Sample records for jiahu bone flutes

  1. Oldest playable musical instruments found at Jiahu early Neolithic site in China

    Microsoft Academic Search

    Juzhong Zhang; Garman Harbottle; Changsui Wang; Zhaochen Kong

    1999-01-01

    Excavations at the early Neolithic site of Jiahu in Henan Province, China have produced what may be the earliest complete, playable, tightly-dated multinote musical instruments. Jiahu was occupied from 7000BC to 5700BC, considerably antedating the well known Peiligang culture. Here we describe six exquisitely made complete flutes which were found in radiocarbon-dated excavation layers, along with fragments of perhaps 30

  2. Stability and Three-Dimensional Analysis of Bone Formation in Longitudinally Fluted Miniscrew Implants 

    E-print Network

    Truong, An Van

    2014-04-22

    The purpose of the present study is to evaluate the effects of longitudinal flutes on mini-screw implant (MSI) bone healing and stability. Using 11 skeletally mature New Zealand White rabbits, 33 longitudinally fluted and ...

  3. Stability and Three-Dimensional Analysis of Bone Formation in Longitudinally Fluted Miniscrew Implants

    E-print Network

    Truong, An Van

    2014-04-22

    The purpose of the present study is to evaluate the effects of longitudinal flutes on mini-screw implant (MSI) bone healing and stability. Using 11 skeletally mature New Zealand White rabbits, 33 longitudinally fluted and 33 non-fluted MSIs were...

  4. 'Neanderthal bone flutes': simply products of Ice Age spotted hyena scavenging activities on cave bear cubs in European cave bear dens.

    PubMed

    Diedrich, Cajus G

    2015-04-01

    Punctured extinct cave bear femora were misidentified in southeastern Europe (Hungary/Slovenia) as 'Palaeolithic bone flutes' and the 'oldest Neanderthal instruments'. These are not instruments, nor human made, but products of the most important cave bear scavengers of Europe, hyenas. Late Middle to Late Pleistocene (Mousterian to Gravettian) Ice Age spotted hyenas of Europe occupied mainly cave entrances as dens (communal/cub raising den types), but went deeper for scavenging into cave bear dens, or used in a few cases branches/diagonal shafts (i.e. prey storage den type). In most of those dens, about 20% of adult to 80% of bear cub remains have large carnivore damage. Hyenas left bones in repeating similar tooth mark and crush damage stages, demonstrating a butchering/bone cracking strategy. The femora of subadult cave bears are intermediate in damage patterns, compared to the adult ones, which were fully crushed to pieces. Hyenas produced round-oval puncture marks in cub femora only by the bone-crushing premolar teeth of both upper and lower jaw. The punctures/tooth impact marks are often present on both sides of the shaft of cave bear cub femora and are simply a result of non-breakage of the slightly calcified shaft compacta. All stages of femur puncturing to crushing are demonstrated herein, especially on a large cave bear population from a German cave bear den. PMID:26064624

  5. ‘Neanderthal bone flutes’: simply products of Ice Age spotted hyena scavenging activities on cave bear cubs in European cave bear dens

    PubMed Central

    Diedrich, Cajus G.

    2015-01-01

    Punctured extinct cave bear femora were misidentified in southeastern Europe (Hungary/Slovenia) as ‘Palaeolithic bone flutes’ and the ‘oldest Neanderthal instruments’. These are not instruments, nor human made, but products of the most important cave bear scavengers of Europe, hyenas. Late Middle to Late Pleistocene (Mousterian to Gravettian) Ice Age spotted hyenas of Europe occupied mainly cave entrances as dens (communal/cub raising den types), but went deeper for scavenging into cave bear dens, or used in a few cases branches/diagonal shafts (i.e. prey storage den type). In most of those dens, about 20% of adult to 80% of bear cub remains have large carnivore damage. Hyenas left bones in repeating similar tooth mark and crush damage stages, demonstrating a butchering/bone cracking strategy. The femora of subadult cave bears are intermediate in damage patterns, compared to the adult ones, which were fully crushed to pieces. Hyenas produced round–oval puncture marks in cub femora only by the bone-crushing premolar teeth of both upper and lower jaw. The punctures/tooth impact marks are often present on both sides of the shaft of cave bear cub femora and are simply a result of non-breakage of the slightly calcified shaft compacta. All stages of femur puncturing to crushing are demonstrated herein, especially on a large cave bear population from a German cave bear den.

  6. Motor bearing fluting

    Microsoft Academic Search

    J. A. Lawson

    1993-01-01

    Electrical motor bearing fluting has been defined as damage due to electrical current discharge through a motor bearing. Bearing race metal is electroplated onto the bearing balls. Close inspection reveals microscopic pits on bearing ball and race surfaces. A DC motor frame was completely isolated from ground except by a single grounding conductor with applied armature and field voltage. No

  7. Non-modular tapered fluted titanium stems in hip revision surgery: gaining attention.

    PubMed

    Konan, S; Garbuz, D S; Masri, B A; Duncan, C P

    2014-11-01

    Non-modular tapered fluted, titanium stems are available for use in femoral revision. The combination of taper and flutes on the stem provides axial and rotational stability, respectively. The material and surface properties of the stem promotes bone on-growth. If the surgeon is confident and reasonably experienced in the surgical use of this sort of design and the case is relatively straightforward, a non-modular design is effective. It also potentially reduces implant inventory, and circumvents the potential problems of taper junction corrosion and fatigue fracture. There are reports of excellent survival, good clinical and functional results and evidence of subsequent increase in proximal bone stock. PMID:25381409

  8. The impact of a modified cutting flute implant design on osseointegration.

    PubMed

    Jimbo, R; Tovar, N; Marin, C; Teixeira, H S; Anchieta, R B; Silveira, L M; Janal, M N; Shibli, J A; Coelho, P G

    2014-07-01

    Information concerning the effects of the implant cutting flute design on initial stability and its influence on osseointegration in vivo is limited. This study evaluated the early effects of implants with a specific cutting flute design placed in the sheep mandible. Forty-eight dental implants with two different macro-geometries (24 with a specific cutting flute design - Blossom group; 24 with a self-tapping design - DT group) were inserted into the mandibular bodies of six sheep; the maximum insertion torque was recorded. Samples were retrieved and processed for histomorphometric analysis after 3 and 6 weeks. The mean insertion torque was lower for Blossom implants (P<0.001). No differences in histomorphometric results were observed between the groups. At 3 weeks, P=0.58 for bone-to-implant contact (BIC) and P=0.52 for bone area fraction occupied (BAFO); at 6 weeks, P=0.55 for BIC and P=0.45 for BAFO. While no histomorphometric differences were observed, ground sections showed different healing patterns between the implants, with better peri-implant bone organization around those with the specific cutting flute design (Blossom group). Implants with the modified cutting flute design had a significantly reduced insertion torque compared to the DT implants with a traditional cutting thread, and resulted in a different healing pattern. PMID:24583140

  9. Creating and Maintaining a Good Flute Embouchure

    ERIC Educational Resources Information Center

    Criswell, Chad

    2009-01-01

    Learning to produce a good tone on the flute is easy for some people and incredibly difficult for others. Not every flute student will be successful, but the suggestions offered in this article may make the difference between a positive musical experience and one that turns the student off to playing an instrument forever. Claire-Anne Williams,…

  10. Doc.381, 'Nose flutes and shell trumpets'

    E-print Network

    Roth, George Kingsley

    of the triton shell or davui. First it is sounded clearly and well, but the other efforts are rather poor. Rakiraki, Kadavu, October 1955. Arranged recording [10.17-11.06] 6) Shell trumpet. Blowing of the triton shell or davui. Somosomo, Cakaudrove, June 1957... flutes and shell trumpets Translation of title Description (to be used in archive entry) Audio recording of nose flutes and shell trumpets, 15 min 51 seconds 1) Nose flute, fangofango - Copy of BBC recording (Library number 20468) made in December 1953...

  11. [Chemical composition analysis of early neolithic pottery unearthed from Xiaohuangshang site, Zhejiang Province and Jiahu site, Henan Province by energy disperse X-ray fluorescence].

    PubMed

    Chen, Qian-Qian; Yang, Yu-Zhang; Zhang, Ju-Zhong; Cui, Wei

    2011-11-01

    The major elements in the early neolithic potteries unearthed from Xiaohuangshan site, Zhejiang Province and Jiahu site, Henan Province were determined by energy disperse X-ray fluorescence (EDXRF). The results show that the chemical compositions of the potteries from these two sites possess obvious regional features respectively. Compared with the specimen from Jiahu site, the potteries from Xiaohuangshan site have the common feature of ancient Chinese southern ceramics with high silicon and low aluminum contents. Simultaneously, the chemical composition of Xiaohuangshan pottery samples nearly unchanged from its early stage to the last stage. This phenomenon indicates that the source of the ceramic raw materials of Xiaohuangshan site was stable, and the continuous improvement of its pottery quality was mainly due to the progress in sintering techniques. However, the chemical composition of Jiahu potteries changed a lot in its three different periods. This change occurred because a large number of admixtures were added to the pottery bodies to improve their operating performances. These results also show that the improvements of pottery making techniques in different Chinese areas may have their own evolution directions respectively for the different geographical environments. PMID:22242535

  12. STATISTICAL ANALYSIS OF OHIO FLUTED POINTS1

    Microsoft Academic Search

    DOUGLAS H. McKENZIE

    Fluted points are important as a marker of the Big Game Hunting Tradition in North America. A sample of 772 fluted points from Ohio is analyzed here; means, standard deviations, medians, and ranges of some measurements of these points are presented for six previously defined types: Convex-Parallel-Sided, Concavo-Convex-Sided, Ross County, Triangular, Pentagonal, and Holcombe. The following measurements are used to

  13. Entropy and the Magic Flute

    NASA Astrophysics Data System (ADS)

    Morowitz, Harold J.

    1996-10-01

    Harold Morowitz has long been highly regarded both as an eminent scientist and as an accomplished science writer. The essays in The Wine of Life , his first collection, were hailed by C.P. Snow as "some of the wisest, wittiest and best informed I have ever read," and Carl Sagan called them "a delight to read." In later volumes he established a reputation for a wide-ranging intellect, an ability to see unexpected connections and draw striking parallels, and a talent for communicating scientific ideas with optimism and wit. With Entropy and the Magic Flute , Morowitz once again offers an appealing mix of brief reflections on everything from litmus paper to the hippopotamus to the sociology of Palo Alto coffee shops. Many of these pieces are appreciations of scientists that Morowitz holds in high regard, while others focus on health issues, such as America's obsession with cheese toppings. There is also a fascinating piece on the American Type Culture Collection, a zoo or warehouse for microbes that houses some 11,800 strains of bacteria, and over 3,000 specimens of protozoa, algae, plasmids, and oncogenes. Here then are over forty light, graceful essays in which one of our wisest experimental biologists comments on issues of science, technology, society, philosophy, and the arts.

  14. Analytical bunch compression studies for FLUTE

    E-print Network

    Schreck, M

    2014-01-01

    The current article deals with analytical bunch compression studies for FLUTE whose results are compared to simulations. FLUTE is a linac-based electron accelerator with a design energy of approximately 40 MeV currently being constructed at the Karlsruhe Institute of Technology. One of the goals of FLUTE is to generate electron bunches with their length lying in the femtosecond regime. In the first phase this will be accomplished using a magnetic bunch compressor. This compressor forms the subject of the studies presented. The paper is divided into three parts. The first part deals with pure geometric investigations of the bunch compressor where space charge effects and the back reaction of bunches with coherent synchrotron radiation (CSR) are neglected. The second part is dedicated to the treatment of space charge effects and the third part gives some analytical results on the emission of CSR. The upshot is that the results of the first and the third part agree quite well with what is obtained from simulatio...

  15. Oxygen flute: A computer music instrument that grows

    Microsoft Academic Search

    Chris Chafe

    2005-01-01

    The quality of the air we breathe depends on a balance of plant and animal life. Oxygen Flute is an interactive computer music environment that makes the exchange of gases audible. Gallery visitors enter a chamber with bamboo and four continuously performing (digitally modeled) flutes. Patterns in levels of carbon dioxide measured inside the chamber create the music. The computer

  16. Flute interchange m = 1 mode in migma

    NASA Astrophysics Data System (ADS)

    Berk, H. L.; Rosenbluth, M. N.; Wong, H. V.

    1988-08-01

    The m = 1 flute interchange mode is investigated for the migma configuration. A previous investigation has indicated a rigid mode stability threshold may be present that is independent of the detailed orbit configuration. Careful analysis of the integral equation indicates instability can arise at a threshold particles storage number considerably below that predicted from the rigid mode theory for a well focused migma. Instability a low particle storage number is found when N/Nrg?8 g2, where N is the particle storage number Nrg is the predicted rigid mode threshold for the particle storage number and it is defined in eq. (9) of the text and ? is a measure of the spread in angular momentum of the ions ( ? = 2 ?P0/M i? cir L2), with ?P 0 the spread of angular momentum centered about zero angular momentum, Mi the ion mass, ?ci the ion cyclotron frequency and rL the ion Larmor radius.

  17. Evolution and Stabilization of Flutes in a Magnetic Mirror

    Microsoft Academic Search

    R. J. Colchin; J. L. Dunlap; H. Postma

    1970-01-01

    This paper deals with flutes as observed in a hot-ion, low-? plasma. This plasma was established in an adiabatic, simple mirror trap by Lorentz or gas-collisional ionization of an energetic H0 beam. The studies emphasize: (1) the detailed evolution of the flute mode and comparisons with linear theory and (2) the stabilizing effects of increased electrical connection of the plasma

  18. Experimental investigation on heat transfer and flow resistance characteristics of spirally fluted tubes

    Microsoft Academic Search

    Kan Cao; Qiwu Dong; Minshan Liu; Lina Zhang

    2011-01-01

    A comparative experimental investigation was carried out for heat transfer and resistance characteristics of smooth tube and 9 spirally fluted tubes with various structural parameters. The results show that the heat transfer and flow resistance performances of spirally fluted tubes are better than smooth tube. The heat transfer coefficient of the spirally fluted tubes are as 2.46~3.08 times as the

  19. Kristina Sorensen Acoustics of a Rotating Grand Piano & the Flute

    E-print Network

    Hart, Gus

    Kristina Sorensen Acoustics of a Rotating Grand Piano & the Flute Kristina Sorensen 1 10 June 2011 will be utilizing an acoustical array of microphones to analyze the three-dimensional sound radiation. Computer Relationships of Sound Propagation in both the Frequency and Time Domains Improve Competence in Acoustical

  20. Finite Larmor radius flute mode theory with end loss

    SciTech Connect

    Kotelnikov, I.A. [AN SSSR, Novosibirsk (Russian Federation). Inst. Yadernoj Fiziki; Berk, H.L. [Texas Univ., Austin, TX (United States). Inst. for Fusion Studies

    1993-08-01

    The theory of flute mode stability is developed for a two-energy- component plasma partially terminated by a conducting limiter. The formalism is developed as a preliminary study of the effect of end-loss in open-ended mirror machines where large Larmor radius effects are important.

  1. Minerals and antinutrients in fluted pumpkin ( Telfairia occidentalis Hook f.)

    Microsoft Academic Search

    Ekpedeme U Akwaowo; Bassey A Ndon; Ekaete U Etuk

    2000-01-01

    Studies were conducted to determine the biochemical composition of fluted pumpkin (Telfairia occidentalis Hook f.) at different stages of growth. Analyses were carried out at 12 and 50 weeks after planting on stems, leaves and roots, while seeds were analysed 8 and 32 weeks, respectively, after antethesis. Proximate moisture and carbohydrate content decreased in stems, leaves, roots and seeds with

  2. Flute growth rate of plasma jet in mirror machine

    NASA Astrophysics Data System (ADS)

    Be'ery, I.; Seemann, O.; Goldstein, G.; Fisher, A.; Ron, A.

    2014-02-01

    The evolution of flute instability in a cold, high-density hydrogen plasma jet, injected into a mirror machine, is studied. The experiment was designed to minimize the interaction of the plasma with the walls, thus bringing it close to the ideal magnetic Rayleigh-Taylor instability conditions. The modal growth rate was measured in various settings to demonstrate the effects of the finite Larmor radius, Bohm diffusion, conductive limiter, biased limiter and neutral background gas. In this paper we will demonstrate that lowering the magnetic field increases stability, as does the insertion of a conducting ring. However, if the ring is biased, the stability is reduced due to inhomogeneous coupling between the plasma and the limiter. It was also found that heavy background gas dramatically reduces the flute instability growth rate.

  3. Fluted pumpkin, Telfairia occidentalis : West African vegetable crop

    Microsoft Academic Search

    Bosa E. Okoli; C. M. Mgbeogu

    1983-01-01

    Fluted pumpkin, Telfairia occidentalis, is native to West Africa but occurs mostly in its cultivated form in various parts\\u000a of southern Nigeria.It is widely cultivated for its palatable and nutritious leaves which are used mainly as vegetable. The\\u000a seeds are also nutritious and rich in an oil which may be used for cooking and soap manufacture. Its taxonomy, morphology\\u000a and

  4. The Virtual Flute: an advanced fingering guide generated via machine intelligence

    Microsoft Academic Search

    Andrew Botros; John Smith; Joe Wolfe

    2006-01-01

    The Virtual Flute is a web service that provides many thousands of machine-predicted alternative fingerings. Alternative fingerings can offer variations in intonation and timbre, and can be easier to play in different musical contexts. Many play multiphonics. An advanced fingering guide is invaluable when exotic effects and demanding passages are required of the player. The Virtual Flute uses an expert

  5. Detection of tool flute breakage in end milling using feed-motor current signatures

    Microsoft Academic Search

    Xiaoli Li

    2001-01-01

    An effective algorithm based on improved time-domain averaging is proposed to detect tool flute breakage during end milling using feed-motor current signatures. The algorithm proposed is demonstrated to be effective in detecting tool flute breakage in real time through a series of milling experiments, and is also demonstrated to be insensitive to the effects for transients, such as cutter runout,

  6. Growth rate reduction of the curvature-driven flute instability by plasma blanket line tying

    Microsoft Academic Search

    David Segal

    1983-01-01

    The effect of an annular, line-tied blanket, on the curvature-driven flute in a magnetic mirror is considered. The blanket is assumed to be line tied to a thermoionically emitting annular end plate. Reduction of the flute growth rate is computed as function of Larmor radius, blanket radius, and axial plasma conductance through either an external plasma or mirror sheath. It

  7. A three-dimensional turbulent compressible flow model for ejector and fluted mixers

    NASA Technical Reports Server (NTRS)

    Rushmore, W. L.; Zelazny, S. W.

    1978-01-01

    A three dimensional finite element computer code was developed to analyze ejector and axisymmetric fluted mixer systems whose flow fields are not significantly influenced by streamwise diffusion effects. A two equation turbulence model was used to make comparisons between theory and data for various flow fields which are components of the ejector system, i.e., (1) turbulent boundary layer in a duct; (2) rectangular nozzle (free jet); (3) axisymmetric nozzle (free jet); (4) hypermixing nozzle (free jet); and (5) plane wall jet. Likewise, comparisons of the code with analytical results and/or other numerical solutions were made for components of the axisymmetric fluted mixer system. These included: (1) developing pipe flow; (2) developing flow in an annular pipe; (3) developing flow in an axisymmetric pipe with conical center body and no fluting and (4) developing fluted pipe flow. Finally, two demonstration cases are presented which show the code's ability to analyze both the ejector and axisymmetric fluted mixers.

  8. An Efficient Analysis Methodology for Fluted-Core Composite Structures

    NASA Technical Reports Server (NTRS)

    Oremont, Leonard; Schultz, Marc R.

    2012-01-01

    The primary loading condition in launch-vehicle barrel sections is axial compression, and it is therefore important to understand the compression behavior of any structures, structural concepts, and materials considered in launch-vehicle designs. This understanding will necessarily come from a combination of test and analysis. However, certain potentially beneficial structures and structural concepts do not lend themselves to commonly used simplified analysis methods, and therefore innovative analysis methodologies must be developed if these structures and structural concepts are to be considered. This paper discusses such an analysis technique for the fluted-core sandwich composite structural concept. The presented technique is based on commercially available finite-element codes, and uses shell elements to capture behavior that would normally require solid elements to capture the detailed mechanical response of the structure. The shell thicknesses and offsets using this analysis technique are parameterized, and the parameters are adjusted through a heuristic procedure until this model matches the mechanical behavior of a more detailed shell-and-solid model. Additionally, the detailed shell-and-solid model can be strategically placed in a larger, global shell-only model to capture important local behavior. Comparisons between shell-only models, experiments, and more detailed shell-and-solid models show excellent agreement. The discussed analysis methodology, though only discussed in the context of fluted-core composites, is widely applicable to other concepts.

  9. FLUTE: A versatile linac-based THz source

    SciTech Connect

    Nasse, M. J.; Schuh, M.; Schwarz, M. [Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); Naknaimueang, S.; Mathis, Y.-L.; Rossmanith, R.; Wesolowski, P.; Huttel, E. [ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Plech, A. [Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Schmelling, M. [Max Planck Institute for Nuclear Physics (MPIK), 69117 Heidelberg (Germany); Mueller, A.-S. [Laboratory for Applications of Synchrotron Radiation (LAS), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe (Germany); ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany); Institute for Photon Science and Synchrotron Radiation (IPS), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen (Germany)

    2013-02-15

    A new compact versatile linear accelerator named FLUTE is currently being designed at the Karlsruhe Institute of Technology. This paper presents the status of this 42 MeV machine. It will be used to generate strong (several 100 MV/m) ultra-short ({approx}1 ps) THz pulses (up to {approx}4-25 THz) for photon science experiments, as well as to conduct a variety of accelerator studies. The latter range from comparing different coherent THz radiation generation schemes to compressing electron bunches and studying the electron beam stability. The bunch charge will cover a wide range ({approx}100 pC-3 nC). Later we plan to also produce ultra-short x-ray pulses from the electron bunches, which, for example, could then be combined for THz pump-x-ray probe experiments.

  10. Active feedback stabilization of multimode flute instability in a mirror trap

    NASA Astrophysics Data System (ADS)

    Be'ery, I.; Seemann, O.; Fisher, A.

    2014-07-01

    The flute instability in a table-top mirror machine has been stabilized by a feedback system consisting of optical sensors, a digital signal processor and charge-injecting electrodes. The use of multiple sensors and actuators enable the feedback to simultaneously stabilize two modes of the fast-growing, slowly rotating flute instability. Step function response and magnetohydrodynamic spectroscopy indicate a smooth frequency response and an inherent delayed response of the plasma drift due to the sheath resistivity. The measured feedback power is very small relative to the heating power of the plasma.

  11. The Effects of Verbal Instruction, Modeling, Rehearsal, and Feedback on Correct Posture during Flute Playing

    ERIC Educational Resources Information Center

    Dib, Nancy Ellen; Sturmey, Peter

    2007-01-01

    A behavioral skills training package, including verbal instruction, modeling, rehearsal, and feedback, was used to teach children correct posture, defined as keeping feet on the floor, legs parallel to each other, and the back and neck perpendicular to the floor, during flute lessons. Three typically developing girls aged 8 to 9 years…

  12. Cascading process in the flute-mode turbulence of a plasma

    SciTech Connect

    Gonzalez, R.; Gomez, D.; Ferro Fontan, C. (Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, (1428) Buenos Aires (Argentina) Instituto de Astronomia y Fisica del Espacio, C C No. 67, Sucursal 28, (1428) Buenos Aires (Argentina)); Sicardi Schifino, A.C.; Montagne, R. (Instituto de Fisica, Facultad de Ciencias, Universidad de la Republica, CC 10773, CP 11200, Montevideo (Uruguay) Instituto de Fisica, Facultad de Ingenieria, Universidad de la Republica, CC No. 30, CP 11000, Montevideo (Uruguay))

    1993-06-01

    The cascades of ideal invariants in the flute-mode turbulence are analyzed by considering a statistics based on an elementary three-mode coupling process. The statistical dynamics of the system is investigated on the basis of the existence of the physically most important (PMI) triad. When finite ion Larmor radius effects are considered, the PMI triad describes the formation of zonal flows.

  13. Generation and saturation of large scale flows in flute turbulence I. Sandberg1,2

    E-print Network

    Vlahos, Loukas

    of large­scale anisotropic modes during the temporal evolution of a magnetic­curvature­driven electrostatic in rotating planetary atmospheres as on the Earth [8] or on Jupiter [9]. During the last years, several #12;[15], [16], and magnetic­curvature­driven flute (interchange) instabilities [17]. The aim

  14. NĹŤkan (NĹŤ Flute) and Oral Transmission: Cohesion and Musicality through Mnemonics

    Microsoft Academic Search

    Mariko Anno

    2010-01-01

    :The nĹŤkan (nĹŤ flute) is traditionally taught in a mode of oral transmission that involves memorization of shĹŤga (mnemonics). ShĹŤga help bring a nĹŤ play to fruition by keeping the timing and allowing improvisation. This case study discusses the teaching of IssĹŤ Yukihiro, an IssĹŤ school performer, arguing that nĹŤkan transmission is changing in contemporary practice by certain masters.

  15. NĹŤkan (NĹŤ Flute) and Oral Transmission: Cohesion and Musicality through Mnemonics

    Microsoft Academic Search

    Mariko Anno

    2010-01-01

    The nĹŤkan (nĹŤ flute) is traditionally taught in a mode of oral transmission that involves memorization of shĹŤga (mnemonics). ShĹŤga help bring a nĹŤ play to fruition by keeping the timing and allowing improvisation. This case study discusses the teaching of IssĹŤ Yukihiro, an IssĹŤ school performer, arguing that nĹŤkan transmission is changing in contemporary practice by certain masters.

  16. Partial line-tying of the flute mode in a magnetic mirror

    Microsoft Academic Search

    Guy Vandegrift; Timothy N. Good

    1986-01-01

    The amount of electron emission required to partially line-tie the m=1 flute mode is measured on an axisymmetric mirror-confined plasma. The results are consistent with an ideal magnetohydrodynamic (MHD) calculation with a sheath dissipation term added. The minimum electron emission required is approximately the ion saturation current. The sheath impedance is also calculated for the case when the electron emission

  17. The sound of oscillating air jets: Physics, modeling and simulation in flute-like instruments

    NASA Astrophysics Data System (ADS)

    de La Cuadra, Patricio

    Flute-like instruments share a common mechanism that consists of blowing across one open end of a resonator to produce an air jet that is directed towards a sharp edge. Analysis of its operation involves various research fields including fluid dynamics, aero-acoustics, and physics. An effort has been made in this study to extend this description from instruments with fixed geometry like recorders and organ pipes to flutes played by the lips. An analysis of the jet's response to a periodic excitation is the focus of this study, as are the parameters under the player's control in forming the jet. The jet is excited with a controlled excitation consisting of two loudspeakers in opposite phase. A Schlieren system is used to visualize the jet, and image detection algorithms are developed to extract quantitative information from the images. In order to study the behavior of jets observed in different flute-like instruments, several geometries of the excitation and jet shapes are studied. The obtained data is used to propose analytical models that correctly fit the observed measurements and can be used for simulations. The control exerted by the performer on the instrument is of crucial importance in the quality of the sound produced for a number of flute-like instruments. The case of the transverse flute is experimentally studied. An ensemble of control parameters are measured and visualized in order to describe some aspects of the subtle control attained by an experienced flautist. Contrasting data from a novice flautist are compared. As a result, typical values for several non-dimensional parameters that characterize the normal operation of the instrument have been measured, and data to feed simulations has been collected. The information obtained through experimentation is combined with research developed over the last decades to put together a time-domain simulation. The model proposed is one-dimensional and driven by a single physical input. All the variables in the model are expressed in terms of pressure which allows for implementation and control in real-time. The model provides both a testbed to compare and validate measurements as well as a highly configurable and real-time musical instrument.

  18. LETTER: Effect of the magnetic field geometry on the flute-like perturbations near the divertor X point

    Microsoft Academic Search

    D. Farina; R. Pozzoli; D. D. Ryutov

    1993-01-01

    It is shown that a very strong squeezing of the magnetic flux tube passing near the divertor X point imposes stringent limitations on the longitudinal correlation length of the flute-like perturbations near the divertor X point, and leads to a decoupling of the perturbations in the main part of the scrape-off layer from possible effects of the boundary conditions on

  19. Influence of the fluctuations of the control pressure on the sound production in flute-like instruments

    E-print Network

    Paris-Sud XI, Université de

    and the instrument. We opted for an electronically- based controlled coupling that will be described below. It makesInfluence of the fluctuations of the control pressure on the sound production in flute-like instruments R. Auvraya , B. Fabrea , P.-Y. Lagr´eeb , S. Terrienc and C. Vergezc a ´Equipe LAM - d

  20. Effect of high-energy particles on ballooning flute modes in a tokamak

    SciTech Connect

    Boiko, A.Y.; Cheremnykh, O.K.

    1988-08-01

    A dispersion relation for ideal ballooning flute modes is derived for a tokamak with a finite pressure (..beta../sub theta/approx. =1), a large aspect ratio, circular magnetic surfaces, and a group of high-energy particles assuming that the potential wells are shallow. In addition to waves which are already known, this dispersion relation describes two neutrally stable natural wave branches with frequencies ..omega..approx. <..omega../sub */, where ..omega../sub */ is the ion drift frequency. Either untrapped or trapped ions can excited one of these branches (with the higher frequency) and can damp the other (with the lower frequency). Analytic expressions are derived for the growth rate and the damping rate. The results found here can be used to explain the fishbone oscillations which have been observed experimentally.

  1. Preparation and properties of flours and protein concentrates from raw, fermented and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds

    Microsoft Academic Search

    Sunday Y. Giami; Isaac Isichei

    1999-01-01

    In vitro protein digestibility, chemical composition and selected functional properties of flours and protein concentrates prepared from raw, fermented and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds were studied. Protein concentrates prepared by an alkaline extraction process had increased crude protein contents (61.5–70.8%) compared to flour samples (46.4–52.7%). The yields of protein concentrates ranged from 24.5% to 29.4% while values

  2. The 3D Structure of Flux Tubes That Admit Flute Instability in the Scrape-Off-Layer (SOL) of Tokamaks

    NASA Astrophysics Data System (ADS)

    Takahashi, Hironori

    2014-10-01

    A severe reduction in size down to an ion gyro-radius scale, commonly known as ``squeezing,'' in a lateral dimension of the cross section of a flux tube is traditionally thought to inhibit the occurrence of the flute instability in the Scrape-off-Layer of a diverted tokamak by isolating the main volume of the flux tube from its ends at electrically conducting target plates. A study reported here in the 3D flux tube structure reveals the absence of squeezing for a flux tube that is sufficiently large in its toroidal extent (small toroidal harmonic number n) and located in a layer of low field-line shear around the ``sweet spot'' (about mid-way between the primary and secondary separatrices). The low-shear layer does not hence inhibit the flute instability through the squeezing mechanism, and may thus restore the flute instability, among the most virulent in the magnetized plasma, to the ranks of candidate electrostatic instabilities thought to underlie the turbulence in the SOL in tokamaks. Variations along the flux tube of geometrical characteristics including the cross section will be calculated to develop criteria for the absence of squeezing. Supported in part by the US DOE under DE-AC02-09CH11466.

  3. Bone Density

    MedlinePLUS

    ... bones Your response to osteoporosis treatment Low bone mass that is not low enough to be osteoporosis is sometimes called osteopenia. Causes of low bone mass include family history, not developing good bone mass ...

  4. Recruitment constraints in Singapore's fluted giant clam (Tridacna squamosa) population—A dispersal model approach

    PubMed Central

    Neo, Mei Lin; Erftemeijer, Paul L. A.; van Beek, Jan K. L.; van Maren, Dirk S.; Teo, Serena L-M.; Todd, Peter A.

    2013-01-01

    Recruitment constraints on Singapore's dwindling fluted giant clam, Tridacna squamosa, population were studied by modelling fertilisation, larval transport, and settlement using real-time hydrodynamic forcing combined with knowledge of spawning characteristics, larval development, behaviour, and settlement cues. Larval transport was simulated using a finite-volume advection-diffusion model coupled to a three-dimensional hydrodynamic model. Three recruitment constraint hypotheses were tested: 1) there is limited connectivity between Singapore's reefs and other reefs in the region, 2) there is limited exchange within Singapore's Southern Islands, and 3) there exist low-density constraints to fertilisation efficacy (component Allee effects). Results showed that connectivity among giant clam populations was primarily determined by residual hydrodynamic flows and spawning time, with greatest chances of successful settlement occurring when spawning and subsequent larval dispersal coincided with the period of lowest residual flow. Simulations suggested poor larval transport from reefs located along the Peninsular Malaysia to Singapore, probably due to strong surface currents between the Andaman Sea and South China Sea combined with a major land barrier disrupting larval movement among reefs. The model, however, predicted offshore coral reefs to the southeast of Singapore (Bintan and Batam) may represent a significant source of larvae. Larval exchange within Singapore's Southern Islands varied substantially depending on the locations of source and sink reefs as well as spawning time; but all simulations resulted in low settler densities (2.1–68.6 settled individuals per 10,000 m2). Poor fertilisation rates predicted by the model indicate that the low density and scattered distribution of the remaining T. squamosa in Singapore are likely to significantly inhibit any natural recovery of local stocks. PMID:23555597

  5. Combined use of straddle packer testing and FLUTe profiling for hydraulic testing in fractured rock boreholes

    NASA Astrophysics Data System (ADS)

    Quinn, Patryk; Cherry, John A.; Parker, Beth L.

    2015-05-01

    A combination of high resolution hydraulic tests using straddle packers and transmissivity (T) profiling using the FLUTe flexible liner method (liner profiling) in densely fractured rock boreholes is shown to be efficient for the determination of the vertical distribution of T along the entire hole. The liner T profiling method takes a few hours or less to scan the entire borehole length resulting in a T profile. Under favorable conditions this method has good reliability for identifying the highest T zones identified by distinct decreases in liner velocity when these zones are covered by the descending liner. In contrast, for one short test interval (e.g., 1-2 m) the multiple-test, straddle-packer method takes a few hours to measure T with good precision and accuracy using a combination of steady-state and transient tests (e.g., constant head step tests, slug tests, and constant rate pumping tests). Because of the time consuming aspect of this multiple-test method, it is most efficient in each borehole to conduct straddle packer testing only in priority zones selected after assessment of other borehole data collected prior to packer testing. The T profile from the liner method is instrumental in selecting high permeable zones for application of the multiple-test method using straddle packers, which in turn, refines the T estimation from the liner profile. Results from three boreholes in densely fractured sandstone demonstrate this approach showing the synergistic use of the methods with emphasis on information important for determining hydraulic apertures.

  6. Monitoring gaseous CO2 and ethanol above champagne glasses: flute versus coupe, and the role of temperature.

    PubMed

    Liger-Belair, Gérard; Bourget, Marielle; Pron, Hervé; Polidori, Guillaume; Cilindre, Clara

    2012-01-01

    In champagne tasting, gaseous CO(2) and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. Simultaneous quantification of gaseous CO(2) and ethanol was monitored through micro-gas chromatography (?GC), all along the first 15 minutes following pouring, depending on whether a volume of 100 mL of champagne was served into a flute or into a coupe. The concentration of gaseous CO(2) was found to be significantly higher above the flute than above the coupe. Moreover, a recently developed gaseous CO(2) visualization technique based on infrared imaging was performed, thus confirming this tendency. The influence of champagne temperature was also tested. As could have been expected, lowering the temperature of champagne was found to decrease ethanol vapor concentrations in the headspace of a glass. Nevertheless, and quite surprisingly, this temperature decrease had no impact on the level of gaseous CO(2) found above the glass. Those results were discussed on the basis of a multiparameter model which describes fluxes of gaseous CO(2) escaping the liquid phase into the form of bubbles. PMID:22347390

  7. Bone scan

    MedlinePLUS

    ... is done to see if you have a bone infection, images may be taken shortly after the radioactive ... feet or legs, or spine fractures) Diagnose a bone infection (osteomyelitis) Diagnose or determine the cause of bone ...

  8. Rubber Bones

    NSDL National Science Digital Library

    2012-07-09

    Over 1 or 2 days, learners use vinegar to remove the calcium from a chicken bone. They then explore how the bones have changed. An accompanying video with Mr. O further explores the relationship between cartilage and bone and explains how bones grow.

  9. Bone Crusher

    NSDL National Science Digital Library

    National Science Foundation GK-12 and Research Experience for Teachers (RET) Programs,

    Students use a tension-compression machine (or an alternative bone-breaking setup) to see how different bones fracture differently and with different amounts of force, depending on their body locations. Teams determine bone mass and volume, calculate bone density, and predict fracture force. Then they each test a small animal bone (chicken, turkey, cat) to failure, examining the break to analyze the fracture type. Groups conduct research about biomedical challenges, materials and repair methods, and design repair treatment plans specific to their bones and fracture types, presenting their design recommendations to the class.

  10. Bone Markers

    MedlinePLUS

    ... Alkaline Phosphatase; Osteocalcin; P1NP; Procollagen Type 1 N-Terminal Propeptide Formal name: Biochemical Markers of Bone Remodeling ... tests for evaluating bone turnover: C-telopeptide (C-terminal telopeptide of type 1 collagen (CTx)) – a marker ...

  11. Bone Infections

    MedlinePLUS

    ... the bloodstream. People who are at risk for bone infections include those with diabetes, poor circulation, or recent ... risk if you are having hemodialysis. Symptoms of bone infections include Pain in the infected area Chills and ...

  12. Fluted Projectile Points: Their Age and Dispersion: Stratigraphically controlled radiocarbon dating provides new evidence on peopling of the New World.

    PubMed

    Haynes, C V

    1964-09-25

    The stratigraphic record shows Clovis projectile points to be restricted to sediments between 11,000 and 11,500 years old. Underlying deposits dating back 11,600 to 13,000 years are without evidence of human occupation. In the High Plains, overlying deposits dating back 10,000 to 11,000 years contain Folsom and Hell Gap artifacts and are without mammoth remains. The glacial history of Alaska, Canada, and the Great Lakes region indicates that, for the first time in at least 15,000 years, an ice-free, trans-Canadian corridor opened up approximately 12,000 years ago. Since Clovis points are distributed from coast to coast south of the Valders ice border, the abrupt appearance of Clovis artifacts in the stratigraphic record of the High Plains some 700 years later suggests that Clovis progenitors passed through Canada during Two Creeks time. If eastern fluted points (for example, Enterline) are older than Clovis points, the difference may be on the order of only a hundred or so years, not thousands. The change from Clovis points to Folsom points in the High Plains may be related to a marked decline in the mammoth population after 11,000 years ago, but whether or not man was a prime factor in the extinction of Pleistocene megafauna is a moot question. On the basis of new data and critical geological evaluation of dates obtained by the radiocarbon method a hypothesis has been offered to explain (i) the abrupt appearance of Clovis points in the stratigraphic record of the United States around 11,500 years ago, and (ii) the lack of a cultural continuum in the United States leading to fluted projectile points. Llano hunters, like the game they pursued, may have persisted longer in some areas of the continent (for example, Bull Brook) than in others, but if a Clovis site can be found for which good stratigraphic evidence supports a date earlier than the Two Creeks interstade, then correlation of this event to the opening of the trans-Canadian ice-free corridor is incorrect (see 41a). Such a misinterpretation of timing would not affect the explanation for the lack of Clovis progenitors in the United States. We must continue to look for an indigenous cultural continuum leading to Clovis points, but if such cannot be demonstrated in the conterminous United States, then it would appear that fluted projectile points were developed elsewhere. Clovis progenitors might best be sought in northern Alaska or the Mackenzie Valley. The interpretations offered here are based on new data and critical geological evaluation of dates previously obtained by the radiocarbon method. How valid these interpretations are can be ascertained only through careful scrutiny of all man-mammoth associations found in the future, to assure precise relating of dates, fossils, and artifacts to the stratigraphic framework. We must pay closer attention to stratigraphic detail if we are to make the fullest use of radiocarbon dating. PMID:17838701

  13. Bone Basics

    NSDL National Science Digital Library

    Twin Cities Public Television, Inc.

    2008-01-01

    This is an activity (on page 2 of the PDF) about the two main components of bone - collagen and minerals (like calcium) - and how they each contribute to its flexibility and strength. Learners will submerge 3 chicken bones in water, bleach, and vinegar, wait 24 hours, then observe and test each bone. This resource includes information about how nanoscientists are trying to produce artificial analogs to these components and relates to linked video, DragonflyTV Nano: Bone Regrowth.

  14. Hepatoprotective property of ethanolic and aqueous extracts of fluted pumpkin (Telfairia occidentalis) leaves against garlic-induced oxidative stress.

    PubMed

    Oboh, Ganiyu

    2005-01-01

    Fluted pumpkin (Telfairia occidentalis) leaf is a darkish-green leafy vegetable popularly used in soup and in herbal preparations for the management of many diseases in Nigeria. In this study, the hepatoprotective property of ethanolic and aqueous extracts of T. occidentalis leaf (earlier confirmed to have a high level of antioxidant activity) against garlic induced-oxidative stress in rat hepatocytes was investigated. Oxidative stress was induced in Wistar strain albino rats by overdosing them with raw garlic (4%) for 14 days, and this caused a significant increase (P < .05) in serum alkaline phosphatase (ALP), glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase (GPT), while there was no significant change (P > .05) in serum bilirubin, albumin, globulin, and total proteins. However, intubation of some of the rats fed raw garlic with 5 mg or 10 mg/0.5 mL of T. occidentalis leaf extract (ethanolic or aqueous) caused a significant decrease (P < .05) in serum ALP, GOT, and GPT when compared with rats fed raw garlic without intubation with the T. occidentalis leaf extract. Moreover, 10 mg/0.5 mL of extract was more effective than 5 mg/0.5 mL of extract, while the aqueous extracts appeared to be more effective than the ethanolic extracts in protecting hepatocytes. It could be inferred that both aqueous and ethanolic extracts of T. occidentalis leaf have hepatoprotective properties, although the aqueous extract is more effective than the ethanolic extract, which could be attributed to the higher antioxidant activity of the aqueous extract than the ethanolic extracts of T. occidentalis leaves. PMID:16379574

  15. Bear Bones

    NSDL National Science Digital Library

    Science Update

    2004-03-08

    An estimated ten million Americans have osteoporosis, an age-related disease in which the bones gradually become brittle and weak. Now, scientists are looking to animals for clues on how to combat this condition. This resource describes the study of sustaining bone strength of hibernating bears.

  16. Talking Bones.

    ERIC Educational Resources Information Center

    Johnson, Jaclyn; Kassing, Sharon

    2002-01-01

    Describes cooperation with the Saint Louis Zoo to provide opportunities for elementary school students to learn about bones, how animals move, what they eat, and how much they grow. Uses biofacts which include bones, skulls, and other parts to make the laboratory a hands-on experience for students. (YDS)

  17. The Effect of the Double-Deck Filament Setup on Enhancing the Uniformity of Temperature Field on Long-Flute Cutting Tools

    NASA Astrophysics Data System (ADS)

    Shen, Bin; Chen, Sulin; Cheng, Lei; Sun, Fanghong

    2014-09-01

    In the present study, a double-deck filament setup is proposed for the hot filament chemical vapor deposition (HFCVD) method and an optimization method is presented to determine its optimal geometry that is able to produce a highly uniform temperature field on the whole flute surface of long-flute cutting tools. The optimization method is based on the finite volume method (FVM) simulation and the Taguchi method. The simulation results show that this double-deck filament setup always produce a highly uniform temperature distribution along the filament direction. Comparatively, for the temperature uniformity along the drill axis, the heights of the two filament decks present virtually significant influence, while the separations between the two filaments in either deck exhibit a relative weak effect. An optimized setup is obtained that can produce a highly uniform temperature field with an average temperature of 834°C, a standard deviation (?) of 2.59°C and a temperature range (R) of 11.75°C. Finally, the precision of the proposed simulation method is verified by an additional temperature measurement. The measured temperature results show that a highly uniform temperature fields with ?/R = 9.6/35.2°C can be generated by the optimized setup and the deviation of the simulated results from the measured actual temperatures are within 0.5-3.5%, which justifies the correctness of the simulation method proposed in present study.

  18. Nutrition and bone

    Microsoft Academic Search

    Gail Goldberg

    2004-01-01

    Throughout life the skeleton is continually renewed. Old, worn out bone is broken down and new bone tissue is formed. During infancy, childhood and adolescence, bone formation is higher than breakdown. At about 30–35 years old adults achieve their peak bone mass. The rate of bone breakdown is equal to the rate of bone formation and bone mass is maintained.

  19. Bone lesion biopsy

    MedlinePLUS

    ... coccidiomycosis, histoplasmosis , and mycobacteria infection Osteitis fibrosa Osteomalacia Osteomyelitis Rickets ... Bone fracture Bone infection (osteomyelitis) Damage to surrounding ... Infection near the biopsy area Some people with bone disorders ...

  20. Bone Stress

    NSDL National Science Digital Library

    2011-12-07

    In this optics activity, learners examine how polarized light can reveal stress patterns in clear plastic. Learners place a fork between two pieces of polarizing material and induce stress by squeezing the tines together. Learners will observe the colored stress pattern in the image of the plastic that is projected onto a screen using an overhead projector. Learners rotate one of the polarizing filters to explore which orientations give the most dramatic color effects. This activity can be related to bones, as bones develop stress patterns from the loads imposed upon them every day.

  1. Dem Bones

    NSDL National Science Digital Library

    Alease Bruce

    2001-09-01

    In this case, students enter the world of a forensic anthropologist who must determine the sex and age of an individual from a collection of bones. Students, in turn, simulate some of the actual procedures conducted in a forensic anthropologist's lab, exa

  2. Changes of bone mineral density after cementless total hip arthroplasty with two different stems.

    PubMed

    Sano, Keiji; Ito, Kouji; Yamamoto, Kengo

    2008-04-01

    Cementless total hip arthroplasty has achieved reliable long-term results since porous coatings were developed, but postoperative changes around the stem remain poorly documented. In this study, changes of the bone mineral density (BMD) were compared between two types of cementless stem. In group B (28 patients with 31 hips), a straight tapered stem with porous plasma spray coating on the proximal 1/4 was used, while group S (24 patients with 26 hips) was given a fluted, tri-slot stem with porous hydroxyapatite coating on the proximal 1/3. In group B, there was an early decrease of BMD, which recovered after 12 months, indicating that stress shielding was minimal. In group S, however, BMD continued to decrease without recovery. The stem shape and radiological findings suggested that the cause of stress shielding in group S was distal fixation. PMID:17225187

  3. Bone banking and sterilization of bones

    NASA Astrophysics Data System (ADS)

    Minamisawa, I.; Itoman, M.; Maehara, H.; Kobayashi, A.; Watanabe, T.

    1995-08-01

    The use of banked bone (preserved allograft bone) is various and essential, because it has numerous advantages including the relative ease in retrieval a large amount of bone material and requisite shape and size. But bone banking and allografting must be promoted under obligation to stably supply safe and high-quality bone. To avoid transferring disease perfectly, irradiation sterilization is especially recommended at the present time.

  4. Food and Your Bones

    MedlinePLUS

    ... You are here Home » Food and Your Bones Food and Your Bones The food that you eat ... taking multivitamins or supplements . Good-for-Your-Bones Foods Food Nutrient Dairy products such as low-fat ...

  5. Osteoporosis: The Bone Thief

    MedlinePLUS

    ... of this makes your bones weaker. Who Has Osteoporosis? Ten million Americans have osteoporosis. They are mostly ... a bone. What Can I Do For My Osteoporosis? Treating osteoporosis means stopping the bone loss and ...

  6. Bone Densitometry

    NSDL National Science Digital Library

    Patient Education Institute

    This patient education program explains bone densitometry and its importance in treating and preventing osteoporosis. This is a MedlinePlus Interactive Health Tutorial from the National Library of Medicine, designed and developed by the Patient Education Institute. NOTE: The tutorial requires a special Flash plug-in, version 4 or above. If you do not have Flash, you will be prompted to obtain a free download of the software before you start the tutorial. You will also need an Acrobat Reader, available as a free download, in order to view the Reference Summary.

  7. Dinosaur Bone Experiments

    NSDL National Science Digital Library

    Lawrence Hall of Science

    2005-01-01

    This activity features two connected hands-on activities about dinosaur bones. Using chicken or turkey bones and regular household items, learners explore the scientific process of studying fossilized bones. By exposing the bones to vinegar or heat, learners begin to understand how paleontologists use chemical processes to study the bones of animals long dead and gone. Use this bone-themed activity around the Thanksgiving holiday and repurpose some leftovers.

  8. INVEST IN YOUR BONES Bone Basics

    E-print Network

    in your bones? Osteoporosis, a major health problem in America, affects over 10 million persons, with 34 million at a high risk of developing the disease (National Osteoporosis Foundation, 2010). Dubbed as the "silent thief", osteoporosis is a debilitating disease which causes normal bones (above bone figure

  9. Bone and thyroid hormones

    Microsoft Academic Search

    F. Tremollieres; J. M. Pouilles; J. P. Louvet; C. Ribot

    1989-01-01

    Bone tissue metabolism in influenced by thyroid hormones. Excess endogenous (hyperthyroidism), and exogenous (thyrotoxicosis) thyroid hormones are well known causes of bone loss (1,2), great enough to be responsible for fractures. Lately, a few studies using noninvasive methods for bone mass measurements, have reported the possibility of bone loss in subjects receiving thyroid hormone replacement therapy. These results are of

  10. Medicines and Bone Loss

    MedlinePLUS

    ... making your bones weak, if used for a long time. Use over a short time is usually not a problem. When you have weak bones—a condition called osteoporosis—your risk of bone fractures goes up. Broken bones can lead to pain ...

  11. Basic bone radiology

    SciTech Connect

    Griffiths, H.J.

    1987-01-01

    This clinical book surveys the skeletal system as seen through radiological imaging. It emphasizing abnormalities, disease, and trauma, and includes vital information on bones, bone growth, and the cells involved in bone pathology. It covers many bone diseases and injuries which are rarely covered in medical texts, as well as descriptions of radiologic procedures that specifically relate to the skeleton. This edition includes many illustrations, information on MR imaging and CT scanning, and discussions of osteoporosis, dysplasias, and metabolic bone disease.

  12. Osteocyte Signaling in Bone

    PubMed Central

    Schaffler, Mitchell B.; Kennedy, Oran D.

    2012-01-01

    Osteocytes, the cells residing within the bone matrix and comprising 90% to 95% of the all bone cells, have long been considered quiescent bystander cells compared to the osteoblasts and osteoclasts whose activities cause bone gain and loss, and whose dysfunction lead to growth defects and osteoporosis. However, recent studies show that osteocytes play a crucial, central role in regulating the dynamic nature of bone in all its diverse functions. Osteocytes are now known to be the principal sensors for mechanical loading of bone. They produce the soluble factors that regulate the onset of both bone formation and resorption. Osteocytes regulate local mineral deposition and chemistry at the bone matrix level, and they also function as endocrine cells producing factors that target distant organs such as the kidney to regulate phosphate transport. Osteocytes appear to be the major local orchestrator of many of bone’s functions. PMID:22552701

  13. Measuring bone quality.

    PubMed

    Torres-del-Pliego, Elisa; Vilaplana, Laia; Güerri-Fernández, Roberto; Diez-Pérez, Adolfo

    2013-11-01

    Osteoporosis is defined as a reduction in bone mass and impairment of bone quality that lead to bone fragility and fracture risk. Bone quality includes a hierarchy of properties from macroscopic to nanoscale level. Several techniques have been developed in an attempt to measure these non-density properties. Densitometry, high-resolution images (radiography, CT scan), and MRI can measure the geometry and microarchitecture of bone. Tissue mineralization and composition can be assessed by use of microradiography, Fourier-transform infrared spectroscopy, or Raman microspectroscopy. Finite-element analysis is an image-based method that enables calculation of bone strength. More recently, microindentation has enabled direct estimation of bone material strength, measured in the cortical bone of the tibia. Most of these techniques are of limited use to clinics, although finite-element analysis and microindentation have high potential for clinical use and can enable more comprehensive and accurate evaluation of bone fragility and fracture susceptibility. PMID:24072603

  14. Bisphosphonates and bone quality

    PubMed Central

    Pazianas, Michael; van der Geest, Stefan; Miller, Paul

    2014-01-01

    Bisphosphonates (BPs) are bone-avid compounds used as first-line medications for the prevention and treatment of osteoporosis. They are also used in other skeletal pathologies such as Paget's and metastatic bone disease. They effectively reduce osteoclast viability and also activity in the resorptive phase of bone remodelling and help preserve bone micro-architecture, both major determinants of bone strength and ultimately of the susceptibility to fractures. The chemically distinctive structure of each BP used in the clinic determines their unique affinity, distribution/penetration throughout the bone and their individual effects on bone geometry, micro-architecture and composition or what we call ‘bone quality'. BPs have no clinically significant anabolic effects. This review will touch upon some of the components of bone quality that could be affected by the administration of BPs. PMID:24876930

  15. Bone-Immune Cell Crosstalk: Bone Diseases

    PubMed Central

    Mori, Giorgio; D'Amelio, Patrizia; Faccio, Roberta

    2015-01-01

    Bone diseases are associated with great morbidity; thus, the understanding of the mechanisms leading to their development represents a great challenge to improve bone health. Recent reports suggest that a large number of molecules produced by immune cells affect bone cell activity. However, the mechanisms are incompletely understood. This review aims to shed new lights into the mechanisms of bone diseases involving immune cells. In particular, we focused our attention on the major pathogenic mechanism underlying periodontal disease, psoriatic arthritis, postmenopausal osteoporosis, glucocorticoid-induced osteoporosis, metastatic solid tumors, and multiple myeloma. PMID:26000310

  16. Paget's Disease of Bone

    MedlinePLUS

    ... What is Paget's Disease of Bone? In This Topic What is Paget's Disease of Bone? Symptoms and ... for More Information National Institute on Aging Related Topics Osteoarthritis Eating Well as You Get Older More ...

  17. Adenosine and Bone Metabolism

    PubMed Central

    Mediero, Aránzazu; Cronstein, Bruce N.

    2013-01-01

    Bone is a dynamic organ that undergoes continuous remodeling whilst maintaining a balance between bone formation and resorption. Osteoblasts, which synthesize and mineralize new bone, and osteoclasts, the cells that resorb bone, act in concert to maintain bone homeostasis. In recent years, there has been increasing appreciation of purinergic regulation of bone metabolism. Adenosine, released locally, mediates its physiologic and pharmacologic actions via interactions with G-protein coupled receptors and recent work has indicated that these receptors are involved in the regulation of osteoclast differentiation and function, as well as osteoblast differentiation and bone formation. Moreover, adenosine receptors also regulate chondrocyte and cartilage homeostasis. These recent findings underscore the potential therapeutic importance of adenosine receptors in regulating bone physiology and pathology. PMID:23499155

  18. Bone mineral density test

    MedlinePLUS

    BMD test; Bone density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis-BMD ... need to undress. This scan is the best test to predict your risk of fractures. Peripheral DEXA ( ...

  19. Tumor metastasis to bone

    PubMed Central

    Virk, Mandeep S; Lieberman, Jay R

    2007-01-01

    Establishment of skeletal metastasis involves bidirectional interactions between the tumor cell and the cellular elements in the bone microenvironment. A better understanding of the pathophysiology of bone metastasis will be critical in developing the means to prevent bone metastasis or inhibit its progression. The receptor activator of nuclear factor-?B (RANK)/RANK ligand pathway has emerged as the key pathway regulating osteolysis in skeletal metastasis. A number of candidate factors, including the Wnt (wingless int) proteins, endothelin-1, and bone morphogenetic proteins, have been implicated in the establishment of osteoblastic metastasis. The complex nature of tumor-bone microenvironment interactions and the presence of multiple pathways that lead to bone metastasis suggests that simultaneous targeting of these pathways in the metastatic cascade are required for effective treatment. This review discusses current understanding of the pathophysiologic mechanisms that underlie the establishment of bone metastasis and potential molecular therapeutic strategies for prevention and treatment of bone metastasis. PMID:17634144

  20. Radionuclide bone imaging

    SciTech Connect

    Bassett, L.W.; Gold, R.H.; Webber, M.M.

    1981-12-01

    Radionuclide bone imaging of the skeleton, now well established as the most important diagnostic procedure in detecting bone metastases, is also a reliable method for the evaluation of the progression or regression of metastatic bone disease. The article concentrates on the technetium-99m agents and the value of these agents in the widespread application of low-dose radioisotope scanning in such bone diseases as metastasis, osteomyelitis, trauma, osteonecrosis, and other abnormal skeletal conditions.

  1. Bone expansion in facial rejuvenation

    Microsoft Academic Search

    Rómulo Guerrero Vicuńa; Adriana Salazar Giottonini

    1994-01-01

    Soft tissues and bone structures of the face are both affected by aging, but the bone is the more important element in the three-dimensional contour and suspension of the soft tissue. Bone expansion augments bone volume in the midface. A lamellar split osteotomy of the midface is used for bone expansion, and cranial bone grafts fill spaces created by the

  2. [Bone tissue engineering for bone defect therapy].

    PubMed

    Boos, A M; Arkudas, A; Kneser, U; Horch, R E; Beier, J P

    2010-12-01

    In critical size bone defects resulting from failed fracture healing or pseudarthrosis surgery is usually required. In this context, autologous bone grafts and callus distraction represent the gold standard, while sometimes even vascularised bone transfer is mandatory including microsurgical techniques. The availability of donor sites for such procedures is limited and the resulting morbidity significant. Therefore, synthetic bone grafts have been developed as an alternative. They consist of a broad range of different materials such as natural and synthetic polymers, ceramic and compound materials, aiming to mimic the three-dimensional character of autografts. In addition, they may act as a delivery vehicle for growth factors, antibiotics or cells. Their main limitation has been the lack of an intrinsic blood supply, limiting the potential for transplantation. This review provides an overview of matrices, cells and other therapeutic substances in the field of bone tissue engineering. PMID:20821364

  3. Bone cysts: unicameral and aneurysmal bone cyst.

    PubMed

    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. PMID:25579825

  4. Osteopetrosis ('marble bone' disease).

    PubMed

    Manusov, E G; Douville, D R; Page, L V; Trivedi, D V

    1993-01-01

    Osteopetrosis is a hereditary disorder in which pathologic alteration of osteoclast resorption of bone results in thickening of cortical and lamellar bone. Before bone marrow transplantation, the infantile recessive form was uniformly fatal within the first two decades of life as a result of invasion of the marrow space by abnormal bone formation. The adult autosomal dominant form causes minimal morbidity and is usually diagnosed incidentally on routine radiographs. Although osteopetrosis is an extremely rare disorder, the study of this disease can provide insights into the formation of bone and the inheritance of disease. PMID:8418580

  5. Physiology of Bone.

    PubMed

    Grabowski, Peter

    2015-01-01

    Bone serves three main physiological functions: its mechanical nature provides support for locomotion and offers protection to vulnerable internal organs, it forms a reservoir for the storage of calcium and phosphate in the body, and it provides an environment for bone marrow production and haematopoietic cell development. The traditional view of bone as a passive tissue that responds to hormonal and dietary influences has changed over the past half century to one of bone as a dynamic adaptive tissue that responds to mechanical demands. This chapter gathers together some recent advances in bone physiology and molecular cell biology and discusses the potential application of the functional adaptation of bone to loading to enhance bone strength during childhood and adolescence. © 2015 S. Karger AG, Basel. PMID:26138834

  6. Bone disease in thyrotoxicosis

    PubMed Central

    Reddy, P. Amaresh; Harinarayan, C. V.; Sachan, Alok; Suresh, V.; Rajagopal, G.

    2012-01-01

    Thyrotoxicosis, a clinical syndrome characterized by manifestations of excess thyroid hormone, is one of the commonly-recognised conditions of the thyroid gland. Thyrotoxicosis causes acceleration of bone remodelling and though it is one of the known risk factors for osteoporosis, the metabolic effects of thyroxine on bone are not well discussed. Studies show that thyroid hormones have effects on bone, both in vitro and in vivo. Treatment of thyrotoxicosis leads to reversal of bone loss and metabolic alterations, and decreases the fracture risk. There are limited studies in India as to whether these changes are fully reversible. In this review we discuss about the effects of thyrotoxicosis (endogenous and exogenous) on bone and mineral metabolism, effects of subclinical thyrotoxicosis on bone and mineral metabolism and effects of various forms of treatment in improving the bone mineral density in thyrotoxicosis. PMID:22561612

  7. Bone regeneration in dentistry

    PubMed Central

    Tonelli, Paolo; Duvina, Marco; Barbato, Luigi; Biondi, Eleonora; Nuti, Niccolň; Brancato, Leila; Rose, Giovanna Delle

    2011-01-01

    Summary The edentulism of the jaws and the periodontal disease represent conditions that frequently leads to disruption of the alveolar bone. The loss of the tooth and of its bone of support lead to the creation of crestal defects or situation of maxillary atrophy. The restoration of a functional condition involves the use of endosseous implants who require adequate bone volume, to deal with the masticatory load. In such situations the bone need to be regenerated, taking advantage of the biological principles of osteogenesis, osteoinduction and osteoconduction. Several techniques combine these principles with different results, due to the condition of the bone base on which we operate changes, the surgical technique that we use, and finally for the bone metabolic conditions of the patient who can be in a state of systemic osteopenia or osteoporosis; these can also affect the result of jaw bone reconstruction. PMID:22461825

  8. Bone grafts, bone substitutes and orthobiologics

    PubMed Central

    Roberts, Timothy T.; Rosenbaum, Andrew J.

    2012-01-01

    The biology of fracture healing is better understood than ever before, with advancements such as the locking screw leading to more predictable and less eventful osseous healing. However, at times one’s intrinsic biological response, and even concurrent surgical stabilization, is inadequate. In hopes of facilitating osseous union, bone grafts, bone substitutes and orthobiologics are being relied on more than ever before. The osteoinductive, osteoconductive and osteogenic properties of these substrates have been elucidated in the basic science literature and validated in clinical orthopaedic practice. Furthermore, an industry built around these items is more successful and in demand than ever before. This review provides a comprehensive overview of the basic science, clinical utility and economics of bone grafts, bone substitutes and orthobiologics. PMID:23247591

  9. Remodeling in bone without osteocytes: Billfish challenge bone structurefunction paradigms

    E-print Network

    Lajeunesse, Marc J.

    Remodeling in bone without osteocytes: Billfish challenge bone structure­function paradigms Ayelet of bone, is considered to be initiated and orchestrated by osteocytes, cells within the bone matrix. It is therefore surprising that most extant fishes (neoteleosts) lack osteocytes, suggesting their bones

  10. Bone Surface Mapping Method

    PubMed Central

    Fan, Yifang; Fan, Yubo; Li, Zhiyu; Lv, Changsheng; Zhang, Bo

    2012-01-01

    Bone shape is an important factor to determine the bone's structural function. For the asymmetrically shaped and anisotropically distributed bone in vivo, a surface mapping method is proposed on the bases of its geometric transformation invariance and its uniqueness of the principal axes of inertia. Using spiral CT scanning, we can make precise measurements to bone in vivo. The coordinate transformations lead to the principal axes of inertia, with which the prime meridian and the contour can be set. Methods such as tomographic reconstruction and boundary development are employed so that the surface of bone in vivo can be mapped. Experimental results show that the surface mapping method can reflect the shape features and help study the surface changes of bone in vivo. This method can be applied to research into the surface characteristics and changes of organ, tissue or cell whenever its digitalized surface is obtained. PMID:22412952

  11. Small Animal Bone Biomechanics

    PubMed Central

    Vashishth, Deepak

    2008-01-01

    Animal models, in particular mice, offer the possibility of naturally achieving or genetically engineering a skeletal phenotype associated with disease and conducting destructive fracture tests on bone to determine the resulting change in bone’s mechanical properties. Several recent developments, including nano- and micro- indentation testing, microtensile and microcompressive testing, and bending tests on notched whole bone specimens, offer the possibility to mechanically probe small animal bone and investigate the effects of aging, therapeutic treatments, disease, and genetic variation. In contrast to traditional strength tests on small animal bones, fracture mechanics tests display smaller variation and therefore offer the possibility of reducing sample sizes. This article provides an analysis of what such tests measure and proposes methods to reduce errors associated with testing smaller than ideal specimens. PMID:18672104

  12. Bone Biology for Kids

    NSDL National Science Digital Library

    Bone Biology for Kids was created by University of Washington professor Dr. Susan Ott as an educational website for 4th - 8th grade students and as a resource for science and biology teachers. The main sections of the site include All About Bones, Bone Diseases, and How to Build Your Bone Strength. The site also offers an interactive Index & Definitions section, a Bone-quiz Yahtzee game, and a question / answer page. The Teacherâ??s Corner section currently contains two supplementary worksheets, and may offer more educational resources in the future. Some of the siteâ??s sections are still in progress, but overall the website contains great images and a good amount of information to explore. The site also links to high school and college curriculum from the American Society for Bone and Mineral Research.

  13. Biomaterials and bone mechanotransduction

    NASA Technical Reports Server (NTRS)

    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.

  14. Bone scanning in clinical practice

    SciTech Connect

    Fogelman, I. (Guys Hospital, London (GB))

    1987-01-01

    The topics covered in this book include the history of bone scanning, mechanisms of uptake of diphosphonate in bone, the normal bone scan, and the role of bone scanning in clinical practice. The aim of this book is to provide a source of reference relating to bone scan imaging for all those who are interested in the skeleton.

  15. Long Bone Fractures

    Microsoft Academic Search

    Jennifer C. Love; Sharon M. Derrick; Jason M. Wiersema

    \\u000a Fractures occurring in the humerus, ulna, radius, femur, tibia, and fibula are collectively categorized as long bone fractures.\\u000a Long bone fractures are further classified by type and location. Interpretation of the forces associated with the fracture\\u000a depends on the location, type, and extent of the fracture. Common long bone fracture types include spiral, oblique, transverse,\\u000a torus (or buckle), greenstick, and

  16. Raman microscopy of bone.

    PubMed

    Goodyear, Simon R; Aspden, Richard M

    2012-01-01

    Raman microscopy is a non-destructive technique requiring minimal sample preparation that can be used to measure the chemical properties of the mineral and collagen parts of bone simultaneously. Modern Raman instruments contain the necessary components and software to acquire the standard information required in most bone studies. The spatial resolution of the technique is about a micron. As it is non-destructive and small samples can be used, it forms a useful part of a bone characterisation toolbox. PMID:22130949

  17. Dinosaur Flesh and Bones

    NSDL National Science Digital Library

    Rick Crosslin

    2004-01-01

    In this activity, learners explore dinosaur skeletons. First, learners listen to "Bones, Bones, Dinosaur Bones" by Byron Barton to learn about the difference between pictures of dinosaurs that have skin and muscle (fleshed-out) and those that show skeletons. Then, learners match pictures of dinosaurs to pictures of the dinosaurs' skeletons. Learners can also explore other animal bones and skeletons online and/or reassemble paper dinosaur skeletons. This activity can also be used to help learners explore scale as they realize that large dinosaurs had large skeletons and small dinosaurs had small skeletons. This activity is featured on page 37 of the "Dinosphere" unit of study for K-2 learners.

  18. Fetal bovine bone cells synthesize bone-specific matrix proteins

    Microsoft Academic Search

    S. WILLIAM WHITSON; WILBUR HARRISON; MARY K. DUNLAP; DANIEL E. BOWERS; LARRY W. FISHER; PAMELA GEHRON ROBEY; JOHN D. TERMINE

    1984-01-01

    We isolatedcellsfrom both calvariaand the outercorticesoflong bones from 3- to 5-mo bovine fetuses. The cellswere identifiedas functionalosteoblastsby indirect immunofluorescence using antibodiesagainstthree bone-specific,noncollagenous matrix proteins(osteonectin,the bone proteoglycan,and the bone sialoprotein)and againsttype I Collagen.Inseparateexperiments,confluentculturesofthecellswere radiolabeledand shown to synthesizeand secreteosteonectin,the bone proteoglycanand the bone sialoproteinby imunoprecipitationand fluorographyofSIDSpolyacrylamidegels.Analysisofthe radiolabeled collagenssynthesizedby theculturesshowed thatthey produced predominantly (-94%) type I collagen,with smallamounts of types IIIand V collagens.

  19. How Is Bone Cancer Staged?

    MedlinePLUS

    ... cancer Previous Topic How is bone cancer diagnosed? Next Topic Survival statistics for bone cancer How is bone cancer staged? Staging is a process that tells the doctor how widespread a cancer ...

  20. [Cytokines and myeloma bone disease].

    PubMed

    Abe, Masahiro

    2014-06-01

    Multiple myeloma (MM) develops and expands almost exclusively in the bone marrow, and generates devastating bone destruction. MM cells produce a variety of cytokines to stimulate RANK ligand-mediated osteoclastogenesis and suppress osteoblastic differentiation from bone marrow stromal cells, leading to extensive bone destruction with rapid loss of bone. MM cells alter through bone destruction the microenvironment in bone where they colonize, which in turn favors tumor growth and survival, thereby forming a progressive vicious cycle between tumor expansion and bone destruction in MM. PMID:24870838

  1. Bone Mineral Measurements.

    PubMed

    Doroudinia, Abtin; Colletti, Patrick M

    2015-08-01

    The accurate measurement of bone mineral density using noninvasive methods can be of value in the detection and evaluation of primary and secondary causes of decreased bone mass. This includes primary osteoporosis and secondary disorders, such as hyperparathyroidism, osteomalacia, multiple myeloma, diffuse metastases, and glucocorticoid therapy or intrinsic excess.By far, the largest patient population is that encompassed by primary osteoporosis with increased susceptibility to fractures in the absence of other recognizable causes of bone loss.Primary osteoporosis is a common clinical disorder and a major public health problem because of the significant number of related bone fractures occurring annually. Because the risk of vertebral and femoral neck fractures rises dramatically as bone mineral density falls, fracture risk in individual patients may be estimated. Furthermore, in estrogen-deficient women, bone mineral density values may be used to make rational decisions about hormone replacement therapy, or other bone mineral therapies, and as follow-up in assessing the success of such treatment.In this article, we discuss different methods of bone densitometry and will focus on dual-energy x-ray absorptiometry (DXA) with discussing the factors which should be considered for interpretation of DXA scan. PMID:26147459

  2. CARTILAGE, BONES, AND JOINTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cartilage is a special type of connective tissue that is of extreme importance in embryonic development, serving as the model upon which true bone is later formed. Cartilage also persists in adult animals, primarily as articular cartilage which cushions the interface between adjacent bones or joint...

  3. Implantable bone substitute materials.

    PubMed

    Hanft, J R; Sprinkle, R W; Surprenant, M S; Werd, M B

    1995-07-01

    This article focuses on materials used as bone substitutes. The materials may be used as substitutes for autografts or, in some cases, along with autografts. Each material has unique properties that may be beneficial for specific applications. Some future developments in bone substitute materials are also discussed. PMID:7553534

  4. Automated trabecular bone histomorphometry

    NASA Technical Reports Server (NTRS)

    Polig, E.; Jee, W. S. S.

    1985-01-01

    The toxicity of alpha-emitting bone-seeking radionuclides and the relationship between bone tumor incidence and the local dosimetry of radionuclides in bone are investigated. The microdistributions of alpha-emitting radionuclides in the trabecular bone from the proximal humerus, distal humerus, proximal ulna, proximal femur, and distal femur of six young adult beagles injected with Am-241 (three with 2.8 micro-Ci/kg and three with 0.9 micro-Ci/kg) are estimated using a computer-controlled microscope photometer system; the components of the University of Utah Optical Track Scanner are described. The morphometric parameters for the beagles are calculated and analyzed. It is observed that the beagles injected with 0.9 micro-Ci of Am-241/kg showed an increase in the percentage of bone and trabecular bone thickness, and a reduction in the width of the bone marrow space and surface/volume ratio. The data reveal that radiation damage causes abnormal bone structure.

  5. Biodegradable synthetic bone composites

    DOEpatents

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.

  6. Hyperparathyroidism and Bone Health.

    PubMed

    Bandeira, Francisco; Cassibba, Sara

    2015-07-01

    Bone pain, proximal muscle weakness, skeletal deformities, and pathological fractures are features of osteitis fibrosa cystica which occur in severe primary hyperparathyroidism (PHPT). In this condition, bone mineral density is usually extremely low, but may be reversible after parathyroidectomy. On X-ray, bone abnormalities are described as having a salt-and-pepper appearance in the skull, with bone erosions and resorption of the phalanges, brown tumors and cysts, as well as diffuse demineralization, along with pathological fractures, particularly in the long bones of the extremities. A marked elevation of the serum calcium and PTH concentrations is seen, and renal involvement is manifested by nephrolithiasis and nephrocalcinosis. In asymptomatic PHPT, the absence of clinically significant bone involvement has led to much more data on bone mineral density becoming available by dual X-ray absorptiometry (DXA) and also on new technologies such as trabecular bone score (TBS), which is a gray-level textural analysis of DXA images that provides an indirect index of trabecular microarchitecture. In addition, high-resolution peripheral computed tomography (HRpQCT), which has a low radiation exposure, provides further understanding of the microstructural skeletal features at both trabecular and cortical sites. PMID:26105042

  7. Gallium scintigraphy in bone infarction. Correlation with bone imaging

    SciTech Connect

    Armas, R.R.; Goldsmith, S.J.

    1984-01-01

    The appearance of gallium-67 images in bone infarction was studied in nine patients with sickle cell disease and correlated with the bone scan findings. Gallium uptake in acute infarction was decreased or absent with a variable bone scan uptake, and normal in healing infarcts, which showed increased uptake on bone scan. The significance of these findings is discussed.

  8. SILICON AND BONE HEALTH

    PubMed Central

    JUGDAOHSINGH, R.

    2009-01-01

    Low bone mass (osteoporosis) is a silent epidemic of the 21st century, which presently in the UK results in over 200,000 fractures annually at a cost of over one billion pounds. Figures are set to increase worldwide. Understanding the factors which affect bone metabolism is thus of primary importance in order to establish preventative measures or treatments for this condition. Nutrition is an important determinant of bone health, but the effects of the individual nutrients and minerals, other than calcium, is little understood. Accumulating evidence over the last 30 years strongly suggest that dietary silicon is beneficial to bone and connective tissue health and we recently reported strong positive associations between dietary Si intake and bone mineral density in US and UK cohorts. The exact biological role(s) of silicon in bone health is still not clear, although a number of possible mechanisms have been suggested, including the synthesis of collagen and/or its stabilization, and matrix mineralization. This review gives an overview of this naturally occurring dietary element, its metabolism and the evidence of its potential role in bone health. PMID:17435952

  9. Aspects of bone healing and bone substitute incorporation. An experimental study in rabbit skull bone defects.

    PubMed

    Isaksson, S

    1992-01-01

    After an initial assessment of the experimental approach this experimental project was undertaken to study the regenerative response and incorporation of various implanted materials in calvarial bone defects in rabbits. Four 5-mm full-thickness defects were trephined in the frontal and parietal bones of the rabbits. After removal of the circular bone plugs the defects were used as recipient sites for inlay bone tissue and bone substitutes. In five separate studies the impact of bone regeneration of autogeneic bone grafts or eight bone substitutes were evaluated mainly by contact radiography, light microscopy and morphometry. The observation periods were four and 15 weeks. The main findings were: Autogeneic bone chips offered only minor advantages over controls in the model used and, also, differences in bone regeneration between diversified amounts of bone chips were negligible. In contrast, after bone paste implantation a cellular and mature bone was rapidly produced. Natural bone mineral (Bio-Oss) and synthetic dense hydroxylapatite ceramic proved to be biocompatible and a definite long term bone regeneration around all implants regardless of granulae size or resorbability was observed. Initial bone regeneration in and around the Bio-Oss particles was more extensive. Demineralized bone matrix of membranous and enchondral origins displayed extensive osteoinductive capacity and early bone production significantly exceeded that of control groups. The embryonic origin implied minor effects on the initial regenerative response only. Lyophilized bone allografts of two embryonic origins showed a low osteoinductive potential and a similar fashion of bone regeneration. No marked difference between these groups were displayed. HTR-polymer alone or combined with membraneous mineralized autogeneic bone chips showed a more rapid early bone regeneration than the groups containing lactomer beads, resorbable gel and controls. Also, the HTR-material proved to be a well-tolerated implant material by the recipient tissue bed. PMID:1334579

  10. Bone Cancer: Questions and Answers

    MedlinePLUS

    ... Are there different types of primary bone cancer? Yes. Cancer can begin in any type of bone tissue. Bones are made up ... follow-up treatment necessary? What does it involve? Yes. Bone cancer ... and should report any unusual symptoms right away. Follow-up varies for ...

  11. What Makes our Bones Strong?

    NSDL National Science Digital Library

    VU Bioengineering RET Program,

    Students will use this activity to determine what keeps our bones strong. Soaking the bones in vinegar will remove the calcium from the bones causing them to become soft and rubbery. Students will find that when we age, calcium is depleted from our bones faster than we can restore it. They will then determine what complications can arise from it.

  12. Healthy Bones Matter

    MedlinePLUS

    ... keep my bones more healthy? Definitions What can go wrong? Reprinted from The Surgeon General’s Report on ... women who don’t smoke, and they often go through menopause earlier. Smokers also may absorb less ...

  13. Fossilized Dinosaur Bones

    NSDL National Science Digital Library

    This slide show presents images of dinosaur bones and shows paleotologists at work excavating and preserving these fossils, the best evidence remaining of these long-lost creatures. A background essay and discussion questons are included.

  14. Metastatic Bone Disease

    MedlinePLUS

    ... in metastatic bone disease or multiple myeloma. Blood chemistries (i.e., electrolytes, calcium, and alkaline phosphatase) may ... multiple myeloma. Final Diagnosis A er the history, physical examination, x-ray and laboratory tests are completed, ...

  15. Temporal bone resection.

    PubMed

    Willging, J P; Pensak, M L

    1991-09-01

    It must be emphasized that the greatest impact of survival can only be obtained through an early diagnosis and a radical treatment program. Any granulation tissue must be sent for biopsy to rule out the possibility of malignancy in the setting of chronic otitis media. Once carcinoma is diagnosed, imaging studies must be obtained to define the extent of the tumor. Under diagnosis is the rule with these malignancies. Tumors limited to the external auditory canal can be adequately resected with a lateral temporal bone resection. Extension into the middle ear and mastoid aircell systems requires either a subtotal temporal bone resection or a lateral temporal bone resection with a radical mastoidectomy and petrousectomy. The inclusion of the petrous apex with the resection, as in a temporal bone resection, does not add to survival but increases morbidity. Radical postoperative radiation therapy is essential for maximum local control and survival with these malignancies. PMID:1743111

  16. Strontium ranelate inhibits bone resorption while maintaining bone formation in alveolar bone in monkeys ( Macaca fascicularis)

    Microsoft Academic Search

    J Buehler; P Chappuis; J. L Saffar; Y Tsouderos; A Vignery

    2001-01-01

    Strontium ranelate (S12911) has previously been shown to stimulate bone formation and inhibit bone resorption in rats. To determine whether strontium ranelate affects normal bone remodeling, we studied the effect of strontium ranelate on alveolar bone in monkeys. Strontium ranelate, at dosages of 100, 275, and 750 mg\\/kg per day, or vehicle, were given by gavage to 31 normal adult

  17. Histomorphometry of bone.

    PubMed Central

    Revell, P A

    1983-01-01

    This review of the histomorphometry of bone outlines methods of biopsy and processing of specimens in the laboratory, the basic principles of morphometry, and the measurements made in order to obtain estimates of the proportional volumes and surfaces occupied by different components of bone. Variability such as that between methods, observers and laboratories is discussed and a brief outline of automatic and semiautomatic methods of image analysis also given. Images PMID:6361070

  18. Automated bone fracture detection

    NASA Astrophysics Data System (ADS)

    Donnelley, Martin; Knowles, Greg

    2005-04-01

    Fractures of bone are a common affliction. In most developed countries the number of fractures associated with age-related bone loss is increasing rapidly. Each year many fractures are missed during x-ray diagnosis, resulting in ineffective patient management and expensive litigation. From both an orthopaedic and radiologic point of view, the fully automatic detection and classification of fractures in long-bones is an important but difficult problem. In this paper, a fully automated method of detecting fractures in the diaphysis of a long-bone is described. X-rays are very difficult to process automatically, so to extract the required information a non-linear anisotropic diffusion method, the Affine Morphological Scale Space, was implemented to smooth the image without losing information about the location of boundaries within the image. Next, an iterative peak detection algorithm is used to accurately locate the bone centreline and articular surfaces. A method based on orthogonal projections calculated from a modified Hough transform is used to automatically locate the long-bone diaphysis. At this point, our algorithm accurately localises the area of the fracture, and would allow further image registration if necessary. Finally, a gradient-based algorithm is used to detect fractures present in the region of interest. The magnitude and direction of the gradient are combined to produce a measure of the likelyhood of the presence of a fracture. A library of long-bone fracture images was created. Experimental tests performed on a series of x-ray images show that the method is capable of accurately segmenting the diaphysis from the epiphyses, and is also able to detect many mid-shaft fractures of long-bones.

  19. Boning up on autophagy

    PubMed Central

    Shapiro, Irving M; Layfield, Robert; Lotz, Martin; Settembre, Carmine; Whitehouse, Caroline

    2014-01-01

    From an evolutionary perspective, the major function of bone is to provide stable sites for muscle attachment and affording protection of vital organs, especially the heart and lungs (ribs) and spinal cord (vertebrae and intervertebral discs). However, bone has a considerable number of other functions: serving as a store for mineral ions, providing a site for blood cell synthesis and participating in a complex system-wide endocrine system. Not surprisingly, bone and cartilage cell homeostasis is tightly controlled, as is the maintenance of tissue structure and mass. While a great deal of new information is accruing concerning skeletal cell homeostasis, one relatively new observation is that the cells of bone (osteoclasts osteoblasts and osteocytes) and cartilage (chondrocytes) exhibit autophagy. The focus of this review is to examine the significance of this process in terms of the functional demands of the skeleton in health and during growth and to provide evidence that dysregulation of the autophagic response is involved in the pathogenesis of diseases of bone (Paget disease of bone) and cartilage (osteoarthritis and the mucopolysaccharidoses). Delineation of molecular changes in the autophagic process is uncovering new approaches for the treatment of diseases that affect the axial and appendicular skeleton. PMID:24225636

  20. The geometry of the bone structure associated with total hip arthroplasty.

    PubMed

    Yang, Zhang; Jian, Wang; Li, Zhi-han; Jun, Xiao; Liang, Zhao; Ge, Yan; Shi, Zhan-jun

    2014-01-01

    Close adaptation of the prosthesis to the bone is the key to achieving optimal stability and fixation for total hip arthroplasty (THA). However, there have been no adequate studies of bone morphology, especially in different races. The aim of this study was to analyze the geometry of the acetabulum and proximal femur of people from South China, based on three-dimensional reconstruction, and to detect differences between different population subsets. CT scans were performed on 80 healthy volunteers (160 hips) from South China, comprising 40 males (80 hips) and 40 females (80 hips). The images were imported into Mimics 10.01 to perform 3D reconstruction. THA-associated anatomical parameters were measured and compared with other published data. In comparison with published data, it seemed that people from South China have smaller acetabular abduction angle, larger acetabular supro-inferior diameter, larger neck-shaft angle, smaller offset, thinner femoral shaft and more proximal isthmus, which needed to be further confirmed. There were significant differences between the genders in most parameters. As significant differences in canal flare index (CFI) and distal canal flare index (DCFI) were found between genders, it was concluded the most significant differences lay in the isthmus of the femur. Among the femora, according to Noble's classification we identified more normal types and fewer stovepipe and champagne-flute types than expected from the literature, indicating that uncemented prostheses would be suitable for most people from South China. Our findings reveal that simply choosing the smallest of a series of prostheses would not necessarily provide a good fit, due to the different trends from the proximal to the distal part of the femur. Significant variation exists in THA-associated anatomy between genders and population subsets. It is therefore imperative that each patient receives individual consideration rather than assuming all patients have the same anatomy, especially for different races. PMID:24608343

  1. Repairing of goat Tibial Bone Defects with BMP2 Gene–Modified Tissue-Engineered Bone

    Microsoft Academic Search

    K. R. Dai; X. L. Xu; T. T. Tang; Z. A. Zhu; C. F. Yu; J. R. Lou; X. L. Zhang

    2005-01-01

    Bone defects larger than a critical size are major challenges in orthopedic medicine. We combined tissue-engineered bone and gene therapy to provide osteoprogenitor cells, osteoinductive factors, and osteoconductive carrier for ideal bone regeneration in critical-sized bone defects. Goat diaphyseal bone defects were repaired with tissue and genetically engineered bone implants, composed of biphasic calcined bone (BCB) and autologous bone marrow

  2. Temporal Bone Meningiomas

    PubMed Central

    Vrionis, Fotios D.; Robertson, Jon H.; Gardner, Gale; Heilman, Carl B.

    1999-01-01

    Meningiomas involving the temporal bone may originate from arachnoid cell nests present within the temporal bone (intratemporal), but more frequently originate from arachnoid cell nests of the posterior or middle cranial fossa with secondary invasion of the TB (extratemporal). In this study, we retrospectively reviewed the charts of 13 patients with meningiomas involving the temporal bone who underwent surgery. Tumors of the posterior fossa with only temporal bone hyperostosis, but without invasion, were excluded. Patients presented primarily with otologic symptoms and signs. The tumors originated in the temporal bone (5/13), jugular foramen (4/13), petroclival region (2/13), the asterion (1/13) or the internal auditory meatus (1/13). All of the intratemporal meningiomas had the radiological appearance of en-plaque menigiomas. The tumor extended into the middle ear (11/13), eustachian tube (5/13), and/or the labyrinth (3/13). A gross total resection was achieved in 11 patients and a subtotal resection in 2 patients. The lower cranial nerves were infiltrated by tumor in 4 patients, and were sacrificed. At a mean follow-up of approximately 6 years, 12 patients are currently alive and doing well and 1 died from tumor progression. Six patients showed tumor recurrence and were reoperated on (5/6) or followed conservatively (1/6). Surgical treatment of temporal bone meningiomas is associated with high recurrence rate due to indiscreet tumor margins. Combined surgical approaches (temporal craniotomy and mastoidectomy) by neurosurgical and otological teams are recommended for meningiomas originating in the temporal bone. ImagesFigure 1Figure 2Figure 3p134-aFigure 4Figure 5Figure 6 PMID:17171128

  3. Gene Expression in Bone

    NASA Astrophysics Data System (ADS)

    D'Ambrogio, A.

    Skeletal system has two main functions, to provide mechanical integrity for both locomotion and protection and to play an important role in mineral homeostasis. There is extensive evidence showing loss of bone mass during long-term Space-Flights. The loss is due to a break in the equilibrium between the activity of osteoblasts (the cells that forms bone) and the activity of osteoclasts (the cells that resorbs bone). Surprisingly, there is scanty information about the possible altered gene expression occurring in cells that form bone in microgravity.(Just 69 articles result from a "gene expression in microgravity" MedLine query.) Gene-chip or microarray technology allows to screen thousands of genes at the same time: the use of this technology on samples coming from cells exposed to microgravity could provide us with many important informations. For example, the identification of the molecules or structures which are the first sensors of the mechanical stress derived from lack of gravity, could help in understanding which is the first event leading to bone loss due to long-term exposure to microgravity. Consequently, this structure could become a target for a custom-designed drug. It is evident that bone mass loss, observed during long-time stay in Space, represents an accelerated model of what happens in aging osteoporosis. Therefore, the discovery and design of drugs able to interfere with the bone-loss process, could help also in preventing negative physiological processes normally observed on Earth. Considering the aims stated above, my research is designed to:

  4. Diabetes, Biochemical Markers of Bone Turnover, Diabetes Control, and Bone

    PubMed Central

    Starup-Linde, Jakob

    2012-01-01

    Diabetes mellitus is known to have late complications including micro vascular and macro vascular disease. This review focuses on another possible area of complication regarding diabetes; bone. Diabetes may affect bone via bone structure, bone density, and biochemical markers of bone turnover. The aim of the present review is to examine in vivo from humans on biochemical markers of bone turnover in diabetics compared to non-diabetics. Furthermore, the effect of glycemic control on bone markers and the similarities and differences of type 1- and type 2-diabetics regarding bone markers will be evaluated. A systematic literature search was conducted using PubMed, Embase, Cinahl, and SveMed+ with the search terms: “Diabetes mellitus,” “Diabetes mellitus type 1,” “Insulin dependent diabetes mellitus,” “Diabetes mellitus type 2,” “Non-insulin dependent diabetes mellitus,” “Bone,” “Bone and Bones,” “Bone diseases,” “Bone turnover,” “Hemoglobin A Glycosylated,” and “HbA1C.” After removing duplicates from this search 1,188 records were screened by title and abstract and 75 records were assessed by full text for inclusion in the review. In the end 43 records were chosen. Bone formation and resorption markers are investigated as well as bone regulating systems. T1D is found to have lower osteocalcin and CTX, while osteocalcin and tartrate-resistant acid are found to be lower in T2D, and sclerostin is increased and collagen turnover markers altered. Other bone turnover markers do not seem to be altered in T1D or T2D. A major problem is the lack of histomorphometric studies in humans linking changes in turnover markers to actual changes in bone turnover and further research is needed to strengthen this link. PMID:23482417

  5. Microarchitecture of irradiated bone: comparison with healthy bone

    NASA Astrophysics Data System (ADS)

    Bléry, Pauline; Amouriq, Yves; Guédon, Jeanpierre; Pilet, Paul; Normand, Nicolas; Durand, Nicolas; Espitalier, Florent; Arlicot, Aurore; Malard, Olivier; Weiss, Pierre

    2012-03-01

    The squamous cell carcinomas of the upper aero-digestive tract represent about ten percent of cancers. External radiation therapy leads to esthetic and functional consequences, and to a decrease of the bone mechanical abilities. For these patients, the oral prosthetic rehabilitation, including possibilities of dental implant placement, is difficult. The effects of radiotherapy on bone microarchitecture parameters are not well known. Thus, the purpose of this study is to assess the effects of external radiation on bone micro architecture in an experimental model of 25 rats using micro CT. 15 rats were irradiated on the hind limbs by a single dose of 20 Grays, and 10 rats were non irradiated. Images of irradiated and healthy bone were compared. Bone microarchitecture parameters (including trabecular thickness, trabecular number, trabecular separation, connectivity density and tissue and bone volume) between irradiated and non-irradiated bones were calculated and compared using a Mann and Whitney test. After 7 and 12 weeks, images of irradiated and healthy bone are different. Differences on the irradiated and the healthy bone populations exhibit a statistical significance. Trabecular number, connectivity density and closed porosity are less important on irradiated bone. Trabecular thickness and separation increase for irradiated bone. These parameters indicate a decrease of irradiated bone properties. Finally, the external irradiation induces changes on the bone micro architecture. This knowledge is of prime importance for better oral prosthetic rehabilitation, including implant placement.

  6. Calcar bone graft

    SciTech Connect

    Bargar, W.L.; Paul, H.A.; Merritt, K.; Sharkey, N.

    1986-01-01

    A canine model was developed to investigate the use of an autogeneic iliac bone graft to treat the calcar deficiency commonly found at the time of revision surgery for femoral component loosening. Five large male mixed-breed dogs had bilateral total hip arthroplasty staged at three-month intervals, and were sacrificed at six months. Prior to cementing the femoral component, an experimental calcar defect was made, and a bicortical iliac bone graft was fashioned to fill the defect. Serial roentgenograms showed the grafts had united with no resorption. Technetium-99 bone scans showed more uptake at three months than at six months in the graft region. Disulfine blue injection indicated all grafts were perfused at both three and six months. Thin section histology, fluorochromes, and microradiographs confirmed graft viability in all dogs. Semiquantitative grading of the fluorochromes indicated new bone deposition in 20%-50% of each graft at three months and 50%-80% at six months. Although the calcar bone graft was uniformly successful in this canine study, the clinical application of this technique should be evaluated by long-term results in humans.

  7. Aging mechanisms in bone

    PubMed Central

    Almeida, Maria

    2012-01-01

    Advancing age and loss of bone mass and strength are closely linked. Elevated osteoblast and osteocyte apoptosis and decreased osteoblast number characterize the age-related skeletal changes in humans and rodents. Similar to other tissues, oxidative stress increases in bone with age. This article reviews current knowledge on the effects of the aging process on bone and its cellular constituents, with particular emphasis on the role of reactive oxygen species (ROS). FoxOs, sirtuins and the p53/p66shc signaling cascade alter osteoblast number and bone formation via ROS-dependent and -independent mechanisms. Specifically, activation of the p53/p66shc signaling increases osteoblast/osteocyte apoptosis in the aged skeleton and decreases bone mass. FoxO activation in osteoblasts prevents oxidative stress to preserve skeletal homeostasis. However, while defending against stress FoxOs bind to ?-catenin and attenuate Wnt/T-cell cell factor transcriptional activity and osteoblast generation. Thus, pathways that impact longevity and several diseases of ageing might also contribute to age-related osteoporosis. PMID:23705067

  8. Bone and space

    NASA Astrophysics Data System (ADS)

    Berthier, Audrey; Braak, Laurent; Zallone, Alberta; Cancedda, Ranieri; Liu, Yi; Vico, Laurence; van der Saag, Paul; Heer, Martina; Pugh, Sydney; Koller, Bruno

    2005-10-01

    In space, astronauts can lose up to 1% of bone mass per month, mainly from the weight-bearing bones. A significant increase in the fracture risk could thus compromise very long-duration missions. On Earth, millions of people suffer from osteoporosis. The ERISTO MAP project aims at better control of the factors and the process of bone remodelling, with the objective of fighting against both space bone loss and osteoporosis. The space environment provides unique mechanical stress-free experimental conditions and can be considered to some extent to provide an accelerated and reversible model of osteoporosis. Research is focusing on providing in vitro and in vivo models and innovative supporting technologies. The main objective is to build 3-D multi-cell models that mimick the process of bone remodelling in order to define the best conditions for tissue engineering. For companies, the ERISTO team is providing not only knowledge and novel experimentation for developing new science but also unique insights into and understanding of complex biological problems.

  9. [Osteostimulating effect of bone xenograft on bone tissue regeneration].

    PubMed

    Balin, V N; Balin, D V; Iordanishvili, A K; Musikin, M I

    2015-01-01

    The aim of experimental case-control study performed in 28 dogs divided in 2 groups was to assess local tissue reactions on bone xenograft transplantation; dynamics of bone remodeling and formation at the site of bone defect wall contacting with bone xenograft; dynamics and mechanisms of xenograft remodeling. Transplantation of xenograft in conventional bone defects did not cause inflammatory of destructive reactions because of high biocompatibility of the material. At transplantation site active fibrous bone trabeculae formation filling the spaces between xenograft participles was observed. On the 90th day newly formed bone showed lammelar structure. Simultaneously from the 42d day the invasion of cell elements from recipient bed into the material was seen leading to xenograft resorption. The observed dynamics may be assessed as gradual substitution of xenograft with newly formed host bone structures. PMID:26145467

  10. [Nutrition and bone health. Lactose and bone].

    PubMed

    Uenishi, Kazuhiro; Yamaura, Tomoko

    2010-03-01

    Lactose, a disaccharide in milk or dairy products, is known to promote calcium absorption. The enzyme lactase is needed to digest lactose. Although lactase is secreted normally in childhood, the secretion is decreased with growth, and the activity becomes lower in adulthood. When the activity of lactase is low, lactose passes intact the small intestine and reaches the large intestine, could cause unpleasantness such as diarrhea and stomach ache. This is called lactose intolerance. In this paper, we discuss promotion of calcium absorption by lactose, lactose intolerance, and bone health. PMID:20190373

  11. Bone Augmentation and Nerve Repositioning

    MedlinePLUS

    ... Types of Bone-Augmentation Procedures Nerve Repositioning For dental implants to be successful, the jawbone must have enough ... of procedures used to "build" bone so that dental implants can be placed. These procedures typically involve grafting ( ...

  12. Vitamin A and Bone Health

    MedlinePLUS

    ... supported by your browser. Home Bone Basics Nutrition Vitamin A and Bone Health Publication available in: PDF (236 KB) Related Resources Calcium and Vitamin D El calcio y la vitamina D (Calcium ...

  13. Exercise for Your Bone Health

    MedlinePLUS

    ... supported by your browser. Home Bone Basics Lifestyle Exercise for Your Bone Health Publication available in: PDF ( ... ??) Related Resources Alcoholism Bed Rest and Immobilization Exercise and Osteogenesis Imperfecta Overtraining Risks for Women Oral ...

  14. Pattern Alteration: Protruding Hip Bone 

    E-print Network

    2006-08-04

    People with very thin figures typically have to alter their clothing for protruding hip bones. This is because diagonal wrinkles radiate from the hip bones. This well-illustrated publication shows how to correct this problem ...

  15. Bone cement implantation syndrome.

    PubMed

    Razuin, R; Effat, O; Shahidan, M N; Shama, D V; Miswan, M F M

    2013-06-01

    Bone cement implantation syndrome (BCIS) is characterized by hypoxia, hypotension, cardiac arrhythmias, increased pulmonary vascular resistance and cardiac arrest. It is a known cause of morbidity and mortality in patients undergoing cemented orthopaedic surgeries. The rarity of the condition as well as absence of a proper definition has contributed to under-reporting of cases. We report a 59-year-old woman who sustained fracture of the neck of her left femur and underwent an elective hybrid total hip replacement surgery. She collapsed during surgery and was revived only to succumb to death twelve hours later. Post mortem findings showed multiorgan disseminated microembolization of bone marrow and amorphous cement material. PMID:23817399

  16. Joint bone radiobiology workshop

    SciTech Connect

    Tomich, P.A. (ed.)

    1991-01-01

    The Joint Bone Radiobiology Workshop was held on July 12--13, 1991 in Toronto, Canada. This document contains the papers presented at the meeting. The five sections were: Dose-effects, Endogenous Cofactors, Tumorigenesis, New Methods and Medical Implications. The papers covered risk assessment, tissue distribution of radionuclides, lifetime studies, biological half-lifes, the influence of age at time of exposure, tumor induction by different radionuclides, microscopic localization of radionuclides, and nuclear medicine issues including tissue distribution in the skeleton and bone marrow transplantation. (MHB)

  17. Bone Density Challenge Introduction

    NSDL National Science Digital Library

    VU Bioenegineering RET Program ,

    Students are introduced to the challenge question, which revolves around proving that a cabinet x-ray system can produce bone mineral density images. Students work independently to generate ideas from the questions provided, then share with partners and then with the class as part of the Multiple Perspectives phase of this unit. Then, as part of the associated activity, students explore multiple websites to gather information about bone mineral density and answer worksheet questions, followed by a quiz on the material covered in the articles.

  18. Bone Health: Sound Suggestions for Stronger Bones

    Microsoft Academic Search

    Laura A. G. Armas; Karen A. Rafferty; Robert P. Heaney

    \\u000a \\u000a \\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a Bone requires calcium, vitamin D, protein, and phosphorus for optimal growth and maintenance.\\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a Food is the best source for most of the nutrients required by bone.\\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a Many in the population are consuming diets with inadequate calcium\\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a Most adults require additional vitamin D supplementation, especially if they have little sun exposure.\\u000a \\u000a \\u000a \\u000a • \\u000a \\u000a \\u000a Improvements in nutrition can make

  19. Transcutaneous Raman Spectroscopy of Bone

    NASA Astrophysics Data System (ADS)

    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 differences in murine bone.

  20. Chemical Makeup of Microdamaged Bone Differs from Undamaged Bone

    SciTech Connect

    Ruppel,M.; Burr, D.; Miller, L.

    2006-01-01

    Microdamage naturally occurs in bone tissue as a result of cyclic loading placed on the body from normal daily activities. While it is usually repaired through the bone turnover process, accumulation of microdamage may result in reduced bone quality and increased fracture risk. It is unclear whether certain areas of bone are more susceptible to microdamage than others due to compositional differences. This study examines whether areas of microdamaged bone are chemically different than undamaged areas of bone. Bone samples (L3 vertebrae) were harvested from 15 dogs. Samples were stained with basic fuchsin, embedded in poly-methylmethacrylate, and cut into 5-{micro}m-thick sections. Fuchsin staining was used to identify regions of microdamage, and synchrotron infrared microspectroscopic imaging was used to determine the local bone composition. Results showed that microdamaged areas of bone were chemically different than the surrounding undamaged areas. Specifically, the mineral stoichiometry was altered in microdamaged bone, where the carbonate/protein ratio and carbonate/phosphate ratio were significantly lower in areas of microdamage, and the acid phosphate content was higher. No differences were observed in tissue mineralization (phosphate/protein ratio) or crystallinity between the microdamaged and undamaged bone, indicating that the microdamaged regions of bone were not over-mineralized. The collagen cross-linking structure was also significantly different in microdamaged areas of bone, consistent with ruptured cross-links and reduced fracture resistance. All differences in composition had well-defined boundaries in the microcrack region, strongly suggesting that they occurred after microcrack formation. Even so, because microdamage results in an altered bone composition, an accumulation of microdamage might result in a long-term reduction in bone quality.

  1. Three quantitative ultrasound parameters reflect bone structure

    Microsoft Academic Search

    C. C. Gluer; C. Y. Wu; M. Jergas; S. A. Goldstein; H. K. Genant

    1994-01-01

    We investigated whether quantitative ultrasound (QUS) parameters are associated with bone structure. In an in vitro study on 20 cubes of trabecular bone, we measured broadband ultrasound attenuation (BUA) and two newly defined parameters—ultrasound velocity through bone (UVB) and ultrasound attenuation in bone (UAB). Bone mineral density (BMD) was measured by dual X-ray absorptiometry (DXA) and bone structure was assessed

  2. Bone augmentation with TiMesh. autologous bone versus autologous bone and bone substitutes. A systematic review

    PubMed Central

    Carini, Fabrizio; Longoni, Salvatore; Amosso, Ernesto; Paleari, Jacopo; Carini, Stefania; Porcaro, Gianluca

    2014-01-01

    Summary Aim of the study Reconstruction of segmental defects and the atrophic maxilla and mandible is performed using various techniques. Bone substitutes have received a wealth of reports in the literature demonstrating a long-term success when used in alveolar bone augmentation procedures. Materials and methods We reviewed articles comparing TiMesh GBR technique with different percentage of bone: autogenous bone alone (AB); anorganic bovine bone alone (ABB); 50:50 or 70:30. From an initial pool of 122, we selected 14 studies. ANOVA followed by Tukey HSD test was used for statistical analysis. Results We present a table analysing fundamental parameters to value a successful GBR therapy. Autogenous bone remains the gold standard in GBR technique with TiMesh; however, the combination between AB/ABB in relation 50:50 and 70:30 allows reducing surgical cost exploiting properties of eterologous bone. Conclusion The use of autologous bone is associated with a height and width gain of bone, which are greater compared to other techniques, with a lower exposure of the mesh and a lower bone resorption. The use of heterologous graft leads to a lower bone earn and to percentage of resorption greater than autologous graft but does not differ from the gain and resorption of the bone of AB/ABB in percentage 50:50 and 70:30. PMID:25678948

  3. Space Stations: Bones of Contention

    NSDL National Science Digital Library

    2014-06-23

    In this activity, learners make models representing bones on Earth and bones that have been in space. They discover what happens to bones without proper exercise and nutrition. This activity station is part of a sequence of stations that can be set up to help learners explore how space affects the human body and why.

  4. Breast cancer metastasis to the bone: mechanisms of bone loss

    PubMed Central

    2010-01-01

    Breast cancer frequently metastasizes to the skeleton, interrupting the normal bone remodeling process and causing bone degradation. Osteolytic lesions are the end result of osteoclast activity; however, osteoclast differentiation and activation are mediated by osteoblast production of RANKL (receptor activator for NF?B ligand) and several osteoclastogenic cytokines. Osteoblasts themselves are negatively affected by cancer cells as evidenced by an increase in apoptosis and a decrease in proteins required for new bone formation. Thus, bone loss is due to both increased activation of osteoclasts and suppression of osteoblasts. This review summarizes the current understanding of the osteolytic mechanisms of bone metastases, including a discussion of current therapies. PMID:21176175

  5. Paget's Disease of Bone

    MedlinePLUS

    ... break easily. The disease can lead to other health problems, too, such as arthritis and hearing loss. You can have Paget's disease in any bone, but it is most common in the spine, pelvis, skull, and legs. The disease might affect ...

  6. [Metabolic bone disease osteomalacia].

    PubMed

    Reuss-Borst, M A

    2014-05-01

    Osteomalacia is a rare disorder of bone metabolism leading to reduced bone mineralization. Underlying vitamin D deficiency and a disturbed phosphate metabolism (so-called hypophosphatemic osteomalacia) can cause the disease. Leading symptoms are dull localized or generalized bone pain, muscle weakness and cramps as well as increased incidence of falls. Rheumatic diseases, such as polymyalgia rheumatica, rheumatoid arthritis, myositis and fibromyalgia must be considered in the differential diagnosis. Alkaline phosphatase (AP) is typically elevated in osteomalacia while serum phosphate and/or 25-OH vitamin D3 levels are reduced. The diagnosis of osteomalacia can be confirmed by an iliac crest bone biopsy. Histological correlate is reduced or deficient mineralization of the newly synthesized extracellular matrix. Treatment strategies comprise supplementation of vitamin D and calcium and for patients with intestinal malabsorption syndromes vitamin D and calcium are also given parenterally. In renal phosphate wasting syndromes substitution of phosphate is the treatment of choice, except for tumor-induced osteomalacia when removal of the tumor leads to a cure in most cases. PMID:24811356

  7. Posttransplant bone disease

    Microsoft Academic Search

    Marianne Rix; Ewa Lewin; Klaus Olgaard

    2003-01-01

    Even after a successful kidney transplantation with good kidney function, many renal transplant patients have disabling skeletal symptoms. Approximately 7% to 10% of renal transplant patients may experience a fracture, mainly of the cancellous bones but also of the vertebrae. The fracture frequency is even higher in female renal transplant patients and much higher still in diabetic renal transplant patients.

  8. Bone Marrow Matters

    ERIC Educational Resources Information Center

    Dunne, Mark; Maklad, Rania; Heaney, Emma

    2014-01-01

    As a final-year student teacher specialising in primary science, Emma Heaney faced the challenge of having to plan, organise, and conduct a small-scale, classroom-based research project. She had to teach about bones in the final block practice session and thought it would be a good idea to bring in some biological specimens obtained from the local…

  9. Bone pain or tenderness

    MedlinePLUS

    Choi L. Overuse injuries. In: DeLee JC, Drez D Jr, Miller MD, eds. DeLee and Drez’s Orthopaedic Sports Medicine. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2009:chap 14. Lorenzo JA, Canalis E, Raisz LG. Metabolic bone ...

  10. Evolutionary patterns of bone histology and bone compactness in xenarthran mammal long bones.

    PubMed

    Straehl, Fiona R; Scheyer, Torsten M; Forasiepi, Analía M; MacPhee, Ross D; Sánchez-Villagra, Marcelo R

    2013-01-01

    Bone microstructure reflects physiological characteristics and has been shown to contain phylogenetic and ecological signals. Although mammalian long bone histology is receiving increasing attention, systematic examination of the main clades has not yet been performed. Here we describe the long bone microstructure of Xenarthra based on thin sections representing twenty-two species. Additionally, patterns in bone compactness of humeri and femora are investigated. The primary bone tissue of xenarthran long bones is composed of a mixture of woven, parallel-fibered and lamellar bone. The vascular canals have a longitudinal, reticular or radial orientation and are mostly arranged in an irregular manner. Concentric rows of vascular canals and laminar organization of the tissue are only found in anteater bones. The long bones of adult specimens are marked by dense Haversian bone, a feature that has been noted for most groups of mammals. In the long bones of armadillos, secondary osteons have an oblique orientation within the three-dimensional bone tissue, thus resulting in their irregular shape when the bones are sectioned transversely. Secondary remodeling is generally more extensive in large taxa than in small taxa, and this could be caused by increased loading. Lines of arrested growth are assumed to be present in all specimens, but they are restricted to the outermost layer in bones of armadillos and are often masked by secondary remodeling in large taxa. Parameters of bone compactness show a pattern in the femur that separates Cingulata and Pilosa (Folivora and Vermilingua), with cingulates having a lower compactness than pilosans. In addition, cingulates show an allometric relationship between humeral and femoral bone compactness. PMID:23874932

  11. Peripheral Leptin Regulates Bone Formation

    PubMed Central

    Turner, Russell T.; Kalra, Satya P.; Wong, Carmen P.; Philbrick, Kenneth A.; Lindenmaier, Laurence B.; Boghossian, Stephane; Iwaniec, Urszula T.

    2012-01-01

    Substantial evidence does not support the prevailing view that leptin, acting through a hypothalamic relay, decreases bone accrual by inhibiting bone formation. To clarify the mechanisms underlying regulation of bone architecture by leptin, we evaluated bone growth and turnover in wild type (WT) mice, leptin receptor-deficient db/db mice, leptin-deficient ob/ob mice and ob/ob mice treated with leptin. We also performed hypothalamic leptin gene therapy to determine the effect of elevated hypothalamic leptin levels on osteoblasts. Finally, to determine the effects of loss of peripheral leptin signaling on bone formation and energy metabolism, we used bone marrow (BM) from WT or db/db donor mice to reconstitute the hematopoietic and mesenchymal stem cell compartments in lethally irradiated WT recipient mice. Decreases in bone growth, osteoblast-lined bone perimeter and bone formation rate were observed in ob/ob mice and greatly increased in ob/ob mice following subcutaneous administration of leptin. Similarly, hypothalamic leptin gene therapy increased osteoblast-lined bone perimeter in ob/ob mice. In spite of normal osteoclast-lined bone perimeter, db/db mice exhibited a mild but generalized osteopetrotic-like (calcified cartilage encased by bone) skeletal phenotype and greatly reduced serum markers of bone turnover. Tracking studies and histology revealed quantitative replacement of BM cells following BM transplantation. WT mice engrafted with db/db BM did not differ in energy homeostasis from untreated WT mice or WT mice engrafted with WT BM. Bone formation in WT mice engrafted with WT BM did not differ from WT mice, whereas bone formation in WT mice engrafted with db/db cells did not differ from the low rates observed in untreated db/db mice. In summary, our results indicate that leptin, acting primarily through peripheral pathways, increases osteoblast number and activity. PMID:22887758

  12. Bone transport and bone graft using auto-tooth bone for alveolar cleft repair.

    PubMed

    Hara, Shingo; Mitsugi, Masaharu; Kanno, Takahiro; Tatemoto, Yukihiro

    2013-01-01

    We herein report the application of a combination of maxillary bone transport and auto-tooth bone grafting for alveolar cleft repair using autogenous extracted teeth developed in Korea.A 9-year-old female patient suffering from unilateral cleft lip and palate was treated with this method. After sagittal interdental right-sided maxillary osteotomy was performed completely between #11 and #12 to the nasal floor, alveolar maxillary bone (#11, 21) was transported in the planned direction and the alveolar cleft was closed. At the end of the transporter activation period, soft tissue in the cleft was removed during so-called "docking surgery" using an electric knife for close bone contact at the docking site. We performed bone transporter removal and simultaneous auto-tooth bone grafting of the patient's supernumerary teeth to the docking site.Maxillary bone transport allowed for simultaneous correction of the nasal septal deviation, maxillary arch deformities, and malocclusion since the dental arch was expanded without donor sacrifice or soft tissue expansion. Auto-tooth bone grafting to the docking site allowed for repair of the bone defects of the nasal floor and alveolar cleft and resulted in a superior bone connection.A combination of maxillary bone transport and auto-tooth bone grafting to the docking site appears to be an effective approach for alveolar cleft repair. PMID:23348343

  13. Bone Woman: poetry and fictions 

    E-print Network

    Airheart-Martin, Tria Ellen

    1997-01-01

    in their durability is transcendent. They are visible links to past biology, a morphological proof of connections between creatures. Their beauty is one of form serving function, the same beauty that blends art and artifact In our language, sayings such as "I know... it in my bones, " also reveal an idea that bones are the physical link to a deep-seated knowledge of our past; our ancestors live in our bones with I share my love of bones with artist Georgia O'KeeAe. Many of her works celebrate bones that she found...

  14. Digital electronic bone growth stimulator

    SciTech Connect

    Kronberg, J.W.

    1995-05-09

    A device is described for stimulating bone tissue by applying a low level alternating current signal directly to the patient`s skin. A crystal oscillator, a binary divider chain and digital logic gates are used to generate the desired waveforms that reproduce the natural electrical characteristics found in bone tissue needed for stimulating bone growth and treating osteoporosis. The device, powered by a battery, contains a switch allowing selection of the correct waveform for bone growth stimulation or osteoporosis treatment so that, when attached to the skin of the patient using standard skin contact electrodes, the correct signal is communicated to the underlying bone structures. 5 figs.

  15. Digital electronic bone growth stimulator

    SciTech Connect

    Kronberg, James W. (Aiken, SC)

    1995-01-01

    A device for stimulating bone tissue by applying a low level alternating current signal directly to the patient's skin. A crystal oscillator, a binary divider chain and digital logic gates are used to generate the desired waveforms that reproduce the natural electrical characteristics found in bone tissue needed for stimulating bone growth and treating osteoporosis. The device, powered by a battery, contains a switch allowing selection of the correct waveform for bone growth stimulation or osteoporosis treatment so that, when attached to the skin of the patient using standard skin contact electrodes, the correct signal is communicated to the underlying bone structures.

  16. Space flight and bone formation

    NASA Technical Reports Server (NTRS)

    Doty, St B.

    2004-01-01

    Major physiological changes which occur during spaceflight include bone loss, muscle atrophy, cardiovascular and immune response alterations. When trying to determine the reason why bone loss occurs during spaceflight, one must remember that all these other changes in physiology and metabolism may also have impact on the skeletal system. For bone, however, the role of normal weight bearing is a major concern and we have found no adequate substitute for weight bearing which can prevent bone loss. During the study of this problem, we have learned a great deal about bone physiology and increased our knowledge about how normal bone is formed and maintained. Presently, we do not have adequate ground based models which can mimic the tissue loss that occurs in spaceflight but this condition closely resembles the bone loss seen with osteoporosis. Although a normal bone structure will respond to application of mechanical force and weight bearing by forming new bone, a weakened osteoporotic bone may have a tendency to fracture. The study of the skeletal system during weightless conditions will eventually produce preventative measures and form a basis for protecting the crew during long term space flight. The added benefit from these studies will be methods to treat bone loss conditions which occur here on earth.

  17. Bone Metabolism in Anorexia Nervosa

    PubMed Central

    Fazeli, Pouneh K.; Klibanski, Anne

    2014-01-01

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

  18. Bone Anchored Hearing Aid

    PubMed Central

    2002-01-01

    Executive Summary Objective The objective of this health technology policy assessment was to determine the effectiveness and cost-effectiveness of bone-anchored hearing aid (BAHA) in improving the hearing of people with conduction or mixed hearing loss. The Technology The (BAHA) is a bone conduction hearing device that includes a titanium fixture permanently implanted into the mastoid bone of the skull and an external percutaneous sound processor. The sound processor is attached to the fixture by means of a skin penetrating abutment. Because the device bypasses the middle ear and directly stimulates the cochlea, it has been recommended for individuals with conduction hearing loss or discharging middle ear infection. The titanium implant is expected to last a lifetime while the external sound processor is expected to last 5 years. The total initial device cost is approximately $5,300 and the external sound processor costs approximately $3,500. Review of BAHA by the Medical Advisory Secretariat The Medical Advisory Secretariat’s review is a descriptive synthesis of findings from 36 research articles published between January 1990 and May 2002. Summary of Findings No randomized controlled studies were found. The evidence was derived from level 4 case series with relative small sample sizes (ranging from 30-188). The majority of the studies have follow-up periods of eight years or longer. All except one study were based on monaural BAHA implant on the side with the best bone conduction threshold. Safety Level 4 evidence showed that BAHA has been be implanted safely in adults and children with success rates of 90% or higher in most studies. No mortality or life threatening morbidity has been reported. Revision rates for tissue reduction or resiting were generally under 10% for adults but have been reported to be as high as 25% in pediatric studies. Adverse skin reaction around the skin penetration site was the most common complication reported. Most of these conditions were successfully treated with antibiotics, and only 1% to 2% required surgical revision. Less than 1% required removal of the fixture. Other complications included failure to osseointegrate and loss of fixture and/or abutment due to trauma or infection. Effectiveness Studies showed that BAHAs were implanted in people who have conduction or mixed hearing loss, congenital atresia or suppurative otitis media who were not candidates for surgical repair, and who cannot use conventional bone conduction hearing aids. The need for BAHA is not age- related. Objective audiometric measures and subjective patient satisfaction surveys showed that BAHA significantly improved the unaided and aided free field and sound field thresholds as well as speech discrimination in quiet and in noise for former users of conventional bone conduction hearing aids. The outcomes were ambiguous for former users of air conduction hearing aids. BAHA has been shown to reduce the frequency of ear infection and reduce the discharge particularly among patients with suppurative otitis media. Patients have reported that BAHA improved their quality of life. Reported benefits were improved speech intelligibility, better sound comfort, less pressure on the head, less skin irritation, greater cosmetic acceptance and increase in confidence. Main reported shortcomings were wind noise, feedback and difficulty in using the telephone. Experts and the BAHA manufacturer recommended that recipients of a BAHA implant be at least 5 years old. Challenges associated with the implantation of BAHA in pediatric patients include thin bone, soft bone, higher rates of fixture loss due to trauma, psychological problems, and higher revision rates due to rapid bone growth. The overall outcomes are comparable to adult BAHA. The benefits of pediatric BAHA (e.g. on speech development) appear to outweigh the disadvantages. Screening according to strict eligibility criteria, preoperative counselling, close monitoring by a physician with BAHA expertise and on-going follow-up were identified as critical factors for long-ter

  19. [Biological activities of bone morphological protein in bone regeneration].

    PubMed

    Smajilagi?, Amer; Redzic, Amira; Filipovi?, S; Hadzihasanovi?, B

    2005-01-01

    Bone matrix contents various development factors which control structuring and absorption and those factors play important role in bone and cartilage development. Bone morphological proteins are members of TGF-beta super family and their activity is certain becoming from the bone. This activity leads to the serial development processes which include chemo taxis, proliferation and differentiation which results in trans resistant formation of cartilage as well as production of life cells of a bone tissue. Biological activities of re combinative human bone morphogenetic protein 7 (rhBMP-7). induction bone formation of non critical size mandible defect of New Zealand rabbits were researched in the study. Markers of osteoblastic differential in the study included ALP specific activity. Histological analysis performed 7, 14, 30, 60 postoperative days, C-T analysis with determination Bone Mineral Density value of new structured tissue within the defect was done 30 days. Results indicate that ectopic bone formation has been inducted with rhBMP-7 and histological analysis shown mature bone with collagen and ostheociti 60th day. Early 7 day granulocyte tissue with angiogenesis was detected, and after 30 days ostheoblastsis shown with a lot of vascular and mezenhimal tissue. Ostheogenetic processes were characteristic for typical inter membraneous ossification without cartilage tissue. ALP activity was significantly increased 21 days. C-T and Bone Mineral Density value shown density of new structured tissue determinate as bone (413 mg/cm3 and 519 mg/cm3). Studies showed that concentration of 100 mg rhBMP-7 in collagen as career had strong ostheo inductive capacity. Conditions which module BMP depend ostheo induction should be considered in the future. Information could lead to improvements of rhBMP as substitution for bone graft in clinical practice. PMID:15875464

  20. Bone fragility and imaging techniques

    PubMed Central

    D’Elia, Giovanni; Caracchini, Giuseppe; Cavalli, Loredana; Innocenti, Paolo

    2009-01-01

    Bone fragility is a silent condition that increases bone fracture risk, enhanced by low bone mass and microarchitecture deterioration of bone tissue that lead to osteoporosis. Fragility fractures are the major clinical manifestation of osteoporosis. A large body of epidemiological data indicates that the current standard for predicting fragility fracture risk is an areal BMD (aBMD) measurement by DXA. Although mineral density measurements assess the quantity of bone, the quality of the tissue is an important predictor of fragility. Thus, bone strength is explained not only by BMD but also by macrostructural and microstructural characteristics of bone tissue. Imaging diagnostics, through the use of X-rays, DXA, Ultrasonography, CT and MR, provides methods for diagnosis and characterization of fractures, and semi- and quantitative methods for assessment of bone consistency and strength, that become precious for bone fragility clinical management if they are integrated by clinical risk factors. The last employment of sophisticated non-invasively imaging techniques in clinical research as high-resolution CT (hrCT), microCT (?-CT), high-resolution MR (hrMR) and, microRM (?RM), combined with finite element analysis methods, open to new challenges in a better bone strength assessment to enhance the comprehension of biomechanical parameters and the prediction of fragility fractures. PMID:22461252

  1. Bone disease in primary hyperparathyroidism.

    PubMed

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

    2014-07-01

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

  2. Calcium, Bone, and Life

    Microsoft Academic Search

    Robert P. Heaney

    \\u000a Calcium is a divalent mineral cation that functions as an intracellular messenger in virtually all life forms. In multicellular\\u000a organisms it functions also as an integrator tying body systems together, and in land-living vertebrates it provides the principal\\u000a mineral component of the endoskeleton (bone). Calcium cannot be synthesized and must be ingested, first to build an adult\\u000a skeleton and then

  3. Shang Oracle Bones

    NASA Astrophysics Data System (ADS)

    Pankenier, David W.

    Astronomical observations first appear in China's archaeological record on turtle plastrons and ox scapulae from the reigns of the last few kings of the Shang Dynasty (1250-1046 BCE). A variety of meteorological and astronomical phenomena were divined about and recorded by scribes in formulaic language that is recognizably archaic Chinese. The oracle bone inscriptions record sacrifices to celestial bodies and the proper ritual response to anomalous phenomena like eclipses.

  4. Gentamicin in bone cement

    PubMed Central

    Chang, Y.; Tai, C-L.; Hsieh, P-H.; Ueng, S. W. N.

    2013-01-01

    Objectives The objective of this study is to determine an optimal antibiotic-loaded bone cement (ALBC) for infection prophylaxis in total joint arthroplasty (TJA). Methods We evaluated the antibacterial effects of polymethylmethacrylate (PMMA) bone cements loaded with vancomycin, teicoplanin, ceftazidime, imipenem, piperacillin, gentamicin, and tobramycin against methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staph. aureus (MRSA), coagulase-negative staphylococci (CoNS), Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Standardised cement specimens made from 40 g PMMA loaded with 1 g antibiotics were tested for elution characteristics, antibacterial activities, and compressive strength in vitro. Results The ALBC containing gentamicin provided a much longer duration of antibiotic release than those containing other antibiotic. Imipenem-loading on the cement had a significant adverse effect on the compressive strength of the ALBC, which made it insufficient for use in prosthesis fixation. All of the tested antibiotics maintained their antibacterial properties after being mixed with PMMA. The gentamicin-loaded ALBC provided a broad antibacterial spectrum against all the test organisms and had the greatest duration of antibacterial activity against MSSA, CoNS, P. aeruginosa and E. coli. Conclusion When considering the use of ALBC as infection prophylaxis in TJA, gentamicin-loaded ALBC may be a very effective choice. Cite this article: Bone Joint Res 2013;2:220–6. PMID:24128666

  5. [Radioactivity of bone cement].

    PubMed

    Scherer, M A; Winkler, R; Ascherl, R; Lenz, E

    1993-01-01

    A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between < 1 and 100 Bq/kg. The content of U-238 and K-40 always was below the limit of detection (< 1-< 10 Bq/kg). Significant differences were detected in the amount of Ra-226, Pb-210, and Ra-228 detected between different samples of the same product from the same manufacturer, as well as between various types of cements. The highest radioactivity level was measured for Ra-226. Although stochastic radiation effects can not totally be excluded, it is extremely unlikely that the small amount of radioactive substances additionally transferred into the body by the bone cement has negative effects on the recipient's organism or on the fate of the alloplastic implant: "The risk factor and extrapolation in a low dosage range ... do not lead to an underestimation but more likely to an overestimation of the radiation hazard" [18]. PMID:8441806

  6. Battling Brittle Bones

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The accuDEXA(R) Bone Mineral Density Assessment System, manufactured by Schick Technologies, Inc., utilizes "camera on a chip" sensor technology invented and developed by NASA's Jet Propulsion Laboratory. Schick's accuDEXA system offers several advantages over traditional osteoporosis tests, which assess bone density loss in the hip and spine, and require specialized personnel to conduct. With accuDEXA, physicians can test the entire body's bone density at a peripheral site, such as the finger, without applying gels or having patients remove garments. Results are achieved in 30 seconds and printed out in less than a minute, compared to the estimated exam time of 15 minutes for hip and spine density analyses. Schick has also applied the CMOS APS technology to a new software product that performs dental radiography using up to 90 percent less radiation exposure than conventional X-rays. Called Computed Dental Radiography(R), the new digital imaging product utilizes an electronic sensor in place of X-ray film to generate sharp and clear images that appear on a computer screen within 3 seconds, and can be enlarged and enhanced to identify problems.

  7. Recombinant Human Bone Morphogenetic Protein Induces Bone Formation

    Microsoft Academic Search

    Elizabeth A. Wang; Vicki Rosen; Josephine S. D'Alessandro; Marc Bauduy; Paul Cordes; Tomoko Harada; David I. Israel; Rodney M. Hewick; Kelvin M. Kerns; Peter Lapan; Deborah H. Luxenberg; David McQuid; Ioannis K. Moutsatsos; John Nove; John M. Wozney

    1990-01-01

    We have purified and characterized active recombinant human bone morphogenetic protein (BMP) 2A. Implantation of the recombinant protein in rats showed that a single BMP can induce bone formation in vivo. A dose-response and time-course study using the rat ectopic bone formation assay revealed that implantation of 0.5-115 mug of partially purified recombinant human BMP-2A resulted in cartilage by day

  8. Bone Marrow Concentrate: a novel tool for bone repair!

    Microsoft Academic Search

    M. Jäger; M. Herten; E. M. Jelinek; U. Fochtmann; R. Krauspe

    \\u000a Background: Recently controversy has arisen regarding the role of mesenchymal stem cell (MSC) in orthopaedic surgery with\\u000a their potential clinical application in cartilage and bone regeneration. Although autologous bone grafting is still the “gold\\u000a standard” to heal critical size bony defects, it is associated with significant donor site morbidity. We present clinical\\u000a and experimental data of autologous bone marrow aspiration

  9. Changes in Bone Mass and Bone Turnover Following Ankle Fracture

    Microsoft Academic Search

    B. M. Ingle; S. M. Hay; H. M. Bottjer; R. Eastell

    1999-01-01

    :   Bone loss and increased bone turnover are recognized local changes after a fracture, but the exact patterns of these changes\\u000a after different fractures are unclear. We aimed to investigate the changes in bone density and biochemical markers following\\u000a ankle fracture. Fourteen subjects (7 postmenopausal women and 7 men, mean age 63 years) were recruited following fracture\\u000a of the distal

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

    NASA Technical Reports Server (NTRS)

    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.

  11. Microgravity and bone cell mechanosensitivity

    NASA Astrophysics Data System (ADS)

    Klein-Nulend, J.; Bacabac, R. G.; Veldhuijzen, J. P.; Van Loon, J. J. W. A.

    2003-10-01

    The capacity of bone tissue to alter its mass and structure in response to mechanical demands has long been recognized but the cellular mechanisms involved remained poorly understood. Bone not only develops as a structure designed specifically for mechanical tasks, but it can adapt during life toward more efficient mechanical performance. Mechanical adaptation of bone is a cellular process and needs a biological system that senses the mechanical loading. The loading information must then be communicated to the effector cells that form new bone or destroy old bone. The in vivo operating cell stress derived from bone loading is likely the flow of interstitial fluid along the surface of osteocytes and lining cells. The response of bone cells in culture to fluid flow includes prostaglandin (PG) synthesis and expression of prostaglandin G/H synthase inducible cyclooxygenase (COX-2). Cultured bone cells also rapidly produce nitric oxide (NO) in response to fluid flow as a result of activation of endothelial nitric oxide synthase (ecNOS), which enzyme also mediates the adaptive response of bone tissue to mechanical loading. Earlier studies have shown that the disruption of the actin-cytoskeleton abolishes the response to stress, suggesting that the cytoskeleton is involved in cellular mechanotransduction. Microgravity, or better near weightlessness, is associated with the loss of bone in astronauts, and has catabolic effects on mineral metabolism in bone organ cultures. This might be explained as resulting from an exceptional form of disuse under near weightlessness conditions. However, under near weightlessness conditions the assembly of cytoskeletal elements may be altered since it has been shown that the direction of the gravity vector determines microtubular pattern formation in vivo. We found earlier that the transduction of mechanical signals in bone cells also involves the cytoskeleton and is related to PGEZ production. Therefore it is possible that the mechanosensitivity of bone cells is altered under near weightlessness conditions, and that this abnormal mechanosensation contributes to disturbed bone metabolism observed in astronauts. In our current project for the International Space Station, we wish to test this hypothesis experimentally using an in vitro model. The specific aim of our research project is to test whether near weightlessness decreases the sensitivity of bone cells for mechanical stress through a decrease in early signaling molecules (NO, PGs) that are involved in the mechanical loading-induced osteogenic response. Bone cells are cultured with or without gravity prior to and during mechanical loading, using our modified in vitro oscillating fluid flow apparatus. In this "FlowSpace" project we are developing a cell culture module that is used to provide further insight in the mechanism of mechanotransduction in bone.

  12. Targeted therapies for bone sarcomas

    PubMed Central

    Heymann, Dominique; Rédini, Françoise

    2013-01-01

    Bone sarcomas include a very large number of tumour subtypes, which originate form bone and more particularly from mesenchymal stem cell lineage. Osteosarcoma, Ewing's sarcoma and chondrosarcoma, the three main bone sarcoma entities develop in a favourable microenvironment composed by bone cells, blood vessels, immune cells, based on the ‘seed and soil theory'. Current therapy associates surgery and chemotherapy, however, bone sarcomas remain diseases with high morbidity and mortality especially in children and adolescents. In the past decade, various new therapeutic approaches emerged and target the tumour niche or/and directly the tumour cells by acting on signalling/metabolic pathways involved in cell proliferation, apoptosis or drug resistance. The present review gives a brief overview from basic to clinical assessment of the main targeted therapies of bone sarcoma cells. PMID:24422100

  13. Bone Health in The Balance

    NSDL National Science Digital Library

    Paula Kiberstis (AAAS; )

    2000-09-01

    Our bones are continuously being remodeled through repeated cycles of destruction and rebuilding. By some estimates, this remodeling process is so extensive that it completely regenerates the adult skeleton every 10 years. Remodeling most likely serves a repair function, especially in bones subjected to mechanical stress. This article introduces a special issue of Science on recent advances in our understanding of the cell and molecular biology of bone remodeling and how these advances are being applied to the development of new therapeutics.

  14. Bone Disease and Idiopathic Hypercalciuria

    Microsoft Academic Search

    Joseph E. Zerwekh

    2008-01-01

    There is sufficient epidemiological and clinical data demonstrating an association between reduced bone mineral density and\\u000a idiopathic hypercalciuria (IH). There have been relatively few studies that have addressed the underlying defect in bone remodeling.\\u000a The limited studies to date suggest that increased bone turnover occurs in some forms of IH such as fasting hypercalciuria\\u000a or renal calcium leak and explains

  15. Prevention of corticosteroid bone loss

    Microsoft Academic Search

    P. Sambrook; J. Birmingham; P. Kelly; S. Kempler; T. Nguyen; N. Pocock; J. Eisman

    1993-01-01

    Prolonged corticosteroid therapy is known to result in an increased risk of osteoporotic fracture, probably as a consequence of enhanced bone resorption and depressed bone formation. We examined the effects of prophylactic treatment with 1,25-dihydroxyvitamin D3 (calcitonin) and nasal salmon calcitonin on corticosteroid-induced bone loss in 103 patients being treated with long-term corticosteroids for the first time in a randomized,

  16. Genetic and Environmental Correlations Between Bone Formation and Bone Mineral Density: A Twin Study

    Microsoft Academic Search

    M Harris; T. V Nguyen; G. M Howard; P. J Kelly; J. A Eisman

    1998-01-01

    Bone mineral density (BMD) and bone turnover are both heritable. Although bone turnover affects bone mass, it is not clear whether these parameters are under common genetic or environmental control. The relative contribution of genetic and environmental factors to the determination of an index of bone turnover, bone specific alkaline phosphatase (BSAP), and the extent of common genetic regulation with

  17. Elastic intramedullary nailing and DBM-Bone marrow injection for the treatment of simple bone cysts

    Microsoft Academic Search

    Anastasios D Kanellopoulos; Andreas F Mavrogenis; Panayiotis J Papagelopoulos; Panayotis N Soucacos

    2007-01-01

    BACKGROUND: Simple or unicameral bone cysts are common benign fluid-filled lesions usually located at the long bones of children before skeletal maturity. METHODS: We performed demineralized bone matrix and iliac crest bone marrow injection combined with elastic intramedullary nailing for the treatment of simple bone cysts in long bones of 9 children with a mean age of 12.6 years (range,

  18. Bone disease in predialysis, hemodialysis, and CAPD patients: Evidence of a better bone response to PTH

    Microsoft Academic Search

    Armando Torres; Victor Lorenzo; Domingo Hernández; José C Rodríguez; María Teresa Concepción; Aurelío P Rodríguez; Alexis Hernández; Eduardo de Bonis; Ernesto Darias; José M González-Posada; Manuel Losada; Margarita Rufino; Arnold J Felsenfeld; Mariano Rodríguez

    1995-01-01

    Bone disease in predialysis, hemodialysis, and CAPD patients: Evidence of a better bone response to PTH. The spectrum of bone disease in predialysis and dialysis patients has changed during the last decade. The incidence of aplastic bone disease has increased and this can not be attributed to bone aluminum deposition; moreover, low bone cellular activity is present despite a moderate

  19. Biomechanical properties of bone allografts

    SciTech Connect

    Pelker, R.R.; Friedlaender, G.E.; Markham, T.C.

    1983-04-01

    The biomechanical properties of allograft bone can be altered by the methods chosen for its preservation and storage. These effects are minimal with deep-freezing or low-level radiation. Freeze-drying, however, markedly diminishes the torsional and bending strength of bone allografts but does not deleteriously affect the compressive or tensile strength. Irradiation of bone with more than 3.0 megarad or irradiation combined with freeze-drying appears to cause a significant reduction in breaking strength. These factors should be considered when choosing freeze-dried or irradiated allogeneic bone that will be subjected to significant loads following implantation.

  20. Dilatational band formation in bone

    PubMed Central

    Poundarik, Atharva A.; Diab, Tamim; Sroga, Grazyna E.; Ural, Ani; Boskey, Adele L.; Gundberg, Caren M.; Vashishth, Deepak

    2012-01-01

    Toughening in hierarchically structured materials like bone arises from the arrangement of constituent material elements and their interactions. Unlike microcracking, which entails micrometer-level separation, there is no known evidence of fracture at the level of bone’s nanostructure. Here, we show that the initiation of fracture occurs in bone at the nanometer scale by dilatational bands. Through fatigue and indentation tests and laser confocal, scanning electron, and atomic force microscopies on human and bovine bone specimens, we established that dilatational bands of the order of 100 nm form as ellipsoidal voids in between fused mineral aggregates and two adjacent proteins, osteocalcin (OC) and osteopontin (OPN). Laser microdissection and ELISA of bone microdamage support our claim that OC and OPN colocalize with dilatational bands. Fracture tests on bones from OC and/or OPN knockout mice (OC?/?, OPN?/?, OC-OPN?/?;?/?) confirm that these two proteins regulate dilatational band formation and bone matrix toughness. On the basis of these observations, we propose molecular deformation and fracture mechanics models, illustrating the role of OC and OPN in dilatational band formation, and predict that the nanometer scale of tissue organization, associated with dilatational bands, affects fracture at higher scales and determines fracture toughness of bone. PMID:23129653

  1. Microgravity and Bone Cell Mechanosensitivity

    NASA Astrophysics Data System (ADS)

    Klein-Nulend, J.; Bacabac, R.; Veldhuijzen, J.; van Loon, J.

    The capacity of bone tissue to alter its mass and structure in response to mechanical demands has long been recognized but the cellular mechanisms involved remained poorly understood. Bone not only develops as a structure designed specifically for mechanical tasks, but it can adapt during life toward more efficient mechanical performance. Mechanical adaptation of bone is a cellular process and needs a biological system that senses the mechanical loading. The loading information must then be communicated to the effector cells that form new bone or destroy old bone.The in vivo operating cell stress derived from bone loading is likely flow of interstitial fluid along the surface of osteocytes and lining cells. The response of bone cells in culture to fluid flow includes prostaglandin (PG) synthesis and expression of prostaglandin G/H synthase inducible cyclooxygenase (COX-2). Cultured bone cells also rapidly produce nitric oxide (NO) in response to fluid flow as a result of activation of endothelial nitric oxide synthase (ecNOS), which enzyme also mediates the adaptive response of bone tissue to mechanical loading. Disruption of the actin-cytoskeleton abolishes the response to stress, suggesting that the cytoskeleton is involved in cellular mechanotransduction.Microgravity, or better near weightlessness, has catabolic effects on the skeleton of astronauts, and on mineral metabolism in bone organ cultures. This might be explained as resulting from an exceptional form of disuse under near weightlessness conditions. However, under near weightlessness conditions the assembly of cytoskeletal elements may be altered since it has been shown that the direction of the gravity vector determines microtubular pattern formation in vivo. We found that the transduction of mechanical signals in bone cells also involves the cytoskeleton and is related to PGE2 production. Therefore it is possible that the mechanosensitivity of bone cells is altered under near weightlessness conditions, and that this abnormal mechanosensation contributes to disturbed bone metabolism observed in astronauts.In our current project for the International Space Station, we wish to test this hypothesis experimentally using an in vitro model. The specific aim of our research project is to test whether near weightlessness decreases the sensitivity of bone cells for mechanical stress through a decrease in early signaling molecules (NO, PGs) that are involved in the mechanical loading-induced osteogenic response. Bone cells are cultured with or without gravity prior to and during mechanical loading, using our modified in vitro oscillating fluid flow apparatus. In this "FlowSpace" project we are developing a cell culture module that is used to provide further insight in the mechanism of mechanotransduction in bone.

  2. Endocortical bone loss in osteoporosis: the role of bone surface availability

    E-print Network

    Buenzli, Pascal R; Clement, John G; Pivonka, Peter

    2012-01-01

    Age-related bone loss and postmenopausal osteoporosis are disorders of bone remodelling, in which less bone is reformed than resorbed. Yet, this dysregulation of bone remodelling does not occur equally in all bone regions. Loss of bone is more pronounced near the endocortex, leading to cortical wall thinning and medullary cavity expansion, a process sometimes referred to as "trabecularisation" or "cancellisation". Cortical wall thinning is of primary concern in osteoporosis due to the strong reduction in bone mechanical properties that it is associated with. In this paper, we examine the possibility that the nonuniformity of microscopic bone surface availability could explain the nonuniformity of bone loss in osteoporosis. We use a simple computational model of bone remodelling, in which microscopic bone surface availability influences bone turnover rate, to simulate the evolution of the bone volume fraction profile across the midshaft of a long bone. We find that bone loss is accelerated near the endocortica...

  3. Mechanical Behavior of Bone Cells micrograph view of bone

    E-print Network

    Gefen, Amit

    of the formation of osteocytes and lining cells from osteoblast From: Burger, 2001, In: Bone Mechanics , S. Cowin, Ed., CRC Press. 3 Morphology of osteocytes, osteoblasts and periosteal fibroblasts From: Burger, 2001, Ed., CRC Press. Schematic representation of how the osteocyte network may regulate bone modeling #12

  4. Medicines That May Cause Bone Loss

    MedlinePLUS

    ... here Home » Medicines that May Cause Bone Loss Medicines that May Cause Bone Loss Some medicines can ... that may cause bone loss. Osteoporosis and Steroid Medicines While steroid medicines can be lifesaving treatments for ...

  5. 21 CFR 892.1180 - Bone sonometer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...sonometer. (a) Identification . A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone that indicate overall bone health and fracture risk. The primary components of the device are a...

  6. Exercise Brings Bone Benefits that Last

    MedlinePLUS

    ... External link, please review our exit disclaimer . Subscribe Exercise Brings Bone Benefits that Last Building bone as ... lose bone. Studies of animals have shown that exercise during periods of rapid growth can lead to ...

  7. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4760 Bone plate. ...plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to...

  8. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Surgical Devices § 872.4760 Bone plate. ...plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to...

  9. Bone-Targeted Therapy

    PubMed Central

    Salmen, J.; Banys-Paluchowski, M.; Fehm, T.

    2015-01-01

    Bisphosphonates and denosumab are well established components of the therapy for osteoporosis and osseous metastases. Their relevance in the adjuvant situation for breast cancer patients is being discussed in part controversially due to the heterogeneous nature of the available data. In particular, it appears that post-menopausal women benefit from an adjuvant therapy with bisphosphonates. In the present contribution we discuss the clinical relevance of osteoprotective therapy in the metastatic and adjuvant settings. Above all the current AGO guidelines on osteo-oncology and bone health have been taken into consideration for recommendations to implement the available data.

  10. Bones in Balance

    NSDL National Science Digital Library

    2009-10-05

    Thirty-first monthly installment of our "What A Year!" website project, introducing life science breakthroughs to middle and high school students and their teachers. Our bones change throughout our lives, building and increasing in density to our 30's and then decreasing in density thereafter. People who don't get exercise, such as those who must remain in bed for long periods of time, can suffer early osteoporosis. But why don't bears, who hibernate for half a year, experience the same problem?

  11. Raman spectroscopy of bone metastasis

    NASA Astrophysics Data System (ADS)

    Esmonde-White, Karen A.; Sottnik, Joseph; Morris, Michael; Keller, Evan

    2012-02-01

    Raman spectroscopy of bone has been used to characterize chemical changes occurring in diseases such as osteoporosis, osteoarthritis and osteomyelitis. Metastasis of cancer into bone causes changes to bone quality that are similar to those observed in osteoporosis, such as decreased bone strength, but with an accelerated timeframe. In particular, osteolytic (bone degrading) lesions in bone metastasis have a marked effect on patient quality of life because of increased risk of fractures, pain, and hypercalcemia. We use Raman spectroscopy to examine bone from two different mouse models of osteolytic bone metastasis. Raman spectroscopy measures physicochemical information which cannot be obtained through standard biochemical and histological measurements. This study was reviewed and approved by the University of Michigan University Committee on the Care and Use of Animals. Two mouse models of prostate cancer bone metastasis, RM1 (n=3) and PC3-luc (n=4) were examined. Tibiae were injected with RM1 or PC3-luc cancer cells, while the contralateral tibiae received a placebo injection for use as controls. After 2 weeks of incubation, the mice were sacrificed and the tibiae were examined by Raman microspectroscopy (?=785 nm). Spectroscopic markers corresponding to mineral stoichiometry, bone mineralization, and mineral crystallinity were compared in spectra from the cancerous and control tibiae. X-ray imaging of the tibia confirmed extensive osteolysis in the RM1 mice, with tumor invasion into adjoining soft tissue and moderate osteolysis in the PC3-luc mice. Raman spectroscopic markers indicate that osteolytic lesions are less mineralized than normal bone tissue, with an altered mineral stoichiometry and crystallinity.

  12. Biomechanics in bone tissue engineering

    Microsoft Academic Search

    Dominique P. Pioletti

    2010-01-01

    Biomechanics may be considered as central in the development of bone tissue engineering. The initial mechanical aspects are essential to the outcome of a functional tissue engineering approach; so are aspects of interface micromotion, bone ingrowths inside the scaffold and finally, the mechanical integrity of the scaffold during its degradation. A proposed view is presented herein on how biomechanical aspects

  13. Interaction between Muscle and Bone.

    PubMed

    Kaji, Hiroshi

    2014-02-01

    The clinical significance of sarcopenia and osteoporosis has increased with the increase in the population of older people. Sarcopenia is defined by decreased muscle mass and impaired muscle function, which is related to osteoporosis independently and dependently. Numerous lines of clinical evidence suggest that lean body mass is positively related to bone mass, which leads to reduced fracture risk. Genetic, endocrine and mechanical factors affect both muscle and bone simultaneously. Vitamin D, the growth hormone/insulin-like growth factor I axis and testosterone are physiologically and pathologically important as endocrine factors. These findings suggest the presence of interactions between muscle and bone, which might be very important for understanding the physiology and pathophysiology of sarcopenia and osteoporosis. Muscle/bone relationships include two factors: local control of muscle to bone and systemic humoral interactions between muscle and bone. As a putative local inducer of muscle ossification, we found Tmem119, a parathyroid hormone-responsive osteoblast differentiation factor. Moreover, osteoglycin might be one of the muscle-derived humoral bone anabolic factors. This issue may be important for the development of novel drugs and biomarkers for osteoporosis and sarcopenia. Further research will be necessary to clarify the details of the linkage of muscle and bone. PMID:24707465

  14. Green Tea and Bone Metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Osteoporosis is a major health problem in elderly men and women. Epidemiological evidence has shown association between tea consumption and age-related bone loss in elderly men and women. The aim of this review is to provide a systemic review of green tea and bone health to cover the following topi...

  15. Flavonoid Intake and Bone Health

    Microsoft Academic Search

    Connie M. Weaver; D. Lee Alekel; Wendy E. Ward; Martin J. Ronis

    2012-01-01

    Flavonoids, found in a wide diversity of plant foods from fruits and vegetables, herbs and spices, essential oils, and beverages, have the most potential of dietary components for promotion of bone health beyond calcium and vitamin D. Recent epidemiological studies show flavonoid consumption to have a stronger association with bone than general fruit and vegetable consumption. Bioactive flavonoids are being

  16. Interaction between Muscle and Bone

    PubMed Central

    2014-01-01

    The clinical significance of sarcopenia and osteoporosis has increased with the increase in the population of older people. Sarcopenia is defined by decreased muscle mass and impaired muscle function, which is related to osteoporosis independently and dependently. Numerous lines of clinical evidence suggest that lean body mass is positively related to bone mass, which leads to reduced fracture risk. Genetic, endocrine and mechanical factors affect both muscle and bone simultaneously. Vitamin D, the growth hormone/insulin-like growth factor I axis and testosterone are physiologically and pathologically important as endocrine factors. These findings suggest the presence of interactions between muscle and bone, which might be very important for understanding the physiology and pathophysiology of sarcopenia and osteoporosis. Muscle/bone relationships include two factors: local control of muscle to bone and systemic humoral interactions between muscle and bone. As a putative local inducer of muscle ossification, we found Tmem119, a parathyroid hormone-responsive osteoblast differentiation factor. Moreover, osteoglycin might be one of the muscle-derived humoral bone anabolic factors. This issue may be important for the development of novel drugs and biomarkers for osteoporosis and sarcopenia. Further research will be necessary to clarify the details of the linkage of muscle and bone. PMID:24707465

  17. Bone and Spinal Muscular Atrophy.

    PubMed

    Vai, Silvia; Bianchi, Maria Luisa; Moroni, Isabella; Mastella, Chiara; Broggi, Francesca; Morandi, Lucia; Arnoldi, Maria Teresa; Bussolino, Chiara; Baranello, Giovanni

    2015-10-01

    Spinal Muscular Atrophy (SMA) is an autosomal recessive neuromuscular disease, leading to progressive denervation atrophy in the involved skeletal muscles. Bone status has been poorly studied. We assessed bone metabolism, bone mineral density (BMD) and fractures in 30 children (age range 15-171months) affected by SMA types 2 and 3. Eighteen children (60%) had higher than normal levels of CTx (bone resorption marker); 25-OH vitamin D was in the lower range of normal (below 20ng/ml in 9 children and below 12ng/ml in 2). Lumbar spine BMAD (bone mineral apparent density) Z-score was below -1.5 in 50% of children. According to clinical records, four children had sustained four peripheral fractures; on spine X-rays, we observed 9 previously undiagnosed vertebral fractures in 7 children. There was a significant inverse regression between PTH and 25-OH D levels, and a significant regression between BMC and BMAD values and the scores of motor-functional tests. Even if this study could not establish the pathogenesis of bone derangements in SMA, its main findings - reduced bone density, low 25OH vitamin D levels, increased bone resorption markers and asymptomatic vertebral fractures also in very young patients - strongly suggest that even young subjects affected by SMA should be considered at risk of osteopenia and even osteoporosis and fractures. PMID:26055105

  18. Bone marrow modified acrylic bone cement for augmentation of osteoporotic cancellous bone.

    PubMed

    Arens, Daniel; Rothstock, Stephan; Windolf, Markus; Boger, Andreas

    2011-11-01

    The use of polymethylmethacrylate (PMMA) cement to reinforce fragile or broken vertebral bodies (vertebroplasty) leads to extensive bone stiffening. This might be one reason for fractures at the adjacent vertebrae following this procedure. PMMA with a reduced Young's modulus may be more suitable. The goal of this study was to produce and characterize PMMA bone cements with a reduced Young's modulus by adding bone marrow. Bone cements were produced by combining PMMA with various volume fractions of freshly harvested bone marrow from sheep. Porosity, Young's modulus, yield strength, polymerization temperature, setting time and cement viscosity of different cement modifications were investigated. The samples generated comprised pores with diameters in the range of 30-250 ?m leading to porosity up to 51%. Compared to the control cement, Young's modulus and yield strength decreased from 1830 to 740 MPa and from 58 to 23 MPa respectively by adding 7.5 ml bone marrow to 23 ml premixed cement. The polymerization temperature decreased from 61 to 38 ?C for cement modification with 7.5 ml of bone marrow. Setting times of the modified cements were lower in comparison to the regular cement (28 min). Setting times increased with higher amounts of added bone marrow from around 16-25 min. The initial viscosities of the modified cements were higher in comparison to the control cement leading to a lower risk of extravasation. The hardening times followed the same trend as the setting times. In conclusion, blending bone marrow with acrylic bone cement seems to be a promising method to increase the compliance of PMMA cement for use in cancellous bone augmentation in osteoporotic patients due to its modified mechanical properties, lower polymerization temperature and elevated initial viscosity. PMID:22098908

  19. Biomaterials for Bone Regenerative Engineering.

    PubMed

    Yu, Xiaohua; Tang, Xiaoyan; Gohil, Shalini V; Laurencin, Cato T

    2015-06-01

    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. PMID:25846250

  20. Animal Models of Bone Metastasis

    PubMed Central

    Rosol, Thomas J.; Tannehill-Gregg, Sarah H.; LeRoy, Bruce E.; Mandl, Stefanie; Contag, Christopher H.

    2011-01-01

    BACKGROUND Animal models are important tools to investigate the pathogenesis and develop treatment strategies for bone metastases in humans. However, there are few spontaneous models of bone metastasis despite the fact that rodents (rats and mice) and other animals (dogs and cats) often spontaneously develop cancer. Therefore, most experimental models of bone metastasis in rodents require injection or implantation of neoplastic cells into orthotopic locations, bones, or the left ventricle of the heart. METHODS The current study reviews the natural incidence and clinical manifestation of bone metastases of mammary and prostate carcinoma in animals, as well as the experimental models developed in mice using animal and human-derived neoplasms. RESULTS Rats, mice, dogs, and cats often develop spontaneous mammary carcinoma, but bone metastases are rare. Intact and neutered dogs develop prostate carcinoma that is usually androgen independent and may be associated with regional bone invasion or distant bone metastasis. Normal dog prostate tissue induces new bone formation in vivo and can serve as a model of osteoblastic metastasis without concurrent bone destruction. Experimental models of osteolytic, osteoblastic, and mixed osteolytic/osteoblastic bone metastases include syngeneic rodent neoplasms or human xenografts implanted at orthotopic sites (e.g., breast or prostate glands) in immunodeficient mice, injection of cancer cells into the left ventricle of the heart, or direct injection into bones. New transgenic mouse models of cancer have a low incidence of spontaneous bone metastasis, but cell lines derived from these tumors can be selected in vivo for increased incidence of bone metastasis. It is essential to validate and correctly interpret the lesions in models of bone metastasis to accurately correlate the data from animal models to human disease. Animal models have provided support for the “seed and soil” hypothesis of bone metastasis. However, the roles of vascular patterns in the metaphyses of long bones and rapid bone turnover in young animals in the pathogenesis of metastasis in experimental models are uncertain. Improvements in the imaging of experimental animals in vivo using fluorescent markers or light emitted from luciferase have led to increased sensitivity of detection and more accurate quantification of bone metastases. For example, imaging of human prostate carcinoma PC-3M cells transfected with luciferase, following injection into the left ventricle, has demonstrated that there is rapid localization of tumor cells to bones and other organs, such as the kidneys and lungs. CONCLUSIONS Animal models of metastasis have supported drug development and have been useful for identification of metastasis suppressor and promoter genes as novel targets for the development of novel therapies. Further refinement of these models will involve spatiotemporal analysis of the metastatic process by imaging and use of image data to stage disease and guide tissue sampling for gene expression profiling via gene array technology. In the future, integrated analyses of these models will be needed to understand the complexities of this important disease process. PMID:15043188

  1. Ethnic Differences in Bone Health

    PubMed Central

    Zengin, Ayse; Prentice, Ann; Ward, Kate Anna

    2015-01-01

    There are differences in bone health between ethnic groups in both men and in women. Variations in body size and composition are likely to contribute to reported differences. Most studies report ethnic differences in areal bone mineral density (aBMD), which do not consistently parallel ethnic patterns in fracture rates. This suggests that other parameters beside aBMD should be considered when determining fracture risk between and within populations, including other aspects of bone strength: bone structure and microarchitecture, as well as muscle strength (mass, force generation, anatomy) and fat mass. We review what is known about differences in bone-densitometry-derived outcomes between ethnic groups and the extent to which they account for the differences in fracture risk. Studies are included that were published primarily between 1994 and 2014. A “one size fits all approach” should definitely not be used to understand better ethnic differences in fracture risk. PMID:25852642

  2. Bone Positron Emission Tomography with or without CT Is More Accurate than Bone Scan for Detection of Bone Metastasis

    PubMed Central

    Lee, Soo Jin; Kim, Sang Eun

    2013-01-01

    Objective Na18F bone positron emission tomography (bone PET) is a new imaging modality which is useful for the evaluation of bone diseases. Here, we compared the diagnostic accuracies between bone PET and bone scan for the detection of bone metastasis (BM). Materials and Methods Sixteen cancer patients (M:F = 10:6, mean age = 60 ± 12 years) who underwent both bone PET and bone scan were analyzed. Bone PET was conducted 30 minutes after the injection of 370 MBq Na18F, and a bone scan was performed 3 hours after the injection of 1295 MBq 99mTc-hydroxymethylene diphosphonate. Results In the patient-based analysis (8 patients with BM and 8 without BM), the sensitivities of bone PET (100% = 8/8) and bone scan (87.5% = 7/8) were not significantly different (p > 0.05), whereas the specificity of bone PET (87.5% = 7/8) was significantly greater than that of the bone scan (25% = 2/8) (p < 0.05). In the lesion-based analysis (43 lesions in 14 patients; 31 malignant and 12 benign), the sensitivity of bone PET (100% = 31/31) was significantly greater than that of bone scan (38.7% = 12/31) (p < 0.01), and the specificity of bone PET (75.0% = 9/12) was also significantly higher than that of bone scan (8.3% = 1/12) (p < 0.05). The receiver operating characteristic curve analysis showed that bone PET was significantly more accurate than the bone scan in the patient (p = 0.0306) and lesion (p = 0.0001) based analyses. Conclusion Na18F bone PET is more accurate than bone scan for BM evaluation. PMID:23690722

  3. Limb bone morphology, bone strength, and cursoriality in lagomorphs.

    PubMed

    Young, Jesse W; Danczak, Robert; Russo, Gabrielle A; Fellmann, Connie D

    2014-10-01

    The primary aim of this study is to broadly evaluate the relationship between cursoriality (i.e. anatomical and physiological specialization for running) and limb bone morphology in lagomorphs. Relative to most previous studies of cursoriality, our focus on a size-restricted, taxonomically narrow group of mammals permits us to evaluate the degree to which 'cursorial specialization' affects locomotor anatomy independently of broader allometric and phylogenetic trends that might obscure such a relationship. We collected linear morphometrics and ?CT data on 737 limb bones covering three lagomorph species that differ in degree of cursoriality: pikas (Ochotona princeps, non-cursorial), jackrabbits (Lepus californicus, highly cursorial), and rabbits (Sylvilagus bachmani, level of cursoriality intermediate between pikas and jackrabbits). We evaluated two hypotheses: cursoriality should be associated with (i) lower limb joint mechanical advantage (i.e. high 'displacement advantage', permitting more cursorial species to cycle their limbs more quickly) and (ii) longer, more gracile limb bones, particularly at the distal segments (as a means of decreasing rotational inertia). As predicted, highly cursorial jackrabbits are typically marked by the lowest mechanical advantage and the longest distal segments, non-cursorial pikas display the highest mechanical advantage and the shortest distal segments, and rabbits generally display intermediate values for these variables. Variation in long bone robusticity followed a proximodistal gradient. Whereas proximal limb bone robusticity declined with cursoriality, distal limb bone robusticity generally remained constant across the three species. The association between long, structurally gracile limb bones and decreased maximal bending strength suggests that the more cursorial lagomorphs compromise proximal limb bone integrity to improve locomotor economy. In contrast, the integrity of distal limb bones is maintained with increasing cursoriality, suggesting that the safety factor takes priority over locomotor economy in those regions of the postcranial skeleton that experience higher loading during locomotion. Overall, these findings support the hypothesis that cursoriality is associated with a common suite of morphological adaptations across a range of body sizes and radiations. PMID:25046350

  4. [Glucocorticoid and bone].

    PubMed

    Soen, Satoshi

    2014-06-01

    Oral glucocorticoids are prescribed for a wide variety of medical disorders. Reduced bone formation is the key process in glucocorticoid-induced osteoporosis. Glucocorticoid-induced osteoporosis is characterized by relative dissociation between the BMD values and the fracture risk, which is higher than expected based on the BMD values. 2014 revised Japanese guidelines indicated that Age, GC dose, lumbar BMD, and prior fragility fractures were identified as factors predicting future fracture and each factor was scored according to the category. Since an age of 65 years or older, prednisolone dose of 7.5mg/day or more, and a history of fragility fracture are independent risk for future fractures, initiation of drug therapy can be decided more easily without evaluation of BMD by DXA when one of these risk factors exists. Alendronate and risedronate were recommended as first-line treatment and teriparatide (rDNA origin) , ibandronate, alfacalcidol and calcitriol were recommended as alternative option. PMID:24870833

  5. Living Bones, Strong Bones - Duration: 3 minutes, 41 seconds.

    NASA Video Gallery

    In this classroom activity, engineering, nutrition, and physical activity collide when students design and build a healthy bone model of a space explorer which is strong enough to withstand increas...

  6. Pharmacological agents and bone healing

    PubMed Central

    Tarantino, Umberto; Cerocchi, Irene; Celi, Monica; Scialdoni, Alessandro; Saturnino, Luca; Gasbarra, Elena

    2009-01-01

    Osteoporosis is the most common alteration of bone metabolism. It derives from an increase in bone resorption with respect to bone formation and is characterized by microarchitectural alterations, decreased bone mass and increased risk of fracture. The coupling between bone formation and resorption is a fundamental concept in skeletal metabolism, and it explains how a certain amount of removed tissue can be replaced by the same amount of new bone. Various substances used to treat osteoporosis may also be used for orthopaedic conditions such as fracture healing, implant fixation, bone grafts and osteonecrosis. Fracture healing consists in the replacement of the lost bone by a tissue that has the same biomechanical properties as those preceding the fracture. The repair process is triggered by the local response to the tissue injury that damaged the continuity of bone. The duration of each phase of the healing process can vary significantly, depending on the site and characteristics of the fracture, on patient related factors and on the treatment choice. While most of the fractures heal with conventional treatment, they can also cause permanent damage and complications, especially in a certain kind of patients. Osteoporosis and old age may contribute in delaying or impairing the reparative process. In animal models the healing process is slower in older and/or ovariectomized animals. Biomechanical tests have also shown that bone strength is compromised in human osteoporotic cadaver bone. The same problems were highlighted in the surgical treatment of fractures in osteoporotic patients. Mainly in the treatment of hip fractures there is an increased risk of cut-out, re-fractures and implant failure in patients with osteoporosis. Preclinical studies have shown that certain pharmacological agents (bisphosphonates, strontium ranelate, teriparatide) may enhance osseointegration and stimulate reparative processes. They may be administered systemically and/or used locally at the fracture site on the implant surface. The aim of fracture treatment is to restore bone biomechanical properties and to allow restoring normal function at the affected site. If the new pharmacological approaches could be translated into clinical benefit and offered to patients with osteoporosis or other factors that put at risk the process of healing (subjects with severe loss of substance or fractures at high risk of complications), they could represent a valuable aid in the treatment of fractures. PMID:22461164

  7. Raman Assessment of Bone Quality

    Microsoft Academic Search

    Michael D. Morris; Gurjit S. Mandair

    Background  Progress in the diagnosis and prediction of fragility fractures depends on improvements to the understating of the compositional\\u000a contributors of bone quality to mechanical competence. Raman spectroscopy has been used to evaluate alterations to bone composition\\u000a associated with aging, disease, or injury.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  In this survey we will (1) review the use of Raman-based compositional measures of bone quality, including mineral-to-matrix

  8. Novel Adipokines and Bone Metabolism

    PubMed Central

    Liu, Yuan; Song, Cheng-Yuan; Wu, Shan-Shan; Liang, Qiu-Hua; Yuan, Ling-Qing; Liao, Er-Yuan

    2013-01-01

    Osteoporosis is a serious social issue nowadays. Both the high morbidity and its common complication osteoporotic fracture load a heavy burden on the whole society. The adipose tissue is the biggest endocrinology organ that has a different function on the bone. The adipocytes are differentiated from the same cell lineage with osteoblast, and they can secrete multiple adipokines with various functions on bone remolding. Recently, several novel adipokines have been identified and investigated thoroughly. In this paper, we would like to highlight the complicated relation between the bone metabolism and the novel adipokines, and it may provide us with a new target for prediction and treatment of osteoporosis. PMID:23431296

  9. Chondrosarcoma of the Temporal Bone and Otosclerosis

    Microsoft Academic Search

    R. Ramírez-Camacho; M. Pinilla; S. Ramón y Cajal; J. R. García Berrocal; J. Vicente

    1998-01-01

    Chondrosarcoma constitutes 6% of all primary bone tumors and 11% of malignant primary bone tumors. Nevertheless, in a review of the tumor registry of the University of Michigan covering a period of 50 years, there were only 3 cases involving the temporal bone. A case of a woman with a chondrosarcoma of the temporal bone that was partially resected by

  10. Role of carotenoid ?-cryptoxanthin in bone homeostasis

    PubMed Central

    2012-01-01

    Bone homeostasis is maintained through a balance between osteoblastic bone formation and osteoclastic bone resorption. Aging induces bone loss due to decreased osteoblastic bone formation and increased osteoclastic bone resorption. Osteoporosis with its accompanying decrease in bone mass is widely recognized as a major public health problem. Nutritional factors may play a role in the prevention of bone loss with aging. Among various carotenoids (carotene and xanthophylls including beta (?)-cryptoxanthin, lutein, lycopene, ?-carotene, astaxanthin, and rutin), ?-cryptoxanthin, which is abundant in Satsuma mandarin orange (Citrus unshiu MARC.), has been found to have a stimulatory effect on bone calcification in vitro. ?-cryptoxanthin has stimulatory effects on osteoblastic bone formation and inhibitory effects on osteoclastic bone resorption in vitro, thereby increasing bone mass. ?-cryptoxanthin has an effect on the gene expression of various proteins that are related osteoblastic bone formation and osteoclastic bone resororption in vitro. The intake of ?-cryptoxanthin may have a preventive effect on bone loss in animal models for osteoporosis and in healthy human or postmenopausal women. Epidemiological studies suggest a potential role of ?-cryptoxanthin as a sustainable nutritional approach to improving bone health of human subjects. ?-Cryptoxanthin may be an osteogenic factor in preventing osteoporosis in human subjects. PMID:22471523

  11. A biomechanical perspective on bone quality

    PubMed Central

    Hernandez, C.J.; Keaveny, T.M

    2007-01-01

    Observations that dual-energy x-ray absorptiometry (DXA) measures of areal bone mineral density cannot completely explain fracture incidence after anti-resorptive treatment have led to renewed interest in bone quality. Bone quality is a vague term, but generally refers to the effects of skeletal factors that contribute to bone strength but are not accounted for by measures of bone mass. Since a clinical fracture is ultimately a mechanical event, it follows then that any clinically relevant modification of bone quality must change bone biomechanical performance relative to bone mass. In this perspective, we discuss a framework for assessing the clinically relevant effects of bone quality based on two general concepts: 1) the biomechanical effects of bone quality can be quantified from analysis of the relationship between bone mechanical performance and bone density; and 2) because of its hierarchical nature, biomechanical testing of bone at different physical scales (<1mm, 1mm, 1 cm, etc.) can be used to isolate the scale at which the most clinically relevant changes in bone quality occur. As an example, we review data regarding the relationship between the strength and density in excised specimens of trabecular bone and highlight the fact that it is not yet clear how this relationship changes during aging, osteoporosis development, and anti-resorptive treatment. Further study of new and existing data using this framework should provide insight into the role of bone quality in osteoporotic fracture risk. PMID:16876493

  12. Mechanical regulation of localized and appositional bone formation around bone-interfacing implants

    E-print Network

    Simmons, Craig A.

    INTRODUCTION The clinical success of bone-interfacing implants for orthopedic and dental applicationsMechanical regulation of localized and appositional bone formation around bone-interfacing implants: The local mechanical environment around bone- interfacing implants determines, in large part, whether bone

  13. Printing bone : the application of 3D fiber deposition for bone tissue engineering

    Microsoft Academic Search

    N. E. Fedorovich

    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. Application of large bone grafts in the operation room is not a clinical reality yet due

  14. Heterotrophic bone formation with bone marrow in the kidney parenchyme

    Microsoft Academic Search

    Mi Mi Oh; Je Jong Kim; Seok Ho Kang; Hong Seok Park; Du Geon Moon; Jae Hyun Bae

    2010-01-01

    Extraosseous metaplasia of the urinary tract is an uncommon condition first described in 1923 by Phemister. Bone formation\\u000a can occur anywhere along the urinary tract but most has been described in renal pelvis, calyx or along the urothelial layer.\\u000a We report a case of extraossesous bone formation within the kidney parenchyma appearing as a calcified multiseptated mass.

  15. Bone tissue engineering with human stem cells

    Microsoft Academic Search

    Darja Marolt; Miomir Knezevic; Gordana Vunjak Novakovic

    2010-01-01

    Treatment of extensive bone defects requires autologous bone grafting or implantation of bone substitute materials. An attractive\\u000a alternative has been to engineer fully viable, biological bone grafts in vitro by culturing osteogenic cells within three-dimensional scaffolds, under conditions supporting bone formation. Such grafts\\u000a could be used for implantation, but also as physiologically relevant models in basic and translational studies of

  16. Bone tissue engineering using marrow stromal cells

    Microsoft Academic Search

    Inho Jo; Jung Min Lee; Hwal Suh; Hyongbum Kim

    2007-01-01

    Bone tissue defects cause a significant socioeconomic problem, and bone is the most frequently transplanted tissue beside\\u000a blood. Autografting is considered the gold standard treatment for bone defects, but its utility is limited due to donor site\\u000a morbidity. Hence much research has focused on bone tissue engineering as a promising alternative method for repair of bone\\u000a defects. Marrow stromal cells

  17. Bone morphogenic protein: application in implant dentistry.

    PubMed

    Bowler, Dustin; Dym, Harry

    2015-04-01

    Alveolar bone that is insufficient to support implant placement due to lack of height or width may be augmented with grafting materials including bone morphogenic protein to create sites that are adequate for implant placement and long-term stability of implant-supported prosthesis. Bone morphogenic protein can be used alone or in concert with other bone graft materials as an alternative to invasive allograft bone harvesting procedures. PMID:25835805

  18. Flavonoid Intake and Bone Health

    PubMed Central

    Weaver, Connie M.; Alekel, D. Lee; Ward, Wendy E.; Ronis, Martin J.

    2014-01-01

    Flavonoids, found in a wide diversity of plant foods from fruits and vegetables, herbs and spices, essential oils, and beverages, have the most potential of dietary components for promotion of bone health beyond calcium and vitamin D. Recent epidemiological studies show flavonoid consumption to have a stronger association with bone than general fruit and vegetable consumption. Bioactive flavonoids are being assessed for properties beyond their chemical anti-oxidant capacity, including anti-inflammatory actions. Some have been reported to enhance bone formation and to inhibit bone resorption through their action on cell signaling pathways that influence osteoblast and osteoclast differentiation. Future research is needed to determine which of the flavonoids and their metabolites are most effective and at what dose, as well as the mechanism of modulating cellular events, in order to set priorities for clinical trials. PMID:22888840

  19. Exercise, lifestyle, and your bones

    MedlinePLUS

    ... pull on your bones. These are called weight-bearing exercises. Some of them are: Brisk walks, jogging, playing tennis, dancing, or other weight-bearing activities such as aerobics and other sports Careful ...

  20. Inherited Bone Marrow Failure Syndromes

    MedlinePLUS

    What are the IBMFS disorders? Amegakaryocytic Thrombocytopenia Diamond-Blackfan Anemia Dyskeratosis Congenita Fanconi Anemia Pearson Syndrome Severe Congenital Neutropenia Shwachman-Diamond Syndrome Thrombocytopenia Absent Radii Other Bone Marrow Failure Syndromes Amegakaryocytic ...

  1. Inhaled Corticosteroids and Bone Health

    PubMed Central

    Chee, Carolyn; Sellahewa, Luckni; Pappachan, Joseph M

    2014-01-01

    Inhaled corticosteroids (ICS) are the cornerstones in the management of bronchial asthma and some cases of chronic obstructive pulmonary disease. Although ICS are claimed to have low side effect profiles, at high doses they can cause systemic adverse effects including bone diseases such as osteopenia, osteoporosis and osteonecrosis. Corticosteroids have detrimental effects on function and survival of osteoblasts and osteocytes, and with the prolongation of osteoclast survival, induce metabolic bone disease. Glucocorticoid-induced osteoporosis (GIO) can be associated with major complications such as vertebral and neck of femur fractures. The American College of Rheumatology (ACR) published criteria in 2010 for the management of GIO. ACR recommends bisphosphonates along with calcium and vitamin D supplements as the first-line agents for GIO management. ACR recommendations can be applied to manage patients on ICS with a high risk of developing metabolic bone disease. This review outlines the mechanisms and management of ICS-induced bone disease. PMID:25674178

  2. Bone fracture repair - series (image)

    MedlinePLUS

    ... three main treatment options for bone fractures are: Casting Open reduction, and internal fixation- this involves a ... fractures not able to be realigned (reduced) by casting, or in cases in which the long-term ...

  3. Bone Grafting the Cleft Maxilla

    MedlinePLUS

    ... graft; 2) prosthetic replacement (dental bridge); or 3) dental metallic bone implants. The best option for an individual patient is best decided by the dental specialists on the cleft palate team. (See Replacing ...

  4. Drugs Approved for Bone Cancer

    Cancer.gov

    This page lists cancer drugs approved by the Food and Drug Administration (FDA) for bone cancer. The list includes generic names and brand names. The drug names link to NCI's Cancer Drug Information summaries.

  5. Inhaled corticosteroids and bone health.

    PubMed

    Chee, Carolyn; Sellahewa, Luckni; Pappachan, Joseph M

    2014-01-01

    Inhaled corticosteroids (ICS) are the cornerstones in the management of bronchial asthma and some cases of chronic obstructive pulmonary disease. Although ICS are claimed to have low side effect profiles, at high doses they can cause systemic adverse effects including bone diseases such as osteopenia, osteoporosis and osteonecrosis. Corticosteroids have detrimental effects on function and survival of osteoblasts and osteocytes, and with the prolongation of osteoclast survival, induce metabolic bone disease. Glucocorticoid-induced osteoporosis (GIO) can be associated with major complications such as vertebral and neck of femur fractures. The American College of Rheumatology (ACR) published criteria in 2010 for the management of GIO. ACR recommends bisphosphonates along with calcium and vitamin D supplements as the first-line agents for GIO management. ACR recommendations can be applied to manage patients on ICS with a high risk of developing metabolic bone disease. This review outlines the mechanisms and management of ICS-induced bone disease. PMID:25674178

  6. Bare Bones of Bioactive Glass

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Paul Ducheyne, a principal investigator in the microgravity materials science program and head of the University of Pernsylvania's Center for Bioactive Materials and Tissue Engineering, is leading the trio as they use simulated microgravity to determine the optimal characteristics of tiny glass particles for growing bone tissue. The result could make possible a much broader range of synthetic bone-grafting applications. Bioactive glass particles (left) with a microporous surface (right) are widely accepted as a synthetic material for periodontal procedures. Using the particles to grow three-dimensional tissue cultures may one day result in developing an improved, more rugged bone tissue that may be used to correct skeletal disorders and bone defects. The work is sponsored by NASA's Office of Biological and Physical Research.

  7. Pregnancy, Breastfeeding, and Bone Health

    MedlinePLUS

    ... supported by your browser. Home Osteoporosis Women Pregnancy, Breastfeeding, and Bone Health Publication available in: PDF (233 ... Anorexia Nervosa Partner Resources An Easy Guide to Breastfeeding (OWH) Pregnancy and Medications (OWH) Prenatal Care (OWH)

  8. Does methamphetamine affect bone metabolism?

    PubMed

    Tomita, Masafumi; Katsuyama, Hironobu; Watanabe, Yoko; Okuyama, Toshiko; Fushimi, Shigeko; Ishikawa, Takaki; Nata, Masayuki; Miyamoto, Osamu

    2014-05-01

    There is a close relationship between the central nervous system activity and bone metabolism. Therefore, methamphetamine (METH), which stimulates the central nervous system, is expected to affect bone turnover. The aim of this study was to investigate the role of METH in bone metabolism. Mice were divided into 3 groups, the control group receiving saline injections, and the 5 and 10mg/kg METH groups (n=6 in each group). All groups received an injection of saline or METH every other day for 8 weeks. Bone mineral density (BMD) was assessed by X-ray computed tomography. We examined biochemical markers and histomorphometric changes in the second cancellous bone of the left femoral distal end. The animals that were administered 5mg/kg METH showed an increased locomotor activity, whereas those receiving 10mg/kg displayed an abnormal and stereotyped behavior. Serum calcium and phosphorus concentrations were normal compared to the controls, whereas the serum protein concentration was lower in the METH groups. BMD was unchanged in all groups. Bone formation markers such as alkaline phosphatase and osteocalcin significantly increased in the 5mg/kg METH group, but not in the 10mg/kg METH group. In contrast, bone resorption markers such as C-terminal telopeptides of type I collagen and tartrate-resistant acid phosphatase 5b did not change in any of the METH groups. Histomorphometric analyses were consistent with the biochemical markers data. A significant increase in osteoblasts, especially in type III osteoblasts, was observed in the 5mg/kg METH group, whereas other parameters of bone resorption and mineralization remained unchanged. These results indicate that bone remodeling in this group was unbalanced. In contrast, in the 10mg/kg METH group, some parameters of bone formation were significantly or slightly decreased, suggesting a low turnover metabolism. Taken together, our results suggest that METH had distinct dose-dependent effects on bone turnover and that METH might induce adverse effects, leading to osteoporosis. PMID:24582730

  9. VersaBond bone cement

    Microsoft Academic Search

    Tore Dalén; Kjell G. Nilsson

    2005-01-01

    VersaBond is a newly developed bone cement. To investigate its clinical performance, VersaBond was compared to Palacos R in a prospective randomized study in total knee replacement. Fifty-nine patients (61 knees) undergoing total knee replacement were randomized to either VersaBond or Palacos R bone cement and followed for 24 months using radiostereometric analysis (RSA).Up to 2 years there were no

  10. Unsuspected pregnancy during bone scintigraphy

    SciTech Connect

    Oates, E.; Ramberg, K.; Becker, J.L. (Tufts-New England Medical Center, Boston, MA (USA))

    1990-06-01

    Despite careful screening efforts to avoid it, nuclear medicine studies are unintentionally performed on pregnant patients. Three-phase bone scanning is a common procedure performed in women of child-bearing age. Unsuspected pregnancies have been discovered on the flow and early view of the pelvis. The authors present a case of a pregnant girl, aged 15, who had a bone scan. They explain how this occurred and how they plan to prevent a recurrence. Dosimetry for the fetus also is considered.

  11. Bone Metastasis and Pathological Fractures

    Microsoft Academic Search

    Laurie A. McDuffee; Nigel Colterjohn; Gurmit Singh

    Bone metastasis commonly occurs in association with solid malignant tumors such as breast, prostate, lung, and renal cancers\\u000a (1–5). Thirty to seventy percent of cancer patients have skeletal metastasis (6), making the axial skeleton the third most common site for metastasis after lung and liver. Because all of these cancers\\u000a (breast, prostate, lung, and renal) are common, metastatic bone lesions

  12. Parathyroid hormone and bone biomechanics

    Microsoft Academic Search

    Matthew R. Allen; David B. Burr

    2006-01-01

    Parathyroid hormone (PTH) treatment, either in the form of teriparatide or recombinant human PTH(1–34), reduces the fracture\\u000a risk of osteoporotic women by enhancing both structural and material biomechanical properties. Cortical bone thickness and\\u000a cross-sectional moment of inertia increase because of new bone formation on periosteal and endocortical surfaces. Intracortical\\u000a porosity is increased yet preferential localization near the endocortical surface limits

  13. Bone Diseases of the Jaws

    PubMed Central

    Slootweg, Pieter Johannes

    2010-01-01

    Lesions specific for the jaws and not occurring in any other bones mostly are related to the teeth or to odontogenic tissues. Moreover, the jaws may harbor nonodontogenic bone lesions not seen in any other part of the skeleton. This paper pays attention to the diseases that are specific for the jaws, odontogenic as well as nonodontogenic. Both neoplastic and nonneoplastic entities will be discussed. PMID:20379356

  14. Bone diseases of the jaws.

    PubMed

    Slootweg, Pieter Johannes

    2010-01-01

    Lesions specific for the jaws and not occurring in any other bones mostly are related to the teeth or to odontogenic tissues. Moreover, the jaws may harbor nonodontogenic bone lesions not seen in any other part of the skeleton. This paper pays attention to the diseases that are specific for the jaws, odontogenic as well as nonodontogenic. Both neoplastic and nonneoplastic entities will be discussed. PMID:20379356

  15. Comparable bone healing capacity of different bone graft matrices in a rabbit segmental defect model

    PubMed Central

    Kim, Jong Min; Kim, Myoung Hwan; Kang, Seong Soo; Kim, Gonhyung

    2014-01-01

    We compared the bone healing capacity of three different demineralized bone matrix (DBM) products applied using different carrier molecules (hyaluronic acid [HA] vs. carboxymethylcellulose [CMC]) or bone compositions (cortical bone vs. cortical bone and cancellous bone) in a rabbit segmental defect model. Overall, 15-mm segmental defects in the left and right radiuses were created in 36 New Zealand White rabbits and filled with HA-based demineralized cortical bone matrix (DBX), CMC-based demineralized cortical bone matrix (DB) or CMC-based demineralized cortical bone with cancellous bone (NDDB), and the wound area was evaluated at 4, 8, and 12 weeks post-implantation. DBX showed significantly lower radiopacity, bone volume fraction, and bone mineral density than DB and NDDB before implantation. However, bone healing score, bone volume fraction, bone mineral density, and residual bone area at 4, 8, and 12 weeks post-implantation revealed no significant differences in bone healing capacity. Overall, three DBM products with different carrier molecules or bone compositions showed similar bone healing capacity. PMID:24675830

  16. [Fetal bone and joint disorders].

    PubMed

    Jakobovits, Akos

    2008-12-21

    The article discusses the physiology and pathology of fetal bone and joint development and functions. The bones provide static support for the body. The skull and the bones of spinal column encase the central and part of the peripheral nervous system. The ribs and the sternum shield the heart and the lungs, while the bones of the pelvis protect the intraabdominal organs. Pathological changes of these bony structures may impair the functions of the respective systems or internal organs. Movements of the bones are brought about by muscles. The deriving motions are facilitated by joints. Bony anomalies of the extremities limit their effective functions. Apart from skeletal and joint abnormalities, akinesia may also be caused by neurological, muscular and skin diseases that secondarily affect the functions of bones and joints. Such pathological changes may lead to various degrees of physical disability and even to death. Some of the mentioned anomalies are recognizable in utero by ultrasound. The diagnosis may serve as medical indication for abortion in those instances when the identified abnormality is incompatible with independent life. PMID:19073454

  17. Infection, Inflammation, and Bone Regeneration

    PubMed Central

    Thomas, M.V.; Puleo, D.A.

    2011-01-01

    Various strategies have been developed to promote bone regeneration in the craniofacial region. Most of these interventions utilize implantable materials or devices. Infections resulting from colonization of these implants may result in local tissue destruction in a manner analogous to periodontitis. This destruction is mediated via the expression of various inflammatory mediators and tissue-destructive enzymes. Given the well-documented association among microbial biofilms, inflammatory mediators, and tissue destruction, it seems reasonable to assume that inflammation may interfere with bone healing and regeneration. Paradoxically, recent evidence also suggests that the presence of certain pro-inflammatory mediators is actually required for bone healing. Bone injury (e.g., subsequent to a fracture or surgical intervention) is followed by a choreographed cascade of events, some of which are dependent upon the presence of pro-inflammatory mediators. If inflammation resolves promptly, then proper bone healing may occur. However, if inflammation persists (which might occur in the presence of an infected implant or graft material), then the continued inflammatory response may result in suboptimal bone formation. Thus, the effect of a given mediator is dependent upon the temporal context in which it is expressed. Better understanding of this temporal sequence may be used to optimize regenerative outcomes. PMID:21248364

  18. Multicentric epithelioid angiosarcoma of bone.

    PubMed

    Yang, Zhengming; Tao, Huimin; Ye, Zhaoming; Yang, Disheng

    2012-08-01

    Bone epithelioid angiosarcoma is rare and generally shows positive immunostaining for epithelial markers. Multicentric bone epithelioid angiosarcoma is easily misdiagnosed as carcinoma, including metastatic carcinoma, multiple myeloma, and multiple lymphoma of bone. This article describes a case of multicentric bone epithelioid angiosarcoma. The patient was first misdiagnosed as having metastatic carcinoma. Examination showed osteolytic lesions in the bilateral heels and the lower left humerus. The diagnosis was confirmed postoperatively and corrected after immunohistochemical analysis of the biopsy. The immunohistochemical analysis revealed that the tumor mass was strongly positive for CD31, factor VIII, vimentin, and neuron-specific enolase. The patient refused chemotherapy and died of lung metastasis 4 months postoperatively.Most bone epithelioid angiosarcomas are immunopositive for epithelial markers (ie, keratin, cytokeratin, high-molecular-weight keratin, and epithelial membrane antigen), vascular endothelial markers (ie, CD31, CD34, and von Willebrand factor), and factor VIII-associated antigen. Bone epithelioid angiosarcoma shows a relatively high degree of malignancy. Patients often die of distant metastasis, including those found in the lung and lymph node tissue. A wide excision of epithelioid angiosarcoma should be performed during the operation of the primary tumor. A better understanding of the clinicopathologic features of this disease may help to clarify the confusion, provide better treatment, and improve the clinical prognosis. PMID:22868625

  19. Bone culture research

    NASA Technical Reports Server (NTRS)

    Partridge, Nicola C.

    1993-01-01

    The experiments described are aimed at exploring PTH regulation of production of collagenase and protein inhibitors of collagenase (tissue inhibitors of metalloproteases, TIMP-1 and -2) by osteoblast-like osteosarcoma cells under conditions of weightlessness. The results of this work will contribute to information as to whether a microgravity environment alters the functions and responsiveness of the osteoblast. The objectives of the Bone Culture Research (BCR) experiment are: to observe the effects of microgravity on the morphology, rate of proliferation, and behavior of the osteoblastic cells, UMR 106-01; to determine whether microgravy affects the hormonal sensitivity of osteroblastic cells; and to measure the secretion of collagenase and its inhibitors into the medium under conditions of microgravity. The methods employed will consist of the following: the osteoblast-like cells, UMR-106-01, will be cultured in four NASDA cell culture chambers; two chambers will be subjected to microgravity on SL-J; two chambers will remain on the ground at KSC as ground controls but subjected to an identical set of culture conditions as on the shuttle; media will be changed four times; twice the cells will receive the hormone parathyroid hormone-related protein (PTHrP) and media collected; cells will be photographed under conditions of microgravity; and media and photographs will be analyzed upon return to determine whether functions of the cells changed.

  20. Bone regeneration in sinus lifts: comparing tissue-engineered bone and iliac bone

    Microsoft Academic Search

    Pit Voss; Sebastian Sauerbier; Margit Wiedmann-Al-Ahmad; Christoph Zizelmann; Andres Stricker; Rainer Schmelzeisen; Ralf Gutwald

    2010-01-01

    Lifting of the sinus floor is a standard procedure for bony augmentation that enables dental implantation. Although cultivated skin and mucosal grafts are often used in plastic and maxillofacial surgery, tissue-engineered bone has not achieved the same success. We present the clinical results of dental implants placed after the insertion of periosteum-derived, tissue-engineered bone grafts in sinus lifts. Periosteal cells

  1. Spine bone texture assessed by trabecular bone score (TBS) to evaluate bone health in thalassemia major.

    PubMed

    Baldini, M; Ulivieri, F M; Forti, S; Serafino, S; Seghezzi, S; Marcon, A; Giarda, F; Messina, C; Cassinerio, E; Aubry-Rozier, B; Hans, D; Cappellini, M D

    2014-12-01

    Due to the increasing survival of thalassemic patients, osteopathy is a mounting clinical problem. Low bone mass alone cannot account for the high fracture risk described; impaired bone quality has been speculated but so far it cannot be demonstrated noninvasively. We studied bone quality in thalassemia major using trabecular bone score (TBS), a novel texture measurement extracted from spine dual-energy X-ray absorptiometry (DXA), proposed in postmenopausal and secondary osteoporosis as an indirect index of microarchitecture. TBS was evaluated in 124 adult thalassemics (age range 19-56 years), followed-up with optimal transfusional and therapeutical regimens, and in 65 non-thalassemic patients (22-52 years) undergoing DXA for different bone diseases. TBS was lower in thalassemic patients (1.04 ± 0.12 [range 0.80-1.30]) versus controls (1.34 ± 0.11 [1.06-1.52]) (p < 0.001), and correlated with BMD. TBS and BMD values correlated with age, indicating that thalassemia negatively affects both bone quality and quantity, especially as the patient gets older. TBS was 1.02 ± 0.11 [0.80-1.28] in the osteoporotic thalassemic patients, 1.08 ± 0.12 [0.82-1.30] in the osteopenic ones and 1.15 ± 0.10 [0.96-1.26] in those with normal BMD. No gender differences were found (males: 1.02 ± 0.13 [0.80-1.30], females 1.05 ± 0.11 [0.80-1.30]), nor between patients with and without endocrine-metabolic disorders affecting bone metabolism. Our findings from a large population with thalassemia major show that TBS is a valuable tool to assess noninvasively bone quality, and it may be related to fragility fracture risk in thalassemic osteopathy. PMID:25348077

  2. Bone metastasis: mechanisms and therapeutic opportunities

    PubMed Central

    Suva, Larry J.; Washam, Charity; Nicholas, Richard W.; Griffin, Robert J.

    2011-01-01

    The skeleton is one of the most common sites for metastatic cancer, and tumors arising from the breast or prostate possess an increased propensity to spread to this site. The growth of disseminated tumor cells in the skeleton requires tumor cells to inhabit the bone marrow, from which they stimulate local bone cell activity. Crosstalk between tumor cells and resident bone and bone marrow cells disrupts normal bone homeostasis, which leads to tumor growth in bone. The metastatic tumor cells have the ability to elicit responses that stimulate bone resorption, bone formation or both. The net result of these activities is profound skeletal destruction that can have dire consequences for patients. The molecular mechanisms that underlie these painful and often incurable consequences of tumor metastasis to bone are beginning to be recognized, and they represent promising new molecular targets for therapy. PMID:21200394

  3. Bone anabolics in osteoporosis: Actuality and perspectives

    PubMed Central

    Montagnani, Andrea

    2014-01-01

    Vertebral and nonvertebral fractures prevention is the main goal for osteoporosis therapy by inhibiting bone resorption and/or stimulating bone formation. Antiresorptive drugs decrease the activation frequency, thereby determining a secondary decrease in bone formation rate and a low bone turnover. Bisphosphonates are today’s mainstay among antiresorptive treatment of osteoporosis. Also, oral selective estrogen receptor modulators and recently denosumab have a negative effect on bone turnover. Agents active on bone formation are considered a better perspective in the treatment of severe osteoporosis. Recombinant-human parathyroid hormone (PTH) has showed to increase bone formation and significantly decrease vertebral fractures in severe patients, but with a modest effect on nonvertebral fractures. The study of Wnt signaling pathway, that induces prevalently an osteoblastic activity, opens large possibilities to antagonists of Wnt-inhibitors, such as sclerostin antibodies and dickkopf-1 antagonists, with potential effects not only on trabecular bone but also on cortical bone. PMID:25035827

  4. Recent advances in bone tissue engineering scaffolds.

    PubMed

    Bose, Susmita; Roy, Mangal; Bandyopadhyay, Amit

    2012-10-01

    Bone disorders are of significant concern due to increase in the median age of our population. Traditionally, bone grafts have been used to restore damaged bone. Synthetic biomaterials are now being used as bone graft substitutes. These biomaterials were initially selected for structural restoration based on their biomechanical properties. Later scaffolds were engineered to be bioactive or bioresorbable to enhance tissue growth. Now scaffolds are designed to induce bone formation and vascularization. These scaffolds are often porous, made of biodegradable materials that harbor different growth factors, drugs, genes, or stem cells. In this review, we highlight recent advances in bone scaffolds and discuss aspects that still need to be improved. PMID:22939815

  5. Asceptic Necrosis of Bone in a Dog

    PubMed Central

    Doige, C. E.; Crowe, S.; Farrow, C. S.

    1986-01-01

    Necrosis of intramedullary bone and bone marrow elements is reported in the long bones of a dog. Radiographically lesions were evident as an irregular increase in intramedullary density. On gross postmortem examination necrotic tissue appeared as yellow-white deposits on the endosteal surface and in the medullary cavity. Microscopically, necrotic bone had empty lacunae and was often covered by basophilic, woven bone. The cause and pathogenesisof aseptic necrosis of bone are discussed. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7. PMID:17422625

  6. Methods for Assessing Bone Quality: A Review

    Microsoft Academic Search

    Eve Donnelly

    Background  Bone mass, geometry, and tissue material properties contribute to bone structural integrity. Thus, bone strength arises from\\u000a both bone quantity and quality. Bone quality encompasses the geometric and material factors that contribute to fracture resistance.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  This review presents an overview of the methods for assessing bone quality across multiple length scales, their outcomes,\\u000a and their relative advantages and disadvantages.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A

  7. Mechanisms of Guided Bone Regeneration: A Review

    PubMed Central

    Liu, Jie; Kerns, David G

    2014-01-01

    Post-extraction crestal bone resorption is common and unavoidable which can lead to significant ridge dimensional changes. To regenerate enough bone for successful implant placement, Guided Bone Regeneration (GBR) is often required. GBR is a surgical procedure that uses barrier membranes with or without particulate bone grafts or/and bone substitutes. There are two approaches of GBR in implant therapy: GBR at implant placement (simultaneous approach) and GBR before implant placement to increase the alveolar ridge or improve ridge morphology (staged approach). Angiogenesis and ample blood supply play a critical role in promoting bone regeneration. PMID:24894890

  8. Recent advances in bone tissue engineering scaffolds

    PubMed Central

    Bose, Susmita; Roy, Mangal; Bandyopadhyay, Amit

    2012-01-01

    Bone disorders are of significant concern due to increase in the median age of our population. Traditionally, bone grafts have been used to restore damaged bone. Synthetic biomaterials are now being used as bone graft substitutes. These biomaterials were initially selected for structural restoration based on their biomechanical properties. Later scaffolds were engineered to be bioactive or bioresorbable to enhance tissue growth. Now scaffolds are designed to induce bone formation and vascularization. These scaffolds are often porous, biodegradable materials that harbor different growth factors, drugs, genes or stem cells. In this review, we highlight recent advances in bone scaffolds and discuss aspects that still need to be improved. PMID:22939815

  9. Bone markers and their prognostic value in metastatic bone disease: Clinical evidence and future directions

    PubMed Central

    Coleman, Robert; Brown, Janet; Terpos, Evangelos; Lipton, Allan; Smith, Matthew R.; Cook, Richard; Major, Pierre

    2011-01-01

    Summary Background Bone metastases are prevalent among patients with advanced solid tumors. Metastatic bone disease alters bone homeostasis, resulting in reduced bone integrity and, consequently, increased skeletal complications. Biochemical markers of bone metabolism may meet an unmet need for useful, noninvasive, and sensitive surrogate information for following patients’ skeletal health. Materials and methods Data for this review were identified by searches of PubMed, and references from relevant articles using the search terms “bone markers” or individual bone marker nomenclature, “cancer,” and “metastases.” Abstracts and reports from meetings were included only when they related directly to previously published work. Only papers published in English between 1990 and 2007 were included. Results Recent retrospective analyses with bisphosphonates, and particularly with zoledronic acid, have shown significant correlations between biochemical markers of bone metabolism levels and clinical outcomes, especially for bone resorption markers. Clinical results for biochemical markers of bone formation and resorption and other emerging markers of bone metabolism including bone sialoprotein, receptor–activator of nuclear factor-?B ligand, osteoprotegerin, and other markers are presented. However, biochemical markers of bone metabolism are not yet an established surrogate endpoint for treatment efficacy. Conclusions Biochemical markers of bone metabolism may allow physicians to identify which patients with metastatic bone disease are at high risk for skeletal-related events or death and who may be responding to therapy. Prospective randomized clinical trials are underway to further assess the utility of markers of bone metabolism in patients with bone metastases. PMID:18579314

  10. Cellular Mechanisms of Multiple Myeloma Bone Disease

    PubMed Central

    Oranger, Angela; Carbone, Claudia; Izzo, Maddalena; Grano, Maria

    2013-01-01

    Multiple myeloma (MM) is a hematologic malignancy of differentiated plasma cells that accumulates and proliferates in the bone marrow. MM patients often develop bone disease that results in severe bone pain, osteolytic lesions, and pathologic fractures. These skeletal complications have not only a negative impact on quality of life but also a possible effect in overall survival. MM osteolytic bone lesions arise from the altered bone remodeling due to both increased osteoclast activation and decreased osteoblast differentiation. A dysregulated production of numerous cytokines that can contribute to the uncoupling of bone cell activity is well documented in the bone marrow microenvironment of MM patients. These molecules are produced not only by malignant plasma cells, that directly contribute to MM bone disease, but also by bone, immune, and stromal cells interacting with each other in the bone microenvironment. This review focuses on the current knowledge of MM bone disease biology, with particular regard on the role of bone and immune cells in producing cytokines critical for malignant plasma cell proliferation as well as in osteolysis development. Therefore, the understanding of MM pathogenesis could be useful to the discovery of novel agents that will be able to both restore bone remodelling and reduce tumor burden. PMID:23818912

  11. Wnt and Wnt inhibitors in bone metastasis

    PubMed Central

    Sottnik, Joseph L; Hall, Christopher L; Zhang, Jian; Keller, Evan T

    2012-01-01

    Bone metastasis is a clinically devastating development of progressive cancers including prostate carcinoma, breast carcinoma and multiple myeloma. Bone metastases are typically painful, lead to adverse skeletal-related events, such as fracture, and are highly resistant to therapy. A major contribution to the ability of cancers to successfully establish bone metastases is their ability to exploit mechanisms of normal bone remodeling. Wnts are a large family of morphogenic proteins that are critical for bone development and contribute to maintaining bone mass in the mature organism. Wnt function is balanced by the presence of a variety of endogenous inhibitors, such as the dickkopf family members, secreted frizzled related proteins and sclerostin. Together, these factors contribute to normal bone homeostasis, allowing for dynamic changes in bone to withstand alterations in physical forces and physiological needs. In this review, we describe the role that Wnts and their inhibitors have in normal bone biology and cancer-related bone pathology. An overview of Wnt signaling pathways is discussed and key bone microenvironment cellular players, as they pertain to Wnt biology, are examined. Finally, we describe clinical trials of several Wnt inhibitor antagonists for patients with tumor-related bone disease. As few options currently exist for the treatment of bone-metastatic disease, Wnt proteins and their inhibitors offer promise for the development of novel therapeutics. PMID:23951488

  12. BIOLOGICAL FRAMEWORKS FOR ENGINEERS Session #23 [m: Bone System

    E-print Network

    Sniadecki, Nathan J.

    on microstructural architecture Composite material that is self-healing Central Framework: Bone contains a great storage- (Cell Factory)- #12;ME411/511 III. Composition of Bone a. Cortical Bone b. Trabecular Bone IV

  13. Using Micro-CT Derived Bone Microarchitecture to Analyze Bone Stiffness - A Case Study on Osteoporosis Rat Bone.

    PubMed

    Wu, Yuchin; Adeeb, Samer; Doschak, Michael R

    2015-01-01

    Micro-computed tomography (Micro-CT) images can be used to quantitatively represent bone geometry through a range of computed attenuation-based parameters. Nonetheless, those parameters remain indirect indices of bone microarchitectural strength and require further computational tools to interpret bone structural stiffness and potential for mechanical failure. Finite element analysis (FEA) can be applied to measure trabecular bone stiffness and potentially predict the location of structural failure in preclinical animal models of osteoporosis, although that procedure from image segmentation of Micro-CT derived bone geometry to FEA is often challenging and computationally expensive, resulting in failure of the model to build. Notably, the selection of resolution and threshold for bone segmentation are key steps that greatly affect computational complexity and validity. In the following study, we evaluated an approach whereby Micro-CT derived grayscale attenuation and segmentation data guided the selection of trabecular bone for analysis by FEA. We further correlated those FEA results to both two- and three-dimensional bone microarchitecture from sham and ovariectomized (OVX) rats (n?=?10/group). A virtual cylinder of vertebral trabecular bone 40% in length from the caudal side was selected for FEA, because Micro-CT based image analysis indicated the largest differences in microarchitecture between the two groups resided there. Bone stiffness was calculated using FEA and statistically correlated with the three-dimensional values of bone volume/tissue volume, bone mineral density, fractal dimension, trabecular separation, and trabecular bone pattern factor. Our method simplified the process for the assessment of trabecular bone stiffness by FEA from Micro-CT images and highlighted the importance of bone microarchitecture in conferring significantly increased bone quality capable of resisting failure due to increased mechanical loading. PMID:26042089

  14. Using Micro-CT Derived Bone Microarchitecture to Analyze Bone Stiffness – A Case Study on Osteoporosis Rat Bone

    PubMed Central

    Wu, Yuchin; Adeeb, Samer; Doschak, Michael R.

    2015-01-01

    Micro-computed tomography (Micro-CT) images can be used to quantitatively represent bone geometry through a range of computed attenuation-based parameters. Nonetheless, those parameters remain indirect indices of bone microarchitectural strength and require further computational tools to interpret bone structural stiffness and potential for mechanical failure. Finite element analysis (FEA) can be applied to measure trabecular bone stiffness and potentially predict the location of structural failure in preclinical animal models of osteoporosis, although that procedure from image segmentation of Micro-CT derived bone geometry to FEA is often challenging and computationally expensive, resulting in failure of the model to build. Notably, the selection of resolution and threshold for bone segmentation are key steps that greatly affect computational complexity and validity. In the following study, we evaluated an approach whereby Micro-CT derived grayscale attenuation and segmentation data guided the selection of trabecular bone for analysis by FEA. We further correlated those FEA results to both two- and three-dimensional bone microarchitecture from sham and ovariectomized (OVX) rats (n?=?10/group). A virtual cylinder of vertebral trabecular bone 40% in length from the caudal side was selected for FEA, because Micro-CT based image analysis indicated the largest differences in microarchitecture between the two groups resided there. Bone stiffness was calculated using FEA and statistically correlated with the three-dimensional values of bone volume/tissue volume, bone mineral density, fractal dimension, trabecular separation, and trabecular bone pattern factor. Our method simplified the process for the assessment of trabecular bone stiffness by FEA from Micro-CT images and highlighted the importance of bone microarchitecture in conferring significantly increased bone quality capable of resisting failure due to increased mechanical loading. PMID:26042089

  15. Bone alterations associated with HIV.

    PubMed

    Warriner, Amy H; Mugavero, Michael; Overton, E Turner

    2014-09-01

    HIV infection and initiation of antiretroviral therapy (ART) have been consistently associated with decreased bone mineral density (BMD), with growing evidence linking HIV to an increased risk of fracture. This is especially concerning with the expanding number of older persons living with HIV. Interestingly, recent data suggest that HIV-infected children and youth fail to achieve peak BMD, possibly increasing their lifetime risk of fracture. Elucidating the causes of the bone changes in HIV-positive persons is challenging because of the multifactorial nature of bone disease in HIV, including contribution of the virus, immunosuppression, ART toxicity, and traditional osteoporosis risk factors, such as age, lower weight, tobacco, and alcohol use. Thus, practitioners must recognize the risk of low BMD and fractures and appropriately screen patients for osteoporosis if risk factors exist. If fractures do occur or elevated fracture risk is detected through screening, treatment with bisphosphonate medications appears safe and effective in the HIV+population. PMID:25064454

  16. Noninvasive imaging of bone microarchitecture

    PubMed Central

    Patsch, Janina M.; Burghardt, Andrew J.; Kazakia, Galateia; Majumdar, Sharmila

    2015-01-01

    The noninvasive quantification of peripheral compartment-specific bone microarchitecture is feasible with high-resolution peripheral quantitative computed tomography (HR-pQCT) and high-resolution magnetic resonance imaging (HR-MRI). In addition to classic morphometric indices, both techniques provide a suitable basis for virtual biomechanical testing using finite element (FE) analyses. Methodical limitations, morphometric parameter definition, and motion artifacts have to be considered to achieve optimal data interpretation from imaging studies. With increasing availability of in vivo high-resolution bone imaging techniques, special emphasis should be put on quality control including multicenter, cross-site validations. Importantly, conclusions from interventional studies investigating the effects of antiosteoporotic drugs on bone microarchitecture should be drawn with care, ideally involving imaging scientists, translational researchers, and clinicians. PMID:22172043

  17. Bone Builders: The Discoveries Behind Preventing and Treating Osteoporosis

    NSDL National Science Digital Library

    Margie Patlak (Federation of American Societies for Experimental Biology Office of Public Affairs)

    2001-08-01

    FASEB Breakthroughs in Bioscience article. Every year, more than 800,000 people in the United States receive bone biomaterials, including bone grafts and bone graft substitutes. Bone is the most commonly transplanted tissue after blood transfusions. Unlike most tissues, bone is able to regenerate and reform without scarring, given the proper conditions and materials. Researchers and scientists have learned to exploit this property over many centuries to create modern day bone grafts and bone biomaterials used as substitutes for bone grafts.

  18. B Vitamins, Homocysteine and Bone Health

    PubMed Central

    Fratoni, Valentina; Brandi, Maria Luisa

    2015-01-01

    Nutrition is one of the most important modifiable factors involved in the development and maintenance of good bone health. Calcium and Vitamin D have confirmed and established roles in the maintenance of proper bone health. However, other nutritional factors could also be implicated. This review will explore the emerging evidence of the supporting role of certain B Vitamins as modifiable factors associated with bone health. Individuals with high levels of homocysteine (hcy) exhibit reduced bone mineral density (BMD), alteration in microarchitecture and increased bone fragility. The pathophysiology caused by high serum homocysteine is not completely clear regarding fractures, but it may involve factors, such as bone mineral density, bone turnover, bone blood flow and collagen cross-linking. It is uncertain whether supplementation with B Vitamins, such as folate, Vitamin B1, and Vitamin B6, could decrease hip fracture incidence, but the results of further clinical trials should be awaited before a conclusion is drawn. PMID:25830943

  19. B vitamins, homocysteine and bone health.

    PubMed

    Fratoni, Valentina; Brandi, Maria Luisa

    2015-04-01

    Nutrition is one of the most important modifiable factors involved in the development and maintenance of good bone health. Calcium and Vitamin D have confirmed and established roles in the maintenance of proper bone health. However, other nutritional factors could also be implicated. This review will explore the emerging evidence of the supporting role of certain B Vitamins as modifiable factors associated with bone health. Individuals with high levels of homocysteine (hcy) exhibit reduced bone mineral density (BMD), alteration in microarchitecture and increased bone fragility. The pathophysiology caused by high serum homocysteine is not completely clear regarding fractures, but it may involve factors, such as bone mineral density, bone turnover, bone blood flow and collagen cross-linking. It is uncertain whether supplementation with B Vitamins, such as folate, Vitamin B1, and Vitamin B6, could decrease hip fracture incidence, but the results of further clinical trials should be awaited before a conclusion is drawn. PMID:25830943

  20. Assessing bone health in children and adolescents

    PubMed Central

    Levine, Michael A.

    2012-01-01

    During normal childhood and adolescence, the skeleton undergoes tremendous change. Utilizing the processes of modeling and remodeling, the skeleton acquires its adult configuration and ultimately achieves peak bone mass. Optimization of peak bone mass requires the proper interaction of environmental, dietary, hormonal, and genetic influences. A variety of acute and chronic conditions, as well as genetic polymorphisms, are associated with reduced bone density, which can lead to an increased risk of fracture both in childhood and later during adulthood. Bone densitometry has an established role in the evaluation of adults with bone disorders, and the development of suitable reference ranges for children now permits the application of this technology to younger individuals. We present a brief overview of the factors that determine bone density and the emerging role of bone densitometry in the assessment of bone mass in growing children and adolescents. PMID:23565379

  1. MicroRNAs regulate bone metabolism.

    PubMed

    Zhao, Xin; Xu, Dan; Li, Yi; Zhang, Jiangyan; Liu, Tingting; Ji, Yinli; Wang, Jufang; Zhou, Guangming; Xie, Xiaodong

    2014-05-01

    Osteoporosis is caused by an unbalance between bone formation and bone resorption. Bone homeostasis is regulated by intricate mechanisms. Recently, a novel class of regulatory factors termed microRNAs (miRNAs) has been found to play a crucial role in cell cycle control, apoptosis and other cellular processes including metabolism and differentiation. Published data have shown that some miRNAs regulate bone homeostasis, including bone formation, resorption, remodeling, repair and bone-related disease, by regulating the expression of certain cytokines and transcription factors. This review highlights the current knowledge of miRNAs and their involvement in the regulation of bone formation, bone resorption and the pathways regulating the progression of osteoporosis. PMID:24311309

  2. Nonosseous abnormalities on bone scans.

    PubMed

    Loutfi, Issa; Collier, B David; Mohammed, Ahmed M

    2003-09-01

    Although bone scanning is a test primarily concerned with skeletal abnormalities, important nonosseous findings are occasionally present on the images. To gauge the significance of such nonosseous uptake and, in particular, to determine whether these findings contain useful diagnostic information, the technical and medical staff in nuclear medicine must recognize the various patterns of nonbony uptake and understand their causes. The objectives of this article are to demonstrate the appearances of nonosseous uptake on bone scans, to categorize the forms of soft-tissue uptake, to emphasize technical artifacts leading to soft-tissue uptake, and to highlight the clinical significance of pathologic soft-tissue uptake. PMID:12968045

  3. Pattern Alteration: Protruding Hip Bone

    E-print Network

    2006-08-04

    corresponding to the hip bone (Fig. 4). 5. Tape the pattern in place. 6. To maintain the original waist measurement, increase a dart, tuck or pleat near the spread by the amount you have added to the waist line; or convert the full- ness to gathers (Fig. 5). 7.... If the pattern has darts, tucks or pleats, move the fullness over the hip bone location. To move a dart, follow the directions on page 1 and refer to Figure 6. Make the new dart the width of the increased dart to maintain the original waistline measurement...

  4. Appropriate use of bone densitometry

    SciTech Connect

    Genant, H.K.; Block, J.E.; Steiger, P.; Glueer, C.C.; Ettinger, B.; Harris, S.T.

    1989-03-01

    The authors discuss current capabilities of three common bone densitometry techniques--single photon absorptiometry, dual photon absorptiometry, and quantitative computed tomography--and potential capabilities of new innovations of each of these techniques. They believe that use of bone densitometry is valid in the following four clinical applications and recommend its usage to (a) assess patients with metabolic diseases known to affect the skeleton, (b) assess perimenopausal women for initiation of estrogen replacement therapy, (c) establish a diagnosis of osteoporosis or assess its severity in the context of general clinical care, and (d) monitor the efficacy of treatment interventions or the natural course of disease.

  5. Bone Mineral Density and Logarithms

    NSDL National Science Digital Library

    VU Bioengineering RET Program,

    Students examine an image produced by a cabinet x-ray system to determine if it is a quality bone mineral density image. They write in their journals about what they need to know to be able to make this judgment. Students learn about what bone mineral density is, how a BMD image can be obtained, and how it is related to the x-ray field. Students examine the process used to obtain a BMD image and how this process is related to mathematics, primarily through logarithmic functions. They study the relationship between logarithms and exponents, the properties of logarithms, common and natural logarithms, solving exponential equations and Beer's law.

  6. Use of serial bone scans in assessing response of bone metastases to systemic treatment

    Microsoft Academic Search

    D. L. Citrin; C. Hougen; W. Zweibel; S. Schlise; B. Pruitt; W. Ershler; T. E. Davis; J. Harberg; A. I. Cohen

    1981-01-01

    The accuracy levels of serial radioisotope bone scans and conventional bone radiographs in assessing the response of bone metastases to systemic therapy were compared in 34 women with metastatic breast cancer. Each patient had measurable or evaluable nonosseous metastases, which were assessed independently of skeletal disease. The bone scan was found to be more accurate and sensitive indicator of the

  7. Bone Appetit: The Role of Food and Nutrition in Building and Maintaining Strong Bones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bone is a living, dynamic, metabolically active tissue. It under goes a process of constant renewal throughout life, through a process called bone turnover in which cells called osteoclasts remove old or damaged bone, and cells called osteoblasts make new bone to replace it. A healthy, balanced di...

  8. Accelerated Bone Resorption, Due to Dietary Calcium Deficiency, Promotes Breast Cancer Tumor Growth in Bone

    Microsoft Academic Search

    Hong Zhou; James R. K. Modzelewski; Robert Kalak; Julie M. Blair; Markus J. Seibel; Colin R. Dunstan

    2007-01-01

    The skeleton is a major site of breast cancer metastases. High bone turnover increases risk of disease progression and death. However, there is no direct evidence that high bone turnover is causally associated with the establishment and progression of metastases. In this study, we investigate the effects of high bone turnover in a model of breast cancer growth in bone.

  9. Osteopontin deficiency increases bone fragility but preserves bone mass Philipp J. Thurner a,b

    E-print Network

    Ritchie, Robert

    Osteopontin deficiency increases bone fragility but preserves bone mass Philipp J. Thurner a 2010 Edited by: D. Burr Keywords: Osteopontin Rodent Fracture toughness Bone matrix properties such as osteopontin to bone matrix material properties remains unclear. Several roles have been ascribed

  10. J Bone Miner Metab . Author manuscript Mineral maturity and crystallinity index are distinct characteristics of bone

    E-print Network

    Paris-Sud XI, Université de

    . To this end, Fourier Transform InfraRed Microspectroscopy (FTIRM) was used. To test our hypothesis, synthetic highly correlated in synthetic apatites, but poorly correlated in normal human bone. In skeletal to assess bone mineral traits in osteoporosis. MESH Keywords Apatites ; chemistry ; Bone and Bones

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

    PubMed

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

    2015-07-01

    Decreased physical activity in mammals increases bone turnover and uncouples bone formation from bone resorption, leading to hypercalcemia, hypercalcuria, bone loss and increased fracture risk. Black bears, however, are physically inactive for up to 6?months annually during hibernation without losing cortical or trabecular bone mass. Bears have been shown to preserve trabecular bone volume and architectural parameters and cortical bone strength, porosity and geometrical properties during hibernation. The mechanisms that prevent disuse osteoporosis in bears are unclear as previous studies using histological and serum markers of bone remodeling show conflicting results. However, previous studies used serum markers of bone remodeling that are known to accumulate with decreased renal function, which bears have during hibernation. Therefore, we measured serum bone remodeling markers (BSALP and TRACP) that do not accumulate with decreased renal function, in addition to the concentrations of serum calcium and hormones involved in regulating bone remodeling in hibernating and active bears. Bone resorption and formation markers were decreased during hibernation compared with when bears were physically active, and these findings were supported by histomorphometric analyses of bone biopsies. The serum concentration of cocaine and amphetamine regulated transcript (CART), a hormone known to reduce bone resorption, was 15-fold higher during hibernation. Serum calcium concentration was unchanged between hibernation and non-hibernation seasons. Suppressed and balanced bone resorption and formation in hibernating bears contributes to energy conservation, eucalcemia and the preservation of bone mass and strength, allowing bears to survive prolonged periods of extreme environmental conditions, nutritional deprivation and anuria. PMID:26157160

  12. Boning up on Wolff's Law: Mechanical regulation of the cells that make and maintain bone

    E-print Network

    Simmons, Craig A.

    a r t i c l e i n f o Article history: Accepted 21 August 2009 Keywords: Osteocyte Osteoprogenitor players in bone mechanobiology: osteocytes, the putative primary mechanosensors in intact bone by the cells in bone: osteocytes, the putative mechanosensors; osteoblasts that deposit bone matrix

  13. Aneurysmal bone cysts treated by curettage, cryotherapy and bone grafting

    Microsoft Academic Search

    H. W. Bart Schreuder; REN ´ E P. H. VETH; Maciej Pruszczynski; J. Albert M. Lemmens; Heimen Schraffordt Koops; Willemina M. Molenaar

    1997-01-01

    We treated 26 patients with 27 aneurysmal bone cysts by curettage and cryotherapy and evaluated local tumour control, complications and functional outcome. The mean follow-up time was 47 months (19 to154). There was local recurrence in one patient. Two patients developed deep wound infections and one had a postoperative fracture. We compared our results with previous reports in which several

  14. Bone malformations in interleukin-18 transgenic mice.

    PubMed

    Kawase, Yusuke; Hoshino, Tomoaki; Yokota, Koichi; Kuzuhara, Akemi; Nakamura, Masanori; Maeda, Yu; Nishiwaki, Eiji; Zenmyo, Michihisa; Hiraoka, Koji; Aizawa, Hisamichi; Yoshino, Kohichiro

    2003-06-01

    The in vivo effects of IL-18 on bone metabolism were investigated by histopathology in IL-18 transgenic mice. Deformed cortical bone and decreased turnover rate of lumbar trabecular bone are consistent with increased expression of IFN-gamma and IL-18 in the bone marrow. Interleukin (IL)-18 has been demonstrated to inhibit osteoclastogenesis in an in vitro co-culture system. We investigated the effects of IL-18 overexpression on bone metabolism by comparing bone characteristics in male IL-18 transgenic (TG) mice, which secrete mature murine IL-18 from their B- and T-cells, and their wildtype littermates (WT). Histopathological analysis revealed that the cortical bone of the femur was thinner and more deformed in IL-18 TG mice. Bone histomorphometry showed that the cortical bone area of the mid-diaphysis of the femur and the trabecular bone volume of the lumbar vertebrae were significantly reduced in IL-18 TG mice. IL-18 TG mice also exhibited significantly fewer osteoclasts and a reduced bone formation rate in the trabecular bones of their lumbar vertebrae. Real-time reverse transcriptase-polymerase chain reaction amplification of bone marrow cell mRNA revealed that interferon (IFN)-gamma mRNA expression was significantly increased, whereas IL-4 mRNA expression was significantly reduced, in IL-18 TG mice. However, the expression ratio of receptor activator of NFkappaB ligand and osteoprotegerin mRNA was not significantly altered. Thus, deformed cortical bone and a decreased turnover rate of lumbar trabecular bone are characteristic of IL-18 TG mice, and these features might be associated with the increased expression of IFN-gamma and IL-18 in the bone marrow. PMID:12817749

  15. Transplanted Endothelial Cells Enhance Orthotopic Bone Regeneration

    Microsoft Academic Search

    D. Kaigler; P. H. Krebsbach; Z. Wang; E. R. West; K. Horger; D. J. Mooney

    2006-01-01

    The aim of this study was to determine if endothelial cells could enhance bone marrow stromal-cell-mediated bone regeneration in an osseous defect. Using poly-lactide-co-glycolide scaffolds as cell carriers, we transplanted bone marrow stromal cells alone or with endothelial cells into 8.5-mm calvarial defects created in nude rats. Histological analyses of blood vessel and bone formation were performed, and microcomputed tomography

  16. Positive modulator of bone morphogenic protein-2

    DOEpatents

    Zamora, Paul O. (Gaithersburg, MD); Pena, Louis A. (Poquott, NY); Lin, Xinhua (Plainview, NY); Takahashi, Kazuyuki (Germantown, MD)

    2009-01-27

    Compounds of the present invention of formula I and formula II are disclosed in the specification and wherein the compounds are modulators of Bone Morphogenic Protein activity. Compounds are synthetic peptides having a non-growth factor heparin binding region, a linker, and sequences that bind specifically to a receptor for Bone Morphogenic Protein. Uses of compounds of the present invention in the treatment of bone lesions, degenerative joint disease and to enhance bone formation are disclosed.

  17. Aneurysmal bone cyst of the hyoid.

    PubMed

    Shadaba, A; Zaidi, S

    1992-01-01

    Aneurysmal bone cyst is a rare lesion usually of the long bones, well documented in the literature. It is a cystic, osteolytic vascular tumour, replete with giant cells and fibrous septa, yet devoid of endothelial lining. It has been reported in the larynx and maxillary sinus. This appears to be the first report of an aneurysmal bone cyst occurring in the hyoid bone. PMID:1541900

  18. Gravity, calcium, and bone - Update, 1989

    NASA Technical Reports Server (NTRS)

    Arnaud, Sara B.; Morey-Holton, Emily

    1990-01-01

    Recent results obtained on skeletal adaptation, calcium metabolism, and bone browth during short-term flights and ground simulated-microgravity experiments are presented. Results demonstrate that two principal components of calcium metabolism respond within days to changes in body position and to weightlessness: the calcium endocrine system and bone characteristics. Furthermore, results of recent studies imply that bone biomechanics are more severely affected by spaceflight exposures than is the bone mass.

  19. Physical activity increases bone mass during growth

    PubMed Central

    Karlsson, Magnus K.; Nordqvist, Anders; Karlsson, Caroline

    2008-01-01

    Background The incidence of fragility fractures has increased during the last half of the 1990?s. One important determinant of fractures is the bone mineral content (BMC) or bone mineral density (BMD), the amount of mineralised bone. If we could increase peak bone mass (the highest value of BMC reached during life) and/or decrease the age-related bone loss, we could possibly improve the skeletal resistance to fracture. Objective This review evaluates the importance of exercise as a strategy to improve peak bone mass, including some aspects of nutrition. Design Publications within the field were searched through Medline (PubMed) using the search words: exercise, physical activity, bone mass, bone mineral content, bone mineral density, BMC, BMD, skeletal structure and nutrition. We included studies dealing with exercise during growth and young adolescence. We preferably based our inferences on randomised controlled trials (RCT), which provide the highest level of evidence. Results Exercise during growth increases peak bone mass. Moderate intensity exercise intervention programs are beneficial for the skeletal development during growth. Adequate nutrition must accompany the exercise to achieve the most beneficial skeletal effects by exercise. Conclusion Exercise during growth seems to enhance the building of a stronger skeleton through a higher peak bone mass and a larger bone size. PMID:19109652

  20. Bioactivation of biomorphous silicon carbide bone implants

    Microsoft Academic Search

    Julia Will; Alexander Hoppe; Frank A. Müller; Carmen T. Raya; Julián M. Fernández; Peter Greil

    2010-01-01

    Wood-derived silicon carbide (SiC) offers a specific biomorphous microstructure similar to the cellular pore microstructure of bone. Compared with bioactive ceramics such as calcium phosphate, however, silicon carbide is considered not to induce spontaneous interface bonding to living bone. Bioactivation by chemical treatment of biomorphous silicon carbide was investigated in order to accelerate osseointegration and improve bone bonding ability. Biomorphous

  1. Paget’s disease of the bone

    MedlinePLUS

    ... but is more common in Europe, Australia, and New Zealand. In people with Paget's disease, there is an abnormal breakdown of bone tissue in specific areas. This is, followed by abnormal bone formation. The new area of bone is larger, but weaker. The ...

  2. Developmental Cell Bone Ridge Patterning during Musculoskeletal

    E-print Network

    Developmental Cell Article Bone Ridge Patterning during Musculoskeletal Assembly Is Mediated.devcel.2009.10.010 SUMMARY During the assembly of the musculoskeletal system, bone ridges provide a stable-skeleton regulatory interactions during musculoskeletal assembly and bone secondary patterning. INTRODUCTION

  3. Construction of tissue engineered bone with vascularization

    Microsoft Academic Search

    Haiying Yu

    2007-01-01

    Because the human bone tissues are essentially composite materials with anisotropic properties, making of various components of tissues with different amount, structural arrangements and function, the repairing bone defect with engineered grafts is a coordinated process, involving interplay among various determinants. Therefore we attempt to develop a systemic approach to construct tissue engineered bone, including (1) a complex scaffold materials

  4. Computer aided long bone fracture detection

    Microsoft Academic Search

    Martin Donnelley; Greg Knowles

    2005-01-01

    We have developed a method of automatically detecting fractures in long bones. While bone fractures are a relatively common occurence, their presence can often be missed during x-ray diagnosis, resulting in ineffective patient management. Detection of fractures in long bones is an important orthopaedic and radiologic problem, so we propose a computer aided detection system to help reduce the miss

  5. Bone densitometry: applications in sports-medicine

    Microsoft Academic Search

    Dieter Felsenberg; Wolfgang Gowin

    1998-01-01

    Physical exercise and sports increase muscular mass and the remodelling process of bones. The increment of bone depends on the type and the quality of sport. Short-term high-performance activities such as sprint, tennis, fencing lead to increased bone mineral density as well as weight lifting or heavy athletics. Swimming, bicycling, walking are associated with good musculature conditioning without an increase

  6. Better Bones Buddies: An Osteoporosis Prevention Program

    ERIC Educational Resources Information Center

    Schrader, Susan L.; Blue, Rebecca; Horner, Arlene

    2005-01-01

    Although osteoporosis typically surfaces in later life, peak bone mass attained before age 20 is a key factor in its prevention. However, most American children's diets lack sufficient calcium during the critical growth periods of preadolescence and adolescence to achieve peak bone mass. "Better Bones (BB) Buddies" is an educational program…

  7. Effects of Inactivity and Exercise on Bone.

    ERIC Educational Resources Information Center

    Smith, Everett L.; Gilligan, Catherine

    1987-01-01

    Research has shown that bone tissue responds to the forces of gravity and muscle contraction. The benefits of weight-bearing exercise in preventing or reversing bone mass loss related to osteoporosis is reviewed. The effects of weightlessness and immobilization, and the possible effects of athletic amenorrhea, on bone mineral density are…

  8. Inflammatory bone loss: pathogenesis and therapeutic intervention

    Microsoft Academic Search

    Kurt Redlich; Josef S. Smolen

    2012-01-01

    Bone is a tissue undergoing continuous building and degradation. This remodelling is a tightly regulated process that can be disturbed by many factors, particularly hormonal changes. Chronic inflammation can also perturb bone metabolism and promote increased bone loss. Inflammatory diseases can arise all over the body, including in the musculoskeletal system (for example, rheumatoid arthritis), the intestine (for example, inflammatory

  9. Bone formation in vitro by stromal cells obtained from bone marrow of young adult rats

    Microsoft Academic Search

    C. Maniatopoulos; J. Sodek; A. H. Melcher

    1988-01-01

    Cells from fetal or neonatal skeleton can synthesize bone-like tissue in vitro. In contrast, formation of bone-like tissue in vitro by cells derived from adult animals has rarely been reported and has not been achieved using cells from bone marrow. We have explored development of bone-like tissue in vitro by bone marrow stromal cells. Marrow stromal cells obtained from 40–43-day-old

  10. Bone X-Ray (Radiography)

    MedlinePLUS

    ... x-rays. top of page What does the equipment look like? View larger with caption The equipment typically used for bone x-rays consists of ... and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely available in emergency ...

  11. Bone and Soft Tissue Ablation

    PubMed Central

    Foster, Ryan C.B.; Stavas, Joseph M.

    2014-01-01

    Bone and soft tissue tumor ablation has reached widespread acceptance in the locoregional treatment of various benign and malignant musculoskeletal (MSK) lesions. Many principles of ablation learned elsewhere in the body are easily adapted to the MSK system, particularly the various technical aspects of probe/antenna design, tumoricidal effects, selection of image guidance, and methods to reduce complications. Despite the common use of thermal and chemical ablation procedures in bone and soft tissues, there are few large clinical series that show longitudinal benefit and cost-effectiveness compared with conventional methods, namely, surgery, external beam radiation, and chemotherapy. Percutaneous radiofrequency ablation of osteoid osteomas has been evaluated the most and is considered a first-line treatment choice for many lesions. Palliation of painful metastatic bone disease with thermal ablation is considered safe and has been shown to reduce pain and analgesic use while improving quality of life for cancer patients. Procedure-related complications are rare and are typically easily managed. Similar to all interventional procedures, bone and soft tissue lesions require an integrated approach to disease management to determine the optimum type of and timing for ablation techniques within the context of the patient care plan. PMID:25053865

  12. [Metabolic bone and joint diseases].

    PubMed

    Endo, Itsuro

    2014-10-01

    Metabolic bone and joint diseases in adults include osteomalacia, rheumatoid arthritis, gouty arthritis. Recently, the newest molecular biology procedures and the clinical observation studies can produce good results for understanding of these diseases. From this perspective, the author introduced updated information of the pathophysiology, the latest diagnostic criteria and the therapy of these diseases. PMID:25509803

  13. Green tea and bone health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Osteoporosis is a major health problem in the elderly, particularly women. Epidemiological evidence has shown an association between tea consumption and the prevention of age-related bone loss in elderly women and men. Ingestion of green tea and green tea bioactive compounds may be beneficial in mit...

  14. Fractal Analysis of Trabecular Bone

    NSDL National Science Digital Library

    Gillespy, Thurman

    Fractals are unusual geometric structures that can be used to analyze many biologic structures not amenable to conventional analysis. The purpose of this exhibit is to teach some of the fundamentals of fractal analysis, and to show how they can be applied to analysis of trabecular bone.

  15. Bone and soft tissue ablation.

    PubMed

    Foster, Ryan C B; Stavas, Joseph M

    2014-06-01

    Bone and soft tissue tumor ablation has reached widespread acceptance in the locoregional treatment of various benign and malignant musculoskeletal (MSK) lesions. Many principles of ablation learned elsewhere in the body are easily adapted to the MSK system, particularly the various technical aspects of probe/antenna design, tumoricidal effects, selection of image guidance, and methods to reduce complications. Despite the common use of thermal and chemical ablation procedures in bone and soft tissues, there are few large clinical series that show longitudinal benefit and cost-effectiveness compared with conventional methods, namely, surgery, external beam radiation, and chemotherapy. Percutaneous radiofrequency ablation of osteoid osteomas has been evaluated the most and is considered a first-line treatment choice for many lesions. Palliation of painful metastatic bone disease with thermal ablation is considered safe and has been shown to reduce pain and analgesic use while improving quality of life for cancer patients. Procedure-related complications are rare and are typically easily managed. Similar to all interventional procedures, bone and soft tissue lesions require an integrated approach to disease management to determine the optimum type of and timing for ablation techniques within the context of the patient care plan. PMID:25053865

  16. Bare Bones of Bioactive Glass

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Paul Ducheyne, a principal investigator in the microgravity materials science program and head of the University of Pernsylvania's Center for Bioactive Materials and Tissue Engineering, is leading the trio as they use simulated microgravity to determine the optimal characteristics of tiny glass particles for growing bone tissue. The result could make possible a much broader range of synthetic bone-grafting applications. Even in normal gravity, bioactive glass particles enhance bone growth in laboratory tests with flat tissue cultures. Ducheyne and his team believe that using the bioactive microcarriers in a rotating bioreactor in microgravity will produce improved, three-dimensional tissue cultures. The work is sponsored by NASA's Office of Biological and Physical Research. The bioreactor is managed by the Biotechnology Cell Science Program at NASA's Johnson Space Center (JSC). NASA-sponsored bioreactor research has been instrumental in helping scientists to better understand normal and cancerous tissue development. In cooperation with the medical community, the bioreactor design is being used to prepare better models of human colon, prostate, breast and ovarian tumors. Cartilage, bone marrow, heart muscle, skeletal muscle, pancreatic islet cells, liver and kidney are just a few of the normal tissues being cultured in rotating bioreactors by investigators. Credit: NASA and University of Pennsylvania Center for Bioactive Materials and Tissue Engineering.

  17. PASSCLAIM - Bone health and osteoporosis

    Microsoft Academic Search

    Ann Prentice; Jean-Philippe Bonjour; Francesco Branca; Cyrus Cooper; Albert Flynn; Michčle Garabedian; Detlef Müller; Daphne Pannemans; Peter Weber

    2003-01-01

    Summary. Background: The EC Concerted Action PASSCLAIM aims to produce a generic tool for assessing the scientific support for health-related claims for foods and food components. Aim: The task of the ITGB Working Group was to critically evaluate the categories of scientific evidence needed to support claims in relation to bone health and osteoporosis. Methods: A framework was developed to

  18. Bone Mineralization in Celiac Disease

    PubMed Central

    Larussa, Tiziana; Suraci, Evelina; Nazionale, Immacolata; Abenavoli, Ludovico; Imeneo, Maria; Luzza, Francesco

    2012-01-01

    Evidence indicates a well-established relationship between low bone mineral density (BMD) and celiac disease (CD), but data on the pathogenesis of bone derangement in this setting are still inconclusive. In patients with symptomatic CD, low BMD appears to be directly related to the intestinal malabsorption. Adherence to a strict gluten-free diet (GFD) will reverse the histological changes in the intestine and also the biochemical evidence of calcium malabsorption, resulting in rapid increase of BMD. Nevertheless, GFD improves BMD but does not normalize it in all patients, even after the recovery of intestinal mucosa. Other mechanisms of bone injury than calcium and vitamin D malabsorption are thought to be involved, such as proinflammatory cytokines, parathyroid function abnormalities, and misbalanced bone remodeling factors, most of all represented by the receptor activator of nuclear factor B/receptor activator of nuclear factor B-ligand/osteoprotegerin system. By means of dual-energy X-ray absorptiometry (DXA), it is now rapid and easy to obtain semiquantitative values of BMD. However, the question is still open about who and when submit to DXA evaluation in CD, in order to estimate risk of fractures. Furthermore, additional information on the role of nutritional supplements and alternative therapies is needed. PMID:22737164

  19. Photodynamic therapy of diseased bone

    NASA Astrophysics Data System (ADS)

    Bisland, Stuart K.; Yee, Albert; Siewerdsen, Jeffery; Wilson, Brian C.; Burch, Shane

    2005-08-01

    Objective: Photodynamic therapy (PDT) defines the oxygen-dependent reaction that occurs upon light-mediated activation of a photosensitizing compound, culminating in the generation of cytotoxic, reactive oxygen species, predominantly, singlet oxygen. We are investigating PDT treatment of diseased bone. Methods: Using a rat model of human breast cancer (MT-1)-derived bone metastasis we confirmed the efficacy of benzoporphyrin-derivative monoacid (BPD-MA)-PDT for treating metastatic lesions within vertebrae or long bones. Results: Light administration (150 J) 15 mins after BPDMA (2.5 mg/Kg, i.v.) into the lumbar (L3) vertebra of rats resulted in complete ablation of the tumour and surrounding bone marrow 48 hrs post-PDT without paralysis. Porcine vertebrae provided a model comparable to that of human for light propagation (at 150 J/cm) and PDT response (BPD-MA; 6 mg/m2, i.v.) in non-tumour vertebrae. Precise fibre placement was afforded by 3-D cone beam computed tomography. Average penetration depth of light was 0.16 +/- 0.04 cm, however, the necrotic/non-necrotic interface extended 0.6 cm out from the treatment fiber with an average incident fluence rate of 4.3 mW/cm2. Non-necrotic tissue damage was evident 2 cm out from the treatment fiber. Current studies involving BPD-MA-PDT treatment of primary osteosarcomas in the forelimbs of dogs are very promising. Magnetic resonance imaging 24 hr post treatment reveal well circumscribed margins of treatment that encompass the entire 3-4 cm lesion. Finally, we are also interested in using 5-aminolevulinic acid (ALA) mediated PDT to treat osteomyelitis. Response to therapy was monitored as changes in bioluminescence signal of staphylococcus aureus (SA)-derived biofilms grown onto 0.5 cm lengths of wire and subjected to ALA-PDT either in vitro or in vivo upon implant into the intramedullary space of rat tibia. Transcutaneous delivery of PDT (75 J/cm2) effectively eradicated SAbiofilms within bone. Conclusions: Results support the application of PDT to the treatment of primary or metastatic lesions within bone. Secondly, that ALA-PDT may be useful as a treatment for osteomyelitis. Further studies aim to optimize the parameters of delivering PDT into bone and explore imaging technologies that can be used for clinical PDT.

  20. Modulating Bone Resorption and Bone Formation in Opposite Directions in the Treatment of Postmenopausal Osteoporosis.

    PubMed

    Appelman-Dijkstra, Natasha M; Papapoulos, Socrates E

    2015-07-01

    Bone remodeling, the fundamental process for bone renewal, is targeted by treatments of osteoporosis to correct the imbalance between bone resorption and bone formation and reduce the risk of fractures and associated clinical consequences. Currently available therapeutics affect bone resorption and bone formation in the same direction and either decrease (inhibitors of bone resorption) or increase (parathyroid hormone [PTH] peptides) bone remodeling. Studies of patients with rare bone diseases and genetically modified animal models demonstrated that bone resorption and bone formation may not necessarily be coupled, leading to identification of molecular targets in bone cells for the development of novel agents for the treatment of osteoporosis. Application of such agents to the treatment of women with low bone mass confirmed that bone resorption and bone formation can be modulated in different directions and so far two new classes of therapeutics for osteoporosis have been defined with distinct mechanisms of action. Such treatments, if combined with a favorable safety profile, will offer new therapeutic options and will improve the management of patients with osteoporosis. PMID:26056029

  1. Interleukin-1 receptor antagonist decreases bone loss and bone resorption in ovariectomized rats.

    PubMed Central

    Kimble, R B; Vannice, J L; Bloedow, D C; Thompson, R C; Hopfer, W; Kung, V T; Brownfield, C; Pacifici, R

    1994-01-01

    Interleukin-1 (IL-1), a cytokine produced by bone marrow cells and bone cells, has been implicated in the pathogenesis of postmenopausal osteoporosis because of its potent stimulatory effects on bone resorption in vitro and in vivo. To investigate whether IL-1 plays a direct causal role in post ovariectomy bone loss, 6-mo-old ovariectomized rats were treated with subcutaneous infusions of IL-1 receptor antagonist (IL-1ra), a specific competitor of IL-1, for 4 wk, beginning either at the time of surgery or 4 wk after ovariectomy. The bone density of the distal femur was measured non invasively by dual-energy X-ray absorptiometry. Bone turnover was assessed by bone histomorphometry and by measuring serum osteocalcin, a marker of bone formation, and the urinary excretion of pyridinoline cross-links, a marker of bone resorption. Ovariectomy caused a rapid increase in bone turnover and a marked decrease in bone density which were blocked by treatment with 17 beta estradiol. Ovariectomy also increased the production of IL-1 from cultured bone marrow cells. Ovariectomy induced-bone loss was significantly decreased by IL-1ra treatment started at the time of ovariectomy and completely blocked by IL-1ra treatment begun 4 wk after ovariectomy. In both studies IL-1ra also decreased bone resorption in a manner similar to estrogen, while it had no effect on bone formation. In contrast, treatment with IL-1ra had no effect on the bone density and the bone turnover of sham-operated rats, indicating that IL-1ra specifically blocked estrogen-dependent bone loss. In conclusion, these data indicate that IL-1, or mediators induced by IL-1, play an important causal role in the mechanism by which ovariectomy induces bone loss in rats, especially following the immediate post ovariectomy period. Images PMID:8182127

  2. NMR assessment on bone simulated under microgravity

    NASA Astrophysics Data System (ADS)

    Ni, Q.; Qin, Y.

    Introduction Microgravity-induced bone loss has been suggested to be similar to disuse-osteoporosis on Earth which constitutes a challenging public health problem No current non-destructive method can provide the microstructural changes in bone particularly on cortical bone Recently the authors have applied low field nuclear magnetic resonance NMR spin-spin relaxation technique and computational analysis method to determine the porosity pore size distribution and microdamage of cortical bone 1-3 The studies by the authors have shown that this technology can be used to characterize microstructural changes as well as bone water distribution bound and mobile water changes of weightless treated simulating a microgravity condition turkey and mouse cortical bone We further determinate that the NMR spin-spin relaxation time T 2 spectrum derived parameters can be used as descriptions of bone quality e g matrix water distribution and porosity size distributions and alone or in combination with current techniques bone mineral density measurements more accurately predict bone mechanical properties Methods underline Bone sample preparation Two kinds of animal samples were collected and prepared for designed experiments from SUNY Cortical bones of the mid-diaphyses of the ulnae of 1-year-old male turkeys were dissected from freshly slaughtered animals Eight samples were categorized from normal or control and four samples were 4-week disuse treated by functionally isolated osteotomies disuse A total of 12

  3. New predictive model for monitoring bone remodeling.

    PubMed

    Bougherara, Habiba; Klika, Václav; Marsík, Frantisek; Marík, Ivo A; Yahia, L'hocine

    2010-10-01

    The aim of this article was to present a new thermodynamic-based model for bone remodeling which is able to predict the functional adaptation of bone in response to changes in both mechanical and biochemical environments. The model was based on chemical kinetics and irreversible thermodynamic principles, in which bone is considered as a self-organizing system that exchanges matter, energy and entropy with its surroundings. The governing equations of the mathematical model have been numerically solved using Matlab software and implemented in ANSYS software using the Finite Element Method. With the aid of this model, the whole inner structure of bone was elucidated. The current model suggested that bone remodeling was a dynamic process which was driven by mechanical loading, metabolic factors and other external contributions. The model clearly indicated that in the absence of mechanical stimulus, the bone was not completely resorbed and reaches a new steady state after about 50% of bone loss. This finding agreed with previous clinical studies. Furthermore, results of virtual computations of bone density in a composite femur showed the development of a dense cortical bone around the medullary canal and a dense trabeculae bone between the femoral head and the calcar region of the medial cortex due to compressive stresses. The comparison of the predicted bone density with the structure of the proximal femur obtained from X-rays and using strain energy density gave credibility to the current model. PMID:20540092

  4. Comparison of lead residues among avian bones.

    PubMed

    Ethier, A L M; Braune, B M; Scheuhammer, A M; Bond, D E

    2007-02-01

    To determine if significant differences exist in lead (Pb) accumulation in different bones, especially those most often used for bone-Pb studies in wildlife, we compared Pb concentrations in radius, ulna, humerus, femur, and tibia of Common Eider (Somateria mollissima); and radius/ulna (combined), femur, and tibia of American Woodcock (Scolopax minor). There were no significant differences in bone-Pb concentrations among woodcock bones over a wide range of Pb concentrations (3-311 microg/g). In eider, where bone-Pb concentrations were low (<10 microg/g), leg bones had significantly higher Pb concentrations (approximately 30-40%) than wing bones from the same individuals. The variation among individual birds was greater than the variation among different bones within a bird. Based on our findings, we conclude that one type of bone may be substituted for another in bone-Pb studies although the same bone type should be analyzed for all birds within a study, whenever possible. PMID:16815605

  5. Expression of vascular antigens by bone cells during bone regeneration in a membranous bone distraction system

    Microsoft Academic Search

    Dina Lewinson; Gila Maor; Nimrod Rozen; Iaron Rabinovich; Shay Stahl; Adi Rachmiel

    2001-01-01

    An in vivo system of membranous bone formation during distraction has been investigated in order to follow cells that express vascular markers with the objective of understanding the neovascularization process. Concomitantly, sustained proliferation of preskeletal cells was achieved through the application of mechanical force. New capillaries and leading edges that arose by angiogenesis from the periosteal and mucosal surfaces and

  6. Title: Patterning Bone Regeneration In Silico Modeling of Bone Morphogenetic Protein (BMP) Driven bone formation

    E-print Network

    Wolper, Pierre

    to overdosing. Recently, in our laboratory, implantation of BMP-coated CaP carriers in a nude mouse model). Implantation of BMP-coated CaP carrier in a nude mouse model will be performed, and the location of bone tissue

  7. Mechanisms of multiple myeloma bone disease

    PubMed Central

    Galson, Deborah L; Silbermann, Rebecca; Roodman, G David

    2012-01-01

    Multiple myeloma is the second most common hematological malignancy and the most frequent cancer to involve the skeleton. Multiple myeloma bone disease (MMBD) is characterized by abnormal bone remodeling with dysfunction of both bone resorption and bone formation, and thus can be used as a paradigm for other inflammatory bone diseases, and the regulation of osteoclasts and osteoblasts in malignancy. Studies of MMBD have identified novel regulators that increase osteoclastogenesis and osteoclast function, repress osteoblast differentiation, increase angiogenesis, or permanently alter stromal cells. This review will discuss the current understanding of mechanisms of osteoclast and osteoblast regulation in MMBD, and therapeutic approaches currently in use and under development that target mediators of bone destruction and blockade of bone formation for myeloma patients, including new anabolic therapies. PMID:23951515

  8. Magnetic resonance microscopy of osteoporotic bone

    NASA Astrophysics Data System (ADS)

    Toffanin, Renato; Szomolanyi, Pavol; Jellúš, Vladimír; Cova, Maria; Pozzi-Mucelli, Roberto S.; Vittur, Franco

    2000-01-01

    Magnetic resonance microscopy (MRM) may be very useful in the ex vivo study of osteoporosis as non destructive technique able to provide three dimensional information of the bone architecture. However, the trabecular width appears larger in conventional MR images, as the susceptibility effect at the bone-marrow interface causes signal dephasing. Such an effect can be minimized if the echo-time (TE) or voxel size are reduced. The purpose of our research was the development of new MRM techniques that have a potential role in the characterization of trabecular bone architecture. In this study we describe the use of short-TE projection reconstruction MRM for the study of normal and osteoporotic bone explants. This method promises to be more accurate than conventional MRM in the analysis of trabecular bone. In vivo projection reconstruction MR imaging could be applied to evaluate bone architecture and bone quality evolution after space flight exposure. .

  9. Imagistic evaluation of matrix bone interface

    NASA Astrophysics Data System (ADS)

    NegruĹŁiu, Meda L.; Sinescu, Cosmin; Manescu, Adrian; Topal?, Florin I.; Hoinoiu, Bogdan; M?rc?uĹŁeanu, Corina; Duma, Virgil; Bradu, Adrian; Podoleanu, Adrian G.

    2014-01-01

    The problematic elements of bone regenerative materials are represented by their quality control methods. The defects repaired by bone grafting material were evaluated by en face optical coherence tomography and by synchrotron radiation micro-CT. The images obtained by efOCT show defects in some of the investigated samples, at the bone interface with different osteoconductive bone substitutes and we were able to detect gaps as small as 50 ?m. After the common synchrotron radiation micro-CT investigations, the slides were reconstructed and the 3D model was obtained. Along with the possibility of navigating inside the structure, one big advantage of this technique was pointed out: the remaining regenerative materials can be separated from the normal bone and the new bone can be visualized. Optical coherence tomography can be performed in vivo and can provide a qualitative and quantitative evaluation of the bone augmentation procedure.

  10. Internal channel structures in trabecular bone

    NASA Astrophysics Data System (ADS)

    Scherf, Heike; Beckmann, Felix; Fischer, Jens; Witte, Frank

    2004-10-01

    Material properties of bone are crucial for studies regarding the mechanical behavior of bone. The mechanical behavior depends on the macro- and micro-architecture as well as the organic and mineral content of bone. The marco-architecture of bone is normally analyzed by plane radiographs. The micro-architecture of the trabecular bone can be imaged by high resolution CT imaging techniques using conventional x-ray tubes. However, fine structures in bone architecture cannot be sufficiently analyzed by this technique due to its limited resolution. High resolution CT imaging technique using synchrotron radiation generates images with a high spatial resolution of bone structures on a micron scale. Additionally, this imaging technique provides superior determination of local differences in the bone mineral density. Two microtomography techniques, first: based on conventional x-ray tubes and second: based on synchrotron radiation were compared in this study to detect fine bone structures such as inner trabecular channels. In two red howler monkeys (Alouatta seniculus) femora channel structures were found inside the trabecular bone by both techniques. Only synchrotron-based microtomography was able to detect layers of lower mineral density in the channel walls. The found structures in trabecular bone are normally expected in the Haversian channel walls of the cortical bone. However, the origin of the trabecular channel structure is not fully understood. We found, that synchrotron-based microtomography is a very valuable technique in the research of fine bone structures. Further research should focus on the impact of these findings on the mechanical properties of trabecular bone.

  11. Interaction among Cells of Bone, Immune System, and Solid Tumors Leads to Bone Metastases

    PubMed Central

    Roato, Ilaria

    2013-01-01

    Bone metastases are a dismal consequence for different types of solid tumors, such as breast, prostate, lung, and kidney cancer. The mechanisms regulating the interactions among bone, immune system, and tumor cells have been deeply investigated, and many studies are ongoing to define the specific role of the different cells in the bone metastatic process. The affinity of some tumors to growth in bone results from the special microenvironment provided by bone. Moreover, immune system and bone have a bidirectional relationship: bone cells express surface molecules ruling the expansion of hemopoietic stem cells from which all cells of the mammalian immune system derive, and various immunoregulatory cytokines influence the fate of bone cells. The last findings allow to extend the concept of vicious cycle and add T cells as mediators of the tumor growth in bone. PMID:23710201

  12. Three-Dimensional Evaluation of Mandibular Bone Regenerated By Bone Transport Distraction Osteogenesis

    PubMed Central

    Kontogiorgos, Elias; Elsalanty, Mohammed E.; Zapata, Uriel; Zakhary, Ibrahim; Nagy, William W.; Dechow, Paul C.; Opperman, Lynne A.

    2011-01-01

    The purpose of this study was to evaluate the structure and material properties of native mandibular bone and those of early regenerate bone, produced by bone transport distraction osteogenesis. Ten adult foxhounds were divided into two groups of five animals each. In all animals, a 3- to 4-cm defect was created on one side of the mandible. A bone transport reconstruction plate, consisting of a reconstruction plate with an attached intraoral transport unit, was utilized to stabilize the mandible and regenerate bone at a rate of 1 mm/day. After the distraction period was finished, the animals were killed at 6 and 12 weeks of consolidation. Micro-computed tomography was used to assess the morphometric and structural indices of regenerate bone and matching bone from the unoperated contralateral side. Significant new bone was formed within the defect in the 6- and 12-week groups. Significant differences (P ? 0.05) between mandibular regenerated and native bone were found in regard to bone volume fraction, mineral density, bone surface ratio, trabecular thickness, trabecular separation, and connectivity density, which increased from 12 to 18 weeks of consolidation. We showed that regenerated bone is still mineralizing and that native bone appears denser because of a thick outer layer of cortical bone that is not yet formed in the regenerate. However, the regenerate showed a significantly higher number of thicker trabeculae. PMID:21556698

  13. Retinoid Receptors in Bone and Their Role in Bone Remodeling

    PubMed Central

    Henning, Petra; Conaway, H. Herschel; Lerner, Ulf H.

    2015-01-01

    Vitamin A (retinol) is a necessary and important constituent of the body which is provided by food intake of retinyl esters and carotenoids. Vitamin A is known best for being important for vision, but in addition to the eye, vitamin A is necessary in numerous other organs in the body, including the skeleton. Vitamin A is converted to an active compound, all-trans-retinoic acid (ATRA), which is responsible for most of its biological actions. ATRA binds to intracellular nuclear receptors called retinoic acid receptors (RAR?, RAR?, RAR?). RARs and closely related retinoid X receptors (RXR?, RXR?, RXR?) form heterodimers which bind to DNA and function as ligand-activated transcription factors. It has been known for many years that hypervitaminosis A promotes skeleton fragility by increasing osteoclast formation and decreasing cortical bone mass. Some epidemiological studies have suggested that increased intake of vitamin A and increased serum levels of retinoids may decrease bone mineral density and increase fracture rate, but the literature on this is not conclusive. The current review summarizes how vitamin A is taken up by the intestine, metabolized, stored in the liver, and processed to ATRA. ATRA’s effects on formation and activity of osteoclasts and osteoblasts are outlined, and a summary of clinical data pertaining to vitamin A and bone is presented. PMID:25814978

  14. Thinking inside and outside the envelopes of bone

    Microsoft Academic Search

    P. Szulc; E. Seeman

    2009-01-01

    Introduction  Bone modeling and remodeling is the final common pathway expressing all genetic and environmental factors that influence the\\u000a attainment and maintenance of bone’s material and structural strength. Modeling and remodeling require a surface, and during\\u000a growth this cellular machinery fashions bone’s external size, shape, and internal architecture by depositing bone on, and\\u000a removing bone from, both its periosteal (external) and

  15. Trabecular bone dosimetry using a Monte Carlo code

    E-print Network

    Zuzarte de Mendonca, Anne

    1993-01-01

    marmw spherical cavity is consideted with a trabecular bone shelL The bone marrow cavity diameter is selected fmm a chord length probablity distribution function. The trabecular bone thickness is computed considering a simple volumetric relationship...L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 4. Standard trabecular bone model developed by Chen 16 5. Schematic representation of the flow control diagram of the EGS4 code 6. Trabecular bone spherical model with x: bone marrow diameter, e: endosteal layer and ttu trabecular bone...

  16. Pathologic bone tissues in a Turkey vulture and a nonavian dinosaur: implications for interpreting endosteal bone and radial fibrolamellar bone in fossil dinosaurs.

    PubMed

    Chinsamy, Anusuya; Tumarkin-Deratzian, Allison

    2009-09-01

    We report on similar pathological bone microstructure in an extant turkey vulture (Cathartes aura) and a nonavian dinosaur from Transylvania. Both these individuals exhibit distinctive periosteal reactive bone deposition accompanied by endosteal bone deposits in the medullary cavity. Our findings have direct implications on the two novel bone tissues recently described among nonavian dinosaurs, radial fibrolamellar bone tissue and medullary bone tissue. On the basis of the observed morphology of the periosteal reactive bone in the turkey vulture and the Transylvanian dinosaur, we propose that the radial fibrolamellar bone tissues observed in mature dinosaurs may have had a pathological origin. Our analysis also shows that on the basis of origin, location, and morphology, pathologically derived endosteal bone tissue can be similar to medullary bone tissues described in nonavian dinosaurs. As such, we caution the interpretation of all endosteally derived bone tissue as homologous to avian medullary bone. PMID:19711479

  17. Percutaneous sclerotherapy with absolute alcohol to treat aneurysmal bone cyst of the frontal bone.

    PubMed

    Han, Yi-feng; Fan, Xin-dong; Su, Li-xin

    2015-03-01

    Aneurysmal bone cysts (ABCs) rarely occur in the cranial bone. Surgical resection can lead to bone defects, deformities, functional abnormalities, and so on. This article describes a frontal ABC in a 73-year-old man who has a rapidly increasing swelling in the frontal bone preceded by an accidental trauma. In this case, we use percutaneous sclerotherapy with absolute alcohol under the guidance of fluoroscopy to treat the ABC instead of traditional surgical resection. When analyzed the follow-up imaging, bone reconstruction happened after using absolute alcohol. It is a feasible alternative treatment for ABC arising from the cranial bone. PMID:25668118

  18. Well-Designed Bone-Seeking Radiolabeled Compounds for Diagnosis and Therapy of Bone Metastases

    PubMed Central

    2015-01-01

    Bone-seeking radiopharmaceuticals are frequently used as diagnostic agents in nuclear medicine, because they can detect bone disorders before anatomical changes occur. Furthermore, their effectiveness in the palliation of metastatic bone cancer pain has been demonstrated in the clinical setting. With the aim of developing superior bone-seeking radiopharmaceuticals, many compounds have been designed, prepared, and evaluated. Here, several well-designed bone-seeking compounds used for diagnostic and therapeutic use, having the concept of radiometal complexes conjugated to carrier molecules to bone, are reviewed.

  19. Analysis of load redistribution in diaphyseal bone following staged screw removal from bone plates 

    E-print Network

    Nixon, Joseph Craig

    1987-01-01

    is to allow early loading of the bone. This early bone loading allows the patient to mobilize sooner, and if the situation warrants, return to work. Early load bearing is also thought to be an aid to fracture healing. The disadvantage of bone plates... removal of the bone plate as healing progresses in order to obtain increased loading of the bone during the healing process. One approach to this load transfer is the selective removal of the screws which hold the plate to the bone. When some healing...

  20. Fetal bone cells for tissue engineering.

    PubMed

    Montjovent, Marc-Olivier; Burri, Nathalie; Mark, Silke; Federici, Ermanno; Scaletta, Corinne; Zambelli, Pierre-Yves; Hohlfeld, Patrick; Leyvraz, Pierre-François; Applegate, Lee L; Pioletti, Dominique P

    2004-12-01

    We envision the use of human fetal bone cells for engineered regeneration of adult skeletal tissue. A description of their cellular function is then necessary. To our knowledge, there is no description of human primary fetal bone cells treated with differentiation factors. The characterization of fetal bone cells is particularly important as the pattern of secreted proteins from osteoblasts has been shown to change during aging. In the first part of this work, human primary fetal bone cells were compared to adult bone cells and mesenchymal stem cells for their ability to proliferate and to differentiate into osteoblasts in vitro. Cell proliferation, gene expression of bone markers, alkaline phosphatase (ALP) activity, and mineralization were analyzed during a time-course study. In the second part of this paper, bone fetal cells behavior exposed to osteogenic factors is further detailed. The doubling time of fetal bone cells was comparable to mesenchymal stem cells but significantly shorter than for adult bone cells. Gene expression of cbfa-1, ALP, alpha1 chain of type I collagen, and osteocalcin were upregulated in fetal bone cells after 12 days of treatment, with higher inductions than for adult and mesenchymal stem cells. The increase of ALP enzymatic activity was stronger for fetal than for adult bone cells reaching a maximum at day 10, but lower than for mesenchymal stem cells. Importantly, the mineralization process of bone fetal cells started earlier than adult bone and mesenchymal stem cells. Proliferation of fetal and adult bone cells was increased by dexamethasone, whereas 1alpha,25-dihydroxyvitamin D3 did not show any proliferative effect. Mineralization studies clearly demonstrated the presence of calcium deposits in the extracellular matrix of fetal bone cells. Nodule formation and calcification were strongly increased by the differentiation treatment, especially by dexamethasone. This study shows for the first time that human primary fetal bone cells could be of great interest for bone research, due to their fast growth rate and their ability to differentiate into mature osteoblasts. They represent an interesting and promising potential for therapeutic use in bone tissue engineering. PMID:15589213

  1. Intervals between bone density testing.

    PubMed

    Reid, Ian R; Gamble, Gregory D

    2014-02-01

    There is a wide range of practices regarding times between bone density (BMD) measurements in osteopenic women. If decisions to treat osteoporosis are to be based on absolute fracture risk, then projections of fracture risk are a logical basis for determining appropriate intervals for BMD testing. Fracture risk depends mainly on age and BMD, and bone loss in older women is relatively constant at ?1% annually, so it is possible to project fracture risk into the future and estimate when an individual's risk will approach the threshold for intervention. Modeling scenarios for a range of osteopenic baseline BMDs in 65-year-old women shows a remarkable consistency in the doubling time for Fracture Risk Assessment Tool (FRAX)-assessed fracture risk: 5 to 6 years. This estimate is of immediate relevance to clinical practice in that it can be used to determine how long to wait before reassessing BMD and fracture risk in women whose other risk factors are stable. PMID:23893403

  2. Primary bone marrow oedema syndromes.

    PubMed

    Patel, Sanjeev

    2014-05-01

    MRI scanning in patients with rheumatological conditions often shows bone marrow oedema, which can be secondary to inflammatory, degenerative, infective or malignant conditions but can also be primary. The latter condition is of uncertain aetiology and it is also uncertain whether it represents a stage in the progression to osteonecrosis in some patients. Patients with primary bone marrow oedema usually have lower limb pain, commonly the hip, knee, ankle or feet. The diagnosis is one of exclusion with the presence of typical MRI findings. Treatment is usually conservative and includes analgesics and staying off the affected limb. The natural history is that of gradual resolution of symptoms over a number of months. Evidence for medical treatment is limited, but open-label studies suggest bisphosphonates may help in the resolution of pain and improve radiological findings. Surgical decompression is usually used as a last resort. PMID:24080251

  3. Traumatic bone cyst of mandible.

    PubMed

    Surej Kumar, L K; Kurien, Nikhil; Thaha, Khaleel Ahamed

    2015-06-01

    The traumatic bone cyst, an uncommon lesion of the jaws, belongs to the category of 'pseudocyst' owing to its lack of a lining epithelial membrane. It is an asymptomatic lesion, which is often diagnosed accidentally during routine radiological examination commonly present in the posterior mandible as a unilocular radiolucency with scalloping borders. The exact etiopathogenesis of the lesion is still debated, though the role of trauma is often associated. Here we report a rare case of traumatic bone cyst in the anterior mandible, in a 16-year-old female patient with a previous history of trauma to chin; diagnosed and treated successfully in our surgical unit. The case is discussed in relation to its clinical presentation, etiopathogenesis, diagnosis, management and prognosis. PMID:26028875

  4. Effortless Effort in Bone Regeneration: A Review

    PubMed Central

    Nazirkar, Girish; Singh, Shailendra; Dole, Vinaykumar; Nikam, Akhilesh

    2014-01-01

    Since the beginning of the 20th century, the concept of osteoconduction in bony changes in the oral cavity showed a wide range of biomaterials and their osteoinductive potential that emerged gradually and has to a large extent improved the quality of the bone prior to the placement of an implant. Alveolar bone loss is a major concern after tooth extraction in patients and therefore atraumatic extraction procedures should be followed to avoid further bone loss. To overcome the alveolar bone loss and to augment support for placing dental implants, many bone regenerative substitutes are available such as allografts, autografts, xenografts, synthetic biomaterials and osteoactive agents. In light of the steady progress in bone grafting techniques and graft materials, it has become possible to improve the volume, width, and height of bone in deficient areas of the oral cavity. These advances in regenerative dentistry thus facilitate an easy and convenient placement of an implant in an ideal position and angulations resulting in superior esthetics and function. Bone grafting materials and their substitutes are the alternative filler materials, which facilitate to reduce additional surgical procedures, risks, chances of cross infection involved in placing autografts and allografts into the bony structures. This review literature highlights various biomaterials that are helpful in bone healing and thus create an anatomically favorable base for ideal implant placement. How to cite the article: Nazirkar G, Singh S, Dole V, Nikam A. Effortless effort in bone regeneration: A review. J Int Oral Health 2014;6(3):120-4. PMID:25083047

  5. Bone tissue engineering: recent advances and challenges.

    PubMed

    Amini, Ami R; Laurencin, Cato T; Nukavarapu, Syam P

    2012-01-01

    The worldwide incidence of bone disorders and conditions has trended steeply upward and is expected to double by 2020, especially in populations where aging is coupled with increased obesity and poor physical activity. Engineered bone tissue has been viewed as a potential alternative to the conventional use of bone grafts, due to their limitless supply and no disease transmission. However, bone tissue engineering practices have not proceeded to clinical practice due to several limitations or challenges. Bone tissue engineering aims to induce new functional bone regeneration via the synergistic combination of biomaterials, cells, and factor therapy. In this review, we discuss the fundamentals of bone tissue engineering, highlighting the current state of this field. Further, we review the recent advances of biomaterial and cell-based research, as well as approaches used to enhance bone regeneration. Specifically, we discuss widely investigated biomaterial scaffolds, micro- and nano-structural properties of these scaffolds, and the incorporation of biomimetic properties and/or growth factors. In addition, we examine various cellular approaches, including the use of mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), adult stem cells, induced pluripotent stem cells (iPSCs), and platelet-rich plasma (PRP), and their clinical application strengths and limitations. We conclude by overviewing the challenges that face the bone tissue engineering field, such as the lack of sufficient vascularization at the defect site, and the research aimed at functional bone tissue engineering. These challenges will drive future research in the field. PMID:23339648

  6. Optimizing Bone Health in Duchenne Muscular Dystrophy

    PubMed Central

    Buckner, Jason L.; Bowden, Sasigarn A.; Mahan, John D.

    2015-01-01

    Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder characterized by progressive muscle weakness, with eventual loss of ambulation and premature death. The approved therapy with corticosteroids improves muscle strength, prolongs ambulation, and maintains pulmonary function. However, the osteoporotic impact of chronic corticosteroid use further impairs the underlying reduced bone mass seen in DMD, leading to increased fragility fractures of long bones and vertebrae. These serious sequelae adversely affect quality of life and can impact survival. The current clinical issues relating to bone health and bone health screening methods in DMD are presented in this review. Diagnostic studies, including biochemical markers of bone turnover and bone mineral density by dual energy X-ray absorptiometry (DXA), as well as spinal imaging using densitometric lateral spinal imaging, and treatment to optimize bone health in patients with DMD are discussed. Treatment with bisphosphonates offers a method to increase bone mass in these children; oral and intravenous bisphosphonates have been used successfully although treatment is typically reserved for children with fractures and/or bone pain with low bone mass by DXA. PMID:26124831

  7. Reduced vertebral bone density in hypercalciuric nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Pietschmann, F.; Breslau, N. A.; Pak, C. Y.

    1992-01-01

    Dual-energy x-ray absorptiometry and single-photon absorptiometry were used to determine bone density at the lumbar spine and radial shaft in 62 patients with absorptive hypercalciuria, 27 patients with fasting hypercalciuria, and 31 nonhypercalciuric stone formers. Lumbar bone density was significantly lower in patients with absorptive (-10%) as well as in those with fasting hypercalciuria (-12%), with 74 and 92% of patients displaying values below the normal mean, whereas only 48% of the nonhypercalciuric stone formers had bone density values below the normal mean. In contrast, radial bone density was similar in all three groups of renal stone formers investigated. The comparison of urinary chemistry in patients with absorptive hypercalciuria and low normal bone density compared to those with high normal bone density showed a significantly increased 24 h urinary calcium excretion on random diet and a trend toward a higher 24 h urinary uric acid excretion and a higher body mass index in patients with low normal bone density. Moreover, among the patients with absorptive hypercalciuria we found a statistically significant correlation between the spinal bone density and the 24 h sodium and sulfate excretion and the urinary pH. These results gave evidence for an additional role of environmental factors (sodium and animal proteins) in the pathogenesis of bone loss in absorptive hypercalciuria. In conclusion, our data suggest an osteopenia of trabecular-rich bone tissues in patients with fasting and absorptive hypercalciurias.

  8. Bone Tissue Engineering: Recent Advances and Challenges

    PubMed Central

    Amini, Ami R.; Laurencin, Cato T.; Nukavarapu, Syam P.

    2013-01-01

    The worldwide incidence of bone disorders and conditions has trended steeply upward and is expected to double by 2020, especially in populations where aging is coupled with increased obesity and poor physical activity. Engineered bone tissue has been viewed as a potential alternative to the conventional use of bone grafts, due to their limitless supply and no disease transmission. However, bone tissue engineering practices have not proceeded to clinical practice due to several limitations or challenges. Bone tissue engineering aims to induce new functional bone regeneration via the synergistic combination of biomaterials, cells, and factor therapy. In this review, we discuss the fundamentals of bone tissue engineering, highlighting the current state of this field. Further, we review the recent advances of biomaterial and cell-based research, as well as approaches used to enhance bone regeneration. Specifically, we discuss widely investigated biomaterial scaffolds, micro- and nano-structural properties of these scaffolds, and the incorporation of biomimetic properties and/or growth factors. In addition, we examine various cellular approaches, including the use of mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), adult stem cells, induced pluripotent stem cells (iPSCs), and platelet-rich plasma (PRP), and their clinical application strengths and limitations. We conclude by overviewing the challenges that face the bone tissue engineering field, such as the lack of sufficient vascularization at the defect site, and the research aimed at functional bone tissue engineering. These challenges will drive future research in the field. PMID:23339648

  9. The temporal response of bone to unloading

    NASA Technical Reports Server (NTRS)

    Globus, R. K.; Bikle, D. D.; Morey-Holton, E.

    1984-01-01

    Rats were suspended by their tails with the forelimbs bearing the weight load to simulate the weightlessness of space flight. Growth in bone mass ceased by 1 week in the hindlimbs and lumbar vertebrae in growing rats, while growth in the forelimbs and cervical vertebrae remained unaffected. The effects of selective skeletal unloading on bone formation during 2 weeks of suspension was investigated using radio iostope incorporation (with Ca-45 and H-3 proline) and histomorphometry (with tetracycline labeling). The results of these studies were confirmed by histomorphometric measurements of bone formation using triple tetracycline labeling. This model of simulated weightlessness results in an initial inhibition of bone formation in the unloaded bones. This temporary cessation of bone formation is followed in the accretion of bone mass, which then resumes at a normal rate by 14 days, despite continued skeletal unloading. This cycle of inhibition and resumption of bone formation has profound implication for understanding bone dynamics durng space flight, immobilization, or bed rest and offers an opportunity to study the hormonal and mechanical factors that regulate bone formation.

  10. Abnormal bone remodelling in inflammatory arthritis.

    PubMed

    Bogoch, E R; Moran, E

    1998-08-01

    Osteopenia is responsible for substantial comorbidity in patients suffering from rheumatoid arthritis and is an important factor in the surgical management of joint disease. In animal models of bone loss stimulated by inflammatory arthritis, increased bone remodelling and altered microstructure of bone have been documented. The subchondral bone plate near the joint surface is narrow and perforated by vascular inflammatory invasion, and in the shaft the thin cortices are weakened by giant resorption defects. Biomechanical tests and a mathematical model of bone strength suggest that cortical defects, much larger than those found in normal osteonal remodelling, are principally responsible for the experimentally observed loss of strength. Similarly, these defects may explain the increased femoral fracture risk in rheumatoid arthritis. The osteoclast, the cell resorbing bone, is demonstrated in increased number and activity in rheumatoid arthritis and in animal models. Bisphosphonates, drugs that inhibit osteoclast function, have been shown experimentally to reduce both focal and generalized osteopenia and to prevent loss of bone strength. Bisphosphonates also protect articular cartilage from damage characteristic of inflammatory arthritis. The mechanism of chondroprotection may be prevention of subchondral bone resorption by the osteoclast and also an altered distribution of bone marrow cells. Thus, bisphosphonates, currently in clinical use for other bone metabolic diseases, appear to have potential as prophylaxis and treatment for osteopenia and joint damage in inflammatory arthritis. PMID:9711159

  11. Inherited bone marrow failure syndromes

    Microsoft Academic Search

    Inderjeet Dokal

    2011-01-01

    The inherited bone marrow failure syndromes are a diverse group of disorders characterized by BM failure usually in association\\u000a with one or more somatic\\/physical abnormality. Over the last two decades, the genes responsible for many of these have been\\u000a identified. The significant advances in their molecular basis have provided insights into several biological pathways, such\\u000a as DNA repair and telomere

  12. New developments in bone densitometry

    SciTech Connect

    Genant, H.K.; Steiger, P.; Glueer, C.C.

    1989-04-01

    The new development in QCT and DPA will reduce the time of diagnostic studies to several minutes and improve precision severalfold. It may therefore be feasible to do selective screening procedures at costs as low as $50 to $100. Thus, these advances in QCT and DPA are promising to provide capabilities that have been needed in bone densitometry--high reliability, excellent patient throughput, and services at economical levels.

  13. Cadmium and postmenopausal bone loss

    SciTech Connect

    Bhattacharyya, M.H.; Whelton, B.D.; Stern, P.H.; Peterson, D.P.; Moretti, E.S.; Dare, H.A.

    1987-01-01

    Neither ovariectomy alone nor dietary cadmium exposure alone caused statistically significant decreases in the mean calcium contents and calcium/dry weight ratios of the femurs and lumbar vertebrae. Exposure to 50 ppM dietary Cd caused a significant increase in the loss of bone calcium after ovariectomy such that the calcium contents and calcium to dry weight ratios of both femurs and lumbar vertebrae were strikingly lower than those of all other groups.

  14. Cannabinoids and bone: friend or foe?

    PubMed

    Idris, Aymen I; Ralston, Stuart H

    2010-10-01

    The endocannabinoid system is recognized to play an important role in regulating a variety of physiological processes, including appetite control and energy balance, pain perception, and immune responses. The endocannabinoid system has also recently been implicated in the regulation of bone metabolism. Endogenously produced cannabinoids are hydrophobic molecules derived from hydrolysis of membrane phospholipids. These substances, along with plant-derived and synthetic cannabinoids, interact with the type 1 (CB(1)) and 2 (CB(2)) cannabinoid receptors and the GPR55 receptor to regulate cellular function through a variety of signaling pathways. Endocannabinoids are produced in bone, but the mechanisms that regulate their production are unclear. Skeletal phenotyping of mice with targeted inactivation of cannabinoid receptors and pharmacological studies have shown that cannabinoids play a key role in the regulation of bone metabolism. Mice with CB(1) deficiency have high peak bone mass as a result of an osteoclast defect but develop age-related osteoporosis as a result of impaired bone formation and accumulation of bone marrow fat. Mice with CB(2) deficiency have relatively normal peak bone mass but develop age-related osteoporosis as a result of increased bone turnover with uncoupling of bone resorption from bone formation. Mice with GPR55 deficiency have increased bone mass as a result of a defect in the resorptive activity of osteoclasts, but bone formation is unaffected. Cannabinoids are also produced within synovial tissues, and preclinical studies have shown that cannabinoid receptor ligands are effective in the treatment of inflammatory arthritis. These data indicate that cannabinoid receptors and the enzymes responsible for ligand synthesis and breakdown play important roles in bone remodeling and in the pathogenesis of joint disease. PMID:20532878

  15. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, J.W.

    1993-01-01

    The present invention relates to the electrical treatment of biological tissue. In particular, the present invention discloses a device that produces discrete electrical pulse trains for treating osteoporosis and accelerating bone growth. According to its major aspects and broadly stated, the present invention consists of an electrical circuit configuration capable of generating Bassett-type waveforms shown with alternative signals provide for the treatment of either fractured bones or osteoporosis. The signal generator comprises a quartz clock, an oscillator circuit, a binary divider chain, and a plurality of simple, digital logic gates. Signals are delivered efficiently, with little or no distortion, and uniformly distributed throughout the area of injury. Perferably, power is furnished by widely available and inexpensive radio batteries, needing replacement only once in several days. The present invention can be affixed to a medical cast without a great increase in either weight or bulk. Also, the disclosed stimulator can be used to treat osteoporosis or to strengthen a healing bone after the cast has been removed by attaching the device to the patient`s skin or clothing.

  16. Vancomycin iontophoresis of allograft bone

    PubMed Central

    Edmondson, M. C.; Day, R.; Wood, D.

    2014-01-01

    Objectives The most concerning infection of allografts and operative procedures is methicillin resistant Staphylococcus aureus (MRSA) and no current iontophoresed antibiotics effectively combat this microbe. It was initially hypothesised that iontophoresis of vancomycin through bone would not be effective due to its large molecular size and lack of charge. The aim of this study was to determine whether this was a viable procedure and to find the optimum conditions for its use. Methods An iontophoresis cell was set up with varying concentrations of Vancomycin within the medulla of a section of sheep tibia, sealed from an external saline solution. The cell was run for varying times, Vancomycin concentrations and voltages, to gain information on optimisation of conditions for impregnating the graft. Each graft was then sectioned and dust ground from the exposed surface. The dust was serially washed to extract the Vancomycin and concentrations measured and plotted for all variables tested. Results Vancomycin was successfully delivered and impregnated to the graft using the iontophoresis technique. The first order fit to the whole data set gave a significant result (p = 0.0233), with a significant concentration (p = 0.02774) component. The time component was the next most significant (p = 0.0597), but did not exceed the 95% confidence level. Conclusions Iontophoresis is an effective method for delivering Vancomycin to allograft bone. The concentrations of the vancomycin solution affected the bone concentration, but results were highly variable. Further study should be done on the effectiveness of delivering different antibiotics using this method. PMID:24729101

  17. Toward automated bone fracture classification

    NASA Astrophysics Data System (ADS)

    Funk, Michael W.; El-Kwae, Essam A.; Kellam, James F.

    2001-07-01

    A model is developed for the automated classification of bone fractures via image analysis techniques. The model is based on the widely used fracture classification system developed by the M.E. Mueller Foundation of Bern, Switzerland. The system describes a hierarchy of fractures, six layers deep. It also describes a series of questions to be asked about a given fracture, in which each question answered classifies the fracture into more descriptive subcategories. The model developed considers fracture classification as a tree traversal problem, in which the lower layers of the tree represent more precise categorizations. At each of the tree's nodes, algorithms specific to that subcategory determine which of the child nodes will be visited. Digital image processing techniques are most readily applicable to the largest number of nodes. Thus, the initial algorithms in this work are based on image processing techniques. The main contributions of this paper include a model for automated bone fracture classification and the algorithms for classification of a subset of long bone fractures. This work aims to provide a solid model and initial results that will serve as the basis for further research into this challenging and potentially rewarding field.

  18. The effects of surgicel and bone wax hemostatic agents on bone healing: An experimental study

    PubMed Central

    Nooh, Nasser; Abdullah, Walid A; Grawish, Mohammed El-Awady; Ramalingam, Sundar; Javed, Fawad; Al-Hezaimi, Khalid

    2014-01-01

    Background: The biological effects of hemostatic agends on the physiological healing process need to be tested. The aim of this study was to assess the effects of oxidized cellulose (surgicel) and bone wax on bone healing in goats’ feet. Materials and Methods: Three congruent circular bone defects were created on the lateral aspects of the right and left metacarpal bones of ten goats. One defect was left unfilled and acted as a control; the remaining two defects were filled with bone wax and surgicel respectively. The 10 animals were divided into two groups of 5 animals each, to be sacrificed at the 3rd and 5th week postoperatively. Histological analysis assessing quality of bone formed and micro-computed tomography (MCT) measuring the quantities of bone volume (BV) and bone density (BD) were performed. The results of MCT analysis pertaining to BV and BD were statistically analyzed using two-way analysis of variance (ANOVA) and posthoc least significant difference tests. Results: Histological analysis at 3 weeks showed granulation tissue with new bone formation in the control defects, active bone formation only at the borders for surgicel filled defects and fibrous encapsulation with foreign body reaction in the bone wax filled defects. At 5 weeks, the control and surgicel filled defects showed greater bone formation; however the control defects had the greatest amount of new bone. Bone wax filled defects showed very little bone formation. The two-way ANOVA for MCT results showed significant differences for BV and BD between the different hemostatic agents during the two examination periods. Conclusion: Surgicel has superiority over bone wax in terms of osseous healing. Bone wax significantly hinders osteogenesis and induces inflammation. PMID:24932041

  19. PuraMatrix facilitates bone regeneration in bone defects of calvaria in mice.

    PubMed

    Misawa, Haruo; Kobayashi, Naoya; Soto-Gutierrez, Alejandro; Chen, Yong; Yoshida, Aki; Rivas-Carrillo, Jorge David; Navarro-Alvarez, Nalu; Tanaka, Kimiaki; Miki, Atsushi; Takei, Jiro; Ueda, Tadayoshi; Tanaka, Masato; Endo, Hirosuke; Tanaka, Noriaki; Ozaki, Toshifumi

    2006-01-01

    Artificial bones have often used for bone regeneration due to their strength, but they cannot provide an adequate environment for cell penetration and settlement. We therefore attempted to explore various materials that may allow the cells to penetrate and engraft in bone defects. PuraMatrix is a self-assembling peptide scaffold that produces a nanoscale environment allowing both cellular penetration and engraftment. The objective of this study was to investigate the effect of PuraMatrix on bone regeneration in a mouse bone defect model of the calvaria. Matrigel was used as a control. The expression of bone-related genes (alkaline phosphatase, Runx2, and Osterix) in the PuraMatrix-injected bone defects was stronger than that in the Matrigel-injected defects. Soft X-ray radiographs revealed that bony bridges were clearly observed in the defects treated with PuraMatrix, but not in the Matrigel-treated defects. Notably, PuraMatrix treatment induced mature bone tissue while showing cortical bone medullary cavities. The area of newly formed bones at the site of the bone defects was 1.38-fold larger for PuraMatrix than Matrigel. The strength of the regenerated bone was 1.72-fold higher for PuraMatrix (146.0 g) than for Matrigel (84.7 g). The present study demonstrated that PuraMatrix injection favorably induced functional bone regeneration. PMID:17299995

  20. Clinical usefulness of bone markers in prostate cancer with bone metastasis.

    PubMed

    Kamiya, Naoto; Suzuki, Hiroyoshi; Endo, Takumi; Yano, Masashi; Naoi, Makito; Nishimi, Daisuke; Kawamura, Koji; Imamoto, Takashi; Ichikawa, Tomohiko

    2012-11-01

    Bone metastases occur in approximately 70% of patients with advanced prostate cancer. Skeletal-related events have been correlated with reduced survival and quality of life of patients with prostate cancer. Biochemical markers of bone metabolism (e.g. bone formation, bone resorption, osteoclastogenesis) might meet an unmet need for useful, non-invasive and sensitive surrogate information for following patients' skeletal health. Recently, zoledronic acid and denosumab have been proven to have the potential for preventing skeletal-related events among prostate cancer patients with bone metastasis. An improved understanding of the mechanisms underlying bone metastasis has also led to the recognition of multiple molecular targets and advances in therapy. However, estimating the efficacy of these agents is difficult. A clinical trial for castration-resistant prostate cancer is currently underway based on the definition of The Prostate Cancer Clinical Trials Working Group, and bone turnover markers are being used as conventional end-points for the clinical trial. Bone turnover markers are useful surrogate markers reflecting the effect of new therapeutic drugs and prognosis, as well as assessment of bone metastases. In particular, N-terminal cross-linked telopeptide of type 1 collagen and bone-specific alkaline phosphatase are widely used bone metabolism markers, and offer reliable surrogate markers to detect bone metastatic spread and to predict prognosis for prostate cancer patients with bone metastases. PMID:22805007

  1. Trabecular bone turnover, bone marrow cell development, and gene expression of bone matrix proteins after low calcium feeding in rats

    Microsoft Academic Search

    H Seto; K Aoki; S Kasugai; K Ohya

    1999-01-01

    Low-calcium-fed animals have been accepted as one of the experimental models showing a reduction in bone mass. However, the effects of short-term low-calcium feeding on bone turnover, the development of osteoprogenitor cells, and gene expression of bone matrix proteins have not been reported. In this study, we examined the effect of a low-calcium diet on rat tibia and analyzed the

  2. Evaluation of Bone Height and Bone Mineral Density Using Cone Beam Computed Tomography After Secondary Bone Graft in Alveolar Cleft.

    PubMed

    Zhang, Dai-Zun; Xiao, Wen-Lin; Zhou, Rong; Xue, Ling-Fa; Ma, Long

    2015-07-01

    The purpose of this study was to assess the optimal timing of subsequent dental implant placement and orthodontics after alveolar bone grafting (ABG) in patients with unilateral complete clefts of the alveolar process. Iliac bone graft surgery was performed on 60 patients. Bone mineral density (BMD) and height of the ABG areas were assessed using cone beam computed tomography at 3 and 6 months postoperatively. The heights of the labial and palatal bone graft areas were classified using the modified Bergland classification. The study found that there was no change in BMD between 3 months (mean?±?SD: 406.51?±?71.28 Hounsfield units [HU]) and 6 months (409.53?±?46.37?HU; P?=?0.381). Significant changes in the distribution of bone height classifications were observed in the labial and palatal sides of the ABG between 3 and 6 months (P?=?0.025 for labial bone height, P?=?0.008 for palatal bone height). These results indicate that the alveolar density remained stable between 3 and 6 months, whereas bone height level declined during that period after ABG, the latter indicating bone graft absorption over time. It is, therefore, suggested that subsequent orthodontic or dental implants be placed 3 months after ABG rather than at 6 months or later. PMID:26114510

  3. Management of unicameral bone cyst by using freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow.

    PubMed

    Datta, N K; Das, K P; Alam, M S; Kaiser, M S

    2014-07-01

    Unicameral bone cyst is a common benign bone tumor and most frequent cause of the pathological fracture in children. We have started a prospective study for that treatment of unicameral bone cyst by using freeze dried radiation sterilized bone allograft impregnated with autogenous bone marrow in the department of Orthopaedics, Bangabandhu Sheikh Mujib Medical University (BSMMU) during May 1999 to April 2012. Aim of this study was to see Freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow a satisfactory graft material in the treatment of unicameral bone cyst as well as factors such as patients age, sex, cyst size and site of lesion influence on cyst healing. A total 35 patients of unicameral bone cyst were operated. In this study out of 35 patients, male were 22(62.86%) and female were 13(37.14). Male Female ratio 22:13(1.70:1) Age of the patients ranging from 2 years 6 month to 20 years, mean age 12.18 years more common 11 years to 20 years 29(82.86%) patients. Common bones sites involvements are proximal end of Humerus 20(57.14%), proximal end of Femur 7(20 %), proximal end of Tibia 3(8.57%), Calcanium 2(5.71%), proximal end of Ulna 1(2.86%), shaft of Radius 1(2.86%) and Phalanx 1(2.86%). Final clinical outcome of unicameral bone cyst treated by thorough curettage of cavity and tightly filled with freeze dried radiation sterilized bone allograft impregnate with autogenous bone marrow in which healed (success rate) 88.57% (31) and recurrence rate is 11.43% (4). P value is <0.001. Follow up period was 6 month to 11 years. From our study it was realized that freeze dried radiation sterilized bone allograft impregnated with autogenous bone marrow is useful graft material for healing of the lesional area as well as restoring structural integrity for the treatment of unicameral bone cyst. PMID:25178604

  4. Bone Vascularization in Normal and Disease Conditions

    PubMed Central

    Carulli, Christian; Innocenti, Massimo; Brandi, Maria Luisa

    2013-01-01

    Bone vasculature is essential for many processes, such as skeletal development and growth, bone modeling and remodeling, and healing processes. Endothelium is an integral part of bone tissue, expressing a physiological paracrine function via growth factors and chemokines release, and interacting with several cellular lines. Alterations of the complex biochemical interactions between vasculature and bone cells may lead to various clinical manifestations. Two different types of pathologies result: a defect or an excess of bone vasculature or endothelium metabolism. Starting from the molecular basis of the interactions between endothelial and bone cells, the Authors present an overview of the recent acquisitions in the physiopathology of the most important clinical patterns, and the modern therapeutic strategies for their treatments. PMID:23986744

  5. [Possibilities in the reconstruction of bone defects].

    PubMed

    Baumgart, R; Betz, A; Kessler, S; Kettler, M; Schweiberer, L

    1994-11-01

    The importance of the functional unit "bone-soft-tissue" for the treatment of bone defects is discussed. A division is made between non-vascular and vascular bone transport. The individual methods are explained and their clinical significance is illustrated partly using case material. In general, the best way to fill small defects in vital soft tissue is to use cancellous autografts. For bridging longer bone defects callus distraction is the method of first choice, but in individual cases vascularized bone transfer can be taken from the iliac crest or the fibula. Homo- or heterografts should only be used in cases where no autologic bone material is available or when there is not enough. PMID:7831053

  6. Bone microenvironment signals in osteosarcoma development.

    PubMed

    Alfranca, Arantzazu; Martinez-Cruzado, Lucia; Tornin, Juan; Abarrategi, Ander; Amaral, Teresa; de Alava, Enrique; Menendez, Pablo; Garcia-Castro, Javier; Rodriguez, Rene

    2015-08-01

    The bone is a complex connective tissue composed of many different cell types such as osteoblasts, osteoclasts, chondrocytes, mesenchymal stem/progenitor cells, hematopoietic cells and endothelial cells, among others. The interaction between them is finely balanced through the processes of bone formation and bone remodeling, which regulates the production and biological activity of many soluble factors and extracellular matrix components needed to maintain the bone homeostasis in terms of cell proliferation, differentiation and apoptosis. Osteosarcoma (OS) emerges in this complex environment as a result of poorly defined oncogenic events arising in osteogenic lineage precursors. Increasing evidence supports that similar to normal development, the bone microenvironment (BME) underlies OS initiation and progression. Here, we recapitulate the physiological processes that regulate bone homeostasis and review the current knowledge about how OS cells and BME communicate and interact, describing how these interactions affect OS cell growth, metastasis, cancer stem cell fate and therapy outcome. PMID:25935149

  7. Regulation of bone mineral loss during lactation

    NASA Technical Reports Server (NTRS)

    Brommage, R.; Deluca, H. F.

    1985-01-01

    The effects of varyng dietary calcium and phosphorous levels, vitamin D deficiency, oophorectomy, adrenalectomy, and simultaneous pregnancy on bone mineral loss during lactation in rats are studied. The experimental procedures and evaluations are described. The femur ash weight of lactating and nonlactating rats are calculated. The data reveals that a decrease in dietary calcium of 0.02 percent results in an increased loss of bone mineral, an increase in calcium to 1.4 percent does not lessen bone mineral loss, and bone mineral loss in vitamin D deficient rats is independent of calcium levels. It is observed that changes in dietary phosphorous level, oophorectomy, adrenalectomy, and simultaneous pragnancy do not reduce bone mineral loss during lactation. The analysis of various hormones to determine the mechanism that triggers bone mineral loss during lactation is presented.

  8. Chronic kidney disease and bone metabolism.

    PubMed

    Kazama, Junichiro James; Matsuo, Koji; Iwasaki, Yoshiko; Fukagawa, Masafumi

    2015-05-01

    Chronic kidney disease-related mineral and bone disease (CKD-MBD) is a syndrome defined as a systemic mineral metabolic disorder associated with CKD, and the term renal osteodystrophy indicates a pathomorphological concept of bone lesions associated with CKD-MBD. Cortical bone thinning, abnormalities in bone turnover and primary/secondary mineralization, elevated levels of circulating sclerostin, increased apoptosis in osteoblasts and osteocytes, disturbance of the coupling phenomenon, iatrogenic factors, accumulated micro-crackles, crystal/collagen disorientation, and chemical modification of collagen crosslinks are all possible candidates found in CKD that could promote osteopenia and/or bone fragility. Some of above factors are the consequences of abnormal systemic mineral metabolism but for others it seem unlikely. We have used the term uremic osteoporosis to describe the uremia-induced bone fragility which is not derived from abnormal systemic mineral metabolism. Interestingly, the disease aspect of uremic osteoporosis appears to be similar to that of senile osteoporosis. PMID:25653092

  9. Finite element modeling of bone tissue stress adaptation

    Microsoft Academic Search

    Tony S. Keller

    2001-01-01

    The design or architecture of bone is quite complex and diverse, ranging from a very porous cellular solid (trabecular bone) to a very dense solid (cortical bone). Significant adaptations to cortical and trabecular bone mass and architecture have been observed in response to changes in stresses acting on the tissue. The purpose of this paper is to examine bone stress-adaptation

  10. Mechanisms of Action and Therapeutic Potential of Strontium in Bone

    Microsoft Academic Search

    P. J. Marie; P. Ammann; G. Boivin; C. Rey

    2001-01-01

    The processes of bone resorption and formation are tightly governed by a variety of systemic and local regulatory agents. In addition, minerals and trace elements affect bone formation and resorption through direct or indirect effects on bone cells or bone mineral. Some trace elements closely chemically related to calcium, such as strontium (Sr), have pharmacological effects on bone when present

  11. Cells, Collagen Fibrils and Vessels in Dinosaur Bone

    Microsoft Academic Search

    R. Pawlicki; A. Korbel; H. KUBIAK

    1966-01-01

    COLLAGEN has been found in mummified human remains several thousand years old, and in mastodon bones preserved under permafrost conditions. It has been stated that bone fragments after glacier preservation had all the appearances of a fresh bone1. Studies on Pleistocene bones have demonstrated that it is also possible to observe collagen and other organic materials in a fossil bone2,3.

  12. The contribution of bone loss to postmenopausal osteoporosis

    Microsoft Academic Search

    S. L. Hui; C. W. Slemenda; C. C. Johnston

    1990-01-01

    We have addressed the relative importance of peak bone mass and subsequent rate of loss in determining postmenopausal women's bone mass in old age, by examining longitudinal measurements of radial mid-shaft bone mass on various samples of healthy white postmenopausal women. Using both the variance estimate of age-specific rates of bone loss and the population variance in bone mass, we

  13. Bone and bone-marrow blood flow in chronic granulocytic leukemia and primary myelofibrosis.

    PubMed

    Lahtinen, R; Lahtinen, T; Romppanen, T

    1982-03-01

    Blood flow in hematopoietic bone marrow and in nonhematopoietic bone has been measured with a Xe-133 washout method in 20 patients with chronic granulocytic leukemia (CGL) and in seven with primary myelofibrosis. Age-matched healthy persons served as controls. Bone-marrow blood flow in CGL was dependent upon the phase of the disease. In the metamorphosis phase, bone-marrow blood flow was high compared with that in the well-controlled phase. Apart from the initial phase, the mean values for bone blood flow in CGL were increased compared with the values of the healthy controls. In myelofibrosis the bone blood flow was also increased. Bone-marrow blood flow in these diseases was dependent upon the cellularity of bone marrow as measured morphometrically. PMID:6950031

  14. Microbial bioerosion of bone – a review

    Microsoft Academic Search

    Miranda M. E. Jans

    Microbial alteration is an important pathway for bone degradation. Organisms involved in bioerosion of bone, mainly bacteria,\\u000a fungi and cyanobacteria, create different types of alteration. While fungi and cyanobacteria dissolve the bone matrix resulting\\u000a in branching tunnels, bacteria create microscopical focal destructions with a complex morphology, reorganising the mineral\\u000a rather than removing it. Different environmental and early post mortem circumstances

  15. Comparison of lead residues among avian bones

    Microsoft Academic Search

    A. L. M. Ethier; B. M. Braune; A. M. Scheuhammer; D. E. Bond

    2007-01-01

    To determine if significant differences exist in lead (Pb) accumulation in different bones, especially those most often used for bone-Pb studies in wildlife, we compared Pb concentrations in radius, ulna, humerus, femur, and tibia of Common Eider (Somateria mollissima); and radius\\/ulna (combined), femur, and tibia of American Woodcock (Scolopax minor). There were no significant differences in bone-Pb concentrations among woodcock

  16. Histidinoalanine-containing phosphoprotein in bone

    Microsoft Academic Search

    Yoshinori Kuboki; Hiroko Takita; Ryuichi Fujisawa; Hiro-o Yamaguchi; Hisashi Yamada; Mariko Tazaki; Youko Ohnuma; Morimichi Mizuno; Mari Tsuzaki

    1991-01-01

    Summary  Histidinoalanine is a naturally occurring cross-linking amino acid found in mammalian bone, dentin, cartilage and aorta, and\\u000a also in the extracellular fluid of bivalve clams. The exact components from which this amino acid derives have not been characterized\\u000a in the case of bone. In this study, the origin of histidinoalanine in bone was investigated in order to clarify the possible

  17. Effects of thyroid hormone on bone

    Microsoft Academic Search

    Nikolaos Stathatos; Leonard Wartofsky

    2004-01-01

    It is relatively well established that thyroid hormone has a clinically significant effect on bone. Although some aspects,\\u000a such as the bone mineral loss associated with overt thyrotoxicosis have been relatively well described, others remain much\\u000a less clear. A major focus of this review is on the effects of chronic exogenous thyroid hormone administration on bone physiology.\\u000a When thyroid hormone

  18. Interventional radiology in bone and joint

    SciTech Connect

    Bard, M.; Laredo, J.D.

    1988-01-01

    Recent radiologic procedures in bone and joints, some of which eliminate the need for surgery are exposed, including: trephine biopsies of the thoracic and lumbar spine, sacro-iliac joints, peripheral bones synovial membrane and soft tissues, using either fluoroscopic echographic or CT guidance - chemonucleolysis - vascular embolization of skeletal tumors and management of vertebral hemangiomas - selective steroid injection in a broad spectrum of diseases including vertebral facet syndrome, cervicobrachial nerve root pain, rotator cuff calcium deposit, bone cysts.

  19. Osteocyte: the unrecognized side of bone tissue

    Microsoft Academic Search

    G. Y. Rochefort; S. Pallu; C. L. Benhamou

    2010-01-01

    Introduction  Osteocytes represent 95% of all bone cells. These cells are old osteoblasts that occupy the lacunar space and are surrounded\\u000a by the bone matrix. They possess cytoplasmic dendrites that form a canalicular network for communication between osteocytes\\u000a and the bone surface. They express some biomarkers (osteopontin, ?3 integrin, CD44, dentin matrix protein 1, sclerostin, phosphate-regulating\\u000a gene with homologies to endopeptidases

  20. Empirical Evaluation of Bone Extraction Protocols

    PubMed Central

    Cleland, Timothy P.; Voegele, Kristyn; Schweitzer, Mary H.

    2012-01-01

    The application of high-resolution analytical techniques to characterize ancient bone proteins requires clean, efficient extraction to obtain high quality data. Here, we evaluated many different protocols from the literature on ostrich cortical bone and moa cortical bone to evaluate their yield and relative purity using the identification of antibody-antigen complexes on enzyme-linked immunosorbent assay and gel electrophoresis. Moa bone provided an ancient comparison for the effectiveness of bone extraction protocols tested on ostrich bone. For the immunological part of this study, we focused on collagen I, osteocalcin, and hemoglobin because collagen and osteocalcin are the most abundant proteins in the mineralized extracellular matrix and hemoglobin is common in the vasculature. Most of these procedures demineralize the bone first, and then the remaining organics are chemically extracted. We found that the use of hydrochloric acid, rather than ethylenediaminetetraacetic acid, for demineralization resulted in the cleanest extractions because the acid was easily removed. In contrast, the use of ethylenediaminetetraacetic acid resulted in smearing upon electrophoretic separation, possibly indicating these samples were not as pure. The denaturing agents sodium dodecyl sulfate, urea, and guanidine HCl have been used extensively for the solubilization of proteins in non-biomineralized tissue, but only the latter has been used on bone. We show that all three denaturing agents are effective for extracting bone proteins. One additional method tested uses ammonium bicarbonate as a solubilizing buffer that is more appropriate for post-extraction analyses (e.g., proteomics) by removing the need for desalting. We found that both guanidine HCl and ammonium bicarbonate were effective for extracting many bone proteins, resulting in similar electrophoretic patterns. With the increasing use of proteomics, a new generation of scientists are now interested in the study of proteins from not only extant bone but also from ancient bone. PMID:22348088

  1. Paget’s Disease of Bone

    Microsoft Academic Search

    Roy D. Altman

    \\u000a Paget’s disease is a chronic disorder of the adult skeleton characterized by increased resorption and deposition of bone resulting\\u000a in replacement of the normal matrix with a softened and enlarged bone. Initially, there is active resorption by large and\\u000a increased numbers of osteoclasts containing multiple nuclei, followed by deposition of bone by numerous osteoblasts which\\u000a most often results in a

  2. Gravity, Calcium, And Bone: Update, 1989

    NASA Technical Reports Server (NTRS)

    Arnaud, Sara B.; Morey-Holton, Emily

    1992-01-01

    Report reviews short-term flight and ground-based experiments on effects of 1 g and 0 g on skeletal adaptation, calcium metabolism, and growth processes. Results indicate two principal components of calcium metabolism-calcium endocrine system and bone - respond within days to changes in orientation of body in gravitation and to weightlessness. Effects of spaceflight or bed rest on biomechanics of bones more severe than on total body bone mass.

  3. Affective Disorders, Bone Metabolism, and Osteoporosis

    Microsoft Academic Search

    Briana Mezuk

    2008-01-01

    The nature of the relationship between affective disorders, bone mineral density (BMD), and bone metabolism is unresolved,\\u000a although there is growing evidence that many medications used to treat affective disorders are associated with low BMD or\\u000a alterations in neuroendocrine systems that influence bone turnover. The objective of this review is to describe the current\\u000a evidence regarding the association of unipolar

  4. Diverse Osteoclastogenesis of Bone Marrow From Mandible versus Long Bone

    PubMed Central

    Chaichanasakul, Thawinee; Kang, Benjamin; Bezouglaia, Olga; Aghaloo, Tara L.; Tetradis, Sotirios

    2015-01-01

    Background Mandible (MB) and maxilla possess unique metabolic and functional properties and demonstrate discrete responses to homeostatic, mechanical, hormonal and developmental stimuli. Osteogenic potential of bone marrow stromal cells (BMSCs) differs between MB versus long bones (LB). Furthermore, MB versus LB derived osteoclasts (OCs) have disparate functional properties. Here, we explored the osteoclastogenic potential of rat MB versus LB marrow in vitro and in vivo under basal and stimulated conditions. Methods Bone marrow from rat MB and LB was cultured in osteoblastic or osteoclastic differentiation media. Tartrate resistant acid phosphatase (TRAP) staining, resorption pit assays, and real-time PCR were performed. Additionally, osmotic mini-pumps were implanted in animals, mandibles and tibiae were isolated and multinucleated cells (MNCs) were measured. Results MB versus LB marrow cultures differentiated with RANKL and M-CSF produced more TRAP+ multinucleated cells (MNCs) and greater resorptive area. To explore MB versus LB BMSC supported osteoclastogenesis, confluent BMSCs were cultured with parathyroid hormone (PTH), 1?,25-dihydroxyvitaminD3 (1,25D3), or PTH+1,25D3. 1,25D3 or PTH+1,25D3 treated LB BMSCs expressed significantly higher RANKL and lower OPG mRNA and increased RANKL:OPG ratio. When whole marrow was cultured with PTH+1,25D3, more TRAP+ MNCs were seen in LB versus MB cultures. Ultimately, rats were infused with PTH+1,25D3 and MB versus tibia MNCs were measured. Hormonal stimulation increased osteoclastogenesis in both MB and tibia. However, higher TRAP+ MNC numbers were observed in tibia versus MB under basal and hormonal stimulation. Conclusions Collectively, our data illustrate differences both on osteoclastogenic potential and OC numbers of MB versus LB marrow. PMID:24003963

  5. Connecting mechanics and bone cell activities in the bone remodeling process: an integrated finite element modeling.

    PubMed

    Hambli, Ridha

    2014-01-01

    Bone adaptation occurs as a response to external loadings and involves bone resorption by osteoclasts followed by the formation of new bone by osteoblasts. It is directly triggered by the transduction phase by osteocytes embedded within the bone matrix. The bone remodeling process is governed by the interactions between osteoblasts and osteoclasts through the expression of several autocrine and paracrine factors that control bone cell populations and their relative rate of differentiation and proliferation. A review of the literature shows that despite the progress in bone remodeling simulation using the finite element (FE) method, there is still a lack of predictive models that explicitly consider the interaction between osteoblasts and osteoclasts combined with the mechanical response of bone. The current study attempts to develop an FE model to describe the bone remodeling process, taking into consideration the activities of osteoclasts and osteoblasts. The mechanical behavior of bone is described by taking into account the bone material fatigue damage accumulation and mineralization. A coupled strain-damage stimulus function is proposed, which controls the level of autocrine and paracrine factors. The cellular behavior is based on Komarova et al.'s (2003) dynamic law, which describes the autocrine and paracrine interactions between osteoblasts and osteoclasts and computes cell population dynamics and changes in bone mass at a discrete site of bone remodeling. Therefore, when an external mechanical stress is applied, bone formation and resorption is governed by cells dynamic rather than adaptive elasticity approaches. The proposed FE model has been implemented in the FE code Abaqus (UMAT routine). An example of human proximal femur is investigated using the model developed. The model was able to predict final human proximal femur adaptation similar to the patterns observed in a human proximal femur. The results obtained reveal complex spatio-temporal bone adaptation. The proposed FEM model gives insight into how bone cells adapt their architecture to the mechanical and biological environment. PMID:25152881

  6. Adverse Effects of Osteocytic Constitutive Activation of ß-Catenin on Bone Strength and Bone Growth.

    PubMed

    Chen, Sixu; Feng, Jianquan; Bao, Quanwei; Li, Ang; Zhang, Bo; Shen, Yue; Zhao, Yufeng; Guo, Qingshan; Jing, Junjun; Lin, Shuxian; Zong, Zhaowen

    2015-07-01

    The activation of the canonical Wnt/?-catenin signaling pathway in both mesenchymal stem cells and osteoblasts has been demonstrated to increase bone mass, showing promise for the treatment of low bone volume conditions such as osteoporosis. However, the possible side effects of manipulating this pathway have not been fully addressed. Previously, we reported that the constitutive activation of ß-catenin in osteoblasts impaired vertebral linear growth. In the present study, ?-catenin was constitutively activated in osteocytes by crossing Catnb+/lox(exon 3) mice with dentin matrix protein 1(DMP1)-Cre transgenic mice, and the effects of this activation on bone mass, bone growth and bone strength were then observed. DMP1-Cre was found to be predominantly expressed in osteocytes, with weak expression in a small portion of osteoblasts and growth plate chondrocytes. After the activation, the cancellous bone mass was dramatically increased, almost filling the entire bone marrow cavity in long bones. However, bone strength decreased significantly. Thinner and more porous cortical bone along with impaired mineralization were responsible for the decrease in bone strength. Furthermore, the mice showed shorter stature with impaired linear growth of the long bones. Moreover, the concentration of serum phosphate decreased significantly after the activation of ß-catenin, and a high inorganic phosphate (Pi) diet could partially rescue the phenotype of decreased mineralization level and impaired linear growth. Taken together, the constitutive activation of ?-catenin in osteocytes may increase cancellous bone mass; however, the activation also had adverse effects on bone strength and bone growth. These adverse effects should be addressed before the adoption of any therapeutic clinical application involving adjustment of the Wnt/?-catenin signaling pathway. © 2015 American Society for Bone and Mineral Research. PMID:25639729

  7. Dietary patterns, bone resorption and bone mineral density in early post-menopausal Scottish women

    Microsoft Academic Search

    A C Hardcastle; L Aucott; W D Fraser; D M Reid; H M Macdonald

    2011-01-01

    Background\\/Objectives:Several nutrients affect bone turnover. Dietary patterns may provide insights into which foods are important and how nutrition affects bone health. The aim of this study was to investigate the associations between dietary patterns, bone turnover and bone mineral density (BMD).Subjects\\/Methods:This cross-sectional study examined 3236 Scottish women age 50–59 years, who were members of the Aberdeen Prospective Osteoporosis Screening Study.

  8. Role of peak bone mass and bone loss in postmenopausal osteoporosis: 12 year study

    Microsoft Academic Search

    M A Hansen; K Overgaard; B J Riis; C Christiansen

    1991-01-01

    OBJECTIVE--To examine the role of peak bone mass and subsequent postmenopausal bone loss in the development of osteoporosis and the reliability of identifying women at risk from one bone mass measurement and one biochemical assessment of the future bone loss. DESIGN--Population based study. SETTING--Outpatient clinic for research into osteoporosis. SUBJECTS--178 healthy early postmenopausal women who had participated in a two

  9. Bone Cancer - Multiple Languages: MedlinePlus

    MedlinePLUS

    ... ????) French (français) Hindi (??????) Japanese (???) Korean (???) Russian (???????) Somali (af Soomaali) Spanish (espańol) ... ????? - ??? (Japanese) Bilingual PDF Health Information Translations Korean (???) Bone Scan ? (?) ?? - ??? (Korean) ...

  10. Bone Diseases - Multiple Languages: MedlinePlus

    MedlinePLUS

    ... ????) French (français) Hindi (??????) Japanese (???) Korean (???) Russian (???????) Somali (af Soomaali) Spanish (espańol) ... ????? - ??? (Japanese) Bilingual PDF Health Information Translations Korean (???) Bone Scan ? (?) ?? - ??? (Korean) ...

  11. About radioactivity in some PMMA bone cements.

    PubMed

    Hopf, W; Hopf, C G; Glöbel, B

    1990-01-01

    Various bone cements containing zirconium oxide (ZrO2) as X-ray contrast medium were tested for radioactivity by means of a gamma spectrometer. All measured bone cements (PALACOS, IMPLAST, SULFIX-6) showed a certain degree of radioactivity. The radiation source in the bone cement is the added zirconium oxide, which is polluted by radioactive elements. As these X-ray contrast media remain in the body for decades as components of the bone cement, the radioactive zirconium oxides should be substituted by high purity radiation-free zirconium oxide or barium sulfate. PMID:2239190

  12. Electrical properties of bone. A review.

    PubMed

    Singh, S; Saha, S

    1984-06-01

    A review of the available data on the electrical properties (resistance, capacitance, dielectric constant, dielectric loss factor, and dissipation factor, etc.) of whole as well as standardized bone specimens suggest that impedance was lowest in the longitudinal direction and highest in the radial direction. This is further evidence of the anisotropic nature of bone. The electrical properties of fully hydrated bone were significantly different from those of dry and partially wet bone and these properties were highly frequency-dependent. Other variables that influence the electrical properties, such as moisture content, principles and methods of measurement, temperature, and pH and conductivity of the immersing fluid, etc., have also been reviewed. Delineation of these variables is important in reporting test results on the electrical properties of bone; only then can the data on different electrical properties of bone reported by various authors be compared. Future research is needed to characterize the effect of age, microstructure, mineral content, and various disease processes on the electrical properties of bone. Such information may lead to new insight on the role of electrical properties on bone remodeling. An understanding of the electrical behavior of bone is also important for the design of electrical stimulation devices and their proper use for maximum osteogenic effect. PMID:6373088

  13. Bone regeneration: current concepts and future directions

    PubMed Central

    2011-01-01

    Bone regeneration is a complex, well-orchestrated physiological process of bone formation, which can be seen during normal fracture healing, and is involved in continuous remodelling throughout adult life. However, there are complex clinical conditions in which bone regeneration is required in large quantity, such as for skeletal reconstruction of large bone defects created by trauma, infection, tumour resection and skeletal abnormalities, or cases in which the regenerative process is compromised, including avascular necrosis, atrophic non-unions and osteoporosis. Currently, there is a plethora of different strategies to augment the impaired or 'insufficient' bone-regeneration process, including the 'gold standard' autologous bone graft, free fibula vascularised graft, allograft implantation, and use of growth factors, osteoconductive scaffolds, osteoprogenitor cells and distraction osteogenesis. Improved 'local' strategies in terms of tissue engineering and gene therapy, or even 'systemic' enhancement of bone repair, are under intense investigation, in an effort to overcome the limitations of the current methods, to produce bone-graft substitutes with biomechanical properties that are as identical to normal bone as possible, to accelerate the overall regeneration process, or even to address systemic conditions, such as skeletal disorders and osteoporosis. PMID:21627784

  14. Measurement of microstructural strain in cortical bone

    PubMed Central

    NICOLELLA, DANIEL P.; BONEWALD, LYNDA F.; MORAVITS, DONALD E.; LANKFORD, JAMES

    2007-01-01

    It is well known that mechanical factors affect bone remodeling such that increased mechanical demand results in net bone formation, whereas decreased demand results in net bone resorption. Current theories suggest that bone modeling and remodeling is controlled at the cellular level through signals mediated by osteocytes. The objective of this study was to investigate how macroscopically applied bone strains similar in magnitude to those that occur in vivo are manifest at the microscopic level in the bone matrix. Using a digital image correlation strain measurement technique, experimentally determined bone matrix strains around osteocyte lacuna resulting from macroscopic strains of approximately 2,000 microstrain (0.2%) reach levels of over 30,000 microstrain (3%) over fifteen times greater than the applied macroscopic strain. Strain patterns were highly heterogeneous and in some locations similar to observed microdamage around osteocyte lacuna indicating the resulting strains may represent the precursors to microdamage. This information may lead to a better understanding of how bone cells are affected by whole bone functional loading. PMID:16123021

  15. Can the adult skeleton recover lost bone?

    NASA Technical Reports Server (NTRS)

    Leblanc, Adrian; Schneider, Victor

    1991-01-01

    The loss of bone mineral with aging and subsequent development of osteoporosis is a common problem in elderly women, and as life expectancy increases, in elderly men as well. Space flight also causes bone loss and could be a limiting factor for long duration missions, such as, a Mars expedition or extended occupation of a Space Station. Before effective countermeasures can be devised, a thorough knowledge of the extent, location, and rate of bone loss during weightlessness is needed from actual space flight data or ground-based disuse models. In addition, the rate and extent that these losses are reversed after return from space flight are of primary importance. Although the mechanisms are not likely to be the same in aging and space flight, there are common elements. For example, strategies developed to prevent disuse bone loss or to enhance the rate of recovery following space flight might have direct applicability to clinical medicine. For various reasons, little attention has been given to recovery of bone mass following space flight. As a prelude to the design of strategies to enhance recovery of bone, this paper reviews published literature related to bone recovery in the adult. We conclude that recovery can be expected, but the rate and extent will be individual and bone site dependent. The development of strategies to encourage or enhance bone formation following space flight may be as important as implementing countermeasures during flight.

  16. Glutamate Signaling in Healthy and Diseased Bone

    PubMed Central

    Cowan, Robert W.; Seidlitz, Eric P.; Singh, Gurmit

    2012-01-01

    Bone relies on multiple extracellular signaling systems to maintain homeostasis of its normal structure and functions. The amino acid glutamate is a fundamental extracellular messenger molecule in many tissues, and is used in bone for both neural and non-neural signaling. This review focuses on the non-neural interactions, and examines the evolutionarily ancient glutamate signaling system in the context of its application to normal bone functioning and discusses recent findings on the role of glutamate signaling as they pertain to maintaining healthy bone structure. The underlying mechanisms of glutamate signaling and the many roles glutamate plays in modulating bone physiology are featured, including those involved in osteoclast and osteoblast differentiation and mature cell functions. Moreover, the relevance of glutamate signaling systems in diseases that affect bone, such as cancer and rheumatoid arthritis, is discussed, and will highlight how the glutamate system may be exploited as a viable therapeutic target. We will identify novel areas of research where knowledge of glutamate communication mechanisms may aid in our understanding of the complex nature of bone homeostasis. By uncovering the contributions of glutamate in maintaining healthy bone, the reader will discover how this complex molecular signaling system may advance our capacity to treat bone pathologies. PMID:22833735

  17. Radionuclide evaluation of nonmalignant bone disorders

    SciTech Connect

    Winzelberg, G.G.

    1983-02-01

    Recent advances in nuclear imaging have improved the noninvasive evaluation of patients with nonmalignant bone disorders. When bone scanning agents are combined with bone marrow scanning agents and gallium-67 scintigraphy, a more accurate diagnosis can be obtained. By selecting the appropriate imaging sequence, it is often possible to distinguish cellulitis from underlying osteomyelitis. In patients with total hip replacements, it may be possible to separate postsurgical changes from prosthetic loosening or infection. Stress fractures in joggers may be detected by radionuclide bone scintigraphy before radiographs become abnormal. These nuclear imaging procedures can be done in most hospitals.

  18. Methylmethacrylate Casting Model of Temporal Bone

    PubMed Central

    Kubo, Shigeki; Fukushima, Takanori; Yoshimine, Toshiki; Miki, Hideyuki; Hayakawa, Toru

    1998-01-01

    Methylmethacrylate casting model of the temporal bone simulating the translabyrinthine approach from the bone surface down to the internal auditory canal was developed in order to help to understand the complex anatomy that is often encountered during skull base surgery. Using a cadaver temporal bone and applying dental impression technique, fine structures, such as semicircular canals and facial nerve, were precisely reproduced in a life-size resin casting model. This simple cost-effective modeling method would facilitate both anatomical research and medical education by improving our understanding of the complex anatomy of the temporal bone. ImagesFigure 2Figure 3Figure 4p21-b PMID:17171038

  19. Bone Adaptation and Regeneration - New Developments

    NASA Astrophysics Data System (ADS)

    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 osteocytes sensing different canalicular flow patterns around cutting cone and reversal zone during loading, thus determining the bone's structure. Disturbances in architecture and permeability of the 3D porous network will affect transduction of mechanical loads to the mechanosensors. Uncovering the cellular and mechanical basis of the osteocyte's response to loading represents a significant challenge to our understanding of cellular mechanotransduction and bone remodeling. In view of the importance of mechanical stress for maintaining bone strength, mechanical stimuli have great potential for providing a therapeutic approach for bone (re)generation.

  20. Bone mineral measurement from Apollo experiment M-078. [derangement of bone mineral metabolism in spacecrews

    NASA Technical Reports Server (NTRS)

    Vogel, J. M.; Rambaut, P. C.; Smith, M. C., Jr.

    1974-01-01

    Loss of mineral from bone during periods of immobilization, recumbency, or weightlessness is examined. This report describes the instrumentation, technique, and bone mineral changes observed preflight and postflight for the Apollo 14, 15, and 16 missions. The bone mineral changes documented during the Apollo Program are reviewed, and their relevance to future missions is discussed.

  1. Semi-quantitative interpretation of the bone scan in metabolic bone disease

    Microsoft Academic Search

    Ignac Fogelman; Dennis L. Citrin; John G. Turner; Ian D. Hay; Rodney G. Bessent; Iain T. Boyle

    1979-01-01

    Certain easily recognisable features are commonly seen in the bone scans of patients with metabolic bone disorders. Seven such features have been numerically graded by three independent observers in the scans of 100 patients with metabolic bone disease and of 50 control subjects. The total score for each patient is defined as the metabolic index. The mean metabolic index for

  2. Vascular endothelial growth factor stimulates bone repair by promoting angiogenesis and bone turnover

    Microsoft Academic Search

    Min Bao; Leo Deguzman; Stuart Bunting; Franklin V. Peale Jr.; Napoleone Ferrara; Hope Steinmetz; John Hoeffel; Jeffrey L. Cleland; Ann Daugherty; Nicholas van Bruggen; H. Paul Redmond; Richard A. D. Carano; Ellen H. Filvaroff

    2002-01-01

    Several growth factors are expressed in distinct temporal and spatial patterns during fracture repair. Of these, vascular endothelial growth factor, VEGF, is of particular interest because of its ability to induce neovascularization (angiogenesis). To determine whether VEGF is required for bone repair, we inhibited VEGF activity during secondary bone healing via a cartilage intermediate (endochondral ossification) and during direct bone

  3. Bone healing of an unfixed bone fragment of the distal segment in sagittal split ramus osteotomy.

    PubMed

    Park, Won-Jong; Hwang, Soon Jung

    2014-03-01

    In bilateral sagittal split ramus osteotomy for the correction of asymmetry of the mandible, yawing movement of the distal segment can displace the proximal segment. This displacement can be minimized through osteotomy of the posterior part of the distal segment (ie, distal cutting). This free bone fragment is usually removed because of the difficulty of fixation. No previous studies have examined whether union of the bone fragment after distal cutting could join and consequently strengthen the thinned mandibular posterior border. This study used CT imaging to evaluate bone union of the unfixed bone fragment at 3 months postoperatively. The location of the bone fragment and the morphology of bone healing were evaluated in 2D and 3D. The amount of cancellous bone healing between the free bone segment and the proximal segment averaged 63.69%. There was no correlation between the size of the bone gap and the degree of bone union. In most cases, the free bone fragment was located between the distal and proximal segments and tended to dislocate in an anterior-superior direction. Because the postoperative follow-up period was only 3 months, a longer-term study of the changes in bone volume after remodeling is necessary. PMID:24621717

  4. Impact of lanthanum carbonate on cortical bone in dialysis patients with adynamic bone disease.

    PubMed

    Yajima, Aiji; Inaba, Masaaki; Tominaga, Yoshihiro; Tanaka, Motoko; Otsubo, Shigeru; Nitta, Kosaku; Ito, Akemi; Satoh, Shigeru

    2013-04-01

    Among the most serious problems in patients with chronic kidney disease (CKD) is fragility of cortical bone caused by cortical thinning and increased cortical porosity; the cortical fragility is sometimes irreversible, with fractures generally initiating from cortical bone. Therefore, development of treatments for problems of cortical bone is urgently desired. Cortical bone has the three surfaces, including the periosteal surface, intracortical spaces and endocortical surface. Bone turnover at the endocortical surface and intracortical resorption spaces are increased as compared with that at cancellous surface. Bone growth sometimes depends on apposition at the periosteal surface. We treated hyperphosphatemia in two hemodialysis patients with adynamic bone disease with 750-1500?mg/day of lanthanum carbonate, which is a non-calcium containing phosphate binder; the treatment resulted in a decrease of the serum phosphorus levels (P levels), without significant change of the serum intact parathyroid hormone levels. We now report that treatment of these patients with lanthanum carbonate increased mineralization of the periosteal surface, increased bone mass within the intracortical resorption spaces and increased mineralization of the minimodeling surface at the endocortical surface. In addition, woven bone volume in cortical bone was decreased and mineralization of bone units, namely, osteons, was increased. Although these findings were not observed across all surfaces of the cortical bone in the patients, it is expected that lanthanum carbonate would increase the cortical stability in CKD patients, with consequent reduction in the fracture rate in these patients. PMID:23586512

  5. Vitamin K, bone turnover, and bone mass in girls1-3

    Microsoft Academic Search

    Heidi J Kalkwarf; Jane C Khoury; Judy Bean; James G Elliot

    Background: Vitamin K has been suggested to have a role in bone metabolism, and low vitamin K intake has been related to low bone density and increased risk of osteoporotic fracture. Objective: The objective of this study was to determine whether phylloquinone (vitamin K1) intake and biochemical indicators of vitamin K status are related to bone mineral content (BMC) and

  6. Application of fracture mechanics concepts to hierarchical biomechanics of bone and bone-like materials

    Microsoft Academic Search

    HUAJIAN GAO

    Fracture mechanics concepts are applied to gain some understanding of the hierarchical nanocomposite structures of hard biological tissues such as bone, tooth and shells. At the most elementary level of structural hierarchy, bone and bone-like materials exhibit a generic structure on the nanometer length scale consisting of hard mineral platelets arranged in a parallel staggered pattern in a soft protein

  7. Diet-induced Obesity Alters Bone Remodeling Leading to Decreased Femoral Trabecular Bone Mass in Mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Body mass derived from an obesity condition may be detrimental to bone health but the mechanism is unknown. This study was to examine changes in bone structure and serum cytokines related to bone metabolism in obese mice induced by a high-fat diet(HFD). Mice fed the HFD were obese and had higher ser...

  8. Bone Forming Potential of An-Organic Bovine Bone Graft: A Cone Beam CT study

    PubMed Central

    Rahman, Shaifulizan AB.; Alam, Mohammad Khursheed; Gillani, Syed Wasif

    2014-01-01

    Purpose: An-organic bovine bone graft is a xenograft with the potential of bone formation. The aim of this study was to evaluate the bone density using cone beam computed tomography scans around functional endosseous implant in the region of both augmented maxillary sinus with the an-organic bovine bone graft and the alveolar bone over which the graft was placed to provide space for the implants. Materials and Methods: Sterile freeze dried bovine bone graft produced by National Tissue Bank, University Sains, Malaysia was used for stage-1 implant placement with maxillary sinus augmentation in a total of 19 subjects with 19 implants. The age of all subjects ranged between 40-60 years with a mean age 51±4.70. All subjects underwent a follow up CT scan using PlanmecaPromax 3D® Cone beam computed tomography scanner at the Radiology department, Hospital University Sains, Malaysia. The collected data was then analysed to evaluate bone density in Hounsfield Units using PlanmecaRomexis” Imaging Software 2.2® which is specialized accompanying software of the cone beam computed tomography machine. Results: There was bone formation seen at the site of the augmented sinus. A significant increase (p<0.005) in bone density was reported at the augmented site compared to the bone density of the existing alveolar bone. Conclusion: An-organic bovine bone graft is an osteoconductive material that can be used for the purpose of maxillary sinus augmentation. PMID:25654037

  9. Thermal processing of bone: in vitro response of mesenchymal cells to bone-conditioned medium.

    PubMed

    Sawada, K; Caballé-Serrano, J; Schuldt Filho, G; Bosshardt, D D; Schaller, B; Buser, D; Gruber, R

    2015-08-01

    The autoclaving, pasteurization, and freezing of bone grafts to remove bacteria and viruses, and for preservation, respectively, is considered to alter biological properties during graft consolidation. Fresh bone grafts release paracrine-like signals that are considered to support tissue regeneration. However, the impact of the autoclaving, pasteurization, and freezing of bone grafts on paracrine signals remains unknown. Therefore, conditioned medium was prepared from porcine cortical bone chips that had undergone thermal processing. The biological properties of the bone-conditioned medium were assessed by examining the changes in expression of target genes in oral fibroblasts. The data showed that conditioned medium obtained from bone chips that had undergone pasteurization and freezing changed the expression of adrenomedullin, pentraxin 3, BTB/POZ domain-containing protein 11, interleukin 11, NADPH oxidase 4, and proteoglycan 4 by at least five-fold in oral fibroblasts. Bone-conditioned medium obtained from autoclaved bone chips, however, failed to change the expression of the respective genes. Also, when bone-conditioned medium was prepared from fresh bone chips, autoclaving blocked the capacity of bone-conditioned medium to modulate gene expression. These in vitro results suggest that pasteurization and freezing of bone grafts preserve the release of biologically active paracrine signals, but autoclaving does not. PMID:25868709

  10. Imaging of bone infection with labelled white blood cells role of contemporaneous bone marrow imaging

    Microsoft Academic Search

    A. D. King; A. M. Peters; A. W. J. Stuttle; J. P. Lavender

    1990-01-01

    The uptake of white blood cells (WBC) into normal bone marrow may lead to difficulty in detecting bone infection. Twenty-one patients in whom the WBC scan was equivocal or positive underwent a technetium 99m colloid scan to show the distribution of bone marrow. Six patients had a positive WBC scan, and in five of them a discordant colloid scan confirmed

  11. A quantification strategy for missing bone mass in case of osteolytic bone lesions

    SciTech Connect

    Fränzle, Andrea, E-mail: a.fraenzle@dkfz.de; Giske, Kristina [Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Bretschi, Maren; Bäuerle, Tobias [Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Department of Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Hillengass, Jens [Department of Internal Medicine V, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg (Germany)] [Department of Internal Medicine V, University of Heidelberg, Im Neuenheimer Feld 410, 69120 Heidelberg (Germany); Bendl, Rolf [Medical Informatics, Heilbronn University, Max-Planck-Strasse 39, 74081 Heilbronn, Germany and Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Medical Informatics, Heilbronn University, Max-Planck-Strasse 39, 74081 Heilbronn, Germany and Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)

    2013-12-15

    Purpose: Most of the patients who died of breast cancer have developed bone metastases. To understand the pathogenesis of bone metastases and to analyze treatment response of different bone remodeling therapies, preclinical animal models are examined. In breast cancer, bone metastases are often bone destructive. To assess treatment response of bone remodeling therapies, the volumes of these lesions have to be determined during the therapy process. The manual delineation of missing structures, especially if large parts are missing, is very time-consuming and not reproducible. Reproducibility is highly important to have comparable results during the therapy process. Therefore, a computerized approach is needed. Also for the preclinical research, a reproducible measurement of the lesions is essential. Here, the authors present an automated segmentation method for the measurement of missing bone mass in a preclinical rat model with bone metastases in the hind leg bones based on 3D CT scans. Methods: The affected bone structure is compared to a healthy model. Since in this preclinical rat trial the metastasis only occurs on the right hind legs, which is assured by using vessel clips, the authors use the left body side as a healthy model. The left femur is segmented with a statistical shape model which is initialised using the automatically segmented medullary cavity. The left tibia and fibula are segmented using volume growing starting at the tibia medullary cavity and stopping at the femur boundary. Masked images of both segmentations are mirrored along the median plane and transferred manually to the position of the affected bone by rigid registration. Affected bone and healthy model are compared based on their gray values. If the gray value of a voxel indicates bone mass in the healthy model and no bone in the affected bone, this voxel is considered to be osteolytic. Results: The lesion segmentations complete the missing bone structures in a reasonable way. The mean ratiov{sub r}/v{sub m} of the reconstructed bone volume v{sub r} and the healthy model bone volume v{sub m} is 1.07, which indicates a good reconstruction of the modified bone. Conclusions: The qualitative and quantitative comparison of manual and semi-automated segmentation results have shown that comparing a modified bone structure with a healthy model can be used to identify and measure missing bone mass in a reproducible way.

  12. Biomechanical competence of microstructural bone in the progress of adaptive bone remodeling

    NASA Astrophysics Data System (ADS)

    Mueller, Ralph; Hayes, Wilson C.

    1997-10-01

    The mechanical behavior of trabecular bone depends on the internal bone structure as well as the load applied. Mechanical stresses and strains influence the modeling process and subsequently the structure and strength of the bone. Although the basic concepts of adaptive bone remodeling are generally accepted, the mathematical laws relating bone remodeling to the stress/strain relations are still under investigation. The aim of this project was to develop an algorithm which allows simulation of the response of the trabecular bone is age-related bone loss and to determine the biomechanical consequences of such a response based on realistic 3D models of the trabecular microstructure. Today, such models can be generated directly using micro-computed tomography ((mu) CT). For the purpose of the study, a compact fan-beam type tomograph was used, also referred to as desktop (mu) CT, providing a nominal isotropic resolution of 14 micrometers . Two groups of seven trabecular bone specimens were measured including specimens from pre- menopausal and post-menopausal women respectively. In order to control bone loss over age, a novel algorithm to simulate bone resorption and adaptive process was developed. The algorithm, also referred to as simulated bone atrophy, generates a set of microstructural models, iteratively derived from the original 3D structure. Simulated bone atrophy was used to 'age-match' the first and the second group incorporating an underlying realistic time-frame for the simulation. Using quantitative bone morphometry and 3D animation tools, the changes in bone density and bone architecture could be monitored in the progress of age- related bone loss over a total observation time of 28 years. The structures at the end-point of the simulations were then compared qualitatively and quantitatively to the structures of the post-menopausal group directly assessed by (mu) CT. The results suggest the possibility of transforming 'normal' to osteopenic' bone on a microstructural level resulting in realistic bone models similar in appearance and structural properties when compared to the post-menopausal group. In the future, the assessment of the biomechanical competence of microstructural bone in the progress of adaptive bone remodeling might result in an improved prospective prediction of individual bone strength as an indicator for fracture risk in patients predisposed to osteoporosis.

  13. Liquid antibiotics in bone cement

    PubMed Central

    Chang, Y. H.; Tai, C. L.; Hsu, H. Y.; Hsieh, P. H.; Lee, M. S.; Ueng, S. W. N.

    2014-01-01

    Objectives The objective of this study was to compare the elution characteristics, antimicrobial activity and mechanical properties of antibiotic-loaded bone cement (ALBC) loaded with powdered antibiotic, powdered antibiotic with inert filler (xylitol), or liquid antibiotic, particularly focusing on vancomycin and amphotericin B. Methods Cement specimens loaded with 2 g of vancomycin or amphotericin B powder (powder group), 2 g of antibiotic powder and 2 g of xylitol (xylitol group) or 12 ml of antibiotic solution containing 2 g of antibiotic (liquid group) were tested. Results Vancomycin elution was enhanced by 234% in the liquid group and by 12% in the xylitol group compared with the powder group. Amphotericin B elution was enhanced by 265% in the liquid group and by 65% in the xylitol group compared with the powder group. Based on the disk-diffusion assay, the eluate samples of vancomycin-loaded ALBC of the liquid group exhibited a significantly larger inhibitory zone than samples of the powder or the xylitol group. Regarding the ALBCs loaded with amphotericin B, only the eluate samples of the liquid group exhibited a clear inhibitory zone, which was not observed in either the xylitol or the powder groups. The ultimate compressive strength was significantly reduced in specimens containing liquid antibiotics. Conclusions Adding vancomycin or amphotericin B antibiotic powder in distilled water before mixing with bone cement can significantly improve the efficiency of antibiotic release than can loading ALBC with the same dose of antibiotic powder. This simple and effective method for preparation of ALBCs can significantly improve the efficiency of antibiotic release in ALBCs. Cite this article: Bone Joint Res 2014;3:246–51. PMID:25104836

  14. [Functional glutamate signaling in bone].

    PubMed

    Hinoi, Eiichi

    2010-09-01

    L-glutamate (Glu) has been thought to be an excitatory amino acid neurotransmitter in the mammalian central nervous system. Relatively little attention has been paid to the functional expression of Glu signaling machineries in peripheral tissues. In this review, therefore, we summarized the possible signaling by Glu as an extracellular signal mediator in mechanisms underlying maintenance of cellular homeostasis in bone tissues. Constitutive expression of mRNAs for particular Glu receptors (GluR), Glu transporters (GluT) was found in osteoblasts. N-methyl-D-aspartic acid receptor antagonist MK-801 significantly prevented differentiation and maturation of osteoblasts through modulation of expression of Runx2. DL-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid significantly increased the release of endogenous Glu from osteoblasts through its receptor expressed by osteoblasts. In addition, [3H]Glu uptake was also seen in a temperature- and sodium-dependent manner with pharmacological profiles similar to those for brain GluTs in osteoblasts. Although no mRNA expression was found for all GluRs examined in primary cultured mouse osteoclasts, constitutive expression of mRNAs was seen with GluT, such as excitatory amino acid transporters and cystine/Glu antiporter. Glu markedly inhibited osteoclastogenesis in a manner sensitive to the antiporter inhibitor. The systemic administration of Glu significantly prevented the decreased bone mineral density in addition to increased osteoclastic indices in ovariectomized mice in vivo. Taken together, Glu could play a pivotal role in mechanisms underlying the maintenance of cellular homeostasis as an extracellular signal mediator in bone. PMID:20823674

  15. ISS Update: Bone Health in Space - Duration: 10 minutes.

    NASA Video Gallery

    NASA Public Affairs Officer Brandi Dean interviews Dr. Jean Sibonga, Bone Lead Human Research Program, about the changes in bone structure and bone loss as a result of long term missions in space a...

  16. How Does Physical Activity Help Build Healthy Bones?

    MedlinePLUS

    ... this: Page Content Bones are living tissue. Weight-bearing physical activity causes new bone tissue to form, ... and tug against bones during physical activity. Weight-bearing physical activity keeps you on your feet so ...

  17. Baseline Bone Mineral Density Measurements Key to Future Testing Intervals

    MedlinePLUS

    ... Spotlight on Research 2012 May 2012 Baseline Bone Mineral Density Measurements Key to Future Testing Intervals How often a woman should have bone mineral density (BMD) tests to track bone mass is ...

  18. BIOLOGICAL FRAMEWORKS FOR ENGINEERS Session #23 [m: Bone System

    E-print Network

    Sniadecki, Nathan J.

    on microstructural architecture Composite material that is self-healing Biomechanics of the musculoskeletal system411/511 (Cell Factory)- III. Composition of Bone a. Cortical Bone b. Trabecular Bone IV. Biomechanical

  19. Bone marrow: all the cells of the immune system are derived from stem cells in the bone marrow. The bone

    E-print Network

    Morante, Silvia

    Bone marrow: all the cells of the immune system are derived from stem cells in the bone marrow as part of the immune system and as a filter #12;Cells of the Immune System Cells destined to become workings of the immune system, while others are cytotoxic and directly contact infected cells and destroy

  20. Ultrasound propagation in cancellous bone

    Microsoft Academic Search

    Holger Steeb

    2010-01-01

    Wave propagation in fluid-saturated cancellous bone is studied on the basis of two approaches: The thermodynamic-consistent\\u000a Theory of Porous Media (TPM) and Biot’s theory. Phase velocities in the low-frequency range, calculated with the Biot-Gassmann\\u000a relations, Wyllie’s equation and the TPM, are demonstrating that a simple, so-called hybrid biphasic TPM model is able to\\u000a capture the main acoustical effects in cancellous

  1. Pericytes in sarcomas of bone.

    PubMed

    Chang, Le; Nguyen, Vi; Nguyen, Alan; Scott, Michelle A; James, Aaron W

    2015-07-01

    Pericytes are mesenchymal cells that closely enwrap small blood vessels, lying in intimate association with the endothelium. Pericytes have recently gained attention as an important mediator of vascular biology and angiogenesis in cancer. Although better studied in carcinoma, pericytes have known interaction with sarcomas of bone, including Ewing's sarcoma, osteosarcoma, and chondrosarcoma. Best studied is Ewing's sarcoma (ES), which displays a prominent perivascular growth pattern. Signaling pathways of known importance in intratumoral pericytes in ES include Notch, PDGF/PDGFR-?, and VEGF signaling. In summary, pericytes serve important functions in the tumor microenvironment. Improved understanding of pericyte biology may hold significant implications for the development of new therapies in sarcoma. PMID:26076804

  2. N-Q Dinosaur Bones

    NSDL National Science Digital Library

    2012-05-01

    This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Quincy is a tour guide at a museum of science and history. During a tour of the museum, he tells some visitors about a fossilized dinosaur bone that is...

  3. [Radioindication of bone graft healing].

    PubMed

    Kuznetsova, L B; Pavlova, L P; Kondrat'ev, V G; Khmelev, O N

    1977-01-01

    To control the state of transplanted bone in different terms following the plastic procedure a radioisotope study by strontium-85 was performed in 29 patients. The results of scannography (in 31 cases) and radiometry (in 42 cases) were analysed. The determination of the character of strontium-85 distribution and the intensity of its accumulation in the operated extremity makes it possible to assess the graft condition and the intensity of osteogenesis a greater precision and earlier than does roentgenography. Radioisotope investigation conducted dynamically enable the prognostication of the course of the graft healing process. PMID:333749

  4. Osteoprotegerin serum levels in women: correlation with age, bone mass, bone turnover and fracture status.

    PubMed

    Fahrleitner-Pammer, Astrid; Dobnig, Harald; Piswanger-Soelkner, Claudia; Bonelli, Christine; Dimai, Hans-Peter; Leb, Georg; Obermayer-Pietsch, Barbara

    2003-05-15

    Pre-clinical data have shown that osteoprotegerin (OPG) inhibits osteoclast function and therefore plays an important role in bone remodelling. This study aimed to evaluate the clinical value of serum OPG. Do higher OPG serum levels reflect decreased bone resorption and perhaps higher bone mass in women? Serum OPG levels were measured in 177 healthy women (aged 17-85 years) and in 48 untreated patients (mean age 71 +/- 5) with established osteoporosis, and related to age, bone mass, markers of bone turnover and, in the case of patients with osteoporosis, to pre-existing vertebral fractures. In healthy women OPG levels showed a positive correlation with age (r = 0.25, p < 0.001) but not to bone mass or markers of bone turnover. In women with osteoporosis, however, there was a strong relationship between serum OPG and markers of bone turnover (serum c-terminal crosslinked telopeptides of thpe I collagen (sCTX): r = +0.82, p < 0.0001; osteocalcin (OC): r = +0.69, p < 0.0001), with patients who had higher levels of bone-turnover markers showing higher serum levels of OPG. After adjustment for bone mass and bone markers, patients with pre-existing vertebral fractures had significantly lower serum OPG levels than patients without fractures (57 +/- 8 vs. 97 +/- 10 pg/ml, [mean +/- SE], p < 0.01). The age-dependent increase of OPG as an antiresorptive factor may reflect an insufficient paracrine mechanism of bone cells to compensate for bone loss in older age. In patients with osteoporosis, however, OPG correlated strongly with markers of bone turnover; this may point toward a higher level of RANKL/OPG expression in these patients. Finally, low OPG serum levels seem to be associated with vertebral fractures. We hypothesise that low OPG levels in preset conditions of bone turnover may indicate a higher risk of fracture in patients with osteoporosis. PMID:12793029

  5. Temporal relationship between bone loss and increased bone turnover: a longitudinal study following natural menopause.

    PubMed

    Rosso, R; Minisola, S; Scarda, A; Pacitti, M T; Carnevale, V; Romagnoli, E; Mazzuoli, G F

    1995-10-01

    We report the results of a longitudinal study aimed at better defining concomitant changes of both bone mineral density (BMD) and of four independent markers of bone turnover (serum osteocalcin, serum alkaline phosphatase activity, fasting urinary hydroxyproline/creatinine and calcium/creatinine ratio) following natural menopause. The results obtained indicate that, within a relatively short period of time since cessation of gonadal function, conventional markers of bone turnover behave differently. In fact, while the mean values of hydroxyproline/creatinine ratio (felt to be a marker of bone resorption) rise immediately at the first control (19.7 +/- 11.7 months), the bone formation markers gradually increase and, as far as serum osteocalcin levels are concerned, this increment appears to be long-lasting. As a result of these changes, a negative skeletal balance follows, which is documented by the prolonged reduction of bone mineral density during the entire observation period. Mean +/- SD % measured yearly bone loss was -2.83 +/- 2.6. There was a highly significant correlation between initial and final BMD values (r = 0.908, p < 0.001; r2 = 82.5) and a weak inverse correlation (r = -0.298, p < 0.046) between initial serum alkaline phosphatase values and % yearly bone loss. In conclusion, measurement of the biological indices of bone remodelling following natural menopause indicate that the increase in osteogenesis is delayed compared to that of bone resorption; furthermore, in the immediate postmenopausal period, the actual bone mass should be considered the best predictor of future bone mass. The inverse correlation found between % yearly bone loss and serum alkaline phosphatase values seems to emphasize the importance of increased bone turnover as an independent predictor of bone loss. PMID:8719304

  6. The Digital Astronaut Project Computational Bone Remodeling Model (Beta Version) Bone Summit Summary Report

    NASA Technical Reports Server (NTRS)

    Pennline, James; Mulugeta, Lealem

    2013-01-01

    Under the conditions of microgravity, astronauts lose bone mass at a rate of 1% to 2% a month, particularly in the lower extremities such as the proximal femur [1-3]. The most commonly used countermeasure against bone loss in microgravity has been prescribed exercise [4]. However, data has shown that existing exercise countermeasures are not as effective as desired for preventing bone loss in long duration, 4 to 6 months, spaceflight [1,3,5,6]. This spaceflight related bone loss may cause early onset of osteoporosis to place the astronauts at greater risk of fracture later in their lives. Consequently, NASA seeks to have improved understanding of the mechanisms of bone demineralization in microgravity in order to appropriately quantify this risk, and to establish appropriate countermeasures [7]. In this light, NASA's Digital Astronaut Project (DAP) is working with the NASA Bone Discipline Lead to implement well-validated computational models to help predict and assess bone loss during spaceflight, and enhance exercise countermeasure development. More specifically, computational modeling is proposed as a way to augment bone research and exercise countermeasure development to target weight-bearing skeletal sites that are most susceptible to bone loss in microgravity, and thus at higher risk for fracture. Given that hip fractures can be debilitating, the initial model development focused on the femoral neck. Future efforts will focus on including other key load bearing bone sites such as the greater trochanter, lower lumbar, proximal femur and calcaneus. The DAP has currently established an initial model (Beta Version) of bone loss due to skeletal unloading in femoral neck region. The model calculates changes in mineralized volume fraction of bone in this segment and relates it to changes in bone mineral density (vBMD) measured by Quantitative Computed Tomography (QCT). The model is governed by equations describing changes in bone volume fraction (BVF), and rates of changes in bone cell populations that remove and replace bone in packets within the bone region. The DAP bone model is unique in several respects. In particular in takes former models of volume fraction changes one step higher in fidelity and separates BVF into separate equations for mineralized and osteoid volume fractions governed by a mineralization rate. This more closely follows the physiology of the remodeling unit cycles where bone is first resorbed and then followed by the action of osteoblasts to lay down collagen matrix which eventually becomes mineralized. In another respect, the modules allow the functional description of the time rate of change of other parameters and variables in the model during a computational simulation. More detailed description of the model, preliminary validation results, current limitation and caveats, and planned advancements are provided in sections 2 through 5. The DAP bone model is being developed primarily as a research tool, and not as a clinical tool like QCT. Even if it transitions to a clinical tool, it is not intended to replace QCT or any other clinical tool. Moreover, the DAP bone model does not predict bone fracture. Its purpose is to provide valuable additional data via "forward prediction" simulations for during and after spaceflight missions to gain insight on, (1) mechanisms of bone demineralization in microgravity, and (2) the volumetric changes at the various bone sites in response to in-flight and post-flight exercise countermeasures. This data can then be used as input to the Keyak [8] (or equivalent) FE analysis method to gain insight on how bone strength may change during and after flight. This information can also be useful to help optimize exercise countermeasure protocols to minimize changes in bone strength during flight, and improve regain of bone strength post-flight. To achieve this goal, the bone model will be integrated with DAP's exercise countermeasure models to simulate the effect of exercise prescriptions on preserving bone. More specifically, the model will accept loading histor

  7. New laboratory tools in the assessment of bone quality

    Microsoft Academic Search

    D. Chappard; M. F. Baslé; E. Legrand; M. Audran

    2011-01-01

    Bone quality is a complex set of intricated and interdependent factors that influence bone strength. A number of methods have\\u000a emerged to measure bone quality, taking into account the organic or the mineral phase of the bone matrix, in the laboratory.\\u000a Bone quality is a complex set of different factors that are interdependent. The bone matrix organization can be described

  8. BONE LOSS IN RELATION TO HYPOTHALAMIC ATROPHY IN ALZHEIMER'S DISEASE

    E-print Network

    Loskutova, Natalia Y.

    2011-05-12

    the human skeleton and fulfill its functions. Cortical bone consists of concentric layers of mineralized collagen (matrix) with embedded osteocytes. Cortical bone comprises 80% of the human skeleton and forms shafts of long bones such as humerus, femur..., ribs, and vertebrae. Bone is a highly dynamic, metabolically active and responsive tissue. These qualities are attributed to actions of bone cells. Osteocytes “sense” molecular and mechanical signals and modulate mineral homeostasis and bone metabolism...

  9. Analysis of load redistribution in diaphyseal bone following staged screw removal from bone plates

    E-print Network

    Nixon, Joseph Craig

    1987-01-01

    channels, through which blood enters and leaves (3). The hollow cavity inside the bone is the marrow cavity which contains plates of lamellar bone called trabecula, oriented parallel to the major loads on the bone (3). The external surface of each bone... the microstructure (2). IN rods are inserted into the marrow of a long bone to stabilize it during healing (1). The rod should be as tight fitting in the marrow cavity as possible. Different configurations have been tried to anchor the rod in the endosteum...

  10. Auto-fluorescence of the bone and its use for delineation of bone necrosis.

    PubMed

    Ristow, O; Pautke, C

    2014-11-01

    Bisphosphonate-related osteonecrosis of the jaw (BRONJ) is a challenging complication of long-term bisphosphonate treatment. Currently, the drawback in the surgical management of BRONJ is the difficulty distinguishing between viable and necrotic bone. Intraoperative bone fluorescence induced by tetracyclines has been shown to be a valuable aid to overcome this problem. In this technical note we report the finding that viable bone is auto-fluorescent using the VELscope Vx fluorescence lamp. Necrotic bone shows an altered fluorescence pattern (pale or no fluorescence). Thus it is suggested that auto-fluorescence of bone might be of similar use during the surgical therapy of BRONJ. PMID:25128260

  11. Bone marrow stromal cells (bone marrow-derived multipotent mesenchymal stromal cells) for bone tissue engineering: Basic science to clinical translation

    Microsoft Academic Search

    Hideaki Kagami; Hideki Agata; Arinobu Tojo

    2011-01-01

    Bone tissue engineering is a promising field of regenerative medicine in which cultured cells, scaffolds, and osteogenic inductive signals are used to regenerate bone. This technology has already been used in several clinical studies and its efficacy has been reported. In this review, we focus on bone marrow stromal cells, which are the most commonly used cell source for bone

  12. Toll-like receptor 4 mediates the regenerative effects of bone grafts for calvarial bone repair.

    PubMed

    Wang, Dan; Gilbert, James R; Shaw, Melissa A; Shakir, Sameer; Losee, Joseph E; Billiar, Timothy R; Cooper, Gregory M

    2015-04-01

    Craniofacial trauma is difficult to repair and presents a significant burden to the healthcare system. The inflammatory response following bone trauma is critical to initiate healing, serving to recruit inflammatory and progenitor cells and to promote angiogenesis. A role for inflammation in graft-induced bone regeneration has been suggested, but is still not well understood. The current study assessed the impact of Toll-like receptor (TLR4) signaling on calvarial repair in the presence of morselized bone components. Calvarial defects in wild-type and global TLR4(-/-) knockout mouse strains were treated with fractionated bone components in the presence or absence of a TLR4 neutralizing peptide. Defect healing was subsequently evaluated over 28 days by microcomputed tomography and histology. The matrix-enriched fraction of morselized bone stimulated calvarial bone repair comparably with intact bone graft, although the capacity for grafts to induce calvarial bone repair was significantly diminished by inhibition or genetic ablation of TLR4. Overall, our findings suggest that the matrix component of bone graft stimulates calvarial bone repair in a TLR4-dependent manner. These results support the need to better understand the role of inflammation in the design and implementation of strategies to improve bone healing. PMID:25603990

  13. Lanthanum carbonate stimulates bone formation in a rat model of renal insufficiency with low bone turnover.

    PubMed

    Fumoto, Toshio; Ito, Masako; Ikeda, Kyoji

    2014-09-01

    Control of phosphate is important in the management of chronic kidney disease with mineral and bone disorder (CKD-MBD), for which lanthanum carbonate, a non-calcium phosphate-binding agent, has recently been introduced; however, it remains to be determined whether it has any beneficial or deleterious effect on bone remodeling. In the present study, the effects of lanthanum carbonate were examined in an animal model that mimics low turnover bone disease in CKD, i.e., thyroparathyroidectomized (TPTX) and 5/6 nephrectomized (NX) rats undergoing a constant infusion of parathyroid hormone (PTH) and thyroxine injections (TPTX-PTH-5/6NX). Bone histomorphometry at the second lumbar vertebra and tibial metaphysis revealed that both bone formation and resorption were markedly suppressed in the TPTX-PTH-5/6NX model compared with the sham-operated control group, and treatment with lanthanum carbonate was associated with the stimulation of bone formation but not an acceleration of bone resorption. Lanthanum treatment caused a robust stimulation of bone formation with an activation of osteoblasts on the endosteal surface of femoral diaphysis, leading to an increase in cortical bone volume. Thus, lanthanum carbonate has the potential to stimulate bone formation in cases of CKD-MBD with suppressed bone turnover. PMID:24126694

  14. Bone strain magnitude is correlated with bone strain rate in tetrapods: implications for models of mechanotransduction.

    PubMed

    Aiello, B R; Iriarte-Diaz, J; Blob, R W; Butcher, M T; Carrano, M T; Espinoza, N R; Main, R P; Ross, C F

    2015-07-01

    Hypotheses suggest that structural integrity of vertebrate bones is maintained by controlling bone strain magnitude via adaptive modelling in response to mechanical stimuli. Increased tissue-level strain magnitude and rate have both been identified as potent stimuli leading to increased bone formation. Mechanotransduction models hypothesize that osteocytes sense bone deformation by detecting fluid flow-induced drag in the bone's lacunar-canalicular porosity. This model suggests that the osteocyte's intracellular response depends on fluid-flow rate, a product of bone strain rate and gradient, but does not provide a mechanism for detection of strain magnitude. Such a mechanism is necessary for bone modelling to adapt to loads, because strain magnitude is an important determinant of skeletal fracture. Using strain gauge data from the limb bones of amphibians, reptiles, birds and mammals, we identified strong correlations between strain rate and magnitude across clades employing diverse locomotor styles and degrees of rhythmicity. The breadth of our sample suggests that this pattern is likely to be a common feature of tetrapod bone loading. Moreover, finding that bone strain magnitude is encoded in strain rate at the tissue level is consistent with the hypothesis that it might be encoded in fluid-flow rate at the cellular level, facilitating bone adaptation via mechanotransduction. PMID:26063842

  15. Clonal Characterization of Bone Marrow Derived Stem Cells and Their Application for Bone Regeneration

    PubMed Central

    Xiao, Yin; Mareddy, Shobha; Crawford, Ross

    2010-01-01

    Tissue engineering allows the design of functionally active cells within supportive bio-scaffolds to promote the development of new tissues such as cartilage and bone for the restoration of pathologically altered tissues. However, all bone tissue engineering applications are limited by a shortage of stem cells. The adult bone marrow stroma contains a subset of nonhematopoietic cells referred to as bone marrow mesenchymal stem cells (BMSCs). BMSCs are of interest because they are easily isolated from a small aspirate of bone marrow and readily generate single-cell-derived colonies. These cells have the capacity to undergo extensive replication in an undifferentiated state ex vivo. In addition, BMSCs have the potential to develop either in vitro or in vivo into distinct mesenchymal tissues, including bone, cartilage, fat, tendon, muscle, and marrow stroma. Thus, BMSCs are an attractive cell source for tissue engineering approaches. However, BMSCs are not homogeneous and the quantity of stem cells decreases in the bone marrow in aged population. A sequential loss of lineage differentiation potential has been found in the mixed culture of bone marrow stromal cells due to a heterogenous population. Therefore, a number of studies have proposed that homogenous bone marrow stem cells can be generated from clonal culture of bone marrow cells and that BMSC clones have the greatest potential for the application of bone regeneration in vivo. PMID:21125790

  16. The role of cortical bone and its microstructure in bone strength.

    PubMed

    Augat, Peter; Schorlemmer, Sandra

    2006-09-01

    Bone's mechanical competence and its fragility in particular depend to a certain extent on the structure and microstructure of the cortical bone compartment. Beyond bone mineral density (BMD) and bone mineral content, a variety of other features of cortical bone contribute to whole bone's resistance to fracture. Structural properties of cortical bone most commonly employed as surrogate for its mechanical competence include thickness of the cortex, cortical cross-sectional area and area moment of inertia. But microstructural properties such as cortical porosity, crystallinity or the presence of microcracks also contribute to bone's mechanical competence. Microcracks in particular not only weaken the cortical bone tissue but also provide an effective mechanism for energy dissipation. Bone is a damageable, viscoelastic composite and most of all a living material capable of self-repair and thus exhibits a complex repertoire of mechanical properties. This review provides an overview of a variety of features of cortical bone known to provide mechanical competence and how these features may be applied for fracture risk prediction. PMID:16926200

  17. Therapeutic Agents for the Prevention and Restoration of Bone Mass

    E-print Network

    Slatton, Clint

    osteoporosis-related bone loss. According to the National Osteoporosis Foundation, osteoporosis is a major osteoporosis Advantages · Selectively blocks osteoclastic bone resorption by a novel mechanism, providing

  18. Virtual temporal bone dissection: a case study

    Microsoft Academic Search

    Jason Bryan; Don Stredney; Gregory J. Wiet; Dennis Sessanna

    2001-01-01

    The Temporal Bone Dissection Simulator is an ongoing research project for the construction of a synthetic environment suitable for virtual dissection of human temporal bone and related anatomy. Funded by the National Institute on Deafness and Other Communication Disorders (NIDCD), the primary goal of this project is to provide a safe, robust, and cost-effective virtual environment for learning the anatomy

  19. [Osteoporosis and metabolic bone diseases; clinical relationship].

    PubMed

    Klaushofer, K; Roschger, P; Nader, A; Glantschnig, H; Varga, F

    1999-01-01

    Metabolic bone diseases with disturbed bone remodeling lead to loss of biomechanical quality and atraumatic fractures. Differential diagnosis, prevention and adequate treatment should already start early in the course of these disorders to prevent fractures. Thus, clinical osteology is more than the simplified connection "low bone mineral density--fractures--osteoporosis". This review summarizes physiological relations between bone tissue and calcium homoeostasis as well as the relation between structure and function. In addition, the main metabolic osteopathies "osteoporosis, primary hyperparathyroidism and osteomalacia" are presented from a clinical point of view. The importance and the diagnostic values of biochemical parameters and of the transiliacal biopsy are discussed. In this respect the quantitative measurement of the mineralization density (bone mineral density distribution = BMDD) seems to be of high value and extends the well established bone histomorphometry. This recently introduced method has the power to distinguish between small differences in the degree of mineralization of the matrix with high precision and reproducibility. The results of quantitative backscattered electron imaging in the scanning electron microscope improve the differential diagnosis of bone diseases with alterations in mineralization density, helps to detect mixed etiology (e.g. osteoporosis plus osteomalacia) and facilitate decision making for treatments. The value of biochemical, radiological, osteodensitometric and histopathological tests for diagnosis and treatment depends on the knowledge of the clinical relations and the complex interactions between calcium-, phosphate- and bone metabolism. PMID:10627983

  20. Esthetic correction of depressed frontal bone fracture

    PubMed Central

    Dayashankara Rao, J. K.; Malhotra, Vijaylaxmi; Batra, Ravi S.; Kukreja, Abhishek

    2011-01-01

    Depressed frontal bone fractures are occasionally seen in maxillofacial trauma patient. If untreated, they look un-esthetic. Although there are numerous options available for correction of these defects, use of bone cement (polymethylmethacrylate or PMMA) is simple and reliable. This is the report of one such case. PMID:22442614

  1. Prostate Cancer and Bone: The Elective Affinities

    PubMed Central

    2014-01-01

    The onset of metastases dramatically changes the prognosis of prostate cancer patients, determining increased morbidity and a drastic fall in survival expectancy. Bone is a common site of metastases in few types of cancer, and it represents the most frequent metastatic site in prostate cancer. Of note, the prevalence of tumor relapse to the bone appears to be increasing over the years, likely due to a longer overall survival of prostate cancer patients. Bone tropism represents an intriguing challenge for researchers also because the preference of prostate cancer cells for the bone is the result of a sequential series of targetable molecular events. Many factors have been associated with the peculiar ability of prostate cancer cells to migrate in bone marrow and to determine mixed osteoblastic/osteolytic lesions. As anticipated by the success of current targeted therapy aimed to block bone resorption, a better understanding of molecular affinity between prostate cancer and bone microenvironment will permit us to cure bone metastasis and to improve prognosis of prostate cancer patients. PMID:24971315

  2. Autonomic healing of acrylic bone cement.

    PubMed

    Gladman, A Sydney; Celestine, Asha-Dee N; Sottos, Nancy R; White, Scott R

    2015-01-28

    Self-healing in orthopedic bone cement is demonstrated with a novel thermoplastic solvent-bonding approach. Low toxicity solvent-filled microcapsules, embedded in a commercial acrylic bone cement matrix, enable recovery of up to 80% of the virgin fracture toughness of the cement at room and body temperature conditions without external stimuli or human intervention. PMID:25116439

  3. Bone lesions in pigmented villonodular synovitis.

    PubMed

    Pantazopoulos, T; Stavrou, Z; Stamos, C; Kehayas, G; Hartofilakidis-Garofalidis, G

    1975-09-01

    Seven cases of pigmented villonodular synovitis with invasion of the bone are described, four affecting the hip and the remaining three involving the knee, shoulder and ankle joint, respectively. The pathogenesis of the bone changes and the radiographical appearance of the involved joints are described. The methods of treatment are discussed. PMID:1180020

  4. Do vegetarians have a normal bone mass?

    Microsoft Academic Search

    Susan A. New

    2004-01-01

    Public health strategies targeting the prevention of poor bone health on a population-wide basis are urgently required, with particular emphasis being placed on modifiable factors such as nutrition. The aim of this review was to assess the impact of a vegetarian diet on indices of skeletal integrity to address specifically whether vegetarians have a normal bone mass. Analysis of existing

  5. Peak bone mass and osteoporosis prevention

    Microsoft Academic Search

    J. A. Eisman; P. J. Kelly; N. A. Morrison; N. A. Pocock; R. Yeoman; J. Birmingham; P. N. Sambrook

    1993-01-01

    The Incidence of osteoporotic fractures increases with advancing age. Despite advances in therapy, reversal of bone loss in established osteoporosis remains problematic and deformities and disability due to fractures often persist. Therefore the logical approach to osteoporosis treatment is preventive. Risk of fracture is determined largely by bone density, which is the end result of peak value achieved at skeletal

  6. Mechanical signals as anabolic agents in bone

    Microsoft Academic Search

    Engin Ozcivici; Yen Kim Luu; Ben Adler; Yi-Xian Qin; Janet Rubin; Stefan Judex; Clinton T. Rubin

    2010-01-01

    Aging and a sedentary lifestyle conspire to reduce bone quantity and quality, decrease muscle mass and strength, and undermine postural stability, culminating in an elevated risk of skeletal fracture. Concurrently, a marked reduction in the available bone-marrow-derived population of mesenchymal stem cells (MSCs) jeopardizes the regenerative potential that is critical to recovery from musculoskeletal injury and disease. A potential way

  7. Intramedullary pressure induced fluid flow in bone

    Microsoft Academic Search

    Y.-X. Qin; K. J. McLeod; C. T. Rubin

    1999-01-01

    IM pressure induced intracortical fluid flow has been evaluated by pore-elastic FEM and measured streaming potentials. The results suggest that oscillating IM P can initiate spatial fluid flow in bone without matrix deformation, and may play an important role in bone adaptation

  8. Cell Stem Cell Endogenous Bone Marrow MSCs

    E-print Network

    Mootha, Vamsi K.

    ). The existence of multipotent bone marrow stromal cells (BMSCs), or skeletal/mesenchymal stem cells (SSCs.02.003 SUMMARY Mesenchymal stem cells (MSCs) commonly defined by in vitro functions have entered clinical bone- marrow-derived, Mx1+ stromal cells with ``MSC'' features. These cells respond to tissue stress

  9. Incorporation and distribution of strontium in bone

    Microsoft Academic Search

    S. G Dahl; P Allain; P. J Marie; Y Mauras; G Boivin; P Ammann; Y Tsouderos; P. D Delmas; C Christiansen

    2001-01-01

    The distribution and incorporation of strontium into bone has been examined in rats, monkeys, and humans after oral administration of strontium (either strontium chloride or strontium ranelate). After repeated administration for a sufficient period of time (at least 4 weeks in rats), strontium incorporation into bone reaches a plateau level. This plateau appears to be lower in females than in

  10. Ultrasound and the biomechanical competence of bone

    Microsoft Academic Search

    Patrick H. F. Nicholson

    2008-01-01

    Ultrasound is a mechanical wave and consequently has a unique potential to characterize the mechanical properties of bone. In some applications, such as determination of the anisotropic elastic constants of cortical bone specimens, this potential has been realized. In other applications, including the hugely important field of clinical measurements, current ultrasonic techniques struggle to provide information directly relating to mechanical

  11. Bregmatic Bones in North American Lynx

    Microsoft Academic Search

    Richard H. Manville

    1959-01-01

    Anomalous bregmatic fontanolle bones were present in 279 of 1790 skulls of Lynx rufus examined, but with no apparent correlation with age, sex, or place of origin of the specimens. Examination of 472 skulls of Lynx canadensis disclosed only one possessing bregmatic bones.

  12. Bregmatic bones in North American lynx.

    PubMed

    MANVILLE, R H

    1959-11-01

    Anomalous bregmatic fontanelle bones were present in 279 of 1790 skulls of Lynx rufus examined, but with no apparent correlation with age, sex, or place of origin of the specimens. Examination of 472 skulls of Lynx canadensis disclosed only one possessing bregmatic bones. PMID:14420785

  13. Impaction bone grafting for total hip revision

    Microsoft Academic Search

    Donald R. Gore

    2002-01-01

    We used impaction bone grafting for total hip revision on 26 hips in 25 patients. Average patient age was 68 (34-89) years, and average duration from last surgery was 9 years. In all cases morselized allograft bone was used for the graft, and the femoral component was a collarless, polished, tapered stem. Average duration of surgery was 2.4 h, intraoperative

  14. Effect of Bone Strontium on BMD Measurements

    Microsoft Academic Search

    Glen M. Blake; Ignac Fogelman

    2007-01-01

    Strontium ranelate is a new treatment for osteoporosis that is of interest for, among other reasons, its unusual effect on measurements of bone mineral density (BMD). When some of the calcium in bone is replaced by strontium, X-ray absorptiometry measurements of BMD are overestimated because strontium attenuates X-rays more strongly than calcium. In this study, we report the first theoretical

  15. Repair of long bone fractures in cats

    Microsoft Academic Search

    Harry Scott

    2005-01-01

    LONG bone fractures are common and account for 50 per cent of all feline fractures. They are usually caused by road traffic accidents, but may also result from falls, fights and gunshot wounds. Fractures of the hindquarters predominate, with reports of 73 per cent of fractures involving the hindlimbs, pelvis or sacrum. Although the broad principles of long bone fracture

  16. Bone Marrow Transplantation for Fanconi Anemia

    Microsoft Academic Search

    Eliane Gluckrnan; Arleen D. Auerbach; Mary M. Horowitz; Kathleen A. Sobocinski; Robert C. Ash; Mortimer M. Bortin; Anna Butturini; Bruce M. Carnitta; Richard E. Charnplin; Wilhelrn Friedrich; Robert A. Good; Edward C. Gordon-Smith; Richard E. Harris; John P. Klein; Juan J. Ortega; Ricardo Pasquini; Norma K. C. Rarnsay; Bruno Speck; Marcus R. Vowels; Mei-Jie Zhang; Robert Peter Gale

    1995-01-01

    Fanconi anemia is a genetic disorder associated with diverse congenital abnormalities, progressive bone marrow failure, and increased risk of leukemia and other cancers. Affected persons often die before 30 years of age. Bone marrow trans- plantation is an effective treatment, but there are few data regarding factors associated with transplant outcome. We analyzed outcomes of HLA-identical sibling (N = 151)

  17. Bone Marrow Lymphoid Aggregates in Malignant Lymphomas

    Microsoft Academic Search

    Mara Dominis; Rajko Kušec

    To examine the usefulness of molecular analysis of IgH gene rearrangement in assessment of clonality in bone marrow biopsies with lymphoid aggregates (LA) and\\/or nodular lymphoid hyperplasia (NLH) in patients with different subtypes of malignant lymphomas. Method Five hundred and twenty nine samples of bone marrow biopsies, taken in a staging procedure at the time of the initial presentation of

  18. Modal behaviour of bones during fracture.

    PubMed

    Horta-Rangel, Jaime; Rivera, Ana Leonor; Castano, Victor M

    2010-02-01

    A common cause of human disability is related to the fracture of bones, complex structural materials whose properties vary with time. An analytical study (using ANSYS, a commercial finite element package) of bones under fracture conditions is presented, focusing on the frequency variation versus depth of crack, as well as on the evolution of strength in the fracture area. PMID:19603306

  19. Bone scintigraphy in the diagnosis of mastoiditis

    SciTech Connect

    Floyd, J.L.; Goodman, E.L.

    1981-07-01

    Bone scintigraphy has proven utility in the early diagnosis of osteomyelitis, but the authors were unable to find any report of its specific application to mastoiditis. Three cases of mastoiditis are presented in which the bone scan findings predicted the histopathologic findings.

  20. Effects of obesity on bone metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite being a risk factor for many chronic health disorders, obesity is thought to promote bone formation and protect against osteoporosis in humans. Although body mass has a positive effect on bone health, whether mass derived from an obesity condition or excessive fat accumulation is beneficial ...

  1. Bone grossing techniques: helpful hints and procedures.

    PubMed

    Dimenstein, Izak B

    2008-06-01

    The present article is intended to offer pathologists and pathology residents helpful hints and procedures as well as some general approaches to technical questions of bone grossing in a surgical pathology laboratory. An emphasis on the personal experience of the author in grossing bones has been made. Three main conditions determine successful gross bone sections: specimen immobilization, the appropriate cutting instrument, and correct specimen orientation. From the technical point of view, the most important seems to be immobilization. A variety of devices and gadgets can be used to make the bone specimen stable while sectioning. Among them, hard-pressed cardboard cartons are the most helpful. They have the advantage in complicated bone specimens to allow the grossing person to cut through the immobilization device, thus assuring a complete section. There are definite particularities in technical approaches to different bone specimens. Even a femoral head, the most popular specimen, requires different grossing techniques depending on the clinical circumstances. Examples of grossing techniques for different bone specimens are described in detail. The technique can be applied in similar clinical situations to other bone specimens. PMID:18486895

  2. Injectable scaffolds for bone regeneration.

    PubMed

    Yasmeen, Sabina; Lo, Man Kit; Bajracharya, Salina; Roldo, Marta

    2014-11-01

    Clinical treatments of significant bone defects involve invasive procedures such as the application of auto- and allografts. These procedures present many limitations including the potential for infection and rejection. There is therefore a need to develop novel therapeutic strategies able to exploit the natural regenerative potential of bone and that can be delivered in a less invasive manner. Among the materials studied for the development of novel scaffolds, stimuli-responsive gels containing hydroxyapatite and carbon nanotubes as nanofillers have generated great interest. In the present work, chitosan gels containing chitosan grafted CNTs and chitosan-hydroxyapatite complex have been formed by cross-linking with glycerol phosphate. The addition of the nanofillers afforded hydrogels with a faster sol/gel transition at 37 °C and enhanced mechanical properties. The thermosensitive composite gels also showed a good bioactivity profile associated with potential for the prolonged delivery of protein drugs. The inclusion of chemically cross-linked CNTs and HA in thermosensitive gels afforded injectable composite materials with enhanced properties, including reduction of gelation time, improved mechanical properties, good bioactivity, and prolonged drug release. PMID:25296391

  3. Adipose-Derived Stem Cells in Functional Bone Tissue Engineering: Lessons from Bone Mechanobiology

    PubMed Central

    Bodle, Josephine C.; Hanson, Ariel D.

    2011-01-01

    This review aims to highlight the current and significant work in the use of adipose-derived stem cells (ASC) in functional bone tissue engineering framed through the bone mechanobiology perspective. Over a century of work on the principles of bone mechanosensitivity is now being applied to our understanding of bone development. We are just beginning to harness that potential using stem cells in bone tissue engineering. ASC are the primary focus of this review due to their abundance and relative ease of accessibility for autologous procedures. This article outlines the current knowledge base in bone mechanobiology to investigate how the knowledge from this area has been applied to the various stem cell-based approaches to engineering bone tissue constructs. Specific emphasis is placed on the use of human ASC for this application. PMID:21338267

  4. Effects of food enriched with egg yolk hydrolysate (bone peptide) on bone metabolism in orchidectomized dogs

    PubMed Central

    KOBAYASHI, Toyokazu; KOIE, Hiroshi; WATANABE, Arisa; INO, Arisa; WATABE, Kazuya; KIM, Mujo; KANAYAMA, Kiichi; OTSUJI, Kazuya

    2015-01-01

    We examined the effects of chicken egg hydrolysate (also known as “bone peptide” or BP) on bone metabolism in 5- to 8-month-old orchidectomized dogs. The bone formation marker serum bone alkaline phosphatase (BAP) and the bone resorption marker urine deoxypyridinoline (DPD) were used as indicators to measure changes in bone metabolism. The following results were observed that Serum BAP was higher in dogs fed BP-enriched food throughout the clinical investigation. Serum BAP was statistically significantly higher in dogs fed BP-enriched food than in dogs fed non-BP-enriched food at 2 months after orchidectomy. This suggests that BP promoted bone formation immediately after orchidectomy. PMID:25649521

  5. Bringing new life to damaged bone: the importance of angiogenesis in bone repair and regeneration.

    PubMed

    Stegen, Steve; van Gastel, Nick; Carmeliet, Geert

    2015-01-01

    Bone has the unique capacity to heal without the formation of a fibrous scar, likely because several of the cellular and molecular processes governing bone healing recapitulate the events during skeletal development. A critical component in bone healing is the timely appearance of blood vessels in the fracture callus. Angiogenesis, the formation of new blood vessels from pre-existing ones, is stimulated after fracture by the local production of numerous angiogenic growth factors. The fracture vasculature not only supplies oxygen and nutrients, but also stem cells able to differentiate into osteoblasts and in a later phase also the ions necessary for mineralization. This review provides a concise report of the regulation of angiogenesis by bone cells, its importance during bone healing and its possible therapeutic applications in bone tissue engineering. This article is part of a Special Issue entitled "Stem Cells and Bone". PMID:25263520

  6. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears ( Ursus arctos horribilis)

    Microsoft Academic Search

    Meghan E. McGee; Aaron J. Maki; Steven E. Johnson; O. Lynne Nelson; Charles T. Robbins; Seth W. Donahue

    2008-01-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and

  7. Studies on the biology of fish bone. III. Ultrastructure of osteogenesis and resorption in osteocytic (cellular) and anosteocytic (acellular) bones

    Microsoft Academic Search

    R. E. Weiss; N. Watabe

    1979-01-01

    Summary  The comparative ultrastructure of fish bone osteogenesis and resorption induced by scale removal was described in the osteocytic\\u000a (cellular-boned)Carassius auratus and the anosteocytic (acellular-boned)Tilapia macrocephala. Osteocytes, present in osteocytic bone, were lacking in anosteocytic bone. In osteocytic bone the osteoblast secreted a\\u000a collagenous preosseous matrix in which it became enmeshed and then was termed a preosteocyte. When the preosseous matrix

  8. Cancer therapy using bone-seeking isotopes

    NASA Astrophysics Data System (ADS)

    Lewington, V. J.

    1996-10-01

    Bone pain is a common symptom in disseminated malignancy and may be difficult to manage effectively. Radiation is of proven benefit for pain palliation and there is growing interest in the therapeutic potential of bone-seeking radiopharmaceuticals. Clinical data relating to the use of phosphorus-32, strontium-89, samarium-153 EDTMP, rhenium-186 HEDP and tin-117m DTPA are reviewed in the context of the pathophysiology of metastatic bone pain. Possible mechanisms of action of palliative radiotherapy and, in particular, the theoretical role of early response genes are discussed. The application of Monte Carlo simulation to targeted radiotherapy for bone metastases may provide the basis for a clearer understanding of the microdosimetry and radiobiology of bone pain palliation and for reliable prediction of clinical response and toxicity.

  9. The controversy of cranial bone motion.

    PubMed

    Rogers, J S; Witt, P L

    1997-08-01

    Cranial bone motion continues to stimulate controversy. This controversy affects the general acceptance of some intervention methods used by physical therapists, namely, cranial osteopathic and craniosacral therapy techniques. Core to these intervention techniques is the belief that cranial bone mobility provides a compliant system where somatic dysfunction can occur and therapeutic techniques can be applied. Diversity of opinion over the truth of this concept characterizes differing viewpoints on the anatomy and physiology of the cranial complex. Literature on cranial bone motion was reviewed for the purpose of better understanding this topic. Published research overall was scant and inconclusive. Animal and human studies demonstrate a potential for small magnitude motion. Physical therapists should carefully scrutinize the literature presented as evidence for cranial bone motion. Further research is needed to resolve this controversy. Outcomes research, however, is needed to validate cranial bone mobilization as an effective treatment. PMID:9243408

  10. Teriparatide: A bone formation treatment for osteoporosis.

    PubMed

    Eriksen, Erik F; Robins, Deborah A

    2004-11-01

    Teriparatide is the recombinant human N-terminal fragment (1-34) of endogenous human parathyroid hormone, and it is the first bone anabolic agent for the treatment of osteoporosis. When given as once-daily subcutaneous injections, teriparatide can reverse the course of osteoporosis by stimulating formation of new bone and restoring lost architecture. Teriparatide (20 microg) treatment of osteoporosis in postmenopausal women rapidly increased markers of bone formation and reduced the incidence of vertebral fractures by 65% and of nonvertebral fragility fractures by 53%. In addition, treatment with this compound increased spine bone mineral density by 10% and hip bone mineral density by 3% at study endpoint. Teriparatide is well tolerated and is not associated with any serious side effects. The compound has been approved in Europe and in the US for the treatment of osteoporosis. Duration of treatment is 18-24 months and the dose does not need to be adjusted for age or gender. PMID:15645006

  11. Bone growth is impaired by uranium intoxication.

    PubMed

    Ubios, A M; Piloni, M J; Marzorati, M; Cabrini, R L

    Acute and chronic uranium intoxication leads to the inhibition of bone formation and impaired bone modeling and remodeling. As these are processes directly involved in bone growth the aim of this paper is to present a biometric study of bone growth--tibiae and mandibles of rats intoxicated with uranium. Wistar ratios weighing 60-80 g were used as follows, a) one intraperitoneal injection (IPI, 2 mg/Kg of body weight)) of uranyl nitrate; b) 30 daily applications on the dorsal skin of aliquots of a mixture of U308, concentrated at 2% and at 4%--percutaneous absorption(PA)-. Tibia and mandible length were smaller in both experimental groups than in their respective controls. Some of the mandibular parameters were lower in intoxicated animals than their controls which in turn results in the alteration of the mandibular shape. We conclude that impairment in bone growth can be achieved by uranium intoxication. PMID:11885227

  12. Fibroblast growth factor 23 and bone mineralisation.

    PubMed

    Guo, Yu-Chen; Yuan, Quan

    2015-03-01

    Fibroblast growth factor 23 (FGF23) is a hormone that is mainly secreted by osteocytes and osteoblasts in bone. The critical role of FGF23 in mineral ion homeostasis was first identified in human genetic and acquired rachitic diseases and has been further characterised in animal models. Recent studies have revealed that the levels of FGF23 increase significantly at the very early stages of chronic kidney disease (CKD) and may play a critical role in mineral ion disorders and bone metabolism in these patients. Our recent publications have also shown that FGF23 and its cofactor, Klotho, may play an independent role in directly regulating bone mineralisation instead of producing a systematic effect. In this review, we will discuss the new role of FGF23 in bone mineralisation and the pathophysiology of CKD-related bone disorders. PMID:25655009

  13. The role of pleiotrophin in bone repair.

    PubMed

    Lamprou, Margarita; Kaspiris, Angelos; Panagiotopoulos, Elias; Giannoudis, Peter V; Papadimitriou, Evangelia

    2014-12-01

    Bone has an enormous capacity for growth, regeneration, and remodelling, largely due to induction of osteoblasts that are recruited to the site of bone formation. Although the pathways involved have not been fully elucidated, it is well accepted that the immediate environment of the cells is likely to play a role via cell–matrix interactions, mediated by several growth factors. Formation of new blood vessels is also significant and interdependent to bone formation, suggesting that enhancement of angiogenesis could be beneficial during the process of bone repair. Pleiotrophin (PTN), also called osteoblast-specific factor 1, is a heparin-binding angiogenic growth factor, with a well-defined and significant role in both physiological and pathological angiogenesis. In this review we summarise the existing evidence on the role of PTN in bone repair. PMID:25456495

  14. [Palliative radiotherapy for metastatic bone tumor].

    PubMed

    Yoshida, Kenji; Hiratsuka, Junichi

    2006-04-01

    Bone metastases are one of the most common conditions requiring radiation therapy today. Its main aim is relief of bone pain, prevention of pathological bone fractures as well as its healing, with anticipated effect upon improving mobility, function, and quality of life. For localized bone pain, external beam radiation therapy (EBRT) will be successful in reducing pain in some 80% of patients. However, optimal fraction dose and total doses of EBRT required for pain relief have been unknown. According to the recent reports, carbon ion radiotherapy seems to be a safe and effective modality in the management of metastatic bone tumor not eligible for conventional EBRT. For scattered painful metastases, the systemic administration of radioisotopes is thought to be effective. PMID:16582516

  15. The Digital Astronaut Project Bone Remodeling Model

    NASA Technical Reports Server (NTRS)

    Pennline, James A.; Mulugeta, Lealem; Lewandowski, Beth E.; Thompson, William K.; Sibonga, Jean D.

    2014-01-01

    Under the conditions of microgravity, astronauts lose bone mass at a rate of 1% to 2% a month, particularly in the lower extremities such as the proximal femur: (1) The most commonly used countermeasure against bone loss has been prescribed exercise, (2) However, current exercise countermeasures do not completely eliminate bone loss in long duration, 4 to 6 months, spaceflight, (3,4) leaving the astronaut susceptible to early onset osteoporosis and a greater risk of fracture later in their lives. The introduction of the Advanced Resistive Exercise Device, coupled with improved nutrition, has further minimized the 4 to 6 month bone loss. But further work is needed to implement optimal exercise prescriptions, and (5) In this light, NASA's Digital Astronaut Project (DAP) is working with NASA physiologists to implement well-validated computational models that can help understand the mechanisms of bone demineralization in microgravity, and enhance exercise countermeasure development.

  16. BONE REGENERATION AND DOCKING SITE HEALING AFTER BONE TRANSPORT DISTRACTION OSTEOGENESIS IN THE CANINE MANDIBLE

    PubMed Central

    Nagashima, Lucy K; Newby, Michelle Rondon; Zakhary, Ibrahim E; Nagy, William W; Zapata, Uriel; Dechow, Paul C; Opperman, Lynne A; Elsalanty, Mohammed E

    2011-01-01

    Purpose Bone transport distraction osteogenesis (BTDO) provides a promising alternative to traditional grafting techniques. However, existing BTDO devices have many limitations. The purpose of this research was to test a new device, the mandibular bone transport reconstruction plate (BTRP), in an animal model with comparable mandible size to humans and to histologically and mechanically examine the regenerate bone. Materials and methods Eleven adult foxhound dogs were divided into an unreconstructed control group of 5 animals, and an experimental group of 6 animals. In each animal, a 34 mm segmental defect was created in the mandible. The defect was reconstructed with BTRP. Histological and biomechanical characteristics of the regenerate and un-repaired defect were analyzed and compared to bone on the contralateral side of the mandible after 4 weeks of consolidation. Results The reconstructed defect was bridged with new bone, with little bone in the control defect. Regenerate density and microhardness were 22.3% and 42.6% lower than the contralateral normal bone, respectively. Likewise, the anisotropy of the experimental group was statistically lower than in the contralateral bone. Half the experimental animals showed non-union at the docking site. Conclusion The device was very stable and easy to install and activate. After one month of consolidation, the defect has been bridged with new bone with evidence of active bone formation. Regenerate bone was less mature than the control bone. Studies are underway to identify when the regenerate properties compare to normal bone, and to identify methods to augment bone union at the docking site. PMID:21601342

  17. A new concept for implant fixation: bone-to-bone biologic fixation.

    PubMed

    Kim, D Y; Kim, J R; Jang, K Y; Lee, K B

    2015-01-01

    Many attempts have been made to reduce complications of bone implant, such as pedicle screw loosening. To address this problem, the authors suggest a new concept of bone-to-bone biologic fixation using recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded cannulated pedicle screws. Recombinant human bone morphogenetic protein-2 is an osteoinductive cytokine. Four types of titanium pedicle screws were tested (uncannulated, cannulated with no loading, beta-tricalcium phosphate (TCP)-loaded, and TCP/BMP2 loaded) using 16 miniature pigs. Radiological evaluation was conducted to assess the fusion and loosening of pedicle screws. Twelve weeks after implantation, peak torsional extraction torque was measured, and the pedicle screw and bone interface was evaluated by micro-computed tomography (µCT) and histologic examination. The mean value of the radiological score was significantly greater in the TCP/BMP2 loaded group at 12 weeks post-operation compared to those in the other groups. CT images showed distinct bone formation surrounding TCP/BMP2 loaded cannulated pedicle screws compared to the other groups. Mean extraction torsional peak torque at 12 weeks postoperative was more than 10-fold higher in the TCP/BMP2 loaded pedicle screw group than in the other groups. Bone surface and bone volume, as quantitated through µCT, were higher in the TCP/BMP2 loaded group. Histologic examination revealed bone-to-bone fixation at the interface of pedicle screws and pre-existing bone. Bone-to-bone biologic fixation through the holes of TCP/BMP2 loaded pedicle screws significantly increased fixation strength and represents a novel method that can be applied to osteoporotic or tumour spine surgeries. PMID:25978116

  18. Normal bone density obtained in the absence of insulin receptor expression in bone.

    PubMed

    Irwin, Regina; Lin, Hua V; Motyl, Katherine J; McCabe, Laura R

    2006-12-01

    Type I diabetes is characterized by little or no insulin production and hyperglycemic conditions. It is also associated with significant bone loss and increased bone marrow adiposity. To examine the role of reduced insulin signaling in type I diabetic bone loss without inducing hyperglycemia, we used genetically reconstituted insulin receptor knockout mice (IRKO-L1) that are euglycemic as a result of human insulin receptor transgene expression in the pancreas, liver, and brain. RT-PCR analyses demonstrated undetectable levels of insulin receptor expression in IRKO-L1 bone, yet IRKO-L1 bones exhibit similar (and trend toward greater) bone density compared with wild-type animals as determined by microcomputed tomography. More detailed bone analyses indicated that cortical bone area was increased in tibias of IRKO-L1 mice. Osteoblast markers (osteocalcin and runx2 mRNA levels) and resorption markers (serum pyridinoline levels) were similar in wild-type and IRKO-L1 bones. When marrow adiposity was examined, we noticed a decrease in adipocyte number and fatty-acid-binding protein 2 expression in IRKO-L1 mice compared with wild-type mice. Bone marrow stromal cell cultures obtained from wild-type and IRKO-L1 mice demonstrated similar adipogenic and osteogenic potentials, indicating that systemic factors likely contribute to differences in marrow adiposity in vivo. Interestingly, IGF-I receptor mRNA levels were elevated in IRKO-L1 bones, suggesting (in combination with hyperinsulinemic conditions) that increased IGF-I receptor signaling may represent a compensatory response and contribute to the changes in cortical bone. Taken together, these results suggest that reduced insulin receptor signaling in bone is not a major factor contributing to bone loss in type I diabetes. PMID:16973725

  19. Pregnane X receptor knockout mice display osteopenia with reduced bone formation and enhanced bone resorption

    PubMed Central

    Azuma, Kotaro; Casey, Stephanie C; Ito, Masako; Urano, Tomohiko; Horie, Kuniko; Ouchi, Yasuyoshi; Kirchner, Séverine; Blumberg, Bruce; Inoue, Satoshi

    2015-01-01

    The steroid and xenobiotic receptor (SXR) and its murine ortholog pregnane X receptor (PXR) are nuclear receptors that are expressed mainly in the liver and intestine where they function as xenobiotic sensors. In addition to its role as a xenobiotic sensor, previous studies in our laboratories and elsewhere have identified a role for SXR/PXR as a mediator of bone homeostasis. Here, we report that systemic deletion of PXR results in marked osteopenia with mechanical fragility in female mice as young as 4 months old. Bone mineral density (BMD) of PXR knockout (PXRKO) mice was significantly decreased compared with the BMD of wild-type (WT) mice. Micro-computed tomography analysis of femoral trabecular bones revealed that the three-dimensional bone volume fraction of PXRKO mice was markedly reduced compared with that of WT mice. Histomorphometrical analysis of the trabecular bones in the proximal tibia showed a remarkable reduction in bone mass in PXRKO mice. As for bone turnover of the trabecular bones, bone formation is reduced, whereas bone resorption is enhanced in PXRKO mice. Histomorphometrical analysis of femoral cortical bones revealed a larger cortical area in WT mice than that in PXRKO mice. WT mice had a thicker cortical width than PXRKO mice. Three-point bending test revealed that these morphological phenotypes actually caused mechanical fragility. Lastly, serum levels of phosphate, calcium, and alkaline phosphatase were unchanged in PXRKO mice compared with WT. Consistent with our previous results, we conclude that SXR/PXR promotes bone formation and suppresses bone resorption thus cementing a role for SXR/PXR as a key regulator of bone homeostasis. PMID:20876238

  20. Is bone transplantation the gold standard for repair of alveolar bone defects?

    PubMed Central

    Raposo-Amaral, Cassio Eduardo; Bueno, Daniela Franco; Almeida, Ana Beatriz; Jorgetti, Vanda; Costa, Cristiane Cabral; Gouveia, Cecília Helena; Vulcano, Luiz Carlos; Fanganiello, Roberto D; Passos-Bueno, Maria Rita

    2014-01-01

    New strategies to fulfill craniofacial bone defects have gained attention in recent years due to the morbidity of autologous bone graft harvesting. We aimed to evaluate the in vivo efficacy of bone tissue engineering strategy using mesenchymal stem cells associated with two matrices (bovine bone mineral and ?-tricalcium phosphate), compared to an autologous bone transfer. A total of 28 adult, male, non-immunosuppressed Wistar rats underwent a critical-sized osseous defect of 5 mm diameter in the alveolar region. Animals were divided into five groups. Group 1 (n = 7) defects were repaired with autogenous bone grafts; Group 2 (n = 5) defects were repaired with bovine bone mineral free of cells; Group 3 (n = 5) defects were repaired with bovine bone mineral loaded with mesenchymal stem cells; Group 4 (n = 5) defects were repaired with ?-tricalcium phosphate free of cells; and Group 5 (n = 6) defects were repaired with ?-tricalcium phosphate loaded with mesenchymal stem cells. Groups 2–5 were compared to Group 1, the reference group. Healing response was evaluated by histomorphometry and computerized tomography. Histomorphometrically, Group 1 showed 60.27% ± 16.13% of bone in the defect. Groups 2 and 3 showed 23.02% ± 8.6% (p = 0.01) and 38.35% ± 19.59% (p = 0.06) of bone in the defect, respectively. Groups 4 and 5 showed 51.48% ± 11.7% (p = 0.30) and 61.80% ± 2.14% (p = 0.88) of bone in the defect, respectively. Animals whose bone defects were repaired with ?-tricalcium phosphate and mesenchymal stem cells presented the highest bone volume filling the defects; both were not statistically different from autogenous bone.

  1. The enigmas of bone without osteocytes

    PubMed Central

    Shahar, Ron; Dean, Mason N

    2013-01-01

    One of the hallmarks of tetrapod bone is the presence of numerous cells (osteocytes) within the matrix. Osteocytes are vital components of tetrapod bone, orchestrating the processes of bone building, reshaping and repairing (modeling and remodeling), and probably also participating in calcium-phosphorus homeostasis via both the local process of osteocytic osteolysis, and systemic effect on the kidneys. Given these critical roles of osteocytes, it is thought-provoking that the entire skeleton of many fishes consists of bone material that does not contain osteocytes. This raises the intriguing question of how the skeleton of these animals accomplishes the various essential functions attributed to osteocytes in other vertebrates, and raises the possibility that in acellular bone some of these functions are either accomplished by non-osteocytic routes or not necessary at all. In this review, we outline evidence for and against the fact that primary functions normally ascribed to osteocytes, such as mechanosensation, regulation of osteoblast/clast activity and mineral metabolism, also occur in fish bone devoid of these cells, and therefore must be carried out through alternative and perhaps ancient pathways. To enable meaningful comparisons with mammalian bone, we suggest thorough, phylogenetic examinations of regulatory pathways, studies of structure and mechanical properties and surveys of the presence/absence of bone cells in fishes. Insights gained into the micro-/nanolevel structure and architecture of fish bone, its mechanical properties and its physiology in health and disease will contribute to the discipline of fish skeletal biology, but may also help answer questions of basic bone biology. PMID:24422081

  2. Mechanosignaling in Bone Health, Trauma and Inflammation

    PubMed Central

    Knapik, Derrick M.; Perera, Priyangi; Nam, Jin; Blazek, Alisa D.; Rath, Björn; Leblebicioglu, Binnaz; Das, Hiranmoy; Wu, Lai Chu; Hewett, Timothy E.; Agarwal, Suresh K.; Robling, Alexander G.; Flanigan, David C.; Lee, Beth S.

    2014-01-01

    Abstract Significance: Mechanosignaling is vital for maintaining the structural integrity of bone under physiologic conditions. These signals activate and suppress multiple signaling cascades regulating bone formation and resorption. Understanding these pathways is of prime importance to exploit their therapeutic potential in disorders associated with bone loss due to disuse, trauma, or disruption of homeostatic mechanisms. Recent Advances: In the case of cells of the bone, an impressive amount of data has been generated that provides evidence of a complex mechanism by which mechanical signals can maintain or disrupt cellular homeostasis by driving transcriptional regulation of growth factors, matrix proteins and inflammatory mediators in health and inflammation. Mechanical signals act on cells in a magnitude dependent manner to induce bone deposition or resorption. During health, physiological levels of these signals are essential for maintaining bone strength and architecture, whereas during inflammation, similar signals can curb inflammation by suppressing the nuclear factor kappa B (NF-?B) signaling cascade, while upregulating matrix synthesis via mothers against decapentaplegic homolog and/or Wnt signaling cascades. Contrarily, excessive mechanical forces can induce inflammation via activation of the NF-?B signaling cascade. Critical Issues: Given the osteogenic potential of mechanical signals, it is imperative to exploit their therapeutic efficacy for the treatment of bone disorders. Here we review select signaling pathways and mediators stimulated by mechanical signals to modulate the strength and integrity of the bone. Future Directions: Understanding the mechanisms of mechanotransduction and its effects on bone lay the groundwork for development of nonpharmacologic mechanostimulatory approaches for osteodegenerative diseases and optimal bone health. Antioxid. Redox Signal. 20, 970–985. PMID:23815527

  3. 22-Oxacalcitriol attenuates bone loss in nonobese type 2 diabetes.

    PubMed

    Goto, Shunsuke; Fujii, Hideki; Kono, Keiji; Nakai, Kentaro; Awata, Rie; Yonekura, Yuriko; Hirata, Michinori; Shinohara, Masami; Nishi, Shinichi; Fukagawa, Masafumi

    2015-05-01

    Active vitamin D is a major therapeutic agent for bone disease. Although some studies have reported that vitamin D ameliorates bone disease related to diabetes, the mechanism remains unclear. Our study investigated the effect of the vitamin D receptor activator 22-oxacalcitriol (OCT) on bone disease in a rat model of diabetes. OCT was administered at a dose of 0.2?g/kg three times per week for 10weeks. We performed blood and urine analyses, single energy X-ray absorptiometry, micro-computed tomography, bone histomorphometry, and oxidative stress assessment in rats at 30weeks of age. OCT did not affect hemoglobin A1c or serum calcium levels. Bone mineral density (BMD), bone volume in the cortical and trabecular bones, and bone turnover were decreased in rats with diabetes. OCT treatment increased BMD and bone formation and tended to increase bone volume in the trabecular bone, but did not change bone volume in the cortical bone or bone resorption. The urinary oxidative stress marker 8-hydroxydeoxyguanosine (8-OHdG) excretion and the number of 8-OHdG-positive cells in bone were increased in rats with diabetes, and OCT treatment suppressed these increases. Our data suggest that OCT attenuated bone loss in a rat model of diabetes. This attenuation may be partially mediated by improved bone formation resulting from the antioxidative effect of OCT. PMID:25645030

  4. Ultrasonic Evaluation of Deeply Located Trabecular Bones - Preliminary Results

    NASA Astrophysics Data System (ADS)

    Cie?lik, Lucyna; Litniewski, Jerzy

    The analysis of ultrasonic signals scattered by soft tissues have been successfully applied for their characterization. Similarly, the trabecular bone backscattered signal contains information about the properties of the bone structure. Therefore scattering-based ultrasonic technique potentially enables the assessment of microstructure characteristics of a bone. The femoral neck fracture often occurs in the course of osteoporosis and can lead to severe complications. Therefore assessment of femoral bone microstructure and condition is important and essential for the diagnosis and treatment monitoring. As far most of the trabecular bone investigations have been performed in vitro. The only in vivo measurements were carried out in transmission and mostly concerned estimation of the attenuation in heel bone. We have built the ultrasonic scanner that could be useful in acquiring the RF (Radio Frequency) echoes backscattered by the trabecular bone in vivo. Moreover, the bone scanner provides data not only from heel bone but from deeply located bones as well (e.g. femoral bone). It can be also used for easily accessible bones like heel bone or breastbone. In this case a gel-pad is applied to assure focusing of ultrasound in trabecular bone (approximately 10 mm beneath the cortical bone). This study presents preliminary results of the attenuating properties evaluation of trabecular bone from the ultrasonic echoes backscattered by heel bone and femoral neck.

  5. Local treatment of a bone graft by soaking in zoledronic acid inhibits bone resorption and bone formation. A bone chamber study in rats

    PubMed Central

    2012-01-01

    Background Bone grafts are frequently used in orthopaedic surgery. Graft remodelling is advantageous but can occur too quickly, and premature bone resorption might lead to decreased mechanical integrity of the graft. Bisphosphonates delay osteoclastic bone resorption but may also impair formation of new bone. We hypothesize that these effects are dose dependent. In the present study we evaluate different ways of applying bisphosphonates locally to the graft in a bone chamber model, and compare that with systemic treatment. Methods Cancellous bone grafts were placed in titanium chambers and implanted in the tibia of 50 male rats, randomly divided into five groups. The first group served as negative control and the grafts were rinsed in saline before implantation. In the second and third groups, the grafts were soaked in a zoledronic acid solution (0.5 mg/ml) for 5 seconds and 10 minutes respectively before being rinsed in saline. In the fourth group, 8 ?L of zoledronic acid solution (0.5 mg/ml) was pipetted onto the freeze-dried grafts without rinsing. The fifth group served as positive control and the rats were given zoledronic acid (0.1 mg/kg) systemically as a single injection two weeks after surgery. The grafts were harvested at 6 weeks and analysed with histomorphometry, evaluating the ingrowth distance of new bone into the graft as an equivalent to the anabolic osteoblast effect and the amount (bone volume/total volume; BV/TV) of remaining bone in the remodelled graft as equivalent to the catabolic osteoclast effect. Results In all chambers, almost the entire graft had been revascularized but only partly remodelled at harvest. The ingrowth distance of new bone into the graft was lower in grafts soaked in zoledronic acid for 10 minutes compared to control (p = 0.007). In all groups receiving zoledronic acid, the BV/TV was higher compared to control. Conclusions This study found a strong inhibitory effect on bone resorption by bisphosphonates but also a limited inhibition of the ingrowth of new bone. Local treatment at surgery resulted in stronger inhibition of both resorption and bone formation compared to systemic treatment. PMID:23217097

  6. Rethinking the nature of fibrolamellar bone: an integrative biological revision of sauropod plexiform bone formation.

    PubMed

    Stein, Koen; Prondvai, Edina

    2014-02-01

    We present novel findings on sauropod bone histology that cast doubt on general palaeohistological concepts concerning the true nature of woven bone in primary cortical bone and its role in the rapid growth and giant body sizes of sauropod dinosaurs. By preparing and investigating longitudinal thin sections of sauropod long bones, of which transverse thin sections were published previously, we found that the amount of woven bone in the primary complex has been largely overestimated. Using comparative cellular and light-extinction characteristics in the two section planes, we revealed that the majority of the bony lamina consists of longitudinally organized primary bone, whereas woven bone is usually represented only by a layer a few cells thin in the laminae. Previous arguments on sauropod biology, which have been based on the overestimated amount, misinterpreted formation process and misjudged role of woven bone in the plexiform bone formation of sauropod dinosaurs, are thereby rejected. To explain the observed pattern in fossil bones, we review the most recent advances in bone biology concerning bone formation processes at the cellular and tissue levels. Differentiation between static and dynamic osteogenesis (SO and DO) and the revealed characteristics of SO- versus DO-derived bone tissues shed light on several questions raised by our palaeohistological results and permit identification of these bone tissues in fossils with high confidence. By presenting the methods generally used for investigating fossil bones, we show that the major cause of overestimation of the amount of woven bone in previous palaeohistological studies is the almost exclusive usage of transverse sections. In these sections, cells and crystallites of the longitudinally organized primary bone are cut transversely, thus cells appear rounded and crystallites remain dark under crossed plane polarizers, thereby giving the false impression of woven bone. In order to avoid further confusion in palaeohistological studies, we introduce new osteohistological terms as well as revise widely used but incorrect terminology. To infer the role of woven bone in the bone formation of fast-growing tetrapods, we review some aspects of the interrelationships between the vascularity of bone tissues, basal metabolic rate, body size and growth rate. By putting our findings into the context of osteogenesis, we provide a new model for the diametrical limb bone growth of sauropods and present new implications for the evolution of fast growth in vertebrates. Since biomechanical studies of bone tissues suggest that predominant collagen fibre orientation (CFO) is controlled by endogenous, functional and perhaps phylogenetic factors, the relationship between CFO and bone growth rate as defined by Amprino's rule, which has been the basis for the biological interpretation of several osteohistological features, must be revised. Our findings draw attention to the urgent need for revising widely accepted basic concepts of palaeohistological studies, and for a more integrative approach to bone formation, biomechanics and bone microstructural features of extant and extinct vertebrates to infer life history traits of long extinct, iconic animals like dinosaurs. PMID:23647662

  7. How tough is Brittle Bone? Investigating Osteogenesis Imperfecta in Mouse Bone††

    PubMed Central

    Carriero, A.; Zimmermann, E. A.; Paluszny, A.; Tang, S. Y.; Bale, H.; Busse, B.; Alliston, T.; Kazakia, G.

    2015-01-01

    The multiscale hierarchical structure of bone is naturally optimized to resist fractures. In osteogenesis imperfecta, or brittle bone disease, genetic mutations affect the quality and/or quantity of collagen, dramatically increasing bone fracture risk. Here we reveal how the collagen defect results in bone fragility in a mouse model of osteogenesis imperfecta (oim), which has homotrimeric ?1(I) collagen. At the molecular level we attribute the loss in toughness to a decrease in the stabilizing enzymatic crosslinks and an increase in non-enzymatic crosslinks, which may break prematurely inhibiting plasticity. At the tissue level, high vascular canal density reduces the stable crack growth, and extensive woven bone limits the crack-deflection toughening during crack growth. This demonstrates how modifications at the bone molecular level have ramifications at larger length scales affecting the overall mechanical integrity of the bone; thus, treatment strategies have to address multiscale properties in order to regain bone toughness. In this regard, findings from the heterozygous oim bone, where defective as well as normal collagen are present, suggest that increasing the quantity of healthy collagen in these bones helps to recover toughness at the multiple length scales. PMID:24420672

  8. Early postoperative bone scintigraphy in the evaluation of microvascular bone grafts in head and neck reconstruction

    PubMed Central

    Schuepbach, Jonas; Dassonville, Olivier; Poissonnet, Gilles; Demard, Francois

    2007-01-01

    Background Bone scintigraphy was performed to monitor anastomotic patency and bone viability. Methods In this retrospective study, bone scans were carried out during the first three postoperative days in a series of 60 patients who underwent microvascular bone grafting for reconstruction of the mandible or maxilla. Results In our series, early bone scans detected a compromised vascular supply to the bone with high accuracy (p < 10-6) and a sensitivity that was superior to the sensitivity of clinical monitoring (92% and 75% respectively). Conclusion When performing bone scintigraphy during the first three postoperative days, it not only helps to detect complications with high accuracy, as described in earlier studies, but it is also an additional reliable monitoring tool to decide whether or not microvascular revision surgery should be performed. Bone scans were especially useful in buried free flaps where early postoperative monitoring depended exclusively on scans. According to our experience, we recommend bone scans as soon as possible after surgery and immediately in cases suspicious of vascularized bone graft failure. PMID:17448223

  9. Bone effects of space flight analysis by quantum concept of bone remodelling

    NASA Astrophysics Data System (ADS)

    Parfitt, A. M.

    During the manned Skylab flights mineral losses from the calcaneum and changes in external calcium balance were in the ranges found for healthy subjects at bedrest. Calcium balance reached a nadir of -200 mg/day by two months with no change thereafter; the negative balance was due to increased urinary excretion with no change in net absorption. The total calcium loss averaged 18 g in the longest flight of 84 days; the densitiometric data suggested that about two-thirds of this came from trabecular bone and about one-third from cortical bone. These data could represent reversible bone loss due to increased birth rate of normal osteoclasts and osteoblasts and consequent increase in bone turnover and in reversible mineral deficit, or irreversible bone loss due to overactive osteoclasts and/or underactive osteoblasts. If the former explanation is correct, significant bone loss is unlikely whatever the duration of future flights, except in older persons already losing bone; if the latter explanation is correct, space flights longer than six months may lead to a significant increase in fracture risk in later life. Neither terrestrial immobilization nor unwilling animals in orbit are ideal models for the effects of space flight on human bone. To choose between reversible and irreversible mechanisms of bone loss, and to determine the effects of space flight on lifelong fracture risk, future astronauts and cosmonauts must undergo adequate histologic study of bone after in vivo tetracycline labeling.

  10. Remodeling in bone without osteocytes: Billfish challenge bone structure–function paradigms

    PubMed Central

    Atkins, Ayelet; Dean, Mason N.; Habegger, Maria Laura; Motta, Phillip J.; Ofer, Lior; Repp, Felix; Shipov, Anna; Weiner, Steve; Currey, John D.; Shahar, Ron

    2014-01-01

    A remarkable property of tetrapod bone is its ability to detect and remodel areas where damage has accumulated through prolonged use. This process, believed vital to the long-term health of bone, is considered to be initiated and orchestrated by osteocytes, cells within the bone matrix. It is therefore surprising that most extant fishes (neoteleosts) lack osteocytes, suggesting their bones are not constantly repaired, although many species exhibit long lives and high activity levels, factors that should induce considerable fatigue damage with time. Here, we show evidence for active and intense remodeling occurring in the anosteocytic, elongated rostral bones of billfishes (e.g., swordfish, marlins). Despite lacking osteocytes, this tissue exhibits a striking resemblance to the mature bone of large mammals, bearing structural features (overlapping secondary osteons) indicating intensive tissue repair, particularly in areas where high loads are expected. Billfish osteons are an order of magnitude smaller in diameter than mammalian osteons, however, implying that the nature of damage in this bone may be different. Whereas billfish bone material is as stiff as mammalian bone (unlike the bone of other fishes), it is able to withstand much greater strains (relative deformations) before failing. Our data show that fish bone can exhibit far more complex structure and physiology than previously known, and is apparently capable of localized repair even without the osteocytes believed essential for this process. These findings challenge the unique and primary role of osteocytes in bone remodeling, a basic tenet of bone biology, raising the possibility of an alternative mechanism driving this process. PMID:25331870

  11. Ostene, a New Alkylene Oxide Copolymer Bone Hemostatic Material, Does Not Inhibit Bone Healing

    PubMed Central

    Magyar, Clara E.; Aghaloo, Tara L.; Atti, Elisa; Tetradis, Sotirios

    2009-01-01

    OBJECTIVE In this study, we investigate the effects of a soft bone hemostatic wax comprised of water-soluble alkylene oxide copolymers (Ostene; Ceremed, Inc., Los Angeles, CA) on bone healing in a rat calvaria defect model. We compared the effects with a control (no hemostatic agent) and bone wax, an insoluble and nonresorbable material commonly used for bone hemostasis. METHODS Two bilateral 3-mm circular noncritical-sized defects were made in the calvariae of 30 rats. Alkylene oxide copolymer or bone wax was applied or no hemostatic material was used (control). After 3, 6, and 12 weeks, rats were sacrificed and the calvariae excised. Bone healing, expressed as fractional bone volume (± standard error of the mean), was measured by microcomputed tomography. RESULTS Immediate hemostasis was achieved equally with bone wax and alkylene oxide copolymer. Bone wax-filled defects remained unchanged at all time points with negligible healing observed. At 3 weeks, no evidence of alkylene oxide copolymer was observed at the application site, with fractional bone volume significantly greater than bone wax-treated defects (0.20 ± 0.03 versus 0.02 ± 0.01; P = 0.0003). At 6 and 12-weeks, alkylene oxide copolymer-treated defects continued to show significantly greater healing versus bone wax (0.18 ± 0.04 versus 0.05 ± 0.01 and 0.31 ± 0.04 versus 0.06 ± 0.02, respectively). At all time points, alkylene oxide copolymer-treated and control defects showed good healing with no significant difference. CONCLUSION Alkylene oxide copolymer is an effective hemostatic agent that does not inhibit osteogenesis or bone healing. PMID:18981846

  12. Whales: From Bone to Book

    NSDL National Science Digital Library

    Smithsonian Libraries presents this remarkable exhibit that looks into the world of natural history via the largest mammals on the planet: whales. On this site, visitors can learn about how the bones and fossils of these amazing animals make their way from discovery on a beach or in rock strata into the museum's vast collections. The first stop should be the Kellogg Illustration Collection, which contains over 350 drawings of over 60 species of whales created by cytologist, Remington Kellogg. Next up, visitors should explore a collection of 13 books from the Biodiversity Heritage Library that deal with different species of cetaceans from around the world. A detailed bibliography of related works authored by Smithsonian affiliates, scientists, and fellows is also available.

  13. The bones of the insane

    PubMed Central

    2013-01-01

    This article examines alienist explanations for fracture among British asylum patients in the late nineteenth to early twentieth centuries. A series of deaths in asylums came to light in the 1870s which, in placing the blame for such incidents on asylum staff, called for a response from the psychiatric profession. This response drew upon other medical fields and employed novel pathological techniques to explain why fractures occurred among the insane, in many cases aligning bone fragility with particular forms of insanity (namely, General Paralysis of the Insane). Although such research aimed to provide a medical explanation for the ‘fracture death’, it also called into question the value of pathological research and the utility of quantitative measurement in understanding mental disease. PMID:24573259

  14. [Bone health in Geneva retirees].

    PubMed

    Biver, E; Durosier, C; Chevalley, T; Rizzoli, R; Ferrari, S

    2015-03-18

    GERICO (Geneva Retirees Cohort) is a cohort of 953 men and women recruited at the age of 65 in Canton of Geneva, Switzerland, providing a picture of bone health at retirement time. Despite few comorbidities and good nutritional intake and vitamin D status, 30% of subjects have a history of vertebral or clinical fracture after the age of 45, 20% of women and 11% of men have osteoporosis assessed by DXA. 22% have a 10-year probability of a major osteoporotic fracture assessed by FRAX greater than 15%, -i.e. the current intervention thresholds recommended in this age-class in Switzerland. Nevertheless, only 1.4% subject benefits of an anti-osteoporotic drug. These data underscore the importance of primary and secondary prevention of osteoporosis and fractures in healthy elderly at time of retirement. PMID:25962224

  15. The bare bones of race.

    PubMed

    Fausto-Sterling, Anne

    2008-10-01

    In this paper I examine claims of racial difference in bone density and find that the use and definitions of race in medicine lack a theoretical foundation. My central argument is that the social produces the biological in a system of constant feedback between body and social experience. By providing a different angle of vision on claimed racial differences I hope to move the conversation away from an ultimately futile discussion of nature versus nurture, where time is held constant and place seen as irrelevant, and begin to build a new paradigm for examining the contributions of geographic ancestry, individual lifecycle experience, race, and gender to varied patterns of health and disease. PMID:19227817

  16. Hypoxia, HIFs and bone development

    PubMed Central

    Araldi, Elisa; Schipani, Ernestina

    2010-01-01

    Oxygen is not only an obviously important substrate, but it is also a regulatory signal that controls expression of a specific genetic program. Crucial mediator of the adaptive response of cells to hypoxia is the family of Hypoxia-Inducible Transcription Factors (HIF?. The fetal growth plate, which is an avascular structure of mesenchymal origin, has a unique out-in gradient of oxygenation. HIF-1? is necessary for chondrogenesis in vivo by controlling a complex homeostatic response that allows chondrocytes to survive and differentiate in a hypoxic environment. Moreover, HIFs are also essential in osteogenesis and joint development. This brief Perspective summarizes the critical role of HIFs in endochondral bone development. PMID:20444436

  17. Advances in noninvasive bone measurement

    SciTech Connect

    Mazess, R.B.; Barden, H.; Vetter, J.; Ettinger, M.

    1989-01-01

    Several noninvasive measurement methods are used for evaluation of metabolic disease. Single-photon (/sup 125/I) scans of the peripheral skeleton are useful in some diseases but are ineffective in osteoporosis (even on the distal radius or os calcis) because they cannot predict spinal or femoral density. Also, peripheral measurements show high percentages of false negatives, that is many patients with fractures have normal peripheral density. Dual-photon (/sup 153/Gd) scans of the spine, femur, and total skeleton are precise and accurate (2% error) and provide direct measurements of bone strength at fracture sites. This gives the best discrimination of abnormality and the most sensitive monitoring. Quantitative computed computed tomography (QCT) allows measurement of the spine but not the critical proximal femur area. QCT has a large accuracy error because (a) the limited area measured (under 5 cm3) fails to represent the total vertebral body, (b) technical errors, and (c) variable fat and osteoid influence the results. 25 references.

  18. Photoacoustic and ultrasound characterization of bone composition

    NASA Astrophysics Data System (ADS)

    Lashkari, Bahman; Yang, Lifeng; Liu, Lixian; Tan, Joel W. Y.; Mandelis, Andreas

    2015-02-01

    This study examines the sensitivity and specificity of backscattered ultrasound (US) and backscattering photoacoustic (PA) signals for bone composition variation assessment. The conventional approach in the evaluation of bone health relies on measurement of bone mineral density (BMD). Although, a crucial and probably the most important parameter, BMD is not the only factor defining the bone health. New trends in osteoporosis research, also pursue the changes in collagen content and cross-links with bone diseases and aging. Therefore, any non-invasive method that can assess any of these parameters can improve the diagnostic tools and also can help with the biomedical studies on the diseases themselves. Our previous studies show that both US and PA are responsive to changes in the BMD, PA is, in addition, sensitive to changes in the collagen content of the bone. Measurements were performed on bone samples before and after mild demineralization and decollagenization at the exact same points. Results show that combining both modalities can enhance the sensitivity and specificity of diagnostic tool.

  19. Composite bone substitutes prepared by two methods

    NASA Astrophysics Data System (ADS)

    Lee, Hoe Y.

    A variety of ceramics and polymers exists that can be used as bone substitute materials with desirable properties such as biocompatibility and osteoconductivity. A key feature missing in these bone substitutes, or scaffolds, is the ability to bear loads. This work explored two methods for solving this problem. The first used cancellous bone taken from bovine femoral bone to create a natural scaffold through a heat treating process that eliminated the organic components and sintered the bone minerals, known as hydroxyapatite, together. The strength and Young's modulus of the natural scaffold were greatly improved after polymer infiltration with polymethylmethacrylate. Unfortunately, compression testing revealed that there was not a good interfacial bond between the mineral and polymer phases. The second method employed a freeze-casting technique to create synthetic hydroxyapatite scaffolds that have an aligned lamellar microstructure. By varying the amount of hydroxyapatite in the initial slurry mixture and the cooling rate, synthetic scaffolds with a range of porosities and strengths was produced. The highest solid loading and fastest cooling rate produced a scaffold with a strength and modulus approaching that of cortical bone. Further study is required to produce a two phase composite that is chemically bonded together for optimal performance. The synthetic scaffolds, with their tunable mechanical properties and ease of fabrication, make them a promising material for a load-bearing bone substitute.

  20. Biomimetic materials for controlling bone cell responses.

    PubMed

    Drevelle, Olivier; Faucheux, Nathalie

    2013-01-01

    Bone defects that cannot "heal spontaneously during life" will become an ever greater health problem as populations age. Harvesting autografts has several drawbacks, such as pain and morbidity at both donor and acceptor sites, the limited quantity of material available, and frequently its inappropriate shape. Researchers have therefore developed alternative strategies that involve biomaterials to fill bone defects. These biomaterials must be biocompatible and interact with the surrounding bone tissue to allow their colonization by bone cells and blood vessels. The latest generation biomaterials are not inert; they control cell responses like adhesion, proliferation and differentiation. These biomaterials are called biomimetic materials. This review focuses on the development of third generation materials. We first briefly describe the bone tissue with its cells and matrix, and then how bone cells interact with the extracellular matrix. The next section covers the materials currently used to repair bone defects. Finally, we describe the strategies employed to modify the surface of materials, such as coating with hydroxyapatite and grafting biomolecules. PMID:23277057

  1. Future human bone research in space

    NASA Technical Reports Server (NTRS)

    LeBlanc, A.; Shackelford, L.; Schneider, V.

    1998-01-01

    Skylab crewmembers demonstrated negative calcium (Ca) balance reaching about -300 mg/day by flight day 84. Limited bone density (BMD) measurements documented that bone was not lost equally from all parts of the skeleton. Subsequent BMD studies during long duration Russian flights documented the regional extent of bone loss. These studies demonstrated mean losses in the spine, femur neck, trochanter, and pelvis of about 1%-1.6% with large differences between individuals as well as between bone sites in a given individual. Limited available data indicate postflight bone recovery occurred in some individuals, but may require several years for complete restoration. Long duration bedrest studies showed a similar pattern of bone loss and calcium balance (-180 mg/day) as spaceflight. During long duration bedrest, resorption markers were elevated, formation markers were unchanged, 1,25 vitamin D (VitD) and calcium absorption were decreased, and serum ionized Ca was increased. Although this information is a good beginning, additional spaceflight research is needed to assess architectural and subregional bone changes, elucidate mechanisms, and develop efficient as well as effective countermeasures. Space research poses a number of unique problems not encountered in ground-based laboratory research. Therefore, researchers contemplating human spaceflight research need to consider a number of unique problems related to spaceflight in their experimental design.

  2. Augmentation of tendon-to-bone healing.

    PubMed

    Atesok, Kivanc; Fu, Freddie H; Wolf, Megan R; Ochi, Mitsuo; Jazrawi, Laith M; Doral, M Nedim; Lubowitz, James H; Rodeo, Scott A

    2014-03-19

    Tendon-to-bone healing is vital to the ultimate success of the various surgical procedures performed to repair injured tendons. Achieving tendon-to-bone healing that is functionally and biologically similar to native anatomy can be challenging because of the limited regeneration capacity of the tendon-bone interface. Orthopaedic basic-science research strategies aiming to augment tendon-to-bone healing include the use of osteoinductive growth factors, platelet-rich plasma, gene therapy, enveloping the grafts with periosteum, osteoconductive materials, cell-based therapies, biodegradable scaffolds, and biomimetic patches. Low-intensity pulsed ultrasound and extracorporeal shockwave treatment may affect tendon-to-bone healing by means of mechanical forces that stimulate biological cascades at the insertion site. Application of various loading methods and immobilization times influence the stress forces acting on the recently repaired tendon-to-bone attachment, which eventually may change the biological dynamics of the interface. Other approaches, such as the use of coated sutures and interference screws, aim to deliver biological factors while achieving mechanical stability by means of various fixators. Controlled Level-I human trials are required to confirm the promising results from in vitro or animal research studies elucidating the mechanisms underlying tendon-to-bone healing and to translate these results into clinical practice. PMID:24647509

  3. Densitometric evaluation of periprosthetic bone remodeling

    PubMed Central

    Parchi, Paolo Domenico; Cervi, Valentina; Piolanti, Nicola; Ciapini, Gianluca; Andreani, Lorenzo; Castellini, Iacopo; Poggetti, Andrea; Lisanti, Michele

    2014-01-01

    Summary The application of Dual-energy X-ray absorptiometry (DEXA) in orthopaedic surgery gradually has been extended from the study of osteoporosis to different areas of interest like the study of the relation between bone and prosthetic implants. Aim of this review is to analyze changes that occur in periprosthetic bone after the implantation of a total hip arthroplasty (THA) or a total knee arthroplasty (TKA). In THA the pattern of adaptive bone remodeling with different cementless femoral stems varies and it appears to be strictly related to the design and more specifically to where the femoral stem is fixed on bone. Short stems with metaphyseal fixation allow the maintenance of a more physiologic load transfer to the proximal femur decreasing the entity of bone loss. Femoral bone loss after TKA seems to be related to the stress shielding induced by the implants while tibial bone remodeling seems to be related to postoperative changes in knee alignment (varus/valgus) and consequently in tibial load transfer. After both THA and TKA stress shielding seems to be an inevitable phenomenon that occurs mainly in the first year after surgery. PMID:25568658

  4. Cellular Plasticity in Prostate Cancer Bone Metastasis

    PubMed Central

    Jadaan, Dima Y.; Jadaan, Mutaz M.; McCabe, John P.

    2015-01-01

    Purpose. Experimental data suggest that tumour cells can reversibly transition between epithelial and mesenchymal states (EMT and MET), a phenomenon known as cellular plasticity. The aim of this review was to appraise the clinical evidence for the role of cellular plasticity in prostate cancer (PC) bone metastasis. Methods. An electronic search was performed using PubMed for studies that have examined the differential expression of epithelial, mesenchymal, and stem cell markers in human PC bone metastasis tissues. Results. The review included nineteen studies. More than 60% of the studies used ?20 bone metastasis samples, and there were several sources of heterogeneity between studies. Overall, most stem cell markers analysed, except for CXCR4, were positively expressed in bone metastasis tissues, while the expression of EMT and MET markers was heterogeneous between and within samples. Several EMT and stemness markers that are involved in osteomimicry, such as Notch, Met receptor, and Wnt/? pathway, were highly expressed in bone metastases. Conclusions. Clinical findings support the role of cellular plasticity in PC bone metastasis and suggest that epithelial and mesenchymal states cannot be taken in isolation when targeting PC bone metastasis. The paper also highlights several challenges in the clinical detection of cellular plasticity. PMID:26146569

  5. Mechanical and electrical interactions in bone remodeling

    SciTech Connect

    Spadaro, J.A. [State Univ. of New York, Syracuse, NY (United States). Dept. of Orthopedic Surgery] [State Univ. of New York, Syracuse, NY (United States). Dept. of Orthopedic Surgery

    1997-05-01

    The natural remodeling and adaptation of skeletal tissues in response to mechanical loading is a classic example of physical regulation in biology. It is largely because it involves forces that do not seem to fit into the familiar schemes of biochemical controls that bone adaptation mechanisms have intrigued us for at least a century. The effect of electromagnetic fields on organisms is another example of this, and the two have become linked in an attempt to explain bone remodeling (Yasuda`s hypothesis). This paper re-examines the roles of endogenous and exogenous electromagnetic fields in the response of bone to mechanical forces. A series of experiments is reviewed in which mechanical and electrical stimuli were applied to implants in the medullary canal of rabbit long bones. The results suggest that endogenously generated electrical currents are not required to initiate mechanically stimulated bone formation, but that direct mechanical effects on bone cells is the more likely scenario. Based on this and other evidence from the literature, it is suggested that when exogenous electromagnetic stimuli are applied, bone cells respond by modulating the activity of more primary activators such as hormones, growth factors, cytokines, and mechanical forces. 76 refs., 8 figs.

  6. Bone regeneration with mesenchymal stem cells

    PubMed Central

    Kon, Elizaveta; Filardo, Giuseppe; Roffi, Alice; Di Martino, Alessandro; Hamdan, Mohammad; De Pasqual, Laura; Merli, Maria Letizia; Marcacci, Maurilio

    2012-01-01

    Summary Bone possesses the intrinsic regeneration capacity as part of the repair process in response to injury, during skeletal development or continuous remodeling throughout adult life. However, some complex clinical conditions require bone regeneration in too large quantity, and tissue engineering approach was developed to favor the regeneration of a new functional tissue. Mesenchymal stem cells (MSCs) have emerged as a promising alternative to the traditional surgical techniques. The purpose of this mini-review is to investigate the role of MSCs in clinical practice for bone regeneration, documenting the state of art and indentifying future research directions. We performed a search of the literature on PUBMED database between 2001 and 2011 using the key words “MSC and bone regeneration”. Inclusion criteria were clinical studies regarding the use of MSC in bone regeneration, for both bone repair and metabolic bone diseases, and in English language. References from selected papers were also screened. Our search resulted in 516 articles. Among these a total of 18 articles were included: 12 case series, 5 case reports and 1 comparative studies. MSCs represent an exciting and promising stem cell population for regeneration of bone in skeletal diseases, especially when tissue engineering or biomaterials are applied. However, literature results are limited, because of the small number and the low quality of trials, the lack of controls and the short follow-up. Researchers have to perform more high quality studies in order to document results and increase the potential of MSCs use in clinical practice, to develop a minimally invasive treatment to favor high quality bone tissue regeneration. PMID:22783331

  7. Botox induced muscle paralysis rapidly degrades bone.

    PubMed

    Warner, Sarah E; Sanford, David A; Becker, Blair A; Bain, Steven D; Srinivasan, Sundar; Gross, Ted S

    2006-02-01

    The means by which muscle function modulates bone homeostasis is poorly understood. To begin to address this issue, we have developed a novel murine model of unilateral transient hindlimb muscle paralysis using botulinum toxin A (Botox). Female C57BL/6 mice (16 weeks) received IM injections of either saline or Botox (n = 10 each) in both the quadriceps and calf muscles of the right hindleg. Gait dysfunction was assessed by multi-observer inventory, muscle alterations were determined by wet mass, and bone alterations were assessed by micro-CT imaging at the distal femur, proximal tibia, and tibia mid-diaphysis. Profound degradation of both muscle and bone was observed within 21 days despite significant restoration of weight bearing function by 14 days. The muscle mass of the injected quadriceps and calf muscles was diminished -47.3% and -59.7%, respectively, vs. saline mice (both P < 0.001). The ratio of bone volume to tissue volume (BV/TV) within the distal femoral epiphysis and proximal tibial metaphysis of Botox injected limbs was reduced -43.2% and -54.3%, respectively, while tibia cortical bone volume was reduced -14.6% (all P < 0.001). Comparison of the contralateral non-injected limbs indicated the presence of moderate systemic effects in the model that were most probably associated with diminished activity following muscle paralysis. Taken as a whole, the micro-CT data implied that trabecular and cortical bone loss was primarily achieved by bone resorption. These data confirm the decisive role of neuromuscular function in mediating bone homeostasis and establish a model with unique potential to explore the mechanisms underlying this relation. Given the rapidly expanding use of neuromuscular inhibitors for indications such as pain reduction, these data also raise the critical need to monitor bone loss in these patients. PMID:16185943

  8. Modeling microdamage behavior of cortical bone.

    PubMed

    Donaldson, Finn; Ruffoni, Davide; Schneider, Philipp; Levchuk, Alina; Zwahlen, Alexander; Pankaj, Pankaj; Müller, Ralph

    2014-11-01

    Bone is a complex material which exhibits several hierarchical levels of structural organization. At the submicron-scale, the local tissue porosity gives rise to discontinuities in the bone matrix which have been shown to influence damage behavior. Computational tools to model the damage behavior of bone at different length scales are mostly based on finite element (FE) analysis, with a range of algorithms developed for this purpose. Although the local mechanical behavior of bone tissue is influenced by microstructural features such as bone canals and osteocyte lacunae, they are often not considered in FE damage models due to the high computational cost required to simulate across several length scales, i.e., from the loads applied at the organ level down to the stresses and strains around bone canals and osteocyte lacunae. Hence, the aim of the current study was twofold: First, a multilevel FE framework was developed to compute, starting from the loads applied at the whole bone scale, the local mechanical forces acting at the micrometer and submicrometer level. Second, three simple microdamage simulation procedures based on element removal were developed and applied to bone samples at the submicrometer-scale, where cortical microporosity is included. The present microdamage algorithm produced a qualitatively analogous behavior to previous experimental tests based on stepwise mechanical compression combined with in situ synchrotron radiation computed tomography. Our results demonstrate the feasibility of simulating microdamage at a physiologically relevant scale using an image-based meshing technique and multilevel FE analysis; this allows relating microdamage behavior to intracortical bone microstructure. PMID:24622917

  9. Interleukin-6 Deficiency Increases Inflammatory Bone Destruction

    PubMed Central

    Balto, Khaled; Sasaki, Hajime; Stashenko, Philip

    2001-01-01

    Periapical bone destruction occurs as a consequence of pulpal infection. In previous studies, we showed that interleukin-1 (IL-1) is the primary stimulator of bone destruction in this model. IL-6 is a pleiotropic cytokine that is induced in these infections and has both pro- and anti-inflammatory activities. In the present study, we determined the role of IL-6 in regulating IL-1 expression and bone resorption. The first molars of IL-6 knockouts (IL-6?/?) and wild-type mice were subjected to surgical pulp exposure and infection with a mixture of four common pulpal pathogens, including Prevotella intermedia, Fusobacterium nucleatum, Peptostreptococcus micros, and Streptococcus intermedius. Mice were killed after 21 days, and bone destruction and cytokine expression were determined. Surprisingly, bone destruction was significantly increased in IL-6?/? mice versus that in wild-type mice (by 30%; P < 0.001). In a second experiment, the effects of chronic (IL-6?/?) IL-6 deficiency and short-term IL-6 deficiency induced by in vivo antibody neutralization were determined. Both IL-6?/? (30%; P < 0.001) and anti-IL-6 antibody-treated mice (40%; P < 0.05) exhibited increased periapical bone resorption, compared to wild-type controls. The increased bone resorption in IL-6-deficient animals correlated with increases in osteoclast numbers, as well as with elevated expression of bone-resorptive cytokines IL-1? and IL-1?, in periapical lesions and with decreased expression of the anti-inflammatory cytokine IL-10. These data demonstrate that endogenous IL-6 expression has significant anti-inflammatory effects in modulating infection-stimulated bone destruction in vivo. PMID:11159963

  10. Evaluation of delamination in drilling of bone.

    PubMed

    Pandey, Rupesh Kumar; Panda, Sudhansu Sekhar

    2015-07-01

    In this paper, delamination of bone associated with drilling is investigated using design of experiments. Experiments have been planned based on L25 design of the orthogonal arrays with different conditions of drill bit, spindle speed and feed rate. Regression analysis is used to develop a mathematical model of delamination as a function of bone drilling process parameters. Analysis of variance (ANOVA) is carried out to find the significance of the developed model along with the percentage contribution of each factor on delamination. Optimum setting of bone drilling parameters for minimum delamination is determined using Taguchi optimization methodology. Finally, the results obtained are validated by conducting confirmation experiments. PMID:25983066

  11. Use of dermestid beetles for cleaning bones.

    PubMed

    Hefti, E; Trechsel, U; Rüfenacht, H; Fleisch, H

    1980-01-01

    Various parts of the skeleton of normal and osteoporotic rats were compared with respect to their dry weight, ash weight, and calcium content when the bones were cleaned by Dermestes maculatus beetles or manually. Both techniques gave similar results. This was also true when whole body calcium measured by neutron activation and total skeletal calcium from bones cleaned by the beetles were compared. Thus dermestid beetles are useful as a technique to clean bones, especially for the parts of the skeleton which are difficult to dissect by hand. PMID:6770972

  12. Paget’s Disease of Bone

    Microsoft Academic Search

    Roy D. Altman

    \\u000a \\u000a \\u000a \\u000a \\u000a  \\u000a \\u000a Paget’s disease affects 1% of the US population over the age of 40 years and is a chronic disorder of adult skeleton characterized\\u000a by increased resorption and deposition of bone resulting in replacement of the normal matrix with softened and enlarged bone.\\u000a \\u000a \\u000a \\u000a \\u000a  \\u000a \\u000a Most adults with Paget’s disease are asymptomatic and diagnosis is found on x-ray of the bones.

  13. Delivering on the promise of bone morphogenetic proteins

    Microsoft Academic Search

    Rebecca H. Li; John M. Wozney

    2001-01-01

    The advent of bone growth factors has been widely anticipated since their successful production using recombinant DNA technology. Bone morphogenetic proteins (BMPs) are an important class of bone growth factors and will be the focus of this article. In the near future these therapeutics might revolutionize how clinicians treat such diverse orthopedic applications as the healing of broken bones, increasing

  14. Novel Regulators of Bone Formation: Molecular Clones and Activities

    Microsoft Academic Search

    John M. Wozney; Vicki Rosen; Anthony J. Celeste; Lisa M. Mitsock; Matthew J. Whitters; Ronald W. Kriz; Rodney M. Hewick; Elizabeth A. Wang

    1988-01-01

    Protein extracts derived from bone can initiate the process that begins with cartilage formation and ends in de novo bone formation. The critical components of this extract, termed bone morphogenetic protein (BMP), that direct cartilage and bone formation as well as the constitutive elements supplied by the animal during this process have long remained unclear. Amino acid sequence has been

  15. Damage to Bird Bones in Pellets of Gyrfalcon Falco rusticolus

    Microsoft Academic Search

    Zbigniew M. Boche?ski; Kauko Huhtala; Päivi Jussila; Erkki Pulliainen; Risto Tornberg; Paavo S. Tunkkari

    1998-01-01

    Fragmentation and digestion of bird bones in pellets of the gyrfalconFalco rusticoluswere studied. Remains of the axial skeleton, including the head, were very scarce. Whole bones were rarely preserved. Tibiotarsi and most other long bones were the best elements for the calculation of the minimum number of individuals. All types of bones were heavily modified by digestion: with a few

  16. Development of laminated fiber-reinforced nanocomposites for bone regeneration

    Microsoft Academic Search

    Weijie Xu

    2009-01-01

    There have been numerous efforts to develop synthetic and\\/or natural tissue engineering scaffolds that are suitable for bone regeneration applications to replace autograft and allograft bones. Current biomaterials as a scaffold for bone regeneration are limited by the extent of degradation concurrent with bone formation, mechanical strength, and the extent of osteogenic differentiation of marrow stromal cells migrating from the

  17. Original article Sources of shared variability in muscle and bone

    E-print Network

    Paris-Sud XI, Université de

    Original article Sources of shared variability in muscle and bone weight distribution, to deduce the factors that control muscle and bone distribution and to predict total carcass muscle and bone content from orthogonal carcass traits. Most of the common variability (88.2%) in muscle and bone weight

  18. The bone diagnostic instrument II: Indentation distance increase

    Microsoft Academic Search

    Paul Hansma; Patricia Turner; Barney Drake; Eugene Yurtsev; Alexander Proctor; Phillip Mathews; Jason Lelujian; Connor Randall; Jonathan Adams; Ralf Jungmann; Federico Garza-de-Leon; Georg Fantner; Haykaz Mkrtchyan; Michael Pontin; Aaron Weaver; Morton B. Brown; Nadder Sahar; Ricardo Rossello; David Kohn

    2008-01-01

    The bone diagnostic instrument (BDI) is being developed with the long-term goal of providing a way for researchers and clinicians to measure bone material properties of human bone in vivo. Such measurements could contribute to the overall assessment of bone fragility in the future. Here, we describe an improved BDI, the Osteoprobe II™. In the Osteoprobe II™, the probe assembly,

  19. Preparation and bioactivity evaluation of bone-like hydroxyapatite nanopowder

    Microsoft Academic Search

    M. H. Fathi; A. Hanifi; V. Mortazavi

    2008-01-01

    Calcium phosphate ceramic such as hydroxyapatite (HA) is good candidate for bone substitutes due to their chemical and structural similarity to bone minerals. The bone mineral consists of tiny hydroxyapatite crystals in the nanoregime. Nanostructured hydroxyapatite is also expected to have better bioactivity than coarser crystals. This paper reports on the preparation and in vitro evaluation of bone-like hydroxyapatite nanopowder.

  20. Vav3 regulates osteoclast function and bone mass

    Microsoft Academic Search

    Roberta Faccio; Steven L Teitelbaum; Keiko Fujikawa; Jean Chappel; Alberta Zallone; Victor L Tybulewicz; F Patrick Ross; Wojciech Swat

    2005-01-01

    Osteoporosis, a leading cause of morbidity in the elderly, is characterized by progressive loss of bone mass resulting from excess osteoclastic bone resorption relative to osteoblastic bone formation. Here we identify Vav3, a Rho family guanine nucleotide exchange factor, as essential for stimulated osteoclast activation and bone density in vivo. Vav3-deficient osteoclasts show defective actin cytoskeleton organization, polarization, spreading and