males is scarce. The aim is to investigate the effect of 12-month participation in osteogenic and non-osteogenic sports on bone development. DESIGN: A 12-month study...

  20. Discoidin domain receptor 2 (DDR2) regulates proliferation of endochondral cells in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Ikuma; Hisaki, Tomoka; Sugiura, Koji; Naito, Kunihiko [Laboratory of Applied Genetics, Graduate School of Agricultural and Life Science, University of Tokyo, Tokyo 113-8657 (Japan); Kano, Kiyoshi, E-mail: kanokiyo@yamaguchi-u.ac.jp [Laboratory of Developmental Biology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan. (Japan); Biomedical Science Center for Translational Research (BSCTR), The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi 753-8515 (Japan)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase. Black-Right-Pointing-Pointer DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. Black-Right-Pointing-Pointer We produced in vitro and in vivo model to better understand the role of DDR2. Black-Right-Pointing-Pointer DDR2 might play an inhibitory role in the proliferation of chondrocyte. -- Abstract: Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase that is activated by fibrillar collagens. DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. The decrement of endogenous DDR2 represses osteoblastic marker gene expression and osteogenic differentiation in murine preosteoblastic cells, but the functions of DDR2 in chondrogenic cellular proliferation remain unclear. To better understand the role of DDR2 signaling in cellular proliferation in endochondral ossification, we inhibited Ddr2 expression via the inhibitory effect of miRNA on Ddr2 mRNA (miDdr2) and analyzed the cellular proliferation and differentiation in the prechondrocyte ATDC5 cell lines. To investigate DDR2's molecular role in endochondral cellular proliferation in vivo, we also produced transgenic mice in which the expression of truncated, kinase dead (KD) DDR2 protein is induced, and evaluated the DDR2 function in cellular proliferation in chondrocytes. Although the miDdr2-transfected ATDC5 cell lines retained normal differentiation ability, DDR2 reduction finally promoted cellular proliferation in proportion to the decreasing ratio of Ddr2 expression, and it also promoted earlier differentiation to cartilage cells by insulin induction. The layer of hypertrophic chondrocytes in KD Ddr2 transgenic mice was not significantly thicker than that of normal littermates, but the layer of proliferative chondrocytes in KD-Ddr2 transgenic mice was significantly thicker than that of normal littermates

  1. Developing bioactive composite scaffolds for bone tissue engineering

    Science.gov (United States)

    Chen, Yun

    Poly(L-lactic acid) (PLLA) films were fabricated using the method of dissolving and evaporation. PLLA scaffold was prepared by solid-liquid phase separation of polymer solutions and subsequent sublimation of solvent. Bonelike apatite coating was formed on PLLA films, PLLA scaffolds and poly(glycolic acid) (PGA) scaffolds in 24 hours through an accelerated biomimetic process. The ion concentrations in the simulated body fluid (SBF) were nearly 5 times of those in human blood plasma. The apatite formed was characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The apatite formed in 5SBF was similar in morphology and composition to that formed in the classical biomimetic process employing SBF or 1.5SBF, and similar to that of natural bone. This indicated that the biomimetic apatite coating process could be accelerated by using concentrated simulated body fluid at 37°C. Besides saving time, the accelerated biomimetic process is particularly significant to biodegradable polymers. Some polymers which degrade too fast to be coated with apatite by a classical biomimetic process, for example PGA, could be coated with bone-like apatite in an accelerated biomimetic process. Collagen and apatite were co-precipitated as a composite coating on poly(L-lactic acid) (PLLA) in an accelerated biomimetic process. The incubation solution contained collagen (1g/L) and simulated body fluid (SBF) with 5 times inorganic ionic concentrations as human blood plasma. The coating formed on PLLA films and scaffolds after 24 hours incubation was characterized using EDX, XRD, FTIR, and SEM. It was shown that the coating contained carbonated bone-like apatite and collagen, the primary constituents of natural bone. SEM showed a complex composite coating of submicron bone-like apatite particulates combined with collagen fibrils. This work provided an efficient process to obtain

  2. Development of forelimb bones in indigenous sheep fetuses

    OpenAIRE

    N. S. Ahmed

    2008-01-01

    The study included detection of the sites of ossification centers and their sequence of appearance in the forelimb bones of indigenous sheep fetuses by using double staining method with younger specimens and radiography or maceration methods with old specimens, as well as, histological study with some ages. The results showed that the primary ossification centers of the forelimb in indigenous sheep fetuses appeared firstly in the diaphyses of radius and ulna, humerus, scapula, metacarpus, pha...

  3. Development of a Calcifiable Matrix for Bone Formation.

    Science.gov (United States)

    1987-09-01

    at 3.5 micrometers, and alternating sections were stained with Masson -Goldner trichrome and von Kossa stains. Histomorphometric analysis was...a modified Masson -Goldner trichrome and von Kossa stains. Histological specimens were assessed for local host responses. Inflammation and cellular...host bone (B), fibrous tissue (F). (Goldner trichrome , 16 x) 0+ Fig. 4b: 42 days, same field as 3a showing numerous calcification islands within

  4. Exercise training, menstrual irregularities and bone development in children and adolescents.

    Science.gov (United States)

    Eliakim, Alon; Beyth, Yoram

    2003-08-01

    Weight bearing physical activity plays an important role in bone development. This is particularly important in children and adolescents since bone mineral density reaches about 90% of its peak by the end of the second decade, and because about one quarter of adult bone is accumulated during the two years surrounding the peak bone growth velocity. Recent studies suggested that the exercise-induced increase in bone mineralization is maturity dependent, and that there is a "window of opportunity" and a critical period for bone response to weight bearing exercise during early puberty and premenarchal years. This supports the idea that increase in physical activity during childhood and adolescence can prevent bone disorders (like osteoporosis) later in life. In contrast, strenuous physical activity may affect the female reproductive system and lead to "athletic amenorrhea". The prevalence of "athletic amenorrhea" is 4-20 times higher than the general population. As a consequence, bone demineralization may develop with increased risk of skeletal fragility, fractures, vertebral instability, and curvature. Menstrual abnormalities in the female athlete result from hypothalamic suppression of the spontaneous pulsatile secretion of gonadotropin releasing hormone. Recent studies suggested that reduced energy availability (increased energy expenditure with inadequate caloric intake) is the main cause of the central suppression of the hypothalamic pituitary-gonadal axis. Therefore, effort should be made to optimize the nutritional state of female athletes, and if not successful, to reduce the training load in order to prevent menstrual abnormalities, and deleterious bone effects in particular during the critical period of rapid bone growth.

  5. Development of forelimb bones in indigenous sheep fetuses

    Directory of Open Access Journals (Sweden)

    N. S. Ahmed

    2008-01-01

    Full Text Available The study included detection of the sites of ossification centers and their sequence of appearance in the forelimb bones of indigenous sheep fetuses by using double staining method with younger specimens and radiography or maceration methods with old specimens, as well as, histological study with some ages. The results showed that the primary ossification centers of the forelimb in indigenous sheep fetuses appeared firstly in the diaphyses of radius and ulna, humerus, scapula, metacarpus, phalanges and lastly in the carpal bone at an estimated age of 43, 45, 46, 47, 49 - 56 and 90-118 days old respectively. The results of statistical analysis of the total lengths of scapula, humerus, radius, ulna and metacarpus with the lengths of their ossified parts through the 7th – 15th weeks of fetus age, showed presence of significant differences in the average of these measurements among most of studied weeks. Also there was a significant differences in the average of relative increase in the total length and length of ossified part of diaphysis of studied bones during the 7th week in comparison to the same average in the other studied weeks (8th-15th week of indigenous sheep fetuses age.

  6. Epigenetic regulation of fetal bone development and placental transfer of nutrients: progress for osteoporosis.

    Science.gov (United States)

    Bocheva, Georgeta; Boyadjieva, Nadka

    2011-12-01

    Osteoporosis is a common age-related disorder and causes acute and long-term disability and economic cost. Many factors influence the accumulation of bone minerals, including heredity, diet, physical activity, gender, endocrine functions, and risk factors such as alcohol, drug abuse, some pharmacological drugs or cigarette smoking. The pathology of bone development during intrauterine life is a factor for osteoporosis. Moreover, the placental transfer of nutrients plays an important role in the building of bones of fetuses. The importance of maternal calcium intake and vitamin D status are highlighted in this review. Various environmental factors including nutrition state or maternal stress may affect the epigenetic state of a number of genes during fetal development of bones. Histone modifications as histone hypomethylation, histone hypermethylation, hypoacetylation, etc. are involved in chromatin remodeling, known to contribute to the epigenetic landscape of chromosomes, and play roles in both fetal bone development and osteoporosis. This review will give an overview of epigenetic modulation of bone development and placental transfer of nutrients. In addition, the data from animal and human studies support the role of epigenetic modulation of calcium and vitamin D in the pathogenesis of osteoporosis. We review the evidence suggesting that various genes are involved in regulation of osteoclast formation and differentiation by osteoblasts and stem cells. Epigenetic changes in growth factors as well as cytokines play a rol in fetal bone development. On balance, the data suggest that there is a link between epigenetic changes in placental transfer of nutrients, including calcium and vitamin D, abnormal intrauterine bone development and pathogenesis of osteoporosis.

  7. Ontogenic Identification and Analysis of Mesenchymal Stromal Cell Populations during Mouse Limb and Long Bone Development

    Directory of Open Access Journals (Sweden)

    Gretel Nusspaumer

    2017-10-01

    Full Text Available Bone-derived mesenchymal stromal cells (MSCs differentiate into multiple lineages including chondro- and osteogenic fates and function in establishing the hematopoietic compartment of the bone marrow. Here, we analyze the emergence of different MSC types during mouse limb and long bone development. In particular, PDGFRαposSCA-1pos (PαS cells and mouse skeletal stem cells (mSSCs are detected within the PDGFRαposCD51pos (PαCD51 mesenchymal progenitors, which are the most abundant progenitors in early limb buds and developing long bones until birth. Long-bone-derived PαS cells and mSSCs are most prevalent in newborn mice, and molecular analysis shows that they constitute distinct progenitor populations from the earliest stages onward. Differential expression of CD90 and CD73 identifies four PαS subpopulations that display distinct chondro- and osteogenic differentiation potentials. Finally, we show that cartilage constructs generated from CD90pos PαS cells are remodeled into bone organoids encompassing functional endothelial and hematopoietic compartments, which makes these cells suited for bone tissue engineering.

  8. Linking bone development on the caudal aspect of the distal phalanx with lameness during life.

    Science.gov (United States)

    Newsome, R; Green, M J; Bell, N J; Chagunda, M G G; Mason, C S; Rutland, C S; Sturrock, C J; Whay, H R; Huxley, J N

    2016-06-01

    Claw horn disruption lesions (CHDL; sole hemorrhage, sole ulcer, and white line disease) cause a large proportion of lameness in dairy cattle, yet their etiopathogenesis remains poorly understood. Untreated CHDL may be associated with damage to the internal anatomy of the foot, including to the caudal aspect of the distal phalanx upon which bone developments have been reported with age and with sole ulcers at slaughter. The primary aim of this study was to assess whether bone development was associated with poor locomotion and occurrence of CHDL during a cow's life. A retrospective cohort study imaged 282 hind claws from 72 Holstein-Friesian dairy cows culled from a research herd using X-ray micro-computed tomography (μ-CT; resolution: 0.11mm). Four measures of bone development were taken from the caudal aspect of each distal phalanx, in caudal, ventral, and dorsal directions, and combined within each claw. Cow-level variables were constructed to quantify the average bone development on all hind feet (BD-Ave) and bone development on the most severely affected claw (BD-Max). Weekly locomotion scores (1-5 scale) were available from first calving. The variables BD-Ave and BD-Max were used as outcomes in linear regression models; the explanatory variables included locomotion score during life, age, binary variables denoting lifetime occurrence of CHDL and of infectious causes of lameness, and other cow variables. Both BD-Max and BD-Ave increased with age, CHDL occurrence, and an increasing proportion of locomotion scores at which a cow was lame (score 4 or 5). The models estimated that BD-Max would be 9.8mm (SE 3.9) greater in cows that had been lame at >50% of scores within the 12mo before slaughter (compared with cows that had been assigned no lame scores during the same period), or 7.0mm (SE 2.2) greater if the cow had been treated for a CHDL during life (compared with cows that had not). Additionally, histology demonstrated that new bone development was osteoma

  9. Mechanistic, mathematical model to predict the dynamics of tissue genesis in bone defects via mechanical feedback and mediation of biochemical factors.

    Directory of Open Access Journals (Sweden)

    Shannon R Moore

    2014-06-01

    Full Text Available The link between mechanics and biology in the generation and the adaptation of bone has been well studied in context of skeletal development and fracture healing. Yet, the prediction of tissue genesis within - and the spatiotemporal healing of - postnatal defects, necessitates a quantitative evaluation of mechano-biological interactions using experimental and clinical parameters. To address this current gap in knowledge, this study aims to develop a mechanistic mathematical model of tissue genesis using bone morphogenetic protein (BMP to represent of a class of factors that may coordinate bone healing. Specifically, we developed a mechanistic, mathematical model to predict the dynamics of tissue genesis by periosteal progenitor cells within a long bone defect surrounded by periosteum and stabilized via an intramedullary nail. The emergent material properties and mechanical environment associated with nascent tissue genesis influence the strain stimulus sensed by progenitor cells within the periosteum. Using a mechanical finite element model, periosteal surface strains are predicted as a function of emergent, nascent tissue properties. Strains are then input to a mechanistic mathematical model, where mechanical regulation of BMP-2 production mediates rates of cellular proliferation, differentiation and tissue production, to predict healing outcomes. A parametric approach enables the spatial and temporal prediction of endochondral tissue regeneration, assessed as areas of cartilage and mineralized bone, as functions of radial distance from the periosteum and time. Comparing model results to histological outcomes from two previous studies of periosteum-mediated bone regeneration in a common ovine model, it was shown that mechanistic models incorporating mechanical feedback successfully predict patterns (spatial and trends (temporal of bone tissue regeneration. The novel model framework presented here integrates a mechanistic feedback system based

  10. Peroxisomes in Different Skeletal Cell Types during Intramembranous and Endochondral Ossification and Their Regulation during Osteoblast Differentiation by Distinct Peroxisome Proliferator-Activated Receptors.

    Science.gov (United States)

    Qian, Guofeng; Fan, Wei; Ahlemeyer, Barbara; Karnati, Srikanth; Baumgart-Vogt, Eveline

    2015-01-01

    Ossification defects leading to craniofacial dysmorphism or rhizomelia are typical phenotypes in patients and corresponding knockout mouse models with distinct peroxisomal disorders. Despite these obvious skeletal pathologies, to date no careful analysis exists on the distribution and function of peroxisomes in skeletal tissues and their alterations during ossification. Therefore, we analyzed the peroxisomal compartment in different cell types of mouse cartilage and bone as well as in primary cultures of calvarial osteoblasts. The peroxisome number and metabolism strongly increased in chondrocytes during endochondral ossification from the reserve to the hypertrophic zone, whereas in bone, metabolically active osteoblasts contained a higher numerical abundance of this organelle than osteocytes. The high abundance of peroxisomes in these skeletal cell types is reflected by high levels of Pex11β gene expression. During culture, calvarial pre-osteoblasts differentiated into secretory osteoblasts accompanied by peroxisome proliferation and increased levels of peroxisomal genes and proteins. Since many peroxisomal genes contain a PPAR-responsive element, we analyzed the gene expression of PPARɑ/ß/ɣ in calvarial osteoblasts and MC3T3-E1 cells, revealing higher levels for PPARß than for PPARɑ and PPARɣ. Treatment with different PPAR agonists and antagonists not only changed the peroxisomal compartment and associated gene expression, but also induced complex alterations of the gene expression patterns of the other PPAR family members. Studies in M3CT3-E1 cells showed that the PPARß agonist GW0742 activated the PPRE-mediated luciferase expression and up-regulated peroxisomal gene transcription (Pex11, Pex13, Pex14, Acox1 and Cat), whereas the PPARß antagonist GSK0660 led to repression of the PPRE and a decrease of the corresponding mRNA levels. In the same way, treatment of calvarial osteoblasts with GW0742 increased in peroxisome number and related gene expression

  11. Development of a Three-Dimensional (3D Printed Biodegradable Cage to Convert Morselized Corticocancellous Bone Chips into a Structured Cortical Bone Graft

    Directory of Open Access Journals (Sweden)

    Ying-Chao Chou

    2016-04-01

    Full Text Available This study aimed to develop a new biodegradable polymeric cage to convert corticocancellous bone chips into a structured strut graft for treating segmental bone defects. A total of 24 adult New Zealand white rabbits underwent a left femoral segmental bone defect creation. Twelve rabbits in group A underwent three-dimensional (3D printed cage insertion, corticocancellous chips implantation, and Kirschner-wire (K-wire fixation, while the other 12 rabbits in group B received bone chips implantation and K-wire fixation only. All rabbits received a one-week activity assessment and the initial image study at postoperative 1 week. The final image study was repeated at postoperative 12 or 24 weeks before the rabbit scarification procedure on schedule. After the animals were sacrificed, both femurs of all the rabbits were prepared for leg length ratios and 3-point bending tests. The rabbits in group A showed an increase of activities during the first week postoperatively and decreased anterior cortical disruptions in the postoperative image assessments. Additionally, higher leg length ratios and 3-point bending strengths demonstrated improved final bony ingrowths within the bone defects for rabbits in group A. In conclusion, through this bone graft converting technique, orthopedic surgeons can treat segmental bone defects by using bone chips but with imitate characters of structured cortical bone graft.

  12. Role of trace elements (Zn, Sr, Fe) in bone development: energy dispersive X-ray fluorescence study of rat bone and tooth tissue.

    Science.gov (United States)

    Maciejewska, Karina; Drzazga, Zofia; Kaszuba, Michał

    2014-01-01

    Osteoporosis is one of the most common debilitating disease around the world and it is more and more established among young people. There are well known recommendations for nutrition of newborns and children concerning adequate calcium and vitamin D intake in order to maintain proper bone density. Nevertheless, important role in structure and function of a healthy bone tissue is played by an integration between all constituents including elements other than Ca, like trace elements, which control vital processes in bone tissue. It is important from scientific point of view as well as prevention of bone diseases, to monitor the mineralization process considering changes of the concentration of minerals during first stage of bone formation. This work presents studies of trace element (zinc, strontium, and iron) concentration in bones and teeth of Wistar rats at the age of 7, 14, and 28 days. Energy dispersive X-ray fluorescence (EDXRF) was used to examine mandibles, skulls, femurs, tibiae, and incisors. The quantitative analysis was performed using fundamental parameters method (FP). Zn and Sr concentrations were highest for the youngest individuals and decreased with age of rats, while Fe content was stable in bone matrix for most studied bones. Our results reveal the necessity of monitoring concentration of not only major, but also minor elements, because the trace elements play special role in the first period of bone development. © 2014 International Union of Biochemistry and Molecular Biology.

  13. The Cross-talk Between TGF-β1 and Dlk1 Mediates Early Chondrogenesis During Embryonic Endochondral Ossification

    DEFF Research Database (Denmark)

    Taipaleenmaki, Hanna; M, Linda; Chen, Li

    2012-01-01

    Dlkl/Pref-1/FA1 (delta like-1/preadipocyte factor-1/Fetal Antigen-1) is a novel surface marker for embryonic chondroprogenitor cells undergoing lineage progression from proliferation to prehypertrophic stages. However, mechanisms mediating control of its expression during chondrogenesis are not k...... its function in embryonic chondrogenesis. The cross-talk between TGF-β1 and Dlk1/FA1 was shown to promote early chondrogenesis during the embryonic endochondral ossification process....

  14. Improving Soldier Recovery from Catastrophic Bone Injuries: Developing an Animal Model for Standarizing the Bone Reparative Potential of Emerging Progenitor Cell Therapies

    Science.gov (United States)

    2008-08-01

    the cellular organization of the cartilage core. Clearly there is a greater complexity than is revealed by a saffron -O histological section and the...superimposed DIC and green/blue mineralization lines of mice that were labeled with calcein and XO 7 and 2 days prior to sacrifice. The quality of the section...callus 3. The cartilage that forms resembles fibrocartilage more than endochondral cartilage. C. Frozen fluorescent histology can produce high quality

  15. Feeding blueberry diets during early development is sufficient to prevent senescence of osteoblasts and bone loss in adulthood

    Science.gov (United States)

    Appropriate nutrition during early development is essential for optimal bone mass accretion; however, linkage between early nutrition, childhood bone mass and prevention of bone loss later in life has not been extensively studied. In this report, we show that feeding a high quality diet supplemented...

  16. Radiographic, densitometric and histological evaluation of the use of bone perforations on fracture consolidation of distal third of radius from dogs

    Directory of Open Access Journals (Sweden)

    Porfírio Candanedo Guerra

    2006-04-01

    Full Text Available To stimulate the bone callus development process from distal third of radius, 24 adult mongrel dogs used were from both sexes. These dogs were separated in two experimental groups of 12 animals each, named control and treated, divided in 4 moments (M1=15 days; M2=30 days; M3=45 days; M4=60 days, who underwent were performed surgical fractures. In treated group, it was performed bone perforations on proximal and distal edges, craniolateral and mediolateral to the fracture site. At the end of each moment, control and treated animals were evaluated by radiography, histology, and bone mineral densitometry (BMD was determined on fracture site. According to the radiographic data of treated dogs, it was verified on days 15 and 30 more intense bone regeneration than control group. During M3 and M4, it wasn't detected any difference in bone reparation process betweencontrol and treated groups. In densitometric study, BMD values were greater in treated animals than in control dogs. Histological studies revealed at 15 and 30 days chondrocyte hyperplasia and initial endochondral ossification on drilled limbs; control group showed sustainment connective tissue and initial chondrocyte hiperplasia. At M3 and M4 of the treated group, were verified development and remodeling of periosteal callus in more advanced phases when comparing with limbs from control group. It can be concluded that using perforations enhances blood flow supply and activation of osteogenic cells on fracture site, stimulating the beginning of fracture consolidation process.

  17. Muscle volume is related to trabecular and cortical bone architecture in typically developing children.

    Science.gov (United States)

    Bajaj, Deepti; Allerton, Brianne M; Kirby, Joshua T; Miller, Freeman; Rowe, David A; Pohlig, Ryan T; Modlesky, Christopher M

    2015-12-01

    Muscle is strongly related to cortical bone architecture in children; however, the relationship between muscle volume and trabecular bone architecture is poorly studied. The aim of this study was to determine if muscle volume is related to trabecular bone architecture in children and if the relationship is different than the relationship between muscle volume and cortical bone architecture. Forty typically developing children (20 boys and 20 girls; 6 to 12y) were included in the study. Measures of trabecular bone architecture [i.e., apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), trabecular thickness (appTb.Th) and trabecular separation (appTb.Sp)] in the distal femur, cortical bone architecture [cortical volume, total volume, section modulus (Z) and polar moment of inertia (J)] in the midfemur, muscle volume in the midthigh and femur length were assessed using magnetic resonance imaging. Total physical activity and moderate-to-vigorous physical activity were assessed using an accelerometer-based activity monitor worn around the waist for four days. Calcium intake was assessed using diet records. Relationships among the measures were tested using multiple linear regression analysis. Muscle volume was moderately-to-strongly related to measures of trabecular bone architecture [appBV/TV (r=0.81), appTb.N (r=0.53), appTb.Th (r=0.67), appTb.Sp (r=-0.71); all parchitecture [cortical volume (r=0.96), total volume (r=0.94), Z (r=0.94) and J (r=0.92; all parchitecture. Sex, physical activity and calcium intake were not related to any measure of bone architecture (p>0.05). Because muscle volume and femur length were strongly related (r=0.91, parchitecture (partial r=0.47 to 0.54; parchitecture in the distal femur of typically developing children. The relationship is weaker than the relationship between muscle volume in the midthigh and cortical bone architecture in the midfemur, but the discrepancy is driven, in large part, by the

  18. Evaluation of clinical parameters influencing the development of bone metastasis in breast cancer.

    Science.gov (United States)

    Diessner, Joachim; Wischnewsky, Manfred; Stüber, Tanja; Stein, Roland; Krockenberger, Mathias; Häusler, Sebastian; Janni, Wolfgang; Kreienberg, Rolf; Blettner, Maria; Schwentner, Lukas; Wöckel, Achim; Bartmann, Catharina

    2016-05-12

    The development of metastases is a negative prognostic parameter for the clinical outcome of breast cancer. Bone constitutes the first site of distant metastases for many affected women. The purpose of this retrospective multicentre study was to evaluate if and how different variables such as primary tumour stage, biological and histological subtype, age at primary diagnosis, tumour size, the number of affected lymph nodes as well as grading influence the development of bone-only metastases. This retrospective German multicentre study is based on the BRENDA collective and included 9625 patients with primary breast cancer recruited from 1992 to 2008. In this analysis, we investigated a subgroup of 226 patients with bone-only metastases. Association between bone-only relapse and clinico-pathological risk factors was assessed in multivariate models using the tree-building algorithms "exhausted CHAID (Chi-square Automatic Interaction Detectors)" and CART(Classification and Regression Tree), as well as radial basis function networks (RBF-net), feedforward multilayer perceptron networks (MLP) and logistic regression. Multivariate analysis demonstrated that breast cancer subtypes have the strongest influence on the development of bone-only metastases (χ2 = 28). 29.9 % of patients with luminal A or luminal B (ABC-patients) and 11.4 % with triple negative BC (TNBC) or HER2-overexpressing tumours had bone-only metastases (p bottom line of different mathematical models is the prior importance of subcategories of breast cancer and the age at primary diagnosis for the appearance of osseous metastases. The primary tumour stage, histological subtype, tumour size, the number of affected lymph nodes, grading and NPI seem to have only a minor influence on the development of bone-only metastases.

  19. Body fat in children does not adversely influence bone development: a 7-year longitudinal study (EarlyBird 18).

    Science.gov (United States)

    Streeter, A J; Hosking, J; Metcalf, B S; Jeffery, A N; Voss, L D; Wilkin, T J

    2013-12-01

    Both negative and positive associations have been reported between body fat and bone density. Extra mechanical loading from excess fat may lead to greater bone mass. Excess ectopic fat may lead to bone demineralisation through inflammatory pathways. Longitudinally collected data from narrow-angle beam densitometry gives a novel insight into bone growth through adolescence. There is no evidence of a deleterious effect of body fat on children's growing bones after adjustment for height and age. Body fat, mediated by puberty, is associated with larger bones in boys and bones that are both denser and larger in girls. Bone growth is an important determinant of peak bone mass and fracture risk, but there is limited data on the impact of fat-on-bone development at a time when childhood obesity is reaching epidemic proportions. Accordingly, we explored the effect of body fat (BF) on bone growth over time in the context of age, pubertal tempo and gender. A cohort of 307 children was measured biannually from 9-16 years for height and weight, and every 12 months for percent BF, bone area (BA), bone mineral content and areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry. Pubertal tempo was determined quantitatively by age at peak height velocity. Percent BF increased and then fell in the boys, but increased throughout in the girls. aBMD and BA increased in both genders (P bones, but also denser bones in girls. The effects of fat and puberty are complex and gender specific, but BF of contemporary UK children does not appear to be deleterious to bone quality. © 2013 The Authors. Pediatric Obesity © 2013 International Association for the Study of Obesity.

  20. Autoclaved Tumor Bone for Skeletal Reconstruction in Paediatric Patients: A Low Cost Alternative in Developing Countries

    Directory of Open Access Journals (Sweden)

    Masood Umer

    2013-01-01

    Full Text Available We reviewed in this series forty patients of pediatric age who underwent resection for malignant tumors of musculoskeletal system followed by biological reconstruction. Our surgical procedure for reconstruction included (1 wide en bloc resection of the tumor; (2 curettage of tumor from the resected bone; (3 autoclaving for 8 minutes (4 bone grafting from the fibula (both vascularized and nonvascularized fibular grafts used; (5 reimplantation of the autoclaved bone into the host bone defect and fixation with plates. Functional evaluation was done using MSTS scoring system. At final followup of at least 18 months (mean 29.2 months, 31 patients had recovered without any complications. Thirty-eight patients successfully achieved a solid bony union between the graft and recipient bone. Three patients had surgical site infection. They were managed with wound debridement and flap coverage of the defect. Local recurrence and nonunion occurred in two patients each. One patient underwent disarticulation at hip due to extensive local disease and one died of metastasis. For patients with non-union, revision procedure with bone graft and compression plates was successfully used. The use of autoclaved tumor grafts provides a limb salvage option that is inexpensive and independent of external resources and is a viable option for musculoskeletal tumor management in developing countries.

  1. Development of the NIST bone ash standard reference material for environmental radioactivity measurement.

    Science.gov (United States)

    Lin, Z; Inn, K G; Altzitzoglou, T; Arnold, D; Cavadore, D; Ham, G J; Korun, M; Wershofen, H; Takata, Y; Young, A

    1998-01-01

    The bone ash standard reference material (SRM), a blend of 4% contaminated human bone and 96% diluent bovine bone, has been developed for radiochemical method validation and quality control for radio-bone analysis. The massic activities of 90Sr, 226Ra, 230Th, 232Th, 234U, 235U, 238U, 238Pu, (239 + 240)Pu and (243 + 244)Cm were certified using a variety of radiochemical procedures and detection methods. Measurements confirmed undetectable radionuclide heterogeneity down to a sample size of 5 g. thereby implying adequate blending of particulate materials with dilution factors of up to 17,900. The results among most of the intercomparison laboratories and their methods were consistent. Disequilibrium was observed for decay chains: 234U(0.67 mBq/g)-230Th(0.47 mBq/g)-226Ra(15.1 mBq/g)-210Pb(23 mBq/g)-210Po(13 mBq/g) and 232Th(0.99 mBq/g)-228 Ra(6.1 mBq/g)-228Th(7.1 mBq/g). The disequilibria were the results of mixing occupationally contaminated human bone with natural bovine bone and the fractionation during internal biological processes. The massic activity of 210Pb, 228Th and 241Am were not certified because of insufficient 228Ra and 241Pu data and lack of knowledge in how 222Rn and its daughters will be fractionated in the SRM bottle over time.

  2. Losartan increases bone mass and accelerates chondrocyte hypertrophy in developing skeleton.

    Science.gov (United States)

    Chen, Shan; Grover, Monica; Sibai, Tarek; Black, Jennifer; Rianon, Nahid; Rajagopal, Abbhirami; Munivez, Elda; Bertin, Terry; Dawson, Brian; Chen, Yuqing; Jiang, Ming-Ming; Lee, Brendan; Yang, Tao; Bae, Yangjin

    2015-05-01

    Angiotensin receptor blockers (ARBs) are a group of anti-hypertensive drugs that are widely used to treat pediatric hypertension. Recent application of ARBs to treat diseases such as Marfan syndrome or Alport syndrome has shown positive outcomes in animal and human studies, suggesting a broader therapeutic potential for this class of drugs. Multiple studies have reported a benefit of ARBs on adult bone homeostasis; however, its effect on the growing skeleton in children is unknown. We investigated the effect of Losartan, an ARB, in regulating bone mass and cartilage during development in mice. Wild type mice were treated with Losartan from birth until 6 weeks of age, after which bones were collected for microCT and histomorphometric analyses. Losartan increased trabecular bone volume vs. tissue volume (a 98% increase) and cortical thickness (a 9% increase) in 6-weeks old wild type mice. The bone changes were attributed to decreased osteoclastogenesis as demonstrated by reduced osteoclast number per bone surface in vivo and suppressed osteoclast differentiation in vitro. At the molecular level, Angiotensin II-induced ERK1/2 phosphorylation in RAW cells was attenuated by Losartan. Similarly, RANKL-induced ERK1/2 phosphorylation was suppressed by Losartan, suggesting a convergence of RANKL and angiotensin signaling at the level of ERK1/2 regulation. To assess the effect of Losartan on cartilage development, we examined the cartilage phenotype of wild type mice treated with Losartan in utero from conception to 1 day of age. Growth plates of these mice showed an elongated hypertrophic chondrocyte zone and increased Col10a1 expression level, with minimal changes in chondrocyte proliferation. Altogether, inhibition of the angiotensin pathway by Losartan increases bone mass and accelerates chondrocyte hypertrophy in growth plate during skeletal development. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Changing bone marrow micro-environment during development of acute myeloid leukaemia in rats

    DEFF Research Database (Denmark)

    Mortensen, B T; Jensen, P O; Helledie, N

    1998-01-01

    The Brown Norwegian rat transplanted with promyelocytic leukaemic cells (BNML) has been used as a model for human acute myeloid leukaemia. We have previously shown that both the blood supply to the bone marrow and the metabolic rate decrease in relation to the leukaemic development in these rats....... Here we have investigated how the development and progression of this leukaemia affect oxygenation, pH and proliferation of normal and leukaemic cells in vivo. Bone marrow pH was measured by a needle electrode. Nitroimidazol-theophylline (NITP) was used to identify hypoxic cells, and we applied...... bromodeoxyuridine (BrdUrd) to identify DNA replicating cells. The leukaemia progressed slowly until day 27 after which a rapid deterioration could be observed leading to severe changes over the following 5 d. In whole blood there was evidence of progressing metabolic acidosis. In bone marrow the fraction...

  4. Maternal Flaxseed Oil During Lactation Enhances Bone Development in Male Rat Pups.

    Science.gov (United States)

    Pereira, Aline D'Avila; Ribeiro, Danielle Cavalcante; de Santana, Fernanda Carvalho; de Sousa Dos Santos, Aline; Mancini-Filho, Jorge; do Nascimento-Saba, Celly Cristina Alves; Velarde, Luis Guillermo Coca; da Costa, Carlos Alberto Soares; Boaventura, Gilson Teles

    2016-08-01

    Flaxseed oil is an alpha linolenic acid source important in the growth and body development stage; furthermore, this acid acts on adipose tissue and bone health. The aim of this study was to evaluate body composition, fatty acid composition, hormone profile, retroperitoneal adipocyte area and femur structure of pups at weaning, whose mothers were fed a diet containing flaxseed oil during lactation. After birth, pups were randomly assigned: control (C, n = 12) and flaxseed oil (FO, n = 12), rats whose mothers were treated with diet containing soybean or flaxseed oil. At 21 days, the pups were weaned and body mass, length, body composition, biochemical parameter, leptin, osteoprotegerin, osteocalcin, fatty acids composition, intra-abdominal fat mass and femur structure were analyzed. FO showed (p < 0.05): higher body mass (+12 %) and length (+9 %); body fat mass (g, +45 %); bone mineral density (+8 %), bone mineral content (+55 %) and bone area (+35 %), osteocalcin (+173 %) and osteoprotegerin (+183 %). Arachidonic acid was lower (p < 0.0001), alpha-linolenic and eicosapentaenoic were higher (p < 0.0001). Intra-abdominal fat mass was higher (+25 %), however, the retroperitoneal adipocytes area was lower (-44 %). Femur mass (+10 %), distance between epiphyses (+4 %) and bone mineral density (+13 %) were higher. The study demonstrates that adequate flaxseed oil content during a lactation diet plays an important role in the development of pups.

  5. Development of virtual simulation platform for investigation of the radiographic features of periapical bone lesion.

    Science.gov (United States)

    Gao, Yuan; Haapasalo, Markus; Shen, Ya; Wu, Hongkun; Jiang, Huiyong; Zhou, Xuedong

    2010-08-01

    The periapical radiograph is used as an important tool in the assessment of periapical bone lesions in endodontic therapy. The purpose of this study was to develop a virtual simulation platform for radiographic research of periapical bone lesions based on a digitally reconstructed radiograph and to investigate the radiographic features of different simulated periapical bone lesions. A cadaver mandible was scanned by microcomputed tomography. The application framework for the creation of a digitally reconstructed radiograph with virtual periapical lesions was constructed. Subsequently, different size and shape periapical lesions were created virtually in an incisor, a premolar, and a molar, and the digitally reconstructed radiographs were produced. The detection of periapical lesions based on digitally reconstructed radiographs was depended on lesion size, position, shape, and tooth position. Virtual periapical lesions could not be visualized with lesions smaller than 1 mm in the incisor, 2 mm in the premolar, and 3 mm in the molar, and these virtual lesions were confined within the cancellous bone. A 4-mm lesion in the molar was still not visualized even if it encroached on the cortical bone. If the lesions encroached on the junctional trabeculae and cortical bone or the lesion was created with the maximal buccal-lingual dimension in ellipsoid shape and confined within the cancellous bone giving it an abnormal shape, it could be seen, except for the "thinnest" 1-mm lesion in incisor region. The virtual simulation platform described here provides a reproducible assessment of periapical lesions and aids in a better understanding of the characteristics of periapical lesions. Copyright 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Injectable bone-graft substitutes: current products, their characteristics and indications, and new developments.

    Science.gov (United States)

    Larsson, Sune; Hannink, Gerjon

    2011-09-01

    More than a decade has passed since the first injectable bone substitutes were introduced for use in orthopaedic trauma, and over recent years the number of commercial products has increased dramatically. Despite the fact that these bone substitutes have been on the market for many years, knowledge amongst potential users on how and when they might be useful is still fairly limited. Most injectable bone substitutes belong to one of two major groups: by far the largest group contains products based on various calcium phosphate (CP) mixtures, whilst the smaller group consists of calcium sulphate (CS) compounds. Following mixing, the CP or CS paste can be injected into--for instance--a fracture space for augmentation as an alternative to bone graft, or around a screw for augmentation if the bone is weak. Within minutes an in situ process makes the substitute hard; the mechanical strength in compression resembles that of cancellous bone, whereas the strength in bending and shear is lower. Over time, CP products undergo remodelling through a cell-mediated process that seems to mimic the normal bone remodelling, whilst CS products are dissolved through a faster process that is not cell-mediated. For CP, a number of clinical studies have shown that it can be useful for augmentation of metaphyseal fractures when a space is present. Randomised studies have verified that CP works especially well in tibial plateau fractures when compared with conventional bone grafting. So far the number of clinical studies on CS products is very low. Development at present seems to be heading towards premixed or directly mixed products as well as new compounds that contain fibres or other components to enhance bending and shear strength. Products that are based on combinations of CP and CS are also being developed to combine the fast-dissolving CS with the stronger and more slowly remodelling CP. Injectable bone substitutes, and especially CS, have also been targeted as potentially good

  7. Bone Signaling in Middle Ear Development: A Genome‐Wide Differential Expression Analysis

    DEFF Research Database (Denmark)

    Nielsen, Michelle Christine; Bertelsen, Tomas Martin; Friis, Morten

    2014-01-01

    Common middle ear diseases may affect bone behavior in the middle ear air cell system. To understand this pathologic pneumatization, the normal development of bone in the middle ear should be investigated. The objective of this study was to analyze gene expression of bone‐related signaling factors...... sets may also play important roles during pathologic pneumatization of the middle ear air cell system in common middle ear diseases. In addition, this study suggests that the control of growth rate and wall thickness from resorptive as well as formative signals all originate from the inner lining cells...

  8. The corepressor Tle4 is a novel regulator of murine hematopoiesis and bone development.

    Directory of Open Access Journals (Sweden)

    Justin C Wheat

    Full Text Available Hematopoiesis is a complex process that relies on various cell types, signaling pathways, transcription factors and a specific niche. The integration of these various components is of critical importance to normal blood development, as deregulation of these may lead to bone marrow failure or malignancy. Tle4, a transcriptional corepressor, acts as a tumor suppressor gene in a subset of acute myeloid leukemia, yet little is known about its function in normal and malignant hematopoiesis or in mammalian development. We report here that Tle4 knockout mice are runted and die at around four weeks with defects in bone development and BM aplasia. By two weeks of age, Tle4 knockout mice exhibit leukocytopenia, B cell lymphopenia, and significant reductions in hematopoietic stem and progenitor cells. Tle4 deficient hematopoietic stem cells are intrinsically defective in B lymphopoiesis and exhaust upon stress, such as serial transplantation. In the absence of Tle4 there is a profound decrease in bone mineralization. In addition, Tle4 knockout stromal cells are defective at maintaining wild-type hematopoietic stem cell function in vitro. In summary, we illustrate a novel and essential role for Tle4 in the extrinsic and intrinsic regulation of hematopoiesis and in bone development.

  9. A novel composite material specifically developed for ultrasound bone phantoms: cortical, trabecular and skull.

    Science.gov (United States)

    Wydra, A; Maev, R Gr

    2013-11-21

    In the various stages of developing diagnostic and therapeutic equipment, the use of phantoms can play a very important role in improving the process, help in implementation, testing and calibrations. Phantoms are especially useful in developing new applications and training new doctors in medical schools. However, devices that use different physical factors, such as MRI, Ultrasound, CT Scan, etc will require the phantom to be made of different physical properties. In this paper we introduce the properties of recently designed new materials for developing phantoms for ultrasonic human body investigation, which in today's market make up more than 30% in the world of phantoms. We developed a novel composite material which allows fabrication of various kinds of ultrasound bone phantoms to mimic most of the acoustical properties of human bones. In contrast to the ex vivo tissues, the proposed material can maintain the physical and acoustical properties unchanged for long periods of time; moreover, these properties can be custom designed and created to suit specific needs. As a result, we introduce three examples of ultrasound phantoms that we manufactured in our laboratory: cortical, trabecular and skull bone phantoms. The paper also presents the results of a comparison study between the acoustical and physical properties of actual human bones (reported in the referenced literatures) and the phantoms manufactured by us.

  10. Height and bone age development in children with a malignant disease

    NARCIS (Netherlands)

    Tamminga, RYJ; Zweens, M; Drayer, NM; Kamps, WA

    2000-01-01

    Because controversy exists about the growth inhibiting effect of chemotherapy, we studied up to 4 years after diagnosis, height, growth and bone age de development in 28 children treated with cytostatic drugs for a solid tumor or Langerhans cell histiocytosis. The results were compared with those

  11. Development and characterization of a rabbit alveolar bone nonhealing defect model.

    NARCIS (Netherlands)

    Young, S.; Bashoura, A.G.; Borden, T.; Baggett, L.S.; Jansen, J.A.; Wong, M.; Mikos, A.G.

    2008-01-01

    The aim of this study was to develop an easily accessible and reproducible, nonhealing alveolar bone defect in the rabbit mandible. Twenty-four adult male New Zealand white rabbits underwent unilateral mandibular defect surgery. Two types of defect in the premolar/molar region were compared: (1) a

  12. Effect of maternal obesity on fetal bone development in the rat

    Science.gov (United States)

    Epidemiological studies show that quality of nutrition during intrauterine and postnatal early life impact the risk of low bone mass and fracture later in life. Maternal consumption of high-fat diets has been demonstrated to affect health outcomes, such as: brain development; obesity; insulin resist...

  13. Changing bone marrow micro-environment during development of acute myeloid leukaemia in rats

    DEFF Research Database (Denmark)

    Mortensen, B T; Jensen, P O; Helledie, N

    1998-01-01

    . Here we have investigated how the development and progression of this leukaemia affect oxygenation, pH and proliferation of normal and leukaemic cells in vivo. Bone marrow pH was measured by a needle electrode. Nitroimidazol-theophylline (NITP) was used to identify hypoxic cells, and we applied...

  14. Development of bioactive porous α-TCP/HAp beads for bone tissue engineering.

    Science.gov (United States)

    Asaoka, Teruo; Ohtake, Shoji; Furukawa, Katsuko S; Tamura, Akito; Ushida, Takashi

    2013-11-01

    Porous beads of bioactive ceramics such as hydroxyapatite (HAp) and tribasic calcium phosphate (TCP) are considered a promising scaffold for cultivating bone cells. To realize this, α-TCP/HAp functionally graded porous beads are fabricated with two main purposes: to maintain the function of the scaffold with sufficient strength up to the growth of new bone, and is absorbed completely after the growth. HAp is a bioactive material that has both high strength and strong tissue-adhesive properties, but is not readily absorbed by the human body. On the contrary, α-TCP is highly bioabsorbable, resulting in a scaffold that is absorbed before it is completely replaced by bone. In this study, we produced porous, bead-shaped carriers as scaffolds for osteoblast culture. To control the solubility in vivo, the fabricated beads contained α-TCP at the center and HAp at the surface. Cell adaptability of these beads for bone tissue engineering was confirmed in vitro. It was found that α-TCP/HAp bead carriers exhibit low toxicity in the initial stages of cell seeding and cell adhesion. The presence of HAp in the composite bead form effectively increased ALP activity. In conclusion, it is suggested that these newly developed α-TCP/HAp beads are a promising tool for bone tissue engineering. Copyright © 2013 Wiley Periodicals, Inc.

  15. Osteoclasts prefer aged bone

    DEFF Research Database (Denmark)

    Henriksen, K; Leeming, Diana Julie; Byrjalsen, I

    2007-01-01

    We investigated whether the age of the bones endogenously exerts control over the bone resorption ability of the osteoclasts, and found that osteoclasts preferentially develop and resorb bone on aged bone. These findings indicate that the bone matrix itself plays a role in targeted remodeling...... of aged bones....

  16. [Bone development trend in the knee joint of Tibetan teenagers in Aba Prefecture of Sichuan Province].

    Science.gov (United States)

    Ding, Shi-Rong; Ying, Chong-Liang; Wan, Lei; Wei, Hua; Wang, Ya-Hui; Zhu, Guang-You

    2013-08-01

    To discuss bone development trend in the knee joint of Tibetan teenagers in Sichuan province and to effectively update the database for estimating the living age of Tibetan teenagers in terms of bone age of the knee joint. Radiographs including epiphysis of distal femur, proximal tibia and proximal fibula were taken from 483 Tibetan male and female teenagers aged from 14 to 19 years old in Aba prefecture of Sichuan province in order to observe epiphyseal growth situation. The descriptive data of the epiphyseal closure ages of these teenagers' knee joints were statistically analyzed by SPSS 16.0 software. The distal femur epiphyseal closure occurred earliest, while the proximal fibula epiphyseal closure occurred latest. The epiphyseal growth of knee joints of females occurred about one year earlier than that of males. The forensic information and data related to Tibetan teenagers' bone age identification should be updated regularly. These results provide potential value for the practice of forensic medicine, anthropology and clinical medicine.

  17. Marker for the pre-clinical development of bone substitute materials

    Directory of Open Access Journals (Sweden)

    de Wild Michael

    2017-09-01

    Full Text Available Thin mechanically stable Ti-cages have been developed for the in-vivo application as X-ray and histology markers for the optimized evaluation of pre-clinical performance of bone graft materials. A metallic frame defines the region of interest during histological investigations and supports the identification of the defect site. This standardization of the procedure enhances the quality of pre-clinical experiments. Different models of thin metallic frameworks were designed and produced out of titanium by additive manufacturing (Selective Laser Melting. The productibility, the mechanical stability, the handling and suitability of several frame geometries were tested during surgery in artificial and in ex-vivo bone before a series of cages was preclinically investigated in the female Göttingen minipigs model. With our novel approach, a flexible process was established that can be adapted to the requirements of any specific animal model and bone graft testing.

  18. Roles of the primary cilium component Polaris in synchondrosis development.

    Science.gov (United States)

    Ochiai, T; Nagayama, M; Nakamura, T; Morrison, T; Pilchak, D; Kondo, N; Hasegawa, H; Song, B; Serra, R; Pacifici, M; Koyama, E

    2009-06-01

    Primary cilia regulate several developmental processes and mediate hedgehog signaling. To study their roles in cranial base development, we created conditional mouse mutants deficient in Polaris, a critical primary cilium component, in cartilage. Mutant post-natal cranial bases were deformed, and their synchondrosis growth plates were disorganized. Expression of Indian hedgehog, Patched-1, collagen X, and MMP-13 was reduced and accompanied by decreases in endochondral bone. Interestingly, there was excessive intramembranous ossification along the perichondrium, accompanied by excessive Patched-1 expression, suggesting that Ihh distribution was wider and responsible for such excessive response. Indeed, expression of heparan sulfate proteoglycans (HS-PGs), normally involved in restricting hedgehog distribution, was barely detectable in mutant synchondroses. Analyses of the data provides further evidence for the essential roles of primary cilia and hedgehog signaling in cranial base development and chondrocyte maturation, and point to a close interdependence between cilia and HS-PGs to delimit targets of hedgehog action in synchondroses.

  19. Infant bone age estimation based on fibular shaft length: model development and clinical validation

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Andy; Stamoulis, Catherine; Bixby, Sarah D.; Breen, Micheal A.; Connolly, Susan A.; Kleinman, Paul K. [Boston Children' s Hospital, Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2016-03-15

    Bone age in infants (<1 year old) is generally estimated using hand/wrist or knee radiographs, or by counting ossification centers. The accuracy and reproducibility of these techniques are largely unknown. To develop and validate an infant bone age estimation technique using fibular shaft length and compare it to conventional methods. We retrospectively reviewed negative skeletal surveys of 247 term-born low-risk-of-abuse infants (no persistent child protection team concerns) from July 2005 to February 2013, and randomized them into two datasets: (1) model development (n = 123) and (2) model testing (n = 124). Three pediatric radiologists measured all fibular shaft lengths. An ordinary linear regression model was fitted to dataset 1, and the model was evaluated using dataset 2. Readers also estimated infant bone ages in dataset 2 using (1) the hemiskeleton method of Sontag, (2) the hemiskeleton method of Elgenmark, (3) the hand/wrist atlas of Greulich and Pyle, and (4) the knee atlas of Pyle and Hoerr. For validation, we selected lower-extremity radiographs of 114 normal infants with no suspicion of abuse. Readers measured the fibulas and also estimated bone ages using the knee atlas. Bone age estimates from the proposed method were compared to the other methods. The proposed method outperformed all other methods in accuracy and reproducibility. Its accuracy was similar for the testing and validating datasets, with root-mean-square error of 36 days and 37 days; mean absolute error of 28 days and 31 days; and error variability of 22 days and 20 days, respectively. This study provides strong support for an infant bone age estimation technique based on fibular shaft length as a more accurate alternative to conventional methods. (orig.)

  20. Continuous and intermittent exposure of neonatal rat calvarial cells to PTHrP (1-36 inhibits bone nodule mineralization in vitro by downregulating bone sialoprotein expression via the cAMP signaling pathway [v2; ref status: indexed, http://f1000r.es/18x

    Directory of Open Access Journals (Sweden)

    Suzan A Kamel

    2013-06-01

    Full Text Available The development and growth of the skeleton in the absence of parathyroid-hormone-related protein (PTHrP is abnormal.  The shortening of appendicular bones in PTHrP gene null mice is explained by an effect of PTHrP on endochondral bone growth.  Whether or not PTHrP influences intramembranous ossification is less clear.  The purpose of this study was to determine the effect of exogenous PTHrP on intramembranous ossification in vitro.  Neonatal rat calvarial cells maintained in primary cell culture conditions that permit spontaneous formation of woven bone nodules by intramembranous ossification were studied. The expression of PTHrP, parathyroid hormone 1 receptor (PTH1R, and alkaline phosphatase (AP by osteogenic cells in developing nodules and the effects of PTHrP (1-36 on nodule development was determined over 3-18 days. PTHrP and PTH1R were detected colonies of osteogenic cells on culture day three, and AP was detected on day six. PTHrP and its receptor were localized in pre-osteoblasts, osteoblasts, and osteocytes, and AP activity was detected in pre-osteoblasts and osteoblasts but not osteocytes. Continuous and intermittent exposure to PTHrP (1-36 decreased the number of mineralized bone nodules and bone sialoprotein (BSP mRNA and protein, but had no effect on the number of AP-positive osteogenic cell colonies, cell proliferation, apoptosis, or osteopontin (OPN mRNA. These results demonstrate that osteogenic cells that participate in the formation of woven bone nodules in vitro exhibit PTHrP and PTH1R before they demonstrate AP activity. Exogenous PTHrP (1-36 inhibits the mineralization of woven bone deposited during bone nodule formation in vitro, possibly by reducing the expression of BSP.

  1. Development and performance analysis of Si-CaP/fine particulate bone powder combined grafts for bone regeneration.

    Science.gov (United States)

    Sun, Chengli; Tian, Ye; Xu, Wenxiao; Zhou, Changlong; Xie, Huanxin; Wang, Xintao

    2015-05-22

    Although autogenous bone grafts as well as several bone graft substitute material have been used for some time, there is high demand for more efficient and less costly bone-substitute materials. Silicon-substituted calcium phosphates (Si-CaP) and fine particulate bone powder (FPBP) preparations have been previously shown to individually possess many of the required features of a bone graft substitute scaffold. However, when applied individually, these two materials fall short of an ideal substitute material. We investigated a new concept of combining Si-CaP with FPBP for improved performance in bone-repair. We assessed Si-CaP/FPBP combined grafts in vitro, by measuring changes in pH, weight loss, water absorption and compressive strength over time. Si-CaP/FPBP combined grafts was found to produce conditions of alkaline pH levels compared to FPBP, and scaffold surface morphology conducive to bone cell adhesion, proliferation, differentiation, tissue growth and transport of nutrients, while maintaining elasticity and mechanical strength and degradation at a rate closer to osteogenesis. Si-CaP/FPBP combined grafts was found to be superior to any of the two components individually.

  2. Gli1 Protein Participates in Hedgehog-mediated Specification of Osteoblast Lineage during Endochondral Ossification*

    Science.gov (United States)

    Hojo, Hironori; Ohba, Shinsuke; Yano, Fumiko; Saito, Taku; Ikeda, Toshiyuki; Nakajima, Keiji; Komiyama, Yuske; Nakagata, Naomi; Suzuki, Kentaro; Takato, Tsuyoshi; Kawaguchi, Hiroshi; Chung, Ung-il

    2012-01-01

    With regard to Hedgehog signaling in mammalian development, the majority of research has focused on Gli2 and Gli3 rather than Gli1. This is because Gli1−/− mice do not show any gross abnormalities in adulthood, and no detailed analyses of fetal Gli1−/− mice are available. In this study, we investigated the physiological role of Gli1 in osteogenesis. Histological analyses revealed that bone formation was impaired in Gli1−/− fetuses compared with WT fetuses. Gli1−/− perichondrial cells expressed neither runt-related transcription factor 2 (Runx2) nor osterix, master regulators of osteogenesis, in contrast to WT cells. In vitro analyses showed that overexpression of Gli1 up-regulated early osteogenesis-related genes in both WT and Runx2−/− perichondrial cells, and Gli1 activated transcription of those genes via its association with their 5′-regulatory regions, underlying the function of Gli1 in the perichondrium. Moreover, Gli1−/−;Gli2−/− mice showed more severe phenotypes of impaired bone formation than either Gli1−/− or Gli2−/− mice, and osteoblast differentiation was impaired in Gli1−/−;Gli3−/− perichondrial cells compared with Gli3−/− cells in vitro. These data suggest that Gli1 itself can induce early osteoblast differentiation, at least to some extent, in a Runx2-independent manner. It also plays a redundant role with Gli2 and is involved in the repressor function of Gli3 in osteogenesis. On the basis of these findings, we propose that upon Hedgehog input, Gli1 functions collectively with Gli2 and Gli3 in osteogenesis. PMID:22493482

  3. Influence of sex steroids on development of cultured fetal rat metatarsal bones.

    Science.gov (United States)

    Chamoux, E; Coxam, V; Lebecque, P; Davicco, M J; Miller, S C; Barlet, J P

    1997-01-01

    The effects of 17 beta-estradiol (E), dihydrotestosterone (D, a non aromatisable androgen), and progesterone (P) on osteogenesis were studied on fetal rat cartilaginous anlagues cultivated in vitro. The three medial metatarsal rudiments were harvested at day 19 of gestation and grown in 1% BSA MEM medium (MO 643, Sigma) without serum nor antibiotics. After a 18h preincubation period, hormones were added for 8 days. Paired controls were incubated in the same volume of medium. The length, the metacarpal thickness and the size of the mineralized zone were measured every day, using a calibrated eyepiece (magnification X 40). DNA and protein synthesis, cartilage metabolism and mineralization were evaluated by monitoring the incorporation of 3H-Thymidine, 3H-Proline, 35S and 45Ca into anlagues for the last three hours of incubation, respectively. The dose/response effect of each steroid was studied at the concentrations of 10(-4) M, 10(-6) M, 10(-7) M and 10(-9) M. No difference was observed between male and female fetuses. A significant positive effect on total length (% of length measured at harvesting day) was observed with the 10(-7) M dose of E (163% +/- 2 vs 148% +/- 4 in controls) or D (158% +/- 3). Endochondral growth was not modified by P treatment. The effect of the three steroids (given at a dose of 10(-7) M) alone or as combinations (E, D, P, EP, ED, PD, EPD) confirmed the positive effect of E on endochondral growth and, to a lesser extend, of D and the association ED. Nevertheless, D had a better effect than E on endomembranous growth. On the contrary, P did not affect growth neither administrated alone nor in combination with E or D, while a positive effect of P on mineralization was demonstrated. The treatment associating the three steroids slowed down all the parameters concerning growth but strongly stimulated calcification.

  4. Peroxisomes in Different Skeletal Cell Types during Intramembranous and Endochondral Ossification and Their Regulation during Osteoblast Differentiation by Distinct Peroxisome Proliferator-Activated Receptors.

    Directory of Open Access Journals (Sweden)

    Guofeng Qian

    Full Text Available Ossification defects leading to craniofacial dysmorphism or rhizomelia are typical phenotypes in patients and corresponding knockout mouse models with distinct peroxisomal disorders. Despite these obvious skeletal pathologies, to date no careful analysis exists on the distribution and function of peroxisomes in skeletal tissues and their alterations during ossification. Therefore, we analyzed the peroxisomal compartment in different cell types of mouse cartilage and bone as well as in primary cultures of calvarial osteoblasts. The peroxisome number and metabolism strongly increased in chondrocytes during endochondral ossification from the reserve to the hypertrophic zone, whereas in bone, metabolically active osteoblasts contained a higher numerical abundance of this organelle than osteocytes. The high abundance of peroxisomes in these skeletal cell types is reflected by high levels of Pex11β gene expression. During culture, calvarial pre-osteoblasts differentiated into secretory osteoblasts accompanied by peroxisome proliferation and increased levels of peroxisomal genes and proteins. Since many peroxisomal genes contain a PPAR-responsive element, we analyzed the gene expression of PPARɑ/ß/ɣ in calvarial osteoblasts and MC3T3-E1 cells, revealing higher levels for PPARß than for PPARɑ and PPARɣ. Treatment with different PPAR agonists and antagonists not only changed the peroxisomal compartment and associated gene expression, but also induced complex alterations of the gene expression patterns of the other PPAR family members. Studies in M3CT3-E1 cells showed that the PPARß agonist GW0742 activated the PPRE-mediated luciferase expression and up-regulated peroxisomal gene transcription (Pex11, Pex13, Pex14, Acox1 and Cat, whereas the PPARß antagonist GSK0660 led to repression of the PPRE and a decrease of the corresponding mRNA levels. In the same way, treatment of calvarial osteoblasts with GW0742 increased in peroxisome number and

  5. Bone up: craniomandibular development and hard-tissue biomineralization in neonate mice.

    Science.gov (United States)

    Thompson, Khari D; Weiss-Bilka, Holly E; McGough, Elizabeth B; Ravosa, Matthew J

    2017-10-01

    The presence of regional variation in the osteogenic abilities of cranial bones underscores the fact that the mechanobiology of the mammalian skull is more complex than previously recognized. However, the relationship between patterns of cranial bone formation and biomineralization remains incompletely understood. In four strains of mice, micro-computed tomography was used to measure tissue mineral density during perinatal development in three skull regions (calvarium, basicranium, mandible) noted for variation in loading environment, embryological origin, and ossification mode. Biomineralization levels increased during perinatal ontogeny in the mandible and calvarium, but did not increase in the basicranium. Tissue mineral density levels also varied intracranially, with density in the mandible being highest, in the basicranium intermediate, and in the calvarium lowest. Perinatal increases in, and elevated levels of, mandibular biomineralization appear related to the impending postweaning need to resist elevated masticatory stresses. Similarly, perinatal increases in calvarial biomineralization may be linked to ongoing brain expansion, which is known to stimulate sutural bone formation in this region. The lack of perinatal increase in basicranial biomineralization could be a result of earlier developmental maturity in the cranial base relative to other skull regions due to its role in supporting the brain's mass throughout ontogeny. These results suggest that biomineralization levels and age-related trajectories throughout the skull are influenced by the functional environment and ontogenetic processes affecting each region, e.g., onset of masticatory loads in the mandible, whereas variation in embryology and ossification mode may only have secondary effects on patterns of biomineralization. Knowledge of perinatal variation in tissue mineral density, and of normal cranial bone formation early in development, may benefit clinical therapies aiming to correct

  6. Development of 3D printing system for human bone model manufacturing using medical images

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Wang Kyun [Dept. of Radiology, Chungcheongbuk-do Cheongju Medical Center, Cheongju (Korea, Republic of)

    2017-09-15

    The 3D printing selective laser sintering (SLS) and stereo lithography apparatus (SLA) method used for bone model production has good precision and resolution, but the printers are expensive and need professional knowledge for operation. The program that converts computed tomography digital imaging and communications in medicine (DICOM) file into STL (stereolithography) file is also expensive so requesting 3D printing companies takes a lot of time and cost, which is why they are not generally utilized in surgery. To produce bone models of fractured patients, the use of 3D imaging conversion program and 3D printing system should be convenient, and the cost of device and operation should be low. Besides, they should be able to produce big size bone models for application to surgery. Therefore, by using an fused deposition modeling (FDM) method 3D printer that uses thermoplastic materials such as DICOM Viewer OsiriX and plastic wires, this study developed 3D printing system for Fracture surgery Patients customized bone model production for many clinics to use for surgery of fracture patients by universalizing with no limit in printing sizes and low maintenance and production cost. It is expected to be widely applied to the overall areas of orthopedics' education, research and clinic. It is also expected to be conveniently used in not only university hospitals but also regular general hospitals.

  7. Localization and function of the anion exchanger Ae2 in developing teeth and orofacial bone in rodents

    NARCIS (Netherlands)

    Bronckers, A.L.J.J.; Lyaruu, D.M.; Jansen, I.D.C.; Medina, J.F.; Kellokumpu, S.; Hoeben, K.A.; Gawenis, L.R.; Oude Elferink, R.P.J.; Everts, V.

    2009-01-01

    To explore the functions of the anion exchanger 2 (Ae2) in the development of bones and teeth we examined the distribution of Ae2 in cells involved in the formation of teeth and surrounding bone in young hamsters, mice and rats. In all three species strongest immunostaining for Ae2 was obtained in

  8. Risk Factors for Developing Skeletal-Related Events in Breast Cancer Patients With Bone Metastases Undergoing Treatment With Bone-Modifying Agents.

    Science.gov (United States)

    Tanaka, Ryota; Yonemori, Kan; Hirakawa, Akihiro; Kinoshita, Fumie; Takahashi, Naoki; Hashimoto, Jun; Kodaira, Makoto; Yamamoto, Harukaze; Yunokawa, Mayu; Shimizu, Chikako; Fujimoto, Manabu; Fujiwara, Yasuhiro; Tamura, Kenji

    2016-04-01

    Bone-modifying agents (BMAs) reduce the incidence of skeletal-related events (SREs) and are thus recommended for breast cancer patients with bone metastases. However, the risk factors for SREs during BMA treatment are not well-understood. This study evaluated the number and timing of SREs from case studies to identify these factors. The medical records of 534 women with breast cancer who developed bone metastases between 1999 and 2011 were reviewed. SREs were defined as a pathologic fracture, spinal cord compression, or the need for bone irradiation or surgery. Multiple variables were assessed and were analyzed by using the Cox proportional hazard analyses and the Andersen and Gill method. Multivariate analyses for both the time to the first SRE and the primary and subsequent SRE frequency demonstrated that significant baseline risk factors included luminal B type disease, a history of palliative radiation therapy, BMA treatment within 2 years, and elevated serum calcium levels at the time of the initial BMA dose. Additionally, for the time to the first SRE and for the primary and subsequent SRE frequency, the presence of extraskeletal metastases and BMA administration initiation ≥6 months after the detection of bone metastases were also significant risk factors, respectively. In breast cancer patients with bone metastases, more vigilant observation should be considered for patients with the identified risk factors. To reduce the risk for SRE, BMAs should be administered within 6 months of bone metastases diagnosis and before palliative radiation therapy. Retrospectively, risk factors were identified for skeletal-related events (SREs) in breast cancer patients with bone metastasis who were treated with bone-modifying agents (BMAs). For the time to the first SRE and for the SRE frequency, presence of extraskeletal metastases and BMA initiation ≥6 months after the detection of bone metastases were risk factors, respectively. Luminal B type disease, a history of

  9. 3D Bioprinting of Developmentally Inspired Templates for Whole Bone Organ Engineering.

    Science.gov (United States)

    Daly, Andrew C; Cunniffe, Gráinne M; Sathy, Binulal N; Jeon, Oju; Alsberg, Eben; Kelly, Daniel J

    2016-09-01

    The ability to print defined patterns of cells and extracellular-matrix components in three dimensions has enabled the engineering of simple biological tissues; however, bioprinting functional solid organs is beyond the capabilities of current biofabrication technologies. An alternative approach would be to bioprint the developmental precursor to an adult organ, using this engineered rudiment as a template for subsequent organogenesis in vivo. This study demonstrates that developmentally inspired hypertrophic cartilage templates can be engineered in vitro using stem cells within a supporting gamma-irradiated alginate bioink incorporating Arg-Gly-Asp adhesion peptides. Furthermore, these soft tissue templates can be reinforced with a network of printed polycaprolactone fibers, resulting in a ≈350 fold increase in construct compressive modulus providing the necessary stiffness to implant such immature cartilaginous rudiments into load bearing locations. As a proof-of-principal, multiple-tool biofabrication is used to engineer a mechanically reinforced cartilaginous template mimicking the geometry of a vertebral body, which in vivo supported the development of a vascularized bone organ containing trabecular-like endochondral bone with a supporting marrow structure. Such developmental engineering approaches could be applied to the biofabrication of other solid organs by bioprinting precursors that have the capacity to mature into their adult counterparts over time in vivo. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Development of cholesterol granuloma in a temporal bone petrous apex previously containing marrow exposed to air cells.

    Science.gov (United States)

    Selman, Yamil; Wood, John W; Telischi, Fred F; Casiano, Roy R; Angeli, Simon I

    2013-07-01

    There is ongoing debate on the pathogenic mechanisms of cholesterol granuloma formation in the temporal bone. The purpose of this report is to provide evidence in support of the exposed marrow hypothesis in explaining the pathogenesis of petrous apex cholesterol granuloma. Retrospective single case study. The primary outcome evaluated was the diagnosis of a new cholesterol granuloma in a petrous apex that previously demonstrated radiologic evidence of bone marrow exposed to petrous apex air cells. A patient with a unilateral petrous apex cholesterol granuloma develops a new, contralateral cholesterol granuloma in a hyperpneumatized temporal bone petrous apex shown previously to have medullary bone exposed to air cells. This report implicates the medullary-air cell interface in a hyperaerated temporal bone petrous apex in the development and growth of a petrous apex cholesterol granuloma.

  11. Theobromine Upregulates Osteogenesis by Human Mesenchymal Stem Cells In Vitro and Accelerates Bone Development in Rats.

    Science.gov (United States)

    Clough, Bret H; Ylostalo, Joni; Browder, Elizabeth; McNeill, Eoin P; Bartosh, Thomas J; Rawls, H Ralph; Nakamoto, Tetsuo; Gregory, Carl A

    2017-03-01

    Theobromine (THB) is one of the major xanthine-like alkaloids found in cacao plant and a variety of other foodstuffs such as tea leaves, guarana and cola nuts. Historically, THB and its derivatives have been utilized to treat cardiac and circulatory disorders, drug-induced nephrotoxicity, proteinuria and as an immune-modulator. Our previous work demonstrated that THB has the capacity to improve the formation of hydroxyl-apatite during tooth development, suggesting that it may also enhance skeletal development. With its excellent safety profile and resistance to pharmacokinetic elimination, we reasoned that it might be an excellent natural osteoanabolic supplement during pregnancy, lactation and early postnatal growth. To determine whether THB had an effect on human osteoprogenitors, we subjected primary human bone marrow mesenchymal stem cells (hMSCs) to osteogenic assays after exposure to THB in vitro and observed that THB exposure increased the rate of osteogenesis and mineralization by hMSCs. Moreover, THB exposure resulted in a list of upregulated mRNA transcripts that best matched an osteogenic tissue expression signature as compared to other tissue expression signatures archived in several databases. To determine whether oral administration of THB resulted in improved skeletal growth, we provided pregnant rats with chow supplemented with THB during pregnancy and lactation. After weaning, offspring received THB continuously until postnatal day 50 (approximately 10 mg kg-1 day-1). Administration of THB resulted in neonates with larger bones, and 50-day-old offspring accumulated greater body mass, longer and thicker femora and superior tibial trabecular parameters. The accelerated growth did not adversely affect the strength and resilience of the bones. These results indicate that THB increases the osteogenic potential of bone marrow osteoprogenitors, and dietary supplementation of a safe dose of THB to expectant mothers and during the postnatal period could

  12. The Development of Biomimetic Spherical Hydroxyapatite/Polyamide 66 Biocomposites as Bone Repair Materials

    Directory of Open Access Journals (Sweden)

    Xuesong Zhang

    2014-01-01

    Full Text Available A novel biomedical material composed of spherical hydroxyapatite (s-HA and polyamide 66 (PA biocomposite (s-HA/PA was prepared, and its composition, mechanical properties, and cytocompatibility were characterized and evaluated. The results showed that HA distributed uniformly in the s-HA/PA matrix. Strong molecule interactions and chemical bonds were presented between the s-HA and PA in the composites confirmed by IR and XRD. The composite had excellent compressive strength in the range between 95 and 132 MPa, close to that of natural bone. In vitro experiments showed the s-HA/PA composite could improve cell growth, proliferation, and differentiation. Therefore, the developed s-HA/PA composites in this study might be used for tissue engineering and bone repair.

  13. Mineral distributions at the developing tendon enthesis.

    Directory of Open Access Journals (Sweden)

    Andrea G Schwartz

    to endochondral bone formation near the tendon insertion. These conserved and time-varying aspects of interface composition may have important implications for the growth and mechanical stability of the tendon-to-bone attachment throughout development.

  14. Altered bone development and an increase in FGF-23 expression in Enpp1(-/- mice.

    Directory of Open Access Journals (Sweden)

    Neil Charles Wallace Mackenzie

    Full Text Available Nucleotide pyrophosphatase phosphodiesterase 1 (NPP1 is required for the conversion of extracellular ATP into inorganic pyrophosphate (PP(i, a recognised inhibitor of hydroxyapatite (HA crystal formation. A detailed phenotypic assessment of a mouse model lacking NPP1 (Enpp1(-/- was completed to determine the role of NPP1 in skeletal and soft tissue mineralization in juvenile and adult mice. Histopathological assessment of Enpp1(-/- mice at 22 weeks of age revealed calcification in the aorta and kidney and ectopic cartilage formation in the joints and spine. Radiographic assessment of the hind-limb showed hyper-mineralization in the talocrural joint and hypo-mineralization in the femur and tibia. MicroCT analysis of the tibia and femur disclosed altered trabecular architecture and bone geometry at 6 and 22 weeks of age in Enpp1(-/- mice. Trabecular number, trabecular bone volume, structure model index, trabecular and cortical thickness were all significantly reduced in tibiae and femurs from Enpp1(-/- mice (P<0.05. Bone stiffness as determined by 3-point bending was significantly reduced in Enpp1(-/- tibiae and femurs from 22-week-old mice (P<0.05. Circulating phosphate and calcium levels were reduced (P<0.05 in the Enpp1(-/- null mice. Plasma levels of osteocalcin were significantly decreased at 6 weeks of age (P<0.05 in Enpp1(-/- mice, with no differences noted at 22 weeks of age. Plasma levels of CTx (Ratlaps™ and the phosphaturic hormone FGF-23 were significantly increased in the Enpp1(-/- mice at 22 weeks of age (P<0.05. Fgf-23 messenger RNA expression in cavarial osteoblasts was increased 12-fold in Enpp1(-/- mice compared to controls. These results indicate that Enpp1(-/- mice are characterized by severe disruption to the architecture and mineralization of long-bones, dysregulation of calcium/phosphate homeostasis and changes in Fgf-23 expression. We conclude that NPP1 is essential for normal bone development and control of physiological

  15. Development and testing of texture discriminators for the analysis of trabecular bone in proximal femur radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Huber, M. B.; Carballido-Gamio, J.; Fritscher, K.; Schubert, R.; Haenni, M.; Hengg, C.; Majumdar, S.; Link, T. M. [Department of Radiology and Biomedical Imaging, University of California, 400 Parnassus Avenue, San Francisco, California 94143 (United States); University of Health Sciences, Medical Informatics and Technology, 6060 Hall (Austria); AO Development Institute, 7270 Davos Platz (Switzerland); Medical University Innsbruck, 6020 Innsbruck (Austria); Department of Radiology and Biomedical Imaging, University of California, 400 Parnassus Avenue, San Francisco, California 94143 (United States)

    2009-11-15

    }=0.61 (MF and MG features, p<0.01) and were partially independent of BMD. The correlations were dependent on the choice of the ROI and the texture measure. The best predictive multiregression model for failure load R{sub adj}{sup 2}=0.86 (p<0.001) included a set of recently developed texture methods (MF and SIM) but excluded bone mineral density and commonly used texture measures. Conclusions: The results suggest that texture information contained in trabecular bone structure visualized on radiographs may predict whether an implant anchorage can be used and may determine the local bone quality from preoperative radiographs.

  16. Bone mineral density of tibae and femura of broiler breeders: growth, development and production

    Directory of Open Access Journals (Sweden)

    ICL Almeida Paz

    2006-06-01

    Full Text Available The aim of this study was to follow-up the physiological variations in the development of the bone tissue, associating them with the egg production curve. This study was carried out in the facilities of the Faculdade de Medicina Veterinária e Zootecnia of the UNESP, Botucatu, Brazil. Twenty-three families of Ross broiler breeders were used, each family consisting of 13 females and 1 male, distributed in 23 pens of 5.0m² each. The management was that recommended by the genetic company manual (Agroceres Ross, 2003, with daily feeding until 6th week of age; and birds were fed according to a 5:2 schedule (5 days fed, 2 days of fasting between 7 and 17 weeks of age, returning to daily feeding starting at 18 weeks of age. Birds did not receive afternoon calcium supplementation. On the fourth week of rearing, 84 females were removed for bone analyses of the right tibia and femur, using optical densitometry in radiographic images technique. These analyses were sequentially carried out in 4, 8, 12, 15, 20, 24, 30, 35, 42, 47, and 52 week-old birds. The egg production curve of the birds was followed-up and associated to bone mineral density results. For bone mineral density evaluation (BMD birds were divided by weight categories as light, intermediate, or heavy within each data age. BMD values of the tibias were not influenced by weight range, but by the age at collection. On the other hand, interactions were found among femur BMD values and weight and age categories. There was no correlation between eggshell quality and femur BMD. A negative correlation (-0.15 was observed between tibia BMD and eggshell percentage. It was possible to conclude that the egg production has little influence on bone mineral density of the birds probably because there was no need of bone mineral mobilization during the production period, since the observed egg production was below that observed under commercial conditions.

  17. Mineralization defects in cementum and craniofacial bone from loss of bone sialoprotein

    Science.gov (United States)

    Foster, B.L.; Ao, M.; Willoughby, C.; Soenjaya, Y.; Holm, E.; Lukashova, L.; Tran, A. B.; Wimer, H.F.; Zerfas, P.M.; Nociti, F.H.; Kantovitz, K.R.; Quan, B.D.; Sone, E.D.; Goldberg, H.A.; Somerman, M.J.

    2015-01-01

    Bone sialoprotein (BSP) is a multifunctional extracellular matrix protein found in mineralized tissues, including bone, cartilage, tooth root cementum (both acellular and cellular types), and dentin. In order to define the role BSP plays in the process of biomineralization of these tissues, we analyzed cementogenesis, dentinogenesis, and osteogenesis (intramembranous and endochondral) in craniofacial bone in Bsp null mice and wild-type (WT) controls over a developmental period (1-60 days post natal; dpn) by histology, immunohistochemistry, undecalcified histochemistry, microcomputed tomography (microCT), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and quantitative PCR (qPCR). Regions of intramembranous ossification in the alveolus, mandible, and calvaria presented delayed mineralization and osteoid accumulation, assessed by von Kossa and Goldner's trichrome stains at 1 and 14 dpn. Moreover, Bsp−/− mice featured increased cranial suture size at the early time point, 1 dpn. Immunostaining and PCR demonstrated that osteoblast markers, osterix, alkaline phosphatase, and osteopontin were unchanged in Bsp null mandibles compared to WT. Bsp−/− mouse molars featured a lack of functional acellular cementum formation by histology, SEM, and TEM, and subsequent loss of Sharpey's collagen fiber insertion into the tooth root structure. Bsp−/− mouse alveolar and mandibular bone featured equivalent or fewer osteoclasts at early ages (1 and 14 dpn), however, increased RANKL immunostaining and mRNA, and significantly increased number of osteoclast-like cells (2-5 fold) were found at later ages (26 and 60 dpn), corresponding to periodontal breakdown and severe alveolar bone resorption observed following molar teeth entering occlusion. Dentin formation was unperturbed in Bsp−/− mouse molars, with no delay in mineralization, no alteration in dentin dimensions, and no differences in odontoblast markers analyzed. No defects were identified

  18. Biosilicate®-gelatine bone scaffolds by the foam replica technique: development and characterization.

    Science.gov (United States)

    Desimone, Deborah; Li, Wei; Roether, Judith A; Schubert, Dirk W; Crovace, Murilo C; Rodrigues, Ana Candida M; Zanotto, Edgar D; Boccaccini, Aldo R

    2013-08-01

    The development of bioactive glass-ceramic materials has been a topic of great interest aiming at enhancing the mechanical strength of traditional bioactive scaffolds. In the present study, we test and demonstrate the use of Biosilicate® glass-ceramic powder to fabricate bone scaffolds by the foam replica method. Scaffolds possessing the main requirements for use in bone tissue engineering (95% porosity, 200-500 μm pore size) were successfully produced. Gelatine coating was investigated as a simple approach to increase the mechanical competence of the scaffolds. The gelatine coating did not affect the interconnectivity of the pores and did not significantly affect the bioactivity of the Biosilicate® scaffold. The gelatine coating significantly improved the compressive strength (i.e. 0.80 ± 0.05 MPa of coated versus 0.06 ± 0.01 MPa of uncoated scaffolds) of the Biosilicate® scaffold. The combination of Biosilicate® glass-ceramic and gelatine is attractive for producing novel scaffolds for bone tissue engineering.

  19. Biosilicate®–gelatine bone scaffolds by the foam replica technique: development and characterization

    Directory of Open Access Journals (Sweden)

    Deborah Desimone, Wei Li, Judith A Roether, Dirk W Schubert, Murilo C Crovace, Ana Candida M Rodrigues, Edgar D Zanotto and Aldo R Boccaccini

    2013-01-01

    Full Text Available The development of bioactive glass-ceramic materials has been a topic of great interest aiming at enhancing the mechanical strength of traditional bioactive scaffolds. In the present study, we test and demonstrate the use of Biosilicate® glass-ceramic powder to fabricate bone scaffolds by the foam replica method. Scaffolds possessing the main requirements for use in bone tissue engineering (95% porosity, 200–500 μm pore size were successfully produced. Gelatine coating was investigated as a simple approach to increase the mechanical competence of the scaffolds. The gelatine coating did not affect the interconnectivity of the pores and did not significantly affect the bioactivity of the Biosilicate® scaffold. The gelatine coating significantly improved the compressive strength (i.e. 0.80 ± 0.05 MPa of coated versus 0.06 ± 0.01 MPa of uncoated scaffolds of the Biosilicate® scaffold. The combination of Biosilicate® glass-ceramic and gelatine is attractive for producing novel scaffolds for bone tissue engineering.

  20. Biosilicate®–gelatine bone scaffolds by the foam replica technique: development and characterization

    Science.gov (United States)

    Desimone, Deborah; Li, Wei; Roether, Judith A; Schubert, Dirk W; Crovace, Murilo C; Rodrigues, Ana Candida M; Zanotto, Edgar D; Boccaccini, Aldo R

    2013-01-01

    The development of bioactive glass-ceramic materials has been a topic of great interest aiming at enhancing the mechanical strength of traditional bioactive scaffolds. In the present study, we test and demonstrate the use of Biosilicate® glass-ceramic powder to fabricate bone scaffolds by the foam replica method. Scaffolds possessing the main requirements for use in bone tissue engineering (95% porosity, 200–500 μm pore size) were successfully produced. Gelatine coating was investigated as a simple approach to increase the mechanical competence of the scaffolds. The gelatine coating did not affect the interconnectivity of the pores and did not significantly affect the bioactivity of the Biosilicate® scaffold. The gelatine coating significantly improved the compressive strength (i.e. 0.80 ± 0.05 MPa of coated versus 0.06 ± 0.01 MPa of uncoated scaffolds) of the Biosilicate® scaffold. The combination of Biosilicate® glass-ceramic and gelatine is attractive for producing novel scaffolds for bone tissue engineering. PMID:27877601

  1. Assessment of safety and efficacy of perinatal or peripubertal exposure to daidzein on bone development in rats

    OpenAIRE

    Tousen, Yuko; Ishiwata, Hajimu; Takeda, Ken; Ishimi, Yoshiko

    2015-01-01

    Neonatal exposure to isoflavones improved bone health in thereafter in previous animal studies. However, since isoflavones possess hormonal activity, it may interfere with reproductive development. In the present study, we assessed the safety and efficiency of perinatal or peripubertal exposure to daidzein on bone and reproductive organ development at early adulthood in rats. Sprague-Dawley pregnant rats (n = 18) were divided into 3 groups: (1) dams and their offspring were fed the control di...

  2. Development of porous polyurethane/strontium-substituted hydroxyapatite composites for bone regeneration.

    Science.gov (United States)

    Sariibrahimoglu, Kemal; Yang, Wanxun; Leeuwenburgh, Sander C G; Yang, Fang; Wolke, Joop G C; Zuo, Yi; Li, Yubao; Jansen, John A

    2015-06-01

    Polyurethane (PU) has been widely used for the biomedical applications but its potential for bone regeneration is limited due to its lack of osteoconductive properties. Strontium substituted hydroxyapatite (SrHA) particles, on the other hand, are known to exhibit a positive effect on bone formation. Therefore, the aim of this study was to (i) develop porous polyurethane scaffolds containing strontium SrHA nanoparticles (PU/SrHA) and (ii) compare their in vitro biological performance for applications in bone regeneration to PU scaffolds. SrHA and HA was synthesized using a conventional wet-chemical neutralization reaction at temperatures of 25, 50, and 80°C. Chemical analysis was performed by inductively coupled plasma-optical emission spectrometry. Synthesizing temperatures at 25 and at 50°C were selected for the composite preparation (abbreviated as HA-25, SrHA-25, HA-50, and SrHA-50, respectively). PU was synthesized from isophorone diisocyanate, polytetramethylene ether glycol, and 1,4-butanediol. Composite scaffolds were prepared by addition of HA or SrHA nanoparticles into PU scaffolds during polymer preparation. The results showed that the Sr content in HA nanoparticles increased with increasing synthesis temperature. The addition of nanoparticles decreased the elongation-at-break and tensile strength, but significantly increased the surface wettability of the PU scaffolds. In vitro degradation tests demonstrated that release of cations was significantly higher from PU/SrHA-50 composite scaffolds. Cell culture tests indicated that PU composites containing either HA or SrHA nanoparticles increased proliferation of bone marrow stem cells as compared to plain PU scaffolds, whereas osteogenic differentiation was not affected by the incorporation of HA nanoparticles irrespective of the incorporation of Sr. © 2014 Wiley Periodicals, Inc.

  3. A Development of a Human Cranial Bone Surrogate for Impact Studies

    Directory of Open Access Journals (Sweden)

    Jack C Roberts

    2013-10-01

    Full Text Available In order to replicate the fracture behavior of the intact human skull under impact it becomes necessary to develop a material having the mechanical properties of cranial bone. The most important properties to replicate in a surrogate human skull were found to be the fracture toughness and tensile strength of the cranial tables as well as the bending strength of the 3-layer (inner table-diplöe-outer table architecture of the human skull. The materials selected to represent the surrogate cranial tables consisted of two different epoxy resins systems with random milled glass fiber to enhance the strength and stiffness and the materials to represent the surrogate diplöe consisted of three low density foams. Forty-one three-point bending fracture toughness tests were performed on nine material combinations. The materials that best represented the fracture toughness of cranial tables were then selected and formed into tensile samples and tested. These materials were then used with the two surrogate diplöe foam materials to create the three layer surrogate cranial bone samples for three point bending tests. Drop tower tests were performed on flat samples created from these materials and the fracture patterns were very similar to the linear fractures seen in pendulum impacts of intact human skulls. The surrogate cranial tables had the quasi-static fracture toughness and tensile strength of 2.5 MPa√m and 53 ± 4.9 MPa, respectively, while the same properties of human compact bone were 3.1 ± 1.8 MPa√m and 68 ± 18 MPa, respectively. The cranial surrogate had a quasi-static bending strength of 68 ± 5.7 MPa, while that of cranial bone was 82 ± 26 MPa. This material/design is currently being used to construct spherical shell samples for drop tower and ballistic tests.

  4. Tooth-bone morphogenesis during postnatal stages of mouse first molar development

    Science.gov (United States)

    Lungová, Vlasta; Radlanski, Ralf J; Tucker, Abigail S; Renz, Herbert; Míšek, Ivan; Matalová, Eva

    2011-01-01

    The first mouse molar (M1) is the most common model for odontogenesis, with research particularly focused on prenatal development. However, the functional dentition forms postnatally, when the histogenesis and morphogenesis of the tooth is completed, the roots form and the tooth physically anchors into the jaw. In this work, M1 was studied from birth to eruption, assessing morphogenesis, proliferation and apoptosis, and correlating these with remodeling of the surrounding bony tissue. The M1 completed crown formation between postnatal (P) days 0–2, and the development of the tooth root was initiated at P4. From P2 until P12, cell proliferation in the dental epithelium reduced and shifted downward to the apical region of the forming root. In contrast, proliferation was maintained or increased in the mesenchymal cells of the dental follicle. At later stages, before tooth eruption (P20), cell proliferation suddenly ceased. This withdrawal from the cell cycle correlated with tooth mineralization and mesenchymal differentiation. Apoptosis was observed during all stages of M1 postnatal morphogenesis, playing a role in the removal of cells such as osteoblasts in the mandibular region and working together with osteoclasts to remodel the bone around the developing tooth. At more advanced developmental stages, apoptotic cells and bodies accumulated in the cell layers above the tooth cusps, in the path of eruption. Three-dimensional reconstruction of the developing postnatal tooth and bone indicates that the alveolar crypts form by resorption underneath the primordia, whereas the ridges form by active bone growth between the teeth and roots to form a functional complex. PMID:21418206

  5. In vitro assessment of biomaterial-induced remodeling of subchondral and cancellous bone for the early intervention of joint degeneration with focus on the spinal disc

    Science.gov (United States)

    McCanless, Jonathan D.

    Osteoarthritis-associated pain of the spinal disc, knee, and hip derives from degeneration of cartilagenous tissues in these joints. Traditional therapies have focused on these cartilage (and disc specific nucleus pulposus) changes as a means of treatment through tissue grafting, regenerative synthetic implants, non-regenerative space filling implants, arthroplasty, and arthrodesis. Although such approaches may seem apparent upon initial consideration of joint degeneration, tissue pathology has shown changes in the underlying bone and vascular bed precede the onset of cartilaginous changes. It is hypothesized that these changes precedent joint degeneration and as such may provide a route for early prevention. The current work proposes an injectable biomaterial-based therapy within these subchondral and cancellous bone regions as a means of preventing or reversing osteoarthritis. Two human concentrated platelet releasate-containing alginate hydrogel/beta-tricalcium phosphate composites have been developed for this potential biomaterial application. The undertaking of assessing these materials through bench-, in vitro, and ex vivo work is described herein. These studies showed the capability of the biomaterials to initiate a wound healing response in monocytes, angiogenic and differentiation behavior in immature endothelial cells, and early osteochondral differentiation in mesenchymal stem cells. These cellular activities are associated with fracture healing and endochondral bone formation, demonstrating the potential of the biomaterials to induce osseous and vascular tissue remodeling underlying osteoarthritic joints as a novel therapy for a disease with rapidly growing healthcare costs.

  6. Development of Collagen/Demineralized Bone Powder Scaffolds and Periosteum-Derived Cells for Bone Tissue Engineering Application

    Directory of Open Access Journals (Sweden)

    Wilairat Leeanansaksiri

    2013-01-01

    Full Text Available The aim of this study was to investigate physical and biological properties of collagen (COL and demineralized bone powder (DBP scaffolds for bone tissue engineering. DBP was prepared and divided into three groups, based on various particle sizes: 75–125 µm, 125–250 µm, and 250–500 µm. DBP was homogeneously mixed with type I collagen and three-dimensional scaffolds were constructed, applying chemical crosslinking and lyophilization. Upon culture with human periosteum-derived cells (PD cells, osteogenic differentiation of PD cells was investigated using alkaline phosphatase (ALP activity and calcium assay kits. The physical properties of the COL/DBP scaffolds were obviously different from COL scaffolds, irrespective of the size of DBP. In addition, PD cells cultured with COL scaffolds showed significantly higher cell adhesion and proliferation than those with COL/DBP scaffolds. In contrast, COL/DBP scaffolds exhibited greater osteoinductive potential than COL scaffolds. The PD cells with COL/DBP scaffolds possessed higher ALP activity than those with COL scaffolds. PD cells cultured with COL/DBP scaffolds with 250–500 mm particle size yielded the maximum calcium deposition. In conclusion, PD cells cultured on the scaffolds could exhibit osteoinductive potential. The composite scaffold of COL/DBP with 250–500 mm particle size could be considered a potential bone tissue engineering implant.

  7. The effects of strontium on skeletal development in zebrafish embryo.

    Science.gov (United States)

    Pasqualetti, Sara; Banfi, Giuseppe; Mariotti, Massimo

    2013-10-01

    The strontium is an alkaline earth metal found in nature as trace element. Chemically similar to calcium, it is known to be involved in the human bone mineral metabolism. The strontium ranelate has been approved in therapy as drug with both anti-resorption and anabolic effects on bone tissues. Since few data in vivo are available, we used Danio rerio as animal model to evaluate the effects of strontium on skeletal development. First, toxicity assay performed on zebrafish embryos estimated the LC50 around 6mM. Since several zebrafish bones are formed from cartilage mineralization, we evaluated whether strontium affects cartilage development during embryogenesis. Strontium does not perturb the development of the cartilage tissues before the endochondral osteogenesis takes place. About the mineralization process, we evidentiated an increase of vertebral mineralization respect to controls at lower strontium concentrations whereas higher concentration inhibited mineral deposition in dose dependent fashion. Our results evidentiated, in addition, that the calcium/strontium rate but not the absolute level of strontium modulates the mineralization process during embryonic osteogenesis. Zebrafish represents an excellent animal model to study the role of micronutrients in the development of the tissues/organs because the ions are not absorbed by intestine but assumed by skin diffusion. Copyright © 2013 Elsevier GmbH. All rights reserved.

  8. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects passed down ...

  9. Bone morphogenetic protein 2 signaling negatively modulates lymphatic development in vertebrate embryos

    DEFF Research Database (Denmark)

    Dunworth, William P; Cardona-Costa, Jose; Bozkulak, Esra Cagavi

    2014-01-01

    RATIONALE: The emergence of lymphatic endothelial cells (LECs) seems to be highly regulated during development. Although several factors that promote the differentiation of LECs in embryonic development have been identified, those that negatively regulate this process are largely unknown. OBJECTIVE...... signaling in zebrafish embryos and mouse embryonic stem cell-derived embryoid bodies substantially decrease the emergence of LECs. Mechanistically, BMP2 signaling induces expression of miR-31 and miR-181a in a SMAD-dependent mechanism, which in turn results in attenuated expression of prospero homeobox......: Our aim was to delineate the role of bone morphogenetic protein (BMP) 2 signaling in lymphatic development. METHODS AND RESULTS: BMP2 signaling negatively regulates the formation of LECs. Developing LECs lack any detectable BMP signaling activity in both zebrafish and mouse embryos, and excess BMP2...

  10. Development of Re-188-labeled radiopharmaceuticals for the treatment of metastatic bone pain

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, J. M.; Lee, S. E.; Lee, Y. J.; Kim, Y. J.; Hong, S. H.; Lee, Y. S.; Chang, Y. S.; Hong, M. K. [Seoul National Univ., Seoul (Korea)

    2000-04-01

    Bone pain is serious problem in end stage cancer patients. We labeled HEDP with Re-188. We found that the Re-188-HEDP accumulates in bone of normal mice and obtained bone-image of rat. A metastatic bone model was established in nude mice by inoculating prostatic cancer cells in thigh. we confirmed the growth of cancer cells in the metastatic region. Re-188-HEDP accumulated in the metastatic bone region when injected through the tail vein. With these results, we concluded that the Re-188-HEDP is a promising agent for the treatment of metastatic bone pain. 6 refs., 33 figs., 4 tabs. (Author)

  11. Development and Characterization of Novel Porous 3D Alginate-Cockle Shell Powder Nanobiocomposite Bone Scaffold

    Directory of Open Access Journals (Sweden)

    B. Hemabarathy Bharatham

    2014-01-01

    Full Text Available A novel porous three-dimensional bone scaffold was developed using a natural polymer (alginate/Alg in combination with a naturally obtained biomineral (nano cockle shell powder/nCP through lyophilization techniques. The scaffold was developed in varying composition mixture of Alg-nCP and characterized using various evaluation techniques as well as preliminary in vitro studies on MG63 human osteoblast cells. Morphological observations using SEM revealed variations in structures with the use of different Alg-nCP composition ratios. All the developed scaffolds showed a porous structure with pore sizes ideal for facilitating new bone growth; however, not all combination mixtures showed subsequent favorable characteristics to be used for biological applications. Scaffolds produced using the combination mixture of 40% Alg and 60% nCP produced significantly promising results in terms of mechanical strength, degradation rate, and increased cell proliferation rates making it potentially the optimum composition mixture of Alg-nCP with future application prospects.

  12. Influence of caffeine administered at 45 °C on bone tissue development

    Directory of Open Access Journals (Sweden)

    Marek Tomaszewski

    2014-11-01

    Full Text Available [b]introduction and objective[/b]. Caffeine is one of the world’s most commonly ingested alkaloids which easily permeates the placenta. The teratogenic and embryotoxic influence of large doses of caffeine has been established in many experimental studies on animals. The objective of this work was to assess the influence of caffeine, administered at 45 °C, on the development of the bone tissue of rats, with particular reference to elemental bone composition using an X-ray microprobe. [b]materials and methods[/b]. The research was conducted on white rats of the Wistar strain. The fertilized females were divided into two groups: an Experimental Group (Group E and a Control Group (Group C. The females in Group E were given caffeine orally (at 45 °C in 30 mg/day doses from the 8 [sup]th [/sup] to the 21 [sup]st[/sup] day of pregnancy. The females in Group C were given water at the same temperature. The fetuses were used to assess the growth and mineralization of the skeleton. A qualitative analysis of the morphology and mineralization of bones was conducted using the alcian-alizarin method. For calcium and potassium analysis, an X-ray microprobe was used. [b]results.[/b] By staining the skeleton using the alcian-alizarin method, changes in 52 of Group E fetuses were observed. The frequency of the development variants in the Group E rats was statistically higher, compared with Group C. [b]conclusions[/b]. Receiving caffeine at a higher temperature may result in different pharmacodynamics and significantly change tolerance to it. In Group E, a significant decrease in the calcium level, as well as an increase in the potassium level, was observed. The X-ray microprobe can be a perfect complement to the methods which enable determination of the mineralization of osseous tissue.

  13. Bone matrix calcification during embryonic and postembryonic rat calvarial development assessed by SEM-EDX spectroscopy, XRD, and FTIR spectroscopy.

    Science.gov (United States)

    Henmi, Akiko; Okata, Hiroshi; Anada, Takahisa; Yoshinari, Mariko; Mikami, Yasuto; Suzuki, Osamu; Sasano, Yasuyuki

    2016-01-01

    Bone mineral is constituted of biological hydroxyapatite crystals. In developing bone, the mineral crystal matures and the Ca/P ratio increases. However, how an increase in the Ca/P ratio is involved in maturation of the crystal is not known. The relationships among organic components and mineral changes are also unclear. The study was designed to investigate the process of calcification during rat calvarial bone development. Calcification was evaluated by analyzing the atomic distribution and concentration of Ca, P, and C with scanning electron microscopy (SEM)-energy-dispersive X-ray (EDX) spectroscopy and changes in the crystal structure with X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. Histological analysis showed that rat calvarial bone formation started around embryonic day 16. The areas of Ca and P expanded, matching the region of the developing bone matrix, whereas the area of C became localized around bone. X-ray diffraction and FTIR analysis showed that the amorphous-like structure of the minerals at embryonic day 16 gradually transformed into poorly crystalline hydroxyapatite, whereas the proportion of mineral to protein increased until postnatal week 6. FTIR analysis also showed that crystallization of hydroxyapatite started around embryonic day 20, by which time SEM-EDX spectroscopy showed that the Ca/P ratio had increased and the C/Ca and C/P ratios had decreased significantly. The study suggests that the Ca/P molar ratio increases and the proportion of organic components such as proteins of the bone matrix decreases during the early stage of calcification, whereas crystal maturation continues throughout embryonic and postembryonic bone development.

  14. Vertical bone growth following autotransplantation of the developing maxillary third molar to replace a retained mandibular permanent molar: a case report.

    Science.gov (United States)

    Plakwicz, Paweł; Czochrowska, Ewa Monika; Milczarek, Anna; Zadurska, Malgorzata

    2014-01-01

    A retained permanent mandibular first molar caused arrested development and a defect of the alveolar bone in a 16-year-old girl. Extraction of the ankylosed tooth was immediately followed by autotransplantation of the developing maxillary third molar. At the 3-year follow-up examination the interproximal bone level at the autotransplanted molar was equal to that of the neighboring teeth. Cone beam computed tomography showed bone at the labial aspect of the transplant. The eruption of the autotransplanted tooth stimulated vertical alveolar bone development and repaired the bone defect. Additionally, there was closure of the posterior open bite that was initially present at the ankylosed molar site.

  15. The influence of genetic variability and proinflammatory status on the development of bone disease in patients with Gaucher disease.

    Directory of Open Access Journals (Sweden)

    Javier Gervas-Arruga

    genotypes. The data suggest that patients with GD1 have increased susceptibility to developing bone disease owing to the coexistence of genetic variants, and that genetic background in GD1 is fundamental to regulate the impact of proinflammatory status on the development of bone disease.

  16. The influence of genetic variability and proinflammatory status on the development of bone disease in patients with Gaucher disease.

    Science.gov (United States)

    Gervas-Arruga, Javier; Cebolla, Jorge Javier; de Blas, Ignacio; Roca, Mercedes; Pocovi, Miguel; Giraldo, Pilar

    2015-01-01

    data suggest that patients with GD1 have increased susceptibility to developing bone disease owing to the coexistence of genetic variants, and that genetic background in GD1 is fundamental to regulate the impact of proinflammatory status on the development of bone disease.

  17. Development of novel aligned nanofibrous composite membranes for guided bone regeneration.

    Science.gov (United States)

    Kharaziha, M; Fathi, M H; Edris, H

    2013-08-01

    The ability to mimic the structure of the natural extracellular matrix is a successful key for guided bone regeneration (GBR). For the regeneration of highly organized structures such as heart and bone, aligned fibrous membranes could provide anisotropic mechanical and biological properties which are adequate topographic guidance to cells. Here, novel nanofibrous membranes were developed through electrospinning of PCL-forsterite nanopowder. The membranes were characterized with regard to structural and mechanical properties, degradation, bioactivity and cellular interactive responses. Results showed that optimized nanofibrous composite membrane with significantly improved tensile strength and elastic modules was achieved through addition of 10 wt% forsterite nanopowder into PCL membrane. Addition of forsterite nanopowder decreased the average fiber diameters from 872±361 nm (pure PCL membrane) to 258±159 nm (PCL-10 wt% forsterite membrane). At higher forsterite contents (>10 wt%), the agglomeration of nanoparticles was observed which resulted in reduced mechanical properties. Aligned fibrous membranes revealed smaller fiber sizes and significantly enhanced and anisotropic mechanical properties compared to random ones suggesting that fiber alignment has a profound effect on the structural properties of membranes. Forsterite nanopowder increased the degradation rate showing enhanced hydrophilicity and induced apatite formation in simulated body fluid. Furthermore, composite nanofibrous membranes possessed significantly improved cellular responses in terms of attachment, proliferation and mineralization of pre-osteoblasts compared to PCL membrane. Thus, the currently developed nanofibrous composite membranes embedded in forsterite nanopowder expected to be attractive in GBR membrane applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. The Role of Ellis-Van Creveld 2(EVC2) in Mice During Cranial Bone Development.

    Science.gov (United States)

    Kwon, Edwin K; Louie, Ke'ale; Kulkarni, Anshul; Yatabe, Marilia; Ruellas, Antonio Carlos de Oliveira; Snider, Taylor N; Mochida, Yoshiyuki; Cevidanes, Lucia H S; Mishina, Yuji; Zhang, Honghao

    2017-09-26

    EvC syndrome is a type of autosomal-recessive chondrodysplasia. Previous case studies in patients suggest abnormal craniofacial development, in addition to dwarfism and tooth abnormalities. To investigate how craniofacial development is affected in EvC patients, surface models were generated from micro-CT scans of control mice, Evc2 global mutant mice and Evc2 neural crest-specific mutant mice. The anatomic landmarks were placed on the surface model to assess the morphological abnormalities in the Evc2 mutants. Through analyzing the linear and angular measurements between landmarks, we identified a smaller overall skull, shorter nasal bone, shorter frontal bone, and shorter cranial base in the Evc2 global mutants. By comparing neural crest-specific Evc2 mutants with control mice, we demonstrated that the abnormalities within the mid-facial regions are not accounted for by the Evc2 mutation within these regions. Additionally, we also identified disproportionate length to width ratios in the Evc2 mutants at all levels from anterior to posterior of the skull. Overall, this study demonstrates a more comprehensive analysis on the craniofacial morphological abnormalities in EvC syndrome and provides the developmental insight to appreciate the impact of Evc2 mutation within the neural crest cells on multiple aspects of skull deformities. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  19. The effect of 1,25-dihydroxyvitamin D3 on MSX2 gene expression during tooth and alveolar bone development

    Directory of Open Access Journals (Sweden)

    Intan Ruspita

    2015-03-01

    Full Text Available Background: 1,25-dihydroxyvitamin D3 has been proven to be able to control the formation and biomineralization of tissue through a regulatory gene. A previous research even showed that a cell responsible for the formation of the enamel (ameloblasts, dentin (odontoblasts and bone (osteoblasts, osteoclasts was the target of  1,25-dihydroxivitamin D3. Purpose: This research was aimed to determine the role of 1,25- dihydroxyvitamin D3 in vivo in the development of teeth and alveolar bone tissue by analyzing MSX2 gene expression as a gene marker responsible for the growth and development of enamel, dentin, tooth root and alveolar bone. Methods: Samples used for RT-PCR analysis were total RNA of insisivus teeth and alveolar bone derived from mice. RT-PCR analysis was conducted by using primer-specific gene, MSX2. Primer gene, GAPDH, was also used as an internal control. Five hundred nanograms of total RNA were used as a template for PCR. Semi quantitative results of PCR were quantified by using ImageJ software. Results: RT-PCR analysis showed that the expression level of MSX2 was enhanced in the samples of teeth and alveolar bone treated with 1,25 dihydroxyvitamin D3. The increasing of MSX2 expression significantly occurred in alveolar bone samples. Conclusion: It can be concluded that 1,25 dihydroxyvitamin D3 could enhance MSX2 expression as a marker of the development of teeth and alveolar bone tissue. Therefore, 1,25-D3 dihydroxyvitamin is expected to be used as an agent to help the regeneration of teeth and bone tissue.

  20. Development of a strain rate dependent material model of human cortical bone for computer-aided reconstruction of injury mechanisms.

    Science.gov (United States)

    Asgharpour, Zahra; Zioupos, Peter; Graw, Matthias; Peldschus, Steffen

    2014-03-01

    Computer-aided methods such as finite-element simulation offer a great potential in the forensic reconstruction of injury mechanisms. Numerous studies have been performed on understanding and analysing the mechanical properties of bone and the mechanism of its fracture. Determination of the mechanical properties of bones is made on the same basis used for other structural materials. The mechanical behaviour of bones is affected by the mechanical properties of the bone material, the geometry, the loading direction and mode and of course the loading rate. Strain rate dependency of mechanical properties of cortical bone has been well demonstrated in literature studies, but as many of these were performed on animal bones and at non-physiological strain rates it is questionable how these will apply in the human situations. High strain-rates dominate in a lot of forensic applications in automotive crashes and assault scenarios. There is an overwhelming need to a model which can describe the complex behaviour of bone at lower strain rates as well as higher ones. Some attempts have been made to model the viscoelastic and viscoplastic properties of the bone at high strain rates using constitutive mathematical models with little demonstrated success. The main objective of the present study is to model the rate dependent behaviour of the bones based on experimental data. An isotropic material model of human cortical bone with strain rate dependency effects is implemented using the LS-DYNA material library. We employed a human finite element model called THUMS (Total Human Model for Safety), developed by Toyota R&D Labs and the Wayne State University, USA. The finite element model of the human femur is extracted from the THUMS model. Different methods have been employed to develop a strain rate dependent material model for the femur bone. Results of one the recent experimental studies on human femur have been employed to obtain the numerical model for cortical femur. A

  1. Stem cell property of postmigratory cranial neural crest cells and their utility in alveolar bone regeneration and tooth development.

    Science.gov (United States)

    Chung, Il-Hyuk; Yamaza, Takayoshi; Zhao, Hu; Choung, Pill-Hoon; Shi, Songtao; Chai, Yang

    2009-04-01

    The vertebrate neural crest is a multipotent cell population that gives rise to a variety of different cell types. We have discovered that postmigratory cranial neural crest cells (CNCCs) maintain mesenchymal stem cell characteristics and show potential utility for the regeneration of craniofacial structures. We are able to induce the osteogenic differentiation of postmigratory CNCCs, and this differentiation is regulated by bone morphogenetic protein (BMP) and transforming growth factor-beta signaling pathways. After transplantation into a host animal, postmigratory CNCCs form bone matrix. CNCC-formed bones are distinct from bones regenerated by bone marrow mesenchymal stem cells. In addition, CNCCs support tooth germ survival via BMP signaling in our CNCC-tooth germ cotransplantation system. Thus, we conclude that postmigratory CNCCs preserve stem cell features, contribute to craniofacial bone formation, and play a fundamental role in supporting tooth organ development. These findings reveal a novel function for postmigratory CNCCs in organ development, and demonstrate the utility of these CNCCs in regenerating craniofacial structures.

  2. Scleraxis-Lineage Cells Contribute to Ectopic Bone Formation in Muscle and Tendon.

    Science.gov (United States)

    Agarwal, Shailesh; Loder, Shawn J; Cholok, David; Peterson, Joshua; Li, John; Breuler, Christopher; Cameron Brownley, R; Hsin Sung, Hsiao; Chung, Michael T; Kamiya, Nobuhiro; Li, Shuli; Zhao, Bin; Kaartinen, Vesa; Davis, Thomas A; Qureshi, Ammar T; Schipani, Ernestina; Mishina, Yuji; Levi, Benjamin

    2017-03-01

    The pathologic development of heterotopic ossification (HO) is well described in patients with extensive trauma or with hyperactivating mutations of the bone morphogenetic protein (BMP) receptor ACVR1. However, identification of progenitor cells contributing to this process remains elusive. Here we show that connective tissue cells contribute to a substantial amount of HO anlagen caused by trauma using postnatal, tamoxifen-inducible, scleraxis-lineage restricted reporter mice (Scx-creERT2/tdTomato fl/fl ). When the scleraxis-lineage is restricted specifically to adults prior to injury marked cells contribute to each stage of the developing HO anlagen and coexpress markers of endochondral ossification (Osterix, SOX9). Furthermore, these adult preinjury restricted cells coexpressed mesenchymal stem cell markers including PDGFRα, Sca1, and S100A4 in HO. When constitutively active ACVR1 (caACVR1) was expressed in scx-cre cells in the absence of injury (Scx-cre/caACVR1 fl/fl ), tendons and joints formed HO. Postnatal lineage-restricted, tamoxifen-inducible caACVR1 expression (Scx-creERT2/caACVR1 fl/fl ) was sufficient to form HO after directed cardiotoxin-induced muscle injury. These findings suggest that cells expressing scleraxis within muscle or tendon contribute to HO in the setting of both trauma or hyperactive BMP receptor (e.g., caACVR1) activity. Stem Cells 2017;35:705-710. © 2016 AlphaMed Press.

  3. [Bizarre parosteal osteochondromatous proliferation of the metatarsal bone].

    Science.gov (United States)

    Hartog, C; Centmaier-Molnar, V; Patzwahl, R; Pfofe, D; Wiewiorski, M

    2016-10-01

    A bizarre parosteal osteochondromatous proliferation (BPOP), also known as a Nora lesion, is a rare benign bone formation. It emanates mainly from the intact cortex of the metaphysis of short tubular bones (hands or feet). Conventional radiographs should be complemented using cross-sectional imaging modalities (CT/MRI). In the absence of symptoms a non-operative regime with radiological and clinical controls is possible. If symptomatic, excision biopsy is the treatment of choice, though a high recurrence rate has been reported. Histopathological examination confirms the diagnosis and typically shows an endochondral ossification zone and an unusually mineralized cartilaginous matrix referred to as "blue bone".

  4. The longitudinal effects of physical activity and dietary calcium on bone mass accrual across stages of pubertal development.

    Science.gov (United States)

    Lappe, Joan M; Watson, Patrice; Gilsanz, Vicente; Hangartner, Thomas; Kalkwarf, Heidi J; Oberfield, Sharon; Shepherd, John; Winer, Karen K; Zemel, Babette

    2015-01-01

    Childhood and adolescence are critical periods of bone mineral content (BMC) accrual that may have long-term consequences for osteoporosis in adulthood. Adequate dietary calcium intake and weight-bearing physical activity are important for maximizing BMC accrual. However, the relative effects of physical activity and dietary calcium on BMC accrual throughout the continuum of pubertal development in childhood remains unclear. The purpose of this study was to determine the effects of self-reported dietary calcium intake and weight-bearing physical activity on bone mass accrual across the five stages of pubertal development in a large, diverse cohort of US children and adolescents. The Bone Mineral Density in Childhood study was a mixed longitudinal study with 7393 observations on 1743 subjects. Annually, we measured BMC by dual-energy X-ray absorptiometry (DXA), physical activity and calcium intake by questionnaire, and pubertal development (Tanner stage) by examination for up to 7 years. Mixed-effects regression models were used to assess physical activity and calcium intake effects on BMC accrual at each Tanner stage. We found that self-reported weight-bearing physical activity contributed to significantly greater BMC accrual in both sexes and racial subgroups (black and nonblack). In nonblack males, the magnitude of the activity effect on total body BMC accrual varied among Tanner stages after adjustment for calcium intake; the greatest difference between high- and low-activity boys was in Tanner stage 3. Calcium intake had a significant effect on bone accrual only in nonblack girls. This effect was not significantly different among Tanner stages. Our findings do not support differential effects of physical activity or calcium intake on bone mass accrual according to maturational stage. The study demonstrated significant longitudinal effects of weight-bearing physical activity on bone mass accrual through all stages of pubertal development. © 2014 American

  5. Impaired meningeal development in association with apical expansion of calvarial bone osteogenesis in the Foxc1 mutant

    Science.gov (United States)

    Vivatbutsiri, Philaiporn; Ichinose, Shizuko; Hytönen, Marjo; Sainio, Kirsi; Eto, Kazuhiro; Iseki, Sachiko

    2008-01-01

    Loss of function of the mouse forkhead/winged helix transcription factor Foxc1 induces congenital hydrocephalus and impaired skull bone development due to failure of apical expansion of the bone. In this study we investigated meningeal development in the congenital hydrocephalus (ch) mouse with spontaneous loss of function mutant of Foxc1, around the period of initiation of skull bone apical expansion. In situ hybridization of Runx2 revealed active apical expansion of the frontal bone begins between embryonic day 13.5 and embryonic day 14.5 in the wild type, whereas expansion was inhibited in the mutant. Ultrastructural analysis revealed that three layers of the meninges begin to develop at E13.5 in the basolateral site of the head and subsequently progress to the apex in wild type. In ch homozygotes, although three layers were recognized at first at the basolateral site, cell morphology and structure of the layers became abnormal except for the pia mater, and arachnoidal and dural cells never differentiated in the apex. We identified meningeal markers for each layer and found that their expression was down-regulated in the mutant arachnoid and dura maters. These results suggest that there is a close association between meningeal development and the apical growth of the skull bones. PMID:18422524

  6. Fetal development of ligaments around the tarsal bones with special reference to contribution of muscles.

    Science.gov (United States)

    Uchiyama, Eiichi; Kim, Ji Hyun; Abe, Hiroshi; Cho, Baik Hwan; Rodríguez-Vázquez, Jose Francisco; Murakami, Gen

    2014-04-01

    Through a histological examination of eight mid-term human fetuses (10-15 weeks) and seven late-stage fetuses (30-34 weeks), we attempted to determine how and when fetal ligaments around the tarsal bones form the regular arrangement seen in adults. Ligaments along the dorsal aspect of the tarsal bones developed early as an elongation of the perichondrium, in contrast to the late development of the plantar-sided ligaments. In contrast, a distal elongation of the tibialis posterior tendon was a limited plantar ligament in the early stage; finally, it extended from the navicular, ran obliquely to cross the dorsal side of the fibularis longus tendon, and inserted to the lateral cuneiform and fourth metatarsal. In the late stage, the adductor hallucis muscle origin provided multiple ligamentous structures along the cuneiforms and metatarsals. The tarsal sinus contained multiple fibrous bundles (possibly, the putative interosseous talocalcanean ligaments) that were derived from (1) insertion tendons of the extensor digitorus brevis muscle and (2) the fibrous sheath of the extensor digitorus longus tendon. The aponeurotic origin of the quadratus plantae muscle seemed to contribute to formation of the long plantar ligament. Therefore, tarsal ligaments appeared likely to develop from the long tendons, their fibrous sheaths and aponeuroses and intramuscular tendons of the proper foot muscles. Under in utero conditions with little or no stress from the plantar side of the foot, the muscle-associated connective tissue seems to play a crucial role in providing a regular arrangement of the ligaments in accordance with tensile stress from muscle contraction. Copyright © 2013 Wiley Periodicals, Inc.

  7. A novel approach for studying the temporal modulation of embryonic skeletal development using organotypic bone cultures and microcomputed tomography.

    Science.gov (United States)

    Kanczler, Janos M; Smith, Emma L; Roberts, Carol A; Oreffo, Richard O C

    2012-10-01

    Understanding the structural development of embryonic bone in a three dimensional framework is fundamental to developing new strategies for the recapitulation of bone tissue in latter life. We present an innovative combined approach of an organotypic embryonic femur culture model, microcomputed tomography (μCT) and immunohistochemistry to examine the development and modulation of the three dimensional structures of the developing embryonic femur. Isolated embryonic chick femurs were organotypic (air/liquid interface) cultured for 10 days in either basal, chondrogenic, or osteogenic supplemented culture conditions. The growth development and modulating effects of basal, chondrogenic, or osteogenic culture media of the embryonic chick femurs was investigated using μCT, immunohistochemistry, and histology. The growth and development of noncultured embryonic chick femur stages E10, E11, E12, E13, E15, and E17 were very closely correlated with increased morphometric indices of bone formation as determined by μCT. After 10 days in the organotpyic culture set up, the early aged femurs (E10 and E11) demonstrated a dramatic response to the chondrogenic or osteogenic culture conditions compared to the basal cultured femurs as determined by a change in μCT morphometric indices and modified expression of chondrogenic and osteogenic markers. Although the later aged femurs (E12 and E13) increased in size and structure after 10 days organotpypic culture, the effects of the osteogenic and chondrogenic organotypic cultures on these femurs were not significantly altered compared to basal conditions. We have demonstrated that the embryonic chick femur organotpyic culture model combined with the μCT and immunohistochemical analysis can provide an integral methodology for investigating the modulation of bone development in an ex vivo culture setting. Hence, these interdisciplinary techniques of μCT and whole organ bone cultures will enable us to delineate some of the temporal

  8. [Animal experimentation of reimplantation of hypertonic saline-induced devitalized bone].

    Science.gov (United States)

    Peng, Chang-liang; Yang, Yi; Sun, Xin; Guo, Wei

    2012-12-18

    To observe the healing process and the change of biomechanical properties of hypertonic saline-induced devitalized bone segment, so as to provide fundamental theory for clinical treatment. A model of New Zealand rabbit ulnar segments devitalized by hypertonic saline was established and then reimplanted in situ. The ulnar specimens were taken for examination of X-rays, light microscope and three-point-bend test at the end of 3, 6, 12, and 24 weeks postoperatively. The devitalized bone healed at the end of 12 weeks in the X-ray film. The histological examination showed that osteoblast multiplied and secreted osteoid gradually. The maximal breaking load of the devitalized bone continuously increased and reached the top at the end of 24 weeks [control group (206.25±16.64) N vs. devitalized group (196.88±8.24) N, P>0.05]. The devitalized bone healed through intramembranous and endochondral ossification, and the endochondral ossification predominated; the biomechanical strength of devitalized bone continually increased as time lasted.

  9. Development and biological evaluation of {sup 90}Y-BPAMD as a novel bone seeking therapeutic agent

    Energy Technology Data Exchange (ETDEWEB)

    Rabiei, Ali; Shamsaei, Mojtaba [Amir Kabir University of Technology, Tehran (Iran, Islamic Republic of). Energy Engineering and Physics Dept.; Yousefnia, Hassan; Zolghadri, Samaneh; Jalilian, Amir Reza [Nuclear Science and Technology Research Institute (NSTRI), Tehran (Iran, Islamic Republic of); Enayati, Razieh [Islamic Azad Univ. (IAU), Tehran (Iran, Islamic Republic of). Faculty of Engineering

    2016-07-01

    Nowadays, the bone-seeking radiopharmaceuticals play an important role in the treatment of the bone-related pathologies. Whereas various phosphonate ligands have already been identified, a DOTA-based bisphosphonate, 4-{[(bis(phosphonomethyl))carbamoyl]methyl}-7,10-bis(carboxymethyl) -1,4,7,10-tetraazacyclododec-1-yl (BPAMD) with better characteristics has recently been synthesized. In this study, {sup 90}Y-BPAMD was developed with radiochemical purity >98% and the specific activity of 3.52 TBq/mmol in the optimized conditions as a new bone-seeking therapeutic agent. The complex demonstrated significant stability at room temperature and in human serum even after 48 h. At even low amount of hydroxyapatite (5 mg), more than 90% binding to hydroxyapatite was observed. Biodistribution studies after injection of the complex into the Syrian rats showed major accumulation of the labelled compound in the bone tissue and an insignificant uptake in the other organs all the times after injection. Generally, {sup 90}Y-BPAMD demonstrated interesting characteristics compared to the other {sup 90}Y bone-seeking agents and even {sup 166}Ho-BPAMD, and can be considered as a new bone-seeking candidate for therapeutic applications.

  10. Bone marrow precursors of nonobese diabetic mice develop into defective macrophage-like dendritic cells in vitro

    NARCIS (Netherlands)

    T. Nikolic (Tatjana); M. Bunk; H.A. Drexhage (Hemmo); P.J. Leenen (Pieter)

    2004-01-01

    textabstractThe NOD mouse spontaneously develops autoimmune diabetes. Dendritic cells (DC) play a crucial role in the autoimmune response. Previous studies have reported a defective DC generation in vitro from the NOD mouse bone marrow (BM), but a deviated development of myeloid

  11. The Effects of Elk Velvet Antler Dietary Supplementation on Physical Growth and Bone Development in Growing Rats

    Directory of Open Access Journals (Sweden)

    Jiongran Chen

    2015-01-01

    Full Text Available Elk velvet antler (EVA has been used in traditional Oriental medicine for centuries to promote general health; however, little evidence for its effect on bone development is available. We investigated the effects of lifelong exposure of Wistar rats to a diet containing 10% EVA on physical growth and bone development. Measurements included weekly body weights, blood chemistry and kidney and testis/ovary indices (sacrificed at 5, 9, or 16 weeks of age, and bone traits of the femur bones by peripheral quantitative computed tomography (pQCT. Mean body weights were higher in the EVA group at 4–8 weeks in males and at 5 weeks of age in females. The kidney indices were greater in EVA dietary supplemented male rats at 5 and 16 weeks of age, in females at 16 weeks of age, and testis/ovary indices at 5 weeks of age. The femoral length was increased in both males and females at 5 weeks, and several pQCT-measured parameters had increased in EVA males and females. The activity of alkaline phosphatase (ALP increased in EVA group while the content of calcium and phosphorus did not differ among groups. Our results seem to support a role for dietary supplementation of EVA on growth and bone development in this model.

  12. Development of the lateral line canal system through a bone remodeling process in zebrafish.

    Science.gov (United States)

    Wada, Hironori; Iwasaki, Miki; Kawakami, Koichi

    2014-08-01

    The lateral line system of teleost fish is composed of mechanosensory receptors (neuromasts), comprising superficial receptors and others embedded in canals running under the skin. Canal diameter and size of the canal neuromasts are correlated with increasing body size, thus providing a very simple system to investigate mechanisms underlying the coordination between organ growth and body size. Here, we examine the development of the trunk lateral line canal system in zebrafish. We demonstrated that trunk canals originate from scales through a bone remodeling process, which we suggest is essential for the normal growth of canals and canal neuromasts. Moreover, we found that lateral line cells are required for the formation of canals, suggesting the existence of mutual interactions between the sensory system and surrounding connective tissues. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Bone marrow transplantation in patients with storage diseases: a developing country experience

    Directory of Open Access Journals (Sweden)

    Lange Marcos C.

    2006-01-01

    Full Text Available Bone marrow transplantation (BMT is a therapeutic option for patients with genetic storage diseases. Between 1979 and 2002, eight patients, four females and four males (1 to 13 years old were submitted to this procedure in our center. Six patients had mucopolysaccharidosis (MPS I in 3; MPS III in one and MPS VI in 2, one had adrenoleukodystrophy (ALD and one had Gaucher disease. Five patients had related and three unrelated BMT donor. Three patients developed graft versus host disease (two MPS I and one MPS VI and died between 37 and 151 days after transplantation. Five patients survived 4 to 16 years after transplantation. Three patients improved (one MPS I; one MPS VI and the Gaucher disease patient, one patient had no disease progression (ALD and in one patient this procedure did not change the natural course of the disease (MPS III.

  14. Development of Magnesium and Siloxane-containing Vaterite and its Composite Materials for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Shinya eYamada

    2015-12-01

    Full Text Available Development of novel biomaterials with Mg2+, Ca2+ and silicate ions releasability for bone regeneration is now in progress. Several inorganic ions have been reported to stimulate bone-forming cells. We featured Ca2+, silicate and especially Mg2+ ions as growth factors for osteoblasts. Various biomaterials, such as ceramic powders and organic-inorganic composites, releasing the ions have been developed and investigated in their cytocompatibilities in our previous work. Through the investigation, providing the three ions was found to be effective to activate osteogenic cells. Mg and siloxane-containing vaterite (MgSiV was prepared by a carbonation process as an inorganic particles, which can provide simultaneously releasing ability of Ca2+, silicate and Mg2+ ions to biodegradable polymers. Poly(L-lactic acid (PLLA- and bioactive PLLA-based composites containing vaterite coatings were discussed on their degradability and cytocompatibility using a metallic Mg substrate as Mg2+ ion source. PLLA/SiV composite film, which has a releasability of silicate ions besides Ca2+ ion, was coated on a pure Mg substrate to be compared with the PLLA/V coating. The degradability and releasability of inorganic ions were morphologically and quantitatively monitored in a cell culture medium. The bonding strength between the coatings and Mg substrates was one of the key factors to control Mg2+ ion release from the substrates. The cell culture tests were conducted using mouse osteoblast-like cells (MC3T3-E1 cells; cellular morphology, proliferation and differentiation on the materials were evaluated. The PLLA/V and PLLA/SiV coatings on Mg substrates were found to enhance the proliferation; especially the PLLA/SiV coating possessed a higher ability of inducing the osteogenic differentiation of the cells.

  15. Runx2-I isoform contributes to fetal bone formation even in the absence of specific N-terminal amino acids.

    Directory of Open Access Journals (Sweden)

    Hideaki Okura

    Full Text Available The Runt-related transcription factor 2 (Runx2 gene encodes the transcription factor Runx2, which is the master regulator of osteoblast development; insufficiency of this protein causes disorders of bone development such as cleidocranial dysplasia. Runx2 has two isoforms, Runx2-II and Runx2-I, and production of each isoform is controlled by a unique promoter: a distal promoter (P1 and a proximal promoter (P2, respectively. Although several studies have focused on differences and similarities between the two Runx2 isoforms, their individual roles in bone formation have not yet been determined conclusively, partly because a Runx2-I-targeted mouse model is not available. In this study, we established a novel Runx2-manipulated mouse model in which the first ATG of Runx2-I was replaced with TGA (a stop codon, and a neomycin-resistant gene (neo cassette was inserted at the first intron of Runx2-I. Homozygous Runx2-Ineo/neo mice showed severely reduced expression of Runx2-I, whereas Runx2-II expression was largely retained. Runx2-Ineo/neo mice showed neonatal lethality, and in these mice, intramembranous ossification was more severely defective than endochondral ossification, presumably because of the greater involvement of Runx2-I, compared with that of Runx2-II in intramembranous ossification. Interestingly, the depletion of neo rescued the above-described phenotypes, indicating that the isoform-specific N-terminal region of Runx2-I is not functionally essential for bone development. Taken together, our results provide a novel clue leading to a better understanding of the roles of Runx2 isoforms in osteoblast development.

  16. Clinical characteristics and risk factors for developing bone metastases in patients with breast cancer

    OpenAIRE

    Chen, Wen-Zhao; Shen, Jun-Feng; Zhou, Yang; Xuan-yin CHEN; Liu, Jia-Ming; Liu, Zhi-Li

    2017-01-01

    The risk factors for predicting bone metastases in patients with breast cancer are still controversial. Here, a total of 2133 patients with breast cancer, including 327 with bone metastases (15.33%) and 1806 without bone metastases (84.67%) were retrospective reviewed from January 2005 to December 2015. The spine was found to be the most common site for bone metastases, followed by ribs (57.5%), pelvis (54.1%) and sternum (44.3%). The results indicated that axillary lymph node metastases and ...

  17. Defective enamel and bone development in sodium-dependent citrate transporter (NaCT Slc13a5 deficient mice.

    Directory of Open Access Journals (Sweden)

    Armando R Irizarry

    Full Text Available There has been growing recognition of the essential roles of citrate in biomechanical properties of mineralized tissues, including teeth and bone. However, the sources of citrate in these tissues have not been well defined, and the contribution of citrate to the regulation of odontogenesis and osteogenesis has not been examined. Here, tooth and bone phenotypes were examined in sodium-dependent citrate transporter (NaCT Slc13a5 deficient C57BL/6 mice at 13 and 32 weeks of age. Slc13a5 deficiency led to defective tooth development, characterized by absence of mature enamel, formation of aberrant enamel matrix, and dysplasia and hyperplasia of the enamel organ epithelium that progressed with age. These abnormalities were associated with fragile teeth with a possible predisposition to tooth abscesses. The lack of mature enamel was consistent with amelogenesis imperfecta. Furthermore, Slc13a5 deficiency led to decreased bone mineral density and impaired bone formation in 13-week-old mice but not in older mice. The findings revealed the potentially important role of citrate and Slc13a5 in the development and function of teeth and bone.

  18. Organization and Development of Bone Marrow Donation and Transplantation in Poland.

    Science.gov (United States)

    Filipiak, Jagoda; Dudkiewicz, Małgorzata; Czerwiński, Jarosław; Kosmala, Karolina; Łęczycka, Anna; Malanowski, Piotr; Żalikowska-Hołoweńko, Jolanta; Małkowski, Piotr; Danielewicz, Roman

    2015-10-01

    This paper describes bone marrow donation and transplantation in Poland in terms of its history, current state, and information on the quality control system. Based on data gathered from the informatics systems of the Polish Central Unrelated Potential Bone Marrow Donor and Cord Blood Registry and the Polish transplant registries, as well as World Marrow Donor Association statistics, we performed an overview study to collect and compare numbers on hematopoietic stem cells donations and transplantations in Poland in the years 2010-2014. In the last 5 years, the number of registered potential hematopoietic stem cells donors in Poland increased by more than 4 times, from about 146,000 to over 750,000. During the same period, the number of patients qualified to hematopoietic stem cells transplantation from unrelated donor increased from 557 in 2010 to 817 in 2014. We observed a striking change in the percentage of transplantations performed in Polish centers using material collected from national donors--from 24% to 60%. This shift was also evident in the number of search procedures closed with acceptation of Polish donors--from 27% in 2010 to 58% in 2014. Another consequence of Polish registry growth is the increasing number of donations from Polish donors for international patients. Between 2010 and 2014, the percent of donation for non-national patient increased from 33% to 76%, placing Poland in 6th place in the ranking of the HSC "exporters" worldwide. Growth of transplantation rates involves standardization process, which is a natural way of development for national organizations in the field of HSCT because of its international character.

  19. Bone morphogenetic protein-2 gene controls tooth root development in coordination with formation of the periodontium.

    Science.gov (United States)

    Rakian, Audrey; Yang, Wu-Chen; Gluhak-Heinrich, Jelica; Cui, Yong; Harris, Marie A; Villarreal, Demitri; Feng, Jerry Q; Macdougall, Mary; Harris, Stephen E

    2013-06-01

    Formation of the periodontium begins following onset of tooth-root formation in a coordinated manner after birth. Dental follicle progenitor cells are thought to form the cementum, alveolar bone and Sharpey's fibers of the periodontal ligament (PDL). However, little is known about the regulatory morphogens that control differentiation and function of these progenitor cells, as well as the progenitor cells involved in crown and root formation. We investigated the role of bone morphogenetic protein-2 (Bmp2) in these processes by the conditional removal of the Bmp2 gene using the Sp7-Cre-EGFP mouse model. Sp7-Cre-EGFP first becomes active at E18 in the first molar, with robust Cre activity at postnatal day 0 (P0), followed by Cre activity in the second molar, which occurs after P0. There is robust Cre activity in the periodontium and third molars by 2 weeks of age. When the Bmp2 gene is removed from Sp7(+) (Osterix(+)) cells, major defects are noted in root, cellular cementum and periodontium formation. First, there are major cell autonomous defects in root-odontoblast terminal differentiation. Second, there are major alterations in formation of the PDLs and cellular cementum, correlated with decreased nuclear factor IC (Nfic), periostin and α-SMA(+) cells. Third, there is a failure to produce vascular endothelial growth factor A (VEGF-A) in the periodontium and the pulp leading to decreased formation of the microvascular and associated candidate stem cells in the Bmp2-cKO(Sp7-Cre-EGFP). Fourth, ameloblast function and enamel formation are indirectly altered in the Bmp2-cKO(Sp7-Cre-EGFP). These data demonstrate that the Bmp2 gene has complex roles in postnatal tooth development and periodontium formation.

  20. Histomorphometric study of trabecular bone remodeling during condylar process fracture healing in the growing period: experimental study.

    Science.gov (United States)

    Yasuoka, T; Oka, N

    1991-09-01

    Trabecular bone remodeling during condylar fracture healing in the growing period was analyzed by histomorphometry with a synchronous system. Data from the study showed displacement of the fractured condyle was compensated by the changes in remodeling ascribed to the pubertal spurt of growth, and that such remodeling still continued even after clinical healing. The regional acceleratory phenomenon, evolved to potentiate tissue healing, was observed 1 week after induction of the fracture. Mesenchymal cells were presumably modulated into chondroblasts that promoted endochondral ossification. It was concluded that trabecular bone remodeling plays an important role in healing of condylar fractures during the growth period.

  1. Final Report for completed IPP Project:"Development of Plasma Ablation for Soft Tissue and Bone Surgery"

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Ian

    2009-09-01

    ArthroCare is a medical device company that develops, manufactures, and markets an advanced surgical tool, a plasma electro-surgical system for cutting and removing tissue. The hand-held electrical discharge device produces plasma in a biocompatible conductive fluid and tissue to which it is applied during surgery. Its products allow surgeons to operate with increased precision and accuracy, limiting damage to surrounding tissue thereby reducing pain and speeding recovery for the patient. In the past, the design of ArthfoCare's plasma wands has been an empirical undertaking. One goal of this R&D program was to put the phenomena involved on a sound scientific footing, allowing optimization of existing plasma based electro-surgery system technology, and the design and manufacture of new and improved kinds of scalpels, in particular for the surgical cutting of bone. Another important related goal of the program was to develop, through an experimental approach, new plasma wand approaches to the cutting ('shaving') of hard bone tissue. The goals of the CRADA were accomplished - computer models were used to predict important parameters of the plasma discharge and the bone environment, and several different approaches to bone-shaving were developed and demonstrated. The primary goal of the project was to develop and demonstrate an atmospheric-pressure plasma tool that is suitable for surgical use for shaving bone in humans. This goal was accomplished, in fact with several different alternative plasma approaches. High bone ablation speeds were measured. The use of probes ('plasma wand' - the surgical tool) with moving active electrodes was also explored, and there are advantages to this method. Another important feature is that the newly-exposed bone surface have only a very thin necrosis layer; this feature was demonstrated. This CRADA has greatly advanced our understanding of bone removal by atmospheric pressure plasmas in liquid, and puts Arthro

  2. Parallels between Nutrition and Physical Activity: Research Questions in Development of Peak Bone Mass

    Science.gov (United States)

    Weaver, Connie M.

    2015-01-01

    Lifestyle choices are attributed to 40% to 60% of adult peak bone mass. The National Osteoporosis Foundation (NOF) sought to update its 2000 consensus statement on peak bone mass and partnered with the American Society for Nutrition, which, in turn, charged a 9-member writing committee with using a systematic review approach to update the previous…

  3. Cortical bone development under the growth plate is regulated by mechanical load transfer.

    NARCIS (Netherlands)

    Tanck, E.J.M.; Hannink, G.J.; Ruimerman, R.; Buma, P.; Burger, E.H.; Huiskes, R.

    2006-01-01

    Longitudinal growth of long bones takes place at the growth plates. The growth plate produces new bone trabeculae, which are later resorbed or merged into the cortical shell. This process implies transition of trabecular metaphyseal sections into diaphyseal sections. We hypothesize that the

  4. LDL receptor-related protein 5 (LRP5) affects bone accrual and eye development

    NARCIS (Netherlands)

    Gong, Y.; Slee, R. B.; Fukai, N.; Rawadi, G.; Roman-Roman, S.; Reginato, A. M.; Wang, H.; Cundy, T.; Glorieux, F. H.; Lev, D.; Zacharin, M.; Oexle, K.; Marcelino, J.; Suwairi, W.; Heeger, S.; Sabatakos, G.; Apte, S.; Adkins, W. N.; Allgrove, J.; Arslan-Kirchner, M.; Batch, J. A.; Beighton, P.; Black, G. C.; Boles, R. G.; Boon, L. M.; Borrone, C.; Brunner, H. G.; Carle, G. F.; Dallapiccola, B.; de Paepe, A.; Floege, B.; Halfhide, M. L.; Hall, B.; Hennekam, R. C.; Hirose, T.; Jans, A.; Jüppner, H.; Kim, C. A.; Keppler-Noreuil, K.; Kohlschuetter, A.; Lacombe, D.; Lambert, M.; Lemyre, E.; Letteboer, T.; Peltonen, L.; Ramesar, R. S.; Romanengo, M.; Somer, H.; Steichen-Gersdorf, E.; Steinmann, B.; Sullivan, B.; Superti-Furga, A.; Swoboda, W.; van den Boogaard, M. J.; van Hul, W.; Vikkula, M.; Votruba, M.; Zabel, B.; Garcia, T.; Baron, R.; Olsen, B. R.; Warman, M. L.

    2001-01-01

    In humans, low peak bone mass is a significant risk factor for osteoporosis. We report that LRP5, encoding the low-density lipoprotein receptor-related protein 5, affects bone mass accrual during growth. Mutations in LRP5 cause the autosomal recessive disorder osteoporosis-pseudoglioma syndrome

  5. LDL receptor-related protein 5 (LRP5) affects bone accrual and eye development.

    NARCIS (Netherlands)

    Gong, Y.; Slee, R.B.; Fukai, N.; Rawadi, G.; Roman-Roman, S.; Reginato, A.M.; Wang, H.; Cundy, T.; Glorieux, F.H.; Lev, D.; Zacharin, M.; Oexle, K.; Marcelino, J.; Suwairi, W.; Heeger, S.; Sabatakos, G.; Apte, S.; Adkins, W.; Allgrove, J.; Arslan-Kirchner, M.; Batch, J.A.; Beighton, P.; Black, G.C.M.; Boles, R.G.; Boon, L.; Borrone, C.; Brunner, H.G.; Carle, G.F.; Dallapicola, B.; Paepe, A. de; Floege, B.; Halfhide, M.L.; Hall, B.D.; Hennekam, R.C.M.; Hirose, T.; Jans, A.; Juppner, H.; Kim, C.; Keppler-Noreuil, K.; Kohlschuetter, A.; Lacombe, D.; Lambert, M.; Lemyre, E.; Letteboer, T.; Peltonen, L.; Ramesar, R.S.; Romanengo, M.; Somer, H.; Steichen-Gersdorf, E.; Steinmann, B.; Sullivan, B.; Superti-Furga, A.; Swoboda, W.; Boogaard, M.J. van den; Hul, W. van; Vikkula, M.; Votruba, M.; Zabel, B.; Garcia, T.; Baron, R.; Olsen, B.R.; Warman, M.L.

    2001-01-01

    In humans, low peak bone mass is a significant risk factor for osteoporosis. We report that LRP5, encoding the low-density lipoprotein receptor-related protein 5, affects bone mass accrual during growth. Mutations in LRP5 cause the autosomal recessive disorder osteoporosis-pseudoglioma syndrome

  6. Changing bone marrow micro-environment during development of acute myeloid leukaemia in rats

    DEFF Research Database (Denmark)

    Mortensen, B T; Jensen, P O; Helledie, N

    1998-01-01

    of leukaemic cells increased to > 90% and the pH dropped to about 6.5. The fraction of NITP+ cells increased to > 80% in bone marrow and to about 40% in blood. The fraction of BrdUrd+ cells was unchanged in blood, but decreased in bone marrow both for normal cells (from about 20% to 5%), and for leukaemic...

  7. Mesenchymal Bone Morphogenetic Protein Signaling Is Required for Normal Pancreas Development

    Science.gov (United States)

    Ahnfelt-Rønne, Jonas; Ravassard, Philippe; Pardanaud-Glavieux, Corinne; Scharfmann, Raphaél; Serup, Palle

    2010-01-01

    OBJECTIVE Pancreas organogenesis is orchestrated by interactions between the epithelium and the mesenchyme, but these interactions are not completely understood. Here we investigated a role for bone morphogenetic protein (BMP) signaling within the pancreas mesenchyme and found it to be required for the normal development of the mesenchyme as well as for the pancreatic epithelium. RESEARCH DESIGN AND METHODS We analyzed active BMP signaling by immunostaining for phospho-Smad1,5,8 and tested whether pancreas development was affected by BMP inhibition after expression of Noggin and dominant negative BMP receptors in chicken and mouse pancreas. RESULTS Endogenous BMP signaling is confined to the mesenchyme in the early pancreas and inhibition of BMP signaling results in severe pancreatic hypoplasia with reduced epithelial branching. Notably, we also observed an excessive endocrine differentiation when mesenchymal BMP signaling is blocked, presumably secondary to defective mesenchyme to epithelium signaling. CONCLUSIONS We conclude that BMP signaling plays a previously unsuspected role in the mesenchyme, required for normal development of the mesenchyme as well as for the epithelium. PMID:20522595

  8. Identification of MicroRNA for Intermuscular Bone Development in Blunt Snout Bream (Megalobrama amblycephala

    Directory of Open Access Journals (Sweden)

    Shi-Ming Wan

    2015-05-01

    Full Text Available Intermuscular bone (IB, which occurs only in the myosepta of the lower teleosts, is attracting more attention of researchers due to its particular development and lack of genetic information. MicroRNAs (miRNAs are emerging as important regulators for biological processes. In the present study, miRNAs from IBs and connective tissue (CT; encircled IBs from six-month-old Megalobrama amblycephala were characterized and compared. The results revealed the sequences and expression levels of 218 known miRNA genes (belonging to 97 families. Of these miRNAs, 44 known microRNA sequences exhibited significant expression differences between the two libraries, with 24 and 20 differentially-expressed miRNAs exhibiting higher expression in the CT and IBs libraries, respectively. The expressions of 11 miRNAs were selected to validate in nine tissues. Among the high-ranked predicted gene targets, differentiation, cell cycle, metabolism, signal transduction and transcriptional regulation were implicated. The pathway analysis of differentially-expressed miRNAs indicated that they were abundantly involved in regulating the development and differentiation of IBs and CT. This study characterized the miRNA for IBs of teleosts for the first time, which provides an opportunity for further understanding of miRNA function in the regulation of IB development.

  9. Bone resorption deficiency affects tooth root development in RANKL mutant mice due to attenuated IGF-1 signaling in radicular odontoblasts.

    Science.gov (United States)

    Huang, Hong; Wang, Jue; Zhang, Yan; Zhu, Guochun; Li, Yi-Ping; Ping, Ji; Chen, Wei

    2017-12-29

    The tooth root is essential for normal tooth physiological function. Studies on mice with mutations or targeted gene deletions revealed that osteoclasts (OCs) play an important role in tooth root development. However, knowledge on the cellular and molecular mechanism underlying how OCs mediate root formation is limited. During bone formation, growth factors (e.g. Insulin-like growth factor-1, IGF-1) liberated from bone matrix by osteoclastic bone resorption stimulate osteoblast differentiation. Thus, we hypothesize that OC-osteoblast coupling may also apply to OC-odontoblast coupling; therefore OCs may have a direct impact on odontoblast differentiation through the release of growth factor(s) from bone matrix, and consequently regulate tooth root formation. To test this hypothesis, we used a receptor activator of NF-κB ligand (RANKL) knockout mouse model in which OC differentiation and function was entirely blocked. We found that molar root formation and tooth eruption were defective in RANKL-/- mice. Disrupted elongation and disorganization of Hertwig's epithelial root sheath (HERS) was observed in RANKL-/- mice. Reduced expression of nuclear factor I C (NFIC), osterix, and dentin sialoprotein, markers essential for radicular (root) odontogenic cell differentiation indicated that odontoblast differentiation was disrupted in RANKL deficient mice likely contributing to the defect in root formation. Moreover, down-regulation of IGF/AKT/mTOR activity in odontoblast indicated that IGF signaling transduction in odontoblasts of the mutant mice was impaired. Treating odontoblast cells in vitro with conditioned medium from RANKL-/- OCs cultured on bone slices resulted in inhibition of odontoblast differentiation. Moreover, depletion of IGF-1 in bone resorption-conditioned medium (BRCM) from wild-type (WT) OC significantly compromised the ability of WT osteoclastic BRCM to induce odontoblast differentiation while addition of IGF-1 into RANKL-/- osteoclastic BRCM rescued

  10. Adipose, bone and muscle tissues as new endocrine organs: role of reciprocal regulation for osteoporosis and obesity development.

    Science.gov (United States)

    Migliaccio, Silvia; Greco, Emanuela A; Wannenes, Francesca; Donini, Lorenzo M; Lenzi, Andrea

    2014-01-01

    The belief that obesity is protective against osteoporosis has recently been revised. In fact, the latest epidemiologic and clinical studies show that a high level of fat mass, but also reduced muscle mass, might be a risk factor for osteoporosis and fragility fractures. Furthermore, increasing evidence seems to indicate that different components such as myokines, adipokines and growth factors, released by both fat and muscle tissues, could play a key role in the regulation of skeletal health and in low bone mineral density and, thus, in osteoporosis development. This review considers old and recent data in the literature to further evaluate the relationship between fat, bone and muscle tissue.

  11. Statistical shape analysis of clavicular cortical bone with applications to the development of mean and boundary shape models.

    Science.gov (United States)

    Lu, Yuan-Chiao; Untaroiu, Costin D

    2013-09-01

    During car collisions, the shoulder belt exposes the occupant's clavicle to large loading conditions which often leads to a bone fracture. To better understand the geometric variability of clavicular cortical bone which may influence its injury tolerance, twenty human clavicles were evaluated using statistical shape analysis. The interior and exterior clavicular cortical bone surfaces were reconstructed from CT-scan images. Registration between one selected template and the remaining 19 clavicle models was conducted to remove translation and rotation differences. The correspondences of landmarks between the models were then established using coordinates and surface normals. Three registration methods were compared: the LM-ICP method; the global method; and the SHREC method. The LM-ICP registration method showed better performance than the global and SHREC registration methods, in terms of compactness, generalization, and specificity. The first four principal components obtained by using the LM-ICP registration method account for 61% and 67% of the overall anatomical variation for the exterior and interior cortical bone shapes, respectively. The length was found to be the most significant variation mode of the human clavicle. The mean and two boundary shape models were created using the four most significant principal components to investigate the size and shape variation of clavicular cortical bone. In the future, boundary shape models could be used to develop probabilistic finite element models which may help to better understand the variability in biomechanical responses and injuries to the clavicle. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. Bone Biopsy

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Bone Biopsy Bone biopsy uses a needle and imaging guidance ... limitations of Bone Biopsy? What is a Bone Biopsy? A bone biopsy is an image-guided procedure ...

  13. Development and Testing of X-Ray Imaging-Enhanced Poly-L-Lactide Bone Screws.

    Directory of Open Access Journals (Sweden)

    Wei-Jen Chang

    Full Text Available Nanosized iron oxide particles exhibit osteogenic and radiopaque properties. Thus, iron oxide (Fe3O4 nanoparticles were incorporated into a biodegradable polymer (poly-L-lactic acid, PLLA to fabricate a composite bone screw. This multifunctional, 3D printable bone screw was detectable on X-ray examination. In this study, mechanical tests including three-point bending and ultimate tensile strength were conducted to evaluate the optimal ratio of iron oxide nanoparticles in the PLLA composite. Both injection molding and 3D printing techniques were used to fabricate the PLLA bone screws with and without the iron oxide nanoparticles. The fabricated screws were implanted into the femoral condyles of New Zealand White rabbits. Bone blocks containing the PLLA screws were resected 2 and 4 weeks after surgery. Histologic examination of the surrounding bone and the radiopacity of the iron-oxide-containing PLLA screws were evaluated. Our results indicated that addition of iron oxide nanoparticles at 30% significantly decreased the ultimate tensile stress properties of the PLLA screws. The screws with 20% iron oxide exhibited strong radiopacity compared to the screws fabricated without the iron oxide nanoparticles. Four weeks after surgery, the average bone volume of the iron oxide PLLA composite screws was significantly greater than that of PLLA screws without iron oxide. These findings suggested that biodegradable and X-ray detectable PLLA bone screws can be produced by incorporation of 20% iron oxide nanoparticles. Furthermore, these screws had significantly greater osteogenic capability than the PLLA screws without iron oxide.

  14. Bone turnover markers during pubertal development: relationships with growth factors and adipocytokines.

    Science.gov (United States)

    Jürimäe, Jaak; Mäestu, Jarek; Jürimäe, Toivo

    2010-01-01

    The rapid increase in skeletal mass that occurs during puberty is caused by increases in longitudinal growth as well as cortical thickness. The measurement of growth changes during puberty using two-dimensional (dual-energy X-ray absorptiometry) and/or three-dimensional (computed tomography, magnetic resonance imaging) measurement devices provides only a static representation of bone tissue parameters. The measurement of bone turnover markers provides a more dynamic picture of the nature of bone tissue that can be repeated at much shorter intervals during puberty. The bone turnover markers are products of osteoblasts and osteoclasts which can be measured in urine or blood. The increase in different markers of bone turnover coincides with the pubertal growth spurt and thereafter markers decline until they converge into adult values. The initiation of puberty is accompanied by increases in androgens and estrogens. The effects of sex hormones on bone mineral accrual are mediated mainly by growth hormone and insulin-like growth factor-1, but they also exert a direct effect on bone metabolism. Important determinants of bone mineral accrual during puberty include optimal nutritional status, body composition parameters and physical activity pattern. All of these determinants are related to the state of energy balance, while peripheral indicators of energy balance, such as different growth factors and adipocytokines, may also have a positive influence of the growing skeleton. Taken together, bone mineral accrual during puberty is a complex interaction between physical activity pattern, various body composition parameters, specific growth factors and adipocytokines, and also sex hormones. Copyright © 2010 S. Karger AG, Basel.

  15. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    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

  16. Factors that predict the development of bone metastases due to prostate cancer: Recommendations for follow-up and therapeutic options.

    Science.gov (United States)

    Rodríguez-Antolín, A; Gómez-Veiga, F; Alvarez-Osorio, J K; Carballido-Rodriguez, J; Palou-Redorta, J; Solsona-Narbón, E; Sánchez-Sánchez, E; Unda, M

    2014-05-01

    Prostate cancer is a public health problem in Spain and in the Western world. Bone involvement, associated to significant morbidity, is practically constant in the advanced stages of the disease. This work aims to review the prognostic factors used in the usual clinical practice that predict the development of bone metastases and to analyze the follow-up and treatment option in these patient profiles. We performed a review of the literature on the useful factors in the context of therapy with intention to cure. We included the classical clinical values in the diagnosis (PSA, clinical stage, Gleason score on the biopsy) pathological factors (pT stage, margins, bladder invasion, tumor volume, lymph node involvement) and PSA kinetics in their different contexts and the histological and molecular parameters. The tumor differentiation "Gleason" score and PSA are the most important predictive factors in the prediction of bone metastases in patients with intention to cure. Kinetic factors such as PSA doubling time (TDPSA) 10 ng/ml in the case of castration-resistant prostate cancer (CPRC), are predictive factors for the development of metastasis. Zoledronic acid and denosumab have demonstrated their effectiveness for the treatment of bone disease in randomized studies. There are predictive factors within the usual clinical practice that make it possible to recognize the "patient at risk" to develop bone metastatic disease. The currently available treatments, zoledronic acid or denosumab, can help us in the management of the patient at risk of developing metastasis or metastatic patient, increasing the quality of life and decreasing skeletal events. Copyright © 2013 AEU. Published by Elsevier Espana. All rights reserved.

  17. [Dental alveolar bone and dental arch remodeling in children: orthodontic diagnosis and treatments based on individual child arch development].

    Science.gov (United States)

    Xiaobing, Li

    2016-12-01

    The etiology of malocclusions basically involves both congenital and environmental factors. Malocclusion is the result of the abnormal development of the orofacial complex (including tooth, dental alveolar bone, upper and lower jaws). Early orthodontic interceptive treatments involve the elimination of all congenital and environmental factors that contribute to the malformation of the orofacial complex, as well as interrupt the deviated development of the orofacial complex and the occlusion. Early orthodontic interceptive treatments mainly aim to use children's growth potential to correct abnormal developments of occlusions and orthodontically treat malocclusions more efficiently. The early orthodontic interceptive treatments include correcting the child's bad oral habits, training the abnormal functioned para-oral muscles, maintaining the normal eruptions of succeeding permanent teeth, applying interceptive treatments to the mal-developed teeth, and employing functional orthopedic treatments for abnormal growths of the upper and lower jaws. In orthodontics, correcting mal-positioned teeth is called orthodontic treatment, while rectifying the abnormal relationships of the upper and lower jaws is called functional orthopedic treatment. However, no clear definition is available as regards to the early orthodontic interceptive treatment of malocclusions caused by the deviated development of the dental alveolar bone. This new theory of "early dental alveolar bone and dental arch remodeling technique" was proposed by Professor Li Xiaobing of the Department of Pediatric Dentistry, Faculty of Pediatric Dentistry and Orthodontics in West China Hospital of Stomatology through his clinical analyses and investigation of his early orthodontic interceptive treatments. He defined the early orthodontic corrections of abnormal growth of dental alveolar bone as "remodel". The "early dental alveolar bone and dental arch remodeling theory and technique" is proved useful in

  18. Mineralization of Synthetic Polymer Scaffolds: A Bottom-upApproach for the Development of Artificial Bone

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jie; Viengkham, Malathong; Bertozzi, Carolyn R.

    2004-09-27

    The controlled integration of organic and inorganic components confers natural bone with superior mechanical properties. Bone biogenesis is thought to occur by templated mineralization of hard apatite crystals by an elastic protein scaffold, a process we sought to emulate with synthetic biomimetic hydrogel polymers. Crosslinked polymethacrylamide and polymethacrylate hydrogels were functionalized with mineral-binding ligands and used to template the formation of hydroxyapatite. Strong adhesion between the organic and inorganic materials was achieved for hydrogels functionalized with either carboxylate or hydroxy ligands. The mineral-nucleating potential of hydroxyl groups identified here broadens the design parameters for synthetic bone-like composites and suggests a potential role for hydroxylated collagen proteins in bone mineralization.

  19. Development of Prototype of Whistling Sound Counter based on Piezoelectric Bone Conduction

    Science.gov (United States)

    Mori, Mikio; Ogihara, Mitsuhiro; Kyuu, Ten; Taniguchi, Shuji; Kato, Shozo; Araki, Chikahiro

    Recently, some professional whistlers have set up music schools that teach musical whistling. Similar to singing, in musical whistling, the whistling sound should not be break, even when the whistling goes on for more than 3 min. For this, it is advisable to practice whistling the “Pii” sound, which involves whistling the “Pii” sound continuously 100 times with the same pitch. However, when practicing alone, a whistler finds it difficult to count his/her own whistling sounds. In this paper, we propose a whistling sound counter based on piezoelectric bone conduction. This system consists of five parts. The gain of the amplifier section of this counter is variable, and the center frequency (f0) of the BPF part is also variable. In this study, we developed a prototype of the system and tested it. For this, we simultaneously counted the whistling sounds of nine people using the proposed system. The proposed system showed a good performance in a noisy environment. We also propose an examination system for awarding grades in musical whistling, which enforces the license examination in musical whistling on the personal computer. The proposed system can be used to administer the 5th grade exam for musical whistling.

  20. Alcohol exposure induces chick craniofacial bone defects by negatively affecting cranial neural crest development.

    Science.gov (United States)

    Zhang, Ping; Wang, Guang; Lin, Zhuangling; Wu, Yushi; Zhang, Jing; Liu, Meng; Lee, Kenneth Ka Ho; Chuai, Manli; Yang, Xuesong

    2017-11-05

    Excess alcohol consumption during pregnancy could lead to fetal alcohol syndrome (FAS). However, the molecular mechanism leading to craniofacial abnormality, a feature of FAS, is still poorly understood. The cranial neural crest cells (NCCs) contribute to the formation of the craniofacial bones. Therefore, NCCs exposed to ethanol was investigated - using chick embryos and in vitro explant culture as experimental models. We demonstrated that exposure to 2% ethanol induced craniofacial defects, which includes parietal defect, in the developing chick fetus. Immunofluorescent staining revealed that ethanol treatment downregulated Ap-2ɑ, Pax7 and HNK-1 expressions by cranial NCCs. Using double-immunofluorescent stainings for Ap-2ɑ/pHIS3 and Ap-2ɑ/c-Caspase3, we showed that ethanol treatment inhibited cranial NCC proliferation and increased NCC apoptosis, respectively. Moreover, ethanol treatment of the dorsal neuroepithelium increased Laminin, N-Cadherin and Cadherin 6B expressions while Cadherin 7 expression was repressed. In situ hybridization also revealed that ethanol treatment up-regulated Cadherin 6B expression but down-regulated slug, Msx1, FoxD3 and BMP4 expressions. In summary, our experimental results demonstrated that ethanol treatment interferes with the production of cranial NCCs by affecting the proliferation and apoptosis of these cells. In addition, ethanol affected the delamination, epithelial-mesenchymal transition (EMT) and cell migration of cranial NCCs, which may have contributed to the etiology of the craniofacial defects. Copyright © 2017. Published by Elsevier B.V.

  1. Development of Flexible Capacitive Ultrasound Transducers and the Use of Ultrasound for Bone Repair

    Science.gov (United States)

    Wentzell, Scott A.

    Ultrasound is a widely applicable technique for therapy in the biomedical arena. However, conventional ultrasound transducers are not conducive for non-planar surfaces. Therefore, we developed flexible transducers capable of performing ultrasound and evaluated their use in biomedical applications. Flexible capacitive ultrasound transducers based on micrometer-thick dielectric tapes were developed and fabricated. These transducers were able to be made by hand at low-cost while still demonstrating good tolerances in center operating frequency. Intensities of up to 120 mW/cm2 were recorded and operation was dependent upon the applied AC and DC voltages along with the thickness of the dielectric insulation. These capacitive ultrasound transducers were used to stimulate MC3T3-E1 murine osteoblast cells to investigate the effects of low-frequency ultrasound on osteogenic gene expression and anabolic signaling pathways. After stimulation by 94.5 kHz continuous wave ultrasound for 20 minutes, significant increases in the activation of the Wnt signaling pathway and concentration of intracellular calcium were observed. Daily stimulation by ultrasound showed a trend of increased osteogenic gene expression across the phases of matrix deposition, maturation and calcification by osteoblasts. Finally, the heating of osteoblasts for stimulating osteoclastogenic responses was investigated. The application of increased temperatures of 42 and 47 degrees Celsius for 5 minutes showed significant increases in the RANKL/OPG ratio in media conditioned by osteoblasts. However, the altered RANKL/OPG ratio was not able to generate increases in osteoclastogenesis for RAW 264.7 murine macrophage cells culture in the condition media. This was possibly due to high overall osteoprotegerin expression, or unwanted inducement of M1 and M2 macrophage activation in the cell population. The overall work of this thesis demonstrates the development of novel capacitive transducers. These conformable

  2. Mutations in fam20b and xylt1 reveal that cartilage matrix controls timing of endochondral ossification by inhibiting chondrocyte maturation.

    Directory of Open Access Journals (Sweden)

    B Frank Eames

    2011-08-01

    Full Text Available Differentiating cells interact with their extracellular environment over time. Chondrocytes embed themselves in a proteoglycan (PG-rich matrix, then undergo a developmental transition, termed "maturation," when they express ihh to induce bone in the overlying tissue, the perichondrium. Here, we ask whether PGs regulate interactions between chondrocytes and perichondrium, using zebrafish mutants to reveal that cartilage PGs inhibit chondrocyte maturation, which ultimately dictates the timing of perichondral bone development. In a mutagenesis screen, we isolated a class of mutants with decreased cartilage matrix and increased perichondral bone. Positional cloning identified lesions in two genes, fam20b and xylosyltransferase1 (xylt1, both of which encode PG synthesis enzymes. Mutants failed to produce wild-type levels of chondroitin sulfate PGs, which are normally abundant in cartilage matrix, and initiated perichondral bone formation earlier than their wild-type siblings. Primary chondrocyte defects might induce the bone phenotype secondarily, because mutant chondrocytes precociously initiated maturation, showing increased and early expression of such markers as runx2b, collagen type 10a1, and ihh co-orthologs, and ihha mutation suppressed early perichondral bone in PG mutants. Ultrastructural analyses demonstrated aberrant matrix organization and also early cellular features of chondrocyte hypertrophy in mutants. Refining previous in vitro reports, which demonstrated that fam20b and xylt1 were involved in PG synthesis, our in vivo analyses reveal that these genes function in cartilage matrix production and ultimately regulate the timing of skeletal development.

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

    Directory of Open Access Journals (Sweden)

    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/

  4. Novel development of carbonate apatite-chitosan scaffolds based on lyophilization technique for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Maretaningtias Dwi Ariani

    2012-09-01

    Full Text Available Background: The natural biopolymer chitosan (Ch is currently regarded as a candidate for bone tissue engineering. However, Ch is poor for cell adhesion and low bone formation ability. In order to enhance cell adhesion and bone formation ability, combination of Ch with carbonate apatite (CA was developed. Purpose: The aim of this study was to make carbonate apatite-chitosan scaffolds (CAChSs and evaluate its osteoconductivity in terms of cell proliferation. Methods: Chitosan scaffolds (ChSs were made by the following procedure. Twenty-five, 50, 100, 200 and 400 mg Ch was dissolved into 5 ml of 2% acetic acid (CH3COOH, shaked for 15 min and neutralized with 15 ml of 0.1 M sodium hydroxide (NaOH solution. After centrifugation, Ch gel was packed into the molds then frozen at -80°C for 2h and dried in a freeze dry machine for 24h. The sponges were subjected to UV radiation for 2h. To make CA-ChSs, 200 mg Ch was selected. After neutralization, 50 mg of 0.06 M CA were added into the 200 mg Ch gel. The structure of CA-ChSs was observed by scanning electron microscope (SEM. Mouse osteoblast-like cell (MC3T3-E1 proliferation in these scaffolds was investigated at 1, 7, 14 and 21 days. Results: Three dimensional porous structures of CA-ChSs were clearly observed by SEM. Proliferated cell numbers in CA-ChSs was significantly higher than those in ChSs (control at each stage (p<0.05. Conclusion: It can be concluded that newly developed CA-ChSs had three-dimensional interconnected porous structure, good handling property and supporting ability of proliferation of osteoblasts. It is suggested that newly developed CA-ChSs could be considered as a scaffolds material for bone tissue enginearing.Latar belakang: Kitosan yang merupakan biopolimer alami dianggap sebagai salah satu kandidat untuk rekayasa jaringan tulang. Namun, kitosan memiliki kelemahan terhadap adhesi sel dan kurang mampu membentuk tulang yang cukup. Untuk meningkatkan adhesi sel dan kemampuan

  5. Poly (glycerol sebacate) elastomer supports bone regeneration by its mechanical properties being closer to osteoid tissue rather than to mature bone.

    Science.gov (United States)

    Zaky, S H; Lee, K W; Gao, J; Jensen, A; Verdelis, K; Wang, Y; Almarza, A J; Sfeir, C

    2017-05-01

    Mechanical load influences bone structure and mass. Arguing the importance of load-transduction, we investigated the mechanisms inducing bone formation using an elastomeric substrate. We characterized Poly (glycerol sebacate) (PGS) in vitro for its mechanical properties, compatibility with osteoprogenitor cells regarding adhesion, proliferation, differentiation under compression versus static cultures and in vivo for the regeneration of a rabbit ulna critical size defect. The load-transducing properties of PGS were compared in vitro to a stiffer poly lactic-co-glycolic-acid (PLA/PGA) scaffold of similar porosity and interconnectivity. Under cyclic compression for 7days, we report focal adhesion kinase overexpression on the less stiff PGS and upregulation of the transcription factor Runx2 and late osteogenic markers osteocalcin and bone sialoprotein (1.7, 4.0 and 10.0 folds increase respectively). Upon implanting PGS in the rabbit ulna defect, histology and micro-computed tomography analysis showed complete gap bridging with new bone by the PGS elastomer by 8weeks while minimal bone formation was seen in empty controls. Immunohistochemical analysis demonstrated the new bone to be primarily regenerated by recruited osteoprogenitors cells expressing periostin protein during early phase of maturation similar to physiological endochondral bone development. This study confirms PGS to be osteoconductive contributing to bone regeneration by recruiting host progenitor/stem cell populations and as a load-transducing substrate, transmits mechanical signals to the populated cells promoting differentiation and matrix maturation toward proper bone remodeling. We hence conclude that the material properties of PGS being closer to osteoid tissue rather than to mineralized bone, allows bone maturation on a substrate mechanically closer to where osteoprogenitor/stem cells differentiate to develop mature load-bearing bone. The development of effective therapies for bone and

  6. Development and validation of the Osteoporosis Risk Assessment Instrument to facilitate selection of women for bone densitometry.

    Science.gov (United States)

    Cadarette, S M; Jaglal, S B; Kreiger, N; McIsaac, W J; Darlington, G A; Tu, J V

    2000-05-02

    Although mass screening for osteoporosis is not recommended among postmenopausal women, there is no consensus on which women should undergo testing for low bone mineral density. The objective of this study was to develop and validate a clinical tool to help clinicians identify which women are at increased risk for osteoporosis and should therefore undergo further testing with bone densitometry. Using Ontario baseline data from the Canadian Multicentre Osteoporosis Study, we identified all cognitively normal women aged 45 years or more who had undergone testing with dual-energy x-ray absorptiometry (DXA) at both the femoral neck and the lumbar spine (L1-L4). Participants who had a previous diagnosis of osteoporosis or were taking bone active medication other than ovarian hormones were excluded. The main outcome measure was low bone mineral density (T score of 2 or more standard deviations below the mean for young Canadian women) at either the femoral neck or the lumbar spine. Logistic regression analysis and receiver operating characteristic (ROC) analysis were used to identify the simplest algorithm that would identify women at increased risk for low bone mineral density. The study population comprised 1376 women, of whom 926 were allocated to the development of the tool and 450 to its validation. A simple algorithm based on age, weight and current estrogen use (yes or no) was developed. Validation of this 3-item Osteoporosis Risk Assessment Instrument (ORAI) showed that the tool had a sensitivity of 93.3% (95% confidence interval [CI] 86.3%-97.0%) and a specificity of 46.4% (95% CI 41.0%-51.8%) for selecting women with low bone mineral density. The sensitivity of the instrument for selecting women with osteoporosis was 94.4% (95% CI 83.7%-98.6%). Use of the ORAI represented a 38.7% reduction in DXA testing compared with screening all women in our study. The ORAI accurately identifies the vast majority of women likely to have low bone mineral density and is

  7. Large diameter femoral heads impose significant alterations on the strains developed on femoral component and bone: a finite element analysis.

    Science.gov (United States)

    Theodorou, E G; Provatidis, C G; Babis, G C; Georgiou, C S; Megas, P D

    2011-01-01

    Total Hip Arthroplasty aims at fully recreating a functional hip joint. Over the past years modular implant systems have become common practice and are widely used, due to the surgical options they provide. In addition Big Femoral Heads have also been implemented in the process, providing more flexibility for the surgeon. The current study aims at investigating the effects that femoral heads of bigger diameter may impose on the mechanical behavior of the bone-implant assembly. Using data acquired by Computed Tomographies and a Coordinate Measurement Machine, a cadaveric femur and a Profemur-E modular stem were fully digitized, leading to a three dimensional finite element model in ANSYS Workbench. Strains and stresses were then calculated, focusing on areas of clinical interest, based on Gruen zones: the calcar and the corresponding below the greater trochanter area in the proximal femur, the stem tip region and a profile line along linea aspera. The performed finite elements analysis revealed that the use of large diameter heads produces significant changes in strain development within the bone volume, especially in the lateral side. The application of Frost's law in bone remodeling, validated the hypothesis that for all diameters normal bone growth occurs. However, in the calcar area lower strain values were recorded, when comparing with the reference model featuring a 28mm femoral head. Along line aspera and for the stem tip area, higher values were recorded. Finally, stresses calculated on the modular neck revealed increased values, but without reaching the yield strength of the titanium alloy used.

  8. Strain-dependent differences in bone development, myeloid hyperplasia, morbidity and mortality in ptpn2-deficient mice.

    Directory of Open Access Journals (Sweden)

    Florian Wiede

    Full Text Available Single nucleotide polymorphisms in the gene encoding the protein tyrosine phosphatase TCPTP (encoded by PTPN2 have been linked with the development of autoimmunity. Here we have used Cre/LoxP recombination to generate Ptpn2(ex2-/ex2- mice with a global deficiency in TCPTP on a C57BL/6 background and compared the phenotype of these mice to Ptpn2(-/- mice (BALB/c-129SJ generated previously by homologous recombination and backcrossed onto the BALB/c background. Ptpn2(ex2-/ex2- mice exhibited growth retardation and a median survival of 32 days, as compared to 21 days for Ptpn2(-/- (BALB/c mice, but the overt signs of morbidity (hunched posture, piloerection, decreased mobility and diarrhoea evident in Ptpn2(-/- (BALB/c mice were not detected in Ptpn2(ex2-/ex2- mice. At 14 days of age, bone development was delayed in Ptpn2(-/- (BALB/c mice. This was associated with increased trabecular bone mass and decreased bone remodeling, a phenotype that was not evident in Ptpn2(ex2-/ex2- mice. Ptpn2(ex2-/ex2- mice had defects in erythropoiesis and B cell development as evident in Ptpn2(-/- (BALB/c mice, but not splenomegaly and did not exhibit an accumulation of myeloid cells in the spleen as seen in Ptpn2(-/- (BALB/c mice. Moreover, thymic atrophy, another feature of Ptpn2(-/- (BALB/c mice, was delayed in Ptpn2(ex2-/ex2- mice and preceded by an increase in thymocyte positive selection and a concomitant increase in lymph node T cells. Backcrossing Ptpn2(-/- (BALB/c mice onto the C57BL/6 background largely recapitulated the phenotype of Ptpn2(ex2-/ex2- mice. Taken together these results reaffirm TCPTP's important role in lymphocyte development and indicate that the effects on morbidity, mortality, bone development and the myeloid compartment are strain-dependent.

  9. Objectively measured physical activity predicts hip and spine bone mineral content in children and adolescents ages 5 - 15 years: Iowa Bone Development Study

    Directory of Open Access Journals (Sweden)

    Kathleen F Janz

    2014-07-01

    Full Text Available This study examined the association between physical activity (PA and bone mineral content (BMC; g from middle childhood to middle adolescence and compared the impact of vigorous-intensity PA (VPA over moderate- to vigorous-intensity PA (MVPA. Participants from the Iowa Bone Development Study were examined at ages 5, 8, 11, 13, and 15 yr (n=369, 449, 452, 410, 307, respectively. MVPA and VPA (min/day were measured using ActiGraph accelerometers. Anthropometry was used to measure body size and somatic maturity. Spine BMC and hip BMC were measured via dual-energy x-ray absorptiometry. Sex-specific multi-level linear models were fit for spine BMC and hip BMC, adjusted for weight (kg, height (cm, linear age (yr, non-linear age (yr2, and maturity (pre peak height velocity vs. at/post peak height velocity. The interaction effects of PA×maturity and PA×age were tested. We also examined differences in spine BMC and hip BMC between the least (10th percentile and most (90th percentile active participants at each examination period. Results indicated that PA added to prediction of BMC throughout the 10-year follow-up, except MVPA did not predict spine BMC in females. Maturity and age did not modify the PA effect for males nor females. At age 5, the males at the 90th percentile for VPA had 8.5% more hip BMC than males in the 10th percentile for VPA. At age 15, this difference was 2.0%. Females at age 5 in the 90th percentile for VPA had 6.1% more hip BMC than those in the 10th percentile for VPA. The age 15 difference was 1.8%. VPA was associated with BMC at weight-bearing skeletal sites from childhood to adolescence, and the effect was not modified by maturity or age. Our findings indicate the importance of early and sustained interventions that focus on VPA. Approaches focused on MVPA may be inadequate for optimal bone health, particularly for females.

  10. Newly Developed Rat Model of Chronic Kidney Disease-Mineral Bone Disorder.

    Science.gov (United States)

    Watanabe, Kentaro; Fujii, Hideki; Goto, Shunsuke; Nakai, Kentaro; Kono, Keiji; Watanabe, Shuhei; Shinohara, Masami; Nishi, Shinichi

    2018-02-01

    Chronic kidney disease-mineral bone disorder (CKD-MBD) is associated with all-cause and cardiovascular morbidity and mortality in patients with CKD. Thus, elucidating its pathophysiological mechanisms is essential for improving the prognosis. We evaluated characteristics of CKD-MBD in a newly developed CKD rat model. We used male Sprague-Dawley (SD) rats and spontaneously diabetic Torii (SDT) rats, which are used as models for nonobese type 2 diabetes. CKD was induced by 5/6 nephrectomy (Nx). At 10 weeks, the rats were classified into six groups and administered with a vehicle or a low- or high-dose paricalcitol thrice a week. At 20 weeks, the rats were sacrificed; blood and urinary biochemical analyses and histological analysis of the aorta were performed. At 20 weeks, hemoglobin A1c (HbA1c) levels, blood pressure, and renal function were not significantly different among the six groups. Serum calcium and phosphate levels tended to be higher in SDT-Nx rats than in SD-Nx rats. The urinary excretion of calcium and phosphate was significantly greater in SDT-Nx rats than in SD-Nx rats. After administering paricalcitol, serum parathyroid hormone (PTH) and fibroblast growth factor 23 (FGF23) levels were significantly higher in SDT-Nx rats than in SD-Nx rats. The degree of aortic calcification was significantly more severe and the aortic calcium content was significantly greater in SDT-Nx rats than in SD-Nx rats. We suggest that our new CKD rat model using SDT rats represents a useful CKD-MBD model, and this model was greatly influenced by paricalcitol administration. Further studies are needed to clarify the detailed mechanisms underlying this model.

  11. Development of a Procedure for the Government Provision of Bone-Anchored Prosthesis Using Osseointegration in Australia

    OpenAIRE

    Frossard, Laurent; Merlo, Gregory; Quincey, Tanya; Burkett, Brendan; Berg, Debra

    2017-01-01

    Background Governmental organizations are facing challenges in adjusting procedures providing equitable assistance to consumers with amputation choosing newly available osseointegrated fixations for bone-anchored prostheses (BAPs) over socket-suspended prostheses. Objectives The aims of this study were to (1) present a procedure focusing on tasks, documents and costs of prosthetic care, and (2) share observed obstacles and facilitators to implementation. Methods This research aimed at develop...

  12. Role of nitric oxide synthase in the development of bone cancer pain and effect of L-NMMA.

    Science.gov (United States)

    Yang, Yan; Zhang, Juan; Liu, Yue; Zheng, Yaguo; Bo, Jinhua; Zhou, Xiaofang; Wang, Junhua; Ma, Zhengliang

    2016-02-01

    Spinal nitric oxide is involved in the mechanisms of pain generation and transmission during inflammatory and neuropathic pain. The aim of the present study was to explore the role of spinal nitric oxide in the development of bone cancer pain. 2 x 10(5) osteosarcoma cells were implanted into the intramedullary space of right femurs of C3H/HeJ mice to induce a model of ongoing bone cancer. Polymerase chain reaction and immunohistochemical analyses were performed to assess the expression of neuronal nitric oxide synthase (nNOS) and inducible (i)NOS in the spinal cord following inoculation. The results showed that inoculation of osteosarcoma cells induced progressive bone cancer, accompanied with pain-associated behavior. The levels of nNOS mRNA in the spinal cord of tumor mice began to increase at day 10 and then decreased to the level in sham mice at day 14, while iNOS mRNA markedly increased in the tumor group at days 10 and 14. Immunohistochemical analysis showed that nNOS- and iNOS-positive neurons were mainly located in the superficial dorsal horn and around the central canal of the L3-L5 spinal cord. Intrathecal injection of 50 µg NOS inhibitor NG-monomethyl-L-arginine (L-NMMA) attenuated cancer-evoked pain behaviors at day 14. These findings indicated that an upregulation of nNOS and iNOS in the spinal cord is associated with bone cancer pain and suggests that exogenously administered L-NMMA may have beneficial effects to alleviate bone cancer pain.

  13. Development of novel radiogallium-labeled bone imaging agents using oligo-aspartic acid peptides as carriers.

    Directory of Open Access Journals (Sweden)

    Kazuma Ogawa

    Full Text Available (68Ga (T 1/2 = 68 min, a generator-produced nuclide has great potential as a radionuclide for clinical positron emission tomography (PET. Because poly-glutamic and poly-aspartic acids have high affinity for hydroxyapatite, to develop new bone targeting (68Ga-labeled bone imaging agents for PET, we used 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA as a chelating site and conjugated aspartic acid peptides of varying lengths. Subsequently, we compared Ga complexes, Ga-DOTA-(Aspn (n = 2, 5, 8, 11, or 14 with easy-to-handle (67Ga, with the previously described (67Ga-DOTA complex conjugated bisphosphonate, (67Ga-DOTA-Bn-SCN-HBP. After synthesizing DOTA-(Aspn by a Fmoc-based solid-phase method, complexes were formed with (67Ga, resulting in (67Ga-DOTA-(Aspn with a radiochemical purity of over 95% after HPLC purification. In hydroxyapatite binding assays, the binding rate of (67Ga-DOTA-(Aspn increased with the increase in the length of the conjugated aspartate peptide. Moreover, in biodistribution experiments, (67Ga-DOTA-(Asp8, (67Ga-DOTA-(Asp11, and (67Ga-DOTA-(Asp14 showed high accumulation in bone (10.5 ± 1.5, 15.1 ± 2.6, and 12.8 ± 1.7% ID/g, respectively but were barely observed in other tissues at 60 min after injection. Although bone accumulation of (67Ga-DOTA-(Aspn was lower than that of (67Ga-DOTA-Bn-SCN-HBP, blood clearance of (67Ga-DOTA-(Aspn was more rapid. Accordingly, the bone/blood ratios of (67Ga-DOTA-(Asp11 and (67Ga-DOTA-(Asp14 were comparable with those of (67Ga-DOTA-Bn-SCN-HBP. In conclusion, these data provide useful insights into the drug design of (68Ga-PET tracers for the diagnosis of bone disorders, such as bone metastases.

  14. Bone-Forming Capabilities of a Newly Developed NanoHA Composite Alloplast Infused with Collagen: A Pilot Study in the Sheep Mandible

    Directory of Open Access Journals (Sweden)

    Charles Marin

    2013-01-01

    Full Text Available Lateral or vertical bone augmentation has always been a challenge, since the site is exposed to constant pressure from the soft tissue, and blood supply only exists from the donor site. Although, for such clinical cases, onlay grafting with autogenous bone is commonly selected, the invasiveness of the secondary surgical site and the relatively fast resorption rate have been reported as a drawback, which motivated the investigation of alternative approaches. This study evaluated the bone-forming capability of a novel nanoHA alloplast infused with collagen graft material made from biodegradable polylactic acid/polyglycolic acid versus a control graft material with the same synthesized alloplast without the nanoHA component and collagen infiltration. The status of newly formed bone and the resorption of the graft material were evaluated at 6 weeks in vivo histologically and three dimensionally by means of 3D microcomputed tomography. The histologic observation showed that newly formed bone ingrowth and internal resorption of the block were observed for the experimental blocks, whereas for the control blocks less bone ingrowth occurred along with lower resorption rate of the block material. The three-dimensional observation indicated that the experimental block maintained the external geometry, but at the same time successfully altered the graft material into bone. It is suggested that the combination of numerous factors contributed to the bone ingrowth and the novel development could be an alternative bone grafting choice.

  15. Development of mandible in indigenous sheep fetuses

    Directory of Open Access Journals (Sweden)

    N. S. Ahmed

    2011-01-01

    Full Text Available The aim of this study was to detect the precise sites of the beginning of primary ossification centers of the mandible of sheep fetuses as well as their onset time, to achieve this goal, samples were taken weekly starting from the 7th week up to 20th week of intrauterine life. Sections of the samples were stained by the alizarin red and alcian blue technique. Primary centers appeared at the beginning of 7th week as big red spot on either sides of mesenchyme of first branchial arch (Meckel’s cartilage that developed by intramembranous ossification. The rostral part of the mandible, however, was developed by endochondral ossification. The successive bone development process (7–20 weeks, were moniterd by macerating the mandibles using either potassium hydroxide or fly larvae. Measuring tape and graph papers were employed for measurements and for localization of mandibular angle. The results revealed significant increase of these measurements during the successive weeks of intrauterine life.

  16. Bridging Plate Development for Treatment of Segmental Bone Defects of the Canine Mandible: Mechanical Tests and Finite Element Method.

    Science.gov (United States)

    de Freitas, Elisângela Perez; Rahal, Sheila Canevese; Shimano, Antonio Carlos; da Silva, Jorge Vicente Lopes; Noritomi, Pedro Yoshito; El-Warrak, Alexander Oliveira; Melchert, Alessandra

    2016-03-01

    With regard to the canine mandible, a mistaken concept of application is to assume that systemic plate-bone resistance is provided by the implant so that biomechanical position could be ignored. Because the alveolar border of the mandible is a tensile zone, the plate would ideally be positioned near this area while avoiding important structures. The aim of this study was to develop 2 bridging plates for the treatment of a segmental bone defect of the canine mandible using monocortical screws to avoid damage to the tooth roots and remaining neurovascular structures. Computed tomography images of the heads of 4 dogs (rottweiler, Doberman, boxer, and miniature poodle breeds) were used as models to develop the project. The images were reconstructed in 3-dimensional (3D) format. For each dog breed, 6 mandible prototypes were produced, each with a segmental bone defect in the right mandible. The mandibular reconstruction was performed with pure titanium bridging plate and locking screws. One plate model was developed for medium- and large-breed dogs and another for small-breed dogs. Mechanical testing showed the platemandible system resists the bite forces in all dog breeds. All safety factors were greater than I in the platemandible system for medium- and large-breed dogs and greater than 10 in the plate-mandible system for small-breed dogs. Thus, bridging plates designed with differentiated geometry and monocortical locking screws showed mechanical resistance to support simulated induced bone model defects and were able to support at least 5 times the value of bite force for each evaluated dog.

  17. Cartilage-specific over-expression of CCN family member 2/connective tissue growth factor (CCN2/CTGF stimulates insulin-like growth factor expression and bone growth.

    Directory of Open Access Journals (Sweden)

    Nao Tomita

    Full Text Available Previously we showed that CCN family member 2/connective tissue growth factor (CCN2 promotes the proliferation, differentiation, and maturation of growth cartilage cells in vitro. To elucidate the specific role and molecular mechanism of CCN2 in cartilage development in vivo, in the present study we generated transgenic mice overexpressing CCN2 and analyzed them with respect to cartilage and bone development. Transgenic mice were generated expressing a ccn2/lacZ fusion gene in cartilage under the control of the 6 kb-Col2a1-enhancer/promoter. Changes in cartilage and bone development were analyzed histologically and immunohistologically and also by micro CT. Primary chondrocytes as well as limb bud mesenchymal cells were cultured and analyzed for changes in expression of cartilage-related genes, and non-transgenic chondrocytes were treated in culture with recombinant CCN2. Newborn transgenic mice showed extended length of their long bones, increased content of proteoglycans and collagen II accumulation. Micro-CT analysis of transgenic bones indicated increases in bone thickness and mineral density. Chondrocyte proliferation was enhanced in the transgenic cartilage. In in vitro short-term cultures of transgenic chondrocytes, the expression of col2a1, aggrecan and ccn2 genes was substantially enhanced; and in long-term cultures the expression levels of these genes were further enhanced. Also, in vitro chondrogenesis was strongly enhanced. IGF-I and IGF-II mRNA levels were elevated in transgenic chondrocytes, and treatment of non-transgenic chondrocytes with recombinant CCN2 stimulated the expression of these mRNA. The addition of CCN2 to non-transgenic chondrocytes induced the phosphorylation of IGFR, and ccn2-overexpressing chondrocytes showed enhanced phosphorylation of IGFR. Our data indicates that the observed effects of CCN2 may be mediated in part by CCN2-induced overexpression of IGF-I and IGF-II. These findings indicate that CCN2

  18. Development and characterization of a bioglass/chitosan composite as an injectable bone substitute.

    Science.gov (United States)

    Khoshakhlagh, Parastoo; Rabiee, Sayed Mahmood; Kiaee, Gita; Heidari, Pedram; Miri, Amir K; Moradi, Roshanak; Moztarzadeh, Fathollah; Ravarian, Roya

    2017-02-10

    SiO 2 -CaO-P 2 O 5 based bioglass (BG) systems constitute a group of materials that have wide applications in bone implants. Chitosan (Cn) is a biocompatible and osteoconductive natural polymer that can promote wound healing. In this study, bioactivity of chitosan/bioglass (CnB) composites as minimally invasive bone regenerative materials was assessed both in vitro and in vivo. Injectability tests and scanning electron microscopy (SEM) results demonstrated the formation of uniform injectable paste-like composites using BG particles and Cn. Fourier transform infrared spectroscopy (FTIR) and SEM images confirmed hydroxyapatite deposition in vitro after incubation in simulated body fluid (SBF). Higher BG content in the composite correlated with increased human osteoblast proliferation. An in vivo study in a rat spinal fusion model confirmed that increasing the amount of BG improved osteoconductivity. Manual palpation, radiographic images and pathological assessments proved that the composites promote bone formation. Based on these data, the synthesized composites have a potential application in orthopedic and reconstructive surgeries as a minimally invasive bone substitute. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Bentonite diminishes DON-induced changes in bone development in mink dams

    Directory of Open Access Journals (Sweden)

    Tomaszewska Ewa

    2016-09-01

    Full Text Available Introduction: The aim of this study was to determine the effect of deoxynivalenol (DON, given alone or with bentonite (which eliminates mycotoxicity in the diet of mink dams throughout mating, pregnancy, and lactation period to pelt harvesting, on the mechanical properties and geometry of their long bones.

  20. Calvarial Suture-Derived Stem Cells and Their Contribution to Cranial Bone Repair

    Directory of Open Access Journals (Sweden)

    Daniel H. Doro

    2017-11-01

    Full Text Available In addition to the natural turnover during life, the bones in the skeleton possess the ability to self-repair in response to injury or disease-related bone loss. Based on studies of bone defect models, both processes are largely supported by resident stem cells. In the long bones, the source of skeletal stem cells has been widely investigated over the years, where the major stem cell population is thought to reside in the perivascular niche of the bone marrow. In contrast, we have very limited knowledge about the stem cells contributing to the repair of calvarial bones. In fact, until recently, the presence of specific stem cells in adult craniofacial bones was uncertain. These flat bones are mainly formed via intramembranous rather than endochondral ossification and thus contain minimal bone marrow space. It has been previously proposed that the overlying periosteum and underlying dura mater provide osteoprogenitors for calvarial bone repair. Nonetheless, recent studies have identified a major stem cell population within the suture mesenchyme with multiple differentiation abilities and intrinsic reparative potential. Here we provide an updated review of calvarial stem cells and potential mechanisms of regulation in the context of skull injury repair.

  1. Evc works in chondrocytes and osteoblasts to regulate multiple aspects of growth plate development in the appendicular skeleton and cranial base.

    Science.gov (United States)

    Pacheco, María; Valencia, María; Caparrós-Martín, José A; Mulero, Francisca; Goodship, Judith A; Ruiz-Perez, Victor L

    2012-01-01

    Ellis-van Creveld syndrome protein homolog (Evc) was previously shown to mediate expression of Indian hedgehog (Ihh) downstream targets in chondrocytes. Consequently disruption of the Ihh/Pthrp axis was demonstrated in Evc(-/-) mice, but the full extent of Evc involvement in endochondral development was not totally characterized. Herein we have examined further the Evc(-/-) growth plate in a homogeneous genetic background and show that Evc promotes chondrocyte proliferation, chondrocyte hypertrophy and the differentiation of osteoblasts in the perichondrium, hence implicating Evc in both Pthrp-dependent and Pthrp-independent Ihh functions. We also demonstrate that Evc, which localizes to osteoblast primary cilia, mediates Hedgehog (Hh) signaling in the osteoblast lineage. In spite of this, bone collar development is mildly affected in Evc(-/-) mutants. The onset of perichondrial osteoblastogenesis is delayed at the initial stages of endochondral ossification in Evc(-/-) mice, and in later stages, the leading edge of expression of osteoblast markers and Wnt/β-catenin signaling components is located closer to the primary spongiosa in the Evc(-/-) perichondrium owing to impaired osteoblast differentiation. Additionally we have used Ptch1-LacZ reporter mice to learn about the different types of Hh-responsive cells that are present in the perichondrium of normal and Evc(-/-) mice. Evc mediates Hh target gene expression in inner perichondrial cells, but it is dispensable in the external layers of the perichondrium. Finally, we report cranial base defects in Evc(-/-) mice and reveal that Evc is essential for intrasphenoidal synchondrosis development. Copyright © 2011. Published by Elsevier Inc.

  2. The interactions of the cells in the development of osteoporotic changes in bones under space flight conditions

    Science.gov (United States)

    Rodionova, Natalia; Kabitskaya, Olga

    2016-07-01

    Using the methods of electron microscopy and autoradiography with ³N-glycine and ³N-thymidine on biosatellites "Bion-11" (Macaca mulatta, the duration of the experiments -10 days), "Bion-M1" (mouse C57 Black, duration of the flight - 30 days) in the experiments with modeled hypokinesia (white rats, hind limbs unloading, the duration of the experiments 28 days) new data about the morpho-functional peculiarities of cellular interactions in adaptive remodeling zones of bone structures under normal conditions and after exposure of animals to microgravity. Our conception on remodeling proposes the following sequence in the development of cellular interactions after decrease of the mechanical loading: a primary response of osteocytes (mechanosensory cells) to the mechanical stimulus; osteocytic remodeling (osteolysis); transmission of the mechanical signals through a system of canals and processes to functionally active osteoblasts and paving endost one as well as to the bone-marrow stromal cells and perivascular cells. As a response to the mechanical stimulus (microgravity) the system of perivascular cell-stromal cell-preosteoblast-osteoblast shows a delay in proliferation, differentiation and specific functioning of the osteogenetic cells, the number of apoptotic osteoblasts increases. Then the osteoclastic reaction occurs (attraction of monocytes and formation of osteoclasts, bone matrix resorption in the loci of apoptosis of osteoblasts and osteocytes). The macrophagal reaction is followed by osteoblastogenesis, which appears to be a rehabilitating process. However, during prolonged absence of mechanical stimuli (microgravity, long-time immobilization) the adaptive activization of osteoblastogenesis doesn't occur (as it is the case during the physiological remodeling of bone tissue) or it occurs to a smaller degree. The loading deficit leads to an adaptive differentiation of stromal cells to fibroblastic cells and adipocytes in remodeling loci. These cell reactions

  3. Development of a Novel Degradation-Controlled Magnesium-Based Regeneration Membrane for Future Guided Bone Regeneration (GBR Therapy

    Directory of Open Access Journals (Sweden)

    Da-Jun Lin

    2017-11-01

    Full Text Available This study aimed to develop and evaluate the ECO-friendly Mg-5Zn-0.5Zr (ECO505 alloy for application in dental-guided bone regeneration (GBR. The microstructure and surface properties of biomedical Mg materials greatly influence anti-corrosion performance and biocompatibility. Accordingly, for the purpose of microstructure and surface modification, heat treatments and surface coatings were chosen to provide varied functional characteristics. We developed and integrated both an optimized solution heat-treatment condition and surface fluoride coating technique to fabricate a Mg-based regeneration membrane. The heat-treated Mg regeneration membrane (ARRm-H380 and duplex-treated regeneration membrane group (ARRm-H380-F24 h were thoroughly investigated to characterize the mechanical properties, as well as the in vitro corrosion and in vivo degradation behaviors. Significant enhancement in ductility and corrosion resistance for the ARRm-H380 was obtained through the optimized solid-solution heat treatment; meanwhile, the corrosion resistance of ARRm-H380-F24 h showed further improvement, resulting in superior substrate integrity. In addition, the ARRm-H380 provided the proper amount of Mg-ion concentration to accelerate bone growth in the early stage (more than 80% new bone formation. From a specific biomedical application point of view, these research results point out a successful manufacturing route and suggest that the heat treatment and duplex treatment could be employed to offer custom functional regeneration membranes for different clinical patients.

  4. Development of an in vitro cell system from zebrafish suitable to study bone cell differentiation and extracellular matrix mineralization.

    Science.gov (United States)

    Vijayakumar, Parameswaran; Laizé, Vincent; Cardeira, João; Trindade, Marlene; Cancela, M Leonor

    2013-12-01

    Mechanisms of bone formation and skeletal development have been successfully investigated in zebrafish using a variety of in vivo approaches, but in vitro studies have been hindered due to a lack of homologous cell lines capable of producing an extracellular matrix (ECM) suitable for mineral deposition. Here we describe the development and characterization of a new cell line termed ZFB1, derived from zebrafish calcified tissues. ZFB1 cells have an epithelium-like phenotype, grow at 28°C in a regular L-15 medium supplemented with 15% of fetal bovine serum, and are maintained and manipulated using standard methods (e.g., trypsinization, cryopreservation, and transfection). They can therefore be propagated and maintained easily in most cell culture facilities. ZFB1 cells show aneuploidy with 2n=78 chromosomes, indicative of cell transformation. Furthermore, because DNA can be efficiently delivered into their intracellular space by nucleofection, ZFB1 cells are suitable for gene targeting approaches and for assessing gene promoter activity. ZFB1 cells can also differentiate toward osteoblast or chondroblast lineages, as demonstrated by expression of osteoblast- and chondrocyte-specific markers, they exhibit an alkaline phosphatase activity, a marker of bone formation in vivo, and they can mineralize their ECM. Therefore, they represent a valuable zebrafish-derived in vitro system for investigating bone cell differentiation and extracellular matrix mineralization.

  5. A study on development of guideline on writing technical document for electrical medical devices: Bone absorptiometric X-ray system

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Youl; Kim, Jae Ryang; Kim, Eun Rim; Lee, Jun Ho; Lee, Chang Hyung; Park, Chang Won [Medical Device Research Division, Ministry of Food and Drug Safety, Cheongju (Korea, Republic of)

    2016-06-15

    The market size of the bone absorptiometric X-ray system and the number of its approval by Ministry of Food and Drug Safety (MFDS) has annually increased, with a trend of increasing aging population and osteoporosis patients. For approval of manufactured or imported medical devices in Republic of Korea, it is required to submit its technical document. Therefore, it is need to develop the technical document guideline for the bone absorptiometric X-ray system for manufacturers, importers and reviewers. First of all, the technical documents which were already approved were examined and analyzed through MFDS approval administration system. Second, safety and performance test standards and methods that match international standards were drawn after conducting survey of the market status and the technology development trend for it, with examination and analysis of applicable domestic and overseas standards. Third, by operating industry-research-government cooperation, the guideline draft on writing technical document for the bone absorptiometric X-ray system was discussed, collecting their opinion. As a result, it is suitable to international and domestic condition, includes test evaluation methods and offer various information with appropriate examples to civil petitioner, when they write the technical documents.

  6. Development of a novel alginate-polyvinyl alcohol-hydroxyapatite hydrogel for 3D bioprinting bone tissue engineered scaffolds.

    Science.gov (United States)

    Bendtsen, Stephanie T; Quinnell, Sean P; Wei, Mei

    2017-05-01

    Three-dimensional printed biomaterials used as personalized tissue substitutes have the ability to promote and enhance regeneration in areas of defected tissue. The challenge with 3D printing for bone tissue engineering remains the selection of a material with optimal rheological properties for printing in addition to biocompatibility and capacity for uniform cell incorporation. Hydrogel biomaterials may provide sufficient printability to allow cell encapsulation and bioprinting of scaffolds with uniform cell distribution. In this study, a novel alginate-polyvinyl alcohol (PVA)-hydroxyapatite (HA) hydrogel formulation with optimal rheological properties for 3D bioprinting of mouse calvaria 3T3-E1 (MC3T3) cells into scaffolds of high shape fidelity has been developed. A systematic investigation was conducted to determine the effect of varying concentrations of alginate, phosphate, calcium, and the PVA-HA suspension in the formulation on the resulting viscosity and thus printability of the hydrogel. HA, the main mineral component in natural bone, was incorporated into the hydrogel formulation to create a favorable bone-forming environment due to its excellent osteoconductivity. Degradation studies in α-MEM cell culture media showed that the 3D printed alginate-PVA-HA scaffolds remained in-tact for 14 days. MC3T3 cells were well distributed and encapsulated throughout the optimal hydrogel formulation and expressed high viability through the completion of the 3D printing process. Thus, the development of this novel, osteoconductive, biodegradable, alginate-PVA-HA formulation and its ability to 3D bioprint tissue engineered scaffolds make it a promising candidate for treating personalized bone defects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1457-1468, 2017. © 2017 Wiley Periodicals, Inc.

  7. Assessment of the Effect of Artesunate on the Developing Bones of Wistar Rat Animal Model of Malaria Treatment

    Directory of Open Access Journals (Sweden)

    Sunday Samuel Adebisi

    2010-02-01

    Full Text Available AIM: Among its contemporaries, artesunate, a semisynthetic artemisinin antimalarial is presently being esteemed above others as a ready combatant against the malaria menace plaguing most parts of the tropics; one, for being less or non-resisted by the parasite and two, less allergy-provoking to the users. However, recent clinical observations and experimental studies had implicated this drug to be embryo-fetal toxic and this had since generated research interests such as this, to ascertain the extent of the effects of artesunate on the morphology, weights and dimensions of the developing Wistar rat bones METHOD: Oral doses of 2mg/kg and 4mg/kg body weight were administered to each experimental pregnant Wistar rat from the 9th to the 11th day of gestation–being the active osteogenic period in this animal. Two rats were sacrificed each day from days 12 to 21 and foetuses retrieved and the following assessed on the skeleton: wet weights, dry weights, ash weights, fat free weights and total body weights, plus dimensions of long bones and pelvic bones. RESULTS: Compared to the control, all the parameters assessed were negatively affected in the treated groups, being more severe in the 4mg/kg rats. CONCLUSION: Artesunate, even at relatively low dosages appears to be hazardous to the structural integrity of bones particularly when administered at critical period of development, a point to note in the global quest to combat malaria cum polio, the presently well acknowledged ravaging twin menace in the tropics. [TAF Prev Med Bull 2010; 9(1.000: 23-28

  8. 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...

  9. Associations among Epstein-Barr virus subtypes, human leukocyte antigen class I alleles, and the development of posttransplantation lymphoproliferative disorder in bone marrow transplant recipients

    NARCIS (Netherlands)

    Görzer, Irene; Puchhammer-Stöckl, Elisabeth; van Esser, Joost W J; Niesters, Hubert G M; Cornelissen, Jan J

    2007-01-01

    The association between Epstein-Barr virus subtype, human leukocyte antigen class I alleles, and the development of posttransplantation lymphoproliferative disorder was examined in a group of 25 bone marrow transplant recipients. A highly statistically significant correlation was observed between

  10. A shared biomechanical environment for bone and posture development in children.

    Science.gov (United States)

    Araújo, Fábio A; Martins, Ana; Alegrete, Nuno; Howe, Laura D; Lucas, Raquel

    2017-10-01

    In each specific habitual standing posture, gravitational forces determine the mechanical setting provided to skeletal structures. Bone quality and resistance to physical stress is highly determined by habitual mechanical stimulation. However, the relationship between bone properties and sagittal posture has never been studied in children. This study aimed to investigate the association between bone physical properties and sagittal standing postural patterns in 7-year-old children. We also analyzed the relationship between fat or fat-free mass and postural patterns. Cross-sectional evaluation. This study was performed in a sample of 1,138 girls and 1,260 boys at 7 years of age participating in the Generation XXI study, a population-based cohort of children followed since birth (2005-2006) and recruited in Porto, Portugal. Sagittal standing posture was measured through photographs of the sagittal right view of children in the standing position. Three angles were considered to quantify the magnitude of major curves of the spine and an overall balance measure (trunk, lumbar, and sway angles). Postural patterns were identified using latent profile analysis in Mplus. Weight and height were measured. Total body less head fat or fat-free mass and bone properties were estimated from whole-body dual-energy X-ray absorptiometry scans. The associations of fat or fat-free mass and bone physical properties with postural patterns were jointly estimated in latent profile analysis using multinomial logistic regressions. The identified patterns were labeled as Sway, Flat, and "Neutral to Hyperlordotic" (in girls), and "Sway to Neutral," Flat, and Hyperlordotic (in boys). In both genders, children in the Flat pattern showed the lowest body mass index, and children with a rounded posture presented the highest: mean differences varying from -0.86 kg/m(2) to 0.60 kg/m(2) in girls and from -0.70 kg/m(2) to 0.62 kg/m(2) in boys (vs. Sway or "Sway to Neutral"). Fat and fat

  11. Development of an Injectable Calcium Phosphate/Hyaluronic Acid Microparticles System for Platelet Lysate Sustained Delivery Aiming Bone Regeneration.

    Science.gov (United States)

    Babo, Pedro S; Santo, Vítor E; Gomes, Manuela E; Reis, Rui L

    2016-11-01

    Despite the biocompatibility and osteoinductive properties of calcium phosphate (CaP) cements their low biodegradability hampers full bone regeneration. Herein the incorporation of CaP cement with hyaluronic acid (HAc) microparticles loaded with platelet lysate (PL) to improve the degradability and biological performance of the cements is proposed. Cement formulations incorporating increasing weight ratios of either empty HAc microparticles or microparticles loaded with PL (10 and 20 wt%) are developed as well as cements directly incorporating PL. The direct incorporation of PL improves the mechanical properties of the plain cement, reaching values similar to native bone. Morphological analysis shows homogeneous particle distribution and high interconnectivity between the HAc microparticles. The cements incorporating PL (with or without the HAc microparticles) present a sustained release of PL proteins for up to 8 d. The sustained release of PL modulates the expression of osteogenic markers in seeded human adipose tissue derived stem cells, thus suggesting the stimulatory role of this hybrid system toward osteogenic commitment and bone regeneration applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Development of a rapid culture method to induce adipocyte differentiation of human bone marrow-derived mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Ninomiya, Yuichi [Translational Research Center, Saitama International Medical, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 (Japan); Sugahara-Yamashita, Yzumi; Nakachi, Yutaka; Tokuzawa, Yoshimi; Okazaki, Yasushi [Division of Functional Genomics and Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University, Saitama 350-1241 (Japan); Nishiyama, Masahiko, E-mail: yamacho@saitama-med.ac.jp [Translational Research Center, Saitama International Medical, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1298 (Japan)

    2010-04-02

    Human mesenchymal stem cells (hMSCs) derived from bone marrow are multipotent stem cells that can regenerate mesenchymal tissues such as adipose, bone or muscle. It is thought that hMSCs can be utilized as a cell resource for tissue engineering and as human models to study cell differentiation mechanisms, such as adipogenesis, osteoblastogenesis and so on. Since it takes 2-3 weeks for hMSCs to differentiate into adipocytes using conventional culture methods, the development of methods to induce faster differentiation into adipocytes is required. In this study we optimized the culture conditions for adipocyte induction to achieve a shorter cultivation time for the induction of adipocyte differentiation in bone marrow-derived hMSCs. Briefly, we used a cocktail of dexamethasone, insulin, methylisobutylxanthine (DIM) plus a peroxisome proliferator-activated receptor {gamma} agonist, rosiglitazone (DIMRo) as a new adipogenic differentiation medium. We successfully shortened the period of cultivation to 7-8 days from 2-3 weeks. We also found that rosiglitazone alone was unable to induce adipocyte differentiation from hMSCs in vitro. However, rosiglitazone appears to enhance hMSC adipogenesis in the presence of other hormones and/or compounds, such as DIM. Furthermore, the inhibitory activity of TGF-{beta}1 on adipogenesis could be investigated using DIMRo-treated hMSCs. We conclude that our rapid new culture method is very useful in measuring the effect of molecules that affect adipogenesis in hMSCs.

  13. Stimulation of Wnt/β-Catenin Signaling to Improve Bone Development by Naringin via Interacting with AMPK and Akt

    Directory of Open Access Journals (Sweden)

    Dawei Wang

    2015-07-01

    Full Text Available Background/Aims: Naringin is a naturally existing compound in citrus fruits and has been elucidated to promote bone development and maintenance. Methods: The biological roles of naringin were investigated in vitro using osteoblast-like UMR-106 cells, and in vivo through performing ovariectomy to mimic osteoporosis in female mice. Since Wnt/β-catenin signaling is involved in osteoblastogenesis, the effect of naringin on Wnt/β-catenin signaling was studied. Results: Naringin promoted the mRNA and protein expressions of β-catenin, and improved Ser552 phosphorylation on β-catenin in UMR-106 cells, which leads to the activation of lymphoid enhancer factor (LEF/ T-cell factor (TCF transcription factors. The recruitments of protein kinase B (Akt inhibitor (Akti-1/2 and AMP-activated protein kinase (AMPK inhibitor (Dorsomorphin reduced the influence of naringin on β-catenin phosphorylation, suggesting naringin activates β-catenin via regulating Akt and AMPK. In ovariectomized (OVX mice naringin treatment improved the bone strength while AMPK and Akt inhibitors partly reversed the effect, which further proved the involvements of Akt and AMPK in the action of naringin in vivo. Conclusion: Our study points to a novel finding on the mechanism of naringin in facilitating bone formation via Akt and AMPK signaling.

  14. The developing temporal bone: computed tomography measurements and assessment of suture closure from birth to 18 years of age.

    Science.gov (United States)

    Paetz, P; Goetz, G F; Lanfermann, H; Giesemann, A M

    2017-06-01

    To describe the normal CT appearance of the developing temporal bone in children from birth to 18 years of age. Two hundred and six temporal bone CTs of children from 0.14 to 18.95 years were retrospectively selected and reviewed. Temporal bones were measured in a standardized slice orientation using the length of the basal turn of the cochlea, the length and width of the petrous bone, the coronal extent, trailing edge and anterior-posterior dimension of the temporal bone and the angle between petrous bone's length and the midsagittal line in the axial plane showing the basal turn of the cochlea in its greatest extent. Two sutures, two synchondroses and three fissures of the temporal bone were evaluated and graded. Chosen measurements and calculations demonstrate an increase of values from 0 to 18 years with the greatest increase occurring during the first 2 years of life. The angle between the basal turn of the cochlea and the midsagittal line shows a large variability. Logarithmic trend lines illustrate larger measurements of males as compared to females. The ratio of the basal turn of the cochlea and the length of the petrous bone is about 1:4.1 (f/m) during the first year of life and about 1:6.1 (f)/1:6.8 (m) from 17 years onwards. Results of suture closure are described using box-and-whisker plots. The developing temporal bone grows the most during the first 2 years of life. Knowledge of changing proportions and suture closure is essential for evaluation of temporal bone CT of children.

  15. Long-term trend of bone development in the contemporary teenagers of Chinese Han nationality.

    Science.gov (United States)

    Wang, Ya-Hui; Ying, Chong-Liang; Wan, Lei; Zhu, Guang-You

    2012-08-01

    To further improve the accuracy of bone age identification using the time of secondary ossification center appearance and epiphyseal fusion of 7 joints to estimate the age of living individuals. DR films were taken from 7 parts including sternal end of clavical and the left side of shoulder, elbow, carpal, hip, knee and ankle joints of 1 709 individuals who came from eastern China, central China and southern China, whose ages were between 11.0 and 20.0 years. From those 7 joints 24 osteal loci were selected as bone age indexes, which could better reflect age growth of teenagers. The characteristics of secondary ossification center appearance and epiphyseal fusion were observed, and the mean and age range of secondary ossification center appearance and epiphyseal fusion were calculated. The fusion time of the 24 epiphyses were advanced at different degrees, the most obvious epiphyses the sternal end of clavicle, scapular acromial end, distal end of the radius, distal end of the ulna, iliac crest, ischial tuberosity, the upper and lower end of tibia and fibula. The appearance time of sternal end of clavicle, scapular acromial end, iliac crest and ischial tuberosity epiphyses were all found to be after the age of 12, and the female's age, approximately 1 year ahead of schedule in comparison with the male's. The relevant forensic information and data for bone age identification should be updated every 10-15 years so as to provide accurate and objective evidence for court testimony, conviction and sentencing.

  16. Development of 166Ho-zoledronate as a bone marrow ablative agent

    Directory of Open Access Journals (Sweden)

    Mirsaeed Nikzad

    2016-02-01

    Full Text Available In this study, production, quality control and biodistribution studies of 166Ho-zoledronate have been presented as a possible bone marrow ablative agent. Ho-166 chloride was produced by thermal neutron irradiation of natural 165Ho(NO33 samples. 166Ho-zoledronate complex was prepared by adding the desired amount of zoledronate solution (0.2 mL, 150 mg/ml in 1 M NaOH to appropriate amount of the 166HoCl3 solution.  Radiochemical purity of the complex was monitored by instant thin layer chromatography (ITLC. Stability studies of the complex in the final preparation and in the presence of human serum were performed up to 48 h. The biodistribution of 166Ho-zoledronate and 166HoCl3 in wild-type mice was checked up to 72 h. 166Ho-zoledronate complex was prepared in high radiochemical purity (> 99%, ITLC and specific activity of 4.4 GBq/mmol. The major accumulation of radiolabelled complex was observed in the bone tissue. These findings suggest 166Ho-zoledronatehas can be a possible candidate for bone marrow ablation in patients with multiple myeloma.

  17. Bone Diseases

    Science.gov (United States)

    ... need to get enough calcium, vitamin D, and exercise. You should also avoid smoking and drinking too much alcohol. Bone diseases can make bones easy to break. Different kinds of bone problems include Low bone density and osteoporosis, which make your bones weak and ...

  18. Skeletal development of the hand and wrist: digital bone age companion - a suitable alternative to the Greulich and Pyle atlas for bone age assessment?

    Energy Technology Data Exchange (ETDEWEB)

    Bunch, Paul M. [Massachusetts General Hospital, Department of Radiology, Boston, MA (United States); Altes, Talissa A. [University of Missouri, Department of Radiology, Columbia, MO (United States); McIlhenny, Joan; Gaskin, Cree M. [University of Virginia Health System, Department of Radiology and Medical Imaging, PO Box 800170, Charlottesville, VA (United States); Patrie, James [University of Virginia Health System, Department of Health Evaluation Sciences, PO Box 800717, Charlottesville, VA (United States)

    2017-06-15

    To assess reader performance and subjective workflow experience when reporting bone age studies with a digital bone age reference as compared to the Greulich and Pyle atlas (G and P). We hypothesized that pediatric radiologists would achieve equivalent results with each method while digital workflow would improve speed, experience, and reporting quality. IRB approval was obtained for this HIPAA-compliant study. Two pediatric radiologists performed research interpretations of bone age studies randomized to either the digital (Digital Bone Age Companion, Oxford University Press) or G and P method, generating reports to mimic clinical workflow. Bone age standard selection, interpretation-reporting time, and user preferences were recorded. Reports were reviewed for typographical or speech recognition errors. Comparisons of agreement were conducted by way of Fisher's exact tests. Interpretation-reporting times were analyzed on the natural logarithmic scale via a linear mixed model and transformed to the geometric mean. Subjective workflow experience was compared with an exact binomial test. Report errors were compared via a paired random permutation test. There was no difference in bone age determination between atlases (p = 0.495). The interpretation-reporting time (p < 0.001) was significantly faster with the digital method. The faculty indicated preference for the digital atlas (p < 0.001). Signed reports had fewer errors with the digital atlas (p < 0.001). Bone age study interpretations performed with the digital method were similar to those performed with the Greulich and Pyle atlas. The digital atlas saved time, improved workflow experience, and reduced reporting errors relative to the Greulich and Pyle atlas when integrated into electronic workflow. (orig.)

  19. Guided bone regeneration : the influence of barrier membranes on bone grafts and bone defects

    NARCIS (Netherlands)

    Gielkens, Pepijn Frans Marie

    2008-01-01

    Guided bone regeneration (GBR) can be described as the use of a barrier membrane to provide a space available for new bone formation in a bony defect. The barrier membrane protects the defect from in-growth of soft tissue cells and allows bone progenitor cells to develop bone within a blood clot

  20. Acceleration of bone development and regeneration through the Wnt/β-catenin signaling pathway in mice heterozygously deficient for GSK-3β

    Energy Technology Data Exchange (ETDEWEB)

    Arioka, Masaki [Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan); Department of Oral and Maxillofacial Surgery, Faculty of Dental Science, Kyushu University, Fukuoka (Japan); Takahashi-Yanaga, Fumi, E-mail: yanaga@clipharm.med.kyushu-u.ac.jp [Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan); Global Medical Science Education Unit, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan); Sasaki, Masanori [Department of Oral and Maxillofacial Surgery, Faculty of Dental Science, Kyushu University, Fukuoka (Japan); Yoshihara, Tatsuya; Morimoto, Sachio [Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan); Takashima, Akihiko [Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Oobu (Japan); Mori, Yoshihide [Department of Oral and Maxillofacial Surgery, Faculty of Dental Science, Kyushu University, Fukuoka (Japan); Sasaguri, Toshiyuki [Department of Clinical Pharmacology, Faculty of Medical Sciences, Kyushu University, Fukuoka (Japan)

    2013-11-01

    Highlights: •The Wnt/β-catenin signaling pathway was activated in GSK-3β{sup +/−} mice. •The cortical and trabecular bone volumes were increased in GSK-3β{sup +/−} mice. •Regeneration of a partial bone defect was accelerated in GSK-3β{sup +/−} mice. -- Abstract: Glycogen synthase kinase (GSK)-3β plays an important role in osteoblastogenesis by regulating the Wnt/β-catenin signaling pathway. Therefore, we investigated whether GSK-3β deficiency affects bone development and regeneration using mice heterozygously deficient for GSK-3β (GSK-3β{sup +/−}). The amounts of β-catenin, c-Myc, cyclin D1, and runt-related transcription factor-2 (Runx2) in the bone marrow cells of GSK-3β{sup +/−} mice were significantly increased compared with those of wild-type mice, indicating that Wnt/β-catenin signals were enhanced in GSK-3β{sup +/−} mice. Microcomputed tomography of the distal femoral metaphyses demonstrated that the volumes of both the cortical and trabecular bones were increased in GSK-3β{sup +/−} mice compared with those in wild-type mice. Subsequently, to investigate the effect of GSK-3β deficiency on bone regeneration, we established a partial bone defect in the femur and observed new bone at 14 days after surgery. The volume and mineral density of the new bone were significantly higher in GSK-3β{sup +/−} mice than those in wild-type mice. These results suggest that bone formation and regeneration in vivo are accelerated by inhibition of GSK-3β, probably through activation of the Wnt/β-catenin signaling pathway.

  1. Development of multisubstituted hydroxyapatite nanopowders as biomedical materials for bone tissue engineering applications.

    Science.gov (United States)

    Baba Ismail, Yanny M; Wimpenny, Ian; Bretcanu, Oana; Dalgarno, Kenneth; El Haj, Alicia J

    2017-06-01

    Ionic substitutions have been proposed as a tool to control the functional behavior of synthetic hydroxyapatite (HA), particularly for Bone Tissue Engineering applications. The effect of simultaneous substitution of different levels of carbonate (CO 3 ) and silicon (Si) ions in the HA lattice was investigated. Furthermore, human bone marrow-derived mesenchymal stem cells (hMSCs) were cultured on multi-substituted HA (SiCHA) to determine if biomimetic chemical compositions were osteoconductive. Of the four different compositions investigates, SiCHA-1 (0.58 wt % Si) and SiCHA-2 (0.45 wt % Si) showed missing bands for CO 3 and Si using FTIR analysis, indicating competition for occupation of the phosphate site in the HA lattice; 500°C was considered the most favorable calcination temperature as: (i) the powders produced possessed a similar amount of CO 3 (2-8 wt %) and Si (<1.0 wt %) as present in native bone; and (ii) there was a minimal loss of CO 3 and Si from the HA structure to the surroundings during calcination. Higher Si content in SiCHA-1 led to lower cell viability and at most hindered proliferation, but no toxicity effect occurred. While, lower Si content in SiCHA-2 showed the highest ALP/DNA ratio after 21 days culture with hMSCs, indicating that the powder may stimulate osteogenic behavior to a greater extent than other powders. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1775-1785, 2017. © 2017 Wiley Periodicals, Inc.

  2. Spatial regulation of bone morphogenetic proteins (BMPs) in postnatal articular and growth plate cartilage

    Science.gov (United States)

    Garrison, Presley; Yue, Shanna; Hanson, Jeffrey; Baron, Jeffrey; Lui, Julian C.

    2017-01-01

    Articular and growth plate cartilage both arise from condensations of mesenchymal cells, but ultimately develop important histological and functional differences. Each is composed of three layers—the superficial, mid and deep zones of articular cartilage and the resting, proliferative and hypertrophic zones of growth plate cartilage. The bone morphogenetic protein (BMP) system plays an important role in cartilage development. A gradient in expression of BMP-related genes has been observed across growth plate cartilage, likely playing a role in zonal differentiation. To investigate the presence of a similar expression gradient in articular cartilage, we used laser capture microdissection (LCM) to separate murine growth plate and articular cartilage from the proximal tibia into their six constituent zones, and used a solution hybridization assay with color-coded probes (nCounter) to quantify mRNAs for 30 different BMP-related genes in each zone. In situ hybridization and immunohistochemistry were then used to confirm spatial expression patterns. Expression gradients for Bmp2 and 6 were observed across growth plate cartilage with highest expression in hypertrophic zone. However, intracellular BMP signaling, assessed by phospho-Smad1/5/8 immunohistochemical staining, appeared to be higher in the proliferative zone and prehypertrophic area than in hypertrophic zone, possibly due to high expression of Smad7, an inhibitory Smad, in the hypertrophic zone. We also found BMP expression gradients across the articular cartilage with BMP agonists primarily expressed in the superficial zone and BMP functional antagonists primarily expressed in the deep zone. Phospho-Smad1/5/8 immunohistochemical staining showed a similar gradient. In combination with previous evidence that BMPs regulate chondrocyte proliferation and differentiation, the current findings suggest that BMP signaling gradients exist across both growth plate and articular cartilage and that these gradients may

  3. Demineralized Bone Matrix to Augment Tendon-Bone Healing: A Systematic Review.

    Science.gov (United States)

    Hexter, Adam T; Pendegrass, Catherine; Haddad, Fares; Blunn, Gordon

    2017-10-01

    Following injury to the rotator cuff and anterior cruciate ligament, a direct enthesis is not regenerated, and healing occurs with biomechanically inferior fibrous tissue. Demineralized bone matrix (DBM) is a collagen scaffold that contains growth factors and is a promising biological material for tendon and ligament repair because it can regenerate a direct fibrocartilaginous insertion via endochondral ossification. To provide a comprehensive review of the literature investigating the use of DBM to augment tendon-bone healing in tendon repair and anterior cruciate ligament reconstruction (ACLR). Systematic review. Electronic databases (MEDLINE and EMBASE) were searched for preclinical and clinical studies that evaluated the use of DBM in tendon repair and ACLR. Search terms included the following: ("demineralized bone matrix" OR "demineralized cortical bone") AND ("tissue scaffold" OR "tissue engineering" OR "ligament" OR "tendon" OR "anterior cruciate ligament" OR "rotator cuff"). Peer-reviewed articles written in English were included, and no date restriction was applied (searches performed February 10, 2017). Methodological quality was assessed with peer-reviewed scoring criteria. The search strategy identified 339 articles. After removal of duplicates and screening according to inclusion criteria, 8 studies were included for full review (tendon repair, n = 4; ACLR, n = 4). No human clinical studies were identified. All 8 studies were preclinical animal studies with good methodological quality. Five studies compared DBM augmentation with non-DBM controls, of which 4 (80%) reported positive findings in terms of histological and biomechanical outcomes. Preclinical evidence indicates that DBM can improve tendon-bone healing, although clinical studies are lacking. A range of animal models of tendon repair and ACLR showed that DBM can re-create a direct fibrocartilaginous enthesis, although the animal models are not without limitations. Before clinical trials are

  4. Different sympathetic pathways control the metabolism of distinct bone envelopes.

    Science.gov (United States)

    Bataille, Caroline; Mauprivez, Cédric; Haÿ, Eric; Baroukh, Brigitte; Brun, Adrian; Chaussain, Catherine; Marie, Pierre J; Saffar, Jean-Louis; Cherruau, Marc

    2012-05-01

    Bone remodeling, the mechanism that modulates bone mass adaptation, is controlled by the sympathetic nervous system through the catecholaminergic pathway. However, resorption in the mandible periosteum envelope is associated with cholinergic Vasoactive Intestinal Peptide (VIP)-positive nerve fibers sensitive to sympathetic neurotoxics, suggesting that different sympathetic pathways may control distinct bone envelopes. In this study, we assessed the role of distinct sympathetic pathways on rat femur and mandible envelopes. To this goal, adult male Wistar rats were chemically sympathectomized or treated with agonists/antagonists of the catecholaminergic and cholinergic pathways; femora and mandibles were sampled. Histomorphometric analysis showed that sympathectomy decreased the number of preosteoclasts and RANKL-expressing osteoblasts in mandible periosteum but had no effect on femur trabecular bone. In contrast, pharmacological stimulation or repression of the catecholaminergic cell receptors impacted the femur trabecular bone and mandible endosteal retromolar zone. VIP treatment of sympathectomized rats rescued the disturbances of the mandible periosteum and alveolar wall whereas the cholinergic pathway had no effect on the catecholaminergic-dependent envelopes. We also found that VIP receptor-1 was weakly expressed in periosteal osteoblasts in the mandible and was increased by VIP treatment, whereas osteoblasts of the retromolar envelope that was innervated only by tyrosine hydroxylase-immunoreactive fibers, constitutively expressed beta-2 adrenergic receptors. These data highlight the complexity of the sympathetic control of bone metabolism. Both the embryological origin of the bone (endochondral for the femur, membranous for the mandibular periosteum and the socket wall) and environmental factors specific to the innervated envelope may influence the phenotype of the sympathetic innervation. We suggest that an origin-dependent imprint of bone cells through

  5. Bone Metastasis

    Science.gov (United States)

    ... help reduce pain and other symptoms of bone metastases. Symptoms Sometimes, bone metastasis causes no signs and ... cancers most likely to cause bone metastasis include: Breast cancer Kidney cancer Lung cancer Lymphoma Multiple myeloma Prostate ...

  6. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  7. A paradigm for the development and evaluation of novel implant topologies for bone fixation: in vivo evaluation.

    Science.gov (United States)

    Long, Jason P; Hollister, Scott J; Goldstein, Steven A

    2012-10-11

    While contemporary prosthetic devices restore some function to individuals who have lost a limb, there are efforts to develop bio-integrated prostheses to improve functionality. A critical step in advancing this technology will be to securely attach the device to remnant bone. To investigate mechanisms for establishing robust implant fixation in bone while undergoing loading, we previously used a topology optimization scheme to develop optimized orthopedic implants and then fabricated selected designs from titanium (Ti)-alloy with selective laser sintering (SLS) technology. In the present study, we examined how implant architecture and mechanical stimulation influence osseointegration within an in vivo environment. To do this, we evaluated three implant designs (two optimized and one non-optimized) using a unique in vivo model that applied cyclic, tension/compression loads to the implants. Eighteen (six per implant design) adult male canines had implants surgically placed in their proximal, tibial metaphyses. Experimental duration was 12 weeks; daily loading (peak load of ±22 N for 1000 cycles) was applied to one of each animal's bilateral implants for the latter six weeks. Following harvest, osseointegration was assessed by non-destructive mechanical testing, micro-computed tomography (microCT) and back-scatter scanning electron microscopy (SEM). Data revealed that implant loading enhanced osseointegration by significantly increasing construct stiffness, peri-implant trabecular morphology, and percentages of interface connectivity and bone ingrowth. While this experiment did not demonstrate a clear advantage associated with the optimized implant designs, osseointegration was found to be significantly influenced by aspects of implant architecture. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Reverse-phase protein array for prediction of patients at low risk of developing bone metastasis from breast cancer.

    Science.gov (United States)

    Hayashi, Naoki; Manyam, Ganiraju C; Gonzalez-Angulo, Ana M; Niikura, Naoki; Yamauchi, Hideko; Nakamura, Seigo; Hortobágyi, Gabriel N; Baggerly, Keith A; Ueno, Naoto T

    2014-09-01

    A biomarker that predicts bone metastasis based on a protein laboratory assay has not been demonstrated. Reverse-phase protein array (RPPA) enables quantification of total and phosphorylated proteins, providing information about their functional status. The aim of this study was to identify bone-metastasis-related markers in patients with primary breast cancer using RPPA analysis. Tumor samples were obtained from 169 patients with primary invasive breast carcinoma who underwent surgery. The patients were categorized by whether they developed breast cancer bone metastasis (BCBM) during follow-up. Clinical characteristics and protein expression by RPPA were compared and verified by leave-one-out cross-validation. Lymph node status (p = .023) and expression level of 22 proteins by RPPA were significantly correlated with BCBM in logistic regression analysis. These variables were used to build a logistic regression model. After filtering the variables through a stepwise algorithm, the final model, consisting of 8 proteins and lymph node status, had sensitivity of 30.0%, specificity of 90.5%, positive predictive value of 30.0%, and negative predictive value of 90.5% in the cross-validation. Most of the identified proteins were associated with cell cycle or signal transduction (CDK2, CDKN1A, Rb1, Src, phosphorylated-ribosomal S6 kinase, HER2, BCL11A, and MYH11). Our validated model, in which the primary tumor is tested with RPPA, can predict patients who are at low risk of developing BCBM and thus who likely would not benefit from receiving a bisphosphonate in the adjuvant setting. Clinical trials excluding these patients have the potential to clarify the benefit of bisphosphonates in the adjuvant setting. ©AlphaMed Press.

  9. Development of finite element model for customized prostheses design for patient with pelvic bone tumor.

    Science.gov (United States)

    Iqbal, Taimoor; Shi, Lei; Wang, Ling; Liu, Yaxiong; Li, Dichen; Qin, Mian; Jin, Zhongmin

    2017-06-01

    The aim of this study was to design a hemi-pelvic prosthesis for a patient affected by pelvic sarcoma. To investigate the biomechanical functionality of the pelvis reconstructed with designed custom-made prosthesis, a patient-specific finite element model of whole pelvis with primary ligaments inclusive was constructed based on the computed tomography images of the patient. Then, a finite element analysis was performed to calculate and compare the stress distribution between the normal and implanted pelvis models when undergoing three different static conditions-both-leg standing, single-leg standing for the healthy and the affected one. No significant differences were observed in the stresses between the normal and reconstructed pelvis for both-leg standing, but 20%-40% larger stresses were predicted for the peak stress of the single-leg standing (affected side). Moreover, two- to threefold of peak stresses were predicted within the prostheses compared to that of the normal pelvis especially for single-leg standing case, however, still below the allowable fatigue limitation. The study on the load transmission functionality of prosthesis indicated that it is crucial to carry out finite element analysis for functional evaluation of the designed customized prostheses before three-dimensional printing manufacturing, allowing better understanding of the possible peak stresses within the bone as well as the implants for safety precaution. The finite element model can be equally applicable to other bone tumor model for biomechanical studying.

  10. Development of Composite Scaffolds for Load-Bearing Segmental Bone Defects

    Directory of Open Access Journals (Sweden)

    Marcello Pilia

    2013-01-01

    Full Text Available The need for a suitable tissue-engineered scaffold that can be used to heal load-bearing segmental bone defects (SBDs is both immediate and increasing. During the past 30 years, various ceramic and polymer scaffolds have been investigated for this application. More recently, while composite scaffolds built using a combination of ceramics and polymeric materials are being investigated in a greater number, very few products have progressed from laboratory benchtop studies to preclinical testing in animals. This review is based on an exhaustive literature search of various composite scaffolds designed to serve as bone regenerative therapies. We analyzed the benefits and drawbacks of different composite scaffold manufacturing techniques, the properties of commonly used ceramics and polymers, and the properties of currently investigated synthetic composite grafts. To follow, a comprehensive review of in vivo models used to test composite scaffolds in SBDs is detailed to serve as a guide to design appropriate translational studies and to identify the challenges that need to be overcome in scaffold design for successful translation. This includes selecting the animal type, determining the anatomical location within the animals, choosing the correct study duration, and finally, an overview of scaffold performance assessment.

  11. Development of 3D CAD/FEM Analysis System for Natural Teeth and Jaw Bone Constructed from X-Ray CT Images

    Directory of Open Access Journals (Sweden)

    Aki Hasegawa

    2010-01-01

    Full Text Available A three-dimensional finite element model of the lower first premolar, with the three layers of enamel, dentin, and pulp, and the mandible, with the two layers of cortical and cancellous bones, was directly constructed from noninvasively acquired CT images. This model was used to develop a system to analyze the stresses on the teeth and supporting bone structure during occlusion based on the finite element method and to examine the possibility of mechanical simulation.

  12. Stimulation of bone cell differentiation by low-intensity ultrasound--a histomorphometric in vitro study.

    Science.gov (United States)

    Korstjens, C M; Nolte, P A; Burger, E H; Albers, G H R; Semeins, C M; Aartman, I H A; Goei, S W; Klein-Nulend, J

    2004-05-01

    Several investigations have established a stimulatory effect of low-intensity ultrasound treatment on osteogenesis and fracture healing. The objective of this study was to examine whether the stimulatory effect of low-intensity ultrasound results in increased bone cell activity and/or proliferation. Twenty-four paired triplets of metatarsal bone rudiments of twelve 17-days-old fetal mice were dissected and divided into two groups. One group of bone rudiments was treated with pulsating low-intensity ultrasound (30 mW/cm(2); 1.5 MHz) for 20 min/day for a period of 3 or 6 days. The other group served as controls. After culture, the metatarsal bone rudiments were prepared for computer aided light microscopy. The following histomorphometric parameters were determined: length, width and volume of the calcified cartilage and of the bone collar, and cell number. GLM analysis demonstrated that bone collar volume and calcified cartilage percentage were significantly higher in the ultrasound-stimulated rudiments compared to untreated controls. Further, the calcified cartilage volume bordering the hypertrophic zone was significantly higher than in the center of the bone rudiment. Ultrasound treatment did not change the number of the cells. These results suggest that the stimulatory effect of low-intensity ultrasound on endochondral ossification is likely due to stimulation of bone cell differentiation and calcified matrix production, but not to changed cell proliferation.

  13. Involvement of chemokine CXCL11 in the development of morphine tolerance in rats with cancer-induced bone pain.

    Science.gov (United States)

    Guo, Genhua; Peng, Yawen; Xiong, Bingrui; Liu, Daiqiang; Bu, Huilian; Tian, Xuebi; Yang, Hui; Wu, Zhen; Cao, Fei; Gao, Feng

    2017-05-01

    Morphine is viewed as one of the classical treatments for intractable pain, but its role is limited by side effects, including analgesic tolerance. A few chemokines have been reported to be engaged in the mechanisms of morphine tolerance. However, the exact roles of CXC chemokine 11 (CXCL11) in chronic morphine tolerance remain unknown. In this study, Walker 256 mammary gland carcinoma cells were inoculated into the tibia of rats to provoke cancer-induced bone pain. Then, morphine was intrathecally administered twice daily for seven consecutive days to induce drug tolerance. We found that the level of CXCL11 in lumbar spinal cord was increased during the development of morphine tolerance in cancer-induced bone pain rats. Meanwhile, CXCL11 was co-localized with markers of astrocytes and neurons in the spinal cord. Inhibition of CXCL11 by neutralizing antibodies could remarkably attenuate the degree of morphine tolerance and decrease the activation of astrocytes. Moreover, blocking astrocyte activation by d, l-Fluorocitric acid could distinctly alleviate morphine tolerance and reduce the expression of CXCL11. Finally, morphine stimulation could induce the release of CXCL11 by cultured astrocytes and neurons in vitro. In summary, our results provide evidence that spinal CXCL11 plays a powerful modulatory role in the development of morphine tolerance through cross-talking between astrocytes and neurons. Read the Review series "Pain". © 2016 International Society for Neurochemistry.

  14. Identification of the bovine Arachnomelia mutation by massively parallel sequencing implicates sulfite oxidase (SUOX in bone development.

    Directory of Open Access Journals (Sweden)

    Cord Drögemüller

    2010-08-01

    Full Text Available Arachnomelia is a monogenic recessive defect of skeletal development in cattle. The causative mutation was previously mapped to a ∼7 Mb interval on chromosome 5. Here we show that array-based sequence capture and massively parallel sequencing technology, combined with the typical family structure in livestock populations, facilitates the identification of the causative mutation. We re-sequenced the entire critical interval in a healthy partially inbred cow carrying one copy of the critical chromosome segment in its ancestral state and one copy of the same segment with the arachnomelia mutation, and we detected a single heterozygous position. The genetic makeup of several partially inbred cattle provides extremely strong support for the causality of this mutation. The mutation represents a single base insertion leading to a premature stop codon in the coding sequence of the SUOX gene and is perfectly associated with the arachnomelia phenotype. Our findings suggest an important role for sulfite oxidase in bone development.

  15. Osseointegration aspects of placed implant in bone reconstruction with newly developed block-type interconnected porous calcium hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Kazuya DOI

    Full Text Available ABSTRACT Artificial bone has been employed to reconstruct bone defects. However, only few reports on implant placement after block bone grafting exist. Objectives The purpose of this study was to evaluate the osseointegration of dental implant in bone reconstructions with interconnected porous calcium hydroxyapatite (IP-CHA. Material and Methods The IP-CHA cylinders (D; 4.3 mm, H; 10.0 mm were placed into bone sockets in each side of the femurs of four male dogs. The IP-CHA on the right side was a 24-week sample. Twelve weeks after placement, a titanium implant was placed into a socket that was prepared in half of the placed IP-CHA cylinder on the right side. On the left side, another IP-CHA cylinder was placed as a 12-week sample. After another 12 weeks, the samples were harvested, and the bone regeneration and bone-implant contact (BIC ratios were measured. Results New bone formation area was superior in the 24-week IP-CHA compared with the 12-week IP-CHA. BIC was not significantly different between IP-CHA and the parent sites. Osseointegration was detected around the implant in IP-CHA-reconstructed bone. Conclusion Our preliminary results suggest that IP-CHA may be a suitable bone graft material for reconstructing bones that require implant placement.

  16. Developing a bone mineral density test result letter to send to patients: a mixed-methods study

    Directory of Open Access Journals (Sweden)

    Edmonds SW

    2014-06-01

    Full Text Available Stephanie W Edmonds,1,2 Samantha L Solimeo,3 Xin Lu,1 Douglas W Roblin,4,8 Kenneth G Saag,5 Peter Cram6,7 1Department of Internal Medicine, 2College of Nursing, University of Iowa, Iowa City, IA, USA; 3Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City Veterans Affairs Health Care System, Iowa City, IA, USA; 4Kaiser Permanente of Atlanta, Atlanta, GA, USA; 5Department of Rheumatology, University of Alabama at Birmingham, Birmingham, AL, USA; 6Faculty of Medicine, University of Toronto, Toronto, ON, Canada; 7University Health Network and Mount Sinai Hospital, Toronto, ON, Canada; 8School of Public Health, Georgia State University, Atlanta, GA, USA Purpose: To use a mixed-methods approach to develop a letter that can be used to notify patients of their bone mineral density (BMD results by mail that may activate patients in their bone-related health care. Patients and methods: A multidisciplinary team developed three versions of a letter for reporting BMD results to patients. Trained interviewers presented these letters in a random order to a convenience sample of adults, aged 50 years and older, at two different health care systems. We conducted structured interviews to examine the respondents’ preferences and comprehension among the various letters. Results: A total of 142 participants completed the interview. A majority of the participants were female (64.1% and white (76.1%. A plurality of the participants identified a specific version of the three letters as both their preferred version (45.2%; P<0.001 and as the easiest to understand (44.6%; P<0.01. A majority of participants preferred that the letters include specific next steps for improving their bone health. Conclusion: Using a mixed-methods approach, we were able to develop and optimize a printed letter for communicating a complex test result (BMD to patients. Our results may offer guidance to clinicians, administrators, and researchers who are

  17. Skeletal development and bone-related gene expression in fish larvae

    OpenAIRE

    Gavaia, Paulo J.; CANCELA, Leonor

    2006-01-01

    The fish skeleton; skeletal malformations; skeletal malformations in mediterranean species; Types of skeletal malformations; Senegal sole skeletal development; Senegal sole skeletal deformities; Skeletal development in Danio rerio; ALP and TRAP in skeletal development; Skeletal development in Pagrus auriga; Time course of skeletal development in Pagrus auriga; Spatio-temporal pattern of bgp expression; bgp / mgp expression during development; In situ localization of zebrafish bgp mRNA;In situ...

  18. Development of a PCL-silica nanoparticles composite membrane for Guided Bone Regeneration.

    Science.gov (United States)

    Castro, Antonio G B; Diba, Mani; Kersten, Monique; Jansen, John A; van den Beucken, Jeroen J J P; Yang, Fang

    2018-04-01

    The pivotal step in Guided Bone Regeneration (GBR) therapy is the insertion of a membrane for support and barrier functions. Here, we studied the effect of the addition of silica nanoparticles (Si-NPs) in electrospun poly(ε-caprolactone) (PCL) membranes to improve the mechanical and osteoconductive properties of the membranes. To this end, Si-NPs were firstly synthesized and then suspended in PCL solutions containing a polar solvent (2,2,2-trifluroethanol) and water with the addition of an anionic surfactant. Nanocomposite membranes were fabricated from the solutions through an electrospinning technique. Morphology, structure and chemical composition, and tensile properties of the membranes were analyzed. Membrane stability was determined by visual examination of the membranes after immersion in phosphate buffered saline. The effect of the materials on osteoblastic differentiation was evaluated by in vitro culture of the membranes with MC3T3-E1 osteoblastic cells. The results indicated that Si-NPs were successfully incorporated in the interior of the PCL electrospun fibers during the electrospinning process. Tensile modulus was significantly increased for composition S50 and tensile strength significantly increased for compositions S25 and S50. Membranes containing Si-NPs have shown to be cytocompatible. The results obtained demonstrate that the Si-NPs were homogeneously incorporated in the electrospun fibers, resulting in an improvement of the tensile properties of the prepared materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Toxicity and biocompatibility profile of 3D bone scaffold developed by Universitas Indonesia: A preliminary study

    Science.gov (United States)

    Rahyussalim A., J.; Kurniawati, T.; Aprilya, D.; Anggraini, R.; Ramahdita, Ghiska; Whulanza, Yudan

    2017-02-01

    Scaffold as a biomaterial must fulfill some requirements to be safely implanted to the human body. Toxicity and biocompatibility test are needed to evaluate scaffold material in mediating cell proliferation and differentiation, secreting extracelullar matrix and carrying biomolecular signals for cell communication. An in vitro study with mesenchymal stem cells consisted of direct contact test and indirect contact test using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) tetrazolium reduction assay was conducted on 4 scaffolds made of poly-L-lactic acid (PLA), polyvinyl alcohol (PVA), and hydroxyapatite-poly (vinyl alcohol) composite. There were cells-substrate adhesion impairment, morphological changes, cell death and reduction in cell proliferation seen at 2nd and 6th day in most tested scaffold. Cell count result at day-6 showed proliferation inhibition of more than 50% cell death (inhibition value >50) in all tested scaffold. In MTT assay, two scaffolds were proven non-toxic. In conclusion, various scaffold materials showed different toxicity effect. The toxicity and biocompatibility profile in this study is a preliminary data for further research aiming to use those local-made scaffolds to fill human bone defect in various needs.

  20. Abnormal bone formation induced by implantation of osteosarcoma-derived bone-inducing substance in the X-linked hypophosphatemic mouse

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, H.; Masuhara, K.; Takaoka, K.; Ono, K.; Tanaka, H.; Seino, Y.

    1985-01-01

    The X-linked hypophosphatemic mouse (Hyp) has been proposed as a model for the human familial hypophosphatemia (the most common form of vitamin D-resistant rickets). An osteosarcoma-derived bone-inducing substance was subcutaneously implanted into the Hyp mouse. The implant was consistently replaced by cartilage tissue at 2 weeks after implantation. The cartilage matrix seemed to be normal, according to the histological examination, and 35sulphur (TVS) uptake was also normal. Up to 4 weeks after implantation the cartilage matrix was completely replaced by unmineralized bone matrix and hematopoietic bone marrow. Osteoid tissue arising from the implantation of bone inducing substance in the Hyp mouse showed no radiologic or histologic sign of calcification. These findings suggest that the abnormalities of endochondral ossification in the Hyp mouse might be characterized by the failure of mineralization in cartilage and bone matrix. Analysis of the effects of bone-inducing substance on the Hyp mouse may help to give greater insight into the mechanism and treatment of human familial hypophosphatemia.

  1. Biomaterials and bone mechanotransduction

    Science.gov (United States)

    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.

  2. Juxtaepiphyseal aneurysmal bone cyst

    Energy Technology Data Exchange (ETDEWEB)

    Capanna, R.; Biagini, R.; Ruggieri, P.; Giunti, A.; Springfield, D.S.

    1985-01-01

    Nine cases of aneurysmal bone cyst arising in juxtaepiphyseal locations with gross invasion of the adjacent growth plate are reported. In five of these patients in abnormality of growth, due to premature fusion of the affected growth plate, ultimately developed. Treatment of these lesions should attempt to avoid this complication, which appears to be more common than has been appreciated in the past. These nine cases represent 23% of 39 cases of aneurysmal bone cyst occurring in a long bone adjacent to an open epiphyseal plate. This series was extrapolated from a total of 198 cases of aneurysmal bone cyst in the files of the Istituto Ortopedico Rizzoli, Bologna, Italy.

  3. Bone marrow aspiration

    Science.gov (United States)

    Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

  4. Histological analyses demonstrate the temporary contribution of yolk sac, liver, and bone marrow to hematopoiesis during chicken development.

    Directory of Open Access Journals (Sweden)

    Priscila Tavares Guedes

    Full Text Available The use of avian animal models has contributed to the understanding of many aspects of the ontogeny of the hematopoietic system in vertebrates. However, specific events that occur in the model itself are still unclear. There is a lack of consensus, among previous studies, about which is the intermediate site responsible for expansion and differentiation of hematopoietic cells, and the liver's contribution to the development of this system. Here we aimed to evaluate the presence of hematopoiesis in the yolk sac and liver in chickens, from the stages of intra-aortic clusters in the aorta-genital ridges-mesonephros (AGM region until hatching, and how it relates to the establishment of the bone marrow. Gallus gallus domesticus L. embryos and their respective yolk sacs at embryonic day 3 (E3 and up to E21 were collected and processed according to standard histological techniques for paraffin embedding. The slides were stained with hematoxylin-eosin, Lennert's Giemsa, and Sirius Red at pH 10.2, and investigated by light microscopy. This study demonstrated that the yolk sac was a unique hematopoietic site between E4 and E12. Hematopoiesis occurred in the yolk sac and bone marrow between E13 and E20. The liver showed granulocytic differentiation in the connective tissue of portal spaces at E15 and onwards. The yolk sac showed expansion of erythrocytic and granulocytic lineages from E6 to E19, and E7 to E20, respectively. The results suggest that the yolk sac is the major intermediate erythropoietic and granulopoietic site where expansion and differentiation occur during chicken development. The hepatic hematopoiesis is restricted to the portal spaces and represented by the granulocytic lineage.

  5. "Bone Development" Is an Ontology Group Upregulated in Porcine Oocytes Before In Vitro Maturation: A Microarray Approach.

    Science.gov (United States)

    Budna, Joanna; Bryja, Artur; Celichowski, Piotr; Kranc, Wiesława; Ciesiółka, Sylwia; Borys, Sylwia; Rybska, Marta; Kolecka-Bednarczyk, Agata; Jeseta, Michal; Bukowska, Dorota; Antosik, Paweł; Brüssow, Klaus P; Bruska, Małgorzata; Nowicki, Michał; Zabel, Maciej; Kempisty, Bartosz

    2017-08-01

    Mammalian cumulus-oocyte complexes (COCs) reach full developmental capability during folliculogenesis and oogenesis. It is well recognized that only gametes achieving MII stage after in vivo or in vitro maturation (IVM) are successfully fertilized by a single spermatozoon. Although the process of oocyte nuclear and/or cytoplasmic maturation in pigs is well determined, there exist many differences that promote these processes in vivo and in vitro. Therefore, this study aimed to investigate the differences in RNA expression profiles between porcine oocytes before and after IVM using microarray and real-time quantitative polymerase chain reaction (RT-qPCR) assays. Experiments were performed on oocytes isolated from 55 pubertal crossbred Landrace gilts. The oocytes were analyzed both before and after IVM and only Brilliant Cresyl Blue (BCB)-positive gametes were used for subsequent microarray analysis (Affymetrix) and RT-qPCR analysis. The microarray assay, which measures expression of 12,258 transcripts, revealed 419 differentially expressed transcripts in porcine oocytes, from which 379 were downregulated and 40 were upregulated before IVM compared to those analyzed after IVM. After DAVID analysis, we found eight different transcripts, including IHH, BMP1, WWTR1, CHRDL1, KLF10, EIF2AK3, MMP14, and STC1. Their expression is related to the "bone development" ontology group and was further subjected to hierarchical clusterization. Using RT-qPCR analysis, we confirmed the results of the microarray assay, showing increased expression of the eight genes in oocytes before IVM compared to oocytes after maturation in vitro. It has been suggested that "bone development" belongs to one ontological group involving genes substantially upregulated in porcine oocytes before IVM. We suggest that the gamete mRNA expression profile before IVM may comprise stored transcripts, which are templates for protein biosynthesis following fertilization. We also hypothesize that these mRNAs may

  6. Bone cysts: unicameral and aneurysmal bone cyst.

    Science.gov (United States)

    Mascard, E; Gomez-Brouchet, A; Lambot, K

    2015-02-01

    Simple and aneurysmal bone cysts are benign lytic bone lesions, usually encountered in children and adolescents. Simple bone cyst is a cystic, fluid-filled lesion, which may be unicameral (UBC) or partially separated. UBC can involve all bones, but usually the long bone metaphysis and otherwise primarily the proximal humerus and proximal femur. The classic aneurysmal bone cyst (ABC) is an expansive and hemorrhagic tumor, usually showing characteristic translocation. About 30% of ABCs are secondary, without translocation; they occur in reaction to another, usually benign, bone lesion. ABCs are metaphyseal, excentric, bulging, fluid-filled and multicameral, and may develop in all bones of the skeleton. On MRI, the fluid level is evocative. It is mandatory to distinguish ABC from UBC, as prognosis and treatment are different. UBCs resolve spontaneously between adolescence and adulthood; the main concern is the risk of pathologic fracture. Treatment in non-threatening forms consists in intracystic injection of methylprednisolone. When there is a risk of fracture, especially of the femoral neck, surgery with curettage, filling with bone substitute or graft and osteosynthesis may be required. ABCs are potentially more aggressive, with a risk of bone destruction. Diagnosis must systematically be confirmed by biopsy, identifying soft-tissue parts, as telangiectatic sarcoma can mimic ABC. Intra-lesional sclerotherapy with alcohol is an effective treatment. In spinal ABC and in aggressive lesions with a risk of fracture, surgical treatment should be preferred, possibly after preoperative embolization. The risk of malignant transformation is very low, except in case of radiation therapy. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. HDAC6 deficiency or inhibition blocks FGFR3 accumulation and improves bone growth in a model of achondroplasia.

    Science.gov (United States)

    Ota, Sara; Zhou, Zi-Qiang; Romero, Megan P; Yang, Guang; Hurlin, Peter J

    2016-10-01

    Mutations that cause increased and/or inappropriate activation of FGFR3 are responsible for a collection of short-limbed chondrodysplasias. These mutations can alter receptor trafficking and enhance receptor stability, leading to increased receptor accumulation and activity. Here, we show that wildtype and mutant activated forms of FGFR3 increase expression of the cytoplasmic deacetylase HDAC6 (Histone Deacetylase 6) and that FGFR3 accumulation is compromised in cells lacking HDAC6 or following treatment of fibroblasts or chondrocytes with small molecule inhibitors of HDAC6. The reduced accumulation of FGFR3 was linked to increased FGFR3 degradation that occurred through a lysosome-dependent mechanism. Using a mouse model of Thanatophoric Dysplasia Type II (TDII) we show that both HDAC6 deletion and treatment with the small molecule HDAC6 inhibitor tubacin reduced FGFR3 accumulation in the growth plate and improved endochondral bone growth. Defective endochondral growth in TDII is associated with reduced proliferation and poor hypertrophic differentiation and the improved bone growth was associated with increased chondrocyte proliferation and expansion of the differentiation compartment within the growth plate. These findings further define the mechanisms that control FGFR3 accumulation and contribute to skeletal pathology caused by mutations in FGFR3. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  8. Development of the long bones in the hands and feet of children: radiographic and MR imaging correlation

    Energy Technology Data Exchange (ETDEWEB)

    Laor, Tal [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Clarke, Jeffrey P. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Children' s Healthcare of Atlanta, Department of Radiology, Atlanta, GA (United States); Yin, Hong [Children' s Healthcare of Atlanta, Department of Pathology, Atlanta, GA (United States)

    2016-04-15

    The long bones of the hands and feet in children have an epiphyseal end with a secondary center of ossification and an adjacent transverse physis. In contrast to other long bones in the body, the opposite end in the hands and feet, termed the non-epiphyseal end, is characterized by direct metaphyseal extension of bone to complete terminal ossification. The purpose of this pictorial essay is to illustrate the developmental stages of each end of the long bones of the hands and feet with radiographic and MR imaging to provide a foundation from which to differentiate normal from abnormal growth. (orig.)

  9. Low Bone Density

    Science.gov (United States)

    ... Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone density ... people with normal bone density. Detecting Low Bone Density A bone density test will determine whether you ...

  10. Neutrophil mediated IFN activation in the bone marrow alters B cell development in human and murine SLE1

    Science.gov (United States)

    Palanichamy, Arumugam; Bauer, Jason W; Yalavarthi, Srilakshmi; Meednu, Nida; Barnard, Jennifer; Owen, Teresa; Cistrone, Christopher; Bird, Anna; Rabinovich, Alfred; Nevarez, Sarah; Knight, Jason S.; Dedrick, Russell; Rosenberg, Alexander; Wei, Chungwen; Rangel-Moreno, Javier; Liesveld, Jane; Sanz, Inaki; Baechler, Emily; Kaplan, Mariana J.; Anolik, Jennifer H

    2014-01-01

    Inappropriate activation of type I interferon (IFN) plays a key role in the pathogenesis of autoimmune disease, including systemic lupus erythematosus (SLE). Here we report the presence of IFN activation in SLE bone marrow (BM), as measured by an IFN gene signature, increased IFN regulated chemokines, and direct production of IFN by BM resident cells, associated with profound changes in B cell development. The majority of SLE patients had an IFN signature in the BM that was more pronounced than the paired peripheral blood (PB) and correlated with both higher autoantibodies and disease activity. Pronounced alterations in B cell development were noted in SLE in the presence of an IFN signature with a reduction in the fraction of pro/pre B cells suggesting an inhibition in early B cell development and an expansion of B cells at the transitional (T2) stage. These B cell changes strongly correlated with an increase in BAFF and APRIL expression in the IFN high BM. Furthermore, we found that BM neutrophils in SLE were prime producers of IFN-α and B cell factors. In NZM lupus-prone mice similar changes in B cell development were observed and mediated by IFN, given abrogation in NZM mice lacking type I IFN receptor. BM neutrophils were abundant, responsive to and producers of IFN, in close proximity to B cells. These results indicate that the BM is an important but previously unrecognized target organ in SLE with neutrophil mediated IFN activation and alterations in B cell ontogeny and selection. PMID:24379124

  11. Development of a Functional Schwann Cell Phenotype from Autologous Porcine Bone Marrow Mononuclear Cells for Nerve Repair

    Directory of Open Access Journals (Sweden)

    Michael J. Rutten

    2012-01-01

    Full Text Available Adult bone marrow mononuclear cells (BM-MNCs are a potential resource for making Schwann cells to repair damaged peripheral nerves. However, many methods of producing Schwann-like cells can be laborious with the cells lacking a functional phenotype. The objective of this study was to develop a simple and rapid method using autologous BM-MNCs to produce a phenotypic and functional Schwann-like cell. Adult porcine bone marrow was collected and enriched for BM-MNCs using a SEPAX device, then cells cultured in Neurobasal media, 4 mM L-glutamine and 20% serum. After 6–8 days, the cultures expressed Schwann cell markers, S-100, O4, GFAP, were FluoroMyelin positive, but had low p75(NGF expression. Addition of neuregulin (1–25 nM increased p75(NGF levels at 24–48 hrs. We found ATP dose-dependently increased intracellular calcium [Ca2+]i, with nucleotide potency being UTP=ATP>ADP>AMP>adenosine. Suramin blocked the ATP-induced [Ca2+]i but α, β,-methylene-ATP had little effect suggesting an ATP purinergic P2Y2 G-protein-coupled receptor is present. Both the Schwann cell markers and ATP-induced [Ca2+]i sensitivity decreased in cells passaged >20 times. Our studies indicate that autologous BM-MNCs can be induced to form a phenotypic and functional Schwann-like cell which could be used for peripheral nerve repair.

  12. Hypercalciuric Bone Disease

    Science.gov (United States)

    Favus, Murray J.

    2008-09-01

    Hypercalciuria plays an important causal role in many patients with calcium oxalate (CaOx) stones. The source of the hypercalciuria includes increased intestinal Ca absorption and decreased renal tubule Ca reabsorption. In CaOx stone formers with idiopathic hypercalciuria (IH), Ca metabolic balance studies have revealed negative Ca balance and persistent hypercalciuria in the fasting state and during low dietary Ca intake. Bone resorption may also contribute to the high urine Ca excretion and increase the risk of bone loss. Indeed, low bone mass by DEXA scanning has been discovered in many IH patients. Thiazide diuretic agents reduce urine Ca excretion and may increase bone mineral density (BMD), thereby reducing fracture risk. Dietary Ca restriction that has been used unsuccessfully in the treatment of CaOx nephrolithiasis in the past may enhance negative Ca balance and accelerate bone loss. DEXA scans may demonstrate low BMD at the spine, hip, or forearm, with no predictable pattern. The unique pattern of bone histologic changes in IH differs from other causes of low DEXA bone density including postmenopausal osteoporosis, male hypogonadal osteoporosis, and glucocorticoid-induced osteoporosis. Hypercalciuria appears to play an important pathologic role in the development of low bone mass, and therefore correction of urine Ca losses should be a primary target for treatment of the bone disease accompanying IH.

  13. High-resolution 3D imaging of osteocytes and computational modelling in mechanobiology: insights on bone development, ageing, health and disease.

    Science.gov (United States)

    Goggin, P M; Zygalakis, K C; Oreffo, R O; Schneider, P

    2016-05-22

    Osteocytes are involved in mechanosensation and mechanotransduction in bone and hence, are key to bone adaptation in response to development, ageing and disease. Thus, detailed knowledge of the three-dimensional (3D) structure of the osteocyte network (ON) and the surrounding lacuno-canalicular network (LCN) is essential. Enhanced understanding of the ON&LCN will contribute to a better understanding of bone mechanics on cellular and sub-cellular scales, for instance through improved computational models of bone mechanotransduction. Until now, the location of the ON within the hard bone matrix and the sub-µm dimensions of the ON&LCN have posed significant challenges for 3D imaging. This review identifies relevant microstructural phenotypes of the ON&LCN in health and disease and summarises how light microscopy, electron microscopy and X-ray imaging techniques have been used in studies of osteocyte anatomy, pathology and mechanobiology to date. In this review, we assess the requirements for ON&LCN imaging and examine the state of the art in the fields of imaging and computational modelling as well as recent advances in high-resolution 3D imaging. Suggestions for future investigations using volume electron microscopy are indicated and we present new data on the ON&LCN using serial block-face scanning electron microscopy. A correlative approach using these high-resolution 3D imaging techniques in conjunction with in silico modelling in bone mechanobiology will increase understanding of osteocyte function and, ultimately, lead to improved pathways for diagnosis and treatment of bone diseases such as osteoporosis.

  14. Development of a nomogram model predicting current bone scan positivity in patients treated with androgen-deprivation therapy for prostate cancer

    Directory of Open Access Journals (Sweden)

    Michael eKattan

    2014-10-01

    Full Text Available Purpose: To develop a nomogram predictive of current bone scan positivity in patients receiving androgen-deprivation therapy (ADT for advanced prostate cancer; to augment clinical judgment and highlight patients in need of additional imaging investigations.Materials and Methods: A retrospective chart review of bone scan records (conventional 99mTc-scintigraphy of 1,293 patients who received ADT at the Memorial Sloan-Kettering Cancer Center from 2000 to 2011. Multivariable logistic regression analysis was used to identify variables suitable for inclusion in the nomogram. The probability of current bone scan positivity was determined using these variables and the predictive accuracy of the nomogram was quantified by concordance index.Results: In total, 2,681 bone scan records were analyzed and 636 patients had a positive result. Overall, the median pre-scan prostate-specific antigen (PSA level was 2.4 ng/ml; median PSA doubling time (PSADT was 5.8 months. At the time of a positive scan, median PSA level was 8.2 ng/ml; 53% of patients had PSA <10 ng/ml; median PSADT was 4.0 months. Five variables were included in the nomogram: number of previous negative bone scans after initiating ADT, PSA level, Gleason grade sum, and history of radical prostatectomy and radiotherapy. A concordance index value of 0.721 was calculated for the nomogram. This was a retrospective study based on limited data in patients treated in a large cancer centre who underwent conventional 99mTc bone scans, which themselves have inherent limitations. Conclusions: This is the first nomogram to predict current bone scan positivity in ADT-treated prostate cancer patients, providing high predictive accuracy.

  15. Bone Markers

    Science.gov (United States)

    ... Diabetes Diarrhea Disseminated Intravascular Coagulation (DIC) Down Syndrome Ebola Virus Infection Endocrine System and Syndromes Epilepsy Excessive ... to keep bones alive and sturdy. During early childhood and in the teenage years, new bone is ...

  16. Biochemical parameters of bone metabolism in bone metastases of solid tumors (Review)

    NARCIS (Netherlands)

    Meijer, Wilhelmus; van der Veer, E; Willemse, P H

    1998-01-01

    The role of biochemical markers of bone metabolism in the diagnosis and monitoring of bone metastases in solid tumors is reviewed. Emphasis is on the recently developed markers, which may provide a more accurate quantitation of bone metabolism. In metastatic bone disease, bone formation and

  17. Rho GTPase protein Cdc42 is critical for postnatal cartilage development

    Energy Technology Data Exchange (ETDEWEB)

    Nagahama, Ryo [Department of Biochemistry, School of Dentistry, Showa University, Tokyo (Japan); Department of Orthodontics, School of Dentistry, Showa University, Tokyo (Japan); Yamada, Atsushi, E-mail: yamadaa@dent.showa-u.ac.jp [Department of Biochemistry, School of Dentistry, Showa University, Tokyo (Japan); Tanaka, Junichi [Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Tokyo (Japan); Aizawa, Ryo [Department of Periodontology, School of Dentistry, Showa University, Tokyo (Japan); Suzuki, Dai [Department of Biochemistry, School of Dentistry, Showa University, Tokyo (Japan); Kassai, Hidetoshi [Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo (Japan); Yamamoto, Matsuo [Department of Periodontology, School of Dentistry, Showa University, Tokyo (Japan); Mishima, Kenji [Department of Oral Diagnostic Sciences, School of Dentistry, Showa University, Tokyo (Japan); Aiba, Atsu [Laboratory of Animal Resources, Center for Disease Biology and Integrative Medicine, Faculty of Medicine, The University of Tokyo, Tokyo (Japan); Maki, Koutaro [Department of Orthodontics, School of Dentistry, Showa University, Tokyo (Japan); Kamijo, Ryutaro [Department of Biochemistry, School of Dentistry, Showa University, Tokyo (Japan)

    2016-02-19

    Cdc42, a small Rho GTPase family member, has been shown to regulate multiple cellular functions in vitro, including actin cytoskeletal reorganization, cell migration, proliferation, and gene expression. However, its tissue-specific roles in vivo remain largely unknown, especially in postnatal cartilage development, as cartilage-specific Cdc42 inactivated mice die within a few days after birth. In this study, we investigated the physiological functions of Cdc42 during cartilage development after birth using tamoxifen-induced cartilage-specific inactivated Cdc42 conditional knockout (Cdc42 {sup fl/fl}; Col2-CreERT) mice, which were generated by crossing Cdc42 flox mice (Cdc42 {sup fl/fl}) with tamoxifen-induced type II collagen (Col2) Cre transgenic mice using a Cre/loxP system. The gross morphology of the Cdc42 cKO mice was shorter limbs and body, as well as reduced body weight as compared with the controls. In addition, severe defects were found in growth plate chondrocytes of the long bones, characterized by a shorter proliferating zone (PZ), wider hypertrophic zone (HZ), and loss of columnar organization of proliferating chondrocytes, resulting in delayed endochondral bone formation associated with abnormal bone growth. Our findings demonstrate the importance of Cdc42 for cartilage development during both embryonic and postnatal stages. - Highlights: • Tamoxifen-induced cartilage specific inactivated Cdc42 mutant mice were generated. • Cdc42 mutant mice were shorter limbs and body. • Severe defects were found in growth plate chondrocytes.

  18. Biochemical development of subchondral bone from birth until age eleven months and the influence of physical activity

    NARCIS (Netherlands)

    Brama, P.A.J.; TeKoppele, J.M.; Bank, R.A.; Barneveld, A.; Weeren, P.R. van

    2002-01-01

    Subchondral bone provides structural support to the overlying articular cartilage, and plays an important role in osteochondral diseases. There is growing insight that the mechanical features of bone are related to the biochemistry of the collagen network and the mineral content. In the present

  19. Bone mineral density, growth, pubertal development and other parameters in Brazilian children and young adults with sickle cell anaemia

    NARCIS (Netherlands)

    Meeuwes, M.; Souza de Carvalho, T. F.; Cipolotti, R.; Gurgel, R. Q.; Ferrão, T. O.; Peters, M.; Agyemang, C.

    2013-01-01

    To evaluate the occurrence of low bone mineral density (BMD) and its relationship with clinical and laboratorial characteristics in children and young adults with sickle cell anaemia living in Northeast-Brazil, and to assess the role of radiography in diagnosing low BMD. Bone mineral density of

  20. Inhibition of WNT signaling in the bone marrow niche prevents the development of MDS in the Apcdel/+ MDS mouse model.

    Science.gov (United States)

    Stoddart, Angela; Wang, Jianghong; Hu, Chunmei; Fernald, Anthony A; Davis, Elizabeth M; Cheng, Jason X; Le Beau, Michelle M

    2017-06-01

    There is accumulating evidence that functional alteration(s) of the bone marrow (BM) microenvironment contribute to the development of some myeloid disorders, such as myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). In addition to a cell-intrinsic role of WNT activation in leukemia stem cells, WNT activation in the BM niche is also thought to contribute to the pathogenesis of MDS and AML. We previously showed that the Apc-haploinsufficient mice (Apcdel/+ ) model MDS induced by an aberrant BM microenvironment. We sought to determine whether Apc, a multifunctional protein and key negative regulator of the canonical β-catenin (Ctnnb1)/WNT-signaling pathway, mediates this disease through modulating WNT signaling, and whether inhibition of WNT signaling prevents the development of MDS in Apcdel/+ mice. Here, we demonstrate that loss of 1 copy of Ctnnb1 is sufficient to prevent the development of MDS in Apcdel/+ mice and that altered canonical WNT signaling in the microenvironment is responsible for the disease. Furthermore, the US Food and Drug Administration (FDA)-approved drug pyrvinium delays and/or inhibits disease in Apcdel/+ mice, even when it is administered after the presentation of anemia. Other groups have observed increased nuclear CTNNB1 in stromal cells from a high frequency of MDS/AML patients, a finding that together with our results highlights a potential new strategy for treating some myeloid disorders. © 2017 by The American Society of Hematology.

  1. Effects of Laser Acupuncture on Longitudinal Bone Growth in Adolescent Rats

    Directory of Open Access Journals (Sweden)

    Mijung Yeom

    2013-01-01

    Full Text Available Longitudinal bone growth is the results of chondrocyte proliferation and hypertrophy and subsequent endochondral ossification in the growth plate. Recently, laser acupuncture (LA, an intervention to stimulate acupoint with low-level laser irradiation, has been suggested as an intervention to improve the longitudinal bone growth. This study investigated the effects of laser acupuncture on growth, particularly longitudinal bone growth in adolescent male rats. Laser acupuncture was performed once every other day for a total of 9 treatments over 18 days to adolescent male rats. Morphometry of the growth plate, longitudinal bone growth rate, and the protein expression of BMP-2 and IGF-1 in growth plate were observed. The bone growth rate and the heights of growth plates were significantly increased by laser acupuncture. BMP-2 but not IGF-1 immunostaining in growth plate was increased as well. In conclusion, LA promotes longitudinal bone growth in adolescent rats, suggesting that laser acupuncture may be a promising intervention for improving the growth potential for children and adolescents.

  2. The Bt-DUX: development of a subjective measure of health-related quality of life in patients who underwent surgery for lower extremity malignant bone tumor.

    NARCIS (Netherlands)

    Bekkering, W.P.; Vlieland, T.P.; Koopman, H.M.; Schaap, G.R.; Schreuder, H.W.B.; Beishuizen, A.; Tissing, W.J.; Hoogerbrugge, P.M.; Anninga, J.K.; Taminiau, A.H.M.

    2009-01-01

    BACKGROUND: To examine the practical applicability, internal consistency, and validity of the Bt-DUX, a disease-specific Health Related Quality of Life (HRQoL) instrument. The Bt-Dux was developed to examine patients' individual values of their life after a malignant bone tumor of the lower

  3. The Bt-DUX : Development of a Subjective Measure of Health-Related Quality of Life in Patients Who Underwent Surgery for Lower Extremity Malignant Bone Tumor

    NARCIS (Netherlands)

    Bekkering, W. Peter; Vlieland, Theodora P. M. Vliet; Koopman, Hendrik M.; Schaap, Gerard R.; Schreuder, H. W. Bart; Beishuizen, Auke; Tissing, Wim J. E.; Hoogerbrugge, Peter M.; Anninga, Jacob K.; Taminiau, Antonie H. M.

    Background To examine the practical applicability, internal consistency, and validity of the Bt-DUX, a disease-specific Health Related Quality of Life (HRQoL) instrument. The Bt-Dux was developed to examine patients' individual values of their life after a malignant bone tumor of the lower extremity

  4. TRANSPLANTATION OF BONE MARROW CELLS AND UMBILICAL CORD BLOOD CELLS AS A WAY FOR CORRECTION OF AUTOIMMUNE MECHANISMS IN DEVELOPMENT OF DIABETES MELLITUS TYPE I

    Directory of Open Access Journals (Sweden)

    D. A. Velikiy

    2009-01-01

    Full Text Available In this review the modern conception of development of autoimmune diabetes mellitus was presented. Possibilities of immune disturbances correction and β-cells regeneration at transplantation of bone marrow and umbilical cord blood cells were considered. 

  5. Collagen XXIV, a vertebrate fibrillar collagen with structural features of invertebrate collagens: selective expression in developing cornea and bone.

    Science.gov (United States)

    Koch, Manuel; Laub, Friedrich; Zhou, Peihong; Hahn, Rita A; Tanaka, Shizuko; Burgeson, Robert E; Gerecke, Donald R; Ramirez, Francesco; Gordon, Marion K

    2003-10-31

    Tissue-specific assembly of fibers composed of the major collagen types I and II depends in part on the formation of heterotypic fibrils, using the quantitatively minor collagens V and XI. Here we report the identification of a new fibrillar-like collagen chain that is related to the fibrillar alpha1(V), alpha1(XI), and alpha2(XI) collagen polypeptides and which is coexpressed with type I collagen in the developing bone and eye. The new collagen was designated the alpha1(XXIV) chain and consists of a long triple helical domain flanked by typical propeptide-like sequences. The carboxyl propeptide is classic, with 8 conserved cysteine residues. The amino-terminal peptide contains a thrombospodin-N-terminal-like (TSP) motif and a highly charged segment interspersed with several tyrosine residues, like the fibril diameter-regulating collagen chains alpha1(V) and alpha1(XI). However, a short imperfection in the triple helix makes alpha1(XXIV) unique from other chains of the vertebrate fibrillar collagen family. The triple helical interruption and additional select features in both terminal peptides are common to the fibrillar chains of invertebrate organisms. Based on these data, we propose that collagen XXIV is an ancient molecule that may contribute to the regulation of type I collagen fibrillogenesis at specific anatomical locations during fetal development.

  6. Development of a guided bone regeneration device using salicylic acid-poly(anhydride-ester) polymers and osteoconductive scaffolds.

    Science.gov (United States)

    Mitchell, Ashley; Kim, Brian; Cottrell, Jessica; Snyder, Sabrina; Witek, Lukasz; Ricci, John; Uhrich, Kathryn E; O'Connor, J Patrick

    2014-03-01

    Successful repair of craniofacial and periodontal tissue defects ideally involves a combined therapy that includes inflammation modulation, control of soft tissue infiltration, and bone regeneration. In this study, an anti-inflammatory polymer, salicylic acid-based poly(anhydride-ester) (SAPAE) and a three-dimensional osteoconductive ceramic scaffold were evaluated as a combined guided bone regeneration (GBR) system for concurrent control of inflammation, soft tissue ingrowth, and bone repair in a rabbit cranial defect model. At time periods of 1, 3, and 8 weeks, five groups were compared: (1) scaffolds with a solid ceramic cap (as a GBR structure); (2) scaffolds with no cap; (3) scaffolds with a poly(lactide-glycolide) cap; (4) scaffolds with a slow release SAPAE polymer cap; and (5) scaffolds with a fast release SAPAE polymer cap. Cellular infiltration and bone formation in these scaffolds were evaluated to assess inflammation and bone repair capacity of the test groups. The SAPAE polymers suppressed inflammation and displayed no deleterious effect on bone formation. Additional work is warranted to optimize the anti-inflammatory action of the SAPAE, GBR suppression of soft tissue infiltration, and stimulation of bone formation in the scaffolds and create a composite device for successful repair of craniofacial and periodontal tissue defects. Copyright © 2013 Wiley Periodicals, Inc.

  7. Effect of the gamma radiation and common antioxidants on some aspects of osteoblast differentiation during the formation of bone tissue in an in-vivo model; Efecto de la radiacion gamma y antioxidantes comunes sobre algunos aspectos de la diferenciacion de los osteoblastos durante la formacion de tejido oseo en un modelo in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Quinones O, M. G.

    2015-07-01

    Gamma radiation is the emission of energy through short electromagnetic waves to a higher level of frequency with respect to ultraviolet light. This type of energy in the medical application is used as a tool to kill cancer cells in humans, however, adverse damages to its exposure can produce secondary effects in the short and long term depending on the damage in cells and tissues nearby to the irradiation zone, the human body will present various injuries and conditions. In bone tissue, secondary effects that have been observed, is an alteration of the architecture and integrity of bone extracellular matrix of cortical and trabecular tissue, which causes loss of bone density. However, the reason that the bone tissue is affected is not clear, but is believed to be related to the formation of free radicals, which generate oxidative damage in biomolecules of the cells, damaging the tissue structure, organs and systems of the human body. The studies to identify the main reasons that will affect bone tissue as a result of radiotherapy have been carried out by models In-vitro and some In-vivo. In most studies in-vitro with cells with osteoblast phenotype, the results suggest alterations in proliferation and differentiation of these cells. However, the etiology and the role of these changes in disorders and bone injuries as adverse secondary effects of the radiotherapy are very poorly understood to date. In the present study an In-vivo model was used, that are ectopic bone plates which are developed by endochondral ossification, after having implanted demineralized bone particles at 16 days of development, at which time they are constituted by bone tissue. Ectopic bone plates were used with the aim of knowing as gamma radiation indirectly modifies to cellular level the osteoblast differentiation, cells that are involved in the formation and mineralization of bone extracellular matrix. One of the well known effects of gamma radiation is the generation of free radicals

  8. Bare bones pattern formation: a core regulatory network in varying geometries reproduces major features of vertebrate limb development and evolution.

    Directory of Open Access Journals (Sweden)

    Jianfeng Zhu

    Full Text Available BACKGROUND: Major unresolved questions regarding vertebrate limb development concern how the numbers of skeletal elements along the proximodistal (P-D and anteroposterior (A-P axes are determined and how the shape of a growing limb affects skeletal element formation. There is currently no generally accepted model for these patterning processes, but recent work on cartilage development (chondrogenesis indicates that precartilage tissue self-organizes into nodular patterns by cell-molecular circuitry with local auto-activating and lateral inhibitory (LALI properties. This process is played out in the developing limb in the context of a gradient of fibroblast growth factor (FGF emanating from the apical ectodermal ridge (AER. RESULTS: We have simulated the behavior of the core chondrogenic mechanism of the developing limb in the presence of an FGF gradient using a novel computational environment that permits simulation of LALI systems in domains of varying shape and size. The model predicts the normal proximodistal pattern of skeletogenesis as well as distal truncations resulting from AER removal. Modifications of the model's parameters corresponding to plausible effects of Hox proteins and formins, and of the reshaping of the model limb, bud yielded simulated phenotypes resembling mutational and experimental variants of the limb. Hypothetical developmental scenarios reproduce skeletal morphologies with features of fossil limbs. CONCLUSIONS: The limb chondrogenic regulatory system operating in the presence of a gradient has an inherent, robust propensity to form limb-like skeletal structures. The bare bones framework can accommodate ancillary gene regulatory networks controlling limb bud shaping and establishment of Hox expression domains. This mechanism accounts for major features of the normal limb pattern and, under variant geometries and different parameter values, those of experimentally manipulated, genetically aberrant and evolutionary early

  9. Bare bones pattern formation: a core regulatory network in varying geometries reproduces major features of vertebrate limb development and evolution.

    Science.gov (United States)

    Zhu, Jianfeng; Zhang, Yong-Tao; Alber, Mark S; Newman, Stuart A

    2010-05-28

    Major unresolved questions regarding vertebrate limb development concern how the numbers of skeletal elements along the proximodistal (P-D) and anteroposterior (A-P) axes are determined and how the shape of a growing limb affects skeletal element formation. There is currently no generally accepted model for these patterning processes, but recent work on cartilage development (chondrogenesis) indicates that precartilage tissue self-organizes into nodular patterns by cell-molecular circuitry with local auto-activating and lateral inhibitory (LALI) properties. This process is played out in the developing limb in the context of a gradient of fibroblast growth factor (FGF) emanating from the apical ectodermal ridge (AER). We have simulated the behavior of the core chondrogenic mechanism of the developing limb in the presence of an FGF gradient using a novel computational environment that permits simulation of LALI systems in domains of varying shape and size. The model predicts the normal proximodistal pattern of skeletogenesis as well as distal truncations resulting from AER removal. Modifications of the model's parameters corresponding to plausible effects of Hox proteins and formins, and of the reshaping of the model limb, bud yielded simulated phenotypes resembling mutational and experimental variants of the limb. Hypothetical developmental scenarios reproduce skeletal morphologies with features of fossil limbs. The limb chondrogenic regulatory system operating in the presence of a gradient has an inherent, robust propensity to form limb-like skeletal structures. The bare bones framework can accommodate ancillary gene regulatory networks controlling limb bud shaping and establishment of Hox expression domains. This mechanism accounts for major features of the normal limb pattern and, under variant geometries and different parameter values, those of experimentally manipulated, genetically aberrant and evolutionary early forms, with no requirement for an independent

  10. Developing a Customized Perfusion Bioreactor Prototype with Controlled Positional Variability in Oxygen Partial Pressure for Bone and Cartilage Tissue Engineering.

    Science.gov (United States)

    Lee, Poh Soo; Eckert, Hagen; Hess, Ricarda; Gelinsky, Michael; Rancourt, Derrick; Krawetz, Roman; Cuniberti, Gianaurelio; Scharnweber, Dieter

    2017-05-01

    Skeletal development is a multistep process that involves the complex interplay of multiple cell types at different stages of development. Besides biochemical and physical cues, oxygen tension also plays a pivotal role in influencing cell fate during skeletal development. At physiological conditions, bone cells generally reside in a relatively oxygenated environment whereas chondrocytes reside in a hypoxic environment. However, it is technically challenging to achieve such defined, yet diverse oxygen distribution on traditional in vitro cultivation platforms. Instead, engineered osteochondral constructs are commonly cultivated in a homogeneous, stable environment. In this study, we describe a customized perfusion bioreactor having stable positional variability in oxygen tension at defined regions. Further, engineered collagen constructs were coaxed into adopting the shape and dimensions of defined cultivation platforms that were precasted in 1.5% agarose bedding. After cultivating murine embryonic stem cells that were embedded in collagen constructs for 50 days, mineralized constructs of specific dimensions and a stable structural integrity were achieved. The end-products, specifically constructs cultivated without chondroitin sulfate A (CSA), showed a significant increase in mechanical stiffness compared with their initial gel-like constructs. More importantly, the localization of osteochondral cell types was specific and corresponded to the oxygen tension gradient generated in the bioreactor. In addition, CSA in complementary with low oxygen tension was also found to be a potent inducer of chondrogenesis in this system. In summary, we have demonstrated a customized perfusion bioreactor prototype that is capable of generating a more dynamic, yet specific cultivation environment that could support propagation of multiple osteochondral lineages within a single engineered construct in vitro. Our system opens up new possibilities for in vitro research on human

  11. The Effects of Irradiation and Calcium-deficient Diet on the Expression of Bone Morphogenetic Protein-2/4 during Early Tooth Development

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dai Hee; Hwang, Eui Hwan; Lee, Sang Rae [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Kyunghee University, Seoul (Korea, Republic of)

    2000-09-15

    To investigate the expression of bone morphogenetic protein (BMP)-2/4 during early tooth development after irradiation and calcium-deficient diet. The pregnant three-week-old Sprague-Dawley rats were used for the study. The control group was non-irradiation/normal diet group (Group 1), and the experimental groups were irradiation/normal diet group (Group 2) and irradiation/calcium-diet group (Group 3). The abdomen of the rats at the 9th day of pregnancy were irradiated with single dose of 350 cGy. The rat pups were sacrificed at embryonic 18 days, 3 days and 14 days after delivery and the maxillae tooth germs were taken. The tissue sections of specimen were stained immunohistochemically with anti-BMP-2/4 antibody. At embryo-18 days, immunoreacivity for BMP-2/4 of the Group 1 was modetate in stratum intermedium of dental organ and weak in dental papilla and dental follicle, but that of Group 2 was weak in cell layer of dental organ, and no immunoreacivity was shown in dental papilla and dental follice of Group 2 and in all tissue components of the Group 3. At postnatal-3 days, immunoreacivity for BMP-2/4 of the Group 1 was strong in cell layer of dental organ, odontoblasts and developing alveolar bone, but that of Group of 2 and Group 3 was weak in odontoblasts and developing alveolar bone. At postnatal-14 days, immunoreacivity for BMP-2/4 of the Group 1 was strong in newly formed cementum, alveolar bone and odontoblasts, but that of Group 2 was weaker than that of Group 1. In the Group 3, tooth forming cell layer showed weak immunoreactivity, but other cell layers showed no immunoreactivity. The expression of bone morphogenetic protein (BMP)-2/4 during early tooth development was disturbed after irradiation and calcium-deficient diet.

  12. Design and development of a cd-rom in dynamic functional rehabilitation of the maxillary bones

    OpenAIRE

    Mosquera, Lorenzo; Cárdenas, Andrea; Moscote, Sofía; Larrahondo, Ritherken; Hurtado, Martha; González, María Alejandra

    2014-01-01

    Introduction: This article is part of a research line entitled “Pedagogy and Didactics in Dental Teaching” carried out in 2012 by the postgraduate dental research group at the Bogotá campus of the Universidad Cooperativa de Colombia. In the context of the era of technology, a teacher-student interaction is made use of when designing, developing and using a teaching tool based on multimedia software, with content-oriented Dynamic Functional Rehabilitation of the Jaws. Objective: To design and ...

  13. The Influence of Primary Microenvironment on Prostate Cancer Osteoblastic Bone LesionDevelopment

    Science.gov (United States)

    2016-11-01

    tic ducts and invasion of prostate cells into the stromal com- partment defines the pathology of prostate adenocarcinoma. Proteases that mediate...proteolytic cascade in epithelial development and pathology . Cell Tissue Res (2013) 351(2):245–53. doi:10. 1007/s00441-012-1348-1 68. Abate-Shen C, Shen MM...J Clin Oncol (2000) 18(5):1135–49. doi:10.1016/j.lfs.2004.06.027 76. Benaud C, Dickson RB, Thompson EW. Matrix metalloproteinases in mammary gland

  14. The enigmatic relationship between epiphyseal fusion and bone development in primates.

    Science.gov (United States)

    Brimacombe, Conrad Stephen

    2017-11-01

    Epiphyseal fusion in primates is a process that occurs in a regular sequence spanning a period of years and thus provides biological anthropologists with a useful marker of maturity that can be used to assess age and stage of development. Despite the many studies that have catalogued fusion timing and sequence pattern, comparatively little research has been devoted to understanding why these sequences exist in the first place. Answering this question is not necessarily intuitive; indeed, given that neither taxonomic affinities nor recent adaptations have been clearly defined, it is a challenge to explain this process in evolutionary terms. In all mammals, there is a tendency for the fusion of epiphyses at joints to occur close in sequence, and this has been proposed to relate to locomotor adaptations. Further consideration of the evidence suggests that linking locomotor behavior to sequence data alone is difficult to prove and may require a different type of evidence. Epiphyseal fusion should be considered in the context of other parameters that affect the developing skeleton, including how joint morphology relates to growth in length, as well as other possible morphological constraints. In recent years, developmental biology has been providing a better understanding of the molecular regulators of epiphyseal fusion. At some point in the near future, we may be able to link our understanding of the genetics of fusion timing to the possible selective mechanisms that are responsible for these sequences. © 2017 Wiley Periodicals, Inc.

  15. Bone loss, contraception and lactation.

    Science.gov (United States)

    Mehta, S

    1993-04-01

    Loss of bone mass with age, is a universal phenomenon and is more pronounced in women than in men. The condition where the bone loss has proceeded to the extent that fractures occur is termed osteoporosis. As the number of elderly persons in the population increases, its magnitude is likely to increase, both in the developing and the developed countries. Bone mass increases rapidly in childhood and the adolescent years, reaching a peak in the third decade of life, and begins to decline soon thereafter. Several factors are thought to influence bone loss: these include race, diet, smoking, and physical exercise. Although the rate of bone loss accelerates in the immediate postmenopausal period, the process actually begins in the premenopausal years. By the time osteoporosis is clinically apparent and manifested by fracture, it probably cannot be reversed. The peak adult bone mass achieved, and the subsequent rate of bone loss are the major factors that determine a woman's susceptibility to postmenopausal osteoporosis. A primary cause of bone loss after menopause is the associated decline in ovarian function. Scanty information is available on the factors that affect bone mineral density or initiate bone loss before menopause, although both estrogens and progestins have been shown to prevent bone loss in postmenopausal women. Available data on the relationship between steroid hormone contraceptive use and bone mass/density is limited to combined oral contraceptives and one report related to the use of depot medroxyprogesterone acetate.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Development and evaluation of novel biodegradable chitosan based metformin intrapocket dental film for the management of periodontitis and alveolar bone loss in a rat model.

    Science.gov (United States)

    Khajuria, Deepak Kumar; Patil, Omprakash Nandikamba; Karasik, David; Razdan, Rema

    2018-01-01

    The aim of this study was to develop a chitosan-metformin based intrapocket dental film (CMIDF) for applications in the treatment of periodontitis and alveolar bone loss in an rat model of periodontitis. CMIDF inserts were fabricated by the solvent casting technique. The fabricated inserts were evaluated for physical characteristics such as folding endurance, surface pH, mucoadhesive strength, metformin content uniformity, and release. X-ray diffraction analysis indicates no crystallinity of metformin in presence of chitosan which confirmed successful entrapment of metformin into the CMIDF. Fourier-transform infrared spectroscopy revealed stability of CMIDF and compatibility between metformin and chitosan. Periodontitis was induced by a combination of Porphyromonas gingivalis- lipopolysaccharide injections in combinations with ligatures around the mandibular first molar. We divided rats into 5 groups (8 rats/group): healthy, untreated periodontitis; periodontitis plus CMIDF-A (1.99±0.09mg metformin; total mass-4.01±0.05mg), periodontitis plus CMIDF-B (2.07±0.06mg metformin; total mass-7.56±0.09mg), and periodontitis plus chitosan film (7.61±0.08mg). After four weeks, mandibles were extracted to evaluate alveolar bone loss by micro-computerized tomography and histological techniques. Alveolar bone was intact in the healthy group. Local administration of CMIDF resulted in significant improvements in the alveolar bone properties when compared to the untreated periodontitis group. The study reported here demonstrates that novel CMIDF showed good antibacterial activity and effectively reduced alveolar bone destruction in a rat model of experimental periodontitis. Novel CMIDF showed good antibacterial activity and improved alveolar bone properties in a rat model. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Using transgenic reporters to visualise bone and cartilage signalling during development in vivo

    Directory of Open Access Journals (Sweden)

    Chrissy L Hammond

    2012-07-01

    Full Text Available Green Fluorescent Protein (GFP was first used as a marker of protein expression in vivo 18 years ago, heralding the beginning of what became known as the Green Revolution. Since then, there has been an explosion in the number of transgenic lines in existence, and these transgenic tools are now being applied to skeletal research. Advances in transgenesis are also leading to increasing use of new model organisms for studying skeletogenesis. Such new models include the small teleosts zebrafish and medaka, which due to their optical translucency offer imaging possibilities in the live animals. In this review, we will introduce a number of recent advances in genetic engineering and transgenesis and the new genetic tools that are currently being developed. We will provide examples of how zebrafish and medaka transgenic lines are helping us to understand the behaviour of skeletal cells in vivo. Finally, we will discuss future prospects for the application of transgenic technology to skeletal research.

  18. Long-Term Expansion, Enhanced Chondrogenic Potential, and Suppression of Endochondral Ossification of Adult Human MSCs via WNT Signaling Modulation

    Directory of Open Access Journals (Sweden)

    Roberto Narcisi

    2015-03-01

    Full Text Available Mesenchymal stem cells (MSCs are a potential source of chondrogenic cells for the treatment of cartilage disorders, but loss of chondrogenic potential during in vitro expansion and the propensity of cartilage to undergo hypertrophic maturation impede their therapeutic application. Here we report that the signaling protein WNT3A, in combination with FGF2, supports long-term expansion of human bone marrow-derived MSCs. The cells retained their chondrogenic potential and other phenotypic and functional properties of multipotent MSCs, which were gradually lost in the absence of WNT3A. Moreover, we discovered that endogenous WNT signals are the main drivers of the hypertrophic maturation that follows chondrogenic differentiation. Inhibition of WNT signals during differentiation prevented calcification and maintained cartilage properties following implantation in a mouse model. By maintaining potency during expansion and preventing hypertrophic maturation following differentiation, the modulation of WNT signaling removes two major obstacles that impede the clinical application of MSCs in cartilage repair.

  19. B cell development in the bone marrow is regulated by homeostatic feedback exerted by mature B cells

    Directory of Open Access Journals (Sweden)

    Gitit eShahaf

    2016-03-01

    Full Text Available Cellular homeostasis in the B cell compartment is strictly imposed to balance cell production and cell loss. However, it is not clear whether B cell development in the bone marrow (BM is an autonomous process or subjected to regulation by the peripheral B cell compartment. To specifically address this question, we used mice transgenic for human CD20, where effective depletion of B lineage cells is obtained upon administration of mouse-anti-human CD20 antibodies, in the absence of any effect on other cell lineages and/or tissues. We followed the kinetics of B cell return to equilibrium by BrdU labeling and flow cytometry and analyzed the resulting data by mathematical modeling. Labeling was much faster in depleted mice. Compared to control mice, B cell-depleted mice exhibited a higher proliferation rate in the pro-/pre-B compartment, and higher cell death and lower differentiation in the immature B cell compartment. We validated the first result by analysis of the expression of Ki67, the nuclear protein expressed in proliferating cells, and the second using Annexin-V staining. Collectively, our results suggest that B lymphopoiesis is subjected to homeostatic feedback mechanisms imposed by mature B cells in the peripheral compartment.

  20. Mimicking the nanostructure of bone matrix to regenerate bone

    Science.gov (United States)

    Kane, Robert; Ma1, Peter X.

    2014-01-01

    Key features of bone tissue structure and composition are capable of directing cellular behavior towards the generation of new bone tissue. Bone tissue, as well as materials derived from bone, have a long and successful history of use as bone grafting materials. Recent developments in design and processing of synthetic scaffolding systems has allowed the replication of the bone’s desirable biological activity in easy to fabricate polymeric materials with nano-scale features exposed on the surface. The biological response to these new tissue-engineering scaffold materials oftentimes exceeds that seen on scaffolds produced using biological materials. PMID:24688283

  1. Evolution, development, and plasticity of the human brain: from molecules to bones

    Directory of Open Access Journals (Sweden)

    Branka eHrvoj-Mihic

    2013-10-01

    Full Text Available Neuroanatomical, molecular, and paleontological evidence is examined in light of human brain evolution. The brain of extant humans differs from the brains of other primates in its overall size and organization, and differences in size and organization of specific cortical areas and subcortical structures implicated into complex cognition and social and emotional processing. The human brain is also characterized by functional lateralizations, reflecting specializations of the cerebral hemispheres in humans for different types of processing, facilitating fast and reliable communication between neural cells in an enlarged brain. The features observed in the adult brain reflect human-specific patterns of brain development. Compared to the brains of other primates, the human brain takes longer to mature, promoting an extended period for establishing cortical microcircuitry and its modifications. Together, these features may underlie the prolonged period of learning and acquisition of technical and social skills necessary for survival, creating a unique cognitive and behavioral niche typical of our species.The neuroanatomical findings are in concordance with molecular analyses, which suggest a trend toward heterochrony in the expression of genes implicated in different functions. These include synaptogenesis, neuronal maturation and plasticity in humans, mutations in genes implicated in neurite outgrowth and plasticity, and an increased role of regulatory mechanisms, potentially promoting fast modification of neuronal morphologies in response to new computational demands. At the same time, endocranial casts of fossil hominins provide an insight into the timing of the emergence of uniquely human features in the course of evolution. We conclude by proposing several ways of combining comparative neuroanatomy, molecular biology and insights gained from fossil endocasts in future research.

  2. Human Bone Derived Collagen for the Development of an Artificial Corneal Endothelial Graft. In Vivo Results in a Rabbit Model.

    Directory of Open Access Journals (Sweden)

    Natalia Vázquez

    Full Text Available Corneal keratoplasty (penetrating or lamellar using cadaveric human tissue, is nowadays the main treatment for corneal endotelial dysfunctions. However, there is a worldwide shortage of donor corneas available for transplantation and about 53% of the world's population have no access to corneal transplantation. Generating a complete cornea by tissue engineering is still a tough goal, but an endothelial lamellar graft might be an easier task. In this study, we developed a tissue engineered corneal endothelium by culturing human corneal endothelial cells on a human purified type I collagen membrane. Human corneal endothelial cells were cultured from corneal rims after corneal penetrating keratoplasty and type I collagen was isolated from remnant cancellous bone chips. Isolated type I collagen was analyzed by western blot, liquid chromatography -mass spectrometry and quantified using the exponentially modified protein abundance index. Later on, collagen solution was casted at room temperature obtaining an optically transparent and mechanically manageable membrane that supports the growth of human and rabbit corneal endothelial cells which expressed characteristic markers of corneal endothelium: zonula ocluddens-1 and Na+/K+ ATPase. To evaluate the therapeutic efficiency of our artificial endothelial grafts, human purified type I collagen membranes cultured with rabbit corneal endothelial cells were transplanted in New Zealand white rabbits that were kept under a minimal immunosuppression regimen. Transplanted corneas maintained transparency for as long as 6 weeks without obvious edema or immune rejection and maintaining the same endothelial markers that in a healthy cornea. In conclusion, it is possible to develop an artificial human corneal endothelial graft using remnant tissues that are not employed in transplant procedures. This artificial endothelial graft can restore the integrality of corneal endothelium in an experimental model of

  3. Developmental Trajectories of Physical Activity, Sports, and Television Viewing During Childhood to Young Adulthood: Iowa Bone Development Study.

    Science.gov (United States)

    Kwon, Soyang; Janz, Kathleen F; Letuchy, Elena M; Burns, Trudy L; Levy, Steven M

    2015-07-01

    The diverse developmental patterns of obesogenic behaviors during childhood and adolescence can be better understood by using new analytic approaches to assess the heterogeneity in variation during growth and development and to map the clustering of behavior patterns. To identify distinct trajectories of daily time spent in moderate- to vigorous-intensity physical activity (MVPA) from ages 5 to 19 years and to examine the associations of MVPA trajectories with sports participation and television viewing trajectories. Cohort members in the prospective population-based Iowa Bone Development Study participated in MVPA assessments via accelerometry from September 16, 1998, to December 9, 2013, at ages 5, 8, 11, 13, 15, 17, and 19 years and completed a questionnaire every 6 months on sports participation and daily time spent in television viewing. Trajectories of MVPA (minutes per day), participation in organized sports (yes or no), and television viewing time (hours per day). Based on the data from 537 participants (50.1% females; 94.6% white), we identified 4 MVPA trajectories: consistently inactive (14.9%), consistently active (18.1%), decreasing moderate physical activity (52.9%), and substantially decreasing high physical activity (14.1%). All participants in the consistently inactive trajectory also followed a trajectory of no participation in sports. The consistently active trajectory was associated with decreasing an already low television viewing trajectory (P Sports participation could be a critical way to avoid the consistently inactive pattern. Most important, we identified a subset of participants who maintained a seemingly healthy level of MVPA from childhood to young adulthood. The developmental pathways of physical activity and television viewing behaviors could be related. Additional studies should examine the determinants and health consequences of these specific MVPA trajectories.

  4. Transcutaneous Raman Spectroscopy of Bone

    Science.gov (United States)

    Maher, Jason R.

    Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral

  5. Evaluation of root and alveolar bone development of unilateral osseous impacted immature maxillary central incisors after the closed-eruption technique.

    Science.gov (United States)

    Shi, Xiangru; Xie, Xiaoyan; Quan, Junkang; Wang, Xiaozhe; Sun, Xiangyu; Zhang, Chenying; Zheng, Shuguo

    2015-10-01

    In this study, we evaluated root and alveolar bone development in unilateral osseous impacted immature maxillary central incisors by cone-beam computed tomography before and after closed-eruption treatment, in comparison with naturally erupted contralateral immature maxillary central incisors. The study included 30 patients, 20 boys and 10 girls, with a mean age of 8.44 ± 1.20 years (range, 6.5-11.2 years). After treatment, the root lengths of both the impacted maxillary central incisors (10.66 ± 2.10 mm) and the contralateral maxillary central incisors (11.04 ± 1.76 mm) were significantly greater than their pretreatment values (6.67 ± 1.94 and 9.02 ± 2.13 mm, respectively). The root canal widths of the incisors decreased significantly after treatment. From the posttreatment cone-beam computed tomography images, the ratio of exposed root length to total root length and the thickness of the alveolar bone at 1 mm under the alveolar crest and at the apex were calculated to evaluate alveolar bone development. Impacted immature maxillary central incisors differed significantly from contralateral immature maxillary central incisors in labial exposed root length, labial ratio to total root length, and lingual alveolar crest. Clinical crown height was higher (statistically but not clinically) for the impacted incisors (9.87 mm) than for the contralateral incisors (9.37 mm). Impacted immature incisors grew to the same stage as did erupted contralateral incisors after closed-eruption treatment. Both incisor types had some alveolar bone loss, and thin alveolar bone surrounded the roots. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  6. A new device for bone anchor fixation in laparoscopic sacrocolpopexy: the Franciscan laparoscopic bone anchor inserter.

    NARCIS (Netherlands)

    Weiden, R.M. van der; Withagen, M.I.J.; Bergkamp, A.B.; Mannaerts, G.H.

    2005-01-01

    BACKGROUND: A laparoscopic modification of the sacrocolpopexy procedure with mesh and bone anchor fixation with the Franciscan laparoscopic bone anchor inserter was developed. METHODS: We developed a laparoscopic bone anchor inserter for the placement of a titanium bone anchor in sacral segment 3 as

  7. [Obesity and bone metabolism].

    Science.gov (United States)

    Holecki, Michał; Zahorska-Markiewicz, Barbara; Wiecek, Andrzej; Nieszporek, Teresa; Zak-Gołab, Agnieszka

    2008-01-01

    Both bone and adipose tissue change their size, shape and distribution during the whole human being's life. Many factors, including genetic factors, hormones and activity of nervous system are responsible for these changes. It is generally accepted that obesity has a protective effect on bone tissue. On the other hand some authors present an opposite results--the lack of beneficial effect of obesity on development of osteoporosis fractures. The aim of this article was to present and discuss the relations between adipose tissue and bone metabolism.

  8. Development and characterization of an injectable cement of nano calcium-deficient hydroxyapatite/multi(amino acid) copolymer/calcium sulfate hemihydrate for bone repair

    Science.gov (United States)

    Qi, Xiaotong; Li, Hong; Qiao, Bo; Li, Weichao; Hao, Xinyan; Wu, Jun; Su, Bao; Jiang, Dianming

    2013-01-01

    A novel injectable bone cement was developed by integration of nano calcium-deficient hydroxyapatite/multi(amino acid) copolymer (n-CDHA/MAC) and calcium sulfate hemihydrate (CSH; CaSO4 · 1/2H2O). The structure, setting time, and compressive strength of the cement were investigated. The results showed that the cement with a liquid to powder ratio of 0.8 mL/g exhibited good injectability and appropriate setting time and mechanical properties. In vitro cell studies indicated that MC3T3-E1 cells cultured on the n-CDHA/MAC/CSH composite spread well and showed a good proliferation state. The alkaline phosphatase activity of the MC3T3-E1 cells cultured on the n-CDHA/MAC/CSH composite was significantly higher than that of the cells on pure CSH at 4 and 7 days of culture. The n-CDHA/MAC/CSH cement was implanted into critical size defects of the femoral condyle in rabbits to evaluate its biocompatibility and osteogenesis in vivo. Radiological and histological results indicated that introduction of the n-CDHA/MAC into CSH enhanced new bone formation, and the n-CDHA/MAC/CSH cement exhibited good biocompatibility and degradability. In conclusion, the injectable n-CDHA/MAC/CSH composite cement has a significant clinical advantage over pure CSH cement, and may be a promising bone graft substitute for the treatment of bone defects. PMID:24293996

  9. Pleomorphic adenoma of parotid gland with extensive bone formation – A rare case report

    Directory of Open Access Journals (Sweden)

    Ashwin Ashok Jaiswal

    2014-07-01

    Full Text Available Pleomorphic adenoma is the most common type of all salivary gland tumors, involving more frequently the parotid gland. In most series, it represents 45–75% of all salivary gland neoplasms. We report an unusual case of a huge tumor that measured 9 × 8 cm & 400 g by weight with extensive bone formation, occurring in the parotid gland of a 22 year old man. Thorough clinical examination was done. FNAC was done which showed Myxochondroid matrix with glandular epithelial cells suggesting pleomorphic adenoma. CT scan head & neck revealed a large mass with nodular areas of calcification within soft tissue with marked narrowing of orophayngeal lumen. Total parotidectomy with preservation of facial nerve was done by the Transcervical Transparotid approach. The histopathological findings suggested the possibility of extensive endochondral ossification in pleomorphic adenoma. Preservation of facial nerve functions is a key to successful parotid surgery.

  10. Relationship between Biochemical Bone Markers and Bone Mineral Density in Patients with Phenylketonuria under Restricted Diet

    OpenAIRE

    Koura, Hala M.; Zaki, Sherif M.; Ismail, Nagwa A.; Salama, Emad E.; El Lebedy, Dalia H.; Effat, Laila K.

    2013-01-01

    Objective: Most of phenylketonuria (PKU) develops bone turnover impairment and low bone mineral density (BMD). Measurements of BMD re?ect only bone mineral status but not the dynamics of bone turnover. Bone?markers?are a noninvasive tool useful for the assessment of bone formation and bone resorption processes. Our study was to assess the levels of bone markers in PKU in order to select a screen marker and detect the most specific marker which can be combined with BMD for appropriate follow u...

  11. Electrophoretic deposition of organic/inorganic composite coatings on metallic substrates for bone replacement applications: mechanisms and development of new bioactive materials based on polysaccharides

    OpenAIRE

    Cordero Arias, Luis Eduardo

    2015-01-01

    Regarding the need to improve the usually encountered osteointegration of metallic implants with the surrounding body tissue in bone replacement applications, bioactive organic/inorganic composite coatings on metallic substrates were developed in this work using electrophoretic deposition (EPD) as coating technology. In the present work three polysaccharides, namely alginate, chondroitin sulfate and chitosan were used as the organic part, acting as the matrix of the coating and enabling the c...

  12. Osteoinduction of bone grafting materials for bone repair and regeneration.

    Science.gov (United States)

    García-Gareta, Elena; Coathup, Melanie J; Blunn, Gordon W

    2015-12-01

    Regeneration of bone defects caused by trauma, infection, tumours or inherent genetic disorders is a clinical challenge that usually necessitates bone grafting materials. Autologous bone or autograft is still considered the clinical "gold standard" and the most effective method for bone regeneration. However, limited bone supply and donor site morbidity are the most important disadvantages of autografting. Improved biomaterials are needed to match the performance of autograft as this is still superior to that of synthetic bone grafts. Osteoinductive materials would be the perfect candidates for achieving this task. The aim of this article is to review the different groups of bone substitutes in terms of their most recently reported osteoinductive properties. The different factors influencing osteoinductivity by biomaterials as well as the mechanisms behind this phenomenon are also presented, showing that it is very limited compared to osteoinductivity shown by bone morphogenetic proteins (BMPs). Therefore, a new term to describe osteoinductivity by biomaterials is proposed. Different strategies for adding osteoinductivity (BMPs, stem cells) to bone substitutes are also discussed. The overall objective of this paper is to gather the current knowledge on osteoinductivity of bone grafting materials for the effective development of new graft substitutes that enhance bone regeneration. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Bone elongation in rats with renal failure and mild or advanced secondary hyperparathyroidism.

    Science.gov (United States)

    Sanchez, Cheryl P; He, Yu-Zhu; Leiferman, Ellen; Wilsman, Norman J

    2004-05-01

    Impairment of growth in children with chronic renal failure may be due, in part to the insensitivity to the actions of growth hormone by insulin-like growth factor-I (IGF-I) because of accumulations of IGF binding proteins. There are a few studies describing the changes that occur in the growth plate in renal failure. None of these studies has simultaneously compared the modifications in the expression of selected markers of endochondral bone formation in renal failure with mild or advanced secondary hyperparathyroidism. Forty-six rats that underwent 5/6 nephrectomy (Nx) were fed either standard rodent diet (Nx-control) or high phosphorus diet to induce advanced secondary hyperparathyroidism (Nx-phosphorus) for 4 weeks. Sections of the tibia were obtained for growth plate histomorphometry, immunohistochemistry studies, and in situ hybridization experiments for selected markers of endochondral bone formation. Weight gain, gain in length, and tibial length were less in Nx animals. Serum parathyroid hormone (PTH) and phosphorus levels were higher and serum calcium levels were lower in the Nx-phosphorus group. The width of the growth plate was much shorter in the Nx-phosphorus group due to a decrease in both proliferative and hypertrophic zones. IGF-I protein and IGF binding protein-3 staining were diminished in both Nx groups without changes in the IGF-I receptor expression; the decline in IGF-I protein expression was much lower in the Nx-phosphorus group. PTH/PTH receptor protein (PTHrP) receptor mRNA transcripts decline and tartrate-resistant acid phosphastase (TRAP) staining increased only in the Nx-phosphorus group. The growth impairment in renal failure may be worsened by the severity of secondary hyperparathyroidism.

  14. Women with previous stress fractures show reduced bone material strength

    OpenAIRE

    Duarte Sosa, Daysi; Fink Eriksen, Erik

    2016-01-01

    Background and purpose ? Bone fragility is determined by bone mass, bone architecture, and the material properties of bone. Microindentation has been introduced as a measurement method that reflects bone material properties. The pathogenesis of underlying stress fractures, in particular the role of impaired bone material properties, is still poorly understood. Based on the hypothesis that impaired bone material strength might play a role in the development of stress fractures, we used microin...

  15. Deficiency and Also Transgenic Overexpression of Timp-3 Both Lead to Compromised Bone Mass and Architecture In Vivo.

    Directory of Open Access Journals (Sweden)

    Behzad Javaheri

    Full Text Available Tissue inhibitor of metalloproteinases-3 (TIMP-3 regulates extracellular matrix via its inhibition of matrix metalloproteinases and membrane-bound sheddases. Timp-3 is expressed at multiple sites of extensive tissue remodelling. This extends to bone where its role, however, remains largely unresolved. In this study, we have used Micro-CT to assess bone mass and architecture, histological and histochemical evaluation to characterise the skeletal phenotype of Timp-3 KO mice and have complemented this by also examining similar indices in mice harbouring a Timp-3 transgene driven via a Col-2a-driven promoter to specifically target overexpression to chondrocytes. Our data show that Timp-3 deficiency compromises tibial bone mass and structure in both cortical and trabecular compartments, with corresponding increases in osteoclasts. Transgenic overexpression also generates defects in tibial structure predominantly in the cortical bone along the entire shaft without significant increases in osteoclasts. These alterations in cortical mass significantly compromise predicted tibial load-bearing resistance to torsion in both genotypes. Neither Timp-3 KO nor transgenic mouse growth plates are significantly affected. The impact of Timp-3 deficiency and of transgenic overexpression extends to produce modification in craniofacial bones of both endochondral and intramembranous origins. These data indicate that the levels of Timp-3 are crucial in the attainment of functionally-appropriate bone mass and architecture and that this arises from chondrogenic and osteogenic lineages.

  16. Incubation lighting schedules and their interaction with matched or mismatched post hatch lighting schedules: Effects on broiler bone development and leg health at slaughter age.

    Science.gov (United States)

    van der Pol, Carla W; van Roovert-Reijrink, Inge A M; Aalbers, Gerald; Kemp, Bas; van den Brand, Henry

    2017-07-17

    The incidence of leg pathologies in broiler chickens with a developmental origin may be decreased by stimulating embryonic bone development through lighting schedules during incubation, but this may depend on post hatch lighting conditions. Aim was to investigate how lighting schedules during incubation and their interactions with matched or mismatched lighting schedules post hatch affected bone development and leg health at slaughter age. In a 3×2 factorial designed experiment, eggs were incubated under continuous cool white LED light (Inc24L), 16h of light, 8h of darkness (Inc16L:8D), or continuous darkness (Inc24D) from set till hatch. After hatch, broilers were housed under continuous light (PH24L, to match Inc24L and Inc24D) or 16h of light, 8h of darkness (PH16L:8D, to match Inc16L:8D). Gait scores were determined on D21, D28, and D34. After slaughter on D35, legs were scored for varus-valgus deformities, rotated tibia, tibial dyschondroplasia, bacterial chondronecrosis with osteomyelitis (BCO), epiphyseolysis, and epiphyseal plate abnormalities from 1=absent to 4=severe. Femur and tibia dimensions and mineral density were determined. Inc24L led to more epiphyseal plate abnormalities than Inc16L:8D or Inc24D. Inc24D led to more BCO than Inc16L:8D. Gait scores on D21, D28, and D34, and bone dimensions did not differ between treatments. Inc24L led to higher femur mineral density than Inc24D with Inc16L:8D intermediate. Providing a chicken with a matched post hatch lighting schedule did not affect most measurements of bone development and health. It can be concluded that a circadian incubation lighting schedule may improve leg health in broilers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Acute development of cortical porosity and endosteal naïve bone formation from the daily but not weekly short-term administration of PTH in rabbit.

    Directory of Open Access Journals (Sweden)

    Hiroshi Yamane

    Full Text Available Teriparatide [human parathyroid hormone (1-34], which exerts an anabolic effect on bone, is used for the treatment of osteoporosis in patients who are at a high risk for fracture. That the once-daily administration of teriparatide causes an increase in cortical porosity in animal models and clinical studies has been a matter of concern. However, it is not well documented that the frequency of administration and/or the total dose of teriparatide affect the cortical porosity. The present study developed 4 teriparatide regimens [20 μg/kg/day (D20, 40 μg/kg/day (D40, 140 μg/kg/week (W140 and 280 μg/kg/week (W280] in the rabbit as a model animal with a well-developed Haversian system and osteons. The total weekly doses were equivalent in the low-dose groups (D20 and W140 and in the high-dose groups (D40 and W280. After the short-term (1 month administration of TPDT, micro-CT, histomorphometry and three-dimensional second harmonic generation (3D-SHG imaging to visualize the bone collagen demonstrated that daily regimens but not weekly regimens were associated with the significant development of cortical porosity and endosteal naïve bone formation by marrow fibrosis. We concomitantly monitored the pharmacokinetics of the plasma teriparatide levels as well as the temporal changes in markers of bone formation and resorption. The analyses in the present study suggested that the daily repeated administration of teriparatide causes more deleterious changes in the cortical microarchitecture than the less frequent administration of higher doses. The findings of the present study may have some implications for use of teriparatide in clinical treatment.

  18. Development of a Patient-Derived Xenograft (PDX of Breast Cancer Bone Metastasis in a Zebrafish Model

    Directory of Open Access Journals (Sweden)

    Laura Mercatali

    2016-08-01

    Full Text Available Bone metastasis is a complex process that needs to be better understood in order to help clinicians prevent and treat it. Xenografts using patient-derived material (PDX rather than cancer cell lines are a novel approach that guarantees more clinically realistic results. A primary culture of bone metastasis derived from a 67-year-old patient with breast cancer was cultured and then injected into zebrafish (ZF embryos to study its metastatic potential. In vivo behavior and results of gene expression analyses of the primary culture were compared with those of cancer cell lines with different metastatic potential (MCF7 and MDA-MB-231. The MCF7 cell line, which has the same hormonal receptor status as the bone metastasis primary culture, did not survive in the in vivo model. Conversely, MDA-MB-231 disseminated and colonized different parts of the ZF, including caudal hematopoietic tissues (CHT, revealing a migratory phenotype. Primary culture cells disseminated and in later stages extravasated from the vessels, engrafting into ZF tissues and reaching the CHT. Primary cell behavior reflected the clinical course of the patient’s medical history. Our results underline the potential for using PDX models in bone metastasis research and outline new methods for the clinical application of this in vivo model.

  19. The development of lameness and bone deformity in the broiler following experimental infection with Mycoplasma gallisepticum or Mycoplasma synoviae.

    Science.gov (United States)

    Morrow, C J; Bradbury, J M; Gentle, M J; Thorp, B H

    1997-01-01

    Groups of eight 7-day-old Mycoplasma-free broiler chicks were inoculated with one of two strains of M. gallisepticum (MG/S6, MG/B31/85) or one of two strains of M. synoviae (MS/B31/88 and MS/B94/91) into the left hock joint. Controls were similarly inoculated with sterile mycoplasma broth. The birds were assessed at 2, 3, 4 and 5 weeks of age (1, 2, 3 and 4 weeks post-injection) for lameness and joint and limb lesions. At 5 weeks of age they were killed and examined for gross skeletal abnormalities and microscopic lesions of both hock joints. The in-contact controls showed no joint swelling or lameness. The mycoplasma did not apparently spread to cause gross pathology in the joints of in-contact control birds, or to other joints in a bird injected with mycoplasma. Each mycoplasma strain caused specific pathologies manifest as varying degrees of lameness, left hock joint swelling, bone deformity and differences in the severity of articular cartilage and chondrodystrophic growth plate pathology. Shortening and bowing of the right tibiotarsus in the birds injected with mycoplasma indicated unilateral increased limb loading contributing to bone deformity. Chondrodystrophy seen with three mycoplasmal strains may have contributed to bone deformity in these birds. Lameness appeared to be a consequence of either joint swelling and/or bone deformity resulting in mechanical dysfunction. The role of joint pain in the lameness was not determined.

  20. Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

    Science.gov (United States)

    Blaber, Elizabeth A.; Cheng-Campbell, Margareth A.; Almeida, Eduardo A. C.

    2016-01-01

    Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31 decrease in bone volume ratio, a 14 decrease in trabecular thickness, and a 20 decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1. This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration

  1. Alcohol and bone.

    Science.gov (United States)

    Mikosch, Peter

    2014-01-01

    Alcohol is widely consumed across the world in different cultural and social settings. Types of alcohol consumption differ between (a) light, only occasional consumption, (b) heavy chronic alcohol consumption, and (c) binge drinking as seen as a new pattern of alcohol consumption among teenagers and young adults. Heavy alcohol consumption is detrimental to many organs and tissues, including bones. Osteoporosis is regularly mentioned as a secondary consequence of alcoholism, and chronic alcohol abuse is established as an independent risk factor for osteoporosis. The review will present the different mechanisms and effects of alcohol intake on bone mass, bone metabolism, and bone strength, including alcoholism-related "life-style factors" such as malnutrition, lack of exercise, and hormonal changes as additional causative factors, which also contribute to the development of osteoporosis due to alcohol abuse.

  2. [Allergy towards bone cement].

    Science.gov (United States)

    Thomas, P; Schuh, A; Summer, B; Mazoochian, F; Thomsen, M

    2006-09-01

    Bone cements based on polymethylmethacrylate are typically used for fixation of artificial joints. Intolerance reactions to endoprostheses not explained by infection or mechanical failure may lead to allergological diagnostics, which mostly focuses on metal allergy. However, also bone cement components may provoke hypersensitivity reactions leading to eczema, implant loosening, or fistula formation. Elicitors of such reactions encompass acrylates and additives such as benzoyl peroxide, N,N-dimethyl-p-toluidine, hydroquinone, or antibiotics (particularly gentamicin). Upon repeated contact with bone cement components, e.g., acrylate monomers, also in medical personnel occasionally hand eczema or even asthma may develop. Therefore, in the case of suspected hypersensitivity reactions to arthroplasty, the allergological diagnostics should include bone cement components.

  3. Vitamin D - Prevalence, mortality and bone pain

    DEFF Research Database (Denmark)

    Durup, Darshana Tiffany; Schwarz, Peter

    2013-01-01

    of the pain syndrome in patients with vitamin D deficiency and bone pain. Furtherme, development of a non-cancer animal model of bone pain, was carried out, to enable investigations of bone pain threshold, bone microenvironment and endocrinology parameters involved in this debilitating disease. A unique......Bone pain is a common and debilitating symptom of many metabolic bone diseases. However, almost nothing is known about the molecular and cellular mechanisms leading to bone pain and the pain states are poorly characterized. It is well-established that osteomalacia due to severe vitamin D deficiency......, where the bones are demineralized can lead to persistent musculoskeletal pain, it can be so debilitating, that is has been mistaken for bone cancer pain. However, osteomalcia is an often-overlooked cause of bone pain, which leads to unnecessarily long period with untreated pain. The purpose...

  4. Ten-year prediction of osteoporosis from baseline bone mineral density: development of prognostic thresholds in healthy postmenopausal women. The Danish Osteoporosis Prevention Study

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Rejnmark, Lars; Nielsen, Stig Pors

    2006-01-01

    Osteopenia is common in healthy women examined in the first year or two following menopause. Short-term fracture risk is low, but we lack algorithms to assess long-term risk of osteoporosis. Because bone loss proceeds at only a few percent per year, we speculated that baseline bone mineral density...... (BMD) would predict a large proportion of 10-year BMD and be useful for deriving predictive thresholds. We aimed to identify prognostic thresholds associated with less than 10% risk of osteoporosis by 10 years in the individual participant, in order to allow rational osteodensitometry and intervention......% risk of fracture or low BMD within 10 years. At the population level, baseline T -score cutoffs below 0 at the LS (68% of the population), 0 at the FN (72%) or -0.6 (62%) at the lower of the two sites capture 90% of the population that developed osteoporosis during the following 10 years. A BMD...

  5. Investigating the impact of socioeconomic status on the effectiveness of a pamphlet on achieving and maintaining bone health in breast cancer survivors: a patient education resource development primer.

    Science.gov (United States)

    Adirim, Tara; Chafranskaia, Aleksandra; Nyhof-Young, Joyce

    2012-03-01

    Considerable need exists to raise awareness of breast cancer (BC) treatment-induced bone loss and provide management and preventative strategies. We describe the development and evaluation process of an educational pamphlet for BC survivors on achieving and maintaining bone health. A Participatory Design approach was used. The pamphlet was first critically evaluated by interdisciplinary healthcare professionals and less vulnerable members of the target audience prior to evaluation by 45 BC survivors, who completed two questionnaires inquiring about demographics and pamphlet evaluation and satisfaction. Pamphlet effectiveness was correlated with income and education to determine differences between socioeconomic groups. Perceived knowledge increased significantly after reading the brochure for all groups. Socioeconomic status had no impact on pamphlet effectiveness. This methodological approach is presented as a blueprint to promote knowledge translation in cancer patient education contexts aiming to provide cancer patients with the best possible resources for effective self-management of their conditions.

  6. Ten-year prediction of osteoporosis from baseline bone mineral density: development of prognostic thresholds in healthy postmenopausal women. The Danish Osteoporosis Prevention Study

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Rejnmark, Lars; Nielsen, Stig Pors

    2006-01-01

    . We analyzed dual energy X-ray absorptometry (DXA) of the lumbar spine (LS) and femoral neck (FN) from 872 women, who participated in the non-HRT arms of the Danish Osteoporosis Prevention Study and had remained on no HRT, bisphosphonates or raloxifene since inclusion 10 years ago. We defined......Osteopenia is common in healthy women examined in the first year or two following menopause. Short-term fracture risk is low, but we lack algorithms to assess long-term risk of osteoporosis. Because bone loss proceeds at only a few percent per year, we speculated that baseline bone mineral density...... development of a T -score below -2.5 at the LS and/or FN or incident fracture as end-point, and we derived prognostic thresholds for baseline BMD, defining 90% NPV (negative predictive value) and 90% sensitivity, respectively. Seventy-six percent of the variation in BMD of the LS at 10 years was predicted...

  7. Estimation of In vivo Cancellous Bone Elasticity

    Science.gov (United States)

    Otani, Takahiko; Mano, Isao; Tsujimoto, Toshiyuki; Yamamoto, Tadahito; Teshima, Ryota; Naka, Hiroshi

    2009-07-01

    The effect of decreasing bone density (a symptom of osteoporosis) is greater for cancellous bone than for dense cortical bone, because cancellous bone is metabolically more active. Therefore, the bone density or bone mineral density of cancellous bone is generally used to estimate the onset of osteoporosis. Elasticity or elastic constant is a fundamental mechanical parameter and is directly related to the mechanical strength of bone. Accordingly, elasticity is a preferable parameter for assessing fracture risk. A novel ultrasonic bone densitometer LD-100 has been developed to determine the mass density and elasticity of cancellous bone with a spatial resolution comparable to that of peripheral quantitative computed tomography. Bone density and bone elasticity are evaluated using ultrasonic parameters based on fast and slow waves in cancellous bone by modeling the ultrasonic wave propagation path. Elasticity is deduced from the measured bone density and the propagation speed of the fast wave. Thus, the elasticity of cancellous bone is approximately expressed by a cubic equation of bone density.

  8. Mechanotransduction pathways in bone pathobiology.

    Science.gov (United States)

    Spyropoulou, Anastasia; Karamesinis, Konstantinos; Basdra, Efthimia K

    2015-09-01

    The skeleton is subject to dynamic changes throughout life and bone remodeling is essential for maintenance of bone functionality. The cell populations which predominantly participate in bone and cartilage remodeling, namely osteocytes, osteoblasts, osteoclasts and chondrocytes sense and respond to external mechanical signals and via a series of molecular cascades control bone metabolism and turnover rate. The aforementioned process, known as mechanotransduction, is the underlying mechanism that controls bone homeostasis and function. A wide array of cross-talking signaling pathways has been found to play an important role in the preservation of bone and cartilage tissue health. Moreover, alterations in bone mechanotransduction pathways, due to genetic, hormonal and biomechanical factors, are considered responsible for the pathogenesis of bone and cartilage diseases. Extensive research has been conducted and demonstrated that aberrations in mechanotransduction pathways result in disease-like effects, however only few signaling pathways have actually been engaged in the development of bone disease. The aim of the present review is to present these signaling molecules and cascades that have been found to be mechano-responsive and implicated in bone disease development, as revealed by research in the last five years. In addition, the role of these molecules as prognostic or diagnostic disease markers and their potential as therapeutic targets are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Printing bone : the application of 3D fiber deposition for bone tissue engineering

    NARCIS (Netherlands)

    Fedorovich, N.E.

    2011-01-01

    Bone chips are used by orthopaedic surgeons for treating spinal trauma and to augment large bone defects. A potential alternative to autologous bone is regeneration of bone tissue in the lab by developing hybrid implants consisting of osteogenic (stem) cells seeded on supportive matrices.

  10. Development of a surrogate model based on patient weight, bone mass and geometry to predict femoral neck strains and fracture loads.

    Science.gov (United States)

    Taylor, Mark; Perilli, Egon; Martelli, Saulo

    2017-04-11

    Osteoporosis and related bone fractures are an increasing global burden in our ageing society. Areal bone mineral density assessed through dual energy X-ray absorptiometry (DEXA), the clinically accepted and most used method, is not sufficient to assess fracture risk individually. Finite element (FE) modelling has shown improvements in prediction of fracture risk, better than aBMD from DEXA, but is not practical for widespread clinical use. The aim of this study was to develop an adaptive neural network (ANN)-based surrogate model to predict femoral neck strains and fracture loads obtained from a previously developed population-based FE model. The surrogate model performance was assessed in simulating two loading conditions: the stance phase of gait and a fall. The surrogate model successfully predicted strains estimated by FE (r 2 =0.90-0.98 for level gait load case, r 2 =0.92-0.96 for the fall load case). Moreover, an ANN model based on three measurements obtainable in clinics (femoral neck length (level gait) or maximum femoral neck diameter (fall), femoral neck bone mass, body weight) was able to give reasonable predictions (r 2 =0.84-0.94) for all of the strain metrics and the estimated femoral neck fracture load. Overall, the surrogate model has potential for clinical applications as they are based on simple measures of geometry and bone mass which can be derived from DEXA images, accurately predicting FE model outcomes, with advantages over FE models as they are quicker and easier to perform. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  11. Experimental study of osteoinduction using a new material as a carrier for bone morphogenetic protein-2.

    Science.gov (United States)

    Koyama, Noriaki; Okubo, Yasunori; Nakao, Kazumasa; Osawa, Kenji; Bessho, Kazuhisa

    2011-06-01

    We evaluated the usefulness of artificial collagen as a new carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2) by comparing it with that of atelopeptide collagen, which is derived from porcine skin, and which we have previously shown to be useful for the induction of bone. rhBMP-2 5μg with either atelopeptide collagen 3mg or artificial collagen 3mg was implanted into the calf muscle of 10-week-old Wistar rats (n=3 in each group). Three rats were given artificial collagen alone and acted as controls (n=3). Radiographic evaluation, histological analysis, and biochemical examinations were made on day 21 after implantation. Soft radiographs (wavelength 10-0.10nm) showed opaque shadows in both groups. Histological analysis showed that new bone had formed in both experimental groups. Endochondral ossification was found at the outermost edge of the implanted collagen in the atelopeptide group. However, there was less ossification in the implanted collagen in the artificial collagen group. On biochemical examination, alkaline phosphatase activity and calcium concentrations in both experimental groups were higher than in the control group, and were higher in the atelopeptide group than in the artificial collagen group. Our results suggest that artificial collagen is useful as a carrier for rhBMP-2 designed to promote the formation of new bone. Copyright © 2010 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. Cyclophilin A (CypA) Plays Dual Roles in Regulation of Bone Anabolism and Resorption.

    Science.gov (United States)

    Guo, Mian; James, Aaron W; Kwak, Jin Hee; Shen, Jia; Yokoyama, Kazunari K; Ting, Kang; Soo, Chia B; Chiu, Robert H

    2016-03-02

    CypA (Cyclophilin A) is a peptidyl-prolyl isomerase previously shown to be required for chondrogenic differentiation and endochondral ossification. However, the effects of CypA on osteoclast activity and bone maintenance are entirely unknown. Here, we show that Ppia(-/-) mice demonstrate low bone mineral density, reduced osteoblast numbers, and increased osteoclast numbers. When isolated from the calvaria, Ppia(-/-) osteoblasts demonstrate decreased osteogenic differentiation, whereas Ppia(-/-) osteoclasts derived from the long bones showed increased osteoclastic activity. Overexpression and gene silencing of CypA verified osteogenic and anti-osteoclastic effects. In osteoblasts, CypA is necessary for BMP-2 (Bone Morphogenetic Protein-2)-induced Smad phosphorylation. In osteoclasts, loss of CypA activates BtK (Bruton's tyrosine kinase) and subsequently integrates with TRAF6 (TNF receptor-associated factor 6) and/or c-fos signaling to induce NFATc1 (nuclear factors of activated T cells, cytoplasmic 1). Collectively, CypA dually exerts pro-osteogenic and anti-osteoclastic effects. Thus, modulation of CypA may be useful in future efforts targeting osteoporosis.

  13. Your Bones

    Science.gov (United States)

    ... the top are called the cervical (say: SIR-vih-kul) vertebrae. These bones are in the back ... purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995- The Nemours Foundation. All ...

  14. Bone Scan

    Science.gov (United States)

    ... posts Join Mayo Clinic Connect Bone scan About Advertisement Mayo Clinic does not endorse companies or products. ... a Job Site Map About This Site Twitter Facebook Google YouTube Pinterest Mayo Clinic is a not- ...

  15. Bone pain

    DEFF Research Database (Denmark)

    Frost, Charlotte Ørsted; Hansen, Rikke Rie; Heegaard, Anne-Marie

    2016-01-01

    Skeletal conditions are common causes of chronic pain and there is an unmet medical need for improved treatment options. Bone pain is currently managed with disease modifying agents and/or analgesics depending on the condition. Disease modifying agents affect the underlying pathophysiology...... of the disease and reduce as a secondary effect bone pain. Antiresorptive and anabolic agents, such as bisphosphonates and intermittent parathyroid hormone (1-34), respectively, have proven effective as pain relieving agents. Cathepsin K inhibitors and anti-sclerostin antibodies hold, due to their disease...... modifying effects, promise of a pain relieving effect. NSAIDs and opioids are widely employed in the treatment of bone pain. However, recent preclinical findings demonstrating a unique neuronal innervation of bone tissue and sprouting of sensory nerve fibers open for new treatment possibilities....

  16. Towards high throughput tissue engineering: development of chitosan-calcium phosphate scaffolds for engineering bone tissue from embryonic stem cells

    OpenAIRE

    Ko, Junghyuk; Kolehmainen, Kathleen; Ahmed, Farid; Jun, Martin BG; Willerth, Stephanie M.

    2011-01-01

    Tissue engineering strategies have shown promise for the repair of damaged organs, including bone. One of the major challenges associated with tissue engineering is how to scale up such processes for high throughput manufacturing of biomaterial scaffolds used to support stem cell culture. Generation of certain types of 3D biomaterial scaffolds, including chitosan-calcium phosphate blends, involves a slow fabrication process followed by a lengthy required freeze drying step. This work investig...

  17. Co-transplantation of fetal bone tissue facilitates the development and reconstitution in human B cells in humanized NOD/SCID/IL-2Rγnull (NSG) mice.

    Science.gov (United States)

    Kim, Miyoung; Choi, Bongkum; Kim, So Yong; Yang, Ji-Hyuk; Roh, Cheong Rae; Lee, Ki-Young; Kim, Sung Joo

    2011-08-01

    In terms of the function and reconstitution efficacy of human immune cells, co-transplantation of human fetal tissues, such as thymus and liver, with CD34(+) hematopoietic stem cells (HSCs) has potential advantages in the generation of humanized mice. To examine the effects of bone tissues in the reconstitution of human immune cells, particularly in B cells, we generated a new humanized mice co-transplanted with human fetal thymus (hFT)/fetal bone (hFB) tissues and human fetal liver-derived CD34(+) cells. Humanized mice exhibited effective reconstitution of human immune cells earlier compared to control humanized mice. In terms of quantity, the number of immune cells, such as human T, B, and monocyte/macrophages was significantly increased. Furthermore, significant increase of B cell progenitors and immature/naïve B cells could be detected in the bone marrow and spleen of humanized mice. Our results demonstrate that co-transplantation of hFB tissue may facilitate the reconstitution of human B and T cells, and therefore the humanized model may be used to develop therapeutic human antibodies for clinical use.

  18. Development of a new carbon nanotube-alginate-hydroxyapatite tricomponent composite scaffold for application in bone tissue engineering.

    Science.gov (United States)

    Rajesh, Rajendiran; Ravichandran, Y Dominic

    2015-01-01

    In recent times, tricomponent scaffolds prepared from naturally occurring polysaccharides, hydroxyapatite, and reinforcing materials have been gaining increased attention in the field of bone tissue engineering. In the current work, a tricomponent scaffold with an oxidized multiwalled carbon nanotube (fMWCNT)-alginate-hydroxyapatite with the required porosity was prepared for the first time by a freeze-drying method and characterized using analytical techniques. The hydroxyapatite for the scaffold was isolated from chicken bones by thermal calcination at 800°C. The Fourier transform infrared spectra and X-ray diffraction data confirmed ionic interactions and formation of the fMWCNT-alginate-hydroxyapatite scaffold. Interconnected porosity with a pore size of 130-170 µm was evident from field emission scanning electron microscopy. The total porosity calculated using the liquid displacement method was found to be 93.85%. In vitro biocompatibility and cell proliferation on the scaffold was checked using an MG-63 cell line by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and cell attachment by Hoechst stain assay. In vitro studies showed better cell proliferation, cell differentiation, and cell attachment on the prepared scaffold. These results indicate that this scaffold could be a promising candidate for bone tissue engineering.

  19. Dynamic Cross Talk between S1P and CXCL12 Regulates Hematopoietic Stem Cells Migration, Development and Bone Remodeling

    Directory of Open Access Journals (Sweden)

    Karin Golan

    2013-09-01

    Full Text Available Hematopoietic stem cells (HSCs are mostly retained in a quiescent non-motile mode in their bone marrow (BM niches, shifting to a migratory cycling and differentiating state to replenish the blood with mature leukocytes on demand. The balance between the major chemo-attractants CXCL12, predominantly in the BM, and S1P, mainly in the blood, dynamically regulates HSC recruitment to the circulation versus their retention in the BM. During alarm situations, stress-signals induce a decrease in CXCL12 levels in the BM, while S1P levels are rapidly and transiently increased in the circulation, thus favoring mobilization of stem cells as part of host defense and repair mechanisms. Myeloid cytokines, including G-CSF, up-regulate S1P signaling in the BM via the PI3K pathway. Induced CXCL12 secretion from stromal cells via reactive oxygen species (ROS generation and increased S1P1 expression and ROS signaling in HSCs, all facilitate mobilization. Bone turnover is also modulated by both CXCL12 and S1P, regulating the dynamic BM stromal microenvironment, osteoclasts and stem cell niches which all functionally express CXCL12 and S1P receptors. Overall, CXCL12 and S1P levels in the BM and circulation are synchronized to mutually control HSC motility, leukocyte production and osteoclast/osteoblast bone turnover during homeostasis and stress situations.

  20. Medicines and Bone Loss

    Science.gov (United States)

    Fact Sheet Medici a ne n s d Bone Loss Some types of medicines can cause bone loss, making your bones weak, if used for a long time. Use over a short time ... old bone and replaces it with new bone. Bone loss occurs when old bone breaks down faster than ...

  1. Animal Models of Bone Metastasis

    Science.gov (United States)

    Simmons, J. K.; Hildreth, B. E.; Supsavhad, W.; Elshafae, S. M.; Hassan, B. B.; Dirksen, W. P.; Toribio, R. E.; Rosol, T. J.

    2015-01-01

    Bone is one of the most common sites of cancer metastasis in humans and is a significant source of morbidity and mortality. Bone metastases are considered incurable and result in pain, pathologic fracture, and decreased quality of life. Animal models of skeletal metastases are essential to improve the understanding of the molecular pathways of cancer metastasis and growth in bone and to develop new therapies to inhibit and prevent bone metastases. The ideal animal model should be clinically relevant, reproducible, and representative of human disease. Currently, an ideal model does not exist; however, understanding the strengths and weaknesses of the available models will lead to proper study design and successful cancer research. This review provides an overview of the current in vivo animal models used in the study of skeletal metastases or local tumor invasion into bone and focuses on mammary and prostate cancer, lymphoma, multiple myeloma, head and neck squamous cell carcinoma, and miscellaneous tumors that metastasize to bone. PMID:26021553

  2. Development of a software to bone age assessment by Tanner and Whitehouse method; Desenvolvimento de um programa computacional para implementacao do metodo de leitura de idade ossea de Tanner e Whitehouse

    Energy Technology Data Exchange (ETDEWEB)

    Caetano, Nattan R. [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Ghilardi Netto, Thomaz; Tomita, Ines [Universidade de Sao Paulo (FMRP/USP), Ribeirao Preto, USP (Brazil). Fac. de Medicina. Hospital das Clinicas

    2011-07-01

    The aim of the present work was to optimize the process of bone age reading. Several methods existent nowadays consist of skeletal maturity analysis, based on the bone details of the hand and wrist. The most effective method is proposed by Tanner and Whitehouse (TW), which produces results about five times more accurate than the other methods like the Grelish and Pyle (GP) one, which is widely used due the simplicity of the reading processes. However, the TW method is not often used at most hospitals because it presents high complexity degree. Thus, a computational program was developed to implement it in pediatric services, where the precision in bone age measurement is important. The program is similar to TW atlas, presenting images of skeletal maturity stages of analyzed bones, followed by explanatory texts. Besides, the reading processes and the calculations are automated by the program. Therefore, the diagnosis based on bone ages is produced faster and safely, taking into account that 19% of readings by means of GP present deviations of about 30% in comparison to TW. The TW method produces results with a precision five times greater than GP and with the program developed in this work, bone age reading becomes simple. The automation of bone age reading turns TW method more dynamic, enabling its use without interference in measurement values. (author)

  3. Regulating Chondrogenesis of Human Mesenchymal Stromal Cells with a Retinoic Acid Receptor-Beta Inhibitor: Differential Sensitivity of Chondral Versus Osteochondral Development

    Directory of Open Access Journals (Sweden)

    Solvig Diederichs

    2014-05-01

    Full Text Available Aim: Main objective was to investigate whether the synthetic retinoic acid receptor (RAR-β antagonist LE135 is able to drive in vitro chondrogenesis of human mesenchymal stromal cells (MSCs or improve differentiation by suppressing hypertrophic chondrocyte development. Methods: Chondrogenesis of human bone marrow and adipose tissue-derived MSCs was induced in micromass pellet culture for six weeks. Effects of LE135 alone and in combinatorial treatment with TGF-β on deposition of cartilaginous matrix including collagen type II and glycosaminoglycans, on deposition of non-hyaline cartilage collagens type I and X, and on hypertrophy markers including alkaline phosphatase (ALP, indian hedghehog (IHH and matrix metalloproteinase (MMP-13 were assessed. Results: LE135 was no inducer of chondrogenesis and failed to stimulate deposition of collagen type II and glycosaminoglycans. Moreover, addition of LE135 to TGF-β-treated pellets inhibited cartilaginous matrix deposition and gene expression of COL2A1. In contrast, non-hyaline cartilage collagens were less sensitive to LE135 and hypertrophy markers remained unaffected. Conclusion: This demonstrates a differential sensitivity of chondral versus endochondral differentiation pathways to RARβ signaling; however, opposite to the desired direction. The relevance of trans-activating versus trans-repressing RAR signaling, including effects on activator protein (AP-1 is discussed and implications for overcoming current limits of hMSC chondrogenesis are considered.

  4. Does the epiphyseal cartilage of the long bones have one or two ossification fronts?

    Science.gov (United States)

    Delgado-Martos, María Jesús; Touza Fernández, Alberto; Canillas, Fernando; Quintana-Villamandos, Begoña; Santos del Riego, Sergio; Delgado-Martos, Emilio; Martos-Rodriguez, Antonia; Delgado-Baeza, Emilio

    2013-10-01

    Epiphyseal cartilage is hyaline cartilage tissue with a gelatinous texture, and it is responsible for the longitudinal growth of the long bones in birds and mammals. It is located between the epiphysis and the diaphysis. Epiphyseal cartilage also is called a growth plate or physis. It is protected by three bone components: the epiphysis, the bone bar of the perichondrial ring and the metaphysis. The epiphysis, which lies over the epiphyseal cartilage in the form a cupola, contains a juxtaposed bone plate that is near the epiphyseal cartilage and is in direct contact with the epiphyseal side of the epiphyseal cartilage. The germinal zone corresponds to a group of cells called chondrocytes. These chondrocytes belong to a group of chondral cells, which are distributed in rows and columns; this architecture is commonly known as a growth plate. The growth plate is responsible for endochondral bone growth. The aim of this study was to elucidate the causal relationship between the juxtaposed bone plate and epiphyseal cartilage in mammals. Our hypothesis is that cells from the germinal zone of the epiphyseal side of the epiphyseal cartilage are involved in forming a second ossification front that is responsible for the origin of the juxtaposed bone plate. We report the following: (a) The juxtaposed bone plate has a morphology and function that differs from that of the epiphyseal trabeculae; (b) on the epiphyseal edge of the epiphyseal cartilage, a new ossification front starts on the chondrocytes of the germinal area, which forms the juxtaposed bone plate. This ossification front is formed by chondrocytes from the germinal zone through a process of mineralisation and ossification, and (c) the process of mineralisation and ossification has a certain morphological analogy to the process of ossification in the metaphyseal cartilage of amphibians and differs from the endochondral ossification process in the metaphyseal side of the growth plate. The close relationship between

  5. Bi-iliac distance and iliac bone position compared to the vertebral column in normal fetal development

    DEFF Research Database (Denmark)

    Hartling, U B; Fischer Hansen, B; Skovgaard, L T

    2001-01-01

    life, the second to evaluate the level of the iliac bones proportional to the ossified vertebral column. Whole body radiographs in antero-posterior projections from 98 human fetuses (36 female and 44 male fetuses, as well as 18 fetuses on which the sex had not been determined) were analyzed...... in the study. The fetuses derived from spontaneous or induced abortions and they were radiographed as part of the required autopsy procedure. The crown-rump-length (CRL) of the fetuses varied from 32 to 245 mm. The outer and inner bi-iliac distance was measured from the radiographs with a digital Helios slide...

  6. [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.

  7. Shaped graft for aneurysmal bone cyst of upper limb bones.

    Science.gov (United States)

    Mostafa, Mohamed F; Abed, Yasser Y; Fawzy, Sallam I

    2017-11-01

    The optimal treatment of aneurysmal bone cyst remains challenging. The aim of this prospective study was to evaluate the results of using bone grafts shaped to the defects caused by aneurysmal bone cysts of upper limb bones. Fifteen patients (12 males and 3 females) with an average age of 12 years (range 6-16 years) were treated for aneurysmal bone cysts of upper limb bones by intralesional resection, argon beam coagulation and shaped bone graft. The grafts were harvested from 14 patients (11 fibulas and 3 iliac bones) and from the mother of one patient (proximal fibula). Osteosynthesis was required to stabilize the graft in four cases. The modified Enneking's scoring system was used for functional evaluation. One patient developed partial recurrence at 6 months and required reoperation. Superficial wound infection was encountered in one patient. Shortening of the humeral segment was seen in two patients (1 and 1.5 cm) but without angular deformity. After a mean follow-up of 45 months (range 24-68 months), the mean functional score was 97.3%. This technique proved to be reliable in obtaining a well reconstructed and growing bone with no or minimal deformity and good function.

  8. The role of hyaluronan produced by Has2 gene expression in development of the spine.

    Science.gov (United States)

    Roughley, Peter J; Lamplugh, Lisa; Lee, Eunice R; Matsumoto, Kazu; Yamaguchi, Yu

    2011-06-15

    Histologic analysis of spine development in cartilage-specific knockout mice. To evaluate the role hyaluronan produced by hyaluronan synthase-2 (Has2) in spine development. The Has2 gene is responsible for most hyaluronan production throughout the body, including the skeleton. However, it is not possible to study the involvement of hyaluronan in skeletal development using constitutive Has2 knockout mice, as the embryonic mice die early before skeletal development has occurred. This problem can be overcome by the use of cartilage-specific knockout mice. Mice possessing floxed Has2 genes were crossed with mice expressing Cre recombinase under control of the type II collagen promoter to generate cartilage-specific Has2 knockout mice. Spine development was studied by histology. Knockout mice died near birth and displayed severe abnormality in skeletal development. The spine showed defects in vertebral body size and the formation of the intervertebral discs. There was no evidence for the formation of an organized primary center of ossification within the vertebrae, and the appearance and organization of the hypertrophic chondrocytes was abnormal. Although no organized endochondral ossification appeared to be taking place, there was excessive bone formation at the center of the vertebrae. There was also a generalized increased cellularity of the vertebral cartilage and a corresponding decrease in the abundance of extracellular matrix. The nucleus pulposus of the intervertebral discs were less flattened than in the control mice and possessed an increased amount of large vacuolated cells. Remnants of the notochord could also be seen between adjacent discs. Hyaluronan production by Has2 is essential for normal vertebral and intervertebral disc development within the spine, and the absence of this synthase impairs the organization of both soft and hard tissue elements.

  9. Human Bone-Forming Chondrocytes Cultured in the Hydrodynamic Focusing Bioreactor Retain Matrix Proteins: Similarities to Spaceflight Results

    Science.gov (United States)

    Duke, P. J.; Hecht, J.; Montufar-Solis, D.

    2006-01-01

    Fracture healing, crucial to a successful Mars mission, involves formation of a cartilaginous fracture callus which differentiates, mineralizes, ossifies and remodels via the endochondral process. Studies of spaceflown and tailsuspended rats found that, without loading, fracture callus formation and cartilage differentiation within the callus were minimal. We found delayed differentiation of chondrocytes within the rat growth plate on Cosmos 1887, 2044, and Spacelab 3. In the current study, differentiation of human bone-forming chondrocytes cultured in the hydrodynamic focusing bioreactor (HFB) was assessed. Human costochondral chondrocytes in suspension were aggregated overnight, then cultured in the HFB for 25 days. Collagen Type II, aggrecan and unsulfated chondroitin were found extracellularly and chondroitin sulfates 4 and 6 within the cell. Lack of secretion was also found in pancreatic cells of spaceflown rats, and in our SL3 studies. The HFB can be used to study cartilage differentiation in simulated microgravity.

  10. Bone mineral content and bone metabolism in young adults with severe periodontitis

    DEFF Research Database (Denmark)

    Wowern von, N.; Westergaard, J.; Kollerup, G.

    2001-01-01

    Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis......Bone loss, bone markers, bone metabolism, bone mineral content, osteoporosis, severe periodontitis...

  11. Nanofunctionalized zirconia and barium sulfate particles as bone cement additives.

    Science.gov (United States)

    Gillani, Riaz; Ercan, Batur; Qiao, Alex; Webster, Thomas J

    2010-02-02

    Zirconia (ZrO(2)) and barium sulfate (BaSO(4)) particles were introduced into a methyl methacrylate monomer (MMA) solution with polymethyl methacrylate (PMMA) beads during polymerization to develop the following novel bone cements: bone cements with unfunctionalized ZrO(2) micron particles, bone cements with unfunctionalized ZrO(2) nanoparticles, bone cements with ZrO(2) nanoparticles functionalized with 3-(trimethoxysilyl)propyl methacrylate (TMS), bone cements with unfunctionalized BaSO(4) micron particles, bone cements with unfunctionalized BaSO(4) nanoparticles, and bone cements with BaSO(4) nanoparticles functionalized with TMS. Results demonstrated that in vitro osteoblast (bone-forming cell) densities were greater on bone cements containing BaSO(4) ceramic particles after four hours compared to control unmodified bone cements. Osteoblast densities were also greater on bone cements containing all of the ceramic particles after 24 hours compared to unmodified bone cements, particularly those bone cements containing nanofunctionalized ceramic particles. Bone cements containing ceramic particles demonstrated significantly altered mechanical properties; specifically, under tensile loading, plain bone cements and bone cements containing unfunctionalized ceramic particles exhibited brittle failure modes whereas bone cements containing nanofunctionalized ceramic particles exhibited plastic failure modes. Finally, all bone cements containing ceramic particles possessed greater radio-opacity than unmodified bone cements. In summary, the results of this study demonstrated a positive impact on the properties of traditional bone cements for orthopedic applications with the addition of unfunctionalized and TMS functionalized ceramic nanoparticles.

  12. Bone Loss in IBD

    Science.gov (United States)

    ... Home > Resources > Bone Loss in IBD Go Back Bone Loss in IBD Email Print + Share As many as ... halt bone loss are so important. CAUSES OF BONE LOSS IN IBD Experts point to several suspected causes ...

  13. Accelerated bone ingrowth by local delivery of Zinc from bioactive ...

    African Journals Online (AJOL)

    Background: Synthetic bone graft substitutes such as bioactive glass (BG) material are developed in order to achieve successful bone regeneration. Zn plays an important role in the proper bone growth, development, and maintenance of healthy bones. Aims: This study aims to evaluate in vivo the performance therapy of ...

  14. Bringing eggs and bones to light

    NARCIS (Netherlands)

    Pol, van der Carla W.

    2017-01-01

    Leg bone pathologies are a common problem in broiler chickens, and they can lead to decreased welfare and poor production performance. It can be speculated that the ae­tiology of some leg bone pathologies lies, to some extent, in suboptimal early life bone development. One factor that can be

  15. Suboccipital neuropathy after bone conduction device placement

    NARCIS (Netherlands)

    Faber, H.T.; Ru, J.A. de

    2013-01-01

    OBJECTIVE: To describe the clinical characteristics of a 70-year-old female with occipital neuropathy following bone conduction device surgery. DESCRIPTION: A 65-year-old woman underwent bone conduction device placement surgery on the left temporal bone. Postoperatively she progressively developed

  16. Bone growth during daily or intermittent calcitriol treatment during renal failure with advanced secondary hyperparathyroidism.

    Science.gov (United States)

    Sanchez, C P; He, Y Z

    2007-09-01

    Calcitriol is a standard therapy for secondary hyperparathyroidism in chronic renal failure. We evaluated whether the effect of daily or intermittent calcitriol administration is more efficient in enhancing bone growth in renal failure with advanced secondary hyperparathyroidism in weanling 5/6 nephrectomized rats loaded with phosphorus to induce severe secondary hyperparathyroidism. The animals were treated daily or three times weekly with calcitriol for 4 weeks but the total weekly dose of calcitriol was the same. Although calcitriol increased the serum calcium, it did not lower parathyroid hormone (PTH) or improve tibia and body length. Animals with renal failure and advanced secondary hyperparathyroidism had decreased PTH/PTHrP, which was accompanied by an increase in the cyclin kinase inhibitor p57(Kip2). Calcitriol treatment upregulated the PTH/PTHrP receptor but also increased inhibitors of cell proliferation such as p21(Waf1/Cip1), IGFBP3, and FGFR3. Calcitriol also enhanced markers of chondrocyte differentiation, such as IGF1, Vitamin D receptor, FGF23, and bone morphogenetic protein-7. Receptor activator of nuclear factor-kappabeta ligand levels improved with calcitriol treatment but without changes in osteoprotegerin suggesting an enhancement of osteo/chondroclastogenesis and mineralization. Overall, both daily and intermittent calcitriol had similar effects on endochondral bone growth in phosphorus-loaded rats with renal failure.

  17. Bone densitometry

    DEFF Research Database (Denmark)

    Ravn, Pernille; Alexandersen, P; Møllgaard, A

    1999-01-01

    is much more expensive and technically complicated. By computerized iteration of single X-ray absorptiometry forearm scans we defined a region with 65% trabecular bone. The region was analyzed in randomized, double-masked, placebo- controlled trials: a 2-year trial with alendronate (n = 69), a 1-year...

  18. Effect of In-Ovo Ascorbic Acid Injection on the Bone Development of Broiler Chickens Submitted to Heat Stress During Incubation and Rearing

    Directory of Open Access Journals (Sweden)

    S Sgavioli

    2016-03-01

    Full Text Available Abstract This experiment was conducted to evaluate the effect of in-ovo ascorbic acid (AA injection on the bone development of broilers submitted to heat stress during incubation and rearing. One thousand (1,000 Cobb(rfertile broiler eggs were randomly distributed according to the weight into five incubators, with 200 eggs per incubator. The incubation treatments were: eggs not injected with AA and incubated at 37.5°C; eggs not injected with AA and incubated at 39°C; and eggs injected with 6 µg AA/100 µL water prior to incubation and incubated at 39ºC. The hatched birds were reared at three different house temperatures: cold, thermoneutral, or and hot. The high incubation temperature negatively influenced broilers' bone characteristics. The femur of the birds hatched from eggs incubated at 39°C and injected with AA presented lower shaft mineral density, lower maximum force and lower elongation at maximum force. Their tibia presented reduced mineral density at the proximal and distal epiphysis. In-ovo AA injection of eggs incubated at high temperature did not minimize the negative effects of high rearing temperature on the performance andbone development of broiler chickens reared until 42 days of age.

  19. Bone marrow transplantation alters lung antigen-presenting cells to promote TH17 response and the development of pneumonitis and fibrosis following gammaherpesvirus infection.

    Science.gov (United States)

    Zhou, X; Loomis-King, H; Gurczynski, S J; Wilke, C A; Konopka, K E; Ptaschinski, C; Coomes, S M; Iwakura, Y; van Dyk, L F; Lukacs, N W; Moore, B B

    2016-05-01

    Hematopoietic stem cell transplantation (HSCT) efficacy is limited by numerous pulmonary complications. We developed a model of syngeneic bone marrow transplantion (BMT) followed by infection with murine gamma herpesvirus-68 that results in pneumonitis and fibrosis and mimics human "noninfectious" HSCT complications. BMT mice experience increased early lytic replication, but establish viral latency by 21 days post infection. CD4 T cells in BMT mice are skewed toward interleukin (IL)-17A rather than interferon (IFN)-γ production. Transplantation of bone marrow from Il-17a(-/-) donors or treatment with anti-IL-17A neutralization antibodies at late stages attenuates pneumonitis and fibrosis in infected BMT mice, suggesting that hematopoietic-derived IL-17A is essential for development of pathology. IL-17A directly influences activation and extracellular matrix production by lung mesenchymal cells. Lung CD11c+ cells of BMT mice secrete more transforming growth factor beta-β1, and pro-TH17 mRNAs for IL-23 and IL-6, and less TH1-promoting cytokine mRNA for IFN-γ but slightly more IL-12 mRNA in response to viral infection. Adoptive transfer of non-BMT lung CD11c-enriched cells restores robust TH1 response and suppresses aberrant TH17 response in BMT mice to improve lung pathology. Our data suggest that "noninfectious" HSCT lung complications may reflect preceding viral infections and demonstrate that IL-17A neutralization may offer therapeutic advantage even after disease onset.

  20. Clinical advances in bone regeneration.

    Science.gov (United States)

    Siddiqui, Nashat A; Owen, John M

    2013-05-01

    Understanding of the biology of bone regeneration has been increasing rapidly, with greater appreciation for the importance of biochemical aspects as well as the mechanical requirements for bone to heal. There are a number of situations where there is difficulty in bone healing such as fracture non-union; or growth such as osteogenesis imperfecta; or a requirement for surplus bone to reconstruct defects such as following surgery for tumour excision or limb lengthening. There is a greater understanding of the complex interplay between osteoblasts and osteoclasts, and the chemical mediators that provide signalling along complex pathways. Although we have known about substances such as Bone Morphogenic Proteins and Growth Hormones for some time, their application in clinical practice is still not widespread, and we need to study them more to understand their role in bone healing. With newer technologies such as stem cells and gene therapy being developed there is the potential for vast improvement in bone regenerative techniques, although we are not at a stage where we can be confident that these techniques will work. In this review article we discuss the basic healing process of bone and how our understanding of this has led to improved techniques as well as the potential for future developments in new technologies.

  1. Occipital foramina development involves localised regulation of mesenchyme proliferation and is independent of apoptosis

    Science.gov (United States)

    Akbareian, Sophia E; Pitsillides, Andrew A; Macharia, Raymond G; McGonnell, Imelda M

    2015-01-01

    Cranial foramina are holes within the skull, formed during development, allowing entry and exit of blood vessels and nerves. Once formed they must remain open, due to the vital structures they contain, i.e. optic nerves, jugular vein, carotid artery, and other cranial nerves and blood vessels. Understanding cranial foramina development is essential as cranial malformations lead to the stenosis or complete closure of these structures, resulting in blindness, deafness, facial paralysis, raised intracranial pressure and lethality. Here we focus on describing early events in the formation of the jugular, carotid and hypoglossal cranial foramina that form in the mesoderm-derived, endochondral occipital bones at the base of the embryonic chick skull. Whole-mount skeletal staining of skulls indicates the appearance of these foramina from HH32/D7.5 onwards. Haematoxylin & eosin staining of sections shows that the intimately associated mesenchyme, neighbouring the contents of these cranial foramina, is initially very dense and gradually becomes sparser as development proceeds. Histological examination also revealed that these foramina initially contain relatively large-diameter nerves, which later become refined, and are closely associated with the blood vessel, which they also innervate within the confines of the foramina. Interestingly cranial foramina in the base of the skull contain blood vessels lacking smooth muscle actin, which suggests these blood vessels belong to glomus body structures within the foramina. The blood vessel shape also appears to dictate the overall shape of the resulting foramina. We initially hypothesised that cranial foramina development could involve targeted proliferation and local apoptosis to cause ‘mesenchymal clearing’ and the creation of cavities in a mechanism similar to joint cavitation. We find that this is not the case, and propose that a mechanism reliant upon local nerve/blood vessel-derived restriction of ossification may

  2. Swimming training repercussion on metabolic and structural bone development; benefits of the incorporation of whole body vibration or pilometric training; the RENACIMIENTO project.

    Science.gov (United States)

    Gómez-Bruton, A; Gonzalez-Agüero, A; Casajus, J A; Vicente-Rodriguez, German

    2014-08-01

    Enviromental factors such as exercise participation and nutrition have often been linked to bone improvements. However, not all sports have the same effects, being non-osteogenic sports such as swimming defined as negative or neutral sports to practice regarding bone mass by some authors, similarly exercise-diet interaction in especific groups is still not clear. To present the methodology of the RENACIMENTO project that aims to evaluate body composition and more specifically bone mass by several techniques in adolescent swimmers and to observe the effects and perdurability of whole body vibration (WBV) and jumping intervention (JIN) on body composition and fitness on this population and explore posible diet interactions. Randomized controlled trial. 78 swimmers (12-17 y) and 26 sex- and age-matched controls will participate in this study. Dual energy X-ray, peripheral Quantitative Computed Tomography, Quantitative Ultrasound, Bioelectrical Impedance Analysis, and anthropometry measurements will be performed in order to evaluate body composition. Physical activity, nutrition, pubertal development and socio-economical status may act as confounders of body composition and therefore will also be registered. Several fitness factors regarding strength, endurance, performance and others will also be registered to evaluate differences with controls and act as confounders. A 7-month WBV therapy will be performed by 26 swimmers consisting of a training of 15 minutes 3 times per week. An 8 month JIM will also be performed by 26 swimmers 3 times per week. The remaining 26 swimmers will continue their normal swimming training. Four evaluations will be performed, the first one in order to describe differences between swimmers and controls. The second one to describe the effects of the interventions and the third and fourth evaluations to describe the perdurability of the effects of the WBV and JIN. The RENACIMIENTO project will allow to answer several questions regarding body

  3. Characterisation of Bone Beneficial Components from Australian Wallaby Bone

    Directory of Open Access Journals (Sweden)

    Weiguo Lao

    2016-08-01

    Full Text Available Background: Osteoporosis is a condition in which the bones become brittle, increasing the risk of fractures. Complementary medicines have traditionally used animal bones for managing bone disorders, such as osteoporosis. This study aimed to discover new natural products for these types of conditions by determining mineral and protein content of bone extracts derived from the Australian wallaby. Methods: Inductively coupled plasma-mass spectrometry and Fourier transform infrared spectroscopic analysis were used for mineral tests, proteome analysis was using LC/MS/MS and the effects of wallaby bone extracts (WBEs on calcium deposition and alkaline phosphatase activity were evaluated in osteogenic cells derived from adipose tissue-derived stem cells (ADSCs. Results: Concentrations of calcium and phosphorus were 26.21% and 14.72% in WBE respectively. Additionally, minerals found were wide in variety and high in concentration, while heavy metal concentrations of aluminium, iron, zinc and other elements were at safe levels for human consumption. Proteome analysis showed that extracts contained high amounts of bone remodelling proteins, such as osteomodulin, osteopontin and osteoglycin. Furthermore, in vitro evaluation of WBEs showed increased deposition of calcium in osteoblasts with enhanced alkaline phosphatase activity in differentiated adipose-derived stem cells. Conclusion: Our results demonstrate that wallaby bone extracts possess proteins and minerals beneficial for bone metabolism. WBEs may therefore be used for developing natural products for conditions such as osteoporosis and further investigation to understand biomolecular mechanism by which WBEs prevent osteoporosis is warranted.

  4. Assessment of Bone Microstructural Changes by NMR

    Science.gov (United States)

    Ni, Qingwen; Wang, Xiaodu

    2008-03-01

    Previous studies have shown that age related increases in bone porosity without significant changes in bone mineral density (BMD) (without bone microstructural information) result in a decrease in bone strength. Bone fracture toughness is also significantly correlated to changes in porosity, microarchitecture, collagen integrity, microdamage, and water distribution, all of which are measures of bone quality. Unfortunately, current technology does not allow the non-destructive and non-invasive detection of bone water distribution or other measures of bone quality including microporosity. On the other hand, Nuclear Magnetic Resonance (NMR) proton spin-spin (T2) relaxation time measurements and computational analytical method have been used to determine microstructural characteristics of various types of fluid filled porous materials. The study in here is to demonstrate that non-destructive and non-invasive NMR proton spin-spin (T2) relaxation techniques has been developed and applied to quantify the porosity, pore size distribution and water distribution in human cortical bone. This new bone microstructural information can then be used as descriptions of bone quality and, along or in combination with existing method (BMD) to more accurately assess bone fracture risk, and the results could help doctors and researchers to detect osteoporosis and other conditions related to weak bones in persons.

  5. Vitamin D - Prevalence, mortality and bone pain

    DEFF Research Database (Denmark)

    Durup, Darshana Tiffany; Schwarz, Peter

    2013-01-01

    of the pain syndrome in patients with vitamin D deficiency and bone pain. Furtherme, development of a non-cancer animal model of bone pain, was carried out, to enable investigations of bone pain threshold, bone microenvironment and endocrinology parameters involved in this debilitating disease. A unique...... deficiency. These subjects might be prone to bone pain. Characterization and quantification of bone pain in patients suffering from vitamin D deficiency is being investigated and might provide clues to the nature of bone pain and assist in evaluating the results from the animal model. So far the study...... of pain questionnaires and quantified by the use of pressure algometry. The pain will decrease by normalization of vitamin D. To invent an animal model for clinical osteomalacic bone pain, fifty seven-month-old, female Spraque-Dawley rats were maintained four months on synthetic diets containing...

  6. Biomaterials for Bone Regenerative Engineering.

    Science.gov (United States)

    Yu, Xiaohua; Tang, Xiaoyan; Gohil, Shalini V; Laurencin, Cato T

    2015-06-24

    Strategies for bone tissue regeneration have been continuously evolving for the last 25 years since the introduction of the "tissue engineering" concept. The convergence of the life, physical, and engineering sciences has brought in several advanced technologies available to tissue engineers and scientists. This resulted in the creation of a new multidisciplinary field termed as "regenerative engineering". In this article, the role of biomaterials in bone regenerative engineering is systematically reviewed to elucidate the new design criteria for the next generation of biomaterials for bone regenerative engineering. The exemplary design of biomaterials harnessing various materials characteristics towards successful bone defect repair and regeneration is highlighted. Particular attention is given to the attempts of incorporating advanced materials science, stem cell technologies, and developmental biology into biomaterials design to engineer and develop the next generation bone grafts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Robotic Long Bone Fracture Reduction

    OpenAIRE

    Graham, A. E.; Xie, S. Q.; Aw, K. C.; Xu, W.L.; Mukherjee, S.

    2008-01-01

    This research into a medical robot for realigning fractured bones aims to develop the interface, robot, and database technologies to improve the working situation for users and outcome for recipients. Compared with other approaches to fracture reduction, the system being developed here has a number of novel features. The geometric modeling has been effective in allowing a surgeon to visualize the fractured bone and has not been reported elsewhere for fracture reduction to the authors knowledg...

  8. Postoperative radiation therapy after hip replacement in high-risk patients for development of heterotopic bone formation; Role de la radiotherapie dans la prevention de l'ossification heterotopique

    Energy Technology Data Exchange (ETDEWEB)

    Hashem, R.; Rene, N.; Souhami, L. [Department of Radiation Oncology, Montreal General Hospital, McGill University Health Centre, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada); Tanzer, M. [Department of Orthopaedic Surgery, Montreal General Hospital, McGill University Health Centre, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada); Evans, M. [Department of Medical Physics, Montreal General Hospital, McGill University Health Centre, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4 (Canada)

    2011-07-15

    Purpose. - To report the results of postoperative radiation therapy in preventing the development of heterotopic bone formation after hip replacement surgery in high-risk patients. Patients and methods. - Between 1991 and 2007, 44 patients were preventively treated with postoperative RT after total hip replacement. In total, 47 hips were treated. All patients were considered at high risk for developing heterotopic bone formation. Most patients (63.5%) were treated because of a history of severe osteoarthritis or ankylosing spondylitis. All patients were treated with shaped parallel-opposed fields with a single fraction of 7 Gy using 6 or 18 MV photons. Most patients (94%) received radiation therapy within 72 hours postoperative and in only three patients radiation therapy was delivered after 72 hours post-surgery (5-8 days). Results. - Minimum follow-up was 1 year. There were 18 females and 26 males. Median age was 63 years (range: 18-80). Treatments were well tolerated and no acute toxicity was seen post-radiation therapy. Only one of the 47 hips (2%) developed heterotopic bone formation. This patient received postoperative radiation therapy to both hips but only developed heterotopic bone formation in one of them. None of the three patients treated beyond 72 hours failed. To date no late toxicity has been observed. Conclusion. - The use of postoperative radiation therapy was an effective and safe treatment in the prevention of heterotopic bone formation in a high-risk group of patients undergoing total hip replacement. (authors)

  9. Bone Circulatory Disturbances in the Development of Spontaneous Bacterial Chondronecrosis with Osteomyelitis: A Translational Model for the Pathogenesis of Femoral Head Necrosis

    Directory of Open Access Journals (Sweden)

    Robert F. Wideman

    2013-01-01

    Full Text Available This review provides a comprehensive overview of the vascularization of the avian growth plate and its subsequent role in the pathogenesis of bacterial chondronecrosis with osteomyelitis (BCO, femoral head necrosis. BCO sporadically causes high incidences of lameness in rapidly growing broiler (meat-type chickens. BCO is believed to be initiated by micro-trauma to poorly mineralized columns of cartilage cells in the proximal growth plates of the leg bones, followed by colonization by hematogenously distributed opportunistic bacteria. Inadequate blood flow to the growth plate, vascular occlusion, and structural limitations of the microvasculature all have been implicated in the pathogenesis of BCO. Treatment strategies have been difficult to investigate because under normal conditions the incidence of BCO typically is low and sporadic. Rearing broilers on wire flooring triggers the spontaneous development of high incidences of lameness attributable to pathognomonic BCO lesions. Wire flooring imposes persistent footing instability and is thought to accelerate the development of BCO by amplifying the torque and shear stress imposed on susceptible leg joints. Wire flooring per se also constitutes a significant chronic stressor that promotes bacterial proliferation attributed to stress-mediated immunosuppression. Indeed, dexamethasone-mediated immunosuppression causes broilers to develop lameness primarily associated with avascular necrosis and BCO. Prophylactic probiotic administration consistently reduces the incidence of lameness in broilers reared on wire flooring, presumably by reducing bacterial translocation from the gastrointestinal tract that likely contributes to hematogenous infection of the leg bones. The pathogenesis of BCO in broilers is directly relevant to osteomyelitis in growing children, as well as to avascular femoral head necrosis in adults. Our new model for reliably triggering spontaneous osteomyelitis in large numbers of

  10. Mixed cell therapy of bone marrow-derived mesenchymal stem cells and articular cartilage chondrocytes ameliorates osteoarthritis development.

    Science.gov (United States)

    Prasadam, Indira; Akuien, Akoy; Friis, Thor E; Fang, Wei; Mao, Xinzhan; Crawford, Ross W; Xiao, Yin

    2018-01-01

    Of the many cell-based treatments that have been tested in an effort to regenerate osteoarthritic articular cartilage, none have ever produced cartilage that compare with native hyaline cartilage. Studies show that different cell types lead to inconsistent results and for cartilage regeneration to be considered successful, there must be an absence of fibrotic tissue. Here we report of a series of experiments in which bone marrow-derived stem cells (BMSCs) and articular cartilage chondrocytes (ACCs) were mixed in a 1:1 ratio and tested for their ability to enhance cartilage regeneration in three different conditions: (1) in an in vitro differentiation model; (2) in an ex vivo cartilage defect model implanted subcutaneously in mice; and (3) as an intra-articular injection in a meniscectomy-induced OA model in rats. The mixed cells were compared with monocultures of BMSCs and ACCs. In all three experimental models there was significantly enhanced cartilage regeneration and decreased fibrosis in the mixed BMSCs+ACCs group compared with the monocultures. Molecular analysis showed a reduction in vascularization and hypertrophy, coupled with higher chondrogenic gene expression resulting from the BMSCs+ACCs treatment. Together, our data suggest that mixed BMSCs+ACCs treatment is highly chondro-protective and is more effective in regenerating damaged cartilage in both the ex vivo cartilage defect and post-trauma OA disease models. The results from this approach could potentially be used for regeneration of cartilage in OA patients.

  11. Brown fat determination and development from muscle precursor cells by novel action of bone morphogenetic protein 6.

    Directory of Open Access Journals (Sweden)

    Ankur Sharma

    Full Text Available Brown adipose tissue (BAT plays a pivotal role in promoting energy expenditure by the virtue of uncoupling protein-1 (UCP-1 that differentiates BAT from its energy storing white adipose tissue (WAT counterpart. The clinical implication of "classical" BAT (originates from Myf5 positive myoblastic lineage or the "beige" fat (originates through trans-differentiation of WAT activation in improving metabolic parameters is now becoming apparent. However, the inducers and endogenous molecular determinants that govern the lineage commitment and differentiation of classical BAT remain obscure. We report here that in the absence of any forced gene expression, stimulation with bone morphogenetic protein 6 (BMP6 induces brown fat differentiation from skeletal muscle precursor cells of murine and human origins. Through a comprehensive transcriptional profiling approach, we have discovered that two days of BMP6 stimulation in C2C12 myoblast cells is sufficient to induce genes characteristic of brown preadipocytes. This developmental switch is modulated in part by newly identified regulators, Optineurin (Optn and Cyclooxygenase-2 (Cox2. Furthermore, pathway analyses using the Causal Reasoning Engine (CRE identified additional potential causal drivers of this BMP6 induced commitment switch. Subsequent analyses to decipher key pathway that facilitates terminal differentiation of these BMP6 primed cells identified a key role for Insulin Like Growth Factor-1 Receptor (IGF-1R. Collectively these data highlight a therapeutically innovative role for BMP6 by providing a means to enhance the amount of myogenic lineage derived brown fat.

  12. Towards high throughput tissue engineering: development of chitosan-calcium phosphate scaffolds for engineering bone tissue from embryonic stem cells.

    Science.gov (United States)

    Ko, Junghyuk; Kolehmainen, Kathleen; Ahmed, Farid; Jun, Martin Bg; Willerth, Stephanie M

    2012-01-01

    Tissue engineering strategies have shown promise for the repair of damaged organs, including bone. One of the major challenges associated with tissue engineering is how to scale up such processes for high throughput manufacturing of biomaterial scaffolds used to support stem cell culture. Generation of certain types of 3D biomaterial scaffolds, including chitosan-calcium phosphate blends, involves a slow fabrication process followed by a lengthy required freeze drying step. This work investigates the use of automated microwave vacuum drying technology as an alternative to traditional freeze drying as a method of fabricating chitosan-calcium phosphate scaffolds for supporting embryonic stem cell cultures. Scaffolds produced using both drying techniques possess similar properties when characterized using scanning electron microscopy and this paper is the first to report that both types of these scaffolds support undifferentiated embryonic stem cell culture as well as promote stem cell differentiation into osteogenic lineages when treated with the appropriate factors. Compared to existing scaffold manufacturing processes using freeze drying, the use of microwave vacuum drying will lead to faster production times while reducing the costs, enabling high-throughput manufacturing of biomaterial scaffolds for stem cell applications.

  13. The role of vascular endothelial growth factor in ossification

    Science.gov (United States)

    Yang, Yan-Qi; Tan, Ying-Ying; Wong, Ricky; Wenden, Alex; Zhang, Lin-Kun; Rabie, A Bakr M

    2012-01-01

    Osteogenesis and angiogenesis are two closely correlated processes during bone growth, development, remodelling and repair. Vascular endothelial growth factor (VEGF) is an essential mediator during the process of angiogenesis. Based on an extensive literature search, which was carried out using the PubMed database and the keywords of osteogenesis, VEGF, endochondral ossification and intramembranous ossification, this manuscript reviews the role of VEGF in ossification, with emphasis on its effect in endochondral and intramembranous ossification. Osteogenesis and angiogenesis are closely correlated processes. VEGF acts as an essential mediator during these processes. It not only functions in bone angiogenesis but also in various aspects of bone development. PMID:22722639

  14. 2016 The Year That Was: Bone Strength.

    Science.gov (United States)

    Janz, Kathleen F

    2017-02-01

    Of all the lifestyle strategies for increasing bone strength during the growing years, physical activity is one of the most efficacious. This commentary highlights two exceptional 2016 publications addressing bone strength in children and adolescents with an eye toward reduced fracture risk later in life. The first by Weaver et al. was selected due to its comprehensive approach to understanding bone development. The second by Mitchell et al explores a new field of inquiry, that is, genetic-environment interaction as represented by bone mineral density-lowering alleles and high-impact physical activity. It is a first look at future precision medicine as it may pertain to pediatric bone strength.

  15. Strontium doping of bone graft extender

    Science.gov (United States)

    2011-01-01

    Background and purpose Allografts are often used during revision hip replacement surgery for stabilization of the implant. Resorption of the allograft may exceed new bone formation, and instability of the prosthesis can develop. We investigated whether strontium could regulate the imbalance of fast resorption of allograft and slower formation of new bone, because it is both an anabolic and an anticatabolic agent. Method Strontium was added to the implant interface environment by doping a hydroxyapatite bone graft extender. 10 dogs each received 2 experimental titanium implants. The implants were inserted within a 2.7-mm concentric gap in cancellous bone. The gap was filled with 50% (v/v) allograft mixed with 50% bone graft extender. The extender either had 5% strontium doping (SrHA) or was undoped (HA). After 4 weeks, osseointegration and mechanical fixation were evaluated by histomorphometry and by push-out test. Results SrHA bone graft extender induced a 1.2-fold increase in volume of new bone, a 1.2-fold increase in allograft remaining in the gap, and a 1.4-fold increase in surface area of the bone graft extender material in contact with new bone compared to HA bone graft extender. All these increases were statistically significant. SrHA bone graft extender did not significantly improve ongrowth of bone onto the implants or improve any of the mechanical push-out parameters compared to HA bone graft extender. Interpretation Doping of the HA bone graft extender with 5% strontium increased gap healing, preserved more of the allograft in the gap, and increased the ongrowth of bone onto the bone graft extender material, but did not improve mechanical fixation. PMID:21895497

  16. Long bone histology of sauropterygia from the lower Muschelkalk of the Germanic basin provides unexpected implications for phylogeny.

    Science.gov (United States)

    Klein, Nicole

    2010-07-21

    Sauropterygia is an abundant and successful group of Triassic marine reptiles. Phylogenetic relationships of Triassic Sauropterygia have always been unstable and recently questioned. Although specimens occur in high numbers, the main problems are rareness of diagnostic material from the Germanic Basin and uniformity of postcranial morphology of eosauropterygians. In the current paper, morphotypes of humeri along with their corresponding bone histologies for Lower to Middle Muschelkalk sauropterygians are described and interpreted for the first time in a phylogenetic context. Nothosaurus shows a typical plesiomorphic lamellar-zonal bone type, but varying growth patterns and the occurrence of a new humerus morphotype point to a higher taxonomic diversity than was known. In contrast to the enormous morphological variability of eosauropterygian humeri not assigned to Nothosaurus, their long bone histology is relatively uniform and can be divided into two histotypes. Unexpectedly, both of these histotypes reveal abundant fibrolamellar bone throughout the cortex. This pushes the origin of fibrolamellar bone in Sauropterygia back from the Cretaceous to the early Middle Triassic (early Anisian). Histotype A is assigned to Cymatosaurus, a basal member of the Pistosauroidea, which includes the plesiosaurs as derived members. Histotype B is related to the pachypleurosaur Anarosaurus. Contrary to these new finds, the stratigraphically younger pachypleurosaur Neusticosaurus shows the plesiomorphic lamellar-zonal bone type and an incomplete endochondral ossification, like Nothosaurus. Histological results hypothetically discussed in a phylogenetical context have a large impact on the current phylogenetic hypothesis of Sauropterygia, leaving the pachypleurosaurs polyphyletic. On the basis of histological data, Neusticosaurus would be related to Nothosaurus, whereas Anarosaurus would follow the pistosaur clade. Furthermore, the presence of fibrolamellar bone, which is accompanied

  17. Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    pain and bacterial or viral contamination. Thus, there is need for development of alternative bone graft materials. The use of osteoinductive materials such as demineralized bone matrix (DBM) alone or in combination with allograft or commercially available human cancellous bone (CB) may substitute allo...

  18. In vitro simulation of pathological bone conditions to predict clinical outcome of bone tissue engineered materials

    Science.gov (United States)

    Nguyen, Duong Thuy Thi

    According to the Centers for Disease Control, the geriatric population of ≥65 years of age will increase to 51.5 million in 2020; 40% of white women and 13% of white men will be at risk for fragility fractures or fractures sustained under normal stress and loading conditions due to bone disease, leading to hospitalization and surgical treatment. Fracture management strategies can be divided into pharmaceutical therapy, surgical intervention, and tissue regeneration for fracture prevention, fracture stabilization, and fracture site regeneration, respectively. However, these strategies fail to accommodate the pathological nature of fragility fractures, leading to unwanted side effects, implant failures, and non-unions. Compromised innate bone healing reactions of patients with bone diseases are exacerbated with protective bone therapy. Once these patients sustain a fracture, bone healing is a challenge, especially when fracture stabilization is unsuccessful. Traditional stabilizing screw and plate systems were designed with emphasis on bone mechanics rather than biology. Bone grafts are often used with fixation devices to provide skeletal continuity at the fracture gap. Current bone grafts include autologous bone tissue and donor bone tissue; however, the quality and quantity demanded by fragility fractures sustained by high-risk geriatric patients and patients with bone diseases are not met. Consequently, bone tissue engineering strategies are advancing towards functionalized bone substitutes to provide fracture reconstruction while effectively mediating bone healing in normal and diseased fracture environments. In order to target fragility fractures, fracture management strategies should be tailored to allow bone regeneration and fracture stabilization with bioactive bone substitutes designed for the pathological environment. The clinical outcome of these materials must be predictable within various disease environments. Initial development of a targeted

  19. Congenic mice confirm that collagen X is required for proper hematopoietic development.

    Directory of Open Access Journals (Sweden)

    Elizabeth Sweeney

    2010-03-01

    Full Text Available The link between endochondral skeletal development and hematopoiesis in the marrow was established in the collagen X transgenic (Tg and null (KO mice. Disrupted function of collagen X, a major hypertrophic cartilage matrix protein, resulted in skeletal and hematopoietic defects in endochondrally derived tissues. Manifestation of the disease phenotype was variable, ranging from perinatal lethality in a subset of mice, to altered lymphopoiesis and impaired immunity in the surviving mice. To exclude contribution of strain specific modifiers to this variable manifestation of the skeleto-hematopoietic phenotype, C57Bl/6 and DBA/2J collagen X congenic lines were established. Comparable disease manifestations confirmed that the skeleto-hematopoietic alterations are an inherent outcome of disrupted collagen X function. Further, colony forming cell assays, complete blood count analysis, serum antibody ELISA, and organ outgrowth studies established altered lymphopoiesis in all collagen X Tg and KO mice and implicated opportunistic infection as a contributor to the severe disease phenotype. These data support a model where endochondral ossification-specific collagen X contributes to the establishment of a hematopoietic niche at the chondro-osseous junction.