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1

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

SciTech Connect

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.

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

2000-11-01

2

Revision total hip arthroplasty in patients with extensive proximal femoral bone loss using a fluted tapered modular femoral component.  

PubMed

Revision total hip arthroplasty (THA) is challenging when there is severe loss of bone in the proximal femur. The purpose of this study was to evaluate the clinical and radiographic outcomes of revision THA in patients with severe proximal femoral bone loss treated with a fluted, tapered, modular femoral component. Between January 1998 and December 2004, 92 revision THAs were performed in 92 patients using a single fluted, tapered, modular femoral stem design. Pre-operative diagnoses included aseptic loosening, infection and peri-prosthetic fracture. Bone loss was categorised pre-operatively as Paprosky types III-IV, or Vancouver B3 in patients with a peri-prosthetic fracture. The mean clinical follow-up was 6.4 years (2 to 12). A total of 47 patients had peri-operative complications, 27 of whom required further surgery. However, most of these further operations involved retention of a well-fixed femoral stem, and 88/92 femoral components (97%) remained in situ. Of the four components requiring revision, three were revised for infection and were well fixed at the time of revision; only one (1%) was revised for aseptic loosening. The most common complications were post-operative instability (17 hips, 19%) and intra-operative femoral fracture during insertion of the stem (11 hips, 12%). Diaphyseal stress shielding was noted in 20 hips (22%). There were no fractures of the femoral component. At the final follow-up 78% of patients had minimal or no pain. Revision THA in patients with extensive proximal femoral bone loss using the Link MP fluted, tapered, modular stem led to a high rate of osseointegration of the stem at mid-term follow-up. Cite this article: Bone Joint J 2015; 97-B:312-17. PMID:25737513

Amanatullah, D F; Howard, J L; Siman, H; Trousdale, R T; Mabry, T M; Berry, D J

2015-03-01

3

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

PubMed

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

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

2012-09-01

4

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

PubMed

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

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

5

Creating and Maintaining a Good Flute Embouchure  

ERIC Educational Resources Information Center

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,…

Criswell, Chad

2009-01-01

6

Entropy and the Magic Flute  

NASA Astrophysics Data System (ADS)

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.

Morowitz, Harold J.

1996-10-01

7

Heat transfer due to film condensation on vertical fluted tubes  

NASA Astrophysics Data System (ADS)

An analysis of film condensation on a vertical fluted tube has been made considering gravitational and surface tension effects over the entire fluted surface, and using surface-oriented coordinates. For the first time surface tension effects are determined, as they should, from the shape of the condensate-vapor interface rather than the shape of the flute. Two-dimensional conduction within the condensate film as well as in the fluted tube is considered. A finite-difference solution of the highly non-linear partial differential equation for the film thickness is coupled with a finite-element solution of the condition problem. The procedure has been tested on a sinusoidal flute with amplitude to pitch ratio approx. 0.2. A linear extrapolation, on a log-log basis, of our results shows good comparison with experimental data.

Garg, V. K.; Marto, P. J.

1984-07-01

8

Characteristics of a fluted nozzle gas eductor system  

NASA Astrophysics Data System (ADS)

Cold flow tests were conducted on a four nozzle and a one nozzle gas eductor system. The nozzles employed were fluted with a constant cross sectional area. The four nozzle tests used a mixing stack length-to-diameter ratio, (L/D), of 1.5; the single nozzle tests used L/D ratios of 2.0, 1.75 and 1.5. The total cross sectional area of the four fluted nozzles to the cross sectional area of the mixing stack was 2.5; for the single fluted nozzle, 2.42. Secondary pumping coefficients, mixing stack pressure distributions and exit velocity profiles were determined. The pumping performance of the four fluted nozzle system was found to be comparable to a straight nozzle system, showing no specific advantages. The single fluted nozzle system pumping performance showed a slight improvement with increased L/D. The system performance was comparable to the four straight nozzle system at the same L/D. The peak exit velocities of the single fluted nozzle system were higher than those for the four straight and four fluted nozzle systems.

Boykin, J. W.

1983-03-01

9

Flute-interchange stability in a hot electron plasma  

SciTech Connect

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.

Dominguez, R.R.

1980-01-01

10

Detailed simulation of fluted tube water heating condensers  

Microsoft Academic Search

Fluted tube-in-tube condensers are key components in advanced energy efficient water heating heat pumps. Therefore, there exists a need for a computer design tool that incorporates all the essential features of these heat exchangers. This paper describes the development of a detailed model to simulate fluted tube refrigerant-to-water condensers. The model allows the surface area to be divided into any

P. G. Rousseau; M. van Eldik; G. P. Greyvenstein

2003-01-01

11

Automatic search for wheel position in flute grinding of cutting tools  

Microsoft Academic Search

The profile of helical flutes has a great influence on properties of cutting tools. This paper presents an automatic method of searching for a wheel position in flute grinding for a given shape of the helical flute and grinding wheel profile. The algorithm is based on the main loop and two subroutines. The first algorithm is dedicated to the simulation

B. Karpuschewski; K. Jandecka; D. Mourek

2011-01-01

12

Evaluation of Analysis Techniques for Fluted-Core Sandwich Cylinders  

NASA Technical Reports Server (NTRS)

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.

Lovejoy, Andrew E.; Schultz, Marc R.

2012-01-01

13

Musica II: Torsion Drum, Buzzer, Maraca, Chirper, Flute  

NSDL National Science Digital Library

In this activity, learners use common household items to build musical instruments. This lesson guide includes step-by-step instructions for building five instruments: a torsion drum; buzzer; maraca; chirper; and flute. Basic tools including a drill and clamp are required. Use this activity to help learners explore elements of sound like vibration, sound waves, pitch, amplitude and volume.

Watsonville Environmental Science Workshop

2011-01-01

14

Fluid mechanics and heat transfer spirally fluted tubing  

Microsoft Academic Search

The objective of this program is to develop an understanding of the fluid mechanics and heat transfer mechanisms that result in the demonstrated performance of the spiral fluted tubing under development at GA Technologies Inc. Particularly emphasized are the processes that result in the augmentation of the heat transfer coefficient without an increase in friction coefficient in the single-phase flow.

J. S. Yampolsky; P. A. Libby; B. E. Launder; J. C. Larue

1984-01-01

15

Kristina Sorensen Acoustics of a Rotating Grand Piano & the Flute  

E-print Network

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

Hart, Gus

16

Compression Behavior of Fluted-Core Composite Panels  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

17

Analysis of Lithic Debitage from Fluted Point Sites in Ontario  

Microsoft Academic Search

This thesis is concerned with the interpretation of lithic debitage from two fluted point sites in Ontario: the Park-hill and McLeod sites. Given the extremely homogenous nature of the debitage collections, a typological analysis was undertaken. Explanation of the variability between debitage attribute clusters (i.e. debitage types) is based on two factors, namely, the types of tools being altered and

Christopher John Ellis

1979-01-01

18

Characteristics of a fluted nozzle gas eductor system  

Microsoft Academic Search

Cold flow tests were conducted on a four nozzle and a one nozzle gas eductor system. The nozzles employed were fluted with a constant cross sectional area. The four nozzle tests used a mixing stack length-to-diameter ratio, (L\\/D), of 1.5; the single nozzle tests used L\\/D ratios of 2.0, 1.75 and 1.5. The total cross sectional area of the four

J. W. Boykin

1983-01-01

19

Utilization of fluted pumpkin fruit (Telfairia occidentalis) in marmalade manufacturing.  

PubMed

Marmalade was produced from fluted pumpkin (Telfairia occidentalis) fruit. The fruit was pulped, boiled and filtered to obtain pectin extract. The extract was boiled at 102 degrees C for 30 min with the pH and sugar levels adjusted to 3.2 and 68.5 degrees Brix, respectively. Fruit shreds were added towards the end of boiling. Results of analyses showed that the pulp is rich in Na, K, Fe, P, Mn and pectin (1.01%), but low in protein (0.86%). The marmalade had a firm gel and was acidic (pH 3.15). Mold was absent and syneresis did not occur. The marmalade contained 68.5% total soluble solids and set at 52-56 degrees C. Sensory evaluation showed no significant difference (p = 0.05) in taste, consistency, spreadability and overall acceptability between fluted pumpkin marmalade and commercial orange marmalade. Both chemical and sensory results denote that the marmalade was highly desirable and compared favourably with similar preserves produced in Nigeria. PMID:9839816

Egbekun, M K; Nda-Suleiman, E O; Akinyeye, O

1998-01-01

20

Life history of the fluted kidneyshell ptychobranchus subtentum  

USGS Publications Warehouse

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.

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

2012-01-01

21

An Efficient Analysis Methodology for Fluted-Core Composite Structures  

NASA Technical Reports Server (NTRS)

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.

Oremont, Leonard; Schultz, Marc R.

2012-01-01

22

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2013-04-29

23

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

PubMed

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

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

2009-06-10

24

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

25

Investigation of the nonlinear stage of driftr flute turbulence in a high bet a plasma in the presence of temperature gradient effects  

Microsoft Academic Search

Summary form only given. Nonlinear stage of instability of flute modes in a plasma with non-uniform density and temperature is investigated on the scales arbitrary to the ion Larmor radius. Nonlinear equations describing the interaction of small-scale flute turbulence with large scale zonal structures and the evolution of the zonal structures are derived. Flute modes can be responsible for the

J. Kindel; V. I. Sotnikov; O. G. Onishchenko; E. Yasin; J. N. Leboeuf

2009-01-01

26

Flute instability growth on a magnetized plasma column.  

SciTech Connect

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.

Genoni, Thomas C. (Voss Scientific, Albuquerque, NM); Rose, David Vincent (Voss Scientific, Albuquerque, NM); Ditmire, T. (University of Austin, Austin, Texas); Mehlhorn, Thomas Alan; Welsh, D. R. (Voss Scientific, Albuquerque, NM); Porter, John Larry, Jr.

2006-01-01

27

Flute instability growth on a magnetized plasma column.  

SciTech Connect

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.

Genoni, Thomas C. (Voss Scientific, LLC, Albuquerque, NM); Welch, Dale Robert (Voss Scientific, LLC, Albuquerque, NM); Ditmire, T. (University of Texas at Austin, Austin, TX); Rose, David Vincent (Voss Scientific, LLC, Albuquerque, NM); Mehlhorn, Thomas Alan; Porter, John Larry, Jr.

2006-08-01

28

Flute instability growth on a magnetized plasma column  

SciTech Connect

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.

Rose, D. V.; Genoni, T. C.; Welch, D. R.; Mehlhorn, T. A.; Porter, J. L.; Ditmire, T. [Voss Scientific, LLC, Albuquerque, New Mexico 87108 (United States); Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); University of Texas at Austin, Austin, Texas 78712 (United States)

2006-09-15

29

Radial mode coupling saturation of a flute mode  

NASA Astrophysics Data System (ADS)

The structure and properties of a centrifugal flute mode driven by E × B rotation of a plasma column have been studied experimentally and theoretically. This mode appears as a single mode (m = 1, kicons/Journals/Common/parallel" ALT="parallel" ALIGN="MIDDLE"/> = 0). The bispectral analysis of the mode clearly indicates strong three-wave coupling in the narrow spectral width of the mode. The amplitudes of the individual frequencies across the plasma cross section are also tracked, giving the radial structure of different frequency amplitudes. Frequencies with self-similar radial structures are grouped together to belong to the same radial harmonic. Clearly, these radial harmonics contribute to the spectral width. These observations suggest that the nonlinear mode coupling between these radial harmonics is the saturation mechanism, as well as the underlying cause of anomalous transport. Prompted by the above observations a three-wave nonlinear coupling model using radial harmonics has been formulated. A proper treatment of two-dimensional (azimuthal and radial) nature of the polarization drift nonlinearity and the inclusion of damped radial harmonics to insure a steady-state have been done. The analysis reveals the generation of damped higher-order radial harmonics by the unstable fundamental radial harmonic, which is the saturation mechanism. The resulting root mean square fluctuation and levels of higher harmonic generation are in fair agreement with the experimental observations.

Ponomarev, A.; Sen, A. K.

1999-12-01

30

Mid term results with the curved modular tapered, fluted titanium Revitan stem in revision hip replacement.  

PubMed

We report our experience of revision total hip replacement (THR) using the Revitan curved modular titanium fluted revision stem in patients with a full spectrum of proximal femoral defects. A total of 112 patients (116 revisions) with a mean age of 73.4 years (39 to 90) were included in the study. The mean follow-up was 7.5 years (5.3 to 9.1). A total of 12 patients (12 hips) died but their data were included in the survival analysis, and four patients (4 hips) were lost to follow-up. The clinical outcome, proximal bone regeneration and subsidence were assessed for 101 hips. The mean Harris Hip Score was 88.2 (45.8 to 100) after five years and there was an increase of the mean Barnett and Nordin-Score, a measure of the proximal bone regeneration, of 20.8 (-3.1 to 52.7). Five stems had to be revised (4.3%), three (2.9%) showed subsidence, five (4.3%) a dislocation and two of 85 aseptic revisions (2.3%) a periprosthetic infection. At the latest follow-up, the survival with revision of the stem as the endpoint was 95.7% (95% confidence interval 91.9% to 99.4%) and with aseptic loosening as the endpoint, was 100%. Peri-prosthetic fractures were not observed. We report excellent results with respect to subsidence, the risk of fracture, and loosening after femoral revision using a modular curved revision stem with distal cone-in-cone fixation. A successful outcome depends on careful pre-operative planning and the use of a transfemoral approach when the anatomy is distorted or a fracture is imminent, or residual cement or a partially-secured existing stem cannot be removed. The shortest appropriate stem should, in our opinion, be used and secured with > 3 cm fixation at the femoral isthmus, and distal interlocking screws should be used for additional stability when this goal cannot be realised. PMID:24986941

Fink, B; Urbansky, K; Schuster, P

2014-07-01

31

Generation and saturation of large-scale flows in flute turbulence  

SciTech Connect

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.

Sandberg, I.; Isliker, H.; Pavlenko, V. P.; Hizanidis, K.; Vlahos, L. [School of Electrical and Computer Engineering, National Technical University of Athens, GR-157 73 Athens (Greece); Department of Physics, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece); Department of Physics, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece); Department of Astronomy and Space Physics, Uppsala University, Box 515, SE-751 20 Uppsala (Sweden); School of Electrical and Computer Engineering, National Technical University of Athens, GR-157 73 Athens (Greece); Department of Physics, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki (Greece)

2005-03-01

32

New Music Ensemble Assistantship Audition Information Flute Clarinet Percussion Piano Violin Cello  

E-print Network

New Music Ensemble ­ Assistantship Audition Information Flute ­ Clarinet ­ Percussion ­ Piano by Udow/Watts Piano Memorization of this part of the audition is optional. Auditionees will be evaluated in sightreading beyond the MM audition level. No prepared piano pieces will be approved for this audition. Berio

Taylor, Jerry

33

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

ERIC Educational Resources Information Center

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…

Kacanek, Hal

2011-01-01

34

Design and analysis of a 5-MW vertical-fluted-tube condenser for geothermal applications  

SciTech Connect

The design and analysis of an industtial-sized vertical-fluted-tube condenser. The condenser is used to condense superheated isobutane vapor discharged from a power turbine in a geothermal test facility operated for the US Department of Energy. The 5-MW condenser has 1150 coolant tubes in a four-pass configuration with a total heat transfer area of 725 m/sup 2/ (7800 ft/sup 2/). The unit is being tested at the Geothermal Components Test Facility in the Imperial Valley of East Mesa, California. The condenser design is based on previous experimental research work done at the Oak Ridge National Laboratory on condensing refrigerants on a wide variety of single vertical tubes. Condensing film coefficients obtained on the high-performance vertical fluted tubes in condensing refrigerants are as much as seven times greater than those obtained with vertical smooth tubes that have the same diameter and length. The overall heat transfer performance expected from the fluted tube condenser is four to five times the heat transfer obtained from the identical units employing smooth tubes. Fluted tube condensers also have other direct applications in the Ocean Thermal Energy Conversion (OTEC) program in condensing ammonia, in the petroleum industry in condensing light hydrocarbons, and in the air conditioning and refrigeration industry in condensing fluorocarbon vapors.

Llewellyn, G.H.

1982-03-01

35

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

E-print Network

severe deepbite. Following this initial report, many clinical studies were performed using endosseous implants for orthodontic purposes, with various degrees of success.14-16 The use of endosseous dental implants for absolute anchorage was promising... that approximately 91% of orthodontists had experience placing MSIs.19 A number of published reports highlight successful treatment outcomes with the use of orthodontic MSIs.20, 21 In a randomized controlled trial of forty patients with bialveolar dental...

Truong, An Van

2014-04-22

36

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

NASA Astrophysics Data System (ADS)

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.

Terrien, Soizic; Vergez, Christophe; Fabre, Benoît

2013-07-01

37

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

PubMed

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

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

2014-09-01

38

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 ...

39

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

PubMed Central

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

2014-01-01

40

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

NASA Technical Reports Server (NTRS)

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.

Cattell, C.; Hudson, M.

1982-01-01

41

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

42

Influence Of Finite Larmor Radius Effects On Development Of Drift Flute Turbulence With The Presence Of Ion Temperature Gradient  

Microsoft Academic Search

Investigation of flute mode instability in the presence of ion temperature gradient effects will be presented. The approached used in this study allows to analyze spatial scales comparable with the ion Larmor radius. Linear analysis of this system shows that the range of unstable wavelengths in a plasma with large ion charge numbers extends into the region of spatial scales

Essam Yasin; V. Sotnikov; J. Kindel; O. G. Onishchnko; J. N. Leboeuf

2010-01-01

43

Adsorption of transition metals in aqueous solutions by fluted pumpkin (Telfairia occidentalis Hook f) waste.  

PubMed

The adsorption of some divalent transition metal (Hg, Rh, Pt, and Pd) ions in aqueous solution onto fluted pumpkin waste biomass has been investigated. The data were discussed in terms of ionic radii, surface area, and the hard-soft acid-base (HSAB) concept. The monolayer sorption capacities as obtained by the Langmuir adsorption isotherm model were determined to be ca. 9.89 mg/g, 9.81 mg/g, 10.59 mg/g, and 6.84 mg/g for for Hg(II), Rh(II), Pt(II), and Pd(II), respectively. The results are relevant for the optimal design of a wastewater treatment plant and for prediction of model parameters of sorbate-sorbent interactions. PMID:17193209

Horsfall, Michael; Spiff, Ayebaemi Ibuteme

2005-09-01

44

Kinetics of ascorbic acid loss during hot water blanching of fluted pumpkin (Telfairia occidentalis) leaves.  

PubMed

The kinetics of thermal degradation of ascorbic acid in fluted pumpkin leaves were investigated from 60 to 90°C (pH 5.0 to 6.5). Ascorbic acid degradation was modeled as a first order rate reaction with the rate constants increasing with increase in pH of the medium. The pH and temperature dependence of the rates of destruction gave highly significant correlations when analyzed by the thermal resistance and activated complex reaction rate methods. Activation energy (Ea) ranged from 41.2 to 18.2 kJ/mol while D-values ranged from 103.3 to 22.4 min. The changes in activation energy affected Ko values which ranged from 5.98?×?10(4) to 41.7 min(-1). PMID:23572770

Ariahu, Charles C; Abashi, Diana K; Chinma, Chiemela Enyinnaya

2011-08-01

45

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 ...

46

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

NASA Technical Reports Server (NTRS)

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.

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

47

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

PubMed

Fluted pumpkin (Telfairia occidentalis) is a minimally-processed green leafy vegetable traditionally used for its antianaemic properties in the form of leaf juice without a heating or inactivation step before consumption. The aim of the study was to assess the presence of surface microbiota on T. occidentalis leaves and also to determine the antimicrobial susceptibility of isolated organisms. Bacterial contaminants on 50 samples of T. occidentalis leaves were isolated and characterized using standard biochemical methods and the antimicrobial susceptibility of isolated organisms was determined using the antibiotic disc diffusion assay. The results obtained show that the leaves of T. occidentalis is contaminated with organisms which included Enterobacter agglomerans (25.9%), Proteus vulgaris (24.9%), Klebsiella spp. (2.6%), and Serratia liquefaciens (2.1%). Other bacterial isolates recovered in order of frequency included: Staphylococcus spp. (33.7%), Bacillus spp. (8.3%), and Pseudomonas fluorescens (2.6%). Of the 193 bacterial isolates from the leaves of T. occidentalis samples tested for antimicrobial resistance, all (100%) were found to be resistant to ampicillin, cloxacillin, augmentin, erythromycin, and tetracycline while 96% of the isolates were resistant to cephalothin. Resistance to trimethoprim (93%) and gentamicin (83%) was also observed. Approximately, 22% of the isolates were resistant to ciprofloxacin; however, only 11 (5.8%) were resistant to ofloxacin. Thus, uncooked T. occidentalis is a potential source of highly-resistant epiphytic bacteria which could be opportunistic pathogens in consumers. PMID:25076655

Igbeneghu, Oluwatoyin A; Abdu, Abdulrasheed B

2014-06-01

48

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

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

49

Multiple Antibiotic-resistant Bacteria on Fluted Pumpkin Leaves, a Herb of Therapeutic Value  

PubMed Central

ABSTRACT Fluted pumpkin (Telfairia occidentalis) is a minimally-processed green leafy vegetable traditionally used for its antianaemic properties in the form of leaf juice without a heating or inactivation step before consumption. The aim of the study was to assess the presence of surface microbiota on T. occidentalis leaves and also to determine the antimicrobial susceptibility of isolated organisms. Bacterial contaminants on 50 samples of T. occidentalis leaves were isolated and characterized using standard biochemical methods and the antimicrobial susceptibility of isolated organisms was determined using the antibiotic disc diffusion assay. The results obtained show that the leaves of T. occidentalis is contaminated with organisms which included Enterobacter agglomerans (25.9%), Proteus vulgaris (24.9%), Klebsiella spp. (2.6%), and Serratia liquefaciens (2.1%). Other bacterial isolates recovered in order of frequency included: Staphylococcus spp. (33.7%), Bacillus spp. (8.3%), and Pseudomonas fluorescens (2.6%). Of the 193 bacterial isolates from the leaves of T. occidentalis samples tested for antimicrobial resistance, all (100%) were found to be resistant to ampicillin, cloxacillin, augmentin, erythromycin, and tetracycline while 96% of the isolates were resistant to cephalothin. Resistance to trimethoprim (93%) and gentamicin (83%) was also observed. Approximately, 22% of the isolates were resistant to ciprofloxacin; however, only 11 (5.8%) were resistant to ofloxacin. Thus, uncooked T. occidentalis is a potential source of highly-resistant epiphytic bacteria which could be opportunistic pathogens in consumers. PMID:25076655

Abdu, Abdulrasheed B.

2014-01-01

50

Rubber Bones  

NSDL National Science Digital Library

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

Children's Museum of Houston

2011-01-01

51

Bone Density  

MedlinePLUS

... Not everyone who has low bone mass gets osteoporosis. But everyone with low bone mass is at higher risk for getting it. If you have low bone mass, there are things you can do to help slow down bone loss. These include eating foods rich in calcium and vitamin D and doing ...

52

Whale bones  

NSDL National Science Digital Library

Vertebrates, or animals that have a skeletal structure for body support, leave bones behind after their death. These bones can be placed together to recreate the skeletal frame of that animal. Bones can be examined to determine what animal the bones came from.

N/A N/A (Go Card USA; )

2007-12-21

53

Hypolipidemic effect of Telfairia occidentalis (fluted pumpkin) in rats fed a cholesterol-rich diet.  

PubMed

Telfairia occidentalis (fluted pumpkin) is one of the commonly consumed leafy vegetables in Nigeria. In order to justify its inclusion in herbal preparations in African traditional medicine, the possible hypolipidemic effect of this vegetable was investigated in rats fed a cholesterol-rich diet. The ability of Questran, a hypolipidemic drug, to attenuate hypercholesterolemia was also examined. Rats were fed with either a basal diet containing cholic acid (0.2%) or a supplemented diet with T. occidentalis at the 3% and 6% levels. Oral administration of cholesterol for 9 consecutive weeks resulted in a significant increase (P < .001) in the relative weight of the heart of cholesterol-fed rats. However, supplemented diets significantly (P < .001) ameliorated the cholesterol-induced enlargement of the heart. Rats fed on supplemented diets had a dose-dependent reduction in plasma and postmitochondrial supernatant fraction (PMF) cholesterol levels. In particular, supplemented diets containing 3% and 6% T. occidentalis decreased plasma and PMF cholesterol levels by 20% and 30% and by 30% and 45%, respectively. A similar decrease in plasma and PMF cholesterol levels was obtained in Questran-treated hypercholesterolemic rats. Furthermore, 3% and 6% T. occidentalis-supplemented diets significantly (P < .05) decreased the cholesterol-induced increase in plasma and PMF low-density lipoprotein (LDL) cholesterol levels by 24% and 48% and by 28% and 52%, respectively. In contrast, there was no significant difference (P > .05) in plasma and PMF triglyceride levels of rats fed on supplemented diets when compared with cholesterol-fed rats. There were significant decreases (P < .05) in lipid peroxidation levels in rats fed on the supplemented diets. Specifically, 3% and 6% T. occidentalis-supplemented diets decreased plasma and PMF lipid peroxidation by 24% and 20% and by 42% and 21%, respectively. This study demonstrates that T. occidentalis may be a useful therapy for hypercholesterolemia through reducing oxidative stress and cholesterol levels. PMID:17651070

Adaramoye, O A; Achem, J; Akintayo, O O; Fafunso, M A

2007-06-01

54

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

PubMed Central

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

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

2013-01-01

55

Recruitment constraints in Singapore's fluted giant clam (Tridacna squamosa) population--a dispersal model approach.  

PubMed

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

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

2013-01-01

56

Bone Crusher  

NSDL National Science Digital Library

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

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

57

Living Bones, Strong Bones  

NSDL National Science Digital Library

In this activity about engineering, nutrition, and physical activity, learners design and build a healthy bone model of a space explorer which is strong enough to withstand increasing amounts of weight. This activity contains several engaging mini-activities and stresses the importance of the scientific method. Learners can complete this activity as part of NASA's Fit Explorer Challenge, in which learners train like astronauts, set goals, track their progress, and accumulate points to progress through Exploration Levels and earn certificates.

NASA Johnson Space Center

2012-06-26

58

Bone tumor  

MedlinePLUS

... exam. Tests that may be done include: Alkaline phosphatase blood level Bone biopsy Bone scan Chest x- ... affect the results of the following tests: Alkaline phosphatase isoenzyme Blood calcium level Parathyroid hormone Blood phosphorus ...

59

Bone Analyzer  

NASA Technical Reports Server (NTRS)

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

1985-01-01

60

Bone Basics  

NSDL National Science Digital Library

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

Twin Cities Public Television, Inc.

2008-01-01

61

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

PubMed

In vitro protein digestibility, chemical composition and selected functional properties of flours and protein concentrates prepared from raw, fermented and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds were studied. Protein concentrates prepared by an alkaline extraction process had increased crude protein contents (61.5-70.8%) compared to flour samples (46.4-52.7%). The yields of protein concentrates ranged from 24.5% to 29.4% while values for protein recoveries varied between 64.8% and 65.2%. Protein concentrates also had increased foam volume and decreased foam stability (100% decrease over a 2 h period), compared to flour samples. Fermentation and germination were observed to significantly (p < 0.05) lower polyphenol and phytic acid contents, but increased protein digestibility of fluted pumpkin seed flours and concentrates. Both raw flour and concentrate were significantly (p < 0.05) higher in water absorption capacity than germinated or fermented flours and concentrates. Protein concentrates had comparatively better fat absorption properties than the flour samples. Hence protein concentrates may prove to have useful applications in ground meat formulations. PMID:10646631

Giami, S Y; Isichei, I

1999-01-01

62

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

PubMed Central

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

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

2012-01-01

63

Bone Densitometry (Bone Density Scan)  

MedlinePLUS

... In some communities, a CT scan with special software can also be used to diagnose or monitor ... patient's bone mineral density. DXA machines feature special software that compute and display the bone density measurements ...

64

Proc. International Symposium on Musical Acoustics, Perugia (2001). D.Bonsi, D.Gonzalez, D.Stanzial, eds. THE BAROQUE AND CLASSICAL FLUTES  

E-print Network

Proc. International Symposium on Musical Acoustics, Perugia (2001). D.Bonsi, D.Gonzalez, D of the features of these in terms of their acoustic impedance. Because flutes are open at the air jet, the minima of these instruments. In most fingerings, the effect of a series of open holes is to produce a 'cut off filter', which

New South Wales, University of

65

Pathologies o Bone Fracture and Bone Repair  

E-print Network

1 Bone Pathologies o Bone Fracture and Bone Repair o Degenerative Changes Associated with Aging o (Bone Cancer) o Paget's Disease o Overuse Damage (Stress Fractures) o Considerations for Bioengineers TOPICS 1 Bone Fracture and Bone Repair A radiograph of a torsional bone fracture from a skiing accident

Gefen, Amit

66

Bendy Bones  

NSDL National Science Digital Library

In this activity (on pages 19-24 of PDF), learners soak chicken bones or eggshells in vinegar for several days. Learners observe what happens to the material as the acid dissolves the calcium that provides the strength to the material. The lesson includes information about calcium, calcium-rich foods that keep bones strong, and an explanation of how the acidic vinegar solution causes the bone or eggshell to become weak.

2012-06-26

67

Bear Bones  

NSDL National Science Digital Library

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

Science Update

2004-03-08

68

Talking Bones.  

ERIC Educational Resources Information Center

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)

Johnson, Jaclyn; Kassing, Sharon

2002-01-01

69

Talking Bones  

NSDL National Science Digital Library

Bones reveal many facts about the animals from which they come, making them a great hands-on educational tool. For several years, the Saint Louis Zoo has offered a summer course on bones, where children in grades three to five learn how animals move, what

Jaclyn Johnson

2002-09-01

70

Changes in nitrogenous and other chemical constituents, protein fractions and in vitro protein digestibility of germinating fluted pumpkin (Telfairia occidentalis Hook) seed.  

PubMed

The effect of 7 days of germination on levels of nitrogenous and other nutrition related parameters, protein fractions and in vitro protein digestibility of fluted pumpkin (Telfairia occidentalis) seed was studied. The non-protein nitrogen gradually increased and the protein nitrogen content decreased during germination. Albumin and globulin fractions were found to be the major seed proteins of fluted pumpkin seeds, constituting about 58.6% of the total protein of the ungerminated (raw) seeds. The protein fractions, albumin and glutelin, were observed to increase by 61.5% and 57.0%, respectively, while a 54.6% decrease was noted in the prolamine fraction. The globulin fraction increased at the beginning of germination but decreased at the end. Germination significantly (p< or =0.05) increased the crude protein, nitrogen solubility and in vitro protein digestibility but decreased the fat, phytic acid and polyphenol contents of the seeds. PMID:10540985

Giami, S Y; Chibor, B S; Edebiri, K E; Achinewhu, S C

1999-01-01

71

Bone Identification  

NSDL National Science Digital Library

This activity (page 3 of the PDF) is a full inquiry investigation into fossil hunting and identification. Groups of learners will sift through a commercially prepared owl pellet, looking for bone pieces that they will attempt to match to an identification chart and subsequently arrange into a rough skeleton. Learners use this exercise to consider how animal skeletons help researchers determine what kinds of animals live together in an ecosystem as well compare the bones they find to the bones in their own body. Relates to linked video, DragonflyTV GPS: Dinosaurs.

Twin Cities Public Television, Inc.

2006-01-01

72

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 ...

73

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

PubMed

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

Haynes, C V

1964-09-25

74

Bone marrow transplant  

MedlinePLUS

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

75

Sorption of lead, cadmium, and zinc on sulfur-containing chemically modified wastes of fluted pumpkin (Telfairia occidentalis Hook f.).  

PubMed

We have tested the applicability of regular as well as sulfanylacetic acid (SA) modified fluted pumpkin waste biomass as adsorbents for Pb2+, Cd2+, and Zn2+ aqueous solutions by means of the batch-sorption technique. The data revealed that SA modification produces a larger surface area, enhancing the metal-ion binding capacity of the biomass. The sorption process was examined by means of Freundlich and Langmuir models. The kinetic study showed that the sorption rates can be described by a pseudo-second-order process. The rate constants for the control biomass (CB) were 2.2x10(-2), 4.4x10(-2), and 1.6x10(-2) mg g(-1) min(-1) for Pb2+, Cd2+, and Zn2+, respectively; and the corresponding rate constants for the SA-modified biomass were 4.0x10(-2), 4.7x10(-2), and 1.7x10(-2) mg g(-1) min(-1), respectively. Thermodynamic considerations indicated a spontaneous exothermic process, which implies that physisorption is the main mechanism in the sorption process. PMID:17191986

Horsfall, Michael; Spiff, Ayebaemi I

2005-03-01

76

[Bone transplant].  

PubMed

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

San Julián, M; Valentí, A

2006-01-01

77

Bone Stress  

NSDL National Science Digital Library

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

The Exploratorium

2011-12-07

78

Bone Tumor  

MedlinePLUS

... taken for other reasons, such as a sprained ankle or rotator cu? problem. Doctor Examination If you think you might have a bone tumor, see your doctor as soon as possible for diagnosis and treatment. Occasionally, infection, stress fractures, and other non-tumor conditions can closely resemble ...

79

From Bone Biology to Bone Analysis  

Microsoft Academic Search

Bone development is one of the key processes characterizing childhood and adolescence. Understanding this process is not only important for physicians treating pediatric bone disorders, but also for clinicians and researchers dealing with postmenopausal and senile osteoporosis. Bone densitometry has great potential to enhance our understanding of bone development. The usefulness of densitometry in children and adolescents would be increased

E. Schoenau; G. Saggese; F. Peter; G. I. Baroncelli; N. J. Shaw; N. J. Crabtree; Z. Zadik; C. M. Neu; C. Noordam; G. Radetti; Z. Hochberg

2004-01-01

80

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

PubMed Central

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

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

2014-01-01

81

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

PubMed

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

Oboh, Ganiyu

2005-01-01

82

Buried Bones  

NSDL National Science Digital Library

In this activity, pairs of learners will create two make-believe dig sites by burying chicken bones in plaster of Paris--a powder that hardens when wet. Then, learners try to excavate (dig out) their partner's "fossils." Learners will discover that excavating fossils requires skill, patience, and the right tools. Note: this activity requires adult supervision as working with plaster of Paris can be dangerous if not done properly.

2012-06-26

83

Bone Densitometry  

NSDL National Science Digital Library

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

Patient Education Institute

84

ABSTRACT Title of dissertation: CHAMBER MUSIC IN FRANCE FEATURING FLUTE AND SOPRANO, 1850-1950, AND A STUDY OF THE INTERACTIONS AMONG THE LEADING FLUTISTS, SOPRANOS, COMPOSERS, ARTISTS, AND LITERARY FIGURES OF THE TIME  

E-print Network

This dissertation, together with the accompanying recital recordings, constitute an examination of chamber music for flute, soprano, and piano and for flute, soprano, and chamber ensemble written by French composers between 1850 and 1950. This examination includes an annotated bibliography of the music, a written document studying the interactions of the leading flutists, sopranos, composers, artists, and literary figures of the time, and two recitals of representative works from the repertoire of about 120 minutes, which were recorded during performances at University of Maryland in March of 2004. The text examines the various types of chamber works written during this period for flute and soprano, with and without additional accompaniment. The amount of repertoire written for flute and voice during this period by composers of a single nationality is exceptional in the history of music. The annotated bibliography lists about 100 pieces in the genre, a truly substantial repertoire. As a performer, I was intrigued by the possibility that several generations of highly gifted, individualistic performers may have inspired these composers to produce

Susan Nanette Hayes

85

Osteoporosis: The Bone Thief  

MedlinePLUS

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

86

Bone lesion biopsy  

MedlinePLUS

Benign (noncancerous) bone tumors include: Bone cyst Fibroma Osteoblastoma Osteoid osteoma Cancerous tumors include: Ewing sarcoma Multiple myeloma Osteosarcoma Other types of cancer that may have spread to the bone Abnormal ...

87

What Is Bone Cancer?  

MedlinePLUS

... 1,800 pounds of pressure to break the femur (thigh bone). The bone itself contains 2 kinds ... lymphoma of the bone is often a widespread disease because multiple sites in the body are usually ...

88

Dinosaur Bone Experiments  

NSDL National Science Digital Library

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

2013-11-07

89

Mechanisms of bone metastasis.  

PubMed

Extract: Cancer frequently spreads to bone, a process termed bone metastasis. Up to 70% of patients with breast cancer or prostate cancer, and 15 to 30% of patients with lung, colon, bladder or kidney cancer develop bone metastasis. Once tumors go to bone, such as in patients with breast cancer or prostate cancer, they are incurable, and only 20% of patients with breast cancer are still alive five years after they are found to have bone metastasis. It is estimated that about 350,000 people die with bone metastasis each year in the United States. Bone metastasis causes severe bone pain and can result in fractures without any injury, as well as other life-threatening conditions. There are two major types of bone metastasis, one in which bone destruction is the predominant feature and the other one in which new bone formation is predominant. Bone metastasis where bone destruction is the predominant feature is known as osteolytic, and that in which new bone formation is the primary feature is called osteoblastic. This classification for metastasis is really two extremes of a continuum because many patients can have both osteolytic and osteoblastic or mixtures of both in their bone metastasis. In fact, patients with prostate cancer who usually have bone metastasis that shows increased new bone formation also have increased bone destruction in the same lesions. PMID:20704976

Roodman, G David

2004-06-01

90

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

91

Histological analysis of bone.  

PubMed

Bone is an important target tissue for alcohol. Moderate alcohol consumption may slow bone loss during aging, but alcohol consumption inhibits bone growth during adolescence, and alcohol abuse in adults is an important risk factor for osteoporosis. Various techniques have been applied for evaluating the impact of alcohol on bone, including densitometry for assessment of bone mass and density, computed tomography for evaluation of bone microarchitecture, serum biochemistry for measurement of markers of global bone resorption and formation, and histomorphometry for assessment of cellular activity. Of these methods, histomorphometry is the gold standard for assessing bone because it is the only method for the direct in situ analysis of bone cells and their activities. The procedures described in this chapter provide tools for the histomorphometric characterization of the effects of alcohol on cancellous and cortical bone growth and turnover. Specifically detailed are processes for embedding, cutting, staining, and evaluating histological bone specimens with a focus on rodent models. PMID:18369927

Iwaniec, Urszula T; Wronski, Thomas J; Turner, Russell T

2008-01-01

92

Gaucher disease and bone  

Microsoft Academic Search

Gaucher disease (GD) is an inherited lysosomal storage disorder affecting multiple organs. Non-neuronopathic GD, the most common form, can present with hepatosplenomegaly, anaemia, bleeding tendencies, thrombocytopenia, skeletal pathologies, growth retardation and, in severe cases, with pulmonary disease. The bone manifestations include bone infarcts, avascular bone necrosis, lytic lesions, osteosclerosis, fractures due to osteoporosis and, rarely, acute osteomyelitis. Bone pain of

P. Mikosch

93

Sex Steroids and Bone  

Microsoft Academic Search

The adult skeleton is periodically remodeled by temporary anatomic structures that comprise juxtaposed osteoclast and osteoblast teams and replace old bone with new. Estrogens and androgens slow the rate of bone remodeling and protect against bone loss. Conversely, loss of estrogen leads to increased rate of remodeling and tilts the balance between bone resorption and formation in favor of the

S. C. MANOLAGAS; S. K OUSTENI; R. L. JILKA

2010-01-01

94

Ultrasound simulation in bone  

Microsoft Academic Search

The manner in which ultrasound interacts with bone is of key interest in therapy and diagnosis alike. These may include applications directly to bone, as, for example, in treatment to accelerate the healing of bone fractures and in assessment of bone density in osteoporosis, or indirectly in diagnostic imaging of soft tissue with interest in assessing exposure levels to nearby

Jonathan J. Kaufman; Gangming Luo; Robert S. Siffert

2008-01-01

95

Bone grafts in dentistry  

PubMed Central

Bone grafts are used as a filler and scaffold to facilitate bone formation and promote wound healing. These grafts are bioresorbable and have no antigen-antibody reaction. These bone grafts act as a mineral reservoir which induces new bone formation. PMID:23946565

Kumar, Prasanna; Vinitha, Belliappa; Fathima, Ghousia

2013-01-01

96

[Bone and androgens].  

PubMed

Sexual steroids are major determinants of skeletal maturation and steady state. Estrogens are mandatory in both sexes. They induce endochondral bone formation and growth plate knitting. Androgens are mainly active in male. They increase length and radial bone growth. These differences explain the duality of biomechanics in both sexes. Deep androgen deficiency induces rapid bone loss and increases bone fracture risk. The androgen treatment of andropause has weak rationale. Androgens interact with bone metabolism within the medulla-bone unit. They activate the whole osteoblastic lineage and interact with preosteoclastic regulation. Androgens found their place in bone metabolism regulation through RANK/osteoprotegerin and Wnt/sclerostin pathways. PMID:24332181

Weryha, Georges; Angelousi, Anna; Diehdiou, Demba; Cuny, Thomas

2014-02-01

97

[Imaging of bone metastases].  

PubMed

Bone metastases are detected at initial diagnosis of cancer in 25% of cases and bone metastases are common in the course of a majority of cancer types. The spine and proximal long bones are the most affected sites. Knowledge of the basic radiological semiology is important to make the proper diagnosis of metastasis(s) bone(s), especially in situations in which the clinical context is not suggestive of metastases (such as cases where bone metastases are inaugural or cases of peripheral solitary metastasis). Tumor aggressiveness can be assessed at the level of the cortical bone and periosteum. Lodwick criteria are useful for the diagnosis of malignancy and tumor aggressiveness at initial diagnosis on plain radiographs, which are very important in the context of bone metastases. A CT scanner is required to confirm the malignancy of a bone lesion. MRI is complementary to the scanner including for the assessment of bone marrow involvement and tumor extensions. PMID:24184968

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

2013-11-01

98

Basic bone radiology  

SciTech Connect

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.

Griffiths, H.J.

1987-01-01

99

Oxytocin and bone.  

PubMed

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

Colaianni, Graziana; Sun, Li; Zaidi, Mone; Zallone, Alberta

2014-10-15

100

Anorexia nervosa and bone.  

PubMed

Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure, and reduced bone strength, all of which contribute to increased fracture risk. Adolescents with AN have decreased rates of bone accrual compared with normal-weight controls, raising additional concerns of suboptimal peak bone mass and future bone health in this age group. Changes in lean mass and compartmental fat depots, and hormonal alterations secondary to nutritional factors contribute to impaired bone metabolism in AN. The best strategy to improve bone density is to regain weight and menstrual function. Oral estrogen-progesterone combinations are not effective in increasing bone density in adults or adolescents with AN, and transdermal testosterone replacement is not effective in increasing bone density in adult women with AN. However, physiological estrogen replacement as transdermal estradiol with cyclic progesterone does increase bone accrual rates in adolescents with AN to approximate that in normal-weight controls, leading to a maintenance of bone density Z-scores. A recent study has shown that risedronate increases bone density at the spine and hip in adult women with AN. However, bisphosphonates should be used with great caution in women of reproductive age, given their long half-life and potential for teratogenicity, and should be considered only in patients with low bone density and clinically significant fractures when non-pharmacological therapies for weight gain are ineffective. Further studies are necessary to determine the best therapeutic strategies for low bone density in AN. PMID:24898127

Misra, Madhusmita; Klibanski, Anne

2014-06-01

101

Bone disease in hypoparathyroidism.  

PubMed

Hypoparathyroidism is a rare disorder that may be acquired or inherited. Postsurgical hypoparathyroidism is responsible for the majority of acquired hypoparathyroidism. Bone disease occurs in hypoparathyroidism due to markedly reduced bone remodeling due to the absence or low levels of parathyroid hormone. Chronically reduced bone turnover in patients with hypoparathyroidism typically leads to higher bone mass than in age- and sex-matched controls. Whether this increased bone density reduces fracture risk is less certain, because while increased bone mineralization may be associated with increased brittleness of bone, this does not appear to be the case in hypoparathyroidism. Treatment of hypoparathyroidism with recombinant parathyroid hormone may reduce bone mineral density but simultaneously strengthen the mechanical properties of bone. PMID:25166046

Clarke, Bart L

2014-07-01

102

Bone Builders: The Science of Grafts, Biomaterials and Bone Engineering  

NSDL National Science Digital Library

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

Steven Stocker (x)

2009-07-22

103

Bone Grafts (Periodontal Regenerative Surgery)  

MedlinePLUS

... include bits of: Your own bone Cadaver bone Cow bone Synthetic glasses Your own bone is best. ... bony defect. Barriers are made from human skin, cow skin or synthetic materials. After the graft is ...

104

JAMA Patient Page: Bone Fractures  

MedlinePLUS

... the American Medical Association JAMA PATIENT PAGE Bone Fractures A bone fracture is a break in a ... below) to treat bone fractures. CAUSES OF BONE FRACTURES FOR MORE INFORMATION • American Academy of Orthopaedic Surgeons ...

105

Porous Surface Modified Bioactive Bone Cement for Enhanced Bone Bonding  

Microsoft Academic Search

BackgroundPolymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low

Qiang He; Huiling Chen; Li Huang; Jingjing Dong; Dagang Guo; Mengmeng Mao; Liang Kong; Yang Li; Zixiang Wu; Wei Lei

2012-01-01

106

Bone continuum of cancer.  

PubMed

Many patients with solid tumors, especially breast and prostate cancers, and with multiple myeloma will develop bone metastases or other skeletal complications. The management of bone loss and symptomatic bone metastases is an important issue in the care and maintenance of quality of life for these patients. Morbidity caused by skeletal complications include pain (bone metastases are known as the most common cause of cancer-related pain), hypercalcemia, pathologic fracture, compression of the spinal cord or cauda equine, and spinal instability. Currently, the only Food and Drug Administration-approved therapy for metastatic bone disease is bisphosphonate therapy. A greater understanding of the biomolecular pathways that govern the bone continuum of cancer has helped identify novel targets for drug development. New therapeutic options are currently being investigated for the treatments of bone loss and symptomatic bone metastases. Some of these new drugs and modalities are in advanced stages of clinical development and may soon reach the clinic. PMID:20526089

Lipton, Allan

2010-06-01

107

Bone Graft Alternatives  

MedlinePLUS

... the form of a powder, crushed granules, putty, chips or as a gel that can be injected ... natural proteins that influence bone growth. Coral— Bone implants made from coral have shown to be useful ...

108

Bone pain or tenderness  

MedlinePLUS

... metastatic malignancy) Disruption of blood supply (as in sickle cell anemia ) Infected bone ( osteomyelitis ) Infection Injury (trauma) ... have? You may have the following tests: Blood studies (such as CBC , blood differential ) Bone x-rays , ...

109

Bone mineral density test  

MedlinePLUS

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

110

[Bone distraction osteogenesis].  

PubMed

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

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

2002-01-01

111

Calcaneus (Heel Bone) Fractures  

MedlinePLUS

... are many types of calcaneus fractures, including: Stable fracture. This type of fracture is nondisplaced. The broken ... bones usually stay in place during healing. Displaced fracture. When a bone breaks and is displaced, the ...

112

Smoking and Bone Health  

MedlinePLUS

... supported by your browser. Home Bone Basics Lifestyle Smoking and Bone Health Publication available in: PDF (217 ... Overtraining Risks for Women Oral Health Partner Resources Smoking: It’s Never Too Late to Stop (NIA)

113

D. Boning, MIT Duane Boning, Brian Lee,  

E-print Network

Current and Future Challenges #12;D. Boning, MIT Pattern-Dependent CMP Concerns Global Nonplanarity Oxide Initial Step CMP: CMP: #12;D. Boning, MIT Wafer-Level vs. Die-Level CMP Modeling n Within die uniformity depends on layout pattern, pad/slurry, process parameters n Chip and feature-scale models n Across wafer

Boning, Duane S.

114

Related disorders of bone  

Microsoft Academic Search

Renal osteodystrophy includes a broad spectrum of abnormalities in bone and mineral metabolism. This review article discusses\\u000a related bone disorders, including calcific uremic arteriolopathy, “osteoporosis” and compromised bone strength, and dialysis-related\\u000a amyloidosis, as well as the contributing roles of glucocorticoids and metabolic acidosis. Bone disorders in the setting of\\u000a renal transplantation, including osteoporosis, osteonecrosis, and presistent hyperparathyroidism, are also reviewed.

Francis L. Weng; Stanley Goldfarb

2007-01-01

115

Bone strength and its determinants  

Microsoft Academic Search

Osteoporosis is a disease defined by decreased bone mass and alteration of microarchitecture which results in increased bone fragility and increased risk of fracture. The major complication of osteoporosis, i.e., fracture, is due to a lower bone strength. Thus, any treatment of osteoporosis implies an improvement in bone strength. Bone strength is determined by bone geometry, cortical thickness and porosity,

P. Ammann; R. Rizzoli

2003-01-01

116

Bone cement implantation syndrome  

Microsoft Academic Search

Bone cement implantation syndrome (BCIS) is characterised by hypotension, hypoxaemia, cardiac arrhythmias, cardiac arrest or any combination of these, leading to death in 0.6–1% of patients. One of the mechanisms suggested to explain these complications is diffuse microembolisation of the lungs as a consequence of extrusion of the bone marrow content by the pressurised bone cement. By reducing intramedullary pressure

W. R. Lamadé; W. Friedl; B. Schmid; P. J. Meeder

1995-01-01

117

Photodynamic Therapy in Bone  

Microsoft Academic Search

Recent work within our group suggests that the application of photodynamic ther- apy (PDT) in bone holds considerable promise for a number of key conditions spe- cific to bone, including the treatment of primary and secondary cancers, infection, and skeletal deformity. In this chapter I will provide a synopsis of preclinical results obtained using PDT in bone that starts with

Stuart K. Bisland

118

Peak bone mass  

Microsoft Academic Search

Peak bone mass, which can be defined as the amount of bony tissue present at the end of the skeletal maturation, is an important determinant of osteoporotic fracture risk.Measurement of bone mass development. The bone mass of a given part of the skeleton is directly dependent upon both its volume or size and the density of the mineralized tissue contained

J.-Ph. Bonjour; G. Theintz; F. Law; D. Slosman; R. Rizzoli

1994-01-01

119

Bone Marrow Diseases  

MedlinePLUS

... with the stem cells or how they develop. Leukemia is a cancer in which the bone marrow produces abnormal white blood cells. With aplastic anemia, the bone marrow doesn't make red blood cells. Other diseases, such as lymphoma, can spread into the bone marrow and affect ...

120

Method for fusing bone  

DOEpatents

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.

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

121

Calcium and bone disease  

PubMed Central

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

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

2013-01-01

122

Remodeling in bone without osteocytes: Billfish challenge bone structurefunction paradigms  

E-print Network

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

Lajeunesse, Marc J.

123

The fate of beta-carotene in processed leaves of fluted pumpkin (Telfairia occidentalis hook. f.): a popular vegetable in Nigerian diet.  

PubMed

The effects of blanching, sun-oven-drying and storage conditions on beta-carotene content of the fresh leaves of fluted pumpkin were investigated. The beta-carotene (mg/100 g) of fresh leaves (unblanched) was 98.9 whereas on blanching the value was reduced to 86.3 for steam blanch and 83.8 for water blanch. After dehydration the losses in the beta-carotene were in the ranges of 37.6 to 48.8%, 40.5 to 51.3% and 68.8-72.0% for the steam-, water-blanched and unblanched leaves, respectively. The lower limit loss values were for the oven-dried leaves whereas the upper limit values were obtained from sundried ones. The ambient (30 +/- 2 degrees C) and refrigeration (7 +/- 1 degree C) storage conditions showed some slight changes in beta-carotene contents of the leaves. The losses were in the ranges of 2.0 to 25.7% (refrigeration) and 9.2 to 36.3% (ambient) conditions. Blancing and storage conditions affected the organoleptic characteristics of the leaves. PMID:8837873

Badifu, G I; Akpapunam, M A; Mgbemere, V M

1995-09-01

124

Bone Surface Mapping Method  

PubMed Central

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

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

2012-01-01

125

Small Animal Bone Biomechanics  

PubMed Central

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

Vashishth, Deepak

2008-01-01

126

Biomaterials and bone mechanotransduction  

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

127

Bone scanning in clinical practice  

SciTech Connect

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.

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

1987-01-01

128

Bone imaging in prostate cancer  

Microsoft Academic Search

Bone metastases of solid tumors are common, and about 80% of them occur in patients with breast, lung or prostate cancer. Bone metastases can be suspected clinically and by laboratory tests; however, a final diagnosis relies on radiographic evidence. Bone metastases of prostate cancer usually have osteoblastic characteristics, manifested by pathological bone resorption and formation. Conventional bone scans (e.g. with

Zohar A Dotan

2008-01-01

129

Better Bone Implants  

NSDL National Science Digital Library

This Web site come from Science@NASA, an online source for news and information about NASA-funded research, and describes the work of researchers at the Center for Commercial Applications of Combustion in Space, who are developing artificial bones for long-lasting, pain-free hip and knee replacements. These ceramic bones are touted as "so much like the real thing that they could actually meld with living bone."

Phillips, Tony.

2002-01-01

130

Method for fusing bone  

DOEpatents

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.

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

1996-03-12

131

Bone Quality in Diabetes  

PubMed Central

Diabetes is associated with increased risk of fracture, although type 2 diabetes is characterized by normal bone mineral density (BMD). The fracture risk of type 1 diabetes increases beyond an explained by a decrease of BMD. Thus, diabetes may be associated with a reduction of bone strength that is not reflected in the measurement of BMD. Based on the present definition, both bone density and quality, which encompass the structural and material properties of bone, are important factors in the determination of bone strength. Diabetes reduces bone quality rather than BMD. Collagen cross-linking plays an important role in bone strength. Collagen cross-links can be divided into lysyl hydroxylase and lysyl oxidase-mediated enzymatic immature divalent cross-links, mature trivalent cross-links, and glycation- or oxidation-induced non-enzymatic cross-links (Advanced Glycation End-products: AGEs) such as pentosidine. These types of cross-links differ in the mechanism of formation and in function. Not only hyperglycemia, but also oxidative stress induces the reduction in enzymatic beneficial cross-links and the accumulation of disadvantageous AGEs in bone. In this review, we describe the mechanism of low bone quality in diabetes. PMID:23785354

Saito, Mitsuru; Marumo, Keishi

2013-01-01

132

Hypercalciuric Bone Disease  

NASA Astrophysics Data System (ADS)

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.

Favus, Murray J.

2008-09-01

133

Dinosaur Flesh and Bones  

NSDL National Science Digital Library

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

Rick Crosslin

2004-01-01

134

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

135

Bone Augmentation and Nerve Repositioning  

MedlinePLUS

... your own bone or be processed (off-the-shelf) bone obtained from a cadaver. After grafting, you ... fuse with the existing bone. Using off-the-shelf grafted materials causes surrounding blood vessels to grow ...

136

Assessment of bone vascularization and its role in bone remodeling.  

PubMed

Bone is a composite organ that fulfils several interconnected functions, which may conflict with each other in pathological conditions. Bone vascularization is at the interface between these functions. The roles of bone vascularization are better documented in bone development, growth and modeling than in bone remodeling. However, every bone remodeling unit is associated with a capillary in both cortical and trabecular envelopes. Here we summarize the most recent data on vessel involvement in bone remodeling, and we present the characteristics of bone vascularization. Finally, we describe the various techniques used for bone vessel imaging and quantitative assessment, including histology, immunohistochemistry, microtomography and intravital microscopy. Studying the role of vascularization in adult bone should provide benefits for the understanding and treatment of metabolic bone diseases. PMID:25861447

Lafage-Proust, Marie-Hélène; Roche, Bernard; Langer, Max; Cleret, Damien; Vanden Bossche, Arnaud; Olivier, Thomas; Vico, Laurence

2015-01-01

137

Medicines and Bone Loss  

MedlinePLUS

... leuprolide acetate. They are used to treat endometriosis, prostate cancer, or female infertility. • Aromatase inhibitors, such as anastrozole, exemestane, and letrozole. They are used to treat breast cancer. FAcT SHEET Medicines Bone Loss and healthy Bone osteoporosis www.hormone.org ...

138

Biodegradable synthetic bone composites  

DOEpatents

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.

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

2013-01-01

139

Cranial nasal bone grafts  

Microsoft Academic Search

Reconstitution of the nasal scaffolding with maintainence of soft tissue proportions either following severe facial trauma or as a sequela to aesthetic rhinoplasty misadventures frequently is best achieved using the stability afforded by bone grafts. Split cranial bone grafts offer many advantages and may be the donor site of choice, and may even allow such surgery to be performed on

Geoffrey G. Hallock

1989-01-01

140

CARTILAGE, BONES, AND JOINTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

141

Broken Bones (For Parents)  

MedlinePLUS

... bones." A fracture through the growing part of a child's bone (called the growth plate ) may not show up on X-ray. If this type of fracture is suspected, the doctor will treat it even if the X-ray doesn't show ...

142

Depression and Bone Metabolism  

Microsoft Academic Search

Background: There are data to suggest low bone mineral density is disproportionately prevalent among those with psychiatric disorders. This paper aims to review the current evidence on the relationship between depression and bone mineral density, and identify potential mechanisms. Methods: Relevant sources were identified from the Pubmed and Web of Science (ISI) databases from the first relevant publication in 1994

Lana J. Williams; Julie A. Pasco; Felice N. Jacka; Margaret J. Henry; Seetal Dodd; Michael Berk

2009-01-01

143

Alveolar bone grafting.  

PubMed

In the 1970s, Boyne and Sands published reports on a new technique for alveolar bone grafting. They recommended that only cancellous bone be used and that the procedure be undertaken in the mixed dentition prior to canine eruption. Alveolar bone grafting prior to canine eruption soon became a routine part of the protocol for 90% of European and North American cleft teams. Several uncertainties remain however, such as the specifics of the surgical and orthodontic procedures, type of bone and donor site, and the best way to manage the space in the dental arch. Probably the commonest timing of the bone graft falls between 8 and 11 years, however there has been a trend in some centres to graft earlier in the hope of better outcome for the unerupted incisors. The influence on maxillary growth of earlier grafting has not been ascertained. A wide range of donor sites has been use but iliac crest remains the most popular. Many teams perform orthodontics prior to grafting to correct severe segment displacement or align incisors to improve surgical access. Following grafting, absence of the lateral incisor may be managed with orthodontic space closure, placement of an implant or bridgework. The introduction of alveolar bone grafting probably represents one of the most significant clinical innovations in cleft care. Hopefully, advances in tissue engineering will replace the need for transplantation of autogenous bone, or will provide an in-situ biological solution to the generation of a continuous bone fill across the alveolar cleft. PMID:22759676

Semb, Gunvor

2012-01-01

144

Bone Fractures and Engineering  

NSDL National Science Digital Library

Students learn about the role engineers and engineering play in repairing severe bone fractures. They acquire knowledge about the design and development of implant rods, pins, plates, screws and bone grafts. They learn about materials science, biocompatibility and minimally-invasive surgery.

Integrated Teaching and Learning Program, College of Engineering,

145

Repairing Broken Bones  

NSDL National Science Digital Library

Students learn about how biomedical engineers aid doctors in repairing severely broken bones. They learn about using pins, plates, rods and screws to repair fractures. They do this by designing, creating and testing their own prototype devices to repair broken turkey bones.

2014-09-18

146

Miscellaneous Bone Disorders  

Microsoft Academic Search

This chapter deals with a few of the important childhood bone disorders associated with high bone mass as well as conditions associated with fragility fractures and limb deformities, which have not been dealt with in previous chapters. A couple of skeletal dysplasias that can be sometimes be confused with rickets are also dealt with in this chapter. The principal features

Zulf Mughal

2009-01-01

147

Automated trabecular bone histomorphometry  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

148

Bone and Brain  

PubMed Central

Nerves have been identified in bone. Their function has recently become the focus of intense study. Metabolic control of bone is influenced by the nervous system. Potential transmitters of this influence include glutamate, calcitonin gene-related protein (CGRP), substance P, vasoactive intestinal peptide (VIP), pituitary adenylate cyclase activating polypeptide (PACAP), leptin, and catecholamines. Disorders of nerves - central or peripheral - can have substantial influence on bone health and repair. Specifically considered are the potential neural influences at work in such conditions as osteoporosis, fracture healing, Charcot osteoarthropathy, musculoskeletal pain syndromes, heterotopic ossification, skeletal growth and development, and obesity-related increased bone density. In this article, we review the current state of experimental and clinical evidence implicating the role of nervous tissue in regulating bone biology and discuss the current understanding of molecular signaling between nervous and osseus tissue in the homeostatic maintenance of the skeleton. PMID:15296219

Jones, Kevin B; Mollano, Anthony V; Morcuende, Jose A; Cooper, Reginald R; Saltzman, Charles L

2004-01-01

149

Ultrasonic bone densitometer  

NASA Technical Reports Server (NTRS)

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.

Hoop, J. M. (inventor)

1974-01-01

150

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

E-print Network

is in turn dependent on the Wnt family of morphogenic factors for autophosphorylation or transactivation and back (i.e., EGF, FGF3) cross a cell-adhesive laminin-1- and proteoglycan-enriched basement membrane. Basement membranes are polymeric sheets capable of both adsorbing and favorably displaying FGF3 and HGF

151

Gallium scintigraphy in bone infarction. Correlation with bone imaging  

SciTech Connect

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.

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

1984-01-01

152

Mimicking the nanostructure of bone matrix to regenerate bone  

PubMed Central

Key features of bone tissue structure and composition are capable of directing cellular behavior towards the generation of new bone tissue. Bone tissue, as well as materials derived from bone, have a long and successful history of use as bone grafting materials. Recent developments in design and processing of synthetic scaffolding systems has allowed the replication of the bone’s desirable biological activity in easy to fabricate polymeric materials with nano-scale features exposed on the surface. The biological response to these new tissue-engineering scaffold materials oftentimes exceeds that seen on scaffolds produced using biological materials. PMID:24688283

Kane, Robert; Ma1, Peter X.

2014-01-01

153

SILICON AND BONE HEALTH  

PubMed Central

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

JUGDAOHSINGH, R.

2009-01-01

154

Aspergillosis of the bone.  

PubMed

Aspergillosis of the long bones has not been reported. Those of the bones of the paranasal sinuses and ear canal have been reported but rare. A young woman reported to us with history of discharging sinuses around the right knee and recent fracture of the right femur. Despite all efforts, she ended up losing the whole limb from the hip. When a patient with Aspergillosis of the long bones presents late, amputation may be the best option. Early diagnosis will prevent this. PMID:25567698

Dabkana, T M; Pindiga, Umaru H; Mayun, Ahmed A; Nggada, Haruna A

2015-01-01

155

Bone hydatid disease  

PubMed Central

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

Song, X H; Ding, L W

2007-01-01

156

[Bone targeting agents: bisphosphonates].  

PubMed

Malignant tumor osteolysis is a frequent complication in many cancers. It can cause skeletal-related events with alteration of quality of life and survival. Bisphosphonates play an important role in the management of this malignant osteolysis, via an inhibition of osteoclast-mediated bone resorption, and a potential direct antitumor activity. Their use constitutes an important therapeutic advance in patients with bone metastases so as to reduce or delay the appearance of these skeletal events. They are also useful for the treatment of hypercalcemia, which could arise in these patients. Their interest as adjuvant therapy before the onset of bone metastases is currently being evaluated. PMID:24158668

Debiais, Françoise

2013-11-01

157

Osteoinduction by demineralised bone  

Microsoft Academic Search

Summary.  \\u000a Bone contains several growth factors, including bone morphogenetic proteins (BMPs), transforming growth factor beta (TGF-?),\\u000a insulin-like growth factors I and II (IGF-I and IGF-II), platelet derived growth factor (PDGF) and basic and acidic fibroblast\\u000a growth factor (bFGF and aFGF). The BMPs are the only factors known to provoke bone formation heterotopically by making undifferentiated\\u000a mesenchymal cells differentiate into osteoblasts

E. Solheim

1998-01-01

158

American Society for Bone and Mineral Research: Bone Curriculum  

NSDL National Science Digital Library

Developed by the Education Committee of the American Society for Bone and Mineral Research (ASBMR), this Bone Curriculum website "is intended for use by students from high school to medical school." The website features sections on Bone Cells, Exercise and Nutrition, Hormones that Effect Bone, Collagen and Bone Matrix, and more. The brief text sections are interspersed with great images, diagrams, slide shows, and animations. The site also contains links for related websites, textbooks, and journals.

159

Dependence of Long Bone Flexural Properties on Bone Mineral Distribution  

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

160

The peak bone mass concept  

Microsoft Academic Search

Summary Peak bone mass (PBM), i.e. the bone mass developed after growth in early adult life, is a major determinant for bone mass in the senescence, resp. for the risk of osteoporosis. Individual differences among young adults are so important that a person with a high PBM has a relatively low risk for osteoporosis, even if its annual bone loss

P. Burckhardt; Ch. Michel

1989-01-01

161

Safety factors in bone strength  

Microsoft Academic Search

Summary Functionalin vivo strain data are examined in relation to bone material properties in an attempt to evaluate the relative importance of osteoporotic bone loss versus fatigue damage accumulation as factors underlying clinical bone fragility. Specifically, does the skeleton have a sufficiently large safety factor (ratio of bone failure strain to maximum functional strain) to require that fatigue damage accumulation

Andrew A. Biewener

1993-01-01

162

The many adaptations of bone  

Microsoft Academic Search

Studies concerned with the ‘adaptations’ in bones usually deal with modelling taking place during the individual's lifetime. However, many adaptations are produced over evolutionary time. This survey samples some adaptations of bone that may occur over both length scales, and tries to show whether short- or long-term adaptation is important. (a) Woven and lamellar bone. Woven bone is less mechanically

J. D Currey

2003-01-01

163

What Makes our Bones Strong?  

NSDL National Science Digital Library

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

VU Bioengineering RET Program,

164

Why do bone strength and \\  

Microsoft Academic Search

:   Trauma excepted, muscle forces cause the largest loads on bones and the largest bone strains. In children, steadily increasing\\u000a muscle strength increases bone loads and strains above a modeling threshold, which allows modeling to increase bone strength\\u000a and \\

Harold M. Frost

1999-01-01

165

Bone Cancer: Questions and Answers  

MedlinePLUS

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

166

Bone Grafts in Craniofacial Surgery  

PubMed Central

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

Elsalanty, Mohammed E.; Genecov, David G.

2009-01-01

167

Fossilized Dinosaur Bones  

NSDL National Science Digital Library

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

168

Angiogenesis in Bone Regeneration  

PubMed Central

Angiogenesis is a key component of bone repair. New blood vessels bring oxygen and nutrients to the highly metabolically active regenerating callus and serve as a route for inflammatory cells and cartilage and bone precursor cells to reach the injury site. Angiogenesis is regulated by a variety of growth factors, notably vascular endothelial growth factor (VEGF), which are produced by inflammatory cells and stromal cells to induce blood vessel in-growth. A variety of studies with transgenic and gene-targeted mice have demonstrated the importance of angiogenesis in fracture healing, and have provided insights into regulatory processes governing fracture angiogenesis. Indeed, in animal models enhancing angiogenesis promotes bone regeneration, suggesting that modifying fracture vascularization could be a viable therapeutic approach for accelerated/improved bone regeneration clinically. PMID:21489534

Hankenson, Kurt D.; Dishowitz, Michael; Gray, Chancellor; Schenker, Mara

2011-01-01

169

Calcium and Bone Health  

MedlinePLUS

... of Child Health and Human Development (NICHD) . Weight-Bearing Physical Activity Regular physical activity has been associated ... strong bones. Like proper calcium consumption, adequate weight-bearing physical activity early in life is important in ...

170

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

PubMed Central

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

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

2011-01-01

171

Nutrition and Bone Health  

Microsoft Academic Search

LEARNING OUTCOME: Fifth graders wil1 be able to select appropriate foods to maximize bone mass.Nutrition and Bone Health is the topic of a nutrition education curriculum for fifth graders based on a collaborative project funded by NASA through the Arkansas Space Grant Consortium. The multi-disciplinary undertaking has many facets. It began with a group of Arkansas educators touring NASA's Johnson

M. M. Shock; J. Johnson; M. H. Harlan

1997-01-01

172

Detecting microdamage in bone  

Microsoft Academic Search

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.

T Clive Lee; Sahar Mohsin; David Taylor; Raman Parkesh; TThorfinnur Gunnlaugsson; Fergal J OBrien; Michael Giehl; Wolfgang Gowin

2003-01-01

173

Boning up on autophagy  

PubMed Central

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

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

2014-01-01

174

GENE DELIVERY TO BONE  

PubMed Central

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

Evans, C. H.

2012-01-01

175

Bone Remodeling Monitor  

NASA Technical Reports Server (NTRS)

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

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

2009-01-01

176

Ghrelin and bone.  

PubMed

Ghrelin is a gut-derived peptide hormone, first isolated from the stomach. Ghrelin was initially characterized as a growth hormone (GH) secretagogue, but it plays a more important role as a potent orexigen and modulator of whole-body energy homeostasis. Ghrelin itself is closely regulated by metabolic status. Bone remodeling constantly renews the skeleton in a highly energy-dependent fashion. Accordingly, bone metabolism is tightly coupled to energy metabolism through the integration of peripheral and central mechanisms, involving the sympathetic nervous system and factors such as leptin. Ghrelin has been shown to modulate osteoblast differentiation and function, both directly and perhaps also through regulation of the GH-insulin-like growth factor axis. However, recently it has also been shown that ghrelin interacts with leptin in modulating bone structure, constituting a new mechanism that couples bone metabolism with energy homeostasis. In this review, we discuss the role that ghrelin plays modulating bone cell function, and its integrative role in coupling bone metabolism with energy metabolism. PMID:23804549

Delhanty, Patric J D; van der Eerden, Bram C J; van Leeuwen, Johannes P T M

2014-01-01

177

Aneurysmal bone cyst of the ethmoid bone.  

PubMed

A 90-year-old woman presented with headache and diplopia, and a mass in the nasal cavity and paranasal sinuses was found on CT scan. The patient underwent examination under anaesthesia showing a mass arising from the ethmoid, apparently from the nasal septum. Biopsies taken showed an aneurysmal bone cyst. The patient opted against surgery and has been managed conservatively. A second CT scan 4 years later showed significant increase in size. PMID:24706701

Janjua, Noor; Cresswell, Manuela; Sharma, Rishi; Maheshwar, Arcot

2014-01-01

178

Porous Surface Modified Bioactive Bone Cement for Enhanced Bone Bonding  

PubMed Central

Background Polymethylmethacrylate bone cement cannot provide an adhesive chemical bonding to form a stable cement-bone interface. Bioactive bone cements show bone bonding ability, but their clinical application is limited because bone resorption is observed after implantation. Porous polymethylmethacrylate can be achieved with the addition of carboxymethylcellulose, alginate and gelatin microparticles to promote bone ingrowth, but the mechanical properties are too low to be used in orthopedic applications. Bone ingrowth into cement could decrease the possibility of bone resorption and promote the formation of a stable interface. However, scarce literature is reported on bioactive bone cements that allow bone ingrowth. In this paper, we reported a porous surface modified bioactive bone cement with desired mechanical properties, which could allow for bone ingrowth. Materials and Methods The porous surface modified bioactive bone cement was evaluated to determine its handling characteristics, mechanical properties and behavior in a simulated body fluid. The in vitro cellular responses of the samples were also investigated in terms of cell attachment, proliferation, and osteoblastic differentiation. Furthermore, bone ingrowth was examined in a rabbit femoral condyle defect model by using micro-CT imaging and histological analysis. The strength of the implant–bone interface was also investigated by push-out tests. Results The modified bone cement with a low content of bioactive fillers resulted in proper handling characteristics and adequate mechanical properties, but slightly affected its bioactivity. Moreover, the degree of attachment, proliferation and osteogenic differentiation of preosteoblast cells was also increased. The results of the push-out test revealed that higher interfacial bonding strength was achieved with the modified bone cement because of the formation of the apatite layer and the osseointegration after implantation in the bony defect. Conclusions Our findings suggested a new bioactive bone cement for prosthetic fixation in total joint replacement. PMID:22905143

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

2012-01-01

179

Bone metabolic markers in bone metastasis of breast cancer  

Microsoft Academic Search

Background. The efficacy and cost-performance benefit of radionuclide bone scintigraphy in monitoring metastatic bone activity remain\\u000a controversial. Bone metabolic markers are now expected to play a role in the diagnosis and follow-up of bone metastasis.\\u000a \\u000a \\u000a Methods. We investigated several bone metabolic markers in patients with breast cancer. We measured three metabolic markers of bone\\u000a resorption: pyridinoline cross-linked carboxy terminal telopeptide

Mitsuru Koizumi; Shunji Takahashi; Etsuro Ogata

1999-01-01

180

Bone metastases: When and how lung cancer interacts with bone  

PubMed Central

Bone metastasis is a common and debilitating consequence of lung cancer: 30%-40% of patients with non-small cell lung cancer develop bone metastases during the course of their disease. Lung cancer cells find a favorable soil in the bone microenvironment due to factors released by the bone matrix, the immune system cells, and the same cancer cells. Many aspects of the cross-talk among lung tumor cells, the immune system, and bone cells are not clear, but this review aims to summarize the recent findings in this field, with particular attention to studies conducted to identify biomarkers for early detection of lung cancer bone metastases. PMID:24829862

Roato, Ilaria

2014-01-01

181

Mimicking the nanostructure of bone matrix to regenerate bone.  

PubMed

Key features of bone tissue structure and composition are capable of directing cellular behavior towards the generation of new bone tissue. Bone tissue, as well as materials derived from bone, have a long and successful history of use as bone grafting materials. Recent developments in design and processing of synthetic scaffolding systems has allowed the replication of the bone's desirable biological activity in easy to fabricate polymeric materials with nano-scale features exposed on the surface. The biological response to these new tissue-engineering scaffold materials oftentimes exceeds that seen on scaffolds produced using biological materials. PMID:24688283

Kane, Robert; Ma1, Peter X

2013-11-01

182

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

Microsoft Academic Search

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

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

2005-01-01

183

Bone health in eating disorders.  

PubMed

Eating disorders (EDs) put adolescents and young adults at risk for impaired bone health. Low bone mineral density (BMD) with ED is caused by failure to accrue peak bone mass in adolescence and bone loss in young adulthood. Although ED patients diagnosed with bone loss may be asymptomatic, some suffer bone pains and have increased incidence of fractures. Adolescents with ED are prone to increased prevalence of stress fractures, kyphoscoliosis and height loss. The clinical picture of the various EDs involves endocrinopathies that contribute to impaired bone health. Anorexia nervosa (AN) is characterized by low bone turnover, with relatively higher osteoclastic (bone resorptive) than osteoblastic (bone formation) activity. Bone loss in AN occurs in both the trabecular and cortical bones, although the former is more vulnerable. Bone loss in AN has been shown to be influenced by malnutrition and low weight, reduced fat mass, oestrogen and androgen deficiency, glucocorticoid excess, impaired growth hormone-insulin-like growth factor 1 axis, and more. Bone loss in AN may not be completely reversible despite recovery from the illness. Treatment modalities involving hormonal therapies have limited effectiveness, whereas increased caloric intake, weight gain and resumption of menses are essential to improved BMD. PMID:24165231

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

2014-03-01

184

Microarchitecture of irradiated bone: comparison with healthy bone  

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

185

The Geometry of the Bone Structure Associated with Total Hip Arthroplasty  

PubMed Central

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

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

2014-01-01

186

Bone imaging in prostate cancer.  

PubMed

Bone metastases of solid tumors are common, and about 80% of them occur in patients with breast, lung or prostate cancer. Bone metastases can be suspected clinically and by laboratory tests; however, a final diagnosis relies on radiographic evidence. Bone metastases of prostate cancer usually have osteoblastic characteristics, manifested by pathological bone resorption and formation. Conventional bone scans (e.g. with (99m)Tc-labeled methylene diphosphonate) are preferred to plain-film radiography for surveillance of the entire skeleton. Radiologic diagnosis of bone metastases, particularly in patients with low burden of disease, is difficult because noncancerous bone lesions that mimic cancer are common. Conventional bone scans are limited by their low sensitivity and high false-negative rate (up to 40%) compared with advanced bone-imaging modalities such as PET, PET-CT and MRI, which might assist or replace conventional scanning methods. The correct diagnosis of bone involvement in prostate cancer is crucial to assess the effects of therapy on the primary tumor, the patient's prognosis, and the efficacy of bone-specific treatments that can reduce future bone-associated morbidity. In addition, predictive tools such as nomograms enable the identification of patients at risk of bone involvement during the course of their disease. Such tools may limit treatment costs by avoidance of unnecessary tests and might reduce both short-term and long-term complication rates. PMID:18682719

Dotan, Zohar A

2008-08-01

187

[Nutrition and bone health. Lactose and bone].  

PubMed

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

Uenishi, Kazuhiro; Yamaura, Tomoko

2010-03-01

188

Evolutionary physiology of bone: bone metabolism in changing environments.  

PubMed

Bone evolved to serve many mechanical and physiological functions. Osteocytes and bone remodeling first appeared in the dermal skeleton of fish, and subsequently adapted to various challenges in terrestrial animals occupying diverse environments. This review discusses the physiology of bone and its role in mechanical and calcium homeostases from an evolutionary perspective. We review how bone physiology responds to changing environments and the adaptations to unique and extreme physiological conditions. PMID:25559152

Doherty, Alison H; Ghalambor, Cameron K; Donahue, Seth W

2015-01-01

189

21 CFR 892.1180 - Bone sonometer.  

Code of Federal Regulations, 2012 CFR

...Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification . A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone that indicate overall bone health and fracture...

2012-04-01

190

21 CFR 892.1180 - Bone sonometer.  

Code of Federal Regulations, 2010 CFR

...Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification . A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone that indicate overall bone health and fracture...

2010-04-01

191

21 CFR 892.1180 - Bone sonometer.  

Code of Federal Regulations, 2011 CFR

...Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification . A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone that indicate overall bone health and fracture...

2011-04-01

192

21 CFR 892.1180 - Bone sonometer.  

Code of Federal Regulations, 2013 CFR

...Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification . A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone that indicate overall bone health and fracture...

2013-04-01

193

21 CFR 892.1180 - Bone sonometer.  

Code of Federal Regulations, 2014 CFR

...Diagnostic Devices § 892.1180 Bone sonometer. (a) Identification. A bone sonometer is a device that transmits ultrasound energy into the human body to measure acoustic properties of bone that indicate overall bone health and fracture...

2014-04-01

194

Percutaneous bone tumor management.  

PubMed

Interventional radiology plays a major role in the management of bone tumors. Many different percutaneous techniques are available. Some aim to treat pain and consolidate a pathological bone (cementoplasty); others aim to ablate tumor or reduce its volume (sclerotherapy, thermal ablation). In this article, image-guided techniques of primary and secondary bone tumors with vertebroplasty, ethanol injection, radiofrequency ablation, laser photocoagulation, cryoablation, and radiofrequency ionization (coblation) will be reviewed. For each modality, the principles, the indications, and the results will be presented. The technical choice depends on the therapeutic intent-curative or palliative-and the need for consolidation, but also on the general status of the patient and the other therapeutic options. For the most complex cases, combined treatments can be required. However, the less disabling technique should always be considered first. PMID:21629402

Gangi, Afshin; Buy, Xavier

2010-06-01

195

[Pain and bone metastases].  

PubMed

Average 20% of the cancer patients will have bone metastasis most of time painful and with variable clinical expressions. Due to animal models, the bone metastasis pain is better known and it explains the different treatments mechanisms. After a suitable evaluation of the pain, several therapeutic approaches can be suggested. In addition to the classical analgesics, several medications are known to be efficient in few indications like neuropathic pain. Besides a local surgery, an external radiotherapy or an interventional radiology treatment can often be useful along with a medical treatment. When there is a bone progression, the anti-cancer treatment by chemotherapy, hormonotherapy or targeted therapies must always be reviewed, because if efficient it could have an analgesic action. PMID:19070823

Wassermann, J; De La Lande, B; Pecking, A; Brasseur, L

2008-11-01

196

Aneurysmal bone cyst of the nasal bone: case report.  

PubMed

The aneurysmal bone cyst (ABC) is a solitary, expansile, non-neoplastic bone lesion, described as a distinct clinicopathological entity by Jaffe and Lichtenstein. We report a case of an ABC arising from the nasal bone in a adult male patient treated with complete surgical excision. PMID:23903447

Galzignato, P; Trevisiol, L; D'itri, L; Bissolotti, G; Mocella, S; De Santis, D; Chiarini, L; Nocini, P F; Bertossi, D

2013-08-01

197

Detecting microdamage in bone  

PubMed Central

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

Lee, TC; Mohsin, S; Taylor, D; Parkesh, R; Gunnlaugsson, T; O'Brien, FJ; Giehl, M; Gowin, W

2003-01-01

198

Bone Density Challenge Introduction  

NSDL National Science Digital Library

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

VU Bioenegineering RET Program ,

199

Bone cement implantation syndrome.  

PubMed

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

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

2013-06-01

200

Graphite-reinforced bone cement  

NASA Technical Reports Server (NTRS)

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.

Knoell, A. C.

1976-01-01

201

Review Tumor metastasis to bone  

E-print Network

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

2007-01-01

202

Pattern Alteration: Protruding Hip Bone  

E-print Network

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....

2006-08-04

203

Cutting thin sections of bone  

NASA Technical Reports Server (NTRS)

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.

Ashley, W. W.

1972-01-01

204

Low Bone Mass in Thalassemia  

MedlinePLUS

... calcium and bone protein. In osteoporosis, bones become porous and brittle, are unable to support weight easily ... per week, with the exercise focusing on weight-bearing activities. For adults, some appropriate activities may include: ...

205

Biochemical Markers of Bone Turnover  

Microsoft Academic Search

\\u000a Bone remodeling is a continuous and dynamic process of renewal, whereby a quantum of new bone is reformed following dissolution.\\u000a As noted previously, this physiologic cycle serves to provide a constant source of calcium for homeostatic functions, while\\u000a preserving the biomechanical properties of bone itself. During bone resorption, calcium and other matrix constituents are\\u000a released into the bloodstream where they

Clifford J. Rosen

206

Transcutaneous Raman Spectroscopy of Bone  

NASA Astrophysics Data System (ADS)

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.

Maher, Jason R.

207

Radionuclide studies of bone metabolism: Do bone uptake and bone plasma clearance provide equivalent measurements of bone turnover?  

Microsoft Academic Search

Quantitative radionuclide imaging using 18F-fluoride positron emission tomography (18F-PET) or 99mTc-methylene diphosphonate (99mTc-MDP) bone scans provides a novel tool for studying regional and whole skeleton bone turnover that complements the information provided by biochemical markers. Radionuclide bone scans can be quantified by measuring either tracer uptake or, if blood sampling is performed, bone plasma clearance. This study examines whether these

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

2011-01-01

208

Three quantitative ultrasound parameters reflect bone structure  

Microsoft Academic Search

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

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

1994-01-01

209

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

PubMed Central

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

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

2014-01-01

210

Space Stations: Bones of Contention  

NSDL National Science Digital Library

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

2014-06-23

211

Female Reproductive System and Bone  

PubMed Central

The female reproductive system plays a major role in regulating the acquisition and loss of bone by the skeleton from menarche through senescence. Onset of gonadal sex steroid secretion at puberty is the major factor responsible for skeletal longitudinal and radial growth, as well as significant gain in bone density, until peak bone density is achieved in third decade of life. Gonadal sex steroids then help maintain peak bone density until menopause, including during the transient changes in skeletal mineral content associated with pregnancy and lactation. At menopause, decreased gonadal sex steroid production normally leads to rapid bone loss. The most rapid bone loss associated with decreased estrogen levels occurs in the first 8–10 years after menopause, with slower age-related bone loss occurring during later life. Age-related bone loss in women after the early menopausal phase of bone loss is caused by ongoing gonadal sex steroid deficiency, vitamin D deficiency, and secondary hyperparathyroidism. Other factors also contribute to age-related bone loss, including intrinsic defects in osteoblast function, impairment of the GH/IGF axis, reduced peak bone mass, age-associated sarcopenia, and various sporadic secondary causes. Further understanding of the relative contributions of the female reproductive system and each of the other factors to development and maintenance of the female skeleton, bone loss, and fracture risk will lead to improved approaches for prevention and treatment of osteoporosis. PMID:20637179

Clarke, Bart L.; Khosla, Sundeep

2010-01-01

212

Bone vascularization: a way to study bone microarchitecture?  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

213

Temporal Bone Myeloid Sarcoma  

PubMed Central

Myeloid sarcoma is a rare condition that's caused by the aggregation of immature myeloid cells in leukemic patients. Myeloid sarcoma occurring in the temporal bone more frequently involves the mastoid bone than is the case for metastatic lesions arising from non-systemic malignancies. The disease is difficult to diagnose when it presents with symptoms that mimic otomastoiditis. However, an early diagnosis is important in order to achieve complete remission of the disease. Magnetic resonance imaging of the temporal bone is useful for making the diagnosis of myeloid sarcoma, and especially to evaluate the extent of disease. High-dose radio- or chemotherapies are the first-line approaches and possibly the only approaches to achieve complete remission and to cure the disease. With the aim of improving our understanding of myeloid sarcoma in the temporal bone, the present report describes our experience with 5 such cases and we compare the clinical features of these 5 patients with those clinical features of patients who have metastatic lesions. PMID:20072695

Kim, Dong-Kee; Jun, Beom-Cho; Park, Yong-Soo

2009-01-01

214

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,

215

Are Bones Alive?  

ERIC Educational Resources Information Center

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…

Caravita, Silvia; Falchetti, Elisabetta

2005-01-01

216

Evaluation of bone matrix and demineralized bone matrix incorporated PLGA matrices for bone repair  

Microsoft Academic Search

The aim of this study was to evaluate the composite matrices prepared using Poly(lactic-co-glycolic acid)- PLGA (85:15) by\\u000a incorporating human bone matrix (BM) powder or demineralized bone matrix (DBM) powder with the weight ratio of polymer: BM\\u000a or DBM (75:25) to apply for bone repair. Murine Bone Marrow Stromal Cell (BMSC) attachment was studied with different time\\u000a points at 30 min,

A. Champa Jayasuriya; Nabil A. Ebraheim

2009-01-01

217

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

PubMed Central

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

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

2013-01-01

218

The role of cortical bone and its microstructure in bone strength  

Microsoft Academic Search

Bone's mechanical competence and its fragility in particular depend to a certain extent on the structure and microstructure of the cortical bone compartment. Beyond bone mineral density (BMD) and bone mineral content, a variety of other features of cortical bone contribute to whole bone's resistance to fracture. Structural properties of cortical bone most commonly employed as surrogate for its mechanical

PETER AUGAT; SANDRA SCHORLEMMER

219

Peripheral Leptin Regulates Bone Formation  

PubMed Central

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

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

2012-01-01

220

Multicellular tumor spheroid interactions with bone cells and bone  

SciTech Connect

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

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

1985-10-01

221

Does Quantitative Ultrasound of Bone Reflect More Bone Mineral Density Than Bone Microarchitecture?  

Microsoft Academic Search

Relationships among quantitative ultrasound of bone (QUS), bone mineral density (BMD) and bone microarchitecture have been poorly investigated in human calcaneus. .Twenty-four specimens, from 12 men and 12 women (mean age 78 ± 10 years; range 53–93), removed from cadavers were studied. The feet were axially sectioned above the ankle. Two variables were measured for QUS (Achilles®, Lunar): broadband ultrasound

B. Cortet; N. Boutry; P. Dubois; I. Legroux-Gérot; A. Cotten; X. Marchandise

2003-01-01

222

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

E-print Network

Title: Patterning Bone Regeneration ­ In Silico Modeling of Bone Morphogenetic Protein (BMP) Driven as BMP-2 and BMP-7) are produced, Food and Drug Administration (FDA)-approved, and thus are being used this phenomenon so that novel tissue engineering strategys can be developed to pattern bone regeneration in a pre

Wolper, Pierre

223

Directing mesenchymal stem cells to bone to augment bone formation and increase bone mass  

Microsoft Academic Search

Aging reduces the number of mesenchymal stem cells (MSCs) that can differentiate into osteoblasts in the bone marrow, which leads to impairment of osteogenesis. However, if MSCs could be directed toward osteogenic differentiation, they could be a viable therapeutic option for bone regeneration. We have developed a method to direct MSCs to the bone surface by attaching a synthetic high-affinity

Min Guan; Ruiwu Liu; Kit S Lam; Jan Nolta; Junjing Jia; Brian Panganiban; Liping Meng; Ping Zhou; Mohammad Shahnazari; Robert O Ritchie; Wei Yao

2012-01-01

224

Digital electronic bone growth stimulator  

DOEpatents

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.

Kronberg, J.W.

1995-05-09

225

Digital electronic bone growth stimulator  

DOEpatents

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.

Kronberg, James W. (Aiken, SC)

1995-01-01

226

Bone Magnesium Pools in Uremia  

PubMed Central

Bone magnesium pools were studied in vitro in bone specimens obtained from control subjects, from patients with chronic renal failure before and after renal transplantation, and in a patient with chronic hypomagnesemia. 30% of bone magnesium is in a surface limited pool present either within the hydration shell or else on the crystal surface. The larger fraction of bone magnesium was shown not to be associated with bone matrix but rather to be an integral part of the bone crystal. With incineration this pool was mobilized at the same temperature that sudden enlargement of bone crystal size occurred. It is suggested that heating causes surface calcium to displace magnesium from the apatite crystal. Both magnesium pools are increased in patients with chronic renal failure. The major factor determining magnesium concentration in bone would appear to be the serum magnesium level. Following renal transplantation, in association with the fall in serum magnesium, surface magnesium was within the normal range; whereas, residual magnesium was not different from the other urenic bones. Both magnesium pools were significantly reduced in a patient with chronic hypomagnesemia. The in vitro studies would suggest that surface magnesium should rapidly reflect changes in serum magnesium levels, whereas, the deeper magnesium pool is probably deposited at time of bone formation with mobilization being dependent upon the resorptive processes. Since magnesium can influence crystal size and stability it seems possible that excess bone magnesium may play a role in renal osteodystrophy. PMID:4584344

Alfrey, Allen C.; Miller, Nancy L.

1973-01-01

227

Space flight and bone formation  

NASA Technical Reports Server (NTRS)

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.

Doty, St B.

2004-01-01

228

Space flight and bone formation.  

PubMed

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. PMID:15895501

Doty, St B

2004-12-01

229

Inducible models of bone loss.  

PubMed

Bone is an essential organ that not only confers structural stability to the organism, but also serves as a reservoir for hematopoietic elements and is thought to affect systemic homeostasis through the release of endocrine factors as well as calcium. The loss of bone mass due to an uncoupling of bone formation and bone resorption leads to increased fragility that can result in devastating fractures. Further understanding of the effects of environmental stimuli on the development of bone disease in humans is needed, and they can be studied using animal models. Here, we present established and novel methods for the induction of bone loss in mice, including manipulation of diet and environment, administration of drugs, irradiation, and surgically induced hormone deficiency. All of these models are directly related to human cases, and thus, can be used to investigate the causes of bone loss resulting from these interventions. PMID:25723184

Doucette, Casey R; Rosen, Clifford J

2014-01-01

230

Bone metabolism in anorexia nervosa.  

PubMed

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

Fazeli, Pouneh K; Klibanski, Anne

2014-03-01

231

Osteopontin Deficiency Increases Bone Fragility but Preserves Bone Mass  

PubMed Central

The ability of bone to resist catastrophic failure is critically dependent upon the material properties of bone matrix, a composite of hydroxyapatite, collagen type I, and noncollagenous proteins. These properties include elastic modulus, hardness, and fracture toughness. Like other aspects of bone quality, matrix material properties are biologically-defined and can be disrupted in skeletal disease. While mineral and collagen have been investigated in greater detail, the contribution of noncollagenous proteins such as osteopontin to bone matrix material properties remains unclear. Several roles have been ascribed to osteopontin in bone, many of which have the potential to impact material properties. To elucidate the role of osteopontin in bone quality, we evaluated the structure, composition, and material properties of bone from osteopontin-deficient mice and wild-type littermates at several length scales. Most importantly, the results show that osteopontin deficiency causes a 30% decrease in fracture toughness, suggesting an important role for OPN in preventing crack propagation. This significant decline in fracture toughness is independent of changes in whole bone mass, structure, or matrix porosity. Using nanoindentation and quantitative backscattered electron imaging to evaluate osteopontin-deficient bone matrix at the micrometer level, we observed a significant reduction in elastic modulus and increased variability in calcium concentration. Matrix heterogeneity was also apparent at the ultrastructural level. In conclusion, we find that osteopontin is essential for the fracture toughness of bone, and reduced toughness in osteopontin-deficient bone may be related to the increased matrix heterogeneity observed at the micro-scale. By exploring the effects of osteopontin-deficiency on bone matrix material properties, composition and organization, this study suggests that reduced fracture toughness is one mechanism by which loss of noncollagenous proteins contribute to bone fragility. PMID:20171304

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

2010-01-01

232

Directing mesenchymal stem cells to bone to augment bone formation and increase bone mass  

PubMed Central

Aging reduces the number of mesenchymal stem cells (MSCs) in the bone marrow which leads to impairment of osteogenesis. However, if MSCs could be directed toward osteogenic differentiation, they could be a viable therapeutic option for bone regeneration. We have developed a method to direct the MSCs to the bone surface by attaching a synthetic high affinity and specific peptidomimetic ligand (LLP2A) against integrin ?4?1 on the MSC surface, to a bisphosphonate (alendronate, Ale) that has high affinity for bone. LLP2A-Ale increased MSCs migration and osteogenic differentiation in vitro. A single intravenous injection of LLP2A-Ale increased trabecular bone formation and bone mass in both xenotransplantation and immune competent mice. Additionally, LLP2A-Ale prevented trabecular bone loss after peak bone acquisition was achieved or following estrogen deficiency. These results provide a proof of principle that LLP2A-Ale can direct MSCs to the bone to form new bone and increase bone strength. PMID:22306732

Guan, Min; Yao, Wei; Liu, Ruiwu; Lam, Kit S.; Nolta, Jan; Jia, Junjing; Panganiban, Brian; Meng, Liping; Zhou, Ping; Shahnazari, Mohammad; Ritchie, Robert O.; Lane, Nancy E.

2013-01-01

233

Bone biopsy in patients with osteoporosis  

Microsoft Academic Search

Although rarely used to diagnose and manage patients with osteoporosis, bone biopsies are performed to establish bone quality,\\u000a including degree of mineralization and microarchitecture; to assess bone turnover and bone loss mechanisms; and to analyze\\u000a treatment effects on bone structure and bone turnover. Bone biopsies are also the only method to diagnose mineralization defect\\u000a or frank osteomalacia. Due to the

Hartmut H. Malluche; Hanna Mawad; Marie-Claude Monier-Faugere

2007-01-01

234

Vitamin D: beyond bone  

PubMed Central

In recent years, vitamin D has been received increased attention due to the resurgence of vitamin D deficiency and rickets in developed countries and the identification of extraskeletal effects of vitamin D, suggesting unexpected benefits of vitamin D in health and disease, beyond bone health. The possibility of extraskeletal effects of vitamin D was first noted with the discovery of the vitamin D receptor (VDR) in tissues and cells that are not involved in maintaining mineral homeostasis and bone health, including skin, placenta, pancreas, breast, prostate and colon cancer cells, and activated T cells. However, the biological significance of the expression of the VDR in different tissues is not fully understood, and the role of vitamin D in extraskeletal health has been a matter of debate. This report summarizes recent research on the roles for vitamin D in cancer, immunity and autoimmune diseases, cardiovascular and respiratory health, pregnancy, obesity, erythropoiesis, diabetes, muscle function, and aging. PMID:23682710

Christakos, Sylvia; Hewison, Martin; Gardner, David G; Wagner, Carol L; Sergeev, Igor N; Rutten, Erica; Pittas, Anastassios G; Boland, Ricardo; Ferrucci, Luigi; Bikle, Daniel D

2013-01-01

235

Bone Metabolism on ISS Missions  

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

236

Cancer-associated bone disease.  

PubMed

Bone is commonly affected in cancer. Cancer-induced bone disease results from the primary disease, or from therapies against the primary condition, causing bone fragility. Bone-modifying agents, such as bisphosphonates and denosumab, are efficacious in preventing and delaying cancer-related bone disease. With evidence-based care pathways, guidelines assist physicians in clinical decision-making. Of the 57 million deaths in 2008 worldwide, almost two thirds were due to non-communicable diseases, led by cardiovascular diseases and cancers. Bone is a commonly affected organ in cancer, and although the incidence of metastatic bone disease is not well defined, it is estimated that around half of patients who die from cancer in the USA each year have bone involvement. Furthermore, cancer-induced bone disease can result from the primary disease itself, either due to circulating bone resorbing substances or metastatic bone disease, such as commonly occurs with breast, lung and prostate cancer, or from therapies administered to treat the primary condition thus causing bone loss and fractures. Treatment-induced osteoporosis may occur in the setting of glucocorticoid therapy or oestrogen deprivation therapy, chemotherapy-induced ovarian failure and androgen deprivation therapy. Tumour skeletal-related events include pathologic fractures, spinal cord compression, surgery and radiotherapy to bone and may or may not include hypercalcaemia of malignancy while skeletal complication refers to pain and other symptoms. Some evidence demonstrates the efficacy of various interventions including bone-modifying agents, such as bisphosphonates and denosumab, in preventing or delaying cancer-related bone disease. The latter includes treatment of patients with metastatic skeletal lesions in general, adjuvant treatment of breast and prostate cancer in particular, and the prevention of cancer-associated bone disease. This has led to the development of guidelines by several societies and working groups to assist physicians in clinical decision making, providing them with evidence-based care pathways to prevent skeletal-related events and bone loss. The goal of this paper is to put forth an IOF position paper addressing bone diseases and cancer and summarizing the position papers of other organizations. PMID:24146095

Rizzoli, R; Body, J-J; Brandi, M-L; Cannata-Andia, J; Chappard, D; El Maghraoui, A; Glüer, C C; Kendler, D; Napoli, N; Papaioannou, A; Pierroz, D D; Rahme, M; Van Poznak, C H; de Villiers, T J; El Hajj Fuleihan, G

2013-12-01

237

Shang Oracle Bones  

NASA Astrophysics Data System (ADS)

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.

Pankenier, David W.

238

Infrared laser bone ablation  

Microsoft Academic Search

The bone ablation characteristics of five infrared lasers, including three pulsed lasers (Nd:YAG, lambda = 1064 micron; Hol:YSGG, lambda = 2.10 micron; and Erb:YAG, lambda = 2.94 micron) and two continuous-wave lasers (Nd:YAG, lambda = 1.064 micron; and COâ, lambda = 10.6 micron), were studied. All laser ablations were performed in vitro, using moist, freshly dissected calvarium of guinea pig

Roger C. Nuss; Richard L. Fabian; Rajabrata Sarkar; Carmen A. Puliafito

1988-01-01

239

Exploring Bone Mineral Density  

NSDL National Science Digital Library

In this activity, students will explore two given websites to gather information on Bone Mineral Density and how it is measured. They will also learn about X-rays in general, how they work and their different uses, along with other imaging modalities. They will answer guiding questions as they explore the websites and take a short quiz after to test the knowledge they gained while reading the articles.

VU Bioengineering RET Program,

240

Bone disease in primary hyperparathyroidism.  

PubMed

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

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

2014-07-01

241

Bone disease in primary hyperparathyroidism  

PubMed Central

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

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

2015-01-01

242

Immune regulation of bone metastasis.  

PubMed

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

Capietto, Aude-Hélène; Faccio, Roberta

2014-01-01

243

Battling Brittle Bones  

NASA Technical Reports Server (NTRS)

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.

2002-01-01

244

Recombinant Human Bone Morphogenetic Protein Induces Bone Formation  

Microsoft Academic Search

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

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

1990-01-01

245

Development of Bone Remodeling Model for Spaceflight Bone Physiology Analysis  

NASA Technical Reports Server (NTRS)

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.

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

2015-01-01

246

Microgravity and bone cell mechanosensitivity.  

PubMed

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 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. PMID:15000126

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

2003-01-01

247

Microgravity and bone cell mechanosensitivity  

NASA Astrophysics Data System (ADS)

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.

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

2003-10-01

248

Clinical value of bone densitometry.  

PubMed

The purpose of this article is to provide insight into the long-standing controversy over the clinical value of noninvasive measurement of bone mass. Results of recent studies have increasingly supported the judicious use of bone densitometry as a clinical tool [1]. These reports contradict editorials on the limitations of bone densitometry that have appeared in a variety of subspecialty publications [2,3]. The importance of bone mass measurement is underscored by the lack of success in predicting bone density from various combinations of anthropometric and historical variables. Growing evidence suggests that densitometry is a useful tool for determining which women near menopause are at risk for osteoporosis and, therefore, are candidates for estrogen-replacement therapy. This article summarizes current concepts on the subject and attempts to prove that bone densitometry is a beneficial and indicated procedure for selected patients. PMID:8010199

Sartoris, D J

1994-07-01

249

Osteoclasts: more than 'bone eaters'.  

PubMed

As the only cells definitively shown to degrade bone, osteoclasts are key mediators of skeletal diseases including osteoporosis. Bone-forming osteoblasts, and hematopoietic and immune system cells, each influence osteoclast formation and function, but the reciprocal impact of osteoclasts on these cells is less well appreciated. We highlight here the functions that osteoclasts perform beyond bone resorption. First, we consider how osteoclast signals may contribute to bone formation by osteoblasts and to the pathology of bone lesions such as fibrous dysplasia and giant cell tumors. Second, we review the interaction of osteoclasts with the hematopoietic system, including the stem cell niche and adaptive immune cells. Connections between osteoclasts and other cells in the bone microenvironment are discussed within a clinically relevant framework. PMID:25008556

Charles, Julia F; Aliprantis, Antonios O

2014-08-01

250

Targeted therapies for bone sarcomas  

PubMed Central

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

Heymann, Dominique; Rédini, Françoise

2013-01-01

251

Targeted therapies for bone sarcomas.  

PubMed

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

Heymann, Dominique; Rédini, Françoise

2013-01-01

252

Magnitude and determinants of premenopausal bone loss  

Microsoft Academic Search

Bone loss prior to menopause may contribute to a woman's risk for fracture due to osteoporosis later in life. Most, but not all, longitudinal and cross-sectional studies suggest that bone mass decreases prior to menopause. This bone loss may be prevented by calcium supplementation. Heredity, exercise and menstrual status also have an impact on bone mass. Prevention of bone loss

D. T. Baran

1994-01-01

253

Stress fractures and bone pain  

SciTech Connect

Stress fractures result from an unusual repetitive physical activity causing absorption of bone in excess of repair and bone formation. This leads to the weakening of the bone and subsequently to a fracture. It is a benign condition that if recognized in time does not need any treatment besides rest. However, if diagnosis is not made and physical activity continues it may result in severe injury to the bone and a frank fracture may result. Pain is the typical clinical feature and bone scintigraphy, being more sensitive than radiography, is done to establish early diagnosis. The presence of asymptomatic sites of abnormal bone uptake typical of stress fracture in which pain appeared only about 2 weeks after scintigraphy, drew the authors' attention to the question of how close is the relationship between stress fractures and bone pain. Sixty-four military recruits diagnosed as suffering from stress fracture were investigated in order to correlate sites with abnormal uptake of Tc-99m MDP on bone scintigraphy with sites of local pain. In 37 (58%) subjects multiple sites of abnormal uptake were recognised. Of 123 sites of abnormal uptake, 31 (25%) were asymptomatic. In three patients bone pain appeared at the site of the abnormal uptake two weeks after scintigraphy. Bone scintigraphy appears to be more sensitive than bone pain in the diagnosis of stress fractures. The osteoblastic activity which manifests itself by abnormal uptake appears in some cases earlier than the pain caused by the fracture. Present findings may suggest that under certain circumstances, in a population prone to stress fracture, bone scan should be considered as a screening method.

Groshar, D.; Even-Sapir, E.; Lam, M.; Israel, O.; Front, D.

1984-01-01

254

Ectopic bone induction by equine bone protein extract.  

PubMed

Demineralized bone matrix from horse has been reported to be osteoinductive. However, its performance was inferior to autogenous bone graft in terms of new bone formation. In the present experiment, an equine bone protein extract-COLLOSS E was investigated for its osteoinductivity in a rat model. At the mean time, carboxymethyl-cellulose (CMC) was tested as a potential carrier for the protein extract. 18 male Wistar rats (8 weeks) were employed in the experiment. Each rat was implanted randomly with the 2 of the following implants, one on each side of the abdominal muscle. 1) COLLOSS E lyophilisate. 2) PEEK ring holder. 3) 3% or 10% CMC .in gel or lyophilized form 4) COLLOSS E lyophilisate with 3% CMC, implanted as gel or in lyophilized form. 5) COLLOSS E suspension with 10% CMC, implanted as gel or in lyophilized form. The rats were followed up for 21 days. After termination, samples were subjected to macroscopic examination, plain radiograph, micro-CT and histological evaluations. The results showed that PEEK ring or CMC alone could not induce ectopic bone formation. COLLOSS E lyophilisate has a slightly higher (6 out of 7) positive bone formation rate over COLLOSS E/3% CMC (3 out of 5, both gel and lyophilized form), however, the difference is non-significant (p=0.36, Fisher's exact test). 10% CMC with COLLOSS E did not show ectopic bone formation when implanted as gel form (0/8), while 1 positive bone formation was found when implanted as the lyophilized form (1/4). Bone tissue volume ranged from 0 mm(3) to 23.1mm(3) for COLLOSS-E lyophilisate alone and 0 to 29.7mm(3) for COLLOSS E/3%CMC (gel or lyophilized form). We concluded that equine bone protein extract has the ability to induce ectopic bone formation in the rat model. CMC could be a potential carrier, however, further studies are needed to verify the proportion and efficacy. PMID:17120797

Li, Haisheng; Springer, Marco; Zou, Xuenong; Briest, Arne; Bünger, Cody

2006-01-01

255

Symmetry analysis of talus bone  

PubMed Central

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

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

2014-01-01

256

Osteocyte-Driven Bone Remodeling  

PubMed Central

Osteocytes, the most abundant cells in bone, have been long postulated to detect and respond to mechanical and hormonal stimuli and to coordinate the function of osteoblasts and osteoclasts. The discovery that the inhibitor of bone formation sclerostin is primarily expressed in osteocytes in bone and it is downregulated by anabolic stimuli provided a mechanism by which osteocytes influence the activity of osteoblasts. Advances of the last few years provided experimental evidence demonstrating that osteocytes also participate in the recruitment of osteoclasts and the initiation of bone remodeling. Apoptotic osteocytes trigger yet to be identified signals that attract osteoclast precursors to specific areas of bone, which in turn differentiate to mature, bone resorbing osteoclasts. Osteocytes are also the source of molecules that regulate generation and activity of osteoclasts, such as OPG and RANKL; and genetic manipulations of the mouse genome leading to loss or gain of function, or to altered expression of either molecule in osteocytes, markedly affect bone resorption. This review highlights these investigations and discusses how the novel concept of osteocyte-driven bone resorption and formation impacts our understanding of the mechanisms by which current therapies control bone remodeling. PMID:24002178

Bellido, Teresita

2013-01-01

257

Bone substitutes in oral surgery.  

PubMed

Osseous defects pose a clinical challenge the operator can meet with the aid of techniques that promote bone tissue regeneration. The current gold standard is autologous bone harvested from intra- and extraoral donor sites; however, autologous bone grafting requires two surgical sites (donor and recipient), resulting in greater morbidity and prolonged operating times, particularly for extraoral sites, with greater discomfort for the patient. Such disadvantages can be overcome with the use of bone substitute materials. There is a notable variety of so-called intelligent biomaterials that can modulate bone response in regeneration. Based on origin, bone substitute materials are classified as allogenic, heterologous and alloplastic materials. The first refer to bone from same-species donors, the second are obtained through processing of bone from different species, while alloplastic materials are synthetic composites. Besides different resorption rates, they possess different chemical and structural characteristics that influence the stimulation or support of bone regeneration. In daily clinical practice, before selecting from the wide variety of biomaterials, a wise step is to analyze and compare the clinical and histological results obtained with these materials. This article examines the clinical applications and osteoconductive and/or osteoinductive properties of some currently available biomaterials. PMID:18091669

Pappalardo, S; Puzzo, S; Carlino, V; Cappello, V

2007-10-01

258

Microgravity and Bone Cell Mechanosensitivity  

NASA Astrophysics Data System (ADS)

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.

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

259

Bone morphogenetic proteins.  

PubMed

Bone morphogenetic proteins (BMPs) are multi-functional growth factors that belong to the transforming growth factor beta (TGFbeta) superfamily. The roles of BMPs in embryonic development and cellular functions in postnatal and adult animals have been extensively studied in recent years. Signal transduction studies have revealed that Smad1, 5 and 8 are the immediate downstream molecules of BMP receptors and play a central role in BMP signal transduction. Studies from transgenic and knockout mice and from animals and humans with naturally occurring mutations in BMPs and related genes have shown that BMP signaling plays critical roles in heart, neural and cartilage development. BMPs also play an important role in postnatal bone formation. BMP activities are regulated at different molecular levels. Preclinical and clinical studies have shown that BMP-2 can be utilized in various therapeutic interventions such as bone defects, non-union fractures, spinal fusion, osteoporosis and root canal surgery. Tissue-specific knockout of a specific BMP ligand, a subtype of BMP receptors or a specific signaling molecule is required to further determine the specific role of a BMP ligand, receptor or signaling molecule in a particular tissue. BMPs are members of the TGFbeta superfamily. The activity of BMPs was first identified in the 1960s (Urist, M.R. (1965) "Bone formation by autoinduction", Science 150, 893-899), but the proteins responsible for bone induction remained unknown until the purification and sequence of bovine BMP-3 (osteogenin) and cloning of human BMP-2 and 4 in the late 1980s (Wozney, J.M. et al. (1988) "Novel regulators of bone formation: molecular clones and activities", Science 242, 1528-1534; Luyten, F.P. et al. (1989) "Purification and partial amino acid sequence of osteogenin, a protein initiating bone differentiation", J. Biol. Chem. 264, 13377-13380; Wozney, J.M. (1992) "The bone morphogenetic protein family and osteogenesis", Mol. Reprod. Dev. 32, 160-167). To date, around 20 BMP family members have been identified and characterized. BMPs signal through serine/threonine kinase receptors, composed of type I and II subtypes. Three type I receptors have been shown to bind BMP ligands, type IA and IB BMP receptors (BMPR-IA or ALK-3 and BMPR-IB or ALK-6) and type IA activin receptor (ActR-IA or ALK-2) (Koenig, B.B. et al. (1994) "Characterization and cloning of a receptor for BMP-2 and BMP-4 from NIH 3T3 cells", Mol. Cell. Biol. 14, 5961-5974; ten Dijke, P. et al. (1994) "Identification of type I receptors for osteogenic protein-1 and bone morphogenetic protein-4", J. Biol. Chem. 269, 16985-16988; Macias-Silva, M. et al. (1998) "Specific activation of Smad1 signaling pathways by the BMP7 type I receptor, ALK2", J. Biol. Chem. 273, 25628-25636). Three type II receptors for BMPs have also been identified and they are type II BMP receptor (BMPR-II) and type II and IIB activin receptors (ActR-II and ActR-IIB) (Yamashita, H. et al. (1995) "Osteogenic protein-1 binds to activin type II receptors and induces certain activin-like effects", J. Cell. Biol. 130, 217-226; Rosenzweig, B.L. et al. (1995) "Cloning and characterization of a human type II receptor for bone morphogenetic proteins", Proc. Natl Acad. Sci. USA 92, 7632-7636; Kawabata, M. et al. (1995) "Cloning of a novel type II serine/threonine kinase receptor through interaction with the type I transforming growth factor-beta receptor", J. Biol. Chem. 270, 5625-5630). Whereas BMPR-IA, IB and II are specific to BMPs, ActR-IA, II and IIB are also signaling receptors for activins. These receptors are expressed differentially in various tissues. Type I and II BMP receptors are both indispensable for signal transduction. After ligand binding they form a heterotetrameric-activated receptor complex consisting of two pairs of a type I and II receptor complex (Moustakas, A. and C.H. Heldi (2002) "From mono- to oligo-Smads: the heart of the matter in TGFbeta signal transducti

Chen, Di; Zhao, Ming; Mundy, Gregory R

2004-12-01

260

Pregnane X receptor knockout mice display osteopenia with reduced bone formation and enhanced bone resorption  

E-print Network

of femoral trabecular bones revealed that the three-dimensional bone volume fraction of PXRKO mice was markedly reduced compared with that of WT mice. Histomorphometrical analysis of the trabecular bones of the trabecular bones, bone formation is reduced, whereas bone resorption is enhanced in PXRKO mice. Histomorphome

Blumberg, Bruce

261

The impact of inflammation on bone mass in children  

Microsoft Academic Search

Bone is a dynamic tissue. Skeletal bone integrity is maintained through bone modeling and remodeling. The mechanisms underlying\\u000a this bone mass regulation are complex and interrelated. An imbalance in the regulation of bone remodeling through bone resorption\\u000a and bone formation results in bone loss. Chronic inflammation influences bone mass regulation. Inflammation-related bone disorders\\u000a share many common mechanisms of bone loss.

Wai W. Cheung; Jian-Ying Zhan; Kyung Hoon Paik; Robert H. Mak

262

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

E-print Network

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...

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

2012-01-01

263

Quantitative Bone Scan and Bone Metastases in Prostatic Cancer  

Microsoft Academic Search

Bone scan is an essential method of investigation for the detection of metastases; it is also used to follow the evolution of the disease and the response to treatment in prostatic cancer. The authors tried a bone scan quantification method to better evaluate the efficiency of hormonal treatment. 28 patients were followed up by this method. Taken as a whole,

J. C. Grob; J. Thiel; G. Méthlin; P. Wolf; C. Bollack

1985-01-01

264

Bone mineral density and bone turnover in spinal osteoarthrosis  

Microsoft Academic Search

OBJECTIVES--To determine whether there was a generalised increase in bone mineral density (BMD) in spinal osteoarthrosis (OA), and to determine the mechanism of this possible protection against osteoporosis as assessed by biochemical markers of bone turnover. METHODS--We studied 375 women (ages 50 to 85) from a population based group. Spinal OA was defined from radiographs as the presence of degenerative

N F Peel; N A Barrington; A Blumsohn; A Colwell; R Hannon; R Eastell

1995-01-01

265

Crosstalk between cartilage and bone: when bone cytokines matter.  

PubMed

The cartilage damage which characterizes osteoarthritis is often accompanied by bone lesions. Joint integrity results from the balance in the physiological interactions between bone and cartilage. Several local factors regulate the physiological remodeling of cartilage, the disequilibrium of these leading to a higher cartilage catabolism. Several cytokines secreted by bone cells can induce chondrocyte differentiation, which suggests their role in the dialogue between both cells. Accumulative in vivo evidence shows that increased bone resorption occurs at an early stage in the development of osteoarthritis and that blocking bone-resorbing cytokines prevents cartilage damage, confirming the role of bone factors in the crosstalk of both tissues. Recently, molecules of the Wnt pathway have emerged as key regulators of bone and cartilage. Activation of Wnt/?catenin induces an imbalance in cartilage homeostasis, and agonists/antagonists of Wnt are potential candidates for this interaction. This review will summarize what is known about the contribution of bone cytokines to the physiological remodeling of cartilage and in the pathophysiology of osteoarthritis. PMID:21596615

Funck-Brentano, Thomas; Cohen-Solal, Martine

2011-04-01

266

Mechanical Behavior of Bone Cells micrograph view of bone  

E-print Network

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

Gefen, Amit

267

Bones in Balance  

NSDL National Science Digital Library

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

2009-10-05

268

Bone marrow stem cells.  

PubMed

The "mesenchymal stem cells (MSCs)" are cells adherent in the bone marrow, which can be isolated to induce differentiation. In contrast to the "embryonic stem cells" whose goal is to develop a new organism, the "MSC adult stem cells" can participate in tissue growth and repair throughout postnatal life. Addition of 5-azacytidine to MSCs in vitro induces the gradual increase in cellular size and begins spontaneous beatings, thereafter differentiating into cardiomyocytes. The "Methods" and "Protocols" to induce structural and functional maturations of MSCs, thus to achieve "Cellular Cardiomyoplasty," are described. With appropriate media, differentiations of MSCs to various kinds of cells such as chondrocytes, osteocytes, and adipocytes are also achievable. PMID:23807784

Duong, Minh Ngoc; Ma, Yu-Ting; Chiu, Ray C J

2013-01-01

269

Effects of osteoporosis therapies on bone biomechanics  

E-print Network

in contrast, anabolic agents stimulate bone remodeling toSince the anabolic agent PTH stimulates bone remodeling andAnabolic agents, such as parathyroid hormone (PTH, the only approved skeletal anabolic agent), stimulate bone

Easley, Sarah Kathleen

2010-01-01

270

How Often Should Women Have Bone Tests?  

MedlinePLUS

... Facts Links Osteoporosis Osteoporosis: The Bone Thief Bone Mass Measurement: What the Numbers Mean Keeping Bones Healthy and Strong CONTACT US NIH Office of Communications and Public Liaison Building 31, Room 5B64 Bethesda, ...

271

Raman spectroscopy of bone metastasis  

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

272

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

PubMed

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, 2014. PMID:25448127

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

2014-11-29

273

Bone induction and bone repair by composites of bone morphogenetic protein and biodegradable synthetic polymers.  

PubMed

We developed adequate delivery systems for bone morphogenetic protein (BMP) to express its bone-inducing activity by combining it with biodegradable synthetic polymers, these causing no unfavorable tissue reaction or anti-BMP effect. Their efficacy was tested for ectopic bone formation in mice and reconstruction of large segmental bone defects of the tibiae in rabbits. Composites of semipurified BMP and polylactic acid--polyethylene glycol block copolymer (PLA-PEG), and composites of BMP, PLA-PEG and lactic acid--glycolic acid copolymer (PLGA) were implanted under the fasciae of the dorsal muscles of mice. Three weeks after implantation, both the BMP/PLA-PEG and BMP/PLA-PEG/PLGA composites were completely absorbed and replaced by newly induced bone with hematopoietic marrow. Because the BMP/PLA-PEG composite is a viscous semiliquid and the BMP/PLA-PEG/PLGA composite is a plastic and moldable, the former can be used as an injectable bone-inducing material and the latter as a plastic mold. The BMP/PLA-PEG/PLGA composites were implanted in large segmental bone defects in the tibiae in rabbits. Twelve weeks after implantation, the bone defect was completely restored by a newly formed bone mass of the original thickness and structure. PMID:8154840

Miyamoto, S; Takaoka, K

1993-01-01

274

Bone densitometry in infants  

SciTech Connect

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.

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

1988-07-01

275

Bone surface modifications in zooarchaeology  

Microsoft Academic Search

Cutmarks made by stone tools, conchoidal flake scars from hammerstone percussion, carnivore tooth marks, striations from sedimentary abrasion, and other surface modifications on bones from archaeological sites constitute a crucial body of evidence for investigating the role of human behaviors and of nonhuman taphonomic processes in site formation. This paper describes the various kinds of bone surface modifications produced by

1995-01-01

276

Interaction between Muscle and Bone.  

PubMed

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

Kaji, Hiroshi

2014-02-01

277

Interaction between Muscle and Bone  

PubMed Central

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

2014-01-01

278

Space Radiation and Bone Loss  

PubMed Central

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

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

2011-01-01

279

Not Bare Bones at All  

NSDL National Science Digital Library

In this lesson, students examine the literal, physiological and figurative significance of bones through experimentation, then create their own skeleton-related exhibits for a “Bone and Skeleton Museum.” The suggested time allowance for this lesson is 1-2 class periods.

Catherine Hutchings

2009-05-05

280

Cystinosis with sclerotic bone lesions.  

PubMed

A 26-year-old male with nephropathic cystinosis treated with cysteamine and renal transplantation presented for evaluation of multiple sclerotic bone lesions, which were an incidental finding on chest computerized tomography. These lesions were in a pattern consistent with osteoblastic metastases. He did not have a history of clinically significant hyperparathyroidism or cytopenias either preceding or following his transplant. Bone and tumor markers (including alkaline phosphatase and calcium) were all normal. A percutaneous bone biopsy of the lesions showed changes compatible with cystine deposition. Our case demonstrates that sclerotic bone lesions can be a feature of cystinosis in patients with normal parathyroid function and that significant bone marrow infiltration with cystine can be present even in the absence of cytopenias. PMID:24097416

Sirrs, S; Munk, P; Mallinson, P I; Ouellette, H; Horvath, G; Cooper, S; Da Roza, G; Rosenbaum, D; O'Riley, M; Nussbaumer, G; Hoang, L N; Lee, C H

2014-01-01

281

Acoustic effects during bone ablation  

NASA Astrophysics Data System (ADS)

In surgical applications of lasers, it is often necessary to know when a laser has penetrated a bone. There are many instances when it is critical to avoid damaging tissue beneath the bone. We are developing a system to monitor the ablation of bone. We have found a method to detect when the bone has been penetrated by measuring the photo acoustic signal generated by a pulsed laser. Using a transducer on samples of temporal bone and several model substances, we can see a decrease in the power spectrum near 350 kHz as softer materials is ablated. The current results are from a carbon dioxide laser operating in the super pulse mode. We are developing the technique for use with the Vanderbilt Free Electron Laser as part of our computer assisted surgery techniques program.

Reinisch, Lou; Ossoff, Robert H.

1993-07-01

282

Ethnic Differences in Bone Health  

PubMed Central

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

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

2015-01-01

283

[Bone and Calcium Research Update 2015. Regulation of bone remodeling by osteocytes].  

PubMed

Bone is constantly renewed by the balanced action of bone formation and bone resorption both of which mainly occur at the bone surface. This restructuring process called "bone remodeling" is important not only for normal bone mass and strength, but also for mineral homeostasis. An imbalance of bone remodeling is often linked to various bone diseases. During bone remodeling, resorption by osteoclasts precedes bone formation by osteoblasts. Based on the osteocyte location within the bone matrix and the cellular morphology, it is proposed that osteocytes potentially contribute to the controls of bone remodeling by sensing mechanical stress and hormones. Furthermore, bone has been traditionally regarded as a part of the skeletal and locomotor system, but recent studies suggest that osteocytes regulate systemic biological functions based on the inseparable link between bone and other systems. PMID:25530519

Nakashima, Tomoki

2015-01-01

284

Denosumab: A bone antiresorptive drug.  

PubMed

Bone remodeling is the continuous process by which old bone is removed by bone-resorbing cells, the osteoclasts and replaced by new bone synthesized by bone forming cells, the osteoblasts. Osteoporosis is characterized by a progressive loss of bone mass and microarchitecture, which leads to increased fracture risk. Denosumab, a human monoclonal antibody resembling natural IgG2 immunoglobulin, has antiresorptive activity and is distinguished from other antiresorptive drugs. It mimics osteoprotegerin (OPG) that binds to RANKL and hence does not allow RANKL to bind with RANK receptor, thereby inhibiting osteoclast differentiation, activation and survival exerting primarily antiresorptive action. Denosumab trials have shown its efficacy in postmenopausal women with osteoporosis, unresectable giant cell tumor of bone and significant effect in non-metastatic prostate cancer and delay in the time-to-first skeletal related events (SRE) and subsequent SRE with denosumab than zoledronic acid in patients. It is available as 60 mg/ml in pre-filled syringes and approved for osteoporosis in postmenopausal women (60 mg s.c. twice yearly), unresectable giant cell tumor of bone in adults and skeletally mature adolescents (120 mh s.c. monthly), prevention of skeletal-related events and to increase bone mass in patients at high risk for fracture including androgen deprivation therapy for non-metastatic prostate cancer or adjuvant aromatase inhibitor therapy for breast cancer. Denosumab offers advantages of twice yearly dosing in osteoporosis and monthly dosing in giant cell tumor of bone with its novel mechanism of action and better tolerability. PMID:25609868

Dahiya, Navdeep; Khadka, Anjan; Sharma, A K; Gupta, A K; Singh, Nishith; Brashier, D B S

2015-01-01

285

Impact of bone geometry on effective properties of bone scaffolds.  

PubMed

The characterization of bone/scaffold composite mechanical properties is essential for translation to the clinic, but in vivo studies require resources and personnel not available to many investigators. Therefore, the ability to predict composite properties could facilitate scaffold evaluation and reduce the number of in vivo studies required. To date, there have been no studies that have used experimental data to formulate a model of bone morphology or that have examined morphology as a variable in composite properties. In this study, a simple model was developed to predict the effective elastic properties of hydroxyapatite (HA) scaffold/bone composites using representative volume elements (RVE) and finite element analysis. While the RVE for the scaffold is clear, the choice of RVE for bone is not. Two bone geometries were generated for the RVE based on data from an in vivo study: a uniform coating and bridges in pores. Three scaffolds were evaluated in order to consider the effects of scaffold material modulus and porosity. Results showed that the bone geometry had little influence on composite elastic properties when compared to experimental error from the in vivo study. The implication is that such properties can be estimated by measuring the volume fraction of bone using a non-destructive method like microcomputerized tomography and the simple RVE model. PMID:18955024

McIntosh, L; Cordell, J M; Wagoner Johnson, A J

2009-02-01

286

Bone composition: relationship to bone fragility and antiosteoporotic drug effects  

PubMed Central

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

Boskey, Adele L

2013-01-01

287

Dissociation of bone formation markers in bone metastasis of prostate cancer  

Microsoft Academic Search

To clarify the meaning and clinical value of bone formation markers in bone metastasis from prostate cancer, we investigated the bone formation markers carboxy-terminal propeptide of type I procollagen (PICP), bone-specific alkaline phosphatase (BA1-p) and osteocalcin, so-called bone gla protein (BGP) in 43 prostate cancer patients with and 46 patients without overt bone metastasis. Patients with bone metastasis were evaluated

M Koizumi; H Maeda; K Yoshimura; T Yamauchi; T Kawai; E Ogata

1997-01-01

288

Bone histologic response to deferoxamine in aluminum–related bone disease  

Microsoft Academic Search

Bone histologic response to deferoxamine in aluminum–related bone disease. We have examined the changes in bone histology in 28 uremic patients after long–term treatment with the aluminum chelator, deferoxamine. Marked declines in stainable bone–surface aluminum were associated with increases in bone formation rate and osteoblastic osteoid following deferoxamine. The increased bone formation resulted from increases in bone apposition and length

Dennis L Andress; Henry G Nebeker; Susan M Ott; David B Endres; Allen C Alfrey; Eduardo A Slatopolsky; Jack W Coburn; Donald J Sherrard

1987-01-01

289

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

PubMed

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

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

2014-10-01

290

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

PubMed Central

Background: Repair of diaphyseal bone defects is a challenging problem for orthopedic surgeons. In large bone defects the quantity of harvested autogenous bone may not be sufficient to fill the gap and then the use of synthetic or allogenic grafts along with autogenous bone becomes mandatory to achieve compact filling. Finding the optimal graft mixture for treatment of large diaphyseal defects is an important goal in contemporary orthopedics and this was the main focus of this study. The aim of this study is to investigate the efficacy of demineralized bone matrix (DBM) and autogenous cancellous bone (ACB) graft composite in a rabbit bilateral ulna segmental defect model. Materials and Methods: Twenty-seven adult female rabbits were divided into five groups. A two-centimeter piece of long bone on the midshaft of the ulna was osteotomized and removed from the rabbits’ forearms. In group 1 (n=7) the defects were treated with ACB, in group 2 (n=7) with DBM, and in group 3 (n=7) with ACB and DBM in the ratio of 1:1. Groups 4 and 5, with three rabbits in each group, were the negative and positive controls, respectively. Twelve weeks after implantation the rabbits were sacrificed and union was evaluated with radiograph (Faxitron), dual-energy x-ray absorptiometry (DEXA), and histological methods (decalcified sectioning). Results: Union rates and the volume of new bone in the different groups were as follows: group 1 - 92.8% union and 78.6% new bone; group 2 - 72.2% union and 63.6% new bone; and group 3 - 100% union and 100% new bone. DEXA results (bone mineral density [BMD]) were as follows: group 1 - 0.164 g/cm2, group 2 - 0.138 g/cm2, and group 3 - 0.194 g/cm2. Conclusions: DBM serves as a graft extender or enhancer for autogenous graft and decreases the need of autogenous bone graft in the treatment of bone defects. In this study, the DBM and ACB composite facilitated the healing process. The union rate was better with the combination than with the use of any one of these grafts alone. PMID:21559101

Ozdemir, Mehmet T; Kir, Mustafa Ç

2011-01-01

291

Androgens and bone.  

PubMed

Testosterone is the major gonadal sex steroid produced by the testes in men. Androgens induce male sexual differentiation before birth and sexual maturation during puberty; in adult men, they maintain the function of the male genital system, including spermatogenesis. Testosterone is also produced in smaller amounts by the ovaries in women. The adrenal glands produce the weaker androgens dehydroepiandrosterone, dehydroepiandrosterone sulfate, and androstenedione. Because testosterone can be metabolized to estradiol by the aromatase enzyme, there has been controversy as to which gonadal sex steroid has the greater skeletal effect. In this respect, there is increasing evidence that at least part of the effects of androgens in men can be explained by their aromatization into estrogens. The current evidence suggests that estradiol plays a greater role in maintenance of skeletal health than testosterone, but that androgens also have direct beneficial effects on bone. PMID:23235187

De Oliveira, D H A; Fighera, T M; Bianchet, L C; Kulak, C A M; Kulak, J

2012-12-01

292

Living Bones, Strong Bones - Duration: 3:41.  

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...

293

Myxoid chondrosarcoma of sphenoid bone  

PubMed Central

The myxoid variant of chondrosarcoma is usually seen in soft tissues where it is known as chordoid sarcoma or parachordoma. Rarely, it involves bone and when it does, cranial bones are the preferred location. This tumor is frequently amalgamated with the chondroid variant of chordoma, especially when the lesion occurs in the sphenoid bone/spheno-occipital region, because of their similar clinical presentations, anatomical locations, radiological findings, and mistaken histopathological features. It is essential to distinguish myxoid chondrosarcoma from the chondroid variant of chordoma, because of the different treatment protocol and prognostic importance. We present such a location-based diagnostic dilemma, solved successfully with ancillary immunohistochemistry. PMID:23189013

Chowhan, Amit K; Rukmangadha, Nandyala; Patnayak, Rashmi; Bodapati, Chandra Mouliswara Prasad; Bodagala, Vijaya Laxmi; Reddy, Mandyam Kumaraswamy

2012-01-01

294

Antiepileptic medication and bone health  

Microsoft Academic Search

Background  Epilepsy is a common chronic neurological disorder, usually requiring long-term treatment with anti-epileptic drugs (AED).\\u000a Many studies have reported that AED therapy is associated with metabolic bone disease and is a major iatrogenic risk factor\\u000a for fractures. There remains uncertainty about the type(s) of bone disease due to AED treatment, and the pathogenesis of AED-associated\\u000a fractures.\\u000a \\u000a \\u000a \\u000a Rationale  Deficits in bone mineral

S. J. Petty; T. J. O’Brien; J. D. Wark

2007-01-01

295

A Boon for Bone Research  

NASA Technical Reports Server (NTRS)

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.

1996-01-01

296

Anabolic Agents and Bone Quality  

Microsoft Academic Search

Background  The definition of bone quality is evolving particularly from the perspective of anabolic agents that can enhance not only\\u000a bone mineral density but also bone microarchitecture, composition, morphology, amount of microdamage, and remodeling dynamics.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  This review summarizes the molecular pathways and physiologic effects of current and potential anabolic drugs.\\u000a \\u000a \\u000a \\u000a Methods  From a MEDLINE search (1996–2010), articles were identified by the search

Tarek Sibai; Elise F. Morgan; Thomas A. Einhorn

297

Gaucher disease and bone manifestations.  

PubMed

Gaucher disease is a relatively rare metabolic disease caused by the inherited deficiency of the lysosomal enzyme glucocerebrosidase. Gaucher disease affects multiple organs, among which is the skeleton. Bone involvement occurs frequently in Gaucher disease, and is one of its most debilitating features, reducing the quality of life of patients. Bone status is an important consideration for treatment to ameliorate symptoms and reduce the risk of irreversible complications. We have conducted a systematic review of all the various aspects of Gaucher disease, focusing on different skeletal manifestations, pathophysiology of bone alterations, clinical symptoms, and current diagnostic and therapeutic approaches. PMID:25377906

Marcucci, Gemma; Zimran, Ari; Bembi, Bruno; Kanis, John; Reginster, Jean-Yves; Rizzoli, Renè; Cooper, Cyrus; Brandi, Maria Luisa

2014-12-01

298

Give the Dog a Bone  

NSDL National Science Digital Library

Ten bones are hidden in the squares of a blank 1-100 grid. Students are given the numbers of the squares one at a time. They attempt to locate the numbers in the hundreds chart and find all 10 bones within 60 seconds. Numbers of the incorrectly guessed squares are left in place to help with the search. The game helps students understand the structure and patterns of our base-10 number system. Children can be encouraged to make use of a found bone to locate the next one.

Mark Cogan

2002-01-01

299

Malignant bone pain: pathophysiology and treatment  

Microsoft Academic Search

The presence of bone metastases predicts the presence of pain and is the most common cause of cancer-related pain. Although bone metastases do not involve vital organs, they may determine deleterious effects in patients with prolonged survival. Bone fractures, hypercalcaemia, neurologic deficits and reduced activity associated with bone metastases result in an overall compromise in the patient's quality of life.

Sebastiano Mercadante

1997-01-01

300

Solid-State NMR Studies of Bone  

Microsoft Academic Search

Solid-state NMR studies on bone, bone mineral standards and collagen are reviewed. NMR spectroscopy was mostly applied to the bone mineral and confirmed that the structure resembles that of calcium carbonatoapatite of type B. Apatite in bone was found to be deficient in structural hydroxyl groups. Concentration and distribution of hydrogenphosphate and carbonate ions, and of water in apatite crystals

Waclaw Kolodziejski

301

Trabecular bone scaffolding using a biomimetic approach  

Microsoft Academic Search

The current treatment of large bone defects has several disadvantages. An alternative for using grafts or bone cement for the filling of bone cavities is the use of a bone scaffold that provides a temporary load-bearing function. This paper describes a biomechanical design procedure for a personalized implant with a geometry that has a good fit inside the defect and

T. van Cleynenbreugel; H. van Oosterwyck; J. Vander Sloten; J. Schrooten

2002-01-01

302

Role of carotenoid ?-cryptoxanthin in bone homeostasis  

PubMed Central

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

2012-01-01

303

Sticks and Stones Will Break That Bone!  

NSDL National Science Digital Library

Students learn about the strength of bones and methods of helping to mend fractured bones. During a class demonstration, a chicken bone is broken by applying a load until it reaches a point of failure (fracture). Then, working as biomedical engineers, students teams design their own splint or cast to help repair a fractured bone, learning about the strength of materials used.

Integrated Teaching and Learning Program,

304

Air-filled (Pneumatic) Bone Experiments  

NSDL National Science Digital Library

Just like birds, some dinosaurs had air-filled (pneumatic) bones, which made the dinosaurs' skeletons lighter. In this activity, learners bake chicken or turkey bones and then rub the ends off the bones with sandpaper to expose air spaces inside. This activity would be great during Thanksgiving vacation, or any other holiday when you have bones left over from dinner.

Lawrence Hall of Science

2005-01-01

305

Bone integrity and bone metastases in breast cancer  

Microsoft Academic Search

Individuals with a history of early-stage breast cancer may be at increased risk of osteoporosis related to adjuvant therapy,\\u000a and those with metastatic breast cancer may experience skeletal-related complications from the cancer affecting the bone.\\u000a Maintaining bone strength is critical in the care of both early- and late-stage breast cancer patients because fractures are\\u000a associated with morbidity and mortality. This

Catherine Van Poznak; Cristina Nadal

2006-01-01

306

Osteoporotic equine bone modeling: 3-point bending of deer metacarpal bone  

Microsoft Academic Search

Current lack of data for equine metacarpal bone mechanical properties hinders the design of plating systems for horses. Due to the difficulties of obtaining equine bones, as well as physical similarities found in deer bones, the goals of this study are to determine if deer (Odocoileus virginianus borealis) metacarpal bones are comparable to equine (Equus ferus caballus) third metacarpal bones

Harry Hovagimian; Chris Molica; Kristen Billiar

2011-01-01

307

Noninvasive assessment of bone architecture by magnetic resonance micro-imaging-based virtual bone biopsy  

Microsoft Academic Search

The mechanical competence of trabecular bone, the type of bone constituting the vertebrae and ends of the long bones, is largely de- termined by the bone's volume fraction and architectural make-up. Experimental and clinical evidence suggests that up to 50% of tra- becular bone strength is determined by parameters characterizing the network's architecture. Although rarely clinically indicated be- cause of

Felix W. Wehrli; Punam K. Saha; Byron R. Gomberg; Hee Kwon Song

2003-01-01

308

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

E-print Network

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

Simmons, Craig A.

309

Markers of bone turnover for the management of patients with bone metastases from prostate cancer  

Microsoft Academic Search

Although increased bone formation is a prominent feature of patients with osteosclerotic metastases from prostate cancer, there is also some evidence for increased bone resorption. The aim of this study was to compare the clinical utility of new bone resorption markers to that of bone formation in patients with bone metastases from prostate cancer before and after bisphosphonate treatment. Thirty-nine

P Garnero; N Buchs; J Zekri; R Rizzoli; R E Coleman; P D Delmas

2000-01-01

310

Super bone scan in metastatic stomach cancer.  

PubMed

Within the imaging literature, the super bone scan has emerged as a distinct type of bone scan with a specific differential diagnosis. Previous reviews have included prostate, breast, bladder and colon cancer, and lymphoma among the causes of a super bone scan but have not included stomach cancer. We report a super bone scan caused by late recurrence of stomach cancer in the bone marrow. Because the management of stomach cancer is significantly different than the management of other causes of a super bone scan, the distinction is clinically relevant. We conclude that stomach cancer should be considered in the differential diagnosis of a super bone scan. PMID:2353494

Saphner, T; Love, R R; Perlman, S

1990-04-01

311

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

PubMed

Bone defects can occur in various forms and present challenges to performing a standard micro-CT evaluation of bone quality because most measures are suited to homogeneous structures rather than ones with spatially focal abnormalities. Such defects are commonly associated with pain and fragility. Research involving bone defects requires quantitative approaches to be developed if micro-CT is to be employed. In this study, we demonstrate that measures of inter-microarchitectural bone spacing are sensitive to the presence of focal defects in the proximal tibia of two distinctly different mouse models: a burr-hole model for fracture healing research, and a model of osteolytic bone metastases. In these models, the cortical and trabecular bone compartments were both affected by the defect and were, therefore, evaluated as a single unit to avoid splitting the defects into multiple analysis regions. The burr-hole defect increased mean spacing (Sp) by 27.6%, spacing standard deviation (SpSD) by 113%, and maximum spacing (Spmax) by 72.8%. Regression modeling revealed SpSD (?=0.974, p<0.0001) to be a significant predictor of the defect volume (R(2)=0.949) and Spmax (?=0.712, p<0.0001) and SpSD (?=0.271, p=0.022) to be significant predictors of the defect diameter (R(2)=0.954). In the mice with osteolytic bone metastases, spacing parameters followed similar patterns of change as reflected by other imaging technologies, specifically bioluminescence data which is indicative of tumor burden. These data highlight the sensitivity of spacing measurements to bone architectural abnormalities from 3D micro-CT data and provide a tool for quantitative evaluation of defects within a bone. PMID:23830560

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

2013-11-01

312

The preparation of bone cement.  

PubMed

The hip joint is subjected to large, repetitive loads. It is therefore clear that the bone cement, which allows the transfer of load across the new joint, must be able to withstand the everyday loads that it will be subjected to. Improving the mechanical properties of the cement to withstand high stresses, fatigue and creep loading will reduce the chances of failure, ultimately increasing the longevity of the joint replacement. To date, work in this area has concentrated on improving the mechanical properties of bone cement through improved bone cement mixing techniques. In the next issue we will be covering the effect that the design of the mixer and vacuum mixing has on improving the mechanical properties, such as the strength, fatigue and creep resistance, of the bone cement. PMID:11892336

Eveleigh, R

2001-02-01

313

Metallic materials stimulating bone formation.  

PubMed

Metallic materials implanted into bone defects are generally encapsulated by a fibrous tissue. Some metallic materials such as titanium and tantalum, however, have been revealed to bond to the living bone without forming the fibrous tissue, when they were subjected to NaOH solution and heat treatments. Thus treated metals form bone tissue around them even in muscle, when they take a porous form. This kind of osteoconductive and osteoinductive properties are attributed to sodium titanate or tantalate layer on their surfaces formed by the NaOH and heat treatments. These layers induce the deposition of bonelike apatite on the surface of the metals in the living body. This kind of bioactive metals are useful as bone substitutes even highly loaded portions, such as hip joint, spine and tooth root. PMID:15468833

Kokubo, T

2004-05-01

314

Heart drugs that affect bone.  

PubMed

There have been important developments in our understanding of the mechanisms underlying the development of osteoporosis, and several of these mechanisms also underlie atherosclerosis. Drugs given to treat cardiovascular disease may impact on bone health in either a beneficial or a harmful way. There is evidence that nitrates are beneficial to bone, but evidence for the benefit of statins, thiazide diuretics, and ?-blockers is weaker. By contrast, it is likely to be that some drugs such as loop-acting diuretics are harmful to bone, whereas evidence for harm caused by drugs such as warfarin is weaker. These observations point towards opportunities for new drug development for bone diseases, and possibly the development of treatments that will benefit more than one disease. PMID:22136934

Walsh, Jennifer S; Newman, Chris; Eastell, Richard

2012-04-01

315

Issues in modern bone histomorphometry.  

PubMed

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

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

2011-11-01

316

Insulin and bone: Recent developments.  

PubMed

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

Klein, Gordon L

2014-02-15

317

Pregnancy, Breastfeeding, and Bone Health  

MedlinePLUS

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

318

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.

319

Healthy Bones at Every Age  

MedlinePLUS

... and water are better beverage alternatives for all age groups. Adolescent pregnancy. Like other adolescents, young women who are ... like soccer and basketball. Healthy Bones at Every Age cont. Adolescents grow rapidly and need 1,300 mg of ...

320

Limb Salvage After Bone Cancer  

MedlinePLUS

... a combination bone graft and metal implant (allo-prosthetic composite). The goal of this type of surgery ... other procedures may be necessary to accommodate growth. Prosthetic loosening – Sometimes the implanted joint can loosen or ...

321

Exercise, lifestyle, and your bones  

MedlinePLUS

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

322

Bone Grafting the Cleft Maxilla  

MedlinePLUS

... 2) prosthetic replacement (dental bridge); or 3) dental metallic bone implants. The best option for an individual ... Finding Nemo 11/26/14 , No Comments CPF’s New Arrival 11/18/14 , No Comments En Español ¿ ...

323

Bone fracture repair - series (image)  

MedlinePLUS

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

324

Bone marrow transplantation: a review.  

PubMed Central

Bone marrow transplantation represents the technical application of basic immunologic principles to the treatment of a variety of neoplastic and allied disorders that originate in the bone marrow. The results have improved during the past 15 years, being most striking for the treatment of the acute and chronic leukemias. The promise of autologous bone marrow transplantation for the treatment of leukemias and solid tumors is awaiting the perfection of techniques for the effective removal of residual neoplastic cells as well as more effective therapy. The use of this technique at its present stage of development for the treatment of benign hematologic disorders, which cause severe morbidity (ie, thalassemia or sickle cell anemia), is controversial, raises serious ethical issues, and cannot be recommended routinely at this time. Complications of bone marrow transplantation such as graft rejection, graft-versus-host disease, and opportunistic infections are discussed. PMID:2664196

Hardy, R. E.; Ikpeazu, E. V.

1989-01-01

325

Inherited Bone Marrow Failure Syndromes  

MedlinePLUS

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

326

[Bone substitutes - basic principles and clinical applications].  

PubMed

Treatment of bone defects and non-unions frequently requires the transplantation of autologous bone. As an alternative, different kinds of bone substitutes have been used more often during the past years. These bone substitutes include synthetic materials, just as well as processed materials from human donors (allogen) or animals (xenogen). The relatively low hurdles in the approval process, compared to pharmaceutical drugs, have led to an almost unmanageable amount of different kinds of bone substitutes. Due to sparse clinical studies, evidence-based decisions for a specific product or a specific indication are hardly possible. Therefore, a deeper knowledge about basic properties of different bone substitutes is needed for a rational clinical decision. The present review aims to clarify the sometimes confusing nomenclature of bone substitutes and discuss their different biological properties. Generally, bone substitutes can be discriminated in osteogenic, osteoinductive and osteoconductive materials. The great majority of bone substitutes and especially synthetic materials serve as a matrix for bone growth and therefore possess mainly osteoconductive properties. The combination of these osteoconductive materials with osteogenic cells or osteoinductive growth factors, leads to composite materials with higher bone forming potential. Clinically, the quality and vitality of the recipient bone defect is of great importance. As a prerequisite for successful transplantation of bone substitutes or autologous bone, the recipient bone defect should be mechanically stable, free of infection with vital bone ends and intact soft tissue coverage. Bone defects in the spine, methaphyseal defects after trauma/tumour and diaphyseal segmental defects are typical indications for the application of bone substitutes. Unfortunately, the current literature does not allow concrete recommendations for specific bone substitutes or specific clinical indications. However, this review aims to discuss clinical benefits and limitations of bone substitutes for frequent indications to help clinicians in their decision making process. PMID:24760455

Garcia, P; Franz, D; Raschke, M

2014-04-01

327

Mineralized three-dimensional bone constructs  

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

328

Mineralized Three-Dimensional Bone Constructs  

NASA Technical Reports Server (NTRS)

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.

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

2013-01-01

329

Bone tissue engineering with human stem cells  

Microsoft Academic Search

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

Darja Marolt; Miomir Knezevic; Gordana Vunjak Novakovic

2010-01-01

330

Research opportunities in bone demineralization, phase 3  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

331

Bone Metastasis and Pathological Fractures  

Microsoft Academic Search

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

Laurie A. McDuffee; Nigel Colterjohn; Gurmit Singh

332

Bone scintigraphy in diabetic osteoarthropathy  

SciTech Connect

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.

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

1981-08-01

333

[Bone marrow scanning (author's transl)].  

PubMed

Personal experience of Technetium-99m-sulfur colloid in the scintiscanning of bone marrow is reported. The method offers technical advantages over other methods and superior protection, while its only limitation is that it does not permit a dynamic study of hematopoiesis. Four pathologic scans typical of four groups of diseases may be distinguished. Further, metastatic bone marrow localisations can be diagnosed much earlier and more precisely than by radiography. PMID:1162751

Salvatore, M; Muto, V; Tarallo, L; Stanzione, R

1975-01-01

334

Unsuspected pregnancy during bone scintigraphy  

SciTech Connect

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.

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

1990-06-01

335

Bone marrow-targeted liposomal carriers  

PubMed Central

Introduction Bone marrow targeted drug delivery systems appear to offer a promising strategy for advancing diagnostic, protective, and/or therapeutic medicine for the hematopoietic system. Liposome technology can provide a drug delivery system with high bone marrow targeting that is mediated by specific phagocytosis in bone marrow. Area covered This review focuses on a bone marrow specific liposome formulation labeled with technetium-99m (99mTc). Interspecies differences in bone marrow distribution of the bone marrow targeted formulation are emphasized. This review provides a liposome technology to target bone marrow. In addition, the selection of proper species for the investigation of bone marrow targeting is suggested. Expert opinion It can be speculated that the bone marrow macrophages have a role in the delivery of lipids to the bone marrow as a source of energy and for membrane biosynthesis or in the delivery of fat soluble vitamins for hematopoiesis. This homeostatic system offers a potent pathway to deliver drugs selectively into bone marrow tissues from blood. High selectivity of the present BMT-liposome formulation for bone marrow suggests the presence of an active and specific mechanism, but specific factors affecting the uptake of the bone marrow MPS are still unknown. Further investigation of this mechanism will increase our understanding of factors required for effective transport of agents to the bone marrow, and may provide an efficient system for bone marrow delivery for therapeutic purposes. PMID:21275831

Sou, Keitaro; Goins, Beth; Oyajobi, Babatunde O.; Travi, Bruno L.; Phillips, William T.

2011-01-01

336

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

PubMed Central

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

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

2014-01-01

337

Bone age in cerebral palsy  

PubMed Central

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

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

338

Giant cell tumor of bone.  

PubMed

Giant cell tumor (GCT) of bone is one type of giant cell-rich lesion of bone. This benign mesenchymal tumor has characteristic multinuclear giant cells. Mononuclear stromal cells are the physiologically active and diagnostic cell type. Most GCTs are located in the epiphyseal regions of long bones. The axial skeleton-primarily the sacrum-is a secondary site of involvement. Most patients present with pain, swelling, joint effusion, and disability in the third and fourth decades of life. Imaging studies are important for tumor staging and radiographic grading. Typically, these clinically active but slow-growing tumors are confined to bone, with relatively well-defined radiographic borders. Monostotic disease is most common. Metastatic spread to the lungs is rare. Extended intralesional curettage with or without adjuvant therapy is the primary treatment choice. Local recurrence is seen in ? 20% of cases, and a second local intralesional procedure is typically sufficient in cases that are detected early. Medical therapies include diphosphonates and denosumab. Denosumab has been approved for use in osteoporosis as well as breast and prostate cancer metastatic to bone. Medical therapy and radiotherapy can alter the management of GCT of bone, especially in multifocal disease, local recurrences, and bulky central/axial disease. PMID:23378375

Raskin, Kevin A; Schwab, Joseph H; Mankin, Henry J; Springfield, Dempsey S; Hornicek, Francis J

2013-02-01

339

Green Tea and Bone metabolism  

PubMed Central

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

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

2009-01-01

340

Vitamin D and Bone Disease  

PubMed Central

Vitamin D is important for normal development and maintenance of the skeleton. Hypovitaminosis D adversely affects calcium metabolism, osteoblastic activity, matrix ossification, bone remodeling and bone density. It is well known that Vit. D deficiency in the developing skeleton is related to rickets, while in adults is related to osteomalacia. The causes of rickets include conditions that lead to hypocalcemia and/or hypophosphatemia, either isolated or secondary to vitamin D deficiency. In osteomalacia, Vit. D deficiency leads to impairment of the mineralisation phase of bone remodeling and thus an increasing amount of the skeleton being replaced by unmineralized osteoid. The relationship between Vit. D and bone mineral density and osteoporosis are still controversial while new evidence suggests that Vit. D may play a role in other bone conditions such as osteoarthritis and stress fractures. In order to maintain a “good bone health” guidelines concerning the recommended dietary intakes should be followed and screening for Vit. D deficiency in individuals at risk for deficiency is required, followed by the appropriate action. PMID:23509720

Christodoulou, S.; Goula, T.; Ververidis, A.; Drosos, G.

2013-01-01

341

Vitamin D and bone disease.  

PubMed

Vitamin D is important for normal development and maintenance of the skeleton. Hypovitaminosis D adversely affects calcium metabolism, osteoblastic activity, matrix ossification, bone remodeling and bone density. It is well known that Vit. D deficiency in the developing skeleton is related to rickets, while in adults is related to osteomalacia. The causes of rickets include conditions that lead to hypocalcemia and/or hypophosphatemia, either isolated or secondary to vitamin D deficiency. In osteomalacia, Vit. D deficiency leads to impairment of the mineralisation phase of bone remodeling and thus an increasing amount of the skeleton being replaced by unmineralized osteoid. The relationship between Vit. D and bone mineral density and osteoporosis are still controversial while new evidence suggests that Vit. D may play a role in other bone conditions such as osteoarthritis and stress fractures. In order to maintain a "good bone health" guidelines concerning the recommended dietary intakes should be followed and screening for Vit. D deficiency in individuals at risk for deficiency is required, followed by the appropriate action. PMID:23509720

Christodoulou, S; Goula, T; Ververidis, A; Drosos, G

2013-01-01

342

Bone matters in lung cancer  

PubMed Central

Background Bone metastases are a significant and undertreated clinical problem in patients with advanced lung cancer. Design We reviewed the incidence of bone metastases and skeletal-related events (SREs) in patients with lung cancer and examined the burden on patients' lives and on health care systems. Available therapies to improve survival and lessen the impact of SREs on quality of life (QoL) were also investigated. Results Bone metastases are common in lung cancer; however, owing to short survival times, data on the incidences of SREs are limited. As with other cancers, the costs associated with treating SREs in lung cancer are substantial. Bisphosphonates reduce the frequency of SREs and improve measures of pain and QoL in patients with lung cancer; however, nephrotoxicity is a common complication of therapy. Denosumab, a recently approved bone-targeted therapy, is superior to zoledronic acid in increasing the time to first on-study SRE in patients with solid tumours, including lung cancer. Additional roles of bone-targeted therapies beyond the prevention of SREs are under investigation. Conclusions With increasing awareness of the consequences of SREs, bone-targeted therapies may play a greater role in the management of patients with lung cancer, with the aim of delaying disease progression and preserving QoL. PMID:22357445

Brodowicz, T.; O'Byrne, K.; Manegold, C.

2012-01-01

343

Infection, Inflammation, and Bone Regeneration  

PubMed Central

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

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

2011-01-01

344

Early Neolithic pig domestication at Jiahu, Henan Province, China: clues from molar shape analyses using geometric morphometric approaches  

Microsoft Academic Search

The zooarchaeology of pig domestication in China is a challenging task due to its wild boar ancestors being widespread throughout Eurasia. However using geometric morphometric approaches on molar tooth (M2), shape and size variations, from modern and Neolithic suids, using Yangshao pigs as a surrogate for the Neolithic domestic form, we have addressed the identification of morphological change during the

T. Cucchi; A. Hulme-Beaman; J. Yuan; K. Dobney

2011-01-01

345

Bioactive silica based nanoparticles stimulate bone forming osteoblasts, suppress bone esorbing osteoclasts, and enhance bone mineral density in vivo  

PubMed Central

Bone is a dynamic tissue that undergoes renewal throughout life by a process whereby osteoclasts resorb worn bone and osteoblasts synthesize new bone. Imbalances in bone turnover lead to bone loss and development of osteoporosis and ultimately fracture, a debilitating condition with high morbidity and mortality. Silica is a ubiquitous biocontaminant that is considered to have high biocompatibility. We report that silica nanoparticles mediate potent inhibitory effects on osteoclasts and stimulatory effects on osteoblasts in vitro. The mechanism of bioactivity is a consequence of an intrinsic capacity to antagonize activation of NF-?B, a signal transduction pathway required for osteoclastic bone resorption, but inhibitory to osteoblastic bone formation. We further demonstrate that silica nanoparticles promote a significant enhancement of bone mineral density (BMD) in mice in vivo providing a proof of principle for the potential application of silica nanoparticles as a pharmacological agent to enhance BMD and protect against bone fracture. PMID:22100753

Beck, George R.; Ha, Shin-Woo; Camalier, Corinne E.; Yamaguchi, Masayoshi; Li, Yan; Lee, Jin-Kyu; Weitzmann, M. Neale

2011-01-01

346

Bone culture research  

NASA Technical Reports Server (NTRS)

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.

Partridge, Nicola C.

1993-01-01

347

Dynamic Bone Quality – A Non-invasive Measure of Bone’s Biomechanical Property in Osteoporosis  

PubMed Central

We describe a novel approach to non-invasively characterize bone quality, a measurement that quantitates aggregate shock absorption capacity of load-bearing bones as a measure of mechanical structural integrity during exposure to real-time self-induced in-vivo loading associated with heel strike. The outcome measure, damping factor, was estimated at five load bearing anatomical sites: ankle, tibial tuberosity, femoral condyle, lower back (at 3rd lumbar vertebra) and upper back (7th thoracic vertebra) plus the forehead in 67 patients with postmenopausal osteoporosis with and without documented vertebral fractures. The damping value was significantly lower in patients with vertebral fractures compared with those without fracture (range ?36% to ?72%, median ?44%). In these women with osteoporosis, damping factor was able to discriminate between patients with and without vertebral fractures, whereas traditional measures of bone density and biomechanical measures obtained from bone geometry were not significantly different between the groups. PMID:20347363

Bhattacharya, Amit; Watts, Nelson B.; Davis, Kermit; Kotowski, Susan; Shukla, Rakesh; Dwivedi, Alok Kumar; Coleman, Robert

2010-01-01

348

Control of bone mass by sclerostin: Inhibiting BMP and WNT-induced bone formation  

Microsoft Academic Search

Bone is continuously replacing itself by the actions of bone-resorbing osteoclasts and bone-forming osteoblasts, a process\\u000a called bone remodeling. Because both cell types control each other’s activity, there is a tight balance between bone resorption\\u000a and bone formation. However, when this delicate balance is disturbed by increased osteoclast or decreased osteoblast activity,\\u000a it can lead to diseases characterized by low

David J. J. Gorter; Carola Krause; Peter Dijke; Clemens W. G. M. Löwik; Rutger L. Bezooijen

349

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

PubMed

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

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

2014-12-01

350

Targeted radiotherapy of bone malignancies.  

PubMed

The severe pain associated with many disorders affecting bone account for a large proportion of cases of patient morbidity, due to the encumbrance of mobility and therefore, compromised quality of life. Skeletal metastasis is one such condition, which generally complicates the treatment of the primary cancers such as that of the breast, prostate and lung - causing intense pain and eventually even mortality. This paper presents examples of various approaches explored and proposed in the ongoing search to identify better radiopharmaceuticals for the treatment of bone disorders such as metastases. The primary objective of these developments is to alleviate the debilitating pain commonly associated with bone lesions. The efficacy of a radiotherapeutic agent intended for the treatment of diseased bone is particularly dependent on the radiation dose to the tumor cells and on the extent to which suppression of bone marrow or other critical organs can be avoided. Therefore, the design rationale requires careful consideration of the choice radionuclide and especially ensuring that the drug selectively targets the lesion or tumor site. The options pursued include the use of radioisotopes with an intrinsic affinity for bone, such as (89)Sr or (223)Ra, or the design of bone-seeking ligands, such as phosphonates, to selectively deliver the radionuclide to the target, e.g. [(153)Sm]Sm-EDTMP. A combination of the above may too be possible, where the bone seeking ligand facilitates the selective accumulation of a radionuclide, which by itself is also bone homing. In terms of therapeutic application radionuclides with various decay modes are proposed, including beta (-) emitters: (153)Sm, (89)Sr, (186)Re, (188)Re, (32)P, (177)Lu and (170)Tm; alpha (?) emitters: (223)Ra and (225)Ra; and Auger or conversion electron emitter: (117)mSn. From a purely diagnostic perspective, the radioisotopes used for imaging include the well known photon emitting (99)mTc, and positron emitters (18)F and (68)Ga. The current status in the development and application of internal radiotherapy for the palliative treatment of bone pain will be discussed, summarizing the progress made and challenges encountered in the process to realizing an effective drug candidate. PMID:21034411

Jansen, David R; Krijger, Gerard C; Kolar, Zvonimir I; Zonnenberg, Bernard A; Zeevaart, Jan Rijn

2010-12-01

351

21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.  

Code of Federal Regulations, 2012 CFR

... Polymethylmethacrylate (PMMA) bone cement. 888.3027 Section 888.3027... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device intended to be...

2012-04-01

352

21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.  

Code of Federal Regulations, 2010 CFR

... Polymethylmethacrylate (PMMA) bone cement. 888.3027 Section 888.3027... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device intended to be...

2010-04-01

353

21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.  

Code of Federal Regulations, 2013 CFR

... Polymethylmethacrylate (PMMA) bone cement. 888.3027 Section 888.3027... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device intended to be...

2013-04-01

354

21 CFR 888.3027 - Polymethylmethacrylate (PMMA) bone cement.  

Code of Federal Regulations, 2011 CFR

... Polymethylmethacrylate (PMMA) bone cement. 888.3027 Section 888.3027... Polymethylmethacrylate (PMMA) bone cement. (a) Identification. Polymethylmethacrylate (PMMA) bone cement is a device intended to be...

2011-04-01

355

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

356

Bone metastasis: mechanisms and therapeutic opportunities  

PubMed Central

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

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

2011-01-01

357

Bone metastasis: mechanisms and therapeutic opportunities.  

PubMed

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

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

2011-04-01

358

Serotonin and the bone assessment  

PubMed Central

Introduction: Lately, the in vitro and in vivo studies on serotonin metabolism have been pointing its influence in bone health. Also, there are no particular recommendations in performing the serum serotonin assessment in order to evaluate the skeletal status. Aim: We aimed to correlate the bone turnover markers and lumbar bone mineral density (BMD) with serotonin. Material and methods: There is a cross-sectional study in Caucasian postmenopausal women. They were not diagnosed with carcinoid syndrome, or bone anomalies, and received no treatment (including antiresorptives). The following bone formation markers were performed: serum alkaline phosphatase (AP), serum osteocalcin (OC), and the bone resorption marker: serum CrossLaps (CL). Serum serotonin (high-pressure liquid chromatography), as well as central DXA (GE Prodigy) were assessed. Results: 191 women of 57.1 years mean age were grouped according to DXA (WHO criteria). The linear regression analysis between serum serotonin and CL were not statistically significant (SS), between serotonin and OC was SS in the newly diagnosed osteoporosis group (N=40, r=0.4, p=0.03), between serotonin and AP SS was found in osteopenia group (N=88, r=0.24, p=0.03), with no changes when adjusting for age and BMI. The partial correlation between serotonin and BMD was not SS. Discussion: The study raises the question of serotonin as a bone metabolism marker seeing that the results were not consistent. The main limit of our study was that we did not analyze the possible use of antidepressants to these women. Overall, this was a pilot study in clinical practice where few reports have been published, but still necessary, because the use of serum serotonin in current skeletal evaluation is still unclear.

Carsote, M; Radoi, V; Geleriu, A; Mihai, A; Ferechide, D; Opris, D; Paun, D; Poiana, C

2014-01-01

359

Extravascular albumin in bone tissue.  

PubMed Central

1. The amount of albumin in extravascular tissue fluid in bone, kidney, intestine, skin and muscle and in plasma of young rabbits has been measured by radial immunodiffusion. 2. The majority of extravascular albumin in kidney, intestine, skin and muscle is exchangeable with plasma albumin, whereas in bone, only the proportion which is in tissue fluid is readily exchangeable; the remaining fraction in calcified matrix is more permanently fixed. 3. About 27% of the albumin in young bone is in tissue fluid, about 57% in calcified matrix and about 16% is intravascular. The total amount of extravascular albumin per unit mass of bone is similar to that found in soft tissues. 4. The volume of intravascular plasma in tissues was determined in two ways: from 51Cr-erythrocyte radioactivity and the venous haematocrit and from the '5 min 125I-fibrinogen space'. 5. The rate of egress of albumin from blood vessels has been estimated from the initial slope of the ratio of extravascular radioactivity in the tissue to plasma radioactivity plotted against time after injection of 125I-albumin. 6. The rate of clearance of the albumin in extravascular tissue fluid in bone is approximately once every hour. This is more rapid than in skin and muscle, comparable with intestine and less rapid than in kidney. 7. The amount of albumin incorporated into calcified matrix of bone per day is calculated to be less than 0-5% of the total albumin passing through the tissue fluid of bone per day. PMID:950595

Owen, M; Triffitt, J T

1976-01-01

360

Bone target radiotracers for palliative therapy of bone metastases.  

PubMed

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

Ogawa, K; Washiyama, K

2012-01-01

361

Recent advances in bone tissue engineering scaffolds  

PubMed Central

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

Bose, Susmita; Roy, Mangal; Bandyopadhyay, Amit

2012-01-01

362

Mechanisms of Guided Bone Regeneration: A Review  

PubMed Central

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

Liu, Jie; Kerns, David G

2014-01-01

363

Methods for Assessing Bone Quality: A Review  

Microsoft Academic Search

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

Eve Donnelly

364

Inhibition of bone formation during space flight  

NASA Technical Reports Server (NTRS)

Parameters of bone formation and resorption were measured in rats orbited for 19.5 days aboard the Soviet Cosmos 782 biological satellite. The most striking effects were on bone formation. During flight, rats formed significantly less periosteal bone than did control rats on the ground. An arrest line at both the periosteum and the endosteum of flight animals suggests that a complete cecessation of bone growth occurred. During a 26-day postflight period, the defect in bone formation was corrected. No significant changes in bone resorption were observed.

Morey, E. R.; Baylink, D. J.

1978-01-01

365

Biomaterials for craniofacial bone engineering.  

PubMed

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

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

366

[Bone and Men's Health. Bone selective androgen receptor modulators].  

PubMed

Androgen, one of the sex steroid hormones shows various biological activities on the corresponding various tissues. Many efforts to produce novel drug materials maintaining a desired biological activity with an adequate tissue selectivity, which is so-called selective androgen receptor modulators (SARMs) , are being performed. As one of such efforts, studies on SARMs against bone tissues which possess a significant potential to stimulate a bone formation with reducing undesirable androgenic virilizing activities are in progress all over the world. This review focuses on the research and development activities of such SARMs and discuses their usefulness for the treatment of osteoporosis. PMID:20118515

Furuya, Kazuyuki

2010-02-01

367

Interspecies differences in bone composition, density, and quality: potential implications for in vivo bone research.  

PubMed

This study compares bone composition, density, and quality in bone samples derived from seven vertebrates that are commonly used in bone research: human, dog, pig, cow, sheep, chicken, and rat. Cortical femoral bone samples were analyzed for their content of ash, collagen, extractable proteins, and insulin-like growth factor-I. These parameters were also measured in bone powder fractions that were obtained after separation of bone particles according to their density. Large interspecies differences were observed in all analyses. Of all species included in the biochemical analyses, rat bone was most different, whereas canine bone best resembled human bone. In addition, bone density and mechanical testing analyses were performed on cylindrical trabecular bone cores. Both analyses demonstrated large interspecies variations. The lowest bone density and fracture stress values were found in the human samples; porcine and canine bone best resembled these samples. The relative contribution of bone density to bone mechanical competence was largely species-dependent. Together, the data reported here suggest that interspecies differences are likely to be found in other clinical and experimental bone parameters and should therefore be considered when choosing an appropriate animal model for bone research. PMID:9449639

Aerssens, J; Boonen, S; Lowet, G; Dequeker, J

1998-02-01

368

[Bone Reconstruction of Autolyzed Antigen-free Allogenic /AAA/ Bone in Children and Adolescents with Benign Bone Tumours.].  

PubMed

The authors describe in detail the preparation of six batches of human AAA/autolyzed antigen-free allogenic bone/ prepared in 1985 to 1988. This bone was administered to a total of 48 children and adolescents aged 6 to 19 years. It was used to fill cavities after metaphyseal connective tissue bone defects /31 x/, solitary bone cysts /10 x/, enchondromas /5 x/ and fibrous dysplasia /2 x/. The observation period was 2 years and 2 months to 5 years and 9 months. The mean volume of the cavities was 21 ml. In all patients the X-ray pictures were evaluated in a chronological sequence and changes on the host s bones in the cavity and the inserted AAA bones were described, and finally also changes of the entire bone complex with incorporated AAA implants. The results were arranged in tables. On the host's bones a periosteal reaction was observed in the area surrounding the focus, the entire cavity was covered with a soft shadow, there was sclerosis of the margins and bottom of the bone bed and gradual diminution of the bone defect from the sides and bottom of the bed. On the AAA bones the following observations were of interest: the connection of AAA bone with the surrounding newly formed bone, less clearly defined outlines of the AAA bone, loss of identity of the AAA bone. Sclerosis or elimination of the AAA bone were not observed. In three patients with batch 5 a "halo" effect was observed. On the entire complex with incorporated AAA bones the following were investigated: sclerosis of the entire portion of the bone, then regression and diminution of sclerosis, differentiation of the corticalis and medullary cavity and formation of a normal bone structure without signs of previous treatment. Preparation of six different batches of AA bone revealed that: 1.The spongious parts are more readily and more rapidly incorporated than the cortical part which is only partly demineralized. 2.Gelatinization with LiCI had a favourable effect on the incorporation of thus prepared implants. X-ray investigation revealed that the course of incorporation and reconstruction of these bones has the following specific features: 1.Reconstruction begins as a rule by the periosteal reaction of the host and its shift above the gap has a favourable effect on healing of the defect. 2.Two months after operation the cavity is covered by a soft shadow when the newly formed vessels and mesenchymal cells of the host infiltrate into the focus. 3.Activation of the bed is manifested by its greater density, sclerotization and by gradual diminution of the volume of the cavity. The greater density is not necessarily associated with diminution of the size of the cavity. 4.Bone implants are connected to the newly formed bone without passing through the stage of densi fication and sclerotization. The newly formed bone infiltrates them, absorbs and replaces the bone proper without signs of the previous stage of scle rosis, as observed in patients with frozen allogenic bones. 5.After incorporation of AAA implants further bone reconstruction takes place, as known from the healing of fractures or bone gaps. Key words: demineralized bone, AAA bone, benign bone tumors, reconstruction of bone transplant. PMID:20483076

Janovec, M; Crha, B; Okác, I; Sommernitz, M; Straka, M; Bajerová, J

1992-01-01

369

Influence of bone parameters on peri-implant bone strain distribution in the posterior mandible  

PubMed Central

Objectives: The success rate of dental implants depends on the type of bone at the implant site. The purpose of the present study was to investigate the effects of the bone parameters at the implant-placement site on peri-implant bone strain distributions. Study Design: The morphologies and bone densities of seventy-five potential implant sites in the posterior mandible were measured using computed tomography (CT). Based on the CT data, we defined bone parameters (low and high in terms of cancellous-bone density and crestal-cortical bone density, and thin and thick in terms of crestal-cortical bone thickness), and we constructed finite-element models simulating the various bone types. A buccolingual oblique load of 200 N was applied to the top of the abutment. The von Mises equivalent (EQV) strains in the crestal-cortical bone and in the cancellous bone around the implant were calculated. Results: Cancellous-bone density greatly affected the maximum EQV strain regardless of the density and thickness of the crestal cortical-bone. The maximum EQV strains in the crestal cortical-bone and the cancellous bone in the low-density cancellous-bone models (of 150 Hounsfield units (HU) were 1.56 to 2.62-fold and 3.49 to 5.31-fold higher than those in the high-density cancellous-bone models (of 850 HU), respectively. The crestal cortical-bone density affected the maximum EQV strains in the crestal cortical-bone and in the cancellous bone in the low-density cancellous-bone models. The crestal cortical-bone thickness affected the maximum EQV strains in the cancellous bone and in the crestal cortical-bone in the low-density cancellous-bone models. Conclusions: Our results confirm the importance of bone types for the peri-implant bone strain distribution. Cancellous-bone density may be a critical factor for peri-implant bone strain. Key words:Dental implant, bone density, finite-element analysis. PMID:25129251

Yamamoto, Kazuhiko; Kawakami, Masayoshi; Horita, Satoshi; Murakami, Kazuhiro; Kirita, Tadaaki

2015-01-01

370

The response of bone to unloading  

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

371

Phytonutrients for bone health during ageing  

PubMed Central

Osteoporosis is a skeletal disease characterized by a decrease in bone mass and bone quality that predispose an individual to an increased risk of fragility fractures. Evidence demonstrating a positive link between certain dietary patterns (e.g. Mediterranean diet or high consumption of fruits and vegetables) and bone health highlights an opportunity to investigate their potential to protect against the deterioration of bone tissue during ageing. While the list of these phytonutrients is extensive, this review summarizes evidence on some which are commonly consumed and have gained increasing attention over recent years, including lycopene and various polyphenols (e.g. polyphenols from tea, grape seed, citrus fruit, olive and dried plum). Evidence to define a clear link between these phytonutrients and bone health is currently insufficient to generate precise dietary recommendations, owing to mixed findings or a scarcity in clinical data. Moreover, their consumption typically occurs within the context of a diet consisting of a mix of phytonutrients and other nutrients rather than in isolation. Future clinical trials that can apply a robust set of outcome measurements, including the determinants of bone strength, such as bone quantity (i.e. bone mineral density) and bone quality (i.e. bone turnover and bone microarchitecture), will help to provide a more comprehensive outlook on how bone responds to these various phytonutrients. Moreover, future trials that combine these phytonutrients with established bone nutrients (i.e. calcium and vitamin D) are needed to determine whether combined strategies can produce more robust effects on skeletal health. PMID:23384080

Sacco, Sandra Maria; Horcajada, Marie?Noëlle; Offord, Elizabeth

2013-01-01

372

Effects of proteasome inhibitors on bone cancer.  

PubMed

Bone metastasis is a frequent complication of cancer, occurring in up to 70% of patients with advanced breast or prostate cancer, while bone disease is also the characteristic clinical feature of multiple myeloma. Skeletal-related events can be devastating, with major effect on the quality of life and survival. Bisphosphonates are the mainstay of therapeutic management of bone disease of solid tumors and myeloma, and denosumab has recently been approved for patients with bone metastases. Both act through inhibition of the osteoclast activity but do not restore bone formation. Proteasome inhibition has direct bone anabolic effects. Proteasome inhibitors have been used in the management of patients with multiple myeloma and mantle-cell lymphoma during the last decade. In multiple myeloma, bortezomib, the first-in-class proteasome inhibitor, has shown both in vitro and in vivo regulation of bone remodeling by inhibiting osteoclast function and promoting osteoblast activity. Bortezomib also reduces bone resorption but more importantly increases bone formation and bone mineral density, at least, in subsets of myeloma patients. Thus, bortezomib is recommended for myeloma patients with extended bone disease in combination with bisphosphonates. This review focuses on the effects of the proteasome system on bone metabolism and the implications into the better management of patients with cancer and bone disease. PMID:24422114

Terpos, Evangelos; Christoulas, Dimitrios

2013-01-01

373

Hematopoietic niche and bone meet  

PubMed Central

Purpose of review To provide an overview of the hematopoietic stem cell (HSC) niche in the bone marrow. In addition to highlighting recent advances in the field, we will also discuss components of the niche that may contribute to the development of cancer, or cancer metastases to the bone. Recent findings Much progress has been very recently made in the understanding of the cellular and molecular interactions in the HSC microenvironment. These recent findings point out the extraordinary complexity of the HSC microenvironment. Emerging data also suggest convergence of signals important for HSC and for leukemia or metastatic disease support. Summary The HSC niche comprises complex interactions between multiple cell types and molecules requiring cell-cell signaling as well as local secretion. These components can be thought of as therapeutic targets not only for HSC expansion, but also to modify behavior of hematopoietic malignancies and cancer metastases to the bone. PMID:18685423

Frisch, Benjamin J.; Porter, Rebecca L.; Calvi, Laura M.

2008-01-01

374

Where did bone come from?  

PubMed Central

Bone is specific to vertebrates, and originated as mineralization around the basal membrane of the throat or skin, giving rise to tooth-like structures and protective shields in animals with a soft cartilage-like endoskeleton. A combination of fossil anatomy and genetic information from modern species has improved our understanding of the evolution of bone. Thus, even in man, there are still similarities in the molecular regulation of skin appendages and bone. This article gives a brief overview of the major milestones in skeletal evolution. Some molecular machineries involving members of core genetic networks and their interactions are described in the context of both old theories and modern genetic approaches. PMID:21657973

2011-01-01

375

Bone alterations associated with HIV.  

PubMed

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

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

2014-09-01

376

Bone health and prostate cancer  

PubMed Central

Bone metastases are a substantial burden to men with advanced prostate cancer as they often cause pain and can cause fractures and spinal cord compression. Osteoblasts and osteoclasts are both pathologically activated in the setting of prostate cancer bone metastases. As osteoclast activation is associated with disease progression, skeletal complications and death, osteoclast-targeted therapies are a rational approach to disease management. Zoledronic acid is standard of care for castration-resistant prostate cancer with bone metastases as it reduces the risk for skeletal-related events. Additional trials are needed to better define the ideal dose, frequency and duration of zoledronic acid therapy. No bisphosphonate has yet been shown to prevent bone metastases or to benefit men with androgen-sensitive disease. Denosumab is an experimental osteoclast-targeted monoclonal antibody against receptor activator of nuclear factor-?B ligand. Two ongoing phase III trials are expected to define its efficacy in preventing bone metastases and disease-related skeletal events in men with prostate cancer. Androgen-deprivation therapy (ADT) for prostate cancer is associated with osteoporosis and fragility fractures. Several bisphosphonates have been shown to improve bone mineral density in men receiving ADT. Two recent phase III trials have shown that denosumab and toremifene reduce the incidence of fragility fractures in these men. The World Health Organization has developed a fracture risk assessment model (FRAX) for the general population to guide the selection of patients who may benefit from pharmacotherapy. In the absence of a prostate cancer-specific algorithm, we advocate the use of FRAX for men receiving ADT. PMID:19901958

Saylor, PJ; Smith, MR

2010-01-01

377

Bone Mineral Density and Logarithms  

NSDL National Science Digital Library

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

2014-09-18

378

Appropriate use of bone densitometry  

SciTech Connect

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.

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

1989-03-01

379

Bone regeneration and stem cells  

PubMed Central

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

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

380

Radioprotection of craniofacial bone growth.  

PubMed

In this review, the potential of pharmacologic therapy for prevention of radiation-induced bone growth inhibition is discussed. Significant radioprotection using the radioprotector Amifostine has been achieved in animal models of radiation-induced retardation of long and craniofacial bone growth. Moreover, radioprotection in vitro has been achieved in a number of cell lines, including osteoblast-like, endothelial, and fibroblastic. This evidence may support future clinical investigations of radioprotector Amifostine or similar substances for radioprotection of the growing craniofacial skeleton. PMID:17912071

Gevorgyan, Artur; La Scala, Giorgio C; Neligan, Peter C; Pang, Cho Y; Forrest, Christopher R

2007-09-01

381

Stem cells for reutilization in bone regeneration.  

PubMed

Bone is one of the most transplanted tissues. While most bone defects heal spontaneously, critical size defects caused by major trauma/malignant tumor and osteonecrosis of femoral head in young adults pose a great challenge in treatment. While the golden standard in treating bone defects is autologous bone grafting, available bone for grafting is quite limited in an individual. To solve the dilemma, stem cell therapy has been tried as a new modality of treatment in lesions not amenable to autologous bone grafting. While successful results were reported from individual studies, the stem cell therapy is still not an established treatment modality for bone regeneration and needs further assessment. Our focus herein is to introduce stem cell sources that have been investigated so far and review the current status of stem cell reutilization for bone regeneration as well as suggesting future perspectives. PMID:25491657

Im, Gun-Il

2015-04-01

382

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 ...

383

Medicines That May Cause Bone Loss  

MedlinePLUS

... include all medicines that may cause bone loss. Osteoporosis and Steroid Medicines While steroid medicines can be ... conditions, they can also cause bone loss and osteoporosis. These medicines are often referred to as steroids, ...

384

Role of Lipids in Osteoporotic Bone Loss  

E-print Network

the anabolic action of these agents on bone is through theiranabolic effects on bone were originally attributed specifically to statins, it seems that they can also be seen with other lipid-lowering agents.

Gharavi, Nima

2002-01-01

385

21 CFR 888.3015 - Bone heterograft.  

Code of Federal Regulations, 2012 CFR

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3015 Bone heterograft. (a) Identification. Bone heterograft is a device intended to be...

2012-04-01

386

21 CFR 892.1170 - Bone densitometer.  

Code of Federal Regulations, 2013 CFR

... 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...

2013-04-01

387

21 CFR 892.1170 - Bone densitometer.  

Code of Federal Regulations, 2011 CFR

... 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...

2011-04-01

388

21 CFR 892.1170 - Bone densitometer.  

Code of Federal Regulations, 2014 CFR

... 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...

2014-04-01

389

21 CFR 892.1170 - Bone densitometer.  

Code of Federal Regulations, 2010 CFR

... 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...

2010-04-01

390

United States Bone and Joint Decade  

MedlinePLUS

... Press Releases Scientific/Professional Journals Welcome to the United States Bone and Joint Initiative! Primary tabs View (active ... industry, have come together as part of the United States Bone and Joint Initiative (USBJI) to improve prevention ...

391

Bone Builders: The Discoveries Behind Preventing and Treating Osteoporosis  

NSDL National Science Digital Library

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

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

2001-08-01

392

Invest in Your Bones Bone Mineral Calcium and Vitamin D  

E-print Network

IU of vitamin D3 (National Osteoporosis Foundation). When available, choose a supplement of vitamin D3 (cholecalciferol) over vitamin D2 (ergocalciferol) to protect bone health. Read dietary supplement calcium and/or vitamin D3 supplements. Dietary Calcium Here's how to add calcium to your dietary choices

393

Bone infections and bone graft substitutes for local antibiotic therapy.  

PubMed

Osteomyelitis is a bone infection by micro-organisms. Despite advances in antibiotics and operative techniques, osteomyelitis remains an orthopaedic challenge and expensive to treat. Antimicrobial therapy is adequate for the treatment of most cases of acute osteomyelitis of any type, provided that diagnosis is made early. The treatment of chronic osteomyelitis is operative followed by adjunctive antibiotic therapy. Apart from surgical debridement and systemic antibiotic treatment, local antibiotic treatment by using various antibiotic delivery vehicles is a preferred method by most surgeons. Antibiotic-loaded bone cement (polymethylmethacrylate, PMMA) is the most widely used material and represents the current standard as an antibiotic delivery vehicle in orthopaedic surgery. Despite that, there are some disadvantages or concerns about the use of antibiotic-loaded PMMA that have led to the use of bioabsorbable or biodegradable material. Although the number of clinical studies is small, it seems that antibiotic-loaded hydroxyapatite and calcium sulfate are safe methods for local antibiotic delivery. They deliver great amounts of antibiotics locally with serum concentrations in safe margins, they obliterate the dead space, and aid in bone repair, while there is no need for a second operation for their removal. The purpose of this article is to review the recent literature concerning osteomyelitis and local antibiotic treatment with special reference to bone graft substitutes as vehicles for local antibiotic delivery. PMID:24504740

Lalidou, Fani; Kolios, George; Drosos, Georgios I

2014-03-01

394

Nanosized particles in bone and dissolution insensitivity of bone mineral.  

PubMed

Most of the mineral crystals in bone are platelets of carbonated apatite with thicknesses of a few nanometers embedded in a collagen matrix. We report that spherical to cylindrical shaped nanosized particles are also an integral part of bone structure observed by high resolution scanning electron microscopy. High resolution back scattered electron imaging reveals that the spherical particles have a contrast similar to the crystal platelets, suggesting that they are thus likely to have similar mineral properties. By means of constant composition (CC) dissolution of bone, similar sized nanoparticles are shown to be insensitive to demineralization and are thought to be dynamically stabilized due to the absence of active pits/defects on the crystallite surfaces. Similar reproducible self-inhibited dissolution was observed with these nanoparticles during CC dissolution of synthetic carbonated apatite. This result rules out the possible influence of complicating biological factors such as the possible presence of organic matrix components and other impurities. This phenomenon can be explained by a unique dissolution model involving size considerations at the nanoscale. The unexpected presence of nanoparticles in mature bone may also be due to the stabilization of some nanosized particles during the formation process in a fluctuating biological milieux. PMID:20408623

Wang, Lijun; Nancollas, George H; Henneman, Zachary J; Klein, Eugenia; Weiner, Steve

2006-09-01

395

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

NASA Technical Reports Server (NTRS)

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.

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

1999-01-01

396

Relationship between bone mineral content, bone mineral density and anaerobic power in professional jumpers  

Microsoft Academic Search

The positive effect of physical activity and exercise on bone mass is well documented in several studies comparing with sedentary subjects. Recent studies have reported that cardiovascular fitness and weight-bearing exercise affect bone mass beneficially. Although it is widely accepted that muscle strength is significantly correlated with bone mass, little is known about anaerobic power and its relation to bone

Mahdi Haydari; Nader Rahnama; Khalil Khayambashi; Mohammad Marandi

2010-01-01

397

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

E-print Network

surface, 76% greater osteoblast surface but similar trabecular bone volume fraction compared to HU. After 3 w of reambulation, trabecular bone of RA+VIB mice had a 30% greater bone volume fraction, 51Low-Level Vibrations Retain Bone Marrow's Osteogenic Potential and Augment Recovery of Trabecular

398

In vivo fatigue microcracks in human bone: Material properties of the surrounding bone matrix  

Microsoft Academic Search

Human bones sustain fatigue damage in the form of in vivo microcracks as a result of the normal everyday loading activities. These microcracks appear to preferentially accumulate in certain regions of bone and most notably in interstitial bone matrix areas. These are remnants of old bone tissue left unremodelled, which show a higher than average mineral content and consequently the

P. ZIOUPOS

2005-01-01

399

Dependence of ultrasonic attenuation on bone mass and microstructure in bovine cortical bone  

Microsoft Academic Search

The development of the axial transmission technique now enables in vivo evaluation of cortical bone quality, which plays an important role in bone fragility. Cortical bone is a complex multiscale material, which may be made of different types of microstructure. The interaction between ultrasound and cortical bone remains unclear and most studies have been confined to wave speed analysis. The

Magali Sasso; Guillaume Haïat; Yu Yamato; Salah Naili; Mami Matsukawa

2008-01-01

400

Assessment of an improved bone washing protocol for deceased donor human bone.  

PubMed

NHSBT Tissue Services issues bone to surgeons in the UK in two formats, fresh-frozen unprocessed bone from living donors and processed bone from deceased donors. Processed bone may be frozen or freeze dried and all processed bone is currently subjected to a washing protocol to remove blood and bone marrow. In this study we have improved the current bone washing protocol for cancellous bone and assessed the success of the protocol by measuring the removal of the bone marrow components: soluble protein, DNA and haemoglobin at each step in the process, and residual components in the bone at the end of the process. The bone washing protocol is a combination of sonication, warm water washes, centrifugation and chemical (ethanol and hydrogen peroxide) treatments. We report that the bone washing protocol is capable of removing up to 99.85 % soluble protein, 99.95 % DNA and 100 % of haemoglobin from bone. The new bone washing protocol does not render any bone cytotoxic as shown by contact cytotoxicity assays. No microbiological cell growth was detected in any of the wash steps. This process is now in use for processed cancellous bone issued by NHSBT. PMID:24696088

Eagle, M J; Man, J; Rooney, P; Hogg, P; Kearney, J N

2015-03-01

401

Bone morphogenetic protein 2 stimulates endochondral ossification by regulating periosteal cell fate during bone repair  

Microsoft Academic Search

Bone repair depends on the coordinated action of numerous growth factors and cytokines to stimulate new skeletal tissue formation. Among all the growth factors involved in bone repair, Bone Morphogenetic Proteins (BMPs) are the only molecules now used therapeutically to enhance healing. Although BMPs are known as strong bone inducers, their role in initiating skeletal repair is not entirely elucidated.

Yan Yiu Yu; Shirley Lieu; Chuanyong Lu; Céline Colnot

2010-01-01

402

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

E-print Network

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

Simmons, Craig A.

403

Radioimmune imaging of bone marrow in patients with suspected bone metastases from primary breast cancer  

SciTech Connect

Radioimmune imaging of bone marrow was performed by technetium-99m- (99mTc) labeled antigranulocyte monoclonal antibody BW 250/183 (AGMoAb) scans in 32 patients with suspected bone metastases from primary breast cancer. AGMoAb scans showed bone marrow defects in 25/32 (78%) patients; bone invasion was subsequently confirmed in 23 (72%) patients. Conventional bone scans performed within the same week detected bone metastases in 17/32 (53%) patients (p less than 0.001). AGMoAb scans detected more sites indicating metastatic disease than bone scans in 12 of these 17 patients (71%). All patients with bone metastases in the axial skeleton had bone marrow defects at least at the sites of bone metastases. Of 15 patients with normal, or indicative of, benign disease bone scans, 8 patients (53%) presented with bone marrow defects in the AGMoAb scans. Bone invasion was confirmed in six of them. AGMoAb bone marrow scans provide a method for the early detection of bone metastatic invasion in patients with breast cancer and suspected bone metastases.

Duncker, C.M.; Carrio, I.; Berna, L.; Estorch, M.; Alonso, C.; Ojeda, B.; Blanco, R.; Germa, J.R.; Ortega, V. (Hospital de Sant Pau, Barcelona (Spain))

1990-09-01

404

Bone architecture assessment with measures of complexity  

Microsoft Academic Search

Architectural changes in trabecular bone by osteoporosis were utilized as a model for the changes which probably occur in human bone while exposed to microgravity conditions. Although there are many concerns about microgravity-induced bone loss, little is known about the impact of microgravity on the three-dimensional architecture of the skeleton [1]. 50 (level L3) and 57 (level L4) vertebral bones

Wolfgang Gowin; Peter Saparin; Jürgen Kurths; Dieter Felsenberg

2001-01-01

405

Cranial bone deformity after forehead tissue expansion.  

PubMed

The expanded forehead flap is frequently used for nasal reconstruction. When expanding the forehead tissue, the underlying cranial bones are compressed by the inserted expander. Many effects of tissue expansion on the bone have been reported including bone remolding, erosion, displacement, and so forth. In this work, we report a peculiar patient of cranial bone deformity after forehead tissue expansion, which demanded a surgical revision. PMID:25723659

Wang, Huan; You, Jianjun; Wang, Sheng; Fan, Fei

2015-03-01

406

Positive modulator of bone morphogenic protein-2  

DOEpatents

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.

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

2009-01-27

407

Anisotropic viscoelastic properties of cortical bone  

Microsoft Academic Search

Relaxation Young’s modulus of cortical bone was investigated for two different directions with respect to the longitudinal axis of bone (bone axis, BA): the modulus parallel (P) and normal (N) to the BA. The relaxation modulus was analyzed by fitting to the empirical equation previously proposed for cortical bones, i.e., a linear combination of two Kohlraush–Williams–Watts (KWW) functions (Iyo et

Toshiya Iyo; Yasuyuki Maki; Naoki Sasaki; Mitsuo Nakata

2004-01-01

408

Optimizing peak bone mass: What are the therapeutic possibilities?  

Microsoft Academic Search

Bone mass in the elderly depends on the rate of involutional bone loss and on the peak bone mass, i.e. the bone mass present around the third decade of life. Factors relating to the attainment of peak bone mass include congenital factors, diet, hormones, physical activity, lifestyle factors, drags and diseases. A therapeutic intervention aimed at increasing peak bone mass

S. Adami

1994-01-01

409

Genetic Modification of Stem Cells to Enhance Bone Repair  

Microsoft Academic Search

Orthopaedic surgeons are often faced with difficult bone loss problems. Conventional bone grafting is usually accomplished with autogenous iliac crest bone graft that provides osteogenic cells, osteoinductive growth factors, and an osteoconductive matrix. Cadaveric bone allograft and bone graft substitutes are inferior to autogenous bone graft because they fail to supply osteogenic cells or a significant amount of osteoinductive growth

Seth C. Gamradt; Jay R. Lieberman

2004-01-01

410

Ultrasound Accelerated Bone Tissue Engineering Monitored with Magnetic Resonance Microscopy  

Microsoft Academic Search

Tissue engineering has the potential to treat bone loss, but current bone restoration methods, including osteogenesis from mesenchymal stem cells (MSCs), require three to four weeks for bone formation to occur. In this study, we stimulated the formation of engineered bone tissue with low-intensity ultrasound, which has been proven to accelerate bone healing in vivo. One group of engineered bone

Jessy J. Moinnes; Neelima Vidula; Nadia Halim; Shadi F. Othman

2006-01-01

411

[Encounter of cancer cells with bone. The bone microenvironment and cancer metastases].  

PubMed

Bone is one of the most preferential metastatic target sites for cancers. However, based on the anatomical structure of the vascular system, bone is not recognized as a preferential metastatic target. Therefore, the biological crosstalk between metastatic cancer cells and bone is critical to the development and progression of bone metastases. Bone microenvironments possess unique biological features characterized by abundant growth factors and diverse cellular network including osteoblasts, osteoclasts and hematopietic cells. Cancers develop bone metastases by utilizing these unique bone environments for colonization and bone destruction. Better understandings of precise molecular mechanisms underlying cancer and bone crosstalk would contribute to the development of new therapeutic approaches for the treatment of bone metastasis at molecular levels. PMID:21358055

Hata, Kenji; Nakanishi, Masako; Morita, Yoshihiro; Yoneda, Toshiyuki

2011-03-01

412

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

SciTech Connect

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.

Colnot, C. [University of California at San Francisco, Department of Orthopaedic Surgery, San Francisco General Hospital, San Francisco, CA 94110 (United States)]. E-mail: colnotc@orthosurg.ucsf.edu; Huang, S. [University of California at San Francisco, Department of Orthopaedic Surgery, San Francisco General Hospital, San Francisco, CA 94110 (United States); Helms, J. [Stanford University, 257 Campus Drive, Stanford, CA 94306 (United States)

2006-11-24

413

Role of Osteal Macrophages in Bone Metabolism  

PubMed Central

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

Cho, Sun Wook

2015-01-01

414

Paget’s disease of the bone  

MedlinePLUS

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

415

Effects of Inactivity and Exercise on Bone.  

ERIC Educational Resources Information Center

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…

Smith, Everett L.; Gilligan, Catherine

1987-01-01

416

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

417

Better Bones Buddies: An Osteoporosis Prevention Program  

ERIC Educational Resources Information Center

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…

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

2005-01-01

418

Bone cell mechanosensitivity, estrogen deficiency, and osteoporosis.  

PubMed

Adaptation of bone to mechanical stresses normally produces a bone architecture that combines a proper resistance against failure with a minimal use of material. This adaptive process is governed by mechanosensitive osteocytes that transduce the mechanical signals into chemical responses, i.e. the osteocytes release signaling molecules, which orchestrate the recruitment and activity of bone forming osteoblasts and/or bone resorbing osteoclasts. Computer models have shown that the maintenance of a mechanically-efficient bone architecture depends on the intensity and spatial distribution of the mechanical stimulus as well as on the osteocyte response. Osteoporosis is a condition characterized by a reduced bone mass and a compromized resistance of bone against mechanical loads, which has led us to hypothesize that mechanotransduction by osteocytes is altered in osteoporosis. One of the major causal factors for osteoporosis is the loss of estrogen, the major hormonal regulator of bone metabolism. Loss of estrogen may increase osteocyte-mediated activation of bone remodeling, resulting in impaired bone mass and architecture. In this review we highlight current insights on how osteocytes perceive mechanical stimuli placed on whole bones. Particular emphasis is placed on the role of estrogen in signaling pathway activation by mechanical stimuli, and on computer simulation in combination with cell biology to unravel biological processes contributing to bone strength. PMID:25582356

Klein-Nulend, Jenneke; van Oers, René F M; Bakker, Astrid D; Bacabac, Rommel G

2015-03-18

419

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...

420

Anabolic effects of parathyroid hormone on bone  

Microsoft Academic Search

Parathyroid hormone (PTH) is classically considered to be a bone catabolic agent; however, when delivered intermittently at low doses, PTH potently stimulates cortical and\\/or trabecular bone growth in animal and clinical studies. Understanding the mechanism of PTH's osteopenic actions has led to the making of small, novel, and possibly noninjectable PTH analogues that can build biomechanically normal bone in osteopenic

Paul Morley; James F. Whitfield; Gordon E. Willick

1997-01-01

421

Biomaterial developments for bone tissue engineering  

Microsoft Academic Search

The development of bone tissue engineering is directly related to changes in materials technology. While the inclusion of materials requirements is standard in the design process of engineered bone substitutes, it is also critical to incorporate clinical requirements in order to engineer a clinically relevant device. This review presents the clinical need for bone tissue-engineered alternatives to the present materials

Karen J. L Burg; Scott Porter; James F Kellam

2000-01-01

422

Local analysis of trabecular bone fracture  

Microsoft Academic Search

Assessment of bone fracture risk is the first step in the prevention of traumatic events. In several previous study the use of bone mineral density and bone volume fraction was suggested for the identification of the failure zone, nonetheless the limits of this approach were also investigated, underling the need of other information to fully describe the failure event. In

Simone Tassani; Fragiskos Demenegas; George K. Matsopoulos

2011-01-01

423

Mechanical properties of Cortical and Cancellous Bone  

E-print Network

1 Mechanical properties of Cortical and Cancellous Bone Schematic drawing showing microstructure Viscoelasticity of bone: strain-rate dependency. 10 #12;7 Creep and recovery. Stress and strain vs. time t. From moment 17 BONE VISCOELASTICITY From Lakes., J. Biomech. Eng. Setup for torsion experiments to determine

Gefen, Amit

424

Stable Isotope Variation in Pathological Bone1  

Microsoft Academic Search

Bone samples taken at autopsy from seven individuals from western Canada are studied histologically and the bone protein is analysed for stable isotopes of carbon and nitrogen. The objective of the study is to determine if pathological conditions result in variations in bone protein stable isotope ratios. Of the seven individuals sampled, three are normal and four are pathological. The

M. ANNE; NANCY C. LOVELLb

425

Vascular Calcification and Renal Bone Disorders  

PubMed Central

At the early stage of chronic kidney disease (CKD), the systemic mineral metabolism and bone composition start to change. This alteration is known as chronic kidney disease-mineral bone disorder (CKD-MBD). It is well known that the bone turnover disorder is the most common complication of CKD-MBD. Besides, CKD patients usually suffer from vascular calcification (VC), which is highly associated with mortality. Many factors regulate the VC mechanism, which include imbalances in serum calcium and phosphate, systemic inflammation, RANK/RANKL/OPG triad, aldosterone, microRNAs, osteogenic transdifferentiation, and effects of vitamins. These factors have roles in both promoting and inhibiting VC. Patients with CKD usually have bone turnover problems. Patients with high bone turnover have increase of calcium and phosphate release from the bone. By contrast, when bone turnover is low, serum calcium and phosphate levels are frequently maintained at high levels because the reservoir functions of bone decrease. Both of these conditions will increase the possibility of VC. In addition, the calcified vessel may secrete FGF23 and Wnt inhibitors such as sclerostin, DKK-1, and secreted frizzled-related protein to prevent further VC. However, all of them may fight back the inhibition of bone formation resulting in fragile bone. There are several ways to treat VC depending on the bone turnover status of the individual. The main goals of therapy are to maintain normal bone turnover and protect against VC. PMID:25136676

Lu, Kuo-Cheng; Wu, Chia-Chao; Yen, Jen-Fen; Liu, Wen-Chih

2014-01-01

426

Bone marrow and the control of immunity  

Microsoft Academic Search

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

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

2012-01-01

427

Revealing bone damage using radiographic image registration  

Microsoft Academic Search

Bone damage assessment is frequently applied to monitor the activity of bone degenerative diseases such as rheumatoid arthritis and osteoarthritis. For an effective treatment it is important that small changes over time can be measured. Radiographs of hands and feet are often used for such measurements. Several scoring methods exist to measure bone and joint damage [1], but they are

Joost Kauffman; Kees Slump; Hein Bernelot Moens; W. Philips

2007-01-01

428

Stress fracture development classified by bone scintigraphy  

Microsoft Academic Search

There is no consensus on classifying stress fractures (SF) appearing on bone scans. The authors present a system of classification based on grading the severity and development of bone lesions by visual inspection, according to three main scintigraphic criteria: focality and size, intensity of uptake compare to adjacent bone, and local medular extension. Four grades of development (I-IV) were ranked,

S. T. Zwas; R. Elkanovich; G. Frank; Z. Aharonson

1985-01-01

429

The usefulness of bone-marrow scintigraphy in the detection of bone metastasis from prostatic cancer  

Microsoft Academic Search

We used a combination of bone and bone-marrow scintigraphy to study 25 patients with prostatic cancer. Of the 18 cases whose 99mTc-methylene diphosphonate (MDP) bone scans showed hot spots in the lower lumbar region of the spine and\\/or the pelvic bone, 8 had normal bone-marrow scintigrams. These 8 patients were subsequently shown to have senile, degenerative changes of the spine.

Nobuaki Otsuka; Masao Fukunaga; Teruki Sone; Masaya Yoneda; Noriaki Saito; Hiroyoshi Tanaka; Tatsushi Tomomitsu; Shinichi Yanagimoto; Akira Muranaka; Rikushi Morita

1985-01-01

430

Bone marrow scintigraphy in the diagnosis of bone metastasis in prostate cancer  

Microsoft Academic Search

We investigated bone marrow scintigraphy in 20 patients with prostate cancer to determine the usefulness of this procedure\\u000a in the diagnosis of bone metastasis. Thirteen of 17 patients whose bone scans revealed hot spots showed accumulation defects\\u000a in bone marrow scintigrams. Follow-up study and X-ray, computed tomography and\\/or magnetic resonance imaging findings confirmed\\u000a the presence of bone metastases in these

H. Fuse; O. Nagakawa; H. Seto; T. Katayama

1994-01-01

431

BONE MASS MEASUREMENT AND BONE METABOLISM IN RHEUMATOID ARTHRITIS: A REVIEW  

Microsoft Academic Search

SUMMARY The involvement of bone in rheumatoid arthritis (RA) is well recognized, and hand bone densitometry appears to be a promising new technique to monitor disease progression by assessing serial changes in hand bone.mass in patients with RA. New bio- chemical markers of bone formation (i.e. osteocalcin) show contradictory results in different studies, although markers of bone resorption (i.e. urinary

A. A. DEODHAR; A. D. WOOLF

1996-01-01

432

Bone density studies in zooarchaeology  

Microsoft Academic Search

Accurate bone density data are essential for assessing the influence of destructive processes in archaeological faunal assemblages. Unfortunately, the diversity of methods employed by different researchers to derive density values has resulted in recent confusion. Two recent publications in this journal (J Archaeol Sci 29 (2002) 883; J Archaeol Sci 29 (2002) 979) exemplify this state of misunderstanding. Both studies

Y. M. Lama; O. M. Pearsonc; Curtis W. Mareand; Xingbin Chene

433

Bone density studies in zooarchaeology  

Microsoft Academic Search

Accurate bone density data are essential for assessing the influence of destructive processes in archaeological faunal assemblages. Unfortunately, the diversity of methods employed by different researchers to derive density values has resulted in recent confusion. Two recent publications in this journal [J Archaeol Sci 29 (2002) 883; J Archaeol Sci 29 (2002) 979] exemplify this state of misunderstanding. Both studies

Y. m. Lam; O. m. Pearson; Curtis W. Marean; Xingbin Chen

2003-01-01

434

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...

435

Bone and soft tissue ablation.  

PubMed

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

Foster, Ryan C B; Stavas, Joseph M

2014-06-01

436

Bare Bones of Bioactive Glass  

NASA Technical Reports Server (NTRS)

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.

2000-01-01

437

PASSCLAIM - Bone health and osteoporosis  

Microsoft Academic Search

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

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

2003-01-01

438

Aspiration and Biopsy: Bone Marrow  

MedlinePLUS

KidsHealth > Parents > Doctors & Hospitals > Medical Tests & Exams > Aspiration and Biopsy: Bone Marrow Print A A A Text Size What's in this article? What It Is Why It's Done Preparation Procedure What to Expect Getting the Results Risks Helping Your Child If ...

439

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...

440

Bone X-Ray (Radiography)  

MedlinePLUS Videos and Cool Tools

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

441

Vegetarian diets and bone status.  

PubMed

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

Tucker, Katherine L

2014-07-01

442

BONE MARROW STORAGE: CURRENT CONCEPTS  

Microsoft Academic Search

Procedures for the collection and storage of human bone marrow are ; described. Two methods of marrow storage were investigated, namely, nutrient ; media and protective freezing. The marrow is aspirated from the donor, diluted ; with an equal volume of nutrient solution, collected in a storage vessel, and ; immediately refrigerated at 4 deg C. Preliminary results with this

A. M. Pappas; V. P. Perry; T. E. Wheeler; G. W. Hyatt

1961-01-01

443

Fractal Analysis of Trabecular Bone  

NSDL National Science Digital Library

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

Gillespy, Thurman

444

885. VEGF Enhances Bone Formation and Bone Healing Elicited by Transduced Muscle-Derived Stem Cells Expressing Human BMP2  

Microsoft Academic Search

Introduction: Bone formation and bone healing require concerted interactions among many different pathways, including osteogenesis and angiogenesis. Previous studies have shown that the angiogenic factor VEGF is important for both normal bone development and BMP4-induced bone formation. More importantly, VEGF can synergistically enhance the bone formation and bone healing elicited by BMP4. The aim of this study was to determine

Hairong Peng; Arvydas Usas; Brian Gearhart; Johnny Huard

2004-01-01

445

Evaluation of the prognosis of cancer patients with metastatic bone tumors based on serial bone scintigrams.  

PubMed

We counted the lesions at the time of detection of bone metastases and calculated the rate of increase in the number of bone metastases from changes in serial bone scintigrams, and investigated the usefulness of serial scintigrams as a prognostic indicator in patients with metastatic bone tumors. Subjects were 112 patients with bone metastases from four types of primary lesion: 21 with prostate cancer, 27 breast cancer, 39 lung cancer and 25 stomach cancer. Of these, 18 (prostate), 19 (breast), nine (lung) and eight (stomach) underwent serial bone scintigrams in which bone metastases were first detected and identified as progressing. The numbers of lesions at the time of detection of bone metastases for prostate and stomach cancers were significantly greater than those for lung cancer. The rate of increase in the number of bone metastases for stomach cancer was significantly higher than that for prostate or breast cancers. There was no correlation between the survival time after the detection of bone metastases and the number of lesions at the time of detection in the four types of cancer. However, in prostate cancer, a negative correlation existed between the survival time after the detection of bone metastases and the rate of increase in the number of bone metastases. Thus, in patients with bone metastases from prostate cancer, it appears that the rate of increase in the number of bone metastases, estimated from serial bone scintigrams, was indicative of prognosis. PMID:9379516

Ohmori, K; Matsui, H; Yasuda, T; Kanamori, M; Yudoh, K; Seto, H; Tsuji, H

1997-08-01

446

THE OXYTOCIN-BONE AXIS  

PubMed Central

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

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

2014-01-01

447

Bone marrow and the control of immunity  

PubMed Central

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

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

2012-01-01

448

Calcium phosphate scaffolds for bone repair  

NASA Astrophysics Data System (ADS)

Calcium phosphates, with their chemical similarity to bone mineral, show biocompatibility with hard and soft tissues and offer massive potential for bone repair, both as scaffolds to be implanted directly into the defect and as structures for cell transplantation or to guide new bone growth in tissue engineering. This paper reviews the requirements and motivation for synthetic bone graft alternatives and the production routes for, particularly, hydroxyapatite porous scaffolds. It also considers the important role of substitution of ions such as silicate into calcium phosphates so as to more closely mirror the chemistry of bone mineral and to elicit specific biological responses.

Shepherd, J. H.; Best, S. M.

2011-04-01

449

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

PubMed Central

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

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

1994-01-01

450

Bone Remodelling Markers in Rheumatoid Arthritis  

PubMed Central

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

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

2014-01-01

451

Drilling of bone: A comprehensive review  

PubMed Central

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.

Pandey, Rupesh Kumar; Panda, S.S.

2013-01-01

452

Evaluation of canine cortical bone graft remodeling.  

PubMed

A stable cortical bone fracture model was developed to evaluate the remodeling rate of cortical bone grafts. Samples of cortical bone were harvested with a trephine and press fit into predrilled holes in the femoral diaphyses of four live dogs. The percentages of new bone, unremodeled graft bone, porosity, forming bone surface area, and resorbing bone surface area were determined morphometrically and compared in cortical autografts, cortical allografts sterilized with 84% ethylene oxide (EO), and allografts sterilized with 12% EO. The host-graft interfaces healed without formation of fibrous tissue or cartilage, indicating a stable fracture surface. The amount of new bone formed in cortical autografts and allografts sterilized with 84% EO was significantly greater than the amount of new bone in allografts sterilized with 12% EO. There was no significant difference between the amounts of new bone formed in the allografts sterilized with 84% EO and the cortical autografts. No significant differences were detected in percentages of porosity or bone surface areas. PMID:1455638

Johnson, A L; Eurell, J A; Schaeffer, D J

1992-01-01

453

Anorexia Nervosa, Obesity and Bone Metabolism  

PubMed Central

Anorexia nervosa and obesity are conditions at the extreme ends of the nutritional spectrum, associated with marked reductions versus increases respectively in body fat content. Both conditions are also associated with an increased risk for fractures. In anorexia nervosa, body composition and hormones secreted or regulated by body fat content are important determinants of low bone density, impaired bone structure and reduced bone strength. In addition, anorexia nervosa is characterized by increases in marrow adiposity and decreases in cold activated brown adipose tissue, both of which are related to low bone density. In obese individuals, greater visceral adiposity is associated with greater marrow fat, lower bone density and impaired bone structure. In this review, we discuss bone metabolism in anorexia nervosa and obesity in relation to adipose tissue distribution and hormones secreted or regulated by body fat content. PMID:24079076

Misra, Madhusmita; Klibanski, Anne

2014-01-01

454

Tenofovir-associated bone density loss  

PubMed Central

Clinical observations have revealed a strong correlation between loss of bone density in HIV-infected individuals, particularly in conjunction with the antiretroviral drug tenofovir, a nucleotide analog that inhibits HIV reverse transcriptase. The most compelling correlations have been observed in clinical studies involving young children and adolescents. These observations strongly suggest that bone density is being affected during active bone growth and development, implicating a role for tenofovir in bone loss. Here we discuss the literature and potential mechanisms for how tenofovir-associated bone loss may arise, which likely involves perturbation of cellular DNA synthesis and gene expression. Elucidation of the mechanism(s) involved in tenofovir-mediated bone loss will help in developing adjuvant therapies to reduce tenofovir-associated bone density loss. PMID:20169035

Grigsby, Iwen F; Pham, Lan; Mansky, Louis M; Gopalakrishnan, Raj; Mansky, Kim C

2010-01-01

455

[Stromal cells of the bone marrow in growing bone].  

PubMed

By means of electron microscopy, cytochemistry and radioautography with 3H-thymidine, the bone marrow stromal cells have been studied in the zones of endochondral osteogenesis in the rabbit and rat femoral bones. In the stromal cells demonstrating a high alkaline phosphatase activity are distinguished: perivascular, reticular fibroblastic, osteogenic cells. Populations of the perivascular phosphatase-positive cells include poorly differentiated DNA-synthesizing forms, as well as cells with signs of differentiation into stromal fibroblasts. Cleft-like spaces in cytoplasm of the fibroblastic reticular cells are, probably, formed as a result of lymphocyte-like mononuclears passing through. Phagocyting stromal elements are presented by macrophages, having perivascular localization and including into composition of erythroblastic islets. Mononuclear macrophages are revealed also on the surface of osseous trabecules, where they participate in destruction of hemopoetic and osteogenic cells. PMID:3800669

Rodionova, N V; Skripchenko, E V

1986-10-01

456

The role of homocysteine in bone remodeling  

PubMed Central

Bone remodeling is a very complex process. Homocysteine (Hcy) is known to modulate this process via several known mechanisms such as increase in osteoclast activity, decrease in osteoblast activity and direct action of Hcy on bone matrix. Evidence from previous studies further support a detrimental effect on bone via decrease in bone blood flow and an increase in matrix metalloproteinases (MMPs) that degrade extracellular bone matrix. Hcy binds directly to extracellular matrix and reduces bone strength. There are several bone markers that can be used as parameters to determine how high levels of plasma Hcy (hyperhomocysteinemia, HHcy) affect bone such as: hydroxyproline, N-terminal collagen 1 telopeptides. Mitochondrion serves an important role in generating reactive oxygen species (ROS). Mitochondrial abnormalities have been identified during HHcy. The mechanism of Hcy-induced bone remodeling via the mitochondrial pathway is largely unknown. Therefore, we propose a mitochondrial mechanism by which Hcy can contribute to alter bone properties. This may occur both through generations of ROS that activate MMPs and could be extruded into matrix to degrade bone matrix. However, there are contrasting reports on whether Hcy affects bone density, with some reports in favour and others not. Earlier studies also found an alteration in bone biomechanical properties with deficiencies of vitamin B12, folate and HHcy conditions. Moreover, existing data opens speculation that folate and vitamin therapy act not only via Hcy-dependent pathways but also via Hcy-independent pathways. However, more studies are needed to clarify he mechanistic role of Hcy during bone diseases. PMID:23449525

Vacek, Thomas P.; Kalani, Anuradha; Voor, Michael J.; Tyagi, Suresh C.; Tyagi, Neetu

2014-01-01

457

Internal channel structures in trabecular bone  

NASA Astrophysics Data System (ADS)

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

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

2004-10-01

458

High-strength mineralized collagen artificial bone  

NASA Astrophysics Data System (ADS)

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.

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

2014-03-01

459

Sintered bone implantation for the treatment of benign bone tumours in the hand.  

PubMed

We report the results of treatment of benign bone tumours in the hand with curettage and sintered bone implantation using bovine sintered bone (True Bone Ceramics). There were 22 patients who underwent sintered bone implantation in our department in 1984 or later. The follow-up survey period varied from 9 months to 11 years and 2 months (mean, 5.8 years). Recurrence of tumours and complications such as infection or fracture were not observed, and there were no clinical symptoms. X-rays revealed new bone formation connecting the implanted blocks to bone. Sintered bone was not absorbed, and lucent zones around the implants or other abnormal findings were not observed. Bone union was achieved in all patients who had pathological fractures before surgery. PMID:10190619

Taniguchi, Y; Tamaki, T; Oura, H; Hashizume, H; Minamide, A

1999-02-01

460

Role of Quantitative Bone Scanning in the Assessment of Bone Turnover in Patients With Charcot Foot  

PubMed Central

OBJECTIVE To assess the new quantitative bone scan parameters as markers of Charcot neuroosteoarthropathy (CNO) activity. RESEARCH DESIGN AND METHODS Forty-two patients with acute (n = 21) and nonacute (n = 21) CNO underwent quantitative bone scanning. Patients with acute CNO were followed for 3–12 months and bone scans were repeated after treatment. New quantitative parameters were assessed and compared with markers of bone turnover and with skin temperature difference (STD). RESULTS Significant correlations between quantitative bone scan parameters and bone turnover markers were observed (all P < 0.05). These parameters decreased after treatment of CNO, and its reduction to the baseline value correlated with differences of bone turnover markers and STD (all P < 0.05). CONCLUSIONS Our study suggests that bone scanning can be used not only for diagnosis of CNO but also for monitoring disease activity by quantitative bone scan parameters. PMID:19933988

Bem, Robert; Jirkovská, Alexandra; Dubský, Michal; Fejfarová, Vladimira; Buncová, Marie; Skibová, Jelena; Jude, Edward B.

2010-01-01

461

Mechanical stimulation of bone marrow in situ induces bone formation in trabecular explants.  

PubMed

Low magnitude high frequency (LMHF) loading has been shown to have an anabolic effect on trabecular bone in vivo. However, the precise mechanical signal imposed on the bone marrow cells by LMHF loading, which induces a cellular response, remains unclear. This study investigates the influence of LMHF loading, applied using a custom designed bioreactor, on bone adaptation in an explanted trabecular bone model, which isolated the bone and marrow. Bone adaptation was investigated by performing micro CT scans pre and post experimental LMHF loading, using image registration techniques. Computational fluids dynamic models were generated using the pre-experiment scans to characterise the mechanical stimuli imposed by the loading regime prior to adaptation. Results here demonstrate a significant increase in bone formation in the LMHF loaded group compared to static controls and media flow groups. The calculated shear stress in the marrow was between 0.575 and 0.7 Pa, which is within the range of stimuli known to induce osteogenesis by bone marrow mesenchymal stem cells in vitro. Interestingly, a correlation was found between the bone formation balance (bone formation/resorption), trabecular number, trabecular spacing, mineral resorption rate, bone resorption rate and mean shear stresses. The results of this study suggest that the magnitude of the shear stresses generated due to LMHF loading in the explanted bone cores has a contributory role in the formation of trabecular bone and improvement in bone architecture parameters. PMID:25281407

Birmingham, E; Kreipke, T C; Dolan, E B; Coughlin, T R; Owens, P; McNamara, L M; Niebur, G L; McHugh, P E

2015-04-01

462

3,3'-Diindolylmethane increases bone mass by suppressing osteoclastic bone resorption in mice.  

PubMed

3,3'-Diindolylmethane (DIM), a major acid-condensation product or metabolite of indole-3-carbinol which is found in cruciferous vegetables, has been shown to have anticancer, anti-inflammatory, and multiple immune stimulating effects. However, its function in bone metabolism is poorly understood. This study evaluated the effect of DIM on bone mass in mice under physiological and pathological conditions. Eight-week-old female mice received injections of a vehicle or 0.1mg/g of DIM, twice a week for four weeks. We found that DIM treatment significantly increased bone mass as assessed by dual-energy X-ray absorptiometry (DEXA) and micro-computed tomography (?CT). Further, Bone histomorphometric analyses showed that this treatment significantly reduced bone resorption parameters, but did not increase bone formation parameters. Furthermore, we use ovariectomized (OVX)-induced osteoporotic mouse model, and explore function of DIM in skeletal pathological processes. Bone phenotype analyses revealed that the administration of DIM in this study effectively prevented OVX-induced bone loss resulting from increased bone resorption. Our results demonstrated that DIM increased bone mass by suppressing osteoclastic bone resorption in bone metabolism under both physiological and pathological conditions. Accordingly, DIM may be of value in the treatment and the possible prevention of bone diseases characterized by bone loss, such as postmenopausal osteoporosis. PMID:25704022

Yu, Tai-Yong; Pang, Wei-Jun; Yang, Gong-She

2015-01-01

463

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

PubMed

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

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

2015-04-01

464

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

PubMed Central

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

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

2011-01-01

465

Retinoid receptors in bone and their role in bone remodeling.  

PubMed

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

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

2015-01-01

466

Retinoid Receptors in Bone and Their Role in Bone Remodeling  

PubMed Central

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.

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

2015-01-01

467

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

NASA Astrophysics Data System (ADS)

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.

Nguyen, Duong Thuy Thi

468

FSH and TSH in the Regulation of Bone Mass: The Pituitary/Immune/Bone Axis  

PubMed Central

Recent evidences have highlighted that the pituitary hormones have profound effects on bone, so that the pituitary-bone axis is now becoming an important issue in the skeletal biology. Here, we discuss the topical evidence about the dysfunction of the pituitary-bone axis that leads to osteoporotic bone loss. We will explore the context of FSH and TSH hormones arguing