Science.gov

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 music

    E-print Network

    Rdo rje don 'grub

    2011-01-01

    Rdo rje don 'grub bought the flute in Xining City in 2010 for fifty RMB. The flute was made of bamboo. The flute player commented that in the past that was made from a vulture bone. When he wanted to learn how to pay the flute, he gave a piece...

  3. Organogenesis of the exocrine gland Jiahu Wang and Gordon W. Laurie*

    E-print Network

    Review Organogenesis of the exocrine gland Jiahu Wang and Gordon W. Laurie* Department of Cell of exocrine glands is a complex stepwise process of epithelial ingrowth, ductal elongation, ductal branching morphogenesis. D 2004 Elsevier Inc. All rights reserved. Keywords: Morphogenesis; Organogenesis; Gland; Exocrine

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

    PubMed Central

    Diedrich, Cajus G.

    2015-01-01

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

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

    PubMed

    Diedrich, Cajus G

    2015-04-01

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

  6. 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.…

  7. 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.

  8. 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)

  9. Doc.382, 'Nose flute'

    E-print Network

    Roth, George Kingsley

    Audio recording of a nose flute played by Josefa Tale of Namata, Tailevu, recorded in Suva on September 1957. Arranged recording, 9 min 49 seconds. Fijian music, songs and dances, recorded by George Kingsley Roth in Fiji in the 1950s. Most...

  10. 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. PMID:22041130

  11. Inverse Doppler Effects in Flute

    E-print Network

    Zhao, Xiao P; Liu, Song; Shen, Fang L; Li, Lin L; Luo, Chun R

    2015-01-01

    Here we report the observation of the inverse Doppler effects in a flute. It is experimentally verified that, when there is a relative movement between the source and the observer, the inverse Doppler effect could be detected for all seven pitches of a musical scale produced by a flute. Higher tone is associated with a greater shift in frequency. The effect of the inverse frequency shift may provide new insights into why the flute, with its euphonious tone, has been popular for thousands of years in Asia and Europe.

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

    E-print Network

    Roth, George Kingsley

    Audio recording of nose flutes and shell trumpets, 15 min 51 seconds 1) Nose flute, fangofango - Copy of BBC recording (Library number 20468) made in December 1953 in Nuku'alofa Tonga. Arranged recording [0.21-4.22] 2) Nose flute - Copy...

  13. Guest Artist Recital Dr. Jennifer Cooper, flute

    E-print Network

    Wang, Xiaorui "Ray"

    PR EVIEW presents a Guest Artist Recital Cooper Duo Dr. Jennifer Cooper, flute Dr. Zachary Cooper become/decay Tyler Kline World Premiere (b. 1991) Trio for Flute, Horn and Piano Hugo Kauder (1888-1972) Hochzeits-Ständchen, Henri Kling Trio for Flute, Horn and Piano (1842-1918) Nocturne Rudolf Tillmetz Trio

  14. Fall Flute Recital in collaboration with

    E-print Network

    Wang, Xiaorui "Ray"

    PR EVIEW presents a Fall Flute Recital in collaboration with Dustin Lin, piano Sunday, November 15 Sonata pour flute et piano Francis Poulenc II. Cantilena (1899-1963) I. Allegro malincolico Shelby Carver Andante et Scherzo pour flute et piano Louis Ganne (1862-1923) Natalie Gregg Acht Stücke Paul Hindemith

  15. ''Flute'' instability in tandem mirrors

    SciTech Connect

    Timofeev, A.V.

    1983-05-01

    This analysis is based on the circumstance that flute-like waves in the end mirror systems of a tandem mirror convert into Alfven waves in the central solenoid. The effect of the end regions on the Alfven waves can be taken into account through boundary conditions at the ends of the central mirror system. A two-dimensional differential wave equation describing the plasma oscillations in a tandem mirror is reduced to a one-dimensional integral equation which determines the radial structure of the flutes in the end regions. If the growth rate is sufficiently high, this integral equation transforms into a differential equation. If the flute waves are stabilized by finite-Larmor-radius effects, the energy transfer into the central mirror system through the excitation of Alfven waves drives an instability of negative-energy waves.

  16. Flute! Practicum for Performers2015 June 15-19, 2015

    E-print Network

    Hi Ma Flute! Practicum for Performers2015 June 15-19, 2015 Flute! Practicum for Performers 2015 Professor of Flute at the University of North Texas, appears as soloist and chamber artist throughout for the National Flute Association and British Flute Society. Her recordings include Sonatas and Sonatinas, after

  17. Flute! High School Camp, 2015 June 26 -28, 2015

    E-print Network

    Hi ic Ma Flute! High School Camp, 2015 June 26 - 28, 2015 Flute! High School Camp 2015 is a class clardy Mary Karen Clardy, Regents Professor of Flute at the University of North Texas, appears as soloist, with numerous performances for the National Flute Association and British Flute Society. Her recordings include

  18. Flute! Fundamentals 2015 June 8-12, 2015

    E-print Network

    Hi Ma Flute! Fundamentals 2015 June 8-12, 2015 Flute! Fundamentals 2015 is a workshop clardy Mary Karen Clardy, Regents Professor of Flute at the University of North Texas, appears as soloist, with numerous performances for the National Flute Association and British Flute Society. Her recordings include

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

    PubMed

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

    2014-07-01

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

  20. 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,…

  1. 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).

  2. Flute! Middle School Day Camp 2015 June 12-13, 2015

    E-print Network

    Hi Ma Flute! Middle School Day Camp 2015 June 12-13, 2015 Flute! Middle School Day Camp 2015 Clardy in every session, and flute choir rehearsals add the opportunity to try other members of the flute family (piccolo, alto flute and bass flute) and build ensemble skills, with a final camp concert of music

  3. 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.

  4. FOARS: FLUTE Based Obstacle-Avoiding Rectilinear Steiner Tree Construction

    E-print Network

    Chu, Chris C.-N.

    FOARS: FLUTE Based Obstacle-Avoiding Rectilinear Steiner Tree Construction Gaurav Ajwani Table based Wire- length Estimation (OA-FLUTE) at a lower level to gen- erate an OAST followed. In this work, we develop a new O(n log n) time algorithm called FOARS for OARSMT generation by leveraging FLUTE

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

    E-print Network

    Hart, Gus

    Kristina Sorensen Acoustics of a Rotating Grand Piano & the Flute Kristina Sorensen 1 10 June 2011 production and radiation from a large Yamaha Grand Piano as well as my Sonóre flute. Methods I Experimental Procedure for Flute Acoustics A x x x x x Visual Data Analysis: Spectra, Spectrogram, Hilbert

  6. 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.

  7. 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.

  8. 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%.

  9. Analytical bunch compression studies for FLUTE

    E-print Network

    Schreck, M

    2014-01-01

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

  10. Paul Taffanel and the Construction of the French Flute School

    E-print Network

    Glick, Dorothy Ellen

    2014-05-31

    Beginning with Paul Taffanel and the introduction of the silver Boehm system flute in the mid-nineteenth century, the French Flute School refers to the use of vibrato, emotional approach to musical line, technique, and tone of French flutists. After...

  11. 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.

  12. ISPD: FOARS: FLUTE Based Obstacle-Avoiding Rectilinear Steiner Tree Construction

    E-print Network

    Chu, Chris C.-N.

    1 ISPD: FOARS: FLUTE Based Obstacle-Avoiding Rectilinear Steiner Tree Construction Gaurav Ajwani subset by an obstacle aware version of the rectilinear Steiner minimal tree (RSMT) algorithm FLUTE for OARSMT and RSMT generation by leveraging FLUTE [15]. FLUTE is a very fast and robust tool for RSMT

  13. IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN, 2007 1 FLUTE: Fast Lookup Table Based Rectilinear

    E-print Network

    Chu, Chris C.-N.

    IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN, 2007 1 FLUTE: Fast Lookup Table Based Rectilinear present a very fast and accu- rate rectilinear Steiner minimal tree (RSMT) algorithm called FLUTE. FLUTE and runtime. FLUTE is optimal for low-degree nets (up to degree 9 in our current implementation) and is still

  14. Flute-interchange stability in a hot electron plasma

    SciTech Connect

    Dominguez, R.R.

    1980-01-01

    Several topics in the kinetic stability theory of flute-interchange modes in a hot electron plasma are discussed. The stability analysis of the hot-electron, curvature-driven flute-interchange mode, previously performed in a slab geometry, is extended to a cylindrical plasma. The cold electron concentration necessary for stability differs substantially from previous criteria. The inclusion of a finite temperature background plasma in the stability analysis results in an ion curvature-driven flute-interchange mode which may be stabilized by either hot-electron diamagnetic effects, hot-electron plasma density, or finite (ion) Larmor radius effects.

  15. 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

  16. 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

  17. 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.

  18. 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

  19. 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

  20. Body vibrational spectra of metal flute models

    NASA Astrophysics Data System (ADS)

    Hurtgen, Clare M.; Lawson, Dewey T.

    2002-11-01

    For years, flutists have argued over the tonal advantages of using different precious metals for their instruments. Occasionally, scientists have entered the fray and attempted to offer an objective point of view based on experimental measurements. However, their research often involved actual instruments and performers, ignoring variations in wall thickness, craftsmanship, and human consistency. These experiments have been conducted using a variety of methods; all have concluded that wall material has no effect on tone. This paper approaches the question using simple tubular models, excited by a wind source through a fipple mouthpiece. The amplitude and phase of the harmonic components of the body vibrational signal were measured with a stereo cartridge. Results demonstrated the existence of complex patterns of wall vibrations in the vicinity of a tone hole lattice, at frequencies that match significant harmonics of the air column. Additionally, the tube wall was found to expand in a nonuniform or ''elliptical'' manner due to the asymmetry of the tone holes. While this method is somewhat removed from direct musical applications, it can provide an objective, quantitative basis for assessing the source of differences among flutes. [Work financed by two Undergraduate Research Support grants from Duke University.

  1. 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.

  2. 24 Physics at a Research University Chapter 4 Xrays, Flutes and More Ether

    E-print Network

    Akerib, Daniel S.

    24 Physics at a Research University Chapter 4 Xrays, Flutes and More Ether: Dayton Clarence Miller of musical flutes and sec- ond, as an experimentalist who found evidence for ether drift. Some an accomplished flute player. At age 16, he entered Baldwin College (now Baldwin Wallace), graduating

  3. FLUTE: Fast Lookup Table Based Wirelength Estimation Technique Electrical and Computer Engineering

    E-print Network

    Chu, Chris C.-N.

    FLUTE: Fast Lookup Table Based Wirelength Estimation Technique Chris Chu Electrical and Computer a novel wirelength estimation technique called FLUTE. Our tech- nique is based on pre-computed lookup experimentally that for FLUTE, RMST, and HPWL, the aver- age error in wirelength are 0.72%, 4.23%, and -8

  4. ION-INDUCED INSTABILITY OF DIOCOTRON MODES IN ELECTRON PLASMAS MODELLING CURVATURE-DRIVEN FLUTE MODES

    E-print Network

    California at San Diego, University of

    ION-INDUCED INSTABILITY OF DIOCOTRON MODES IN ELECTRON PLASMAS MODELLING CURVATURE-DRIVEN FLUTE, La Jolla, CA, USA 92093-0319, aakpla@physics.ucsd.edu We study ion-induced instability of flute in the periodic wave perturbation. I. INTRODUCTION Curvature-driven flute modes have been a problem for magnetic

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

    E-print Network

    Vlahos, Loukas

    Generation and saturation of large scale flows in flute turbulence I. Sandberg1,2 , H. Isliker2 flute insta- bility is numerically investigated. The formation of streamer-like structures is attributed of the non­linear coupling between linearly grown flute modes. When the amplitudes of the zonal modes be

  6. 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. PMID:17977805

  7. 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.

  8. 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.

  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. Flute instability in an open min B system

    SciTech Connect

    Arsenin, V.V.

    1983-01-01

    In a confinement system with an average min B, in part of which the particles undergo an unfavorable magnetic drift, the familiar MHD flute waves may be accompanied by some natural flute waves with an azimuthal phase velocity on the order of or smaller than the magnetic drift velocity of the ions in the region of favorable curvature. This wave branch is not described in the MHD approximation; it arises in the two-fluid model. These waves have a negative energy and may thus be excited by dissipative effects.

  11. 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.

  12. Active feedback stabilization of flute instability in a mirror trap

    NASA Astrophysics Data System (ADS)

    Be'Ery, Ilan; Seemann, Omri; Fruchtman, Amnon; Fisher, Amnon; Ron, Amiram

    2013-10-01

    The flute instability in a table-top mirror machine has been stabilized by a feedback system consisting of optical probes, digital signal processor, and needle electrodes. The total response time of the system is 5 ?s, which is considerably faster than the typical flute growth time. Simulation and a dynamic model of the plasma's response to the needle actuators were tested against cyclic bias experiments. The plasma density is increased by the stabilization by a factor of two and is limited by other decay processes.

  13. 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.

  14. 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.

  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. 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 schemata and…

  17. Stability boundary for flute waves in an axisymmetric tandem mirror

    SciTech Connect

    Mikhailovskaya, L.V.

    1980-07-01

    Timofeev has shown )Pis'ma v ZhETF 29, 227 (1979) (JETP Lett. 29, 204 (1979))) that flute modes can be stabilized in an axisymmetric confinement system consisting of three ordinary mirrors because of the large central section, which increases the inertia of the system. The stability boundary for these waves is found in the present paper.

  18. 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.

  19. 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.

  20. 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 approximately 40% on the subscale test articles and by less than 20% on the full-scale test articles. Nondestructive inspection of the damage zones indicated that the detectable damage was limited to no more than one flute on either side of any given impact. More study is needed, but this may indicate that an inherent damage-arrest capability of fluted core could provide benefits over traditional sandwich designs in certain weight-critical applications.

  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. PMID:17069326

  3. 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.

  4. Flute growth rate of plasma jet in mirror machine

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

  5. 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.

  6. A real variable characterization of Gromov hyperbolicity of flute surfaces

    E-print Network

    Portilla, Ana; Touris, Eva

    2008-01-01

    In this paper we give a characterization of the Gromov hyperbolicity of trains (a large class of Denjoy domains which contains the flute surfaces) in terms of the behavior of a real function. This function describes somehow the distances between some remarkable geodesics in the train. This theorem has several consequences; in particular, it allows to deduce a result about stability of hyperbolicity, even though the original surface and the modified one are not quasi-isometric.

  7. Current gradient driven flute vortices in magnetized plasmas

    SciTech Connect

    Shukla, P.K.

    1987-07-01

    It is shown that an external electron current gradient in a nonuniform magnetized plasma can drive a purely growing instability involving coupled convective cells and magnetostatic modes. Accounting for the mode coupling, it is demonstrated that the quasistationary state of the unstable flute modes can lead to a spatially ordered dipolar vortex structure. The latter could alter the transport properties and it may also be responsible for a relaxed state in a force-free magnetized plasma.

  8. 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.

  9. Sedimentary anisotropy diverges from flute trends in south-east Finnish Lapland

    NASA Astrophysics Data System (ADS)

    Sutinen, Raimo; Hyvönen, Eija; Närhi, Paavo; Haavikko, Paula; Piekkari, Matti; Middleton, Maarit

    2010-12-01

    Subglacial flutes are parallel-to-ice flow lineations indicative of glacial streamlining, yet their depositional/erosional origin or sedimentary anisotropy is not fully understood. The flutes, aligned NW-SE with a flow direction to the SE, are superimposed on westerly oriented drumlins, in Kuusamo, south-eastern Finnish Lapland (65°45'N and 29°40'E) and reflect ice stream flow pattern towards the Younger Dryas End Moraines (YDEMs) in Russian Karelia. We investigated bedform morphology (flutes, drumlins and crescentic troughs), as well as sedimentary anisotropy of flute ridges and troughs using digital elevation models (DEMs), airborne radiometric (AR) data, and measurements of azimuthal electrical conductivity ( ?a). The DEM-AR revealed elongation ratios ( L/ W) from 2:1 to 25:1, yet the highest ratios reached L/ W = 48:1. Flutes in the study area fan towards the east and south-east, whereas the drumlins on which they are superimposed show ice flow from the west (280°). The ?a-anisotropy of the flute ridges and troughs indicates sedimentation from 340° to 350°, diagonal with respect to both drumlins and flutes. We found erosional crescentic troughs with down-flow rims indicative of both phases, but failed to find evidence for subglacial meltwater boulder lags or ice-flow erosional bedrock bump sticky spots. We contend that the studied flutes are erosional and date to the YDEM-phase, yet the origin of the precursory sediments may date to Early Weichselian.

  10. 1 THE LEONARD AND MARGARET DOMAN UNDERGRADUATE SCHOLARSHIP FOR FLUTE (1356/2010) THE AUSTRALIAN NATIONAL UNIVERSITY

    E-print Network

    Botea, Adi

    1 ­ THE LEONARD AND MARGARET DOMAN UNDERGRADUATE SCHOLARSHIP FOR FLUTE (1356/2010) THE AUSTRALIAN NATIONAL UNIVERSITY THE LEONARD AND MARGARET DOMAN UNDERGRADUATE SCHOLARSHIP FOR FLUTE CONDITIONS of AWARD 1. GENERAL 1.1 Eligibility All new applicants commencing a Bachelor of Music degree in Flute

  11. 1 THE LEONARD AND MARGARET DOMAN GRADUATE SCHOLARSHIP FOR FLUTE (1355/2010) THE AUSTRALIAN NATIONAL UNIVERSITY

    E-print Network

    Botea, Adi

    1 ­ THE LEONARD AND MARGARET DOMAN GRADUATE SCHOLARSHIP FOR FLUTE (1355/2010) THE AUSTRALIAN NATIONAL UNIVERSITY THE LEONARD AND MARGARET DOMAN GRADUATE SCHOLARSHIP FOR FLUTE CONDITIONS OF AWARD 1. GENERAL 1.1 Eligibility All students enrolled in a graduate coursework program in Flute Performance

  12. 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.

  13. 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.

  14. How opening a hole affects the sound of a flute

    E-print Network

    Joly, Romain

    2011-01-01

    In this paper, we consider an open tube of diameter $\\epsilon>0$, on the side of which a small hole of size $\\epsilon^2$ is pierced. The resonances of this tube correspond to the eigenvalues of the Laplacian operator with homogeneous Neumann condition on the inner surface of the tube and Dirichlet one the open parts of the tube. We show that this spectrum converges when $\\epsilon$ goes to 0 to the spectrum of an explicit one-dimensional operator. At a first order of approximation, the limit spectrum describes the note produced by a flute, for which one of its holes is open.

  15. 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 20052006 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 (r 2 = 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. sciera and 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. ?? 2012, American Midland Naturalist.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Axial feedback stabilization of flute modes for mirror machines

    SciTech Connect

    Kang, B.K.; Lieberman, M.A.; Sen, A.K.

    1988-02-01

    A novel scheme of feedback stabilization of the m = 1 flute mode for axisymmetric mirror machines is proposed, which has potential for reactor extrapolation. A three-region plasma model is analyzed, consisting of a hot core surrounded by a warm transition annulus, which in turn is surrounded by a warm halo annulus that is in contact with segmented annular feedback plates at the two endwalls. For plasma parameters characteristic of the TMX-U and MFTF-B devices at the Lawrence Livermore National Laboratory and the MMX device at the University of California, Berkeley, the required feedback power is calculated. The results show that stability can be achieved in the MMX and TMX-U devices with a modest feedback gain and power. The power requirement for the near-reactor conditions of MFTF-B is more severe, but can be reduced by a modified choice of plasma parameters.

  2. 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.

  3. 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.

  4. FLUTE: A versatile linac-based THz source

    NASA Astrophysics Data System (ADS)

    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.

  5. 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. PMID:23464187

  6. 78 FR 25041 - Endangered and Threatened Wildlife and Plants; Endangered Status for the Fluted Kidneyshell and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-29

    ...DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR...Wildlife and Plants; Endangered Status for the Fluted Kidneyshell and Slabside Pearlymussel...SUMMARY: We, the U.S. Fish and Wildlife Service...

  7. 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)

  8. 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. PMID:19419170

  9. 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. PMID:26309391

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

    SciTech Connect

    Segal, D.

    1983-09-01

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

  11. Analysis of Lung Flute–collected Sputum for Lung Cancer Diagnosis

    PubMed Central

    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. PMID:26309391

  12. 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.

  13. 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.

  14. Management of femoral bone loss in revision total hip arthroplasty.

    PubMed

    Sculco, Peter K; Abdel, Matthew P; Lewallen, David G

    2015-01-01

    Femoral bone loss is frequently encountered during revision total hip arthroplasty. The quality and quantity of remaining bone helps determine the best method for reconstruction. Extensively porous-coated cylindrical stems or titanium fluted tapered devices that achieve fixation in the diaphysis have both demonstrated excellent long-term survivorship. Titanium fluted tapered stems with a modular proximal body allow for more accurate leg length, offset, and version adjustments independent of the distal stem which may optimise hip biomechanics. Intraoperative fractures are more common with cylindrical stems and subsidence with tapered stems, particularly monoblock designs and in both dislocation continues to be one of the most common postoperative complications. In salvage situations in which an ectatic femoral canal is unable to support an uncemented device, impaction bone grafting, allograft-prosthetic composite, or a segmental proximal femoral replacement may be required. PMID:26351121

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

    NASA Astrophysics Data System (ADS)

    Cossette, Isabelle A.; Sabourin, Patrick

    2001-05-01

    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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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)). PMID:20058998

  1. 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. PMID:20390911

  2. 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.

  3. Join the BC Flute Ensemble!! Rehearsals: Monday evenings from 8:00 -9:30 in Lyons Hall 423, beginning Sept. 16.

    E-print Network

    Huang, Jianyu

    Join the BC Flute Ensemble!! Rehearsals: Monday evenings from 8:00 - 9:30 in Lyons Hall 423, beginning Sept. 16. Concerts: The Flute Ensemble performs throughout the semester in conjunction flute solos with piano. Students have also enjoyed partnering with one another to play duos and trios

  4. 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.

  5. 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.

  6. 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.

  7. DNA Taxonomy of Paranemertes (Nemertea: Hoplonemertea) with Spirally Fluted Stylets.

    PubMed

    Hao, Yue; Kajihara, Hiroshi; Chernyshev, Alexei V; Okazaki, Robert K; Sun, Shi-Chun

    2015-12-01

    Of the 14 nominal species that are now or have ever been assigned to the genus Paranemertes Coe, 1901 , four have been reported to have stylets with a spirally fluted or braided appearance. Although differentiation in color patterns has been documented among species/populations, these nemerteans share similar external characters. Using the sequence datasets of mitochondrial cytochrome c oxidase subunit I (COI), 16S rRNA, and nuclear 28S rRNA genes of specimens from 14 localities of Canada, USA, Russia, Japan, and China, we analyzed the genetic differentiation and reconstructed the phylogenetic trees for these nemerteans. In conjunction with the external characters, we discuss their taxonomy and species delimitation. An analysis based on COI dataset showed high genetic variations among populations and even among worms from the same geographic area. The analyzed 111 individuals were assigned into seven networks by statistical parsimony analysis. The inter-network uncorrected p-distances ranged from 0.044 to 0.172 and the mean intra-network uncorrected p-distances varied from 0.001 to 0.005. With the exception of two networks that contain specimens from the East China Sea, all networks were well-supported by the results of Bayesian and neighbor-joining analyses on the COI data. Phylogenetic trees based on 16S rRNA and 28S rRNA datasets were basically similar to the COI trees, but specimens in some networks were merged into larger clades. Present molecular analyses support the validity of P. sanjuanensis and the synonymization of P. cylindracea with P. peregrina. Nemerteans previously recorded as P. peregrina may contain several species and sympatric speciation might have been occurred in this nemertean group. PMID:26654040

  8. 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. PMID:17548536

  9. Stability theory of drift-type flute modes in finite-. beta. plasmas

    SciTech Connect

    Migliuolo, S.

    1982-12-01

    The linear theory of flute modes in a finite-..beta.., inhomogeneous, magnetized plasma is developed. The collisionless Vlasov equation is used in a slab geometry, including the effects of a constant gravity field. The magnetic drift mode and the g x B mode are examined, and their stability properties are described. These two ''modes'' are shown to be different limits of the general finite-..beta.. interchange mode. The wave-particle resonances, between the flute modes and the particles that delB drift perpendicular to the unperturbed magnetic field, are included in a self-consistent manner.

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  11. 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…

  12. 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.

  13. 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…

  14. 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.

  15. 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.

  16. 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.

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

    E-print Network

    Truong, An Van

    2014-04-22

    bands.8 Small endosseous implants were also utilized as orthodontic anchorage when they were placed in the retromolar pad area and palate to aid in the closure of extraction spaces.9, 10 Other studies also report the use of palatal onplants... could be applied to further alleviate the titanium metal artifacts. In another study by Stoppie et al, 3.5 mm wide and 13 mm long titanium implant screws were placed in the femoral condyles of female Saanen goats.61 The implant and surrounding...

  18. Bone Diseases

    MedlinePLUS

    ... break Osteogenesis imperfecta makes your bones brittle Paget's disease of bone makes them weak Bone disease can make bones easy to break Bones can also develop cancer and infections Other bone diseases are caused by poor nutrition, genetic factors or ...

  19. 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.

  20. Regime change thresholds in flute-like instruments: influence of the mouth pressure dynamics

    E-print Network

    Terrien, Soizic; Vergez, Christophe; Fabre, Benoît

    2014-01-01

    Since they correspond to a jump from a given note to another one, the mouth pressure thresholds leading to regime changes are particularly important quantities in flute-like instruments. In this paper, a comparison of such thresholds between an artificial mouth, an experienced flutist and a non player is provided. It highlights the ability of the experienced player to considerabily shift regime change thresholds, and thus to enlarge its control in terms of nuances and spectrum. Based on recent works on other wind instruments and on the theory of dynamic bifurcations, the hypothe- sis is tested experimentally and numerically that the dynamics of the blowing pressure influences regime change thresholds. The results highlight the strong influence of this parameter on thresholds, suggesting its wide use by experienced musicians. Starting from these observations and from an analysis of a physical model of flute-like instruments, involving numerical continuation methods and Floquet stability analysis, a phenomenolo...

  1. Flute instability of an anisotropic plasma in toroidal devices with a three-dimensional magnetic axis

    SciTech Connect

    Cheremnykh, O.K.

    1981-11-01

    A theory is derived for the flute instability in a low-pressure anisotropic plasma in a toroidal device with a three-dimensional magnetic axis and a large aspect ratio. A local stability condition of the Mercier type is derived for these plasma perturbations. The primary distinction between the stability condition derived here and the corresponding condition for an isotropic plasma is a change in the magnetic well. Analysis of the change in the well when fast ions are injected into the plasma shows that the stability of the plasma with respect to flute perturbations is improved during longitudinal injection but degraded in the case of transverse injection. The stability condition is also used to analyze a device with a three-dimensional magnetic axis: a helical plasma column.

  2. Is the jet-drive flute model able to produce modulated sounds like Flautas de Chinos ?

    E-print Network

    Terrien, Soizic; De La Cuadra, Patricio; Fabre, Benoît

    2014-01-01

    Flautas de chinos - prehispanic chilean flutes played during ritual celebrations in central Chile - are known to produce very particular beating sounds, the so-called sonido rajado. Some previous works have focused on the spectral analysis of these sounds, and on the input impedance of the complex resonator. However, the beating sounds origin remains to be investigated. Throughout this paper, a comparison is provided between the characteristics of both the sound produced by flautas de chinos and a synthesis sound obtained through time-domain simulation of the jet-drive model for flute-like instruments. Jet-drive model appears to be able to produce quasiperiodic sounds similar to sonido rajado. Finally, the analysis of the system dynamics through numerical continuation methods allows to explore the production mechanism of these quasiperiodic regimes.

  3. Flute-like musical instruments: a toy model investigated through numerical continuation

    E-print Network

    Terrien, Soizic; Fabre, Benoît

    2013-01-01

    Self-sustained musical instruments (bowed string, woodwind and brass instruments) can be modeled by nonlinear dynamical systems. Among these instruments, flutes and flue organ pipes present the particularity to be modeled 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 quasi-periodic regime. Throughout the paper, experimental results on a real instrument are presented to illustrate various phenomena, and allow some qualitative comparisons with numerical results.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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. PMID:25194113

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

    NASA Astrophysics Data System (ADS)

    de La Cuadra, Patricio

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

  12. The songs of Tlaloc: Interference of ten ceramical duct flutes, Offering 89 of the Aztec Templo Mayor

    NASA Astrophysics Data System (ADS)

    Both, M. A. Adje

    2002-11-01

    Among the many preserved sound artefacts deposited in the offerings of the Aztec Templo Mayor are a set of ten tubular duct flutes made from clay, dating Late Postclassic Mesoamerica, 1350-1521 AD. The aerophones are completely painted in blue, and characterized by: (1) a short mouthpiece; (2) a framed aperture; (3) a tube with four fingerholes; and (4) an applicated mask with features of the Aztec rain god Tlaloc, basically three rings and a standardized relief structure of two clouds. While all measurements follow the same pattern, one particular organological distinction was made, as five flutes show an exit hole in the middle ring of the mask and five flutes are stopped. Thus, five instruments sound considerably higher, apart from the minimal pitch deviation of each specimen. Both the tonal capacity of each flute and the acoustics of several flutes played simultaneously were recorded and measured. A series of remarkable interference effects could be produced, which were strongly related to the ritual complex reflected in the offering. Taking in consideration the Aztec concept of music, it could be supposed that they were perceived as a principle of the song, or proper voice of Tlaloc.

  13. Simultaneous and integrated neutron-based techniques for material analysis of a metallic ancient flute

    NASA Astrophysics Data System (ADS)

    Festa, G.; Pietropaolo, A.; Grazzi, F.; Sutton, L. F.; Scherillo, A.; Bognetti, L.; Bini, A.; Barzagli, E.; Schooneveld, E.; Andreani, C.

    2013-09-01

    A metallic 19th century flute was studied by means of integrated and simultaneous neutron-based techniques: neutron diffraction, neutron radiative capture analysis and neutron radiography. This experiment follows benchmark measurements devoted to assessing the effectiveness of a multitask beamline concept for neutron-based investigation on materials. The aim of this study is to show the potential application of the approach using multiple and integrated neutron-based techniques for musical instruments. Such samples, in the broad scenario of cultural heritage, represent an exciting research field. They may represent an interesting link between different disciplines such as nuclear physics, metallurgy and acoustics.

  14. Flute-model acoustic metamaterials with simultaneously negative bulk modulus and mass density

    NASA Astrophysics Data System (ADS)

    Zeng, Hong-Cheng; Luo, Chun-Rong; Chen, Huai-Jun; Zhai, Shi-Long; Ding, Chang-Lin; Zhao, Xiao-Peng

    2013-11-01

    We experimentally constructed a three-dimensional flute-model meta-molecule structure acoustic metamaterial (AM) from a periodic array of perforated hollow steel tubes (PHSTs) and investigated its transmission and reflection behaviors in an impedance tube system. The AM exhibited a peak and dip, and an inverse phase, thus exhibiting the local resonance of the PHSTs. Based on the homogeneous media theory, the effective bulk modulus and mass density of the AM were calculated to be simultaneously negative; the refractive index was also negative. PHST AM slab focusing experiments showed that the medium with a resonant structure exhibited a distinct metamaterial property.

  15. Excitation of flute waves by an ion beam in an open confinement system

    SciTech Connect

    Stupakov, G.V.

    1988-04-01

    This paper analyzes the electrostatic instability driven by a fast ion beam in a low-..beta.. plasma in a mirror system as the result of a resonance between the wave and the longitudinal bounces of ions between the mirrors. The frequency of this instability is close to the ion bounce frequency, and its growth rate is several times low than that of the flute instability. This electrostatic instability is characteristic of beams with a small angular spread and is sensitive to the magnetic field profile in the mirror system.

  16. 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.

  17. Flute-Model Acoustic Metamaterials with Simultaneously Negative Bulk Modulus and Mass Density

    E-print Network

    Zeng, H C; Chen, H J; Zhai, S L; Zhao, X P

    2012-01-01

    We experimentally constructed a three-dimensional flute-model "molecular" structure acoustic metamaterial(AM)from a periodic array of perforated hollow steel tubes (PHSTs) and investigated its transmission and reflection behaviors in impedance tube system. The AM exhibited a transmission peak and an inverse phase, thus exhibiting the local resonance of the PHSTs. Based on the homogeneous media theory, the effective bulk modulus and mass density of the AM were calculated to be simultaneously negative; the refractive index was also negative. PHST AM slab focusing experiments showed that the medium with a resonant structure exhibited a distinct metamaterial property.

  18. 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.

  19. 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.

  20. 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.

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

    SciTech Connect

    Similon, P.L.

    1987-02-02

    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.

  2. Stabilization of flute perturbations in an axisymmetric open system with instreaming ions

    SciTech Connect

    Kotel'nikov, I.A.; Roslyakov, G.V.; Ryutov, D.D.

    1987-04-01

    The stability of flute waves in a paraxial axisymmetric mirror system with instreaming ions is analyzed. These ions are produced when fast neutral atoms or partially ionized ions with z>1 are injected into a plasma. A method is described for choosing a magnetic field configuration which minimizes the injection energy and power required for stabilization. The injection parameters corresponding to the optimum choice of magnetic field configuration are found. Methods for further reducing the injection energy and power, by attaching an auxiliary mirror system and by selectively pumping off the instreaming ions, are described. Results of related calculations are reported.

  3. 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 The Lung Flute is a safe and effective treatment in COPD with chronic bronchitis, providing a wide array of benefits. ClinicalTrials.gov Identifier NCT01186822 PMID:25625006

  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. 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.

  6. 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. PMID:24767961

  7. 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 ...

  8. Active feedback stabilization of the flute instability in a mirror machine using field-aligned coils

    NASA Astrophysics Data System (ADS)

    Lifshitz, A.; Be'ery, I.; Fisher, A.; Ron, A.; Fruchtman, A.

    2012-12-01

    A plasma confined in linear mirror machines is unstable even at low ?, mainly because of the flute instability. One possible way to stabilize the plasma is to use active feedback to correct the plasma shape in real time. The theoretically investigated apparatus consists of feedback coils aligned with the magnetic field, immersed in a cold plasma around the hot core. When the current through the feedback coils changes, the plasma moves to conserve the magnetic flux via compressional Alfvén waves. An analytical model is used to find a robust feedback algorithm with zero residual currents. It is shown that due to the plasma's rotation, maximal stability is obtained with a large phase angle between the perturbations' modes and the feedback integral-like term. Finally, a two-dimensional MHD simulation implementing the above algorithm in fact shows stabilization of the plasma with zero residual currents.

  9. 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.

  10. 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.

  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. 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.

  13. Champagne Flutes and Brandy Snifters: Modelling Protostellar Outflow-Cloud Chemical Interfaces

    E-print Network

    Rollins, Richard P; Williams, David A; Redman, Matt P

    2014-01-01

    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 interface 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 chemo-dynamic 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 natu...

  14. 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.

  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. Bone Infections

    MedlinePLUS

    ... of the body, bones can get infected. The infections are usually bacterial, but can also be fungal. ... bloodstream. People who are at risk for bone infections include those with diabetes, poor circulation, or recent ...

  17. Bone tumor

    MedlinePLUS

    ... Bone metastases. In: Niederhuber JE, Armitage JO, Doroshow JH, et al., eds. Abeloff's Clinical Oncology . 5th ed. ... aggressive tumors of bone. In: Canale ST, Beaty JH, eds. Campbell's Operative Orthopaedics. Philadelphia, Pa: Elsevier Mosby; ...

  18. Bone Markers

    MedlinePLUS

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

  19. 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.

  20. 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.

  1. Experimental investigation of a coherent flute instability using a heavy ion beam probe

    SciTech Connect

    Glowienka, J.C.; Jennings, W.C.; Hickok, R.L.

    1988-09-01

    A coherent, low-frequency instability found in a cylindrical, hollow cathode arc plasma has been investigated by using a heavy ion beam probe (HIBP). The energy density of the plasma was high enough to render it inaccessible to Langmuir probes, but the HIBP was able to provide measurements throughout the plasma cross section. The data clearly show that azimuthal symmetry does not exist. Radial profiles of steady-state density and space potential and of simultaneous n-italic-tilde, phi-tilde amplitude and phase were obtained to allow detailed comparison between theory and experiment. Predictions from a cylindrically symmetric, small-perturbation theoretical model provide reasonably conclusive identification of the instability as a Kelvin--Helmholtz flute driven by and localized in a region of fluid shear. The most serious discrepancy was with regard to the oscillation frequency, which was consistently predicted to be three to four times lower than that observed experimentally. The reason for the discrepancy is not understood, but it is probably related to inadequacies in the theory caused by assumptions of azimuthal symmetry and of small linear perturbations.

  2. 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.

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

    E-print Network

    Almeida, André; Smith, John; Wolfe, Joe

    2009-01-01

    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 is typically 10 ms when pushed by a finger or 16 ms when moved by a spring. Delays between the motion of the fingers were typically tens of ms, with longer delays as more fingers are involved. 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. In transitions with multiple fingers, players, on average, used safe transitions more frequently than unsafe transitions. Professionals exhibited smaller average delays betw...

  4. 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. PMID:19739765

  5. 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. PMID:21442138

  6. 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.

  7. 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.

  8. 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)

  9. Monitoring Gaseous CO2 and Ethanol above Champagne Glasses: Flute versus Coupe, and the Role of Temperature

    PubMed Central

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

    2012-01-01

    In champagne tasting, gaseous CO2 and volatile organic compounds progressively invade the headspace above glasses, thus progressively modifying the chemical space perceived by the consumer. Simultaneous quantification of gaseous CO2 and ethanol was monitored through micro-gas chromatography (?GC), all along the first 15 minutes following pouring, depending on whether a volume of 100 mL of champagne was served into a flute or into a coupe. The concentration of gaseous CO2 was found to be significantly higher above the flute than above the coupe. Moreover, a recently developed gaseous CO2 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 CO2 found above the glass. Those results were discussed on the basis of a multiparameter model which describes fluxes of gaseous CO2 escaping the liquid phase into the form of bubbles. PMID:22347390

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

  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. Broken bone

    MedlinePLUS

    Bone - broken; Fracture; Stress fracture ... as those caused by running, can cause stress fractures of the foot, ankle, tibia, or hip ... circulation. Press firmly over the skin beyond the fracture site. (For example, if the fracture is in ...

  13. 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 ...

  14. Bone marrow aspiration

    MedlinePLUS

    ... the hollow part of most bones. Bone marrow aspiration is the removal of a small amount of ... tissue in liquid form for examination. Bone marrow aspiration is not the same as bone marrow biopsy . ...

  15. Bone Marrow Transplantation

    MedlinePLUS

    Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. ... platelets, which help the blood to clot. A bone marrow transplant is a procedure that replaces a person's ...

  16. [Bone transplant].

    PubMed

    San Julián, M; Valentí, A

    2006-01-01

    We describe the methodology of the Bone and Soft Tissue Bank, from extraction and storage until use. Since the year 1986, with the creation of the Bone Bank in the University Clinic of Navarra, more than 3,000 grafts have been used for very different types of surgery. Bone grafts can be classified into cortical and spongy; the former are principally used in surgery to save tumour patients, in large post-traumatic reconstructions and in replacement surgery where there are massive bone defects and a structural support is required. The spongy grafts are the most used due to their numerous indications; they are especially useful in filling cavities that require a significant quantity of graft when the autograft is insufficient, or as a complement. They are also of special help in treating fractures when there is bone loss and in the treatment of delays in consolidation and pseudoarthrosis in little vascularized and atrophic zones. They are also used in prosthetic surgery against the presence of cavity type defects. Allografts of soft tissues are specially recognised in multiple ligament injuries that require reconstructions. Nowadays, the most utilised are those employed in surgery of the anterior cruciate ligament although they can be used for filling any ligament or tendon defect. The principal difficulties of the cortical allografts are in the consolidation of the ends with the bone itself and in tumour surgery, given that these are patients immunodepressed by the treatment, the incidence of infection is increased with respect to spongy grafts and soft tissues, which is irrelevant. In short, the increasingly widespread use of allografts is an essential therapeutic weapon in orthopaedic surgery and traumatology. It must be used by expert hands. PMID:16998521

  17. Removing the bone brake.

    PubMed

    Schett, Georg; Bozec, Aline

    2014-09-01

    Osteoporosis results from an imbalance between bone resorption and bone formation. While bone resorption inhibitors are widely used to treat osteoporosis, stimulating bone formation is more challenging. Recently, McClung et al. (2014) found that neutralization of sclerostin, a potent inhibitor of bone formation, effectively increased bone mass in postmenopausal women. PMID:25185946

  18. Laboratory and Computer Simulations of Non-MHD Flute Instability Structuring the Plasma Clouds During their Artificial Releases at near-Earth Space

    NASA Astrophysics Data System (ADS)

    Zakharov, Yu. P.; Nakashima, H.; Antonov, V. M.; Boyarintsev, E. L.; Melekhov, A. V.; Posukh, V. G.; Shaikhislamov, I. F.; Mourenas, D.; Simonet, F.

    2003-06-01

    The fast non-MHD development of large-scale flutes at the boundary of plasma clouds expanding into magnetic field is a very common but still unclear phenomenon in a lot of geophysical (AMPTE Barium releases) and laboratory (laser plasma) experiments. To study its specific physics under conditions of the finite value of ion Larmor radius we had compared the data of AMPTE simulation at KI-1 facility with computer runs by electron Hall/MHD and Hybrid codes with taking into account magnetic field's diffusion relevant to the effect of anomalous electron collision frequency. It was found that the main experimentally observed features of flutes (their increment and non-linear stage) could be correctly described by these models. However, it requires this collision frequency of electrons to be proportional to their gyrofrequency, with values close to estimates derived earlier from KI-1 experiments through the phenomenology analysis of diamagnetic properties of exploding plasmas.

  19. 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.

  20. 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.

  1. [Frontier in bone biology].

    PubMed

    Takeda, Shu

    2015-10-01

    Bone is an active organ in which bone mass is maintained by the balance between osteoblastic bone formation and osteoclastic bone resorption, i.e., coupling of bone formation and bone resorption. Recent advances in molecular bone biology uncovered the molecular mechanism of the coupling. A fundamental role of osteocyte in the maintenance of bone mass and whole body metabolism has also been revealed recently. Moreover, neurons and neuropeptides have been shown to be intimately involved in bone homeostasis though inter-organ network, in addition to "traditional" regulators of bone metabolism such as soluble factors and cytokines PMID:26529922

  2. 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 ?/h where ? 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. PMID:24993223

  3. Osteoporosis: The Bone Thief

    MedlinePLUS

    ... raquo Osteoporosis: The Bone Thief Heath and Aging Osteoporosis: The Bone Thief Who Has Osteoporosis? What Is ... of this makes your bones weaker. Who Has Osteoporosis? Ten million Americans have osteoporosis. They are mostly ...

  4. Menopause and Bone Loss

    MedlinePLUS

    ... or no exercise • Smoking cigarettes • Drinking too much alcohol Healthy Bone Osteoporosis Over time, this bone loss ... osteoporosis? • How often should I have a bone density test? • Should I take calcium and vitamin D ...

  5. Bone Lesions and Damage

    MedlinePLUS

    ... the risk of fractures. Bone loss frequently accompanies multiple myeloma, and 85% of patients diagnosed with multiple myeloma have ... result in pain, bone fractures, spinal cord compression, and hypercalcemia. Multiple myeloma bone lesions may be treated with bisphosphonates or ...

  6. Uncemented femoral revision arthroplasty using a modular tapered, fluted titanium stem

    PubMed Central

    Wirtz, Dieter C; Gravius, Sascha; Ascherl, Rudolf; Forst, Raimund; Noeth, Ulrich; Maus, Uwe M; Zeiler, Günther; Moritz C, Deml

    2014-01-01

    Background and purpose — Due to the relative lack of reports on the medium- to long-term clinical and radiographic results of modular femoral cementless revision, we conducted this study to evaluate the medium- to long-term results of uncemented femoral stem revisions using the modular MRP-TITAN stem with distal diaphyseal fixation in a consecutive patient series. Patients and methods — We retrospectively analyzed 163 femoral stem revisions performed between 1993 and 2001 with a mean follow-up of 10 (5–16) years. Clinical assessment included the Harris hip score (HHS) with reference to comorbidities and femoral defect sizes classified by Charnley and Paprosky. Intraoperative and postoperative complications were analyzed and the failure rate of the MRP stem for any reason was examined. Results — Mean HHS improved up to the last follow-up (37 (SD 24) vs. 79 (SD 19); p < 0.001). 99 cases (61%) had extensive bone defects (Paprosky IIB–III). Radiographic evaluation showed stable stem anchorage in 151 cases (93%) at the last follow-up. 10 implants (6%) failed for various reasons. Neither a breakage of a stem nor loosening of the morse taper junction was recorded. Kaplan-Meier survival analysis revealed a 10-year survival probability of 97% (95% CI: 95–100). Interpretation — This is one of the largest medium- to long-term analyses of cementless modular revision stems with distal diaphyseal anchorage. The modular MRP-TITAN was reliable, with a Kaplan-Meier survival probability of 97% at 10 years. PMID:25175667

  7. Bone and bone marrow involvement in sarcoidosis.

    PubMed

    Yachoui, Ralph; Parker, Brian J; Nguyen, Thanhcuong T

    2015-11-01

    Bone and bone marrow involvement in sarcoidosis have been infrequently reported. We aimed to describe the clinical features, radiological descriptions, pathological examinations, and outcomes of three patients with osseous sarcoidosis and one patient with bone marrow sarcoidosis seen at our institution. Our case series included fluorodeoxyglucose positron emission tomography descriptions in assessing the whole-body extent of sarcoidosis. In the era of advanced imaging, large bone and axial skeleton sarcoidosis lesions are more common than previously reported. PMID:26248533

  8. INVEST IN YOUR BONES Bone Basics

    E-print Network

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

  9. Basic bone radiology

    SciTech Connect

    Griffiths, H.J.

    1987-01-01

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

  10. Does running strengthen bone?

    PubMed

    Boudenot, Arnaud; Achiou, Zahra; Portier, Hugues

    2015-12-01

    Bone is a living tissue needing mechanical stress to maintain strength. Traditional endurance exercises offer only modest effects on bone. Walking and running produce low impact but lead to bone fatigue. This article is specifically addressed to therapists and explains the mechanisms involved for the effects of exercise on bone. Intermittent exercise limits bone fatigue, and downhill exercises increase ground impact forces and involve eccentric muscle contractions, which are particularly osteogenic. PMID:26562001

  11. Estrogen and bone metabolism.

    PubMed

    Väänänen, H K; Härkönen, P L

    1996-05-01

    Estrogen plays an important role in the growth and maturation of bone as well as in the regulation of bone turnover in adult bone. During bone growth estrogen is needed for proper closure of epiphyseal growth plates both in females and in males. Also in young skeleton estrogen deficiency leads to increased osteoclast formation and enhanced bone resorption. In menopause estrogen deficiency induces cancellous as well as cortical bone loss. Highly increased bone resorption in cancellous bone leads to general bone loss and destruction of local architecture because of penetrative resorption and microfractures. In cortical bone the first response of estrogen withdrawal is enhanced endocortical resorption. Later, also intracortical porosity increases. These lead to decreased bone mass, disturbed architecture and reduced bone strength. At cellular level in bone estrogen inhibits differentiation of osteoclasts thus decreasing their number and reducing the amount of active remodeling units. This effect is probably mediated through some cytokines, IL-1 and IL-6 being strongest candidates. Estrogen regulates the expression of IL-6 in bone marrow cells by a so far unknown mechanism. It is still uncertain if the effects of estrogen on osteoblasts is direct or is due to coupling phenomenon between bone formation to resorption. PMID:8865143

  12. Oxytocin and bone

    PubMed Central

    Sun, Li; Zaidi, Mone; Zallone, Alberta

    2014-01-01

    One of the most meaningful results recently achieved in bone research has been to reveal that the pituitary hormones have profound effect on bone, so that the pituitary-bone axis has become one of the major topics in skeletal physiology. Here, we discuss the relevant evidence about the posterior pituitary hormone oxytocin (OT), previously thought to exclusively regulate parturition and breastfeeding, which has recently been established to directly regulate bone mass. Both osteoblasts and osteoclasts express OT receptors (OTR), whose stimulation enhances bone mass. Consistent with this, mice deficient in OT or OTR display profoundly impaired bone formation. In contrast, bone resorption remains unaffected in OT deficiency because, even while OT stimulates the genesis of osteoclasts, it inhibits their resorptive function. Furthermore, in addition to its origin from the pituitary, OT is also produced by bone marrow osteoblasts acting as paracrine-autocrine regulator of bone formation modulated by estrogens. In turn, the power of estrogen to increase bone mass is OTR-dependent. Therefore, OTR?/? mice injected with 17?-estradiol do not show any effects on bone formation parameters, while the same treatment increases bone mass in wild-type mice. These findings together provide evidence for an anabolic action of OT in regulating bone mass and suggest that bone marrow OT may enhance the bone-forming action of estrogen through an autocrine circuit. This established new physiological role for OT in the maintenance of skeletal integrity further suggests the potential use of this hormone for the treatment of osteoporosis. PMID:25209411

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  14. 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.

  15. Bone-Immune Cell Crosstalk: Bone Diseases

    PubMed Central

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

    2015-01-01

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

  16. 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…

  17. Bone X-Ray (Radiography)

    MedlinePLUS Videos and Cool Tools

    ... Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone What is Bone X-ray (Radiography)? ... Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  18. [Bone distraction osteogenesis].

    PubMed

    Malevez, Ch; Dujardin, Th; Glorieux, V; Swennen, G; Schutyser, F; Van Cleynenbreugel, J

    2002-01-01

    Bone osteogenesis has been used by many surgeons to compensate dissymmetry due to congenital malformations, diseases or traumas. Bone distraction is the process of generating new bone in a gap between two bone segments in response to the application of graduated tensile stress across the bone gap. Different types of distraction are actually proposed to be an alternative to facial osteotomies or bone grafting techniques. Distraction can be unilateral, bilateral and correct the deficiencies in one, two or three dimensions. The advantages of the distraction osteogenesis are the possibilities to obtain bone lengthening together with simultaneous expansion of the functional soft tissue matrix including skin, muscles, nerves, cartilage, blood vessels and periosteum. Distractors are internal or external devices made of pins or miniplates fixed on the bone and connected by lengthening--screw--systems allowing elongation. PMID:12649984

  19. Bone Marrow Diseases

    MedlinePLUS

    ... blood clotting. If you have a bone marrow disease, there are problems with the stem cells or ... marrow doesn't make red blood cells. Other diseases, such as lymphoma, can spread into the bone ...

  20. Calcaneus (Heel Bone) Fractures

    MedlinePLUS

    ... the calcaneus grow together and form one bone. Fusion also means that no more motion can occur ... some or all of the deformity along with fusion of the bones. These surgeries usually require several ...

  1. Smoking and Bone Health

    MedlinePLUS

    ... supported by your browser. Home Bone Basics Lifestyle Smoking and Bone Health Publication available in: PDF (61 ... Overtraining Risks for Women Oral Health Partner Resources Smoking: It’s Never Too Late to Stop (NIA)

  2. Bone marrow biopsy

    MedlinePLUS

    Biopsy - bone marrow ... A bone marrow biopsy may be done in the health care provider's office or in a hospital. The sample may ... This captures a tiny sample, or core, of bone marrow within the needle. The sample and needle are ...

  3. [Bone metabolism: molecular mechanisms].

    PubMed

    Neumann, E; Schett, G

    2007-07-01

    In order to accommodate individual load, the skeletal system is in a continual state of change. Bone metabolism guarantees optimal bone structure. The osteoblasts are responsible for the synthesis and the osteoclasts for resorption of the bone. A finely adjusted interplay between molecular mechanisms leads, via cytokines, hormones and growth factors, to an homeostasis in bone metabolism. Disturbances of this process lead via increased bone resorption to osteoporosis, and via increased synthesis to osteopetrosis. This contribution describes the known molecular mechanisms in this remodelling process. PMID:17562055

  4. Method for fusing bone

    DOEpatents

    Mourant, Judith R. (Los Alamos, NM); Anderson, Gerhard D. (Velarde, NM); Bigio, Irving J. (Los Alamos, NM); Johnson, Tamara M. (Los Alamos, NM)

    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 turnover marker].

    PubMed

    Miura, Masakazu; Satoh, Yuki

    2015-10-01

    Recently the clinical application of bone turnover markers (BTMs) have been achieved significant progress and the measurements of these indices give us better understanding of pathogenesis of osteoporosis. BTMs are known the bone formation marker, the bone resorption marker and the bone matrix-related marker, respectively. In the Guidelines for the Use of Bone Metabolic Markers in the Diagnosis and Treatment of Osteoporosis (2012 Edition) from publishing Japan Osteoporosis Society Committee, the newly and commonly BTMs were considered to give the normal reference value in Japanese people, the influence of renal function on BTMs. The flow chart of the measurement of bone resorption markers and bone formation markers when selecting drug treatment for osteoporosis, the evaluation of therapeutic effects of bone antiresorption drugs and/or bone formation promoting drug using bone resorption markers and/or bone formation marker were corrected newly in the guideline 2012 edition. Moreover, BTMs were suggested to contribute to adhere with osteoporosis treatment. BTMs are adapted to selection of the drug for osteoporosis and to evaluate the drug efficacy. Therefore, it is very important to guide the proper application and assessment of BTMs in clinical practice. PMID:26529926

  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 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/?-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. PMID:26119318

  8. 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.

  9. Healthy Bones at Every Age

    MedlinePLUS

    ... keep our bones strong and healthy. Peak Bone Mass Our maximum bone size and strength is called peak bone mass. Genes play a large role in how much ... is determined by genetic factors. Although peak bone mass is largely determined by our genes, there are ...

  10. 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.

  11. 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.

  12. Osteocytes and Bone Diseases 

    E-print Network

    Ren, Yinshi

    2015-05-06

    and maintaining bone homeostasis; thus, osteocytes could be a potential target for treating bone diseases such as osteomalacia, periodontitis or osteoporosis. To address our hypothesis, three specific aims are proposed: Specific Aim 1: To investigate... into Ocy), and thus maintains overall healthy bone homeostasis. Last we utilized three different animal models (Dmp1 null mice as osteomalacia disease model, Periostin null mice as the periodontal disease model, and OVX rat as an osteoporosis model...

  13. Review of Bone Substitutes

    PubMed Central

    Pryor, Landon S.; Gage, Earl; Langevin, Claude-Jean; Herrera, Fernando; Breithaupt, Andrew D.; Gordon, Chad R.; Afifi, Ahmed M.; Zins, James E.; Meltzer, Hal; Gosman, Amanda; Cohen, Steve R.; Holmes, Ralph

    2009-01-01

    Bone substitutes are being increasingly used in craniofacial surgery and craniomaxillofacial trauma. We will review the history of the biomaterials and describe the ideal characteristics of bone substitutes, with a specific emphasis on craniofacial reconstruction. Some of the most commonly used bone substitutes are discussed in more depth, such as calcium phosphate and hydroxyapatite ceramics and cements, bioactive glass, and polymer products. Areas of active research and future directions include tissue engineering, with an increasing emphasis on bioactivity of the implant. PMID:22110809

  14. 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.

  15. 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.

  16. Bone marrow (stem cell) donation

    MedlinePLUS

    ... fatty tissue inside your bones. Bone marrow contains stem cells, which are immature cells that become blood ... marrow transplant . This is now often called a stem cell transplant. For this type of treatment, bone ...

  17. Exercise for Your Bone Health

    MedlinePLUS

    ... supported by your browser. Home Bone Basics Lifestyle Exercise for Your Bone Health Publication available in: PDF (53 KB) Español Chinese ( ???? ) Related Resources Alcoholism Bed Rest and ... Health Smoking Partner Resources Children’s Bone Health and Calcium: ...

  18. Fusion of the ear bones

    MedlinePLUS

    Fusion of the ear bones is the joining of the bones of the inner ear. These are the incus, malleus, and stapes bones. Related topics include: Chronic ear infection Otosclerosis Middle ear malformations

  19. Children's Bone Health and Calcium

    MedlinePLUS

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

  20. 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. PMID:19417423

  1. Biodegradable synthetic bone composites

    DOEpatents

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

    2013-01-01

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

  2. Low Bone Density (Osteopenia)

    MedlinePLUS

    ... Ways to Help Shop Bone Source Practice Education Research Join NOF Partners NBHA NOF is a founding partner of the National Bone Health Alliance. Visit NBHA Accountability BBND NHC NOF is in full compliance with the National Health Council. Learn more Follow ...

  3. 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 THE DAY-TO-DAY…

  4. Automated trabecular bone histomorphometry

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  5. Bone Mineral Measurements.

    PubMed

    Doroudinia, Abtin; Colletti, Patrick M

    2015-08-01

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

  6. 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.

  7. Normal Bone Anatomy and Physiology

    PubMed Central

    Clarke, Bart

    2008-01-01

    This review describes normal bone anatomy and physiology as an introduction to the subsequent articles in this section that discuss clinical applications of iliac crest bone biopsy. The normal anatomy and functions of the skeleton are reviewed first, followed by a general description of the processes of bone modeling and remodeling. The bone remodeling process regulates the gain and loss of bone mineral density in the adult skeleton and directly influences bone strength. Thorough understanding of the bone remodeling process is critical to appreciation of the value of and interpretation of the results of iliac crest bone histomorphometry. Osteoclast recruitment, activation, and bone resorption is discussed in some detail, followed by a review of osteoblast recruitment and the process of new bone formation. Next, the collagenous and noncollagenous protein components and function of bone extracellular matrix are summarized, followed by a description of the process of mineralization of newly formed bone matrix. The actions of biomechanical forces on bone are sensed by the osteocyte syncytium within bone via the canalicular network and intercellular gap junctions. Finally, concepts regarding bone remodeling, osteoclast and osteoblast function, extracellular matrix, matrix mineralization, and osteocyte function are synthesized in a summary of the currently understood functional determinants of bone strength. This information lays the groundwork for understanding the utility and clinical applications of iliac crest bone biopsy. PMID:18988698

  8. 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.

  9. 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. PMID:17435952

  10. 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

  11. [Determinants of bone quality and strength independent of bone remodeling].

    PubMed

    Saito, Mitsuru; Marumo, Keishi

    2016-01-01

    Bone mineral density(BMD)and bone microstructure are regulated mainly by bone remodeling. In contrast, bone collagen enzymatic immature and mature cross-links and advanced glycation end products such as pentosidine and carboxyl methyl lysine are affected by various factors. Aging bone tissue is repaired in the process of bone remodeling. However, deterioration of bone material properties markedly advances due to increases in oxidative stress, glycation stress, reactive oxygen species, carbonyl stress associated with aging and reduced sex hormone levels, and glucocorticoid use. To improve bone material properties in osteoporosis, we should use different drug(Saito M, Calcif Tissue Int, REVIEW, 97;242-261, 2015). In this review, we summarized determinants of bone quality and strength independent of bone remodeling. PMID:26728528

  12. 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.

  13. Bone hydatid disease

    PubMed Central

    Song, X H; Ding, L W

    2007-01-01

    Bone hydatid disease lacks a typical clinical appearance and image characteristics on x ray or CT are similar to those of tuberculosis, metastases and giant cell tumour or bone cysts. However, MRI does show distinctive diagnostic features of bone hydatid disease, especially in the spine. Until recently, treatment of osseous hydatid disease has been entirely surgical. Effective chemotherapy using benzimidazoles, particularly mebendazole, albendazole and combination treatments, has now been achieved in experimental studies and clinical practice. However, most of these drugs are still in the experimental stage or are in the early stages of clinical use. PMID:17675547

  14. 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

  15. 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.

  16. 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. PMID:24477631

  17. Immunoregulation of bone remodelling

    PubMed Central

    Singh, Ajai; Mehdi, Abbass A; Srivastava, Rajeshwer N; Verma, Nar Singh

    2012-01-01

    Remodeling, a continuous physiological process maintains the strength of the bones, which maintains a delicate balance between bone formation and resorption process. This review gives an insight to the complex interaction and correlation between the bone remodeling and the corresponding changes in host immunological environment and also summarises the most recent developments occuring in the understanding of this complex field. T cells, both directly and indirectly increase the expression of receptor activator of nuclear factor kB ligand (RANKL); a vital step in the activation of osteoclasts, thus positively regulates the osteoclastogenesis. Though various cytokines, chemikines, transcription factors and co-stimulatory molecules are shared by both skeletal and immune systems, but researches are being conducted to establish and analyse their role and / or control on this complex but vital process. The understanding of this part of research may open new horizons in the management of inflammatory and autoimmune diseases, resulting into bone loss and that of osteoporosis also. PMID:22837895

  18. Bone Loss in IBD

    MedlinePLUS

    ... formation occurred at exactly the same pace, bone mass would remain the same. But that isn’t ... experts, increasing age, female gender, and low body mass index (BMI) put people with IBD at greater ...

  19. Bone Graft Alternatives

    MedlinePLUS

    ... a product of processed allograft bone. DMB contains collagen, proteins and growth factors that are extracted from ... substances. Among the combinations in use are a collagen/ceramic composite, which closely reproduces the composition of ...

  20. 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 ( ...

  1. Food and Your Bones

    MedlinePLUS

    ... more than 2 - 3 drinks per day. Caffeine. Coffee, tea and soft drinks (sodas) contain caffeine, which ... to bone loss. Choose these drinks in moderation. Coffee/tea . Drinking more than three cups of coffee ...

  2. Facts about Broken Bones

    MedlinePLUS

    ... Puberty Video: Am I Normal? (Girls and Puberty) Movie: Digestive System How the Body Works Main Page ... Help Kids Heal Getting an X-ray (Video) Movie: Bones & Skeletal System Checking Out Cuts, Scratches, and ...

  3. 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- ...

  4. 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 ...

  5. Wormian bones: a review.

    PubMed

    Bellary, Sharath S; Steinberg, Ashley; Mirzayan, Nadine; Shirak, Michelle; Tubbs, R Shane; Cohen-Gadol, Aaron A; Loukas, Marios

    2013-11-01

    Wormian bones are abnormal ossicles that develop from extra ossification centers within the cranium. They are most frequently located in the lambdoid suture or the coronal suture, and have been seen in the fontanelles, particularly the posterior fontanelle. It is unclear at this time exactly how or why they are formed, although genetic as well as environmental factors have been proposed. Their initial formation is thought to be caused by a degree of dural strain and increased sutural width. These conditions can result from mechanically induced stress due to intentional deformation like that practiced in ancient cultures, premature sutural closure, or from reduced skull ossification as seen in metabolic bone diseases. The cause of the malformation can have an influence on the number and location of Wormian bones. Clinically, Wormian bones are used as markers in the diagnoses of many autosomal dominant genetic disorders, namely, craniosynostosis and osteogenesis imperfecta. PMID:23959948

  6. Histomorphometry of bone.

    PubMed Central

    Revell, P A

    1983-01-01

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

  7. 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...

  8. The obesity of bone.

    PubMed

    Greco, Emanuela A; Lenzi, Andrea; Migliaccio, Silvia

    2015-12-01

    During the last decades, obesity and osteoporosis have become important global health problems, and the belief that obesity is protective against osteoporosis has recently come into question. In fact, some recent epidemiologic and clinical studies have shown that a high level of fat mass might be a risk factor for osteoporosis and fragility fractures. Several potential mechanisms have been proposed to explain the complex relationship between adipose tissue and bone. Indeed, adipose tissue secretes various molecules, named adipokines, which are thought to have effects on metabolic, skeletal and cardiovascular systems. Moreover, fat tissue is one of the major sources of aromatase, an enzyme that synthesizes estrogens from androgen precursors, hormones that play a pivotal role in the maintenance of skeletal homeostasis, protecting against osteoporosis. Moreover, bone cells express several specific hormone receptors and recent observations have shown that bone-derived factors, such as osteocalcin and osteopontin, affect body weight control and glucose homeostasis. Thus, the skeleton is considered an endocrine target organ and an endocrine organ itself, likely influencing other organs as well. Finally, adipocytes and osteoblasts originate from a common progenitor, a pluripotential mesenchymal stem cell, which has an equal propensity for differentiation into adipocytes or osteoblasts (or other lines) under the influence of several cell-derived transcription factors. This review will highlight recent insights into the relationship between fat and bone, evaluating both potential positive and negative influences between adipose and bone tissue. It will also focus on the hypothesis that osteoporosis might be considered the obesity of bone. PMID:26623005

  9. GENE DELIVERY TO BONE

    PubMed Central

    Evans, C. H.

    2012-01-01

    Gene delivery to bone is useful both as an experimental tool and as a potential therapeutic strategy. Among its advantages over protein delivery are the potential for directed, sustained and regulated expression of authentically processed, nascent proteins. Although no clinical trials have been initiated, there is a substantial pre-clinical literature documenting the successful transfer of genes to bone, and their intraosseous expression. Recombinant vectors derived from adenovirus, retrovirus and lentivirus, as well as non-viral vectors, have been used for this purpose. Both ex vivo and in vivo strategies, including gene-activated matrices, have been explored. Ex vivo delivery has often employed mesenchymal stem cells (MSCs), partly because of their ability to differentiate into osteoblasts. MSCs also have the potential to home to bone after systemic administration, which could serve as a useful way to deliver transgenes in a disseminated fashion for the treatment of diseases affecting the whole skeleton, such as osteoporosis or osteogenesis imperfecta. Local delivery of osteogenic transgenes, particularly those encoding bone morphogenetic proteins, has shown great promise in a number of applications where it is necessary to regenerate bone. These include healing large segmental defects in long bones and the cranium, as well as spinal fusion and treating avascular necrosis. PMID:22480730

  10. 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

  11. The obesity of bone

    PubMed Central

    Greco, Emanuela A.; Lenzi, Andrea; Migliaccio, Silvia

    2015-01-01

    During the last decades, obesity and osteoporosis have become important global health problems, and the belief that obesity is protective against osteoporosis has recently come into question. In fact, some recent epidemiologic and clinical studies have shown that a high level of fat mass might be a risk factor for osteoporosis and fragility fractures. Several potential mechanisms have been proposed to explain the complex relationship between adipose tissue and bone. Indeed, adipose tissue secretes various molecules, named adipokines, which are thought to have effects on metabolic, skeletal and cardiovascular systems. Moreover, fat tissue is one of the major sources of aromatase, an enzyme that synthesizes estrogens from androgen precursors, hormones that play a pivotal role in the maintenance of skeletal homeostasis, protecting against osteoporosis. Moreover, bone cells express several specific hormone receptors and recent observations have shown that bone-derived factors, such as osteocalcin and osteopontin, affect body weight control and glucose homeostasis. Thus, the skeleton is considered an endocrine target organ and an endocrine organ itself, likely influencing other organs as well. Finally, adipocytes and osteoblasts originate from a common progenitor, a pluripotential mesenchymal stem cell, which has an equal propensity for differentiation into adipocytes or osteoblasts (or other lines) under the influence of several cell-derived transcription factors. This review will highlight recent insights into the relationship between fat and bone, evaluating both potential positive and negative influences between adipose and bone tissue. It will also focus on the hypothesis that osteoporosis might be considered the obesity of bone. PMID:26623005

  12. 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. PMID:24898231

  13. 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

  14. Recombinant human bone morphogenetic protein induces bone formation

    SciTech Connect

    Wang, E.A.; Rosen, V.; D'Alessandro, J.S.; Bauduy, M.; Cordes, P.; Harada, T.; Israel, D.I.; Hewick, R.M.; Kerns, K.M.; LaPan, P.; Luxenberg, D.P.; McQuaid, D.; Moutsatsos, I.K.; Nove, J.; Wozney, J.M. )

    1990-03-01

    The authors have purified and characterized active recombinant human bone morphogenetic protein (BMP) 2A. Implantation of the recombinant protein in rats showed that a single BMP can induce bone formation in vivo. A dose-response and time-course study using the rat ectopic bone formation assay revealed that implantation of 0.5-115 {mu}g of partially purified recombinant human BMP-2A resulted in cartilage by day 7 and bone formation by day 14. The time at which bone formation occurred was dependent on the amount of BMP-2A implanted; at high doses bone formation could be observed at 5 days. The cartilage- and bone-inductive activity of the recombinant BMP-2A is histologically indistinguishable from that of bone extracts. Thus, recombinant BMP-2A has therapeutic potential to promote de novo bone formation in humans.

  15. [Bone quality and fracture susceptibility].

    PubMed

    Zák, J

    2002-04-12

    Prevention of fractures brings about the effort to eliminate their potential causes. Osteoporosis syndrome belongs to the most frequent causes of the bone fractures. The use of densitometric methods may bring an overestimation of the bone quantity. Because of the independent contribution to mechanical resistance, the bone quality needs to be also evaluated. Qualitative changes of the bone can occur at the level of the bone as an organ, or at levels of its components--cortex, spongiosis and bone matrix. Bone quality is influenced mainly genetically; however, it can deteriorate also with age or in some diseases. Measurement of the bone quality is not yet practically accessible. Some ultrasonographic methods have a character of qualitative assessment. Osteoporosis can worsen the bone quality at different levels. PMID:12053754

  16. 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. PMID:26584264

  17. Gene Expression in Bone

    NASA Astrophysics Data System (ADS)

    D'Ambrogio, A.

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

  18. 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 (16-68years) 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. PMID:26164477

  19. 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.

  20. 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.

  1. 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

  2. The virtual temporal bone.

    PubMed

    Mason, T P; Applebaum, E L; Rasmussen, M; Millman, A; Evenhouse, R; Panko, W

    1998-01-01

    The human temporal bone is a 3-dimensionally complex portion of the skull that contains delicate and vital anatomic structures imbedded within dense bone. Current teaching tools have proven to be only marginally adequate for the needs of the aspiring otologic surgeon in learning this anatomy. A variety of image processing and reconstruction techniques were used to reconstruct an anatomically accurate 3-dimensional model of the human temporal bone from serial histologic sections. Using CAVE technology, the model can be manipulated in a stereoscopic virtual environment so that it can be studied from any viewpoint, greatly simplifying the task of learning this anatomy. Applications in surgical planning and Internet based teaching are discussed. PMID:10180566

  3. Invest in Your Bones Bone Mineral Calcium and Vitamin D

    E-print Network

    Invest in Your Bones Bone Mineral Calcium and Vitamin D Leaflet 4 One common misconception is that calcium is only needed for growing children. In reality, both calcium and vitamin D are needed to maintain of calcium from your bones. Vitamin D promotes the absorption of calcium in the gut, which is necessary

  4. Detecting microdamage in bone.

    PubMed

    Lee, T C; Mohsin, S; Taylor, D; Parkesh, R; Gunnlaugsson, T; O'Brien, F J; Giehl, M; Gowin, W

    2003-08-01

    Fatigue-induced microdamage in bone contributes to stress and fragility fractures and acts as a stimulus for bone remodelling. Detecting such microdamage is difficult as pre-existing microdamage sustained in vivo must be differentiated from artefactual damage incurred during specimen preparation. This was addressed by bulk staining specimens in alcohol-soluble basic fuchsin dye, but cutting and grinding them in an aqueous medium. Nonetheless, some artefactual cracks are partially stained and careful observation under transmitted light, or epifluorescence microscopy, is required. Fuchsin lodges in cracks, but is not site-specific. Cracks are discontinuities in the calcium-rich bone matrix and chelating agents, which bind calcium, can selectively label them. Oxytetracycline, alizarin complexone, calcein, calcein blue and xylenol orange all selectively bind microcracks and, as they fluoresce at different wavelengths and colours, can be used in sequence to label microcrack growth. New agents that only fluoresce when involved in a chelate are currently being developed--fluorescent photoinduced electron transfer (PET) sensors. Such agents enable microdamage to be quantified and crack growth to be measured and are useful histological tools in providing data for modelling the material behaviour of bone. However, a non-invasive method is needed to measure microdamage in patients. Micro-CT is being studied and initial work with iodine dyes linked to a chelating group has shown some promise. In the long term, it is hoped that repeated measurements can be made at critical sites and microdamage accumulation monitored. Quantification of microdamage, together with bone mass measurements, will help in predicting and preventing bone fracture failure in patients with osteoporosis. PMID:12924817

  5. Pattern Alteration: Protruding Hip Bone 

    E-print Network

    2006-08-04

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

  6. Oral Health and Bone Disease

    MedlinePLUS

    ... supported by your browser. Home Bone Basics Lifestyle Oral Health and Bone Disease Publication available in: PDF (58 ... Imperfecta Overtraining Risks for Women Smoking Partner Resources Oral Health FAQs (OWH) Periodontal (Gum) Disease (NIDCR) Seal Out ...

  7. Calcium Intake and Bone health

    MedlinePLUS Videos and Cool Tools

    ... Calcium_Intake_100115.html Calcium Intake and Bone health HealthDay News Video - October 2, 2015 To use ... reading – health news for healthier living. Related MedlinePlus Health Topics Bone Diseases Calcium Fractures Seniors' Health About ...

  8. Vitamin A and Bone Health

    MedlinePLUS

    ... supported by your browser. Home Bone Basics Nutrition Vitamin A and Bone Health Publication available in: PDF (100 KB) Related Resources Calcium and Vitamin D El calcio y la vitamina D (Calcium ...

  9. [Pharmacology of bone anabolic agents].

    PubMed

    Matsumoto, Toshio

    2015-10-01

    Bone is constantly remodeled to maintain its volume, structural integrity and strength Currently available bone anabolic agent is teriparatide. Teriparatide increases bone mass and strength via both remodeling-dependent and -independent mechanisms, although remodeling-dependent mechanism overweighs the other. Canonical Wnt signal plays an important role in enhancing osteoblast differentiation and bone formation, and its osteocyte-derived inhibitor, sclerostin, regulates bone formation via the regulation of Wnt signaling. Anti-sclerostin antibody stimulates Wnt signaling and enhances bone formation. Phase II clinical trials with anti-sclerostin antibodies, romosozumab and blosozumab, demonstrated a marked increase in bone mineral density after one year of treatment. The new modality of anabolic agents via remodeling-independent stimulation of bone formation may open up a new avenue for the treatment of osteoporosis. PMID:26529924

  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. Aspiration and Biopsy: Bone Marrow

    MedlinePLUS

    ... Irvine Pregnant? What to Expect Aspiration and Biopsy: Bone Marrow KidsHealth > Parents > Doctors & Hospitals > Medical Tests & Exams > Aspiration and Biopsy: Bone Marrow Print A A A Text Size What's in ...

  12. 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.

  13. 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.

  14. [Interferon and bone].

    PubMed

    Miyamoto, Takeshi

    2015-11-01

    Interferon(IFN)?, ? and ? were identified, and demonstrated played a crucial role in regulating immune system. Expression of IFN ? and ? are both promoted by viral infection, and these factors have been utilized to treat the patients with hepatitis C. Meanwhile, IFN ? is expressed in activated T cells, such as Th1 cells, and also plays a crucial role in immune system. Beside the immune roles, IFNs were demonstrated to regulate bone homeostasis via osteoclasts, osteoblasts or both. In this review, I will discuss the roles of IFNs in bone system. PMID:26503870

  15. Transcutaneous Raman Spectroscopy of Bone

    NASA Astrophysics Data System (ADS)

    Maher, Jason R.

    Clinical diagnoses of bone health and fracture risk typically rely upon measurements of bone density or structure, but the strength of a bone is also dependent upon its chemical composition. One technology that has been used extensively in ex vivo, exposed-bone studies to measure the chemical composition of bone is Raman spectroscopy. This spectroscopic technique provides chemical information about a sample by probing its molecular vibrations. In the case of bone tissue, Raman spectra provide chemical information about both the inorganic mineral and organic matrix components, which each contribute to bone strength. To explore the relationship between bone strength and chemical composition, our laboratory has contributed to ex vivo, exposed-bone animal studies of rheumatoid arthritis, glucocorticoid-induced osteoporosis, and prolonged lead exposure. All of these studies suggest that Raman-based predictions of biomechanical strength may be more accurate than those produced by the clinically-used parameter of bone mineral density. The utility of Raman spectroscopy in ex vivo, exposed-bone studies has inspired attempts to perform bone spectroscopy transcutaneously. Although the results are promising, further advancements are necessary to make non-invasive, in vivo measurements of bone that are of sufficient quality to generate accurate predictions of fracture risk. In order to separate the signals from bone and soft tissue that contribute to a transcutaneous measurement, we developed an overconstrained extraction algorithm that is based upon fitting with spectral libraries derived from separately-acquired measurements of the underlying tissue components. This approach allows for accurate spectral unmixing despite the fact that similar chemical components (e.g., type I collagen) are present in both soft tissue and bone and was applied to experimental data in order to transcutaneously detect, to our knowledge for the first time, age- and disease-related spectral differences in murine bone.

  16. [Bone structure in rheumatoid arthritis].

    PubMed

    Ono, Kumiko; Ohashi, Satoru; Tanaka, Sakae; Matsumoto, Takuya

    2013-07-01

    In rheumatoid arthritis (RA) , the osteoclast pathway is activated by abnormal immune conditions accompanied by chronic inflammation, resulting in periarticular osteoporosis and local bone destruction around joints. In addition, multiple factors, including reduced physical activity and pharmacotherapies such as steroids, lead to systemic osteoporosis. These conditions cause decreasing bone mineral density and deterioration of bone quality, and expose patients to increased risk of fracture. Understanding the bone structures of RA and evaluating fracture risk are central to the treatment of RA. PMID:23811586

  17. 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

  18. Bone grafts and their substitutes.

    PubMed

    Fillingham, Y; Jacobs, J

    2016-01-01

    The continual cycle of bone formation and resorption is carried out by osteoblasts, osteocytes, and osteoclasts under the direction of the bone-signaling pathway. In certain situations the host cycle of bone repair is insufficient and requires the assistance of bone grafts and their substitutes. The fundamental properties of a bone graft are osteoconduction, osteoinduction, osteogenesis, and structural support. Options for bone grafting include autogenous and allograft bone and the various isolated or combined substitutes of calcium sulphate, calcium phosphate, tricalcium phosphate, and coralline hydroxyapatite. Not all bone grafts will have the same properties. As a result, understanding the requirements of the clinical situation and specific properties of the various types of bone grafts is necessary to identify the ideal graft. We present a review of the bone repair process and properties of bone grafts and their substitutes to help guide the clinician in the decision making process. Cite this article: Bone Joint J 2016;98-B(1 Suppl A):6-9. PMID:26733632

  19. 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 9?m. 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.

  20. Osteoinduction of bone grafting materials for bone repair and regeneration.

    PubMed

    García-Gareta, Elena; Coathup, Melanie J; Blunn, Gordon W

    2015-12-01

    Regeneration of bone defects caused by trauma, infection, tumours or inherent genetic disorders is a clinical challenge that usually necessitates bone grafting materials. Autologous bone or autograft is still considered the clinical "gold standard" and the most effective method for bone regeneration. However, limited bone supply and donor site morbidity are the most important disadvantages of autografting. Improved biomaterials are needed to match the performance of autograft as this is still superior to that of synthetic bone grafts. Osteoinductive materials would be the perfect candidates for achieving this task. The aim of this article is to review the different groups of bone substitutes in terms of their most recently reported osteoinductive properties. The different factors influencing osteoinductivity by biomaterials as well as the mechanisms behind this phenomenon are also presented, showing that it is very limited compared to osteoinductivity shown by bone morphogenetic proteins (BMPs). Therefore, a new term to describe osteoinductivity by biomaterials is proposed. Different strategies for adding osteoinductivity (BMPs, stem cells) to bone substitutes are also discussed. The overall objective of this paper is to gather the current knowledge on osteoinductivity of bone grafting materials for the effective development of new graft substitutes that enhance bone regeneration. PMID:26163110

  1. Survivorship Clinic Bone Health

    E-print Network

    Brent, Roger

    as part of the normal aging process. Osteoporosis: A Silent Disease Osteoporosis (or osteopenia occur after minimal trauma, such as a fall. Osteoporosis may occur in any bone, but most commonly of height, spinal curvature, and chronic pain. How is osteoporosis diagnosed? Although osteoporosis may

  2. Immunology and bone.

    PubMed

    Danks, Lynett; Takayanagi, Hiroshi

    2013-07-01

    It is now well acknowledged that the immune and skeletal systems interact and affect one another during developmental physiology and pathology. With the aid of modern conditional gene targeting and transgenic technologies, this field of interdisciplinary research, known as osteoimmunology, is rapidly advancing. Numerous bone phenotypes have been described in immune-compromised gene-deficient mice and, albeit to a lesser extent, immune deficiencies exist in osteo-compromised gene-deficient mice, suggesting that bone cells themselves actually regulate the development of immune cells directly. In this review, I discuss the essential role of key cytokines, signalling transduction pathways and transcription factors during immune and bone development, and how pathology driven dysregulation of these shared mechanisms can lead to clinical manifestations. Diseases that are within the remit of osteoimmunology continue to cause significant morbidity, for example, rheumatoid arthritis, osteoporosis, multiple myeloma and breast/prostate cancer. The complexity and overlapping cellular and molecular interactions between the immune and bone tissues, mean that despite fervent research of these diseases, it remains a major challenge to discover therapeutics that can specifically target one system without detrimentally affecting the other. PMID:23750028

  3. 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 the concept of life…

  4. [Pelvic bone angiomas].

    PubMed

    Christ, F; Siemes, H D; Stiens, R

    1984-01-01

    Three patients were seen with angiomas of the pelvic bones; the radiological and clinical features are described and the literature reviewed. The patients had been observed for four to six years. The differential diagnosis includes infiltrating mesenchymal neoplasms and the histologically similar, but rare, Gorham-Stout syndrome. Recommended treatment is irradiation, which is effective up to a point. PMID:6420271

  5. 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…

  6. Autogenous bone grafting.

    PubMed

    Hofbauer, M H; Delmonte, R J; Scripps, M L

    1996-01-01

    Complex, out-of-the-ordinary problems are often encountered when evaluating patients for reconstructive foot and ankle surgery. Salvage of these complex problems in the foot and ankle often requires the use of autogenous bone grafts. This article provides a brief overview of autografts including indications, healing, graft types, and perioperative management. PMID:8915859

  7. Bones Surgery Codes

    Cancer.gov

    Bones, Joints, And Articular Cartilage C400–C419 Peripheral Nerves And Autonomic Nervous System C470–C479 Connective, Subcutaneous, And Other Soft Tissues C490–C499 (Except for M9727, 9733, 9741-9742, 9764-9809, 9832, 9840-9931, 9945-9946, 9950-9967,

  8. 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

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

    PubMed

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

    2013-01-01

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

  10. [Bone histomorphometry;A role of evaluation for bone quality and mechanical strength].

    PubMed

    Yamamoto, Noriaki; Takahashi, Hideaki; Shimakura, Taketoshi

    2016-01-01

    Bone histomorphometry is defined as a quantitative evaluation of bone remodeling and bone turnover. Bone remodeling is the important mechanism for calcium metabolism and mechanical usage. The changes of bone remodeling in special condition with metabolic bone disease or osteoporosis agents have the effectiveness on bone mechanical strength. PMID:26728526

  11. Peripheral Leptin Regulates Bone Formation

    PubMed Central

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

    2012-01-01

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

  12. Bone quality and bone strength: benefits of the bone-forming approach

    PubMed Central

    Iolascon, Giovanni; Frizzi, Laura; Di Pietro, Gioconda; Capaldo, Annarita; Luciano, Fabrizio; Gimigliano, Francesca

    2014-01-01

    Summary The ability of bone to resist fracture depends on the intrinsic properties of the materials that comprise the bone matrix mineralization, the amount of bone (i.e. mass), and the spatial distribution of the bone mass (i.e. microarchitecture). Antiresorptive agents may prevent the decay of cancellous bone and cortical thinning, with no improvement of bone microstructure, leading to a partial correction of the principal bone quality defect in osteoporosis, the disruption of trabecular microarchitecture. Anabolic agents promote bone formation at both trabecular and endocortical surfaces, resulting in an increase of cancellous bone volume and cortical thickness. The improvement of cortical bone strength may be limited by an increase in cortical porosity. strontium ranelate improves trabecular network and cortical thickness that will contribute to anti-fracture efficacy at both vertebral and non-vertebral sites. The results of clinical and experimental studies are consistent with the mode of action of strontium involving dissociation between bone formation and resorption leading to a stimulation both trabecular and cortical bone formation without increasing cortical porosity. PMID:25002875

  13. 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.

  14. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, James W. (Aiken, SC)

    1995-01-01

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

  15. 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.

  16. TARGETING POLYMER THERAPEUTICS TO BONE

    PubMed Central

    Low, Stewart; Kope?ek, Jind?ich

    2012-01-01

    An aging population in the developing world has led to an increase in musculoskeletal diseases such as osteoporosis and bone metastases. Left untreated many bone diseases cause debilitating pain and in the case of cancer, death. Many potential drugs are effective in treating diseases but result in side effects preventing their efficacy in the clinic. Bone, however, provides an unique environment of inorganic solids, which can be exploited in order to effectively target drugs to diseased tissue. By integration of bone targeting moieties to drug-carrying water-soluble polymers, the payload to diseased area can be increased while side effects decreased. The realization of clinically relevant bone targeted polymer therapeutics depends on (1) understanding bone targeting moiety interactions, (2) development of controlled drug delivery systems, as well as (3) understanding drug interactions. The latter makes it possible to develop bone targeted synergistic drug delivery systems. PMID:22316530

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

    1984-01-01

    We isolated cells from both calvaria and the outer cortices of long bones from 3- to 5-mo bovine fetuses. The cells were identified as functional osteoblasts by indirect immunofluorescence using antibodies against three bone-specific, noncollagenous matrix proteins (osteonectin, the bone proteoglycan, and the bone sialoprotein) and against type 1 collagen. In separate experiments, confluent cultures of the cells were radiolabeled and shown to synthesize and secrete osteonectin, the bone proteoglycan and the bone sialoprotein by immunoprecipitation and fluorography of SDS polyacrylamide gels. Analysis of the radiolabeled collagens synthesized by the cultures showed that they produced predominantly (approximately 94%) type I collagen, with small amounts of types III and V collagens. In agreement with previous investigators who have employed the rodent bone cell system, we confirmed in bovine bone cells that (a) there was a typical cyclic AMP response to parathyroid hormone, (b) freshly isolated cells possessed high levels of alkaline phosphatase, which diminished during culture but returned to normal levels in mineralizing cultures, and (c) cells grown in the presence of ascorbic acid and beta-glycerophosphate rapidly produced and mineralized an extracellular matrix containing largely type I collagen. These results show that antibodies directed against bone-specific, noncollagenous proteins can be used to clearly identify bone cells in vitro. PMID:6086672

  19. Bone marrow macrophages support prostate cancer growth in bone.

    PubMed

    Soki, Fabiana N; Cho, Sun Wook; Kim, Yeo Won; Jones, Jacqueline D; Park, Serk In; Koh, Amy J; Entezami, Payam; Daignault-Newton, Stephanie; Pienta, Kenneth J; Roca, Hernan; McCauley, Laurie K

    2015-11-01

    Resident macrophages in bone play important roles in bone remodeling, repair, and hematopoietic stem cell maintenance, yet their role in skeletal metastasis remains under investigated. The purpose of this study was to determine the role of macrophages in prostate cancer skeletal metastasis, using two in vivo mouse models of conditional macrophage depletion. RM-1 syngeneic tumor growth was analyzed in an inducible macrophage (CSF-1 receptor positive cells) ablation model (MAFIA mice). There was a significant reduction in tumor growth in the tibiae of macrophage-ablated mice, compared with control non-ablated mice. Similar results were observed when macrophage ablation was performed using liposome-encapsulated clodronate and human PC-3 prostate cancer cells where tumor-bearing long bones had increased numbers of tumor associated-macrophages. Although tumors were consistently smaller in macrophage-depleted mice, paradoxical results of macrophage depletion on bone were observed. Histomorphometric and micro-CT analyses demonstrated that clodronate-treated mice had increased bone volume, while MAFIA mice had reduced bone volume. These results suggest that the effect of macrophage depletion on tumor growth was independent of its effect on bone responses and that macrophages in bone may be more important to tumor growth than the bone itself. In conclusion, resident macrophages play a pivotal role in prostate cancer growth in bone. PMID:26459393

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

    PubMed

    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

  1. [Bone architecture and strength on unloading].

    PubMed

    Endo, Itsuro; Matsumoto, Toshio

    2013-07-01

    The bone loss due to space flight or prolonged bed rest observes early stage of unloading and causes both decreased bone formation and increased bone resorption. Mechanical unloading induced not only both tarbecular and cortical bone loss but also greater decline bone structure in weight-bearing bone. These findings and further examination concern about pathophysiolosy will allow for better understanding of unloading-associated bone loss and for development of effective countermeasures. PMID:23811590

  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 that existed before space flight. Studies to assess bone strength after flight are underway at NASA, to better understand the results of bone remodeling. Studies are also underway to evaluate optimized exercise protocols and nutritional countermeasures. Regardless, there is clear evidence of progress being made to protect bone during spaceflight.

  3. Temporal Bone Localized Chondroblastoma.

    PubMed

    Demirhan, Hasan; Acio?lu, Engin; Durna, Yusuf Muhammed; Yi?it, Özgür; Bozkurt, Erol Rü?tü; Karagöz, Ye?im

    2015-11-01

    Chondroblastoma is a highly destructive tumor originating from immature cartilage cells. Although chondroblastoma is defined as a benign tumor, it may exhibit malign tumor behaviors such as invasion or metastasis on neighboring structures. Magnetic resonance (MR) image is a solid mass lesion, which included heterogeneous hypointense in T2A and heterogeneous minimal hyperintense in T1A with destructive expansile characteristics and millimetric calcifications. Temporal bone chondroblastomas may complicate the diagnosis because of their different histologic characteristics. Microscopically, chondroblastic cell nests and calcification of locally "chicken wire" type around the cells are observed. These tumors secrete s-100 and vimentin and are used for differential diagnosis. In this study, a temporal bone localized chondroblastoma case is presented. PMID:26517458

  4. Immune regulation of bone metastasis

    PubMed Central

    Capietto, Aude-Hélène; Faccio, Roberta

    2014-01-01

    Metastases to bone occur in about 70% of patients with metastatic prostate and breast cancers. Unfortunately, bone metastases result in significant morbidity and mortality and treatment options are limited. Thus, significant effort has focused on understanding the mechanisms that drive tumor dissemination to bone. Bone metastases are typically characterized by a self-perpetuating ‘vicious' cycle wherein tumor cells and bone-resorbing cells (osteoclasts) are locked in a cycle that leads to osteoclast-driven bone destruction and the release of bone-stored factors that in turn stimulate tumor cell proliferation and survival. To break this ‘vicious' cycle, potent antiresorptive agents such as zoledronic acid (ZOL) have been used. However, in the clinical setting, ZOL failed to improve the overall survival of cancer patients even though it inhibited osteoclast resorptive activity. Thus, other cells in addition to osteoclasts are likely involved in modulating tumor growth in the bone. The immune system has the ability to eliminate tumor cells. Nevertheless, tumor cells can acquire the ability to escape immune control. Our recent observations indicated that a decline in the ability of the immune cells to recognize and kill the tumor drives tumor dissemination to bone even when osteoclasts are inhibited by potent antiresorptive agents. This review focuses on the antitumor and protumor effects of various immune cell populations involved in the bone metastatic process. We also discuss strategies to enhance antitumor immune responses and bypass cancer immune resistance. PMID:25512853

  5. 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.

  6. Battling Brittle Bones

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  7. Author's personal copy Rolling bones Taphonomy of Jurassic dinosaur bones inferred from diagenetic

    E-print Network

    Schöne, Bernd R.

    Author's personal copy Rolling bones ­ Taphonomy of Jurassic dinosaur bones inferred from 2010 Accepted 28 January 2011 Available online 4 February 2011 Keywords: Dinosaurs Taphonomy Diagenesis Bone histology Pyrolusite Junggar Basin Dinosaur bones from the Upper Jurassic Shishugou Formation near

  8. 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.

  9. 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.

  10. Microgravity and bone cell mechanosensitivity

    NASA Astrophysics Data System (ADS)

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

    2003-10-01

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

  11. Bone impairment in primary hyperoxaluria: a review.

    PubMed

    Bacchetta, Justine; Boivin, Georges; Cochat, Pierre

    2016-01-01

    Deposition of calcium oxalate crystals in the kidney and bone is a hallmark of primary hyperoxaluria (PH). 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 X-ray. Bone biopsy from the iliac crest displays specific features such as oxalate crystals surrounded by a granulomatous reaction corresponding to an invasion of bone surface by macrophages. The objective of this manuscript is therefore to provide an overview of bone impairment in PH, by reviewing the current literature on bone and dental symptoms as well as imaging techniques used for assessing bone disease. PMID:25631241

  12. 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

  13. Targeted therapies for bone sarcomas

    PubMed Central

    Heymann, Dominique; Rédini, Françoise

    2013-01-01

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

  14. [Bone metastasis from prostate cancer].

    PubMed

    Uemura, Motohide; Nonomura, Norio

    2014-08-01

    Bone metastases are often observed in patients with lung cancer, kidney cancer, breast cancer, myeloma, and prostate cancer. Bone metastases from prostate cancer often show characteristics different from those that originated from other organs : For instance, bone is often the only target organ for prostate cancer metastases, and bone metastatic lesions from prostate cancer are more osteoblastic than osteolytic. It is thought that metastatic prostate cancer cells interact specifically with osseous tissue and that this tissue-specific interaction is a critical factor in cancer progression. An understanding of bone metastasis in prostate cancer may lead to novel treatments against the disease. Here, we present the mechanisms that underlie osteoblastic bone metastasis of prostatic origin. PMID:25065868

  15. 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.

  16. [Diabetes mellitus, antidiabetics and bone].

    PubMed

    Svacina, Stepán

    2010-01-01

    A short review of current opinions on a questionable and controversial disease--diabetic osteopathy--is presented. Bone metabolism is influenced by antidiabetic drugs. Positive effects are attributed to the insulin and metformin therapy. Use of thiazolidindiones is accompanied by a higher risk of bone fractures in diabetic women. Very interesting and also promising is the effect of glucagon like peptide-1 and the new antidiabetic drug class- incretin analogues on bone metabolism. PMID:20662475

  17. 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.

  18. How Tough Is Brittle Bone? Investigating Osteogenesis Imperfecta in Mouse Bone

    E-print Network

    Ritchie, Robert

    How Tough Is Brittle Bone? Investigating Osteogenesis Imperfecta in Mouse Bone Alessandra Carriero the collagen defect results in bone fragility in a mouse model of osteogenesis imperfecta (oim), which has Research. KEY WORDS: BRITTLE BONE; BONE FRACTURE; FRACTURE MECHANICS; MOUSE BONE; CRACK INITIATION; CRACK

  19. Microgravity and Bone Cell Mechanosensitivity

    NASA Astrophysics Data System (ADS)

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

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

  20. 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.

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

    E-print Network

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

    2012-01-01

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

  2. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...CONTINUED) MEDICAL 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...

  3. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of device may include...

  4. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of device may include...

  5. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of device may include...

  6. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... A bone densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of device may include...

  7. Bone-marrow transplant - series (image)

    MedlinePLUS

    Bone-marrow is a soft, fatty tissue found inside of bones that produces blood cells (red blood cells, ... Bone-marrow transplants are performed for: deficiencies in red blood cells (aplastic anemia) and white blood cells (leukemia ...

  8. Medicines That May Cause Bone Loss

    MedlinePLUS

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

  9. 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/?-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. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1478-1487, 2015. PMID:25448127

  10. Raman spectroscopy of bone metastasis

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

  11. 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. PMID:22826632

  12. Sclerostin Antibody Treatment Increases Bone Formation, Bone Mass, and Bone Strength of Intact Bones in Adult Male Rats

    PubMed Central

    Suen, Pui Kit; Zhu, Tracy Y.; Chow, Dick Ho Kiu; Huang, Le; Zheng, Li-Zhen; Qin, Ling

    2015-01-01

    We investigated the systemic effect of sclerostin monoclonal antibody (Scl-Ab) treatment on intact non-operated bones in an open osteotomy male Sprague Dawley (SD) rat model. Six-month-old male SD rats were subjected to transverse osteotomy at the right femur mid-shaft. Rats were injected subcutaneously with vehicle or Scl-Ab (25?mg/kg, 2 times per week) treatment for 9 weeks. Compared with vehicle control, Scl-Ab treatment significantly improved trabecular and cortical bone mass and microarchitecture at L5 vertebrae and left femora by micro-CT at week 6 and 9. Mechanical testing showed that Scl-Ab treatment resulted in significantly higher stiffness, energy to failure and ultimate load at the femora at week 9. Mineral apposition rate, mineralizing surface and bone formation rate on the trabecular bone in the distal femora was significantly increased in Scl-Ab group at week 6 and 9. The administered Scl-Ab was localized in the osteocytes and beta-catenin was strongly expressed in osteoblasts. Scl-Ab treatment significantly increased serum P1NP level and there was no between-group difference in serum level of CTX-1. In conclusion, Scl-Ab treatment could induce rapid and sustained increase in bone formation, bone mass and bone strength in non-operated bones. Sclerostin inhibition might be advantageous to prevent secondary fracture(s). PMID:26494536

  13. Interaction between Muscle and Bone

    PubMed Central

    2014-01-01

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

  14. Green Tea and Bone Metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  15. Sclerostin Antibody Treatment Increases Bone Formation, Bone Mass, and Bone Strength of Intact Bones in Adult Male Rats.

    PubMed

    Suen, Pui Kit; Zhu, Tracy Y; Chow, Dick Ho Kiu; Huang, Le; Zheng, Li-Zhen; Qin, Ling

    2015-01-01

    We investigated the systemic effect of sclerostin monoclonal antibody (Scl-Ab) treatment on intact non-operated bones in an open osteotomy male Sprague Dawley (SD) rat model. Six-month-old male SD rats were subjected to transverse osteotomy at the right femur mid-shaft. Rats were injected subcutaneously with vehicle or Scl-Ab (25?mg/kg, 2 times per week) treatment for 9 weeks. Compared with vehicle control, Scl-Ab treatment significantly improved trabecular and cortical bone mass and microarchitecture at L5 vertebrae and left femora by micro-CT at week 6 and 9. Mechanical testing showed that Scl-Ab treatment resulted in significantly higher stiffness, energy to failure and ultimate load at the femora at week 9. Mineral apposition rate, mineralizing surface and bone formation rate on the trabecular bone in the distal femora was significantly increased in Scl-Ab group at week 6 and 9. The administered Scl-Ab was localized in the osteocytes and beta-catenin was strongly expressed in osteoblasts. Scl-Ab treatment significantly increased serum P1NP level and there was no between-group difference in serum level of CTX-1. In conclusion, Scl-Ab treatment could induce rapid and sustained increase in bone formation, bone mass and bone strength in non-operated bones. Sclerostin inhibition might be advantageous to prevent secondary fracture(s). PMID:26494536

  16. 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.

  17. 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. PMID:25377971

  18. Mechanical Signaling for Bone Modeling and Remodeling

    PubMed Central

    Robling, Alexander G.; Turner, Charles H.

    2012-01-01

    Proper development of the skeleton in utero and during growth requires mechanical stimulation. Loading results in adaptive changes in bone that strengthen bone structure. Bone’s adaptive response is regulated by the ability of resident bone cells to perceive and translate mechanical energy into a cascade of structural and biochemical changes within the cells — a process known as mechanotransduction. Mechanotransduction pathways are among the most anabolic in bone, and consequently, there is great interest in elucidating how mechanical loading produces its observed effects, including increased bone formation, reduced bone loss, changes in bone cell differentiation and lifespan, among others. A molecular understanding of these processes is developing, and with it comes a profound new insight into the biology of bone. In this article, we review the nature of the physical stimulus to which bone cells mount an adaptive response, including the identity of the sensor cells, their attributes and physical environment, and putative mechanoreceptors they express. Particular attention is allotted to the focal adhesion and Wnt signaling, in light of their emerging role in bone mechanotransduction. The cellular mechanisms for increased bone loss during disuse, and reduced bone loss during loading are considered. Finally, we summarize the published data on bone cell accommodation, whereby bone cells stop responding to mechanical signaling events. Collectively, these data highlight the complex yet finely orchestrated process of mechanically regulated bone homeostasis. PMID:19817708

  19. 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. PMID:25865873

  20. [Pharmacological Treatment for Bone Metastasis].

    PubMed

    Yamaguchi, Shigeo; Kageyama, Shunichiro; Miura, Kayo; Kato, Shunsuke

    2015-11-01

    An objective of improvement of treatment outcomes of cancer is alleviation of bone metastasis that occurs in many types of cancers. Recently, the guidelines for the diagnosis and treatment of bone metastasis were published by the Japanese Society of Medical Oncology in cooperation with other groups. These guidelines are essentially evidence based for the pharmacological treatment of bone metastasis by using bone modifying agents(BMA). Cancer cells inhibit osteoblast formation and promote osteoclast proliferation. Many growth factors that are produced by the bone marrow promote osteoclast proliferation. Furthermore, many growth factors enhance the rate of cancer cell growth. These processes underlie bone metastasis. Evidence for the effectiveness of BMA for the treatment of lung cancer, breast cancer, prostate cancer, multiple myeloma, and other cancers is provided in each section of the guidelines. These guidelines also provide evidence for the suppression of skeletal related events(SRE)in lung, breast, and prostate cancers. With regard to multiple myeloma, the guidelines provide evidence for the improvement of overall survival in addition to that for suppression of SRE. Based on these evidences, the guidelines recommend aggressive treatment with BMA for bone metastasis in such cancers. PMID:26602392

  1. [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. PMID:26119312

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

    NASA Video Gallery

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

  3. 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.

  4. Hindawi Publishing Corporation Bone Marrow Research

    E-print Network

    Simon, Scott I.

    Hindawi Publishing Corporation Bone Marrow Research Volume 2012, Article ID 165107, 8 pages doi:10 for maintenance and replenishment of blood cells in the bone marrow, these cells are not limited to the bone marrow compartment and function beyond their role in hematopoiesis. HSPC can leave bone marrow

  5. 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.

  6. 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.

  7. 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.

  8. Insulin and bone: Recent developments.

    PubMed

    Klein, Gordon L

    2014-02-15

    While insulin-like growth factor?I?is a well-known anabolic agent in bone evidence is beginning to accumulate that its homologue, insulin, also has some anabolic properties for bone. There is specific evidence that insulin may work to stimulate osteoblast differentiation, which in turn would enhance production of osteocalcin, the osteoblast-produced peptide that can stimulate pancreatic ? cell proliferation and skeletal muscle insulin sensitivity. It is uncertain whether insulin stimulates bone directly or indirectly by increasing muscle work and therefore skeletal loading. We raise the question of the sequence of events that occurs with insulin resistance, such as type 2 diabetes. Evidence to date suggests that these patients have lower serum concentrations of osteocalcin, perhaps reduced skeletal loading, and reduced bone strength as evidenced by micro-indentation studies. PMID:24567798

  9. Flavonoid Intake and Bone Health

    PubMed Central

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

    2014-01-01

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

  10. Aspiration and Biopsy: Bone Marrow

    MedlinePLUS

    ... cancers of the blood, such as leukemia whether cancers that started elsewhere have spread to the bone marrow (the assessment of how much a cancer has spread is called staging, and is important ...

  11. Understanding the Structure of Bones

    MedlinePLUS

    ... Reports Policies & Bylaws National Conference National Walk-n-Wheel Regional Conference 50,000 Laps, One Unbreakable Spirit ... is needed to carry the increased stature and weight of a growing child. Unfortunately, the only bone ...

  12. Bone Woman: poetry and fictions 

    E-print Network

    Airheart-Martin, Tria Ellen

    1997-01-01

    This creative thesis is a collection of poetry and short fiction. The Native American legend of Bone Woman is explored as an analogy for the creative process; the author's works are intended to reflect this poetic. The introduction addresses...

  13. Bone biopsy in haematological disorders.

    PubMed Central

    Burkhardt, R; Frisch, B; Bartl, R

    1982-01-01

    Bone marrow biopsies are now widely used in the investigation and follow-up of many diseases. Semi-thin sections of 8216 undecalcified biopsies of patients with haematological disorders were studied. Observations were made on the cytopenias and the myelodysplastic syndromes, the acute leukaemias the myeloproliferative disorders, Hodgkin's disease and the malignant lymphomas including multiple myeloma, hairy cell leukaemia and angioimmunoblastic lymphadenopathy. Bone marrow biopsies are essential for the differential diagnosis of most cytopenias and for the early recognition of fibrosis which most frequently occurred as a consequence of megakaryocytic proliferation in the myeloproliferative disorders. Different patterns of bone marrow involvement were found in the lymphoproliferative disorders and both their type and extent constituted factors of prognostic significance. A survey of the literature is given and the conclusion is drawn that bone marrow biopsies provide indispensible information for the diagnostic evaluation and the follow-up of patients with haematological disorders. Images PMID:7040489

  14. Bone fracture repair - series (image)

    MedlinePLUS

    The three main treatment options for bone fractures are: Casting Open reduction, and internal fixation- this involves a surgery to repair the fracture-frequently, metal rods, screws or plates are used to repair the ...

  15. Bone Cancer: Questions and Answers

    MedlinePLUS

    ... cancer that arise in soft tissue are called soft tissue sarcomas . They are not bone cancer and are not ... are more likely to develop osteosarcoma ( 4 ). Ewing sarcoma is not strongly associated with any heredity cancer ...

  16. 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.

  17. 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.

  18. Unsuspected pregnancy during bone scintigraphy

    SciTech Connect

    Oates, E.; Ramberg, K.; Becker, J.L. )

    1990-06-01

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

  19. Inherited Bone Marrow Failure Syndromes

    Cancer.gov

    Inherited bone marrow failure syndromes (IBMFS) are rare disorders in which there is usually some form of aplastic anemia (failure of the bone marrow to produce blood), associated with a family history of the same disorder. Some of these conditions have typical changes in physical appearance or in laboratory findings which suggest a specific diagnosis. There are several well-described syndromes, which can be recognized by health care experts.

  20. Bone scintigraphy in diabetic osteoarthropathy

    SciTech Connect

    Eymontt, M.J.; Alavi, A.; Dalinka, M.K.; Kyle, G.C.

    1981-08-01

    Bone scans of patients with diabetic osteoarthropathy of the ankle and foot were characterized by a combination of diffuse and focal increased uptake, similar to that seen with hyperemia and reactive new bone formation. Scintigraphy showed more extensive abnormalities than radiography, with the scan abnormalities sometimes preceding the radiographic changes. The clinical and scintigraphic appearance of osteoarthropathy may improve following strict diabetic control and non-weight-bearing.

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

    PubMed Central

    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. PMID:26247020

  2. Green Tea and Bone metabolism

    PubMed Central

    Shen, Chwan-Li; Yeh, James K.; Cao, Jay; Wang, Jia-Sheng

    2009-01-01

    Osteoporosis is a major health problem in both elderly women and men. Epidemiological evidence has shown an association between tea consumption and the prevention of age-related bone loss in elderly women and men. Ingestion of green tea and green tea bioactive compounds may be beneficial in mitigating bone loss of this population and decreasing their risk of osteoporotic fractures. This review describes the effect of green tea or its bioactive components on bone health, with an emphasis on: (i) the prevalence and etiology of osteoporosis, (ii) the role of oxidative stress and antioxidants in osteoporosis, (iii) green tea composition and bioavailability, (iv) the effects of green tea and its active components on osteogenesis, osteoblastogenesis, and osteoclastogenesis from human epidemiological, animal, as well as cell culture studies, (v) possible mechanisms explaining the osteo-protective effects of green tea bioactive compounds, (vi) other bioactive components in tea that benefit bone health, and (vii) a summary and future direction of green tea and bone health research and the translational aspects. In general, tea and its bioactive components might decrease the risk of fracture by improving bone mineral density (BMD) and supporting osteoblastic activities while suppressing osteoclastic activities. PMID:19700031

  3. 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

  4. 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

  5. Low-Level Vibrations Retain Bone Marrow's Osteogenic Potential and Augment Recovery of Trabecular Bone

    E-print Network

    Low-Level Vibrations Retain Bone Marrow's Osteogenic Potential and Augment Recovery of Trabecular Mechanical disuse will bias bone marrow stromal cells towards adipogenesis, ultimately compromising% greater marrow osteoprogenitor population, 83% greater osteoblast surfaces, 59% greater bone formation

  6. 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.

  7. Method for improved prediction of bone fracture risk using bone mineral density in structural analysis

    NASA Technical Reports Server (NTRS)

    Cann, Christopher E. (Inventor); Faulkner, Kenneth G. (Inventor)

    1992-01-01

    A non-invasive in-vivo method of analyzing a bone for fracture risk includes obtaining data from the bone such as by computed tomography or projection imaging which data represents a measure of bone material characteristics such as bone mineral density. The distribution of the bone material characteristics is used to generate a finite element method (FEM) mesh from which load capability of the bone can be determined. In determining load capability, the bone is mathematically compressed, and stress, strain force, force/area versus bone material characteristics are determined.

  8. Bone metastasis: mechanisms and therapeutic opportunities

    PubMed Central

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

    2011-01-01

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

  9. 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

  10. Bone Grafting: Sourcing, Timing, Strategies, and Alternatives.

    PubMed

    Egol, Kenneth A; Nauth, Aaron; Lee, Mark; Pape, Hans-Christoph; Watson, J Tracy; Borrelli, Joseph

    2015-12-01

    Acute fractures, nonunions, and nonunions with bone defects or osteomyelitis often need bone graft to facilitate union. There are several factors to consider when it is determined that a bone graft is needed. These factors include the source of the bone graft (autograft vs. allograft), proper timing for placement of the bone graft, strategies to avoid further complications (particularly in the setting of osteomyelitis), and with the development of a variety of bone graft substitutes, whether alternatives to autograft are available and appropriate for the task at hand. Autograft bone has commonly been referred to as the "gold standard" of bone grafts, against which the efficacy of other grafts has been measured. The best timing for when to place a bone graft or substitute is also somewhat controversial, particularly after an open fracture or a potentially contaminated bed. The treatment of infected nonunions, particularly those that require a graft to facilitate healing, can be quite challenging. Typically, the infection is completely eradicated before placement of a bone graft, but achieving a sterile bed and the timing of a bone graft require strategic thinking and planning. This review outlines the benefits of autografts, the most suitable sites for harvesting bone grafts, the timing of bone graft procedures, the potential risks and benefits of grafting in the face of infection, and the currently available bone graft extenders. PMID:26584259

  11. Bone target radiotracers for palliative therapy of bone metastases.

    PubMed

    Ogawa, K; Washiyama, K

    2012-01-01

    The skeleton is one of the most common organs affected by metastatic cancer, and bone metastases often cause severe pain, which significantly affects quality of life. Internal radiotherapy using specifically localized bone-seeking radiopharmaceuticals has proven to be an effective alternative and shows fewer side effects than those associated with other forms of treatment. In this review article, we highlight not only radiopharmaceuticals, which have been approved for the palliation of bone metastases but also boneseeking radiolabeled compounds under investigation in basic research. Specifically, we review the efficacy and prospects of phosphorus- 32, strontium-89 chloride, samarium-153-EDTMP, rhenium-186/188-HEDP, rhenium-186/188-complex conjugated bisphosphonate compounds, yttrium-90-DOTA conjugated bisphosphonate, rhenium-186/188-DMSA, radium-223 chloride, thorium-227-EDTMP, thorium-227-DOTMP, and lead/bismuth-212-DOTMP. PMID:22664247

  12. Recent advances in bone tissue engineering scaffolds

    PubMed Central

    Bose, Susmita; Roy, Mangal; Bandyopadhyay, Amit

    2012-01-01

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

  13. Biomaterials for craniofacial bone engineering.

    PubMed

    Tevlin, R; McArdle, A; Atashroo, D; Walmsley, G G; Senarath-Yapa, K; Zielins, E R; Paik, K J; Longaker, M T; Wan, D C

    2014-12-01

    Conditions such as congenital anomalies, cancers, and trauma can all result in devastating deficits of bone in the craniofacial skeleton. This can lead to significant alteration in function and appearance that may have significant implications for patients. In addition, large bone defects in this area can pose serious clinical dilemmas, which prove difficult to remedy, even with current gold standard surgical treatments. The craniofacial skeleton is complex and serves important functional demands. The necessity to develop new approaches for craniofacial reconstruction arises from the fact that traditional therapeutic modalities, such as autologous bone grafting, present myriad limitations and carry with them the potential for significant complications. While the optimal bone construct for tissue regeneration remains to be elucidated, much progress has been made in the past decade. Advances in tissue engineering have led to innovative scaffold design, complemented by progress in the understanding of stem cell-based therapy and growth factor enhancement of the healing cascade. This review focuses on the role of biomaterials for craniofacial bone engineering, highlighting key advances in scaffold design and development. PMID:25139365

  14. Biomaterials for Craniofacial Bone Engineering

    PubMed Central

    Tevlin, R.; McArdle, A.; Atashroo, D.; Walmsley, G.G.; Senarath-Yapa, K.; Zielins, E.R.; Paik, K.J.; Longaker, M.T.; Wan, D.C.

    2014-01-01

    Conditions such as congenital anomalies, cancers, and trauma can all result in devastating deficits of bone in the craniofacial skeleton. This can lead to significant alteration in function and appearance that may have significant implications for patients. In addition, large bone defects in this area can pose serious clinical dilemmas, which prove difficult to remedy, even with current gold standard surgical treatments. The craniofacial skeleton is complex and serves important functional demands. The necessity to develop new approaches for craniofacial reconstruction arises from the fact that traditional therapeutic modalities, such as autologous bone grafting, present myriad limitations and carry with them the potential for significant complications. While the optimal bone construct for tissue regeneration remains to be elucidated, much progress has been made in the past decade. Advances in tissue engineering have led to innovative scaffold design, complemented by progress in the understanding of stem cell–based therapy and growth factor enhancement of the healing cascade. This review focuses on the role of biomaterials for craniofacial bone engineering, highlighting key advances in scaffold design and development. PMID:25139365

  15. Analyzing FDDI-based networks using BONeS

    NASA Astrophysics Data System (ADS)

    Tari, Farzad; Schaffer, Steve; Poon, Charles; Mick, Colin K.

    1992-03-01

    The growing size and complexity of FDDI-based networks has made computer simulation the most effective tool for analyzing such networks. This paper demonstrates how the block oriented network simulator (BONeS) can be used to study the steady state performance of several FDDI LANs. The simulation studies are designed to show how various parameter settings and network configurations can affect delay, throughput, and utilization of such computer networks. The performance of the asynchronous priority scheme is studied in the presence of synchronous traffic. A simulation of a single-priority campus area network (CAN) using FDDI as a backbone is also presented.

  16. [Bone biopsies of cortical bone segments (technique, evaluation)].

    PubMed

    Pfister, A; Ochsner, P E; Jundt, G

    1993-12-01

    13 drill biopsies were microscopically examined and evaluated in respect of their histologic quality. 8 biopsies were obtained with a diamond hollow cutter, the other 5 specimens were sampled with a modified milling cutter according to Burkhardt. Regarding proper evaluation of bone biopsies e.g. in cases of osteomyelitis, factors as presence of bone marrow cavity or drill powder play an important role. Considering these factors the modified milling cutter according to Burkhardt yields, precise and careful handling provided, better results than the diamond hollow cutter. PMID:8147260

  17. The response of bone to unloading

    NASA Technical Reports Server (NTRS)

    Bikle, D. D.; Halloran, B. P.

    1999-01-01

    Skeletal unloading leads to decreased bone formation and decreased bone mass. Bone resorption is uncoupled from bone formation, contributing to the bone loss. During spaceflight bone is lost principally from the bones most loaded in the 1-g environment, and some redistribution of bone from the lower extremities to the head appears to take place. Although changes in calcitropic hormones have been demonstrated during skeletal unloading (PTH and 1,25(OH)2D decrease), it remains unclear whether such changes account for or are in response to the changes in bone formation and resorption. Bed rest studies with human volunteers and hindlimb elevation studies with rats have provided useful data to help explain the changes in bone formation during spaceflight. These models of skeletal unloading reproduce a number of the conditions associated with microgravity, and the findings from such studies confirm many of the observations made during spaceflight. Determining the mechanism(s) by which loading of bone is sensed and translated into a signal(s) controlling bone formation remains the holy grail in this field. Such investigations couple biophysics to biochemistry to cell and molecular biology. Although studies with cell cultures have revealed biochemical responses to mechanical loads comparable to that seen in intact bone, it seems likely that matrix-cell interactions underlie much of the mechanocoupling. The role for systemic hormones such as PTH, GH, and 1,25(OH)2D compared to locally produced factors such as IGF-I, PTHrP, BMPs, and TGF-beta in modulating the cellular response to load remains unclear. As the mechanism(s) by which bone responds to mechanical load with increased bone formation are further elucidated, applications of this knowledge to other etiologies of osteoporosis are likely to develop. Skeletal unloading provides a perturbation in bone mineral homeostasis that can be used to understand the mechanisms by which bone mineral homeostasis is maintained, with the expectation that such understanding will lead to effective treatment for disuse osteoporosis.

  18. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

  19. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

  20. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

  1. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

  2. 21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Polymethylmethacrylate (PMMA) bone cement. 888... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device...: Polymethylmethacrylate (PMMA) Bone Cement.”...

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

    PubMed Central

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

    2015-01-01

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

  4. Epigenetic pathways regulating bone homeostasis.

    PubMed

    Lian, Jane B

    2015-12-01

    Epigenetic control of the genome involves a complex series of unique, physiologically responsive and integrated pathways, each with distinct mechanisms. Insight into epigenetic regulation has transformed understanding of inheritance, development and a broad spectrum of biological processes as well as advances in mechanistic and clinical characterization of tissues and disease states. The dynamics of bone tissue undergoing continuous remodeling during growth and turnover in the adult skeleton, involves epigenetic mechanisms that have emerged as an important component to maintaining skeletal homeostasis. A series of four reviews are presented in the journal BONE covering different aspects of epigenetic control mechanisms that have impacted on the skeleton. Authorship on each of the reviews is shared by investigators from different institutions to present a consensus of emerging concepts and future directions for understanding regulation of the bone epigenome and skeletal pathologies. PMID:26036171

  5. Bone-Derived Growth Factors

    PubMed Central

    Capanna, R.; Campanacci, D.A.; De Biase, P.; Cuomo, P.; Lorenzoni, A.

    2010-01-01

    Bone regeneration is based on the synergy between osteconduction, osteoinduction and osteogenesis. In recent years, we have witnessed the birth and development of numerous osteoconductive substrates, created with the intention of replacing bone grafts, both autologous and homologous. Recently, attention has shifted to osteogenesis, in other words, to the study of mesenchymal cells and their differentiation into osteoblastic cell lines that can be cultured in vitro (as already seen with chondroblasts). Osteoinduction, too, has been shown to be equally important, ever since Urist’s 1967 study which drew attention to the demineralised bone matrix and its properties. The following twenty years led to the definition of bone morphogenetic protein (BMP) and finally to the marketing of the first ostegenic protein (OP-1) obtained by means of the gene recombination technique. The BMPs produced using this technique that, so far, have been shown to be most active are BMP-2 (Infuse) and BMP-7 (Osigraft). The BMPs are not the only molecules with osteoinductive capacity. Other molecules capable of influencing bone regeneration are: platelet-derived growth factors (PDGFs), the transforming growth factor-beta (TGF-?) family, insulin-like growth factor (IGF-I) and the acidic and basic fibroblast growth factors (FGFs). All these growth factors act in synergy with the BMPs, modulating their action and exerting an inductive and proliferative action on the cell lines responsible for regenerating the bone matrix. The literature has been literally invaded by studies, both experimental and preclinical, on these proteins (Termaat, 2005), and they have provided ample demonstration that the BMPs are effective in improving healing of fractures, pseudoarthrosis and spinal fusions. Important advantages of BMPs are the complete absence of risk of transmissible disease, given that they are produced using recombination technology; their purity, and thus absence of an immune response (although such a response could be linked to the carrier used to administer them); their efficacy, which derives from the use of a pre-established dose and not from the individual variability that is a specific feature of demineralized bone matrix homologous bone grafts. In addition to their use in fractures, pseudoarthrosis and spinal fusions, very recent studies are opening up new possibilities which may represent the future field of application of these proteins: Cook et al. (Cook, 2001, Barrack, 2003) have presented the first results obtained using OP-1 in prosthetic revisions carried out in the presence of bone defects; other authors have published a case report on osteonecrosis of the femoral head treated with grafts in association with OP-1; an Italian group is currently experimenting the use of OP-1 in distraction osteogenesis with the aim of speeding up the results that can be obtained using this already well-established technique. However, the most interesting results on the use of recombinant morphogenetic proteins are those obtained by Warnke et al. (2004), maxillo-facial surgeons who, by mixing synthetic spongious bone grafts, bone marrow concentrate and morphogenetic proteins, prepared a new, replacement mandible for implantation in a patient who had lost his own due to cancer, thereby creating new vacularised bone, tailored to that specific patient. The experimental applications of these new drugs are countless and, with regard to their therapeutic potential, the general feeling is that what we are seeing is only the tip of the iceberg. However, it is necessary to ensure that experiments in this field are always geared towards sustainable clinical applications and, to this end, they should be concentrated in a smaller number of centres and conducted in accordance with approved and recognised guidelines.

  6. Osteoporosis: Peak Bone Mass in Women

    MedlinePLUS

    ... not supported by your browser. Home Osteoporosis Women Osteoporosis: Peak Bone Mass in Women Publication available in: ... Fitness: Overtraining Risks Pregnancy, Nursing and Bone Health Osteoporosis and African American Women Osteoporosis and Asian American ...

  7. 21 CFR 892.1180 - Bone sonometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification . A bone sonometer is a...

  8. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1170 Bone densitometer. (a) Identification. A bone densitometer...

  9. Aging changes in the bones - muscles - joints

    MedlinePLUS

    ... skeleton provides support and structure to the body. Joints are the areas where bones come together. They ... skeleton to be flexible for movement. In a joint, bones do not directly contact each other. Instead, ...

  10. Transplant Outcomes (Bone Marrow and Cord Blood)

    MedlinePLUS

    ... reports show patient survival and transplant data of bone marrow and umbilical cord blood transplants in the transplant ... Data by Center Report —View the number of bone marrow and cord blood transplants performed at a specific ...

  11. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...made from mature (adult) bovine bones and used to replace human bone following surgery in the cervical region of the spinal column. (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP is required. As of...

  12. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...made from mature (adult) bovine bones and used to replace human bone following surgery in the cervical region of the spinal column. (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP is required. As of...

  13. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...made from mature (adult) bovine bones and used to replace human bone following surgery in the cervical region of the spinal column. (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP is required. As of...

  14. 21 CFR 888.3015 - Bone heterograft.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...made from mature (adult) bovine bones and used to replace human bone following surgery in the cervical region of the spinal column. (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP is required. As of...

  15. Mechanical bone strength in the proximal tibia 

    E-print Network

    Prommin, Danu

    2000-01-01

    Six bone slices from one canine tibia were tested by compressive load to determine the ultimate strength as a function of distance from the knee. Both the ultimate compressive strength and overall modulus of elasticity of tibial bone increased...

  16. Neuronal control of bone and muscle.

    PubMed

    Houweling, Peter; Kulkarni, Rishikesh N; Baldock, Paul A

    2015-11-01

    The functional interplay between bone and muscle that enables locomotion is a fundamental aspect of daily life. However, other interactions between bone and muscle continue to attract attention as our understanding of the breath and importance of this inter-relationship continues to expand. Of particular interest is the regulatory connection between bone and muscle, which adds a new insight to the coordination of the bone/muscle unit. We have appreciated the importance of neuronal signaling to the control of bone turnover and muscle contraction, but recent data indicate that neuronal inputs control a far wider range of bone and muscle physiology than previously appreciated. This review outlines the role of the sympathetic nervous system and neuronal/neuropeptide inputs upon the regulation of bone and muscle tissue, and the potential for co-regulatory actions, particularly involving the sympathetic nervous system. This article is part of a Special Issue entitled "Muscle Bone Interactions". PMID:26453499

  17. B Vitamins, Homocysteine and Bone Health

    PubMed Central

    Fratoni, Valentina; Brandi, Maria Luisa

    2015-01-01

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

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

    MedlinePLUS

    ... Best Self Smart Snacking Losing Weight Safely Bones, Muscles, and Joints KidsHealth > Teens > Body > Body Basics Library > ... against each other. Back Continue What Are the Muscles and What Do They Do? Bones don't ...

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

    MedlinePLUS

    ... Deal With Bullies Pregnant? What to Expect Bones, Muscles, and Joints KidsHealth > Parents > General Health > Body Basics > ... where they rub against each other. Back Continue Muscles and What They Do Bones don't work ...

  20. Metallic Nanomaterials for Bone Tissue Engineering.

    PubMed

    Dhivya, S; Ajita, J; Selvamurugan, N

    2015-10-01

    Conventional grafting techniques for bone regeneration are currently being replaced by tissue engineering approaches of using 3D biomimetic materials. Of these biomaterials, metals have the highest mechanical strength; moreover, they play a major role in accelerating bone formation and promoting bone regeneration. They act as cofactors for enzymes, serving as a structural component of bone forming enzymes and proteins, stimulating angiogenesis, increasing extra-cellular matrix synthesis, promoting bone formation, and inhibiting bone resorption. Metals have the inherent ability to promote osseointegration and osteoconductivity and possess antimicrobial activity. The current developments in bone tissue engineering focus on metal surface modifications by physical and chemical treatments to improve their bioactivity. Based on the recent literature available, this review aims at discussing the biological role of metals, namely Zn, Ti, Zr, B, Sr, Mg, Ag, and Cu along with their surface modifications for significantly enhanced bone regeneration. PMID:26502634

  1. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of...

  2. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of...

  3. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of...

  4. 21 CFR 892.1170 - Bone densitometer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... densitometer is a device intended for medical purposes to measure bone density and mineral content by x-ray or gamma ray transmission measurements through the bone and adjacent tissues. This generic type of...

  5. How Often Should Women Have Bone Tests?

    MedlinePLUS

    ... say that older women should have regular bone density tests to screen for osteoporosis . But it’s been ... new study suggests that women with healthy bone density on their first test might wait 15 years ...

  6. Appropriate use of bone densitometry

    SciTech Connect

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

    1989-03-01

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

  7. Bone regeneration and stem cells

    PubMed Central

    Arvidson, K; Abdallah, B M; Applegate, L A; Baldini, N; Cenni, E; Gomez-Barrena, E; Granchi, D; Kassem, M; Konttinen, Y T; Mustafa, K; Pioletti, D P; Sillat, T; Finne-Wistrand, A

    2011-01-01

    Abstract This invited review covers research areas of central importance for orthopaedic and maxillofacial bone tissue repair, including normal fracture healing and healing problems, biomaterial scaffolds for tissue engineering, mesenchymal and foetal stem cells, effects of sex steroids on mesenchymal stem cells, use of platelet-rich plasma for tissue repair, osteogenesis and its molecular markers. A variety of cells in addition to stem cells, as well as advances in materials science to meet specific requirements for bone and soft tissue regeneration by addition of bioactive molecules, are discussed. PMID:21129153

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

    PubMed

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

    2015-07-01

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

  9. Aneurysmal Bone Cyst of Sphenoid Bone and Clivus Misdiagnosed as Chordoma: A Case Report

    PubMed Central

    Samanci, Cesur; Asik, Murat; Yanik, Inanc; Ozkanli, Seyma; Tutar, Onur; Hasiloglu, Zehra Isik

    2015-01-01

    Aneurysmal bone cysts (ABCs) are benign and rapidly expanding bone destructive lesions of any bone. They are commonly localized in the metaphysis of long bones, whereas skull base ABCs are rare. We report a case of a 21-year-old man who had been misdiagnosed as chordoma and undergone surgery. However, histopathological examination revealed it to be an ABC. PMID:26605267

  10. Effects of Spaceflight on Bone: The Rat as an Animal Model for Human Bone Loss

    NASA Technical Reports Server (NTRS)

    Halloran, B.; Weider, T.; Morey-Holton, E.

    1999-01-01

    The loss of weight bearing during spaceflight results in osteopenia in humans. Decrements in bone mineral reach 3-10% after as little as 75-184 days in space. Loss of bone mineral during flight decreases bone strength and increases fracture risk. The mechanisms responsible for, and the factors contributing to, the changes in bone induced by spaceflight are poorly understood. The rat has been widely used as an animal model for human bone loss during spaceflight. Despite its potential usefulness, the results of bone studies performed in the rat in space have been inconsistent. In some flights bone formation is decreased and cancellous bone volume reduced, while in others no significant changes in bone occur. In June of 1996 Drs. T. Wronski, S. Miller and myself participated in a flight experiment (STS 78) to examine the effects of glucocorticoids on bone during weightlessness. Technically the 17 day flight experiment was flawless. The results, however, were surprising. Cancellous bone volume and osteoblast surface in the proximal tibial metaphysis were the same in flight and ground-based control rats. Normal levels of cancellous bone mass and bone formation were also detected in the lumbar vertebrae and femoral neck of flight rats. Furthermore, periosteal bone formation rate was found to be identical in flight and ground-based control rats. Spaceflight had little or no effect on bone metabolism! These results prompted us to carefully review the changes in bone observed in, and the flight conditions of previous spaceflight missions.

  11. A Trabecular Bone Explant Model of OsteocyteOsteoblast Co-Culture for Bone Mechanobiology

    E-print Network

    Lu, Helen H.

    A Trabecular Bone Explant Model of Osteocyte­Osteoblast Co-Culture for Bone Mechanobiology MEILIN--The osteocyte network is recognized as the major mechanical sensor in the bone remodeling process, and osteocyte, we developed a novel 3D trabecular bone explant co-culture model that allows live osteocytes situated

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

    E-print Network

    You, Lidan

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

  13. [Newly developed drugs to improve bone strength].

    PubMed

    Hagino, Hiroshi

    2016-01-01

    Drugs for the treatment of osteoporosis improve bone strength by inhibiting bone resorption or stimulating bone formation. New drugs already using some action mechanism such as bisphosphonate or parathyroid hormone-related peptide analog are being developed in Japan. In addition, new drugs with new action mechanisms such as cathepsin K inhibitor or anti-sclerostin antibody are also being developed and it has been reported that they have good potential to increase bone mineral density. PMID:26728536

  14. Radiology of bone diseases. 5th edition

    SciTech Connect

    Greenfield, G.

    1990-01-01

    This book reports on anatomy, physiology, and biochemistry of bone. This book presents alterations in overall characteristics such as density and bone texture. It describes Salterations in specific anatomic regions of bone, as well ad discuss solitary bone lesions. The style in which the diseases are grouped according to specific regions and morphologic alterations rather than by individual pathologic condition is the most powerful aspect of this format.

  15. Positive modulator of bone morphogenic protein-2

    DOEpatents

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

    2009-01-27

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

  16. Temporal response of bone to unloading

    SciTech Connect

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

    1986-02-01

    A model of weightlessness in which the hindlimbs of rats are elevated by their tails at a 40 degrees angle to unload the hindlimbs while maintaining normal weight bearing on the forelimbs has been used to simulate certain conditions of space flight. When we used this model in growing rats, we found that growth in bone weight ceased by 1 week in the hindlimbs and lumbar vertebrae, whereas growth in bone weight in the forelimbs and cervical vertebrae remained unaffected. Within 2 weeks, however, the accretion of bone weight in the hindlimbs and lumbar vertebrae returned to normal despite continued skeletal unloading. Since bone weight in the growing rat is primarily determined by bone formation (bone resorption is modest), we investigated the effects of selective skeletal unloading on bone formation during 2 weeks of hindlimb elevation using radioisotope incorporation (with /sup 45/Ca and (/sup 3/H)proline) and histomorphometry (with tetracycline labeling). The studies using radioisotope incorporation showed that bone formation was inhibited by the fifth day of skeletal unloading. By the 10th to 12th day, bone formation had returned toward normal. In comparison with cortical bone, cancellous bone (lumbar vertebrae and proximal tibiae) incorporated more /sup 45/Ca and (/sup 3/H)proline (indicating greater metabolic activity) and had a greater absolute response to skeletal unloading. The results of these studies were confirmed by histomorphometric measurements of bone formation using triple tetracycline labeling. We conclude that this model of simulated weightlessness results in an initial inhibition of bone formation in the unloaded bones. This temporary cessation of bone formation is followed by a cessation in the accretion of bone weight, which then resumes at a normal rate by 14 days despite continued skeletal unloading.

  17. Analyzing the cellular contribution of bone marrow to fracture healing using bone marrow transplantation in mice

    SciTech Connect

    Colnot, C. . E-mail: colnotc@orthosurg.ucsf.edu; Huang, S.; Helms, J.

    2006-11-24

    The bone marrow is believed to play important roles during fracture healing such as providing progenitor cells for inflammation, matrix remodeling, and cartilage and bone formation. Given the complex nature of bone repair, it remains difficult to distinguish the contributions of various cell types. Here we describe a mouse model based on bone marrow transplantation and genetic labeling to track cells originating from bone marrow during fracture healing. Following lethal irradiation and engraftment of bone marrow expressing the LacZ transgene constitutively, wild type mice underwent tibial fracture. Donor bone marrow-derived cells, which originated from the hematopoietic compartment, did not participate in the chondrogenic and osteogenic lineages during fracture healing. Instead, the donor bone marrow contributed to inflammatory and bone resorbing cells. This model can be exploited in the future to investigate the role of inflammation and matrix remodeling during bone repair, independent from osteogenesis and chondrogenesis.

  18. INVEST IN YOUR BONES Living with Osteoporosis

    E-print Network

    INVEST IN YOUR BONES Living with Osteoporosis Leaflet 5 Living with osteoporosis can be done environment safe to avoid falls. Early detection of bone loss or osteoporosis is now possible with bone). Remember the following about osteoporosis: is largely preventable and treatable is a serious

  19. Better Bones Buddies: An Osteoporosis Prevention Program

    ERIC Educational Resources Information Center

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

    2005-01-01

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

  20. Effects of Inactivity and Exercise on Bone.

    ERIC Educational Resources Information Center

    Smith, Everett L.; Gilligan, Catherine

    1987-01-01

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

  1. Napier's bones and Genaille-Lucas's rods

    E-print Network

    Roegel, Denis

    virgulas libri duo [26], John Napier (1550­1617) introduced his famous "bones." Three years afterNapier's bones and Genaille-Lucas's rods Denis Roegel 20 May 2015 Abstract This note presents a survey of Napier's bones and of their more "auto- matic" evolution, the Genaille-Lucas rods

  2. Hormonal and Local Regulation of Bone Formation.

    ERIC Educational Resources Information Center

    Canalis, Ernesto

    1985-01-01

    Reviews effects of hormones, systemic factors, and local regulators on bone formation. Identifies and explains the impact on bone growth of several hormones as well as the components of systemic and local systems. Concentrates on bone collagen and DNA synthesis. (Physicians may earn continuing education credit by completing an appended test). (ML)

  3. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  4. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  5. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  6. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  7. 21 CFR 888.3000 - Bone cap.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bone cap. 888.3000 Section 888.3000 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3000 Bone cap. (a) Identification. A bone cap is a...

  8. Bone changes in alcoholic liver disease

    PubMed Central

    González-Reimers, Emilio; Quintero-Platt, Geraldine; Rodríguez-Rodríguez, Eva; Martínez-Riera, Antonio; Alvisa-Negrín, Julio; Santolaria-Fernández, Francisco

    2015-01-01

    Alcoholism has been associated with growth impairment, osteomalacia, delayed fracture healing, and aseptic necrosis (primarily necrosis of the femoral head), but the main alterations observed in the bones of alcoholic patients are osteoporosis and an increased risk of fractures. Decreased bone mass is a hallmark of osteoporosis, and it may be due either to decreased bone synthesis and/or to increased bone breakdown. Ethanol may affect both mechanisms. It is generally accepted that ethanol decreases bone synthesis, and most authors have reported decreased osteocalcin levels (a “marker” of bone synthesis), but some controversy exists regarding the effect of alcohol on bone breakdown, and, indeed, disparate results have been reported for telopeptide and other biochemical markers of bone resorption. In addition to the direct effect of ethanol, systemic alterations such as malnutrition, malabsorption, liver disease, increased levels of proinflammatory cytokines, alcoholic myopathy and neuropathy, low testosterone levels, and an increased risk of trauma, play contributory roles. The treatment of alcoholic bone disease should be aimed towards increasing bone formation and decreasing bone degradation. In this sense, vitamin D and calcium supplementation, together with biphosphonates are essential, but alcohol abstinence and nutritional improvement are equally important. In this review we study the pathogenesis of bone changes in alcoholic liver disease and discuss potential therapies. PMID:26019741

  9. Pediatric Oncology/Bone Marrow Guest Expert

    E-print Network

    O'Hern, Corey S.

    Pediatric Oncology/Bone Marrow Transplant Guest Expert: Debbie Chirnomas, MD Assistant Professor of Pediatrics, Hematology/Oncology; Director, Pediatric Bone Marrow Transplant Program, Yale School of Medicine a conversation about pediatric cancers and bone marrow transplant with Dr. Debbie Chirnomas. Dr. Chirnomas

  10. Planning for a Bone Marrow Transplant (BMT)

    MedlinePLUS

    ... us Digg Facebook Google Bookmarks Planning for a Bone Marrow Transplant (BMT) When a bone marrow transplant (also called a BMT) or umbilical cord ... to a friend or family member undergoing a bone marrow or cord blood transplant. Help Your Loved One ...

  11. www.yalecancercenter.org Bone Marrow Transplant

    E-print Network

    O'Hern, Corey S.

    www.yalecancercenter.org Bone Marrow Transplant Guest Expert: Sunil Abhyankar, MD Associate Professor of Medicine and Pediatrics; Director, Bone Marrow Transplant Phoresis & Cell Processing and Pediatrics, and Director of Bone Marrow Transplant Phoresis & Cell Processing at the University of Kansas

  12. Bone age: assessment methods and clinical applications

    PubMed Central

    Satoh, Mari

    2015-01-01

    Abstract. The main bone age assessment methods are the Greulich-Pyle and Tanner-Whitehouse 2 methods, both of which involve left hand and wrist radiographs. Several other bone age assessment methods have been developed, including ultrasonographic, computerized, and magnetic resonance (MR) imaging methods. The ultrasonographic method appears unreliable in children with delayed and advanced bone age. MR imaging is noninvasive; however, bone age assessment using MR imaging is relatively new, and further examinations are needed. An automated method for determining bone age, named BoneXpert, has been validated for Caucasian children with growth disorders and children of various ethnic groups. Sex hormones are necessary for bone growth and maturation in children with a bone age corresponding to normal pubertal age, and estrogen is essential for growth plate closure. Bone age is an effective indicator for diagnosing and treating various diseases. A new method for adult height prediction based on bone age has been developed using BoneXpert, in addition to the commonly used Bayley-Pinneau and Tanner-Whitehouse mark II methods. Furthermore, bone age may become a predictor for the timing of peak height velocity and menarche. PMID:26568655

  13. CENTER FOR SARCOMA AND BONE ONCOLOGY LIPOSARCOMA

    E-print Network

    Liu, Xiaole Shirley

    CENTER FOR SARCOMA AND BONE ONCOLOGY LIPOSARCOMA RESEARCH DESCRIPTION Reliable research models had not been effectively modeled. However, investigators at the Center for Sarcoma and Bone Oncology trials testing different MDM2 inhibitors. The Center for Sarcoma and Bone Oncology's leadership

  14. VITAMIN K, ORAL ANTICOAGULANTS AND BONE HEALTH

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vitamin K is a fat-soluble vitamin that may have a protective role against age-related bone loss. It is assumed that any putative role of vitamin K in bone health is mediated through the gamma-carboxylation of the vitamin K-dependent proteins present in bone, although other mechanisms of action have...

  15. Mechanics of intact bone marrow.

    PubMed

    Jansen, Lauren E; Birch, Nathan P; Schiffman, Jessica D; Crosby, Alfred J; Peyton, Shelly R

    2015-10-01

    The current knowledge of bone marrow mechanics is limited to its viscous properties, neglecting the elastic contribution of the extracellular matrix. To get a more complete view of the mechanics of marrow, we characterized intact yellow porcine bone marrow using three different, but complementary techniques: rheology, indentation, and cavitation. Our analysis shows that bone marrow is elastic, and has a large amount of intra- and inter-sample heterogeneity, with an effective Young?s modulus ranging from 0.25 to 24.7 kPa at physiological temperature. Each testing method was consistent across matched tissue samples, and each provided unique benefits depending on user needs. We recommend bulk rheology to capture the effects of temperature on tissue elasticity and moduli, indentation for quantifying local tissue heterogeneity, and cavitation rheology for mitigating destructive sample preparation. We anticipate the knowledge of bone marrow elastic properties for building in vitro models will elucidate mechanisms involved in disease progression and regenerative medicine. PMID:26189198

  16. Different approaches to bone densitometry.

    PubMed

    Fogelman, I; Blake, G M

    2000-12-01

    From 1990 to 2000, several effective new treatments were introduced for the prevention of osteoporotic fractures; these treatments were proven effective in large, international, clinical trials. At the same time, there was rapid technologic innovation, with the introduction of new radiologic methods for the noninvasive assessment of patients' bone density status. These developments led to the publication of guidelines for the clinical use of bone densitometry that include criteria for the referral of patients for investigation as well as recommendations for intervention thresholds for the initiation of preventive treatment of osteoporosis. Dual-energy x-ray absorptiometry scanning of the spine and hip remains the technique of choice for bone densitometry studies, although there is now a wider appreciation of the need for smaller, cheaper devices for scanning the peripheral skeleton if the millions of women most at risk of a fragility fracture are to be identified and treated. This article reviews these developments, concentrating in particular on the advantages and disadvantages of the different types of equipment available for performing bone densitometry investigations, the guidelines for the referral of patients, and the principles for the interpretation of the scan findings. PMID:11138687

  17. Bone-Conduction ABR Tests.

    ERIC Educational Resources Information Center

    Cone-Wesson, Barbara

    1995-01-01

    This article discusses the accuracy of bone-conduction auditory brainstem response (BC-ABR) tests to determine the presence and severity of conductive hearing impairment. It provides warnings about technical pitfalls and recommends incorporating BC-ABR protocols for routine clinical use. It concludes that the method allows estimating cochlear…

  18. Bone and Soft Tissue Ablation

    PubMed Central

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

    2014-01-01

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

  19. [Hyperprolactinaemia and bone mineral density].

    PubMed

    Kostrzak, Anna; M?czekalski, B?a?ej

    2015-08-01

    Hyperprolactinaemia is one of the most common endocrinological disorder at women at the reproductive age. Prolactin is produced by the anterior lobe of the pituitary.The main role of prolactin is associated with mamotrophic action and lactogenesis. Hyperprolactinaemia causes several symptoms such as menstrual disorders, infertility, decrease of sexual function, galactorrhea in women and gynecomasty, impotence and decrease of semen quality in men. Recent studies have presented prolactin as a homone involved in many metabolic processes. Long-term consequences of high prolactin serum concentration are related to higher risk of cardiovascular system disease, disturbances in lipid profile and immunological system. Hyperprolactiaemia causes decrease of bone mass density (BMD). High serum prolactin levels lead to increase of the risk of osteopenia or/and osteoporosis. Decrease of BMD results from hypoestrogenism induced by hyperprolactinaemia and also by the direct negative influence of prolactin on bone. Hyperprolactinaemia related to prolactinoma significantly (more than functional hyperprolactiaemia) increases the risk of osteopenia, osteoporosis and bone fractures. Important group of patients threatened by osteoporosis and bone fracture is constituted by women which use antipsychotic drugs (which induce hyperprolactinaemia). Hyperprolactinaemia diagnosed in patients should be treated as soon as possible. Hyperprolactinaemic patients should be diagnosed in the direction of osteopenia and osteoporosis. When diagnosis is confirmed proper treatment is indicated. PMID:26319389

  20. Mathematical model for bone mineralization

    PubMed Central

    Komarova, Svetlana V.; Safranek, Lee; Gopalakrishnan, Jay; Ou, Miao-jung Yvonne; McKee, Marc D.; Murshed, Monzur; Rauch, Frank; Zuhr, Erica

    2015-01-01

    Defective bone mineralization has serious clinical manifestations, including deformities and fractures, but the regulation of this extracellular process is not fully understood. We have developed a mathematical model consisting of ordinary differential equations that describe collagen maturation, production and degradation of inhibitors, and mineral nucleation and growth. We examined the roles of individual processes in generating normal and abnormal mineralization patterns characterized using two outcome measures: mineralization lag time and degree of mineralization. Model parameters describing the formation of hydroxyapatite mineral on the nucleating centers most potently affected the degree of mineralization, while the parameters describing inhibitor homeostasis most effectively changed the mineralization lag time. Of interest, a parameter describing the rate of matrix maturation emerged as being capable of counter-intuitively increasing both the mineralization lag time and the degree of mineralization. We validated the accuracy of model predictions using known diseases of bone mineralization such as osteogenesis imperfecta and X-linked hypophosphatemia. The model successfully describes the highly nonlinear mineralization dynamics, which includes an initial lag phase when osteoid is present but no mineralization is evident, then fast primary mineralization, followed by secondary mineralization characterized by a continuous slow increase in bone mineral content. The developed model can potentially predict the function for a mutated protein based on the histology of pathologic bone samples from mineralization disorders of unknown etiology. PMID:26347868

  1. Glucocorticoids, bone and energy metabolism.

    PubMed

    Cooper, Mark S; Seibel, Markus J; Zhou, Hong

    2016-01-01

    Prolonged exposure to excessive levels of endogenous or exogenous glucocorticoids is associated with serious clinical features including altered body composition and the development of insulin resistance, impaired glucose tolerance and diabetes. It had been assumed that these adverse effects were mediated by direct effects of glucocorticoids on tissues such as adipose or liver. Recent studies have however indicated that these effects are, at least in part, mediated through the actions of glucocorticoids on bone and specifically the osteoblast. In mice, targeted abrogation of glucocorticoid signalling in osteoblasts significantly attenuated the changes in body composition and systemic fuel metabolism seen during glucocorticoid treatment. Heterotopic expression of osteocalcin in the liver of normal mice was also able to protect against the metabolic changes induced by glucocorticoids indicating that osteocalcin was the likely factor connecting bone osteoblasts to systemic fuel metabolism. Studies are now needed in humans to determine the extent to which glucocorticoid induced changes in body composition and systemic fuel metabolism are mediated through bone. This article is part of a Special Issue entitled Bone and diabetes. PMID:26051468

  2. Green tea and bone health

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. Hematologic Disorders: Bone Marrow Failure.

    PubMed

    Baltierra, David; Harper, Tiffany; Jones, Matthew Page; Nau, Konrad C

    2015-06-01

    Pancytopenia with hypocellular bone marrow most often is caused by idiopathic aplastic anemia, but can be caused by inherited bone marrow failure syndromes, drugs, infections, nutritional deficiencies, and rheumatologic disease. Aplastic anemia (AA) can remain stable for years but can become severe or transform into a myelodysplastic syndrome, acute leukemia, or paroxysmal nocturnal hemoglobinuria. Corticosteroids and erythropoietin are ineffective for management of aplastic anemia; and granulocyte colony-stimulating factor is only indicated in severe infections that do not improve with antibiotics. Supportive care with leukocyte-poor red blood cell transfusions reduces HLA antigen alloimmunization and platelet transfusion refractoriness. Horse or rabbit antithymocyte globulin plus cyclosporine typically is first-line therapy for patients with nonsevere AA who are transfusion-dependent, patients older than 40 years with severe AA, and patients with severe AA who lack an HLA antigen-matched sibling for bone marrow transplantation. The overall 5-year survival rate among patients taking antithymocyte globulin plus cyclosporine therapy is 75% to 85%. Bone marrow transplantation from an HLA antigen-matched sibling is considered the treatment of choice for severe AA in children and adults younger than 40 years. Less than approximately 33% of patients with AA have an HLA antigen-matched sibling donor, so matched unrelated donor hematopoietic stem cells are increasingly used. Umbilical cord stem cell transplantation is in clinical trials. PMID:26080455

  4. Rhabdomyolysis detected by bone imaging

    SciTech Connect

    Sanders, J.A.

    1989-06-01

    Rhabdomyolysis involves necrosis of skeletal muscle and may arise from multiple conditions both traumatic and nontraumatic. Bone imaging with Technetium-99m phosphates is a very sensitive indicator of acute muscle damage and may be used to visualize the extent of rhabdomyolysis and its resolution. A case of alcohol-induced rhabdomyolysis is presented.

  5. Bare Bones of Bioactive Glass

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  6. New perspectives on bone densitometry.

    PubMed

    Ring, F

    1997-01-01

    Methods of bone mineral density measurement are presented. Radiological photogrammetry, single photon absorptiometry, dual photon absorptiometry and dual energy X-ray absorptiometry are described. Mode of work of densitometers and their characteristics ares presented. Modern development of densitometric equipment and possible application in diagnosing of osteoporosis is discussed. PMID:9333871

  7. Vegetarian diets and bone status.

    PubMed

    Tucker, Katherine L

    2014-07-01

    Osteoporosis is a common chronic condition associated with progressive loss of bone mineral density (BMD) and compromised bone strength, with increasing risk of fracture over time. Vegetarian diets have been shown to contain lower amounts of calcium, vitamin D, vitamin B-12, protein, and n-3 (?-3) fatty acids, all of which have important roles in maintaining bone health. Although zinc intakes are not necessarily lower quantitatively, they are considerably less bioavailable in vegetarian diets, which suggests the need for even higher intakes to maintain adequate status. At the same time, healthy vegetarian diets tend to contain more of several protective nutrients, including magnesium, potassium, vitamin K, and antioxidant and anti-inflammatory phytonutrients. On balance, there is evidence that vegetarians, and particularly vegans, may be at greater risk of lower BMD and fracture. Attention to potential shortfall nutrients through the careful selection of foods or fortified foods or the use of supplements can help ensure healthy bone status to reduce fracture risk in individuals who adhere to vegetarian diets. PMID:24898237

  8. Flavonoid intake and bone health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavonoids, found in a wide diversity of plant foods, from fruits and vegetables, herbs and spices, essential oils, and beverages, have the most potential of dietary components for promotion of bone health beyond calcium and vitamin D. Recent epidemiological studies show flavonoid consumption to ha...

  9. Electromagnetic pulses bone healing booster

    NASA Astrophysics Data System (ADS)

    Sintea, S. R.; Pomazan, V. M.; Bica, D.; Grebenisan, D.; Bordea, N.

    2015-11-01

    Posttraumatic bone restoration triggered by the need to assist and stimulate compensatory bone growth in periodontal condition. Recent studies state that specific electromagnetic stimulation can boost the bone restoration, reaching up to 30% decrease in recovery time. Based on the existing data on the electromagnetic parameters, a digital electronic device is proposed for intra oral mounting and bone restoration stimulation in periodontal condition. The electrical signal is applied to an inductive mark that will create and impregnate magnetic field in diseased tissue. The device also monitors the status of the electromagnetic field. Controlled wave forms and pulse frequency signal at programmable intervals are obtained with optimized number of components and miniaturized using surface mounting devices (SMD) circuits and surface mounting technology (SMT), with enhanced protection against abnormal current growth, given the intra-oral environment. The system is powered by an autonomous power supply (battery), to limit the problems caused by powering medical equipment from the main power supply. Currently the device is used in clinical testing, in cycles of six up to twelve months. Basic principles for the electrical scheme and algorithms for pulse generation, pulse control, electromagnetic field control and automation of current monitoring are presented, together with the friendly user interface, suitable for medical data and patient monitoring.

  10. [Bone metabolism and cardiovascular function update. The estimation of bone material quality in the concept of bone and vascular linkage].

    PubMed

    Saito, Mitsuru; Kida, Yoshikuni; Marumo, Keishi

    2014-07-01

    It has become clear that a reduction in sex hormones from middle age onwards, increasing age, and an increase in oxidative stress related to lifestyle-related diseases can also reduce bone material properties in terms of collagen post-translational modification, crosslink formation. These changes lead to both qualitative and quantitative abnormalities in collagen, which is the major bone matrix protein. The intermolecular cross-link formation of collagen, which regulates bone-material attributes, is a mechanism independent of bone remodeling. In other words, cross-link formation is controlled by the environment surrounding the bone matrix, comprising cellular functions, oxidative stress, and glycation level. Because oxidative stress is also risk factor of arteriosclerosis and cardiovascular event, there is link between low bone quality and arteriosclerosis. High levels of pentosidine in urine or blood, or mild hyperhomocysteinemia which suggest bone collagen abnormalities, might be used as surrogate markers for evaluating bone quality, assessing the risk of bone fracture. Patients with osteoporosis can be divided into 3 types on the basis of bone density and with bone quality. We are entering an age in which the treatment of osteoporosis will be personalized, with drugs administered depending on these types. PMID:24976053

  11. Photodynamic therapy of diseased bone

    NASA Astrophysics Data System (ADS)

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

    2005-08-01

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

  12. [Updates on Lifestyle-Related Diseases and Bone Metabolism. Increase in bone fragility from the viewpoint of bone structural properties].

    PubMed

    Ito, Masako; Chiba, Ko

    2014-11-01

    Diabetes mellitus (DM) and chronic renal disease (CKD) show the dissociation between their bone mineral density (BMD) and their fracture risk. High-resolution peripheral computed tomography (HR-pQCT) contributes to investigate the deterioration of structural properties in these diseases. In type2 DM, the increase in cortical porosity account for its high fracture risk. In CKD, parathyroid hormone (PTH) is anabolic in trabecular bone and catabolic in cortical bone, which produces complicated bone feature. If hyperparathyroidism is severe, cortical thinning and increased cortical porosity appear in the compact bone, and irregular thickened trabeculae and dissecting intra-trabecular resorption appear in the cancellous bone. Even in the early stage of CKD, the bone microstructural changes are observed. For further investigation of the structural changes in relation to biomechanical properties in type2 DM and CKD, the longitudinal studies are required using in vivo HR-pQCT. PMID:25355145

  13. Bone age assessment meets SIFT

    NASA Astrophysics Data System (ADS)

    Kashif, Muhammad; Jonas, Stephan; Haak, Daniel; Deserno, Thomas M.

    2015-03-01

    Bone age assessment (BAA) is a method of determining the skeletal maturity and finding the growth disorder in the skeleton of a person. BAA is frequently used in pediatric medicine but also a time-consuming and cumbersome task for a radiologist. Conventionally, the Greulich and Pyle and the Tanner and Whitehouse methods are used for bone age assessment, which are based on visual comparison of left hand radiographs with a standard atlas. We present a novel approach for automated bone age assessment, combining scale invariant feature transform (SIFT) features and support vector machine (SVM) classification. In this approach, (i) data is grouped into 30 classes to represent the age range of 0- 18 years, (ii) 14 epiphyseal ROIs are extracted from left hand radiographs, (iii) multi-level image thresholding, using Otsu method, is applied to specify key points on bone and osseous tissues of eROIs, (iv) SIFT features are extracted for specified key points for each eROI of hand radiograph, and (v) classification is performed using a multi-class extension of SVM. A total of 1101 radiographs of University of Southern California are used in training and testing phases using 5- fold cross-validation. Evaluation is performed for two age ranges (0-18 years and 2-17 years) for comparison with previous work and the commercial product BoneXpert, respectively. Results were improved significantly, where the mean errors of 0.67 years and 0.68 years for the age ranges 0-18 years and 2-17 years, respectively, were obtained. Accuracy of 98.09 %, within the range of two years was achieved.

  14. THE OXYTOCIN-BONE AXIS

    PubMed Central

    Colaianni, G.; Tamma, R.; Di Benedetto, A.; Yuen, T.; Sun, L.; Zaidi, M.; Zallone, A.

    2014-01-01

    We recently demonstrated a direct action of oxytocin (OT) on skeletal homeostasis mainly mediated through stimulation of osteoblasts (OBs) formation and through the reciprocal modulation of osteoclast (OCs) formation and function. Thus, mice lacking the hormone or its receptor develop a low turnover osteoporosis that worsens with age in both sexes. The skeleton of OT and OT receptor (Oxtr) null mice display a pronounced decrease in vertebral and femoral trabecular volume. At cellular level OBs from OT?/? and Oxtr?/? mice exhibit lower mineralization activity and, at mRNA level, all master genes for osteoblast differentiation are down regulated. Moreover, OT has dual effects on OCs: it increases osteoclast formation both directly, by activating NF-kB and MAP kinase signaling, and indirectly, through the up-regulation of RANK-L synthesis by OBs. On the other hand, it inhibits bone resorption by triggering cytosolic Ca2+ release and nitric oxide synthesis in mature OCs. OT is locally produced by osteoblasts acting as paracrine-autocrine regulator of bone formation modulated by estrogens. The estrogen signal involved in this feed forward circuit is non genomic, since it requires an intact MAPK kinase signal transduction pathway, instead of the classical nuclear translocation of estrogen receptor. The ability of estrogen to increase bone mass in vivo is to an extent OTR-dependent. Thus Oxtr?/? mice injected 17?-estradiol did not show any effects on bone formation parameters, while the same treatment increases trabecular and cortical bone in wild type mice. An intact OT autocrine-paracrine circuit seems to be essential for optimal skeletal remodeling. PMID:24219627

  15. [Bone changes in Gaucher disease].

    PubMed

    Butora, M; Kissling, R; Frick, P

    1989-01-01

    Among Ashkenazi-Jews, Gaucher' disease, an autosomal-recessive hereditary genetic defect of sphingolipid metabolism, occurs more frequently than in the general population. Because of lack of the specific b-glucosidase, glucocerebrosidase, there is increased deposition of glucocerebrosides in the reticulo-endothelial system, mostly in the spleen, liver, and bone-marrow. In the chronic adult form (type 1), in addition to the hematologic complications (which are mostly associated with a splenomegaly), a less known involvement of the skeletal system occurs, which can lead to significant rheumatologic and orthopedic problems. These are: nonspecific skeletal and joint pain, purulent osteomyelitis, pseudo-osteomyelitis, aseptic necrosis of the femoral head, pathologic fractures of the long bones, acutely occurring kyphosis secondary to pathologic vertebral fractures with or without spinal compression, bony deformities, growth disturbances, arthritis, and bursitis. One sees a wide variety of bone lesions which can be solitary or multiple. Various pathogenic mechanisms have been discussed: toxic reaction to the Gaucher cells, disturbance of the osteoblastic and osteoclastic function, compression of osseous blood vessels by pathological cells, pressure-induced atrophy of the surrounding osseous tissue, local hemorrhage, local thrombosis, invasion of the arterioles with subsequent occlusion, and bone infarcts. The therapy is purely symptomatic. For orthopedic problems there is a greater tendency towards conservative treatment. There is disagreement as to whether splenectomy, which is often performed for hematologic or mechanical reasons, accelerates involvement of the bone. The case of a patient with multiple fractures of the spine and a slight spinal compression is presented. PMID:2623978

  16. Bone marrow and the control of immunity

    PubMed Central

    Zhao, Ende; Xu, Huanbin; Wang, Lin; Kryczek, Ilona; Wu, Ke; Hu, Yu; Wang, Guobin; Zou, Weiping

    2012-01-01

    Bone marrow is thought to be a primary hematopoietic organ. However, accumulated evidences demonstrate that active function and trafficking of immune cells, including regulatory T cells, conventional T cells, B cells, dendritic cells, natural killer T (NKT) cells, neutrophils, myeloid-derived suppressor cells and mesenchymal stem cells, are observed in the bone marrow. Furthermore, bone marrow is a predetermined metastatic location for multiple human tumors. In this review, we discuss the immune network in the bone marrow. We suggest that bone marrow is an immune regulatory organ capable of fine tuning immunity and may be a potential therapeutic target for immunotherapy and immune vaccination. PMID:22020068

  17. [Bone architecture and strength in diabetes mellitus].

    PubMed

    Okazaki, Ryo

    2013-07-01

    Increased fracture risks in diabetes mellitus (DM) have been attributed to deteriorated bone quality both in type 1 and 2 DM because increased risks are disproportionate to their bone mineral densities (BMD) . Although still very little is known about bone architecture in type 1 DM, recent advancement in the techniques, such as high-resolution peripheral quantitative CT (HR-pQCT) and trabecular bone score (TBS) , have revealed that, in type 2 DM, bone microstructure is compromised despite preserved BMD, which may account for high fracture risk in DM. PMID:23811588

  18. [Molecular mechanisms of bone cancer pain].

    PubMed

    Hiraga, Toru

    2014-08-01

    Bone pain is one of the most frequent complications of bone metastasis, leading to a marked reduction in the quality of life of patients. The mechanisms of bone cancer pain are highly complicated ; however, noxious stimuli produced by cancer tissues and cancer-induced nerve injury are considered to be the major causes. Recent studies also suggest the possible involvement of acidic microenvironments created by cancer tissues and osteoclasts in cancer-induced bone pain. Understanding the molecular events may lead to the design of novel mechanism-based approaches for the management of bone pain associated with cancer metastasis. PMID:25065870

  19. Effect of alendronate administration on bone mineral density and bone strength in castrated rats.

    PubMed

    Broulik, P D; Rosenkrancová, J; R?zicka, P; Sedlácek, R

    2005-07-01

    Castration of male rats leads to increased bone turnover and osteopenia. This study was conducted to examine the effects of the aminobisphosphonate alendronate on castration-induced bone changes. Bisphosphonates are drugs that inhibit bone turnover by decreasing the resorption. Since they suppress bone remodeling, they may also prevent the repair of microdamage and decrease bone strength. Although the mechanical properties of bones are directly related to the determination of fracture risk, bisphosphonate effects on the related variables have scarcely been investigated. Twenty-four male Wistar rats at two months of age were castrated or sham-operated to evaluate the effects of long-term administration (six months) of sodium alendronate at a dose of 1 mg/kg/day. The bones were tested mechanically by a three-point bending test in a Mini Bionix (MTS) testing system. High bone remodeling seen in castrated rats expressed by increased TrACP and B-ALP was suppressed by alendronate administration. Bone from castrated rats was characterized by a reduction in bone density as well as ash, calcium and phosphate content. Castration significantly altered mechanical properties of bone and femoral cortical thickness. When castrated rats were treated with high dose of alendronate, the changes in bone density resulting from castration were entirely prevented, and mechanical analysis revealed preserved mechanical strength of femur and cortical thickness. We conclude that castration induces cortical bone loss associated with high bone turnover in the male rat, and this bone loss can be prevented by alendronate through the inhibition of osteoclastic activity, while preserving the mechanical properties of bone. These results document the efficacy of alendronate, even at high doses, in preventing bone loss, loss of bone mechanical strength, and the rise in biochemical bone turnover indicators due to castration in rats, and raises the possibility that a alendronate could be equally effective in humans. PMID:16034712

  20. NMR assessment on bone simulated under microgravity

    NASA Astrophysics Data System (ADS)

    Ni, Q.; Qin, Y.

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

  1. Predicting cancellous bone failure during screw insertion.

    PubMed

    Reynolds, Karen J; Cleek, Tammy M; Mohtar, Aaron A; Hearn, Trevor C

    2013-04-01

    Internal fixation of fractures often requires the tightening of bone screws to stabilise fragments. Inadequate application of torque can leave the fracture unstable, while over-tightening results in the stripping of the thread and loss of fixation. The optimal amount of screw torque is specific to each application and in practice is difficult to attain due to the wide variability in bone properties including bone density. The aim of the research presented in this paper is to investigate the relationships between motor torque and screw compression during powered screw insertion, and to evaluate whether the torque during insertion can be used to predict the ultimate failure torque of the bone. A custom test rig was designed and built for bone screw experiments. By inserting cancellous bone screws into synthetic, ovine and human bone specimens, it was established that variations related to bone density could be automatically detected through the effects of the bone on the rotational characteristics of the screw. The torque measured during screw insertion was found to be directly related to bone density and can be used, on its own, as a good predictor of ultimate failure torque of the bone. PMID:23466167

  2. Biomaterial scaffolds for treating osteoporotic bone

    PubMed Central

    Sterling, Julie A.

    2014-01-01

    Healing fractures resulting from osteoporosis or cancer remains a significant clinical challenge. In these populations, healing is often impaired not only due to age and disease, but also by other therapeutic interventions such as radiation, steroids, and chemotherapy. Despite substantial improvements in the treatment of osteoporosis over the few decades, osteoporotic fractures are still a major clinical challenge in the elderly population due to impaired healing. Similar fractures with impaired healing are also prevalent in cancer patients, especially those with tumor growing in bone. Treatment options for cancer patients are further complicated by the fact that bone anabolic therapies are contraindicated in patients with tumors. Therefore, many patients undergo surgery to repair the fracture, and bone grafts are often used to stabilize orthopaedic implants and provide a scaffold for ingrowth of new bone. Both synthetic and naturally occurring biomaterials have been investigated as bone grafts for repair of osteoporotic fractures, including calcium phosphate bone cements, resorbable polymers, and allograft or autograft bone. In order to re-establish normal bone repair, bone grafts have been augmented with anabolic agents, such as mesenchymal stem cells (MSC) or recombinant human bone morphogenetic protein-2 (rhBMP2). These developing approaches to bone grafting are anticipated to improve the clinical management of osteoporotic and cancer-induced fractures. PMID:24458428

  3. New predictive model for monitoring bone remodeling.

    PubMed

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

    2010-10-01

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

  4. Drilling of bone: A comprehensive review

    PubMed Central

    Pandey, Rupesh Kumar; Panda, S.S.

    2013-01-01

    Background Bone fracture treatment usually involves restoring of the fractured parts to their initial position and immobilizing them until the healing takes place. Drilling of bone is common to produce hole for screw insertion to fix the fractured parts for immobilization. Orthopaedic drilling during surgical process causes increase in the bone temperature and forces which can cause osteonecrosis reducing the stability and strength of the fixation. Methods A comprehensive review of all the relevant investigations carried on bone drilling is conducted. The experimental method used, results obtained and the conclusions made by the various researchers are described and compared. Result Review suggests that the further improvement in the area of bone drilling is possible. The systematic review identified several consequential factors (drilling parameters and drill specifications) affecting bone drilling on which there no general agreement among investigators or are not adequately evaluated. These factors are highlighted and use of more advanced methods of drilling is accentuated. The use of more precise experimental set up which resembles the actual situation and the development of automated bone drilling system to minimize human error is addressed. Conclusion In this review, an attempt has been made to systematically organize the research investigations conducted on bone drilling. Methods of treatment of bone fracture, studies on the determination of the threshold for thermal osteonecrosis, studies on the parameters influencing bone drilling and methods of the temperature measurement used are reviewed and the future work for the further improvement of bone drilling process is highlighted. PMID:26403771

  5. Bone remodelling markers in rheumatoid arthritis.

    PubMed

    Fardellone, Patrice; Séjourné, Alice; Paccou, Julien; Goëb, Vincent

    2014-01-01

    Bone loss in rheumatoid arthritis (RA) patients results from chronic inflammation and can lead to osteoporosis and fractures. A few bone remodeling markers have been studied in RA witnessing bone formation (osteocalcin), serum aminoterminal propeptide of type I collagen (PINP), serum carboxyterminal propeptide of type I collagen (ICTP), bone alkaline phosphatase (BAP), osteocalcin (OC), and bone resorption: C-terminal telopeptide of type 1 collagen (I-CTX), N-terminal telopeptide of type 1 collagen (I-NTX), pyridinolines (DPD and PYD), and tartrate-resistant acid phosphatase (TRAP). Bone resorption can be seen either in periarticular bone (demineralization and erosion) or in the total skeleton (osteoporosis). Whatever the location, bone resorption results from activation of osteoclasts when the ratio between osteoprotegerin and receptor activator of nuclear factor kappa-B ligand (OPG/RANKL) is decreased under influence of various proinflammatory cytokines. Bone remodeling markers also allow physicians to evaluate the effect of drugs used in RA like biologic agents, which reduce inflammation and exert a protecting effect on bone. We will discuss in this review changes in bone markers remodeling in patients with RA treated with biologics. PMID:24839355

  6. Organ printing: the future of bone regeneration?

    PubMed

    Fedorovich, Natalja E; Alblas, Jacqueline; Hennink, Wim E; Oner, F Cumhur; Dhert, Wouter J A

    2011-12-01

    In engineered bone grafts, the combined actions of bone-forming cells, matrix and bioactive stimuli determine the eventual performance of the implant. The current notion is that well-built 3D constructs include the biological elements that recapitulate native bone tissue structure to achieve bone formation once implanted. The relatively new technology of organ/tissue printing now enables the accurate 3D organization of the components that are important for bone formation and also addresses issues, such as graft porosity and vascularization. Bone printing is seen as a great promise, because it combines rapid prototyping technology to produce a scaffold of the desired shape and internal structure with incorporation of multiple living cell types that can form the bone tissue once implanted. PMID:21831463

  7. Effects of thirty elements on bone metabolism.

    PubMed

    Dermience, Michael; Lognay, Georges; Mathieu, Françoise; Goyens, Philippe

    2015-10-01

    The human skeleton, made of 206 bones, plays vital roles including supporting the body, protecting organs, enabling movement, and storing minerals. Bones are made of organic structures, intimately connected with an inorganic matrix produced by bone cells. Many elements are ubiquitous in our environment, and many impact bone metabolism. Most elements have antagonistic actions depending on concentration. Indeed, some elements are essential, others are deleterious, and many can be both. Several pathways mediate effects of element deficiencies or excesses on bone metabolism. This paper aims to identify all elements that impact bone health and explore the mechanisms by which they act. To date, this is the first time that the effects of thirty minerals on bone metabolism have been summarized. PMID:26302917

  8. BMPs and the muscle-bone connection.

    PubMed

    Sartori, Roberta; Sandri, Marco

    2015-11-01

    Muscle and bone are two intimately connected tissues. A coordinated interplay between these tissues at mechanical levels is required for their development, function and ageing. Evidence is emerging that several genes and molecular pathways exert a pleiotropic effect on both muscle and bone. Bone morphogenetic proteins (BMPs) are secreted signal factors belonging to the transforming growth factor ? (TGF?) superfamily. BMPs have an essential role during bone and cartilage formation and maintenance. Recently, we and others have demonstrated that the BMP pathway also has a role in controlling adult skeletal muscle mass. Thus, BMPs become crucial regulators of both bone and muscle formation and homeostasis. In this review we will discuss the signalling downstream BMP and its role in muscle-bone interaction. This article is part of a Special Issue entitled "Muscle Bone Interactions". PMID:26036170

  9. Decreased bone mineral density and periodontal management.

    PubMed

    Reddy, Michael S; Morgan, Sarah L

    2013-02-01

    The definition of osteoporosis has evolved beyond low bone mineral density to include impaired bone morphology and matrix properties. As such, the subsequent bone density insufficiencies extend beyond the skeletal risks of fracture and have implications for oral health management patients. As our population ages there is a worldwide increase in the risk of decreased bone mineral density and its subsequent morbidity. This makes age an independent risk factor for fracture and decreased bone mineral density. Multiple examinations and diagnostic tests are currently used in combination to develop an algorithm to assess osteoporotic risk. Oral health care professionals should follow these principles and caution should be used in applying a single independent assessment to determine a patient's osteoporotic or bone metabolism risk. Therapeutic approaches for osteoporosis are often divided into nonpharmacological interventions and pharmacological therapies. The periodontist and other oral health care professionals should have a full understanding of the therapeutic options, benefits and implementation of preventive therapies. Bone turnover is a coupled event of bone formation and bone resorption and it is the imbalance of this homeostasis that results in osteoporosis. Based on this uncoupling of bone resorption and formation, osteoporosis or decreased bone mineral density and osteopenia, may be a risk factor for alveolar bone loss in periodontitis. The role of prevention and maintenance with a history of periodontitis and oesteopenia extends beyond biofilm control and should include management of bone mineral density. The chronic periodontal infection in a patient with osteopenia may place the patient at greatly increased risk for alveolar bone loss, gingival recession and root caries. A key component in the management is the oral health professional's knowledge of the interrelationship between skeletal health and periodontal health. PMID:23240950

  10. High-strength mineralized collagen artificial bone

    NASA Astrophysics Data System (ADS)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  11. Silicon calcium phosphate ceramic as novel biomaterial to simulate the bone regenerative properties of autologous bone.

    PubMed

    Manchón, A; Alkhraisat, M; Rueda-Rodriguez, C; Torres, J; Prados-Frutos, J C; Ewald, A; Gbureck, U; Cabrejos-Azama, J; Rodriguez-González, A; López-Cabarcos, E

    2015-02-01

    This study was conducted to develop novel ceramic bone substitute that resembles the autologous bone behavior when used as graft material. Solid-state reaction at 1100°C was performed to synthesize ?-tricalcium phosphate (?-TCP) and biphasic calcium phosphate (BCP). The ceramics were further analyzed to characterize phase composition, microstructural properties, cytocompatability and then challenged to regenerate critical bone defects in the parietal bone of rabbits. X-ray diffraction analysis confirmed the production of ?-TCP and indicated the synthesis of novel BCP composed of ?-TCP and silicocarnotite (calcium phosphate silicate mineral). The cytocompatibility test with human osteoblast cell line revealed enhanced cell proliferation on the BCP ceramic. The novel BCP induced the filling of about 73% of the bone defect with a newly formed bone tissue and an almost complete degradation after 12 weeks of healing. This novel ceramic resembles the autologous bone properties of complete degradation and efficient enhancement of bone formation, making it promising as bone graft material. PMID:24737706

  12. Bone apatite composition of necrotic trabecular bone in the femoral head of immature piglets.

    PubMed

    Aruwajoye, Olumide O; Kim, Harry K W; Aswath, Pranesh B

    2015-04-01

    Ischemic osteonecrosis of the femoral head (IOFH) can lead to excessive resorption of the trabecular bone and collapse of the femoral head as a structure. A well-known mineral component to trabecular bone is hydroxyapatite, which can be present in many forms due to ionic substitution, thus altering chemical composition. Unfortunately, very little is known about the chemical changes to bone apatite following IOFH. We hypothesized that the apatite composition changes in necrotic bone possibly contribute to increased osteoclast resorption and structural collapse of the femoral head. The purpose of this study was to assess the macroscopic and local phosphate composition of actively resorbed necrotic trabecular bone to isolate differences between areas of increased osteoclast resorption and normal bone formation. A piglet model of IOFH was used. Scanning electron microscopy (SEM), histology, X-ray absorbance near edge structure (XANES), and Raman spectroscopy were performed on femoral heads to characterize normal and necrotic trabecular bone. Backscattered SEM, micro-computed tomography and histology showed deformity and active resorption of necrotic bone compared to normal. XANES and Raman spectroscopy obtained from actively resorbed necrotic bone and normal bone showed increased carbonate-to-phosphate content in the necrotic bone. The changes in the apatite composition due to carbonate substitution may play a role in the increased resorption of necrotic bone due to its increase in solubility. Indeed, a better understanding of the apatite composition of necrotic bone could shed light on osteoclast activity and potentially improve therapeutic treatments that target excessive resorption of bone. PMID:25660159

  13. Bone mass and bone metabolic indices in male master rowers.

    PubMed

    ?liwicka, Ewa; Nowak, Alicja; Zep, Wojciech; Leszczy?ski, Piotr; Pilaczy?ska-Szcze?niak, ?ucja

    2015-09-01

    The purpose of this study was to assess bone mass and bone metabolic indices in master athletes who regularly perform rowing exercises. The study was performed in 29 men: 14 master rowers and 15 non-athletic, body mass index-matched controls. Dual-energy X-ray absorptiometry measurements of the areal bone mineral density (aBMD) were performed for the total body, regional areas (arms, total forearms, trunk, thoracic spine, pelvis, and legs), lumbar spine (L1-L4), left hip (total hip and femoral neck), and forearm (33 % radius of the dominant and nondominant forearm). Serum concentrations of osteocalcin, collagen type I cross-linked C-telopeptide, visfatin, resistin, insulin, and glucose were determined. Comparative analyses showed significantly lower levels of body fat and higher lean body mass values in the rowers compared to the control group. The rowers also had significantly higher values of total and regional (left arm, trunk, thoracic spine, pelvis, and leg) BMD, as well as higher BMD values for the lumbar spine and the left hip. There were significant differences between the groups with respect to insulin, glucose, and the index of homeostasis model assessment insulin resistance. In conclusion, the systematic training of master rowers has beneficial effects on total and regional BMD and may be recommended for preventing osteoporosis. PMID:25224128

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

    PubMed Central

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

    2015-01-01

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

  15. In vitro simulation of pathological bone conditions to predict clinical outcome of bone tissue engineered materials

    NASA Astrophysics Data System (ADS)

    Nguyen, Duong Thuy Thi

    According to the Centers for Disease Control, the geriatric population of ?65 years of age will increase to 51.5 million in 2020; 40% of white women and 13% of white men will be at risk for fragility fractures or fractures sustained under normal stress and loading conditions due to bone disease, leading to hospitalization and surgical treatment. Fracture management strategies can be divided into pharmaceutical therapy, surgical intervention, and tissue regeneration for fracture prevention, fracture stabilization, and fracture site regeneration, respectively. However, these strategies fail to accommodate the pathological nature of fragility fractures, leading to unwanted side effects, implant failures, and non-unions. Compromised innate bone healing reactions of patients with bone diseases are exacerbated with protective bone therapy. Once these patients sustain a fracture, bone healing is a challenge, especially when fracture stabilization is unsuccessful. Traditional stabilizing screw and plate systems were designed with emphasis on bone mechanics rather than biology. Bone grafts are often used with fixation devices to provide skeletal continuity at the fracture gap. Current bone grafts include autologous bone tissue and donor bone tissue; however, the quality and quantity demanded by fragility fractures sustained by high-risk geriatric patients and patients with bone diseases are not met. Consequently, bone tissue engineering strategies are advancing towards functionalized bone substitutes to provide fracture reconstruction while effectively mediating bone healing in normal and diseased fracture environments. In order to target fragility fractures, fracture management strategies should be tailored to allow bone regeneration and fracture stabilization with bioactive bone substitutes designed for the pathological environment. The clinical outcome of these materials must be predictable within various disease environments. Initial development of a targeted treatment strategy should focus on simulating, in vitro, a physiological bone environment to predict clinical effectiveness of engineered bone and understand cellular responses due to the proposed agents and bioactive scaffolds. An in vitro test system can be the necessary catalyst to reduce implant failures and non-unions in fragility fractures.

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

    PubMed Central

    2015-01-01

    Bone-seeking radiopharmaceuticals are frequently used as diagnostic agents in nuclear medicine, because they can detect bone disorders before anatomical changes occur. Furthermore, their effectiveness in the palliation of metastatic bone cancer pain has been demonstrated in the clinical setting. With the aim of developing superior bone-seeking radiopharmaceuticals, many compounds have been designed, prepared, and evaluated. Here, several well-designed bone-seeking compounds used for diagnostic and therapeutic use, having the concept of radiometal complexes conjugated to carrier molecules to bone, are reviewed. PMID:26075256

  17. Predicting Bone Mechanical Properties of Cancellous Bone from DXA, MRI, and Fractal Dimensional Measurements

    NASA Technical Reports Server (NTRS)

    Harrigan, Timothy P.; Ambrose, Catherine G.; Hogan, Harry A.; Shackleford, Linda; Webster, Laurie; LeBlanc, Adrian; Lin, Chen; Evans, Harlan

    1997-01-01

    This project was aimed at making predictions of bone mechanical properties from non-invasive DXA and MRI measurements. Given the bone mechanical properties, stress calculations can be made to compare normal bone stresses to the stresses developed in exercise countermeasures against bone loss during space flight. These calculations in turn will be used to assess whether mechanical factors can explain bone loss in space. In this study we assessed the use of T2(sup *) MRI imaging, DXA, and fractal dimensional analysis to predict strength and stiffness in cancellous bone.

  18. Gene Therapy for Bone Engineering

    PubMed Central

    Balmayor, Elizabeth Rosado; van Griensven, Martijn

    2015-01-01

    Bone has an intrinsic healing capacity that may be exceeded when the fracture gap is too big or unstable. In that moment, osteogenic measures need to be taken by physicians. It is important to combine cells, scaffolds and growth factors, and the correct mechanical conditions. Growth factors are clinically administered as recombinant proteins. They are, however, expensive and needed in high supraphysiological doses. Moreover, their half-life is short when administered to the fracture. Therefore, gene therapy may be an alternative. Cells can constantly produce the protein of interest in the correct folding, with the physiological glycosylation and in the needed amounts. Genes can be delivered in vivo or ex vivo by viral or non-viral methods. Adenovirus is mostly used. For the non-viral methods, hydrogels and recently sonoporation seem to be promising means. This review will give an overview of recent advancements in gene therapy approaches for bone regeneration strategies. PMID:25699253

  19. Osedax borings in fossil marine bird bones

    NASA Astrophysics Data System (ADS)

    Kiel, Steffen; Kahl, Wolf-Achim; Goedert, James L.

    2011-01-01

    The bone-eating marine annelid Osedax consumes mainly whale bones on the deep-sea floor, but recent colonization experiments with cow bones and molecular age estimates suggesting a possible Cretaceous origin of Osedax indicate that this worm might be able grow on a wider range of substrates. The suggested Cretaceous origin was thought to imply that Osedax could colonize marine reptile or fish bones, but there is currently no evidence that Osedax consumes bones other than those of mammals. We provide the first evidence that Osedax was, and most likely still is, able to consume non-mammalian bones, namely bird bones. Borings resembling those produced by living Osedax were found in bones of early Oligocene marine flightless diving birds (family Plotopteridae). The species that produced these boreholes had a branching filiform root that grew to a length of at least 3 mm, and lived in densities of up to 40 individuals per square centimeter. The inclusion of bird bones into the diet of Osedax has interesting implications for the recent suggestion of a Cretaceous origin of this worm because marine birds have existed continuously since the Cretaceous. Bird bones could have enabled this worm to survive times in the Earth's history when large marine vertebrates other than fish were rare, specifically after the disappearance of large marine reptiles at the end-Cretaceous mass extinction event and before the rise of whales in the Eocene.

  20. Optimizing Bone Health in Duchenne Muscular Dystrophy

    PubMed Central

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

    2015-01-01

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

  1. Reduced vertebral bone density in hypercalciuric nephrolithiasis

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  2. Bone Tissue Engineering: Recent Advances and Challenges

    PubMed Central

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

    2013-01-01

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

  3. The temporal response of bone to unloading

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  4. New developments in bone densitometry

    SciTech Connect

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

    1989-04-01

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

  5. Cadmium and postmenopausal bone loss

    SciTech Connect

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

    1987-01-01

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

  6. [Silicon, bone tissue and immunity].

    PubMed

    Schiano, A; Eisinger, F; Detolle, P; Laponche, A M; Brisou, B; Eisinger, J

    1979-01-01

    The authors study the activity of a soluble salt of silicium on the evolution of the trabecular bone volume (TBV). They note a significant increase in the TBV, both in drinkable and in injectable form, in relation to a control population not receiving osteotrope medication. They moreover note, in a series of patients treated with silicium compared to a control group, a net increase in circulating lymphocytes and immunoglobulins (especially IgG). PMID:504950

  7. Decreased potassium stimulates bone resorption.

    PubMed

    Bushinsky, D A; Riordon, D R; Chan, J S; Krieger, N S

    1997-06-01

    Metabolic acidosis induces net calcium efflux (JCa+) from cultured bone, in part, through an increase in osteoclastic resorption and a decrease in osteoblastic formation. In humans provision of base as potassium (K+) citrate, but not sodium (Na+) citrate, reduces urine Ca (UCa), and oral KHCO3 decreases bone resorption and UCa in postmenopausal women. Potassium deprivation alone leads to an increase in UCa. To determine whether decreased extracellular K+ concentration ([K+]) at a constant pH, PCO2, and [HCO-3] alters JCa+ and bone cell activity, we measured JCa+, osteoblastic collagen synthesis, and osteoclastic beta-glucuronidase release from neonatal mouse calvariae cultured for 48 h in medium of varying [K+]. Calvariae were cultured in control medium (approximately 4 mM [K+]) or medium with mildly low K+ (MLK, approximately 3 mM [K+]), very low K+ (VLK, approximately 2 mM [K+]), or extremely low K+ (ELK, approximately 1 mM [K+]) (n > or = 9 in each group). Compared with control, ELK, but not MLK or VLK, resulted in a marked increase in JCa+ and an increase in beta-glucuronidase release and a decrease in collagen synthesis. JCa+ was correlated directly with medium beta-glucuronidase activity and inversely with collagen synthesis. To determine whether the reduction in medium [K+] was associated with a decrease in intracellular pH (pHi), we measured pHi in MC3T3-E1 cells, a mouse osteoblastic cell line. Incubation in 1 mM [K+] led to a significant decrease in pHi compared with 3 mM [K+]. Thus incubation in a reduced [K+] medium stimulates JCa+ and osteoclastic enzyme release and inhibits osteoblastic collagen synthesis, which may be mediated by a reduction in bone cell pH. PMID:9227639

  8. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, J.W.

    1993-01-01

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

  9. Skeletal remodelling and bone related hormones in two adults with increased bone mass.

    PubMed

    Manzke, E; Gruber, H E; Hiness, R W; Baylink, D J

    1982-01-01

    This study of two cases documents increased bone mass in a 30-yr old man and osteopetrosis in a 38-yr-old woman and examines the patients in terms of radiologic features, bone photon absorptiometry and bone biopsy analyses which include tetracycline kinetics. Both patients had elevated bone mass based on quantitative bone histology of iliac crest biopsies normal, or low PTH, and normal calcitonin values. However, they differed markedly from each other in other respects: One patient possessed significantly increased rates of bone formation and mineralization, had elevated serum alkaline phosphatase, increased total hydroxyproline over a 24 hour urine collection but displayed a normal amount of bone surface involved in resorption. The other subject had normal bone formation parameters, but had elevated serum acid phosphatase and a significantly elevated resorbing (crenated) surface. Although most theories ascribe and cause of osteopetrosis to decreased resorption, our study shows that increased bone formation, even when accompanied by normal resorption, can lead to the abnormal accumulation of bone mass. In this respect, the resorptive response of this patient was abnormal; the normal coupled relationship between bone formation and bone resorption, which ensures proper control of endosteal bone volume, had been lost. PMID:7078404

  10. Rosiglitazone induces decreases in bone mass and strength that are reminiscent of aged bone

    PubMed Central

    Lazarenko, Oxana P.; Rzonca, Sylwia O.; Hogue, William R.; Swain, Frances L.; Suva, Larry J.; Lecka-Czernik, Beata

    2007-01-01

    PPAR? regulates both glucose metabolism and bone mass. Recent evidence suggests that the therapeutic modulation of PPAR? activity with anti-diabetic thiazolidinediones elicits unwanted effects on bone. In this study, the effects of rosiglitazone on the skeleton of growing (1 month), adult (6 month), and aged (24 month) C57BL/6 mice were determined. Aging was identified as a confounding factor for rosiglitazone-induced bone loss that correlated with the increased expression of PPAR? in bone marrow mesenchymal stem cells. The bone of young growing mice was least affected, although a significant decrease in bone formation rate was noted. In both adult and aged animals bone volume was significantly decreased by rosiglitazone. In adult animals bone loss correlated with attenuated bone formation, whereas in aged animals bone loss was associated with increased osteoclastogenesis, mediated by increased RANKL expression. PPAR? activation led to changes in marrow structure and function such as a decrease in osteoblast number, an increase in marrow fat cells, an increase in osteoclast number, and a loss of the multipotential character of marrow mesenchymal stem cells. In conclusion, rosiglitazone induces changes in bone reminiscent of aged bone and appears to induce bone loss by altering the phenotype of marrow mesenchymal stem cells. PMID:17332064

  11. Bone and Calcium Metabolism During Space Flight

    NASA Technical Reports Server (NTRS)

    Smith, Scott M.

    2004-01-01

    Understanding bone loss during space flight is one of the most critical challenges for maintaining astronaut health on space exploration missions. Flight and ground-based studies have been conducted to better understand the nature and mechanisms of weightlessness-induced bone loss, and to identify a means to counteract the loss. Maintenance of bone health requires a balance between bone formation and bone resorption. Early space research identified bone loss as a critical health issue, but could not provide a distinction between the bone formation and breakdown processes. The recent identification of collagen crosslinks as markers of bone resorption has made possible a clear understanding that a decrease in bone resorption is an important effect of space flight, with bone formation being unchanged or only slightly decreased. Calcium regulatory factors have also been studied, in an attempt to understand their role in bone loss. The lack of ultraviolet light exposure and insufficient dietary sources of vitamin D often lead to reduced vitamin D stores on long-duration flights. Serum parathyroid hormone (PTH) concentrations are decreased during flight compared to before flight, although small subject numbers often make this hard to document statistically. As expected, reduced PTH concentrations are accompanied by reduced 1,25-dihydroxyvitamin D concentrations. Calcium kinetic studies during space flight confirm and extend the information gained from biochemical markers of bone metabolism. Calcium kinetic studies demonstrate that bone resorption is increased, bone formation is unchanged or decreased, and dietary calcium absorption is reduced during space flight. Evaluations have also been conducted of countermeasures, including dietary, exercise, and pharmacological treatments. In recent studies, many potential countermeasures show promise at mitigating bone loss in ground-based analogs of weightlessness (e.g., bed rest), but require further ground and flight testing to ensure that the beneficial effects are seen in space flight. As we begin to plan for missions to go back to the Moon, and even off to Mars, many questions are yet to be answered. Maintaining bone is one of the greatest challenges, but with a better understanding of the mechanical processes of bone loss, countermeasures can be designed more efficiently, and the solution (or solutions) may be just over the horizon.

  12. Onlay Bone Grafts in Head and Neck Reconstruction

    PubMed Central

    Yazar, Sukru

    2010-01-01

    Bone grafts are used in a variety of clinical situations and can be divided into two categories: treatment of bone gaps (inlay bone grafting) and bone projection (onlay bone grafting). Cortical grafts are useful in situations requiring immediate mechanical strength. These grafts can survive with or without complete revascularization or resorption and are primarily used by plastic surgeons in the treatment of bone volume deficiency. Cancellous grafts, in contrast, have no mechanical strength and therefore require additional support to bridge bone defects. Thus, they are used primarily for the treatment of bone gaps and in general revascularize quickly, resorb completely, and stimulate significant new bone formation. PMID:22550447

  13. Hydrochlorothiazide inhibits osteoclastic bone resorption in vitro.

    PubMed

    Hall, T J; Schaueblin, M

    1994-10-01

    Long-term thiazide diuretic use is associated with higher bone mineral density and reduced hip fracture rates, which are attributed to increased serum calcium levels and decreased parathyroid activity that lead to decreased bone resorption. The present study shows that 1-100 microM hydrochlorothiazide (HCTZ) dose dependently inhibits bone resorption by isolated rat osteoclasts in the bone slice assay with an IC50 of approximately 20 microM. At these concentrations, HCTZ did not affect osteoclast survival on bone slices and had no effect on the proliferation of UMR-106 rat osteoblasts, indicating that the compound is not cytotoxic. However, such concentrations of HCTZ are unlikely to be achieved in man where therapeutic doses are usually 12.5-100 mg/day. That the in vitro effect of HCTZ on bone resorption may be due to inhibition of osteoclast carbonic anhydrase is discussed. PMID:7820777

  14. Prostaglandins in Bone: Bad Cop, Good Cop?

    PubMed Central

    Blackwell, Katherine A.; Raisz, Lawrence G.; Pilbeam, Carol C.

    2010-01-01

    Prostaglandins (PGs) are multifunctional regulators of bone metabolism that stimulate both bone resorption and formation. PGs have been implicated in bone resorption associated with inflammation and metastatic bone disease and also in bone formation associated with fracture healing and heterotopic ossification. Recent studies identified roles for inducible cyclooxygenase-2 (COX-2) and PGE2 receptors in these processes. Although the effects of PGs have been most often associated with cAMP production and PKA activation, PGs can engage an extensive G-protein signaling network. Further analysis of COX-2 and PG receptors and their downstream G-protein signaling in bone could provide us with important clues to the regulation of skeletal cell growth in both health and disease. PMID:20079660

  15. Novel therapeutic targets in myeloma bone disease

    PubMed Central

    Webb, S L; Edwards, C M

    2014-01-01

    Multiple myeloma is a neoplastic disorder of plasma cells characterized by clonal proliferation within the bone marrow. One of the major clinical features of multiple myeloma is the destructive osteolytic bone disease that occurs in the majority of patients. Myeloma bone disease is associated with increased osteoclast activity and suppression of osteoblastogenesis. Bisphosphonates have been the mainstay of treatment for many years; however, their use is limited by their inability to repair existing bone loss. Therefore, research into novel approaches for the treatment of myeloma bone disease is of the utmost importance. This review will discuss the current advances in our understanding of osteoclast stimulation and osteoblast suppression mechanisms in myeloma bone disease and the treatments that are under development to target this destructive and debilitating feature of myeloma. PMID:24750110

  16. Bone Metabolism in Obesity and Weight Loss

    PubMed Central

    Shapses, Sue A.; Sukumar, Deeptha

    2014-01-01

    Excess body weight due to obesity has traditionally been considered to have a positive effect on bone; however, more recent findings suggest that bone quality is compromised. Both obesity and caloric restriction increase fracture risk and are regulated by endocrine factors and cytokines that have direct and indirect effects on bone and calcium absorption. Weight reduction will decrease bone mass and mineral density, but this varies by the individual’s age, gender, and adiposity. Dietary modifications, exercise, and medications have been shown to attenuate the bone loss associated with weight reduction. Future obesity and weight loss trials would benefit from assessment of key hormones, adipokine and gut peptides that regulate calcium absorption, and bone mineral density and quality by using sensitive techniques in high-risk populations. PMID:22809104

  17. Benign tumours of the bone: A review?

    PubMed Central

    Hakim, David N.; Pelly, Theo; Kulendran, Myutan; Caris, Jochem A.

    2015-01-01

    Benign tumours of the bone are not cancerous and would not metastasise to other regions of the body. However, they can occur in any part of the skeleton, and can still be dangerous as they may grow and compress healthy bone tissue. There are several types of benign tumours that can be classified by the type of matrix that the tumour cells produce; such as bone, cartilage, fibrous tissue, fat or blood vessel. Overall, 8 different types can be distinguished: osteochondroma, osteoma, osteoid osteoma, osteoblastoma, giant cell tumour, aneurysmal bone cyst, fibrous dysplasia and enchondroma. The incidence of benign bone tumours varies depending on the type. However, they most commonly arise in people less than 30 years old, often triggered by the hormones that stimulate normal growth. The most common type is osteochondroma. This review discusses the different types of common benign tumours of the bone based on information accumulated from published literature. PMID:26579486

  18. Regulation of bone mineral loss during lactation

    NASA Technical Reports Server (NTRS)

    Brommage, R.; Deluca, H. F.

    1985-01-01

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

  19. Vestibular Schwannoma Atypically Invading Temporal Bone

    PubMed Central

    Park, Soo Jeong; Yang, Na-Rae

    2015-01-01

    Vestibular schwannoma (VS) usually present the widening of internal auditory canal (IAC), and these bony changes are typically limited to IAC, not extend to temporal bone. Temporal bone invasion by VS is extremely rare. We report 51-year-old man who revealed temporal bone destruction beyond IAC by unilateral VS. The bony destruction extended anteriorly to the carotid canal and inferiorly to the jugular foramen. On histopathologic examination, the tumor showed typical benign schwannoma and did not show any unusual vascularity or malignant feature. Facial nerve was severely compressed and distorted by tumor, which unevenly eroded temporal bone in surgical field. Vestibular schwannoma with atypical invasion of temporal bone can be successfully treated with combined translabyrinthine and lateral suboccipiral approach without facial nerve dysfunction. Early detection and careful dissection of facial nerve with intraoperative monitoring should be considered during operation due to severe adhesion and distortion of facial nerve by tumor and eroded temporal bone. PMID:25932298

  20. Metaphyseal bone loss in revision knee arthroplasty.

    PubMed

    Ponzio, Danielle Y; Austin, Matthew S

    2015-12-01

    The etiology of bone loss encountered during revision total knee arthroplasty (TKA) is often multifactorial and can include stress shielding, osteolysis, osteonecrosis, infection, mechanical loss due to a grossly loose implant, and iatrogenic loss at the time of implant resection. Selection of the reconstructive technique(s) to manage bone deficiency is determined by the location and magnitude of bone loss, ligament integrity, surgeon experience, and patient factors including the potential for additional revision, functional demand, and comorbidities. Smaller, contained defects are reliably managed with bone graft, cement augmented with screw fixation, or modular augments. Large metaphyseal defects require more extensive reconstruction such as impaction bone grafting with or without mesh augmentation, prosthetic augmentation, use of bulk structural allografts, or use of metaphyseal cones or sleeves. While each technique has advantages and disadvantages, the most optimal method for reconstruction of large metaphyseal bone defects during revision TKA is not clearly established. PMID:26362647