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Sample records for jiahu bone flutes

  1. DISCOVERY AND RESEARCH ON JIAHU BONE FLUTES IN WUYANG, CHINA.

    SciTech Connect

    JUZHONG, Z.; HARBOTTLE, G.; XINGHUA, X.; CHANGSUI, W.

    2000-11-01

    The site of Jiahu is located in Jiahu village, Wuyang County, Henan province, on the Western edge of the broad plain of Huanhuaihai. On its north the site borders the Sha River, in the upper reaches of the Huai River; its latitude is 33{degree} 36 minutes North, longitude 113{degree} 40 minutes East, and it is 67.5 meters above sea level. Between 1983 and 1987, the Henan Cultural Relics and Archaeology Institute carried out six campaigns of excavation here, revealing an area of 2400 square meters. Except for the trial excavation in the spring of 1983, Zhang Juzhong has been in charge of all the excavations. In early May 1986, while excavating tomb 78, Zhang Juzhong and Yang Zhenwei first discovered two funerary bone flutes. They soon found other, similar bone flutes in tombs 73, 94 and 121 respectively. Mr. Zhang's attention was instantly focused on these remarkable finds. In the campaign of autumn 1986, one or two more bone flutes were discovered in each of tombs 233,273, 263 and 270. Finally, in the spring of 1987, again one or two bone flutes were found in each of the tombs 282, 363,341,411,344 and 387. Up to the end of excavation in June 1987, altogether 25 bone flutes had been found, of which 17 were complete or almost complete, 6 broken or fragmentary and 2 were half-finished examples. Among the 17 complete bone flutes, there were 14 having seven holes, one five-hole, one six-hole and one eight-hole bone flute. In particular, the bone flute M282:20 was exquisitely made, and complete. Zhang Juzhong, the discoverer of the bone flutes, researcher Pei Mingxiang, the. ex-director of the division, who came to the digging site to see the progress of the work, and their coworkers were all understandably very excited.

  2. Flute Choir Fundamentals

    ERIC Educational Resources Information Center

    Chappell, Jon

    2007-01-01

    The flute is one of the more accessible instruments for beginners and is a popular choice for many elementary and middle school students. It is relatively easy to create a decent, usable sound with a flute, and it is more portable than most instruments. While starting a flute choir has a lot of benefits, arranging a band has a lot of challenges.…

  3. Construction practices in pre-Hispanic flutes

    NASA Astrophysics Data System (ADS)

    Rawcliffe, Susan

    2002-11-01

    The ancient cultures of the Americas were separated by thousands of miles and thousand of years. There was a long history of trade over the miles and the years with many shared cultural ideals and artifacts, as evidenced by their musical instruments. Flutes were the most prevalent instruments found throughout the ancient Americas. Some types are unique to the pre-Hispanic world. Although flutes were constructed from a variety of materials, including bone, cane, seed pods, skulls, it is primarily the ceramic ones that survived, and it is ceramic flutes which form the bulk of this writer's work and research. This paper includes musical demonstrations to show how ancient flutemakers could have manipulated timbre during construction. Clay's plasticity enabled the construction of some instruments, and limited the development of others. Pitch jump flutes, certain Veracruzano whistles, and chamberduct flutes and whistles all share the addition of clay flaps or chambers around the aperture, as do hooded pipes. Some instruments exhibit a seemingly cultural predilection for complex tones that are windy, raspy, or animalistic. Simple adjustments of the airduct promote these timbres. Also included will be samples of the original sounds of ancient flutes.

  4. Improvising on an Indian Flute.

    ERIC Educational Resources Information Center

    Giles, Martha Mead

    1984-01-01

    The Indian flute can be used by teachers to supplement classroom study of Indian culture. Indians used it as a personal instrument. Describes how an Indian flute can be made, and suggests improvising bird calls and melodies on it. (CS)

  5. The effects of flute shape and thread profile on the insertion torque and primary stability of dental implants.

    PubMed

    Wu, Shu-Wei; Lee, Chia-Ching; Fu, Ping-Yuen; Lin, Shang-Chih

    2012-09-01

    Easy insertion of the implant and stable bone purchase is essential for an ideal dental implantation. At the implant tip, the cutting flutes and conical profile are respectively designed to reduce insertion resistance and facilitate the initial insertion. However, the tapered tip might reduce the self-tapping and bone-purchasing abilities of the flutes and the tip threads. Using sawbone blocks as standard specimens, this study experimentally measures the insertion torque, holding power, and bending strength of eight varieties of implant (4 shapes×2 profiles). The bony contact, interfacial mechanism, and the altered shape of the flutes, at different section planes, are used to explain the experimental results. The results reveal that the bone-implant gaps at the tip region significantly suppress both the self-tapping and bone-purchasing abilities of the flutes and the tip threads. This makes initial insertion of the conical implant easier. However, the conical implant eventually requires a higher insertion torque and holding power, due to tighter bony contact, at the tail threads. The bowl-fluted design has the least flute space to store the squeezed bone chips, so both insertion torque and bending strength are significantly higher. For the conical group, the holding powers of three flute designs are nearly comparable. Overall, the conical implant with bowl flutes is the optimal design, with a lower resistance to initial insertion and higher stability, for final instrumentation.

  6. 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.

  7. 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,…

  8. Pits and Flutes on Stimpy

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The rock 'Stimpy' is seen in this close-up image taken by the Sojourner rover's left front camera on Sol 70 (September 13). Detailed texture on the rock, such as pits and flutes, are clearly visible.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  9. An illuminated flute needle for vitreoretinal surgery.

    PubMed

    Davison, C N; Rosen, P H

    1994-06-01

    We have developed a simple self-illuminated flute needle for internal drainage of subretinal fluid during three-port vitrectomy. This instrument facilitates visualization and drainage through peripheral retinal breaks.

  10. 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.

  11. Flute waves in a tandem mirror

    SciTech Connect

    Mikhailovskaya, L.V.

    1984-03-01

    Stability conditions are derived for flute waves in a short tandem mirror stabilized by end cells with a min B. The frequency spectrum of the flute waves is analyzed. Those conditions under which the resonant excitation of waves by ions and electrons must be taken into account are found. When end cells without a min B are added to a central mirror system, the system becomes destabilized as the result of resonant excitation of waves at a frequency near the precession frequency of ions having a finite energy distribution.

  12. Flute vortices in nonuniform magnetic fields

    SciTech Connect

    Yu, M.Y.; Shukla, P.K.; Varma, R.K.

    1985-09-01

    Localized double vortices associated with the flute modes are shown to exist. Special emphasis is given to the effect of the convective variation of the fluid magnetic moment. It is shown that the latter effect considerably modifies the existence regions of the vortices.

  13. A flute syringe for vitreous surgery.

    PubMed

    Escoffery, R F; Grand, M G

    1980-11-01

    We have devised a method whereby an inexpensive, disposable tuberculin syringe may be used as a flute syringe with retrograde flushing capability. This syringe is particularly useful in vitreous surgery and alleviates problems that occur with commercially available instruments of this type.

  14. A generalized correlation for condensation on vertical fluted surfaces

    SciTech Connect

    Panchal, C.B.

    1996-03-01

    A correlation was developed for laminar film condensation on vertical fluted surfaces. The theoretical analysis of Panchal and Bell was used for defining important physical property groups. The experimental data of Combs et al. were used to validate the proposed correlation. The experimental database used in the present study included four flute geometries that could be approximated to cosine type flutes and seven fluids. The resulting correlation can predict the average condensate heat-transfer coefficient within {plus_minus} 20%.

  15. Gage for measuring fluted oil field tubular members

    SciTech Connect

    Case, W.A.; Burt, J.R.

    1987-03-17

    A gage is described for measuring the nominal diameter of an elongated tubular member having circumferentially spaced apart radially outwardly extending flutes and for calibrating the amount of wear to the flutes and predicting the future wear life of the tubular member. The gage comprises: a first gage part including a pair of spaced apart colinear elongated first handlebar halves with a generally semi-circular first half ring positioned between the first handlebar halves. The first half ring includes at least one flute engaging surface which includes stepped arcuate flute engaging portions positioned at radii from the center of the first ring half corresponding to different diameters to be measured; a second gage part including a pair of spaced apart colinear elongated second handlebar halves with a generally semicircular second half ring positioned between the second handlebar halves. The second half ring includes at least one flute engaging surface which includes stepped arcuate flute engaging portions positioned a radii from the center of the second ring half corresponding to different diameters to be measured. The number of flute engaging surfaces of the first and second ring halves is equal to the number of flutes on the tubular member; and a hinge pivotally connecting together one handlebar half of the first gage part to one handlebar half of the second gage part.

  16. 25. Detail of cast iron lamp post base with fluted ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. Detail of cast iron lamp post base with fluted wooded post at top, located at north end of bridge. VIEW NORTHEAST - Chelsea Street Bridge & Draw Tender's House, Spanning Chelsea River, Boston, Suffolk County, MA

  17. 14. DETAIL VIEW, FLUTED PILASTER AND PANELLED REVEAL IN DOORWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. DETAIL VIEW, FLUTED PILASTER AND PANELLED REVEAL IN DOORWAY BETWEEN VESTIBULE AND STAIRHALL (NOTE WOOD GRAINING), WITH SCALE - Bowieville, 522 Church Road South, Leeland, Prince George's County, MD

  18. 52. DETAIL VIEW OF FRONT DOOR (EXTERIOR), FLUTED BUTTRESSES, AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. DETAIL VIEW OF FRONT DOOR (EXTERIOR), FLUTED BUTTRESSES, AND PARAPETED GABLE, NORTHWEST SIDE OF CAPTAIN'S GALLEY, LOOKING EAST - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

  19. 53. DETAIL VIEW OF FLUTED BUTTRESSES, AND PARAPET, NORTHWEST SIDE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    53. DETAIL VIEW OF FLUTED BUTTRESSES, AND PARAPET, NORTHWEST SIDE OF CAPTAIN'S GALLEY, LOOKING SOUTHEAST - Huntington Beach Municipal Pier, Pacific Coast Highway at Main Street, Huntington Beach, Orange County, CA

  20. Feedback effect on flute dynamics in a mirror machine

    NASA Astrophysics Data System (ADS)

    Be'Ery, Ilan; Seemann, Omri

    2015-11-01

    Active feedback techniques may stabilize the flute instability in mirror traps and make them viable candidates for fusion machines. A fast feedback with optical sensors and electrical actuators was implemented in a table-top mirror machine and used to study several aspects of feedback stabilization. For a cold, dense plasma the feedback reduces dramatically the flute amplitude of the first two mode. For higher temperature plasma, a significant increase of plasma density due to feedback stabilization is also demonstrated. The effect of changing feedback gain and phase has some interesting feature such as asymmetry with respect to positive and negative phase shifts and non-monotonic dependence of flute amplitude on feedback gain. These effects are explained using simplified analytic model of the flute and feedback.

  1. Flute stabilization by a cold line-tied blanket

    SciTech Connect

    Segal, D.; Wickham, M.; Rynn, N.

    1982-09-01

    The curvature-driven flute instability in an axisymmetric mirror was stabilized by an annular line-tied plasma blanket. A significant temperature difference was maintained between core and blanket. Theoretical calculations support the experimental observations.

  2. Fluid mechanics and heat transfer spirally fluted tubing

    NASA Astrophysics Data System (ADS)

    Larue, J. C.; Libby, P. A.; Yampolsky, J. S.

    1981-08-01

    The objective of this program is to develop both a qualitative and a quantitative understanding of the fluid mechanics and heat transfer mechanisms that underlie the measured performance of the spirally fluted tubes under development at General Atomic. The reason for the interest in the spirally fluted tubes is that results to date have indicated three advantages to this tubing concept: The fabrication technique of rolling flutes on strip and subsequently spiralling and simultaneously welding the strip to form tubing results in low fabrication costs, approximately equal to those of commercially welded tubing. The heat transfer coefficient is increased without a concomitant increase of the friction coefficient on the inside of the tube. In single-phase axial flow of water, the helical flutes continuously induce rotation of the flow both within and without the tube as a result of the effect of curvature. An increase in condensation heat transfer on the outside of the tube is achieved. In a vertical orientation with fluid condensing on the outside of the helically fluted tube, the flutes provide a channel for draining the condensed fluid.

  3. Evaluation of Analysis Techniques for Fluted-Core Sandwich Cylinders

    NASA Technical Reports Server (NTRS)

    Lovejoy, Andrew E.; Schultz, Marc R.

    2012-01-01

    Buckling-critical launch-vehicle structures require structural concepts that have high bending stiffness and low mass. Fluted-core, also known as truss-core, sandwich construction is one such concept. In an effort to identify an analysis method appropriate for the preliminary design of fluted-core cylinders, the current paper presents and compares results from several analysis techniques applied to a specific composite fluted-core test article. The analysis techniques are evaluated in terms of their ease of use and for their appropriateness at certain stages throughout a design analysis cycle (DAC). Current analysis techniques that provide accurate determination of the global buckling load are not readily applicable early in the DAC, such as during preliminary design, because they are too costly to run. An analytical approach that neglects transverse-shear deformation is easily applied during preliminary design, but the lack of transverse-shear deformation results in global buckling load predictions that are significantly higher than those from more detailed analysis methods. The current state of the art is either too complex to be applied for preliminary design, or is incapable of the accuracy required to determine global buckling loads for fluted-core cylinders. Therefore, it is necessary to develop an analytical method for calculating global buckling loads of fluted-core cylinders that includes transverse-shear deformations, and that can be easily incorporated in preliminary design.

  4. Bone foreshafts from a clovis burial in southwestern montana.

    PubMed

    Lahren, L; Bonnichsen, R

    1974-10-11

    Formal and functional analyses of bone artifacts from a Clovis burial in southwestern Montana suggest that they were constructed to serve as (detachable or nondetachable) foreshafts for attaching fluted projectile points to lance shafts.

  5. Deconstruction and analysis of multiphonic clusters in the modern flute

    NASA Astrophysics Data System (ADS)

    Barravecchio, Shauna

    The modern flute has been acoustically analyzed in great detail by many, but only from the point of view of traditional playing techniques. Very little research exists to date on more modem, "extended" technique performance. This paper explores the production of multiphonic note clusters as played on the modern flute. Several clusters as notated in James Pellerite's book on flute fingerings are recorded and analyzed for frequency content. Each one is then compared to the expected frequency content based on John Backus' 1978 paper on woodwind multiphonics. Using this information, the fingering configuration of each cluster can be deconstructed and each component pitch explained in terms of the root frequencies, overtone series, and sideband frequencies.

  6. Flute mode fluctuations in the divertor mirror cell

    SciTech Connect

    Katanuma, I.; Yagi, K.; Nakashima, Y.; Ichimura, M.; Imai, T.

    2010-03-15

    The computer code by reduced magnetohydrodynamic equations were made which can simulate the flute interchange modes (similar to the Rayleigh-Taylor instability) and the instability associated with the presence of nonuniform plasma flows (similar to the Kelvin-Helmholtz instability). This code is applied to a model divertor and the GAMMA10 [M. Inutake et al., Phys. Rev. Lett. 55, 939 (1985)] with divertor in order to investigate the flute modes in these divertor cells. The linear growth rate of the flute instability determined by the nonlocal linear analysis agrees with that in the linear phase of the simulations. There is a stable nonlinear steady state in both divertor cells, but the nonlinear steady state is different between the model divertor and the GAMMA10 with divertor.

  7. Chest wall dynamics and muscle recruitment during professional flute playing.

    PubMed

    Cossette, Isabelle; Monaco, Pierpaolo; Aliverti, Andrea; Macklem, Peter T

    2008-02-01

    Respiratory parameters and sound were recorded during professional flute playing in order to assess what physiological processes were associated with the control of sound production that results in 'breath support' which in turn is associated with high quality playing. Four standing young professional flautists played flute excerpts with and without breath support. Recordings included optoelectronic plethysmographic measurements of chest wall volume (V(cw)) and its compartments, surface electromyography of the scalene, lateral abdominal, rectus abdominus, parasternal and sternocleidomastoid muscles, mouth pressure, and sound. Flow was estimated from differentiating V(cw) during playing. Results showed that flute support entails antagonistic contraction of non-diaphragmatic inspiratory muscles that tends to hold the rib cage at higher lung volume. This relieves the expiratory muscles from the task of producing the right mouth pressure, especially at the end of the phrases, so they can contribute more to the finer control of mouth pressure modulations required for high quality playing.

  8. Fluid Mechanics and Heat Transfer Spirally Fluted Tubing,

    DTIC Science & Technology

    1981-08-01

    rolling flutes on strip and subsequently spiralling and simultaneously welding the strip to form tubing results in low fabrication costs. approximately...AD-AI07 983 GENERAL ATOMIC CO SAN DIEGO CALIF FIG 20/4 FLUI D MECHANICS AND HEAT TRANSFER SPIRALLY FLUTED TUBING,(U) AUG 81 J C LARUE, P A LIBBY. J S...YAMPOLSKY N0001-79-C0773 UNCLASSIFIED GA-A6541 NL II- "N m oom o 1111_____ ~fI.2.. 1 1. GA-Al6541 LEVEL"’ FLUID MECHANICS AND HEAT TRANSFER SPIRALLY

  9. Flute vortices in a plasma with hot particles

    SciTech Connect

    Andrushchenko, Zh.N.; Pavlenko, V.P.; Cheremnykh, O.K.

    1992-01-01

    Flute perturbations in a plasma with {open_quotes}hot{close_quotes} are considered. Steady-state solutions are found which describe localized vortex structures. Two types of vortex solutions are considered: a dipolar vortex and a combination of a dipolar and a monopolar vortex. It is shown that the presence of {open_quotes}hot{close_quotes} particles has an effect on the region in which the vortex solutions exist in velocity space, which can give rise to a change in the particle flux leaving the plasma due to eddy convection. It is shown that the perturbed density profile in flute vortices must be nonmonotonic. 10 refs.

  10. Low-frequency flute instabilities of a bounded plasma column.

    NASA Technical Reports Server (NTRS)

    Rognlien, T. D.

    1973-01-01

    Derivation of exact solutions for unstable waves (called flute waves) which occur in a radially bounded plasma column at frequencies below the ion cyclotron frequency. Both analytical and numerical solutions are presented for the m = 1 and m = 2 azimuthal modes for a variety of radial electric field profiles. It is shown that the behavior of the flute waves can depend sensitively on the radial extent of the plasma column. Moreover, it is found that the m = 1 mode and the m = 2 mode do not respond in the same way to changes in the radial boundary position or in the electric field profile.

  11. Nonlinear behavior of the tarka flute's distinctive sounds.

    PubMed

    Gérard, Arnaud; Yapu-Quispe, Luis; Sakuma, Sachiko; Ghezzi, Flavio; Ramírez-Ávila, Gonzalo Marcelo

    2016-09-01

    The Andean tarka flute generates multiphonic sounds. Using spectral techniques, we verify two distinctive musical behaviors and the nonlinear nature of the tarka. Through nonlinear time series analysis, we determine chaotic and hyperchaotic behavior. Experimentally, we observe that by increasing the blow pressure on different fingerings, peculiar changes from linear to nonlinear patterns are produced, leading ultimately to quenching.

  12. Finite Larmor radius flute mode theory with end loss

    SciTech Connect

    Kotelnikov, I.A.; Berk, H.L.

    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.

  13. Theoretical investigation of flute modes in a magnetic quadrupole

    SciTech Connect

    Wu, H.S.

    1988-01-01

    This research developed theories and conducted numerical investigations of electrostatic flute modes in a plasma confined in a magnetic quadrupole. Chapter I presents the discussion of relevant background. Chapter II contains a brief discussion of the basic flute-mode operator L{sub 0} for intermediate- and low-frequency regimes. Chapter III develops a simple theory for a flute mode with frequency between the electron and ion bounce frequencies in the uniform density and temperature regions of a magnetic quadrupole. The frequency is predicted to be inversely proportional to the wave number. Chapter IV describes the kinetic approach. Chapter V contains the derivation of an eigenvalue equation for electrostatic waves with frequencies below the ion frequency in the private flux region of a magnetic quadrupole. Chapter VI develops a theory for electrostatic waves with frequency below the ion bounce frequency in the shared flux region of a magnetic quadrupole. Chapter VII contains the derivation of a dispersion equation for flute modes with frequencies between the electron and ion bounce frequencies in a plasma confined to a magnetic quadrupole. Chapter VIII presents a summary of the research described.

  14. Theoretical investigation of flute modes in a magnetic quadrupole

    SciTech Connect

    Wu, H.S.

    1988-01-01

    The objective of this research is to develop theories and conduct numerical investigations of electrostatic flute modes in a plasma confined in magnetic quadrupole. Chapter I presents the discussion of relevant background. Chapter II contains a brief discussion of the basic flute-mode operator L{sub 0} for intermediate- and low frequency regimes. Chapter III develops a simple theory for a flute mode with frequency between the electron and ion bounce frequencies in the uniform density and temperature regions of a magnetic quadrupole. Chapter IV describes the kinetic approach. Chapter V contains the derivation of an eigenvalue equation for electrostatic waves with frequencies below the ion frequency in the private flux region of a magnetic quadrupole. Chapter VI develops a theory for electrostatic waves with frequency below the ion bounce frequency in the shared flux region of a magnetic quadrupole. Chapter VII contains the derivation of a dispersion equation for flute modes with frequencies between the electron and ion ounce frequencies in a plasma confined to a magnetic quadrupole. Two intermediate-frequency modes are predicted.

  15. Pre-School Children's Encounters with "The Magic Flute"

    ERIC Educational Resources Information Center

    Nyland, Berenice; Acker, Aleksandra; Ferris, Jill; Deans, Jan

    2011-01-01

    This article describes a music programme in an Australian early learning centre. Through a repertoire of songs, games and instruments, the children were introduced to music forms, including opera. Mozart's Magic Flute was presented to these children by watching the Metropolitan Opera's latest film performance. Because this opera seized the…

  16. Nonlinear behavior of the tarka flute's distinctive sounds

    NASA Astrophysics Data System (ADS)

    Gérard, Arnaud; Yapu-Quispe, Luis; Sakuma, Sachiko; Ghezzi, Flavio; Ramírez-Ávila, Gonzalo Marcelo

    2016-09-01

    The Andean tarka flute generates multiphonic sounds. Using spectral techniques, we verify two distinctive musical behaviors and the nonlinear nature of the tarka. Through nonlinear time series analysis, we determine chaotic and hyperchaotic behavior. Experimentally, we observe that by increasing the blow pressure on different fingerings, peculiar changes from linear to nonlinear patterns are produced, leading ultimately to quenching.

  17. Generalized energy principle for flute perturbations in axisymmetric mirror machines

    SciTech Connect

    Lansky, I.M.; Ryutov, D.D.

    1993-01-20

    Axial symmetry is a very desirable property of the mirror devices both for fusion and neutron source applications. The main obstacle to be circumvented in the development of such systems, is the flute instability of axisymmetric mirrors. In recent years there appeared a number of proposals, devoted to the stabilization of the flute perturbations in the framework of axisymmetric magnetic configurations, which are based on the combining of the MHD unstable central cell with various types of end-cell stabilizers. In the present paper we concentrate ourselves just on this scheme, including long solenoid with a uniform field, conjugated with the end stabilizing anchor, intended to provide MHD stability of the system as a whole. The attractive feature of such a configuration is that it allows to exploit finite larmor radius (FLR) effects for the stabilization of the flute perturbations. As is well known, FLR effects, being strong, stabilize all flute modes, except the one with azimuthal number m = 1, corresponding to the ``rigid`` displacement of the plasma column (the ``global`` mode). Consequently, in the conditions when FLR effects dominate, the anchor has to stabilize the ``global` mode only. Bearing in mind a favorable influence of FLR effects we, however, don`t restrict our paper by discussion of only ``global`` mode stability and consider a general case of an arbitrary azimuthal mode.

  18. Garry Disher's "Bamboo Flute": Negotiating Multiple Aesthetic Responses.

    ERIC Educational Resources Information Center

    Day, Karen S.

    2000-01-01

    Discusses the integration of photographs and text in fictional works specifically regarding Garry Disher's "Bamboo Flute." Introduces the story and explores questions in detail regarding the presentation of its photographs in American publications. Attempts to make the readers become aware of alternative reading strategies that expand…

  19. Compression Behavior of Fluted-Core Composite Panels

    NASA Technical Reports Server (NTRS)

    Schultz, Marc R.; Oremont, Leonard; Guzman, J. Carlos; McCarville, Douglas; Rose, Cheryl A.; Hilburger, Mark W.

    2011-01-01

    In recent years, fiber-reinforced composites have become more accepted for aerospace applications. Specifically, during NASA s recent efforts to develop new launch vehicles, composite materials were considered and baselined for a number of structures. Because of mass and stiffness requirements, sandwich composites are often selected for many applications. However, there are a number of manufacturing and in-service concerns associated with traditional honeycomb-core sandwich composites that in certain instances may be alleviated through the use of other core materials or construction methods. Fluted-core, which consists of integral angled web members with structural radius fillers spaced between laminate face sheets, is one such construction alternative and is considered herein. Two different fluted-core designs were considered: a subscale design and a full-scale design sized for a heavy-lift-launch-vehicle interstage. In particular, axial compression of fluted-core composites was evaluated with experiments and finite-element analyses (FEA); axial compression is the primary loading condition in dry launch-vehicle barrel sections. Detailed finite-element models were developed to represent all components of the fluted-core construction, and geometrically nonlinear analyses were conducted to predict both buckling and material failures. Good agreement was obtained between test data and analyses, for both local buckling and ultimate material failure. Though the local buckling events are not catastrophic, the resulting deformations contribute to material failures. Consequently, an important observation is that the material failure loads and modes would not be captured by either linear analyses or nonlinear smeared-shell analyses. Compression-after-impact (CAI) performance of fluted core composites was also investigated by experimentally testing samples impacted with 6 ft.-lb. impact energies. It was found that such impacts reduced the ultimate load carrying capability by

  20. Alpha-particle effects on ballooning flute modes in tokamaks

    SciTech Connect

    Andrushchenko, Z.N.; Bijko, A.Y.; Cheremnykh, O.K. )

    1990-11-01

    In this paper a more accurate dispersion equation for ideal ballooning flute modes in a plasma with alpha particles is obtained. It is shown that circulating and trapped alpha particles generate the eigenbranches of the mode oscillations with frequencies {omega} {approx lt} {omega}{sub *i}, where {omega}{sub *i}, is the ion drift frequency. The relevant growth rates and frequencies are found. It is ascertained that in the frequency range {omega}{sub *i} {lt} {omega} {lt} {bar {omega}{sub Db}}, where {bar {omega}{sub Db}} is the magnetic drift frequency average over a bounce period, trapped alpha particles may generate forced oscillations that influence the ideal ballooning flute mode stability boundary. It is shown that the stability may be improved for certain plasma parameters and trapped alpha-particle pressures.

  1. Feedback effect on flute dynamics in a mirror machine

    NASA Astrophysics Data System (ADS)

    Be'ery, I.; Seemann, O.

    2015-08-01

    The effect of active feedback on flute instability is experimentally studied in a table-top mirror machine. Changing the plasma conditions from mirror-loss dominated to flute-loss dominated, it is demonstrated that while the feedback has no effect on plasma density in the first case, it increases the plasma density by up to 50% in the second case. Measurements of the dependence of instability amplitude on feedback gain show that large gain stimulates high frequency perturbations. The period of these perturbations corresponds to the inherent delay of immersed electrode feedback. Variation of the spatial phase between the input and output of the phase reveals a large asymmetry between positive and negative phase shifts. A simplified model is introduced to explain how a negative phase shift causes positive feedback between the external feedback and the centrifugally driven rotation.

  2. Jet offset, harmonic content, and warble in the flute.

    PubMed

    Coltman, John W

    2006-10-01

    The effects of jet offset in the flute, directing the jet above or below the edge, were explored by two distinct means-experiments with a Boehm flute sounded by an artificial blower, and time domain simulation. Very large changes in harmonic content and dynamics were observed, changing greatly with blowing pressure. Warble, a modulation of the tone at frequencies of the order of 20 Hz, was observed both in the experiment and in the simulation. The phenomenon is explained as a beat between the frequency of a second harmonic generated by nonlinearity in the jet current and a neighboring partial sustained by jet feedback near the second mode resonance. A second type of warble, in which amplitude modulation occurs in all partials but with different phases, is yet to be explained.

  3. Self-organized zonal flow in the flute-mode turbulence of a plasma

    SciTech Connect

    Kodama, Y.; Pavlenko, V.P.

    1988-04-11

    Flute-mode turbulence has a forward spectral cascade unlike the case of drift-wave turbulence. Therefore the linear flute instability may be reduced by this energy cascading toward large wave numbers. As a consequence of three-wave cascade processes derivable from model equations including the effects of density gradient and finite ion Larmor radius the formation of zonal flows in flute mode turbulence is predicted.

  4. Fluid Mechanics and Heat Transfer Spirally Fluted Tubing.

    DTIC Science & Technology

    1984-12-01

    on a flat strip and subsequently welding the corregated strip to form spiral fluted tubing results in a low fabrication cost approximately equal to...G., "Intensification of Convective Heat Exchange by Spiral Swirlers in the Flow of Anomalously Viscous Liquid in Pipes ", Journal of Engineering...axial velocity at the pipe axis w (V w ( velocity components in the (Z ( z ,(Z)) co-ordinate system x x x ( co-ordinate system following the spiralling Of

  5. Thermal-Balance Strip for Fluted LFC Panels

    NASA Technical Reports Server (NTRS)

    Bono, P.

    1985-01-01

    Waviness of less than 0.004 inch achieved using titanium strips. Process uses titanium balancing strips to keep waviness within 0.004inch limit. Balancing strips reduce thermal bonding stresses on lower fiberglass fluted sections and placed so fiberglass ends up sandwiched between porous titanium skin and titanium balance strip. Method requires less skill and less labor intensive than composite-wrapped-mandrel method.

  6. 77 FR 60803 - Endangered and Threatened Wildlife and Plants; Endangered Species Status for the Fluted...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

    ... the development of reproductive cells or gametes) of fluted kidneyshell, like most mussels, is..., North Fork Holston Rivers). However, all other populations are of questionable viability, with some...

  7. Flute instability in the plasma shell of the earth's magnetosphere

    SciTech Connect

    Ivanov, V.N.; Pokhotelov, O.A.

    1987-12-01

    In the plasma shell of the earth's magnetosphere, the surfaces of constant pressure may not coincide with surfaces of constant specific volume. This circumstance forces a reexamination of the theory for the flute instability, in which the pressure has been assumed to remain constant on surfaces of constant specific volume. The MHD equations for flute waves in a curvilinear magnetic field are used to show that an instability of a new type, with a pressure which does not remain constant on surfaces of constant specific volume, can occur in the plasma shell of the magnetosphere. An expression is derived for the growth rate of this instability. Analysis of the equation also shows that perturbations with wavelengths shorter than the ion Larmor radius are stable by virtue of magnetodrift effects. The growth rates of the flute instabilities are calculated for both a dipole magnetic field and an arbitrary magnetic-field configuration. Growth rates calculated for typical values of the characteristics of the earth's plasma shell are reported.

  8. 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.

  9. Flute instability and the associated radial transport in the tandem mirror with a divertor mirror cell

    SciTech Connect

    Katanuma, I.; Yagi, K.; Haraguchi, Y.; Ichioka, N.; Masaki, S.; Ichimura, M.; Imai, T.

    2010-11-15

    The flute instability and the associated radial transport are investigated in the tandem mirror with a divertor mirror cell (the GAMMA10 A-divertor) with help of computer simulation, where GAMMA10 is introduced [Inutake et al., Phys. Rev. Lett. 55, 939 (1985)]. The basic equations used in the simulation were derived on the assumption of an axisymmetric magnetic field. So the high plasma pressure in a nonaxisymmetric minimum-B anchor mirror cell, which is important for the flute mode stability, is taken into account by redefining the specific volume of a magnetic field line. It is found that the flute modes are stabilized by the minimum-B magnetic field even with a divertor mirror although its stabilizing effects are weaker than that without the divertor mirror. The flute instability enhances the radial transport by intermittently repeating the growing up and down of the Fourier amplitude of the flute instability in time.

  10. Heat Transfer due to Film Condensation on Vertical Fluted Tubes.

    DTIC Science & Technology

    1984-07-01

    report is authorized. This report was prepared by: L Vijay K . Garg P. J. Mr" Adjlmct Professor of Chairrmn, Department of Mechanical Engineering...7AD-AiW47 258 HEAT TRNSFER’DUE TO FILM CONDENSATION ON VERTICAL i/iFLUTED TUBES(U) NAVAL POSTGRA UATE SCHOOL MONTEREY CA U R V K GARG ET AL. JUL 84...J. Marto, Code 69Mx 5 Department of Mechanical Engineering Naval. Postgraduate School Monterey, CA 939143 5. Professor V. K . Garg 3 Department of

  11. 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.

  12. Bone

    NASA Astrophysics Data System (ADS)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

    The typical clinical signs in bone tumours are pain, destruction and destabilization, immobilization, neurologic deficits, and finally functional impairment. Primary malignant bone tumours are a rare entity, accounting for about 0.2% of all malignancies. Also benign primary bone tumours are in total rare and mostly asymptomatic. The most common symptomatic benign bone tumour is osteoid osteoma with an incidence of 1:2000.

  13. Tank tests of a model of a flying-boat hull with a fluted bottom

    NASA Technical Reports Server (NTRS)

    Dawson, John R

    1935-01-01

    A 1/5-scale model of a flying-boat hull having flutes in the bottom both forward and aft of the step (NACA model 19) was tested to determine its water performance. The model was also tested after the successive removal of the flutes on the afterbody and forebody. The results from these tests are compared with those from tests of a model of the hull of the Navy PN-8 flying boat and it is concluded that the fluted-bottom model and its modifications are inferior to the model of the PN-8.

  14. Suppression of the first flute mode in a long axisymmetric mirror system

    SciTech Connect

    Arsenin, V.V.

    1982-05-01

    The lowest mode of the flute instability of a plasma with ..beta..<<1 in a confinement system with a simple mirror field: the displacement of the plasma as a whole: can be suppressed if the confinement system is connected with another plasma-filled, axisymmetric, annular confinement system, so that there is a sharp maximum in B beyond the outer boundary of the bell-shaped plasma in the annular system. If the simple mirror is so long that all the other flute modes are stabilized by the finite-Larmor-radius effect, the plasma proves stable with respect to flute perturbations.

  15. FLUTE: a versatile linac-based THz source.

    PubMed

    Nasse, M J; Schuh, M; Naknaimueang, S; Schwarz, M; Plech, A; Mathis, Y-L; Rossmanith, R; Wesolowski, P; Huttel, E; Schmelling, M; Müller, A-S

    2013-02-01

    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 (~1 ps) THz pulses (up to ~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 (~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.

  16. Flute waves at the ion Larmor radius scales

    SciTech Connect

    Onishchenko, O. G.

    2010-12-14

    The theory of the magnetic Rayleigh-Taylor instability (RTI) is discussed. Modified linear kinetic theory allows us to investigate RTI and flute waves with arbitrary perpendicular spatial scales compared to the ion Larmor radius. It is shown that in the linear limit a Fourier transform of these equations yields the dispersion relation which in the so-called Pade approximation corresponds to results of the kinetic theory. This analysis represents an extension of the previous study of the magnetic RTI obtained in the large wave scale approximation. It is shown that incorporation of the effects associated with wave scales of the order of the ion Larmor radius leads to a broader wave number range of the magnetic RTI.

  17. Global modes of flute instability of a rotating cylindrical plasma

    SciTech Connect

    Sorokina, E. A.

    2009-05-15

    The influence of rotation on the flute instability of a cylindrical gravitating plasma in a straight inhomogeneous magnetic field is studied in the framework of one-fluid magnetohydrodynamics. The dispersion relation and integral expression for the instability growth rate of eigenmodes are derived. It is shown that, in the framework of the given problem, rotation is a destabilizing factor, and the corresponding theorem is proved for the general case. For a linear radial profile of the rotation frequency, the structure of eigenmodes is calculated. The growth rate of these modes is shown to increase with increasing rotation velocity and azimuthal mode number. It is found that plasma rotation in the eigenmode localization region leads to the displacement of perturbation from the rotation region, which results in a decrease in the instability growth rate. The absence of eigenmodes (i.e., exponential instability of the system) for certain profiles of the density and rotation frequency is demonstrated.

  18. FLUTE: A versatile linac-based THz source

    SciTech Connect

    Nasse, M. J.; Schuh, M.; Schwarz, M.; Naknaimueang, S.; Mathis, Y.-L.; Rossmanith, R.; Wesolowski, P.; Huttel, E.; Plech, A.; Schmelling, M.; Mueller, A.-S.

    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.

  19. Life history of the fluted kidneyshell Ptychobranchus subtentum

    USGS Publications Warehouse

    Davis, V.M.; Layzer, J.B.

    2012-01-01

    The fluted kidneyshell Ptychobranchus subtentum (Say, 1825) is a candidate for listing under the Endangered Species Act by the US Fish and Wildlife Service. Fecundity, fish hosts, and selected population demographics were determined during 2005–2006 for the fluted kidneyshell in the upper Clinch River, Hancock County, Tennessee. Females were fertilized in Aug. within a 5 d period and contained viable glochidia about 4 wk later. As the embryos began to develop, the marsupium gradually changed color from white to dark brown. Glochidia were contained within conglutinates that resemble Simuliidae pupae likely to attract benthic insectivorous fish and were held over winter and released in May. Fecundity was positively related to mussel length (r2  =  0.81) and ranged from 43,000 to 500,000 glochidia. Eight species of darters (Etheostoma spp. and Percina spp.) were infested with glochidia in the laboratory to examine potential hosts and host suitability. Juveniles transformed on bluebreast darters E. camurum and dusky darters P. scieraand previously reported hosts: rainbow darters E. caeruleum and fantail darters E. flabellare. In addition, fantail darters and rainbow darters were infested with glochidia from two river systems. The median time of glochidial metamorphosis did not differ significantly between the two mussel populations. The observed ratio of adult females to males (1.9∶1) in the Clinch River differed significantly from 1∶1. Based upon thin-sections, individuals live to at least 26 y and females become sexually mature at age five.

  20. Discrimination between Tone Quality and Intonation in Unaccompanied Flute/Oboe Duets.

    ERIC Educational Resources Information Center

    Madsen, Clifford K.; Geringer, John M.

    1981-01-01

    Reports the results of a study that investigated patterns of judgmental discriminations and preferences with regard to tone quality versus intonation of accompanied flute and oboe duet performances of simple melodies among music and nonmusic graduate and undergraduate students. (AM)

  1. CO2 volume fluxes outgassing from champagne glasses in tasting conditions: flute versus coupe.

    PubMed

    Liger-Belair, Gérard; Villaume, Sandra; Cilindre, Clara; Polidori, Guillaume; Jeandet, Philippe

    2009-06-10

    Measurements of CO(2) fluxes outgassing from glasses containing a standard Champagne wine initially holding about 11.5 g L(-1) of dissolved CO(2) were presented, in tasting conditions, during the first 10 min following the pouring process. Experiments were performed at room temperature, with a flute and a coupe, respectively. The progressive loss of dissolved CO(2) concentration with time was found to be significantly higher in the coupe than in the flute, which finally constitutes the first analytical proof that the flute prolongs the drink's chill and helps it to retain its effervescence in contrast with the coupe. Moreover, CO(2) volume fluxes outgassing from the coupe were found to be much higher in the coupe than in the flute in the early moments following pouring, whereas this tendency reverses from about 3 min after pouring. Correlations were proposed between CO(2) volume fluxes outgassing from the flute and the coupe and their continuously decreasing dissolved CO(2) concentration. The contribution of effervescence to the global kinetics of CO(2) release was discussed and modeled by use of results developed over recent years. Due to a much shallower liquid level in the coupe, bubbles collapsing at the free surface of the coupe were found to be significantly smaller than those collapsing at the free surface of the flute, and CO(2) volume fluxes released by collapsing bubbles only were found to be approximately 60% smaller in the coupe than in the flute. Finally, the contributions of gas discharge by invisible diffusion through the free surface areas of the flute and coupe were also approached and compared for each type of drinking vessel.

  2. Analysis of Lung Flute-collected Sputum for Lung Cancer Diagnosis.

    PubMed

    Su, Jian; Anjuman, Nigar; Guarnera, Maria A; Zhang, Howard; Stass, Sanford A; Jiang, Feng

    2015-01-01

    Molecular analysis of sputum can help diagnose lung cancer. We have demonstrated that Lung Flute can be used to collect sputum from individuals who cannot spontaneously expectorate sputum. The objective of this study is to further evaluate the performance of the Lung Flute by comparing the characteristics of parallel samples collected with and without the Lung Flute and the usefulness for diagnosis of lung cancer. Fifty-six early-stage lung cancer patients (40 current smokers and 16 former smokers) and 73 cancer-free individuals (52 current smokers and 21 former smokers) were instructed to spontaneously cough and use Lung Flute for sputum sampling. Sputum cytology and polymerase chain reaction analysis of three miRNAs (miRs-21, 31, and 210) were performed in the specimens. All 92 current smokers and 11 (28.7%) of 37 former smokers spontaneously expectorated sputum and also produced sputum when using the Lung Flute. Twenty-seven former smokers (70.3%) who could not spontaneously expectorate sputum, however, were able to produce sputum when using the Lung Flute. The specimens were of low respiratory origin without contamination from other sources, eg, saliva. There was no difference of sputum volume and cell populations, diagnostic efficiency of cytology, and analysis of the miRNAs in the specimens collected by the two approaches. Analysis of the sputum miRNAs produced 83.93% sensitivity and 87.67% specificity for identifying lung cancer. Therefore, sputum collected by the Lung Flute has comparable features as spontaneously expectorated sputum. Using the Lung Flute enables former smokers who cannot spontaneously expectorate to provide adequate sputum to improve sputum collection for lung cancer diagnosis.

  3. Spatiotemporal control and synchronization of flute modes and drift waves in a magnetized plasma column

    SciTech Connect

    Brochard, F.; Bonhomme, G.; Gravier, E.; Oldenbuerger, S.; Philipp, M.

    2006-05-15

    An open-loop spatiotemporal synchronization method is applied to flute modes in a cylindrical magnetized plasma. It is demonstrated that synchronization can be achieved only if the exciter signal rotates in the same direction as the propagating mode. Moreover, the efficiency of the synchronization is shown to depend on the radial properties of the instability under consideration. It is also demonstrated that the control disposition can alternatively be used to produce strongly developed turbulence of drift waves or flute instabilities.

  4. Experimental Study of the Compression Response of Fluted-Core Composite Panels with Joints

    NASA Technical Reports Server (NTRS)

    Schultz, Marc R.; Rose, Cheryl A.; Guzman, J. Carlos; McCarville, Douglas; Hilburger, Mark W.

    2012-01-01

    Fluted-core sandwich composites consist of integral angled web members spaced between laminate face sheets, and may have the potential to provide benefits over traditional sandwich composites for certain aerospace applications. However, fabrication of large autoclave-cured fluted-core cylindrical shells with existing autoclaves will require that the shells be fabricated in segments, and joined longitudinally to form a complete barrel. Two different longitudinal fluted-core joint designs were considered experimentally in this study. In particular, jointed fluted-core-composite panels were tested in longitudinal compression because longitudinal compression is the primary loading condition in dry launch-vehicle barrel sections. One of the joint designs performed well in comparison with unjointed test articles, and the other joint design failed at loads approximately 14% lower than unjointed test articles. The compression-after-impact (CAI) performance of jointed fluted-core composites was also investigated by testing test articles that had been subjected to 6 ft-lb impacts. It was found that such impacts reduced the load-carrying capability by 9% to 40%. This reduction is dependent on the joint concept, component flute size, and facesheet thickness.

  5. Flute ``breath support'' perception and its acoustical correlates

    NASA Astrophysics Data System (ADS)

    Cossette, Isabelle A.; Sabourin, Patrick

    2004-05-01

    Music educators and performers commonly refer to ``breath support'' in flute playing, yet the term ``support'' is neither well-defined nor consistently used. Different breathing strategies used by professional flautists who were instructed to play with and without support were previously identified by the authors. In the current study, 14 musical excerpts with and without support were recorded by five professional flautists. Eleven professional flautists listened to the recordings in a random order and ranked (1 to 6) how much of the following sound qualities they judged to be in each example: support, intonation, control and musical expressiveness. Answers to the test showed that musical expressiveness was associated more closely with the supported excerpts than the answers about support itself. The ratings for each sound quality were highly intercorrelated. Acoustical parameters were analyzed (frequency and centroid variation within each note) and compared with the results of the perception test in order to better understand how the acoustical and psychological variables were related. The acoustical analysis of the central part of the notes did not show evident correlation with the answers of the perception test. [Work funded by the Social Sciences and Humanities Research Council of Canada.

  6. Excitation of collective modes in a quantum flute

    NASA Astrophysics Data System (ADS)

    Torfason, Kristinn; Manolescu, Andrei; Molodoveanu, Valeriu; Gudmundsson, Vidar

    2012-06-01

    We use a generalized master equation (GME) formalism to describe the nonequilibrium time-dependent transport of Coulomb interacting electrons through a short quantum wire connected to semi-infinite biased leads. The contact strength between the leads and the wire is modulated by out-of-phase time-dependent potentials that simulate a turnstile device. We explore this setup by keeping the contact with one lead at a fixed location at one end of the wire, whereas the contact with the other lead is placed on various sites along the length of the wire. We study the propagation of sinusoidal and rectangular pulses. We find that the current profiles in both leads depend not only on the shape of the pulses, but also on the position of the second contact. The current reflects standing waves created by the contact potentials, like in a wind musical instrument (for example, a flute), but occurring on the background of the equilibrium charge distribution. The number of electrons in our quantum “flute” device varies between two and three. We find that for rectangular pulses the currents in the leads may flow against the bias for short time intervals, due to the higher harmonics of the charge response. The GME is solved numerically in small time steps without resorting to the traditional Markov and rotating wave approximations. The Coulomb interaction between the electrons in the sample is included via the exact diagonalization method. The system (leads plus sample wire) is described by a lattice model.

  7. Flute instability growth on a magnetized plasma column.

    SciTech Connect

    Genoni, Thomas C.; Welch, Dale Robert; Ditmire, T.; Rose, David Vincent; Mehlhorn, Thomas Alan; Porter, John Larry, Jr.

    2006-08-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r{sub i}, where R is the Gaussian characteristic radius and r{sub i} is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation. Keywords: Microinstabilities, Magnetic confinement and equilibrium, Particle-in-cell method.

  8. Flute instability growth on a magnetized plasma column.

    SciTech Connect

    Genoni, Thomas C.; Rose, David Vincent; Ditmire, T.; Mehlhorn, Thomas Alan; Welsh, D. R.; Porter, John Larry, Jr.

    2006-01-01

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r{sub i}, where R is the Gaussian characteristic radius and r{sub i} is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation.

  9. Detecting overblown flute fingerings from the residual noise spectrum.

    PubMed

    Verfaille, Vincent; Depalle, Philippe; Wanderley, Marcelo M

    2010-01-01

    Producing a tone by increasing the blowing pressure to excite a higher frequency impedance minimum, or overblowing, is widely used in standard flute technique. In this paper, the effect of overblowing a fingering is explored with spectral analysis, and a fingering detector is designed based on acoustical knowledge and pattern classification techniques. The detector performs signal analysis of the strong broadband signal, that is, spectrally shaped by the pipe impedance, and measures the spectral energy during the attack around multiples of the fundamental frequency sub-multiples over the first octave and a half. It is trained and evaluated on sounds recorded with four expert performers. They played six series of tones from overblown and regular fingerings, with frequencies that are octave- and non-octave-related to the playing frequency. The best of the four proposed sound descriptors allows for a detection error below 1.3% for notes with two and three fingerings (C(5), D(5), C(6), and Cmusical sharp(6)) and below 14% for four (E(6)) or five fingerings (G(6)). The error is shown to dramatically increase when two fingerings' impedance become too similar (E(6) and A(4) and G(6) and C(5)).

  10. Development of flute modes on expanding plasma clouds

    SciTech Connect

    Winske, D.

    1989-09-01

    Structuring that results from plasma streaming at sub-Alfvenic speeds across an external magnetic field is considered. Previously, it has been proposed the lower hybrid drift instability enhanced by the deceleration of the plasma by the field produces the flute modes observed on the surface of expanding laser produced plasmas and the AMPTE magnetotail releases (Eos (Trans) /bold 63/, 843 (1982)). An appropriate dispersion equation to describe the properties of the unstable waves has been derived and particle simulations carried out to show the growth and evolution of the instability. The salient features of this earlier work are reviewed here, and then additions and refinements to the theory and simulations are described. In particular, the scaling of the wave properties with the ratio of the ion gyroradius to the magnetic confinement radius is discussed and the nonlinear evolution of the instability is investigated more thoroughly. The consequences of these results, both for the laser experiments and for AMPTE, are also considered. To this end, a comparison of the linear and nonlinear properties of the waves observed in the simulations with those seen in the experiments is carried out. While there is considerable discrepancy between the observed and predicted wavelengths of the modes, the effects considered here are in the direction of reducing the disagreement.

  11. Flute instability growth on a magnetized plasma column

    SciTech Connect

    Rose, D. V.; Genoni, T. C.; Welch, D. R.; Mehlhorn, T. A.; Porter, J. L.; Ditmire, T.

    2006-09-15

    The growth of the flute-type instability for a field-aligned plasma column immersed in a uniform magnetic field is studied. Particle-in-cell simulations are compared with a semi-analytic dispersion analysis of the drift cyclotron instability in cylindrical geometry with a Gaussian density profile in the radial direction. For the parameters considered here, the dispersion analysis gives a local maximum for the peak growth rates as a function of R/r{sub i}, where R is the Gaussian characteristic radius and r{sub i} is the ion gyroradius. The electrostatic and electromagnetic particle-in-cell simulation results give azimuthal and radial mode numbers that are in reasonable agreement with the dispersion analysis. The electrostatic simulations give linear growth rates that are in good agreement with the dispersion analysis results, while the electromagnetic simulations yield growth rate trends that are similar to the dispersion analysis but that are not in quantitative agreement. These differences are ascribed to higher initial field fluctuation levels in the electromagnetic field solver. Overall, the simulations allow the examination of both the linear and nonlinear evolution of the instability in this physical system up to and beyond the point of wave energy saturation.

  12. Color removal from textile wastewater by using treated flute reed in a fixed bed column.

    PubMed

    Inthorn, Duangrat; Tipprasertsin, Kannika; Thiravetyan, Paitip; Khan, Eakalak

    2010-01-01

    This study investigated the ability of acid treated flute reed to adsorb color (dye) from synthetic reactive dye solutions, and actual dyeing and printing textile wastewaters in a laboratory scale fixed bed column. The effects of particle size, initial reactive dye concentration, bed depth and flow rate on adsorption performances were examined. The results from experiments with synthetic reactive dye solutions showed that the volume treated (until the breakthrough occurred) increased with decreasing particle size, influent reactive dye concentration and flow rate, and increasing bed depth. The bed depth service time model was suitable for describing the experimental data. The treated flute reed was able to reduce color efficiently, 99% for dyeing textile wastewater with ten adsorption columns in series and 78% for printing textile wastewater with a single adsorption column. The difference in the numbers of columns used for the two types of actual textile wastewater led to a substantial discrepancy in suspended solids removal, 99% for dyeing wastewater and 12% for printing wastewater. Similar pH and chemical oxygen demand (COD) results were obtained for the two types of textile wastewater. The acid pretreatment of flute reed resulted in dramatic decreases in pH after the adsorption and very acidic effluents (pH 3). Increases of COD after the adsorption due to organic leaching from the treated flute reed were observed. A different pretreatment method to solve these pH and COD problems is needed before flute reed can be used in practice.

  13. Analysis of heat transfer and fluid flow through a spirally fluted tube using a porous substrate approach

    SciTech Connect

    Srinivasan, V.; Vafai, K.; Christensen, R.N. )

    1994-08-01

    An innovative approach was opted for modeling the flow and heat transfer through spirally fluted tubes. The model divided the flow domain into two regions. The flutes were modeled as a porous substrate with direction-dependent permeabilities. This enabled modeling the swirl component in the fluted tube. The properties of the porous substrate such as its thickness, porosity, and ratio of the direction-dependent permeabilities were obtained from the geometry of the fluted tube. Experimental data on laminar Nusselt numbers and friction factors for different types of fluted tubes representing a broad range of flute geometry were available. Experimental data from a few of the tubes tested were used to propose a relationship between the permeability of the porous substrate and the flute parameters, particularly the flute spacing. The governing equations were discretized using the Finite Element Method. The model was verified and applied to the other tubes in the test matrix. Very good agreement was found between the numerical predictions and the experimental data. 20 refs., 13 figs., 4 tabs.

  14. Generation and saturation of large-scale flows in flute turbulence

    SciTech Connect

    Sandberg, I.; Isliker, H.; Pavlenko, V. P.; Hizanidis, K.; Vlahos, L.

    2005-03-01

    The excitation and suppression of large-scale anisotropic modes during the temporal evolution of a magnetic-curvature-driven electrostatic flute instability are numerically investigated. The formation of streamerlike structures is attributed to the linear development of the instability while the subsequent excitation of the zonal modes is the result of the nonlinear coupling between linearly grown flute modes. When the amplitudes of the zonal modes become of the same order as that of the streamer modes, the flute instabilities get suppressed and poloidal (zonal) flows dominate. In the saturated state that follows, the dominant large-scale modes of the potential and the density are self-organized in different ways, depending on the value of the ion temperature.

  15. Low-frequency flute instabilities of self-pinched ion beams

    SciTech Connect

    Uhm, Han S.; Davidson, Ronald C.

    2005-12-15

    The stability properties of the low-frequency flute instabilities in a self-pinched ion beam propagating through a preformed plasma channel are investigated for long-wavelength and low-frequency perturbations. Consistent with the flute instabilities, the stability analysis is restricted to the surface perturbations on the ion beam. A closed algebraic dispersion relation of the flute instabilities for Bennett [Phys. Rev. 45, 890 (1934)] density profile is obtained, by making use of the energy group model. From the analytical and numerical calculations of the dispersion relation for highly collisional plasma, we find the necessary condition for instability in terms of the fractional current neutralization f. Threshold values of the fractional current neutralization for instability are tabulated for each azimuthal mode number l.

  16. Particle simulation on radio frequency stabilization of flute modes in a tandem mirror. I. Parallel antenna

    SciTech Connect

    Kadoya, Y.; Abe, H.

    1988-04-01

    A two- and one-half-dimensional electromagnetic particle code (PS2M) (H. Abe and S. Nakajima, J. Phys. Soc. Jpn. 53, xxx (1987)) is used to study how an electric field applied parallel to the magnetic field affects the radio frequency stabilization of flute modes in a tandem mirror plasma. The parallel electric field E/sub parallel/ perturbs the electron velocity v/sub parallel/ parallel to the magnetic field and also induces a perpendicular magnetic field perturbation B/sub perpendicular/. The unstable growth of the flute mode in the absence of such a radio frequency electric field is first studied as a basis for comparison. The ponderomotive force originating from the time-averaged product is then shown to stabilize the flute modes. The stabilizing wave power threshold, the frequency dependency, and the dependence on delchemically bondE/sub parallel/chemically bond all agree with the theoretical predictions.

  17. The effects of verbal instruction, modeling, rehearsal, and feedback on correct posture during flute playing.

    PubMed

    Dib, Nancy Ellen; Sturmey, Peter

    2007-07-01

    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 participated. All three students' posture improved from 0% during baseline to nearly 100% after training for all sessions, generalization probes, and after a 1- to 2-month follow-up. The training package was proven effective in the acquisition, generalization, and maintenance of correct posture for flute playing.

  18. 78 FR 59269 - Endangered and Threatened Wildlife and Plants; Endangered Species Status for the Fluted...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-26

    ...). The gametogenic cycle (annual cycle in the development of reproductive cells or gametes) of fluted... other populations are of questionable viability, with some on the verge of extirpation (e.g., Horse Lick... apparent viability in just two streams (Duck and Paint Rock Rivers). Two of the four largest populations...

  19. Experimental correlation for flooding vapor velocity in a fluted tube with a twisted insert

    SciTech Connect

    Kang, Y.T.; Stout, R.; Christensen, R.N.

    1996-12-31

    This paper develops a flooding correlation from experiments in a fluted tube with a twisted insert for application to absorption heat pump systems. Fluted tubes have been used to enhance both heat and mass transfer during absorption and desorption processes. In the present tests, a plastic twisted tape was inserted to increase the absorption rate in counter current absorption. The effects of the twisted insert and the angle of inclination on the flooding were examined. Water and Ethyl alcohol solution flows downward in the fluted tube while air flows counter current in an upward direction. The flooding mechanism in a fluted tube with a twisted insert was analyzed by visual observation, and experimental correlations for the flooding for both vertical and nearly horizontal positions were developed. The experimental data from this paper were compared with those for smooth tubes from the literature. The results show that the flooding initiated form the bottom for the vertical tube, and from the top of the tube for the nearly horizontal tube. The fluctuation of the pressure drop for the vertical tube was much stronger than that for the horizontal tube. The effect of the position of the insert was not significant for the nearly horizontal tube while it was somewhat significant for the vertical tube. The superficial flooding vapor velocity for the nearly horizontal position is lower than that for the vertical position for a given liquid mass flow rate.

  20. Idea Bank: The Native American Flute--A Possibility for Your Classroom

    ERIC Educational Resources Information Center

    Kacanek, Hal

    2011-01-01

    The sound of the Native American flute seems to convey care, sadness, loneliness, longing, heartfelt emotion, a sense of the natural world, wisdom, the human spirit, and a sense of culture. It is a sound that competes for attention, dramatically punctuating messages about First Nation peoples on television and in movies. A relatively small group…

  1. Flute stabilization due to ponderomotive force created by an rf field with a variable gradient

    SciTech Connect

    Yasaka, Y.; Itatani, R.

    1986-06-30

    An rf-stabilization experiment was performed in the axisymmetric single-mirror device HIEI by controlling the radial-gradient scale length of the rf field with the aid of an azimuthally phased antenna array. The flute stability depends sensitively on the scale length of the perpendicular rf electric field, which shows that rf stabilization is caused by the ponderomotive force for ions.

  2. Formation of isobaric discontinuities in large-scale flute drift motions

    SciTech Connect

    Dreizin, Y.A.; Sokolov, E.P.

    1982-05-01

    The flute drift motion in MHD-stable plasma configurations with closed lines of force is analyzed qualitatively. The onset of this motion can lead to isobaric discontinuities in experimentally observable quantitites: the electric potential and the electron and ion densities and temperatures.

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

    SciTech Connect

    Gonzalez, R.; Gomez, D.; Ferro Fontan, C. Buenos Aires Instituto de Astronomia y Fisica del Espacio, C C No. 67, Sucursal 28, Buenos Aires ); Sicardi Schifino, A.C.; Montagne, R. Instituto de Fisica, Facultad de Ingenieria, Universidad de la Republica, CC No. 30, CP 11000, Montevideo )

    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.

  4. 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…

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

    NASA Technical Reports Server (NTRS)

    Gonzalez, R.; Gomez, D.; Fontan, C. F.; Schifino, A. C. S.; Montagne, R.

    1993-01-01

    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.

  6. Particle simulation of radio frequency stabilization of the flute mode in a tandem mirror. II. Perpendicular antenna

    SciTech Connect

    Abe, H.; Kadoya, Y.

    1988-10-01

    A two-and-a-half-dimensional electromagnetic particle code PS2M (J. Phys. Soc. Jpn. 56, 3899 (1987)) is used to study how an electric field applied perpendicularly to the magnetic field affects the radio frequency stabilization of flute modes in a tandem mirror plasma. The electric field perpendicular to the magnetic field stabilizes or destabilizes the flute mode through the mechanism of the ponderomotive force acting on electrons and ions and through the mechanism of sideband coupling. In the simulations two typical examples have been shown: (i) when the sideband coupling effects (in which the electron terms are dominant) stabilize the flute modes and (ii) when the perpendicular ponderomotive force acting on the electrons destabilizes the flute modes.

  7. Flute-like musical instruments: A toy model investigated through numerical continuation

    NASA Astrophysics Data System (ADS)

    Terrien, Soizic; Vergez, Christophe; Fabre, Benoît

    2013-07-01

    Self-sustained musical instruments (bowed string, woodwind and brass instruments) can be modelled by nonlinear lumped dynamical systems. Among these instruments, flutes and flue organ pipes present the particularity to be modelled as a delay dynamical system. In this paper, such a system, a toy model of flute-like instruments, is studied using numerical continuation. Equilibrium and periodic solutions are explored with respect to the blowing pressure, with focus on amplitude and frequency evolutions along the different solution branches, as well as "jumps" between periodic solution branches. The influence of a second model parameter (namely the inharmonicity) on the behaviour of the system is addressed. It is shown that harmonicity plays a key role in the presence of hysteresis or quasiperiodic regime. Throughout the paper, experimental results on a real instrument are presented to illustrate various phenomena, and allow some qualitative comparisons with numerical results.

  8. Comparative biogas generation from fruit peels of fluted pumpkin (Telfairia occidentalis) and its optimization.

    PubMed

    Dahunsi, S O; Oranusi, S; Owolabi, J B; Efeovbokhan, V E

    2016-12-01

    This study evaluated the potentials of fluted pumpkin fruit peels for biogas generation using three different pre-treatment methods (A, B, C) and the optimization of its process parameters. The physic-chemical characteristics of the substrates revealed it to be rich in nutrients and mineral elements needed by microorganisms. Gas chromatography analysis revealed the gas composition to be within the range of 58.5±2.5% Methane and 27±3% Carbon dioxide for all the three digestions. The study revealed that combination of three pre-treatment methods enhanced enormous biogas yield from the digested substrates as against the use of two methods and no pre-treatment experiment. Optimization of the generated biogas data revealed that RSM predicted higher gas yield than ANN, the latter gives higher accuracy and efficiency than the former. It is advocated that fluted pumpkin fruit peels be used for energy generation especially in the locations of its abundance.

  9. Experimental study of curvature-driven flute instability in the gas-dynamic trap

    SciTech Connect

    Ivanov, A.A.; Anikeev, A.V.; Bagryansky, P.A.; Bocharov, V.N.; Deichuli, P.P.; Karpushov, A.N.; Maximov, V.V.; Pod'minogin, A.A.; Rogozin, A.I.; Salikova, T.V.; Tsidulko, Y.A. )

    1994-05-01

    A curvature-driven flute instability will be excited in the magnetized plasmas if the magnetic field lines curve toward the entire plasma boundary. Conditions under which it can be effectively stabilized in axisymmetric geometry have been experimentally studied in a gas-dynamic trap (GDT) at Novosibirsk. Flexible design of the experimental device and the availability of neutral beams and ion cyclotron heating enabled the pressure-weighted curvature to be varied over a wide range. The stability limits were thus measured and compared with those predicted by the modified Rosenbluth--Longmire criterion. Characteristics of unstable curvature-driven flute modes were also measured and found to conform to a theory including finite ion Larmor radius (FLR) effects. Stable operation during neutral beam injection was achieved with a cusp end cell, resulting in an increase in [ital T][sub [ital e

  10. Flute instability of an ion-focused slab electron beam in a broad plasma

    SciTech Connect

    Whittum, D.H. , 1-1 Oho, Tsukuba, Ibaraki 305 ); Lampe, M.; Joyce, G.; Slinker, S.P. ); Yu, S.S.; Sharp, W.M. )

    1992-11-15

    An intense relativistic electron beam with an elongated cross section, propagating in the ion-focused regime through a broad, uniform, unmagnetized plasma, is shown to suffer a transverse flute instability. This instability arises from the electrostatic coupling between the beam and the plasma electrons at the ion-channel edge. The instability is found to be absolute and the asymptotic growth of the flute amplitude is computed in the frozen-field'' approximation and the large skin-depth limit. The minimum growth length is shown to be much less than the betatron period, with the consequence that focusing is rendered ineffective. It is further shown that growth is much reduced when the beam propagates through a narrow channel where the ion density greatly exceeds that of the surrounding plasma. In this limit, a modest spread in betatron frequency produces rapid saturation. The effect of plasma electron collisions is also considered. Results of beam breakup simulations are noted.

  11. Large-scale flows and coherent structure phenomena in flute turbulence

    SciTech Connect

    Sandberg, I.; Andrushchenko, Zh.N.; Pavlenko, V.P.

    2005-04-15

    The properties of zonal and streamer flows in the flute mode turbulence are investigated. The stability criteria and the frequency of these flows are determined in terms of the spectra of turbulent fluctuations. Furthermore, it is shown that zonal flows can undergo a further nonlinear evolution leading to the formation of long-lived coherent structures which consist of self-bound wave packets supporting stationary shear layers, and thus can be characterized as regions with a reduced level of anomalous transport.

  12. Development of Table-Top mirror trap for flute stabilization research

    NASA Astrophysics Data System (ADS)

    Seemann, Omri; Be'Ery, Ilan

    2015-11-01

    Mirror traps might be viable candidates for fusion machines. These machines are technically and physically simple but suffer from the Rayleigh-Taylor-like flute instability. A new table top mirror machine was built in order to research ways to mitigate this instability. One possible solution for this problem which was researched in the past is using oscillatory fields. A description of the system and diagnostics, preliminary results and a review of the main mechanisms with which stabilization might occur are presented.

  13. Forced organization of flute-type turbulence by convective cell injection

    SciTech Connect

    Iizuka, S.; Huld, T.; Pecseli, H.L.; Rasmussen, J.J.

    1988-03-14

    Nonlinear interactions between flute-type turbulence and an externally excited convective cell in a strongly magnetized plasma are investigated. During the interaction the azimuthal-mode-number spectrum of the turbulence is deformed and a broad spectrum evolves, indicating an inverse cascade. As a result of a modification in phase and amplitude of the fluctuations, an organized structure is created in turbulence. The macroscopic behavior is well explained by a Van der Pol--type equation.

  14. Pitted and fluted rocks in the Western Desert of Egypt - Viking comparisons

    NASA Technical Reports Server (NTRS)

    Mccauley, J. F.; Breed, C. S.; Grolier, M. J.; El-Baz, F.; Whitney, M. I.; Ward, A. W.

    1979-01-01

    The Western Desert of Egypt is one of the most arid regions on earth and is probably the closest terrestrial analog to the surface of Mars. An expedition to the area in 1978 revealed an abundance of quartzite and basalt rocks that have been pitted and fluted by wind erosion and deflation of the desert surface. These pitted rocks are internally homogeneous, show no internal holes or vesicles, and are considered an important but neglected type of ventifact. They bear a striking resemblance to the pitted and fluted rocks seen by the Viking Landers, rocks that have generally been interpreted as vesicular basalts only slightly modified by wind erosion. Wind tunnel studies of the air flow over and around nonstreamlined hand specimens from the Western Desert show that windward abrasion coupled with negative flow, secondary flow, and vorticity in a unidirectional wind can explain the complex arrays of pits and flutes. These field and laboratory observations suggest that the pitted rocks at the Viking Lander sites are also ventifacts, and thus the Martian surface may be far more wind eroded than previously thought.

  15. Contributing factors, prevention, and management of playing-related musculoskeletal disorders among flute players internationally.

    PubMed

    Lonsdale, Karen; Laakso, E-Liisa; Tomlinson, Vanessa

    2014-09-01

    Major studies have shown that flutists report playing-related pain in the neck, middle/upper back, shoulders, wrists, and hands. The current survey was designed to establish the injury concerns of flute players and teachers of all backgrounds, as well as their knowledge and awareness of injury prevention and management. Questions addressed a range of issues including education, history of injuries, preventative and management strategies, lifestyle factors, and teaching methods. At the time of the survey, 26.7% of all respondents were suffering from flute playing-related discomfort or pain; 49.7% had experienced flute playing-related discomfort or pain that was severe enough to distract while performing; and 25.8% had taken an extended period of time off playing because of discomfort or pain. Consistent with earlier studies, the most common pain sites were the fingers, hands, arms, neck, middle/upper back, and shoulders. Further research is needed to establish possible links between sex, instrument types, and ergonomic set up. Further investigation is recommended to ascertain whether certain types of physical training, education, and practice approaches may be more suitable than current methods. A longitudinal study researching the relationship between early education, playing position, ergonomic set-up, and prevalence of injury is recommended.

  16. Transitions to spatiotemporal chaos and turbulence of flute instabilities in a magnetized plasma.

    PubMed

    Brochard, F; Gravier, E; Bonhomme, G

    2006-03-01

    The spatiotemporal transition scenario of flute instabilities from a regular to a turbulent state is experimentally investigated in the plasma column of a thermionic discharge. The same transition scenario, i.e., the Ruelle-Takens route to turbulence, is found for both the Kelvin-Helmholtz and the Rayleigh-Taylor instabilities. It is demonstrated that the transition can be more or less smooth, according to the discharge mode. In both cases, a strong radial dependence is observed, which is linked to the velocity shear layer in the case of the Kelvin-Helmholtz instability.

  17. Ponderomotive stabilization of flute modes in mirrors Feedback control and numerical results

    NASA Technical Reports Server (NTRS)

    Similon, P. L.

    1987-01-01

    Ponderomotive stabilization of rigid plasma flute modes is numerically investigated by use of a variational principle, for a simple geometry, without eikonal approximation. While the near field of the studied antenna can be stabilizing, the far field has a small contribution only, because of large cancellation by quasi mode-coupling terms. The field energy for stabilization is evaluated and is a nonnegligible fraction of the plasma thermal energy. A new antenna design is proposed, and feedback stabilization is investigated. Their use drastically reduces power requirements.

  18. Flute instability in a plasma confined by perfectly reflecting end walls

    SciTech Connect

    Farina, D.; Pozzoli, R.; Ryutov, D. )

    1993-11-01

    The magnetohydrodynamic stability of a low-pressure plasma confined along the magnetic field by the end walls that are perfectly reflecting the impinging particles is considered. It is shown that, if the magnetic field lines do not intersect the walls along the normal, a fast instability can develop. An explicit expression for the growth rate has been derived, and an analogy with the usual flute instability has been traced. The instability can play some role in the scrape-off layers of tokamaks with poloidal limiter.

  19. Transitions to spatiotemporal chaos and turbulence of flute instabilities in a low-{beta} magnetized plasma

    SciTech Connect

    Brochard, F.; Gravier, E.; Bonhomme, G.

    2006-03-15

    The spatiotemporal transition scenario of flute instabilities from a regular to a turbulent state is experimentally investigated in the low-{beta} plasma column of a thermionic discharge. The same transition scenario, i.e., the Ruelle-Takens route to turbulence, is found for both the Kelvin-Helmholtz and the Rayleigh-Taylor instabilities. It is demonstrated that the transition can be more or less smooth, according to the discharge mode. In both cases, a strong radial dependence is observed, which is linked to the velocity shear layer in the case of the Kelvin-Helmholtz instability.

  20. Flute mode waves near the lower hybrid frequency excited by ion rings in velocity space

    NASA Technical Reports Server (NTRS)

    Cattell, C.; Hudson, M.

    1982-01-01

    Discrete emissions at the lower hybrid frequency are often seen on the S3-3 satellite. Simultaneous observation of perpendicularly heated ions suggests that these ions may provide the free energy necessary to drive the instability. Studies of the dispersion relation for flute modes excited by warm ion rings in velocity space show that waves are excited with real frequencies near the lower hybrid frequency and with growth rates ranging from about 0.01 to 1 times the ion cyclotron frequency. Numerical results are therefore consistent with the possibility that the observed ions are the free energy source for the observed waves.

  1. Lung flute improves symptoms and health status in COPD with chronic bronchitis: A 26 week randomized controlled trial

    PubMed Central

    2014-01-01

    Background Chronic obstructive pulmonary disease (COPD) is characterized by mucus hypersecretion that contributes to disease related morbidity and is associated with increased mortality. The Lung Flute® is a new respiratory device that produces a low frequency acoustic wave with moderately vigorous exhalation to increase mucus clearance. We hypothesized that the Lung Flute, used on a twice daily basis will provide clinical benefit to patients with COPD with chronic bronchitis. Methods We performed a 26 week randomized, non-intervention controlled, single center, open label trial in 69 patients with COPD and Chronic Bronchitis. The primary endpoint was change in respiratory symptoms measured with the Chronic COPD Questionnaire (CCQ). Secondary endpoints included health status, assessed by the St. George Respiratory questionnaire (SGRQ), BODE (Body-Mass Index, Airflow Obstruction, Dyspnea, and Exercise Capacity) index score and exacerbation frequency. Results While the control patients did not demonstrate any significant changes in the primary endpoint (CCQ change at 26 weeks of +0.01, p = 0.8), a trend (p = 0.08) to decrease (improvement) in the CCQ (-0.23 at 26 weeks) was seen with the Lung Flute. Furthermore, a significant improvement in the symptom domain of the CCQ was seen only with the lung flute (-0.42, p = 0.004). Health status (SGRQ) improvement, was also only seen with the Lung Flute (-3.23, p = 0.03). The BODE score increased in the control group (3.31 at baseline, 4.14 at 26 weeks), however it remained stable in the Lung Flute arm (3.16 at baseline and 26 weeks), with the changes from baseline being significantly different between the 2 arms (p = 0.01). There was a trend for less exacerbations in the Lung Flute group (p = 0.07). Adverse effects were minor, with only 1 patient discontinuing treatment because of lack of efficacy. Serious adverse effects seen were all determined to be unrelated to the device use. Conclusions

  2. The magnetic Rayleigh-Taylor instability and flute waves at the ion Larmor radius scales

    SciTech Connect

    Onishchenko, O. G.; Pokhotelov, O. A.; Stenflo, L.; Shukla, P. K.

    2011-02-15

    The theory of flute waves (with arbitrary spatial scales compared to the ion Larmor radius) driven by the Rayleigh-Taylor instability (RTI) is developed. Both the kinetic and hydrodynamic models are considered. In this way we have extended the previous analysis of RTI carried out in the long wavelength limit. It is found that complete finite ion Larmor radius stabilization is absent when the ion diamagnetic velocity attains the ion gravitation drift velocity. The hydrodynamic approach allowed us to deduce a new set of nonlinear equations for flute waves with arbitrary spatial scales. It is shown that the previously deduced equations are inadequate when the wavelength becomes of the order of the ion Larmor radius. In the linear limit a Fourier transform of these equations yields the dispersion relation which in the so-called Pade approximation corresponds to the results of the fully kinetic treatment. The development of such a theory gives us enough grounds for an adequate description of the RTI stabilization by the finite ion Larmor radius effect.

  3. Individuality of movements in music--finger and body movements during playing of the flute.

    PubMed

    Albrecht, Stefan; Janssen, Daniel; Quarz, Esther; Newell, Karl M; Schöllhorn, Wolfgang I

    2014-06-01

    The achievement of mastery in playing a composition by means of a musical instrument typically requires numerous repetitions and corrections according to the keys and notations of the music piece. Nevertheless, differences in the interpretation of the same music piece by highly skilled musicians seem to be recognizable. The present study investigated differences within and between skilled flute players in their finger and body movements playing the same piece several times on the same and on different days. Six semiprofessional and four professional musicians played an excerpt of Mozart's Flute Concerto No. 2 several times on three different days. Finger and body movements were recorded by 3D motion capture and analyzed by linear and nonlinear classification approaches. The findings showed that the discrete and continuous movement timing data correctly identified individuals up to 100% by means of their finger movements and up to 94% by means of their body movements. These robust examples of identifying individual movement patterns contradict the prevailing models of small, economic finger movements that are favored in the didactic literature for woodwind players and question traditional recommendations for teaching the learning of motor skills.

  4. Stability criteria for edge flute modes in the two-fluid regime

    SciTech Connect

    Zheng, L. )

    1993-05-01

    Necessary and sufficient stability criteria for flute modes localized at the edge of toroidal plasmas are obtained from the Braginskii's two-fluid equations without taking into account the collisional effects. It is assumed that the plasma pressure tends to vanish, but its gradient remains finite at the edge of the plasma. The results show that the free-boundary edge flute modes (namely, the peeling modes) are more dangerous than the fixed-boundary modes (namely, the Mercier modes). Numerical investigation of the criterion for peeling modes shows that the finite ion-gyroradius effect can substantially stabilize the modes, especially for the case [Delta][ge]0, where the equilibrium quantity [Delta][equivalent to]1/2+[ital S][sup [minus]1][lt][bold j][center dot][bold B][vert bar][del][ital v][vert bar][sup [minus]2][gt], with [ital S] denoting the global shear, [bold B] the magnetic field, [bold j] the current density, [ital v] the volume inside the reference magnetic surface, and [lt]...[gt] denoting the average over the magnetic surface. Equilibria with [Delta][ge]0 are shown to be more stable to the peeling modes than those with [Delta][le]0.

  5. Buckling loads and natural frequencies of drill bits and fluted cutters

    SciTech Connect

    Mayrab, E.B.; Gilsinn, D.E.

    1984-08-01

    The buckling loads, natural frequencies and mode shapes of twist-drill bits and certain fluted cutters under a variety of combinations of twist angle, cross-section geometry, and axial loading have been obtained. The drill bit is modelled as a twisted Euler beam under axial loading that is clamped at both ends. The governing system of differential equations is solved by the Galerkin procedure. Explicit forms for the basis functions used to generate the Galerkin coefficients are presented in general form in an appendix. They may be used for obtaining numerical results for that class of problems which use the Rayleigh-Ritz-Galerkin methods with beamtype functions as the basis functions. The representative set of modes obtained exhibit a complex out-of-plane twisting-type motion that suggests a possible explanation for the out-of-roundness of certain drilled holes.

  6. Complete genome sequence of a new bipartite begomovirus infecting fluted pumpkin (Telfairia occidentalis) plants in Cameroon.

    PubMed

    Leke, Walter N; Khatabi, Behnam; Fondong, Vincent N; Brown, Judith K

    2016-08-01

    The complete genome sequence was determined and characterized for a previously unreported bipartite begomovirus from fluted pumpkin (Telfairia occidentalis, family Cucurbitaceae) plants displaying mosaic symptoms in Cameroon. The DNA-A and DNA-B components were ~2.7 kb and ~2.6 kb in size, and the arrangement of viral coding regions on the genomic components was like those characteristic of other known bipartite begomoviruses originating in the Old World. While the DNA-A component was more closely related to that of chayote yellow mosaic virus (ChaYMV), at 78 %, the DNA-B component was more closely related to that of soybean chlorotic blotch virus (SbCBV), at 64 %. This newly discovered bipartite Old World virus is herein named telfairia mosaic virus (TelMV).

  7. Low-frequency flute instabilities of a hollow cathode arc discharge - Theory and experiment.

    NASA Technical Reports Server (NTRS)

    Ilic, D. B.; Rognlien, T. D.; Self, S. A.; Crawford, F. W.

    1973-01-01

    The characteristics of two low-frequency electrostatic flute instabilities of a low-pressure hollow cathode arc discharge are reported. Mode I has azimuthal mode number m = 1, and occurs when the radial electric field is negative (directed inward), while mode II has m = - 1 and occurs when the field is positive. The radial electric field is controlled by varying the potential of a secondary anode cylinder located close to the outer discharge radius. A linear perturbation analysis, based on the two-fluid equations, is given for a low-beta, collisionless, cylindrical plasma column, immersed in a uniform axial magnetic field, having a Gaussian density profile and an arbitrary radial electric field profile. Reasonable correlation between theory and experiment is demonstrated for both modes.

  8. Flute instability in the tandem mirror with the divertor/dipole regions

    SciTech Connect

    Katanuma, I.; Masaki, S.; Sato, S.; Sekiya, K.; Ichimura, M.; Imai, T.

    2011-11-15

    The numerical simulation is performed in GAMMA10 A-divertor magnetic configuration, which is a candidate of remodeled device of the GAMMA10 tandem mirror [M. Inutake et al., Phys. Rev. Lett. 55, 939 (1985)]. Both divertor and dipole regions are included in the numerical calculation, which is a new point. The electron short circuit effect along x-point, therefore, is not assumed so that it is not used the boundary condition of the electrostatic perturbations being zero at the separatrix on which the magnetic field lines pass through x-point. The simulation results reveal that the dipole field plays a role of a good magnetic field line curvature to the GAMMA10 A-divertor, and so the flute modes are stabilized without help of electron short circuit effects.

  9. [Problems with flute playing: an otological problem? Case report of a peculiar cerebellar astrocytoma].

    PubMed

    Forton, G; Verlooy, J; Cras, P; Parizel, P; Van de Heyning, P

    1992-01-01

    A rare case of cerebellar astrocytoma presenting as a cerebellopontine angle tumour is discussed. A 35-year old woman noticed a bizarre twitching and fatigability of the left upper lip while playing the flute. There was also a mild hearing loss on the left side and she sometimes felt unsure of herself when walking. A thorough examination by means of speech audiometry, electronystagmography, ABR, CT-scan and MRI revealed a large, partly calcified mass occupying the cerebellopontine angle. Only the histological examination of the surgical specimen revealed the true nature of the tumour. The special characteristics of this tumour and the unusual clinical course are discussed. The importance of a good histological diagnosis is stressed.

  10. Fit to play: the fitness effect on physically challenging flute repertoire.

    PubMed

    Borkowski, Jennifer A

    2011-03-01

    This case study was done to determine whether physical fitness plays a part in performing flute repertoire. Most repertoire allows performers the choice of where to breathe. However, there exists a "brute" repertoire where breathing is prescribed by the composer, which poses physical challenges for performers. The author contrasted pieces from traditional repertoire with Heinz Holliger's (t)air(e), which requires passages of breath-holding and measured inhalations. The author was tested for cardiovascular fitness (VO2max) and corresponded these levels to pulse rates while playing at baseline and 6 months after undertaking a physical fitness program. After the exercise program, expertise with standard repertoire combined with the unmeasured variables of resonance, openness of the chest and oral cavities, embouchure size, and air speed saw little improvement with increased fitness levels. However, when air regulation is out of the performer's control, the effect of cardiovascular training brought the "brute" repertoire into the same range of difficulty as the standard repertoire.

  11. The flute instability as the trigger mechanism for disruption of cometary plasma tails

    NASA Technical Reports Server (NTRS)

    Ip, W.-H.; Mendis, D. A.

    1978-01-01

    The sporadic disruption of the plasma tails of some comets has recently been explained to be caused by magnetic-field-line reconnection in the cometary ionospheres due to magnetic-sector-boundary traversals. An alternative model is proposed in which the tail disruption is the end result of compression of the cometary ionosphere by high-velocity solar-wind streams, triggering the flute instability in the marginally stable tangential-discontinuity surface which separates the cometary ionosphere from the solar-wind plasma. According to the proposed model, the tail-disruption events could occur at all heliographic latitudes, whereas the Niedner-Brandt (1978) model should predict that these events are restricted to low heliographic latitudes in view of the present understanding of the sector structure of the heliosphere. Consequently, the high-latitude disruption events observed seem to present a difficulty for the latter model.

  12. 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.

  13. A model for spiral flows in basal ice and the formation of subglacial flutes based on a Reiner-Rivlin rheology for glacial ice

    NASA Astrophysics Data System (ADS)

    Schoof, Christian G.; Clarke, Garry K. C.

    2008-05-01

    Flutes are elongated sediment ridges formed at the base of glaciers and ice sheets. In this paper, we show that flutes can be the product of a corkscrew-like spiral flow in basal ice that removes sediment from troughs between flutes and deposits it at their crests, as first suggested by Shaw and Freschauf. In order to generate the type of basal ice flow required for this mechanism, the viscous rheology of ice must allow for the generation of deviatoric normal stresses transverse to the main flow direction. This type of behavior, which is commonly observed in real nonlinearly viscous and viscoelastic fluids, can be described by a Reiner-Rivlin rheology. Here, we develop a mathematical model that describes the role of these transverse stresses in generating spiral flows in basal ice and investigate how these flows lead to the amplification of initially small basal topography and the eventual formation of assemblies of evenly spaced subglacial flutes.

  14. Bone graft

    MedlinePlus

    Autograft - bone; Allograft - bone; Fracture - bone graft; Surgery - bone graft; Autologous bone graft ... Fuse joints to prevent movement Repair broken bones (fractures) that have bone loss Repair injured bone that ...

  15. 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.

  16. Erosion of Fluted Cliffs on the Na Pali Coast, Kauai, Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Osborn, G.; Mohr, S.; Blay, C.

    2015-12-01

    Precipitous sea cliffs on the northwest side of Kauai, sculpted into deep bedrock gullies and sharp divides, are known as "Na Pali", Hawaiian for "the cliffs", and are commonly referred to as fluted cliffs. Rising 500 m above the coast, they constitute some of the most dramatic scenery on planet Earth and are a world famous tourist attraction. After the discovery of flank collapses on some Hawaiian volcanoes the great Na Pali escarpment was hypothesized to have been generated by a megalandslide, but bathymetric data show the shallow submarine shelf off the Na Pali coast bears no landslide deposits. It is likely that wave erosion at the base of the local thin-bedded lavas, particularly in winter, is responsible for the escarpment. Superimposed on the escarpment are the deep gullies, or grooves, and divides, which constitute drainage networks that happen to be developed on very steep slopes. Networks are poorly developed on relatively young parts of the escarpment and well developed on older parts, which feature coalescing tributaries and very deep gullies. In most cases gullies shallow going upslope, and many fade out completely just below drainage divides, just like in drainage networks developed on more gently sloping landscapes. The drainage networks show that the basalts along this coast are relatively easily eroded by runoff. Rocks easily eroded by runoff generally do not stand in 500-m-high cliffs because they are not mechanically strong enough to resist failure and mass movement. The key to development of high fluted cliffs is a mix of mechanical strength and erodibiity, a combination whose rarity explains why analogs to the Na Pali cliffs are not found outside the Hawaiian Islands. The combination here is provided by basalt which is strong where unweathered but rotten and in some case completely decomposed close to the surface, courtesy of the Hawaiian climate. Weathering must proceed downward at about the same rate as removal of mass by runoff erosion

  17. Bone tumor

    MedlinePlus

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

  18. Multiple antibiotic-resistant bacteria on fluted pumpkin leaves, a herb of therapeutic value.

    PubMed

    Igbeneghu, Oluwatoyin A; Abdu, Abdulrasheed B

    2014-06-01

    Fluted pumpkin (Telfairia occidentalis) is a minimally-processed green leafy vegetable traditionally used for its antianaemic properties in the form of leaf juice without a heating or inactivation step before consumption. The aim of the study was to assess the presence of surface microbiota on T. occidentalis leaves and also to determine the antimicrobial susceptibility of isolated organisms. Bacterial contaminants on 50 samples of T. occidentalis leaves were isolated and characterized using standard biochemical methods and the antimicrobial susceptibility of isolated organisms was determined using the antibiotic disc diffusion assay. The results obtained show that the leaves of T. occidentalis is contaminated with organisms which included Enterobacter agglomerans (25.9%), Proteus vulgaris (24.9%), Klebsiella spp. (2.6%), and Serratia liquefaciens (2.1%). Other bacterial isolates recovered in order of frequency included: Staphylococcus spp. (33.7%), Bacillus spp. (8.3%), and Pseudomonas fluorescens (2.6%). Of the 193 bacterial isolates from the leaves of T. occidentalis samples tested for antimicrobial resistance, all (100%) were found to be resistant to ampicillin, cloxacillin, augmentin, erythromycin, and tetracycline while 96% of the isolates were resistant to cephalothin. Resistance to trimethoprim (93%) and gentamicin (83%) was also observed. Approximately, 22% of the isolates were resistant to ciprofloxacin; however, only 11 (5.8%) were resistant to ofloxacin. Thus, uncooked T. occidentalis is a potential source of highly-resistant epiphytic bacteria which could be opportunistic pathogens in consumers.

  19. Cutoff frequencies and cross fingerings in baroque, classical, and modern flutes

    NASA Astrophysics Data System (ADS)

    Wolfe, Joe; Smith, John

    2003-10-01

    Baroque, classical, and modern flutes have successively more and larger tone holes. This paper reports measurements of the standing waves in the bores of instruments representing these three classes. It presents the frequency dependence of propagation of standing waves in lattices of open tone holes and compares these measurements with the cutoff frequency: the frequency at which, in an idealized system, the standing waves propagate without loss in such a lattice. It also reports the dependence of the sound field in the bore of the instrument as a function of both frequency and position along the bore for both simple and ``cross fingerings'' (configurations in which one or more tone holes are closed below an open hole). These measurements show how ``cross fingerings'' produce a longer standing wave, a technique used to produce the nondiatonic notes on instruments with a small number of tone holes closed only by the unaided fingers. They also show why the changes from baroque to classical to modern gave the instruments a louder, brighter sound and a greater range.

  20. Cutoff frequencies and cross fingerings in baroque, classical, and modern flutes.

    PubMed

    Wolfe, Joe; Smith, John

    2003-10-01

    Baroque, classical, and modern flutes have successively more and larger tone holes. This paper reports measurements of the standing waves in the bores of instruments representing these three classes. It presents the frequency dependence of propagation of standing waves in lattices of open tone holes and compares these measurements with the cutoff frequency: the frequency at which, in an idealized system, the standing waves propagate without loss in such a lattice. It also reports the dependence of the sound field in the bore of the instrument as a function of both frequency and position along the bore for both simple and "cross fingerings" (configurations in which one or more tone holes are closed below an open hole). These measurements show how "cross fingerings" produce a longer standing wave, a technique used to produce the nondiatonic notes on instruments with a small number of tone holes closed only by the unaided fingers. They also show why the changes from baroque to classical to modern gave the instruments a louder, brighter sound and a greater range.

  1. Elevated Serum Titanium Level as a Marker for Failure in a Titanium Modular Fluted Tapered Stem.

    PubMed

    McAlister, Ian P; Abdel, Matthew P

    2016-07-01

    Serum ion concentrations of cobalt and chromium are commonly used to monitor for the development of local metal reactions in metal-on-metal total hip arthroplasties, as well as dual-modular constructs. Although rarely used in clinical practice, elevated serum titanium levels have the ability to indicate a failure with contemporary revision constructs, such as with titanium modular fluted tapered (TMFT) stems. The authors report the case of a 64-year-old man with a TMFT stem after revision total hip arthroplasty for a dual-modular neck construct who had set screw disengagement with subsequent proximal body loosening. The patient's serum cobalt and chromium levels were normal, but he had a markedly elevated serum titanium level, indicating failure of the titanium modular junction. Implant failures at modular junctions in femoral components are well described. Although several different failure mechanisms have been defined, to the authors' knowledge this is the first reported failure of this particular TMFT stem. In addition, this is the first report describing the use of serum titanium levels in identifying a novel failure mechanism. With the popularity of this stem, surgeons should be aware that an elevated serum titanium level may aid in the diagnosis of this unique complication. [Orthopedics. 2016; 39(4):e768-e770.].

  2. Fabrication and Testing of Durable Redundant and Fluted-Core Joints for Composite Sandwich Structures

    NASA Technical Reports Server (NTRS)

    Lin, Shih-Yung; Splinter, Scott C.; Tarkenton, Chris; Paddock, David A.; Smeltzer, Stanley S.; Ghose, Sayata; Guzman, Juan C.; Stukus, Donald J.; McCarville, Douglas A.

    2013-01-01

    The development of durable bonded joint technology for assembling composite structures is an essential component of future space technologies. While NASA is working toward providing an entirely new capability for human space exploration beyond low Earth orbit, the objective of this project is to design, fabricate, analyze, and test a NASA patented durable redundant joint (DRJ) and a NASA/Boeing co-designed fluted-core joint (FCJ). The potential applications include a wide range of sandwich structures for NASA's future launch vehicles. Three types of joints were studied -- splice joint (SJ, as baseline), DRJ, and FCJ. Tests included tension, after-impact tension, and compression. Teflon strips were used at the joint area to increase failure strength by shifting stress concentration to a less sensitive area. Test results were compared to those of pristine coupons fabricated utilizing the same methods. Tensile test results indicated that the DRJ design was stiffer, stronger, and more impact resistant than other designs. The drawbacks of the DRJ design were extra mass and complex fabrication processes. The FCJ was lighter than the DRJ but less impact resistant. With barely visible but detectable impact damages, all three joints showed no sign of tensile strength reduction. No compression test was conducted on any impact-damaged sample due to limited scope and resource. Failure modes and damage propagation were also studied to support progressive damage modeling of the SJ and the DRJ.

  3. The kinetics and acoustics of fingering and note transitions on the flute.

    PubMed

    Almeida, André; Chow, Renee; Smith, John; Wolfe, Joe

    2009-09-01

    Motion of the keys was measured in a transverse flute while beginner, amateur, and professional flutists played a range of exercises. The time taken for a key to open or close was typically 10 ms when pushed by a finger or 16 ms when moved by a spring. Because the opening and closing of keys will never be exactly simultaneous, transitions between notes that involve the movement of multiple fingers can occur via several possible pathways with different intermediate fingerings. A transition is classified as "safe" if it is possible to be slurred from the initial to final note with little perceptible change in pitch or volume. Some transitions are "unsafe" and possibly involve a transient change in pitch or a decrease in volume. Players, on average, used safe transitions more frequently than unsafe transitions. Delays between the motion of the fingers were typically tens of milliseconds, with longer delays as more fingers become involved. Professionals exhibited smaller average delays between the motion of their fingers than did amateurs.

  4. Phosphorylation of G protein-coupled receptors: from the barcode hypothesis to the flute model.

    PubMed

    Yang, Zhao; Yang, Fan; Zhang, Daolai; Liu, Zhixin; Lin, Amy; Liu, Chuan; Xiao, Peng; Yu, Xiao; Sun, Jin-Peng

    2017-02-28

    Seven transmembrane G protein-coupled receptors (GPCRs) are often phosphorylated at the C-terminus and on intracellular loops in response to various extracellular stimuli. Phosphorylation of GPCRs by GPCR kinases (GRKs) and certain other kinases can promote the recruitment of arrestin molecules. The arrestins critically regulate GPCR functions, not only by mediating receptor desensitization and internalization, but also by redirecting signalling to G protein-independent pathways via interactions with numerous downstream effector molecules. Accumulating evidence over the past decade has given rise to the phospho-barcode hypothesis, which states that ligand-specific phosphorylation patterns of a receptor direct its distinct functional outcomes. Our recent work, using unnatural amino acid incorporation and fluorine-19 nuclear magnetic resonance (19F-NMR) spectroscopy, led to the flute model, which provides preliminary insight into the receptor phospho-coding mechanism, by which receptor phosphorylation patterns are recognized by an array of phosphate-binding pockets on arrestin and are translated into distinct conformations. These selective conformations are recognized by various effector molecules downstream of arrestin. The phospho-barcoding mechanism enables arrestin to recognize a wide range of phosphorylation patterns of GPCRs, contributing to their diverse functions.

  5. Champagne flutes and brandy snifters: modelling protostellar outflow-cloud chemical interfaces

    NASA Astrophysics Data System (ADS)

    Rollins, R. P.; Rawlings, J. M. C.; Williams, D. A.; Redman, M. P.

    2014-10-01

    A rich variety of molecular species has now been observed towards hot cores in star-forming regions and in the interstellar medium. An increasing body of evidence from millimetre interferometers suggests that many of these form at the interfaces between protostellar outflows and their natal molecular clouds. However, current models have remained unable to explain the origin of the observational bias towards wide-angled `brandy snifter' shaped outflows over narrower `champagne flute' shapes in carbon monoxide imaging. Furthermore, these wide-angled systems exhibit unusually high abundances of the molecular ion HCO+. We present results from a chemodynamic model of such regions where a rich chemistry arises naturally as a result of turbulent mixing between cold, dense molecular gas and the hot, ionized outflow material. The injecta drives a rich and rapid ion-neutral chemistry in qualitative and quantitative agreement with the observations. The observational bias towards wide-angled outflows is explained naturally by the geometry-dependent ion injection rate causing rapid dissociation of CO in the younger systems.

  6. Reducing temperature elevation of robotic bone drilling.

    PubMed

    Feldmann, Arne; Wandel, Jasmin; Zysset, Philippe

    2016-12-01

    This research work aims at reducing temperature elevation of bone drilling. An extensive experimental study was conducted which focused on the investigation of three main measures to reduce the temperature elevation as used in industry: irrigation, interval drilling and drill bit designs. Different external irrigation rates (0 ml/min, 15 ml/min, 30 ml/min), continuously drilled interval lengths (2 mm, 1 mm, 0.5 mm) as well as two drill bit designs were tested. A custom single flute drill bit was designed with a higher rake angle and smaller chisel edge to generate less heat compared to a standard surgical drill bit. A new experimental setup was developed to measure drilling forces and torques as well as the 2D temperature field at any depth using a high resolution thermal camera. The results show that external irrigation is a main factor to reduce temperature elevation due not primarily to its effect on cooling but rather due to the prevention of drill bit clogging. During drilling, the build up of bone material in the drill bit flutes result in excessive temperatures due to an increase in thrust forces and torques. Drilling in intervals allows the removal of bone chips and cleaning of flutes when the drill bit is extracted as well as cooling of the bone in-between intervals which limits the accumulation of heat. However, reducing the length of the drilled interval was found only to be beneficial for temperature reduction using the newly designed drill bit due to the improved cutting geometry. To evaluate possible tissue damage caused by the generated heat increase, cumulative equivalent minutes (CEM43) were calculated and it was found that the combination of small interval length (0.5 mm), high irrigation rate (30 ml/min) and the newly designed drill bit was the only parameter combination which allowed drilling below the time-thermal threshold for tissue damage. In conclusion, an optimized drilling method has been found which might also enable drilling in more

  7. 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

  8. 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.

  9. Anomalous resistivity at the field null of the FRC: a quasi-linear expression based upon flute-type modes

    SciTech Connect

    Gerwin, R.

    1983-10-01

    In the Field-Reversed Theta Pinch (FRC) experiment, the poloidal flux is observed to be lost at a rate several times greater than classical resistivity would allow. Thus, there must be anomalous resistivity at the field null. Assuming that an electromagnetic microinstability of the flute mode type is responsible for this, we derived a general expression for the anomalous resistivity at the field null based upon a quasi-linear model of the microturbulence. This general expression does not depend upon the details of the ion-species model, for example, whether the ions are fluid or kinetic.

  10. 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 (μGC), 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.

  11. Particle-in-cell Simulations of Electromagnetic Wave Scattering From Numerically Generated Flute-type Density Irregularities

    NASA Astrophysics Data System (ADS)

    Main, D. S.; Caplinger, J.; Kim, T. C.; Sotnikov, V. I.

    2014-12-01

    The propagation of electromagnetic (EM) waves can be influenced by the presence of plasma turbulence. It is known that Flute-type density irregularities can develop during the nonlinear stage of an interchange instability in Earth's ionosphere and can affect radio communication channels. These density structures play an important role in the refraction and scattering of EM waves in Earth's ionosphere and also in laser diagnostic scattering experiments. To generate Flute-type density irregularities, we will use previously obtained numerical solution of nonlinear fluid equations involving the electrostatic potential and density. The solutions to these fluid equations govern the development of an interchange instability and results in the spatial dependence of density irregularities which can be used to analyze scattering of high frequency EM waves. This solution contains both large scale vortex density structures coexisting with short scale density perturbations. Next we will initialize a PIC simulation with the density structure from the fluid simulation to calculate the scattering cross-section and compare the results with an analytic solution obtained using numerically calculated density spectra. Because the linear and non-linear stages are well separated in time, we will compare the effect of scattering from density irregularities which form in both the linear and non-linear stages.

  12. Bone Biopsy

    MedlinePlus

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

  13. Infrared Thermal Imaging During Ultrasonic Aspiration of Bone

    NASA Astrophysics Data System (ADS)

    Cotter, D. J.; Woodworth, G.; Gupta, S. V.; Manandhar, P.; Schwartz, T. H.

    Ultrasonic surgical aspirator tips target removal of bone in approaches to tumors or aneurysms. Low profile angled tips provide increased visualization and safety in many high risk surgical situations that commonly were approached using a high speed rotary drill. Utilization of the ultrasonic aspirator for bone removal raised questions about relative amount of local and transmitted heat energy. In the sphenoid wing of a cadaver section, ultrasonic bone aspiration yielded lower thermal rise in precision bone removal than rotary mechanical drills, with maximum temperature of 31 °C versus 69 °C for fluted and 79 °C for diamond drill bits. Mean ultrasonic fragmentation power was about 8 Watts. Statistical studies using tenacious porcine cranium yielded mean power levels of about 4.5 Watts to 11 Watts and mean temperature of less than 41.1 °C. Excessively loading the tip yielded momentary higher power; however, mean thermal rise was less than 8 °C with bone removal starting at near body temperature of about 37 °C. Precision bone removal and thermal management were possible with conditions tested for ultrasonic bone aspiration.

  14. Field tests of a vertical-fluted-tube condenser in the prototype power plant at the Raft River Geothermal Test Site

    SciTech Connect

    Murphy, R.W.

    1983-04-01

    A vertical-fluted-tube condenser was designed, fabricated, and tested with isobutane as the shell-side working fluid in a binary prototype power plant at the Raft River Geothermal Test Site. After shakedown and contamination removal operations were completed, the four-pass water-cooled unit (with 102 outside-fluted Admiralty tubes) achieved performance predictions while operating with the plant surface evaporator on-line. A sample comparison shows that use of this enhanced condenser concept offers the potential for a reduction of about 65% from the size suggested by corresponding designs using conventional horizontal-smooth-tube concepts. Subsequent substitution of a direct-contact evaporator for the surface evaporator brought drastic reductions in system performance, the apparent consequence of high concentrations of noncondensible gases introduced by the brine/working-fluid interaction.

  15. Additional ECR heating of a radially inhomogeneous plasma via the absorption of satellite harmonics of the surface flute modes in a rippled magnetic field

    SciTech Connect

    Girka, V. O.; Girka, I. O.

    2006-12-15

    A theoretical study is made of the possibility of additional heating of a radially inhomogeneous plasma in confinement systems with a rippled magnetic field via the absorption of satellite harmonics of the surface flute modes with frequencies below the electron gyrofrequency in the local resonance region, {epsilon}{sub 1} (r{sub 1}) = [2{pi}c/({omega}L)]{sup 2}, where {epsilon}{sub 1} is the diagonal element of the plasma dielectric tensor in the hydrodynamic approximation, L is the period of a constant external rippled magnetic field, and the radical coordinate r{sub 1} determines the position of the local resonance. It is found that the high-frequency power absorbed near the local resonance is proportional to the square of the ripple amplitude of the external magnetic field. The mechanism proposed is shown to ensure the absorption of the energy of surface flute modes and, thereby, the heating of a radially inhomogeneous plasma.

  16. Living Bones, Strong Bones

    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...

  17. Bone Cancer

    MedlinePlus

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

  18. Bone Diseases

    MedlinePlus

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  19. Bone Metastasis

    MedlinePlus

    ... metastasis, surgeons can stabilize the bone using metal plates, screws and nails (orthopedic fixation). Orthopedic fixation can ... that can't be easily reinforced with metal plates or screws, such as pelvic bones and bones ...

  20. Sub-Alfvénic reduced full-f Kinetic MHD equations to study flute like instabilities

    NASA Astrophysics Data System (ADS)

    Sengupta, W.; Hassam, A.; Antonsen, T. M., Jr.

    2016-10-01

    We develop a set of reduced sub-Alfvénic fluid as well as kinetic MHD equations which are suitable for studying flute like instabilities in MHD ordering. The full-f kinetic equations are obtained by reducing Kulsrud's complete set of kinetic MHD system and includes trapped ion dynamics in a toroidal geometry. The nonlinear equations show the presence of Mercier modes, electromagnetic effects, GAMs and Rosenbluth-Hinton zero frequency zonal flows. Linear stability based on our equations shall be compared to the well known Kruskal-Oberman Kinetic MHD stability criteria. In the supersonic limit, for large q, our system can be shown to be equivalent to CGL double adiabatic theory. In the marginal stability limit, we shall discuss trapped particle stabilization of interchange modes. Comparison will also be made to the sub-Alfvénic reduced MHD fluid equations in a large aspect ratio tokamak. We shall show that the trapped particle effects in kinetic theory can be treated as a boundary layer of width the square root of the inverse aspect ratio in phase space. Work supported by DOE.

  1. Time-domain simulation of flute-like instruments: comparison of jet-drive and discrete-vortex models.

    PubMed

    Auvray, Roman; Ernoult, Augustin; Fabre, Benoît; Lagrée, Pierre-Yves

    2014-07-01

    This paper presents two models of sound production in flute-like instruments that allow time-domain simulations. The models are based on different descriptions of the jet flow within the window of the instrument. The jet-drive model depicts the jet by its transverse perturbation that interacts with the labium to produce sound. The discrete-vortex model depicts the jet as two independent shear layers along which vortices are convected and interact with the acoustic field within the window. The limit of validity between both models is usually discussed according to the aspect ratio of the jet W/h, with W the window length and h the flue channel height. The present simulations, compared with experimental data gathered on a recorder, allow to extend the aspect ratio criterion to the notion of dynamic aspect ratio defined as λ/h where λ is the hydrodynamic wavelength that now accounts for geometrical properties, such as W/h, as well as for dynamic properties, such as the Strouhal number. The two models are found to be applicable over neighboring values of geometry and blowing pressure.

  2. Bone and bone turnover.

    PubMed

    Crofton, Patricia M

    2009-01-01

    Children with cancer are exposed to multiple influences that may adversely affect bone health. Some treatments have direct deleterious effects on bone whilst others may have indirect effects mediated through various endocrine abnormalities. Most clinical outcome studies have concentrated on survivors of acute lymphoblastic leukaemia (ALL). There is now good evidence that earlier treatment protocols that included cranial irradiation with doses of 24 Gy or greater may result in growth hormone deficiency and low bone mineral density (BMD) in the lumbar spine and femoral neck. Under current protocols, BMD decreases during intensive chemotherapy and fracture risk increases. Although total body BMD may eventually return to normal after completion of chemotherapy, lumbar spine trabecular BMD may remain low for many years. The implications for long-term fracture risk are unknown. Risk factors for low BMD include high dose methotrexate, higher cumulative doses of glucocorticoids, male gender and low physical activity. BMD outcome in non-ALL childhood cancers has been less well studied but there is evidence that survivors of childhood brain or bone tumours, and survivors of bone marrow transplants for childhood malignancy, all have a high risk of long-term osteopenia. Long-term follow-up is required, with appropriate treatment of any endocrine abnormalities identified.

  3. Bone marrow aspiration

    MedlinePlus

    Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

  4. 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 (σ) 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 σ/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.

  5. Influence of Non-MHD Flutes on the Efficiency of Energy Transfer from the Laser-Produced, ICF and Space Exploding Plasmas to Magnetic Field

    SciTech Connect

    Zakharov, Yuri P.; Antonov, Vladimir M.; Boyarintsev, Eduard L.; Melekhov, Alexandr V.; Posukh, Vitaliy G.; Shaikhislamov, Ildar F.; Nakashima, Hideki; Vchivkov, Konstantin V

    2005-01-15

    The results of <> experiment with quasispherical Laser-produced Plasma Clouds (LPC) expanding into strong (B{sub 0} {approx}10 kG) and uniform magnetic field at KI-1 facility of ILP are presented. Main characteristics and the influence of non-MHD flute instability onto effectiveness of plasma-field interaction were studied especially for the purpose of plasma confinement and the direct conversion of its kinetic energy into magnetic and electric ones (of pick-up coils). A new model of enhanced field penetration into plasma due to Hall-effect in its flutes and under conditions of finite ion Larmor radius is discussed. The data obtained on the current generation by LPC in short-circuited surrounding coils (with total conversion efficiency up to {approx}10%) are compared with the models of ILP and last results of relevant 3D/PIC calculations done at KU. All these results show the opportunities of LPC-experiments to simulate both space exploding plasmas (AMPTE) and MHD-effects of ICF micro-explosions in planned NIF experiments for study Laser Fusion Rocket like a VISTA.

  6. Bone Scan

    MedlinePlus

    ... Mayo Clinic Staff A bone scan is a nuclear imaging test that helps diagnose and track several ... you're nursing. A bone scan is a nuclear imaging procedure. In nuclear imaging, tiny amounts of ...

  7. Bone grafts.

    PubMed

    Hubble, Matthew J W

    2002-09-01

    Bone grafts are used in musculoskeletal surgery to restore structural integrity and enhance osteogenic potential. The demand for bone graft for skeletal reconstruction in bone tumor, revision arthroplasty, and trauma surgery, couple with recent advances in understanding and application of the biology of bone transplantation, has resulted in an exponential increase in the number of bone-grafting procedures performed over the last decade. It is estimated that 1.5 million bone-grafting procedures are currently performed worldwide each year, compared to a fraction of that number 20 years ago. Major developments also have resulted in the harvesting, storage, and use of bone grafts and production of graft derivatives, substitutes, and bone-inducing agents.

  8. Bone cement

    PubMed Central

    Vaishya, Raju; Chauhan, Mayank; Vaish, Abhishek

    2013-01-01

    The knowledge about the bone cement is of paramount importance to all Orthopaedic surgeons. Although the bone cement had been the gold standard in the field of joint replacement surgery, its use has somewhat decreased because of the advent of press-fit implants which encourages bone in growth. The shortcomings, side effects and toxicity of the bone cement are being addressed recently. More research is needed and continues in the field of nanoparticle additives, enhanced bone–cement interface etc. PMID:26403875

  9. Bone Analyzer

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The danger of disuse osteoporosis under weightless condition in space led to extensive research into measurements of bone stiffness and mass by the Biomedical Research Division of Ames and Stanford University. Through its Technology Utilization Program, NASA funded an advanced SOBSA, a microprocessor-controlled bone probe system. SOBSA determines bone stiffness by measuring responses to an electromagnetic shaker. With this information, a physician can identify bone disease, measure deterioration and prescribe necessary therapy. The system is now undergoing further testing.

  10. Bone Infections

    MedlinePlus

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

  11. The Comparison of the Effect of Block Flute Accompanied Song Teaching with Multi-Sound Notation and Vocalization Program Accompanied Song Teaching on the Success of Students' Song Learning Behavior

    ERIC Educational Resources Information Center

    Saktanli, S. Cem

    2011-01-01

    This experimental study was done to see if using computer supported notation and vocalization program for teaching songs instead of using block flute accompanied song teaching has any significant effect on students' singing behavior. The study group is composed of the 5th, 6th and 7th graders of 2008-2009 educational term in T.O.K.I. Yahya Kemal…

  12. Bone poroelasticity.

    PubMed

    Cowin, S C

    1999-03-01

    Poroelasticity is a well-developed theory for the interaction of fluid and solid phases of a fluid-saturated porous medium. It is widely used in geomechanics and has been applied to bone by many authors in the last 30 years. The purpose of this work is, first, to review the literature related to the application of poroelasticity to the interstitial bone fluid and, second, to describe the specific physical and modeling considerations that establish poroelasticity as an effective and useful model for deformation-driven bone fluid movement in bone tissue. The application of poroelasticity to bone differs from its application to soft tissues in two important ways. First, the deformations of bone are small while those of soft tissues are generally large. Second, the bulk modulus of the mineralized bone matrix is about six times stiffer than that of the fluid in the pores while the bulk moduli of the soft tissue matrix and the pore water are almost the same. Poroelasticity and electrokinetics can be used to explain strain-generated potentials in wet bone. It is noted that strain-generated potentials can be used as an effective tool in the experimental study of local bone fluid flow, and that the knowledge of this technique will contribute to the answers of a number of questions concerning bone mineralization, osteocyte nutrition and the bone mechanosensory system.

  13. Heat accumulation during sequential cortical bone drilling.

    PubMed

    Palmisano, Andrew C; Tai, Bruce L; Belmont, Barry; Irwin, Todd A; Shih, Albert; Holmes, James R

    2016-03-01

    Significant research exists regarding heat production during single-hole bone drilling. No published data exist regarding repetitive sequential drilling. This study elucidates the phenomenon of heat accumulation for sequential drilling with both Kirschner wires (K wires) and standard two-flute twist drills. It was hypothesized that cumulative heat would result in a higher temperature with each subsequent drill pass. Nine holes in a 3 × 3 array were drilled sequentially on moistened cadaveric tibia bone kept at body temperature (about 37 °C). Four thermocouples were placed at the center of four adjacent holes and 2 mm below the surface. A battery-driven hand drill guided by a servo-controlled motion system was used. Six samples were drilled with each tool (2.0 mm K wire and 2.0 and 2.5 mm standard drills). K wire drilling increased temperature from 5 °C at the first hole to 20 °C at holes 6 through 9. A similar trend was found in standard drills with less significant increments. The maximum temperatures of both tools increased from <0.5 °C to nearly 13 °C. The difference between drill sizes was found to be insignificant (P > 0.05). In conclusion, heat accumulated during sequential drilling, with size difference being insignificant. K wire produced more heat than its twist-drill counterparts. This study has demonstrated the heat accumulation phenomenon and its significant effect on temperature. Maximizing the drilling field and reducing the number of drill passes may decrease bone injury.

  14. Space Flute Duet

    NASA Video Gallery

    Harmony reaches new heights as NASA Astronaut Cady Coleman, circling Earth aboard the International Space Station, and musician Ian Anderson, founder of the rock band Jethro Tull, join together for...

  15. [Bone diseases].

    PubMed

    Uebelhart, Brigitte; Rizzoli, René

    2016-01-13

    Calcium intake shows a small impact on bone mineral density and fracture risk. Denosumab is a more potent inhibitor of bone resorption than zoledronate. Abaloparatide, PTHrP analog, increases bone mineral density and decreases fracture incidence. Teriparatide could be delivered via a transdermic device. Romosozumab and odanacatib improve calculated bone strength. Sequential or combined treatments with denosumab and teriparatide could be of interest, but not denosumab followed by teriparatide. Fibrous dysplasia, Paget disease and hypophosphatasia are updated, as well as atypical femoral fracture and osteonecrosis of the jaw.

  16. Bone cutting.

    PubMed

    Giraud, J Y; Villemin, S; Darmana, R; Cahuzac, J P; Autefage, A; Morucci, J P

    1991-02-01

    Bone cutting has always been a problem for surgeons because bone is a hard living material, and many osteotomes are still very crude tools. Technical improvement of these surgical tools has first been their motorization. Studies of the bone cutting process have indicated better features for conventional tools. Several non-conventional osteotomes, particularly ultrasonic osteotomes are described. Some studies on the possible use of lasers for bone cutting are also reported. Use of a pressurised water jet is also briefly examined. Despite their advantages, non-conventional tools still require improvement if they are to be used by surgeons.

  17. Development and Reproduction of Brethesiella cf. abnormicornis (Girault) (Hymenoptera: Encyrtidae), a Parasitoid of the Colombian Fluted Scale, Crypticerya multicicatrices Kondo & Unruh (Hemiptera: Monophlebidae).

    PubMed

    Montealegre, X; Sotelo, P; Kondo, T

    2016-04-01

    Studies on the development and reproduction of Brethesiella cf. abnormicornis (Girault) (Hymenoptera: Encyrtidae), a parasitoid of the Colombian fluted scale, Crypticerya multicicatrices Kondo & Unruh (Hemiptera: Monophlebidae), were conducted under laboratory conditions. The duration of the life cycle, adult longevity, fecundity, and population parameters were determined. The parasitoid takes about 29 d to complete a single generation (from egg to adult). In addition, population parameters show that one female wasp is replaced by nearly 32 females, with a female-to-male sex ratio of 2:1. Population parameters estimated in this study can be considered baseline information for a mass-rearing protocol. This is the first detailed study of the biology of a species of Brethesiella, where the duration of all larval stages of the parasitoid is determined, being an important contribution for further biological studies of endoparasitoids.

  18. Characterization of chlorinated solvent contamination in limestone using innovative FLUTe® technologies in combination with other methods in a line of evidence approach

    NASA Astrophysics Data System (ADS)

    Broholm, Mette M.; Janniche, Gry S.; Mosthaf, Klaus; Fjordbøge, Annika S.; Binning, Philip J.; Christensen, Anders G.; Grosen, Bernt; Jørgensen, Torben H.; Keller, Carl; Wealthall, Gary; Kerrn-Jespersen, Henriette

    2016-06-01

    Characterization of dense non-aqueous phase liquid (DNAPL) source zones in limestone aquifers/bedrock is essential to develop accurate site-specific conceptual models and perform risk assessment. Here innovative field methods were combined to improve determination of source zone architecture, hydrogeology and contaminant distribution. The FACT™ is a new technology and it was applied and tested at a contaminated site with a limestone aquifer, together with a number of existing methods including wire-line coring with core subsampling, FLUTe® transmissivity profiling and multilevel water sampling. Laboratory sorption studies were combined with a model of contaminant uptake on the FACT™ for data interpretation. Limestone aquifers were found particularly difficult to sample with existing methods because of core loss, particularly from soft zones in contact with chert beds. Water FLUTe™ multilevel groundwater sampling (under two flow conditions) and FACT™ sampling and analysis combined with FLUTe® transmissivity profiling and modeling were used to provide a line of evidence for the presence of DNAPL, dissolved and sorbed phase contamination in the limestone fractures and matrix. The combined methods were able to provide detailed vertical profiles of DNAPL and contaminant distributions, water flows and fracture zones in the aquifer and are therefore a powerful tool for site investigation. For the limestone aquifer the results indicate horizontal spreading in the upper crushed zone, vertical migration through fractures in the bryozoan limestone down to about 16-18 m depth with some horizontal migrations along horizontal fractures within the limestone. Documentation of the DNAPL source in the limestone aquifer was significantly improved by the use of FACT™ and Water FLUTe™ data.

  19. Characterization of chlorinated solvent contamination in limestone using innovative FLUTe® technologies in combination with other methods in a line of evidence approach.

    PubMed

    Broholm, Mette M; Janniche, Gry S; Mosthaf, Klaus; Fjordbøge, Annika S; Binning, Philip J; Christensen, Anders G; Grosen, Bernt; Jørgensen, Torben H; Keller, Carl; Wealthall, Gary; Kerrn-Jespersen, Henriette

    2016-06-01

    Characterization of dense non-aqueous phase liquid (DNAPL) source zones in limestone aquifers/bedrock is essential to develop accurate site-specific conceptual models and perform risk assessment. Here innovative field methods were combined to improve determination of source zone architecture, hydrogeology and contaminant distribution. The FACT™ is a new technology and it was applied and tested at a contaminated site with a limestone aquifer, together with a number of existing methods including wire-line coring with core subsampling, FLUTe® transmissivity profiling and multilevel water sampling. Laboratory sorption studies were combined with a model of contaminant uptake on the FACT™ for data interpretation. Limestone aquifers were found particularly difficult to sample with existing methods because of core loss, particularly from soft zones in contact with chert beds. Water FLUTe™ multilevel groundwater sampling (under two flow conditions) and FACT™ sampling and analysis combined with FLUTe® transmissivity profiling and modeling were used to provide a line of evidence for the presence of DNAPL, dissolved and sorbed phase contamination in the limestone fractures and matrix. The combined methods were able to provide detailed vertical profiles of DNAPL and contaminant distributions, water flows and fracture zones in the aquifer and are therefore a powerful tool for site investigation. For the limestone aquifer the results indicate horizontal spreading in the upper crushed zone, vertical migration through fractures in the bryozoan limestone down to about 16-18m depth with some horizontal migrations along horizontal fractures within the limestone. Documentation of the DNAPL source in the limestone aquifer was significantly improved by the use of FACT™ and Water FLUTe™ data.

  20. Your Bones

    MedlinePlus

    ... shoulder blade or scapula (say: SKA-pyuh-luh), a large triangular bone on the upper back corner of each side of the ribcage. The arm is made up of three bones: the humerus (say: HYOO-muh-rus), which is above your elbow, and the radius (say: RAY-dee-us) and ulna (say: UL- ...

  1. 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)

  2. Paget's Disease of Bone

    MedlinePlus

    ... page please turn Javascript on. Paget's Disease of Bone What is Paget's Disease of Bone? Click for more information Enlarged and Misshapen Bones Paget's disease of bone causes affected bones to ...

  3. Bone densitometry.

    PubMed

    Chun, Kwang J

    2011-05-01

    Conventional radiographic methods allow physicians to visualize bone structure. However, they do not offer information on the bone mineral density (BMD), which can facilitate early diagnosis and treatment of osteoporosis. Bone densitometry, by contrast, helps to detect bone mineral loss at an early stage because it provides accurate quantitative measurement of BMD. With an emphasis on quantification, shorter scanning time and precision, scientists have been developing BMD measurement devices that use absorption technique. They first developed single-energy absorptiometry (single-photon absorptiometry) by using I-125, which could measure BMD of peripheral bones. Single-photon absorptiometry was replaced by dual-energy absorptiometry (dual photon absorptiometry [DPA]) that used gadolinium-153. DPA had greater accuracy in measuring the BMD of central skeletal bones. Single-energy x-ray absorptiometry was also developed but it had limitations in measuring central skeletal BMD. In the mid-1980s, dual-energy x-ray absorptiometry (DXA) was introduced and widely accepted for the early detection, treatment, and follow-up study of osteoporosis. There are several reasons for the popularity. DXA can measure BMD of posteroanterior spine and hip in a much shorter time than DPA while being capable of measuring BMD of peripheral bones. Other advantages include very low radiation doses to the patients, high image resolution, precision, and stable calibration of the instruments. In recent years, DXA has also been applied to lateral spine for the density of trabecular bone, to the whole body for the measurement of total body bone density and for the body composition, and to the spine for the vertebral fracture assessment. Still, posteroanterior spine and hip scans remain the most common applications of DXA because data on the normal range of BMD of the skeletal sites for different age, sex, and ethnic groups are compiled and made available with the devices, which gives the physician

  4. Interpreting Bones.

    ERIC Educational Resources Information Center

    Weymouth, Patricia P.

    1986-01-01

    Describes an activity which introduces students to the nature and challenges of paleoanthropology. In the exercise, students identify diagrammed bones and make interpretations about the creature. Presents questions and tasks employed in the lesson. (ML)

  5. Bone and bone marrow: the same organ.

    PubMed

    Del Fattore, Andrea; Capannolo, Marta; Rucci, Nadia

    2010-11-01

    Interplays between bone and bone marrow are not limited to merely anatomic and histological connections, but include a tight functional correlation. Bone marrow resides within the medullary cavity of the bones and the process of hematopoiesis is regulated, at least in part, by bone cells. Moreover, osteoclasts and osteoblasts derive from precursors of hematopoietic and mesenchymal origin, respectively, both residing within the bone marrow. Alterations in one of these components typically cause impairment in the other, so diseases of the bone marrow compartment often affect the bone and vice versa. All these findings could make us to speculate that bone and bone marrow are not two separate districts, but can be considered as the two elements of the same unique functional unit, the bone-bone marrow organ. Here we will describe histological and functional interplays between bone and bone marrow, and will illustrate some diseases in which this tight correlation is evident.

  6. Gallium-assisted growth of flute-like MgO nanotubes, Ga2O3-filled MgO nanotubes, and MgO/Ga2O3 co-axial nanotubes.

    PubMed

    Jie, Jiansheng; Wu, Chunyan; Yu, Yongqiang; Wang, Li; Hu, Zhizhong

    2009-02-18

    Flute-like MgO nanotubes were successfully synthesized via a simple thermal evaporation method by using Mg(3)N(2) and Ga(2)O(3) as the source materials. The nanotubes are single-crystal cubic MgO, and have [100] orientation. In contrast to conventional nanotubes with intact walls, the flute-like MgO nanotubes possess a unique porous structure. On the nanotubes there are series of holes aligned along the nanotube length with approximate equidistance. Ga(2)O(3)-filled MgO nanotubes and MgO/Ga(2)O(3) co-axial nanotubes were also found in the product. Further investigation confirms that the inner beta-Ga(2)O(3) has an epitaxial growth relation with the outer MgO nanotube due to their perfect lattice matching. A gallium-assisted growth mechanism was proposed to interpret the growth of the flute-like MgO nanotubes. The thermal expansion and evaporation of the filled liquid gallium in MgO nanotubes are likely responsible for the formation of the hole structures on the side walls.

  7. Bone Densitometry (Bone Density Scan)

    MedlinePlus

    ... and display the bone density measurements on a computer monitor. top of page How is the procedure performed? ... passed over the area, generating images on a computer monitor. You must hold very still and may be ...

  8. Bone marrow transplant

    MedlinePlus

    Transplant - bone marrow; Stem cell transplant; Hematopoietic stem cell transplant; Reduced intensity nonmyeloablative transplant; Mini transplant; Allogenic bone marrow transplant; Autologous bone marrow transplant; ...

  9. Effect of femoral canal shape on mechanical stress distribution and adaptive bone remodelling around a cementless tapered-wedge stem

    PubMed Central

    Oba, M.; Kobayashi, N.; Ike, H.; Tezuka, T.; Saito, T.

    2016-01-01

    Objectives In total hip arthroplasty (THA), the cementless, tapered-wedge stem design contributes to achieving initial stability and providing optimal load transfer in the proximal femur. However, loading conditions on the femur following THA are also influenced by femoral structure. Therefore, we determined the effects of tapered-wedge stems on the load distribution of the femur using subject-specific finite element models of femurs with various canal shapes. Patients and Methods We studied 20 femurs, including seven champagne flute-type femurs, five stovepipe-type femurs, and eight intermediate-type femurs, in patients who had undergone cementless THA using the Accolade TMZF stem at our institution. Subject–specific finite element (FE) models of pre- and post-operative femurs with stems were constructed and used to perform FE analyses (FEAs) to simulate single-leg stance. FEA predictions were compared with changes in bone mineral density (BMD) measured for each patient during the first post-operative year. Results Stovepipe models implanted with large-size stems had significantly lower equivalent stress on the proximal-medial area of the femur compared with champagne-flute and intermediate models, with a significant loss of BMD in the corresponding area at one year post-operatively. Conclusions The stovepipe femurs required a large-size stem to obtain an optimal fit of the stem. The FEA result and post-operative BMD change of the femur suggest that the combination of a large-size Accolade TMZF stem and stovepipe femur may be associated with proximal stress shielding. Cite this article: M. Oba, Y. Inaba, N. Kobayashi, H. Ike, T. Tezuka, T. Saito. Effect of femoral canal shape on mechanical stress distribution and adaptive bone remodelling around a cementless tapered-wedge stem. Bone Joint Res 2016;5:362–369. DOI: 10.1302/2046-3758.59.2000525. PMID:27601435

  10. Broken Bones (For Parents)

    MedlinePlus

    ... Feeding Your 1- to 2-Year-Old Broken Bones KidsHealth > For Parents > Broken Bones Print A A ... bone fragments in place. When Will a Broken Bone Heal? Fractures heal at different rates, depending upon ...

  11. Bone lesion biopsy

    MedlinePlus

    Bone biopsy; Biopsy - bone ... the cut, then pushed and twisted into the bone. Once the sample is obtained, the needle is ... sample is sent to a lab for examination. Bone biopsy may also be done under general anesthesia ...

  12. Bone biopsy (image)

    MedlinePlus

    A bone biopsy is performed by making a small incision into the skin. A biopsy needle retrieves a sample of bone and it ... examination. The most common reasons for bone lesion biopsy are to distinguish between benign and malignant bone ...

  13. Surgery for Bone Cancer

    MedlinePlus

    ... amputation. This is called limb-salvage or limb-sparing surgery . In going over treatment options, it is ... 2016 Treating Bone Cancer Surgery for Bone Cancer Radiation Therapy for Bone Cancer Chemotherapy for Bone Cancer Targeted ...

  14. Facts about Broken Bones

    MedlinePlus

    ... Room? What Happens in the Operating Room? Broken Bones KidsHealth > For Kids > Broken Bones Print A A ... sticking through the skin . What Happens When a Bone Breaks? It hurts to break a bone! It's ...

  15. Bone image segmentation.

    PubMed

    Liu, Z Q; Liew, H L; Clement, J G; Thomas, C D

    1999-05-01

    Characteristics of microscopic structures in bone cross sections carry essential clues in age determination in forensic science and in the study of age-related bone developments and bone diseases. Analysis of bone cross sections represents a major area of research in bone biology. However, traditional approaches in bone biology have relied primarily on manual processes with very limited number of bone samples. As a consequence, it is difficult to reach reliable and consistent conclusions. In this paper we present an image processing system that uses microstructural and relational knowledge present in the bone cross section for bone image segmentation. This system automates the bone image analysis process and is able to produce reliable results based on quantitative measurements from a large number of bone images. As a result, using large databases of bone images to study the correlation between bone structural features and age-related bone developments becomes feasible.

  16. Biomechanical and histologic basis of osseodensification drilling for endosteal implant placement in low density bone. An experimental study in sheep.

    PubMed

    Lahens, Bradley; Neiva, Rodrigo; Tovar, Nick; Alifarag, Adham M; Jimbo, Ryo; Bonfante, Estevam A; Bowers, Michelle M; Cuppini, Marla; Freitas, Helora; Witek, Lukasz; Coelho, Paulo G

    2016-10-01

    A bone drilling concept, namely osseodensification, has been introduced for the placement of endosteal implants to increase primary stability through densification of the osteotomy walls. This study investigated the effect of osseodensification on the initial stability and early osseointegration of conical and parallel walled endosteal implants in low density bone. Five male sheep were used. Three implants were inserted in the ilium, bilaterally, totaling 30 implants (n=15 conical, and n=15 parallel). Each animal received 3 implants of each type, inserted into bone sites prepared as follows: (i) regular-drilling (R: 2mm pilot, 3.2mm, and 3.8mm twist drills), (ii) clockwise osseodensification (CW), and (iii) counterclockwise (CCW) osseodensification drilling with Densah Bur (Versah, Jackson, MI, USA): 2.0mm pilot, 2.8mm, and 3.8mm multi-fluted burs. Insertion torque as a function of implant type and drilling technique, revealed higher values for osseodensification relative to R-drilling, regardless of implant macrogeometry. A significantly higher bone-to-implant contact (BIC) for both osseodensification techniques (p<0.05) was observed compared to R-drilling. There was no statistical difference in BIC as a function of implant type (p=0.58), nor in bone-area-fraction occupancy (BAFO) as a function of drilling technique (p=0.22), but there were higher levels of BAFO for parallel than conic implants (p=0.001). Six weeks after surgery, new bone formation along with remodeling sites was observed for all groups. Bone chips in proximity with the implants were seldom observed in the R-drilling group, but commonly observed in the CW, and more frequently under the CCW osseodensification technique. In low-density bone, endosteal implants present higher insertion torque levels when placed in osseodensification drilling sites, with no osseointegration impairment compared to standard subtractive drilling methods.

  17. Bone Density Test

    MedlinePlus

    Tests and Procedures Bone density test By Mayo Clinic Staff A bone density test determines if you have osteoporosis — a disease that causes bones to ... your bones could be quite weak. A bone density test enhances the accuracy of calculating your risk ...

  18. Proximal Tibial Bone Graft

    MedlinePlus

    ... All Site Content AOFAS / FootCareMD / Treatments Proximal Tibial Bone Graft Page Content What is a bone graft? Bone grafts may be needed for various ... the proximal tibia. What is a proximal tibial bone graft? Proximal tibial bone graft (PTBG) is a ...

  19. Bone scan in metabolic bone diseases. Review.

    PubMed

    Abdelrazek, Saeid; Szumowski, Piotr; Rogowski, Franciszek; Kociura-Sawicka, Agnieszka; Mojsak, Małgorzata; Szorc, Małgorzata

    2012-08-25

    Metabolic bone disease encompasses a number of disorders that tend to present a generalized involvement of the whole skeleton. The disorders are mostly related to increased bone turnover and increased uptake of radiolabelled diphosphonate. Skeletal uptake of 99mTc-labelled diphosphonate depends primarily upon osteoblastic activity, and to a lesser extent, skeletal vascularity. A bone scan image therefore presents a functional display of total skeletal metabolism and has valuable role to play in the assessment of patients with metabolic bone disorders. However, the bone scan appearances in metabolic bone disease are often non-specific, and their recognition depends on increased tracer uptake throughout the whole skeleton. It is the presence of local lesions, as in metastatic disease, that makes a bone scan appearance obviously abnormal. In the early stages, there will be difficulty in evaluating the bone scans from many patients with metabolic bone disease. However, in the more severe cases scan appearances can be quite striking and virtually diagnostic.

  20. Bone scan appearances following bone and bone marrow biopsy

    SciTech Connect

    McKillop, J.H.; Maharaj, D.; Boyce, B.F.; Fogelman, I.

    1984-01-01

    Bone marrow and bone biopsies are performed not infrequently in patients referred for bone scans and represent a potential cause of a ''false positive'' focal abnormality on the bone scan. The authors have therefore examined the scan appearances in a series of patients who had undergone either sternal marrow biopsy, (Salah needle, diameter 1.2 mm) trephine iliac crest marrow biopsy (Jamshidi 11 gauge needle, diameter 3.5 mm) or a transiliac bone biopsy (needle diameter 8 mm). Of 18 patients studied 1 to 45 days after sternal marrow 17 had normal scan appearances at the biopsy site and 1 had a possible abnormality. None of 9 patients studied 4 to 19 days after trephine iliac crest marrow biopsy had a hot spot at the biopsy site. A focal scan abnormality was present at the biopsy site in 9/11 patients studied 5 to 59 days after a trans iliac bone biopsy. No resultant scan abnormality was seen in 4 patients imaged within 3 days of the bone biopsy or in 3 patients imaged 79 to 138 days after the procedure. Bone marrow biopsy of the sternum or iliac crest does not usually cause bone scan abnormalities. A focal abnormality at the biopsy site is common in patients imaged 5 days to 2 months after bone biopsy. The gauge of the needle employed in the biopsy and thus the degree of bone trauma inflicted, is likely to be main factor determining the appearance of bone scan abnormalities at the biopsy site.

  1. Bone development

    PubMed Central

    Berendsen, Agnes D.; Olsen, Bjorn R.

    2015-01-01

    The development of the vertebrate skeleton reflects its evolutionary history. Cartilage formation came before biomineralization and a head skeleton evolved before the formation of axial and appendicular skeletal structures. This review describes the processes that result in endochondral and intramembranous ossification, the important roles of growth and transcription factors, and the consequences of mutations in some of the genes involved. Following a summary of the origin of cartilage, muscle, and tendon cell lineages in the axial skeleton, we discuss the role of muscle forces in the formation of skeletal architecture and assembly of musculoskeletal functional units. Finally, ontogenetic patterning of bones in response to mechanical loading is reviewed. PMID:26453494

  2. Menopause and Bone Loss

    MedlinePlus

    ... You reach your highest bone mass (size and density) at about age 30. Then, sometime between age ... your bones, your doctor may do a bone density test (DEXA scan). This test gives exact measurements ...

  3. Bone density scan (image)

    MedlinePlus

    ... bone the higher the risk of fractures. A bone scan, along with a patient's medical history, is a ... and whether any preventative treatment is needed. A bone density scan has the advantage of being painless and exposing ...

  4. Dietary restrictions, bone density, and bone quality.

    PubMed

    Huang, Tsang-hai; Ables, Gene P

    2016-01-01

    Caloric restriction (CR), protein restriction (PR), and specific amino acid restriction (e.g., methionine restriction (MR)) are different dietary interventions that have been confirmed with regard to their comprehensive benefits to metabolism and health. Based on bone densitometric measurements, weight loss induced by dietary restriction is known to be accompanied by reduced areal bone mineral density, bone mass, and/or bone size, and it is considered harmful to bone health. However, because of technological advancements in bone densitometric instruments (e.g., high-resolution X-ray tomography), dietary restrictions have been found to cause a reduction in bone mass/size rather than volumetric bone mineral density. Furthermore, when considering bone quality, bone health consists of diverse indices that cannot be fully represented by densitometric measurements alone. Indeed, there is evidence that moderate dietary restrictions do not impair intrinsic bone material properties, despite the reduction in whole-bone strength because of a smaller bone size. In the present review, we integrate research evidence from traditional densitometric measurements, metabolic status assays (e.g., energy metabolism, oxidative stresses, and inflammatory responses), and biomaterial analyses to provide revised conclusions regarding the effects of CR, PR, and MR on the skeleton.

  5. Bone marrow transplant - discharge

    MedlinePlus

    Transplant - bone marrow - discharge; Stem cell transplant - discharge; Hematopoietic stem cell transplant - discharge; Reduced intensity; Non-myeloablative transplant - discharge; Mini transplant - discharge; Allogenic bone marrow transplant - ...

  6. Factors affecting bone growth.

    PubMed

    Gkiatas, Ioannis; Lykissas, Marios; Kostas-Agnantis, Ioannis; Korompilias, Anastasios; Batistatou, Anna; Beris, Alexandros

    2015-02-01

    Bone growth and development are products of the complex interactions of genetic and environmental factors. Longitudinal bone growth depends on the growth plate. The growth plate has 5 different zones-each with a different functional role-and is the final target organ for longitudinal growth. Bone length is affected by several systemic, local, and mechanical factors. All these regulation systems control the final length of bones in a complicated way. Despite its significance to bone stability, bone growth in width has not been studied as extensively as longitudinal bone growth. Bone growth in width is also controlled by genetic factors, but mechanical loading regulates periosteal apposition. In this article, we review the most recent data regarding bone growth from the embryonic age and analyze the factors that control bone growth. An understanding of this complex system is important in identifying metabolic and developmental bone diseases and fracture risk.

  7. Bone scan appearances following biopsy of bone and bone marrow

    SciTech Connect

    McKillop, J.H.; Maharaj, D.; Boyce, B.F.; Fogelman, I.

    1984-10-01

    The influence of sternal marrow aspiration, iliac crest marrow aspiration, and iliac crest bone biopsy on bone scan appearances was examined. Eighteen patients were scanned a mean of 9.9 days after sternal marrow aspiration with a Salah needle. Bone scans obtained in 9 patients a mean of 10 days aftr iliac crest trephine marrow biopsy with a Jamshidi needle showed no abnormality at the biopsy site. In 18 patients with metabolic bone disease who had undergone iliac crest bone biopsy with an 8 mm needle, a scan abnormality due to the biopsy was usually present when the interval between the biopsy and the scan was 5 days to 2 months. Patients who were scanned within 3 days of iliac crest bone biopsy or more than 2 months after biopsy had normal scan appearance at the biopsy site.

  8. Bone Marrow Diseases

    MedlinePlus

    Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains stem cells. The stem cells can ... the platelets that help with blood clotting. With bone marrow disease, there are problems with the stem ...

  9. Metastatic Bone Disease

    MedlinePlus

    ... secrete factors that interact with the naturally occurring cells in the bone and cause bone destruction, new bone formation, or both. Effects Because MBD weakens the affected bones, people with the disease are prone to fractures. Broken ...

  10. Bone Health and Osteoporosis.

    PubMed

    Lupsa, Beatrice C; Insogna, Karl

    2015-09-01

    Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue leading to decreased bone strength and an increased risk of low-energy fractures. Central dual-energy X-ray absorptiometry measurements are the gold standard for determining bone mineral density. Bone loss is an inevitable consequence of the decrease in estrogen levels during and following menopause, but additional risk factors for bone loss can also contribute to osteoporosis in older women. A well-balanced diet, exercise, and smoking cessation are key to maintaining bone health as women age. Pharmacologic agents should be recommended in patients at high risk for fracture.

  11. [Imaging of bone metastases].

    PubMed

    Amoretti, Nicolas; Thariat, Juliette; Nouri, Yasir; Foti, Pauline; Hericord, Olivier; Stolear, Sandy; Coco, Lucia; Hauger, Olivier; Huwart, Laurent; Boileau, Pascal

    2013-11-01

    Bone metastases are detected at initial diagnosis of cancer in 25% of cases and bone metastases are common in the course of a majority of cancer types. The spine and proximal long bones are the most affected sites. Knowledge of the basic radiological semiology is important to make the proper diagnosis of metastasis(s) bone(s), especially in situations in which the clinical context is not suggestive of metastases (such as cases where bone metastases are inaugural or cases of peripheral solitary metastasis). Tumor aggressiveness can be assessed at the level of the cortical bone and periosteum. Lodwick criteria are useful for the diagnosis of malignancy and tumor aggressiveness at initial diagnosis on plain radiographs, which are very important in the context of bone metastases. A CT scanner is required to confirm the malignancy of a bone lesion. MRI is complementary to the scanner including for the assessment of bone marrow involvement and tumor extensions.

  12. [Bone involvement in endocrinopathies].

    PubMed

    Ribot, C; Trémollières, F; Pouillès, J M

    1994-06-04

    Progress in bone densitometry, particularly biphotonic absoptiometry, has made it possible to better identify the effects of endocrinopathies on bone. Both cortical and trabecular bone structures can be evaluated quantitatively and topographically revealing important information on the pathophysiology of bone loss. Sex hormones play a major role in the regulation of bone mineralization and hypogonadism, whatever the origin, can lead to deleterious effects. Bone loss is known to be significative in high performance female athletes with amenorrhoea; long-term consequences are not yet determined, but stress fractures have been reported in up to 50%. Other hypogonadisms leading to bone demineralization include anorexia nervosa, chronic intake of gonadotrophin releasing hormone analogues and anti-oestrogens, and hyperprolactinism. Hyperthyroidism leads to a negative calcium balance and demineralization with remodelling, predominantly in cortical bone. In hypothyroid states a 10% bone loss is observed in vertebrae. In both cases, bone densitometry should be performed in order to evaluate the effect of treatment. The deleterious effect of spontaneous or iatrogenic hypercortisism is well known, leading to spontaneous wedge fractures of the vertebrae due to predominating trabecular bone loss. The mechanism of action of corticosteroids on bone metabolism is complex, but the major effect is an inhibition of osteoblast maturation. Recovery may be possible, but no large long-term series have yet been reported. Hyperparathyroidism and acromegaly also affect bone mineralization. The information provided by bone densitometry is essential to properly manage patients with endocrinopathies affecting bone mineralization.

  13. Factors stimulating bone formation.

    PubMed

    Lind, M; Bünger, C

    2001-10-01

    The aim of this review is to describe major approaches for stimulating bone healing and to review other factors affecting bone healing. Spinal bone fusion after surgery is a demanding process requiring optimal conditions for clinical success. Bone formation and healing can be enhanced through various methods. Experimental studies have revealed an array of stimulative measures. These include biochemical stimulation by use of hormones and growth factors, physical stimulation through mechanical and electromagnetic measures, and bone grafting by use of bone tissue or bone substitutes. Newer biological techniques such as stem cell transplantation and gene therapy can also be used to stimulate bone healing. Apart from bone transplantation, clinical experience with the many stimulation modalities is limited. Possible areas for clinical use of these novel methods are discussed.

  14. Regulation of Bone Metabolism

    PubMed Central

    Shahi, Maryam; Peymani, Amir; Sahmani, Mehdi

    2017-01-01

    Bone is formed through the processes of endochondral and intramembranous ossification. In endochondral ossification primary mesenchymal cells differentiate to chondrocytes and then are progressively substituted by bone, while in intramembranous ossification mesenchymal stem cells (MSCs) differentiate directly into osteoblasts to form bone. The steps of osteogenic proliferation, differentiation, and bone homeostasis are controlled by various markers and signaling pathways. Bone needs to be remodeled to maintain integrity with osteoblasts, which are bone-forming cells, and osteoclasts, which are bone-degrading cells.In this review we considered the major factors and signaling pathways in bone formation; these include fibroblast growth factors (FGFs), bone morphogenetic proteins (BMPs), wingless-type (Wnt) genes, runt-related transcription factor 2 (RUNX2) and osteoblast-specific transcription factor (osterix or OSX). PMID:28367467

  15. 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

  16. [Microdestruction of the bone].

    PubMed

    Iankovskiĭ, V É

    2014-01-01

    The objective of the present study was the detection of microcracks in the compact bone tissue surrounding the fracture and in deformed bone undergoing subcritical loading. The portions of deformed bone tissue and terminal fragments of broken bones were obtained in the form of blocks longitudinally sawcut from the regions of primary and secondary bone rupture. A total of 300 such blocks were available for the examination. All portions of the deformed bone tissue and terminal fragments of broken bones showed up microcracks commensurate with the bone structures. They were actually hardened traces of deformation that preceded the fracture and reflected the volume of the destroyed bone tissue; moreover, in certain cases they allowed to identify the kind of the object that exerted the external action (either a blow or slow bending).

  17. Regulation of Bone Metabolism.

    PubMed

    Shahi, Maryam; Peymani, Amir; Sahmani, Mehdi

    2017-04-01

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

  18. Bone-immune cell crosstalk: bone diseases.

    PubMed

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

    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.

  19. Bone marrow culture

    MedlinePlus

    ... There may be some bleeding at the puncture site. More serious risks, such as serious bleeding or infection, are very rare. Alternative Names Culture - bone marrow Images Bone marrow aspiration References ...

  20. Bone fracture repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100077.htm Bone fracture repair - series—Indications To use the sharing features ... Go to slide 4 out of 4 Overview Fractures of the bones are classified in a number ...

  1. Smoking and Bone Health

    MedlinePlus

    ... Management Strategies Resources For Your Information Facts About Osteoporosis Osteoporosis is a condition in which bones weaken ... adopt new habits for healthy bones. Smoking and Osteoporosis Cigarette smoking was first identified as a risk ...

  2. Medicines and Bone Loss

    MedlinePlus

    ... studies also show that drinking a lot of alcohol might weaken bones. Questions to ask your doctor • Do any of my medicines cause bone loss? • Are there different medicines I can take? • Do I need a bone density test? • What should I do to protect my ...

  3. Temporal bone meningiomas.

    PubMed

    Hooper, R; Siu, K; Cousins, V

    1990-10-01

    Meningiomas should be considered in the differential diagnosis of space-occupying lesions of the temporal bone. Five cases of meningiomas of the temporal bone are described and the literature reviewed. These tumours may stimulate Schwannomas and glomus tumours in their presentation and radiological findings. The tumours were managed by combining standard neurosurgical approaches with temporal bone and skull base techniques.

  4. Method for fusing bone

    DOEpatents

    Mourant, Judith R.; Anderson, Gerhard D.; Bigio, Irving J.; Johnson, Tamara M.

    1996-01-01

    Method for fusing bone. The present invention is a method for joining hard tissue which includes chemically removing the mineral matrix from a thin layer of the surfaces to be joined, placing the two bones together, and heating the joint using electromagnetic radiation. The goal of the method is not to produce a full-strength weld of, for example, a cortical bone of the tibia, but rather to produce a weld of sufficient strength to hold the bone halves in registration while either external fixative devices are applied to stabilize the bone segments, or normal healing processes restore full strength to the tibia.

  5. Bone regeneration in dentistry

    PubMed Central

    Tonelli, Paolo; Duvina, Marco; Barbato, Luigi; Biondi, Eleonora; Nuti, Niccolò; 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

  6. Nanomaterials and bone regeneration

    PubMed Central

    Gong, Tao; Xie, Jing; Liao, Jinfeng; Zhang, Tao; Lin, Shiyu; Lin, Yunfeng

    2015-01-01

    The worldwide incidence of bone disorders and conditions has been increasing. Bone is a nanomaterials composed of organic (mainly collagen) and inorganic (mainly nano-hydroxyapatite) components, with a hierarchical structure ranging from nanoscale to macroscale. In consideration of the serious limitation in traditional therapies, nanomaterials provide some new strategy in bone regeneration. Nanostructured scaffolds provide a closer structural support approximation to native bone architecture for the cells and regulate cell proliferation, differentiation, and migration, which results in the formation of functional tissues. In this article, we focused on reviewing the classification and design of nanostructured materials and nanocarrier materials for bone regeneration, their cell interaction properties, and their application in bone tissue engineering and regeneration. Furthermore, some new challenges about the future research on the application of nanomaterials for bone regeneration are described in the conclusion and perspectives part. PMID:26558141

  7. Bone scintiscanning updated.

    PubMed

    Lentle, B C; Russell, A S; Percy, J S; Scott, J R; Jackson, F I

    1976-03-01

    Use of modern materials and methods has given bone scintiscanning a larger role in clinical medicine, The safety and ready availability of newer agents have led to its greater use in investigating both benign and malignant disease of bone and joint. Present evidence suggests that abnormal accumulation of 99mTc-polyphosphate and its analogues results from ionic deposition at crystal surfaces in immature bone, this process being facilitated by an increase in bone vascularity. There is, also, a component of matrix localization. These factors are in keeping with the concept that abnormal scintiscan sites represent areas of increased osteoblastic activity, although this may be an oversimplification. Increasing evidence shows that the bone scintiscan is more sensitive than conventional radiography in detecting focal disease of bone, and its ability to reflect the immediate status of bone further complements radiographic findings. The main limitation of this method relates to nonspecificity of the results obtained.

  8. Calcium and bone disease

    PubMed Central

    Blair, Harry C.; Robinson, Lisa J.; Huang, Christopher L.-H.; Sun, Li; Friedman, Peter A.; Schlesinger, Paul H.; Zaidi, Mone

    2013-01-01

    Calcium transport and calcium signaling are of basic importance in bone cells. Bone is the major store of calcium and a key regulatory organ for calcium homeostasis. Bone, in major part, responds to calcium-dependent signals from the parathyroids and via vitamin D metabolites, although bone retains direct response to extracellular calcium if parathyroid regulation is lost. Improved understanding of calcium transporters and calcium-regulated cellular processes has resulted from analysis of genetic defects, including several defects with low or high bone mass. Osteoblasts deposit calcium by mechanisms including phosphate and calcium transport with alkalinization to absorb acid created by mineral deposition; cartilage calcium mineralization occurs by passive diffusion and phosphate production. Calcium mobilization by osteoclasts is mediated by acid secretion. Both bone forming and bone resorbing cells use calcium signals as regulators of differentiation and activity. This has been studied in more detail in osteoclasts, where both osteoclast differentiation and motility are regulated by calcium. PMID:21674636

  9. Marble Bone Disease: A Rare Bone Disorder

    PubMed Central

    Harinathbabu, Maheswari; Thillaigovindan, Ranjani; Prabhu, Geetha

    2015-01-01

    Osteopetrosis, or marble bone disease, is a rare skeletal disorder due to a defective function of the osteoclasts. This defect renders bones more susceptible to osteomyelitis due to decreased vascularity. This disorder is inherited as autosomal dominant and autosomal recessive. Healthcare professionals should urge these patients to maintain their oral health as well as general health, as this condition makes these patients more susceptible to frequent infections and fractures. This case report emphasizes the signs and symptoms of marble bone disease and presents clinical and radiographic findings.  PMID:26594603

  10. Biological Regulation of Bone Quality

    PubMed Central

    Alliston, Tamara

    2014-01-01

    The ability of bone to resist fracture is determined by the combination of bone mass and bone quality. Like bone mass, bone quality is carefully regulated. Of the many aspects of bone quality, this review focuses on biological mechanisms that control the material quality of the bone extracellular matrix (ECM). Bone ECM quality depends upon ECM composition and organization. Proteins and signaling pathways that affect the mineral or organic constituents of bone ECM impact bone ECM material properties, such as elastic modulus and hardness. These properties are also sensitive to pathways that regulate bone remodeling by osteoblasts, osteoclasts, and osteocytes. Several extracellular proteins, signaling pathways, intracellular effectors, and transcription regulatory networks have been implicated in the control of bone ECM quality. A molecular understanding of these mechanisms will elucidate the biological control of bone quality and suggest new targets for the development of therapies to prevent bone fragility. PMID:24894149

  11. [Bone and Nutrition. Sclerostin and bone metabolism].

    PubMed

    Tatsumi, Sawako; Nagamoto, Kenta; Ogata, Mao; Miyamoto, Ken-ichi

    2015-07-01

    Osteocytes orchestrate bone resorption and bone formation by controlling osteoclast and osteoblast activity. On the other hand, osteocytes secret FGF23 (fibroblast growth factor 23), FGF23 acts on the kidney to control phosphate homeostasis. Sclerostin is also released from osteocytes and it regulated osteoblast activity through Wnt/β-catenin pathway. Therefore, an antibody that targets sclerostin is currently in phase- III clinical trials for the treatment of osteoporosis and it is expected as new therapeutics.

  12. [Fibrous dysplasia of bone].

    PubMed

    Orcel, Philippe; Chapurlat, Roland

    2007-10-31

    Fibrous dysplasia of bone is a congenital non hereditary benign bone disease, where normal bone is replaced by a fibrous-like tissue with immature osteogenesis. Prevalence is difficult to estimate, due to frequent asymptomatic lesions. Bone lesions are mono- or polyostotic and may be associated with bone pain and fragility, leading to fractures. In some patients or bone sites, they are hypertrophic, responsible for neurological complications. Imaging and, when necessary, histology are the cornerstones of the diagnosis. A common molecular defect, i.e. activating mutations of the GNAS gene, encoding the a subunit of the Gs protein in target cells, is responsible for bone cell alterations as well as for the involvement of other cells/tissues bearing the same molecular defect (melanocytes, endocrine cells). These mutations affect only somatic cells and are therefore not hereditary: antenatal diagnosis is not appropriate for this disease and genetic counselling is not very useful, except for reassuring the patients. The conventional therapeutic approach is essentially symptomatic (pain killers) and orthopaedic (prevention and treatment of bone complications). Recent publications have focused attention on pamidronate, which rapidly relieves bone pain in most patients, and progressively increases bone mineralization in osteolytic areas in about half of the patients. Tubular phosphate wasting is common and should be treated with phosphate supplement and calcitriol. The prognosis should improve with therapeutic advances, but this remains to be properly evaluated.

  13. Assessment of Long Bone Flexural Properties from Bone Densitometry

    NASA Technical Reports Server (NTRS)

    Whalen, Robert; Cleek, Tammy; Katz, BethAnn

    1994-01-01

    While bone densitometry is the accepted non-invasive method of quantifying bone mineral content in bones, its assessment of bone structural properties is less well understood. The objective of our current work is to compare cross-section shape or areal properties of long bones computed from densitometry data with cross-section flexural properties obtained from surface strain measurements.

  14. Genetic regulation of bone mass: from bone density to bone strength.

    PubMed

    Langman, Craig B

    2005-03-01

    Osteoporosis is a common disease characterized in adults by diminished bone density. Bone is an organ that evolves and grows throughout life, and establishing optimal bone density in childhood and adolescence serves to buffer bone loss later in life. Bone density, a measurable entity, is the clinical substitute for bone strength, or the ability to defend against fracture. Chronic diseases may adversely affect optimal peak bone density. Bone density is under genetic control, as revealed by three lines of investigations. These include (1) the finding of quantitative trait loci for bone density, (2) the finding that specific mutations in genes that are important in the development of osteoblast or osteoclast lineages alter bone density, and (3) the linkeage of known polymorphisms for genes involved in mineral homeostasis to bone density and/or fracture. Future therapeutics for improving peak bone density or delaying bone loss later in life may take advantage of the genetic nature of bone density development.

  15. 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.

  16. 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

  17. Biophotonics and Bone Biology

    NASA Technical Reports Server (NTRS)

    Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

    2004-01-01

    One of the more-serious side effects of extended space flight is an accelerated bone loss [Bioastronautics Critical Path Roadmap, http://research.hq.nasa.gov/code_u/bcpr/index.cfm]. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It shows that an extrapolation of the microgravity induced bone loss rates to longer time scales, such as a 2.5 year round-trip to Mars (6 months out at 0 g, 1.5 year stay on Mars at 0.38 g, 6 months back at 0 g), could severely compromise the skeletal system of such a person.

  18. Biomaterials and bone mechanotransduction.

    PubMed

    Sikavitsas, V I; Temenoff, J S; Mikos, A G

    2001-10-01

    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.

  19. Adrenal gland and bone.

    PubMed

    Hardy, Rowan; Cooper, Mark S

    2010-11-01

    The adrenal gland synthesizes steroid hormones from the adrenal cortex and catecholamines from the adrenal medulla. Both cortisol and adrenal androgens can have powerful effects on bone. The overproduction of cortisol in Cushing's disease leads to a dramatic reduction in bone density and an increase risk of fracture. Overproduction of adrenal androgens in congenital adrenal hyperplasia (CAH) leads to marked changes in bone growth and development with early growth acceleration but ultimately a significant reduction in final adult height. The role of more physiological levels of glucocorticoids and androgens on bone metabolism is less clear. Cortisol levels measured in elderly individuals show a weak correlation with measures of bone density and change in bone density over time with a high cortisol level associated with lower bone density and more rapid bone loss. Cortisol levels and the dynamics of cortisol secretion change with age which could also explain some age related changes in bone physiology. It is also now clear that adrenal steroids can be metabolized within bone tissue itself. Local synthesis of cortisol within bone from its inactive precursor cortisone has been demonstrated and the amount of cortisol produced within osteoblasts appears to increase with age. With regard to adrenal androgens there is a dramatic reduction in levels with aging and several studies have examined the impact that restoration of these levels back to those seen in younger individuals has on bone health. Most of these studies show small positive effects in women, not men, but the skeletal sites where benefits are seen varies from study to study.

  20. Nanocomposites and bone regeneration

    NASA Astrophysics Data System (ADS)

    James, Roshan; Deng, Meng; Laurencin, Cato T.; Kumbar, Sangamesh G.

    2011-12-01

    This manuscript focuses on bone repair/regeneration using tissue engineering strategies, and highlights nanobiotechnology developments leading to novel nanocomposite systems. About 6.5 million fractures occur annually in USA, and about 550,000 of these individual cases required the application of a bone graft. Autogenous and allogenous bone have been most widely used for bone graft based therapies; however, there are significant problems such as donor shortage and risk of infection. Alternatives using synthetic and natural biomaterials have been developed, and some are commercially available for clinical applications requiring bone grafts. However, it remains a great challenge to design an ideal synthetic graft that very closely mimics the bone tissue structurally, and can modulate the desired function in osteoblast and progenitor cell populations. Nanobiomaterials, specifically nanocomposites composed of hydroxyapatite (HA) and/or collagen are extremely promising graft substitutes. The biocomposites can be fabricated to mimic the material composition of native bone tissue, and additionally, when using nano-HA (reduced grain size), one mimics the structural arrangement of native bone. A good understanding of bone biology and structure is critical to development of bone mimicking graft substitutes. HA and collagen exhibit excellent osteoconductive properties which can further modulate the regenerative/healing process following fracture injury. Combining with other polymeric biomaterials will reinforce the mechanical properties thus making the novel nano-HA based composites comparable to human bone. We report on recent studies using nanocomposites that have been fabricated as particles and nanofibers for regeneration of segmental bone defects. The research in nanocomposites, highlight a pivotal role in the future development of an ideal orthopaedic implant device, however further significant advancements are necessary to achieve clinical use.

  1. Bone scanning in otolaryngology.

    PubMed

    Noyek, A M

    1979-09-01

    Modern radionuclide bone scanning has introduced a new concept in physiologic and anatomic diagnostic imaging to general medicine. As otolaryngologists must diagnose and treat disease in relation to the bony and/or cartilaginous supporting structures of the neurocranium and upper airway, this modality should be included in the otolaryngologist's diagnostic armamentarium. It is the purpose of this manuscript to study the specific applications of bone scanning to our specialty at this time, based on clinical experience over the past three years. This thesis describes the development of bone scanning in general (history of nuclear medicine and nuclear physics; history of bone scanning in particular). General concepts in nuclear medicine are then presented; these include a discussion of nuclear semantics, principles of radioactive emmissions, the properties 99mTc as a radionuclide, and the tracer principle. On the basis of these general concepts, specific concepts in bone scanning are then brought forth. The physiology of bone and the action of the bone scan agents is presented. Further discussion considers the availability and production of the bone scan agent, patient factors, the gamma camera, the triphasic bone scan and the ultimate diagnostic principle of the bone scan. Clinical applications of bone scanning in otolaryngology are then presented in three sections. Proven areas of application include the evaluation of malignant tumors of the head and neck, the diagnosis of temporomandibular joint disorders, the diagnosis of facial fractures, the evaluation of osteomyelitis, nuclear medicine imaging of the larynx, and the assessment of systemic disease. Areas of adjunctive or supplementary value are also noted, such as diagnostic imaging of meningioma. Finally, areas of marginal value in the application of bone scanning are described.

  2. Radionuclide bone imaging and densitometry

    SciTech Connect

    Mettler, F.A.

    1988-01-01

    This book contains 13 selections. Some of the titles are: Radionuclides and the Normal Bone Scan; The Radionuclide Bone Scan in Malignant Disease; Pediatric Applications of Radionuclide Bone Imaging; The Radionuclide Bone Scan in Arthritis and Metabolic and Miscellaneous Disorders; and Soft Tissue Activity on the Radionuclide Bone Scan.

  3. Bone scanning in clinical practice

    SciTech Connect

    Fogelman, I. )

    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.

  4. Aging and Bone

    PubMed Central

    Boskey, A.L.; Coleman, R.

    2010-01-01

    Bones provide mechanical and protective function, while also serving as housing for marrow and a site for regulation of calcium ion homeostasis. The properties of bones do not remain constant with age; rather, they change throughout life, in some cases improving in function, but in others, function deteriorates. Here we review the modifications in the mechanical function and shape of bones, the bone cells, the matrix they produce, and the mineral that is deposited on this matrix, while presenting recent theories about the factors leading to these changes. PMID:20924069

  5. Biophotonics and Bone Biology

    NASA Technical Reports Server (NTRS)

    Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

    2004-01-01

    One of the more serious side effects of extended space flight is an accelerated bone loss. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It is well known that bone remodeling responds to mechanical forces. We are developing two-photon microscopy techniques to study bone tissue and bone cell cultures to better understand the fundamental response mechanism in bone remodeling. Osteoblast and osteoclast cell cultures are being studied, and the goal is to use molecular biology techniques in conjunction with Fluorescence Lifetime Imaging Microscopy (FLIM) to study the physiology of in-vitro cell cultures in response to various stimuli, such as fluid flow induced shear stress and mechanical stress. We have constructed a two-photon fluorescence microscope for these studies, and are currently incorporating FLIM detection. Current progress will be reviewed. This work is supported by the NASA John Glenn Biomedical Engineering Consortium.

  6. Autoinflammatory bone diseases.

    PubMed

    Stern, Sara M; Ferguson, Polly J

    2013-11-01

    Autoinflammatory bone disease is a new branch of autoinflammatory diseases caused by seemingly unprovoked activation of the innate immune system leading to an osseous inflammatory process. The inflammatory bone lesions in these disorders are characterized by chronic inflammation that is typically culture negative with no demonstrable organism on histopathology. The most common autoinflammatory bone diseases in childhood include chronic nonbacterial osteomyelitis (CNO), synovitis, acne, pustulosis, hyperostosis, osteitis syndrome, Majeed syndrome, deficiency of interleukin-1 receptor antagonist, and cherubism. In this article, the authors focus on CNO and summarize the distinct genetic autoinflammatory bone syndromes.

  7. Hypercalciuric Bone Disease

    NASA Astrophysics Data System (ADS)

    Favus, Murray J.

    2008-09-01

    Hypercalciuria plays an important causal role in many patients with calcium oxalate (CaOx) stones. The source of the hypercalciuria includes increased intestinal Ca absorption and decreased renal tubule Ca reabsorption. In CaOx stone formers with idiopathic hypercalciuria (IH), Ca metabolic balance studies have revealed negative Ca balance and persistent hypercalciuria in the fasting state and during low dietary Ca intake. Bone resorption may also contribute to the high urine Ca excretion and increase the risk of bone loss. Indeed, low bone mass by DEXA scanning has been discovered in many IH patients. Thiazide diuretic agents reduce urine Ca excretion and may increase bone mineral density (BMD), thereby reducing fracture risk. Dietary Ca restriction that has been used unsuccessfully in the treatment of CaOx nephrolithiasis in the past may enhance negative Ca balance and accelerate bone loss. DEXA scans may demonstrate low BMD at the spine, hip, or forearm, with no predictable pattern. The unique pattern of bone histologic changes in IH differs from other causes of low DEXA bone density including postmenopausal osteoporosis, male hypogonadal osteoporosis, and glucocorticoid-induced osteoporosis. Hypercalciuria appears to play an important pathologic role in the development of low bone mass, and therefore correction of urine Ca losses should be a primary target for treatment of the bone disease accompanying IH.

  8. Method for fusing bone

    DOEpatents

    Mourant, J.R.; Anderson, G.D.; Bigio, I.J.; Johnson, T.M.

    1996-03-12

    The present invention is a method for joining hard tissue which includes chemically removing the mineral matrix from a thin layer of the surfaces to be joined, placing the two bones together, and heating the joint using electromagnetic radiation. The goal of the method is not to produce a full-strength weld of, for example, a cortical bone of the tibia, but rather to produce a weld of sufficient strength to hold the bone halves in registration while either external fixative devices are applied to stabilize the bone segments, or normal healing processes restore full strength to the tibia.

  9. Bone fractal analysis.

    PubMed

    Feltrin, Gian Pietro; Stramare, Roberto; Miotto, Diego; Giacomini, Dario; Saccavini, Claudio

    2004-06-01

    Fractal analysis is a quantitative method used to evaluate complex anatomic findings in their elementary component. Its application to biologic images, particularly to cancellous bones, has been well practiced within the past few years. The aims of these applications are to assess changes in bone and the loss of spongious architecture, indicate bone fragility, and to show the increased risk for fracture in primary or secondary osteoporosis. The applications are very promising to help complete the studies that can define bone density (bone mineral density by dual energy x-ray absorptiometry or quantitative computed tomography), and also have the capacity to distinguish the patients with a high or low risk for fracture. Their extension to the clinical fields, to define a test for fracture risk, is still limited by difficult application to the medical quantitative imaging of bones, between correct application at superficial bones and unreliable application to deep bones. The future evolution and validity do not depend upon fractal methods but upon well-detailed imaging of the bones in clinical conditions.

  10. Horizontal bone augmentation by means of guided bone regeneration.

    PubMed

    Benic, Goran I; Hämmerle, Christoph H F

    2014-10-01

    The development of bone augmentation procedures has allowed placement of dental implants into jaw bone areas lacking an amount of bone sufficient for standard implant placement. Thus, the indications for implants have broadened to include jaw regions with bone defects and those with a bone anatomy that is unfavorable for implant anchorage. Of the different techniques, the best documented and the most widely used method to augment bone in localized alveolar defects is guided bone regeneration. A large body of evidence has demonstrated the successful use of guided bone regeneration to regenerate missing bone at implant sites with insufficient bone volume and the long-term success of implants placed simultaneously with, or after, guided bone regeneration. However, the influence of guided bone regeneration on implant survival and success rates, and the long-term stability of the augmented bone, remain unknown. Many of the materials and techniques currently available for bone regeneration of alveolar ridge defects were developed many years ago. Recently, various new materials and techniques have been introduced. Many of them have, however, not been sufficiently documented in clinical studies. The aim of this review was to present the scientific basis of guided bone regeneration and the accepted clinical procedures. A classification of bone defects has been presented, aiming at simplifying the decision-making process regarding the choice of strategy for bone augmentation. Finally, an outlook into actual research and the possible future options related to bone augmentation has been provided.

  11. Exercise, lifestyle, and your bones

    MedlinePlus

    Osteoporosis - exercise; Low bone density - exercise; Osteopenia - exercise ... To build up bone density, the exercise must make your muscles pull on your bones. These are called weight-bearing exercises. Some of them are: ...

  12. Children's Bone Health and Calcium

    MedlinePlus

    ... Research Information Clinical Trials Resources and Publications Children's Bone Health and Calcium: Condition Information Skip sharing on ... media links Share this: Page Content What is bone health and how do you build strong bones? ...

  13. Exercise for Your Bone Health

    MedlinePlus

    ... supported by your browser. Home Bone Basics Lifestyle Exercise for Your Bone Health Publication available in: PDF ( ... A Complete Osteoporosis Program For Your Information Why Exercise? Like muscle, bone is living tissue that responds ...

  14. Biodegradable synthetic bone composites

    SciTech Connect

    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.

  15. 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.

  16. BONES, TEACHER'S GUIDE.

    ERIC Educational Resources Information Center

    Elementary Science Study, Newton, MA.

    THIS GUIDE WAS DEVELOPED FOR USE WITH THE ELEMENTARY SCIENCE STUDY UNIT ON "BONES.""BONES" HAS BEEN TAUGHT IN THE FOURTH GRADE AND REQUIRES FROM 10 TO 25 LESSONS, DEPENDING ON THE NUMBER OF ACTIVITIES USED. THE GUIDE DOES NOT PROVIDE DETAILED INSTRUCTION FOR CONDUCTING CLASSES, BUT RATHER SOME POSSIBLE ACTIVITIES, AND LEAVES…

  17. Osteocyte and bone structure.

    PubMed

    Klein-Nulend, Jenneke; Nijweide, Peter J; Burger, Elisabeth H

    2003-06-01

    The osteocyte is the most abundant cell type of bone. There are approximately 10 times as many osteocytes as osteoblasts in adult human bone, and the number of osteoclasts is only a fraction of the number of osteoblasts. Our current knowledge of the role of osteocytes in bone metabolism is far behind our insight into the properties and functions of the osteoblasts and osteoclasts. However, the striking structural design of bone predicts an important role for osteocytes in determining bone structure. Over the past several years, the role of osteocytes as the professional mechanosensory cells of bone, and the lacunocanalicular porosity as the structure that mediates mechanosensing have become clear. Strain-derived flow of interstitial fluid through this porosity seems to mechanically activate the osteocytes, as well as ensure transport of cell signaling molecules, nutrients, and waste products. This concept explains local bone gain and loss--as well as remodeling in response to fatigue damage--as processes supervised by mechanosensitive osteocytes. Alignment during remodeling seems to occur as a result of the osteocyte's sensing different canalicular flow patterns around the cutting cone and reversal zone during loading, therefore determining the bone's structure.

  18. [Metabolic bone diseases].

    PubMed

    Jakob, F

    2007-10-01

    Osteomalacia is caused by impaired vitamin D receptor (VDR) signaling, calcium deficiency, and altered bone mineralization. This can be due to insufficient sunlight exposure, malabsorption, reduced D hormone activation in chronic kidney disease, and rare alterations of VDR signaling and phosphate metabolism. Leading symptoms are bone pain, muscular cramps, and increased incidence of falls in the elderly. The adequate respective countermeasures are to optimize the daily intake of calcium and vitamin D3 and to replace active D hormone and phosphate if deficient. Osteoporosis is characterized by bone fragility fractures upon minor physical impact. Indications for diagnosis and treatment can be established by estimating the absolute fracture risk, taking into account bone mineral density, age, gender, and individual risk factors. Exercise, intervention programs to avoid falls, and specific drugs are capable of substantially reducing fracture risk even in the elderly. Secondary osteoporosis primarily requires both bone-altering medications and effective treatment of underlying diseases.

  19. Bone and Celiac Disease.

    PubMed

    Zanchetta, María Belén; Longobardi, Vanesa; Bai, Julio César

    2016-04-01

    More than 50% of untreated patients with celiac disease (CD) have bone loss detected by bone densitometry (dual-energy X-ray absorptiometry:DXA). Moreover, patients with CD are more likely to have osteoporosis and fragility fractures, especially of the distal radius. Although still controversial, we recommend DXA screening in all celiac disease patients, particularly in those with symptomatic CD at diagnosis and in those who present risk factors for fracture such as older age, menopausal status, previous fracture history, and familial hip fracture history. Bone microarchitecture, especially the trabecular network, may be deteriorated, explaining the higher fracture risk in these patients. Adequate calcium and vitamin D supplementation are also recommended to optimize bone recovery, especially during the first years of gluten free diet (GFD). If higher fracture risk persists after 1 or 2 years of GFD, specific osteoactive treatment may be necessary to improve bone health.

  20. Ultrasonic bone densitometer

    NASA Technical Reports Server (NTRS)

    Hoop, J. M. (Inventor)

    1974-01-01

    A device, for measuring the density of a bone structure so as to monitor the calcium content, is described. A pair of opposed spaced ultrasonic transducers are held within a clamping apparatus closely adjacent the bone being analyzed. These ultrasonic transducers incude piezoelectric crystals shaped to direct signals through the bone encompassed in the heel and finger of the subject being tested. A pulse generator is coupled to one of the transducers and generates an electric pulse for causing the transducers to generate an ultrasonic sound wave which is directed through the bone structure to the other transducer. An electric circuit, including an amplifier and a bandpass filter couples the signals from the receiver transducer back to the pulse generator for retriggering the pulse generator at a frequency proportional to the duration that the ultrasonic wave takes to travel through the bone structure being examined.

  1. Juxtaphyseal aneurysmal bone cysts.

    PubMed

    Rizzo, M; Dellaero, D T; Harrelson, J M; Scully, S P

    1999-07-01

    Aneurysmal bone cysts are benign primary or secondary lesions that commonly arise in long bones and often before skeletal maturity. Little has been written about aneurysmal bone cysts that abut the physeal plate. The records of 15 patients with juxtaphyseal aneurysmal bone cysts were reviewed. Fourteen of the patients were referred with abnormal radiographs after evaluation for pain in the affected limb. One patient presented with abnormal radiographs after fracture about the aneurysmal bone cyst. None of the patients had evidence of growth plate disruption. The children's ages ranged from 2 to 14 years, with a mean of 9.8 years. There were 10 boys and five girls. Lesion locations included: six in the proximal tibia, three in the distal fibula, two in the distal tibia, two in the proximal femur, one in the distal femur, and one in the distal radius. All of the lesions abutted the physeal plate and fell into one of the types in Campanacci's classification of juxtaphyseal aneurysmal bone cysts. Three lesions were classified as Type 1, eight were Type 2, and four were Type 3. This study included no cases of Type 4 or 5 lesions. Treatment of all lesions consisted of excision, curettage, and bone grafting with care taken to preserve the growth plate. Adjunctive cauterization was performed in two cases. There were no incidences of postoperative physeal plate arrest. Overgrowth of the fibula occurred in one patient. Three patients experienced recurrent lesions. One of the children underwent repeat curettage and bone grafting with no additional recurrence. In the other two children with recurrence, the lesion had grown away from the physeal plate while remaining static in size and asymptomatic. Based on this study, juxtaphyseal aneurysmal bone cysts may be treated satisfactorily with intralesional surgery and bone grafting with expectation of normal physeal growth.

  2. Malignant lymphoma of bone.

    PubMed

    Dürr, Hans Roland; Müller, Peter Ernst; Hiller, Erhard; Maier, Markus; Baur, Andrea; Jansson, Volkmar; Refior, Hans Jürgen

    2002-02-01

    Malignant lymphoma of bone is rare. In many cases, its diagnosis is delayed because of unspecific clinical signs and equivocal radiographs. Therapy in general is multimodal, including surgery and radio- and chemotherapy. Our objective was to demonstrate the clinical and radiological aspects of the lesion to optimize diagnostic approaches and to evaluate treatment and prognostic factors. Thirty-six patients with malignant lymphoma of bone who were surgically treated over a 15-year-period were retrospectively reviewed. Seventeen of them showed a singular bone non-Hodgkin's lymphoma (NHL) which was classified as primary lymphoma of the bone (PLB). In 13 cases, dissemination of the disease with multiple bone or visceral involvement was apparent (dNHL). Six patients suffered from bone involvement due to Hodgkin's disease (HD). Surgical treatment was indicated for diagnostic reasons or complications due to the disease. Radiation and chemotherapy were part of the oncological treatment. The patients' mean age was 57 years. The main symptom in malignant bone lymphoma in 33 patients was pain, with an average duration of 8 months. In the secondary cases, bone involvement appeared on average 57 months after the initial diagnosis. An osteolytic pattern was seen in 58% of the lesions. Soft-tissue involvement was seen in 71% of cases (PLB 80%, dNHL 73%, HD 40%) and was the primary diagnostic sign associated with this disease. The 5-year survival rate was 61% (PLB 88%, dNHL 38%, HD 50%). Multiple vs solitary bone involvement was the most significant factor in the prognosis. Extraskeletal involvement significantly decreased survival. No correlation was found between gender, age, location, or histological subtypes and survival. Bone involvement in NHL appears late in the extraskeletal disease. The clinical appearance is nonspecific, and the delay between the onset of symptoms and diagnosis is often long. One of the major radiologic signs is the existence of a soft-tissue tumor

  3. What Happens After Treatment for Bone Cancer?

    MedlinePlus

    ... Cancer After Treatment What Happens After Treatment for Bone Cancer? For some people with bone cancer, treatment ... Treatment for Bone Cancer Stops Working More In Bone Cancer About Bone Cancer Causes, Risk Factors, and ...

  4. 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.

  5. 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

  6. Silicon and bone health.

    PubMed

    Jugdaohsingh, R

    2007-01-01

    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.

  7. Growth and bone development.

    PubMed

    Cooper, Cyrus; Harvey, Nicholas; Javaid, Kassim; Hanson, Mark; Dennison, Elaine

    2008-01-01

    Osteoporosis is a major cause of morbidity and mortality through its association with age-related fractures. Although most effort in fracture prevention has been directed at retarding the rate of age-related bone loss, and reducing the frequency and severity of trauma among elderly people, evidence is growing that peak bone mass is an important contributor to bone strength during later life. The normal patterns of skeletal growth have been well characterized in cross-sectional and longitudinal studies. It has been confirmed that boys have higher bone mineral content, but not volumetric bone density, than girls. Furthermore, there is a dissociation between the peak velocities for height gain and bone mineral accrual, in both genders. Puberty is the period during which volumetric density appears to increase in both axial and appendicular sites. Many factors influence the accumulation of bone mineral during childhood and adolescence, including heredity, gender, diet, physical activity, endocrine status, and sporadic risk factors such as cigarette smoking. In addition to these modifiable factors during childhood, evidence has also accrued that fracture risk might be programmed during intrauterine life. Epidemiological studies have demonstrated a relationship between birthweight, weight in infancy, and adult bone mass. This appears to be mediated through modulation of the set-point for basal activity of pituitary-dependent endocrine systems such as the hypothalamicpituitary-adrenal and growth hormone/insulin-like growth factor-1 axes. Maternal smoking, diet (particularly vitamin D deficiency), and physical activity also appear to modulate bone mineral acquisition during intrauterine life; furthermore, both low birth size and poor childhood growth are directly linked to the later risk of hip fracture. The optimization of maternal nutrition and intrauterine growth should also be included within preventive strategies against osteoporotic fracture, albeit for future

  8. Craniofacial bone tissue engineering.

    PubMed

    Wan, Derrick C; Nacamuli, Randall P; Longaker, Michael T

    2006-04-01

    Repair and reconstruction of the craniofacial skeleton represents a significant biomedical burden, with thousands of procedures per-formed annually secondary to injuries and congenital malformations. Given the multitude of current approaches, the need for more effective strategies to repair these bone deficits is apparent. This article explores two major modalities for craniofacial bone tissue engineering: distraction osteogenesis and cellular based therapies. Current understanding of the guiding principles for each of these modalities is elaborated on along with the knowledge gained from clinical and investigative studies. By laying this foundation, future directions for craniofacial distraction and cell-based bone engineering have emerged with great promise for the advancement of clinical practice.

  9. Bone graft substitutes.

    PubMed

    Bhatt, Reena A; Rozental, Tamara D

    2012-11-01

    Replacement of missing bone stock is a reconstructive challenge to upper extremity surgeons and decision-making with regards to available choices remains difficult. Preference is often given to autograft in the form of cancellous, cortical, or corticocancellous grafts from donor sites. However, the available volume from such donor sites is limited and fraught with potential complications. Advances in surgical management and medical research have produced a wide array of potential substances that can be used for bone graft substitute. Considerations in selecting bone grafts and substitutes include characteristic capabilities, availability, patient morbidity, immunogenicity, potential disease transmission, and cost variability.

  10. Paget Disease of Bone.

    PubMed

    Al-Rashid, Mamun; Ramkumar, Dipak B; Raskin, Kevin; Schwab, Joseph; Hornicek, Francis J; Lozano-Calderón, Santiago A

    2015-10-01

    The current understanding of Paget disease of bone (PDB) has vastly changed since Paget described the first case in 1877. Medical management of this condition remains the mainstay of treatment. Surgical intervention is usually only used in fractures through pagetic bone, need for realignment to correct deformity in major long bones, prophylactic treatment of impending fractures, joint arthroplasty in severe arthritis, or spinal decompression in cases of bony compression of neural elements. Advances in surgical technique have allowed early return to function and mobilization. Despite medical and surgical intervention, a small subset of patients with PDB develops Paget sarcoma.

  11. Dependence of Long Bone Flexural Properties on Bone Mineral Distribution

    NASA Technical Reports Server (NTRS)

    Katz, BethAnn; Cleek, Tammy M.; Whalen, Robert T.; Connolly, James P. (Technical Monitor)

    1995-01-01

    The objective of this study is to assess whether a non-invasive determination of long bone cross-sectional areal properties using bone densitometry accurately estimates true long bone flexural properties. In this study, section properties of two pairs of human female embalmed tibiae were compared using two methods: special analysis of bone densitometry data, and experimental determination of flexural regidities from bone surface strain measurements during controlled loading.

  12. Bone Grafts in Craniofacial Surgery

    PubMed Central

    Elsalanty, Mohammed E.; Genecov, David G.

    2009-01-01

    Reconstruction of cranial and maxillofacial defects is a challenging task. The standard reconstruction method has been bone grafting. In this review, we shall describe the biological principles of bone graft healing, as pertinent to craniofacial reconstruction. Different types and sources of bone grafts will be discussed, as well as new methods of bone defect reconstruction. PMID:22110806

  13. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... Your 1- to 2-Year-Old Aspiration and Biopsy: Bone Marrow KidsHealth > For Parents > Aspiration and Biopsy: Bone Marrow A A A What's in this ... ósea What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy ...

  14. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness Aspiration and Biopsy: Bone Marrow KidsHealth > For Teens > Aspiration and Biopsy: Bone Marrow A A A What's in this ... Questions What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy ...

  15. Paget disease of the bone

    MedlinePlus

    ... that may indicate Paget disease include: Bone scan Bone x-ray Elevated markers of bone breakdown (for example, N-telopeptide) This disease may ... of Paget disease. Alternative Names Osteitis deformans Images ... X-ray References Ralston SH. Paget disease of bone. In: Goldman L, Schafer AI, eds. Goldman's Cecil ...

  16. Instrumentation for bone density measurement

    NASA Technical Reports Server (NTRS)

    Meharg, L. S.

    1968-01-01

    Measurement system evaluates the integrated bone density over a specific cross section of bone. A digital computer converts stored bone scan data to equivalent aluminum calibration wedge thickness, and bone density is then integrated along the scan by using the trapezoidal approximation integration formula.

  17. 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 ...

  18. What Is Bone Cancer?

    MedlinePlus

    ... in parts of the face. The trachea (windpipe), larynx (voice box), and the outer part of the ... bone. Occasionally, chondrosarcoma will develop in the trachea, larynx, and chest wall. Other sites are the scapula ( ...

  19. 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 ...

  20. Bone marrow biopsy

    MedlinePlus

    ... myelodysplastic syndrome; MDS) A nerve tissue tumor called neuroblastoma Bone marrow disease that leads to an abnormal ... Hairy cell leukemia Hodgkin lymphoma Multiple myeloma Myelofibrosis Neuroblastoma Non-Hodgkin lymphoma Platelet count Polycythemia vera Primary ...

  1. Bone mineral density test

    MedlinePlus

    ... density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis-BMD ... most common and accurate way uses a dual-energy x-ray absorptiometry (DEXA) scan. DEXA uses low- ...

  2. Bone pain or tenderness

    MedlinePlus

    ... 13. Weber TJ. Osteoporosis. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: ... other disorders of bone. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: ...

  3. Bone Densitometry in Children.

    PubMed

    Adams, Judith E

    2016-07-01

    Maximizing peak bone mass in childhood is relevant to optimizing bone health in later life, so the study of the skeleton in children in health and disease is important. Dual-energy X-ray absorptiometry (DXA) is the most widely used clinical tool for the assessment of bone status in children. Technological developments in DXA enable vertebral fracture assessment at much lower ionizing radiation doses than spinal radiographs. Quantitative computed tomography remains predominantly a research tool but has some advantages over DXA in not being size dependent. High-resolution peripheral computed tomography measures trabecular and cortical bone microstructure but is technically challenging, particularly in children, and not widely available, so it is unlikely to be used in clinical practice. Other quantitative techniques (quantitative magnetic resonance imaging, digital X-ray absorptiometry, quantitative ultrasound) have been applied in children but remain research applications, and they are only covered briefly in this review.

  4. Bone Loss in IBD

    MedlinePlus

    ... individuals who have used corticosteroids for some time. VITAMIN D DEFICIENCY Vitamin D is necessary for the absorption of calcium. ... small bowel involvement—are at increased risk for vitamin D deficiency. This, in turn, may result in bone loss ...

  5. Alcohol and bone.

    PubMed

    Mikosch, Peter

    2014-01-01

    Alcohol is widely consumed across the world in different cultural and social settings. Types of alcohol consumption differ between (a) light, only occasional consumption, (b) heavy chronic alcohol consumption, and (c) binge drinking as seen as a new pattern of alcohol consumption among teenagers and young adults. Heavy alcohol consumption is detrimental to many organs and tissues, including bones. Osteoporosis is regularly mentioned as a secondary consequence of alcoholism, and chronic alcohol abuse is established as an independent risk factor for osteoporosis. The review will present the different mechanisms and effects of alcohol intake on bone mass, bone metabolism, and bone strength, including alcoholism-related "life-style factors" such as malnutrition, lack of exercise, and hormonal changes as additional causative factors, which also contribute to the development of osteoporosis due to alcohol abuse.

  6. Bone x-ray

    MedlinePlus

    ... not being scanned. Alternative Names X-ray - bone Images Skeleton Skeletal spine Osteogenic sarcoma - x-ray References ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  7. Bone Loss in IBD

    MedlinePlus

    ... individuals who have used corticosteroids for some time. VITAMIN D DEFICIENCY Vitamin D is necessary for the absorption of calcium. ... are critical for building healthy bone. Because this vitamin is absorbed in the small intestine, people with ...

  8. Children with Brittle Bones.

    ERIC Educational Resources Information Center

    Alston, Jean

    1982-01-01

    Special help given to children with Osteogenesis Imperfecta (brittle bone disease) is described, including adapted equipment to allow for writing and use of a classroom assistant to aid participation in a regular classroom. (CL)

  9. What causes bone loss?

    MedlinePlus

    ... Any treatment or condition that causes calcium or vitamin D to be poorly absorbed can also lead to weak bones. Some of these are: Gastric bypass (weight-loss surgery) Cystic fibrosis Other conditions that ...

  10. What Is Bone?

    MedlinePlus

    ... during your bone-building years. Women, Men, and Osteoporosis Women are more likely than men to develop ... loss and a greater risk of developing osteoporosis. Osteoporosis Prevention Osteoporosis is preventable for many people. Prevention ...

  11. Reduction of bone strength

    NASA Technical Reports Server (NTRS)

    Bingham, Cindy

    1990-01-01

    Viewgraphs on reduction of bone strength are presented. WEHI 231 B growth rates, experimental chambers used to apply the electric field to the cell cultures, and a mouse suspended by rotating cuff in electromagnetic field are shown.

  12. 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

  13. [Incretin and bone].

    PubMed

    Yamada, Yuichiro

    2009-09-01

    Gastrointestinal hormones including gastric inhibitory polypeptide (GIP) and glucagon-like peptide (GLP) -1 are incretin, which are secreted immediately after meal ingestion and stimulate insulin secretion from pancreatic beta-cells. Characterization of extra-pancreatic GIP and GLP-1 receptors has revealed that these hormones regulate bone turnover. GIP intermittently stimulates osteoblasts and GLP-1 suppresses osteoclasts through a calcitonin-dependent pathway to increase the bone volume.

  14. Bone morphogenetic protein

    SciTech Connect

    Xiao Yongtao; Xiang Lixin; Shao Jianzhong

    2007-10-26

    Bone morphogenetic proteins (BMPs) are multi-functional growth factors belonging to the transforming growth factor-beta superfamily. It has been demonstrated that BMPs had been involved in the regulation of cell proliferation, survival, differentiation and apoptosis. However, their hallmark ability is that play a pivotal role in inducing bone, cartilage, ligament, and tendon formation at both heterotopic and orthotopic sites. In this review, we mainly concentrate on BMP structure, function, molecular signaling and potential medical application.

  15. SEPARATION OF NEWLY FORMED BONE FROM OLDER COMPACT BONE REVEALS CLEAR COMPOSITIONAL DIFFERENCES IN BONE MATRIX

    PubMed Central

    Midura, Ronald J.; Midura, Sharon B.; Su, Xiaowei; Gorski, Jeffrey P.

    2011-01-01

    In long bone diaphyses, woven bone forms first and then transitions into a more mineralized compact bone tissue. Prior evidence suggests that the non-collagenous protein composition of woven bone may be distinct from that of more mature bone tissue, particularly with respect to a diverse group of phosphorylated, extracellular matrix proteins. To critically test this hypothesis, we developed an in situ approach to isolate newly formed bone from more mature bone within the same long bone, and combine this anatomical approach with Western blotting to make relative comparisons of 7 phosphorylated matrix proteins important for bone physiology and biomineralization. Interestingly, 75 kDa bone sialoprotein (BSP), 63 kDa osteopontin, and the 75 kDa form of bone acidic glycoprotein-75 (BAG-75) were enriched in primary bone as opposed to more mature cortical bone, while osteonectin, fetuin A, matrix extracellular phosphoglycoprotein (MEPE) and dentin matrix protein-1 (DMP-1) appeared to be equally distributed between these two bone tissue compartments. Analyses also revealed the presence of larger sized forms of osteopontin (and to a lesser degree BSP) mostly in newly formed bone, while larger forms of BAG-75 were mostly detected in more mature cortical bone. Smaller sized forms of DMP-1 and BAG-75 were detected in both newly formed and more mature bone tissue extracts, and they are likely the result of proteolytic processing in vivo. Intact DMP-1 (97 kDa) was only detected in unmineralized matrix extracts. These findings indicate that newly formed bone exhibits a non-collagenous matrix protein composition distinct from that of more mature compact bone even within the same long bone, and suggest that the temporal fate of individual non-collagenous proteins is variable in growing bone. PMID:21958842

  16. Systems analysis of bone.

    PubMed

    Jepsen, Karl J

    2009-01-01

    The genetic variants contributing to variability in skeletal traits has been well studied, and several hundred QTLs have been mapped and several genes contributing to trait variation have been identified. However, many questions remain unanswered. In particular, it is unclear whether variation in a single gene leads to alterations in function. Bone is a highly adaptive system and genetic variants affecting one trait are often accompanied by compensatory changes in other traits. The functional interactions among traits, which is known as phenotypic integration, has been observed in many biological systems, including bone. Phenotypic integration is a property of bone that is critically important for establishing a mechanically functional structure that is capable of supporting the forces imparted during daily activities. In this paper, bone is reviewed as a system and primarily in the context of functionality. A better understanding of the system properties of bone will lead to novel targets for future genetic analyses and the identification of genes that are directly responsible for regulating bone strength. This systems analysis has the added benefit of leaving a trail of valuable information about how the skeletal system works. This information will provide novel approaches to assessing skeletal health during growth and aging and for developing novel treatment strategies to reduce the morbidity and mortality associated with fragility fractures.

  17. Bone nutrients for vegetarians.

    PubMed

    Mangels, Ann Reed

    2014-07-01

    The process of bone mineralization and resorption is complex and is affected by numerous factors, including dietary constituents. Although some dietary factors involved in bone health, such as calcium and vitamin D, are typically associated with dairy products, plant-based sources of these nutrients also supply other key nutrients involved in bone maintenance. Some research suggests that vegetarian diets, especially vegan diets, are associated with lower bone mineral density (BMD), but this does not appear to be clinically significant. Vegan diets are not associated with an increased fracture risk if calcium intake is adequate. Dietary factors in plant-based diets that support the development and maintenance of bone mass include calcium, vitamin D, protein, potassium, and soy isoflavones. Other factors present in plant-based diets such as oxalic acid and phytic acid can potentially interfere with absorption and retention of calcium and thereby have a negative effect on BMD. Impaired vitamin B-12 status also negatively affects BMD. The role of protein in calcium balance is multifaceted. Overall, calcium and protein intakes in accord with Dietary Reference Intakes are recommended for vegetarians, including vegans. Fortified foods are often helpful in meeting recommendations for calcium and vitamin D. Plant-based diets can provide adequate amounts of key nutrients for bone health.

  18. 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

  19. Bone Remodeling Monitor

    NASA Technical Reports Server (NTRS)

    Foucar, Charlie; Goldberg, Leslie; Hon, Bodin; Moore, Shannon; Williams, Evan

    2009-01-01

    The impact of bone loss due to different mechanical loadings in microgravity is a major concern for astronauts upon reintroduction to gravitational forces in exploration missions to the Moon and Mars. it has been shown that astronauts not only lose bone at differing rates, with levels up to 2% per month, but each astronaut will respond to bone loss treatments differently. Pre- and post-flight imaging techniques and frozen urine samples for post-flight laboratory immunoassays To develop a novel, non-invasive, highly . sensitive, portable, intuitive, and low-powered device to measure bone resorption levels in 'real time' to provide rapid and Individualized feedback to maximize the efficacy of bone loss countermeasures 1. Collect urine specimen and analyze the level of bone resorption marker, DPD (deoxypridinoline) excreted. 2. Antibodies specific to DPD conjugated with nanoshells and mixed with specimen, the change in absorbance from agglutination is measured by an optical device. 3. The concentration of DPD is displayed and recorded on a PDA

  20. Endochondral bone growth, bone calcium accretion, and bone mineral density: how are they related?

    PubMed

    Wongdee, Kannikar; Krishnamra, Nateetip; Charoenphandhu, Narattaphol

    2012-07-01

    Endochondral bone growth in young growing mammals or adult mammals with persistent growth plates progresses from proliferation, maturation and hypertrophy of growth plate chondrocytes to mineralization of cartilaginous matrix to form an osseous tissue. This complex process is tightly regulated by a number of factors with different impacts, such as genetics, endocrine/paracrine factors [e.g., PTHrP, 1,25(OH)(2)D(3), IGF-1, FGFs, and prolactin], and nutritional status (e.g., dietary calcium and vitamin D). Despite a strong link between growth plate function and elongation of the long bone, little is known whether endochondral bone growth indeed determines bone calcium accretion, bone mineral density (BMD), and/or peak bone mass. Since the process ends with cartilaginous matrix calcification, an increase in endochondral bone growth typically leads to more calcium accretion in the primary spongiosa and thus higher BMD. However, in lactating rats with enhanced trabecular bone resorption, bone elongation is inversely correlated with BMD. Although BMD can be increased by factors that enhance endochondral bone growth, the endochondral bone growth itself is unlikely to be an important determinant of peak bone mass since it is strongly determined by genetics. Therefore, endochondral bone growth and bone elongation are associated with calcium accretion only in a particular subregion of the long bone, but do not necessarily predict BMD and peak bone mass.

  1. [Is bone biopsy necessary for the diagnosis of metabolic bone diseases? Necessity of bone biopsy].

    PubMed

    Ito, Akemi; Yajima, Aiji

    2011-09-01

    Histological analysis of undecalcified bone biopsy specimens is a valuable clinical and research tool for studying the etiology, pathogenesis and treatment of metabolic bone diseases. In case of osteoporosis, bone biopsy is not usually required for the diagnosis ; however, bone histomorphometry may be useful in rare cases with unusual skeletal fragility. Bone histomorphometry also provides valuable information on the mechanism of action, safety and efficacy of new anti-osteoporosis drugs. Bone histomorphometry is useful for the diagnosis and the assessment of treatment response in rickets/osteomalacia and in CKD-MBD (chronic kidney disease-mineral and bone disorders) . In Japan, bone biopsy is often performed to establish the diagnosis of Paget's disease of bone, especially to differentiate it from metastatic bone disease.

  2. Bone formation: roles of genistein and daidzein

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bone remodeling consists of a balance between bone formation by osteoblasts and bone resorption by osteoclasts. Osteoporosis is the result of increased bone resorption and decreased bone formation causing a decreased bone mass density, loss of bone microarchitecture, and an increased risk of fractu...

  3. Porous Surface Modified Bioactive Bone Cement for Enhanced Bone Bonding

    PubMed Central

    Huang, Li; Dong, Jingjing; Guo, Dagang; Mao, Mengmeng; Kong, Liang; Li, Yang; Wu, Zixiang; Lei, Wei

    2012-01-01

    Background Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth. Materials and Methods The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant–bone interface was also investigated by push-out tests. Results The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect. Conclusions

  4. Osteocyte density in woven bone.

    PubMed

    Hernandez, C J; Majeska, R J; Schaffler, M B

    2004-11-01

    Woven bone forms rapidly during tissue growth, following injury and in response to certain anabolic stimuli. Functional differences between woven and lamellar bone may be due, in part, to differences in osteocyte density (cells per unit tissue). Woven bone has been estimated to contain four to eight times more osteocytes than lamellar bone, although primary data to support this assertion are limited. Given recent findings implicating osteocytes as regulators of bone remodeling, bone formation and bone volume, such large differences in osteocyte density between woven and lamellar bone may have important consequences. In this study, we compared the density of osteocyte lacunae (lacunae/mm(2) tissue) in rat lamellar bone with that in woven bone formed under several different circumstances. We found that the lacunar density of lamellar cortical bone in the rat (834+/-83 cells/mm2, mean+/-SD) did not differ significantly from that of periosteal woven bone formed via intramembranous osteogenesis, either in response to mechanical loading (921+/-204 cells/mm2) or in the periosteal buttressing region of the fracture callus (1138+/-168 cells/mm2). In contrast, lacunar density of endochondrally derived woven bone in the center (gap) region of fracture callus was nearly 100% greater (1875+/-270 cells/mm2) than in lamellar cortical bone while lacunar density of primary spongiosa of the growth plate was 40% greater (1674+/-228 cells/mm2) than that in lamellar cancellous bone (1189+/-164). These findings demonstrate that lacunar density in woven bone varies depending on skeletal site and developmental history and appears to be elevated in endochondrally derived woven bone adjacent to marrow space. Given the considerable evidence supporting osteocytes as local initiators of bone remodeling, we suggest that woven bone with increased lacunar density may undergo remodeling at an accelerated rate.

  5. Role of bone marrow macrophages in controlling homeostasis and repair in bone and bone marrow niches.

    PubMed

    Kaur, Simranpreet; Raggatt, Liza Jane; Batoon, Lena; Hume, David Arthur; Levesque, Jean-Pierre; Pettit, Allison Robyn

    2017-01-01

    Macrophages, named for their phagocytic ability, participate in homeostasis, tissue regeneration and inflammatory responses. Bone and adjacent marrow contain multiple functionally unique resident tissue macrophage subsets which maintain and regulate anatomically distinct niche environments within these interconnected tissues. Three subsets of bone-bone marrow resident tissue macrophages have been characterised; erythroblastic island macrophages, haematopoietic stem cell niche macrophages and osteal macrophages. The role of these macrophages in controlling homeostasis and repair in bone and bone marrow niches is reviewed in detail.

  6. 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

  7. Bone Graft Substitution and Augmentation.

    PubMed

    Nauth, Aaron; Lane, Joseph; Watson, J Tracy; Giannoudis, Peter

    2015-12-01

    Selection of appropriate bone graft or bone graft substitute requires careful recognition of the bone healing needs of the patient's specific clinical problem and a thorough understanding of the different properties possessed by the available bone grafts and substitutes. Although autogenous iliac crest bone graft remains the gold standard of treatment for delayed unions, nonunions, and bone defects, there are a number of promising alternatives available, and emerging evidence suggests that they can be very effective when used in the proper setting. Among these, reamer-irrigator-aspirator bone graft, bone marrow concentrate, bone morphogenetic proteins, and calcium phosphate cements have received a great deal of attention in the literature. This review describes these grafts in detail along with the evidence for their use. In addition, a framework is provided for selecting the appropriate graft or substitute based on their provided properties.

  8. Bone health in eating disorders.

    PubMed

    Zuckerman-Levin, N; Hochberg, Z; Latzer, Y

    2014-03-01

    Eating disorders (EDs) put adolescents and young adults at risk for impaired bone health. Low bone mineral density (BMD) with ED is caused by failure to accrue peak bone mass in adolescence and bone loss in young adulthood. Although ED patients diagnosed with bone loss may be asymptomatic, some suffer bone pains and have increased incidence of fractures. Adolescents with ED are prone to increased prevalence of stress fractures, kyphoscoliosis and height loss. The clinical picture of the various EDs involves endocrinopathies that contribute to impaired bone health. Anorexia nervosa (AN) is characterized by low bone turnover, with relatively higher osteoclastic (bone resorptive) than osteoblastic (bone formation) activity. Bone loss in AN occurs in both the trabecular and cortical bones, although the former is more vulnerable. Bone loss in AN has been shown to be influenced by malnutrition and low weight, reduced fat mass, oestrogen and androgen deficiency, glucocorticoid excess, impaired growth hormone-insulin-like growth factor 1 axis, and more. Bone loss in AN may not be completely reversible despite recovery from the illness. Treatment modalities involving hormonal therapies have limited effectiveness, whereas increased caloric intake, weight gain and resumption of menses are essential to improved BMD.

  9. Bone impairment in oxalosis: An ultrastructural bone analysis.

    PubMed

    Bacchetta, Justine; Farlay, Delphine; Abelin-Genevois, Kariman; Lebourg, Ludivine; Cochat, Pierre; Boivin, Georges

    2015-12-01

    Deposition of calcium oxalate crystals in the kidney and bone is a hallmark of systemic oxalosis. Since the bone compartment can store massive amounts of oxalate, patients present with recurrent low-trauma fractures, bone deformations, severe bone pains and specific oxalate osteopathy on plain X-ray. Bone biopsy from the iliac crest displays specific features such as oxalate crystals surrounded by a granulomatous reaction due to an invasion of bone surface by macrophages. We present data obtained in 10 samples from 8 patients with oxalosis (16-68 years) who underwent iliac crest bone biopsy and bone quality analysis using modern methods (microradiography, microindentation, Fourier Transform InfraRed Microspectroscopy, transmission electron microscopy) in addition to histomorphometry. Disseminated calcium oxalate deposits (whewellite) were found in the bone marrow space (with a granulomatous reaction) but not in the bone matrix. Calcium oxalate deposits were totally surrounded by macrophages and multinucleated giant cells, and a phagocytosis activity was sometimes observed. Very few calcium oxalate crystals were directly in close contact with the mineral substance of the bone. Bone mineralization was not modified by the presence of calcium oxalate even in close vicinity. Bone quality analysis also revealed a harder bone than normal, perhaps in relationship with decreased carbonate content in the mineral. This increase in bone hardness could explain a more "brittle" bone. In patients with oxalosis, the formation and growth of calcium oxalate crystals in the bone appeared independent of apatite. The mechanisms leading to nucleation and growth of oxalate deposits are still unclear and deserve further studies.

  10. Diabetes, biochemical markers of bone turnover, diabetes control, and bone.

    PubMed

    Starup-Linde, Jakob

    2013-01-01

    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.

  11. 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.

  12. 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.

  13. [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.

  14. Bone cells and bone turnover in diabetes mellitus.

    PubMed

    Rubin, Mishaela R

    2015-06-01

    Substantial evidence exists that in addition to the well-known complications of diabetes, increased fracture risk is an important morbidity. This risk is probably due, at least in part, to altered bone remodeling and bone cell function in diabetes. Circulating biochemical markers of bone formation, including P1NP, osteocalcin and bone-specific alkaline phosphatase have been found to be decreased in type 2 diabetes (T2D) and may be predictive of fractures independently of bone mineral density (BMD). These findings have been corroborated by preliminary histomorphometric data. Reductions in the bone resorption marker serum CTx in T2D have also been reported. Serum sclerostin levels have been found to be increased in T2D and appear to be predictive of fracture risk independent of BMD. Other factors such as bone marrow fat saturation, advanced glycation endproduct (AGE) accumulation, and microarchitectural changes might also relate to bone cell function and fracture risk in diabetes.

  15. Periodontitis and bone metabolism

    PubMed Central

    Barbato, Luigi; Francioni, Edoardo; Bianchi, Massimiliano; Mascitelli, Eleonora; Marco, Leila Brancato; Tonelli, Duvina Paolo

    2015-01-01

    Summary Periodontitis is a plaque induced disease characterized by tissue destruction. The extent of the alveolar bone loss depends on the host response stimulated by bacterial infection. Recently researchers have focused on the role of the immune system, of RANK/RANKL/OPG pathway and of cytokines network. Another recent field of interest is osteoimmunology that try to explain the relationship between immune and bone cells in activating bone resorption. Advances in the understanding of the pathogenic mechanisms allowed a better understanding of the relationship with other diseases like osteoporosis and also to hypothesize new therapies based on modulation of host response (host modulatory therapy - HMT). The purpose of this mini-review is to briefly discuss these topics. PMID:26604945

  16. Bone healing in 2016

    PubMed Central

    Buza, John A.; Einhorn, Thomas

    2016-01-01

    Summary Delayed fracture healing and nonunion occurs in up to 5–10% of all fractures, and can present a challenging clinical scenario for the treating physician. Methods for the enhancement of skeletal repair may benefit patients that are at risk of, or have experienced, delayed healing or nonunion. These methods can be categorized into either physical stimulation therapies or biological therapies. Physical stimulation therapies include electrical stimulation, low-intensity pulsed ultrasonography, or extracorporeal shock wave therapy. Biological therapies can be further classified into local or systemic therapy based on the method of delivery. Local methods include autologous bone marrow, autologous bone graft, fibroblast growth factor-2, platelet-rich plasma, platelet-derived growth factor, and bone morphogenetic proteins. Systemic therapies include parathyroid hormone and bisphosphonates. This article reviews the current applications and supporting evidence for the use of these therapies in the enhancement of fracture healing. PMID:27920804

  17. Diabetes and bone health.

    PubMed

    Antonopoulou, Marianna; Bahtiyar, Gül; Banerji, Mary Ann; Sacerdote, Alan S

    2013-11-01

    The increasing prevalence of diabetes especially type 2 diabetes worldwide is indisputable. Diabetics suffer increased morbidity and mortality, compared to their non-diabetic counterparts, not only because of vascular complications, but also because of an increased fracture incidence. Both types 1 and 2 diabetes and some medications used to treat it are associated with osteoporotic fractures. The responsible mechanisms remain incompletely elucidated. In this review, we evaluate the role of glycemic control in bone health, and the effect of anti-diabetic medications such as thiazolidinediones, sulfonylureas, DPP-4 inhibitors, and GLP-1 agonists. In addition, we examine the possible role of insulin and metformin as anabolic agents for bone. Lastly, we identify the current and future screening tools that help evaluate bone health in diabetics and their limitations. In this way we can offer individualized treatment, to the at-risk diabetic population.

  18. [Infectious bone diseases].

    PubMed

    Tiemann, A H; Krenn, V; Krukemeyer, M G; Seyfert, C; Jakobs, M; Baumhoer, D; Hofmann, G O

    2011-05-01

    Bacterial infection of the bone is a severe disease with complications, potentially including long-term physical disability. The diagnosis and therapy of osteomyelitis include several elements: histopathology, microbiology, radiologic imagining, as well as antibiotic and surgical therapy. Histopathologists differentiate between acute osteomyelitis (infiltration of cancellous bone with neutrophil granulocytes); specific osteomyelitis (epithelioid-like granulomatous inflammation, tuberculosis, mycotic infections); primary/secondary chronic osteomyelitis (lymphocytic infiltration); and special forms of chronic osteomyelitis (varying histomorphology, Brodie abscess, SAPHO syndrome). Another important task in the histopathological diagnosis of inflammatory bone diseases is to differentiate osteomyelitis from malignant entities (sarcoma, lymphoma). Therefore, biopsy samples should be of sufficient size for safe diagnosis. Clinical information and imaging as well as interdisciplinary teamwork between radiologists, microbiologists, orthopedic surgeons and pathologists is mandatory to verify these diagnoses.

  19. Analysis of bone biopsies.

    PubMed

    Goodrich, J A; Difiore, R J; Tippens, J K

    1983-11-01

    The orthopedic surgeon is frequently confronted with the decision of when to perform a bone biopsy and whether to do a needle biopsy or an open biopsy. Frequently consultations are received from other services requesting bone biopsies with questionable indications. The indications and contraindications for performing bone biopsies are discussed as well as advantages and disadvantages of either closed or open technique. Four selective cases are discussed with illustrations. The challenge of undiagnosed osseous lesions is best met by rational evaluation of each individual case and coordinated with the team effort of the primary care physician, surgeon, pathologist, and radiologist. The decision for either an open or closed biopsy technique must be based on the experience and skills of the surgeon and pathologist.

  20. Sex steroids and bone.

    PubMed

    Manolagas, S C; Kousteni, S; Jilka, R L

    2002-01-01

    The adult skeleton is periodically remodeled by temporary anatomic structures that comprise juxtaposed osteoclast and osteoblast teams and replace old bone with new. Estrogens and androgens slow the rate of bone remodeling and protect against bone loss. Conversely, loss of estrogen leads to increased rate of remodeling and tilts the balance between bone resorption and formation in favor of the former. Studies from our group during the last 10 years have elucidated that estrogens and androgens decrease the number of remodeling cycles by attenuating the birth rate of osteoclasts and osteoblasts from their respective progenitors. These effects result, in part, from the transcriptional regulation of genes responsible for osteoclastogenesis and mesenchymal cell replication and/or differentiation and are exerted through interactions of the ligand-activated receptors with other transcription factors. However, increased remodeling alone cannot explain why loss of sex steroids tilts the balance of resorption and formation in favor of the former. Estrogens and androgens also exert effects on the lifespan of mature bone cells: pro-apoptotic effects on osteoclasts but anti-apoptotic effects on osteoblasts and osteocytes. These latter effects stem from a heretofore unexpected function of the classical "nuclear" sex steroid receptors outside the nucleus and result from activation of a Src/Shc/extracellular signal-regulated kinase signal transduction pathway probably within preassembled scaffolds called caveolae. Strikingly, estrogen receptor (ER) alpha or beta or the androgen receptor can transmit anti-apoptotic signals with similar efficiency, irrespective of whether the ligand is an estrogen or an androgen. More importantly, these nongenotropic, sex-nonspecific actions are mediated by the ligand-binding domain of the receptor and can be functionally dissociated from transcriptional activity with synthetic ligands. Taken together, these lines of evidence strongly suggest that

  1. Miscellaneous indications in bone scintigraphy: metabolic bone diseases and malignant bone tumors.

    PubMed

    Cook, Gary J R; Gnanasegaran, Gopinath; Chua, Sue

    2010-01-01

    The diphosphonate bone scan is ideally suited to assess many global, focal or multifocal metabolic bone disorders and there remains a role for conventional bone scintigraphy in metabolic bone disorders at diagnosis, investigation of complications, and treatment response assessment. In contrast, the role of bone scintigraphy in the evaluation of primary malignant bone tumors has reduced with the improvement of morphologic imaging, such as computed tomography and magnetic resonance imaging. However, an increasing role for (18)F-fluorodeoxyglucose positron emission tomography and positron emission tomography/computed tomography is emerging as a functional assessment at diagnosis, staging, and neoadjuvant treatment response assessment.

  2. Vascularized bone grafts for the treatment of carpal bone pathology.

    PubMed

    Derby, Brian M; Murray, Peter M; Shin, Alexander Y; Bueno, Reuben A; Mathoulin, Christophe L; Ade, Tim; Neumeister, Michael W

    2013-03-01

    Primary bone healing fails to occur in 5-15 % of scaphoid bones that undergo fracture fixation. Untreated, occult fractures result in nonunion up to 12 % of the time. Conventional bone grafting is the accepted management in the treatment algorithm of scaphoid nonunion if the proximal pole is vascularized. Osteonecrosis of the proximal scaphoid pole intuitively suggests a need for transfer of the vascularized bone to the nonunion site. Scaphoid nonunion treatment aims to prevent biological and mechanical subsidence of the involved bone, destabilization of the carpus, and early degenerative changes associated with scaphoid nonunion advanced collapse. Pedicled distal radius and free vascularized bone grafts (VBGs) offer hand surgeons an alternative treatment option in the management of carpal bone nonunion. VBGs are also indicated in the treatment of avascular necrosis of the scaphoid (Preiser's disease), lunate (Kienböck's disease), and capitate. Relative contraindications to pedicled dorsal radius vascularized bone grafting include humpback deformity, carpal instability, or collapse. The free medial femoral condyle bone graft has offered a novel treatment option for the humpback deformity to restore geometry of the carpus, otherwise not provided by pedicled grafts. In general, VBGs are contraindicated in the setting of a carpal bone without an intact cartilaginous shell, in advanced carpal collapse with degenerative changes, and in attempts to salvage small or collapsed bone fragments. Wrist salvage procedures are generally accepted as the more definitive treatment option under such circumstances. This manuscript offers a current review of the techniques and outcomes of VBGs to the carpal bones.

  3. Genetics Home Reference: Paget disease of bone

    MedlinePlus

    ... Conditions Paget disease of bone Paget disease of bone Enable Javascript to view the expand/collapse boxes. ... Open All Close All Description Paget disease of bone is a disorder that causes bones to grow ...

  4. Bones, Muscles, and Joints: The Musculoskeletal System

    MedlinePlus

    ... are where two bones meet. They make the skeleton flexible — without them, movement would be impossible. Muscles ... Bones and What Do They Do? The human skeleton has 206 bones. Our bones begin to develop ...

  5. Vitamin D, Calcium, and Bone Health

    MedlinePlus

    ... in Balance › Vitamin D, Calcium, and Bone Health Vitamin D, Calcium, and Bone Health March 2012 Download ... also helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin ...

  6. Altered bone turnover during spaceflight

    NASA Technical Reports Server (NTRS)

    Turner, R. T.; Morey, E. R.; Liu, C.; Baylink, D. J.

    1982-01-01

    Modifications in calcium metabolism during spaceflight were studied, using parameters that reflect bone turnover. Bone formation rate, medullary area, bone length, bone density, pore size distribution, and differential bone cell number were evaluated in growing rate both immediately after and 25 days after orbital spaceflights aboard the Soviet biological satellites Cosmos 782 and 936. The primary effect of space flight on bone turnover was a reversible inhibition of bone formation at the periosteal surface. A simultaneous increase in the length of the periosteal arrest line suggests that bone formation ceased along corresponding portions of that surface. Possible reasons include increased secretion of glucocorticoids and mechanical unloading of the skeleton due to near-weightlessness, while starvation and immobilization are excluded as causes.

  7. How Is Bone Cancer Diagnosed?

    MedlinePlus

    ... solid. The cancer can also appear as a hole in the bone. Sometimes doctors can see a ... the bone scan image as dense, gray to black areas, called “hot spots.” These areas suggest metastatic ...

  8. Bone regeneration during distraction osteogenesis.

    PubMed

    Amir, Lisa R; Everts, Vincent; Bronckers, Antonius L J J

    2009-07-01

    Bone has the capacity to regenerate in response to injury. During distraction osteogenesis, the renewal of bone is enhanced by gradual stretching of the soft connective tissues in the gap area between two separated bone segments. This procedure has received much clinical attention as a way to correct congenital growth retardation of bone tissue or to generate bone to fill skeletal defects. The process of bone regeneration involves a complex system of biological changes whereby mechanical stress is converted into a cascade of signals that activate cellular behavior resulting in (enhanced) formation of bone. Over the last decade, significant progress has been made in understanding the bone regeneration process during distraction osteogenesis. The mechanical and biological factors that are important for the success of the distraction treatment have been partially characterized and are discussed in this review.

  9. Pregnancy, Breastfeeding, and Bone Health

    MedlinePlus

    ... supported by your browser. Home Osteoporosis Women Pregnancy, Breastfeeding, and Bone Health Publication available in: PDF (63 ... to get enough calcium during pregnancy and breastfeeding. Breastfeeding and Bone Health Breastfeeding also affects a mother’s ...

  10. Graphite-reinforced bone cement

    NASA Technical Reports Server (NTRS)

    Knoell, A. C.

    1976-01-01

    Chopped graphite fibers added to surgical bone cement form bonding agent with mechanical properties closely matched to those of bone. Curing reaction produces less heat, resulting in reduced traumatization of body tissues. Stiffness is increased without affecting flexural strength.

  11. Cutting thin sections of bone

    NASA Technical Reports Server (NTRS)

    Ashley, W. W.

    1972-01-01

    Medical equipment for obtaining repetitive planoparallel sections of bone to study healing of bone structure under high gravity stress is described. Device consists of modified saw with diamond cutting edges. Construction of device and manner of use are explained.

  12. Bone and cancer: the osteoncology

    PubMed Central

    Ibrahim, Toni; Mercatali, Laura; Amadori, Dino

    2013-01-01

    Summary In recent years clinicians have witnessed a radical change in the relationship between bone and cancer, with in particular an increase in bone metastases incidence due to an improvement of patients survival. Bone metastases are responsible for the high morbidity in cancer patients with a strong clinical impact. For all these reasons, efforts have been directed to this important field with the foundation of the osteoncology, a new scientific and clinical branch involved in the management of patients with bone cancer disease, including primary bone tumors and bone metastases. Another innovative and important osteoncology topic is the Cancer Treatment Induced Bone Loss (CTIBL) that is mainly caused by antitumoral treatment with bone resorption induction. The diagnostic and therapeutic options are described briefly in order to highlight the importance of the multidisciplinary approach in this new field. PMID:24133529

  13. Bone-marrow transplant - slideshow

    MedlinePlus

    ... this page: //medlineplus.gov/ency/presentations/100112.htm Bone-marrow transplant - series—Normal anatomy To use the sharing ... Go to slide 4 out of 4 Overview Bone-marrow is a soft, fatty tissue found inside of ...

  14. A soluble bone morphogenetic protein type IA receptor increases bone mass and bone strength.

    PubMed

    Baud'huin, Marc; Solban, Nicolas; Cornwall-Brady, Milton; Sako, Dianne; Kawamoto, Yoshimi; Liharska, Katia; Lath, Darren; Bouxsein, Mary L; Underwood, Kathryn W; Ucran, Jeffrey; Kumar, Ravindra; Pobre, Eileen; Grinberg, Asya; Seehra, Jasbir; Canalis, Ernesto; Pearsall, R Scott; Croucher, Peter I

    2012-07-24

    Diseases such as osteoporosis are associated with reduced bone mass. Therapies to prevent bone loss exist, but there are few that stimulate bone formation and restore bone mass. Bone morphogenetic proteins (BMPs) are members of the TGFβ superfamily, which act as pleiotropic regulators of skeletal organogenesis and bone homeostasis. Ablation of the BMPR1A receptor in osteoblasts increases bone mass, suggesting that inhibition of BMPR1A signaling may have therapeutic benefit. The aim of this study was to determine the skeletal effects of systemic administration of a soluble BMPR1A fusion protein (mBMPR1A-mFc) in vivo. mBMPR1A-mFc was shown to bind BMP2/4 specifically and with high affinity and prevent downstream signaling. mBMPR1A-mFc treatment of immature and mature mice increased bone mineral density, cortical thickness, trabecular bone volume, thickness and number, and decreased trabecular separation. The increase in bone mass was due to an early increase in osteoblast number and bone formation rate, mediated by a suppression of Dickkopf-1 expression. This was followed by a decrease in osteoclast number and eroded surface, which was associated with a decrease in receptor activator of NF-κB ligand (RANKL) production, an increase in osteoprotegerin expression, and a decrease in serum tartrate-resistant acid phosphatase (TRAP5b) concentration. mBMPR1A treatment also increased bone mass and strength in mice with bone loss due to estrogen deficiency. In conclusion, mBMPR1A-mFc stimulates osteoblastic bone formation and decreases bone resorption, which leads to an increase in bone mass, and offers a promising unique alternative for the treatment of bone-related disorders.

  15. Imaging of the temporal bone.

    PubMed

    Abele, Travis A; Wiggins, Richard H

    2015-01-01

    A variety of congenital, infectious, inflammatory, vascular, and benign and malignant neoplastic pathology affects the temporal bone. Knowledge of normal temporal bone anatomy and space-specific differential diagnoses is key to imaging interpretation of temporal bone. Correlation with clinical history and physical examination is vital to making the correct diagnosis or providing an appropriate differential. Computed tomography and magnetic resonance imaging are complementary imaging modalities in the evaluation of temporal bone abnormalities.

  16. 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

  17. 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.

  18. Chemical makeup of microdamaged bone differs from undamaged bone.

    PubMed

    Ruppel, Meghan E; Burr, David B; Miller, Lisa M

    2006-08-01

    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-microm-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.

  19. Scaffold Design for Bone Regeneration

    PubMed Central

    Polo-Corrales, Liliana; Latorre-Esteves, Magda; Ramirez-Vick, Jaime E.

    2014-01-01

    The use of bone grafts is the standard to treat skeletal fractures, or to replace and regenerate lost bone, as demonstrated by the large number of bone graft procedures performed worldwide. The most common of these is the autograft, however, its use can lead to complications such as pain, infection, scarring, blood loss, and donor-site morbidity. The alternative is allografts, but they lack the osteoactive capacity of autografts and carry the risk of carrying infectious agents or immune rejection. Other approaches, such as the bone graft substitutes, have focused on improving the efficacy of bone grafts or other scaffolds by incorporating bone progenitor cells and growth factors to stimulate cells. An ideal bone graft or scaffold should be made of biomaterials that imitate the structure and properties of natural bone ECM, include osteoprogenitor cells and provide all the necessary environmental cues found in natural bone. However, creating living tissue constructs that are structurally, functionally and mechanically comparable to the natural bone has been a challenge so far. This focus of this review is on the evolution of these scaffolds as bone graft substitutes in the process of recreating the bone tissue microenvironment, including biochemical and biophysical cues. PMID:24730250

  20. Update on pediatric bone health.

    PubMed

    Henwood, Maria J; Binkovitz, Larry

    2009-01-01

    Osteoporosis has long been considered a health problem unique to older adults. Children and adolescents with chronic illness, primary bone disease, or poor nutrition, however, are also predisposed to impaired skeletal health. The present review discusses normal skeletal development, risk factors for low bone mineral density, and prevention and treatment strategies that can help optimize bone health in the pediatric population.

  1. Breast Cancer and Bone Loss

    MedlinePlus

    ... Balance › Breast Cancer and Bone Loss Fact Sheet Breast Cancer and Bone Loss July, 2010 Download PDFs English ... JoAnn Pinkerton, MD What is the link between breast cancer and bone loss? Certain treatments for breast cancer ...

  2. [Cytokines in bone diseases. Wnt signal and excessive bone formation].

    PubMed

    Hosoi, Takayuki

    2010-10-01

    Wnt signal has been known to play various roles in many organ from the beginning of embryogensis. Its role in bone metabolism has also been investigated and established. Lipoprotein receptor-related protein 5 (LRP5) is one of the important molecules in wnt signal pathway whose point mutations are related to both bone loss and excessive bone formation. Wnt signal is involved in the action of sclerostin which was found as a gene for osteosclerosis, one of the diseases of excessive bone formation. Wnt signal is keeping the position as an important research target for normal and pathological bone formation.

  3. Bone vascularization: a way to study bone microarchitecture?

    NASA Astrophysics Data System (ADS)

    Blery, P.; Autrusseau, F.; Crauste, E.; Freuchet, Erwan; Weiss, Pierre; Guédon, J.-P.; Amouriq, Y.

    2014-03-01

    Trabecular bone and its microarchitecture are of prime importance for health. Studying vascularization helps to better know the relationship between bone and vascular microarchitecture. This research is an animal study (nine Lewis rats), based on the perfusion of vascularization by a contrast agent (a mixture of 50% barium sulfate with 1.5% of gelatin) before euthanasia. The samples were studied by micro CT at a resolution of 9μm. Softwares were used to show 3D volumes of bone and vessels, to calculate bone and vessels microarchitecture parameters. This study aims to understand simultaneously the bone microarchitecture and its vascular microarchitecture.

  4. Multiscale Modeling of Bone

    DTIC Science & Technology

    2014-12-01

    Dimensional Haversian System Structure ............................. 48 2. Layered Composite Model...concentric layers forms an osteon, or Haversian system , and is the representative subunit of cortical bone [5]. They contain a Haversian canal, which...skeletal system , HA serves as the storage site for ions [16]. HA is responsible for 99%, 90%, 90% and 50% of the body’s store of calcium, phosphorus

  5. Bones of the Earth

    ERIC Educational Resources Information Center

    Correa, Jose Miguel

    2014-01-01

    The film "Bones of the Earth" (Riglin, Cunninham & Correa, 2014) is an experience in collective inquiry and visual creation based on arts-based research. Starting from the meeting of different subjectivities and through dialogue, planning, shooting and editing, an audiovisual text that reconstructs a reflexive process of collective…

  6. Calcium and bones

    MedlinePlus

    ... very bad at absorbing calcium. Most people absorb only 15% to 20% of the calcium they eat in their diet. Vitamin D is the hormone that helps the gut absorb more calcium. Many older adults have common risks that make bone health worse. ...

  7. Management of Bone Sarcoma.

    PubMed

    Gutowski, Christina J; Basu-Mallick, Atrayee; Abraham, John A

    2016-10-01

    Treatment of bone sarcoma requires careful planning and involvement of an experienced multidisciplinary team. Significant advancements in systemic therapy, radiation, and surgery in recent years have contributed to improved functional and survival outcomes for patients with these difficult tumors, and emerging technologies hold promise for further advancement.

  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. Are Bones Alive?

    ERIC Educational Resources Information Center

    Caravita, Silvia; Falchetti, Elisabetta

    2005-01-01

    Many studies have investigated the classification of living things. Our study deals with a different problem: the attribution of life to one component of a living organism, specifically the bones. The task involves not only specifying what we mean by "alive", but also requires "informed thinking" leading to an understanding of…

  10. Calcaneus (Heel Bone) Fractures

    MedlinePlus

    ... Calcaneus (Heel Bone) Fractures cont. Page ( 5 ) • Early motion. Many doctors encourage motion of the foot and ankle early in the ... therapy. Specific exercises can improve the range of motion in your foot and ankle, and strengthen supporting ...

  11. Infrared laser bone ablation

    SciTech Connect

    Nuss, R.C.; Fabian, R.L.; Sarkar, R.; Puliafito, C.A.

    1988-01-01

    The bone ablation characteristics of five infrared lasers, including three pulsed lasers (Nd:YAG, lambda = 1064 micron; Hol:YSGG, lambda = 2.10 micron; and Erb:YAG, lambda = 2.94 micron) and two continuous-wave lasers (Nd:YAG, lambda = 1.064 micron; and CO/sub 2/, lambda = 10.6 micron), were studied. All laser ablations were performed in vitro, using moist, freshly dissected calvarium of guinea pig skulls. Quantitative etch rates of the three pulsed lasers were calculated. Light microscopy of histologic sections of ablated bone revealed a zone of tissue damage of 10 to 15 micron adjacent to the lesion edge in the case of the pulsed Nd:YAG and the Erb:YAG lasers, from 20 to 90 micron zone of tissue damage for bone ablated by the Hol:YSGG laser, and 60 to 135 micron zone of tissue damage in the case of the two continuous-wave lasers. Possible mechanisms of bone ablation and tissue damage are discussed.

  12. [Radiotherapy of bone metastases].

    PubMed

    Thureau, S; Vieillard, M-H; Supiot, S; Lagrange, J-L

    2016-09-01

    Radiotherapy plays a major role in palliative treatment of bone metastases. Recent developments of stereotactic radiotherapy and intensity modulated radiation therapy give the possibility to treat oligometastatic diseases. The objective of this paper is to report indications and treatment modalities of radiotherapy in these situations.

  13. Calcium and bones (image)

    MedlinePlus

    ... for the growth, maintenance, and reproduction of the human body. Bones, like other tissues in the body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the formation of and maintenance of healthy teeth.

  14. Low Bone Density

    MedlinePlus

    ... Media Kit NOF Events Blog Advocacy NOF Store Shopping Cart Home › Patients › Diagnosis Information › Bone Density Exam/ ... Media Kit NOF Events Blog Advocacy NOF Store Shopping Cart Contact Us Privacy Policy Legal Disclaimer Medical ...

  15. Hyponatremia and bone disease.

    PubMed

    Negri, Armando Luis; Ayus, Juan Carlos

    2016-09-24

    Hip fractures represent a serious health risk in the elderly, causing substantial morbidity and mortality. There is now a considerable volume of literature suggesting that chronic hyponatremia increases the adjusted odds ratio (OR) for both falls and fractures in the elderly. Hyponatremia appears to contribute to falls and fractures by two mechanisms. First, it produces mild cognitive impairment, resulting in unsteady gait and falls; this is probably due to the loss of glutamate (a neurotransmitter involved in gait function) as an osmolyte during brain adaptation to chronic hyponatremia. Second, hyponatremia directly contributes to osteoporosis and increased bone fragility by inducing increased bone resorption to mobilize sodium stores in bone. Low extracellular sodium directly stimulates osteoclastogenesis and bone resorptive activity through decreased cellular uptake of ascorbic acid and the induction of oxidative stress; these effects occur in a sodium level-dependent manner. Hyponatremic patients have elevated circulating arginine-vasopressin (AVP) levels, and AVP acting on two receptors expressed in osteoblasts and osteoclasts, Avpr1α and Avpr2, can increase bone resorption and decrease osteoblastogenesis. Should we be screening for low serum sodium in patients with osteoporosis or assessing bone mineral density (BMD) in patients with hyponatremia? The answers to these questions have not been established. Definitive answers will require randomized controlled studies that allocate elderly individuals with mild hyponatremia to receive either active treatment or no treatment for hyponatremia, to determine whether correction of hyponatremia prevents gait disturbances and changes in BMD, thereby reducing the risk of fractures. Until such studies are conducted, physicians caring for elderly patients must be aware of the association between hyponatremia and bone disorders. As serum sodium is a readily available, simple, and affordable biochemical measurement

  16. 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.

  17. Evolutionary Patterns of Bone Histology and Bone Compactness in Xenarthran Mammal Long Bones

    PubMed Central

    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

  18. Multicellular tumor spheroid interactions with bone cells and bone

    SciTech Connect

    Wezeman, F.H.; Guzzino, K.M.; Waxler, B.

    1985-10-01

    In vitro coculture techniques were used to study HSDM1C1 murine fibrosarcoma multicellular tumor spheroid (HSDM1C1-MTS) interactions with mouse calvarial bone cells having osteoblastic characteristics and mouse bone explants. HSDM1C1-MTS attached to confluent bone cell monolayers and their attachment rate was quantified. HSDM1C1-MTS interaction with bone cells was further demonstrated by the release of /sup 3/H-deoxyuridine from prelabeled bone cells during coculture with multicellular tumor spheroids. HSDM1C1-MTS-induced cytotoxicity was mimicked by the addition of 10(-5) M prostaglandin E2 (PGE2) to /sup 3/H-deoxyuridine-labeled bone cells. The effects of low (10(-9) M) and high (10(-5) M) concentrations of PGE2 on bone cell proliferation were also studied. Higher concentrations of PGE2 inhibited bone cell proliferation. HSDM1C1-MTS resorbed living explants in the presence of indomethacin, suggesting that other tumor cell products may also participate in bone resorption. HSDM1C1-MTS caused direct bone resorption as measured by the significantly elevated release of /sup 45/Ca from prelabeled, devitalized calvaria. However, the growth of a confluent bone cell layer on devitalized, /sup 45/Ca-prelabeled calvaria resulted in a significant reduction in the amount of /sup 45/Ca released subsequent to the seeding of HSDM1C1-MTS onto the explants. Bone cells at the bone surface may act as a barrier against invasion and tumor cell-mediated bone resorption. Violation of this cellular barrier is achieved, in part, by tumor cell products.

  19. Predicting bone remodeling around tissue- and bone-level dental implants used in reduced bone width.

    PubMed

    Eser, Atilim; Tonuk, Ergin; Akca, Kivanc; Dard, Michel M; Cehreli, Murat Cavit

    2013-09-03

    The objective of this study was to predict time-dependent bone remodeling around tissue- and bone-level dental implants used in patients with reduced bone width. The remodeling of bone around titanium tissue-level, and titanium and titanium-zirconium alloy bone-level implants was studied under 100 N oblique load for one month by implementing the Stanford theory into three-dimensional finite element models. Maximum principal stress, minimum principal stress, and strain energy density in peri-implant bone and displacement in x- and y- axes of the implant were evaluated. Maximum and minimum principal stresses around tissue-level implant were higher than bone-level implants and both bone-level implants experienced comparable stresses. Total strain energy density in bone around titanium implants slightly decreased during the first two weeks of loading followed by a recovery, and the titanium-zirconium implant showed minor changes in the axial plane. Total strain energy density changes in the loading and contralateral sides were higher in tissue-level implant than other implants in the cortical bone at the horizontal plane. The displacement values of the implants were almost constant over time. Tissue-level implants were associated with higher stresses than bone-level implants. The time-dependent biomechanical outcome of titanium-zirconium alloy bone-level implant was comparable to the titanium implant.

  20. Bone repair and stem cells.

    PubMed

    Ono, Noriaki; Kronenberg, Henry M

    2016-10-01

    Bones are an important component of vertebrates; they grow explosively in early life and maintain their strength throughout life. Bones also possess amazing capabilities to repair-the bone is like new without a scar after complete repair. In recent years, a substantial progress has been made in our understanding on mammalian bone stem cells. Mouse genetic models are powerful tools to understand the cell lineage, giving us better insights into stem cells that regulate bone growth, maintenance and repair. Recent findings about these stem cells raise new questions that require further investigations.

  1. Digital electronic bone growth stimulator

    DOEpatents

    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.

  2. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, James W.

    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.

  3. Resorbable calcium phosphate bone substitute.

    PubMed

    Knaack, D; Goad, M E; Aiolova, M; Rey, C; Tofighi, A; Chakravarthy, P; Lee, D D

    1998-01-01

    The in vitro and in vivo properties of a novel, fully resorbable, apatitic calcium phosphate bone substitute (ABS) are described. The ABS was prepared from calcium phosphate precursors that were hydrated to form an injectable paste that hardens endothermically at 37 degrees C to form a poorly crystalline apatitic calcium phosphate (PCA). The PCA reaction product is stable in vivo as determined by FTIR and XRD analysis of rabbit intramuscular implants of ABS retrieved 4, 7, and 14 days postimplantation. Bone formation and resorption characteristics of the ABS material were characterized in a canine femoral slot defect model. Femoral slot defects in dogs were filled with either autologous bone implants or the ABS material. Sections of femoral bone defect site from animals sacrificed at 3, 4, 12, 26, and 52 weeks demonstrated that new bone formation proceeded similarly in both autograft and ABS filled slots. Defects receiving either material were filled with trabecular bone in the first 3 to 4 weeks after implantation; lamellar or cortical bone formation was well established by week 12. New bone formation in ABS filled defects followed a time course comparable to autologous bone graft filled defects. Histomorphometric evaluation of ABS resorption and new bone formation indicated that the ABS material was greater than 99% resorbed within 26 weeks; residual ABS occupied 0.36+/-0.36% (SEM, n = 4) of the original defect area at 26 weeks. Quantitatively and qualitatively, the autograft and ABS were associated with similar new bone growth and defect filling characteristics.

  4. Bone remodeling after renal transplantation.

    PubMed

    Bellorin-Font, Ezequiel; Rojas, Eudocia; Carlini, Raul G; Suniaga, Orlando; Weisinger, José R

    2003-06-01

    Several studies have indicated that bone alterations after transplantation are heterogeneous. Short-term studies after transplantation have shown that many patients exhibit a pattern consistent with adynamic bone disease. In contrast, patients with long-term renal transplantation show a more heterogeneous picture. Thus, while adynamic bone disease has also been described in these patients, most studies show decreased bone formation and prolonged mineralization lag-time faced with persisting bone resorption, and even clear evidence of generalized or focal osteomalacia in many patients. Thus, the main alterations in bone remodeling are a decrease in bone formation and mineralization up against persistent bone resorption, suggesting defective osteoblast function, decreased osteoblastogenesis, or increased osteoblast death rates. Indeed, recent studies from our laboratory have demonstrated that there is an early decrease in osteoblast number and surfaces, as well as in reduced bone formation rate and delayed mineralization after transplantation. These alterations are associated with an early increase in osteoblast apoptosis that correlates with low levels of serum phosphorus. These changes were more frequently observed in patients with low turnover bone disease. In contrast, PTH seemed to preserve osteoblast survival. The mechanisms of hypophosphatemia in these patients appear to be independent of PTH, suggesting that other phosphaturic factors may play a role. However, further studies are needed to determine the nature of a phosphaturic factor and its relationship to the alterations of bone remodeling after transplantation.

  5. 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.

  6. Function of osteocytes in bone.

    PubMed

    Aarden, E M; Burger, E H; Nijweide, P J

    1994-07-01

    Although the structural design of cellular bone (i.e., bone containing osteocytes that are regularly spaced throughout the bone matrix) dates back to the first occurrence of bone as a tissue in evolution, and although osteocytes represent the most abundant cell type of bone, we know as yet little about the role of the osteocyte in bone metabolism. Osteocytes descend from osteoblasts. They are formed by the incorporation of osteoblasts into the bone matrix. Osteocytes remain in contact with each other and with cells on the bone surface via gap junction-coupled cell processes passing through the matrix via small channels, the canaliculi, that connect the cell body-containing lacunae with each other and with the outside world. During differentiation from osteoblasts to mature osteocyte the cells lose a large part of their cell organelles. Their cell processes are packed with microfilaments. In this review we discuss the various theories on osteocyte function that have taken in consideration these special features of osteocytes. These are 1) osteocytes are actively involved in bone turnover; 2) the osteocyte network is through its large cell-matrix contact surface involved in ion exchange; and 3) osteocytes are the mechanosensory cells of bone and play a pivotal role in functional adaptation of bone. In our opinion, especially the last theory offers an exciting concept for which some biomechanical, biochemical, and cell biological evidence is already available and which fully warrants further investigations.

  7. [Bone lesion in multiple myeloma].

    PubMed

    Ise, Mikiko; Takagi, Toshiyuki

    2007-12-01

    Bone destruction is a hallmark of multiple myeloma(MM). Almost all MM patients develop osteolytic bone lesions that can cause pathologic fractures and severe bone pain. Osteolytic lesions result from increased bone resorption due to osteoclast stimulation and decreased bone formation due to osteoblast inhibition. Plain radiography, CT, and MRI are established imaging techniques in MM. FDG-PET imaging is promising newer scanning technique under current evaluation. The aggressive features of MM bone lesions have significantly contributed to poor prognosis. Therefore, a systemic approach to analgesia, which includes radiotherapy and orthopedic intervention, must be applied as a part of the comprehensive care plan of MM patient. Bisphosphonates have been shown to reduce vertebral fractures and bone pain.

  8. [Vitamin K and bone quality].

    PubMed

    Hara, Kuniko; Akiyama, Yasuhiro

    2007-11-01

    Meta-analysis involving previous clinical studies showed that VK(2) decreased the incidence of fracture. In particular, the results based on the data on bone mineral density and fracture suggested that VK(2) improves bone quality. Preclinical studies regarding bone quality reported that VK(2) improved the trabecular microarchitecture (connectivity and width) in an ovariectomized model, and that VK(2) increased the bone strength without influencing the bone mineral content in a model fed a low-Mg diet and a vitamin C deficiency model, increasing the collagen level and proline hydroxylation. Thus, improvement in bone quality via actions on the bone geometry and collagen level/quality may be involved in a VK(2)-related decrease in the incidence of new fracture in clinical studies.

  9. Molecular Mechanisms of Bone Metastasis.

    PubMed

    Weidle, Ulrich H; Birzele, Fabian; Kollmorgen, Gwendlyn; Rüger, Rüdiger

    2016-01-01

    Metastasis of breast and prostate cancer as well as multiple myeloma to the bones represents a significant medical problem. We herein discuss the molecular basis of the creation of pre-metastatic niches, the process of bone metastasis and the phenomenon of tumor dormancy in the bone marrow as well as its regulation. We describe the identification and validation of genes mediating bone metastasis by use of pre-clinical models of bone metastasis. Additionally, we discuss the role of small integrin binding N-linked glycoproteins (SIBLINGS), the chemokine/chemokine receptor CXCL12/CXCR4 pathway and the role of micro RNAs (miRNAs) as mediators of bone metastasis. Finally, we summarize clinical achievements for the treatment of bone metastases.

  10. Hypothalamic control of bone metabolism.

    PubMed

    Sharan, Kunal; Yadav, Vijay K

    2014-10-01

    Bones are structures in vertebrates that provide support to organs, protect soft organs, and give them shape and defined features, functions that are essential for their survival. To perform these functions, bones are constantly renewed throughout life. The process through which bones are renewed is known as bone remodeling, an energy demanding process sensitive to changes in energy homeostasis of the organism. A close interplay takes place between the diversity of nutritional cues and metabolic signals with different elements of the hypothalamic circuits to co-ordinate energy metabolism with the regulation of bone mass. In this review, we focus on how mouse and human genetics have elucidated the roles of hormonal signals and neural circuits that originate in, or impinge on, the hypothalamus in the regulation of bone mass. This will help to understand the mechanisms whereby regulation of bone is gated and dynamically regulated by the hypothalamus.

  11. Cancer to bone: a fatal attraction

    PubMed Central

    Weilbaecher, Katherine N.; Guise, Theresa A.; McCauley, Laurie K.

    2013-01-01

    When cancer metastasizes to bone, considerable pain and deregulated bone remodelling occurs, greatly diminishing the possibility of cure. Metastasizing tumour cells mobilize and sculpt the bone microenvironment to enhance tumour growth and to promote bone invasion. Understanding the crucial components of the bone microenvironment that influence tumour localization, along with the tumour-derived factors that modulate cellular and protein matrix components of bone to favour tumour expansion and invasion, is central to the pathophysiology of bone metastases. Basic findings of tumour–bone interactions have uncovered numerous therapeutic opportunities that focus on the bone microenvironment to prevent and treat bone metastases. PMID:21593787

  12. Response of canine bone to a synthetic bone graft material.

    PubMed

    St John, K R; Zardiackas, L D; Black, R J; Armstrong, R

    1993-01-01

    A model simulating a spiral diaphyseal fracture with butterfly fragments and bone loss was utilized to evaluate an hydroxyapatite/tricalcium phosphate, and collagen composite bone graft substitute in twelve dogs. The resultant grafted and contralateral control femora were tested in torsion at one year. This study examines the histological response to the graft material as well as crack propagation and fracture surface morphology using light microscopy and SEM. SEM and gross evaluation of the grafted bones revealed that 8/12 had fractured through bone outside the osteotomy site and all fractures included bone outside the graft site. No graft material was demonstrated at the points of initiation or termination of fracture for any of the bones. It was apparent that recorticalization had begun to occur at the graft site but the canal had not yet fully formed. The HA/TCP was seen to be tightly bound in tissue which had the appearance of new bone. Bone was found to be in direct apposition to the surface of the ceramic and within pores with no intervening soft tissue. Much of the new bone had remodeled into well organized Haversian systems with some patchy areas of woven bone and osteoid seen with polarized light illumination.

  13. Osteopontin Deficiency Increases Bone Fragility but Preserves Bone Mass

    PubMed Central

    Thurner, Philipp J.; Chen, Carol G.; Ionova-Martin, Sophi; Sun, Luling; Harman, Adam; Porter, Alexandra; Ager, Joel W.; Ritchie, Robert O.; Alliston, Tamara

    2010-01-01

    The ability of bone to resist catastrophic failure is critically dependent upon the material properties of bone matrix, a composite of hydroxyapatite, collagen type I, and noncollagenous proteins. These properties include elastic modulus, hardness, and fracture toughness. Like other aspects of bone quality, matrix material properties are biologically-defined and can be disrupted in skeletal disease. While mineral and collagen have been investigated in greater detail, the contribution of noncollagenous proteins such as osteopontin to bone matrix material properties remains unclear. Several roles have been ascribed to osteopontin in bone, many of which have the potential to impact material properties. To elucidate the role of osteopontin in bone quality, we evaluated the structure, composition, and material properties of bone from osteopontin-deficient mice and wild-type littermates at several length scales. Most importantly, the results show that osteopontin deficiency causes a 30% decrease in fracture toughness, suggesting an important role for OPN in preventing crack propagation. This significant decline in fracture toughness is independent of changes in whole bone mass, structure, or matrix porosity. Using nanoindentation and quantitative backscattered electron imaging to evaluate osteopontin-deficient bone matrix at the micrometer level, we observed a significant reduction in elastic modulus and increased variability in calcium concentration. Matrix heterogeneity was also apparent at the ultrastructural level. In conclusion, we find that osteopontin is essential for the fracture toughness of bone, and reduced toughness in osteopontin-deficient bone may be related to the increased matrix heterogeneity observed at the micro-scale. By exploring the effects of osteopontin-deficiency on bone matrix material properties, composition and organization, this study suggests that reduced fracture toughness is one mechanism by which loss of noncollagenous proteins contribute

  14. Osteopontin deficiency increases bone fragility but preserves bone mass.

    PubMed

    Thurner, Philipp J; Chen, Carol G; Ionova-Martin, Sophi; Sun, Luling; Harman, Adam; Porter, Alexandra; Ager, Joel W; Ritchie, Robert O; Alliston, Tamara

    2010-06-01

    The ability of bone to resist catastrophic failure is critically dependent upon the material properties of bone matrix, a composite of hydroxyapatite, collagen type I, and noncollagenous proteins. These properties include elastic modulus, hardness, and fracture toughness. Like other aspects of bone quality, matrix material properties are biologically-defined and can be disrupted in skeletal disease. While mineral and collagen have been investigated in greater detail, the contribution of noncollagenous proteins such as osteopontin to bone matrix material properties remains unclear. Several roles have been ascribed to osteopontin in bone, many of which have the potential to impact material properties. To elucidate the role of osteopontin in bone quality, we evaluated the structure, composition, and material properties of bone from osteopontin-deficient mice and wild-type littermates at several length scales. Most importantly, the results show that osteopontin deficiency causes a 30% decrease in fracture toughness, suggesting an important role for OPN in preventing crack propagation. This significant decline in fracture toughness is independent of changes in whole bone mass, structure, or matrix porosity. Using nanoindentation and quantitative backscattered electron imaging to evaluate osteopontin-deficient bone matrix at the micrometer level, we observed a significant reduction in elastic modulus and increased variability in calcium concentration. Matrix heterogeneity was also apparent at the ultrastructural level. In conclusion, we find that osteopontin is essential for the fracture toughness of bone, and reduced toughness in osteopontin-deficient bone may be related to the increased matrix heterogeneity observed at the micro-scale. By exploring the effects of osteopontin deficiency on bone matrix material properties, composition and organization, this study suggests that reduced fracture toughness is one mechanism by which loss of noncollagenous proteins contribute

  15. Acidic microenvironment and bone pain in cancer-colonized bone

    PubMed Central

    Yoneda, Toshiyuki; Hiasa, Masahiro; Nagata, Yuki; Okui, Tatsuo; White, Fletcher A

    2015-01-01

    Solid cancers and hematologic cancers frequently colonize bone and induce skeletal-related complications. Bone pain is one of the most common complications associated with cancer colonization in bone and a major cause of increased morbidity and diminished quality of life, leading to poor survival in cancer patients. Although the mechanisms responsible for cancer-associated bone pain (CABP) are poorly understood, it is likely that complex interactions among cancer cells, bone cells and peripheral nerve cells contribute to the pathophysiology of CABP. Clinical observations that specific inhibitors of osteoclasts reduce CABP indicate a critical role of osteoclasts. Osteoclasts are proton-secreting cells and acidify extracellular bone microenvironment. Cancer cell-colonized bone also releases proton/lactate to avoid intracellular acidification resulting from increased aerobic glycolysis known as the Warburg effect. Thus, extracellular microenvironment of cancer-colonized bone is acidic. Acidosis is algogenic for nociceptive sensory neurons. The bone is densely innervated by the sensory neurons that express acid-sensing nociceptors. Collectively, CABP is evoked by the activation of these nociceptors on the sensory neurons innervating bone by the acidic extracellular microenvironment created by bone-resorbing osteoclasts and bone-colonizing cancer cells. As current treatments do not satisfactorily control CABP and can elicit serious side effects, new therapeutic interventions are needed to manage CABP. Understanding of the cellular and molecular mechanism by which the acidic extracellular microenvironment is created in cancer-colonized bone and by which the expression and function of the acid-sensing nociceptors on the sensory neurons are regulated would facilitate to develop novel therapeutic approaches for the management of CABP. PMID:25987988

  16. BoneNET: a network model of bone microstructure and dynamics.

    PubMed

    Kim, Taehyong; Bone, Lawrence; Ramanathan, Murali; Zhang, Aidong

    2013-01-01

    We develop a network model of bone microstructure and dynamics, BoneNET, which is capable of quantitative assessment of Bone Mineral Density (BMD) and bone remodelling dynamics. First, we introduce a network model of bone microstructure by describing structural properties and process of bone network modelling. Secondly, we explain a mathematical model of bone microstructure by analysing the density for mineralised fibres of bone microstructure. Finally, we provide a bone remodelling dynamics among osteoblast and osteoclast and study bone networks by proposing several measurements to calculate bone strength and identify critical elements in bone microstructure.

  17. Bridge of bone canthopexy.

    PubMed

    Yaremchuk, Michael J; Chen, Yi-Chieh

    2009-01-01

    Bridge of bone canthopexy has utility when significant movements of canthal position are required. It is a technique whereby the lateral canthal structures are purchased with a figure-of-eight suture of titanium wire. Drill holes are placed in the lateral orbital rim using the zygomaticofrontal sutures as reference landmarks. A canthal fixation point (the inferior drill hole) creates a measured distance from a fixed anatomic point (the zygomaticofrontal suture) assuring accurate and symmetric canthus positioning. Wire suture fixation over the bridge of bone created by the two drill holes provides maximum stability to counter soft tissue deforming forces. Fine adjustments can be made to the canthal position by twisting or untwisting the wire ends.

  18. Radiotherapy for bone pain.

    PubMed Central

    Needham, P R; Mithal, N P; Hoskin, P J

    1994-01-01

    Painful bone metastases are a common problem for cancer patients. Although current evidence supports the use of a single fraction of radiotherapy as the treatment of choice, many radiotherapists, for a variety of reasons, continue to use fractionated regimens. Over one six month period 105 patients received external beam irradiation for painful bone metastases at the Royal London Hospital (RLH). Thirty-one per cent of the patients were aged 70 or over. The treatment of 97 of these patients was assessed. They had a total of 280 sites treated over the course of their disease. Fifty-nine per cent of sites treated received a fractionated course of radiotherapy. Site significantly influenced fractionation. Overall response rates of 82% were achieved. Fractionation did not appear to influence this. Ten patients received large field irradiation. Fifteen patients had five or more sites irradiated, of whom only one received hemibody irradiation. PMID:7523672

  19. 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.

  20. Androgens and Bone

    PubMed Central

    Clarke, Bart L.; Khosla, Sundeep

    2009-01-01

    Testosterone is the major gonadal sex steroid produced by the testes in men. Testosterone is also produced in smaller amounts by the ovaries in women. The adrenal glands produce the weaker androgens dehydroepiandrosterone, dehydroepiandrosterone sulfate, and androstenedione. These androgens collectively affect skeletal homeostasis throughout life in both men and women, particularly at puberty and during adult life. Because testosterone can be metabolized to estradiol by the aromatase enzyme, there has been controversy as to which gonadal sex steroid has the greater skeletal effect. The current evidence suggests that estradiol plays a greater role in maintenance of skeletal health than testosterone, but that androgens also have direct beneficial effects on bone. Supraphysiological levels of testosterone likely have similar effects on bone as lower levels via direct interaction with androgen receptors, as well as effects mediated by estrogen receptors after aromatization to estradiol. Whether high doses of synthetic, non-aromatizable androgens may, in fact, be detrimental to bone due to suppression of endogenous testosterone (and estrogen) levels is a potential concern that warrants further study. PMID:18992761

  1. 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.

  2. Bone Metabolism on ISS Missions

    NASA Technical Reports Server (NTRS)

    Smith, S. M.; Heer, M. A.; Shackelford, L. C.; Zwart, S. R.

    2014-01-01

    Spaceflight-induced bone loss is associated with increased bone resorption (1, 2), and either unchanged or decreased rates of bone formation. Resistive exercise had been proposed as a countermeasure, and data from bed rest supported this concept (3). An interim resistive exercise device (iRED) was flown for early ISS crews. Unfortunately, the iRED provided no greater bone protection than on missions where only aerobic and muscular endurance exercises were available (4, 5). In 2008, the Advanced Resistive Exercise Device (ARED), a more robust device with much greater resistance capability, (6, 7) was launched to the ISS. Astronauts who had access to ARED, coupled with adequate energy intake and vitamin D status, returned from ISS missions with bone mineral densities virtually unchanged from preflight (7). Bone biochemical markers showed that while the resistive exercise and adequate energy consumption did not mitigate the increased bone resorption, bone formation was increased (7, 8). The typical drop in circulating parathyroid hormone did not occur in ARED crewmembers. In 2014, an updated look at the densitometry data was published. This study confirmed the initial findings with a much larger set of data. In 42 astronauts (33 male, 9 female), the bone mineral density response to flight was the same for men and women (9), and those with access to the ARED did not have the typical decrease in bone mineral density that was observed in early ISS crewmembers with access to the iRED (Figure 1) (7). Biochemical markers of bone formation and resorption responded similarly in men and women. These data are encouraging, and represent the first in-flight evidence in the history of human space flight that diet and exercise can maintain bone mineral density on long-duration missions. However, the maintenance of bone mineral density through bone remodeling, that is, increases in both resorption and formation, may yield a bone with strength characteristics different from those

  3. Denosumab for bone diseases: translating bone biology into targeted therapy.

    PubMed

    Tsourdi, Elena; Rachner, Tilman D; Rauner, Martina; Hamann, Christine; Hofbauer, Lorenz C

    2011-12-01

    Signalling of receptor activator of nuclear factor-κB (RANK) ligand (RANKL) through RANK is a critical pathway to regulate the differentiation and activity of osteoclasts and, hence, a master regulator of bone resorption. Increased RANKL activity has been demonstrated in diseases characterised by excessive bone loss such as osteoporosis, rheumatoid arthritis and osteolytic bone metastases. The development and approval of denosumab, a fully MAB against RANKL, has heralded a new era in the treatment of bone diseases by providing a potent, targeted and reversible inhibitor of bone resorption. This article summarises the molecular and cellular biology of the RANKL/RANK system and critically reviews preclinical and clinical studies that have established denosumab as a promising novel therapy for metabolic and malignant bone diseases. We will discuss the potential indications for denosumab along with a critical review of safety and analyse its potential within the concert of established therapies.

  4. 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 (μ-CT), high-resolution MR (hrMR) and, microRM (μRM), 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

  5. Bone Morphogenetic Proteins: Periodontal Regeneration

    PubMed Central

    Rao, Subramaniam M; Ugale, Gauri M; Warad, Shivaraj B

    2013-01-01

    Periodontitis is an infectious inflammatory disease that results in attachment loss and bone loss. Regeneration of the periodontal tissues entails de novo formation of cementum, periodontal ligament, and alveolar bone. Several different approaches are currently being explored to achieve complete, reliable, and reproducible regeneration of periodontal tissues. The therapeutic management of new bone formation is one of the key issues in successful periodontal regeneration. Bone morphogenetic proteins form a unique group of proteins within the transforming growth factor superfamily of genes and have a vital role in the regulation in the bone induction and maintenance. The activity of bone morphogenetic proteins was first identified in the 1960s, but the proteins responsible for bone induction were unknown until the purification and cloning of human bone morphogenetic proteins in the 1980s, because of their osteoinductive potential. Bone morphogenetic proteins have gained a lot of interest as therapeutic agents for treating periodontal defects. A systematic search for data related to the use of bone morphogenetic proteins for the regeneration of periodontal defects was performed to recognize studies on animals and human (PUBMED, MEDLINE, COCHRANE, and Google search). All the studies included showed noticeable regeneration of periodontal tissues with the use of BMP. PMID:23626951

  6. [Bone grafts using tissue engineering].

    PubMed

    Delloye, C

    2001-01-01

    An overview of bone grafts and, in particular, the allografts is presented. The availability of bone allografts, has promoted their use at the expense of the autograft. However, the loss of the cellular activity in an allograft, makes them less performant than an autograft. The use of an allograft in a small size defect can be advocated provided that the implantation technique is stringent. In case of a large segmental bone defect, an allograft can be considered whereas an autograft is not anymore possible. A massive bone allograft allows an anatomical reconstruction and the preservation of strong tendon insertions. In tumor surgery, a bone allograft has become one of the best options to reshape the skeleton. To offset the poor remodeling of the massive bone allografts, and to improve the take of small size bone allografts, researches are presently carried on, using tissue engineering in order to recover a cellular population. The aim is to combine an acellular bone graft with the cells of the recipient. Cells are procured from the bone marrow. Stromal cells are isolated, cultured, so that they will grow with an osteoblastic phenotype. They can be used alone or in association with a bone graft. It is believed that tomorrow such cellular therapy will become a routine procedure.

  7. Gene therapy for bone regeneration.

    PubMed

    Luo, Jeffrey; Sun, Michael H; Kang, Quan; Peng, Ying; Jiang, Wei; Luu, Hue H; Luo, Qing; Park, Jae Yoon; Li, Yien; Haydon, Rex C; He, Tong-Chuan

    2005-04-01

    Efficacious bone regeneration could revolutionize the clinical management of many bone and musculoskeletal disorders. Bone has the unique ability to regenerate and continuously remodel itself throughout life. However, clinical situations arise when bone is unable to heal itself, as with segmental bone loss, fracture non-union, and failed spinal fusion. This leads to significant morbidity and mortality. Current attempts at improved bone healing have been met with limited success, fueling the development of improved techniques. Gene therapy in many ways represents an ideal approach for augmenting bone regeneration. Gene therapy allows specific gene products to be delivered to a precise anatomic location. In addition, the level of transgene expression as well as the duration of expression can be regulated with current techniques. For bone regeneration, the gene of interest should be delivered to the fracture site, expressed at appropriate levels, and then deactivated once the fracture has healed. Delivery of biological factors, mostly bone morphogenetic proteins (BMPs), has yielded promising results both in animal and clinical studies. There has also been tremendous work on discovering new growth factors and exploring previously defined ones. Finally, significant advances are being made in the delivery systems of the genes, ranging from viral and non-viral vectors to tissue engineering scaffolds. Despite some public hesitation to gene therapy, its use has great potential to expand our ability to treat a variety of human bone and musculoskeletal disorders. It is conceivable that in the near future gene therapy can be utilized to induce bone formation in virtually any region of the body in a minimally invasive manner. As bone biology and gene therapy research progresses, the goal of successful human gene transfer for augmentation of bone regeneration draws nearer.

  8. Method for Automated Bone Shape Correction within Bone Distraction Procedure

    NASA Astrophysics Data System (ADS)

    Blynskiy, F. Yu

    2016-01-01

    The method for automated bone shape correction within bone distraction procedure is presented. High precision deformation angle measurement is provided by the software for X- Ray images processing. Special BDC v.1.0.1. application is designed. The purpose of the BDC is modeling of the bone geometry structure to calculate the appropriate distraction forces. The correction procedure control is realized by the hardware of the distraction system.

  9. Engineering bone grafts with enhanced bone marrow and native scaffolds.

    PubMed

    Hung, Ben P; Salter, Erin K; Temple, Josh; Mundinger, Gerhard S; Brown, Emile N; Brazio, Philip; Rodriguez, Eduardo D; Grayson, Warren L

    2013-01-01

    The translation of tissue engineering approaches to the clinic has been hampered by the inability to find suitable multipotent cell sources requiring minimal in vitro expansion. Enhanced bone marrow (eBM), which is obtained by reaming long bone medullary canals and isolating the solid marrow putty, has large quantities of stem cells and demonstrates significant potential to regenerate bone tissues. eBM, however, cannot impart immediate load-bearing mechanical integrity or maintain the gross anatomical structure to guide bone healing. Yet, its putty-like consistency creates a challenge for obtaining the uniform seeding necessary to effectively combine it with porous scaffolds. In this study, we examined the potential for combining eBM with mechanically strong, osteoinductive trabecular bone scaffolds for bone regeneration by creating channels into scaffolds for seeding the eBM. eBM was extracted from the femurs of adult Yorkshire pigs using a Synthes reamer-irrigator-aspirator device, analyzed histologically, and digested to extract cells and characterize their differentiation potential. To evaluate bone tissue formation, eBM was seeded into the channels in collagen-coated or noncoated scaffolds, cultured in osteogenic conditions for 4 weeks, harvested and assessed for tissue distribution and bone formation. Our data demonstrates that eBM is a heterogenous tissue containing multipotent cell populations. Furthermore, coating scaffolds with a collagen hydrogel significantly enhanced cellular migration, promoted uniform tissue development and increased bone mineral deposition. These findings suggest the potential for generating customized autologous bone grafts for treating critical-sized bone defects by combining a readily available eBM cell source with decellularized trabecular bone scaffolds.

  10. Bone Health in Adolescence.

    PubMed

    Carey, Dennis E; Golden, Neville H

    2015-08-01

    Osteoporosis occurs during childhood and adolescence as a heritable condition such as OI, with acquired disease (eg, IBD), or iatrogenically as a result of high-dose glucocorticoid therapy. However, the number of children affected by osteoporosis during youth is small compared to the numbers who will develop osteoporosis in adulthood. Prevention of adult osteoporosis requires that an optimal environment for the achievement of peak bone mass be established during the growing years. Detection of low BMD can be achieved using modalities such as DXA and pQCT. Standard radiologic studies, especially vertebral radiography, may also be helpful in children and adolescents at high risk for osteoporosis. It is critical to the development of healthy bones that adolescents have proper nutrition with adequate calcium and vitamin D intake and that they participate in regular physical activity (especially weight-bearing exercise). In the recent past, the dual goals of proper nutrition and exercise were not being achieved by many, if not most, adolescents. Those caring for adolescents should strive to educate teens and their families on the importance of dietary calcium and vitamin D as well as advocate for supportive environments in schools and communities that foster the development of healthy habits with regard to diet and exercise. In order to help identify the population at risk for osteoporosis, a bone health screen with assessment of calcium intake and determination of family history of adult osteoporosis (hip fracture, kyphosis) should be a routine part of adolescent health care. Universal screening of healthy adolescents with serum 25OHD levels is not recommended. Adolescents with conditions associated with reduced bone mass should undergo bone densitometry or other studies as a baseline, and BMD should be monitored at intervals no more frequently than yearly. Although controversy remains regarding the optimum dose of vitamin D for treatment of osteoporosis, all would

  11. 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.

  12. Roles of leptin in bone metabolism and bone diseases.

    PubMed

    Chen, Xu Xu; Yang, Tianfu

    2015-09-01

    Adipose tissue has been more accepted as an active contributor to whole body homeostasis, rather than just a fat depot, since leptin, a 16 kDa protein, was discovered as the product of the obese gene in 1994. With more and more studies conducted on this hormone, it has been shown that there is a close relationship between adipose tissue and bone, which have important effects on each other. Bone is the source of many hormones, such as osteocalcin, that can affect energy metabolism and then the anabolism or catabolism of fat tissue. In contrast, the adipose tissue synthesizes and releases a series of adipokines, which are involved in bone metabolism through direct or indirect effects on bone formation and resorption. Interestingly, leptin, one of the most important cytokines derived from fat tissue, seems to account for the largest part of effects on bone, through direct or indirect involvement in bone remodeling and by playing a significant role in many bone diseases, such as osteoporosis, osteoarthritis, rheumatic arthritis, bone tumors and even fractures. In this review, we will discuss the progress in leptin research, particularly focusing on the roles of leptin in bone diseases.

  13. Effect of cadmium on bone resorption in cultured fetal bone

    SciTech Connect

    Miyahara, T.; Miyakoshi, M.; Kozuka, H.

    1980-08-01

    Itai-itai disease which occurred in Toyama Prefecture, Japan, was thought to be due, at least partly, to chronic cadmium poisoning. Patients suffered severe pain in the waist, back and joints as well as kyphosis spinal column. In addition, x-ray film of these patients revealed abnormalities in the humerus and ribs. These bone lesions have been considered to be caused secondarily by dysfunction of other tissues, especially that of the kidneys, but there are some reports that the bone lesions appear before the occurrence of pathological changes in the kidneys of Cd-administered rat. It is currently unclear whether bone lesions by Cd are due to the direct action on the bone or indirect action which is caused by dysfunction of the kidney or intestine. To clarify the direct action of Cd on the bone, we studied the effect of Cd on the ossification of chick-embryo cultured bones biochemically and histologically. The results showed that Cd inhibited the bone matrix formation and brought about a malfunction in the ossification process. In the present work the effect of Cd on demineralization was studied using /sup 45/Ca-prelabeled bone in tissue culture and low levels of Cd were found to stimulate /sup 45/Ca from the bone.

  14. Carbon nanohorns accelerate bone regeneration in rat calvarial bone defect.

    PubMed

    Kasai, Takao; Matsumura, Sachiko; Iizuka, Tadashi; Shiba, Kiyotaka; Kanamori, Takeshi; Yudasaka, Masako; Iijima, Sumio; Yokoyama, Atsuro

    2011-02-11

    A recent study showed that carbon nanohorns (CNHs) have biocompatibility and possible medical uses such as in drug delivery systems. It was reported that some kinds of carbon nanomaterials such as carbon nanotubes were useful for bone formation. However, the effect of CNHs on bone tissue has not been clarified. The purpose of this study was to evaluate the effect of CNHs on bone regeneration and their possible application for guided bone regeneration (GBR). CNHs dispersed in ethanol were fixed on a porous polytetrafluoroethylene membrane by vacuum filtration. Cranial defects were created in rats and covered by a membrane with/without CNHs. At two weeks, bone formation under the membrane with CNHs had progressed more than under that without CNHs and numerous macrophages were observed attached to CNHs. At eight weeks, there was no significant difference in the amount of newly formed bone between the groups and the appearance of macrophages was decreased compared with that at two weeks. Newly formed bone attached to some CNHs directly. These results suggest that macrophages induced by CNHs are related to bone regeneration. In conclusion, the present study indicates that CNHs are compatible with bone tissue and effective as a material for GBR.

  15. Carbon nanohorns accelerate bone regeneration in rat calvarial bone defect

    NASA Astrophysics Data System (ADS)

    Kasai, Takao; Matsumura, Sachiko; Iizuka, Tadashi; Shiba, Kiyotaka; Kanamori, Takeshi; Yudasaka, Masako; Iijima, Sumio; Yokoyama, Atsuro

    2011-02-01

    A recent study showed that carbon nanohorns (CNHs) have biocompatibility and possible medical uses such as in drug delivery systems. It was reported that some kinds of carbon nanomaterials such as carbon nanotubes were useful for bone formation. However, the effect of CNHs on bone tissue has not been clarified. The purpose of this study was to evaluate the effect of CNHs on bone regeneration and their possible application for guided bone regeneration (GBR). CNHs dispersed in ethanol were fixed on a porous polytetrafluoroethylene membrane by vacuum filtration. Cranial defects were created in rats and covered by a membrane with/without CNHs. At two weeks, bone formation under the membrane with CNHs had progressed more than under that without CNHs and numerous macrophages were observed attached to CNHs. At eight weeks, there was no significant difference in the amount of newly formed bone between the groups and the appearance of macrophages was decreased compared with that at two weeks. Newly formed bone attached to some CNHs directly. These results suggest that macrophages induced by CNHs are related to bone regeneration. In conclusion, the present study indicates that CNHs are compatible with bone tissue and effective as a material for GBR.

  16. 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

  17. Animal Models of Bone Metastasis

    PubMed Central

    Simmons, J. K.; Hildreth, B. E.; Supsavhad, W.; Elshafae, S. M.; Hassan, B. B.; Dirksen, W. P.; Toribio, R. E.; Rosol, T. J.

    2015-01-01

    Bone is one of the most common sites of cancer metastasis in humans and is a significant source of morbidity and mortality. Bone metastases are considered incurable and result in pain, pathologic fracture, and decreased quality of life. Animal models of skeletal metastases are essential to improve the understanding of the molecular pathways of cancer metastasis and growth in bone and to develop new therapies to inhibit and prevent bone metastases. The ideal animal model should be clinically relevant, reproducible, and representative of human disease. Currently, an ideal model does not exist; however, understanding the strengths and weaknesses of the available models will lead to proper study design and successful cancer research. This review provides an overview of the current in vivo animal models used in the study of skeletal metastases or local tumor invasion into bone and focuses on mammary and prostate cancer, lymphoma, multiple myeloma, head and neck squamous cell carcinoma, and miscellaneous tumors that metastasize to bone. PMID:26021553

  18. Clinical value of bone densitometry.

    PubMed

    Sartoris, D J

    1994-07-01

    The purpose of this article is to provide insight into the long-standing controversy over the clinical value of noninvasive measurement of bone mass. Results of recent studies have increasingly supported the judicious use of bone densitometry as a clinical tool [1]. These reports contradict editorials on the limitations of bone densitometry that have appeared in a variety of subspecialty publications [2,3]. The importance of bone mass measurement is underscored by the lack of success in predicting bone density from various combinations of anthropometric and historical variables. Growing evidence suggests that densitometry is a useful tool for determining which women near menopause are at risk for osteoporosis and, therefore, are candidates for estrogen-replacement therapy. This article summarizes current concepts on the subject and attempts to prove that bone densitometry is a beneficial and indicated procedure for selected patients.

  19. Bone disease and HIV infection.

    PubMed

    Amorosa, Valerianna; Tebas, Pablo

    2006-01-01

    The high prevalence of bone demineralization among human immunodeficiency virus (HIV)-infected patients in the current therapeutic era has been described in multiple studies, sounding the alarm that we may expect an epidemic of fragility fractures in the future. However, despite noting high overall prevalences of osteopenia and osteoporosis, recent longitudinal studies that we review here have generally not observed accelerated bone loss during antiretroviral therapy beyond the initial period after treatment initiation. We discuss the continued progress toward understanding the mechanisms of HIV-associated bone loss, particularly the effects of HIV infection, antiretroviral therapy, and host immune factors on bone turnover. We summarize results of clinical trials published in the past year that studied the safety and efficacy of treatment of bone loss in HIV-infected patients and provide provisional opinions about who should be considered for bone disease screening and treatment.

  20. Drinking water fluoridation and bone.

    PubMed

    Allolio, B; Lehmann, R

    1999-01-01

    Drinking water fluoridation has an established role in the prevention of dental caries, but may also positively or negatively affect bone. In bone fluoride is incorporated into hydroxylapatite to form the less soluble fluoroapatite. In higher concentrations fluoride stimulates osteoblast activity leading to an increase in cancellous bone mass. As optimal drinking water fluoridation (1 mg/l) is widely used, it is of great interest, whether long-term exposition to artificial water fluoridation has any impact on bone strength, bone mass, and -- most importantly -- fracture rate. Animal studies suggest a biphasic pattern of the effect of drinking water fluoridation on bone strength with a peak strength at a bone fluoride content of 1200 ppm followed by a decline at higher concentrations eventually leading to impaired bone quality. These changes are not paralleled by changes in bone mass suggesting that fluoride concentrations remain below the threshold level required for activation of osteoblast activity. Accordingly, in most epidemiological studies in humans bone mass was not altered by optimal drinking water fluoridation. In contrast, studies on the effect on hip fracture rate gave conflicting results ranging from an increased fracture incidence to no effect, and to a decreased fracture rate. As only ecological studies have been performed, they may be biased by unknown confounding factors -- the so-called ecological fallacy. However, the combined results of these studies indicate that any increase or decrease in fracture rate is likely to be small. It has been calculated that appropriately designed cohort studies to solve the problem require a sample size of >400,000 subjects. Such studies will not be performed in the foreseeable future. Future investigations in humans should, therefore, concentrate on the effect of long-term drinking water fluoridation on bone fluoride content and bone strength.

  1. Diagnosis of metabolic bone disease

    SciTech Connect

    Grech, P.; Martin, T.J.; Barrington, N.A.; Ell, P.J.

    1986-01-01

    This book presents a reference on the radiologic evaluation, features, and differential diagnosis of metabolic diseases involving the whole skeleton, calcium deficiencies resulting from pharmacologic agents, and bone changes related to endocrine disturbances. It also stresses how radiology, nuclear medicine, and biochemistry - either alone or in concert - contribute to clinical diagnosis. It covers renal bone disease, Paget's disease, hyperphosphatasia, extraskeletal mineralization, metabolic bone disorders related to malnutrition, tumors, plus radionuclide studies including materials and methods.

  2. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone plate. 872.4760 Section 872.4760 Food and... DENTAL DEVICES Surgical Devices § 872.4760 Bone plate. (a) Identification. A bone plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to...

  3. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bone plate. 872.4760 Section 872.4760 Food and... DENTAL DEVICES Surgical Devices § 872.4760 Bone plate. (a) Identification. A bone plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to...

  4. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bone plate. 872.4760 Section 872.4760 Food and... DENTAL DEVICES Surgical Devices § 872.4760 Bone plate. (a) Identification. A bone plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to...

  5. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bone plate. 872.4760 Section 872.4760 Food and... DENTAL DEVICES Surgical Devices § 872.4760 Bone plate. (a) Identification. A bone plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to...

  6. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bone plate. 872.4760 Section 872.4760 Food and... DENTAL DEVICES Surgical Devices § 872.4760 Bone plate. (a) Identification. A bone plate is a metal device intended to stabilize fractured bone structures in the oral cavity. The bone segments are attached to...

  7. [Is bone biopsy necessary for the diagnosis of metabolic bone diseases? Non- invasive assessment of bone turn over markers could define the cause of metabolic bone diseases].

    PubMed

    Suzuki, Atsushi

    2011-09-01

    Recent advances of the measurement of bone turn over markers contribute to non-invasive assessment of bone-metabolic disorders. We can detect the cause of the metabolic disorders with bone turn over markers and hormonal profiles more easily than before. Today, we can diagnose and treat metabolic bone diseases without invasive procedure such as bone biopsy.

  8. Aneurysmal bone cyst and other nonneoplastic conditions

    SciTech Connect

    Dahlin, D.C.; McLeod, R.A.

    1982-08-01

    Aneurysmal bone cyst is a benign proliferative tumefaction of bone. Histologic similarities indicate a kinship among classic aneurysmal bone cysts, essentially 'solid' proliferative lesions in bones; giant cell reparative granulomas of the jaws, at the base of the skull, and in the small bones of the hands and feet; skeletal lesions of hyperparathyroidism; and even pseudosarcomatous myositis ossificans, proliferative myositis, and proliferative fasciitis.

  9. Bone Transport for Reconstruction in Benign Bone Tumors

    PubMed Central

    Oh, Chang Seon; Cho, Yong Jin; Ahn, Yeong Seub; Na, Bo Ram

    2015-01-01

    Background The aim of this study was to assess the results of using the Ilizarov apparatus to transport bones in the treatment of benign bone tumors. Methods Seven patients (six males and one female) with benign bone tumors were treated by bone transport with an Ilizarov apparatus at our institution. Their mean age at surgery was 14.4 years (range, 4.8 to 36.9 years). The histological diagnoses were osteofibrous dysplasia (4), giant-cell tumor (1), intraosseous cavernous hemangioma (1), and aneurysmal bone cyst (1). Three radiological indices were used for evaluating the results: an external fixation index, a distraction index, and a maturation index. The bone and functional results were evaluated according to the Association for the Study and Application of the Method of Ilizarov classification. Results Five patients had bone union at the reconstructed site, one patient had a local recurrence, and the other had a nonunion at the docking site. The mean length of distraction was 7.3 cm (range, 5.1 to 12.1 cm). The mean external fixation index was 26.0 day/cm (range, 19.8 to 32.5 day/cm), the distraction index was 9.6 day/cm (range, 6.8 to 12.0 day/cm), and the maturation index was 14.9 day/cm (range, 8.0 to 22.5 day/cm). Ultimately, the bone and the functional results were rated excellent in six cases and good in one case. Conclusions Bone transport using the Ilizarov apparatus is a good treatment option in patients with bone defects after the resection of an active or aggressive benign bone tumor. PMID:26217473

  10. Respiratory parameters during professional flute playing.

    PubMed

    Cossette, I; Sliwinski, P; Macklem, P T

    2000-06-01

    We studied three professional flautists while playing to determine: (1) what respiratory muscles and percent vital capacity (%VC) were used; (2) how mouth pressure (Pm), embouchure resistance (Rem), embouchure aperture (Aem), flow (V) and velocity (Vel) affect sound loudness (I) and frequency (F). We measured Pm, esophageal, gastric, transdiaphragmatic, transpulmonary (PL) pressures, diaphragmatic EMG, sound and chest wall displacements directly. Lung volume (VL) was estimated from PL during playing and the static deflation PL-VL curve measured separately; V from Delta VL/Delta t; Rem from Pm/(Delta VL/Delta t). Staccati and sustained notes at different F and I were performed. I increased mainly with V and F with Vel. V and Vel are independently controlled by Pm and Aem. The variation of mean Pm was small (6-11 cm H(2)O) and large for VC (72-83%) suggesting braking inspiratory muscle activity while playing. However, rib cage (RC) and abdominal (Ab) motion were different for each subject. One displaced Ab>RC at high VL and RC>Ab at low VL, another the opposite pattern; the third was in between. We conclude that while different flautists use different strategies to control Pm, the results are similar. Independent control of V and Vel by Pm and Aem allow flautists to control I and F regardless of how Pm is generated.

  11. Fluid in the flute: Reversible hydromyelia.

    PubMed

    Wehner, Tim; Ross, Jeffrey S; Ransohoff, Richard M

    2005-09-15

    Non-communicating syrinx formation in association with demyelinating disease has been reported in approximately 50 patients. It has been unknown whether this is a permanent or potentially reversible phenomenon. We report a patient with acute transverse myelitis who developed a syrinx that resolved within 6 months. Mechanisms of syrinx formation in demyelinating disease are discussed.

  12. Sharp boundary analysis of electrostatic flute modes

    SciTech Connect

    Lemons, D. S.

    1989-07-01

    A linear, electrostatic, stability analysis of a magnetized cross-fielddrifting plasma with a sharp boundary is presented. The analysis corrects anerror in a previously published sharp boundary theory (Phys. Fluids /bold 19/,882 (1976)) and extends another theory (Geophys. Res. Lett. /bold 14/, 60(1987)) to include finite electron mass and non-neutral perturbations. Theinstability's long wavelength structure is associated with the classical fluteinstability, while the peak of the growth rate curve, at much shorterwavelengths, is a Buneman-like instability.

  13. The biology of bone lengthening.

    PubMed

    Hvid, Ivan; Horn, Joachim; Huhnstock, Stefan; Steen, Harald

    2016-12-01

    Distraction osteogenesis biologically resembles fracture healing with distinctive characteristics notably in the distraction phase of osteogenesis. In the latency phase of bone lengthening, like in the inflammatory phase of fracture repair, interleukines are released and act with growth factors released from platelets in the local haematoma, leading to attraction, proliferation and differentiation of mesenchymal stem cells into osteoblasts and other differentiated mesenchymal cells. These in turn produce matrix, collagen fibers and growth factors. A callus containing cells, collagen fibers, osteoid and cartilage matrix is formed. Provided stable fixation, distraction will trigger intramembranous bone formation. As distraction proceeds, the distraction gap develops five distinctive zones with unmineralized bone in the middle, remodelling bone peripherally, and mineralizing bone in between. During consolidation, the high concentration of anabolic growth factors in the regenerate diminishes with time as remodelling takes over to form mature cortical and cancellous bone. Systemic disease, congenital bone deficiencies, medications and substance abuse can influence the quality and quantity of regenerate bone, usually in a negative way. The regenerate bone can be manipulated when needed by using injection of mesenchymal stem cells and platelets, growth factors (BMP-2 and -7), and systemic medications (bisphosphonates and parathyroid hormone). Growth factors and systemic anabolic and antiresorptive drugs are prescribed on special indications, while distraction osteogenesis is not an authorized indication. To some extent, however, these compounds can be used off-label. Use in children presents special problems since growth factors and specific anabolic medications may involve a risk of inducing cancer.

  14. Bone Disease and Idiopathic Hypercalciuria

    PubMed Central

    Zerwekh, Joseph E.

    2008-01-01

    Observational and epidemiological studies alike have demonstrated that idiopathic hypercalciuric (IH) stone-forming patients typically demonstrate bone mineral density scores significantly less than those observed for age- and gender-matched normal subjects or those for non-hypercalciuric stone-forming patients. Most of these studies have relied on changes in bone mineral density (BMD) and have not explored the mechanism(s) involved. There have been a small number of studies that have relied on dynamic bone histomorphometry to ascertain the nature of the bone defect in IH patients. When performed, these studies have clearly demonstrated increased bone resorption and high bone turnover in patients with fasting hypercalciuria while suppressed bone formation indices are the most consistent finding in patients with the absorptive variant of IH. The causes of this apparent difference in bone remodeling between the two variants of IH is still uncertain. Available evidence suggests that potential mechanisms may be dependent in large part to genetic, metabolic, and nutritional causes of hypercalciuria and bone loss in patients with IH. PMID:18359394

  15. 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

  16. Symmetry analysis of talus bone

    PubMed Central

    Islam, K.; Dobbe, A.; Komeili, A.; Duke, K.; El-Rich, M.; Dhillon, S.; Adeeb, S.; Jomha, N. M.

    2014-01-01

    Objective The main object of this study was to use a geometric morphometric approach to quantify the left-right symmetry of talus bones. Methods Analysis was carried out using CT scan images of 11 pairs of intact tali. Two important geometric parameters, volume and surface area, were quantified for left and right talus bones. The geometric shape variations between the right and left talus bones were also measured using deviation analysis. Furthermore, location of asymmetry in the geometric shapes were identified. Results Numerical results showed that talus bones are bilaterally symmetrical in nature, and the difference between the surface area of the left and right talus bones was less than 7.5%. Similarly, the difference in the volume of both bones was less than 7.5%. Results of the three-dimensional (3D) deviation analyses demonstrated the mean deviation between left and right talus bones were in the range of -0.74 mm to 0.62 mm. It was observed that in eight of 11 subjects, the deviation in symmetry occurred in regions that are clinically less important during talus surgery. Conclusions We conclude that left and right talus bones of intact human ankle joints show a strong degree of symmetry. The results of this study may have significance with respect to talus surgery, and in investigating traumatic talus injury where the geometric shape of the contralateral talus can be used as control. Cite this article: Bone Joint Res 2014;3:139–45. PMID:24802391

  17. 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.

  18. Bone. Maximizing bone health--magnesium, BMD and fractures.

    PubMed

    Nieves, Jeri W

    2014-05-01

    The contribution of nutrition to bone health has been heavily debated for many years resulting in unclear recommendations for patients regarding prevention of bone loss and subsequent fractures. A recent cohort study has examined the relationships between magnesium intake, BMD and fractures.

  19. Bone turnover predicts change in volumetric bone density and bone geometry at the radius in men.

    PubMed

    Pye, S R; Ward, K A; Cook, M J; Laurent, M R; Gielen, E; Borghs, H; Adams, J E; Boonen, S; Vanderschueren, D; Wu, F C; O'Neill, T W

    2017-03-01

    Peripheral quantitative computed tomography scans of the distal and midshaft radius were performed in 514 European men aged 40-79 years at baseline and a median of 4.3 years later. Age-related changes in volumetric bone mineral density (vBMD) and bone geometry were greater in men with higher biochemical markers of bone turnover at baseline.

  20. Bone healing around nanocrystalline hydroxyapatite, deproteinized bovine bone mineral, biphasic calcium phosphate, and autogenous bone in mandibular bone defects.

    PubMed

    Broggini, Nina; Bosshardt, Dieter D; Jensen, Simon S; Bornstein, Michael M; Wang, Chun-Cheng; Buser, Daniel

    2015-10-01

    The individual healing profile of a given bone substitute with respect to osteogenic potential and substitution rate must be considered when selecting adjunctive grafting materials for bone regeneration procedures. In this study, standardized mandibular defects in minipigs were filled with nanocrystalline hydroxyapatite (HA-SiO), deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate (BCP) with a 60/40% HA/β-TCP (BCP 60/40) ratio, or particulate autogenous bone (A) for histological and histomorphometric analysis. At 2 weeks, percent filler amongst the test groups (DBBM (35.65%), HA-SiO (34.47%), followed by BCP 60/40 (23.64%)) was significantly higher than the more rapidly substituted autogenous bone (17.1%). Autogenous bone yielded significantly more new bone (21.81%) over all test groups (4.91%-7.74%) and significantly more osteoid (5.53%) than BCP 60/40 (3%) and DBBM (2.25%). At 8 weeks, percent filler amongst the test groups (DBBM (31.6%), HA-SiO (31.23%), followed by BCP 60/40 (23.65%)) demonstrated a similar pattern and was again significantly higher as compared to autogenous bone (9.29%). Autogenous bone again exhibited statistically significantly greater new bone (55.13%) over HA-SiO (40.62%), BCP 60/40 (40.21%), and DBBM (36.35%). These results suggest that the osteogenic potential of HA-SiO and BCP is inferior when compared to autogenous bone. However, in instances where a low substitution rate is desired to maintain the volume stability of augmented sites, particularly in the esthetic zone, HA-SiO and DBBM may be favored.

  1. 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 (λ=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.

  2. Mesenchymal stem cells for bone repair and metabolic bone diseases.

    PubMed

    Undale, Anita H; Westendorf, Jennifer J; Yaszemski, Michael J; Khosla, Sundeep

    2009-10-01

    Human mesenchymal stem cells offer a potential alternative to embryonic stem cells in clinical applications. The ability of these cells to self-renew and differentiate into multiple tissues, including bone, cartilage, fat, and other tissues of mesenchymal origin, makes them an attractive candidate for clinical applications. Patients who experience fracture nonunion and metabolic bone diseases, such as osteogenesis imperfecta and hypophosphatasia, have benefited from human mesenchymal stem cell therapy. Because of their ability to modulate immune responses, allogeneic transplant of these cells may be feasible without a substantial risk of immune rejection. The field of regenerative medicine is still facing considerable challenges; however, with the progress achieved thus far, the promise of stem cell therapy as a viable option for fracture nonunion and metabolic bone diseases is closer to reality. In this review, we update the biology and clinical applicability of human mesenchymal stem cells for bone repair and metabolic bone diseases.

  3. Mesenchymal Stem Cells for Bone Repair and Metabolic Bone Diseases

    PubMed Central

    Undale, Anita H.; Westendorf, Jennifer J.; Yaszemski, Michael J.; Khosla, Sundeep

    2009-01-01

    Human mesenchymal stem cells offer a potential alternative to embryonic stem cells in clinical applications. The ability of these cells to self-renew and differentiate into multiple tissues, including bone, cartilage, fat, and other tissues of mesenchymal origin, makes them an attractive candidate for clinical applications. Patients who experience fracture nonunion and metabolic bone diseases, such as osteogenesis imperfecta and hypophosphatasia, have benefited from human mesenchymal stem cell therapy. Because of their ability to modulate immune responses, allogeneic transplant of these cells may be feasible without a substantial risk of immune rejection. The field of regenerative medicine is still facing considerable challenges; however, with the progress achieved thus far, the promise of stem cell therapy as a viable option for fracture nonunion and metabolic bone diseases is closer to reality. In this review, we update the biology and clinical applicability of human mesenchymal stem cells for bone repair and metabolic bone diseases. PMID:19797778

  4. [Bone and Stem Cells. Intravital imaging of bone marrow microenvironment].

    PubMed

    Mizuno, Hiroki; Kikuta, Junichi; Ishii, Masaru

    2014-04-01

    Various kinds of cell types, such as osteoclasts, osteoblasts, hematopoietic cells, and mesenchymal cells, have been reported to exist in the bone marrow and communicate with each other. Although there have been many previous studies about bone marrow microenvironment, most of them were analyzed by conventional methods such as histological analysis and flow cytometry. These methods could not observe the dynamic cell movement in living bone marrow. Recently rapid development of fluorescent imaging techniques enables us to understand the cellular dynamics in vivo . That's why we have originally established an advanced imaging system for visualizing living bone tissues with intravital two-photon microscopy. Here we show the latest data and the detailed methodology of intravital imaging of bone marrow microenvironment, and also discuss its further application.

  5. Broken Bones, Sprains, and Strains (For Parents)

    MedlinePlus

    ... Feeding Your 1- to 2-Year-Old Broken Bones, Sprains, and Strains KidsHealth > For Parents > Broken Bones, ... home. What to Do: For a Suspected Broken Bone: Do not move a child whose injury involves ...

  6. ISS Update: Bone Health in Space

    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...

  7. Frontal bone fractures.

    PubMed

    Marinheiro, Bruno Henrique; de Medeiros, Eduardo Henrique Pantosso; Sverzut, Cássio Edvard; Trivellato, Alexandre Elias

    2014-11-01

    The aim of this retrospective study was to evaluate the epidemiology, treatment, and complications of frontal bone fractures associated, or not, with other facial fractures. This evaluation also sought to minimize the influence of the surgeon's skills and the preference for any rigid internal fixation system. The files from 3758 patients who attended the Oral and Maxillofacial Surgery Department of the School of Dentistry of Ribeirao Preto, University of Sao Paulo, from March 2004 to November 2011 and presented with facial trauma were scanned, and 52 files were chosen for the review. Eleven (21.15%) of these patients had pure fractures of the frontal bone, and trauma incidence was more prevalent in men (92.3%), whites (61.53%), and adults (50%). Despite the use of helmets at the moment of the trauma, motorcycle crashes were the most common etiological factor (32.69%). Fracture of the anterior wall of the frontal sinus with displacement was the main injury observed (54.9%), and the most common treatment was internal fixation with a plate and screws (45.09%). Postoperative complications were observed in 35.29% of the cases. The therapy applied was effective in handling this type of fracture, and the success rate was comparable to that reported in other published studies.

  8. Bone densitometry in infants

    SciTech Connect

    Barden, H.S.; Mazess, R.B.

    1988-07-01

    Bone mineral mass and density can be measured noninvasively by various absorptiometric procedures. Two methods, dual-photon absorptiometry (DPA) and quantitative computed tomography, have widespread application in adults but only limited use in children. One method, single-photon absorptiometry (SPA), has been used extensively in adults and children and has been modified for use in infants. The radius shaft has been used for most research on infants. However, the difficulty of using older SPA methods on this small bone (4 to 7 mm width) has led a few investigators to measure the shaft of the humerus. The typical precision of measurement in a newborn is about 5% with the use of computerized rectilinear scanners for the radius; older linear scanners have a precision error of 5% to 10% on the humerus. Linear scanners cannot measure precisely the radius in individual neonates. The SPA scans typically take about 5 minutes. The DPA technique using /sup 153/Gd has been modified for use on smaller animals (5 to 10 kg monkeys and dogs), but it has not been used on infants because DPA scans take 20 minutes. New methods using x-ray absorptiometry allow rapid (1 minute), precise (1%) measurements in the perinate. The need for a soft tissue bolus is eliminated, and both the axial and peripheral skeletons can be measured with dual-energy x-ray absorptiometry. Ultrasonic measurements do not yet offer adequate precision in the neonate, given the limited biologic range of values. 83 references.

  9. Space Radiation and Bone Loss.

    PubMed

    Willey, Jeffrey S; Lloyd, Shane A J; Nelson, Gregory A; Bateman, Ted A

    2011-01-01

    Exposure to ionizing radiation may negatively impact skeletal integrity during extended spaceflight missions to the moon, Mars, or near-Earth asteroids. However, our understanding of the effects of radiation on bone is limited when compared to the effects of weightlessness. In addition to microgravity, astronauts will be exposed to space radiation from solar and cosmic sources. Historically, radiation exposure has been shown to damage both osteoblast precursors and local vasculature within the irradiated volume. The resulting suppression of bone formation and a general state of low bone-turnover is thought to be the primary contributor to bone loss and eventual fracture. Recent investigations using mouse models have identified a rapid, but transient, increase in osteoclast activity immediately after irradiation with both spaceflight and clinically-relevant radiation qualities and doses. Together with a chronic suppression of bone formation after radiation exposure, this acute skeletal damage may contribute to long-term deterioration of bone quality, potentially increasing fracture risk. Direct evidence for the damaging effects of radiation on human bone are primarily demonstrated by the increased incidence of fractures at sites that absorb high doses of radiation during cancer therapy: exposures are considerably higher than what could be expected during spaceflight. However, both the rapidity of bone damage and the chronic nature of the changes appear similar between exposure scenarios. This review will outline our current knowledge of space and clinical exploration exposure to ionizing radiation on skeletal health.

  10. How Is Bone Cancer Staged?

    MedlinePlus

    ... the bone or nearby lymph nodes M1: Distant metastasis (the cancer has spread) M1a: The cancer has spread only to the lung M1b: The cancer has spread to other sites (like the brain, the liver, etc.) Grades of bone cancer G1- ...

  11. 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...

  12. Bone Disease in Multiple Myeloma.

    PubMed

    Eda, Homare; Santo, Loredana; David Roodman, G; Raje, Noopur

    2016-01-01

    Bone involvement represented by osteolytic bone disease (OBD) or osteopenia is one of the pathognomonic and defining characteristics of multiple myeloma (MM). Nearly 90 % of patients with MM develop osteolytic bone lesions, frequently complicated by skeletal-related events (SRE) such as severe bone pain, pathological fractures, vertebral collapse, hypercalcemia, and spinal cord compression. All of these not only result in a negative impact on quality of life but also adversely impact overall survival. OBD is a consequence of increased osteoclast (OC) activation along with osteoblast (OB) inhibition, resulting in altered bone remodeling. OC number and activity are increased in MM via cytokine deregulation within the bone marrow (BM) milieu, whereas negative regulators of OB differentiation suppress bone formation. Inhibition of osteolysis and stimulation of OB differentiation leads to reduced tumor growth in vivo. Therefore, novel agents targeting OBD are promising therapeutic strategies not only for the treatment of MM OBD but also for the treatment of MM. Several novel agents in addition to bisphosphonates are currently under investigation for their positive effect on bone remodeling via OC inhibition or OB stimulation. Future studies will look to combine or sequence all of these agents with the goal of not only alleviating morbidity from MM OBD but also capitalizing on the resultant antitumor activity.

  13. 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 15-171 months) 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 20 ng/ml in 9 children and below 12 ng/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.

  14. [Bone disease in Gaucher's disease].

    PubMed

    Roca Espiau, Mercedes

    2011-09-01

    The exposition aims, is to review the pathophysiological mechanisms of bone marrow involvement and the patterns of marrow infiltration by Gaucher cells. We have reviewed the different methods of assessment of bone marrow infiltration and its temporal development. Qualitative methods include simple radiography, magnetic resonance imaging (MRI), computed tomography (CT) and radioisotope. The simple radiography is the basic element, but its sensitivity is limited and only allows for assessing changes and trabecular bone remodeling MRI allows us to appreciate the bone marrow infiltration, detection of complications and response to therapy. Radioisotopes can contribute to the differential diagnosis of osteomyelitis and bone crises. Among the quantitative methods are the QCSI (quantitative chemical shift imaging) and the dual-energy X-ray absorptiometry (DEXA), as well as new quantitative techniques of CT, MRI and ultrasound densitometry. The QCSI performed an assessment of fat content of bone marrow in the spine. DEXA quantifies bone density by measuring the attenuation coefficient. The semiquantitative methods have various "scores" to establish criteria for generalized bone disease endpoints of disease progression and response to therapy.

  15. Bone tissue engineering in osteoporosis.

    PubMed

    Jakob, Franz; Ebert, Regina; Ignatius, Anita; Matsushita, Takashi; Watanabe, Yoshinobu; Groll, Juergen; Walles, Heike

    2013-06-01

    Osteoporosis is a polygenetic, environmentally modifiable disease, which precipitates into fragility fractures of vertebrae, hip and radius and also confers a high risk of fractures in accidents and trauma. Aging and the genetic molecular background of osteoporosis cause delayed healing and impair regeneration. The worldwide burden of disease is huge and steadily increasing while the average life expectancy is also on the rise. The clinical need for bone regeneration applications, systemic or in situ guided bone regeneration and bone tissue engineering, will increase and become a challenge for health care systems. Apart from in situ guided tissue regeneration classical ex vivo tissue engineering of bone has not yet reached the level of routine clinical application although a wealth of scaffolds and growth factors has been developed. Engineering of complex bone constructs in vitro requires scaffolds, growth and differentiation factors, precursor cells for angiogenesis and osteogenesis and suitable bioreactors in various combinations. The development of applications for ex vivo tissue engineering of bone faces technical challenges concerning rapid vascularization for the survival of constructs in vivo. Recent new ideas and developments in the fields of bone biology, materials science and bioreactor technology will enable us to develop standard operating procedures for ex vivo tissue engineering of bone in the near future. Once prototyped such applications will rapidly be tailored for compromised conditions like vitamin D and sex hormone deficiencies, cellular deficits and high production of regeneration inhibitors, as they are prevalent in osteoporosis and in higher age.

  16. Gut microbiota-bone axis.

    PubMed

    Villa, Christopher R; Ward, Wendy E; Comelli, Elena M

    2017-05-24

    The gut microbiota (GM) is an important regulator of body homeostasis, including intestinal and extra-intestinal effects. This review focuses on the GM-bone axis, which we define as the effect of the gut-associated microbial community or the molecules they synthesize, on bone health. While research in this field is limited, findings from preclinical studies support that gut microbes positively impact bone mineral density and strength parameters. Moreover, administration of beneficial bacteria (probiotics) in preclinical models has demonstrated higher bone mineralization and greater bone strength. The preferential bacterial genus that has shown these beneficial effects in bone is Lactobacillus and thus lactobacilli are among the best candidates for future clinical intervention trials. However, their effectiveness is dependent on stage of development, as early life constitutes an important time for impacting bone health, perhaps via modulation of the GM. In addition, sex-specific difference also impacts the efficacy of the probiotics. Although auspicious, many questions regarding the GM-bone axis require consideration of potential mechanisms; sex-specific efficacy; effective dose of probiotics; and timing and duration of treatment.

  17. 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 μm 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.

  18. Biomaterials for Bone Regenerative Engineering.

    PubMed

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

    2015-06-24

    Strategies for bone tissue regeneration have been continuously evolving for the last 25 years since the introduction of the "tissue engineering" concept. The convergence of the life, physical, and engineering sciences has brought in several advanced technologies available to tissue engineers and scientists. This resulted in the creation of a new multidisciplinary field termed as "regenerative engineering". In this article, the role of biomaterials in bone regenerative engineering is systematically reviewed to elucidate the new design criteria for the next generation of biomaterials for bone regenerative engineering. The exemplary design of biomaterials harnessing various materials characteristics towards successful bone defect repair and regeneration is highlighted. Particular attention is given to the attempts of incorporating advanced materials science, stem cell technologies, and developmental biology into biomaterials design to engineer and develop the next generation bone grafts.

  19. Bone composition: relationship to bone fragility and antiosteoporotic drug effects

    PubMed Central

    Boskey, Adele L

    2013-01-01

    The composition of a bone can be described in terms of the mineral phase, hydroxyapatite, the organic phase, which consists of collagen type I, noncollagenous proteins, other components and water. The relative proportions of these various components vary with age, site, gender, disease and treatment. Any drug therapy could change the composition of a bone. This review, however, will only address those pharmaceuticals used to treat or prevent diseases of bone: fragility fractures in particular, and the way they can alter the composition. As bone is a heterogeneous tissue, its composition must be discussed in terms of the chemical makeup, properties of its chemical constituents and their distributions in the ever-changing bone matrix. Emphasis, in this review, is placed on changes in composition as a function of age and various diseases of bone, particularly osteoporosis. It is suggested that while some of the antiosteoporotic drugs can and do modify composition, their positive effects on bone strength may be balanced by negative ones. PMID:24501681

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

    PubMed Central

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

    2014-01-01

    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 μCT 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

  1. Repair of long bone defects with demineralized bone matrix and autogenous bone composite

    PubMed Central

    Ozdemir, Mehmet T; Kir, Mustafa Ç

    2011-01-01

    Background: Repair of diaphyseal bone defects is a challenging problem for orthopedic surgeons. In large bone defects the quantity of harvested autogenous bone may not be sufficient to fill the gap and then the use of synthetic or allogenic grafts along with autogenous bone becomes mandatory to achieve compact filling. Finding the optimal graft mixture for treatment of large diaphyseal defects is an important goal in contemporary orthopedics and this was the main focus of this study. The aim of this study is to investigate the efficacy of demineralized bone matrix (DBM) and autogenous cancellous bone (ACB) graft composite in a rabbit bilateral ulna segmental defect model. Materials and Methods: Twenty-seven adult female rabbits were divided into five groups. A two-centimeter piece of long bone on the midshaft of the ulna was osteotomized and removed from the rabbits’ forearms. In group 1 (n=7) the defects were treated with ACB, in group 2 (n=7) with DBM, and in group 3 (n=7) with ACB and DBM in the ratio of 1:1. Groups 4 and 5, with three rabbits in each group, were the negative and positive controls, respectively. Twelve weeks after implantation the rabbits were sacrificed and union was evaluated with radiograph (Faxitron), dual-energy x-ray absorptiometry (DEXA), and histological methods (decalcified sectioning). Results: Union rates and the volume of new bone in the different groups were as follows: group 1 - 92.8% union and 78.6% new bone; group 2 - 72.2% union and 63.6% new bone; and group 3 - 100% union and 100% new bone. DEXA results (bone mineral density [BMD]) were as follows: group 1 - 0.164 g/cm2, group 2 - 0.138 g/cm2, and group 3 - 0.194 g/cm2. Conclusions: DBM serves as a graft extender or enhancer for autogenous graft and decreases the need of autogenous bone graft in the treatment of bone defects. In this study, the DBM and ACB composite facilitated the healing process. The union rate was better with the combination than with the use of any one of

  2. [Bone and Men's Health. Androgen replacement therapy and bone metabolism].

    PubMed

    Ogawa, Sumito

    2010-02-01

    During aging process in men, decline of androgen level is involved in symptoms of hypogonadism, and recent findings suggest that sex hormones are crucial for skeletal development and maintenance of bone mineral properties. In practice, androgen replacement therapy has not been established for bone-related symptoms in late onset hypogonadisim or male osteoporosis. Whereas recent evidences suggest that bone mineral properties are improved by androgen replacement therapy in aging male, further studies including large clinical trials are necessary to assess long-term benefits and risks by the therapy.

  3. Improved repair of bone defects with prevascularized tissue-engineered bones constructed in a perfusion bioreactor.

    PubMed

    Li, De-Qiang; Li, Ming; Liu, Pei-Lai; Zhang, Yuan-Kai; Lu, Jian-Xi; Li, Jian-Min

    2014-10-01

    Vascularization of tissue-engineered bones is critical to achieving satisfactory repair of bone defects. The authors investigated the use of prevascularized tissue-engineered bone for repairing bone defects. The new bone was greater in the prevascularized group than in the non-vascularized group, indicating that prevascularized tissue-engineered bone improves the repair of bone defects. [Orthopedics. 2014; 37(10):685-690.].

  4. Re-evaluation of bone pain in patients with type 1 Gaucher disease suggests that bone crises occur in small bones as well as long bones.

    PubMed

    Baris, Hagit N; Weisz Hubshman, Monika; Bar-Sever, Zvi; Kornreich, Liora; Shkalim Zemer, Vered; Cohen, Ian J

    2016-09-01

    Bone crises in type 1 Gaucher disease are reported in long bones and occasionally in weight bearing bones and other bones, but rarely in small bones of the hands and feet. We retrospectively examined the incidence of bone pain in patients followed at the Rabin Medical Center, Israel, before and following the initiation of enzyme replacement therapy (ERT) and evaluated them for bone crises. Of 100 type I Gaucher disease patients, 30 (30%) experienced one or more bone crises. Small bone crises represented 31.5% of all bone crises and were always preceded by crises in other bones. While the incidence of long bone crises reduced after the initiation of ERT, small bone crises increased. Almost 60% of patients with bone crises were of the N370S/84GG genotype suggesting a greater susceptibility of N370S/84GG patients to severe bone complications. These patients also underwent the greatest number of splenectomies (70.6% of splenectomised patients). Splenectomised patients showed a trend towards increased long and small bone crises after surgery. Active investigation of acute pain in the hands and feet in patients in our cohort has revealed a high incidence of small bone crises. Physicians should consider imaging studies to investigate unexplained pain in these areas.

  5. Diet, nutrition, and bone health.

    PubMed

    Cashman, Kevin D

    2007-11-01

    Osteoporosis is a debilitating disease that affects many older people. Fragility fractures are the hallmark of osteoporosis. Although nutrition is only 1 of many factors that influence bone mass and fragility fractures, there is an urgent need to develop and implement nutritional approaches and policies for the prevention and treatment of osteoporosis that could, with time, offer a foundation for population-based preventive strategies. However, to develop efficient and precocious strategies in the prevention of osteoporosis, it is important to determine which modifiable factors, especially nutritional factors, are able to improve bone health throughout life. There are potentially numerous nutrients and dietary components that can influence bone health, and these range from the macronutrients to micronutrients as well as bioactive food ingredients. The evidence-base to support the role of nutrients and food components in bone health ranges from very firm to scant, depending on the nutrient/component. This article initially overviews osteoporosis, including its definition, etiology, and incidence, and then provides some information on possible dietary strategies for optimizing bone health and preventing osteoporosis. The potential benefits of calcium, vitamin D, vitamin K(1), phytoestrogens, and nondigestible oligosaccharides are briefly discussed, with particular emphasis on the evidence base for their benefits to bone. It also briefly considers some of the recent findings that highlight the importance of some dietary factors for bone health in childhood and adolescence.

  6. Bone as a Structural Material.

    PubMed

    Zimmermann, Elizabeth A; Ritchie, Robert O

    2015-06-24

    As one of the most important natural materials, cortical bone is a composite material comprising assemblies of tropocollagen molecules and nanoscale hydroxyapatite mineral crystals, forming an extremely tough, yet lightweight, adaptive and multi-functional material. Bone has evolved to provide structural support to organisms, and therefore its mechanical properties are vital physiologically. Like many mineralized tissues, bone can resist deformation and fracture from the nature of its hierarchical structure, which spans molecular to macroscopic length-scales. In fact, bone derives its fracture resistance with a multitude of deformation and toughening mechanisms that are active at most of these dimensions. It is shown that bone's strength and ductility originate primarily at the scale of the nano to submicrometer structure of its mineralized collagen fibrils and fibers, whereas bone toughness is additionally generated at much larger, micro- to near-millimeter, scales from crack-tip shielding associated with interactions between the crack path and the microstructure. It is further shown how the effectiveness with which bone's structural features can resist fracture at small to large length-scales can become degraded by biological factors such as aging and disease, which affect such features as the collagen cross-linking environment, the homogeneity of mineralization, and the density of the osteonal structures.

  7. 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

  8. Targeted disruption of TGFBI in mice reveals its role in regulating bone mass and bone size through periosteal bone formation.

    PubMed

    Yu, Hongrun; Wergedal, Jon E; Zhao, Yongliang; Mohan, Subburaman

    2012-07-01

    Transforming growth factor-beta induced (TGFBI) and periostin are two closely related proteins in structure as well as in function. A previous study found that periostin positively regulates bone size. Here, we hypothesize that TGFBI has a similar function in bone development. To test this hypothesis, we employed TGFBI-deficient mice, which were generated by targeted disruption of the TGFBI gene. We bred these mice with C57BL/6J mice to generate homozygous TGFBI-deficient (TGFBI(-/-)) mice and homozygous wild-type littermates. All mice were raised to 12 weeks of age. Bone mass parameters were determined by PIXImus and micro-CT, bone strength parameters by three-point bending, and bone formation and resorption parameters by histomorphometry. We found that targeted disruption of TGFBI led to reduced body size, bone mass, bone size, and bone strength. This indicates that, like periostin, TGFBI also positively regulates bone size and that changes in bone size affect bone strength. Furthermore, there was also a significant decrease in periosteal, but not endosteal, bone formation rate of cortical bone in TGFBI(-/-) mice, suggesting that the observed effect of TGFBI on bone mass and bone size was largely caused by the effect of TGFBI on periosteal bone formation.

  9. Bone sialoprotein and osteopontin in bone metastasis of osteotropic cancers.

    PubMed

    Kruger, Thomas E; Miller, Andrew H; Godwin, Andrew K; Wang, Jinxi

    2014-02-01

    The mechanisms underlying malignant cell metastasis to secondary sites such as bone are complex and no doubt multifactorial. Members of the small integrin-binding ligand N-linked glycoproteins (SIBLINGs) family, particularly bone sialoprotein (BSP) and osteopontin (OPN), exhibit multiple activities known to promote malignant cell proliferation, detachment, invasion, and metastasis of several osteotropic cancers. The expression level of BSP and OPN is elevated in a variety of human cancers, particularly those that metastasize preferentially to the skeleton. Recent studies suggest that the "osteomimicry" of malignant cells is not only conferred by transmembrane receptors bound by BSP and OPN, but includes the "switch" in gene expression repertoire typically expressed in cells of skeletal lineage. Understanding the role of BSP and OPN in tumor progression, altered pathophysiology of bone microenvironment, and tumor metastasis to bone will likely result in development of better diagnostic approaches and therapeutic regimens for osteotropic malignant diseases.

  10. Sweet Bones: The Pathogenesis of Bone Alteration in Diabetes

    PubMed Central

    2016-01-01

    Diabetic patients have increased fracture risk. The pathogenesis underlying the status of bone alterations in diabetes mellitus is not completely understood but is multifactorial. The major deficits appear to be related to a deficit in mineralized surface area, a decrement in the rate of mineral apposition, deceased osteoid surface, depressed osteoblast activity, and decreased numbers of osteoclasts due to abnormal insulin signaling pathway. Other prominent features of diabetes mellitus are an increased urinary excretion of calcium and magnesium, accumulation of advanced glycation end products, and oxidative stress leading to sweet bones (altered bone's strength, metabolism, and structure). Every diabetic patient should be assessed for risk factors for fractures and osteoporosis. The pathogenesis of the bone alterations in diabetes mellitus as well as their molecular mechanisms needs further study. PMID:27777961

  11. [Bone and Nutrition. Effect of isoflavones on bone health].

    PubMed

    Ishimi, Yoshiko

    2015-07-01

    Effects of isoflavones on bone health in postmenopausal women are expected, since it shows weak estrogenic activity. In the observational study in Asia, association between intake of soy foods or isoflavone and bone mineral density and fracture prevention has been observed. In the meta-analysis of intervention trials of isoflavone in 60 years or less of postmenopausal women, 75 mg by day about 6 months to 1 year intervention of isoflavones induced suppression of significant decline of bone resorption markers in the urine was observed. On the other hand, intended for Westerners women in the study intervened isoflavones with calcium and vitamin D simultaneously, it is not observed effectiveness of isoflavones on the bone. Such a difference might be due to diversity in the individual metabolic capacity for isoflavones as well as the effects of presence or absence of other co-interventions nutrients.

  12. Bone Sialoprotein and Osteopontin in Bone Metastasis of Osteotropic Cancers

    PubMed Central

    Kruger, Thomas E.; Miller, Andrew H.; Godwin, Andrew K.; Wang, Jinxi

    2013-01-01

    The mechanisms underlying malignant cell metastasis to secondary sites such as bone are complex and no doubt multifactorial. Members of the small integrin-binding ligand N-linked glycoproteins (SIBLINGs) family, particularly bone sialoprotein (BSP) and osteopontin (OPN), exhibit multiple activities known to promote malignant cell proliferation, detachment, invasion, and metastasis of several osteotropic cancers. The expression level of BSP and OPN is elevated in a variety of human cancers, particularly those that metastasize preferentially to the skeleton. Recent studies suggest that the “osteomimicry” of malignant cells is not only conferred by transmembrane receptors bound by BSP and OPN, but includes the “switch” in gene expression repertoire typically expressed in cells of skeletal lineage. Understanding the role of BSP and OPN in tumor progression, altered pathophysiology of bone microenvironment, and tumor metastasis to bone will likely result in development of better diagnostic approaches and therapeutic regimens for osteotropic malignant diseases. PMID:24071501

  13. Avascular necrosis of carpal bones.

    PubMed

    Golimbu, C N; Firooznia, H; Rafii, M

    1995-05-01

    MR imaging is extremely well suited to detection of early phases of avascular necrosis, permitting diagnosis before collapse of the carpal bones has occurred. The sensitivity of this imaging modality allows differentiation of subtle changes in the bone marrow signal. This is used as criteria for a new stage classification of Kienböck's disease based on MR imaging appearance. The prognosis of scaphoid fractures and estimation of likelihood of avascular necrosis of the proximal fragment can be inferred by using gadolinium enhancement to evaluate the bone marrow vascularity.

  14. Radionuclide studies of bone metabolism: do bone uptake and bone plasma clearance provide equivalent measurements of bone turnover?

    PubMed

    Blake, Glen M; Siddique, Musib; Frost, Michelle L; Moore, Amelia E B; Fogelman, Ignac

    2011-09-01

    Quantitative radionuclide imaging using (18)F-fluoride positron emission tomography (18F-PET) or (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) bone scans provides a novel tool for studying regional and whole skeleton bone turnover that complements the information provided by biochemical markers. Radionuclide bone scans can be quantified by measuring either tracer uptake or, if blood sampling is performed, bone plasma clearance. This study examines whether these two methods provide equivalent information about bone turnover. We examined data from two clinical trials of the bone anabolic agent teriparatide. In Study 1 twenty osteoporotic women had 18F-PET scans of the lumbar spine at baseline and after 6 months treatment with teriparatide. Bone uptake in the lumbar spine was expressed as standardised uptake values (SUV) and blood samples taken to evaluate plasma clearance. In Study 2 ten women had (99m)Tc-MDP scans at baseline, 3 and 18 months after starting teriparatide. Blood samples were taken and whole skeleton plasma clearance and bone uptake calculated. In Study 1 spine plasma clearance increased by 23.8% after 6-months treatment (P=0.0003), whilst SUV increased by only 3.0% (P=0.84). In Study 2 whole skeleton plasma clearance increased by 37.1% after 18-months treatment (P=0.0002), whilst the 4-hour whole skeleton uptake increased by only 25.5% (P=0.0001). During treatment the 18F- plasma concentration decrease by 20% and (99m)Tc-MDP concentration by 13%, and these latter changes were sufficient to explain the differences between the uptake and plasma clearance results. Measurements of response to treatment using bone uptake and plasma clearance gave different results because the effects of teriparatide on bone resulted in a sufficiently increased demand for radionuclide tracer from the skeleton that the concentration in the circulation decreased. Similar effects may occur with other therapies that have a large enough effect on bone metabolism. In these

  15. Freeze-dried bank bone.

    PubMed

    Delloye, C; Buccafusca, G C

    1989-09-01

    The authors present their experience with freeze-dried bone of human origin. Since 1983, 500 preserved allografts have been implanted in 228 patients. The implants were monitored radiographically and, based on perfect fusion with the recipient bone, the results were as follows: excellent: 78%; good: 8.6%; failure: 12.4%. In nearly all the cases of failure this was attributed to an erronous implant method or an improper use of the graft. Bank bone is only osteoconductive: thus, in the absence of osteogenetic properties, a perfect method of implant and its correct use are essential.

  16. A Boon for Bone Research

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NASA studies for astronaut health in long-term space missions led to the development of the Mechanical Response Tissue Analyzer (MRTA), a research tool for astronaut disuse, osteoporosis and related bone disorders among the general population. Ames Research Center and Stanford University generated a workable device and with Gait Scan, Inc., refined and commercialized it. The MRTA is a portable dsinstrument that measures the bending stiffness of bones using electrically-induced vibration and detects and analyzes the frequencies of the resonating bone. Unlike some other methods, the MRTA uses no radiation and is fast, simple and relatively inexpensive.

  17. Post-traumatic bone loss of the femur treated with segmental bone allograft and bone morphogenetic protein: a case report.

    PubMed

    D'Agostino, Priscilla; Stassen, Pierre; Delloye, Christian

    2007-06-01

    Reconstruction of a major bone loss remains a challenge for the orthopaedic surgeon. Most of the bone defects result from a bone tumour resection whereas a post-traumatic bone loss is more rare due to the numerous options available for bone fixation. However in high-energy trauma, the injury to bone may be so extensive as to justify removal of fragmented bone. A 57-year-old man presented with a severe injury at the thigh after a hunting accident, including a comminuted fracture of the femoral shaft. After thorough debridement, he was left with a large diaphyseal bone defect which was subsequently treated with a structural bone allograft, autogenous graft and rhBMP-7. Bone healing was achieved after several months.

  18. Regional bone change in intramuscular haemangioma mimicking primary bone tumour.

    PubMed

    Shikhare, Sumer; Chacko, Julio K; Chuah, Khoon L

    2015-04-01

    Intramuscular haemangiomas are benign soft-tissue tumours, commonly located in the extremities. We present a right-leg intramuscular haemangioma with florid periosteal reaction in adjacent tibia, mimicking a primary bone tumour. Plain radiograph and magnetic resonance imaging features are illustrated with the surgical and histopathological findings. Radiologists need to be familiar with reactive bone changes secondary to deep-seated intramuscular haemangiomas to avoid potential misdiagnosis.

  19. TGF-β in cancer and bone: implications for treatment of bone metastases.

    PubMed

    Juárez, Patricia; Guise, Theresa A

    2011-01-01

    Bone metastases are common in patients with advanced breast, prostate and lung cancer. Tumor cells co-opt bone cells to drive a feed-forward cycle which disrupts normal bone remodeling to result in abnormal bone destruction or formation and tumor growth in bone. Transforming growth factor-beta (TGF-β) is a major bone-derived factor, which contributes to this vicious cycle of bone metastasis. TGF-β released from bone matrix during osteoclastic resorption stimulates tumor cells to produce osteolytic factors further increasing bone resorption adjacent to the tumor cells. TGF-β also regulates 1) key components of the metastatic cascade such as epithelial-mesenchymal transition, tumor cell invasion, angiogenesis and immunosuppression as well as 2) normal bone remodeling and coupling of bone resorption and formation. Preclinical models demonstrate that blockade of TGF-β signaling is effective to treat and prevent bone metastases as well as to increase bone mass.

  20. Endoscopically and Fluoroscopically Assisted Curettage and Bone Grafting of the Navicular Bone Cyst.

    PubMed

    Lui, Tun Hing

    2016-12-01

    Simple bone cyst is a common tumorlike lesion of the bone and can involve the bones of the foot. It is usually asymptomatic but can also present with pain or pathologic fracture. The purpose of this technical note is to describe the uni-osseous portal approach of endoscopic curettage and bone grafting of simple bone cyst of the navicular bone. The single-portal approach reduces the risk of iatrogenic fracture of the navicular bone. This is indicated for painful bone cyst of the navicular bone resistant to conservative treatment. It is contraindicated in multiple septated cysts, the presence of pathologic fracture, or the presence of aggressive cystic lesions.

  1. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bone densitometer. 892.1170 Section 892.1170 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1170 Bone densitometer. (a) Identification. A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray...

  2. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bone heterograft. 888.3015 Section 888.3015 Food... DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3015 Bone heterograft. (a) Identification. Bone heterograft is a device intended to be implanted that is made from mature (adult) bovine bones and used...

  3. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bone heterograft. 888.3015 Section 888.3015 Food... DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3015 Bone heterograft. (a) Identification. Bone heterograft is a device intended to be implanted that is made from mature (adult) bovine bones and used...

  4. 21 CFR 892.1180 - Bone sonometer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bone sonometer. 892.1180 Section 892.1180 Food and... RADIOLOGY DEVICES Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification. A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone...

  5. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bone heterograft. 888.3015 Section 888.3015 Food... DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3015 Bone heterograft. (a) Identification. Bone heterograft is a device intended to be implanted that is made from mature (adult) bovine bones and used...

  6. 21 CFR 892.1180 - Bone sonometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone sonometer. 892.1180 Section 892.1180 Food and... RADIOLOGY DEVICES Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification. A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone...

  7. 21 CFR 892.1180 - Bone sonometer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bone sonometer. 892.1180 Section 892.1180 Food and... RADIOLOGY DEVICES Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification. A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone...

  8. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bone densitometer. 892.1170 Section 892.1170 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1170 Bone densitometer. (a) Identification. A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray...

  9. 21 CFR 892.1180 - Bone sonometer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bone sonometer. 892.1180 Section 892.1180 Food and... RADIOLOGY DEVICES Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification. A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone...

  10. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bone densitometer. 892.1170 Section 892.1170 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1170 Bone densitometer. (a) Identification. A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray...

  11. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bone densitometer. 892.1170 Section 892.1170 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1170 Bone densitometer. (a) Identification. A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray...

  12. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone densitometer. 892.1170 Section 892.1170 Food... DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1170 Bone densitometer. (a) Identification. A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray...

  13. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone heterograft. 888.3015 Section 888.3015 Food... DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3015 Bone heterograft. (a) Identification. Bone heterograft is a device intended to be implanted that is made from mature (adult) bovine bones and used...

  14. 21 CFR 892.1180 - Bone sonometer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bone sonometer. 892.1180 Section 892.1180 Food and... RADIOLOGY DEVICES Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification. A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone...

  15. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bone heterograft. 888.3015 Section 888.3015 Food... DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3015 Bone heterograft. (a) Identification. Bone heterograft is a device intended to be implanted that is made from mature (adult) bovine bones and used...

  16. Decellularized bone matrix grafts for calvaria regeneration

    PubMed Central

    Lee, Dong Joon; Diachina, Shannon; Lee, Yan Ting; Zhao, Lixing; Zou, Rui; Tang, Na; Han, Han; Chen, Xin; Ko, Ching-Chang

    2016-01-01

    Decellularization is a promising new method to prepare natural matrices for tissue regeneration. Successful decellularization has been reported using various tissues including skin, tendon, and cartilage, though studies using hard tissue such as bone are lacking. In this study, we aimed to define the optimal experimental parameters to decellularize natural bone matrix using 0.5% sodium dodecyl sulfate and 0.1% NH4OH. Then, the effects of decellularized bone matrix on rat mesenchymal stem cell proliferation, osteogenic gene expression, and osteogenic differentiations in a two-dimensional culture system were investigated. Decellularized bone was also evaluated with regard to cytotoxicity, biochemical, and mechanical characteristics in vitro. Evidence of complete decellularization was shown through hematoxylin and eosin staining and DNA measurements. Decellularized bone matrix displayed a cytocompatible property, conserved structure, mechanical strength, and mineral content comparable to natural bone. To study new bone formation, implantation of decellularized bone matrix particles seeded with rat mesenchymal stem cells was conducted using an orthotopic in vivo model. After 3 months post-implantation into a critical-sized defect in rat calvaria, new bone was formed around decellularized bone matrix particles and also merged with new bone between decellularized bone matrix particles. New bone formation was analyzed with micro computed tomography, mineral apposition rate, and histomorphometry. Decellularized bone matrix stimulated mesenchymal stem cell proliferation and osteogenic differentiation in vitro and in vivo, achieving effective bone regeneration and thereby serving as a promising biological bone graft. PMID:28228929

  17. Estimation of In vivo Cancellous Bone Elasticity

    NASA Astrophysics Data System (ADS)

    Otani, Takahiko; Mano, Isao; Tsujimoto, Toshiyuki; Yamamoto, Tadahito; Teshima, Ryota; Naka, Hiroshi

    2009-07-01

    The effect of decreasing bone density (a symptom of osteoporosis) is greater for cancellous bone than for dense cortical bone, because cancellous bone is metabolically more active. Therefore, the bone density or bone mineral density of cancellous bone is generally used to estimate the onset of osteoporosis. Elasticity or elastic constant is a fundamental mechanical parameter and is directly related to the mechanical strength of bone. Accordingly, elasticity is a preferable parameter for assessing fracture risk. A novel ultrasonic bone densitometer LD-100 has been developed to determine the mass density and elasticity of cancellous bone with a spatial resolution comparable to that of peripheral quantitative computed tomography. Bone density and bone elasticity are evaluated using ultrasonic parameters based on fast and slow waves in cancellous bone by modeling the ultrasonic wave propagation path. Elasticity is deduced from the measured bone density and the propagation speed of the fast wave. Thus, the elasticity of cancellous bone is approximately expressed by a cubic equation of bone density.

  18. 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

  19. Micro-CT evaluation of bone defects: applications to osteolytic bone metastases, bone cysts, and fracture.

    PubMed

    Buie, Helen R; Bosma, Nick A; Downey, Charlene M; Jirik, Frank R; Boyd, Steven K

    2013-11-01

    Bone defects can occur in various forms and present challenges to performing a standard micro-CT evaluation of bone quality because most measures are suited to homogeneous structures rather than ones with spatially focal abnormalities. Such defects are commonly associated with pain and fragility. Research involving bone defects requires quantitative approaches to be developed if micro-CT is to be employed. In this study, we demonstrate that measures of inter-microarchitectural bone spacing are sensitive to the presence of focal defects in the proximal tibia of two distinctly different mouse models: a burr-hole model for fracture healing research, and a model of osteolytic bone metastases. In these models, the cortical and trabecular bone compartments were both affected by the defect and were, therefore, evaluated as a single unit to avoid splitting the defects into multiple analysis regions. The burr-hole defect increased mean spacing (Sp) by 27.6%, spacing standard deviation (SpSD) by 113%, and maximum spacing (Spmax) by 72.8%. Regression modeling revealed SpSD (β=0.974, p<0.0001) to be a significant predictor of the defect volume (R(2)=0.949) and Spmax (β=0.712, p<0.0001) and SpSD (β=0.271, p=0.022) to be significant predictors of the defect diameter (R(2)=0.954). In the mice with osteolytic bone metastases, spacing parameters followed similar patterns of change as reflected by other imaging technologies, specifically bioluminescence data which is indicative of tumor burden. These data highlight the sensitivity of spacing measurements to bone architectural abnormalities from 3D micro-CT data and provide a tool for quantitative evaluation of defects within a bone.

  20. Issues in modern bone histomorphometry☆

    PubMed Central

    Recker, R.R.; Kimmel, D.B.; Dempster, D.; Weinstein, R.S.; Wronski, T.J.; Burr, D.B.

    2012-01-01

    This review reports on proceedings of a bone histomorphometry session conducted at the Fortieth International IBMS Sun Valley Skeletal Tissue Biology Workshop held on August 1, 2010. The session was prompted by recent technical problems encountered in conducting histomorphometry on bone biopsies from humans and animals treated with anti-remodeling agents such as bisphosphonates and RANKL antibodies. These agents reduce remodeling substantially, and thus cause problems in calculating bone remodeling dynamics using in vivo fluorochrome labeling. The tissue specimens often contain few or no fluorochrome labels, and thus create statistical and other problems in analyzing variables such as mineral apposition rates, mineralizing surface and bone formation rates. The conference attendees discussed these problems and their resolutions, and the proceedings reported here summarize their discussions and recommendations. PMID:21810491

  1. What Are Bone Marrow Tests?

    MedlinePlus

    ... for people with certain bleeding disorders such as hemophilia. Bone marrow tests can be done in a ... reading Anemia Aplastic Anemia Blood Tests Clinical Trials Hemophilia Thrombocythemia and Thrombocytosis Thrombocytopenia Rate This Content: Updated: ...

  2. Brown adipose tissue and bone

    PubMed Central

    Lidell, M E; Enerbäck, S

    2015-01-01

    Brown adipose tissue (BAT) is capable of transforming chemically stored energy, in the form of triglycerides, into heat. Recent studies have shown that metabolically active BAT is present in a large proportion of adult humans, where its activity correlates with a favorable metabolic status. Hence, the tissue is now regarded as an interesting target for therapies against obesity and associated diseases such as type 2 diabetes, the hypothesis being that an induction of BAT would be beneficial for these disease states. Apart from the association between BAT activity and a healthier metabolic status, later studies have also shown a positive correlation between BAT volume and both bone cross-sectional area and bone mineral density, suggesting that BAT might stimulate bone anabolism. The aim of this review is to give the reader a brief overview of the BAT research field and to summarize and discuss recent findings regarding BAT being a potential player in bone metabolism. PMID:27152171

  3. 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.

  4. Scintigraphy of aneurysmal bone cysts

    SciTech Connect

    Hudson, T.M.

    1984-04-01

    Bone scintigrams with Tc-99m radiopharmaceuticals of 25 aneurysmal bone cysts showed abnormal activity in every case. In 22 cases, the activity was correlated with the true pathologic extent of the lesions; only three exhibited a false-positive extended pattern of uptake beyond the true tumor margins. Sixteen scintigrams (64%) revealed increased uptake, chiefly around the periphery of the lesions, with less activity in their centers. This feature could not be explained simply by the cystic nature of the lesions, since aneurysmal bone cysts may contain considerable fibrous tissue septa containing trabeculae of reactive new bone. However, there was no correlation between any specific anatomic or histologic pattern and the intensity and pattern of abnormal scintigraphic activity.

  5. [Classification of primary bone tumors].

    PubMed

    Dominok, G W; Frege, J

    1986-01-01

    An expanded classification for bone tumors is presented based on the well known international classification as well as earlier systems. The current status and future trends in this area are discussed.

  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. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... in determining treatment and prognosis) viral, bacterial, or fungal infections in the bone marrow that might be causing lasting fever or other symptoms certain genetic diseases (such as lipid storage diseases) They also ...

  8. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... in determining treatment and prognosis) viral, bacterial, or fungal infections in the bone marrow that might be causing a lasting fever or other symptoms certain genetic diseases (such as lipid storage diseases) They also ...

  9. 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

  10. Oral Health and Bone Disease

    MedlinePlus

    ... and ill-fitting or loose dentures. Effects of Osteoporosis Treatments on Oral Health It is not known ... Resources For more information on osteoporosis, visit: NIH Osteoporosis and Related Bone Diseases ~ National Resource Center Website: ...

  11. Healthy Bones at Every Age

    MedlinePlus

    ... at every age and stage of life. The skeleton is our body’s storage bank for calcium — a ... the actual size and structure of a person’s skeleton is determined by genetic factors. Although peak bone ...

  12. Vitamin A and Bone Health

    MedlinePlus

    ... good health. It promotes growth, the immune system, reproduction, and vision. However, recent research suggests that too ... play an important role in vision, bone growth, reproduction, cell division, and cell differentiation. We get vitamin ...

  13. The cartilage-bone interface.

    PubMed

    Hoemann, Caroline D; Lafantaisie-Favreau, Charles-Hubert; Lascau-Coman, Viorica; Chen, Gaoping; Guzmán-Morales, Jessica

    2012-05-01

    In the knee joint, the purpose of the cartilage-bone interface is to maintain structural integrity of the osteochondral unit during walking, kneeling, pivoting, and jumping--during which tensile, compressive, and shear forces are transmitted from the viscoelastic articular cartilage layer to the much stiffer mineralized end of the long bone. Mature articular cartilage is integrated with subchondral bone through a approximately 20 to approximately 250 microm thick layer of calcified cartilage. Inside the calcified cartilage layer, perpendicular chondrocyte-derived collagen type II fibers become structurally cemented to collagen type I osteoid deposited by osteoblasts. The mature mineralization front is delineated by a thin approximately 5 microm undulating tidemark structure that forms at the base of articular cartilage. Growth plate cartilage is anchored to epiphyseal bone, sometimes via a thin layer of calcified cartilage and tidemark, while the hypertrophic edge does not form a tidemark and undergoes continual vascular invasion and endochondral ossification (EO) until skeletal maturity upon which the growth plates are fully resorbed and replaced by bone. In this review, the formation of the cartilage-bone interface during skeletal development and cartilage repair, and its structure and composition are presented. Animal models and human anatomical studies show that the tidemark is a dynamic structure that forms within a purely collagen type II-positive and collagen type I-negative hyaline cartilage matrix. Cartilage repair strategies that elicit fibrocartilage, a mixture of collagen type I and type II, are predicted to show little tidemark/calcified cartilage regeneration and to develop a less stable repair tissue-bone interface. The tidemark can be regenerated through a bone marrow-driven growth process of EO near the articular surface.

  14. Bone Repair and Military Readiness

    DTIC Science & Technology

    2014-08-01

    Detrick, Maryland 21702-5012 Approved for public release; distribution is unlimited. Even though commercial bone cements have not significantly changed in...associated reduction in mechanical properties. The specific aims for this project are: Specific Aim 1: Develop a silorane bone cement suitable for in vivo...studies and to optimize the formulation of the chemically and mixed cured cement prototypes. Specific Aim 2: Determine the biocompatibility

  15. Nanoscale deformation mechanisms in bone.

    PubMed

    Gupta, Himadri S; Wagermaier, Wolfgang; Zickler, Gerald A; Raz-Ben Aroush, D; Funari, Sérgio S; Roschger, Paul; Wagner, H Daniel; Fratzl, Peter

    2005-10-01

    Deformation mechanisms in bone matrix at the nanoscale control its exceptional mechanical properties, but the detailed nature of these processes is as yet unknown. In situ tensile testing with synchrotron X-ray scattering allowed us to study directly and quantitatively the deformation mechanisms at the nanometer level. We find that bone deformation is not homogeneous but distributed between a tensile deformation of the fibrils and a shearing in the interfibrillar matrix between them.

  16. Mineralized Three-Dimensional Bone Constructs

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)

    2013-01-01

    The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.

  17. Mineralized three-dimensional bone constructs

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)

    2011-01-01

    The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.

  18. Prostate Cancer Presenting with Parietal Bone Metastasis

    PubMed Central

    Pare, Abdoul Karim; Abubakar, Babagana Mustapha; Kabore, Moussa

    2017-01-01

    Bone metastases from prostate cancer are very common. They are usually located on the axial skeleton. However, cranial bone metastases especially to the parietal bone are rare. We report a case of metastatic prostate cancer presenting with left parietal bone metastasis in a patient with no urological symptoms or signs. We should consider prostate cancer in any man above 60 years presenting unusual bone lesions.

  19. Determinants of Long Bone Structural Properties

    NASA Technical Reports Server (NTRS)

    Cleek, T. M.; Katz, B.; Whalen, R. T.; Wade, Charles E. (Technical Monitor)

    1994-01-01

    The objective of our research is to determine whether a non-invasive determination of long bone cross-sectional areal properties using only the mineral component of bone accurately predicts the true structural properties. In this study section properties of a whole long bone were compared using two methods: (1) special analysis of bone densitometry data, and (2) experimental determination of flexural rigidities from bone surface strain measurements during controlled loading.

  20. Research opportunities in bone demineralization, phase 3

    NASA Technical Reports Server (NTRS)

    Anderson, S. A. (Editor); Cohn, S. H. (Editor)

    1984-01-01

    An overview of bone demineralization during space flight, observations in bone demineralization and experiments related to bone loss planned for Spacelab flights, and suggestions for further research are investigated. The observations of the working group focused upon the following topics: (1) pathogenesis of bone demineralization, (2) potential for occurrence of renal stones consequent to prolonged hypercalciuria, (3) development of appropriate ground based and inflight models to study bone demineralization, (4) integration of research efforts, and (5) development of effective countermeasures.

  1. [Hormones and osteoporosis update. Glucocorticoids and bone].

    PubMed

    Ikeda, Kyoji

    2009-07-01

    Glucocorticoids are a class of vital steroid hormone which exhibit permissive effects on transactivation in a variety of cells, including those in bone. Glucocorticoid-induced osteoporosis, on the other hand, predisposes to fragility fracture by compromising bone strength and can be understood as a disease primarily characterized by a deficiency in bone quality. It is a major challenge in bone biology to understand these two contrasting sides of glucocorticoid activity in bone.

  2. 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.

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

    SciTech Connect

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

    2011-08-01

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

  4. [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.

  5. 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

  6. Bone age in cerebral palsy

    PubMed Central

    Miranda, Eduardo Régis de Alencar Bona; Palmieri, Maurício D'arc; de Assumpção, Rodrigo Montezuma César; Yamada, Helder Henzo; Rancan, Daniela Regina; Fucs, Patrícia Maria de Moraes Barros

    2013-01-01

    Objective To compare the chronological age and bone age among cerebral palsy patients in the outpatient clinic and its correlation with the type of neurological involvement, gender and functional status. Methods 401 patients with spastic cerebral palsy, and ages ranging from three months to 20 years old, submitted to radiological examination for bone age and analyzed by two independent observers according Greulich & Pyle. Results In the topographic distribution, there was a significant delay (p<0.005) in tetraparetic (17.7 months), hemiparetic (10.1 months), and diparetic patients (7.9 months). In the hemiparetic group, the mean bone age in the affected side was 96.88 months and the uncompromised side was 101.13 months (p<0.005). Regarding functional status, the ambulatory group showed a delay of 18.73 months in bone age (p<0.005). Comparing bone age between genders, it was observed a greater delay in males (13.59 months) than in females (9.63 months), but not statistically significant (p = 0.54). Conclusion There is a delay in bone age compared to chronological age influenced by the topography of spasticity, functional level and gender in patients with cerebral palsy. Level of Evidence IV, Case Series. PMID:24453693

  7. Chondroblastoma of the Temporal Bone

    PubMed Central

    Selesnick, Samuel H.; Levine, Jennifer M.

    1999-01-01

    The objective of this study is to describe the presentation and clinical course of two patients with temporal bone chondroblastoma, and to review the literature on temporal bone chondroblastoma to identify characteristic clinical and radiological presentations, and optimal treatment regimens. MEDLINE literature searches covering the period from 1966 to January 1998, in all languages, were performed as well as a review of the bibliographies of the identified studies. Strict inclusion criteria were upheld, In total 18 studies had patients whose data could be analyzed. From the 18 studies, 34 patients were identified, but only 21 cases met the inclusion criteria. Demographic, clinical presentation, radiological, operative and treatment parameters were analyzed in this cohort of patients. Ninety-five percent of patients were found to have invasion of the middle cranial fossa and 76% were found to have erosion into the superior aspect of the external auditory canal by temporal bone chondroblastoma. The characteristic growth pattern of temporal bone chondroblastoma may result from embryonal or cartilagenous rests entrapped in the tympanosquamous suture line in the middle fossa floor. Temporal bone chondroblastoma represents a pathology that does not arise from, or have a growth pattern resembling other pathologies in the temporal bone. ImagesFigure 1Figure 2 PMID:17171120

  8. Dairy products, yogurts, and bone health.

    PubMed

    Rizzoli, René

    2014-05-01

    Fracture risk is determined by bone mass, geometry, and microstructure, which result from peak bone mass (the amount attained at the end of pubertal growth) and from the amount of bone lost subsequently. Nutritional intakes are an important environmental factor that influence both bone mass accumulation during childhood and adolescence and bone loss that occurs in later life. Bone growth is influenced by dietary intake, particularly of calcium and protein. Adequate dietary calcium and protein are essential to achieve optimal peak bone mass during skeletal growth and to prevent bone loss in the elderly. Dairy products are rich in nutrients that are essential for good bone health, including calcium, protein, vitamin D, potassium, phosphorus, and other micronutrients and macronutrients. Studies supporting the beneficial effects of milk or dairy products on bone health show a significant inverse association between dairy food intake and bone turnover markers and a positive association with bone mineral content. Fortified dairy products induce more favorable changes in biochemical indexes of bone metabolism than does calcium supplementation alone. The associations between the consumption of dairy products and the risk of hip fracture are less well established, although yogurt intake shows a weakly positive protective trend for hip fracture. By consuming 3 servings of dairy products per day, the recommended daily intakes of nutrients essential for good bone health may be readily achieved. Dairy products could therefore improve bone health and reduce the risk of fractures in later life.

  9. Muscle Power Predicts Adolescent Bone Strength: Iowa Bone Development Study

    PubMed Central

    Janz, Kathleen F.; Letuchy, Elena M.; Burns, Trudy L.; Francis, Shelby L.; Levy, Steven M.

    2015-01-01

    Purpose To assess association between lower body muscle power and bone strength, as well as the mediating effect of muscle cross-sectional area (MCSA) on that association. Methods Participants (N=141 males; 162 females) were approximately 17 years. Muscle power was predicted using vertical jump and the Sayers equation. Using peripheral quantitative computed tomography (pQCT), bone strength indices were obtained at two locations of the tibia, corresponding to primary stressors acting upon each site: bone strength index for compression (BSI) at the distal 4% site; density-weighted polar section modulus strength-strain index [SSIp] and cortical bone area (CoA) at the 66% mid-shaft site for torsion. Muscle cross-sectional area (MCSA) was measured at the 66% site. Pearson bivariate and partial correlation coefficients were estimated to quantify the strength of the associations among variables. Direct and indirect mediation model effects were estimated and 95% bootstrap confidence intervals were constructed to test the causal hypothesis. Height and maturity were examined as covariates. Results Pearson correlation coefficients among muscle power, MCSA, and bone strength were statistically significant (p<0.01) and ranged from r=0.54 to 0.78. After adjustment for covariates, associations were reduced (r=0.37 to 0.69) (p<0.01). Mediation models for males for BSI, SSIp, and CoA accounted for 38%, 66%, and 54% of the variance in bone strength, respectively. Models for females for BSI, SSIp, and CoA accounted for 46%, 77%, and 66% of the variance, respectively. Conclusions We found strong and consistent associations, as well as direct and indirect pathways, among muscle power, MCSA, and tibia strength. These results support the use of muscle power as a component of health-related fitness in bone health interventions for older adolescents. PMID:25751769

  10. Interleukin-10 inhibits bone resorption: a potential therapeutic strategy in periodontitis and other bone loss diseases.

    PubMed

    Zhang, Qian; Chen, Bin; Yan, Fuhua; Guo, Jianbin; Zhu, Xiaofeng; Ma, Shouzhi; Yang, Wenrong

    2014-01-01

    Periodontitis and other bone loss diseases, decreasing bone volume and strength, have a significant impact on millions of people with the risk of tooth loss and bone fracture. The integrity and strength of bone are maintained through the balance between bone resorption and bone formation by osteoclasts and osteoblasts, respectively, so the loss of bone results from the disruption of such balance due to increased resorption or/and decreased formation of bone. The goal of therapies for diseases of bone loss is to reduce bone loss, improve bone formation, and then keep healthy bone density. Current therapies have mostly relied on long-term medication, exercise, anti-inflammatory therapies, and changing of the life style. However there are some limitations for some patients in the effective treatments for bone loss diseases because of the complexity of bone loss. Interleukin-10 (IL-10) is a potent anti-inflammatory cytokine, and recent studies have indicated that IL-10 can contribute to the maintenance of bone mass through inhibition of osteoclastic bone resorption and regulation of osteoblastic bone formation. This paper will provide a brief overview of the role of IL-10 in bone loss diseases and discuss the possibility of IL-10 adoption in therapy of bone loss diseases therapy.

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

    PubMed

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

    2015-01-01

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

  12. Bone allografts: What they can offer and what they cannot.

    PubMed

    Delloye, C; Cornu, O; Druez, V; Barbier, O

    2007-05-01

    Bone allografts can be used in any kind of surgery involving bone from minor defects to major bone loss after tumour resection. This review describes the various types of bone grafts and the current knowledge on bone allografts, from procurement and preparation to implantation. The surgical conditions for optimising the incorporation of bone are outlined, and surgeon expectations from a bone allograft discussed.

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

    PubMed

    Avrunin, A S; Doktorov, A A

    2016-01-01

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

  14. Regulation of bone mass by growth hormone.

    PubMed

    Olney, Robert C

    2003-09-01

    Growth hormone (GH) is a peptide hormone secreted from the pituitary gland under the control of the hypothalamus. It has a many actions in the body, including regulating a number of metabolic pathways. Some, but not all, of its effects are mediated through insulin-like growth factor-I (IGF-I). Both GH and IGF-I play significant roles in the regulation of growth and bone metabolism and hence are regulators of bone mass. Bone mass increases steadily through childhood, peaking in the mid 20s. Subsequently, there is a slow decline that accelerates in late life. During childhood, the accumulation in bone mass is a combination of bone growth and bone remodeling. Bone remodeling is the process of new bone formation by osteoblasts and bone resorption by osteoclasts. GH directly and through IGF-I stimulates osteoblast proliferation and activity, promoting bone formation. It also stimulates osteoclast differentiation and activity, promoting bone resorption. The result is an increase in the overall rate of bone remodeling, with a net effect of bone accumulation. The absence of GH results in a reduced rate of bone remodeling and a gradual loss of bone mineral density. Bone growth primarily occurs at the epiphyseal growth plates and is the result of the proliferation and differentiation of chondrocytes. GH has direct effects on these chondrocytes, but primarily regulates this function through IGF-I, which stimulates the proliferation of and matrix production by these cells. GH deficiency severely limits bone growth and hence the accumulation of bone mass. GH deficiency is not an uncommon complication in oncology and has long-term effects on bone health.

  15. Biomimetically enhanced demineralized bone matrix for bone regenerative applications

    PubMed Central

    Ravindran, Sriram; Huang, Chun-Chieh; Gajendrareddy, Praveen; Narayanan, Raghuvaran

    2015-01-01

    Demineralized bone matrix (DBM) is one of the most widely used bone graft materials in dentistry. However, the ability of DBM to reliably and predictably induce bone regeneration has always been a cause for concern. The quality of DBM varies greatly depending on several donor dependent factors and also manufacturing techniques. In order to standardize the quality and to enable reliable and predictable bone regeneration, we have generated a biomimetically-enhanced version of DBM (BE-DBM) using clinical grade commercial DBM as a control. We have generated the BE-DBM by incorporating a cell-derived pro-osteogenic extracellular matrix (ECM) within clinical grade DBM. In the present study, we have characterized the BE-DBM and evaluated its ability to induce osteogenic differentiation of human marrow derived stromal cells (HMSCs) with respect to clinical grade commercial DBM. Our results indicate that the BE-DBM contains significantly more pro-osteogenic factors than DBM and enhances HMSC differentiation and mineralized matrix formation in vitro and in vivo. Based on our results, we envision that the BE-DBM has the potential to replace DBM as the bone graft material of choice. PMID:26557093

  16. Bone morphogenetic proteins: Signaling periodontal bone regeneration and repair.

    PubMed

    Anusuya, G Sai; Kandasamy, M; Jacob Raja, S A; Sabarinathan, S; Ravishankar, P; Kandhasamy, Balu

    2016-10-01

    Bone morphogenetic proteins (BMPs) are a group of growth factors also known as cytokines and as metabologens. Originally discovered by their ability to induce the formation of bone and cartilage, BMPs are now considered to constitute a group of pivotal morphogenetic signals, orchestrating tissue architecture throughout the body. The important functioning of BMP signals in physiology is emphasized by the multitude of roles for dysregulated BMP signaling in pathological processes. A study done wherein it was found that protein extracts from bone implanted into the animals at nonbone sites induced the formation of new cartilage and bone tissue. This protein extract contained multiple factors that stimulated bone formation and was termed as "BMP." There are at least 15 different BMPs identified to date and are a part of the transforming growth factor-β super family. The most widely studied BMPs are BMP-2, BMP-3 (osteogenin), BMP-4, and BMP-7 (osteogenic protein-1). Now, any recombination type of morphogenic proteins have been synthesized, for example - recombinant human BMPs.

  17. Bone morphogenetic proteins: Signaling periodontal bone regeneration and repair

    PubMed Central

    Anusuya, G. Sai; Kandasamy, M.; Jacob Raja, S. A.; Sabarinathan, S.; Ravishankar, P.; Kandhasamy, Balu

    2016-01-01

    Bone morphogenetic proteins (BMPs) are a group of growth factors also known as cytokines and as metabologens. Originally discovered by their ability to induce the formation of bone and cartilage, BMPs are now considered to constitute a group of pivotal morphogenetic signals, orchestrating tissue architecture throughout the body. The important functioning of BMP signals in physiology is emphasized by the multitude of roles for dysregulated BMP signaling in pathological processes. A study done wherein it was found that protein extracts from bone implanted into the animals at nonbone sites induced the formation of new cartilage and bone tissue. This protein extract contained multiple factors that stimulated bone formation and was termed as “BMP.” There are at least 15 different BMPs identified to date and are a part of the transforming growth factor-β super family. The most widely studied BMPs are BMP-2, BMP-3 (osteogenin), BMP-4, and BMP-7 (osteogenic protein-1). Now, any recombination type of morphogenic proteins have been synthesized, for example - recombinant human BMPs. PMID:27829744

  18. Biomimetics of Bone Implants: The Regenerative Road

    PubMed Central

    Brett, Elizabeth; Flacco, John; Blackshear, Charles; Longaker, Michael T.; Wan, Derrick C.

    2017-01-01

    Abstract The current strategies for healing bone defects are numerous and varied. At the core of each bone healing therapy is a biomimetic mechanism, which works to enhance bone growth. These range from porous scaffolds, bone mineral usage, collagen, and glycosaminoglycan substitutes to transplanted cell populations. Bone defects face a range of difficulty in their healing, given the composite of dense outer compact bone and blood-rich inner trabecular bone. As such, the tissue possesses a number of inherent characteristics, which may be clinically harnessed as promoters of bone healing. These include mechanical characteristics, mineral composition, native collagen content, and cellular fraction of bone. This review charts multiple biomimetic strategies to help heal bony defects in large and small osseous injury sites, with a special focus on cell transplantation. PMID:28163982

  19. Evidence for arrested bone formation during spaceflight

    NASA Technical Reports Server (NTRS)

    Turner, R. T.; Bobyn, J. D.; Duvall, P.; Morey, E. R.; Baylink, D. J.; Spector, M.

    1982-01-01

    Addressing the question of whether the bone formed in space is unusual, the morphology of bone made at the tibial diaphysis of rats before, during, and after spaceflight is studied. Evidence of arrest lines in the bone formed in space is reported suggesting that bone formation ceases along portions of the periosteum during spaceflight. Visualized by microradiography, the arrest lines are shown to be less mineralized than the surrounding bone matrix. When viewed by scanning electron microscopy, it is seen that bone fractures more readily at the site of an arrest line. These observations are seen as suggesting that arrest lines are a zone of weakness and that their formation may result in decreased bone strength in spite of normalization of bone formation after flight. The occurrence, location, and morphology of arrest lines are seen as suggesting that they are a visible result of the phenomenon of arrested bone formation.

  20. [Normal bone marrow and common reactive alterations].

    PubMed

    Tzankov, A; Dirnhofer, S; Beham-Schmid, C

    2012-11-01

    Histological examination of bone marrow biopsies is an important and powerful diagnostic tool to assess various hematological and non-hematological disorders. Morphological examination of such biopsies requires knowledge of the composition of normal bone marrow and its variations, such as age-related changes. Diagnostic problems may arise due to poor specimen quality, insufficient sections or stainings and insufficient experience with reactive bone marrow changes which occasionally resemble neoplastic disorders. Reactive bone marrow processes can affect one or more hematopoietic cell lines, lead to disruption of the normal architecture and specifically affect the bone marrow stroma. Optimal bone marrow diagnosis requires adequately stained slides and, when needed, immunophenotyping and molecular examinations. Furthermore, rather than biopsy interpretation of other organs, pathologists routinely need clinical history information for correct interpretation and diagnosis of bone marrow changes. In this article, the normal features of bone marrow as well as the most frequent reactive bone marrow alterations are described.