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Sample records for cancellous bone site

  1. Increased presence of capillaries next to remodeling sites in adult human cancellous bone

    DEFF Research Database (Denmark)

    Kristensen, Helene Bjoerg; Andersen, Thomas Levin; Marcussen, Niels

    2013-01-01

    and at the level of the light-microscopically assessed contact of these three entities with the bone or canopy surfaces. Between 51 and 100 microm, their densities leveled to that found above quiescent surfaces. Electron microscopy asserted the close proximity between BRC canopies and capillaries lined...

  2. Combined Treatment of Alendronate and Low-Intensity Pulsed Ultrasound (LIPUS Increases Bone Mineral Density at the Cancellous Bone Osteotomy Site in Aged Rats: A Preliminary Study.

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    H Aonuma

    2011-12-01

    Full Text Available Introduction: During fracture healing, alendronate encourages callus volume by inhibiting bone resorption, whereas low-intensity pulsed ultrasound (LIPUS enhances bone regeneration by promoting an anabolic response. Methods: In the present study, 9-month-old Sprague-Dawley rats, with a unilateral proximal tibial osteotomy, were treated with alendronate (daily, 1 g/kg plus sham-LIPUS (n = 14, saline plus LIPUS (20 min/day (n = 18, alendronate plus LIPUS (n = 16, or saline plus sham- LIPUS as a control (n = 13 for 4 weeks. The rats were then examined for changes in bone mineral density (BMD during metaphyseal bone repair. Results: The combined therapy signi cantly increased BMD at the osteotomy site at 4 weeks (p < 0.001 compared with the control, without affecting the contralateral, non-osteotomized tibia. Both alendronate and LIPUS alone also exerted a positive, albeit less, effect on BMD in the affected limb (p < 0.001 and p = 0.006, respectively. Conclusions: Alendronate and LIPUS cooperate to enhance BMD during metaphyseal bone healing. Keywords: LIPUS, bisphosphonate, bone mineral density.

  3. Swine cortical and cancellous bone: histomorphometric and densitometric characterisation

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    Maria Elena Andreis

    2017-06-01

    Full Text Available Introduction: Swine bone morphology, composition and remodelling are similar to humans’, therefore they are considered good models in bone-related research. They have been used for several studies involving bone growth, bone and cartilage fractures and femoral head osteonecrosis. Nevertheless, the literature about pig normal bone features is incomplete. This work aims to fill the literature gaps on the microarchitecture and Bone Mineral Density (BMD of swine femoral diaphysis and distal epiphysis and tibial plateau and diaphysis. Materials and methods: Five hind limbs were collected from slaughtered 80-100 kg pigs. Microscopic analysis of cortical and cancellous bone from middle/distal femur and proximal/middle tibia was performed to determine basic histomorphometric parameters at different sites. Dual-energy X-Rays Absorptiometry was also employed to evaluate BMD. ANOVA and correlation between BMD, bone area (BA and cortical thickness were performed. Results and discussion: Diaphyseal cortical bone was mostly plexiform both in the tibia and the femur; primary/secondary osteons without clear organization were also found. Mean values for bone area, bone perimeter, trabecular width, number and separation and BMD at different anatomical sites were defined. No significant difference was found for these values at different anatomical sites. BMD proved to be positively correlated with cortical thickness (r=0,80; p<0,01. Despite the small sample size, these results seem homogeneous. They could therefore represent reference values for normal bone parameters in pigs. Applied anatomy and regenerative medicine, in fact, demand very precise information about bone micromorphology, composition and density to provide reliable indication in bone substitutes building. Moreover, since the interpretation of bone abnormalities is based on mastering normal bone characteristics, the definition of reference parameters is mandatory to avoid misinterpretation and

  4. Three-dimensional microarchitecture of adolescent cancellous bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl Christian; Hvid, Ivan

    2012-01-01

    , the adolescent cancellous bone had similar bone volume fraction (BV/TV), structure type (plate, rod or mixtures), and connectivity (3-D trabecular networks) as the adult cancellous bone. The adolescent cancellous bone had significantly lower bone surface density (bone surface per total volume of specimen...... and lateral condyle. These samples were micro-CT scanned (vivaCT 40, Scanco Medical AG, Switzerland) resulting in cubic voxel sizes of 10.5⁎10.5⁎10.5μm(3). Microarchitectural properties were calculated. The samples were then tested in compression followed by collagen and mineral determination. Interestingly...

  5. Osteoblast recruitment routes in human cancellous bone remodeling

    DEFF Research Database (Denmark)

    Kristensen, Helene Bjørg; Andersen, Thomas Levin; Marcussen, Niels

    2014-01-01

    It is commonly proposed that bone forming osteoblasts recruited during bone remodeling originate from bone marrow perivascular cells, bone remodeling compartment canopy cells, or bone lining cells. However, an assessment of osteoblast recruitment during adult human cancellous bone remodeling...... is lacking. We addressed this question by quantifying cell densities, cell proliferation, osteoblast differentiation markers, and capillaries in human iliac crest biopsy specimens. We found that recruitment occurs on both reversal and bone-forming surfaces, as shown by the cell density and osterix levels...

  6. Three-dimensional Microarchitecture of Adolescent Cancellous Bone

    DEFF Research Database (Denmark)

    Ding, Ming; Hvid, I; Overgaard, Søren

    regarding three-dimensional (3-D) microarchitecture of normal adolescent cancellous bone. The objective of this study was to investigate 3-D microarchitecture of normal adolescent cancellous bone, and compared them with adult cancellous bone, thus seeking more insight into the subchondral bone adaptations...... of lateral condyle in the young adult. There were no statistical significances in the mechanical properties apart from the Young’s modulus of adolescent in anterior-posterior direction was significantly lower than the other groups. DISCUSSION: This is the first study on the 3-D microarchitecture of human......, Switzerland) resulting in cubic voxel sizes of 10*10*10 m3. Microarchitectural properties were calculated, and the mean values for either tibia, medial or lateral condyle were used in analyses. Furthermore, the samples were first tested non-destructively in compression in antero-posterior (AP) and medial...

  7. Histologic Evaluation of Wound Healing After Ridge Preservation With Cortical, Cancellous, and Combined Cortico-Cancellous Freeze-Dried Bone Allograft: A Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Demetter, Randy S; Calahan, Blaine G; Mealey, Brian L

    2017-09-01

    Cortical and cancellous mineralized freeze-dried bone allografts (FDBA) are available for use in alveolar ridge preservation after tooth extraction. There are currently no data regarding use of a combination 50%/50% cortico-cancellous FDBA compared with a 100% cortical or 100% cancellous FDBA in ridge preservation. The primary objective of this study is to dimensionally and histologically evaluate healing after ridge preservation in non-molar sites using 50%/50% cortico-cancellous FDBA versus 100% cortical and 100% cancellous FDBA. Sixty-six patients requiring extraction of a non-molar tooth were enrolled and randomized into three groups to receive ridge preservation with the following: 1) 100% cortical FDBA; 2) 100% cancellous FDBA; or 3) 50%/50% cortico-cancellous FDBA. After 18 to 20 weeks of healing, a biopsy was harvested, and an implant was placed. The alveolar ridge was measured pre- and postoperatively to evaluate change in ridge height and width. Percentages of vital bone, residual graft, and connective tissue (CT)/other were determined via histomorphometric analysis. Histomorphometric analysis revealed no significant differences among groups regarding percentage of vital bone or CT/other. The 100% cortical FDBA group had significantly greater residual graft material (P = 0.04). Dimensional analysis revealed no significant between-group differences in any parameter measured. To the best knowledge of the authors, this study offers the first histologic evidence demonstrating no significant difference in vital bone formation or dimensional changes among 50%/50% cortico-cancellous FDBA, 100% cortical FDBA, and 100% cancellous FDBA when used in ridge preservation of non-molar tooth sites.

  8. Dynamic Mechanical Testing Techniques for Cortical and Cancellous Bone

    Science.gov (United States)

    Cloete, Trevor

    2017-06-01

    Bone fracture typically occurs as an impact loading event (sporting accidents, vehicle collisions), the simulation of which requires in-depth understanding of dynamic bone behavior. Bone is a natural composite material with a complex multi length-scale hierarchical microstructure. At a macroscopic level, it is classified into hard/compact cortical bone and soft/spongy cancellous (trabecular) bone, though both are low-impedance materials relative to steels. Cortical bone is predominant in long bones, while in complex bone geometries (joints, flat bones) a cancellous bone core supports a thin cortical shell. Bone has primarily been studied at quasi-static strain rates (ɛ˙ failure, with interrupted quasi-static tests revealing a strong microstructure dependence. However, bone specimens are typically destroyed during dynamic tests, leading to a lack of dynamic microstructural damage investigations. In this paper, a short overview of dynamic bone testing is presented to give context to the challenges of testing low impedance, strain-rate dependent, non-linear, visco-elastic-brittle materials. Recent state-of-the-art experimental developments in dynamic bone testing are reviewed, with emphasis on pulse shaping, momentum trapping and ISR testing. These techniques allow for dynamic bone testing at small strains and near-constant strain rates with intact specimen recovery. The results are compared to those obtained with varying strain rate tests. Interrupted dynamic test results with microstructural analysis of the recovered specimens are presented and discussed. The paper concludes with a discussion of the experimental and modeling challenges that lie ahead in the field of dynamic bone behavior. The financial assistance of the National Research Foundation and the University of Cape Town towards this research is hereby acknowledged. Opinions expressed and conclusions arrived at are those of the author alone.

  9. Cosserat moduli of anisotropic cancellous bone : A micromechanical analysis

    NARCIS (Netherlands)

    Fatemi, J.; Onck, P.R.; Poort, G.; Van Keulen, F.

    A micromechanical-based approach is proposed to quantify the effective (in the macroscopic sense) elastic constants of Cosserat materials. The material under investigation (cancellous bone) is cellular and classically elastic at the microscopic level and assumed to be dense Cosserat elastic at the

  10. An Ultrasonic Backscatter Instrument for Cancellous Bone Evaluation in Neonates

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    Chengcheng Liu

    2015-09-01

    Full Text Available Ultrasonic backscatter technique has shown promise as a noninvasive cancellous bone assessment tool. A novel ultrasonic backscatter bone diagnostic (UBBD instrument and an in vivo application for neonatal bone evaluation are introduced in this study. The UBBD provides several advantages, including noninvasiveness, non-ionizing radiation, portability, and simplicity. In this study, the backscatter signal could be measured within 5 s using the UBBD. Ultrasonic backscatter measurements were performed on 467 neonates (268 males and 199 females at the left calcaneus. The backscatter signal was measured at a central frequency of 3.5 MHz. The delay (T1 and duration (T2 of the backscatter signal of interest (SOI were varied, and the apparent integrated backscatter (AIB, frequency slope of apparent backscatter (FSAB, zero frequency intercept of apparent backscatter (FIAB, and spectral centroid shift (SCS were calculated. The results showed that the SOI selection had a direct influence on cancellous bone evaluation. The AIB and FIAB were positively correlated with the gestational age (|R| up to 0.45, P10 µs. Moderate positive correlations (|R| up to 0.45, P10 µs. The T2 mainly introduced fluctuations in the observed correlation coefficients. The moderate correlations observed with UBBD demonstrate the feasibility of using the backscatter signal to evaluate neonatal bone status. This study also proposes an explicit standard for in vivo SOI selection and neonatal cancellous bone assessment.

  11. Microstructural Assessment of Cancellous Bone Using 3D Microtomography

    International Nuclear Information System (INIS)

    Silva A M H; Alves J M; Da Silva O L; Silva Junior N F; Gazziro M; Pereira J C; Lasso P R O; Vaz C M P; Pereira C A M; Leiva T P; Guarniero R

    2011-01-01

    Cancellous bones have a porous microstructure and can be modeled as linear elastic solid, heterogeneous and anisotropic. Few studies regarding the morphometric analysis of trabecular bone samples with 3D microtomography have been published so far. The technique has spread worldwide for the characterization of trabecular structures in studies related to bone quality and its relationship with metabolic diseases bone like osteoporosis. In our study cancellous bone samples with cubic and cylindrical geometry were extracted from bovine femur were used to investigate the structural arrangement of bone through high resolution x-ray 3D microtomography (μCT). Four trabecular microstructural parameters (tissue volume, bone volume, bone volume fraction and tissue surface) were measured by 2D (stereological method) and 3D morphometric analysis using the software CTan Analyser supplied by the manufacturer of the microtomograph (SkyScan, model 1172, Belgium). The measurements were done in three main directions (superior-inferior, medial-lateral and anterior-posterior) to investigate the correlation between the 2D and 3D morphometric analysis. The results show a high correlation between the analysis. The x-ray 3D microtomography technique has a great potential for the assessment of bone quality.

  12. OSTEOPENIA in cancellous bone of sheep induced by Glucocorticoid alone

    DEFF Research Database (Denmark)

    Ding, Ming; Cheng, L.; Bollen, Peter

    2008-01-01

    Introduction: There is a great need for suitable large animal models that closely resemble osteoporosis in humans, and that they have adequate bone size for bone prosthesis and biomaterial research. Previous investigations have shown that osteoporotic sheep model requires glucocorticoid (GC......) microarchitectural properties and mechanical properties of sheep cancellous bone after a 7 months steroid treatment; and thus to validate a large animal model for orthopaedic implant/biomaterial research. Materials and Methods: Eighteen female sheep were randomly allocated into 3 groups: group 1 (GC-1) received GC......, osteocalcin was significantly reduced after 7 months but a rebound phenomenon was observed 3 months after cessation of GC. In conclusion, this study has validated an osteopenia sheep model. Bone quality was significantly reduced following a 7 months GC-treatment and recovered after further 3 month observation...

  13. Bone augmentation for cancellous bone- development of a new animal model

    Science.gov (United States)

    2013-01-01

    Background Reproducible and suitable animal models are required for in vivo experiments to investigate new biodegradable and osteoinductive biomaterials for augmentation of bones at risk for osteoporotic fractures. Sheep have especially been used as a model for the human spine due to their size and similar bone metabolism. However, although sheep and human vertebral bodies have similar biomechanical characteristics, the shape of the vertebral bodies, the size of the transverse processes, and the different orientation of the facet joints of sheep are quite different from those of humans making the surgical approach complicated and unpredictable. Therefore, an adequate and safe animal model for bone augmentation was developed using a standardized femoral and tibia augmentation site in sheep. Methods The cancellous bone of the distal femur and proximal tibia were chosen as injection sites with the surgical approach via the medial aspects of the femoral condyle and proximal tibia metaphysis (n = 4 injection sites). For reproducible drilling and injection in a given direction and length, a custom-made c-shaped aiming device was designed. Exact positioning of the aiming device and needle positioning within the intertrabecular space of the intact bone could be validated in a predictable and standardized fashion using fluoroscopy. After sacrifice, bone cylinders (∅ 32 mm) were harvested throughout the tibia and femur by means of a diamond-coated core drill, which was especially developed to harvest the injected bone area exactly. Thereafter, the extracted bone cylinders were processed as non-decalcified specimens for μCT analysis, histomorphometry, histology, and fluorescence evaluation. Results The aiming device could be easily placed in 63 sheep and assured a reproducible, standardized injection area. In four sheep, cardiovascular complications occurred during surgery and pulmonary embolism was detected by computed tomography post surgery in all of these animals

  14. Radiographic healing and remodelling of cortical and cancellous bone grafts after rigid plate fixation

    International Nuclear Information System (INIS)

    Waris, P.; Karaharju, E.; Slaetis, P.; Paavolainen, P.

    1980-01-01

    Cortical and cancellous interposition grafts, with rigid plate fixation, in the tibiofibular bones of 130 rabbits were followed radiographically for one year. The cancellous grafts healed earlier, but by 12 weeks both graft types had been incorporated, the distal host-graft interface being the last to heal. Progressive cancellous transformation in both the graft and host bone led to an increased over-all bone diameter, a widened medullary canal and a thinned porotic wall. (Auth.)

  15. Ultrasonic characterization of cancellous bone using apparent integrated backscatter

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmeister, B K [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); III, C I Jones [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); Caldwell, G J [Department of Physics, Rhodes College, 2000 North Parkway, Memphis, TN 38112 (United States); Kaste, S C [Department of Diagnostic Imaging, St Jude Children' s Research Hospital, Memphis, TN 38105 (United States)

    2006-06-07

    Apparent integrated backscatter (AIB) is a measure of the frequency-averaged (integrated) backscattered power contained in some portion of a backscattered ultrasonic signal. AIB has been used extensively to study soft tissues, but its usefulness as a tissue characterization technique for cancellous bone has not been demonstrated. To address this, we performed measurements on 17 specimens of cancellous bone over two different frequency ranges using a 1 MHz and 5 MHz broadband ultrasonic transducer. Specimens were obtained from bovine tibiae and prepared in the shape of cubes (15 mm side length) with faces oriented along transverse (anterior, posterior, medial and lateral) and longitudinal (superior and inferior) principal anatomic directions. A mechanical scanning system was used to acquire multiple backscatter signals from each direction for each cube. AIB demonstrated highly significant linear correlations with bone mineral density (BMD) for both the transverse (R{sup 2} = 0.817) and longitudinal (R{sup 2} = 0.488) directions using the 5 MHz transducer. In contrast, the correlations with density were much weaker for the 1 MHz transducer (R{sup 2} = 0.007 transverse, R{sup 2} = 0.228 longitudinal). In all cases where a significant correlation was observed, AIB was found to decrease with increasing BMD.

  16. Changed morphology and mechanical properties of cancellous bone in the mandibular condyles of edentate people

    DEFF Research Database (Denmark)

    Ding, Ming

    2004-01-01

    Since edentate subjects have a reduced masticatory function, it can be expected that the morphology of the cancellous bone of their mandibular condyles has changed according to the altered mechanical environment. In the present study, the morphology of cylindrical cancellous bone specimens...

  17. Bone cement allocation analysis in artificial cancellous bone structures

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    Ivan Zderic

    2017-01-01

    Conclusion: The simulated leakage path seemed to be the most important adverse injection factor influencing the uniformity of cement distribution. Another adverse factor causing dispersion of this distribution was represented by the simulated bone marrow. However, the rather uniform distribution of the totally injected cement amount, considered as one unit, could be ascribed to the medium viscosity of the used cement. Finally, with its short waiting time of 45 s, the stepwise injection procedure was shown to be ineffective in preventing cement leakage.

  18. Managment of frontal sinus fracture: obliteration sinus with cancellous bone graft.

    Science.gov (United States)

    Muminagic, Sahib; Masic, Tarik; Babajic, Emina; Asotic, Mithat

    2011-01-01

    Frontal sinus fractures make up about 2-15% of all facial fractures.This is relatively low frequency of occurrence, but it has a large potential of complication and may involve not only the frontal sinuse but more importantly the brain and the eyes. The management depends of the complexity. If anterior wall is fractured with grossly involved nasofrontal duct (NFD) in the injury it is paramount to occlude NFD. Very often, sinus obliteration is done at the same time. In our expirience autogenous cancellous bone graft is considered to be the best grafting material. It has the less short - or long-term complications and the donor site morbidity is insignificant.

  19. Defect nonunion of a metatarsal bone fracture in a cow: successful management with bone plating and autogenous cancellous bone graft.

    Science.gov (United States)

    Raghunath, M; Singh, N; Singh, T; Gopinathan, A; Mohindroo, J; Atri, K

    2013-01-01

    A two-and-half-year-old cow was presented with a defect nonunion of the right metatarsal III/IV bone following a severely comminuted open fracture two months previously. The animal underwent open fixation using a 4.5 mm, broad, 10-hole, dynamic compression plate and autogenous cancellous bone graft collected from the contralateral iliac shaft. The animal started partial weight bearing after the third postoperative day and resumed complete weight bearing after the 10th day. Fracture healing was complete and the implants were removed after the 120th postoperative day. Stable fixation by means of a bone plate in conjunction with a cancellous bone graft facilitated complete healing and restoration of the bone column of the defect and the metatarsal fracture. The animal made a complete recovery.

  20. Pharmacokinetics of Cefuroxime in Cortical and Cancellous Bone Obtained by Microdialysis - a Porcine Study

    DEFF Research Database (Denmark)

    Tøttrup, Mikkel; Forsingdal Hardlei, Tore; Bendtsen, Michael

    2014-01-01

    . As reference, free and total plasma concentrations were also measured. The animals received a bolus of 1500 mg cefuroxime over 30 min. No significant differences between key pharmacokinetic parameters for sealed and unsealed drill holes in cortical bone were found. The mean area under the concentration...... (MD) technique for measurement of cefuroxime in bone, and to obtain pharmacokinetic profiles for the same drug in porcine cortical and cancellous bone. Measurements were conducted in bone-wax sealed and unsealed drill holes in cortical bone, in drill holes in cancellous bone and in subcutaneous tissue...

  1. Age-related variations in the microstructure of human tibial cancellous bone

    DEFF Research Database (Denmark)

    Ding, M.; Odgaard, A.; Linde, F.

    2002-01-01

    -related changes in the three-dimensional (3D) microstructure of human tibial cancellous bone. One hundred and sixty cylindrical cancellous bone specimens were produced from 40 normal proximal tibiae from 40 donors, aged 16-85 years. These specimens were micro-computed tomography (micro-CT) scanned......, and microstructural properties were determined. The specimens were then tested in compression to obtain Young's modulus. The degree of anisotropy, mean marrow space volume, and bone surface-to-volume ratio increased significantly with age. Bone volume fraction, mean trabecular volume, and bone surface density...

  2. Cancellous bone structure of iliac crest biopsies following 370 days of head-down bed rest

    DEFF Research Database (Denmark)

    Thomsen, Jesper Skovhus; Morukov, Boris V.; Vico, Laurence

    2005-01-01

    INTRODUCTION: Static bone histomorphometry was applied to existing iliac bone sections originating from a 370-d 5 degrees head-down bed rest experiment. This bed rest experiment is the longest ever to have been conducted. We hypothesized that bed rest would decrease cancellous bone volume fractio...

  3. Mechanical properties of cancellous bone in the human mandibular condyle are anisotropic

    DEFF Research Database (Denmark)

    Giesen, EB; Ding, Ming; Dalstra, M

    2001-01-01

    The objective of the present study was (1) to test the hypothesis that the elastic and failure properties of the cancellous bone of the mandibular condyle depend on the loading direction, and (2) to relate these properties to bone density parameters. Uniaxial compression tests were performed......). Archimedes' principle was applied to determine bone density parameters. The cancellous bone was in axial loading 3.4 times stiffer and 2.8 times stronger upon failure than in transverse loading. High coefficients of correlation were found among the various mechanical properties and between them...

  4. Comparative biomechanical and microstructural analysis of native versus peracetic acid-ethanol treated cancellous bone graft.

    Science.gov (United States)

    Rauh, Juliane; Despang, Florian; Baas, Jorgen; Liebers, Cornelia; Pruss, Axel; Gelinsky, Michael; Günther, Klaus-Peter; Stiehler, Maik

    2014-01-01

    Bone transplantation is frequently used for the treatment of large osseous defects. The availability of autologous bone grafts as the current biological gold standard is limited and there is a risk of donor site morbidity. Allogenic bone grafts are an appealing alternative, but disinfection should be considered to reduce transmission of infection disorders. Peracetic acid-ethanol (PE) treatment has been proven reliable and effective for disinfection of human bone allografts. The purpose of this study was to evaluate the effects of PE treatment on the biomechanical properties and microstructure of cancellous bone grafts (CBG). Forty-eight human CBG cylinders were either treated by PE or frozen at -20 °C and subjected to compression testing and histological and scanning electron microscopy (SEM) analysis. The levels of compressive strength, stiffness (Young's modulus), and fracture energy were significantly decreased upon PE treatment by 54%, 59%, and 36%, respectively. Furthermore, PE-treated CBG demonstrated a 42% increase in ultimate strain. SEM revealed a modified microstructure of CBG with an exposed collagen fiber network after PE treatment. We conclude that the observed reduced compressive strength and reduced stiffness may be beneficial during tissue remodeling thereby explaining the excellent clinical performance of PE-treated CBG.

  5. Comparative Biomechanical and Microstructural Analysis of Native versus Peracetic Acid-Ethanol Treated Cancellous Bone Graft

    Directory of Open Access Journals (Sweden)

    Juliane Rauh

    2014-01-01

    Full Text Available Bone transplantation is frequently used for the treatment of large osseous defects. The availability of autologous bone grafts as the current biological gold standard is limited and there is a risk of donor site morbidity. Allogenic bone grafts are an appealing alternative, but disinfection should be considered to reduce transmission of infection disorders. Peracetic acid-ethanol (PE treatment has been proven reliable and effective for disinfection of human bone allografts. The purpose of this study was to evaluate the effects of PE treatment on the biomechanical properties and microstructure of cancellous bone grafts (CBG. Forty-eight human CBG cylinders were either treated by PE or frozen at −20°C and subjected to compression testing and histological and scanning electron microscopy (SEM analysis. The levels of compressive strength, stiffness (Young’s modulus, and fracture energy were significantly decreased upon PE treatment by 54%, 59%, and 36%, respectively. Furthermore, PE-treated CBG demonstrated a 42% increase in ultimate strain. SEM revealed a modified microstructure of CBG with an exposed collagen fiber network after PE treatment. We conclude that the observed reduced compressive strength and reduced stiffness may be beneficial during tissue remodeling thereby explaining the excellent clinical performance of PE-treated CBG.

  6. Comparative Biomechanical and Microstructural Analysis of Native versus Peracetic Acid-Ethanol Treated Cancellous Bone Graft

    Science.gov (United States)

    Rauh, Juliane; Despang, Florian; Baas, Jorgen; Liebers, Cornelia; Pruss, Axel; Günther, Klaus-Peter; Stiehler, Maik

    2014-01-01

    Bone transplantation is frequently used for the treatment of large osseous defects. The availability of autologous bone grafts as the current biological gold standard is limited and there is a risk of donor site morbidity. Allogenic bone grafts are an appealing alternative, but disinfection should be considered to reduce transmission of infection disorders. Peracetic acid-ethanol (PE) treatment has been proven reliable and effective for disinfection of human bone allografts. The purpose of this study was to evaluate the effects of PE treatment on the biomechanical properties and microstructure of cancellous bone grafts (CBG). Forty-eight human CBG cylinders were either treated by PE or frozen at −20°C and subjected to compression testing and histological and scanning electron microscopy (SEM) analysis. The levels of compressive strength, stiffness (Young's modulus), and fracture energy were significantly decreased upon PE treatment by 54%, 59%, and 36%, respectively. Furthermore, PE-treated CBG demonstrated a 42% increase in ultimate strain. SEM revealed a modified microstructure of CBG with an exposed collagen fiber network after PE treatment. We conclude that the observed reduced compressive strength and reduced stiffness may be beneficial during tissue remodeling thereby explaining the excellent clinical performance of PE-treated CBG. PMID:24678514

  7. Three-dimensional microarchitecture of human osteoporotic, osteoarthrotic and rheumatoid arthritic cancellous bones

    DEFF Research Database (Denmark)

    Ding, Ming; Overgaard, Søren

    , OP often leads to skeletal fractures, and OA and RA result in severe joint disability. Over the last a few decades, much significant research on the properties has been carried out on these diseases, however, a detailed comparison of the microarchitecture of cancellous bones of these diseases...... is not available. In this study, we investigated three-dimensional (3-D) microarchitectural properties of OP, OA and RA cancellous bone. We hypothesized that there were significant differences in microarchitecture among OP, OA and RA bone tissues that might lead to different bone quality. Materials and Method...... Twenty OP, fifty OA, and twelve RA femur heads were harvested from patients undergone total hip replacement surgery. Cubic cancellous bone samples (8*8*8 mm3) were prepared and scanned with a high resolution microtomographic system (vivaCT 40, Scanco Medical AG., Brüttisellen, Switzerland). Then micro...

  8. Mutual associations among microstructural, physical and mechanical properties of human cancellous bone

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Danielsen, CC

    2002-01-01

    structure and mechanical properties. In this study, 160 cancellous bone specimens were produced from 40 normal human tibiae aged from 16 to 85 years at post-mortem. The specimens underwent micro-CT and the microstructural properties were calculated using unbiased three-dimensional methods. The specimens...... were tested to determine the mechanical properties and the physical/compositional properties were evaluated. The type of structure together with anisotropy correlated well with Young's modulus of human tibial cancellous bone. The plate-like structure reflected high mechanical stress and the rod......-like structure low mechanical stress. There was a strong correlation between the type of trabecular structure and the bone-volume fraction. The most effective microstructural properties for predicting the mechanical properties of cancellous bone seem to differ with age....

  9. Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    Best Poster 5Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants AuthorsBabiker , H.; Ding M.; Overgaard S.InstitutionOrthopaedic Research Laboratory, Department of Orthopaedic Surgery, Odense University Hospital, Clinical Institute, University of Southern...... from human tissue were included (IsoTis OrthoBiologics, Inc. USA). Both materials are commercially available. Titanium alloy implants (Biomet Inc.) of 10 mm in length and 10 mm in diameter were inserted bilaterally into the femoral condyles of 8 skeletally mature sheep. Thus four implants...... with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: DBM; DBM/CB with ratio of 1/3; DBM/allograft with ratio of 1/3; or allograft (Gold standard), respectively. Standardised surgical procedure was used1. At sacrifice, 6 weeks after surgery, both distal femurs were harvested...

  10. [A long-term follow-up of treatment of adult unicameral bone cysts with allograft of lyophilized cancellous bone].

    Science.gov (United States)

    Zhang, Yonggang; Wang, Yan; Cheng, Jiying

    2005-08-01

    To investigate the long-term clinical results of treatment of adult unicameral bone cyst with cancellous allograft. From 1993 to 1998, 15 patients with unicameral bone cyst were treated by allograft with lyophilized cancellous bone. Among 15 patients, there were 5 males and 10 females, aging 19-41 years with an average of 27 years. The average follow-up time was 7.5 years (6-11 years). The X-ray films were taken and the CT scanning were carried out. The X-ray films showed that the allograft particles became vague 2-3 months after operation, that the allograft particles fused and began to form new bone and the bone density increased 5 months after operation, and that new bone formation completed after 7 months of operation. At the end of follow-up, remodelling in new bone occurred. Recurrence was not found in all patients. The symptom of pain disappeared or relieved obviously. Allograft of lyophilized cancellous bone is an effective treatment for adult unicameral bone cysts.

  11. Empirical angle-dependent Biot and MBA models for acoustic anisotropy in cancellous bone

    International Nuclear Information System (INIS)

    Lee, Kang ll; Hughes, E R; Humphrey, V F; Leighton, T G; Choi, Min Joo

    2007-01-01

    The Biot and the modified Biot-Attenborough (MBA) models have been found useful to understand ultrasonic wave propagation in cancellous bone. However, neither of the models, as previously applied to cancellous bone, allows for the angular dependence of acoustic properties with direction. The present study aims to account for the acoustic anisotropy in cancellous bone, by introducing empirical angle-dependent input parameters, as defined for a highly oriented structure, into the Biot and the MBA models. The anisotropy of the angle-dependent Biot model is attributed to the variation in the elastic moduli of the skeletal frame with respect to the trabecular alignment. The angle-dependent MBA model employs a simple empirical way of using the parametric fit for the fast and the slow wave speeds. The angle-dependent models were used to predict both the fast and slow wave velocities as a function of propagation angle with respect to the trabecular alignment of cancellous bone. The predictions were compared with those of the Schoenberg model for anisotropy in cancellous bone and in vitro experimental measurements from the literature. The angle-dependent models successfully predicted the angular dependence of phase velocity of the fast wave with direction. The root-mean-square errors of the measured versus predicted fast wave velocities were 79.2 m s -1 (angle-dependent Biot model) and 36.1 m s -1 (angle-dependent MBA model). They also predicted the fact that the slow wave is nearly independent of propagation angle for angles about 50 0 , but consistently underestimated the slow wave velocity with the root-mean-square errors of 187.2 m s -1 (angle-dependent Biot model) and 240.8 m s -1 (angle-dependent MBA model). The study indicates that the angle-dependent models reasonably replicate the acoustic anisotropy in cancellous bone

  12. Comparative study on inorganic composition and crystallographic properties of cortical and cancellous bone.

    Science.gov (United States)

    Wang, Xiao-Yan; Zuo, Yi; Huang, Di; Hou, Xian-Deng; Li, Yu-Bao

    2010-12-01

    To comparatively investigate the inorganic composition and crystallographic properties of cortical and cancellous bone via thermal treatment under 700 °C. Thermogravimetric measurement, infrared spectrometer, X-ray diffraction, chemical analysis and X-ray photo-electron spectrometer were used to test the physical and chemical properties of cortical and cancellous bone at room temperature 250 °C, 450 °C, and 650 °C, respectively. The process of heat treatment induced an extension in the a-lattice parameter and changes of the c-lattice parameter, and an increase in the crystallinity reflecting lattice rearrangement after release of lattice carbonate and possible lattice water. The mineral content in cortical and cancellous bone was 73.2wt% and 71.5wt%, respectively. For cortical bone, the weight loss was 6.7% at the temperature from 60 °C to 250 °C, 17.4% from 250 °C to 450 °C, and 2.7% from 450 °C to 700 °C. While the weight loss for the cancellous bone was 5.8%, 19.9%, and 2.8 % at each temperature range, the Ca/P ratio of cortical bone was 1.69 which is higher than the 1.67 of stoichiometric HA due to the B-type CO₃²⁻ substitution in apatite lattice. The Ca/P ratio of cancellous bone was lower than 1.67, suggesting the presence of more calcium deficient apatite. The collagen fibers of cortical bone were arrayed more orderly than those of cancellous bone, while their mineralized fibers ollkded similar. The minerals in both cortical and cancellous bone are composed of poorly crystallized nano-size apatite crystals with lattice carbonate and possible lattice water. The process of heat treatment induces a change of the lattice parameter, resulting in lattice rearrangement after the release of lattice carbonate and lattice water and causing an increase in crystal size and crystallinity. This finding is helpful for future biomaterial design, preparation and application. Copyright © 2010 The Editorial Board of Biomedical and Environmental Sciences

  13. In vitro cartilage tissue engineering using cancellous bone matrix gelatin as a biodegradable scaffold

    International Nuclear Information System (INIS)

    Yang Bo; Yin Zhanhai; Cao Junling; Shi Zhongli; Zhang Zengtie; Liu Fuqiang; Song Hongxing; Caterson, Bruce

    2010-01-01

    In this study, we constructed tissue-engineered cartilage using allogeneic cancellous bone matrix gelatin (BMG) as a scaffold. Allogeneic BMG was prepared by sequential defatting, demineralization and denaturation. Isolated rabbit chondrocytes were seeded onto allogeneic cancellous BMG, and cell-BMG constructs were harvested after 1, 3 and 6 weeks for evaluation by hematoxylin and eosin staining for overall morphology, toluidine blue for extracellular matrix (ECM) proteoglycans, immunohistochemical staining for collagen type II and a transmission electron microscope for examining cellular microstructure on BMG. The prepared BMG was highly porous with mechanical strength adjustable by duration of demineralization and was easily trimmed for tissue repair. Cancellous BMG showed favorable porosity for cell habitation and metabolism material exchange with larger pore sizes (100-500 μm) than in cortical BMG (5-15 μm), allowing cell penetration. Cancellous BMG also showed good biocompatibility, which supported chondrocyte proliferation and sustained their differentiated phenotype in culture for up to 6 weeks. Rich and evenly distributed cartilage ECM proteoglycans and collagen type II were observed around chondrocytes on the surface and inside the pores throughout the cancellous BMG. Considering the large supply of banked bone allografts and relatively convenient preparation, our study suggests that allogeneic cancellous BMG is a promising scaffold for cartilage tissue engineering.

  14. In vitro cartilage tissue engineering using cancellous bone matrix gelatin as a biodegradable scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Yang Bo; Yin Zhanhai; Cao Junling; Shi Zhongli; Zhang Zengtie; Liu Fuqiang [College of Medicine, Xi' an Jiaotong University, Yanta West Road, No 76, Yanta District, Xi' an, Shaanxi Province 710061 (China); Song Hongxing [Department of Orthopedics, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Caterson, Bruce, E-mail: caojl@mail.xjtu.edu.c [Connective Tissue Biology Laboratories, Cardiff School of Biosciences, Cardiff University, Biomedical Building, Museum Avenue, Cardiff, CF10 3US (United Kingdom)

    2010-08-01

    In this study, we constructed tissue-engineered cartilage using allogeneic cancellous bone matrix gelatin (BMG) as a scaffold. Allogeneic BMG was prepared by sequential defatting, demineralization and denaturation. Isolated rabbit chondrocytes were seeded onto allogeneic cancellous BMG, and cell-BMG constructs were harvested after 1, 3 and 6 weeks for evaluation by hematoxylin and eosin staining for overall morphology, toluidine blue for extracellular matrix (ECM) proteoglycans, immunohistochemical staining for collagen type II and a transmission electron microscope for examining cellular microstructure on BMG. The prepared BMG was highly porous with mechanical strength adjustable by duration of demineralization and was easily trimmed for tissue repair. Cancellous BMG showed favorable porosity for cell habitation and metabolism material exchange with larger pore sizes (100-500 {mu}m) than in cortical BMG (5-15 {mu}m), allowing cell penetration. Cancellous BMG also showed good biocompatibility, which supported chondrocyte proliferation and sustained their differentiated phenotype in culture for up to 6 weeks. Rich and evenly distributed cartilage ECM proteoglycans and collagen type II were observed around chondrocytes on the surface and inside the pores throughout the cancellous BMG. Considering the large supply of banked bone allografts and relatively convenient preparation, our study suggests that allogeneic cancellous BMG is a promising scaffold for cartilage tissue engineering.

  15. Effects of gas produced by degradation of Mg–Zn–Zr Alloy on cancellous bone tissue

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingbo; Jiang, Hongfeng [Tianjin Hospital, 300211 Tianjin (China); Bi, Yanze; Sun, Jin e; Chen, Minfang; Liu, Debao [School of Materials Science and Engineering, Tianjin University of Technology, 300384 Tianjin (China)

    2015-10-01

    Mg–Zn–Zr alloy cylinders were implanted into the femoral condyles of Japanese big-ear white rabbits. X-ray showed that by 12 weeks following implantation the implant became obscure, around which the low-density area appeared and enlarged. By 24 weeks, the implant was more obscure and the density of the surrounding cancellous bone increased. Scanning electron microscopy examination showed bone tissue on the surface of the alloy attached by living fibers at 12 weeks. Micro-CT confirmed that new bone tissue on the surface of the residual alloy implant increased from 12 weeks to 24 weeks. By 12 weeks, many cavities in the cancellous bone tissue around the implant were noted with a CT value, similar to gas value, and increasing by 24 weeks (P < 0.01). Histological examination of hard tissue slices showed that bone tissue was visibly attached to the alloy in the femoral condyle at 12 weeks. The trabecular bone tissues became more intact and dense, and the cavities were filled with soft tissue at 24 weeks. In general, gas produced by the degradation of the Mg–Zn–Zr alloy can cause cavitation within cancellous bone, which does not affect osteogenesis of Mg alloy. - Highlights: • The degradation of Mg alloy in cancellous bone causes cavitation around the alloy. • At first, the CT value of the cavities is similar to the gas value. • The area of the cavities enlarges gradually by 12 weeks. • The cavities are filled with bone tissue and soft tissue gradually.

  16. Effect of the cortex on ultrasonic backscatter measurements of cancellous bone

    International Nuclear Information System (INIS)

    Hoffmeister, Brent K; Holt, Andrew P; Kaste, Sue C

    2011-01-01

    Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

  17. Effect of the cortex on ultrasonic backscatter measurements of cancellous bone

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmeister, Brent K; Holt, Andrew P [Department of Physics, Rhodes College, Memphis, TN (United States); Kaste, Sue C, E-mail: hoffmeister@rhodes.edu [Department of Diagnostic Imaging, St Jude Children' s Research Hospital, Memphis, TN (United States)

    2011-10-07

    Ultrasonic backscatter techniques offer a promising new approach for detecting changes in bone caused by osteoporosis. However, several challenges impede clinical implementation of backscatter techniques. This study examines how the dense outer surface of bone (the cortex) affects backscatter measurements of interior regions of porous (cancellous) bone tissue. Fifty-two specimens of bone were prepared from 13 human femoral heads so that the same region of cancellous bone could be ultrasonically interrogated through the cortex or along directions that avoided the cortex. Backscatter signals were analyzed over a frequency range of 0.8-3.0 MHz to determine two ultrasonic parameters: apparent integrated backscatter (AIB) and frequency slope of apparent backscatter (FSAB). The term 'apparent' means that the parameters are sensitive to the frequency-dependent effects of diffraction and attenuation. Significant (p < 0.001) changes in AIB and FSAB indicated that measurements through the cortex decreased the apparent backscattered power and increased the frequency dependence of the power. However, the cortex did not affect the correlation of AIB and FSAB with the x-ray bone mineral density of the specimens. This suggests that results from many previous in vitro backscatter studies of specimens of purely cancellous bone may be extrapolated with greater confidence to in vivo conditions.

  18. Compacted cancellous bone has a spring-back effect

    DEFF Research Database (Denmark)

    Kold, S; Bechtold, JE; Ding, Ming

    2003-01-01

    A new surgical technique, compaction, has been shown to improve implant fixation. It has been speculated that the enhanced implant fixation with compaction could be due to a spring-back effect of compacted bone. However, such an effect has yet to be shown. Therefore we investigated in a canine mo....... Thus we found a spring-back effect of compacted bone, which may be important for increasing implant fixation by reducing initial gaps between the implant and bone....

  19. The role of an effective isotropic tissue modulus in the elastic properties of cancellous bone

    NARCIS (Netherlands)

    Kabel, J.; Rietbergen, van B.; Dalstra, M.; Odgaard, A.; Huiskes, H.W.J.

    1999-01-01

    Conceptually, the elastic characteristics of cancellous bone could be predicted directly from the trabecular morphology-or architecture-and by the elastic properties of the tissue itself. Although hardly any experimental evidence exists, it is often implicitly assumed that tissue anisotropy has a

  20. Kit W-sh Mutation Prevents Cancellous Bone Loss during Calcium Deprivation.

    Science.gov (United States)

    Lotinun, Sutada; Suwanwela, Jaijam; Poolthong, Suchit; Baron, Roland

    2018-01-01

    Calcium is essential for normal bone growth and development. Inadequate calcium intake increases the risk of osteoporosis and fractures. Kit ligand/c-Kit signaling plays an important role in regulating bone homeostasis. Mice with c-Kit mutations are osteopenic. The present study aimed to investigate whether impairment of or reduction in c-Kit signaling affects bone turnover during calcium deprivation. Three-week-old male WBB6F1/J-Kit W /Kit W-v /J (W/W v ) mice with c-Kit point mutation, Kit W-sh /HNihrJaeBsmJ (W sh /W sh ) mice with an inversion mutation in the regulatory elements upstream of the c-Kit promoter region, and their wild-type controls (WT) were fed either a normal (0.6% calcium) or a low calcium diet (0.02% calcium) for 3 weeks. μCT analysis indicated that both mutants fed normal calcium diet had significantly decreased cortical thickness and cancellous bone volume compared to WT. The low calcium diet resulted in a comparable reduction in cortical bone volume and cortical thickness in the W/W v and W sh /W sh mice, and their corresponding controls. As expected, the low calcium diet induced cancellous bone loss in the W/W v mice. In contrast, W sh /W sh cancellous bone did not respond to this diet. This c-Kit mutation prevented cancellous bone loss by antagonizing the low calcium diet-induced increase in osteoblast and osteoclast numbers in the W sh /W sh mice. Gene expression profiling showed that calcium deficiency increased Osx, Ocn, Alp, type I collagen, c-Fms, M-CSF, and RANKL/OPG mRNA expression in controls; however, the W sh mutation suppressed these effects. Our findings indicate that although calcium restriction increased bone turnover, leading to osteopenia, the decreased c-Kit expression levels in the W sh /W sh mice prevented the low calcium diet-induced increase in cancellous bone turnover and bone loss but not the cortical bone loss.

  1. Material heterogeneity in cancellous bone promotes deformation recovery after mechanical failure.

    Science.gov (United States)

    Torres, Ashley M; Matheny, Jonathan B; Keaveny, Tony M; Taylor, David; Rimnac, Clare M; Hernandez, Christopher J

    2016-03-15

    Many natural structures use a foam core and solid outer shell to achieve high strength and stiffness with relatively small amounts of mass. Biological foams, however, must also resist crack growth. The process of crack propagation within the struts of a foam is not well understood and is complicated by the foam microstructure. We demonstrate that in cancellous bone, the foam-like component of whole bones, damage propagation during cyclic loading is dictated not by local tissue stresses but by heterogeneity of material properties associated with increased ductility of strut surfaces. The increase in surface ductility is unexpected because it is the opposite pattern generated by surface treatments to increase fatigue life in man-made materials, which often result in reduced surface ductility. We show that the more ductile surfaces of cancellous bone are a result of reduced accumulation of advanced glycation end products compared with the strut interior. Damage is therefore likely to accumulate in strut centers making cancellous bone more tolerant of stress concentrations at strut surfaces. Hence, the structure is able to recover more deformation after failure and return to a closer approximation of its original shape. Increased recovery of deformation is a passive mechanism seen in biology for setting a broken bone that allows for a better approximation of initial shape during healing processes and is likely the most important mechanical function. Our findings suggest a previously unidentified biomimetic design strategy in which tissue level material heterogeneity in foams can be used to improve deformation recovery after failure.

  2. Mechanical Modelling of Cancellous Bone from their Microstructure

    Directory of Open Access Journals (Sweden)

    Ruiz–Cervantes O.

    2010-04-01

    Full Text Available In this paper is established a spongy bone bidimensional models methodology for its analysis by finite element software. The models are focused to represent the bone trabecular structure by Voronoi cells, using the coordinates of the porous center, contained within the bone structure, obtained by optical microscope images. Looking for a better geometrical similarity, it was assigned a thicker transversal area in the trabecula union zone, because has been reported that this factor gives a better approximation to experimental results. To feed the finite element models, compression test has been done to trabecular specimens, taking the maximum strain and maximum stress, to obtain the elastic modulus. By means of strained specimen images analysis, it has been established the structure collapse moment. It was when the 36% of total trabeculae failed. Finally it was obtained a tissue Young modulus of 323 [MPa] and with this value, the resistance variation in function of density and trabecular architecture.

  3. Relationships among ultrasonic and mechanical properties of cancellous bone in human calcaneus in vitro.

    Science.gov (United States)

    Wear, Keith A; Nagaraja, Srinidhi; Dreher, Maureen L; Sadoughi, Saghi; Zhu, Shan; Keaveny, Tony M

    2017-10-01

    Clinical bone sonometers applied at the calcaneus measure broadband ultrasound attenuation and speed of sound. However, the relation of ultrasound measurements to bone strength is not well-characterized. Addressing this issue, we assessed the extent to which ultrasonic measurements convey in vitro mechanical properties in 25 human calcaneal cancellous bone specimens (approximately 2×4×2cm). Normalized broadband ultrasound attenuation, speed of sound, and broadband ultrasound backscatter were measured with 500kHz transducers. To assess mechanical properties, non-linear finite element analysis, based on micro-computed tomography images (34-micron cubic voxel), was used to estimate apparent elastic modulus, overall specimen stiffness, and apparent yield stress, with models typically having approximately 25-30 million elements. We found that ultrasound parameters were correlated with mechanical properties with R=0.70-0.82 (pmechanical properties beyond that provided by bone quantity alone (p≤0.05). Adding ultrasound variables to linear regression models based on bone quantity improved adjusted squared correlation coefficients from 0.65 to 0.77 (stiffness), 0.76 to 0.81 (apparent modulus), and 0.67 to 0.73 (yield stress). These results indicate that ultrasound can provide complementary (to bone quantity) information regarding mechanical behavior of cancellous bone. Published by Elsevier Inc.

  4. Numerical and experimental study on the wave attenuation in bone--FDTD simulation of ultrasound propagation in cancellous bone.

    Science.gov (United States)

    Nagatani, Yoshiki; Mizuno, Katsunori; Saeki, Takashi; Matsukawa, Mami; Sakaguchi, Takefumi; Hosoi, Hiroshi

    2008-11-01

    In cancellous bone, longitudinal waves often separate into fast and slow waves depending on the alignment of bone trabeculae in the propagation path. This interesting phenomenon becomes an effective tool for the diagnosis of osteoporosis because wave propagation behavior depends on the bone structure. Since the fast wave mainly propagates in trabeculae, this wave is considered to reflect the structure of trabeculae. For a new diagnosis method using the information of this fast wave, therefore, it is necessary to understand the generation mechanism and propagation behavior precisely. In this study, the generation process of fast wave was examined by numerical simulations using elastic finite-difference time-domain (FDTD) method and experimental measurements. As simulation models, three-dimensional X-ray computer tomography (CT) data of actual bone samples were used. Simulation and experimental results showed that the attenuation of fast wave was always higher in the early state of propagation, and they gradually decreased as the wave propagated in bone. This phenomenon is supposed to come from the complicated propagating paths of fast waves in cancellous bone.

  5. Multi-element determination in cancellous bone of human femoral head by PIXE

    International Nuclear Information System (INIS)

    Yuanxun Zhang; Yongping Zhang; Yongpeng Tong; Shijing Qiu; Xiaotao Wu; Kerong Dai

    1996-01-01

    Proton Induced X-ray Emission (PIXE) method is used for the determination of elemental concentrations in cancellous bone of human femoral head from five autopsies and seven patients with femoral neck broken. The specimen preparation and experimental procedure are described in detail. Using the t test, the results show that the concentrations of P, Ca, Fe, Cu, Sr in control group are higher than those in patient group, but the concentrations of S, K, Zn, Mn are not significantly different. The physiological functions of metallic elements in human bone are also discussed. (author). 19 refs., 1 fig., 4 tabs

  6. Preoperative assessment of the cancellous bone mineral density of the proximal humerus using CT data

    International Nuclear Information System (INIS)

    Krappinger, Dietmar; Roth, Tobias; Gschwentner, Martin; Suckert, Armin; Blauth, Michael; Hengg, Clemens; Kralinger, Franz

    2012-01-01

    Osteoporotic fractures of the proximal humerus show an increasing incidence. Osteoporosis not only influences the fracture risk after low-energy trauma, but also affects the mechanical stability of internal fixation. Preoperative assessment of the local bone quality may be useful in the surgical treatment of patients sustaining these injuries. The aim of the present study was to present a method for the preoperative assessment of the local cancellous bone mineral density (BMD) of the proximal humerus using CT data. In the first part of the study, CT scans of 30 patients with unilateral fractures of the proximal humerus after low-energy trauma were used. The local BMD was assessed on the contralateral uninjured side. All 30 patients additionally underwent dual-emission X-ray absorptiometry (DXA) of the lumbar spine, proximal femur, and forearm of the side of the uninjured proximal humerus within 6 weeks after trauma. Three independent trauma surgeons performed measurements on the uninjured proximal humerus twice with a time interval of 4 weeks in order to assess the inter- and intraobserver reliability of the method. In the second part of the study, the local BMD of 507 patients with either proximal humerus fractures or chronic shoulder instability was assessed by a single trauma surgeon. In both parts, the average HU values in standardized ROIs of the humeral head were automatically calculated after correcting for HU values below the water equivalent. A linear calibration equation was computed for the calculation from HU to BMD using a calibration device (EFP). The intra- and interobserver reliability was high (ICC > 0.95). Correlation coefficients between the local BMD of the proximal humerus and other anatomical sites were between 0.35 (lumbar spine) and 0.64 (forearm). We found a high correlation between the local BMD and age. The BMD in the fracture group was significantly lower than in the instability group. These patients were significantly older and more

  7. Preoperative assessment of the cancellous bone mineral density of the proximal humerus using CT data

    Energy Technology Data Exchange (ETDEWEB)

    Krappinger, Dietmar; Roth, Tobias; Gschwentner, Martin; Suckert, Armin; Blauth, Michael; Hengg, Clemens; Kralinger, Franz [Innsbruck Medical University, Department of Trauma Surgery and Sports Medicine, Innsbruck (Austria)

    2012-03-15

    Osteoporotic fractures of the proximal humerus show an increasing incidence. Osteoporosis not only influences the fracture risk after low-energy trauma, but also affects the mechanical stability of internal fixation. Preoperative assessment of the local bone quality may be useful in the surgical treatment of patients sustaining these injuries. The aim of the present study was to present a method for the preoperative assessment of the local cancellous bone mineral density (BMD) of the proximal humerus using CT data. In the first part of the study, CT scans of 30 patients with unilateral fractures of the proximal humerus after low-energy trauma were used. The local BMD was assessed on the contralateral uninjured side. All 30 patients additionally underwent dual-emission X-ray absorptiometry (DXA) of the lumbar spine, proximal femur, and forearm of the side of the uninjured proximal humerus within 6 weeks after trauma. Three independent trauma surgeons performed measurements on the uninjured proximal humerus twice with a time interval of 4 weeks in order to assess the inter- and intraobserver reliability of the method. In the second part of the study, the local BMD of 507 patients with either proximal humerus fractures or chronic shoulder instability was assessed by a single trauma surgeon. In both parts, the average HU values in standardized ROIs of the humeral head were automatically calculated after correcting for HU values below the water equivalent. A linear calibration equation was computed for the calculation from HU to BMD using a calibration device (EFP). The intra- and interobserver reliability was high (ICC > 0.95). Correlation coefficients between the local BMD of the proximal humerus and other anatomical sites were between 0.35 (lumbar spine) and 0.64 (forearm). We found a high correlation between the local BMD and age. The BMD in the fracture group was significantly lower than in the instability group. These patients were significantly older and more

  8. Application of INAA in the assessment of selected elements in cancellous bone of human iliac crest

    International Nuclear Information System (INIS)

    Zaichick, V.

    2007-01-01

    The effect of age and sex was investigated on the concentration of chemical elements in intact cancellous bone of iliac crest of 74 relatively healthy, 15-55 years old women (n = 29) and men (n = 45). Concentrations of Ca, Cl, K, Mg, Mn, Na, P, and Sr in bone samples were determined by instrumental neutron activation analysis using short-lived radionuclides. Mean values (M±S.E.M.) of the mass fraction of the investigated elements (on dry weight basis) for female and male all together were: 127±4 g/kg, 1620±80 mg/kg, 1310±70 mg/kg, 1550±50 mg/kg, <0.32±0.02 mg/kg, 4240±110 mg/kg, 61.8±1.8 g/kg, and 235±18 mg/kg, respectively. The statistically significant (≤0.05) decrease of Ca, Mg, and P concentrations in the iliac cancellous bone with age was found only for women. Sex-related comparison has shown that the mean values of Mg mass fractions in male bone samples were less than in female ones. (author)

  9. Demineralized bone matrix and human cancellous bone enhance fixation of porous-coated titanium implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2016-01-01

    matrix (DBM), alone or in combination with allograft or commercially available human cancellous bone (CB), may replace allografts, as they have the capability of inducing new bone and improving implant fixation through enhancing bone ongrowth. The purpose of this study was to investigate the effect...... of DBM alone, DBM with CB, or allograft on the fixation of porous-coated titanium implants. DBM100 and CB produced from human tissue were included. Both materials are commercially available. DBM granules are placed in pure DBM and do not contain any other carrier. Titanium alloy implants, 10 mm long × 10...... mm diameter, were inserted bilaterally into the femoral condyles of eight skeletally mature sheep. Thus, four implants with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: (a) DBM; (b) DBM:CB at a ratio of 1:3; (c) DBM:allograft at a ratio of 1:3; or (d) allograft...

  10. Free Radicals Formation of Irradiated Lyophilized Can-Cellous Human and Bovine Bone

    International Nuclear Information System (INIS)

    Abbas, Basril; Sudiro, Sutjipto; Hilmy, Nazly

    2000-01-01

    Radiation sterilization of lyophilized human and bovine bone as allograft and xenograft have been produced and used in orthopaedic practice in Indonesia routinely. It is well known from radio biologic studies that one of the most pronounce effects of ionizing radiation on biologic species produced the free radicals that influence the physico-chemical as well as the mechanical properties of irradiated bone. The aim of our study is to investigate the free radicals formation of irradiated lyophilized cancellous triple A bone (Autolyzed Antigen-Extracted Allograft) produced by Batan Research Tissue Bank in Jakarta. The cancellous triple A were prepared according to AATB (American Association of Tissue Bank) method. Gamma Irradiations was done at doses of 10, 20 and 30 kGy with a dose rate of 7,5 kGy/h at room temperature (30 o C± 2 o C). Measurements of free radicals was done at 24 o C ±1 o C within 30 minutes after irradiational and measurement were continued up to 9 months of storage using a JES-REIX ESR Spectrophotometer (JEOL) with Mn exp. ++ standard. Parameters measured, were the effects of mechanical grinding, water immersion and irradiation dose on free radicals formation in the bone. Results show that the signal area of ESR spectra from irradiated bovine bone of 30 kGy was higher than those of human bone I.e. 1,4 x 10 exp. 7 dan 6,4 x 10 exp. 6 Au (arbitrary unit)/g samples respectively. The signal of ESR spectra increased linearly with increasing dose in the range of 10-30 kGy and it will reduce about 30% caused by water immersion. The ESR signal reduced sharply after 2 days and gradually decreased up to 14 days and then became constant up to 9 months of storage at room temperature. A certain method of crushing can produce free radicals. Key Words: free radical, irradiation, allograft, xenograft, mechanical-grinding

  11. Safe Harvesting of Outer Table Parietal Bone Grafts Using an Oscillating Saw and a Bone Scraper : A Refinement of Technique for Harvesting Cortical and "Cancellous"-Like Calvarial Bone

    NARCIS (Netherlands)

    Schortinghuis, Jurjen; Putters, Thomas F.; Raghoebar, Gerry M.

    Calvarial bone is a readily available source of bone for preimplantation augmentation procedures of the alveolar process. However, the calvaria consist mostly of cortical bone, and cancellous bone of the diploic space is scarce. A bone scraper (Safescraper Twist; META, Reggio Emilia, Italy) was used

  12. The variation of cancellous bones at lumbar vertebra, femoral neck, mandibular angle and rib in ovariectomized sheep.

    Science.gov (United States)

    Zhang, Yongqiang; Li, Yongfeng; Gao, Qi; Shao, Bo; Xiao, Jianrui; Zhou, Hong; Niu, Qiang; Shen, Mingming; Liu, Baolin; Hu, Kaijin; Kong, Liang

    2014-07-01

    This study aimed to compare the variation of cancellous bones at four skeletal sites: lumbar vertebra, femoral neck, mandibular angle and rib in ovariectomized sheep. Sixteen adult sheep were randomly divided into two groups: eight sheep were ovariectomized served as experimental group; the other eight untreated sheep were served as control group. Bone mineral density was assessed by dual-energy X-ray absorptiometry on lumbar vertebrae at baseline and twelve months after ovariectomy. After 12 months, lumbar vertebrae L3 and L4, femoral necks, mandibular angles and the fourth ribs were harvested for micro-CT scanning, histological analysis and biomechanical test. The results showed that bone mineral density of lumbar vertebra decreased significantly in twelfth month (pbone volume/total volume decreased by 45.6%, 36.1% 21.3% and 18.7% in lumbar vertebrae, femoral necks, mandibular angles and ribs in experimental group (pbones to oestrogen deficiency in ovariectomized sheep was site-specific on a pattern as follows: lumbar vertebra, femoral neck, mandibular angle and rib. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Microstructures and properties of cancellous bone of avascular necrosis of femoral heads

    Science.gov (United States)

    Yao, Xuefeng; Wang, Peng; Dai, Ruchun; Yeh, Hsien Yang

    2010-03-01

    The aim of this study is to investigate microscopic structure and characterize cancellous bone of avascular necrosis of the femoral head (ANFH). The rabbit model of the ANFH is established. The histopathologic features are studied successfully. The differences between the steroid-injection group (S.G.) and the controlled group (C.G.) are examined, including the weight of rabbits, the hematological examination and the three-dimensional structures. It is found that the plasma levels of cholesterol (CHO), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) in S.G. are lower than those in C.G. when the triglyceride (TG) increased in the S.G.; but the bone mineral content (BMC) and the structural model index (SMI) of the organ and tissue decreased significantly in S.G. Three-dimensional structures of the femoral head are obtained using micro-computed tomography (CT) scanning and the mechanical model is established to analyze the influences of these structural changes on the mechanical properties of the cancellous bone.

  14. Variability of tissue mineral density can determine physiological creep of human vertebral cancellous bone.

    Science.gov (United States)

    Kim, Do-Gyoon; Shertok, Daniel; Ching Tee, Boon; Yeni, Yener N

    2011-06-03

    Creep is a time-dependent viscoelastic deformation observed under a constant prolonged load. It has been indicated that progressive vertebral deformation due to creep may increase the risk of vertebral fracture in the long-term. The objective of this study was to examine the relationships of creep with trabecular architecture and tissue mineral density (TMD) parameters in human vertebral cancellous bone at a physiological static strain level. Architecture and TMD parameters of cancellous bone were analyzed using microcomputerized tomography (micro-CT) in specimens cored out of human vertebrae. Then, creep and residual strains of the specimens were measured after a two-hour physiological compressive constant static loading and unloading cycle. Creep developed (3877 ± 2158 με) resulting in substantial levels of non-recoverable post-creep residual strain (1797 ± 1391 με). A strong positive linear correlation was found between creep and residual strain (r = 0.94, p creep rate. The TMD variability (GL(COV)) was the strongest correlate of creep rate (r = 0.79, p < 0.001). This result suggests that TMD variability may be a useful parameter for estimating the long-term deformation of a whole vertebral body. The results further suggest that the changes in TMD variability resulting from bone remodeling are of importance and may provide an insight into the understanding of the mechanisms underlying progressive failure of vertebral bodies and development of a clinical fracture. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Accuracy of cancellous bone volume fraction measured by micro-CT scanning

    DEFF Research Database (Denmark)

    Ding, Ming; Odgaard, A; Hvid, I

    1999-01-01

    Volume fraction, the single most important parameter in describing trabecular microstructure, can easily be calculated from three-dimensional reconstructions of micro-CT images. This study sought to quantify the accuracy of this measurement. One hundred and sixty human cancellous bone specimens...... which covered a large range of volume fraction (9.8-39.8%) were produced. The specimens were micro-CT scanned, and the volume fraction based on Archimedes' principle was determined as a reference. After scanning, all micro-CT data were segmented using individual thresholds determined by the scanner...

  16. In vitro comparison of DE-QCT parameters with the compressive strength of cancellous bone

    International Nuclear Information System (INIS)

    Oravez, W.T.; Robertson, D.D.

    1986-01-01

    Quantitative computed tomography (QCT) is used as a method for assessing bone mineral in patients with osteoporosis. The implication being that if the mass of bone mineral is low enough then the patient is at risk for developing symptoms, i.e., fracture. The authors performed an in vitro test which compared dual-energy-QCT (DE-QCT) parameters with compressive strength. The bone samples were placed in a water bath and CT scanned using a Siemens DR-3. Alternating x-ray pulses of 125 and 85 kVp were used to generate the dual energy images. Four images, high kVp, low kVp, monoenergenic, and calcium equivalent, were reconstructed from each scan. A specially constructed bone mineral calibration phantom, consisting of a polyethylene rod and varying tubes of K2HP04, was placed within the water bath along with the specimens. Comparisons will be made between the various DE parameters and their relationship to the compressive strength of cancellous bone. The critical effect of trabecular bone orientation will also be discussed

  17. Generating 3D tissue constructs with mesenchymal stem cells and a cancellous bone graft for orthopaedic applications

    International Nuclear Information System (INIS)

    Arca, Turkan; Genever, Paul; Proffitt, Joanne

    2011-01-01

    Bone matrix (BM) is an acellular crosslinked porcine-derived cancellous bone graft, and therefore may provide advantages over other synthetic and naturally derived materials for use in orthopaedic surgery. Here, we analysed the potential of BM to support the growth and differentiation of primary human multipotent stromal cells/mesenchymal stem cells (MSCs) in order to predict in vivo bone regeneration events. Imaging with laser scanning confocal microscopy and scanning electron microscopy showed that 1 day after static seeding, a dense population of viable MSCs could be achieved on scaffolds suggesting they could be used for in vivo delivery of cells to the implant site. Long-term growth analysis by confocal imaging and histology demonstrated that BM was permissive to the growth and the 3D population of primary MSCs and an enhanced green fluorescent protein expressing osteosarcoma cell line, eGFP.MG63s, over several days in culture. Measurement of alkaline phosphatase (ALP) activities and mRNA expression levels of osteogenic markers (Runx-2, ALP, collagen type I, osteonectin, osteocalcin and osteopontin) indicated that BM supported osteogenesis of MSCs when supplemented with osteogenic stimulants. Upregulation of some of these osteogenic markers on BM, but not on tissue culture plastic, under non-osteogenic conditions suggested that BM also had osteoinductive capacities.

  18. Generating 3D tissue constructs with mesenchymal stem cells and a cancellous bone graft for orthopaedic applications

    Energy Technology Data Exchange (ETDEWEB)

    Arca, Turkan; Genever, Paul [Department of Biology, University of York, York, YO10 5DD (United Kingdom); Proffitt, Joanne, E-mail: paul.genever@york.ac.uk [TSL Centre of Biologics, Covidien, Allerton Bywater, Castleford, WF10 2DB (United Kingdom)

    2011-04-15

    Bone matrix (BM) is an acellular crosslinked porcine-derived cancellous bone graft, and therefore may provide advantages over other synthetic and naturally derived materials for use in orthopaedic surgery. Here, we analysed the potential of BM to support the growth and differentiation of primary human multipotent stromal cells/mesenchymal stem cells (MSCs) in order to predict in vivo bone regeneration events. Imaging with laser scanning confocal microscopy and scanning electron microscopy showed that 1 day after static seeding, a dense population of viable MSCs could be achieved on scaffolds suggesting they could be used for in vivo delivery of cells to the implant site. Long-term growth analysis by confocal imaging and histology demonstrated that BM was permissive to the growth and the 3D population of primary MSCs and an enhanced green fluorescent protein expressing osteosarcoma cell line, eGFP.MG63s, over several days in culture. Measurement of alkaline phosphatase (ALP) activities and mRNA expression levels of osteogenic markers (Runx-2, ALP, collagen type I, osteonectin, osteocalcin and osteopontin) indicated that BM supported osteogenesis of MSCs when supplemented with osteogenic stimulants. Upregulation of some of these osteogenic markers on BM, but not on tissue culture plastic, under non-osteogenic conditions suggested that BM also had osteoinductive capacities.

  19. Advances in allogenic bone graft processing and usage: preparation and evaluation of chitosan-demineralized cancellous bone powder composite scaffolds as a bone graft substitute

    International Nuclear Information System (INIS)

    Yongyudh Vajaradul

    2008-01-01

    Full text: Demineralized bone matrix (DBM) is currently used by surgeons. It usually exists as a lyophilized powder which is difficult to handle and operated. In this study, we try to improve these disadvantages by combining DBM with a biomaterial. It focuses on a natural biodegradable polymer, chitosan, to act as a temporary matrix for bone growth that easily prepare in any size and shape by using tissue engineering knowledge to get a proper temporary matrix. Thus, the development of chitosan-demineralized bone powder composite scaffold is an alternative way. Polymeric scaffold has been demonstrated to have great potential for tissue engineering because the scaffold or three dimension (3D) construct provides the necessary support for cells to proliferate, extracellular matrix deposition and vascularization of neo-tissue. Moreover, chitosan, a natural cationic polymer which its structural is similar to extracellular matrix glycosaminoblycans, is biodegradable, biocompatible, non-antigenic and biofunctional. It can enhance osteoblast cells proliferation and mineral matrix deposition in culture. The first study was to fabricate and analyze composite scaffold composed of either chitosan-demineralized cancellous bone powders or chitosan-demineralized cancellous cartilage bone powders in a ratio 50:50 and 70:30 w/w (chitosan : bone powders) based on physical properties composing of average pore diameter, mechanical integrity and swelling property. Secondly, scaffolds were evaluated in term of biological properties composing of their ability to support neo osteogenesis, including assessments of cell attachment and viability, cell morphology, and the biosynthesis of extracellular matrix. Results indicated that chitosan-demineralized cancellous bone powder composite scaffolds possessing an interconnecting, porous structure could be easily created through a simple freezing and lyophilization process. (Author)

  20. Effect of ovariectomy on BMD, micro-architecture and biomechanics of cortical and cancellous bones in a sheep model.

    Science.gov (United States)

    Wu, Zi-xiang; Lei, Wei; Hu, Yun-yu; Wang, Hai-qiang; Wan, Shi-yong; Ma, Zhen-sheng; Sang, Hong-xun; Fu, Suo-chao; Han, Yi-sheng

    2008-11-01

    Osteoporotic/osteopenia fractures occur most frequently in trabeculae-rich skeletal sites. The purpose of this study was to use a high-resolution micro-computed tomography (micro-CT) and dual energy X-ray absorptionmeter (DEXA) to investigate the changes in micro-architecture and bone mineral density (BMD) in a sheep model resulted from ovariectomy (OVX). Biomechanical tests were performed to evaluate the strength of the trabecular bone. Twenty adult sheeps were randomly divided into three groups: sham group (n=8), group 1 (n=4) and group 2 (n=8). In groups 1 and 2, all sheep were ovariectomized (OVX); in the sham group, the ovaries were located and the oviducts were ligated. In all animals, BMD for lumbar spine was obtained during the surgical procedure. BMD at the spine, femoral neck and femoral condyle was determined 6 months (group 1) and 12 months (group 2) post-OVX. Lumbar spines and femora were obtained and underwent BMD scan, micro-CT analysis. Compressive mechanical properties were determined from biopsies of vertebral bodies and femoral condyles. BMD, micro-architectural parameters and mechanical properties of cancellous bone did not decrease significantly at 6 months post-OVX. Twelve months after OVX, BMD, micro-architectural parameters and mechanical properties decreased significantly. The results of linear regression analyses showed that trabecular thickness (Tb.Th) (r=0.945, R2=0.886) and bone volume fraction (BV/TV) (r=0.783, R2=0.586) had strong (R2>0.5) correlation to compression stress. In OVX sheep, changes in the structural parameters of trabecular bone are comparable to the human situation during osteoporosis was induced. The sheep model presented seems to meet the criteria for an osteopenia model for fracture treatment with respect to morphometric and mechanical properties. But the duration of OVX must be longer than 12 months to ensure the animal model can be established successfully.

  1. Room temperature housing results in premature cancellous bone loss in growing female mice: implications for the mouse as a preclinical model for age-related bone loss.

    Science.gov (United States)

    Iwaniec, U T; Philbrick, K A; Wong, C P; Gordon, J L; Kahler-Quesada, A M; Olson, D A; Branscum, A J; Sargent, J L; DeMambro, V E; Rosen, C J; Turner, R T

    2016-10-01

    Room temperature housing (22 °C) results in premature cancellous bone loss in female mice. The bone loss was prevented by housing mice at thermoneutral temperature (32 °C). Thermogenesis differs markedly between mice and humans and mild cold stress induced by standard room temperature housing may introduce an unrecognized confounding variable into preclinical studies. Female mice are often used as preclinical models for osteoporosis but, in contrast to humans, mice exhibit cancellous bone loss during growth. Mice are routinely housed at room temperature (18-23 °C), a strategy that exaggerates physiological differences in thermoregulation between mice (obligatory daily heterotherms) and humans (homeotherms). The purpose of this investigation was to assess whether housing female mice at thermoneutral (temperature range where the basal rate of energy production is at equilibrium with heat loss) alters bone growth, turnover and microarchitecture. Growing (4-week-old) female C57BL/6J and C3H/HeJ mice were housed at either 22 or 32 °C for up to 18 weeks. C57BL/6J mice housed at 22 °C experienced a 62 % cancellous bone loss from the distal femur metaphysis during the interval from 8 to 18 weeks of age and lesser bone loss from the distal femur epiphysis, whereas cancellous and cortical bone mass in 32 °C-housed mice were unchanged or increased. The impact of thermoneutral housing on cancellous bone was not limited to C57BL/6J mice as C3H/HeJ mice exhibited a similar skeletal response. The beneficial effects of thermoneutral housing on cancellous bone were associated with decreased Ucp1 gene expression in brown adipose tissue, increased bone marrow adiposity, higher rates of bone formation, higher expression levels of osteogenic genes and locally decreased bone resorption. Housing female mice at 22 °C resulted in premature cancellous bone loss. Failure to account for species differences in thermoregulation may seriously confound interpretation of studies

  2. Glycation of human cortical and cancellous bone captures differences in the formation of Maillard reaction products between glucose and ribose.

    Directory of Open Access Journals (Sweden)

    Grażyna E Sroga

    Full Text Available To better understand some aspects of bone matrix glycation, we used an in vitro glycation approach. Within two weeks, our glycation procedures led to the formation of advanced glycation end products (AGEs at the levels that corresponded to approx. 25-30 years of the natural in vivo glycation. Cortical and cancellous bones from human tibias were glycated in vitro using either glucose (glucosylation or ribose (ribosylation. Both glucosylation and ribosylation led to the formation of higher levels of AGEs and pentosidine (PEN in cancellous than cortical bone dissected from all tested donors (young, middle-age and elderly men and women. More efficient glycation of bone matrix proteins in cancellous bone most likely depended on the higher porosity of this tissue, which facilitated better accessibility of the sugars to the matrix proteins. Notably, glycation of cortical bone from older donors led to much higher AGEs levels as compared to young donors. Such efficient in vitro glycation of older cortical bone could result from aging-related increase in porosity caused by the loss of mineral content. In addition, more pronounced glycation in vivo would be driven by elevated oxidation processes. Interestingly, the levels of PEN formation differed pronouncedly between glucosylation and ribosylation. Ribosylation generated very high levels of PEN (approx. 6- vs. 2.5-fold higher PEN level than in glucosylated samples. Kinetic studies of AGEs and PEN formation in human cortical and cancellous bone matrix confirmed higher accumulation of fluorescent crosslinks for ribosylation. Our results suggest that in vitro glycation of bone using glucose leads to the formation of lower levels of AGEs including PEN, whereas ribosylation appears to support a pathway toward PEN formation. Our studies may help to understand differences in the progression of bone pathologies related to protein glycation by different sugars, and raise awareness for excessive sugar

  3. A deconvolution method for deriving the transit time spectrum for ultrasound propagation through cancellous bone replica models.

    Science.gov (United States)

    Langton, Christian M; Wille, Marie-Luise; Flegg, Mark B

    2014-04-01

    The acceptance of broadband ultrasound attenuation for the assessment of osteoporosis suffers from a limited understanding of ultrasound wave propagation through cancellous bone. It has recently been proposed that the ultrasound wave propagation can be described by a concept of parallel sonic rays. This concept approximates the detected transmission signal to be the superposition of all sonic rays that travel directly from transmitting to receiving transducer. The transit time of each ray is defined by the proportion of bone and marrow propagated. An ultrasound transit time spectrum describes the proportion of sonic rays having a particular transit time, effectively describing lateral inhomogeneity of transit times over the surface of the receiving ultrasound transducer. The aim of this study was to provide a proof of concept that a transit time spectrum may be derived from digital deconvolution of input and output ultrasound signals. We have applied the active-set method deconvolution algorithm to determine the ultrasound transit time spectra in the three orthogonal directions of four cancellous bone replica samples and have compared experimental data with the prediction from the computer simulation. The agreement between experimental and predicted ultrasound transit time spectrum analyses derived from Bland-Altman analysis ranged from 92% to 99%, thereby supporting the concept of parallel sonic rays for ultrasound propagation in cancellous bone. In addition to further validation of the parallel sonic ray concept, this technique offers the opportunity to consider quantitative characterisation of the material and structural properties of cancellous bone, not previously available utilising ultrasound.

  4. X-treme CT analysis of cancellous bone at the rotator cuff insertion in human individuals with osteoporosis: superficial versus deep quality.

    Science.gov (United States)

    Kirchhoff, Chlodwig; Kirchhoff, Sonja; Sprecher, Christoph M; Ahrens, Philipp; Imhoff, Andreas B; Hinterwimmer, Stefan; Milz, Stefan; Braunstein, Volker

    2013-03-01

    Rotator cuff (RC) repair-especially in the elderly population-is problematic since the patients suffer to a high extent from bone mineral density loss at the reattachment site. Therefore, the study was primarily driven by the question whether it is possible to reach more or qualitatively better cancellous bone and thus a more stable postoperative result if anchors with greater length are used for RC repair and/or the conventional anchors are screwed deeper into the bone. In anatomical terms, the question is raised whether cancellous bone is of better quality close to or far off the RC enthesis. Axial HRqCT scans (X-tremeCT, Scanco Medical) of 36 human cadaveric humeral heads (75 ± 11 years) were performed to determine the ratio of bone volume to total volume (BV/TV), trabecular thickness (Trab Th), number of trabecles (Trab N), trabecular separation (Trab Sp) as well as non-metric indices such as connectivity density (Conn Dens) and structure model index (SMI). Within the greater tuberosity (GT), 6 volumes of interest (VOI) (A1, B1, C1, A2, B2, C2), in the lesser tuberosity (LT) 2 VOIs (D1, D2) and one control VOI in the subchondral bone were set. The analyzed bone cylinder of each VOI was divided into a superficial and a deep portion. The parameters BV/TV, Trab N, Trab Th and Conn Dens in all volumes of the GT and LT revealed higher values in the superficial portion reaching different levels of significance (p significance for the non-metric parameter SMI in no volume of the GT/LT, although the higher values were found superficially. Our data show that cancellous bone presents with decreasing bone quality when analyzing increasingly deeper portions of the bone cylinders of the GT and LT starting at the articular surface. This information seems to be crucial for shoulder surgeons, especially when treating elderly patients. Our results clearly prove that screwing in anchors to a deeper extent will not improve stability, since the deeper bone stock is of worse

  5. Use of dual-energy computed tomography to measure skeletal-wide marrow composition and cancellous bone mineral density.

    Science.gov (United States)

    Arentsen, Luke; Hansen, Karen E; Yagi, Masashi; Takahashi, Yutaka; Shanley, Ryan; McArthur, Angela; Bolan, Patrick; Magome, Taiki; Yee, Douglas; Froelich, Jerry; Hui, Susanta K

    2017-07-01

    Temporal and spatial variations in bone marrow adipose tissue (MAT) can be indicative of several pathologies and confound current methods of assessing immediate changes in bone mineral remodeling. We present a novel dual-energy computed tomography (DECT) method to monitor MAT and marrow-corrected volumetric BMD (mcvBMD) throughout the body. Twenty-three cancellous skeletal sites in 20 adult female cadavers aged 40-80 years old were measured using DECT (80 and 140 kVp). vBMD was simultaneous recorded using QCT. MAT was further sampled using MRI. Thirteen lumbar vertebrae were then excised from the MRI-imaged donors and examined by microCT. After MAT correction throughout the skeleton, significant differences (p < 0.05) were found between QCT-derived vBMD and DECT-derived mcvBMD results. McvBMD was highly heterogeneous with a maximum at the posterior skull and minimum in the proximal humerus (574 and 0.7 mg/cc, respectively). BV/TV and BMC have a nearly significant correlation with mcvBMD (r = 0.545, p = 0.057 and r = 0.539, p = 0.061, respectively). MAT assessed by DECT showed a significant correlation with MRI MAT results (r = 0.881, p < 0.0001). Both DECT- and MRI-derived MAT had a significant influence on uncorrected vBMD (r = -0.86 and r = -0.818, p ≤ 0.0001, respectively). Conversely, mcvBMD had no correlation with DECT- or MRI-derived MAT (r = 0.261 and r = 0.067). DECT can be used to assess MAT while simultaneously collecting mcvBMD values at each skeletal site. MAT is heterogeneous throughout the skeleton, highly variable, and should be accounted for in longitudinal mcvBMD studies. McvBMD accurately reflects the calcified tissue in cancellous bone.

  6. Evidence for reduced cancellous bone mass in the spontaneously hypertensive rat

    Science.gov (United States)

    Wang, T. M.; Hsu, J. F.; Jee, W. S.; Matthews, J. L.

    1993-01-01

    The histomorphometric changes in the proximal tibial metaphysis and epiphyseal growth plate and midtibial shaft of 26-week-old spontaneously hypertensive rats (SHR) compared with those of the corresponding normotensive Wistar-Kyoto (WKY) rats were studied. A decrease in body weight, growth plate thickness, and longitudinal growth rate of the proximal tibial epiphysis, trabecular bone volume, trabecular thickness and number, the number of osteoblasts and osteoprogenitor cells per millimeter square surface of the proximal tibial metaphysis, periosteal and endocortical apposition rate and bone formation rate of the tibial diaphysis were observed in the SHR. Additionally, systolic blood pressure, the number of osteoclasts per millimeter square surface and average number of nuclei per osteoclast of the proximal tibial metaphysis were significantly increased. Thus, osteoclastic activity is dominant over osteoblastic and chondroblastic activity in the SHR that results in a cancellous bone deficit in the skeleton. It will require additional work to ascertain the underlying cause for this condition as several factors in the SHR with a potential for causing this change are present, including elevated parathyroid hormone (PTH), depressed 1,25-(OH)2D3, low calcium absorption, reduced body weight (reduced loading) elevated blood pressure and possibly other direct cell differences in the mutant strain. At present elevated PTH and adaptation to underloading from reduced weight are postulated to be a likely cause, but additional studies are required to test this interpretation.

  7. Bioactive Ti metal analogous to human cancellous bone: Fabrication by selective laser melting and chemical treatments.

    Science.gov (United States)

    Pattanayak, Deepak K; Fukuda, A; Matsushita, T; Takemoto, M; Fujibayashi, S; Sasaki, K; Nishida, N; Nakamura, T; Kokubo, T

    2011-03-01

    Selective laser melting (SLM) is a useful technique for preparing three-dimensional porous bodies with complicated internal structures directly from titanium (Ti) powders without any intermediate processing steps, with the products being expected to be useful as a bone substitute. In this study the necessary SLM processing conditions to obtain a dense product, such as the laser power, scanning speed, and hatching pattern, were investigated using a Ti powder of less than 45 μm particle size. The results show that a fully dense plate thinner than 1.8 mm was obtained when the laser power to scanning speed ratio was greater than 0.5 and the hatch spacing was less than the laser diameter, with a 30 μm thick powder layer. Porous Ti metals with structures analogous to human cancellous bone were fabricated and the compressive strength measured. The compressive strength was in the range 35-120 MPa when the porosity was in the range 75-55%. Porous Ti metals fabricated by SLM were heat-treated at 1300 °C for 1h in an argon gas atmosphere to smooth the surface. Such prepared specimens were subjected to NaOH, HCl, and heat treatment to provide bioactivity. Field emission scanning electron micrographs showed that fine networks of titanium oxide were formed over the whole surface of the porous body. These treated porous bodies formed bone-like apatite on their surfaces in a simulated body fluid within 3 days. In vivo studies showed that new bone penetrated into the pores and directly bonded to the walls within 12 weeks after implantation into the femur of Japanese white rabbits. The percentage bone affinity indices of the chemical- and heat-treated porous bodies were significantly higher than that of untreated implants. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  8. Enxerto ósseo esponjoso autólogo em pequenos animais Autologous cancellous bone graft in small animals

    Directory of Open Access Journals (Sweden)

    Fernanda Carpi dos Santos

    2004-12-01

    Full Text Available O enxerto ósseo esponjoso autólogo é formado por osso trabecular, poroso e altamente celular. Visto ser de fundamental importância na cirurgia ortopédica de pequenos animais, o trabalho teve por objetivo discorrer sobre a função, locais de colheita, cuidados, formas de aplicação, indicações e contra-indicações desse enxerto. Ele estimula a formação óssea devido ao fornecimento de células vivas e fatores de crescimento, mas não possui suporte mecânico. A asa do ílio craniodorsal, úmero proximal, tíbia proximal e fêmur distal, são os locais de colheita mais utilizados em cães. A asa do ílio consiste no local mais satisfatório para gatos. Para maximizar a incorporação do enxerto com o tecido hospedeiro, devem ser tomados alguns cuidados entre a colheita e a transferência para a área receptora. Além disso, pode ser aplicado sem compressão dentro do local recipiente. A freqüência de complicações é considerada baixa.The autologous cancellous bone is formed by trabecular bone, porous, and highly cellular. Since this graft is very important in orthopedic surgery of small animals, the purpose of this paper is to describe the function, donor sites, precautions, application methods, indications, and contraindications. It stimulates the bone formation because it provides live cells and growth factors, but it did not have mechanical support. Cranial dorsal wing of the ilium, proximal humerus, proximal tibia, and distal femur are the most common harvest sites used in dogs. The wing of the ilium is the most satisfactory harvest site in cats. To maximize the graft incorporation with the tissue it is necessary to take care during the harvest and transference to recipient site. In addition, it may be put into the recipient site with no compression. The frequency of complications is considered low.

  9. Late Effects of Heavy Ion Irradiation on Ex Vivo Osteoblastogenesis and Cancellous Bone Microarchitecture

    Science.gov (United States)

    Tran, Luan Hoang; Alwood, Joshua; Kumar, Akhilesh; Limoli, C. L.; Globus, Ruth

    2012-01-01

    . Thus, both low and high doses of heavy ion irradiation cause time dependent, adaptive changes in redox state within marrow cells but only high doses (50, 200cGy) inhibit osteoblastogenesis and cause cancellous bone loss. We conclude space radiation has the potential to cause persistent damage to bone marrow derived stem and progenitor cells for osteoblasts despite adaptive changes in cellular redox state.

  10. Glucocorticoid induced osteopenia in cancellous bone of sheep: validation of large animal model for spine fusion and biomaterial research.

    Science.gov (United States)

    Ding, Ming; Cheng, Liming; Bollen, Peter; Schwarz, Peter; Overgaard, Søren

    2010-02-15

    Glucocorticoid with low calcium and phosphorus intake induces osteopenia in cancellous bone of sheep. To validate a large animal model for spine fusion and biomaterial research. A variety of ovariectomized animals has been used to study osteoporosis. Most experimental spine fusions were based on normal animals, and there is a great need for suitable large animal models with adequate bone size that closely resemble osteoporosis in humans. Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 (GC-1) received prednisolone (GC) treatment (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 (GC-2) received the same treatment as GC-1 for 7 months followed by 3 months without treatment. Group 3 was left untreated and served as the controls. All sheep received restricted diet with low calcium and phosphorus during experiment. After killing the animals, cancellous bone specimens from the vertebra, femurs, and tibias were micro-CT scanned and tested mechanically. Serum biomarkers were determined. In lumbar vertebra, the GC treatment resulted in significant decrease of cancellous bone volume fraction and trabecular thickness, and bone strength. However, the microarchitecture and bone strength of GC-2 recovered to a similar level of the controls. A similar trend of microarchitectural changes was also observed in the distal femur and proximal tibia of both GC treated sheep. The bone formation marker serum-osteocalcin was largely reduced in GC-1 compared to the controls, but recovered with a rebound increase at month 10 in GC-2. The current investigation demonstrates that the changes in microarchitecture and mechanical properties were comparable with those observed in humans after long-term GC treatment. A prolonged GC treatment is needed for a long-term observation to keep osteopenic bone. This model resembles long-term glucocorticoid treated osteoporotic model, and is useful in preclinical studies.

  11. Age-related new bone formation following the use of cancellous bone-block allografts for reconstruction of atrophic alveolar ridges.

    Science.gov (United States)

    Nissan, Joseph; Kolerman, Roni; Chaushu, Liat; Vered, Marilena; Naishlos, Sarit; Chaushu, Gavriel

    2018-02-01

    An age-related decrease in the number of osteogenic progenitor cells may compromise bone augmentation. Histomorphometrical assessment of age-related new bone formation, following atrophic alveolar ridge reconstruction, using cancellous bone-block allografts. Ninety-three consecutive patients (58 females and 35 males) were referred for implant-supported restoration of 122 severe atrophic alveolar ridges. Alveolar ridge deficiency locations were classified as anterior maxilla (n = 58), posterior maxilla (n= 32), and posterior mandible (n = 32). A bony deficiency of at least 3 mm horizontally and up to 3 mm vertically according to computerized tomography (CT) in the posterior mandible and anterior maxilla, served as inclusion criteria. In the posterior maxilla, a residual alveolar ridge up to 4 mm vertically according to CT served as inclusion criteria. Augmentation was performed by the use of cancellous bone-block allografts. Bone biopsies (9-month posterior maxilla, 4 months anterior maxilla and posterior mandible) of young (≤40 years) versus older (>40 years) patients were histomorphometrically evaluated. In the posterior maxilla, no statistically significant histomorphometric differences were noted. While at the anterior maxilla and posterior mandible, statistically significant more newly formed bone was found in young versus older individuals, respectively (38.6% vs 19.8%, P = 0.04 and 69% vs 31%, P = .05). New bone formation following residual alveolar ridge bone grafting is age-related. Longer bone consolidation and healing time may be recommended for older individuals. © 2017 Wiley Periodicals, Inc.

  12. Evaluation of the bone microstructures after the mandibular reconstruction, using bioresorbable hydroxyapatite/poly-L-lactide mesh tray and the particulate cancellous bone

    International Nuclear Information System (INIS)

    Takahashi, Hidetoshi; Matsuo, Akira; Chiba, Hiroshige

    2010-01-01

    The combination of particulate cancellous bone and marrow (PCBM) and a titanium tray is frequently used for mandibular reconstruction. However, there are difficulties in bending the tray and forming a suitable contour. In addition, the metallic ions elute into the living body and the hinders the implant insertion; therefore, a removable operation is required after reconstruction. Hydroxyapatite/poly-L-lactide (HA/PLLA) is a bone-bonding material that has both bio-activity and bio-resorbability. It may overcome the weakness of a titanium tray, but the bone microstructures have not been evaluated after the use of this tray for PCBM reconstruction. We created defects on the mandible of a beagle and reconstructed it by filling it with a mixture of PCBM and PRP using the HA/PLLA tray. We examined the bone-formation mechanism using a confocal laser microscope and bone microstructural analysis using microCT. As a result, compared to the titanium tray, the bone-formation is delayed during the first 3 to 6 months with an HA/PLLA tray. However, a formation of new bone with equal quality is observed after 12 months. According to the bone microstructural measurement, both of them had higher bone volume fraction than the native bone but other parameters were the same. From the above, the quantity of the new bone in the HA/PLLA tray is the same as the bone in the titanium tray, and has equal bone microstructures with the surrounding native bone. (author)

  13. Effects of vitamin K2 on cortical and cancellous bone mass, cortical osteocyte and lacunar system, and porosity in sciatic neurectomized rats.

    Science.gov (United States)

    Iwamoto, Jun; Matsumoto, Hideo; Takeda, Tsuyoshi; Sato, Yoshihiro; Yeh, James K

    2010-09-01

    The purpose of the present study was to examine the effects of vitamin K2 on cortical and cancellous bone mass, cortical osteocyte and lacunar system, and porosity in sciatic neurectomized rats. Thirty-four female Sprague-Dawley retired breeder rats were randomized into three groups: age-matched control, sciatic neurectomy (NX), and NX + vitamin K2 administration (menatetrenone, 30 mg/kg/day p.o., three times a week). At the end of the 8-week experiment, bone histomorphometric analysis was performed on cortical and cancellous bone of the tibial diaphysis and proximal metaphysis, respectively, and osteocyte lacunar system and porosity were evaluated on cortical bone of the tibial diaphysis. NX decreased cortical and cancellous bone mass compared with age-matched controls as a result of increased endocortical and trabecular bone erosion and decreased trabecular mineral apposition rate (MAR). Vitamin K2 ameliorated the NX-induced increase in bone erosion, prevented the NX-induced decrease in MAR, and increased bone formation rate (BFR/bone surface) in cancellous bone, resulting in an attenuation of NX-induced cancellous bone loss. However, vitamin K2 did not significantly influence cortical bone mass. NX also decreased osteocyte density and lacunar occupancy and increased porosity in cortical bone compared with age-matched controls. Vitamin K2 ameliorated the NX-induced decrease in lacunar occupancy by viable osteocytes and the NX-induced increase in porosity. The present study showed the efficacy of vitamin K2 for cancellous bone mass and cortical lacunar occupancy by viable osteocytes and porosity in sciatic NX rats.

  14. Horizontal Bone Reconstruction on sites with different amounts of native bone: a retrospective study

    Directory of Open Access Journals (Sweden)

    André Antonio Pelegrine

    2018-04-01

    Full Text Available Abstract: The lack of guidelines for bone augmentation procedures might compromise decision making in implantology. The objective of this study was to perform a retrospective study to verify the outcomes of horizontal bone reconstruction in implant dentistry with different types of materials and amounts of native bone in the recipient bed to allow for a new guideline for horizontal bone reconstruction. One hundred preoperative CT scans were retrospectively evaluated and categorized in accordance to horizontal bone defects as presence (Group P or absence (Group A of cancellous bone in the recipient bed. Different approaches were used to treat the edentulous ridge and the outcomes were defined either as satisfactory or unsatisfactory regarding the possibility of implant placement. The percentage distribution of the patients according to the presence or absence of cancellous bone was 92% for Group P and 8% for Group A. In Group P, 98% of the patients had satisfactory outcomes, and the use of autografts had 100% of satisfactory outcomes in this group. In Group A, 37.5% of the patients had satisfactory outcomes, and the use of autografts also yielded 100% of satisfactory outcomes. The use of allografts and xenografts in Group A had 0% and 33.3% of satisfactory outcomes, respectively. Therefore, it seems reasonable to speculate that the presence of cancellous bone might be predictive and predictable when the decision includes bone substitutes. In cases of absence of cancellous bone in the recipient bed, the use of a vitalized graft seems to be mandatory.

  15. Compressive behaviour of gyroid lattice structures for human cancellous bone implant applications

    International Nuclear Information System (INIS)

    Yánez, A.; Herrera, A.; Martel, O.; Monopoli, D.; Afonso, H.

    2016-01-01

    Electron beam melting (EBM) was used to fabricate porous titanium alloy structures. The elastic modulus of these porous structures was similar to the elastic modulus of the cancellous human bone. Two types of cellular lattice structures were manufactured and tested: gyroids and diamonds. The design of the gyroid structures was determined by the main angle of the struts with respect to the axial direction. Thus, structures with angles of between 19 and 68.5° were manufactured. The aim of the design was to reduce the amount of material needed to fabricate a structure with the desired angles to increase the range of stiffness of the scaffolds. Compression tests were conducted to obtain the elastic modulus and the strength. Both parameters increased as the angle decreased. Finally, the specific strength of the gyroid structures was compared with that of the diamond structures and other types of structures. It is shown that, for angles lower than 35°, the gyroid structures had a high strength to weight ratios. - Highlights: • Gyroid and diamond lattice structures were fabricated by electron beam melting. • Compression tests were conducted to obtain the elastic modulus and the strength. • Some gyroid structures show a higher specific strength than other types of structures.

  16. Compressive behaviour of gyroid lattice structures for human cancellous bone implant applications

    Energy Technology Data Exchange (ETDEWEB)

    Yánez, A., E-mail: alejandro.yanez@ulpgc.es [Department of Mechanical Engineering, University of Las Palmas de Gran Canaria (Spain); Herrera, A. [Julius Wolff Institute, Berlin (Germany); Martel, O. [Department of Mechanical Engineering, University of Las Palmas de Gran Canaria (Spain); Monopoli, D.; Afonso, H. [Department of Mechanical Engineering, Instituto Tecnológico de Canarias (Spain)

    2016-11-01

    Electron beam melting (EBM) was used to fabricate porous titanium alloy structures. The elastic modulus of these porous structures was similar to the elastic modulus of the cancellous human bone. Two types of cellular lattice structures were manufactured and tested: gyroids and diamonds. The design of the gyroid structures was determined by the main angle of the struts with respect to the axial direction. Thus, structures with angles of between 19 and 68.5° were manufactured. The aim of the design was to reduce the amount of material needed to fabricate a structure with the desired angles to increase the range of stiffness of the scaffolds. Compression tests were conducted to obtain the elastic modulus and the strength. Both parameters increased as the angle decreased. Finally, the specific strength of the gyroid structures was compared with that of the diamond structures and other types of structures. It is shown that, for angles lower than 35°, the gyroid structures had a high strength to weight ratios. - Highlights: • Gyroid and diamond lattice structures were fabricated by electron beam melting. • Compression tests were conducted to obtain the elastic modulus and the strength. • Some gyroid structures show a higher specific strength than other types of structures.

  17. [Fusion of reconstructed titanic plate, vertebral pedical screws and autogenous granulated cancellous bone graft in posterior occipitocervical region].

    Science.gov (United States)

    Zhong, Dejun; Song, Yueming

    2006-08-01

    To explore the technique of fusing the reconstructed titanic plate, the C2 pedical screws, and the autogenous granulated cancellous bone graft in the occipitocervical region. From April 2002 to January 2005, 19 patients aged 31-67 years with occipitocervical instability underwent the occipitocervical fusion using the reconstructed plate, C2 pedical screws, and autogenous granulated cancellous bone graft. Of the patients, 8 had complex occipitocervical deformity, 8 had old atlantoaxial fracture and dislocation, 2 had rheumatoid arthritis and anterior dislocation of the atlantoaxial joint, and 1 had cancer of the deltoid process of the axis. No complication occurred during and after operation. The follow-up for an average of 16 months in 19 patients showed that all the patients achieved solid bony fusion in the occipitocervical region. There was no broken plate, broken screw, looseness of the internal fixation or neurovascular injury. The fixation of the C2 pedical screws with the reconstructed titanic plate is reliable, the insertion is easy, and the autogenous granulated cancellous bone graft has a high fusion rate, thus resulting in a satisfactory effect in the occipitocervical fusion.

  18. Defective cancellous bone structure and abnormal response to PTH in cortical bone of mice lacking Cx43 cytoplasmic C-terminus domain

    Science.gov (United States)

    Pacheco-Costa, Rafael; Davis, Hannah M.; Sorenson, Chad; Hon, Mary C.; Hassan, Iraj; Reginato, Rejane D.; Allen, Matthew R.; Bellido, Teresita; Plotkin, Lilian I.

    2015-01-01

    Connexin43 (Cx43) forms gap junction channels and hemichannels that allow the communication among osteocytes, osteoblasts, and osteoclasts. Cx43 carboxy-terminal (CT) domain regulates channel opening and intracellular signaling by acting as a scaffold for structural and signaling proteins. To determine the role of Cx43 CT domain in bone, mice in which one allele of full length Cx43 was replaced by a mutant lacking the CT domain (Cx43ΔCT/fl) were studied. Cx43ΔCT/fl mice exhibit lower cancellous bone volume but higher cortical thickness than Cx43fl/fl controls, indicating that the CT domain is involved in normal cancellous bone gain but opposes cortical bone acquisition. Further, Cx43ΔCT is able to exert the functions of full length osteocytic Cx43 on cortical bone geometry and mechanical properties, demonstrating that domains other than the CT are responsible for Cx43 function in cortical bone. In addition, parathyroid hormone (PTH) failed to increase endocortical bone formation or energy to failure, a mechanical property that indicates resistance to fracture, in cortical bone in Cx43ΔCT mice with or without osteocytic full length Cx43. On the other hand, bone mass and bone formation markers were increased by the hormone in all mouse models, regardless of whether full length or Cx43ΔCT were or not expressed. We conclude that Cx43 CT domain is involved in proper bone acquisition; and that Cx43 expression in osteocytes is dispensable for some but not all PTH anabolic actions. PMID:26409319

  19. Higher number of pentosidine cross-links induced by ribose does not alter tissue stiffness of cancellous bone

    Energy Technology Data Exchange (ETDEWEB)

    Willems, Nop M.B.K., E-mail: n.willems@acta.nl [Dept. of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Langenbach, Geerling E.J. [Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Stoop, Reinout [Dept. of Metabolic Health Research, TNO, P.O. Box 2215, 2301 CE Leiden (Netherlands); Toonder, Jaap M.J. den [Dept. of Mechanical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Mulder, Lars [Dept. of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands); Zentner, Andrej [Dept. of Orthodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands); Everts, Vincent [Dept. of Oral Cell Biology and Functional Anatomy, MOVE Research Institute, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University, Gustav Mahlerlaan 3004, 1081 LA Amsterdam (Netherlands)

    2014-09-01

    The role of mature collagen cross-links, pentosidine (Pen) cross-links in particular, in the micromechanical properties of cancellous bone is unknown. The aim of this study was to examine nonenzymatic glycation effects on tissue stiffness of demineralized and non-demineralized cancellous bone. A total of 60 bone samples were derived from mandibular condyles of six pigs, and assigned to either control or experimental groups. Experimental handling included incubation in phosphate buffered saline alone or with 0.2 M ribose at 37 °C for 15 days and, in some of the samples, subsequent complete demineralization of the sample surface using 8% EDTA. Before and after experimental handling, bone microarchitecture and tissue mineral density were examined by means of microcomputed tomography. After experimental handling, the collagen content and the number of Pen, hydroxylysylpyridinoline (HP), and lysylpyridinoline (LP) cross-links were estimated using HPLC, and tissue stiffness was assessed by means of nanoindentation. Ribose treatment caused an up to 300-fold increase in the number of Pen cross-links compared to nonribose-incubated controls, but did not affect the number of HP and LP cross-links. This increase in the number of Pen cross-links had no influence on tissue stiffness of both demineralized and nondemineralized bone samples. These findings suggest that Pen cross-links do not play a significant role in bone tissue stiffness. - Highlights: • The assessment of effects of glycation in bone using HPLC, microCT, and nanoindentation • Ribose incubation: 300‐fold increase in the number of pentosidine cross-links • 300‐fold increase in the number of pentosidine cross-links: no changes in bone tissue stiffness.

  20. A soluble activin type IIA receptor mitigates the loss of femoral neck bone strength and cancellous bone mass in a mouse model of disuse osteopenia.

    Science.gov (United States)

    Lodberg, Andreas; Eijken, Marco; van der Eerden, Bram C J; Okkels, Mette Wendelboe; Thomsen, Jesper Skovhus; Brüel, Annemarie

    2018-05-01

    Disuse causes a rapid and substantial bone loss distinct in its pathophysiology from the bone loss associated with cancers, age, and menopause. While inhibitors of the activin-receptor signaling pathway (IASPs) have been shown to prevent ovariectomy- and cancer-induced bone loss, their application in a model of disuse osteopenia remains to be tested. Here, we show that a soluble activin type IIA receptor (ActRIIA-mFc) increases diaphyseal bone strength and cancellous bone mass, and mitigates the loss of femoral neck bone strength in the Botulinum Toxin A (BTX)-model of disuse osteopenia in female C57BL/6J mice. We show that ActRIIA-mFc treatment preferentially stimulates a dual-effect (anabolic-antiresorptive) on the periosteal envelope of diaphyseal bone, demonstrating in detail the effects of ActRIIA-mFc on cortical bone. These observations constitute a previously undescribed feature of IASPs that mediates at least part of their ability to mitigate detrimental effects of unloading on bone tissue. The study findings support the application of IASPs as a strategy to combat bone loss during disuse. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Human periodontal ligament stem cells cultured onto cortico-cancellous scaffold drive bone regenerative process

    Directory of Open Access Journals (Sweden)

    F Diomede

    2016-09-01

    Full Text Available The purpose of this work was to test, in vitro and in vivo, a new tissue-engineered construct constituted by porcine cortico-cancellous scaffold (Osteobiol Dual Block (DB and xeno-free ex vivo culture of human Periodontal Ligament Stem Cells (hPDLSCs. hPDLSCs cultured in xeno-free media formulation preserved the stem cells’ morphological features, the expression of stemness and pluripotency markers, and their ability to differentiate into mesenchymal lineage. Transmission electron microscopy analysis suggested that after one week of culture, both noninduced and osteogenic differentiation induced cells joined and grew on DB secreting extracellular matrix (ECM that in osteogenic induced samples was hierarchically assembled in fibrils. Quantitative RT-PCR (qRT-PCR showed the upregulation of key genes involved in the bone differentiation pathway in both differentiated and undifferentiated hPDLSCs cultured with DB (hPDLSCs/DB. Functional studies revealed a significant increased response of calcium transients in the presence of DB, both in undifferentiated and differentiated cells stimulated with calcitonin and parathormone, suggesting that the biomaterial could drive the osteogenic differentiation process of hPDLSCs. These data were confirmed by the increase of gene expression of L-type voltage-dependent Ca2+ (VDCCL, subunits α1C and α2D1 in undifferentiated cells in the presence of DB. In vivo implantation of the hPDLSCs/DB living construct in the mouse calvaria evidenced a precocious osteointegration and vascularisation process. Our results suggest consideration of DB as a biocompatible, osteoinductive and osteoconductive biomaterial, making it a promising tool to regulate cell activities in biological environments and for a potential use in the development of new custom-made tissue engineering.

  2. Measurement of microvascular blood flow in cancellous bone using laser Doppler flowmetry and 133Xe-clearance

    International Nuclear Information System (INIS)

    Hellem, S.; Jacobsson, L.S.; Nilsson, G.E.; Lewis, D.H.

    1983-01-01

    Blood flow in cancelleous bone with varying vascular density was investigated simultaneously with Laser Doppler Flowmeter (LDF) and 113 Xe-clearance. The cancellous bone subapical to 2 contralateral incisors in the mandibles of 17 young pigs was used as an experimental model. Light from a 2 mW He-Ne-laser was guided through an optical fibre to a flowmeter probe. Stainless steel probe-holders firmly inserted in the pulpal canals of the two incisors served as the probe entrance to cancellous bone for blood flow recording. Due to the Doppler effect, the light scattered by circulating blood cells undergoes a frequency shift. The back-scattered light picked up by optical fibres in the probe, was guided to a photosensitive device, where it was demodulated. After signal processing, a signal referred to as the Blood Flow Value (BFV) was recorded on a pen recorder. Rhythmical variations (vasomotion) in BFV with frequencies from 2-11 cycles/min were observed in 6% of recordings made initially after probeholder implantation, and in 34% of the recordings made 5 weeks later. On this occasion, a marked increase in BFV was recorded. Histological examination showed increased vascularity in the bone tissue. The reproducibility error of LDF was 7.4% and temporal changes in BFV, apart from vasomotion, were 8.3%, provided no injections or manipulations of the probe were made. Spatial variations in BFV were found to be related to the vascular density. 2 successive recordings by LDF from the same bone area were highly correlated (r=0.98). The corresponding figure for 2 logarithmic decay rates of locally injected 133 Xe was 0.76. No correlation between BFV and 133 Xe-clearance could be demonstrated. (author)

  3. Estradiol-loaded PLGA nanoparticles for improving low bone mineral density of cancellous bone caused by osteoporosis: Application of enhanced charged nanoparticles with iontophoresis.

    Science.gov (United States)

    Takeuchi, Issei; Kobayashi, Shiori; Hida, Yukari; Makino, Kimiko

    2017-07-01

    Postmenopausal osteoporosis among older women, which occurs by an ovarian hormone deficiency, is one of the major public health problems. 17 β-estradiol (E2) is used to prevent and treat this disease as a drug of hormone replacement therapy. In oral administration, E2 is significantly affected by first-pass hepatic metabolism, and high dose administration must be needed to obtain drug efficacy. Therefore, alternative administration route is needed, and we have focused on the transdermal drug delivery system. In this study, we have prepared E2-loaded poly(DL-lactide-co-glycolide) (PLGA) nanoparticles for osteoporosis by using a combination of an antisolvent diffusion method with preferential solvation. The average particle diameter of the nanoparticles was 110.0±41.0nm and the surface charge number density was 82 times higher than that of conventional E2-loaded PLGA nanoparticles. Therapeutic evaluation of E2-loaded PLGA nanoparticles was carried out using ovariectomized female rats. Therapeutic efficacy was evaluated to measure bone mineral density of cancellous bone using an X-ray CT system. When the E2-loaded PLGA nanoparticles were administrated once a week, bone mineral density was significantly higher than that of the non-treated group at 60days after the start of treatment. Also, in the group administered this nanoparticle twice a week, the bone mineral density increased significantly at 45days after the start of treatment. From these results, it was revealed that E2-loaded PLGA nanoparticles with iontophoresis were useful to recover bone mineral density of cancellous bone, and it was also suggested that they extend the dosing interval of E2. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Glucocorticoid induced osteopenia in cancellous bone of sheep: validation of large animal model for spine fusion and biomaterial research

    DEFF Research Database (Denmark)

    Ding, Ming; Cheng, Liming; Bollen, Peter

    2010-01-01

    STUDY DESIGN: Glucocorticoid with low calcium and phosphorus intake induces osteopenia in cancellous bone of sheep. OBJECTIVE: To validate a large animal model for spine fusion and biomaterial research. SUMMARY OF BACKGROUND DATA: A variety of ovariectomized animals has been used to study...... osteoporosis. Most experimental spine fusions were based on normal animals, and there is a great need for suitable large animal models with adequate bone size that closely resemble osteoporosis in humans. METHODS: Eighteen female skeletal mature sheep were randomly allocated into 3 groups, 6 each. Group 1 (GC......-1) received prednisolone (GC) treatment (0.60 mg/kg/day, 5 times weekly) for 7 months. Group 2 (GC-2) received the same treatment as GC-1 for 7 months followed by 3 months without treatment. Group 3 was left untreated and served as the controls. All sheep received restricted diet with low calcium...

  5. Finite element analysis of dental implant loading on atrophic and non-atrophic cancellous and cortical mandibular bone - a feasibility study.

    Science.gov (United States)

    Marcián, Petr; Borák, Libor; Valášek, Jiří; Kaiser, Jozef; Florian, Zdeněk; Wolff, Jan

    2014-12-18

    The first aim of this study was to assess displacements and micro-strain induced on different grades of atrophic cortical and trabecular mandibular bone by axially loaded dental implants using finite element analysis (FEA). The second aim was to assess the micro-strain induced by different implant geometries and the levels of bone-to-implant contact (BIC) on the surrounding bone. Six mandibular bone segments demonstrating different grades of mandibular bone atrophy and various bone volume fractions (from 0.149 to 0.471) were imaged using a micro-CT device. The acquired bone STL models and implant (Brånemark, Straumann, Ankylos) were merged into a three-dimensional finite elements structure. The mean displacement value for all implants was 3.1 ±1.2 µm. Displacements were lower in the group with a strong BIC. The results indicated that the maximum strain values of cortical and cancellous bone increased with lower bone density. Strain distribution is the first and foremost dependent on the shape of bone and architecture of cancellous bone. The geometry of the implant, thread patterns, grade of bone atrophy and BIC all affect the displacement and micro-strain on the mandible bone. Preoperative finite element analysis could offer improved predictability in the long-term outlook of dental implant restorations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Molt performance and bone density of cortical, medullary, and cancellous bone in laying hens during feed restriction or alfalfa-based feed molt.

    Science.gov (United States)

    Kim, W K; Donalson, L M; Bloomfield, S A; Hogan, H A; Kubena, L F; Nisbet, D J; Ricke, S C

    2007-09-01

    A study was conducted to evaluate the effects of alfalfa-based molt diets on molting performance and bone qualities. A total of 36 Single Comb White Leghorn hens were used for the study. There were 6 treatments: pretrial control (PC), fully fed (FF), feed withdrawal (FW), 90% alfalfa:10% layer ration (A90), 80% alfalfa:20% layer ration (A80), and 70% alfalfa:30% layer ration (A70). For the PC treatment, hens were euthanized by CO(2) gas, and bones were collected before molt was initiated. At the end of the 9-d molt period, hens were euthanized, and femurs and tibias were collected to evaluate bone qualities by peripheral quantitative computed tomography, mechanical testing, and conventional ash weights. The hens fed alfalfa-based molt diets and FW stopped laying eggs within 5 d after molt started, and all hens in these groups had reduced ovary weights compared with those of the FF hens. In the FW and A90 groups, total femur volumetric bone mineral densities (vBMD) at the midshaft were significantly lower, but those of the A80 and A70 groups were not significantly different from the values for the PC and FF hens. In cortical bone density, the midshaft tibial vBMD were significantly higher for FF and A70 hens than for PC hens. The medullary bone densities at the midshaft femur or tibia of the FW, A90, A80, and A70 hens were reduced compared with those of the PC hens. Femur cancellous densities at the distal femur for the FW and A90 hens were significantly reduced compared with those of the PC and FF hens. The FW, A80, and A70 hens yielded significantly higher elastic moduli, and the A80 hens had higher ultimate stress compared with the PC hens, suggesting that the mechanical integrity of the midshaft bone was maintained even though the medullary vBMD was reduced. These results suggest that alfalfa-based molt diets exhibit molt performance similar to FW, that medullary and cancellous bones are labile bone compartments during molting, and that alfalfa-based molt diets

  7. Assessment of cancellous bone mechanical properties from micro-FE models based on micro-CT, pQCT and MR images.

    NARCIS (Netherlands)

    Rietbergen, van B.; Majumdar, S.; Pistoia, W.; Newitt, D.C.; Kothari, M.; Laib, A.; Rüegsegger, P.

    1998-01-01

    Recently, new micro-finite element (micro-FE) techniques have been introduced to calculate cancellous bone mechanical properties directly from high-resolution images of its internal architecture. Also recently, new peripheral quantitative computed tomography (pQCT) and magnetic resonance (MR)

  8. An animal model in sheep for biocompatibility testing of biomaterials in cancellous bones.

    Science.gov (United States)

    Nuss, Katja M R; Auer, Joerg A; Boos, Alois; von Rechenberg, Brigitte

    2006-08-15

    The past years have seen the development of many synthetic bone replacements. To test their biocompatibility and ability for osseointegration, osseoinduction and -conduction requires their placement within bone preferably in an animal experiment of a higher species. A suitable experimental animal model in sheep with drill holes of 8 mm diameter and 13 mm depth within the proximal and distal humerus and femur for testing biocompatibility issues is introduced. This present sheep model allows the placing of up to 8 different test materials within one animal and because of the standardization of the bone defect, routine evaluation by means of histomorphometry is easily conducted. This method was used successfully in 66 White Alpine Sheep. When the drill holes were correctly placed no complications such as spontaneous fractures were encountered. This experimental animal model serves an excellent basis for testing the biocompatibility of novel biomaterials to be used as bone replacement or new bone formation enhancing materials.

  9. An animal model in sheep for biocompatibility testing of biomaterials in cancellous bones

    Science.gov (United States)

    Nuss, Katja MR; Auer, Joerg A; Boos, Alois; Rechenberg, Brigitte von

    2006-01-01

    Background The past years have seen the development of many synthetic bone replacements. To test their biocompatibility and ability for osseointegration, osseoinduction and -conduction requires their placement within bone preferably in an animal experiment of a higher species. Methods A suitable experimental animal model in sheep with drill holes of 8 mm diameter and 13 mm depth within the proximal and distal humerus and femur for testing biocompatibility issues is introduced. Results This present sheep model allows the placing of up to 8 different test materials within one animal and because of the standardization of the bone defect, routine evaluation by means of histomorphometry is easily conducted. This method was used successfully in 66 White Alpine Sheep. When the drill holes were correctly placed no complications such as spontaneous fractures were encountered. Conclusion This experimental animal model serves an excellent basis for testing the biocompatibility of novel biomaterials to be used as bone replacement or new bone formation enhancing materials. PMID:16911787

  10. An animal model in sheep for biocompatibility testing of biomaterials in cancellous bones

    OpenAIRE

    Nuss, Katja MR; Auer, Joerg A; Boos, Alois; Rechenberg, Brigitte von

    2006-01-01

    Abstract Background The past years have seen the development of many synthetic bone replacements. To test their biocompatibility and ability for osseointegration, osseoinduction and -conduction requires their placement within bone preferably in an animal experiment of a higher species. Methods A suitable experimental animal model in sheep with drill holes of 8 mm diameter and 13 mm depth within the proximal and distal humerus and femur for testing biocompatibility issues is introduced. Result...

  11. An animal model in sheep for biocompatibility testing of biomaterials in cancellous bones

    Directory of Open Access Journals (Sweden)

    Boos Alois

    2006-08-01

    Full Text Available Abstract Background The past years have seen the development of many synthetic bone replacements. To test their biocompatibility and ability for osseointegration, osseoinduction and -conduction requires their placement within bone preferably in an animal experiment of a higher species. Methods A suitable experimental animal model in sheep with drill holes of 8 mm diameter and 13 mm depth within the proximal and distal humerus and femur for testing biocompatibility issues is introduced. Results This present sheep model allows the placing of up to 8 different test materials within one animal and because of the standardization of the bone defect, routine evaluation by means of histomorphometry is easily conducted. This method was used successfully in 66 White Alpine Sheep. When the drill holes were correctly placed no complications such as spontaneous fractures were encountered. Conclusion This experimental animal model serves an excellent basis for testing the biocompatibility of novel biomaterials to be used as bone replacement or new bone formation enhancing materials.

  12. Sequential treatment with basic fibroblast growth factor and parathyroid hormone restores lost cancellous bone mass and strength in the proximal tibia of aged ovariectomized rats

    DEFF Research Database (Denmark)

    Wronski, T.J.; Ratkus, A.M.; Thomsen, Jesper Skovhus

    2001-01-01

    This study was designed to determine whether sequential treatment with basic fibroblast growth factor (bFGF) and parathyroid hormone (PTH) can restore lost cancellous bone mass and strength at a severely osteopenic skeletal site in aged ovariectomized (OVX) rats. Female Sprague-Dawley rats were...... intravenously (iv) daily with bFGF for 14 days at a dose of 200 microg/kg body weight. At the end of bFGF treatment, one group was killed whereas the other group was subjected to 8 weeks of treatment with synthetic human PTH 1-34 [hPTH(1-34)] consisting of subcutaneous (sc) injections 5 days/week at a dose...... of 80 microg/kg. Another group of OVX rats was treated iv with vehicle for 2 weeks followed by treatment with PTH alone for 8 weeks. Other groups of sham-operated control rats and OVX rats were treated iv and sc with vehicle alone. The right proximal tibia from each rat was processed undecalcified...

  13. Architectural Measures of the Cancellous Bone of the Mandibular Condyle Identified by Principal Components Analysis

    DEFF Research Database (Denmark)

    Giese, E.B.; Ding, M.; Dalstra, M.

    2003-01-01

    embalmed mandibular condyles; the angle of the first principal direction and the axis of the specimen, expressing the orientation of the trabeculae, ranged from 10 degrees to 87 degrees. Morphological parameters were determined by a method based on Archimedes' principle and by micro-CT scanning......-like trabeculae, and not with more or thicker trabeculae. The trabecular orientation was most determinative (about 50%) in explaining stiffness, strength, and failure energy. The amount of bone was second most determinative and increased the explained variance to about 72%. These results suggest that trabecular...

  14. The micro-architecture of human cancellous bone from fracture neck of femur patients in relation to the structural integrity and fracture toughness of the tissue

    Directory of Open Access Journals (Sweden)

    C. Greenwood

    2015-12-01

    Full Text Available Osteoporosis is clinically assessed from bone mineral density measurements using dual energy X-ray absorption (DXA. However, these measurements do not always provide an accurate fracture prediction, arguably because DXA does not grapple with ‘bone quality’, which is a combined result of microarchitecture, texture, bone tissue properties, past loading history, material chemistry and bone physiology in reaction to disease. Studies addressing bone quality are comparatively few if one considers the potential importance of this factor. They suffer due to low number of human osteoporotic specimens, use of animal proxies and/or the lack of differentiation between confounding parameters such as gender and state of diseased bone. The present study considers bone samples donated from patients (n = 37 who suffered a femoral neck fracture and in this very well defined cohort we have produced in previous work fracture toughness measurements (FT which quantify its ability to resist crack growth which reflects directly the structural integrity of the cancellous bone tissue. We investigated correlations between BV/TV and other microarchitectural parameters; we examined effects that may suggest differences in bone remodelling between males and females and compared the relationships with the FT properties. The data crucially has shown that TbTh, TbSp, SMI and TbN may provide a proxy or surrogate for BV/TV. Correlations between FT critical stress intensity values and microarchitecture parameters (BV/TV, BS/TV, TbN, BS/BV and SMI for osteoporotic cancellous tissue were observed and are for the first time reported in this study. Overall, this study has not only highlighted that the fracture model based upon BMD could potentially be improved with inclusion of other microarchitecture parameters, but has also given us clear clues as to which of them are more influential in this role.

  15. Functional adaptation to mechanical loading in both cortical and cancellous bone is controlled locally and is confined to the loaded bones.

    Science.gov (United States)

    Sugiyama, Toshihiro; Price, Joanna S; Lanyon, Lance E

    2010-02-01

    In order to validate whether bones' functional adaptation to mechanical loading is a local phenomenon, we randomly assigned 21 female C57BL/6 mice at 19 weeks of age to one of three equal numbered groups. All groups were treated with isoflurane anesthesia three times a week for 2 weeks (approximately 7 min/day). During each anaesthetic period, the right tibiae/fibulae in the DYNAMIC+STATIC group were subjected to a peak dynamic load of 11.5 N (40 cycles with 10-s intervals between cycles) superimposed upon a static "pre-load" of 2.0 N. This total load of 13.5 N engendered peak longitudinal strains of approximately 1400 microstrain on the medial surface of the tibia at a middle/proximal site. The right tibiae/fibulae in the STATIC group received the static "pre-load" alone while the NOLOAD group received no artificial loading. After 2 weeks, the animals were sacrificed and both tibiae, fibulae, femora, ulnae and radii analyzed by three-dimensional high-resolution (5 mum) micro-computed tomography (microCT). In the DYNAMIC+STATIC group, the proximal trabecular percent bone volume and cortical bone volume at the proximal and middle levels of the right tibiae as well as the cortical bone volume at the middle level of the right fibulae were markedly greater than the left. In contrast, the left bones in the DYNAMIC+STATIC group showed no differences compared to the left or right bones in the NOLOAD or STATIC group. These microCT data were confirmed by two-dimensional examination of fluorochrome labels in bone sections which showed the predominantly woven nature of the new bone formed in the loaded bones. We conclude that the adaptive response in both cortical and trabecular regions of bones subjected to short periods of dynamic loading, even when this response is sufficiently vigorous to stimulate woven bone formation, is confined to the loaded bones and does not involve changes in other bones that are adjacent, contra-lateral or remote to them. (c) 2009 Elsevier Inc

  16. Partial Cancellation

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Partial Cancellation. Full Cancellation is desirable. But complexity requirements are enormous. 4000 tones, 100 Users billions of flops !!! Main Idea: Challenge: To determine which cross-talker to cancel on what “tone” for a given victim. Constraint: Total complexity is ...

  17. Donor site complications in bone grafting: comparison of iliac crest, calvarial, and mandibular ramus bone.

    Science.gov (United States)

    Scheerlinck, Laura M E; Muradin, Marvick S M; van der Bilt, Andries; Meijer, Gert J; Koole, Ronald; Van Cann, Ellen M

    2013-01-01

    To compare the donor site complication rate and length of hospital stay following the harvest of bone from the iliac crest, calvarium, or mandibular ramus. Ninety-nine consecutively treated patients were included in this retrospective observational single-center study. Iliac crest bone was harvested in 55 patients, calvarial bone in 26 patients, and mandibular ramus bone in 18 patients. Harvesting of mandibular ramus bone was associated with the lowest percentages of major complications (5.6%), minor complications (22.2%), and total complications (27.8%). Harvesting of iliac crest bone was related to the highest percentages of minor complications (56.4%) and total complications (63.6%), whereas harvesting of calvarial bone induced the highest percentage of major complications (19.2%). The length of the hospital stay was significantly influenced by the choice of donor site (P = .003) and age (P = .009); young patients with the mandibular ramus as the donor site had the shortest hospital stay. Harvesting of mandibular ramus bone was associated with the lowest percentage of complications and the shortest hospital stay. When the amount of bone to be obtained is deemed sufficient, mandibular ramus bone should be the first choice for the reconstruction of maxillofacial defects.

  18. 脱蛋白松质骨作为异种骨移植材料的修复作用%Repair effect of deproteinised cancellous bone as xenogeneic bone graft material

    Institute of Scientific and Technical Information of China (English)

    高春阳; 姜宏春; 金春明

    2011-01-01

    BACKGROUND: Unequal size, mutual communication, and open pore network structure can be seen in cancellous bone treated with deproteinization. Its inorganic component is hydroxyapatite, and the organic component is collagen, which has a good mechanical property and biocompatibility. It may be a new type of bone graft material.OBJECTIVE: To study the properties of xenogeneic deproteinised cancellous bone being carrier of bone tissue engineering in bone fusion.METHODS: Taking “xenogeneic deproteinised cancellous bone, bone fusion, carrier” in Chinese as search terms, the articles from January 1998 to December 2009 in VIP database, CNKI database, Pubmed database were retrieved by computer. The relevant literatures were included, the literature of irrelevant purpose and repetitive content were excluded, and 33 of them were involved for further analysis.RESULTS AND CONCLUSION: Compared with synthetic bone material, animal bones have similar biomaterial structure, modeling, excellent cell attachment, and cell growth and proliferation environment. However, the compatibility of bone tissue is poor, because of the differences in species when xenogeneic deproteinised cancellous bone transplantation, and gravis immune rejection, the key question is implantation of immune problems. How to overcome immunogenicity, xenogeneic deproteinised cancellous bone is a good carrier of bone tissue engineering, which can provide a stable environment for revascularization and differentiation of osteoblasts.%背景:采用脱蛋白处理后的松质骨可见大小不等、相互交通、开放孔隙的网架结构,其无机成分为羟基磷灰石,有机成分为胶原,力学性能保存良好,有良好的细胞相容性,可能是一种新型骨移植材料.目的:介绍异种脱蛋白松质骨作为骨组织工程载体的性能,以及其用于骨融合的作用.方法:分别以"异种脱蛋白松质骨、骨融合、载体",为检索词,应用计算机检索重庆

  19. Benefits of mineralized bone cortical allograft for immediate implant placement in extraction sites: an in vivo study in dogs.

    Science.gov (United States)

    Orti, Valérie; Bousquet, Philippe; Tramini, Paul; Gaitan, Cesar; Mertens, Brenda; Cuisinier, Frédéric

    2016-10-01

    The aim of the present study was to evaluate the effectiveness of using a mineralized bone cortical allograft (MBCA), with or without a resorbable collagenous membrane derived from bovine pericardium, on alveolar bone remodeling after immediate implant placement in a dog model. Six mongrel dogs were included. The test and control sites were randomly selected. Four biradicular premolars were extracted from the mandible. In control sites, implants without an allograft or membrane were placed immediately in the fresh extraction sockets. In the test sites, an MBCA was placed to fill the gap between the bone socket wall and implant, with or without a resorbable collagenous membrane. Specimens were collected after 1 and 3 months. The amount of residual particles and new bone quality were evaluated by histomorphometry. Few residual graft particles were observed to be closely embedded in the new bone without any contact with the implant surface. The allograft combined with a resorbable collagen membrane limited the resorption of the buccal wall in height and width. The histological quality of the new bone was equivalent to that of the original bone. The MBCA improved the quality of new bone formation, with few residual particles observed at 3 months. The preliminary results of this animal study indicate a real benefit in obtaining new bone as well as in enhancing osseointegration due to the high resorbability of cortical allograft particles, in comparison to the results of xenografts or other biomaterials (mineralized or demineralized cancellous allografts) that have been presented in the literature. Furthermore, the use of an MBCA combined with a collagen membrane in extraction and immediate implant placement limited the extent of post-extraction resorption.

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

    Science.gov (United States)

    McCanless, Jonathan D.

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

  1. Finite element analysis of functionally graded bone plate at femur bone fracture site

    Science.gov (United States)

    Satapathy, Pravat Kumar; Sahoo, Bamadev; Panda, L. N.; Das, S.

    2018-03-01

    This paper focuses on the analysis of fractured Femur bone with functionally graded bone plate. The Femur bone is modeled by using the data from the CT (Computerized Tomography) scan and the material properties are assigned using Mimics software. The fracture fixation plate used here is composed of Functionally Graded Material (FGM). The functionally graded bone plate is considered to be composed of different layers of homogeneous materials. Finite element method approach is adopted for analysis. The volume fraction of the material is calculated by considering its variation along the thickness direction (z) according to a power law and the effective properties of the homogeneous layers are estimated. The model developed is validated by comparing numerical results available in the literature. Static analysis has been performed for the bone plate system by considering both axial compressive load and torsional load. The investigation shows that by introducing FG bone plate instead of titanium, the stress at the fracture site increases by 63 percentage and the deformation decreases by 15 percentage, especially when torsional load is taken into consideration. The present model yields better results in comparison with the commercially available bone plates.

  2. Iatrogenic giant cell tumor at bone graft harvesting site

    Directory of Open Access Journals (Sweden)

    Zile S Kundu

    2013-01-01

    Full Text Available 30 year old female patient with giant cell tumor of the distal tibia initially treated at a peripheral nononcological center by curettage and autologous bone grafting from the ipsilateral iliac crest reported to us with local recurrence and an implantation giant cell tumor at the graft harvesting site which required extensive surgeries at both sites. The risk of iatrogenic direct implantation of tumor, often attributable to inadequate surgical planning or poor surgical techniques, and the steps to prevent such complication is reported here.

  3. Alien Noise Cancellation

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Full FEXT Cancellation. Expectation Maximization based Algorithms. Partial Cancellation. Optimal Choice of what to Cancel and what not to! Alien Noise Cancellation. Efficient Crosstalk channel estimation. In addition:

  4. The homing of bone marrow MSCs to non-osseous sites for ectopic bone formation induced by osteoinductive calcium phosphate.

    NARCIS (Netherlands)

    Song, G.; Habibovic, Pamela; Bao, Chongyun; Hu, J.; van Blitterswijk, Clemens; Yuan, Huipin; Chen, W.; Xu, H.H.K.

    2013-01-01

    Osteoinductive biomaterials are promising for bone repair. There is no direct proof that bone marrow mesenchymal stem cells (BMSCs) home to non-osseous sites and participate in ectopic bone formation induced by osteoinductive bioceramics. The objective of this study was to use a sex-mismatched

  5. Effects of combined therapy of alendronate and low-intensity pulsed ultrasound on metaphyseal bone repair after osteotomy in the proximal tibia of glucocorticoid-induced osteopenia rats

    Directory of Open Access Journals (Sweden)

    Tetsuya Kawano

    2017-12-01

    Conclusions: ALN monotherapy and combined ALN and LUPUS treatment augmented BMD and stimulated cancellous bone repair with increased Runx2 expression at the osteotomy site in GIO rats. However, the combined treatment had no additional effect on cancellous bone healing compared to ALN monotherapy.

  6. Effects of young-coconut juice on increasing mandibular cancellous bone in orchidectomized rats: Preliminary novel findings

    Directory of Open Access Journals (Sweden)

    Pranee Suwanpal

    2011-12-01

    Full Text Available Androgens play a very important role in building the skeleton in young adults and help to prevent bone loss andosteoporosis in aging men. In addition, in hypogonadism or elderly men, bone mass has been related to estrogen levels ratherthan to testosterone. Estrogen replacement therapy has therefore been proposed to prevent bone loss in males as well as infemales. Estrogen, however, has been considered to be one of the hormonal risk factors for benign prostatic hyperplasia andprostate cancer and also has other side effects. Young coconut juice (YCJ presumably containing phytoestrogen was investigatedin the present study for its possible beneficial effects on delaying osteoporosis using a male rat model, and by this totest the possibility that it might be able to replace estrogen replacement therapy without side effects. In this study, mandibularcancellous bone was used as the osteoporotic model. Using the same model, we have previously found that total cartilagethickness particularly the hypertrophic zone of mandibular condylar cartilage was thicker in the sham-operated rats receivingYCJ orally fed for a 14 day period, compared with sham, orchidectomized animal, orchidectomized rats receiving estradiolbenzoate, and orchidectomized rats receiving YCJ. The present study confirmed our former study that mandibular cancellousbone in the sham-operated rats and in the orchidectomized rats receiving YCJ orally fed for a 14–day period were thicker thanthose of the sham and orchidectomized rat groups. This study results are novel and they indicate that YCJ may have beneficialeffects in the treatment of osteoporosis in andropause men.

  7. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    D. O. Joshi

    2010-08-01

    Full Text Available Bone grafting is the process by which bone is transferred from a source (donor to site (recipient. Due to trauma from accidents by speedy vehicles, falling down from height or gunshot injury particularly in human being, acquired or developmental diseases like rickets, congenital defects like abnormal bone development, wearing out because of age and overuse; lead to bone loss and to replace the loss we need the bone grafting. Osteogenesis, osteoinduction, osteoconduction, mechanical supports are the four basic mechanisms of bone graft. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. An ideal bone graft material is biologically inert, source of osteogenic, act as a mechanical support, readily available, easily adaptable in terms of size, shape, length and replaced by the host bone. Except blood, bone is grafted with greater frequency. Bone graft indicated for variety of orthopedic abnormalities, comminuted fractures, delayed unions, non-unions, arthrodesis and osteomyelitis. Bone graft can be harvested from the iliac crest, proximal tibia, proximal humerus, proximal femur, ribs and sternum. By adopting different procedure of graft preservation its antigenicity can be minimized. The concept of bone banking for obtaining bone grafts and implants is very useful for clinical application. Absolute stability require for successful incorporation. Ideal bone graft must possess osteogenic, osteoinductive and osteocon-ductive properties. Cancellous bone graft is superior to cortical bone graft. Usually autologous cancellous bone graft are used as fresh grafts where as allografts are employed as an alloimplant. None of the available type of bone grafts possesses all these properties therefore, a single type of graft cannot be recomm-ended for all types of orthopedic abnormalities. Bone grafts and implants can be selected as per clinical problems, the equipments available and preference of

  8. Contributing factors of elective surgical case cancellation: a retrospective cross-sectional study at a single-site hospital.

    Science.gov (United States)

    Yu, Kaiye; Xie, Xiaolei; Luo, Li; Gong, Renrong

    2017-09-11

    Case cancellation (CC) has significant impact on the efficiency of operating room (OR) management, which can be mitigated by taking preventive measures. In this study, using the data of the West China Hospital (WCH), we identified the effect of contributing factors and recommended hospital interventions to facilitate CC prevention. We conducted a retrospective review of 11,331 elective surgical cases from January 1 to December 31, 2014. CC reasons were grouped into six categories. The methods of descriptive statistics and hypothesis test were used to identify the effect of factors. CC reasons (746) were divided into six broad categories: workup related (preoperative diagnostic assessment issues or sudden medical condition changes) (25.8%), non-specified reasons (25.8%), coordination issues (15.1%), patient related (13.0%), support system issues (11.8%), and doctor related (8.5%). The types of the most frequently performed operations are identified, as well as their CRs. The cancellation rate (CR) of males was lower than that of females (16.7% to 18.3%). A large difference in the CRs existed among doctors. The CR on Monday was significantly higher than the other four weekdays. Workup related issues, the types of procedures, the menstrual cycle of females, highly imbalanced CRs among doctors, and tendency of cancellation on Monday are the major identified factors, which account for a significant amount of preventable cancellations. It is suggested that corresponding hospital interventions can reduce CR and improve OR efficiency, including maintaining effective coordination, good communication and well-designed preoperative assessment processes, focusing on the type of procedures which are more time-consuming and complex, paying special attention to the physiology of females during surgery planning, taking measures to reduce CR of top eight doctors, and improving surgery scheduling on Monday.

  9. Healing of Large Segmental Bone Defect after Implantation of Autogenous Cancellous Bone Graft in Comparison to Hydroxyapatite and 0.5% Collagen Scaffold Combined with Mesenchymal Stem Cells

    Czech Academy of Sciences Publication Activity Database

    Nečas, A.; Proks, P.; Urbanová, L.; Srnec, R.; Stehlík, L.; Crha, M.; Raušer, P.; Plánka, L.; Janovec, J.; Dvořák, M.; Amler, Evžen; Vojtová, L.; Jančář, J.

    2010-01-01

    Roč. 79, č. 4 (2010), s. 607-612 ISSN 0001-7213 R&D Projects: GA MŠk 2B06130 Institutional support: RVO:68378041 Keywords : fracture fixation * bone healing * comminuted fracture Subject RIV: FI - Traumatology, Orthopedics Impact factor: 0.534, year: 2010

  10. Biological Differences Between Prostate Cancer Cells that Metastasize to Bone Versus Soft Tissue Sites

    National Research Council Canada - National Science Library

    Pienta, Kenneth J

    2004-01-01

    .... Comparisons were made between patients as well as within the same patient. No consistent differences were found between bone and soft tissue sites that could explain the predilection of prostate cancer cells to metastasize to bone...

  11. Quantitative dual-energy CT for phantomless evaluation of cancellous bone mineral density of the vertebral pedicle: correlation with pedicle screw pull-out strength

    Energy Technology Data Exchange (ETDEWEB)

    Wichmann, Julian L.; Booz, Christian; Bauer, Ralf W.; Kerl, J.M.; Fischer, Sebastian; Lehnert, Thomas; Vogl, Thomas J.; Khan, M.F. [University Hospital Frankfurt, Department of Diagnostic and Interventional Radiology, Frankfurt am Main (Germany); Wesarg, Stefan [Fraunhofer IGD, Cognitive Computing and Medical Imaging, Darmstadt (Germany); Kafchitsas, Konstantinos [Spine Center, Asklepios Klinik Lindenlohe, Schwandorf (Germany)

    2015-06-01

    To evaluate quantitative dual-energy computed tomography (DECT) for phantomless analysis of cancellous bone mineral density (BMD) of vertebral pedicles and to assess the correlation with pedicle screw pull-out strength. Twenty-nine thoracic and lumbar vertebrae from cadaver specimens were examined with DECT. Using dedicated post-processing software, a pedicle screw vector was mapped (R1, intrapedicular segment of the pedicle vector; R2, intermediate segment; R3, intracorporal segment; global, all segments) and BMD was calculated. To invasively evaluate pedicle stability, pedicle screws were drilled through both pedicles and left pedicle screw pull-out strength was measured. Resulting values were correlated using the paired t test and Pearson's linear correlation. Average pedicle screw vector BMD (R1, 0.232 g/cm{sup 3}; R2, 0.166 g/cm{sup 3}; R3, 0.173 g/cm{sup 3}; global, 0.236 g/cm{sup 3}) showed significant differences between R1-R2 (P < 0.002) and R1-R3 (P < 0.034) segments while comparison of R2-R3 did not reach significance (P > 0.668). Average screw pull-out strength (639.2 N) showed a far stronger correlation with R1 (r = 0.80; P < 0.0001) than global BMD (r = 0.42; P = 0.025), R2 (r = 0.37; P = 0.048) and R3 (r = -0.33; P = 0.078) segments. Quantitative DECT allows for phantomless BMD assessment of the vertebral pedicle. BMD of the intrapedicular segment shows a significantly stronger correlation with pedicle screw pull-out strength than other segments. (orig.)

  12. The homing of bone marrow MSCs to non-osseous sites for ectopic bone formation induced by osteoinductive calcium phosphate

    Science.gov (United States)

    Song, Guodong; Habibovic, Pamela; Bao, Chongyun; Hu, Jing; van Blitterswijk, Clemens A.; Yuan, Huipin; Chen, Wenchuan; Xu, Hockin H.K.

    2013-01-01

    Osteoinductive biomaterials are promising for bone repair. There is no direct proof that bone marrow mesenchymal stem cells (BMSCs) home to non-osseous sites and participate in ectopic bone formation induced by osteoinductive bioceramics. The objective of this study was to use a sex-mismatched beagle dog model to investigate BMSC homing via blood circulation to participate in ectopic bone formation via osteoinductive biomaterial. BMSCs of male dogs were injected into female femoral marrow cavity. The survival and stable chimerism of donor BMSCs in recipients were confirmed with polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH). Biphasic calcium phosphate (BCP) granules were implanted in dorsal muscles of female dogs. Y chromosomes were detected in samples harvested from female dogs which had received male BMSCs. At 4 weeks, cells with Y-chromosomes were distributed in the new bone matrix throughout the BCP granule implant. At 6 weeks, cells with Y chromosomes were present in newly mineralized woven bone. TRAP positive osteoclast-like cells were observed in 4-week implants, and the number of such cells decreased from 4 to 6 weeks. These results show that osteoprogenitors were recruited from bone marrow and homed to ectopic site to serve as a cell source for calcium phosphate-induced bone formation. In conclusion, BMSCs were demonstrated to migrate from bone marrow through blood circulation to non-osseous bioceramic implant site to contribute to ectopic bone formation in a canine model. BCP induced new bone in muscles without growth factor delivery, showing excellent osteoinductivity that could be useful for bone tissue engineering. PMID:23298780

  13. Management of stage I and II A/B avascular necrosis of femoral head with core decompression autologous cancellous bone grafting and platelet rich plasma factors

    Directory of Open Access Journals (Sweden)

    Tushar Agarwal

    2015-01-01

    Full Text Available Background: Avascular necrosis (AVN of the femoral head is a progressive disease that generally affects patients in the third through fifth decades of life; if left untreated, it leads to complete deterioration of the hip joint. Treatments range from simple decompression of the femoral head, to bone grafting of the involved area, or by using a vascularized fibular graft with varying degree of success. In most instances, the disease progresses further causing secondary arthritis. We present a study of management of early stage AVN (stage I and II A/B of Ficat Arlet classification with core decompression autologous cancellous bone grafting along with platelet rich plasma. Aims: To evaluate the results of the above modality in the management of AVN of the hip. Settings and Design: This prospective study of 30 cases was done during the period of 2011-2013. Materials and Methods: Patients with stage I and II A/B were treated with the above modality and were followed up for 1-year. The results were evaluated on the basis of progression or remission of the disease by radiographic studies, preoperative and postoperative Harris hip score (HHS, age and sex distribution. Statistical Analysis Used: Primer software for calculating the statistical data was used and paired t-test was applied to all the data. Results: Show males were more affected than females and average age group of presentation in stage I and II was 29 years (22-55. The most common cause was idiopathic followed by steroid use. Average preoperative HHS was 56.80 and postoperative HHS was 79.73. 60% (18 showed remission of the disease (radiographically compared to preoperative stage at 1-year follow-up, in 30% (9 disease did not progress further and 10% (3 progressed and required arthroplasty. Conclusion: Management of stage I and II A/B AVN of femur showed good satisfactory results in terms of disease remission and prevention of the further progress of the disease by the above method at 1

  14. Plasma-sprayed titanium coating to polyetheretherketone improves the bone-implant interface.

    Science.gov (United States)

    Walsh, William R; Bertollo, Nicky; Christou, Chrisopher; Schaffner, Dominik; Mobbs, Ralph J

    2015-05-01

    Rapid and stable fixation at the bone-implant interface would be regarded as one of the primary goals to achieve clinical efficacy, regardless of the surgical site. Although mechanical and physical properties of polyetheretherketone (PEEK) provide advantages for implant devices, the hydrophobic nature and the lack of direct bone contact remains a limitation. To examine the effects of a plasma-sprayed titanium coated PEEK on the mechanical and histologic properties at the bone-implant interface. A preclinical laboratory study. Polyetheretherketone and plasma-sprayed titanium coated PEEK implants (Ti-bond; Spinal Elements, Carlsbad, CA, USA) were placed in a line-to-line manner in cortical bone and in a press-fit manner in cancellous bone of adult sheep using an established ovine model. Shear strength was assessed in the cortical sites at 4 and 12 weeks, whereas histology was performed in cortical and cancellous sites at both time points. The titanium coating dramatically improved the shear strength at the bone-implant interface at 4 weeks and continued to improve with time compared with PEEK. Direct bone ongrowth in cancellous and cortical sites can be achieved using a plasma-sprayed titanium coating on PEEK. Direct bone to implant bonding can be achieved on PEEK in spite of its hydrophobic nature using a plasma-sprayed titanium coating. The plasma-sprayed titanium coating improved mechanical properties in the cortical sites and the histology in cortical and cancellous sites. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Three-dimensional quantitative CT of the proximal femur: Relationship to vertebral trabecular bone density

    International Nuclear Information System (INIS)

    Bhasin, S.; Zlatkin, M.B.; Sartoris, D.J.; Andre, M.; Resnick, D.

    1987-01-01

    Integrated cancellous, cortical, and total bone density in the femoral neck and inter-trochanteric region was measured bilaterally in 25 women aged 35-90 years (mean age, 65). Contiguous-section (1-cm-thick) data were analyzed using three-dimensional histogram software on a Cemax 1000 image processor. Single-section quantitative CT was used to determine mean mineral equivalent values for vertebral cancellous bone from T-11 to L-3 in each woman. Significant correlation was found between cancellous bone density at the two sites. Cortical and total bone densities in the proximal femur were predicted less well with vertebral cancellous data, suggesting a greater dependence on weight-bearing and activity factors

  16. Impaired bone healing at tooth extraction sites in CD24-deficient mice: A pilot study.

    Science.gov (United States)

    Avivi-Arber, Limor; Avivi, Doran; Perez, Marilena; Arber, Nadir; Shapira, Shiran

    2018-01-01

    To use a micro-computed tomography (micro-CT) to quantify bone healing at maxillary first molar extraction sites, and test the hypothesis that bone healing is impaired in CD24-knockout mice as compared with wild-type C57BL/6J mice. Under ketamine-xylazine general anaesthesia, mice had either extraction of the right maxillary first molar tooth or sham operation. Mice were sacrificed 1 (n = 12/group), 2 (n = 6/group) or 4 (n = 6/group) weeks postoperatively. The right maxillae was disected. Micro-CT was used to quantify differences in bone microstructural features at extrction sites, between CD24-knockout mice and wild-type mice. CD24-Knockout mice displayed impaired bone healing at extraction sites that was manifested as decreased trabecular bone density, and decreased number and thickness of trabeculae. This pilot study suggests that CD24 plays an important role in extraction socket bone healing and may be used as a novel biomarker of bone quality and potential therapeutic target to improve bone healing and density following alveolar bone injury.

  17. Uncommon sites of bone infarction in a sickle cell anemia patient

    International Nuclear Information System (INIS)

    Garty, I.; Koren, A.; Katzumi, E.

    1983-01-01

    Unusual sites of bone infarction, in the skull and sternum, were observed in a patient suffering from sickle cell anemia. Asup(99m)Tc-MDP scan was performed and demonstrated foci of decreased activity in the symptomatic regions. The differentiation of bone infarction from osteomyelitis in sickle cell anemia patients is illustrated. (orig.)

  18. Bone scintigraphy in Ewing's sarcoma during and after treatment - prognostic information from the primary tumor site

    International Nuclear Information System (INIS)

    Piers, D.A.; Veenhoven, R.H.; Kamps, W.A.; Woldring, M.G.

    1988-01-01

    A bone scan can be negative in Ewing's sarcoma. The bone scan during and after treatment can give prognostic information on the primary tumor site: A persisting hot spot strongly suggests the presence of local malignancy, while a hot spot becomming negative points to local cure of Ewing's sarcoma. (orig.)

  19. Correlation Between Resonance Frequency Analysis and Bone Quality Assessments at Dental Implant Recipient Sites.

    Science.gov (United States)

    Fu, Min-Wen; Fu, Earl; Lin, Fu-Gong; Chang, Wei-Jeng; Hsieh, Yao-Dung; Shen, E-Chin

    To evaluate whether primary implant stability could be used to predict bone quality, the association between the implant stability quotient (ISQ) value and the bone type at the implant site was evaluated. Ninety-five implant sites in 50 patients were included. Bone type (categorized by Lekholm and Zarb) at the implant site was initially assessed using presurgical dental radiography. During the preparation of the implant site, a bone core specimen was carefully obtained. The bone type was assessed by tactile sensation during the drilling operation, according to the Misch criteria. The primary stability of the inserted implant was evaluated by resonance frequency analysis (RFA). The ISQ value was recorded. The bone core specimen was then examined by stereomicroscopy or microcomputed tomography (micro-CT), and the bone type was determined by the surface characteristics of the specimen, based on Lekholm and Zarb classification. Agreement between the bone quality assessed by the four methods (ie, presurgical radiography, tactile sensation, stereomicroscopy, and micro-CT) was tested by Cohen's kappa statistics, whereas the association between the ISQ value and the bone type was evaluated by the generalized linear regression model. The mean ISQ score was 72.6, and the score was significantly influenced by the maxillary or mandibular arch (P = .001). The bone type at the implant sites varied according to the assessment method. However, a significant influence of the arch was repeatedly noted when using radiography or tactile sensation. Among the four bone-quality assessment methods, a weak agreement existed only between stereomicroscopy and micro-CT, especially in the maxilla (κ = 0.469). A negative association between the ISQ value and the bone type assessed by stereomicroscopy or by micro-CT was significant in the maxilla, but not in the mandible, after adjustments for sex, age, and right/left side (P = .013 and P = .027 for stereomicroscopy and micro-CT, respectively

  20. MicroCT analysis of calcium/phosphorus ratio maps at different bone sites

    Energy Technology Data Exchange (ETDEWEB)

    Speller, R. [Medical Physics and Bioengineering Department, UCL, London, WC1E 6BT (United Kingdom)]. E-mail: rspeller@medphys.ucl.ac.uk; Pani, S. [Department of Physics, University of Trieste (Italy); Tzaphlidou, M. [Lab Medical Physics, Medical School, University of Ioannina, 45110 Ioannina (Greece); Horrocks, J. [Clinical Physics Group, St Bartholomew' s Hospital, London, EC1A 6BT (United Kingdom)

    2005-08-11

    The Ca/P ratio was measured in cortical bone samples from the femoral neck, front and rear tibia of rats, rabbits and lambs using synchrotron microCT. Use of a monoenergetic X-ray beam, as provided by the synchrotron facility, generates accurate 3-D maps of the linear attenuation coefficient within the sample and hence gives the ability to map different chemical components. Data were taken at 20keV for each bone sample and calibration phantoms. From the 3-D data sets, multiple 2-D slices were reconstructed with a slice thickness of {approx}28{mu}m and converted to Ca/P ratios using the calibration phantom results. Average values for each animal and bone site were estimated. Differences between the same bone sites from different animals are not significant (0.3bone sites and different animals are highly significant (p<10{sup -3}) demonstrating a dependence upon lifestyle and bone use. The spatial distribution of Ca/P was found to be non-uniform for some bones and some animals possibly indicating the structural mechanism for obtaining bone strength.

  1. An Intraoperative Site-specific Bone Density Device: A Pilot Test Case.

    Science.gov (United States)

    Arosio, Paolo; Moschioni, Monica; Banfi, Luca Maria; Di Stefano, Anilo Alessio

    2015-08-01

    This paper reports a case of all-on-four rehabilitation where bone density at implant sites was assessed both through preoperative computed tomographic (CT) scans and using a micromotor working as an intraoperative bone density measurement device. Implant-supported rehabilitation is a predictable treatment option for tooth replacement whose success depends on the clinician's experience, the implant characteristics and location and patient-related factors. Among the latter, bone density is a determinant for the achievement of primary implant stability and, eventually, for implant success. The ability to measure bone density at the placement site before implant insertion could be important in the clinical setting. A patient complaining of masticatory impairment was presented with a plan calling for extraction of all her compromised teeth, followed by implant rehabilitation. A week before surgery, she underwent CT examination, and the bone density on the CT scans was measured. When the implant osteotomies were created, the bone density was again measured with a micromotor endowed with an instantaneous torque-measuring system. The implant placement protocols were adapted for each implant, according to the intraoperative measurements, and the patient was rehabilitated following an all-on-four immediate loading protocol. The bone density device provided valuable information beyond that obtained from CT scans, allowing for site-specific, intraoperative assessment of bone density immediately before implant placement and an estimation of primary stability just after implant insertion. Measuring jaw-bone density could help clinicians to select implant-placement protocols and loading strategies based on site-specific bone features.

  2. Site specific measurements of bone formation using [18F] sodium fluoride PET/CT.

    Science.gov (United States)

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

    2018-02-01

    Dynamic positron emission tomography (PET) imaging with fluorine-18 labelled sodium fluoride ([ 18 F]NaF) allows the quantitative assessment of regional bone formation by measuring the plasma clearance of fluoride to bone at any site in the skeleton. Today, hybrid PET and computed tomography (CT) dual-modality systems (PET/CT) are widely available, and [ 18 F]NaF PET/CT offers a convenient non-invasive method of studying bone formation at the important osteoporotic fracture sites at the hip and spine, as well as sites of pure cortical or trabecular bone. The technique complements conventional measurements of bone turnover using biochemical markers or bone biopsy as a tool to investigate new therapies for osteoporosis, and has a potential role as an early biomarker of treatment efficacy in clinical trials. This article reviews methods of acquiring and analyzing dynamic [ 18 F]NaF PET/CT scan data, and outlines a simplified approach combining venous blood sampling with a series of short (3- to 5-minute) static PET/CT scans acquired at different bed positions to estimate [ 18 F]NaF plasma clearance at multiple sites in the skeleton with just a single injection of tracer.

  3. Phenotypic Dissection of Bone Mineral Density Reveals Skeletal Site Specificity and Facilitates the Identification of Novel Loci in the Genetic Regulation of Bone Mass Attainment

    NARCIS (Netherlands)

    J.P. Kemp (John); M.C. Medina-Gomez (Carolina); K. Estrada Gil (Karol); B. St Pourcain (Beate); D.H.M. Heppe (Denise); N.M. Warrington (Nicole); L. Oei (Ling); S.M. Ring (Susan); C.J. Kruithof (Claudia); N.J. Timpson (Nicholas); L.E. Wolber (Lisa); S. Reppe (Sjur); K.M. Gautvik (Kaare); E. Grundberg (Elin); B. Ge (Bing); B.C.J. van der Eerden (Bram); J. van de Peppel (Jeroen); M.A. Hibbs (Matthew); C.L. Ackert-Bicknell (Cheryl); K. Choi (Kunho); D.L. Koller (Daniel); M.J. Econs (Michael); F.M. Williams (Frances); T. Foroud (Tatiana); M.C. Zillikens (Carola); C. Ohlsson (Claes); A. Hofman (Albert); A.G. Uitterlinden (André); G. Davey-Smith (George); V.W.V. Jaddoe (Vincent); J.H. Tobias (Jon); F. Rivadeneira Ramirez (Fernando); D.M. Evans (David)

    2014-01-01

    textabstractHeritability of bone mineral density (BMD) varies across skeletal sites, reflecting different relative contributions of genetic and environmental influences. To quantify the degree to which common genetic variants tag and environmental factors influence BMD, at different sites, we

  4. MicroCT analysis of calcium/phosphorus ratio maps at different bone sites

    International Nuclear Information System (INIS)

    Speller, R.; Pani, S.; Tzaphlidou, M.; Horrocks, J.

    2005-01-01

    The Ca/P ratio was measured in cortical bone samples from the femoral neck, front and rear tibia of rats, rabbits and lambs using synchrotron microCT. Use of a monoenergetic X-ray beam, as provided by the synchrotron facility, generates accurate 3-D maps of the linear attenuation coefficient within the sample and hence gives the ability to map different chemical components. Data were taken at 20keV for each bone sample and calibration phantoms. From the 3-D data sets, multiple 2-D slices were reconstructed with a slice thickness of ∼28μm and converted to Ca/P ratios using the calibration phantom results. Average values for each animal and bone site were estimated. Differences between the same bone sites from different animals are not significant (0.3 -3 ) demonstrating a dependence upon lifestyle and bone use. The spatial distribution of Ca/P was found to be non-uniform for some bones and some animals possibly indicating the structural mechanism for obtaining bone strength

  5. Human bone hardness seems to depend on tissue type but not on anatomical site in the long bones of an old subject.

    Science.gov (United States)

    Ohman, Caroline; Zwierzak, Iwona; Baleani, Massimiliano; Viceconti, Marco

    2013-02-01

    It has been hypothesised that among different human subjects, the bone tissue quality varies as a function of the bone segment morphology. The aim of this study was to assess and compare the quality, evaluated in terms of hardness of packages of lamellae, of cortical and trabecular bones, at different anatomical sites within the human skeleton. The contralateral six long bones of an old human subject were indented at different levels along the diaphysis and at both epiphyses of each bone. Hardness value, which is correlated to the degree of mineralisation, of both cortical and trabecular bone tissues was calculated for each indentation location. It was found that the cortical bone tissue was harder (+18%) than the trabecular one. In general, the bone hardness was found to be locally highly heterogeneous. In fact, considering one single slice obtained for a bone segment, the coefficient of variation of the hardness values was up to 12% for cortical bone and up to 17% for trabecular bone. However, the tissue hardness was on average quite homogeneous within and among the long bones of the studied donor, although differences up to 9% among levels and up to 7% among bone segments were found. These findings seem not to support the mentioned hypothesis, at least not for the long bones of an old subject.

  6. High doses of ionizing radiation on bone repair: is there effect outside the irradiated site?

    Science.gov (United States)

    Rocha, Flaviana Soares; Dias, Pâmella Coelho; Limirio, Pedro Henrique Justino Oliveira; Lara, Vitor Carvalho; Batista, Jonas Dantas; Dechichi, Paula

    2017-03-01

    Local ionizing radiation causes damage to bone metabolism, it reduces blood supply and cellularity over time. Recent studies indicate that radiation promotes biological response outside the treatment field. The aim of this study was to investigate the effects of ionizing radiation on bone repair outside the irradiated field. Ten healthy male Wistar rats were used; and five animals were submitted to radiotherapy on the left femur. After 4 weeks, in all animals were created bone defects in the right and left femurs. Seven days after surgery, animals were euthanized. The femurs were removed and randomly divided into 3 groups (n=5): Control (C) (right femur of the non-irradiated animals); Local ionizing radiation (IR) (left femur of the irradiated animals); Contralateral ionizing radiation (CIR) (right femur of the irradiated animals). The femurs were processed and embedded in paraffin; and bone histologic sections were evaluated to quantify the bone neoformation. Histomorphometric analysis showed that there was no significant difference between groups C (24.6±7.04) and CIR (25.3±4.31); and IR group not showed bone neoformation. The results suggest that ionizing radiation affects bone repair, but does not interfere in bone repair distant from the primary irradiated site. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Site-Specific Difference of Bone Geometry Indices in Hypoparathyroid Patients

    Directory of Open Access Journals (Sweden)

    Hye-Sun Park

    2017-02-01

    Full Text Available BackgroundHypoparathyroid patients often have a higher bone mineral density (BMD than the general population. However, an increase in BMD does not necessarily correlate with a solid bone microstructure. This study aimed to evaluate the bone microstructure of hypoparathyroid patients by using hip structure analysis (HSA.MethodsNinety-five hypoparathyroid patients >20 years old were enrolled and 31 of them had eligible data for analyzing bone geometry parameters using HSA. And among the control data, we extracted sex-, age-, and body mass index-matched three control subjects to each patient. The BMD data were reviewed retrospectively and the bone geometry parameters of the patients were analyzed by HSA.ResultsThe mean Z-scores of hypoparathyroid patients at the lumbar spine, femoral neck, and total hip were above zero (0.63±1.17, 0.48±1.13, and 0.62±1.10, respectively. The differences in bone geometric parameters were site specific. At the femoral neck and intertrochanter, the cross-sectional area (CSA and cortical thickness (C.th were higher, whereas the buckling ratio (BR was lower than in controls. However, those trends were opposite at the femoral shaft; that is, the CSA and C.th were low and the BR was high.ConclusionOur study shows the site-specific effects of hypoparathyroidism on the bone. Differences in bone components, marrow composition, or modeling based bone formation may explain these findings. However, further studies are warranted to investigate the mechanism, and its relation to fracture risk.

  8. Likelihood of Bone Recurrence in Prior Sites of Metastasis in Patients With High-Risk Neuroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Polishchuk, Alexei L. [Department of Radiation Oncology, University of California at San Francisco School of Medicine and UCSF Benioff Children' s Hospital, San Francisco, California (United States); Li, Richard [Division of Radiation Oncology, Dana Farber/Boston Children' s Cancer and Blood Disorders Center, Brigham and Women' s Hospital, Harvard Medical School, Boston, Massachusetts (United States); Hill-Kayser, Christine [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania (United States); Little, Anthony [Division of Oncology, Children' s Hospital of Philadelphia, Philadelphia, Pennsylvania (United States); Hawkins, Randall A. [Department of Radiology, University of California at San Francisco School of Medicine and UCSF Benioff Children' s Hospital, San Francisco, California (United States); Hamilton, Jeffrey; Lau, Michael [Department of Radiation Oncology, University of California at San Francisco School of Medicine and UCSF Benioff Children' s Hospital, San Francisco, California (United States); Tran, Hung Chi [Division of Hematology/Oncology, Children' s Hospital of Los Angeles, Los Angeles, California (United States); Strahlendorf, Caron [Division of Hematology and Oncology, Department of Pediatrics, The University of British Columbia, Vancouver, British Columbia (Canada); Lemons, Richard S. [Division of Pediatric Hematology/Oncology, University of Utah School of Medicine, Salt Lake City, Utah (United States); Weinberg, Vivian [Department of Radiation Oncology, University of California at San Francisco School of Medicine and UCSF Benioff Children' s Hospital, San Francisco, California (United States); Matthay, Katherine K.; DuBois, Steven G. [Department of Pediatrics, University of California at San Francisco School of Medicine and UCSF Benioff Children' s Hospital, San Francisco, California (United States); and others

    2014-07-15

    Purpose/Objectives: Despite recent improvements in outcomes, 40% of children with high-risk neuroblastoma will experience relapse, facing a guarded prognosis for long-term cure. Whether recurrences are at new sites or sites of original disease may guide decision making during initial therapy. Methods and Materials: Eligible patients were retrospectively identified from institutional databases at first metastatic relapse of high-risk neuroblastoma. Included patients had disease involving metaiodobenzylguanidine (MIBG)-avid metastatic sites at diagnosis and first relapse, achieved a complete or partial response with no more than one residual MIBG-avid site before first relapse, and received no total body irradiation or therapy with {sup 131}I-MIBG before first relapse. Anatomically defined metastatic sites were tracked from diagnosis through first relapse to determine tendency of disease to recur at previously involved versus uninvolved sites and to assess whether this pattern was influenced by site irradiation. Results: Of 159 MIBG-avid metastatic sites identified among 43 patients at first relapse, 131 (82.4%) overlapped anatomically with the set of 525 sites present at diagnosis. This distribution was similar for bone sites, but patterns of relapse were more varied for the smaller subset of soft tissue metastases. Among all metastatic sites at diagnosis in our subsequently relapsed patient cohort, only 3 of 19 irradiated sites (15.8%) recurred as compared with 128 of 506 (25.3%) unirradiated sites. Conclusions: Metastatic bone relapse in neuroblastoma usually occurs at anatomic sites of previous disease. Metastatic sites identified at diagnosis that did not receive radiation during frontline therapy appeared to have a higher risk of involvement at first relapse relative to previously irradiated metastatic sites. These observations support the current paradigm of irradiating metastases that persist after induction chemotherapy in high-risk patients. Furthermore

  9. Strontium incorporates at sites critical for bone mineralization in rats with renal failure

    International Nuclear Information System (INIS)

    Oste, Line; Verberckmoes, Steven C.; Behets, Geert J.; Dams, Geert; Bervoets, An R.; De Broe, Marc E.; D'Haese, Patrick C.; Van Hoof, Viviane O.; Bohic, Sylvain; Drakopoulos, Michael

    2007-01-01

    We previously demonstrated the development of a mineralization defect during strontium administration and its reversibility after withdrawal in rats with chronic renal failure. Recently, strontium ranelate has been introduced as a therapeutic agent for osteoporosis. However, caution has to be taken, as this bone disorder mainly develops in elderly people who may present a moderately decreased renal function. In order to assess the ultra-structural localization of strontium in bone and thereby to get a better insight into the element's systemic effects on bone, synchrotron-based x-ray micro-fluorescence was applied, which showed that after 2 weeks of strontium loading (2 g l -1 in drinking water) in rats with renal failure, concomitant with the development of impaired mineralization, the element was localized mainly at the outer edge of the mineralized bone, while after longer loading periods, a more homogeneous distribution was found. After washout, strontium was found at sites deeper within the trabeculae, while newly deposited low-strontium-containing mineral was found at the outer edges. Synchrotron x-ray micro-diffraction analysis showed that strontium is incorporated in the apatite crystal lattice through exchange with calcium. The results show that strontium is initially incorporated in bone at sites of active bone mineralization, close to the osteoid/mineralization front.Most likely, strontium binds to matrix proteins serving as crystal nucleation points and by hetero-ionic substitution with calcium within the hydroxyapatite crystals, thereby impairing further hydroxyapatite formation. After withdrawal, strontium is released from these sites, by which mineralization is restored and the previously formed strontium-containing hydroxyapatite is buried under a new layer of mineralized bone. (authors)

  10. Finite element analysis of dental implant loading on atrophic and non-atrophic cancellous and cortical mandibular bone - a feasibility study

    NARCIS (Netherlands)

    Marcián, P.; Borák, L.; Valášek, J.; Kaiser, J.; Florian, Z.; Wolff, J.

    2014-01-01

    The first aim of this study was to assess displacements and micro-strain induced on different grades of atrophic cortical and trabecular mandibular bone by axially loaded dental implants using finite element analysis (FEA). The second aim was to assess the micro-strain induced by different implant

  11. Finite element analysis of dental implant loading on atrophic and non-atrophic cancellous and cortical mandibular bone – a feasibility study

    NARCIS (Netherlands)

    Marcian, P.; Borak, L.; Valasek, J.; Kaiser, J.; Florian, Z.; Wolff, J.E.H.

    2014-01-01

    The first aim of this study was to assess displacements and micro-strain induced on different grades of atrophic cortical and trabecular mandibular bone by axially loaded dental implants using finite element analysis (FEA). The second aim was to assess the micro-strain induced by different implant

  12. Handball Practice Enhances Bone Mass in Specific Sites Among Prepubescent Boys.

    Science.gov (United States)

    Missawi, Kawther; Zouch, Mohamed; Chakroun, Yosra; Chaari, Hamada; Tabka, Zouhair; Bouajina, Elyès

    2016-01-01

    This investigation's purpose is to focus on the effects of practicing handball for at least 2 yr on bone acquisition among prepubescent boys. One hundred prepubescent boys aged 10.68 ± 0.85 yr were divided into 2 groups: 50 handball players (HP group) and 50 controls (C group). Bone mineral density (BMD), bone mineral content (BMC), and bone area (BA) were evaluated by using dual-photon X-ray absorptiometry on the whole body, lumbar spine (L2-L4), legs, arms, femoral necks, hips and radiuses. Results showed greater values of BMD in both right and left femoral neck and total hip in handball players than in controls. In addition, handball players had higher values of legs and right total hip BMC than controls without any obvious variation of BA measurement in all sites between groups. All results of the paired t-test displayed an obviously marked variation of bone mass parameters between the left and right sides in the trained group without any marked variation among controls. Data showed an increased BMD of the supporting sites between the left and the right leg among handball players. However, "BMC" results exhibited higher values in the right than in the left total hip, and in the right total radius than in the left correspondent site. In addition, differences in the "BA" measurements were observed in the left total hip and in the right arm. Specific bone sites are markedly stimulated by handball training in prepubescent boys. Copyright © 2016 International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  13. Impact of radiation history, gender and age on bone quality in sites for orthodontic skeletal anchorage device placement.

    Science.gov (United States)

    Konermann, A; Appel, T; Wenghoefer, M; Sirokay, S; Dirk, C; Jäger, A; Götz, W

    2015-05-01

    Stability of orthodontic miniscrew implants is prerequisite to their success and durability in orthodontic treatment. As investigations revealed a positive correlation of miniscrew stability to periimplant bone quality, it has been the aim of this study to analyze the bone structure of resection preparations of human mandibles histologically by investigating the samples according to age, gender and exposure to radiotherapy. Inflammation- and tumor-free alveolar bone sections from human mandibles (n = 31) with previously diagnosed carcinoma, chronic osteomyelitis or cysts were analyzed histomorphologically and histomorphometrically as to the dimension of trabeculae in cancellous areas. Group A investigated the impact of a history of radiation therapy, group B of gender and group C contrasted biopsies from individuals aging under 60 or over 60 years. Statistics were performed using the Kruskal-Wallis-test. Radiation, gender and age did not significantly influence bone density. The mean bone density averaged 40.7 ± 15.0% of spongiosa for the total collective with a median age of 58.4 years ± 14.7 years. Our findings provide new information on bone quality, thus contributing to a more precise evaluation of the parameters affecting and those not affecting miniscrew implant stability. On the basis of these results, the formulation of clinical guidelines for risk assessment of therapeutic approaches in patients prior to insertion of orthodontic skeletal anchorage devices seems to be conceivable. Copyright © 2014 Elsevier GmbH. All rights reserved.

  14. CERN Library - Scientific journal cancellations

    CERN Multimedia

    2004-01-01

    Due to the constant increase of the subscription costs of scientific journals and the current budget restrictions, the Scientific Information Policy Board has mandated the Working Group for Acquisitions (WGA) together with the Library to propose a list of titles to be cancelled at the end of 2004. As a first step, the WGA has identified the scientific journals listed at the web site below as candidates for cancellation. The choice has been guided by the personal experience of the WGA members, consultation of other expert CERN staff for highly specialized titles, and by criteria such as subscription price, impact factor, and - where available - access statistics for electronic journals. The list also accounts for the fact that many titles are subscribed to in 'packages' such that a cancellation of individual titles would not lead to any cost savings. We invite users to carefully check the list on the Library homepage (http://library.cern.ch/). If you find any title that you consider critically important for y...

  15. Scientific journal cancellations

    CERN Multimedia

    The Library

    2001-01-01

    Earlier this year the Scientific Information Policy Board (SIPB) requested the Library and the Working Group for Acquisitions to revise the current printed journal collection in order to cancel those titles that are less required. Savings could then be used for the development of other collections and particularly electronic resources needed to support CERN current research activities. A list of proposed cancellations was drawn and posted on the Library web pages: http://library.cern.ch/library_general/cancel.html The SIPB invites every one to check if any of the titles are of importance to their work, in which case you are invited to inform the Library before the 25th of September by sending an e-mail to: eliane.chaney@cern.ch Titles not reconsidered by the users will be cancelled by the end of the year. Thank you, The Library

  16. Plutonium and Uranium in Human Bones from Areas surrounding the Semipalatinsk Nuclear Test Site

    OpenAIRE

    Masayoshi, YAMAMOTO; Masaharu, HOSHI; Aya, SAKAGUCHI; Kunihiko, SHINOHARA; Osamu, KURIHARA; Kazbek N., APSALIKOV; Boris I., GUSEV; Low Level Radioactivity Laboratory, K-INET, Kanazawa University; Research Institute for Radiation Biology and Medicine, Hiroshima University; Low Level Radioactivity Laboratory, K-INET, Kanazawa University; Japan Nuclear Cycle Development Institute; Japan Nuclear Cycle Development Institute; Kazakh Science Research Institute for Radiation, Medicine and Ecology; Kazakh Science Research Institute for Radiation, Medicine and Ecology

    2006-01-01

    To evaluate the present levels of^Pu and U in residents living near the Semipalatinsk nuclear test site, more than 70 bone samples were obtained at autopsy. The subjects ranged in age from 30 to 86 years (mean 59.3±12.9). Most of the samples consisted of victims who died of various diseases. Plutonium and U were radiochemically separated and determined by α-ray spectrometry. The mean concentrations of ^Pu and ^U observed were 0.050±0.041 mBq/g-ash (vertebrae 71, long-bones 18) and 0.28±0.13 m...

  17. WE-AB-207A-01: BEST IN PHYSICS (IMAGING): High-Resolution Cone-Beam CT of the Extremities and Cancellous Bone Architecture with a CMOS Detector

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Q; Brehler, M; Sisniega, A; Marinetto, E; Stayman, J; Siewerdsen, J; Zbijewski, W [Johns Hopkins University, Baltimore, MD (United States); Zyazin, A; Peters, I [Teledyne DALSA, Eindhoven (Netherlands); Yorkston, J [Carestream Health, Inc, Penfield, NY (United States)

    2016-06-15

    Purpose: Extremity cone-beam CT (CBCT) with an amorphous silicon (aSi) flat-panel detector (FPD) provides low-dose volumetric imaging with high spatial resolution. We investigate the performance of the newer complementary metal-oxide semiconductor (CMOS) detectors to enhance resolution of extremities CBCT to ∼0.1 mm, enabling morphological analysis of trabecular bone. Quantitative in-vivo imaging of bone microarchitecture could present an important advance for osteoporosis and osteoarthritis diagnosis and therapy assessment. Methods: Cascaded systems models of CMOS- and FPD-based extremities CBCT were implemented. Performance was compared for a range of pixel sizes (0.05–0.4 mm), focal spot sizes (0.3–0.6 FS), and x-ray techniques (0.05–0.8 mAs/projection) using detectability of high-, low-, and all-frequency tasks for a nonprewhitening observer. Test-bench implementation of CMOS-based extremity CBCT involved a Teledyne DALSA Xineos3030HR detector with 0.099 mm pixels and a compact rotating anode x-ray source with 0.3 FS (IMD RTM37). Metrics of bone morphology obtained using CMOS-based CBCT were compared in cadaveric specimens to FPD-based system using a Varian PaxScan4030 (0.194 mm pixels). Results: Finer pixel size and reduced electronic noise for CMOS (136 e compared to 2000 e for FPD) resulted in ∼1.9× increase in detectability for high-frequency tasks and ∼1.1× increase for all-frequency tasks. Incorporation of the new x-ray source with reduced focal spot size (0.3 FS vs. 0.5 FS used on current extremities CBCT) improved detectability for CMOS-based CBCT by ∼1.7× for high-frequency tasks. Compared to FPD CBCT, the CMOS detector yielded improved agreement with micro-CT in measurements of trabecular thickness (∼1.7× reduction in relative error), bone volume (∼1.5× reduction), and trabecular spacing (∼3.5× reduction). Conclusion: Imaging performance modelling and experimentation indicate substantial improvements for high

  18. WE-AB-207A-01: BEST IN PHYSICS (IMAGING): High-Resolution Cone-Beam CT of the Extremities and Cancellous Bone Architecture with a CMOS Detector

    International Nuclear Information System (INIS)

    Cao, Q; Brehler, M; Sisniega, A; Marinetto, E; Stayman, J; Siewerdsen, J; Zbijewski, W; Zyazin, A; Peters, I; Yorkston, J

    2016-01-01

    Purpose: Extremity cone-beam CT (CBCT) with an amorphous silicon (aSi) flat-panel detector (FPD) provides low-dose volumetric imaging with high spatial resolution. We investigate the performance of the newer complementary metal-oxide semiconductor (CMOS) detectors to enhance resolution of extremities CBCT to ∼0.1 mm, enabling morphological analysis of trabecular bone. Quantitative in-vivo imaging of bone microarchitecture could present an important advance for osteoporosis and osteoarthritis diagnosis and therapy assessment. Methods: Cascaded systems models of CMOS- and FPD-based extremities CBCT were implemented. Performance was compared for a range of pixel sizes (0.05–0.4 mm), focal spot sizes (0.3–0.6 FS), and x-ray techniques (0.05–0.8 mAs/projection) using detectability of high-, low-, and all-frequency tasks for a nonprewhitening observer. Test-bench implementation of CMOS-based extremity CBCT involved a Teledyne DALSA Xineos3030HR detector with 0.099 mm pixels and a compact rotating anode x-ray source with 0.3 FS (IMD RTM37). Metrics of bone morphology obtained using CMOS-based CBCT were compared in cadaveric specimens to FPD-based system using a Varian PaxScan4030 (0.194 mm pixels). Results: Finer pixel size and reduced electronic noise for CMOS (136 e compared to 2000 e for FPD) resulted in ∼1.9× increase in detectability for high-frequency tasks and ∼1.1× increase for all-frequency tasks. Incorporation of the new x-ray source with reduced focal spot size (0.3 FS vs. 0.5 FS used on current extremities CBCT) improved detectability for CMOS-based CBCT by ∼1.7× for high-frequency tasks. Compared to FPD CBCT, the CMOS detector yielded improved agreement with micro-CT in measurements of trabecular thickness (∼1.7× reduction in relative error), bone volume (∼1.5× reduction), and trabecular spacing (∼3.5× reduction). Conclusion: Imaging performance modelling and experimentation indicate substantial improvements for high

  19. A histomorphometric and micro-computed tomography study of bone regeneration in the maxillary sinus comparing biphasic calcium phosphate and deproteinized cancellous bovine bone in a human split-mouth model

    NARCIS (Netherlands)

    de Lange, G.L.; Overman, J.R.; Farre-Guasch, E.; Korstjens, C.M.; Hartman, B.; Langenbach, G.E.J.; van Duin, M.A.; Klein-Nulend, J.

    2014-01-01

    Objective The gain of mineralized bone was compared between deproteinized bovine bone allograft (DBA) and biphasic calcium phosphate (BCP) for dental implant placement. Study Design Five patients with atrophic maxillae underwent bilateral sinus elevation with DBA (Bio-Oss) and BCP (Straumann

  20. Comparison of bioengineered human bone construct from four sources of osteogenic cells.

    Science.gov (United States)

    Ng, Angela Min-Hwei; Saim, Aminuddin Bin; Tan, Kok-Keong; Tan, G H; Mokhtar, Sabarul Afian; Rose, Isa Mohamed; Othman, Fauziah; Idrus, Ruszymah Binti Haji

    2005-01-01

    Osteoprogenitor cells have been reported to be present in periosteum, cancellous and cortical bone, and bone marrow; but no attempt to identify the best cell source for bone tissue engineering has yet been reported. In this study, we aimed to investigate the growth and differentiation pattern of cells derived from these four sources in terms of cell doubling time and expression of osteoblast-specific markers in both monolayer cells and three-dimensional cell constructs in vitro. In parallel, human plasma derived-fibrin was evaluated for use as biomaterial when forming three-dimensional bone constructs. Our findings showed osteoprogenitor cells derived from periosteum to be most proliferative followed by cortical bone, cancellous bone, and then bone marrow aspirate. Bone-forming activity was observed in constructs formed with cells derived from periosteum, whereas calcium deposition was seen throughout the constructs formed with cells derived from cancellous and cortical bones. Although no mineralization activity was seen in constructs formed with osteoprogenitor cells derived from bone marrow, well-organized lacunae as would appear in the early phase of bone reconstruction were noted. Scanning electron microscopy evaluation showed cell proliferation throughout the fibrin matrix, suggesting the possible application of human fibrin as the bioengineered tissue scaffold at non-load-bearing sites.

  1. A case for bone canaliculi as the anatomical site of strain generated potentials

    Science.gov (United States)

    Cowin, S. C.; Weinbaum, S.; Zeng, Y.

    1995-01-01

    We address the question of determining the anatomical site that is the source of the experimentally observed strain generated potentials (SGPs) in bone tissue. There are two candidates for the anatomical site that is the SGP source, the collagen-hydroxyapatite porosity and the larger size lacunar-canalicular porosity. In the past it has been argued, on the basis of experimental data and a reasonable model, that the site of the SGPs in bone is the collagen-hydroxyapatite porosity. The theoretically predicted pore radius necessary for the SGPs to reside in this porosity is 16 nm, which is somewhat larger than the pore radii estimated from gas adsorption data where the preponderance of the pores were estimated to be in the range 5-12.5 nm. However, this pore size is significantly larger than the 2 nm size of the small tracer, microperoxidase, which appears to be excluded from the mineralized matrix. In this work a similar model, but one in which the effects of fluid dynamic drag of the cell surface matrix in the bone canaliculi are included, is used to show that it is possible for the generation of SGPs to be associated with the larger size lacunar-canalicular porosity when the hydraulic drag and electrokinetic contribution of the bone fluid passage through the cell coat (glycocalyx) is considered. The consistency of the SGP data with this model is demonstrated. A general boundary condition is introduced to allow for current leakage at the bone surface. The results suggest that the current leakage is small for the in vitro studies in which the strain generated potentials have been measured.

  2. Paleopathological analysis of changes on animal bones originating from archaeological sites Caricin Grad and Studenica Monastery

    Directory of Open Access Journals (Sweden)

    Marković Nemanja

    2014-01-01

    Full Text Available This work presents the estimation of incidence and analysis of paleopathological changes on skeletal remains of the animals from archaeological sites Caricin Grad and Studenica Monastery. Moreover, there has been carried out the assessment of the skeletal elements, as well as taxonomic and age determination. The total of 2595 bones or bone fragments were examined. In 22 specimens there were noticed various abnormal skeletal changes in following animal species: cattle, sheep, goats, pigs, horses, donkeys and camels. Pathological changes were noticed on the teeth, mandibles, joints of long bones and phalanxes. By macroscopic analysis of these acquired pathological changes on bones of the animals, there was determined that the observed lesions had had proliferative, hypertrophic and chronic character. Proliferative changes on the bones of the cattle, horses, donkeys and camels point out to the fact that these animals were used for towing and/or load carrying. Identified diseases of oral cavity in small ruminants point out to improper and inadequate nutrition of these animals in the past.

  3. SPECIFIC SITES OF BONE EXPANSION DEPEND ON THE LEVEL OF VOLLEYBALL PRACTICE IN PREPUBESCENT BOYS

    Directory of Open Access Journals (Sweden)

    Hamada Chaari

    2013-06-01

    Full Text Available The purpose of this study was to investigate the effect of 18 months of high and low levels of volleyball practice on bone acquisition. 130 prepubescent boys (mean age 11.4 ± 0.7 were divided into a high-level training group (HLG, low-level training group (LLG, and controls. Bone mineral content (BMC and bone area at the whole body, lumbar spine L2-L4, femoral neck of the dominant leg, and right and left radius were measured using dual-photon X-ray absorptiometry. Enhanced BMC resulted from high-training volleyball activity in all measured sites except the third left and right distal radius, which is not modified by low-level training in prepubescent players but it was accompanied by a bone area expansion in radius and weight-bearing sites for the HLG, and in legs, whole right and left radius for the LLG. Significant improvement of skeletal tissues is associated with the intensity and duration of volleyball training.

  4. Bone volume fraction and structural parameters for estimation of mechanical stiffness and failure load of human cancellous bone samples; in-vitro comparison of ultrasound transit time spectroscopy and X-ray μCT.

    Science.gov (United States)

    Alomari, Ali Hamed; Wille, Marie-Luise; Langton, Christian M

    2018-02-01

    Conventional mechanical testing is the 'gold standard' for assessing the stiffness (N mm -1 ) and strength (MPa) of bone, although it is not applicable in-vivo since it is inherently invasive and destructive. The mechanical integrity of a bone is determined by its quantity and quality; being related primarily to bone density and structure respectively. Several non-destructive, non-invasive, in-vivo techniques have been developed and clinically implemented to estimate bone density, both areal (dual-energy X-ray absorptiometry (DXA)) and volumetric (quantitative computed tomography (QCT)). Quantitative ultrasound (QUS) parameters of velocity and attenuation are dependent upon both bone quantity and bone quality, although it has not been possible to date to transpose one particular QUS parameter into separate estimates of quantity and quality. It has recently been shown that ultrasound transit time spectroscopy (UTTS) may provide an accurate estimate of bone density and hence quantity. We hypothesised that UTTS also has the potential to provide an estimate of bone structure and hence quality. In this in-vitro study, 16 human femoral bone samples were tested utilising three techniques; UTTS, micro computed tomography (μCT), and mechanical testing. UTTS was utilised to estimate bone volume fraction (BV/TV) and two novel structural parameters, inter-quartile range of the derived transit time (UTTS-IQR) and the transit time of maximum proportion of sonic-rays (TTMP). μCT was utilised to derive BV/TV along with several bone structure parameters. A destructive mechanical test was utilised to measure the stiffness and strength (failure load) of the bone samples. BV/TV was calculated from the derived transit time spectrum (TTS); the correlation coefficient (R 2 ) with μCT-BV/TV was 0.885. For predicting mechanical stiffness and strength, BV/TV derived by both μCT and UTTS provided the strongest correlation with mechanical stiffness (R 2 =0.567 and 0.618 respectively) and

  5. Addition of Adipose-Derived Stem Cells to Mesenchymal Stem Cell Sheets Improves Bone Formation at an Ectopic Site

    Directory of Open Access Journals (Sweden)

    Zhifa Wang

    2016-02-01

    Full Text Available To determine the effect of adipose-derived stem cells (ADSCs added to bone marrow-derived mesenchymal stem cell (MSC sheets on bone formation at an ectopic site. We isolated MSCs and ADSCs from the same rabbits. We then prepared MSC sheets for implantation with or without ADSCs subcutaneously in the backs of severe combined immunodeficiency (SCID mice. We assessed bone formation at eight weeks after implantation by micro-computed tomography and histological analysis. In osteogenic medium, MSCs grew to form multilayer sheets containing many calcium nodules. MSC sheets without ADSCs formed bone-like tissue; although neo-bone and cartilage-like tissues were sparse and unevenly distributed by eight weeks after implantation. In comparison, MSC sheets with ADSCs promoted better bone regeneration as evidenced by the greater density of bone, increased mineral deposition, obvious formation of blood vessels, large number of interconnected ossified trabeculae and woven bone structures, and greater bone volume/total volume within the composite constructs. Our results indicate that although sheets of only MSCs have the potential to form tissue engineered bone at an ectopic site, the addition of ADSCs can significantly increase the osteogenic potential of MSC sheets. Thus, the combination of MSC sheets with ADSCs may be regarded as a promising therapeutic strategy to stimulate bone regeneration.

  6. Auger electron spectroscopy for the determination of sex and age related Ca/P ratio at different bone sites

    International Nuclear Information System (INIS)

    Balatsoukas, Ioannis; Kourkoumelis, Nikolaos; Tzaphlidou, Margaret

    2010-01-01

    The Ca/P ratio of normal cortical and trabecular rat bone was measured by Auger electron spectroscopy (AES). Semiquantitative analysis was carried out using ratio techniques to draw conclusions on how age, sex and bone site affect the relative composition of calcium and phosphorus. Results show that Ca/P ratio is not sex dependent; quite the opposite, bone sites exhibit variations in elemental stoichiometry where femoral sections demonstrate higher Ca/P ratio than rear and front tibias. Age-related changes are more distinct for cortical bone in comparison with the trabecular bone. The latter's Ca/P ratio remains unaffected from all the parameters under study. This study confirms that AES is able to successfully quantify bone mineral main elements when certain critical points, related to the experimental conditions, are addressed effectively.

  7. Influence of Piezosurgery on Bone Healing around Titanium Implants: A Histological Study in Rats.

    Science.gov (United States)

    Sirolli, Marcelo; Mafra, Carlos Eduardo Secco; Santos, Rodrigo Albuquerque Basílio Dos; Saraiva, Luciana; Holzhausen, Marinella; César, João Batista

    2016-01-01

    The aim of this study was to evaluate histomorphometrically the influence of two techniques of dental implant site preparation on bone healing around titanium implants. Fifteen male Wistar rats (±300 g) were used in the study. Each tibia was randomly assigned to receive the implant site preparation either with a conventional drilling technique (control - DRILL group) or with a piezoelectric device (PIEZO group). The animals were sacrificed after 30 days and then the following histomorphometric parameters were evaluated (percentage) separately for cortical and cancellous regions: proportion of mineralized tissue (PMT) adjacent to implant threads (500 μm adjacent); bone area within the threads (BA) and bone-implant contact (BIC). The results demonstrated that there were no statistically significant differences between both groups for cancellous BIC (p>0.05) and cortical PMT (p>0.05). On the other hand, a higher percentage of BA was observed in the PIEZO group in the cortical (71.50±6.91 and 78.28±4.38 for DRILL and PIEZO groups, respectively; ppiezosurgery also showed higher PMT values in the cancellous zone (9.35±5.54 and 18.72±13.21 for DRILL and PIEZO groups, respectively; ppiezosurgery was beneficial to bone healing rates in the cancellous bone region, while the drill technique produced better results in the cortical bone.

  8. Scaling relations between trabecular bone volume fraction and microstructure at different skeletal sites.

    Science.gov (United States)

    Räth, Christoph; Baum, Thomas; Monetti, Roberto; Sidorenko, Irina; Wolf, Petra; Eckstein, Felix; Matsuura, Maiko; Lochmüller, Eva-Maria; Zysset, Philippe K; Rummeny, Ernst J; Link, Thomas M; Bauer, Jan S

    2013-12-01

    In this study, we investigated the scaling relations between trabecular bone volume fraction (BV/TV) and parameters of the trabecular microstructure at different skeletal sites. Cylindrical bone samples with a diameter of 8mm were harvested from different skeletal sites of 154 human donors in vitro: 87 from the distal radius, 59/69 from the thoracic/lumbar spine, 51 from the femoral neck, and 83 from the greater trochanter. μCT images were obtained with an isotropic spatial resolution of 26μm. BV/TV and trabecular microstructure parameters (TbN, TbTh, TbSp, scaling indices ( and σ of α and αz), and Minkowski Functionals (Surface, Curvature, Euler)) were computed for each sample. The regression coefficient β was determined for each skeletal site as the slope of a linear fit in the double-logarithmic representations of the correlations of BV/TV versus the respective microstructure parameter. Statistically significant correlation coefficients ranging from r=0.36 to r=0.97 were observed for BV/TV versus microstructure parameters, except for Curvature and Euler. The regression coefficients β were 0.19 to 0.23 (TbN), 0.21 to 0.30 (TbTh), -0.28 to -0.24 (TbSp), 0.58 to 0.71 (Surface) and 0.12 to 0.16 (), 0.07 to 0.11 (), -0.44 to -0.30 (σ(α)), and -0.39 to -0.14 (σ(αz)) at the different skeletal sites. The 95% confidence intervals of β overlapped for almost all microstructure parameters at the different skeletal sites. The scaling relations were independent of vertebral fracture status and similar for subjects aged 60-69, 70-79, and >79years. In conclusion, the bone volume fraction-microstructure scaling relations showed a rather universal character. © 2013.

  9. Predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography intensity values

    OpenAIRE

    Alkhader, Mustafa; Hudieb, Malik; Khader, Yousef

    2017-01-01

    Objective: The aim of this study was to investigate the predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography (CBCT) intensity values. Materials and Methods: CBCT cross-sectional images for 436 posterior mandibular implant sites were selected for the study. Using Invivo software (Anatomage, San Jose, California, USA), two observers classified the bone density into three categories: low, intermediate, and high, and CBCT intensity values were g...

  10. Combined nanoindentation testing and scanning electron microscopy of bone and articular calcified cartilage in an equine fracture predilection site

    OpenAIRE

    M Doube; EC Firth; A Boyde; AJ Bushby

    2010-01-01

    Condylar fracture of the third metacarpal bone (Mc3) is the commonest cause of racetrack fatality in Thoroughbred horses. Linear defects involving hyaline articular cartilage, articular calcified cartilage (ACC) and subchondral bone (SCB) have been associated with the fracture initiation site, which lies in the sagittal grooves of the Mc3 condyle. We discovered areas of thickened and abnormally-mineralised ACC in the sagittal grooves of several normal 18-month-old horses, at the same site tha...

  11. Plutonium and uranium in human bones from areas surrounding the Semipalatinsk nuclear test site.

    Science.gov (United States)

    Yamamoto, Masayoshi; Hoshi, Masaharu; Sakaguchi, Aya; Shinohara, Kunihiko; Kurihara, Osamu; Apsalikov, Kazbek N; Gusev, Boris I

    2006-02-01

    To evaluate the present levels of 239,240Pu and U in residents living near the Semipalatinsk nuclear test site, more than 70 bone samples were obtained at autopsy. The subjects ranged in age from 30 to 86 years (mean 59.3+/-12.9). Most of the samples consisted of victims who died of various diseases. Plutonium and U were radiochemically separated and determined by alpha-ray spectrometry. The mean concentrations of 239,240Pu and 238U observed were 0.050+/-0.041 mBq/g-ash (vertebrae 71, long-bones 18) and 0.28+/-0.13 mBq/g-ash (22.8+/-10.6 microg U/kg-ash) (vertebrae 58, long bones 16), respectively. The present 239,240Pu levels were within the range found for human bone samples from other countries due solely to global fallout in the early 1980s. The average U concentration was close to the estimate (mean 22.5 microg U/kg-ash) for the UK, and about 10 times higher than those estimated for residents in New York City and Japan. By assuming that the average concentration of 239,240Pu in bone samples is the value at 45 years after instantaneous inhalation in 1955, the initial total intake and the effective dose for 45 years were estimated as 10 Bq and 0.2 mSv, respectively. The annual intake of total U (234,235,238U) and its effective dose for 60 years were estimated as 30 Bq for adult and 0.1 mSv, respectively, for chronic ingestion.

  12. A decorated raven bone from the Zaskalnaya VI (Kolosovskaya) Neanderthal site, Crimea

    Science.gov (United States)

    Evans, Sarah; Stepanchuk, Vadim; Tsvelykh, Alexander; d’Errico, Francesco

    2017-01-01

    We analyze a radius bone fragment of a raven (Corvus corax) from Zaskalnaya VI rock shelter, Crimea. The object bears seven notches and comes from an archaeological level attributed to a Micoquian industry dated to between 38 and 43 cal kyr BP. Our study aims to examine the degree of regularity and intentionality of this set of notches through their technological and morphometric analysis, complemented by comparative experimental work. Microscopic analysis of the notches indicate that they were produced by the to-and-fro movement of a lithic cutting edge and that two notches were added to fill in the gap left between previously cut notches, probably to increase the visual consistency of the pattern. Multivariate analysis of morphometric data recorded on the archaeological notches and sets of notches cut by nine modern experimenters on radii of domestic turkeys shows that the variations recorded on the Zaskalnaya set are comparable to experimental sets made with the aim of producing similar, parallel, equidistant notches. Identification of the Weber Fraction, the constant that accounts for error in human perception, for equidistant notches cut on bone rods and its application to the Zaskalnaya set of notches and thirty-six sets of notches incised on seventeen Upper Palaeolithic bone objects from seven sites indicate that the Zaskalnaya set falls within the range of variation of regularly spaced experimental and Upper Palaeolithic sets of notches. This suggests that even if the production of the notches may have had a utilitarian reason the notches were made with the goal of producing a visually consistent pattern. This object represents the first instance of a bird bone from a Neanderthal site bearing modifications that cannot be explained as the result of butchery activities and for which a symbolic argument can be built on direct rather than circumstantial evidence. PMID:28355292

  13. A decorated raven bone from the Zaskalnaya VI (Kolosovskaya) Neanderthal site, Crimea.

    Science.gov (United States)

    Majkić, Ana; Evans, Sarah; Stepanchuk, Vadim; Tsvelykh, Alexander; d'Errico, Francesco

    2017-01-01

    We analyze a radius bone fragment of a raven (Corvus corax) from Zaskalnaya VI rock shelter, Crimea. The object bears seven notches and comes from an archaeological level attributed to a Micoquian industry dated to between 38 and 43 cal kyr BP. Our study aims to examine the degree of regularity and intentionality of this set of notches through their technological and morphometric analysis, complemented by comparative experimental work. Microscopic analysis of the notches indicate that they were produced by the to-and-fro movement of a lithic cutting edge and that two notches were added to fill in the gap left between previously cut notches, probably to increase the visual consistency of the pattern. Multivariate analysis of morphometric data recorded on the archaeological notches and sets of notches cut by nine modern experimenters on radii of domestic turkeys shows that the variations recorded on the Zaskalnaya set are comparable to experimental sets made with the aim of producing similar, parallel, equidistant notches. Identification of the Weber Fraction, the constant that accounts for error in human perception, for equidistant notches cut on bone rods and its application to the Zaskalnaya set of notches and thirty-six sets of notches incised on seventeen Upper Palaeolithic bone objects from seven sites indicate that the Zaskalnaya set falls within the range of variation of regularly spaced experimental and Upper Palaeolithic sets of notches. This suggests that even if the production of the notches may have had a utilitarian reason the notches were made with the goal of producing a visually consistent pattern. This object represents the first instance of a bird bone from a Neanderthal site bearing modifications that cannot be explained as the result of butchery activities and for which a symbolic argument can be built on direct rather than circumstantial evidence.

  14. Papineau debridement, Ilizarov bone transport, and negative-pressure wound closure for septic bone defects of the tibia.

    Science.gov (United States)

    Karargyris, Orestis; Polyzois, Vasilios D; Karabinas, Panayiotis; Mavrogenis, Andreas F; Pneumaticos, Spyros G

    2014-08-01

    Ilizarov pioneered bone transport using a circular external fixator. Papineau described a staged technique for the treatment for infected pseudarthrosis of the long bones. This article presents a single-stage Papineau technique and Ilizarov bone transport, and postoperative negative-pressure wound dressing changes for septic bone defects of the tibia. We studied the files of seven patients (mean age, 32 years) with septic bone defects of the tibia treated with a Papineau technique and Ilizarov bone transport in a single stage, followed by postoperative negative-pressure wound dressing changes. All patients had septic pseudarthrosis and skin necrosis of the tibia. The technique included a single-stage extensive surgical debridement of necrotic bone, open bone grafting with cancellous bone autograft and bone transport, and postoperative negative-pressure wound dressing changes for wound closure. The mean time from the initial injury was 6 months (range, 4-8 months). The mean follow-up was 14 months (range, 10-17 months). All patients experienced successful wound healing at a mean of 29 days. Six patients experienced successful bone regeneration and union at the docking side at a mean of 6 months. One patient experienced delayed union at the docking site, which was treated with autologous cancellous bone grafting. Two patients experienced pin track infection, which was successfully treated with antibiotics and pin site dressing changes. All patients were able to return to their work and previous levels of activity, except one patient who had a stiff ankle joint and had to change his job. No patient experienced recurrence of infection, or fracture of the regenerated or transported bone segment until the period of this study. The combined Papineau and Ilizarov bone transport technique with negative-pressure wound closure provides for successful eradication of the infection, reconstruction of the bone defect, and soft-tissue closure. A single-stage surgical treatment is

  15. High-strength mineralized collagen artificial bone

    Science.gov (United States)

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

    2014-03-01

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

  16. Site-Directed Immobilization of Bone Morphogenetic Protein 2 to Solid Surfaces by Click Chemistry.

    Science.gov (United States)

    Siverino, Claudia; Tabisz, Barbara; Lühmann, Tessa; Meinel, Lorenz; Müller, Thomas; Walles, Heike; Nickel, Joachim

    2018-03-29

    Different therapeutic strategies for the treatment of non-healing long bone defects have been intensively investigated. Currently used treatments present several limitations that have led to the use of biomaterials in combination with osteogenic growth factors, such as bone morphogenetic proteins (BMPs). Commonly used absorption or encapsulation methods require supra-physiological amounts of BMP2, typically resulting in a so-called initial burst release effect that provokes several severe adverse side effects. A possible strategy to overcome these problems would be to covalently couple the protein to the scaffold. Moreover, coupling should be performed in a site-specific manner in order to guarantee a reproducible product outcome. Therefore, we created a BMP2 variant, in which an artificial amino acid (propargyl-L-lysine) was introduced into the mature part of the BMP2 protein by codon usage expansion (BMP2-K3Plk). BMP2-K3Plk was coupled to functionalized beads through copper catalyzed azide-alkyne cycloaddition (CuAAC). The biological activity of the coupled BMP2-K3Plk was proven in vitro and the osteogenic activity of the BMP2-K3Plk-functionalized beads was proven in cell based assays. The functionalized beads in contact with C2C12 cells were able to induce alkaline phosphatase (ALP) expression in locally restricted proximity of the bead. Thus, by this technique, functionalized scaffolds can be produced that can trigger cell differentiation towards an osteogenic lineage. Additionally, lower BMP2 doses are sufficient due to the controlled orientation of site-directed coupled BMP2. With this method, BMPs are always exposed to their receptors on the cell surface in the appropriate orientation, which is not the case if the factors are coupled via non-site-directed coupling techniques. The product outcome is highly controllable and, thus, results in materials with homogeneous properties, improving their applicability for the repair of critical size bone defects.

  17. Flux Cancellation Leading to CME Filament Eruptions

    Science.gov (United States)

    Popescu, Roxana M.; Panesar, Navdeep K.; Sterling, Alphonse C.; Moore, Ronald L.

    2016-01-01

    Solar filaments are strands of relatively cool, dense plasma magnetically suspended in the lower density hotter solar corona. They trace magnetic polarity inversion lines (PILs) in the photosphere below, and are supported against gravity at heights of up to approx.100 Mm above the chromosphere by the magnetic field in and around them. This field erupts when it is rendered unstable, often by magnetic flux cancellation or emergence at or near the PIL. We have studied the evolution of photospheric magnetic flux leading to ten observed filament eruptions. Specifically, we look for gradual magnetic changes in the neighborhood of the PIL prior to and during eruption. We use Extreme Ultraviolet (EUV) images from the Atmospheric Imaging Assembly (AIA), and magnetograms from the Helioseismic and Magnetic Imager (HMI), both on board the Solar Dynamics Observatory (SDO), to study filament eruptions and their photospheric magnetic fields. We examine whether flux cancellation or/and emergence leads to filament eruptions. We find that continuous flux cancellation was present at the PIL for many hours prior to each eruption. We present two CME-producing eruptions in detail and find the following: (a) the pre-eruption filament-holding core field is highly sheared and appears in the shape of a sigmoid above the PIL; (b) at the start of the eruption the opposite arms of the sigmoid reconnect in the middle above the site of (tether-cutting) flux cancellation at the PIL; (c) the filaments first show a slow-rise, followed by a fast-rise as they erupt. We conclude that these two filament eruptions result from flux cancellation in the middle of the sheared field, and thereafter evolve in agreement with the standard model for a CME/flare filament eruption from a closed bipolar magnetic field [flux cancellation (van Ballegooijen and Martens 1989 and Moore and Roumelrotis 1992) and runaway tether-cutting (Moore et. al 2001)].

  18. Adaptive noise cancellation

    International Nuclear Information System (INIS)

    Akram, N.

    1999-01-01

    In this report we describe the concept of adaptive noise canceling, an alternative method of estimating signals corrupted by additive noise of interference. The method uses 'primary' input containing the corrupted signal and a 'reference' input containing noise correlated in some unknown way with the primary noise, the reference input is adaptively filtered and subtracted from the primary input to obtain the signal estimate. Adaptive filtering before subtraction allows the treatment of inputs that are deterministic or stochastic, stationary or time variable. When the reference input is free of signal and certain other conditions are met then noise in the primary input can be essentially eliminated without signal distortion. It is further shown that the adaptive filter also acts as notch filter. Simulated results illustrate the usefulness of the adaptive noise canceling technique. (author)

  19. Geneva University - Cancelled

    CERN Multimedia

    Université de Genève

    2010-01-01

    École de physique - Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 GENEVA 4 Tel: (022) 379 62 73 - Fax: (022) 379 69 92 Monday 19 April 2010 17h00 - Stückelberg Auditorium Into the darkness: Simulating the distribution of dark matter in our Universe Prof. Volker Springel - Heidelberg Institute for Theoretical Studies   THE COLLOQUIUM IS CANCELLED. Prof. Markus Büttiker

  20. Generating cancelable fingerprint templates.

    Science.gov (United States)

    Ratha, Nalini K; Chikkerur, Sharat; Connell, Jonathan H; Bolle, Ruud M

    2007-04-01

    Biometrics-based authentication systems offer obvious usability advantages over traditional password and token-based authentication schemes. However, biometrics raises several privacy concerns. A biometric is permanently associated with a user and cannot be changed. Hence, if a biometric identifier is compromised, it is lost forever and possibly for every application where the biometric is used. Moreover, if the same biometric is used in multiple applications, a user can potentially be tracked from one application to the next by cross-matching biometric databases. In this paper, we demonstrate several methods to generate multiple cancelable identifiers from fingerprint images to overcome these problems. In essence, a user can be given as many biometric identifiers as needed by issuing a new transformation "key." The identifiers can be cancelled and replaced when compromised. We empirically compare the performance of several algorithms such as Cartesian, polar, and surface folding transformations of the minutiae positions. It is demonstrated through multiple experiments that we can achieve revocability and prevent cross-matching of biometric databases. It is also shown that the transforms are noninvertible by demonstrating that it is computationally as hard to recover the original biometric identifier from a transformed version as by randomly guessing. Based on these empirical results and a theoretical analysis we conclude that feature-level cancelable biometric construction is practicable in large biometric deployments.

  1. Radiocarbon reservoir between charred seeds and fish bone in Neolithic sites, northeastern Qinghai-Tibetan Plateau

    Science.gov (United States)

    Zhou, A.; Dong, G.; Ren, L.

    2017-12-01

    Many efforts have been done to understand the reservoir effect of Qinghai Lake, yet no agreement has been reached. Five archaeological sites, located around the junction between the estuary of Rivers and Qinghai Lake, are the earliest Neolithic Age sites in the Qinghai- Tibetan Plateau (QTP), which is critical for understanding patterns of prehistoric human inhabitation in the high plateau extreme environments. This study compares radiocarbon dates of fish bones and terrestrial plant remains uncovered from the same archaeological strata to see whether there was reservoir effect reference to reliable data. Results demonstrate that there were reservoir effects ranging from 300 to 600 years back to 3600 years ago, nevertheless, no reservoir was observed of the modern fish. Besides, stable isotopic analysis illustrated that modern fish consumed similar food to those of millennias ago.

  2. Effects of Implant-Associated Osteomyelitis on Cefuroxime Bone Pharmacokinetics

    DEFF Research Database (Denmark)

    Tøttrup, Mikkel; Bue, Mats; Koch, Janne

    2016-01-01

    Background: The prolonged antibiotic therapy that is often needed for successful management of osteomyelitis may be related to incomplete penetration of antibiotics into the target site. The objective of this study was to assess the effects of implant-associated osteomyelitis on cefuroxime...... cavity up to MICs of 2 mg/L compared with the other tissues, but the time was shorter for higher MICs.  Conclusions: Cefuroxime penetration into infected cancellous bone was incomplete but comparable with that in healthy bone. The destructive bone processes associated with acute osteomyelitis reduced...

  3. Comparison of Site-Specific Bone Mineral Densities between Endurance Runners and Sprinters in Adolescent Women

    Directory of Open Access Journals (Sweden)

    Aoi Ikedo

    2016-11-01

    Full Text Available We aimed to compare site-specific bone mineral densities (BMDs between adolescent endurance runners and sprinters and examine the relationship of fat-free mass (FFM and nutrient intake on BMD. In this cross-sectional study, 37 adolescent female endurance runners and sprinters (16.1 ± 0.8 years were recruited. BMD and FFM were assessed by dual-energy X-ray absorptiometry. Nutrient intake and menstrual state were evaluated by questionnaires. After adjusting for covariates, spine and total bone less head (TBLH BMDs were significantly higher in sprinters than endurance runners (TBLH, 1.02 ± 0.05 vs. 0.98 ± 0.06 g/cm2; spine, 0.99 ± 0.06 vs. 0.94 ± 0.06 g/cm2; p < 0.05. There was no significant difference between groups in other sites. The rate of menstrual abnormality was higher in endurance runners compared with sprinters (56.3% vs. 23.8%; p < 0.05. FFM was a significant covariate for BMD on all sites except the spine (p < 0.05. Dietary intake of vitamin D was identified as a significant covariate only for pelvic BMD (p < 0.05. The BMDs of different sites among endurance runners and sprinters were strongly related to FFM. However, the association of FFM with spine BMD cannot be explained by FFM alone. Other factors, including nutrition and/or mechanical loading, may affect the spine BMD.

  4. A cadaveric study of bone tissue temperature during pin site drilling utilizing fluoroptic thermography.

    Science.gov (United States)

    Muffly, Matthew; Winegar, Corbett; Miller, Mark Carl; Altman, Gregory

    2018-05-03

    Using fluoroptic thermography, temperature was measured during pin site drilling of intact cortical human cadaver bone with a combination of one-step drilling, graduated drilling, and one-step drilling with irrigation of 5.0 mm Schanz pins. A 1440 rpm constant force drilling was used to on tibial diaphyses while a sensor probe placed 0.5 mm adjacent to the drill hole measured temperature. Four drilling techniques on each of the tibial segments were performed: 3.5mm drill bit, 5.0mm Schanz pin, 5.0 mm Schanz pin in 3.5 mm pre-drilled entry site, 5.0 mm Schanz pin utilizing irrigation. One-step drilling using a 5.0 mm Schanz pin without irrigation produced a temperature that exceeded the threshold temperature for heat-induced injury in 5 of the 8 trials. With the other three drilling techniques, only one in24 trials produced a temperature that would result in thermal injury. This difference was found to be statistically significant (p = 0.003). The use of irrigation significantly reduced the maximum bone tissue temperature in one-step drilling of a 5.0 mm Schanz pin (p = 0.02). One-step drilling with a 3.5 mm drill bit achieved maximum temperature significantly faster than graduated drilling and drilling with irrigation using a 5.0 mm Schanz pin (p drilling with a 5.0 mm Schanz pin into cortical bone can produce temperatures that can lead to heat-induced injury. Irrigation alone can reduce the temperatures sufficiently to avoid damage. Pre-drilling can increase temperatures significantly but the extent of any injury should be small.

  5. Structural strength of cancellous specimens from bovine femur under cyclic compression

    Directory of Open Access Journals (Sweden)

    Kaori Endo

    2016-01-01

    Full Text Available The incidence of osteoporotic fractures was estimated as nine million worldwide in 2000, with particular occurrence at the proximity of joints rich in cancellous bone. Although most of these fractures spontaneously heal, some fractures progressively collapse during the early post-fracture period. Prediction of bone fragility during progressive collapse following initial fracture is clinically important. However, the mechanism of collapse, especially the gradual loss of the height in the cancellous bone region, is not clearly proved. The strength of cancellous bone after yield stress is difficult to predict since structural and mechanical strength cannot be determined a priori. The purpose of this study was to identify whether the baseline structure and volume of cancellous bone contributed to the change in cancellous bone strength under cyclic loading. A total of fifteen cubic cancellous bone specimens were obtained from two 2-year-old bovines and divided into three groups by collection regions: femoral head, neck, and proximal metaphysis. Structural indices of each 5-mm cubic specimen were determined using micro-computed tomography. Specimens were then subjected to five cycles of uniaxial compressive loading at 0.05 mm/min with initial 20 N loading, 0.3 mm displacement, and then unloading to 0.2 mm with 0.1 mm displacement for five successive cycles. Elastic modulus and yield stress of cancellous bone decreased exponentially during five loading cycles. The decrease ratio of yield stress from baseline to fifth cycle was strongly correlated with bone volume fraction (BV/TV, r = 0.96, p < 0.01 and structural model index (SMI, r = − 0.81, p < 0.01. The decrease ratio of elastic modulus from baseline to fifth cycle was also correlated with BV/TV (r = 0.80, p < 0.01 and SMI (r = − 0.78, p < 0.01. These data indicate that structural deterioration of cancellous bone is associated with bone strength after yield stress. This study suggests that

  6. Comparison of fracture site callus with iliac crest bone marrow as the source of plastic-adherent cells

    Directory of Open Access Journals (Sweden)

    Achmad Zaki

    2013-05-01

    Full Text Available Background: Red marrow has been described as the main source of mesenchymal stem cells although its aspiration and isolation from bone marrow was reported to have significant donor site morbidity. Since secondary bone healing occurs through formation of callus as the result of proliferation and differentiation of mesenchymal stem cells, callus may become alternative source for mesenchymal stem cells. In this study, we compared the number of plastic-adherent cells from fracture site callus and bone marrow of iliac crest after two and four weeks of culture.Methods: Sixteen New Zealand rabbits were fracturized at the femoral shaft. Then, these rabbits were taken care. After two weeks of fracturization, 3 mL iliac crest bone marrow aspiration and callus extraction of eight rabbits were cultured (group I. The other eight rabbits were treated equally after four weeks of fracturization (group II. Simultaneously, the cultures were observed after one and two weeks. Four weeks later, they were harvested. Cells were counted using Neubauer hemocytometer. The average number of cells between the sources and groups were statistically analyzed using the unpaired t-test. Results: In group I, there were 2.6 ± 0.1 x 104 cells in the culture of iliac crest bone marrow aspirate and 2.5 ± 0.1 x 104 cells in culture of callus extract from fracture site (p = 0.34. In group II, there were 2.7 ± 0.1 x 104 cells and 2.1 ± 0.1 x 104 cells, respectively (p < 0.001.Conclusion: Fracture site callus at the second week post-fracturization may be potential as source of plastic-adherent cells compared with iliac crest bone marrow. (Med J Indones. 2013;22:70-5Keywords: Bone marrow, fracture site callus, iliac crest, long bone, mesenchymal stem cell, plastic-adherent cells

  7. Predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography intensity values.

    Science.gov (United States)

    Alkhader, Mustafa; Hudieb, Malik; Khader, Yousef

    2017-01-01

    The aim of this study was to investigate the predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography (CBCT) intensity values. CBCT cross-sectional images for 436 posterior mandibular implant sites were selected for the study. Using Invivo software (Anatomage, San Jose, California, USA), two observers classified the bone density into three categories: low, intermediate, and high, and CBCT intensity values were generated. Based on the consensus of the two observers, 15.6% of sites were of low bone density, 47.9% were of intermediate density, and 36.5% were of high density. Receiver-operating characteristic analysis showed that CBCT intensity values had a high predictive power for predicting high density sites (area under the curve [AUC] =0.94, P < 0.005) and intermediate density sites (AUC = 0.81, P < 0.005). The best cut-off value for intensity to predict intermediate density sites was 218 (sensitivity = 0.77 and specificity = 0.76) and the best cut-off value for intensity to predict high density sites was 403 (sensitivity = 0.93 and specificity = 0.77). CBCT intensity values are considered useful for predicting bone density at posterior mandibular implant sites.

  8. Iliac Crest Donor Site for Children With Cleft Lip and Palate Undergoing Alveolar Bone Grafting: A Long-term Assessment.

    Science.gov (United States)

    Wheeler, Jonathan; Sanders, Megan; Loo, Stanley; Moaveni, Zac; Bartlett, Glenn; Keall, Heather; Pinkerton, Mark

    2016-05-01

    The authors aimed to accurately assess the donor site morbidity from iliac crest bone grafts for secondary bone grafting in patients with cleft lip and palate alveolar defects. Fifty patients between 3 months and 10 years following alveolar bone grafting for cleft lip and palate were entered into the study. Two-thirds of patients had no significant concerns about the donor site. The remaining third had some concerns about the appearance of their hips and less than 10% of patients expressing strong agreement with statements about concerns with shape, appearance, and self-consciousness about the iliac crest donor site. Examination findings showed the average length of scar being 5.4 cm and a third of patients having some minor palpable boney irregularities of the iliac crest. The authors found that the alveolar crest donor site is well tolerated by patients long term but has a measurable morbidity long term.

  9. [Progress of Masquelet technique to repair bone defect].

    Science.gov (United States)

    Yin, Qudong; Sun, Zhenzhong; Gu, Sanjun

    2013-10-01

    To summarize the progress of Masquelet technique to repair bone defect. The recent literature concerning the application of Masquelet technique to repair bone defect was extensively reviewed and summarized. Masquelet technique involves a two-step procedure. First, bone cement is used to fill the bone defect after a thorough debridement, and an induced membrane structure surrounding the spacer formed; then the bone cement is removed after 6-8 weeks, and rich cancellous bone is implanted into the induced membrane. Massive cortical bone defect is repaired by new bone forming and consolidation. Experiments show that the induced membrane has vascular system and is also rich in vascular endothelial growth factor, transforming growth factor beta1, bone morphogenetic protein 2, and bone progenitor cells, so it has osteoinductive property; satisfactory results have been achieved in clinical application of almost all parts of defects, various types of bone defect and massive defect up to 25 cm long. Compared with other repair methods, Masquelet technique has the advantages of reliable effect, easy to operate, few complications, low requirements for recipient site, and wide application. Masquelet technique is an effective method to repair bone defect and is suitable for various types of bone defect, especially for bone defects caused by infection and tumor resection.

  10. Fixador esquelético pino-resina acrílica e enxerto ósseo esponjoso no tratamento de complicações secundárias à imobilização inadequada de fratura do rádio e ulna em cães Acrylic-pin external fixator and cancellous bone graft in the treatment of complications caused by inadequate immobilization of radius and ulna fracture in dogs

    Directory of Open Access Journals (Sweden)

    Sheila Canevese Rahal

    2005-10-01

    Full Text Available O objetivo do estudo foi avaliar a eficácia do fixador esquelético pino-resina, configuração tipo II, coadjuvado pelo enxerto ósseo esponjoso autólogo, no tratamento das complicações secundárias à imobilização inadequada de fraturas do rádio e ulna em 10 cães, com peso entre 1,8 e 33,6 kg. Detectou-se não-união (n=4, osteomielite (n=1, má-união (n=1, falência ou quebra de implante (n=4, sendo 60% das lesões referente ao uso prévio de pino intramedular no rádio. A montagem do fixador foi realizada com transfixação de pinos lisos em sua maioria angulados, cujas extremidades excedentes foram dobradas e estabilizadas com resina acrílica. Em todos os casos, utilizou-se enxerto esponjoso autólogo fresco, após debridamento do foco de fratura. O tempo de permanência do aparelho variou entre 45 dias e 5 meses e a maior complicação foi o afrouxamento dos pinos transfixantes. A consolidação das fraturas ocorreu por formação de calo periosteal de mínimo a moderado, indicando boa rigidez da montagem.The aim of this study was to evaluate the acrylic-pin external fixator, type II-configuration, and cancellous bone autograft for treating complications of radius and ulna fractures in 10 dogs weighing between 1.8 and 33.6 kg. Nonunion (n=4, osteomyelitis (n=1, malunion (n=1, failure or breakage of implant (n=4 were detected, and 60 % of them were associated with previous intramedullary pin placement in the radius. The fixator frame was constructed using most of the smooth transfixation pins angled. The fixation rods were constructed by placing acrylic resin over the ends of the transfixation pins that were previously bent. In all cases fresh cancellous bone autograft was used after cleaning of the fracture site. The permanence time of the external fixator ranged from 45 days to 5 months, and the most important complication was pin loosening. Fracture healing was by minimal to moderate periosteal callus, suggesting good rigidity

  11. Mass and elemental concentrations of air bone particles at Kuala Lumpur site in 2000 to 2006

    International Nuclear Information System (INIS)

    Abdul Khalik Wood; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman

    2008-01-01

    Atmospheric Pollution due to air bone particle is a major concern to many cities in the Southeast Asian region, including Kuala Lumpur. Within the last six years air particulate samples have been collected from a site in Kuala Lumpur and measured for their PM10, PM2.5 and elemental concentrations. The results showed that the daily PM10 (<10μ diameter) concentrations were generally acceptable but the values occasionally very high, especially during the haze episodes. The PM10 annual average values were just below the national set standard and these values were mostly contributed by the fine particles (<2μ diameter) concentration. The annual average for PM2.5 (fine particle) concentrations over the past few years were considerably high where elemental carbon, sulfur and potassium were the main components. (Author)

  12. The indications and donor-site morbidity of tibial cortical strut autografts in the management of defects in long bones.

    Science.gov (United States)

    Lauthe, O; Soubeyrand, M; Babinet, A; Dumaine, V; Anract, P; Biau, D J

    2018-05-01

    Aims The primary aim of this study was to determine the morbidity of a tibial strut autograft and characterize the rate of bony union following its use. Patients and Methods We retrospectively assessed a series of 104 patients from a single centre who were treated with a tibial strut autograft of > 5 cm in length. A total of 30 had a segmental reconstruction with continuity of bone, 27 had a segmental reconstruction without continuity of bone, 29 had an arthrodesis and 18 had a nonunion. Donor-site morbidity was defined as any event that required a modification of the postoperative management. Union was assessed clinically and radiologically at a median of 36 months (IQR, 14 to 74). Results Donor-site morbidity occurred in four patients (4%; 95% confidence interval (CI) 1 to 10). One patient had a stress fracture of the tibia, which healed with a varus deformity, requiring an osteotomy. Two patients required evacuation of a haematoma and one developed anterior compartment syndrome which required fasciotomies. The cumulative probability of union was 90% (95% CI 80 to 96) at five years. The type of reconstruction (p = 0.018), continuity of bone (p = 0.006) and length of tibial graft (p = 0.037) were associated with the time to union. Conclusion The tibial strut autograft has a low risk of morbidity and provides adequate bone stock for treating various defects of long bones. Cite this article: Bone Joint J 2018;100-B:667-74.

  13. 48 CFR 552.238-73 - Cancellation.

    Science.gov (United States)

    2010-10-01

    ... may cancel this contract in whole or in part by providing written notice. The cancellation will take... elects to cancel this contract, the Government will not reimburse the minimum guarantee. (End of clause) ...

  14. Special proliferative sites are not needed for seeding and proliferation of transfused bone marrow cells in normal syngeneic mice

    International Nuclear Information System (INIS)

    Brecher, G.; Ansell, J.D.; Micklem, H.S.; Tjio, J.H.; Cronkite, E.P.

    1982-01-01

    The widely held view that transfused bone marrow cells will not proliferate in normal mice, not exposed to irradiation or other forms of bone marrow ablation, was reinvestigated. Forty million bone marrow cells from male donors were given to female recipients on each of 5 consecutive days, 5 to 10 times the number customarily used in the past. When the recipients were examined 2-13 weeks after the last transfusion, donor cells were found to average 16-25% of total marrow cells. Similar percentages of donor cells were found when variants of the enzyme phosphoglycerate kinase determined electrophoretically were used for identification of donor and recipient cells. Evidence is presented that the proportion of donor cells is compatible with a nonlinear dependence on the number of cells transfused over the range tested - i.e., 20-200 million bone marrow cells injected intravenously. Special proliferative sites thus do not appear to be required

  15. Cortical and trabecular bone microstructure did not recover at weight-bearing skeletal sites and progressively deteriorated at non-weight-bearing sites during the year following international space station missions

    NARCIS (Netherlands)

    Vico, L.; van Rietbergen, B.; Vilayphiou, N.; Linossier, M.T.; Locrelle, H.; Normand, M.; Zouch, M.; Gerbaix, M.; Bonnet, N.; Novikov, V.; Thomas, T.; Vassilieva, G.

    2017-01-01

    Risk for premature osteoporosis is a major health concern in astronauts and cosmonauts; the reversibility of the bone lost at the weight-bearing bone sites is not established, although it is suspected to take longer than the mission length. The bone three-dimensional structure and strength that

  16. The temporal course of mucoperiosteal flap revascularization at guided bone regeneration treated implant sites: a pilot study

    NARCIS (Netherlands)

    Milstein, D.M.J.; Mathura, K.R.; Lindeboom, J.A.H.; Ramsoekh, D.; Lindeboom, R.; Ince, C.

    2009-01-01

    Aims: To investigate post-operative capillary density regeneration in healing mucoperiosteal flaps at guided bone regeneration-treated implant sites. Material and Methods: A non-invasive post-operative investigation was performed in 10 patients using orthogonal polarization spectral (OPS) imaging

  17. The temporal course of mucoperiosteal flap revascularization at guided bone regeneration-treated implant sites: a pilot study

    NARCIS (Netherlands)

    Milstein, Dan M. J.; Mathura, Keshen R.; Lindeboom, Jerôme A. H.; Ramsoekh, Dewkoemar; Lindeboom, Robert; Ince, Can

    2009-01-01

    P>Aims To investigate post-operative capillary density regeneration in healing mucoperiosteal flaps at guided bone regeneration-treated implant sites. Material and Methods A non-invasive post-operative investigation was performed in 10 patients using orthogonal polarization spectral (OPS) imaging

  18. Eliciting Cervical Vestibular-Evoked Myogenic Potentials by Bone-Conducted Vibration via Various Tapping Sites.

    Science.gov (United States)

    Tseng, Chia-Chen; Young, Yi-Ho

    2016-01-01

    This study compared bone-conducted vibration (BCV) cervical vestibular-evoked myogenic potentials (cVEMPs) via tapping at various skull sites in healthy subjects and patients with vestibular migraine (VM) to optimize stimulation conditions. Twenty healthy subjects underwent a series of cVEMP tests by BCV tapping via a minishaker at the Fz (forehead), Cz (vertex), and inion (occiput) sites in a randomized order of tapping sites. Another 20 VM patients were also enrolled in this study for comparison. All 20 healthy subjects had clear BCV cVEMPs when tapping at the inion (100%) or Cz (100%), but not at the Fz (75%). Mean p13 and n23 latencies from the Cz tapping were significantly longer than those from the Fz tapping, but not longer than those from the inion tapping. Unlike healthy subjects, tapping at the Cz (95%) elicited a significantly higher response rate of present cVEMPs than tapping at the inion (78%) in 20 VM patients (40 ears), because seven of nine VM ears with absent cVEMPs by inion tapping turned out to be present cVEMPs by Cz tapping. While both inion and Cz tapping elicited 100% response rate of cVEMPs for healthy individuals, Cz tapping had a higher response rate of cVEMPs than inion tapping for the VM group. In cases of total loss of saccular function, cVEMPs could not be activated by either inion or Cz tapping. However, if residual saccular function remains, Cz tapping may activate saccular afferents more efficiently than inion tapping.

  19. Piezoelectricity could predict sites of formation/resorption in bone remodelling and modelling.

    Science.gov (United States)

    Fernández, J R; García-Aznar, J M; Martínez, R

    2012-01-07

    We have developed a mathematical approach for modelling the piezoelectric behaviour of bone tissue in order to evaluate the electrical surface charges in bone under different mechanical conditions. This model is able to explain how bones change their curvature, where osteoblasts or osteoclasts could detect in the periosteal/endosteal surfaces the different electrical charges promoting bone formation or resorption. This mechanism also allows to understand the BMU progression in function of the electro-mechanical bone behaviour. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. The temporal bones from Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain). A phylogenetic approach.

    Science.gov (United States)

    Martínez, I; Arsuaga, J L

    1997-01-01

    Three well-preserved crania and 22 temporal bones were recovered from the Sima de los Huesos Middle Pleistocene site up to and including the 1994 field season. This is the largest sample of hominid temporal bones known from a single Middle Pleistocene site and it offers the chance to characterize the temporal bone morphology of an European Middle Pleistocene population and to study the phylogenetic relationships of the SH sample with other Upper and Middle Pleistocene hominids. We have carried out a cladistic analysis based on nine traits commonly used in phylogenetic analysis of Middle and Late Pleistocene hominids: shape of the temporal squama superior border, articular eminence morphology, contribution of the sphenoid bone to the median glenoid wall, postglenoid process projection, tympanic plate orientation, presence of the styloid process, mastoid process projection, digastric groove morphology and anterior mastoid tubercle. We have found two autapomorphies on the Home erectus temporal bone: strong reduction of the postglenoid process and absence of the styloid process. Modern humans, Neandertals and the Middle Pleistocene fossils from Europe and Africa constitute a clade characterized by a convex superior border of the temporal squama. The European Middle Pleistocene fossils from Sima de los Huesos, Petralona, Steinheim, Bilzingsleben and Castel di Guido share a Neandertal apomorphy: a relatively flat articular eminence. The fossils from Ehringsdorf, La Chaise Suardi and Biache-Saint-Vaast also display another Neandertal derived trait: an anteriorly obliterated digastric groove. Modern humans and the African Middle Pleistocene fossils share a synapomorphy: a sagittally orientated tympanic plate.

  1. Low cortical bone density measured by computed tomography in children and adolescents with untreated hyperthyroidism.

    Science.gov (United States)

    Numbenjapon, Nawaporn; Costin, Gertrude; Gilsanz, Vicente; Pitukcheewanont, Pisit

    2007-05-01

    To determine whether increased thyroid hormones levels have an effect on various bone components (cortical vs cancellous bone). The anthropometric and 3-dimensional quantitative computed tomography (CT) bone measurements, including bone density (BD), cross-sectional area (CSA) of the lumbar spine and femur, and cortical bone area (CBA) of the femur, of 18 children and adolescents with untreated hyperthyroidism were reviewed and compared with those of age-, sex-, and ethnicity-matched historical controls. No significant differences in height, weight, body mass index (BMI), or pubertal staging between patients and controls were found. Cortical BD was significantly lower (P hyperthyroidism compared with historical controls. After adjusting for weight and height, no difference in femur CSA between hyperthyroid children and historical controls was evident. No significant correlations among thyroid hormone levels, antithyroid antibody levels, and cortical BD values were found. As determined by CT, cortical bone is the preferential site of bone loss in children and adolescents with untreated hyperthyroidism.

  2. Animal Bone Remnants from Trench CLXII of the Bolgar City Site: Some New Methods of Archaeozoological Materials Processing and Evaluation

    Directory of Open Access Journals (Sweden)

    Yavorskaya Lilia V.

    2012-03-01

    Full Text Available It is for the first time in the study of animal bone remnants from the Bolgar city site that modern techniques have been applied, which have made it possible to solve archaeological and historical problems rather than purely biological ones. A detailed description of the work process based on these techniques and of the results obtained is offered. In particular, it has been found out that the cattle intended for slaughter in Bolgar had not been bred within the city limits but rather supplied from outside. Also for the first time, a change in the distribution structure of finds of wild animals’ bones as per chronological periods has been recorded.

  3. Effects of cast-mediated immobilization on bone mineral mass at various sites in adolescents with lower-extremity fracture.

    Science.gov (United States)

    Ceroni, Dimitri; Martin, Xavier; Delhumeau, Cécile; Rizzoli, René; Kaelin, André; Farpour-Lambert, Nathalie

    2012-02-01

    Leg or ankle fractures occur commonly in the pediatric population and are primarily treated with closed reduction and cast immobilization. The most predictable consequences of immobilization and subsequent weight-bearing restriction are loss of bone mineral mass, substantial muscle atrophy, and functional limitations. The purposes of this study were to determine if lower-limb fractures in adolescents are associated with abnormal bone mineral density or content at the time of fracture, and to quantify bone mineral loss at various sites due to cast-mediated immobilization and limited weight-bearing. We recruited fifty adolescents aged ten to sixteen years who had undergone cast immobilization for a leg or ankle fracture. Dual x-ray absorptiometry scans of the total body, lumbar spine, hip, leg, and calcaneus were performed at the time of fracture and at cast removal. Patients with a fracture were paired with healthy controls according to sex and age. Values at baseline and at cast removal, or at equivalent time intervals in the control group, were compared between groups and between the injured and uninjured legs of the adolescents with the fracture. At the time of fracture, there were no observed differences in the bone mineral density or bone mineral content Z-scores of the total body or the lumbar spine, or in the bone mineral density Z-scores of the calcaneus, between the injured and healthy subjects. At cast removal, bone mineral parameters on the injured side were significantly lower than those on the uninjured side in the injured group. Differences ranged from -5.8% to -31.7% for bone mineral density and from -5.2% to -19.4% for bone mineral content. During the cast period, the injured adolescents had a significant decrease of bone mineral density at the hip, greater trochanter, calcaneus, and total lower limb as compared with the healthy controls. Lower-limb fractures are not related to osteopenia in adolescents at the time of fracture. However, osteopenia

  4. HUD Initiated Activity Cancellation Reports

    Data.gov (United States)

    Department of Housing and Urban Development — This monthly report displays all HOME activities automatically cancelled by IDIS. Effective January 1, 2011, and the beginning of every month thereafter, committed...

  5. Human hyoid bones from the middle Pleistocene site of the Sima de los Huesos (Sierra de Atapuerca, Spain).

    Science.gov (United States)

    Martínez, I; Arsuaga, J L; Quam, R; Carretero, J M; Gracia, A; Rodríguez, L

    2008-01-01

    This study describes and compares two hyoid bones from the middle Pleistocene site of the Sima de los Huesos in the Sierra de Atapuerca (Spain). The Atapuerca SH hyoids are humanlike in both their morphology and dimensions, and they clearly differ from the hyoid bones of chimpanzees and Australopithecus afarensis. Their comparison with the Neandertal specimens Kebara 2 and SDR-034 makes it possible to begin to approach the question of temporal variation and sexual dimorphism in this bone in fossil humans. The results presented here show that the degree of metric and anatomical variation in the fossil sample was similar in magnitude and kind to living humans. Modern hyoid morphology was present by at least 530 kya and appears to represent a shared derived feature of the modern human and Neandertal evolutionary lineages inherited from their last common ancestor.

  6. Primary clear cell sarcoma of bone: a unique site of origin

    International Nuclear Information System (INIS)

    Gelczer, R.K.; Wenger, D.E.; Wold, L.E.

    1999-01-01

    Clear cell sarcoma is a rare soft tissue neoplasm, accounting for less than 1% of soft tissue sarcomas. We are presenting a case of a clear cell sarcoma of bone which, to our knowledge, is the only report of a primary clear cell sarcoma of bone. (orig.)

  7. Bone Texture Fractal Dimension Analysis of Ultrasound-Treated Bone around Implant Site: A Double-Blind Clinical Trial

    Directory of Open Access Journals (Sweden)

    Elaf Akram Abdulhameed

    2018-01-01

    Full Text Available Objectives. To evaluate the efficacy of bone texture fractal dimension (FD analysis method in predicting implant stability from intraoral periapical radiographs using two implant protocols. Materials and Methods. A double-blind clinical trial was conducted on 22 subjects who needed dental implants. The participants were randomized into two groups, the control group with standard implant protocol treatment and the intervention group with added low-intensity power ultrasound treatment (LIPUS besides the standard implant protocol. The FD values of bone density were carried out on the mesial and distal sides of the implant on digital intraoral radiographs using the box-counting method. Both resonance frequency (RF and fractal dimension (FD were assessed in three time intervals: after surgery and before and after loading. Results. FD on both the mesial and distal sides serve as very good-to-excellent tests with high validity (ROC area exceeding 0.8 in predicting high implant stability (ISQ ≥ 70. The mesial side measurements were consistently better than the distal side among the intervention groups. The optimum cutoff value for the FD-mesial side that predicts a highly stable implant (ISQ ≥ 70 is ≥1.505. At this optimum cutoff value, the mesial side FD is associated with a perfect sensitivity (100% and fairly high specificity (86.5%. Conclusion. The FD analysis could be recommended as an adjunctive quantitative method in prediction of the implant stability with very high sensitivity and specificity. This trial is registered with ISRCTN72648040.

  8. Divergent Significance of Bone Mineral Density Changes in Aging Depending on Sites and Sex Revealed through Separate Analyses of Bone Mineral Content and Area

    Directory of Open Access Journals (Sweden)

    Yasumoto Matsui

    2012-01-01

    Full Text Available Bone mineral density (aBMD is equivalent to bone mineral content (BMC divided by area. We rechecked the significance of aBMD changes in aging by examining BMC and area separately. Subjects were 1167 community-dwelling Japanese men and women, aged 40–79 years. ABMDs of femoral neck and lumbar spine were assessed by DXA twice, at 6-year intervals. The change rates of BMC and area, as well as aBMD, were calculated and described separately by the age stratum and by sex. In the femoral neck region, aBMDs were significantly decreased in all age strata by an increase in area as well as BMC loss in the same pattern in both sexes. In the lumbar spine region, aBMDs decreased until the age of 60 in women, caused by the significant BMC decrease accompanying the small area change. Very differently in men, aBMDs increased after their 50s due to BMC increase, accompanied by an area increase. Separate analyses of BMC and area change revealed that the significance of aBMD changes in aging was very divergent among sites and between sexes. This may explain in part the dissociation of aBMD change and bone strength, suggesting that we should be more cautious when interpreting the meaning of aBMD change.

  9. The reliability of cone-beam computed tomography to assess bone density at dental implant recipient sites: a histomorphometric analysis by micro-CT.

    Science.gov (United States)

    González-García, Raúl; Monje, Florencio

    2013-08-01

    The aim of this study was to objectively assess the reliability of the cone-beam computed tomography (CBCT) as a tool to pre-operatively determine radiographic bone density (RBD) by the density values provided by the system, analyzing its relationship with histomorphometric bone density expressed as bone volumetric fraction (BV/TV) assessed by micro-CT of bone biopsies at the site of insertion of dental implants in the maxillary bones. Thirty-nine bone biopsies of the maxillary bones at the sites of 39 dental implants from 31 edentulous healthy patients were analyzed. The NobelGuide™ software was used for implant planning, which also allowed fabrication of individual stereolithographic surgical guides. The analysis of CBCT images allowed pre-operative determination of mean density values of implant recipient sites along the major axis of the planned implants (axial RBD). Stereolithographic surgical guides were used to guide implant insertion and also to extract cylindrical bone biopsies from the core of the exact implant site. Further analysis of several osseous micro-structural variables including BV/TV was performed by micro-CT of the extracted bone biopsies. Mean axial RBD was 478 ± 212 (range: 144-953). A statistically significant difference (P = 0.02) was observed among density values of the cortical bone of the upper maxilla and mandible. A high positive Pearson's correlation coefficient (r = 0.858, P micro-CT at the site of dental implants in the maxillary bones. Pre-operative estimation of density values by CBCT is a reliable tool to objectively determine bone density. © 2012 John Wiley & Sons A/S.

  10. Bone quality evaluation at dental implant site using multislice CT, micro-CT, and cone beam CT.

    Science.gov (United States)

    Parsa, Azin; Ibrahim, Norliza; Hassan, Bassam; van der Stelt, Paul; Wismeijer, Daniel

    2015-01-01

    The first purpose of this study was to analyze the correlation between bone volume fraction (BV/TV) and calibrated radiographic bone density Hounsfield units (HU) in human jaws, derived from micro-CT and multislice computed tomography (MSCT), respectively. The second aim was to assess the accuracy of cone beam computed tomography (CBCT) in evaluating trabecular bone density and microstructure using MSCT and micro-CT, respectively, as reference gold standards. Twenty partially edentulous human mandibular cadavers were scanned by three types of CT modalities: MSCT (Philips, Best, the Netherlands), CBCT (3D Accuitomo 170, J Morita, Kyoto, Japan), and micro-CT (SkyScan 1173, Kontich, Belgium). Image analysis was performed using Amira (v4.1, Visage Imaging Inc., Carlsbad, CA, USA), 3Diagnosis (v5.3.1, 3diemme, Cantu, Italy), Geomagic (studio(®) 2012, Morrisville, NC, USA), and CTAn (v1.11, SkyScan). MSCT, CBCT, and micro-CT scans of each mandible were matched to select the exact region of interest (ROI). MSCT HU, micro-CT BV/TV, and CBCT gray value and bone volume fraction of each ROI were derived. Statistical analysis was performed to assess the correlations between corresponding measurement parameters. Strong correlations were observed between CBCT and MSCT density (r = 0.89) and between CBCT and micro-CT BV/TV measurements (r = 0.82). Excellent correlation was observed between MSCT HU and micro-CT BV/TV (r = 0.91). However, significant differences were found between all comparisons pairs (P micro-CT BV/TV (P = 0.147). An excellent correlation exists between bone volume fraction and bone density as assessed on micro-CT and MSCT, respectively. This suggests that bone density measurements could be used to estimate bone microstructural parameters. A strong correlation also was found between CBCT gray values and BV/TV and their gold standards, suggesting the potential of this modality in bone quality assessment at implant site. © 2013 John Wiley & Sons A/S. Published by

  11. TGIF1 Gene Silencing in Tendon-Derived Stem Cells Improves the Tendon-to-Bone Insertion Site Regeneration

    Directory of Open Access Journals (Sweden)

    Liyang Chen

    2015-11-01

    Full Text Available Background/Aims: The slow healing process of tendon-to-bone junctions can be accelerated via implanted tendon-derived stem cells (TDSCs with silenced transforming growth interacting factor 1 (TGIF1 gene. Tendon-to-bone insertion site is the special form of connective tissues derivatives of common connective progenitors, where TGF-β plays bidirectional effects (chondrogenic or fibrogenic through different signaling pathways at different stages. A recent study revealed that TGF-β directly induces the chondrogenic gene Sox9. However, TGIF1 represses the expression of the cartilage master Sox9 gene and changes its expression rate against the fibrogenesis gene Scleraxis (Scx. Methods: TGIF1 siRNA was transduced or TGIF1 was over-expressed in tendon-derived stem cells. Following suprapinatus tendon repair, rats were either treated with transduced TDSCs or nontransduced TDSCs. Histologic examination and Western blot were performed in both groups. Results: In this study, the silencing of TGIF1 significantly upregulated the chondrogenic genes and markers. Similarly, TGIF1 inhibited TDSC differentiation into cartilage via interactions with TGF-β-activated Smad2 and suppressed the phosphorylation of Smad2. The area of fibrocartilage at the tendon-bone interface was significantly increased in the TGIF1 (- group compared with the control and TGIF1-overexpressing groups in the early stages of the animal model. The interface between the tendon and bone showed a increase of new bone and fibrocartilage in the TGIF1 (- group at 4 weeks. Fibrovascular scar tissue was observed in the TGIF1-overexpressing group and the fibrin glue only group. Low levels of fibrocartilage and fibrovascular scar tissue were found in the TDSCs group. Conclusion: Collectively, this study shows that the tendon-derived stem cell modified with TGIF1 gene silencing has promising effects on tendon-to-bone healing which can be further explored as a therapeutic tool in regenerative medicine.

  12. Bone grafting in surgery about the foot and ankle: indications and techniques.

    Science.gov (United States)

    Fitzgibbons, Timothy C; Hawks, Michael A; McMullen, Scott T; Inda, David J

    2011-02-01

    Bone grafting is a common procedure in foot and ankle surgery. Historically, autogenous bone graft has most often been harvested from the ipsilateral iliac crest. However, other sites offer similar volumes of cancellous bone and are associated with fewer complications. The ipsilateral proximal tibia, distal tibia, and calcaneus provide adequate amounts of bone graft material for most arthrodesis procedures about the foot and ankle. Emerging techniques have enabled the development of a seemingly unlimited supply of alternative bone graft materials with osteoconductive properties. The osteoprogenitor cells in bone marrow aspirates can be concentrated by use of selective retention systems. These aspirate-matrix composites may be combined with allograft preparations, resulting in a product that promotes osteoconduction, osteoinduction, and osteogenesis with limited morbidity.

  13. Correlation between the thickness of the crestal and buccolingual cortical bone at varying depths and implant stability quotients.

    Directory of Open Access Journals (Sweden)

    Kanthanat Chatvaratthana

    Full Text Available Resonance frequency analysis (RFA is clinically used in dentistry to access the stiffness of dental implants in surrounding bone. However, the clear advantages and disadvantages of this method are still inconclusive. The aim of this study was to investigate and compare implant stability quotient (ISQ values obtained from RFA with parameters obtained from a cone beam computed tomography (CBCT scan of the same region.Nineteen implants (Conelog were inserted in the posterior maxillary and mandibular partially edentulous regions of 16 patients. At the time of implant placement, the ISQ values were obtained using RFA (Osstell. CBCT was used to measure the thickness of the crestal, cortical, buccolingual cortical, and cancellous bone at 3, 6, and 9 mm below the crestal bone level, as indicated by radiographic markers. The ratio of the thickness of the cortical to cancellous bone at varying depths was also calculated and classified into 4 groups (Group 1-4.There was a strong correlation between the crestal cortical bone thickness and ISQ values (P<0.001. The thickness of the buccolingual cortical bone and ratio of the cortical to cancellous bone thickness at 3 mm were significantly related to the ISQ (P = 0.018 and P = 0.034, respectively. Furthermore, the ISQs in Group 1 were the highest compared with those in Group 2 and Group 3, whereas the CBCT parameters at 6 and 9 mm did not have any specific correlation with the ISQ values.This study showed that the ISQ values obtained from RFA highly correlated with the quantity and quality of bone 3 mm below the crestal bone level. The correlation between the ISQ and bone surrounding the implant site was dependent on the depth of measurement. Therefore, RFA can help to predict the marginal bone level, as confirmed in this study.

  14. Vancomycin graft composite for infected bone defects

    International Nuclear Information System (INIS)

    Winkler, H.; Janata, O.; Georgopoulos, A.

    1999-01-01

    Reconstructive surgery under septic conditions represents a major challenge in orthopaedics. Local application of antibiotics can provide high drug levels at the site of infection without systemic effects. However, removal of non-resorbable implants and filling of defects usually requires additional operative procedures. An ideal antibiotic carrier should provide for : 1) Effective bactericidal activity, especially against staphylococci including MRSA; 2) High and long lasting levels at the site of infection without local or systemic toxicity; 3) Repair of defects without a second stage procedure. Allogeneic cancellous bone is proven to be effective in restoration of bone stock. Vancomycin is effective against all gram-positive populations and the agent of choice for infections with MRSA. The aim of our study is to investigate the efficacy of a combination of both components in bone infection. Cancellous bone of human origin was processed during several steps and incubated in 10% vancomycin solution. The antimicrobial activity of the vancomycin graft composite (VGC) was evaluated using an agar diffusion bioassay against staphylococcus aureus and high performance liquid chromatography (HPLC). The testing period was up to 9 weeks. Elution of vancomycin from the graft was evaluated in 2.5% human albumin solution, which was exchanged every 24 hours. Concentration of vancomycin in allograft-bone was between 6.653[tg/g and 23.194gg/g with an average of 15.250 [tg/g, which is equivalent to 10.000 times the minimum inhibitory concentration (MIC) for s. aureus. The initial activity decreased to approx. 50% during the first week and approx. 30% at the end of the 9th week. The lowest values measured exceeded the MIC by 2000 times. Concentration in surrounding fluid decreased from 24.395,80 to 18,43pg/ml after 11 complete exchanges. Human cancellous bone, processed in an adequate way, offers capability to store high quantities of vancomycin. Vancomycin graft composites are

  15. Phenotypic dissection of bone mineral density reveals skeletal site specificity and facilitates the identification of novel loci in the genetic regulation of bone mass attainment.

    Directory of Open Access Journals (Sweden)

    John P Kemp

    2014-06-01

    Full Text Available Heritability of bone mineral density (BMD varies across skeletal sites, reflecting different relative contributions of genetic and environmental influences. To quantify the degree to which common genetic variants tag and environmental factors influence BMD, at different sites, we estimated the genetic (rg and residual (re correlations between BMD measured at the upper limbs (UL-BMD, lower limbs (LL-BMD and skull (SK-BMD, using total-body DXA scans of ∼ 4,890 participants recruited by the Avon Longitudinal Study of Parents and their Children (ALSPAC. Point estimates of rg indicated that appendicular sites have a greater proportion of shared genetic architecture (LL-/UL-BMD rg = 0.78 between them, than with the skull (UL-/SK-BMD rg = 0.58 and LL-/SK-BMD rg = 0.43. Likewise, the residual correlation between BMD at appendicular sites (r(e = 0.55 was higher than the residual correlation between SK-BMD and BMD at appendicular sites (r(e = 0.20-0.24. To explore the basis for the observed differences in rg and re, genome-wide association meta-analyses were performed (n ∼ 9,395, combining data from ALSPAC and the Generation R Study identifying 15 independent signals from 13 loci associated at genome-wide significant level across different skeletal regions. Results suggested that previously identified BMD-associated variants may exert site-specific effects (i.e. differ in the strength of their association and magnitude of effect across different skeletal sites. In particular, variants at CPED1 exerted a larger influence on SK-BMD and UL-BMD when compared to LL-BMD (P = 2.01 × 10(-37, whilst variants at WNT16 influenced UL-BMD to a greater degree when compared to SK- and LL-BMD (P = 2.31 × 10(-14. In addition, we report a novel association between RIN3 (previously associated with Paget's disease and LL-BMD (rs754388: β = 0.13, SE = 0.02, P = 1.4 × 10(-10. Our results suggest that BMD at different skeletal sites is under a mixture of shared and

  16. Phenotypic dissection of bone mineral density reveals skeletal site specificity and facilitates the identification of novel loci in the genetic regulation of bone mass attainment.

    Science.gov (United States)

    Kemp, John P; Medina-Gomez, Carolina; Estrada, Karol; St Pourcain, Beate; Heppe, Denise H M; Warrington, Nicole M; Oei, Ling; Ring, Susan M; Kruithof, Claudia J; Timpson, Nicholas J; Wolber, Lisa E; Reppe, Sjur; Gautvik, Kaare; Grundberg, Elin; Ge, Bing; van der Eerden, Bram; van de Peppel, Jeroen; Hibbs, Matthew A; Ackert-Bicknell, Cheryl L; Choi, Kwangbom; Koller, Daniel L; Econs, Michael J; Williams, Frances M K; Foroud, Tatiana; Zillikens, M Carola; Ohlsson, Claes; Hofman, Albert; Uitterlinden, André G; Davey Smith, George; Jaddoe, Vincent W V; Tobias, Jonathan H; Rivadeneira, Fernando; Evans, David M

    2014-06-01

    Heritability of bone mineral density (BMD) varies across skeletal sites, reflecting different relative contributions of genetic and environmental influences. To quantify the degree to which common genetic variants tag and environmental factors influence BMD, at different sites, we estimated the genetic (rg) and residual (re) correlations between BMD measured at the upper limbs (UL-BMD), lower limbs (LL-BMD) and skull (SK-BMD), using total-body DXA scans of ∼ 4,890 participants recruited by the Avon Longitudinal Study of Parents and their Children (ALSPAC). Point estimates of rg indicated that appendicular sites have a greater proportion of shared genetic architecture (LL-/UL-BMD rg = 0.78) between them, than with the skull (UL-/SK-BMD rg = 0.58 and LL-/SK-BMD rg = 0.43). Likewise, the residual correlation between BMD at appendicular sites (r(e) = 0.55) was higher than the residual correlation between SK-BMD and BMD at appendicular sites (r(e) = 0.20-0.24). To explore the basis for the observed differences in rg and re, genome-wide association meta-analyses were performed (n ∼ 9,395), combining data from ALSPAC and the Generation R Study identifying 15 independent signals from 13 loci associated at genome-wide significant level across different skeletal regions. Results suggested that previously identified BMD-associated variants may exert site-specific effects (i.e. differ in the strength of their association and magnitude of effect across different skeletal sites). In particular, variants at CPED1 exerted a larger influence on SK-BMD and UL-BMD when compared to LL-BMD (P = 2.01 × 10(-37)), whilst variants at WNT16 influenced UL-BMD to a greater degree when compared to SK- and LL-BMD (P = 2.31 × 10(-14)). In addition, we report a novel association between RIN3 (previously associated with Paget's disease) and LL-BMD (rs754388: β = 0.13, SE = 0.02, P = 1.4 × 10(-10)). Our results suggest that BMD at different skeletal sites is under a mixture of shared and

  17. Combined nanoindentation testing and scanning electron microscopy of bone and articular calcified cartilage in an equine fracture predilection site.

    Science.gov (United States)

    Doube, M; Firth, E C; Boyde, A; Bushby, A J

    2010-06-03

    Condylar fracture of the third metacarpal bone (Mc3) is the commonest cause of racetrack fatality in Thoroughbred horses. Linear defects involving hyaline articular cartilage, articular calcified cartilage (ACC) and subchondral bone (SCB) have been associated with the fracture initiation site, which lies in the sagittal grooves of the Mc3 condyle. We discovered areas of thickened and abnormally-mineralised ACC in the sagittal grooves of several normal 18-month-old horses, at the same site that linear defects and condylar fracture occur in older Thoroughbreds and questioned whether this tissue had altered mechanical properties. We embedded bone slices in PMMA, prepared flat surfaces normal to the articular surface and studied ACC and SCB using combined quantitative backscattered electron scanning electron microscopy (qBSE) and nanoindentation testing: this allowed correlation of mineralisation density and tissue stiffness (E) at the micron scale. We studied both normal and affected grooves, and also normal condylar regions. Large arrays of indentations could be visualised as 2-dimensional maps of E with a limit to resolution of indentation spacing, which is much larger than qBSE pixel spacing. ACC was more highly mineralised but less stiff in early linear defects than in control regions, while subchondral bone was more highly mineralised and stiffer in specimens with early linear defects than those without. Thus both ACC and SCB mineralisation may be abnormal in a class of early linear defect in 18-month-old Thoroughbred horses, and this may possibly contribute to later fracture of the Mc3 condyle.

  18. Combined nanoindentation testing and scanning electron microscopy of bone and articular calcified cartilage in an equine fracture predilection site

    Directory of Open Access Journals (Sweden)

    M Doube

    2010-06-01

    Full Text Available Condylar fracture of the third metacarpal bone (Mc3 is the commonest cause of racetrack fatality in Thoroughbred horses. Linear defects involving hyaline articular cartilage, articular calcified cartilage (ACC and subchondral bone (SCB have been associated with the fracture initiation site, which lies in the sagittal grooves of the Mc3 condyle. We discovered areas of thickened and abnormally-mineralised ACC in the sagittal grooves of several normal 18-month-old horses, at the same site that linear defects and condylar fracture occur in older Thoroughbreds and questioned whether this tissue had altered mechanical properties. We embedded bone slices in PMMA, prepared flat surfaces normal to the articular surface and studied ACC and SCB using combined quantitative backscattered electron scanning electron microscopy (qBSE and nanoindentation testing: this allowed correlation of mineralisation density and tissue stiffness (E at the micron scale. We studied both normal and affected grooves, and also normal condylar regions. Large arrays of indentations could be visualised as 2-dimensional maps of E with a limit to resolution of indentation spacing, which is much larger than qBSE pixel spacing. ACC was more highly mineralised but less stiff in early linear defects than in control regions, while subchondral bone was more highly mineralised and stiffer in specimens with early linear defects than those without. Thus both ACC and SCB mineralisation may be abnormal in a class of early linear defect in 18-month-old Thoroughbred horses, and this may possibly contribute to later fracture of the Mc3 condyle.

  19. BoneCeramic graft regenerates alveolar defects but slows orthodontic tooth movement with less root resorption.

    Science.gov (United States)

    Ru, Nan; Liu, Sean Shih-Yao; Bai, Yuxing; Li, Song; Liu, Yunfeng; Wei, Xiaoxia

    2016-04-01

    BoneCeramic (Straumann, Basel, Switzerland) can regenerate bone in alveolar defects after tooth extraction, but it is unknown whether it is feasible to move a tooth through BoneCeramic grafting sites. The objective of this study was to investigate 3-dimensional real-time root resorption and bone responses in grafted sites during orthodontic tooth movement. Sixty 5-week-old rats were randomly assigned to 3 groups to receive BoneCeramic, natural bovine cancellous bone particles (Bio-Oss; Geistlich Pharma, Wolhusen, Switzerland), or no graft, after the extraction of the maxillary left first molar. After 4 weeks, the maxillary left second molar was moved into the extraction site for 28 days. Dynamic bone microstructures and root resorption were evaluated using in-vivo microcomputed tomography. Stress distribution and corresponding tissue responses were examined by the finite element method and histology. Mixed model analysis of variance was performed to compare the differences among time points with Bonferroni post-hoc tests at the significance level of P root resorption volumes and craters, and the highest bone volume fraction, trabecular number, and mean trabecular thickness, followed by the Bio-Oss and the control groups. The highest stress accumulated in the cervical region of the mesial roots. BoneCeramic has better osteoconductive potential and induces less root resorption compared with Bio-Oss grafting and naturally recovered extraction sites. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  20. 77 FR 19747 - Proposed Cancelation

    Science.gov (United States)

    2012-04-02

    ... DEPARTMENT OF TRANSPORTATION Office of the Secretary [Order 2012-3-7; Docket DOT-OST-2012-0022] Proposed Cancelation of the Air Taxi Authority Of VIH Cougar Helicopters, Inc. AGENCY: Department of... order finding that VIH Cougar Helicopters, Inc. is not a U.S. citizen as defined in 49 U.S.C. 40102(a...

  1. Methodological approach for the evaluation of homologous bone graft use in post-extractive atrophic alveolar ridges

    Directory of Open Access Journals (Sweden)

    B. Musante

    2013-01-01

    Full Text Available The aim of this study is to investigate the in vivo efficacy of Puros® cancellous particulate allograft bone in the regeneration of post-extractive sites. Twelve molar or premolar sites were selected. Seven days after minimally invasive tooth extraction, Puros® cancellous particulate allografts were inserted into the elected sites. TC Cone-Beam investigation and at 4 months from surgery; bone height and width were evaluated. Five months after surgery, biopsy samples of the regenerated sites were taken and histologically analyzed to qualitatively evaluate bone regeneration. TC analysis showed, a mean bone gain of 4.1 mm in height and 2.02 mm in width. The histological analysis of the samples showed intense bone metabolic activity with active osteoblasts on the implant surface, at the level of the native bone-graft interface and in the grafted area. The radiographic and histological analyses demonstrate an optimal bonen regeneration, both in terms of quality and quantity using Puros®.

  2. Remoção da cartilagem articular associada ou não a implante homógeno ou enxerto autógeno de osso esponjoso em cães submetidos à artrodese atlantoaxial Joint cartilage removal associated or not to homologous implant or autologous cancellous bone graft in dogs submitted to atlantoaxial arthrodesis

    Directory of Open Access Journals (Sweden)

    Rafael Festugatto

    2013-03-01

    Full Text Available O objetivo deste estudo foi avaliar o grau de fusão articular e formação óssea na articulação atlantoaxial de cães submetidos à artrodese após a remoção da cartilagem articular associada ou não ao implante homógeno ou enxerto autógeno de osso esponjoso. Foram utilizados 12 cães, adultos, distribuídos aleatoriamente em três grupos iguais. Grupo I (GI: realizada apenas a remoção da cartilagem articular e imobilização articular com pinos e resina acrílica. Grupo II (GII: feita a remoção da cartilagem articular e imobilização da articulação, seguida da colocação e modelagem do implante ósseo esponjoso homógeno entre as superfícies articulares. Grupo III (GIII: foi realizado o mesmo procedimento do GII, mais o enxerto ósseo esponjoso autógeno no local determinado. Realizaram-se exames radiográficos em todos os animais aos 30, 60 e 90 dias de pós-operatório (PO. Aos 90 dias de PO foi feita a eutanásia para o emprego do teste de palpação manual, avaliação tomográfica e histopatológica. Para análise estatística da associação entre o grau de fusão articular, aplicou-se o Teste Qui-quadrado de independência. Os resultados dos testes foram avaliados pela significância exata e considerados significantes a 5% (PThe aim of this study was to evaluate the degree of joint fusion and bone formation in dogs undergoing atlantoaxial arthrodesis after removal of articular cartilage associated or not to implant homogenous or autogenous cancellous bone. Twelve dogs, weighing between 8 and 12kg were randomly divided into three groups. Group I (GI performed only the removal of joint cartilage and joint immobilization with acrylic resin and pins. Group II (GII: after removel of joint cartilage and articular immobilization was performed modeling and placement of homogenous cancellous bone at the given location. The volume of homograft placed in the joint was measured using a precision balance and all animals received the

  3. Favorable effects of skeletal muscle on bone are distinguished according to gender and skeletal sites

    Directory of Open Access Journals (Sweden)

    Kyoung Min Kim

    2017-03-01

    Conclusions: Higher RASM was significantly associated with lower risk for osteoporosis and the areas at the femur neck and total hip appeared to more likely be affected positively by muscle. Moreover, because males showed faster muscle loss with aging than females, the bones of males may be more prone to favorable effects of muscle.

  4. Transcriptional profile of fibroblasts obtained from the primary site, lymph node and bone marrow of breast cancer patients

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Del Valle

    2014-09-01

    Full Text Available Cancer-associated fibroblasts (CAF influence tumor development at primary as well as in metastatic sites, but there have been no direct comparisons of the transcriptional profiles of stromal cells from different tumor sites. In this study, we used customized cDNA microarrays to compare the gene expression profile of stromal cells from primary tumor (CAF, n = 4, lymph node metastasis (N+, n = 3 and bone marrow (BM, n = 4 obtained from breast cancer patients. Biological validation was done in another 16 samples by RT-qPCR. Differences between CAF vs N+, CAF vs BM and N+ vs BM were represented by 20, 235 and 245 genes, respectively (SAM test, FDR < 0.01. Functional analysis revealed that genes related to development and morphogenesis were overrepresented. In a biological validation set, NOTCH2 was confirmed to be more expressed in N+ (vs CAF and ADCY2, HECTD1, HNMT, LOX, MACF1, SLC1A3 and USP16 more expressed in BM (vs CAF. Only small differences were observed in the transcriptional profiles of fibroblasts from the primary tumor and lymph node of breast cancer patients, whereas greater differences were observed between bone marrow stromal cells and the other two sites. These differences may reflect the activities of distinct differentiation programs.

  5. Animal Bone Remnants from Trench CLXII of the Bolgar City Site: Some New Methods of Archaeozoological Materials Processing and Evaluation

    OpenAIRE

    Yavorskaya Lilia V.

    2012-01-01

    It is for the first time in the study of animal bone remnants from the Bolgar city site that modern techniques have been applied, which have made it possible to solve archaeological and historical problems rather than purely biological ones. A detailed description of the work process based on these techniques and of the results obtained is offered. In particular, it has been found out that the cattle intended for slaughter in Bolgar had not been bred within the city limits but rather supplied...

  6. Recent progress of the bone densitometer

    International Nuclear Information System (INIS)

    Tamegai, Toshiaki

    1996-01-01

    A Bone Densitometer is the equipment which non-invasively evaluates bone mineral such as calcium contained in the bone of human. It is widely accepted as a useful equipment for the purpose of diagnosis of the bone, especially of the osteoporosis. Human body is considered as two-component system composed of bone and soft tissue at the point of view of radiation absorption. Therefore it is necessary to eliminate soft tissue component to determine bone mineral content or density. To cancel soft tissue component, there are a few methods employed to the bone densitometers. Accordingly the bone densitometers are classified into two types. In SXA, X-ray source having effective energy of approximately 30keV is used. The measurement site of patient should be soaked in water to eliminate soft tissue component according to the theory that the linear attenuation coefficient of water is nearly equal to that of soft tissue. Therefore the difference between the intensity of X-ray transmitted through soft tissue and that of X-ray through soft tissue plus bone indicates amount of bone mineral directly under the constant water thickness condition. SXA is a very convenient method, but the necessity of water may not be desirable in the clinical use. Therefore, clinical applications of SXA are limited to peripheral site such as forearm or calcaneus. In DXA, X-ray source having dual effective energies of approximately 40keV and 80keV is used. The theory is based on the difference of intensities between X-ray transmitted through soft tissue and that of transmitted through bone. The amount of bone mineral is then estimated by the theoretical calculations. Therefore, DXA is applicable for not only spine or femur but also all sites of patients. The bone densitometers based on SXA or DXA are widely accepted as the equipments for the measurement of bone mineral. However, recently, equipments based on other theoretical method, pQCT and QUS are proposed. (J.P.N.)

  7. Synovial sarcoma of primary bone origin: a rare case in a rare site with atypical features

    International Nuclear Information System (INIS)

    Jung, Seung Chai; Choi, Jung-Ah; Lee, Joon Woo; Kang, Heung Sik; Chung, Jin-Haeng; Oh, Joo Han

    2007-01-01

    Synovial sarcoma of bone origin is extremely rare and difficult to diagnose. We present a case in which the lesion arose in the cortex of the distal tibia. It showed heterogeneous intermediate signal intensity on T1-weighted images and heterogeneous intermediate to low signal intensity on T2-weighted images with heterogeneous contrast enhancement on MRI. The lesion was confirmed as synovial sarcoma using a combination of histological and molecular genetic studies. (orig.)

  8. Three-dimensional trabecular bone architecture of the lumbar spine in bone metastasis from prostate cancer: comparison with degenerative sclerosis

    International Nuclear Information System (INIS)

    Tamada, Tsutomu; Sone, Teruki; Imai, Shigeki; Kajihara, Yasumasa; Fukunaga, Masao; Jo, Yoshimasa

    2005-01-01

    Prostate cancer frequently metastasizes to bone, inducing osteosclerotic lesions. The objective of this study was to clarify the three-dimensional (3D) trabecular bone microstructure in bone metastasis from prostate cancer by comparison with normal and degenerative sclerotic bone lesions, using microcomputed tomography (micro-CT). A total of 32 cancellous bone samples were excised from the lumbar spine of six autopsy patients: 15 metastatic samples (one patient), eight degenerative sclerotic samples (four patients) and the rest from normal sites (three patients). The samples were serially scanned cross-sectionally by micro-CT with a pixel size of 23.20 μm, slice thickness of 18.56 μm, and image matrix of 512 x 512. Each image data set consisted of 250 consecutive slices. The volumes of interest (96 x 96 x 120 voxels) were defined in the original image sets and 3D indices of the trabecular microstructure were determined. The trabecular thickness (Tb.Th) in degenerative sclerotic lesions was significantly higher than that in normal sites, whereas no significant difference was observed in trabecular number (Tb.N). By contrast, in metastatic lesions, the Tb.N was significantly higher with increased bone volume fraction (BV/TV) than in normal sites, and no significant difference was found in Tb.Th. The characteristics of the trabecular surface in the metastatic samples showed concave structural elements with an increase in BV/TV, indicating osteolysis of the trabecular bone. In 3D reconstructed images, increased trabecular bone with an irregular surface was observed in samples from metastatic sites, which were uniformly sclerotic on soft X-ray radiographs. These results support, through 3D morphological features, the strong bone resorption effect in bone metastasis from prostate cancer. (orig.)

  9. Human talus bones from the Middle Pleistocene site of Sima de los Huesos (Sierra de Atapuerca, Burgos, Spain).

    Science.gov (United States)

    Pablos, Adrián; Martínez, Ignacio; Lorenzo, Carlos; Gracia, Ana; Sala, Nohemi; Arsuaga, Juan Luis

    2013-07-01

    Here we present and describe comparatively 25 talus bones from the Middle Pleistocene site of the Sima de los Huesos (SH) (Sierra de Atapuerca, Burgos, Spain). These tali belong to 14 individuals (11 adult and three immature). Although variation among Middle and Late Pleistocene tali tends to be subtle, this study has identified unique morphological characteristics of the SH tali. They are vertically shorter than those of Late Pleistocene Homo sapiens, and show a shorter head and a broader lateral malleolar facet than all of the samples. Moreover, a few shared characters with Neanderthals are consistent with the hypothesis that the SH population and Neanderthals are sister groups. These shared characters are a broad lateral malleolar facet, a trochlear height intermediate between modern humans and Late Pleistocene H. sapiens, and a short middle calcaneal facet. It has been possible to propose sex assignment for the SH tali based on their size. Stature estimates based on these fossils give a mean stature of 174.4 cm for males and 161.9 cm for females, similar to that obtained based on the long bones from this same site. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Stress fracture as a complication of autogenous bone graft harvest from the distal tibia.

    Science.gov (United States)

    Chou, Loretta B; Mann, Roger A; Coughlin, Michael J; McPeake, William T; Mizel, Mark S

    2007-02-01

    Autogenous bone graft from the distal tibia provides cancellous bone graft for foot and ankle operations, and it has osteogenic and osteoconductive properties. The site is in close proximity to the foot and ankle, and published retrospective studies show low morbidity from the procedure. One-hundred autografts were obtained from the distal tibia between 2000 and 2003. In four cases the distal tibial bone graft harvest resulted in a stress fracture. There were three women and one man. The average time of diagnosis of the stress fracture from the operation was 1.8 months. All stress fractures healed with a short course (average 2.4 months) of cast immobilization. This study demonstrated that a stress fracture from the donor site of autogenous bone graft of the distal tibia occurs and can be successfully treated nonoperatively.

  11. Effect of surgical drill guide and irrigans temperature on thermal bone changes during drilling implant sites - thermographic analysis on bovine ribs.

    Science.gov (United States)

    Marković, Aleksa; Lazić, Zoran; Mišić, Tijana; Šćepanović, Miodrag; Todorović, Aleksandar; Thakare, Kaustubh; Janjić, Bojan; Vlahović, Zoran; Glišić, Mirko

    2016-08-01

    During drilling implant sites, mechanical energy is converted into thermal one resulting in transient rise in temperature of surrounding bone. The temperature of 47°C exeeding one minute impairs osseointegration, compromises mechanical properties of the local bone and could cause early implant failure. This in vitro study aimed to assess the effect of surgical drill guide and temperature of irrigans on thermal changes of the local bone during drilling implant sites, and to test the influence of irrigans temperature on the temperature of surgical drill guide. A total of 48 specimens obtained from bovine ribs were randomly allocated to four experimental conditions according to the 2 x 2 factorial design: drill guide (with or without) and saline (at 25°C or 5°C). Real-time infrared thermography was used as a method for temperature measurement. The primary outcome was bone temperature change during drilling implant sites measured at 3 osteotomy depths, whereas the second one was change in the temperature of the drill guide. Data were analyzed by Brunner and Langer nonparametric analysis and Wilcoxon test. The effect of drill guide on the changes of bone temperature was significant at the entrance of osteotomy, whereas the effect of saline temperature was significant at all osteotomy levels (p 0.05). Guided surgery and irrigation with saline at 25°C were associated with the highest bone temperature increase. Increase in drill guide temperature was significantly higher when saline at 25°C was used (p < 0.001). Guided implant site preparation generates higher temperature of the local bone than conventional drilling, not exceeding the threshold for thermal bone necrosis. Although saline at room temperature provides sufficient heat control during drilling, cooled saline is more effective regardless the use of surgical drill guide.

  12. Effect of surgical drill guide and irrigans temperature on thermal bone changes during drilling implant sites - thermographic analysis on bovine ribs

    Directory of Open Access Journals (Sweden)

    Marković Aleksa

    2016-01-01

    Full Text Available Background/Aim. During drilling implant sites, mechanical energy is converted into thermal one resulting in transient rise in temperature of surrounding bone. The temperature of 47°C exeeding one minute impairs osseointegration, compromises mechanical properties of the local bone and could cause early implant failure. This in vitro study aimed to assess the effect of surgical drill guide and temperature of irrigans on thermal changes of the local bone during drilling implant sites, and to test the influence of irrigans temperature on the temperature of surgical drill guide. Methods. A total of 48 specimens obtained from bovine ribs were randomly allocated to four experimental conditions according to the 2 x 2 factorial design: drill guide (with or without and saline (at 25°C or 5°C. Real-time infrared thermography was used as a method for temperature measurement. The primary outcome was bone temperature change during drilling implant sites measured at 3 osteotomy depths, whereas the second one was change in the temperature of the drill guide. Data were analyzed by Brunner and Langer nonparametric analysis and Wilcoxon test. Results. The effect of drill guide on the changes of bone temperature was significant at the entrance of osteotomy, whereas the effect of saline temperature was significant at all osteotomy levels (p 0.05. Guided surgery and irrigation with saline at 25°C were associated with the highest bone temperature increase. Increase in drill guide temperature was significantly higher when saline at 25°C was used (p < 0.001. Conclusion. Guided implant site preparation generates higher temperature of the local bone than conventional drilling, not exceeding the threshold for thermal bone necrosis. Although saline at room temperature provides sufficient heat control during drilling, cooled saline is more effective regardless the use of surgical drill guide.

  13. Later Age at Onset of Independent Walking Is Associated With Lower Bone Strength at Fracture-Prone Sites in Older Men.

    Science.gov (United States)

    Ireland, Alex; Muthuri, Stella; Rittweger, Joern; Adams, Judith E; Ward, Kate A; Kuh, Diana; Cooper, Rachel

    2017-06-01

    Later age at onset of independent walking is associated with lower leg bone strength in childhood and adolescence. However, it is unknown whether these associations persist into older age or whether they are evident at axial (central) or upper limb sites. Therefore, we examined walking age obtained at age 2 years and bone outcomes obtained by dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT) scans at ages 60 to 64 years in a nationally representative cohort study of British people, the MRC National Survey of Health and Development. It was hypothesized that later walking age would be associated with lower bone strength at all sites. Later independent walking age was associated with lower height-adjusted hip (standardized regression coefficients with 95% confidence interval [CI] -0.179 [-0.251 to -0.107]), spine (-0.157 [-0.232 to -0.082]), and distal radius (-0.159 [-0.245 to -0.073]) bone mineral content (BMC, indicating bone compressive strength) in men (all p lower lean mass and adolescent sporting ability in later walkers. These associations were also evident for a number of hip geometric parameters (including cross-sectional moment of inertia [CSMI], indicating bone bending/torsional strength) assessed by hip structural analysis (HSA) from DXA scans. Similar height-adjusted associations were also observed in women for several hip, spine, and upper limb outcomes, although adjustment for fat or lean mass led to complete attenuation for most outcomes, with the exception of femoral shaft CSMI and spine bone area (BA). In conclusion, later independent walking age appears to have a lifelong association with bone strength across multiple skeletal sites in men. These effects may result from direct effects of early life loading on bone growth and mediation by adult body composition. Results suggest that late walking age may represent a novel risk factor for subsequent low bone strength. Existing interventions effective in

  14. Oreopithecus was a bipedal ape after all: Evidence from the iliac cancellous architecture

    Science.gov (United States)

    Rook, Lorenzo; Bondioli, Luca; Köhler, Meike; Moyà-Solà, Salvador; Macchiarelli, Roberto

    1999-01-01

    Textural properties and functional morphology of the hip bone cancellous network of Oreopithecus bambolii, a 9- to 7-million-year-old Late Miocene hominoid from Italy, provide insights into the postural and locomotor behavior of this fossil ape. Digital image processing of calibrated hip bone radiographs reveals the occurrence of trabecular features, which, in humans and fossil hominids, are related to vertical support of the body weight, i.e., to bipedality. PMID:10411955

  15. Applications of the direct photon absorption technique for measuring bone mineral content in vivo. Determination of body composition in vivo

    Science.gov (United States)

    Cameron, J. R.

    1972-01-01

    The bone mineral content, BMC, determined by monoenergetic photon absorption technique, of 29 different locations on the long bones and vertebral columns of 24 skeletons was measured. Compressive tests were made on bone from these locations in which the maximum load and maximum stress were measured. Also the ultimate strain, modulus of elasticity and energy absorbed to failure were determined for compact bone from the femoral diaphysis and cancellous bone from the eighth through eleventh thoracic vertebrae. Correlations and predictive relationships between these parameters were examined to investigate the applicability of using the BMC at sites normally measured in vivo, i.e. radius and ulna in estimating the BMC and/or strength of the spine or femoral neck. It was found that the BMC at sites on the same bone were highly correlated r = 0.95 or better; the BMC at sites on different bones were also highly interrelated, r = 0.85. The BMC at various sites on the long bones could be estimated to between 10 and 15 per cent from the BMC of sites on the radius or ulna.

  16. Intramedullary placement of ventricular shunts: a review of using bone as a distal cerebrospinal absorption site in treating hydrocephalus.

    Science.gov (United States)

    Kassem, Mohammad W; Chern, Joshua; Loukas, Marios; Tubbs, R Shane

    2017-12-01

    Intraosseous (IO) vascular access has been used since the Second World War and is warranted when there is an emergency and/or urgent need to replenish the vascular pool. Despite long-term and satisfactory results from delivering large quantities of intravenous fluid via the medullary space of bone, use of this space for a distant receptacle for cerebrospinal fluid (CSF) diversion has seldom been considered. The current paper reviews the literature regarding the bony medullary space as a receptacle for intravenous fluid and CSF. Previous authors have demonstrated the potential of the diploic space of the calvaria for CSF shunting. Pugh and colleagues tested the ability of the cranium to receive and absorb a small amount of tracer fluid. The literature suggests that intraosseous placement of ventricular diversionary shunts is an alternative to more traditional sites such as the pleural cavity and peritoneum. When these latter locations are not available or are contraindicated, placement in the medullary space of bone is another option available to the surgeon.

  17. Microscopic and radiographic analysis of the effect of particle size of demineralized bovine cancellous bone matrix on the repair of bone defects in femurs of rabbits Análise microscópica e radiográfica do efeito do tamanho das partículas de matriz de osso medular bovino desmineralizado na reparação de defeito ósseo em fêmures de coelhos

    Directory of Open Access Journals (Sweden)

    Everdan Carneiro

    2005-06-01

    Full Text Available The bone tissue has a great regenerative potential, with ability to completely restore its structure and original functions. In some situations, though, bone defects cannot be self-repaired, thus requiring the use of grafts for a correct treatment and good prognosis. This work aimed at microscopically analyzing the effect of the particle size of demineralized bovine cancellous bone matrix in micro and macrogranular forms on the repair of bone defects in femurs of rabbits, with blood clot used as control. At 1, 3 and 6 months after implantation of the materials, the animals were killed and the anatomic specimens were removed. A foreign body-type granulomatous reaction containing macrophages and multinucleated giant cells in contact with the implanted particles was observed. These results suggest a failure in demineralization and/or interruption of the antigenic potential during production of the biomaterial. It is concluded that the size of the particles did not influence the evolution of the repair process of bone defects, acting only as bone-filler substances, and that the material implanted should be improved by quality control during production, since it may represent a good alternative for bone graft.O tecido ósseo possui grande potencial regenerativo com capacidade para restaurar completamente sua estrutura e função originais. Há situações em que os defeitos ósseos não conseguem por si só obter o reparo, casos em que se fazem necessários o uso de enxertos, para um correto tratamento e bom prognóstico. Este experimento teve o propósito de analisar microscopicamente o efeito do tamanho das partículas de matriz de osso medular bovino desmineralizado, nas formas micro e macrogranular, na reparação de defeito ósseo em fêmures de coelhos, tendo como controle o coágulo sanguíneo. Após 1,3 e 6 meses da implantação dos materiais, os animais foram mortos e as peças anatômicas removidas. Uma reação granulomatosa tipo corpo

  18. Study of Cancelled Elective Surgical Operations

    Directory of Open Access Journals (Sweden)

    M Amrollahi

    2004-07-01

    Full Text Available Introduction: Cancellation of an elective operation is a very important problem, which is the cause for different types of stresses for patients and their families and results in loss of significant amount of time, money and hospital resources. Therefore, finding the main causes of operation postponement may help us to understand and reduce these problems. Material & Method: A special questionnaire was designed to gather information about different causes of operation cancellation and filled from October 23rd (Aban 1st till November 21st (Azar 30 th, 2001 (1380 in all of the teaching hospitals of Yazd university. (S.Dr Rahnemoon, Afshar, Rah Ahan, Bahman and Savaneg Sukhteghy Results were statistically evaluated.. Results: 180 of the 31437 scheduled operations had been cancelled (12.52% Majority of cases (33.3% had been cancelled due to the absence of the surgeons. This group ((Surgeons absent was the most common cause for the postponement of operations (36.7%. The secondary cause of cancellations was related to anesthetic team and operating room problems (25%, the patient’s reasons for cancellation was 16.2% and the most minimal cause of cancellation was insufficient hospital revenue (0.5%. The basis of disease or high risk patients for operation were the main causes of dysfunction of the anesthetic team (68.9% and also the first cause of cancellation. The rate of cancellation was the most in the "older than 60 years" age group. (15.4% The cancellation in women was 12.6% and in males 12.5%. Conclusion: Surgeons schedule more patients keeping in mind cancellations which occur regularly due to patients, hospital, anesthesia, and operating room problems. This over scheduling is a problem itself, so preadmission evaluation clinics are recommended to decrease the rate of cancellations thereby saving the socioeconomic resources and decreasing patient’s stress.

  19. Using Comics to Communicate Legal Contract Cancellation

    OpenAIRE

    Marietjie Botes

    2017-01-01

    This article investigates how comics can be used to adequately communicate the correct process of contract cancellation and whether comics can enhance understanding of the legal process. A survey of pre-owned vehicle buyers of various levels of education in Pretoria, South Africa found that when comics are used to communicate contract cancellation, a significant increase in the comprehension of the legal cancellation process occurs. The results may influence how contracting parties may choose...

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

    Science.gov (United States)

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

    1999-01-01

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

  1. Vocal Noise Cancellation From Respiratory Sounds

    National Research Council Canada - National Science Library

    Moussavi, Zahra

    2001-01-01

    Although background noise cancellation for speech or electrocardiographic recording is well established, however when the background noise contains vocal noises and the main signal is a breath sound...

  2. Bone status in rheumatoid arthritis assessed at peripheral sites by three different quantitative ultrasound devices

    DEFF Research Database (Denmark)

    Madsen, O R; Suetta, C; Egsmose, C

    2004-01-01

    sites in 27 women with RA (mean disease duration 15 years) and in 36 healthy women matched for age, height and weight. Speed of sound (SOS, m/s), broadband ultrasound attenuation (BUA, dB/MHz) and stiffness of the calcaneus were assessed by a Lunar Achilles device. Amplitude-dependent SOS (Ad-SOS, m...

  3. 20 CFR 217.27 - Effect of cancellation.

    Science.gov (United States)

    2010-04-01

    ... ANNUITY OR LUMP SUM Cancellation of Application § 217.27 Effect of cancellation. When a person cancels an application the effect is the same as though an application was never filed. When an employee cancels his or her application, any application filed by the employee's spouse is also cancelled. However, a request...

  4. 34 CFR 674.59 - Cancellation for military service.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Cancellation for military service. 674.59 Section 674... Cancellation for military service. (a) Cancellation on a Defense loan. (1) An institution must cancel up to 50... cancellation rate is 121/2 percent of the original loan principal, plus the interest on the unpaid balance...

  5. Multiple-energy tissue-cancellation applications of a digital beam attenuator to chest radiography

    International Nuclear Information System (INIS)

    Dobbins, J.T. III.

    1985-01-01

    The digitally-formed primary beam attenuator (DBA) spatially modulates the x-ray fluence incident upon the patient to selectively attenuate regions of interest. The DBA attenuating mask is constructed from CeO 2 powder by a modified printing technique and uses image information from an initial low-dose exposure. Two tissue-cancellation imaging techniques are investigated with the DBA: (1) energy-dependent information is used to form a beam attenuator that attenuates specific tissues in the primary x-ray beam for tissue-cancelled film radiography; (2) the beam attenuator is used to improve image signal-to-noise and scattered radiation properties in traditional energy-subtraction tissue-cancellation imaging with digital detectors. The tissue-cancellation techniques in the primary x-ray beam were capable of adequately removing either soft-tissue or bone from the final compensated film radiograph when using a phantom with well defined soft-tissue and bone sections. However, when tried on an anthropomorphic chest phantom the results were adequate for cancellation of large soft tissue structures, but unsatisfactory for cancellation of bony structures such as the ribs, because of the limited spatial frequency content of the attenuating mask. The second technique (with digital detectors) showed improved uniformity of image signal-to-noise and a two-fold increase in soft-tissue nodule contrast due to improved scattered radiation properties. The tissue-cancelled images contained residual image contributions from the presence of the attenuating mask, but this residual may be correctable by future algorithms

  6. Adapted preparation technique for screw-type implants: explorative in vitro pilot study in a porcine bone model.

    Science.gov (United States)

    Beer, Andreas; Gahleitner, André; Holm, Anders; Birkfellner, Wolfgang; Homolka, Peter

    2007-02-01

    The aim of this study was to quantify the effect of adapted preparation on the insertion torque of self-tapping implants in cancellous bone. In adapted preparation, bone condensation - and thus, insertion torque - is controlled by changing the diameter of the drilling. After preparation of cancellous porcine vertebral bone with drills of 2.85, 3, 3.15 or 3.35 mm final diameters, Brånemark sytem Mk III implants (3.75 x 11.5 mm) were inserted in 141 sites. During implantation, the insertion torque was recorded. Prior to implant insertion, bone mineralization (bone mineral density (BMD)) was measured with dental quantative computed tomography. The BMD values measured at the implant position were correlated with insertion torque for varying bone condensation. Based on the average torque recorded during implant insertion into the pre-drilled canals with a diameter of 3 mm, torque increased by approximately 17% on reducing the diameter of the drill by 5% (to 2.85 mm). On increasing the diameter of the osteotomy to 3.15 mm (5%) or 3.35 mm (12%), torque values decreased by approximately 21% and 50%, respectively. The results demonstrate a correlation between primary stability (average insertion torque) and the diameter of the implant bed on using a screw-shaped implant. Thus, using an individualized bone mineralization-dependent drilling technique, optimized torque values could be achieved in all tested bone qualities with BMDs ranging from 330 to 500 mg/cm(3). The results indicate that using a bone-dependent drilling technique, higher torque values can also be achieved in poor bone using an individualized drilling resulting in higher bone condensation. As immediate function is dependent on primary stability (high insertion torque), this indicates that primary stability can be increased using a modified drilling technique in lesser mineralized bone.

  7. 30 CFR 250.181 - When may the Secretary cancel my lease and when am I compensated for cancellation?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may the Secretary cancel my lease and when... may the Secretary cancel my lease and when am I compensated for cancellation? If the Secretary cancels.... Section 250.185 states conditions under which you will receive no compensation. The Secretary may cancel a...

  8. Galloping exercise induces regional changes in bone density within the third and radial carpal bones of Thoroughbred horses

    International Nuclear Information System (INIS)

    Firth, E.C.; Delahunt, J.; Wichtel, J.W.; Birch, H.L.; Goodship, A.E.

    1999-01-01

    This study was performed to test the hypothesis that a localised bone hypertrophy could occur within the subchondral cancellous architecture of the third and radial carpal bones. Using 2 levels of controlled and defined exercise, it was observed that a high intensity treadmill exercise protocol resulted in functional adaptation of the carpal bones. The increase in trabecular thickening and density was seen to be localised to those regions underlying common sites of cartilage degradation, the interface of the thickened trabeculae with the normal architecture in the third carpal hone was coincident with a common site of clinical fractures. The bone changes were determined both qualitatively on examination of slab radiographs and quantified by dual energy x-ray absorptiometry. The findings from this study are relevant to mechanical factors involved in the pathophysiology of joint degeneration. The potential clinical implications of this study are in relation to changes in the type and duration of exercise regimens used in training of equine athletes. The rapid response of bone to mechanical stimulation has implications in the longer term for localised cartilage degradation. Imaging techniques could be developed to monitor these early bone changes in the specific areas identified in this study and thus allow appropriate changes in training intensity to minimise subsequent damage to the articular surface

  9. Noise canceling in-situ detection

    Science.gov (United States)

    Walsh, David O.

    2014-08-26

    Technologies applicable to noise canceling in-situ NMR detection and imaging are disclosed. An example noise canceling in-situ NMR detection apparatus may comprise one or more of a static magnetic field generator, an alternating magnetic field generator, an in-situ NMR detection device, an auxiliary noise detection device, and a computer.

  10. Surgery cancellations at a public hospital

    Directory of Open Access Journals (Sweden)

    Erika Pittelkow

    2008-12-01

    Full Text Available Objective: To determine the frequency of cancellation of scheduledsurgeries at a public hospital in the city of São Paulo, and to identifythe reasons of cancellation. Methods: A descriptive, exploratory,retrospective study, with quantitative analysis, of records ofprocedures cancelled and medical charts of patients whose surgerieswere cancelled, between January 2006 and July 2007. Results: Ofthe 6,149 (100% surgeries scheduled for the period surveyed, 701(11.4% were canceled and 5,448 (88.6% conducted; among thesurgeries cancelled, most were general surgeries (237/33.8% andorthopedic surgery (200/28.5%; surgeons or assistant surgeons(518/73.9% and anesthesiologists (183/26.1% were responsible forcancellations. The primary reasons for cancellation were unfavorableclinical status of patients (225/32.1%, no show up of patients(119/17.0%, change in medical management (79/11.3%, patientnot appropriately prepared (53/7.5% and lack of material (52/7.4%.Conclusions: This study enabled identifying the frequency and causesof surgical cancellations at a public hospital, so as to contribute toimproving professional performance in this area.

  11. Nuclear plant cancellations: causes, costs, and consequences

    International Nuclear Information System (INIS)

    1983-04-01

    This study was commissioned in order to help quantify the effects of nuclear plant cancellations on the Nation's electricity prices. This report presents a historical overview of nuclear plant cancellations through 1982, the costs associated with those cancellations, and the reasons that the projects were terminated. A survey is presented of the precedents for regulatory treatment of the costs, the specific methods of cost recovery that were adopted, and the impacts of these decisions upon ratepayers, utility stockholders, and taxpayers. Finally, the report identifies a series of other nuclear plants that remain at risk of canellation in the future, principally as a result of similar demand, finance, or regulatory problems cited as causes of cancellation in the past. The costs associated with these potential cancellations are estimated, along with their regional distributions, and likely methods of cost recovery are suggested

  12. The Histone Deacetylase Inhibitor, Vorinostat, Reduces Tumor Growth at the Metastatic Bone Site and Associated Osteolysis, but Promotes Normal Bone Loss

    OpenAIRE

    Pratap, Jitesh; Akech, Jacqueline; Wixted, John J.; Szabo, Gabriela; Hussain, Sadiq; McGee-Lawrence, Meghan E.; Li, Xiaodong; Bedard, Krystin; Dhillon, Robinder J.; van Wijnen, Andre J.; Stein, Janet L.; Stein, Gary S.; Westendorf, Jennifer J.; Lian, Jane B.

    2010-01-01

    Vorinostat, an oral histone deacetylase inhibitor with anti-tumor activity, is in clinical trials for hematological and solid tumors that metastasize and compromise bone structure. Consequently, there is a requirement to establish the effects of vorinostat on tumor growth within bone. Breast (MDA-231) and prostate (PC3) cancer cells were injected into tibias of SCID/NCr mice and the effects of vorinostat on tumor growth and osteolytic disease were assessed by radiography, μCT, histological an...

  13. Tibial bone fractures occurring after medioproximal tibial bone grafts for oral and maxillofacial reconstruction.

    Science.gov (United States)

    Kim, Il-Kyu; Cho, Hyun-Young; Pae, Sang-Pill; Jung, Bum-Sang; Cho, Hyun-Woo; Seo, Ji-Hoon

    2013-12-01

    Oral and maxillofacial defects often require bone grafts to restore missing tissues. Well-recognized donor sites include the anterior and posterior iliac crest, rib, and intercalvarial diploic bone. The proximal tibia has also been explored as an alternative donor site. The use of the tibia for bone graft has many benefits, such as procedural ease, adequate volume of cancellous and cortical bone, and minimal complications. Although patients rarely complain of pain, swelling, discomfort, or dysfunction, such as gait disturbance, both patients and surgeons should pay close attention to such after effects due to the possibility of tibial fracture. The purpose of this study is to analyze tibial fractures that occurring after osteotomy for a medioproximal tibial graft. An analysis was intended for patients who underwent medioproximal tibial graft between March 2004 and December 2011 in Inha University Hospital. A total of 105 subjects, 30 females and 75 males, ranged in age from 17 to 78 years. We investigated the age, weight, circumstance, and graft timing in relation to tibial fracture. Tibial fractures occurred in four of 105 patients. There were no significant differences in graft region, shape, or scale between the fractured and non-fractured patients. Patients who undergo tibial grafts must be careful of excessive external force after the operation.

  14. Utilizing time-lapse micro-CT-correlated bisphosphonate binding kinetics and soft tissue-derived input functions to differentiate site-specific changes in bone metabolism in vivo.

    Science.gov (United States)

    Tower, R J; Campbell, G M; Müller, M; Glüer, C C; Tiwari, S

    2015-05-01

    The turnover of bone is a tightly regulated process between bone formation and resorption to ensure skeletal homeostasis. This process differs between bone types, with trabecular bone often associated with higher turnover than cortical bone. Analyses of bone by micro-computed tomography (micro-CT) reveal changes in structure and mineral content, but are limited in the study of metabolic activity at a single time point, while analyses of serum markers can reveal changes in bone metabolism, but cannot delineate the origin of any aberrant findings. To obtain a site-specific assessment of bone metabolic status, bisphosphonate binding kinetics were utilized. Using a fluorescently-labeled bisphosphonate, we show that early binding kinetics monitored in vivo using fluorescent molecular tomography (FMT) can monitor changes in bone metabolism in response to bone loss, stimulated by ovariectomy (OVX), or bone gain, resulting from treatment with the anabolic bone agent parathyroid hormone (PTH), and is capable of distinguishing different, metabolically distinct skeletal sites. Using time-lapse micro-CT, longitudinal bone turnover was quantified. The spine showed a significantly greater percent resorbing volume and surface in response to OVX, while mice treated with PTH showed significantly greater resorbing volume per bone surface in the spine and significantly greater forming surfaces in the knee. Correlation studies between binding kinetics and micro-CT suggest that forming surfaces, as assessed by time-lapse micro-CT, are preferentially reflected in the rate constant values while forming and resorbing bone volumes primarily affect plateau values. Additionally, we developed a blood pool correction method which now allows for quantitative multi-compartment analyses to be conducted using FMT. These results further expand our understanding of bisphosphonate binding and the use of bisphosphonate binding kinetics as a tool to monitor site-specific changes in bone metabolism in

  15. A Graphic Overlay Method for Selection of Osteotomy Site in Chronic Radial Head Dislocation: An Evaluation of 3D-printed Bone Models.

    Science.gov (United States)

    Kim, Hui Taek; Ahn, Tae Young; Jang, Jae Hoon; Kim, Kang Hee; Lee, Sung Jae; Jung, Duk Young

    2017-03-01

    Three-dimensional (3D) computed tomography imaging is now being used to generate 3D models for planning orthopaedic surgery, but the process remains time consuming and expensive. For chronic radial head dislocation, we have designed a graphic overlay approach that employs selected 3D computer images and widely available software to simplify the process of osteotomy site selection. We studied 5 patients (2 traumatic and 3 congenital) with unilateral radial head dislocation. These patients were treated with surgery based on traditional radiographs, but they also had full sets of 3D CT imaging done both before and after their surgery: these 3D CT images form the basis for this study. From the 3D CT images, each patient generated 3 sets of 3D-printed bone models: 2 copies of the preoperative condition, and 1 copy of the postoperative condition. One set of the preoperative models was then actually osteotomized and fixed in the manner suggested by our graphic technique. Arcs of rotation of the 3 sets of 3D-printed bone models were then compared. Arcs of rotation of the 3 groups of bone models were significantly different, with the models osteotomized accordingly to our graphic technique having the widest arcs. For chronic radial head dislocation, our graphic overlay approach simplifies the selection of the osteotomy site(s). Three-dimensional-printed bone models suggest that this approach could improve range of motion of the forearm in actual surgical practice. Level IV-therapeutic study.

  16. Comparison of the distributions of bromine, lead, and zinc in tooth and bone for an ancient Peruvian burial site by X-ray fluorescence

    International Nuclear Information System (INIS)

    Martin, R.R.; Naftel, S.J.; Nelson, A.J.; Sapp, W.D.

    2007-01-01

    Synchrotron micro X-ray fluorescence was used to study the distribution of selected trace elements (Zn, Pb, and Br) in tooth and bone samples obtained from an individual from a pre-Columbian archaeological site (Caber) located on the north coast of Peru. The results show that Zn, Pb, and Br are present in both the teeth and bone samples and that the Zn and Pb seem to be confined to similar regions (cementum and periostium), while Br shows a novel distribution with enrichment close to the Haversian canals and (or) in regions that appear to be Ca deficient. (author)

  17. Dating of cremated bones

    OpenAIRE

    Lanting, JN; Aerts-Bijma, AT; van der Plicht, J; Boaretto, E.; Carmi, I.

    2001-01-01

    When dating unburnt bone, bone collagen, the organic fraction of the bone, is used. Collagen does not survive the heat of the cremation pyre, so dating of cremated bone has been considered impossible. Structural carbonate in the mineral fraction of the bone, however, survives the cremation process. We developed a method of dating cremated bone by accelerator mass spectrometry (AMS), using this carbonate fraction. Here we present results for a variety of prehistoric sites and ages, showing a r...

  18. Effects of long-term estrogen replacement therapy on bone turnover in periarticular tibial osteophytes in surgically postmenopausal cynomolgus monkeys.

    Science.gov (United States)

    Olson, Erik J; Lindgren, Bruce R; Carlson, Cathy S

    2008-05-01

    The aims of the present study were to assess the effects of long-term estrogen replacement therapy (ERT) on size and indices of bone turnover in periarticular osteophytes in ovariectomized cynomolgus monkeys and to compare dynamic indices of bone turnover in osteophyte bone with those of subchondral bone (SCB) and epiphyseal/metaphyseal cancellous (EMC) bone. One hundred sixty-five adult female cynomolgus macaques were bilaterally ovariectomized and randomly divided into three age- and weight-matched treatment groups for a 36-month treatment period. Group 1 (OVX control) received no treatment, Group 2 (SPE) received soy phytoestrogens, and Group 3 (ERT) received conjugated equine estrogens in the diet; all monkeys were labeled with calcein before necropsy. A midcoronal, plastic-embedded section of the right proximal tibia from 20 randomly selected animals per treatment group was examined histologically. Forty-nine of the sections (OVX control, n=16; SPE, n=16; ERT, n=17) contained lateral abaxial osteophytes, and static and dynamic histomorphometry measurements were taken from osteophyte bone, SCB from the lateral tibial plateau, and EMC bone. Data were analyzed using the ANOVA and Kruskal-Wallis test, correlation and regression methods, and the Friedman and Wilcoxon signed rank test. There was no significant effect of long-term ERT on osteophyte area or on any static or dynamic histomorphometry parameters. The bone volume, trabecular number, and trabecular thickness in osteophyte bone were considerably higher than in EMC bone; whereas, trabecular separation was considerably lower in osteophyte bone. In all three treatment groups, BS/BV was significantly lower in osteophyte bone vs. EMC bone and significantly higher in osteophyte bone vs. lateral SCB. We conclude that osteophyte area and static and dynamic histomorphometry parameters within periarticular tibial osteophytes in ovariectomized cynomolgus monkeys are not significantly influenced by long-term ERT, but

  19. Effects of long-term estrogen replacement therapy on bone turnover in periarticular tibial osteophytes in surgically postmenopausal cynomolgus monkeys

    Science.gov (United States)

    Olson, Erik J.; Lindgren, Bruce R.; Carlson, Cathy S.

    2008-01-01

    The aims of the present study were to assess the effects of long-term estrogen replacement therapy (ERT) on size and indices of bone turnover in periarticular osteophytes in ovariectomized cynomolgus monkeys and to compare dynamic indices of bone turnover in osteophyte bone with those of subchondral bone (SCB) and epiphyseal/metaphyseal cancellous (EMC) bone. One hundred sixty-five adult female cynomolgus macaques were bilaterally ovariectomized and randomly divided into three age- and weight-matched treatment groups for a 36-month treatment period. Group 1 (OVX control) received no treatment, Group 2 (SPE) received soy phytoestrogens, and Group 3 (ERT) received conjugated equine estrogens in the diet; all monkeys were labeled with calcein before necropsy. A midcoronal, plastic-embedded section of the right proximal tibia from 20 randomly selected animals per treatment group was examined histologically. Forty-nine of the sections (OVX control, n=16; SPE, n=16; ERT, n=17) contained lateral abaxial osteophytes, and static and dynamic histomorphometry measurements were taken from osteophyte bone, SCB from the lateral tibial plateau, and EMC bone. Data were analyzed using the ANOVA and Kruskal-Wallis test, correlation and regression methods, and the Friedman and Wilcoxon signed rank test. There was no significant effect of long-term ERT on osteophyte area or on any static or dynamic histomorphometry parameters. The bone volume, trabecular number, and trabecular thickness in osteophyte bone were considerably higher than in EMC bone; whereas, trabecular separation was considerably lower in osteophyte bone. In all three treatment groups, BS/BV was significantly lower in osteophyte bone vs. EMC bone and significantly higher in osteophyte bone vs. lateral SCB. We conclude that osteophyte area and static and dynamic histomorphometry parameters within periarticular tibial osteophytes in ovariectomized cynomolgus monkeys are not significantly influenced by long-term ERT, but

  20. Late Pleistocene steppe lion Panthera leo spelaea (Goldfuss, 1810) footprints and bone records from open air sites in northern Germany - Evidence of hyena-lion antagonism and scavenging in Europe

    Science.gov (United States)

    Diedrich, Cajus G.

    2011-07-01

    Bone remains and a trackway of Pantheraichnus bottropensis nov. ichg. ichnsp. of the Late Pleistocene lion Panthera leo spelaea ( Goldfuss, 1810) have been recovered from Bottrop and other open air sites in northern Germany. Some of these bones are from open air hyena den sites. A relative high proportion of lion bones (20%) exhibit bite, chew or nibble marks, or bone crushing and nibbling caused by a large carnivore. Repeated patterns of similar bone damage have been compared to bone remains found at hyena dens in gypsum karst areas and cave sites in northern Germany. Ice Age spotted hyenas have been the main antagonists and the main scavengers on lion carcasses. The remains appear to have been imported often by hyenas into their communal dens, supporting the theory of strong hyena-lion antagonism, similar to the well documented antagonism between modern African lions and spotted hyenas. Most of the lion bones from the open air hyena den at Bottrop are probably a result of such antagonism, as are the rare remains of these carnivores found within large hyena prey bone accumulations along the Pleistocene rivers. The Emscher River terrace also has the largest quantity of hyena remains from open air river terrace sites in northern Germany. Their cub remains, and incomplete chewed prey bones from mammoths and woolly rhinoceroses, typical of hyena activity, underline the character of these sites as cub-raising and communal dens, where their prey was accumulated along the riverbanks in a similar manner to modern African hyenas.

  1. Carbonate substitution in the mineral component of bone: Discriminating the structural changes, simultaneously imposed by carbonate in A and B sites of apatite

    Science.gov (United States)

    Madupalli, Honey; Pavan, Barbara; Tecklenburg, Mary M. J.

    2017-11-01

    The mineral component of bone and other biological calcifications is primarily a carbonate substituted calcium apatite. Integration of carbonate into two sites, substitution for phosphate (B-type carbonate) and substitution for hydroxide (A-type carbonate), influences the crystal properties which relate to the functional properties of bone. In the present work, a series of AB-type carbonated apatites (AB-CAp) having varying A-type and B-type carbonate weight fractions were prepared and analyzed by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and carbonate analysis. A detailed characterization of A-site and B-site carbonate assignment in the FTIR ν3 region is proposed. The mass fractions of carbonate in A-site and B-site of AB-CAp correlate differently with crystal axis length and crystallite domain size. In this series of samples reduction in crystal domain size correlates only with A-type carbonate which indicates that carbonate in the A-site is more disruptive to the apatite structure than carbonate in the B-site. High temperature methods were required to produce significant A-type carbonation of apatite, indicating a higher energy barrier for the formation of A-type carbonate than for B-type carbonate. This is consistent with the dominance of B-type carbonate substitution in low temperature synthetic and biological apatites.

  2. Investigating the tool marks on oracle bones inscriptions from the Yinxu site (ca., 1319-1046 BC), Henan province, China.

    Science.gov (United States)

    Zhao, Xiaolong; Tang, Jigen; Gu, Zhou; Shi, Jilong; Yang, Yimin; Wang, Changsui

    2016-09-01

    Oracle Bone Inscriptions in the Shang dynasty (1600-1046 BC) are the earliest well-developed writing forms of the Chinese character system, and their carving techniques have not been studied by tool marks analysis with microscopy. In this study, a digital microscope with three-dimensional surface reconstruction based on extended depth of focus technology was used to investigate tool marks on the surface of four pieces of oracle bones excavated at the eastern area of Huayuanzhuang, Yinxu site(ca., 1319-1046 BC), the last capital of the Shang dynasty, Henan province, China. The results show that there were two procedures to carve the characters on the analyzed tortoise shells. The first procedure was direct carving. The second was "outlining design," which means to engrave a formal character after engraving a draft with a pointed tool. Most of the strokes developed by an engraver do not overlap the smaller draft, which implies that the outlining design would be a sound way to avoid errors such as wrong and missing characters. The strokes of these characters have different shape at two ends and variations on width and depth of the grooves. Moreover, the bottom of the grooves is always rugged. Thus, the use of rotary wheel-cutting tools could be ruled out. In most cases, the starting points of the strokes are round or flat while the finishing points are always pointed. Moreover, the strokes should be engraved from top to bottom. When vertical or horizontal strokes had been engraved, the shell would be turned about 90 degrees to engrave the crossed strokes from top to bottom. There was no preferred order to engrave vertical or horizontal strokes. Since both sides of the grooves of the characters are neat and there exists no unorganized tool marks, then it is suggested that some sharp tools had been used for engraving characters on the shells. Microsc. Res. Tech. 79:827-832, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. 20 CFR 217.25 - Who may cancel an application.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Who may cancel an application. 217.25 Section... APPLICATION FOR ANNUITY OR LUMP SUM Cancellation of Application § 217.25 Who may cancel an application. An application may be cancelled by the claimant or a person described in § 217.17. If the claimant is deceased...

  4. 20 CFR 217.26 - How to cancel an application.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false How to cancel an application. 217.26 Section... APPLICATION FOR ANNUITY OR LUMP SUM Cancellation of Application § 217.26 How to cancel an application. An application may be cancelled under the following conditions: (a) Before an annuity is awarded. The application...

  5. Active noise cancellation in hearing devices

    DEFF Research Database (Denmark)

    2013-01-01

    Disclosed is a hearing device system comprising at least one hearing aid circuitry and at least one active noise cancellation unit, the at least one hearing aid circuitry comprises at least one input transducer adapted to convert a first audio signal to an electric audio signal; a signal processor...... connected to the at least one input transducer and adapted to process said electric audio signal by at least partially correcting for a hearing loss of a user; an output transducer adapted to generate from at least said processed electric audio signal a sound pressure in an ear canal of the user, whereby...... the generated sound pressure is at least partially corrected for the hearing loss of the user; ; the at least one active noise cancellation unit being adapted to provide an active noise cancellation signal adapted to perform active noise cancellation of an acoustical signal entering the ear canal in addition...

  6. Optimal Reinsertion of Cancelled Train Lines

    DEFF Research Database (Denmark)

    Groth, Julie Jespersen; Clausen, Jens

    2006-01-01

    One recovery strategy in case of a major disruption in rail network is to cancel all trains on a specific line of the network. When the disturbance has ended, the cancelled line must be reinserted as soon as possible. In this article we present a mixed integer programming (MIP) model for calculat....... The model finds the optimal solution in an average of 0.5 CPU seconds in each test case....

  7. Biomechanical study of the bone tissue with dental implants interaction

    Directory of Open Access Journals (Sweden)

    Navrátil P.

    2011-12-01

    Full Text Available The article deals with the stress-strain analysis of human mandible in the physiological state and after the dental implant application. The evaluation is focused on assessing of the cancellous bone tissue modeling-level. Three cancellous bone model-types are assessed: Non-trabecular model with homogenous isotropic material, nontrabecular model with inhomogeneous material obtained from computer tomography data using CT Data Analysis software, and trabecular model built from mandible section image. Computational modeling was chosen as the most suitable solution method and the solution on two-dimensional level was carried out. The results show that strain is more preferable value than stress in case of evaluation of mechanical response in cancellous bone. The non-trabecular model with CT-obtained material model is not acceptable for stress-strain analysis of the cancellous bone for singularities occurring on interfaces of regions with different values of modulus of elasticity.

  8. Mineral and Skeletal Homeostasis Influence the Manner of Bone Loss in Metabolic Osteoporosis due to Calcium-Deprived Diet in Different Sites of Rat Vertebra and Femur

    Directory of Open Access Journals (Sweden)

    Marzia Ferretti

    2015-01-01

    Full Text Available Rats fed calcium-deprived diet develop osteoporosis due to enhanced bone resorption, secondary to parathyroid overactivity resulting from nutritional hypocalcemia. Therefore, rats provide a good experimental animal model for studying bone modelling alterations during biochemical osteoporosis. Three-month-old Sprague-Dawley male rats were divided into 4 groups: (1 baseline, (2 normal diet for 4 weeks, (3 calcium-deprived diet for 4 weeks, and (4 calcium-deprived diet for 4 weeks and concomitant administration of PTH (1-34 40 µg/Kg/day. Histomorphometrical analyses were made on cortical and trabecular bone of lumbar vertebral body as well as of mid-diaphysis and distal metaphysis of femur. In all rats fed calcium-deprived diet, despite the reduction of trabecular number (due to the maintenance of mineral homeostasis, an intense activity of bone deposition occurs on the surface of the few remaining trabeculae (in answering to mechanical stresses and, consequently, to maintain the skeletal homeostasis. Different responses were detected in different sites of cortical bone, depending on their main function in answering mineral or skeletal homeostasis. This study represents the starting point for work-in-progress researches, with the aim of defining in detail timing and manners of evolution and recovery of biochemical osteoporosis.

  9. Bone quality evaluation at dental implant site using multislice CT, micro-CT, and cone beam CT

    NARCIS (Netherlands)

    Parsa, A.; Ibrahim, N.; Hassan, B.; van der Stelt, P.; Wismeijer, D.

    2015-01-01

    Objectives The first purpose of this study was to analyze the correlation between bone volume fraction (BV/TV) and calibrated radiographic bone density Hounsfield units (HU) in human jaws, derived from micro-CT and multislice computed tomography (MSCT), respectively. The second aim was to assess the

  10. Dispersion cancellation in a triple Laue interferometer

    International Nuclear Information System (INIS)

    Lemmel, Hartmut

    2014-01-01

    The concept of dispersion cancellation has been established in light optics to improve the resolution of interferometric measurements on dispersive media. Odd order dispersion cancellation allows to measure phase shifts without defocusing the interferometer due to wave packet displacements, while even order dispersion cancellation allows to measure time lags without losing resolution due to wave packet spreading. We report that either type of dispersion cancellation can be realized very easily in a triple Laue interferometer. Such interferometers are Mach–Zehnder interferometers based on Bragg diffraction, and are commonly used for neutrons and x-rays. Although the first x-ray interferometer was built nearly five decades ago, the feature of dispersion cancellation hasn't been recognized so far because the concept was hardly known in the neutron and x-ray community. However, it explains right away the surprising decoupling of phase shift and spatial displacement that we have discovered recently in neutron interferometry (Lemmel and Wagh 2010 Phys. Rev. A 82 033626). Furthermore, this article might inspire the light optics community to consider whether a triple Laue interferometer for laser light would be useful and feasible. We explain how dispersion cancellation works in neutron interferometry, and we describe the setup rigorously by solving the Schrödinger equation and by calculating the path integral. We point out, that the latter has to be evaluated with special care since in our setup the beam trajectory moves with respect to the crystal lattice of the interferometer. (paper)

  11. Osteoblastic mesenchymal stem cell sheet combined with Choukroun platelet-rich fibrin induces bone formation at an ectopic site.

    Science.gov (United States)

    Wang, Zhifa; Weng, Yanming; Lu, Shengjun; Zong, Chunlin; Qiu, Jianyong; Liu, Yanpu; Liu, Bin

    2015-08-01

    To analyze the effects of platelet-rich fibrin (PRF) on mesenchymal stem cells (MSCs) in vitro and investigate in vivo bone formation by MSC sheets with PRF. Cell proliferation and expression of osteogenesis-related genes within MSC sheets were assessed upon exposure to PRF from the same donors. We then injected MSC sheet fragments with or without PRF subcutaneously in nude mice and assessed bone formation by micro-computed tomography and histological analyses. PRF significantly stimulated MSC proliferation and osteogenesis in vitro. MSC sheets injected with or without PRF formed new bone, but those with PRF produced significantly more and denser bone. MSC sheets can be used to generate tissue engineered bone upon injection, and PRF increases the osteogenic capacity of MSC sheets in vitro and in vivo. © 2014 Wiley Periodicals, Inc.

  12. Experimental studies of the visualisation of spongious bone by high resolution computed tomography

    International Nuclear Information System (INIS)

    Henschel, M.G.; Freyschmidt, J.; Holland, B.R.

    1995-01-01

    18 native human lumbar vertebrae were placed in a water phantom and examined by HR-CT. The scans were compared with contact radiographs of correlating thin bone sections by morphologic criteria. The measured lower limit of visualisation of cancellous bone structures is celarly worse than expected from the measurements of spatial resolution with standard phantoms used for HR-CT (0.6 versus 0.4 mm). True and exact imaging of normal cancellous bone cannot be achieved even by modern HR-CT. Noise creates structures mimicking cancellous bone. (orig./MG) [de

  13. Bone density does not reflect mechanical properties in early-stage arthrosis

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, CC; Hvid, I

    2001-01-01

    : medial arthrosis, lateral control, normal medial and normal lateral controls. The specimens were tested in compression to determine mechanical properties and then physical/compositional properties. Compared to the normal medial control, we found reductions in ultimate stress, Young's modulus, and failure...... cancellous bone and the 3 controls. None of the mechanical properties of arthrotic cancellous bone could be predicted by the physical/compositional properties measured. The increase in bone tissue in early-stage arthrotic cancellous bone did not make up for the loss of mechanical properties, which suggests...

  14. Patient experiences with interventions to reduce surgery cancellations

    DEFF Research Database (Denmark)

    Hovlid, Einar; von Plessen, Christian; Haug, Kjell

    2013-01-01

    The cancellation of planned surgery harms patients, increases waiting times and wastes scarce health resources. Previous studies have evaluated interventions to reduce cancellations from medical and management perspectives; these have focused on cost, length of stay, improved efficiency......, and reduced post-operative complications. In our case a hospital had experienced high cancellation rates and therefore redesigned their pathway for elective surgery to reduce cancelations. We studied how patients experienced interventions to reduce cancellations....

  15. Primary implant stability in augmented sinuslift-sites after completed bone regeneration: a randomized controlled clinical study comparing four subantrally inserted biomaterials

    OpenAIRE

    Angelo Troedhan; Izabela Schlichting; Andreas Kurrek; Marcel Wainwright

    2014-01-01

    Implant-Insertion-Torque-Value (ITV) proved to be a significant clinical parameter to predict long term implant success-rates and to decide upon immediate loading. The study evaluated ITVs, when four different and commonly used biomaterials were used in sinuslift-procedures compared to natural subantral bone in two-stage-implant-procedures. The tHUCSL-INTRALIFT-method was chosen for sinuslifting in 155 sinuslift-sites for its minimal invasive transcrestal approach and scalable augmentation vo...

  16. An alternative method to record rising temperatures during dental implant site preparation: a preliminary study using bovine bone

    Directory of Open Access Journals (Sweden)

    Domenica Laurito

    2010-12-01

    Full Text Available Overheating is constantly mentioned as a risk factor for bone necrosis that could compromise the dental implant primary stability. Uncontrolled thermal injury can result in a fibrous tissue, interpositioned at the implant-bone interface, compromising the long-term prognosis. The methods used to record temperature rise include either direct recording by thermocouple instruments or indirect estimating by infrared thermography. This preliminary study was carried out using bovine bone and a different method of temperatures rising estimation is presented. Two different types of drills were tested using fluoroptic thermometer and the effectiveness of this alternative temperature recording method was evaluated.

  17. Thermal evaluation by infrared measurement of implant site preparation between single and gradual drilling in artificial bone blocks of different densities.

    Science.gov (United States)

    Möhlhenrich, S C; Abouridouane, M; Heussen, N; Hölzle, F; Klocke, F; Modabber, A

    2016-11-01

    The aim of this study was to investigate the influence of bone density and drilling protocol on heat generation during implant bed preparation. Ten single and 10 gradual implant sites with diameters of 2.8, 3.5, and 4.2mm were prepared in four artificial bone blocks (density types I-IV; D1-D4). Drilling was done at constant speed (1500rpm) and with external irrigation (50ml/min); vertical speed was set at 2mm/s. An infrared camera was used for temperature measurements. Significantly higher temperatures for single drilling were found between 2.8-mm drills in D1 (P=0.0014) and D4 (P<0.0001) and between 3.5-mm drills in D3 (P=0.0087) and D4 (P<0.0001), as well as between 4.2-mm drills in D1 (P<0.0001) and D4 (P=0.0014). Low bone density led to a thermal decrease after single drilling and a thermal increase after gradual drilling. Burs with a large diameter always showed a higher temperature generation. In comparisons between 2.8- and 4.2-mm diameters for both single and gradual drills, significant differences (P<0.001) were noted for bone types II, III, and IV. Single drilling could generate more heat than traditional sequential drilling, and bone density, as well as drill diameter, influenced thermal increases. Particularly in lower-density bone, conventional sequential drilling seems to raise the temperature less. Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. Applications of the direct photon absorption technique for measuring bone mineral content in vivo. Determination of body composition in vivo. Annual progress report, 15 July 1971--15 July 1972

    International Nuclear Information System (INIS)

    Cameron, J.R.

    1972-01-01

    The bone mineral content, BMC, determined by monoenergetic photon absorption technique, of 29 different locations on the long bones and vertebral columns of 24 skeletons was measured. Compressive tests were made on bone from these locations in which the maximum load and maximum stress were measured. Also the ultimate strain, modulus of elasticity and energy absorbed to failure were determined for compact bone from the femoral diaphysis and cancellous bone from the eighth through eleventh thoracic vertebrae. Correlations and predictive relationships between these parameters were examined to investigate the applicability of using the BMC at sites normally measured in vivo, i.e. radius and ulna in estimating the BMC and/or strength of the spine or femoral neck. It was found that the BMC at sites on the same bone were highly correlated and the BMC at sites on different bones were also highly interrelated. The BMC at various sites on the long bones could be estimated to between 10 and 15 per cent from the BMC of sites on the radius or ulna. (U.S.)

  19. The assessment of cortical and spongy bone mineral content with quantitative computed tomography; A comparison of measurement sites in relation to certain diseases with metabolic bone disorder

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Kiyoko; Matsubayashi, Takashi; Aritomi, Hiroshi; Iwanami, Shigeru; Kusano, Shouichi (Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine); Marumo, Fumiaki

    1991-12-01

    The CT numbers of cortex at the level of 20 cm (CT20) and spongiosa in the lateral condyle at the level of 2 cm (CT02) proximal from the distal end of the femur, and the bone mineral density of spongiosa in the L3 body (BMD), were obtained by QCT. The study included 43 female patients with rheumatoid arthritis (RA), 71 female patients with primary osteoporosis (OP), 20 female nondialyzed patients with chronic renal failure (CRF: nonHD), 37 hemodialyzed patients (CRF: HD),including 13 parathyroidectomized patients (CRF: HD, PTX), and 10 healthy volunteers. CT20 correlated closely with age in RA. CT02 and BMD correlated closely with age in RA and OP. CT20 and CT02 correlated closely with the duration of hemodialysis in CRF:HD, but not with the duration of disease in RA. The values of CT20 and CT02 in the CRF: HD. PTX group was significantly lower than those in the other CRF groups. BMD in the RA group was not different from that of healthy volunteers. The CT20 values of the one-third of RA patients older than 60 years were extremely low compared with those of the other two-thirds. The results indicated that BMD was useful in assessing bone mineral content in OP, but not in RA. CT02 and CT20 were useful in assessing bone mineral content in these three diseases, CT20 was especially useful for patients in the CRF: HD group and those with RA older than 60 years, but it was not useful in the CRF: nonHD group. (author).

  20. Primary implant stability in augmented sinuslift-sites after completed bone regeneration: a randomized controlled clinical study comparing four subantrally inserted biomaterials.

    Science.gov (United States)

    Troedhan, Angelo; Schlichting, Izabela; Kurrek, Andreas; Wainwright, Marcel

    2014-07-30

    Implant-Insertion-Torque-Value (ITV) proved to be a significant clinical parameter to predict long term implant success-rates and to decide upon immediate loading. The study evaluated ITVs, when four different and commonly used biomaterials were used in sinuslift-procedures compared to natural subantral bone in two-stage-implant-procedures. The tHUCSL-INTRALIFT-method was chosen for sinuslifting in 155 sinuslift-sites for its minimal invasive transcrestal approach and scalable augmentation volume. Four different biomaterials were inserted randomly (easy-graft CRYSTAL n = 38, easy-graft CLASSIC n = 41, NanoBone n = 42, BioOss n = 34), 2 ccm in each case. After a mean healing period of 8,92 months uniform tapered screw Q2-implants were inserted and Drill-Torque-Values (DTV) and ITV were recorded and compared to a group of 36 subantral sites without need of sinuslifting. DTV/ITV were processed for statistics by ANOVA-tests. Mean DTV/ITV obtained in Ncm were: Control Group 10,2/22,2, Bio-Oss 12,7/26,2, NanoBone 17,5/33,3, easy-graft CLASSIC 20,3/45,9, easy-graft CRYSTAL 23,8/56,6 Ncm, significance-level of differences throughout p < 0,05. Within the limits of this study the results suggest self-hardening solid-block-like bone-graft-materials to achieve significantly better DTV/ITV than loose granulate biomaterials for its suspected improvement of vascularization and mineralization of the subantral scaffold by full immobilization of the augmentation site towards pressure changes in the human sinus at normal breathing.

  1. Bone healing and bone substitutes.

    Science.gov (United States)

    Costantino, Peter D; Hiltzik, David; Govindaraj, Satish; Moche, Jason

    2002-02-01

    With the advent of new biomaterials and surgical techniques, the reconstructive surgeon has a wider range of treatment modalities for the rehabilitation and reconstruction of craniofacial skeletal deformities than ever before. These innovative substances act as true bone graft substitutes, thereby allowing the surgeon to avoid the use of autogenous bone grafts and their associated donor site morbidity. Surgeons have long been interested in producing a composite graft that can heal faster by induction, incorporate with surrounding tissues, and be remodeled to resemble native bone. Currently, there are a host of bone graft substitutes available that vary in both their composition and properties. Craniomaxillofacial surgeons must therefore become comfortable with numerous biomaterials to best tailor the treatment for each patient individually. Ongoing investigations into the next phase of tissue engineering will continue to bring us closer to the ability to regenerate or replace bone.

  2. A three-dimensional cell-loading system using autologous plasma loaded into a porous β-tricalcium-phosphate block promotes bone formation at extraskeletal sites in rats

    International Nuclear Information System (INIS)

    Tajima, Nobutaka; Sotome, Shinichi; Marukawa, Eriko; Omura, Ken; Shinomiya, Kenichi

    2007-01-01

    The effects of platelet-rich plasma (PRP) and platelet-poor plasma (PPP) on bone marrow stromal cells (MSCs) with respect to proliferation, osteogenic differentiation, and bone formation capability were investigated. MSCs derived from rats were cultured in medium containing mixtures of PRP and PPP. Fibrinogen was eliminated prior to the experiment. The DNA content and alkaline phosphatase (ALP) activity were measured. PRP stimulated cell proliferation and inhibited osteoblastic differentiation. To examine the effects of fibrin in plasma, MSCs were cultured in PRP or PPP fibrin gels formed both on a cell culture insert installed in a culture well and on the bottom surface of the same culture well. The ALP activities of the MSCs in both of the gels were higher than those on the surface of the culture wells. The MSCs cultured on the PPP gel showed the highest ALP activity. The effects of PRP and PPP used as scaffolds for bone formation were also investigated. MSCs were suspended in PRP or PPP, introduced into porous β-tricalcium phosphate blocks, and then implanted into subcutaneous sites. Subsequently, bone formation was quantified. Further in vivo studies found that implants prepared using PPP had a greater osteoinductive capability than implants prepared with PRP

  3. A three-dimensional cell-loading system using autologous plasma loaded into a porous {beta}-tricalcium-phosphate block promotes bone formation at extraskeletal sites in rats

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, Nobutaka [Oral and Maxillofacial Surgery, Graduate school, Tokyo Medical and Dental University (Japan); Orthopaedic and Spinal Surgery, Graduate school, Tokyo Medical and Dental University (Japan); Sotome, Shinichi [Orthopaedic and Spinal Surgery, Graduate school, Tokyo Medical and Dental University (Japan); Marukawa, Eriko [Oral and Maxillofacial Surgery, Graduate school, Tokyo Medical and Dental University (Japan); Orthopaedic and Spinal Surgery, Graduate school, Tokyo Medical and Dental University (Japan); Omura, Ken [Oral and Maxillofacial Surgery, Graduate school, Tokyo Medical and Dental University (Japan); Center of Excellence Program for Frontier Research on Molecular Destruction and Reconstruction of Tooth and Bone, Tokyo Medical and Dental University (Japan); Shinomiya, Kenichi [Orthopaedic and Spinal Surgery, Graduate school, Tokyo Medical and Dental University (Japan) and Center of Excellence Program for Frontier Research on Molecular Destruction and Reconstruction of Tooth and Bone, Tokyo Medical and Dental University (Japan) and Advanced Bone and Joint Science (Japan)]. E-mail: shinomiya.orth@tmd.ac.jp

    2007-05-16

    The effects of platelet-rich plasma (PRP) and platelet-poor plasma (PPP) on bone marrow stromal cells (MSCs) with respect to proliferation, osteogenic differentiation, and bone formation capability were investigated. MSCs derived from rats were cultured in medium containing mixtures of PRP and PPP. Fibrinogen was eliminated prior to the experiment. The DNA content and alkaline phosphatase (ALP) activity were measured. PRP stimulated cell proliferation and inhibited osteoblastic differentiation. To examine the effects of fibrin in plasma, MSCs were cultured in PRP or PPP fibrin gels formed both on a cell culture insert installed in a culture well and on the bottom surface of the same culture well. The ALP activities of the MSCs in both of the gels were higher than those on the surface of the culture wells. The MSCs cultured on the PPP gel showed the highest ALP activity. The effects of PRP and PPP used as scaffolds for bone formation were also investigated. MSCs were suspended in PRP or PPP, introduced into porous {beta}-tricalcium phosphate blocks, and then implanted into subcutaneous sites. Subsequently, bone formation was quantified. Further in vivo studies found that implants prepared using PPP had a greater osteoinductive capability than implants prepared with PRP.

  4. Reoperative surgical stabilization of a painful nonunited rib fracture using bone grafting and a metal plate.

    Science.gov (United States)

    Cho, Yang Hyun; Kim, Hyun Koo; Kang, Du-Young; Choi, Young Ho

    2009-09-01

    We report a case of a nonunited sixth rib in a patient with multiple rib fractures who underwent internal fixation using a wire and Judet strut 3 times. During the following 3 years, the patient continued to complain of pain and instability. At surgery, a pseudarthrosis between the ends of the sixth rib was excised. A longitudinal gutter crossing the fracture site was fashioned and splinted with an inlay block of cancellous bone grafted from the iliac crest; stabilization was accomplished with a reconstruction plate and screws. The following 2 years of follow-up demonstrated no instability or pain.

  5. Mandibular reconstruction using bone allografts

    International Nuclear Information System (INIS)

    Chang Joon Yim

    1999-01-01

    . Combinations of allografts and autografts for mandibular reconstruction have enjoyed great success since their introduction in the late 1960's and early 1970's. Due to its high osteogenic potential, marrow and cancellous bone was used for reconstruction of the mandible. For reconstruction of large defects, surgeons used a scaffold to support the cancellous bone. This practice led to the use of allogeneic bone crib in which the cancellous bone could be packed. Reconstruction of the mandible by this combination is now very commonplace

  6. Maintenance of marginal bone support and soft tissue esthetics at immediately provisionalized OsseoSpeed implants placed into extraction sites: 2-year results.

    Science.gov (United States)

    Noelken, Robert; Neffe, Bettina Anna; Kunkel, Martin; Wagner, Wilfried

    2014-02-01

    proof of principle for the preservation of marginal bone height at immediately placed and provisionalized OsseoSpeed implants after a follow-up of at least 12 months. Even implant sites with facial bony deficiencies can be successfully treated with a favorable esthetic outcome using the immediate implant insertion, immediate reconstruction, and immediate provisionalization technique. © 2013 John Wiley & Sons A/S.

  7. Interpixel crosstalk cancellation on holographic memory

    Science.gov (United States)

    Ishii, Toshiki; Fujimura, Ryushi

    2017-09-01

    In holographic memory systems, there have been no practical techniques to minimize interpixel crosstalk thus far. We developed an interpixel crosstalk cancellation technique using a checkerboard phase pattern with a phase difference of π/2, which can decrease the size of the spatial filter along the Fourier plane with the signal-to-noise ratio (SNR) kept high. This interpixel crosstalk cancellation technique is simple because it requires only one phase plate in the signal beam path. We verified the effect of such a cancellation technique by simulation. The improvement of SNR is maximized to 6.5 dB when the filter size specified in the Nyquist areal ratio is approximately 1.05 in ideal optical systems with no other fixed noise. The proposed technique can improve SNR by 0.85 in an assumed monocular architecture at an actual noise intensity. This improvement of SNR is very useful for realizing high-density recording or enhancing system robustness.

  8. 76 FR 55890 - Cancellation of Supplemental Environmental Impact Statement for Ancillary Facilities for the...

    Science.gov (United States)

    2011-09-09

    ... (SPR). In April 2011, Congress rescinded all funding for the SPR expansion project. FOR FURTHER... included no new funding to continue SPR expansion efforts and proposed cancellation of previously... expansion project, DOE prepared an environmental impact statement for the Site Selection for the Expansion...

  9. Bone tumor

    Science.gov (United States)

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

  10. Theory of the cancellation of 4-photon resonances by an off-resonance 3-photon cancellation

    DEFF Research Database (Denmark)

    Elk, M.; Lambropoulos, P.; Tang, X.

    1992-01-01

    We present a complete account of our recent work [Phys. Rev. A 44, 31 (1991)] in which we investigate the theory of cancellation by interference between the absorption of three fundamental laser photons and one third-harmonic photon. The theory is formulated in terms of the density matrix so...... as to take detunings, dephasing, and laser bandwidth into account. The result is a theory of cancellation for finite detuning that explains how four-photon resonances can be canceled by a three-photon mechanism if there is an atomic level at near-three-photon resonance. The treatment is extended to focused...

  11. Imperfect generalized transmit beamforming with co-channel interference cancelation

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh; Alouini, Mohamed-Slim

    2010-01-01

    of outdated statistical ordering of the interferers instantaneous powers on the effectiveness of dominant interference cancelation is investigated against the less complex adaptive arbitrary cancelation scheme. For the system models described above, new exact

  12. Recurrent surgical site infection of the spine diagnosed by dual 18F-NaF-bone PET/CT with early-phase scan

    International Nuclear Information System (INIS)

    Shim, Jai-Joon; Lee, Jeong Won; Jeon, Min Hyok; Lee, Sang Mi

    2016-01-01

    We report a case of a 31-year-old man who showed recurrently elevated level of the serum inflammatory marker C-reactive protein (CRP) after spinal operation. He underwent 18 F-flurodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) and dual 18 F-sodium-fluoride ( 18 F-NaF) PET/CT with an additional early-phase scan to find a hidden inflammation focus. Only mildly increased 18 F-FDG was found at the surgical site of T11 spine on 18 F-FDG PET/CT. In contrast, dual 18 F-NaF bone PET/CT with early-phase scan demonstrated focal active inflammation at the surgical site of T11 spine. After a revision operation of the T11 spine, serum CRP level decreased to the normal range without any symptom or sign of inflammation. Inflammatory focus in the surgical site of the spine can be detected with using dual 18 F-NaF bone PET/CT scan with early-phase scan. (orig.)

  13. Distortion Cancellation via Polyphase Multipath Circuits

    NARCIS (Netherlands)

    Mensink, E.; Klumperink, Eric A.M.; Nauta, Bram

    The central question of this paper is: can we enhance the spectral purity of nonlinear circuits with the help of polyphase multipath circuits. Polyphase multipath circuits are circuits with two or more paths that exploit phase differences between the paths to cancel unwanted signals. It turns out

  14. 75 FR 28543 - Sunshine Act Meeting: Canceled

    Science.gov (United States)

    2010-05-21

    ... BROADCASTING BOARD OF GOVERNORS Sunshine Act Meeting: Canceled Date and Time: Tuesday, May 18, 2010, 11 a.m.-12:15 p.m. Place: Cohen Building, Room 3321, 330 Independence Ave., SW., Washington, DC 20237. Closed Meeting: The members of the Broadcasting Board of Governors (BBG) will meet in closed...

  15. Measurement of drag and its cancellation

    Energy Technology Data Exchange (ETDEWEB)

    DeBra, D B; Conklin, J W, E-mail: johnwc@stanford.edu [Department of Aeronautics and Astronautics, Stanford University, Stanford, CA 94305-4035 (United States)

    2011-05-07

    The design of drag cancellation missions of the future will take advantage of the technology experience of the past. The importance of data for modeling of the atmosphere led to at least six types of measurement: (a) balloon flights, (b) missile-launched falling spheres, (c) the 'cannonball' satellites of Ken Champion with accelerometers for low-altitude drag measurement (late 1960s and early 1970s), (d) the Agena flight of LOGACS (1967), a Bell MESA accelerometer mounted on a rotating platform to spectrally shift low-frequency errors in the accelerometer, (e) a series of French low-level accelerometers (e.g. CACTUS, 1975), and (f) correction of differential accelerations for drag errors in measuring gravity gradient on a pair of satellites (GRACE, 2002). The independent invention of the drag-free satellite concept by Pugh and Lange (1964) to cancel external disturbance added implementation opportunities. Its first flight application was for ephemeris prediction improvement with the DISCOS flight (1972)-still the only extended free test mass flight. Then successful flights for reduced disturbance environment for science measurement with gyros on GP-B (2004) and for improved accuracy in geodesy and ocean studies (GOCE, 2009) each using accelerometer measurements to control the drag-canceling thrust. LISA, DECIGO, BBO and other gravity wave-measuring satellite systems will push the cancellation of drag to new levels.

  16. Measurement of drag and its cancellation

    International Nuclear Information System (INIS)

    DeBra, D B; Conklin, J W

    2011-01-01

    The design of drag cancellation missions of the future will take advantage of the technology experience of the past. The importance of data for modeling of the atmosphere led to at least six types of measurement: (a) balloon flights, (b) missile-launched falling spheres, (c) the 'cannonball' satellites of Ken Champion with accelerometers for low-altitude drag measurement (late 1960s and early 1970s), (d) the Agena flight of LOGACS (1967), a Bell MESA accelerometer mounted on a rotating platform to spectrally shift low-frequency errors in the accelerometer, (e) a series of French low-level accelerometers (e.g. CACTUS, 1975), and (f) correction of differential accelerations for drag errors in measuring gravity gradient on a pair of satellites (GRACE, 2002). The independent invention of the drag-free satellite concept by Pugh and Lange (1964) to cancel external disturbance added implementation opportunities. Its first flight application was for ephemeris prediction improvement with the DISCOS flight (1972)-still the only extended free test mass flight. Then successful flights for reduced disturbance environment for science measurement with gyros on GP-B (2004) and for improved accuracy in geodesy and ocean studies (GOCE, 2009) each using accelerometer measurements to control the drag-canceling thrust. LISA, DECIGO, BBO and other gravity wave-measuring satellite systems will push the cancellation of drag to new levels.

  17. 78 FR 52513 - Sunshine Act Meeting; Cancellation

    Science.gov (United States)

    2013-08-23

    ..., August 21, 2013, page 51713. ANNOUNCED TIME AND DATE OF MEETING: Wednesday, August 21, 2013, 10 a.m.-11 a.m. MEETING CANCELED. For a recorded message containing the latest agenda information, call (301) 504... West Highway, Bethesda, MD 20814 (301) 504- 7923. Dated: August 21, 2013. Todd A. Stevenson, Secretary...

  18. Thermal Noise Canceling in LNAs : A Review

    NARCIS (Netherlands)

    Nauta, Bram; Klumperink, Eric A.M.; Bruccoleri, Frederico

    2004-01-01

    Most wide-band amplifiers suffer from a fundamental trade-off between noise figure NF and source impedance matching, which limits NF to values typically above 3dB. Recently, a feed-forward noise canceling technique has been proposed to break this trade-off. This paper reviews the principle of the

  19. Amplifiers Exploiting Thermal Noise Canceling: A Review

    NARCIS (Netherlands)

    Klumperink, Eric A.M.; Bruccoleri, F.; Stroet, P.M.; Stroet, Peter; Nauta, Bram

    2004-01-01

    Wide-band LNAs suffer from a fundamental trade-off between noise figure NF and source impedance matching, which limits NF to values typically above 3dB. Recently, a feed-forward noise canceling technique has been proposed to break this trade-off. This paper reviews the principle of the technique and

  20. Multi moment cancellation of participant fluctuations

    OpenAIRE

    Begun, Viktor; Mackowiak-Pawlowska, Maja

    2017-01-01

    We summarize the new method for the correction of participant fluctuations in high energy nucleus-nucleus collisions. It allows to estimate a fluctuation baseline in comparison to a useful signal. In particular cases of a weak signal compared to baseline, it allows to cancel the baseline contribution from participants.

  1. Database Cancellation: The "Hows" and "Whys"

    Science.gov (United States)

    Shapiro, Steven

    2012-01-01

    Database cancellation is one of the most difficult tasks performed by a librarian. This may seem counter-intuitive but, psychologically, it is certainly true. When a librarian or a team of librarians has invested a great deal of time doing research, talking to potential users, and conducting trials before deciding to subscribe to a database, they…

  2. 40 CFR 152.99 - Petitions to cancel registration.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Petitions to cancel registration. 152... Submitters' Rights § 152.99 Petitions to cancel registration. An original data submitter may petition the Agency to deny or cancel the registration of a product in accordance with this section if he has...

  3. Case review analysis of operating room decisions to cancel surgery.

    Science.gov (United States)

    Chang, Ju-Hsin; Chen, Ke-Wei; Chen, Kuen-Bao; Poon, Kin-Shing; Liu, Shih-Kai

    2014-07-23

    Cancellation of surgery close to scheduled time causes a waste of healthcare resources. The current study analyzes surgery cancellations occurring after the patient has been prepared for the operating room, in order to see whether improvements in the surgery planning process may reduce the number of cancellations. In a retrospective chart review of operating room surgery cancellations during the period from 2006 to 2011, cancellations were divided into the following categories: inadequate NPO; medical; surgical; system; airway; incomplete evaluation. The relative use of these reasons in relation to patient age and surgical department was then evaluated. Forty-one percent of cancellations were for other than medical reasons. Among these, 17.7% were due to incomplete evaluation, and 8.2% were due to family issues. Sixty seven percent of cancelled cases eventually received surgery. The relative use of individual reasons for cancellation varied with patient age and surgical department. The difference between cancellations before and after anesthesia was dependent on the causes of cancellation, but not age, sex, ASA status, or follow-up procedures required. Almost half of the cancellations were not due to medical reasons, and these cancellations could be reduced by better administrative and surgical planning and better communication with the patient and/or his family.

  4. Voluntary Cancellation of a Pesticide Product or Use

    Science.gov (United States)

    A registrant can cancel the registration of a pesticide product or cancel a use from the product’s label at any time as stated in Section 6(f) of FIFRA. Learn how to request a voluntary cancellation or use deletion.

  5. Different expression of MIB1 in primary site of non-Hodgkin lymphoma and its bone marrow deposits, a pilot study

    Directory of Open Access Journals (Sweden)

    Malysz J

    2017-02-01

    Full Text Available Jozef Malysz,1 Juanita J Evans,2 Malcolm Acon-Laws,3 Michael G Bayerl,1 Michael H Creer1 1Department of Pathology, Penn State Milton S Hershey Medical Center, Hershey, PA, 2Department of Pathology, St. John Heath – Providence, Southfield, MI, USA; 3Laboratorio de Patologia Hospital Cima, San Jose, Costa Rica Abstract: Evaluation of mindbomb E3 ubiquitin protein ligase 1 (MIB1 (Ki67 proliferation index (PI in B-cell non-Hodgkin lymphomas is increasingly a common addition to classification of lymphoma and staging procedures. Clinicians relay on PI as a surrogate marker of biologic activity; however, no established guidelines have been published whether PI at the primary site of the tumor gives the same answer as evaluation of tumor in staging marrow. In our study, dual immunohistochemical staining for MIB1 and CD20 was performed on tissue from primary site and bone marrow involved by B-cell non-Hodgkin lymphoma to compare PI for each individual patient. For all patients, MIB1 expression was higher at primary tumor site as compared to staging marrow. Additional analysis was performed to investigate the degree of difference depending on lymphoma morphology. Patients with large cell lymphoma at the primary site and large cell morphology in the marrow (LCL-L, those with large cell morphology at the primary site and small cell morphology in the marrow (LCL-S, and those with small cell morphology at the primary site and small cells in the marrow (SCL-S were compared. As expected, LCL cases had a higher mean PI at the primary site when compared to SCL cases (28.5% vs 2.8%, P=0.0001. In addition, the most significant difference between medullary and extramedullary PI was observed in cases with discordant morphology (LCL-S (21% vs 1.1%, P=0.009. Our results indicate that PI of lymphoma within the bone marrow should not be used as a surrogate prognostic indicator of lymphoma biology in its primary site. Keywords: proliferation index, biologic behavior

  6. The penetration of cefazolin, erythromycin and methicillin into human bone tissue

    DEFF Research Database (Denmark)

    Sørensen, T S; Colding, H; Schroeder, E

    1978-01-01

    The penetration of cefazolin, erythromycin and methicillin into normal bone was studied in 20 patients undergoing surgery for fracture in the trochanteric region of the femur. The antibiotic concentrations were determined in serum, bone marrow, and cancellous and cortical bone. For all three...... antibiotics the bone marrow concentrations were of the same order of magnitude as the serum concentrations. In the eight patients receiving erythromycin, detectable concentrations were found in all the cancellous bone specimens (ranging from 1/7 to 1/2 of the serum concentration) and in three cortical bone...... specimens (ranging from 1/50 to 1/5 of the serum concentration). In the six patients receiving cefazolin, a detectable concentration was found in only one cancellous bone sample. In the six patients receiving methicillin, detectable concentrations were found only in the blood contaminated specimens of one...

  7. Performance comparison of optical interference cancellation system architectures.

    Science.gov (United States)

    Lu, Maddie; Chang, Matt; Deng, Yanhua; Prucnal, Paul R

    2013-04-10

    The performance of three optics-based interference cancellation systems are compared and contrasted with each other, and with traditional electronic techniques for interference cancellation. The comparison is based on a set of common performance metrics that we have developed for this purpose. It is shown that thorough evaluation of our optical approaches takes into account the traditional notions of depth of cancellation and dynamic range, along with notions of link loss and uniformity of cancellation. Our evaluation shows that our use of optical components affords performance that surpasses traditional electronic approaches, and that the optimal choice for an optical interference canceller requires taking into account the performance metrics discussed in this paper.

  8. Scanning electron microscopy of bone.

    Science.gov (United States)

    Boyde, Alan

    2012-01-01

    This chapter described methods for Scanning Electron Microscopical imaging of bone and bone cells. Backscattered electron (BSE) imaging is by far the most useful in the bone field, followed by secondary electrons (SE) and the energy dispersive X-ray (EDX) analytical modes. This chapter considers preparing and imaging samples of unembedded bone having 3D detail in a 3D surface, topography-free, polished or micromilled, resin-embedded block surfaces, and resin casts of space in bone matrix. The chapter considers methods for fixation, drying, looking at undersides of bone cells, and coating. Maceration with alkaline bacterial pronase, hypochlorite, hydrogen peroxide, and sodium or potassium hydroxide to remove cells and unmineralised matrix is described in detail. Attention is given especially to methods for 3D BSE SEM imaging of bone samples and recommendations for the types of resin embedding of bone for BSE imaging are given. Correlated confocal and SEM imaging of PMMA-embedded bone requires the use of glycerol to coverslip. Cathodoluminescence (CL) mode SEM imaging is an alternative for visualising fluorescent mineralising front labels such as calcein and tetracyclines. Making spatial casts from PMMA or other resin embedded samples is an important use of this material. Correlation with other imaging means, including microradiography and microtomography is important. Shipping wet bone samples between labs is best done in glycerol. Environmental SEM (ESEM, controlled vacuum mode) is valuable in eliminating -"charging" problems which are common with complex, cancellous bone samples.

  9. Bone taphonomy of the Schöningen "Spear Horizon South" and its implications for site formation and hominin meat provisioning.

    Science.gov (United States)

    Starkovich, Britt M; Conard, Nicholas J

    2015-12-01

    This paper presents the faunal remains from the new excavation area at the Lower Paleolithic site of Schöningen. The focus of the study is on the southern extension of the main find horizon (Spear Horizon South), which includes the layer that yielded the famous Schöningen spears (13 II-4). Taxonomic data corroborate previous studies, that hominins primarily hunted Equus mosbachensis, a large Pleistocene horse. Equid body part representation at the site suggests that the animals were hunted and butchered locally. There is no evidence for density-mediated attrition in the assemblage. Weathering damage is uncommon, though there is ample evidence that carnivores had access to the bone. Carnivore bite sizes were measured and compared to experimental data provided by previous authors. Based on relationships between bite size and carnivore behavior and body size, we conclude that the primary modifying agents were large carnivores (i.e., wolves or saber-toothed cats). Previous studies show that carnivores often had secondary access to the remains, after hominins. Cut marks are commonly arranged haphazardly on the bones. This may indicate that multiple hominins participated in the butchery of horse skeletons, or that they were butchered over the course of hours or days. Cut marks on axial elements are more "orderly," which probably reflects the physical logistics of orienting one's body in relation to a large carcass. These data differ from sites formed by Middle and Upper Paleolithic hominins, which might suggest that in later times, a system of organized meat provisioning was already in place. Taken together, the faunal evidence from the Spear Horizon South indicates that late Lower Paleolithic hominins using the site understood the behaviors of different prey species, hunted socially to take down large game, and successfully competed with large carnivores on the landscape for primary access to ungulate remains. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Optimizing Segmental Bone Regeneration Using Functionally Graded Scaffolds

    Science.gov (United States)

    2012-10-01

    mechanical strength (130– 190 MPa).4 Cancellous bone accounts for the other 20% of the total bone mass and is highly porous (50%–90%), with *10% of the...bionanotechnology. Adv Mater 18, 1345, 2006. 96. Drury , J.L., and Mooney, D.J. Hydrogels for tissue engi- neering: scaffold design variables and applications. Bio

  11. Bone growth and turnover in progesterone receptor knockout mice.

    Energy Technology Data Exchange (ETDEWEB)

    Rickard, David J.; Iwaniec, Urszula T.; Evans, Glenda; Hefferan, Theresa E.; Hunter, Jaime C.; Waters, Katrina M.; Lydon, John P.; O' Malley, Bert W.; Khosla, Sundeep; Spelsberg, Thomas C.; Turner, Russell T.

    2008-05-01

    The role of progesterone receptor (PR) signaling in skeletal metabolism is controversial. To address whether signaling through the PR is necessary for normal bone growth and turnover, we performed histomorphometric and mCT analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 weeks of age. These mice possess a null mutation of the PR locus, which blocks the gene expression of A and B isoforms of PR. Body weight gain, uterine weight gain and tibia longitudinal bone growth was normal in PRKO mice. In contrast, total and cortical bone mass were increased in long bones of post-pubertal (12 and 26-week-old) PRKO mice, whereas cancellous bone mass was normal in the tibia but increased in the humerus. The striking 57% decrease in cancellous bone from the proximal tibia metaphysis which occurred between 6 and 26 weeks in WT mice was abolished in PRKO mice. The improved bone balance in aging PRKO mice was associated with elevated bone formation and a tendency toward reduced osteoclast perimeter. Taken together, these findings suggest that PR signaling in mice attenuates the accumulation of cortical bone mass during adolescence and is required for early age-related loss of cancellous bone.

  12. Properties of deproteinized bone for reparation of big segmental defect in long bone

    Institute of Scientific and Technical Information of China (English)

    JIAN Yue-kui; TIAN Xiao-bin; LI Bo; QIU Bing; ZHOU Zuo-jia; YANG Zheng; LI Qi-hong

    2008-01-01

    Objective: To explore suitable scaffold material for big segmental long bone defect by studying the properties of the prepared deproteinized bone. Methods: Cancellated bone were made as 30 mm ×3 mm ×3 mm bone blocks from inferior extremity of pig femur along bone trabecula. The deproteinized bone was prepared with an improved method. Their morphological features, components, cell compatibility, mechanical and immunological properties were investigated respectively. Results: Deproteinized bone maintained natural re ticular pore system. The main organic material is collagen Ⅰand inorganic composition is hydroxyapatite. It has good mechanical properties, cell adhesion rate and histocompatibility. Conlusion: This deproteinized bone can be applicable as scaffold for reparation of big segmental defect in long bone.

  13. Elective surgery cancelation on day of surgery: An endless dilemma

    Directory of Open Access Journals (Sweden)

    A Fayed

    2016-01-01

    Full Text Available Background: Cancelation of surgery is a constant agonizing dilemma for nearly all healthcare services that has been intensively investigated to find out its roots, consequences, and possible solutions. The rates of cancelation of surgery vary between centers and more so among surgical specialties with numerous reasons standing behind this phenomenon. Patients and Methods: In the current study, analysis of monthly cancelation rates from January 2009 to December 2012, and assessment of establishing new operating rooms (ORs using statistical process control charts was conducted. A detailed review of a total of 1813 cases canceled on the day of surgery from January to December 2012, to examine the various reasons of cancelation among surgical specialties. Results: The average cancelation rate was 11.1%, which dropped to 9.0% after launching of new theaters. Four reasons explained about 80% of cancelations; Patients "no show" was the leading cause of cancelation (27%. One-fourth of cancelations (24.3% were due to the need for further optimization, and the third most prominent cause of cancelation was a lack of OR time (19.5%. Unavailability of staff/equipment/implants accounted for only 0.7% of cancelations. The "no show" was the most common cause of cancelation among all surgical specialties ranging from 21% for plastic surgery to 32% in ophthalmic surgeries. Conclusion: It was confirmed that there is a unique profile of cancelation of surgery problem for every institute, an extension of infrastructure may not be the only solution. Control charts helped to enhance the general picture and are functional in monitoring and evaluating changes in the cancelation of surgery.

  14. Cloaking through cancellation of diffusive wave scattering

    KAUST Repository

    Farhat, Mohamed

    2016-08-10

    A new cloaking mechanism, which makes enclosed objects invisible to diffusive photon density waves, is proposed. First, diffusive scattering from a basic core-shell geometry, which represents the cloaked structure, is studied. The conditions of scattering cancellation in a quasi-static scattering regime are derived. These allow for tailoring the diffusivity constant of the shell enclosing the object so that the fields scattered from the shell and the object cancel each other. This means that the photon flow outside the cloak behaves as if the cloaked object were not present. Diffusive light invisibility may have potential applications in hiding hot spots in infrared thermography or tissue imaging. © 2016 The Author(s) Published by the Royal Society. All rights reserved.

  15. Active microphonic noise cancellation in radiation detectors

    International Nuclear Information System (INIS)

    Zimmermann, Sergio

    2013-01-01

    A new adaptive filtering technique to reduce microphonic noise in radiation detectors is presented. The technique is based on system identification that actively cancels the microphonic noise. A sensor is used to measures mechanical disturbances that cause vibration on the detector assembly, and the digital adaptive filtering estimates the impact of these disturbances on the microphonic noise. The noise then can be subtracted from the actual detector measurement. In this paper the technique is presented and simulations are used to support this approach. -- Highlights: •A sensor is used to measures mechanical disturbances that cause vibration on the detector assembly. •Digital adaptive filtering estimates the impact of these disturbances on the microphonic noise. •The noise is then subtracted from the actual detector measurement. •We use simulations to demonstrate the performance of this approach. •After cancellation, we recover most of the original energy resolution

  16. Amplifiers Exploiting Thermal Noise Canceling: A Review

    OpenAIRE

    Klumperink, Eric A.M.; Bruccoleri, Federico; Stroet, Peter; Nauta, Bram

    2004-01-01

    Wide-band LNAs suffer from a fundamental trade-off between noise figure NF and source impedance matching, which limits NF to values typically above 3dB. Recently, a feed-forward noise canceling technique has been proposed to break this trade-off. This paper reviews the principle of the technique and its key properties. Although the technique has been applied to wideband CMOS LNAs, it can just as well be implemented exploiting transconductance elements realized with oth...

  17. Evaluation of the effect of platelet rich plasma (PRP) on enhancement of bone healing in diaphyseal bone defects by radiography and computed tomography

    International Nuclear Information System (INIS)

    Özak, Ahmet; Yardimci, Cenk; Nİsbet, Özlem H.; Bayrak, İlkay Koray; Nİsbet, Cevat

    2010-01-01

    The effect of platelet-rich plasma (PRP) with autogenous cancellous bone graft on enhancement of bone healing in diaphyseal bone defects was evaluated. A 4-mm defect was created in the middiaphysis of the tibias of 20 rabbits. Rabbits were divided into two groups of ten animals each: only autogenous cancellous graft, PRP and autogenous cancellous graft. In animals of group 1, only autogenous cancellous grafts, and to those in group 2, PRP and autogenous cancellous grafts, were applied to the defect. Radiographical and computed tomography (CT) views were taken and evaluated on postoperative days 0, 15, 30, 60, and 90. According to the bone formation, union, and remodeling scores, group 1 had better scores than group 2 on days 30, 60, and 90. The density was significantly increased on day 60 than on days 0, 15, and 30 in group 1. In conclusion, it was evaluated that PRP could not enhance the bone regeneration in diaphyseal defects when used with autogenous cancellous bone graft

  18. Using Comics to Communicate Legal Contract Cancellation

    Directory of Open Access Journals (Sweden)

    Marietjie Botes

    2017-10-01

    Full Text Available This article investigates how comics can be used to adequately communicate the correct process of contract cancellation and whether comics can enhance understanding of the legal process. A survey of pre-owned vehicle buyers of various levels of education in Pretoria, South Africa found that when comics are used to communicate contract cancellation, a significant increase in the comprehension of the legal cancellation process occurs. The results may influence how contracting parties may choose to communicate complex legal issues in future, specifically to consumers with little formal education or when parties are confronted with severe language barriers, which is highly relevant in a country such as South Africa with eleven official languages and generally low levels of education. The article argues that representatives tasked with explaining contractual content to contracting parties should consider making use of comics to aid them in their communication process to ensure proper understanding and execution of terms and conditions, which in turn may lead to fewer disputes and avoid expensive litigation.

  19. Closing the medullary canal after retrograde nail removal using a bioabsorbable bone plug: technical tip

    NARCIS (Netherlands)

    Schepers, T.; Vogels, L. M. M.

    2012-01-01

    We describe a simple technique for closure of the intra-articular opening after the removal of a retrograde femur nail. With the use of a gelatine bioabsorbable bone plug the medullary canal is closed, reducing leakage of blood and cancellous bone particles from the bone into the knee joint

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose ... limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  2. Bone X-Ray (Radiography)

    Science.gov (United States)

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

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  4. Macrophage inflammatory protein-1α shows predictive value as a risk marker for subjects and sites vulnerable to bone loss in a longitudinal model of aggressive periodontitis.

    Science.gov (United States)

    Fine, Daniel H; Markowitz, Kenneth; Fairlie, Karen; Tischio-Bereski, Debbie; Ferrandiz, Javier; Godboley, Dipti; Furgang, David; Gunsolley, John; Best, Al

    2014-01-01

    Improved diagnostics remains a fundamental goal of biomedical research. This study was designed to assess cytokine biomarkers that could predict bone loss (BL) in localized aggressive periodontitis. 2,058 adolescents were screened. Two groups of 50 periodontally healthy adolescents were enrolled in the longitudinal study. One group had Aggregatibacter actinomycetemcomitans (Aa), the putative pathogen, while the matched cohort did not. Cytokine levels were assessed in saliva and gingival crevicular fluid (GCF). Participants were sampled, examined, and radiographed every 6 months for 2-3 years. Disease was defined as radiographic evidence of BL. Saliva and GCF was collected at each visit, frozen, and then tested retrospectively after detection of BL. Sixteen subjects with Aa developed BL. Saliva from Aa-positive and Aa-negative healthy subjects was compared to subjects who developed BL. GCF was collected from 16 subjects with BL and from another 38 subjects who remained healthy. GCF from BL sites in the 16 subjects was compared to healthy sites in these same subjects and to healthy sites in subjects who remained healthy. Results showed that cytokines in saliva associated with acute inflammation were elevated in subjects who developed BL (i.e., MIP-1α MIP-1β IL-α, IL-1β and IL-8; p<0.01). MIP-1α was elevated 13-fold, 6 months prior to BL. When MIP-1α levels were set at 40 pg/ml, 98% of healthy sites were below that level (Specificity); whereas, 93% of sites with BL were higher (Sensitivity), with comparable Predictive Values of 98%; p<0.0001; 95% C.I. = 42.5-52.7). MIP-1α consistently showed elevated levels as a biomarker for BL in both saliva and GCF, 6 months prior to BL. MIP-1α continues to demonstrate its strong candidacy as a diagnostic biomarker for both subject and site vulnerability to BL.

  5. Macrophage inflammatory protein-1α shows predictive value as a risk marker for subjects and sites vulnerable to bone loss in a longitudinal model of aggressive periodontitis.

    Directory of Open Access Journals (Sweden)

    Daniel H Fine

    Full Text Available Improved diagnostics remains a fundamental goal of biomedical research. This study was designed to assess cytokine biomarkers that could predict bone loss (BL in localized aggressive periodontitis. 2,058 adolescents were screened. Two groups of 50 periodontally healthy adolescents were enrolled in the longitudinal study. One group had Aggregatibacter actinomycetemcomitans (Aa, the putative pathogen, while the matched cohort did not. Cytokine levels were assessed in saliva and gingival crevicular fluid (GCF. Participants were sampled, examined, and radiographed every 6 months for 2-3 years. Disease was defined as radiographic evidence of BL. Saliva and GCF was collected at each visit, frozen, and then tested retrospectively after detection of BL. Sixteen subjects with Aa developed BL. Saliva from Aa-positive and Aa-negative healthy subjects was compared to subjects who developed BL. GCF was collected from 16 subjects with BL and from another 38 subjects who remained healthy. GCF from BL sites in the 16 subjects was compared to healthy sites in these same subjects and to healthy sites in subjects who remained healthy. Results showed that cytokines in saliva associated with acute inflammation were elevated in subjects who developed BL (i.e., MIP-1α MIP-1β IL-α, IL-1β and IL-8; p<0.01. MIP-1α was elevated 13-fold, 6 months prior to BL. When MIP-1α levels were set at 40 pg/ml, 98% of healthy sites were below that level (Specificity; whereas, 93% of sites with BL were higher (Sensitivity, with comparable Predictive Values of 98%; p<0.0001; 95% C.I. = 42.5-52.7. MIP-1α consistently showed elevated levels as a biomarker for BL in both saliva and GCF, 6 months prior to BL. MIP-1α continues to demonstrate its strong candidacy as a diagnostic biomarker for both subject and site vulnerability to BL.

  6. Intermittent Parathyroid Hormone Enhances Cancellous Osseointegration of a Novel Murine Tibial Implant

    Science.gov (United States)

    Yang, Xu; Ricciardi, Benjamin F.; Dvorzhinskiy, Aleksey; Brial, Caroline; Lane, Zachary; Bhimani, Samrath; Burket, Jayme C.; Hu, Bin; Sarkisian, Alexander M.; Ross, F. Patrick; van der Meulen, Marjolein C.H.; Bostrom, Mathias P.G.

    2015-01-01

    Background: Long-term fixation of uncemented joint implants requires early mechanical stability and implant osseointegration. To date, osseointegration has been unreliable and remains a major challenge in cementless total knee arthroplasty. We developed a murine model in which an intra-articular proximal tibial titanium implant with a roughened stem can be loaded through the knee joint. Using this model, we tested the hypothesis that intermittent injection of parathyroid hormone (iPTH) would increase proximal tibial cancellous osseointegration. Methods: Ten-week-old female C57BL/6 mice received a subcutaneous injection of PTH (40 μg/kg/day) or a vehicle (n = 45 per treatment group) five days per week for six weeks, at which time the baseline group was killed (n = 6 per treatment group) and an implant was inserted into the proximal part of the tibiae of the remaining mice. Injections were continued until the animals were killed at one week (n = 7 per treatment group), two weeks (n = 14 per treatment group), or four weeks (n = 17 per treatment group) after implantation. Outcomes included peri-implant bone morphology as analyzed with micro-computed tomography (microCT), osseointegration percentage and bone area fraction as shown with backscattered electron microscopy, cellular composition as demonstrated by immunohistochemical analysis, and pullout strength as measured with mechanical testing. Results: Preimplantation iPTH increased the epiphyseal bone volume fraction by 31.6%. When the data at post-implantation weeks 1, 2, and 4 were averaged for the iPTH-treated mice, the bone volume fraction was 74.5% higher in the peri-implant region and 168% higher distal to the implant compared with the bone volume fractions in the same regions in the vehicle-treated mice. Additionally, the trabecular number was 84.8% greater in the peri-implant region and 74.3% greater distal to the implant. Metaphyseal osseointegration and bone area fraction were 28.1% and 70.1% higher

  7. Flow cytometric evaluation of peripheral blood and bone marrow and fine-needle aspirate samples from multiple sites in dogs with multicentric lymphoma.

    Science.gov (United States)

    Joetzke, Alexa E; Eberle, Nina; Nolte, Ingo; Mischke, Reinhard; Simon, Daniela

    2012-06-01

    To determine whether the extent of disease in dogs with lymphoma can be assessed via flow cytometry and to evaluate the suitability of fine-needle aspirates from the liver and spleen of dogs for flow cytometric examination. 44 dogs with multicentric B-cell (n = 35) or T-cell lymphoma (9) and 5 healthy control dogs. Procedures-Peripheral blood and bone marrow samples and fine-needle aspirates of lymph node, liver, and spleen were examined via flow cytometry. Logarithmically transformed T-cell-to-B-cell percentage ratio (log[T:B]) values were calculated. Thresholds defined by use of log(T:B) values of samples from control dogs were used to determine extranodal lymphoma involvement in lymphoma-affected dogs; results were compared with cytologic findings. 12 of 245 (5%) samples (9 liver, 1 spleen, and 2 bone marrow) had insufficient cellularity for flow cytometric evaluation. Mean log(T:B) values of samples from dogs with B-cell lymphoma were significantly lower than those of samples from the same site in dogs with T-cell lymphoma and in control dogs. In dogs with T-cell lymphoma, the log(T:B) of lymph node, bone marrow, and spleen samples was significantly higher than in control dogs. Of 165 samples assessed for extranodal lymphoma involvement, 116 (70%) tested positive via flow cytometric analysis; results agreed with cytologic findings in 133 of 161 (83%) samples evaluated via both methods. Results suggested that flow cytometry may aid in detection of extranodal lymphoma involvement in dogs, but further research is needed. Most fine-needle aspirates of liver and spleen were suitable for flow cytometric evaluation.

  8. Site-matched assessment of structural and tissue properties of cortical bone using scanning acoustic microscopy and synchrotron radiation μCT

    International Nuclear Information System (INIS)

    Raum, K; Leguerney, I; Chandelier, F; Talmant, M; Saied, A; Peyrin, F; Laugier, P

    2006-01-01

    200 MHz scanning acoustic microscopy (SAM) and synchrotron radiation μCT (SR-μCT) were used to assess microstructural parameters and tissue properties in site-matched regions of interest in cortical bone. Anterior and postero-lateral regions of ten cross sections from human cortical radius were explored. Structural parameters, including diameter and number of Haversian canals per cortical area (Ca.Dm, N.Ca/Ar) and porosity Po were assessed with both methods using a custom-developed image fusion and analysis software. Acoustic impedance Z and degree of mineralization of bone DMB were extracted separately for osteonal and interstitial tissues from the fused images. Structural parameter estimations obtained from radiographic and acoustic images were almost identical. DMB and impedance values were in the range between 0.77 and 1.28 g cm -3 and 5.13 and 12.1 Mrayl, respectively. Interindividual and regional variations were observed, whereas the strongest difference was found between osteonal and interstitial tissues (Z: 7.2 ± 1.1 Mrayl versus 9.3 ± 1.0 Mrayl, DMB: 1.06 ± 0.07 g cm -3 versus 1.16 ± 0.05 g cm -3 , paired t-test, p 2 = 0.174, p -4 ) and for the pooled (osteonal and interstitial) data. The regression of the pooled osteonal and interstitial tissue data follows a second-order polynomial (R 2 = 0.39, p -4 ). Both modalities fulfil the requirement for a simultaneous evaluation of cortical bone microstructure and material properties at the tissue level. While SAM inspection is limited to the evaluation of carefully prepared sample surfaces, SR-μCT provides volumetric information on the tissue without substantial preparation requirements. However, SAM provides a quantitative estimate of elastic properties at the tissue level that cannot be captured by SR-μCT

  9. Quantitative ultrasound of the calcaneus with parametric imaging: correlation with bone mineral density at different sites and with anthropometric data in menopausal women

    International Nuclear Information System (INIS)

    Louis, O.; Kaufman, L.; Osteaux, M.

    2000-01-01

    Objective: To prospectively study the relationship of quantitative ultrasound of the calcaneus with anthromopometric variables and with bone mineral density (BMD) assessed at the level of the calcaneus as well as at other sites. Method: Osteosonography of the non-dominant calcaneus was performed in 135 menopausal women, using a DTU-one device with parametric imaging. Broadband ultrasound attenuation (BUA) and speed of sound (SOS) were assessed. BMD of the calcaneus (BMDcal) was measured using dual energy X-ray absorptiometry (DXA), in a subregion matched with the region of interest for osteosonography. BMD of the lumbar trabecular bone was measured using quantitative computed tomography (BMD QCT) while the non-dominant hip was studied using DXA, which provided the total bone mineral density (BMDhip) and that of the Ward triangle (BMDWard). Results: The Pearson correlation coefficients between BUA, SOS and the various measurements of BMD ranged from 0.305 (SOS versus BMDhip) to 0.717 (BUA versus BMDcal). BMD QCT and BMDWard were found to depend on age, but not on weight or height, while BUA, SOS, BMDcal, BMDhip were unrelated to age, but correlated with weight (SOS, BMDhip) or with weight and height (BUA, BMDcal). In a multiple stepwise regression analysis, age was a significant predictor for BMD QCT, BMD hip and BMDWard; BMD QCT, BMDWard and BMDhip admitted BUA as sole predictor, while BMDcal was significantly related to both BUA and SOS. Conclusion: BUA and SOS of the calcaneus, assessed in 135 menopausal women using a parametric imaging device, reflected BMDcal, measured with DXA at a matched region of interest, and did not decline significantly with age

  10. Quantitative ultrasound of the calcaneus with parametric imaging: correlation with bone mineral density at different sites and with anthropometric data in menopausal women

    Energy Technology Data Exchange (ETDEWEB)

    Louis, O.; Kaufman, L.; Osteaux, M

    2000-07-01

    Objective: To prospectively study the relationship of quantitative ultrasound of the calcaneus with anthromopometric variables and with bone mineral density (BMD) assessed at the level of the calcaneus as well as at other sites. Method: Osteosonography of the non-dominant calcaneus was performed in 135 menopausal women, using a DTU-one device with parametric imaging. Broadband ultrasound attenuation (BUA) and speed of sound (SOS) were assessed. BMD of the calcaneus (BMDcal) was measured using dual energy X-ray absorptiometry (DXA), in a subregion matched with the region of interest for osteosonography. BMD of the lumbar trabecular bone was measured using quantitative computed tomography (BMD QCT) while the non-dominant hip was studied using DXA, which provided the total bone mineral density (BMDhip) and that of the Ward triangle (BMDWard). Results: The Pearson correlation coefficients between BUA, SOS and the various measurements of BMD ranged from 0.305 (SOS versus BMDhip) to 0.717 (BUA versus BMDcal). BMD QCT and BMDWard were found to depend on age, but not on weight or height, while BUA, SOS, BMDcal, BMDhip were unrelated to age, but correlated with weight (SOS, BMDhip) or with weight and height (BUA, BMDcal). In a multiple stepwise regression analysis, age was a significant predictor for BMD QCT, BMD hip and BMDWard; BMD QCT, BMDWard and BMDhip admitted BUA as sole predictor, while BMDcal was significantly related to both BUA and SOS. Conclusion: BUA and SOS of the calcaneus, assessed in 135 menopausal women using a parametric imaging device, reflected BMDcal, measured with DXA at a matched region of interest, and did not decline significantly with age.

  11. Post-genome wide association studies and functional analyses identify association of MPP7 gene variants with site-specific bone mineral density.

    Science.gov (United States)

    Xiao, Su-Mei; Kung, Annie Wai Chee; Gao, Yi; Lau, Kam-Shing; Ma, Alvin; Zhang, Zhen-Lin; Liu, Jian-Min; Xia, Wiebo; He, Jin-Wei; Zhao, Lin; Nie, Min; Fu, Wei-Zhen; Zhang, Min-Jia; Sun, Jing; Kwan, Johnny S H; Tso, Gloria Hoi Wan; Dai, Zhi-Jie; Cheung, Ching-Lung; Bow, Cora H; Leung, Anskar Yu Hung; Tan, Kathryn Choon Beng; Sham, Pak Chung

    2012-04-01

    Our previous genome-wide association study (GWAS) in a Hong Kong Southern Chinese population with extreme bone mineral density (BMD) scores revealed suggestive association with MPP7, which ranked second after JAG1 as a candidate gene for BMD. To follow-up this suggestive signal, we replicated the top single-nucleotide polymorphism rs4317882 of MPP7 in three additional independent Asian-descent samples (n= 2684). The association of rs4317882 reached the genome-wide significance in the meta-analysis of all available subjects (P(meta)= 4.58 × 10(-8), n= 4204). Site heterogeneity was observed, with a larger effect on spine than hip BMD. Further functional studies in a zebrafish model revealed that vertebral bone mass was lower in an mpp7 knock-down model compared with the wide-type (P= 9.64 × 10(-4), n= 21). In addition, MPP7 was found to have constitutive expression in human bone-derived cells during osteogenesis. Immunostaining of murine MC3T3-E1 cells revealed that the Mpp7 protein is localized in the plasma membrane and intracytoplasmic compartment of osteoblasts. In an assessment of the function of identified variants, an electrophoretic mobility shift assay demonstrated the binding of transcriptional factor GATA2 to the risk allele 'A' but not the 'G' allele of rs4317882. An mRNA expression study in human peripheral blood mononuclear cells confirmed that the low BMD-related allele 'A' of rs4317882 was associated with lower MPP7 expression (P= 9.07 × 10(-3), n= 135). Our data suggest a genetic and functional association of MPP7 with BMD variation.

  12. Bone tumors

    International Nuclear Information System (INIS)

    Unni, K.K.

    1988-01-01

    This book contains the proceedings on bone tumors. Topics covered include: Bone tumor imaging: Contribution of CT and MRI, staging of bone tumors, perind cell tumors of bone, and metastatic bone disease

  13. The development of a composite bone model for training on placement of dental implants.

    Science.gov (United States)

    Alkhodary, Mohamed Ahmed; Abdelraheim, Abdelraheim Emad Eldin; Elsantawy, Abd Elaleem Hassan; Al Dahman, Yousef Hamad; Al-Mershed, Mohammed

    2015-04-01

    It takes a lot of training on patients for both undergraduate to develop clinical sense as regards to the placement of dental implants in the jaw bones, also, the models provided by the dental implant companies for training are usually made of strengthened synthetic foams, which are far from the composition, and tactile sense provided by natural bone during drilling for clinical placement of dental implants. This is an in-vitro experimental study which utilized bovine femur bone, where the shaft of the femur provided the surface compact layer, and the head provided the cancellous bone layer, to provide a training model similar to jaw bones macroscopic anatomy. Both the compact and cancellous bone samples were characterized using mechanical compressive testing. The elastic moduli of the cancellous and cortical femur bone were comparable to those of the human mandible, and the prepared training model provided a more lifelike condition during the drilling and placement of dental implants. The composite bone model developed simulated the macroscopic anatomy of the jaw bones having a surface layer of compact bone, and a core of cancellous bone, and provided a better and a more natural hands-on experience for placement of dental implants as compared to plastic models made of polyurethane.

  14. 75 FR 54147 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2010-09-03

    ... cancellation is effective September 3, 2010. FOR FURTHER INFORMATION CONTACT: Leonard Cole, Biopesticides and... 23, 2010. W. Michael McDavit. Acting Director, Biopesticides and Pollution Prevention Division...

  15. Thermal Noise Canceling in LNAs: A Review

    OpenAIRE

    Nauta, Bram; Klumperink, Eric A.M.; Bruccoleri, Frederico

    2004-01-01

    Most wide-band amplifiers suffer from a fundamental trade-off between noise figure NF and source impedance matching, which limits NF to values typically above 3dB. Recently, a feed-forward noise canceling technique has been proposed to break this trade-off. This paper reviews the principle of the technique and its key properties. Although the technique has been applied to wideband CMOS LNAs, it can just as well be implemented exploiting transconductance elements realized with other types of t...

  16. Sparse adaptive filters for echo cancellation

    CERN Document Server

    Paleologu, Constantin

    2011-01-01

    Adaptive filters with a large number of coefficients are usually involved in both network and acoustic echo cancellation. Consequently, it is important to improve the convergence rate and tracking of the conventional algorithms used for these applications. This can be achieved by exploiting the sparseness character of the echo paths. Identification of sparse impulse responses was addressed mainly in the last decade with the development of the so-called ``proportionate''-type algorithms. The goal of this book is to present the most important sparse adaptive filters developed for echo cancellati

  17. Anomaly cancellation for super-W-gravity

    Energy Technology Data Exchange (ETDEWEB)

    Mansfield, P. (Dept. of Theoretical Physics, Univ. of Oxford (United Kingdom)); Spence, B. (Dept. of Physics, Univ. of Southampton (United Kingdom))

    1991-08-08

    We generalise the description of minimal superconformal models coupled to supergravity, due to Distler, Hlousek and Kawaii, to super-W-gravity. When the chiral algebra is the generalisation of the W-algebra associated to any contragredient Lie superalgebra the total central charge vanishes as a result of Lie superalgebra identities. When the algebra has only fermionic simple roots there is N=1 superconformal invariance and for this case we describe the Lax operators and construct gravitationally dressed primary superfields of weight zero. We also prove the anomaly cancellation associated with the generalised non-abelian Toda theories. (orig.).

  18. Anomaly cancellation for super- W -gravity

    Science.gov (United States)

    Mansfield, P.; Spence, B.

    1991-08-01

    We generalise the description of minimal superconformal models coupled to supergravity, due to Distler, Hlousek and Kawaii, to super- W -gravity. When the chiral algebra is the generalisation of the W-algebra associated to any contragredient Lie superalgebra the total central charge vanishes as a result of Lie superalgebra identities. When the algebra has only fermionic simple roots there is N = 1 superconformal invariance and for this case we describe the Lax operators and construct gravitationally dressed primary superfields of weight zero. We also prove the anomaly cancellation associated with the generalised non-abelian Toda theories. Address from 1 October 1991: Physics Department, Imperial College, London SW7 2BZ, UK.

  19. Anomaly cancellation for super-W-gravity

    International Nuclear Information System (INIS)

    Mansfield, P.; Spence, B.

    1991-01-01

    We generalise the description of minimal superconformal models coupled to supergravity, due to Distler, Hlousek and Kawaii, to super-W-gravity. When the chiral algebra is the generalisation of the W-algebra associated to any contragredient Lie superalgebra the total central charge vanishes as a result of Lie superalgebra identities. When the algebra has only fermionic simple roots there is N=1 superconformal invariance and for this case we describe the Lax operators and construct gravitationally dressed primary superfields of weight zero. We also prove the anomaly cancellation associated with the generalised non-abelian Toda theories. (orig.)

  20. In vivo analysis of biocompatibility and vascularization of the synthetic bone grafting substitute NanoBone.

    Science.gov (United States)

    Abshagen, K; Schrodi, I; Gerber, T; Vollmar, B

    2009-11-01

    One of the major challenges in the application of bone substitutes is adequate vascularization and biocompatibility of the implant. Thus, the temporal course of neovascularization and the microvascular inflammatory response of implants of NanoBone (fully synthetic nanocrystalline bone grafting material) were studied in vivo by using the mouse dorsal skinfold chamber model. Angiogenesis, microhemodynamics, and leukocyte-endothelial cell interaction were analyzed repetitively after implantation in the center and in the border zone of the implant up to 15 days. Both NanoBone granules and plates exhibited high biocompatibility comparable to that of cancellous bone, as indicated by a lack of venular leukocyte activation after implantation. In both synthetic NanoBone groups, signs of angiogenesis could be observed even at day 5 after implantation, whereas granules showed higher functional vessel density compared with NanoBone plates. The angiogenic response of the cancellous bone was markedly accelerated in the center of the implant tissue. Histologically, implant tissue showed an ingrowth of vascularized fibrous tissue into the material combined with an increased number of foreign-body giant cells. In conclusion, NanoBone, particularly in granular form, showed high biocompatibility and high angiogenic response, thus improving the healing of bone defects. Our results underline that, beside the composition and nanostructure, the macrostructure is also of importance for the incorporation of the biomaterial by the host tissue. (c) 2008 Wiley Periodicals, Inc.

  1. Evaluation of demineralized bone and bone transplants in vitro and in vivo with cone beam computed tomography imaging.

    Science.gov (United States)

    Draenert, F G; Gebhart, F; Berthold, M; Gosau, M; Wagner, W

    2010-07-01

    The objective of this study was to determine the ability of two flat panel cone beam CT (CBCT) devices to identify demineralized bone and bone transplants in vivo and in vitro. Datasets from patients with autologous bone grafts (n = 9, KaVo 3DeXam (KaVo, Biberach, Germany); n = 38, Accuitomo 40 (Morita, Osaka, Japan)) were retrospectively evaluated. Demineralized and non-demineralized porcine cancellous bone blocks were examined with the two CBCT devices. A SawBone skull (Pacific Research Laboratories, Vashon, WA) was used as a positioning tool for the bone blocks. Descriptive evaluation and image quality assessment were conducted on the KaVo 3DeXam data (voxel size 0.3 mm) using the OsiriX viewer as well as on the Morita Accuitomo data (voxel size 0.25 mm) using proprietary viewer software. Both in vivo and in vitro, the descriptive analysis of the images of the two devices showed well-visualized bone transplants with clearly defined cancellous bones and well-defined single bone trabeculae in all cross-sections. In vitro, demineralized samples showed lower radiographic opacity but no significant loss of quality compared with fresh bone (P = 0.070). Single cancellous bone trabeculae were significantly better visualized with the Morita 3D Accuitomo device than with the KaVo 3DeXam device (P = 0.038). Both the KaVo 3DeXam and Morita 3D Accuitomo devices produce good-quality images of cancellous bones in in vivo remodelling as well as after in vitro demineralization.

  2. 5 CFR 894.602 - May I cancel my enrollment at any time?

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false May I cancel my enrollment at any time... Cancellation of Coverage § 894.602 May I cancel my enrollment at any time? No. You may only cancel your enrollment during an open season. Exceptions: You may cancel your dental and/or vision enrollment if you...

  3. 5 CFR 837.803 - Cancellation of retirement by judicial or administrative authority.

    Science.gov (United States)

    2010-01-01

    ... Canceled Retirements § 837.803 Cancellation of retirement by judicial or administrative authority. (a... may only be canceled by the former employing agency in response to a direct and final order of a... requiring cancellation of the annuitant's separation or after the annuitant and the agency agree to cancel...

  4. Pilot Study: Unique Response of Bone Tissue During an Investigation of Radio-Adaptive Effects in Mice

    Science.gov (United States)

    Sibonga, J. D.; Iwaniec, U.; Wu, H.

    2011-01-01

    PURPOSE: We obtained bone tissue to evaluate the collateral effects of experiments designed to investigate molecular mechanisms of radio-adaptation in a mouse model. Radio-adaptation describes a process by which the prior exposure to low dose radiation can protect against the toxic effect of a subsequent high dose exposure. In the radio-adaptation experiments, C57Bl/6 mice were exposed to either a Sham or a priming Low Dose (5 cGy) of Cs-137 gamma rays before being exposed to either a Sham or High Dose (6 Gy) 24 hours later. ANALYSIS: Bone tissue were obtained from two experiments where mice were sacrificed at 3 days (n=3/group, 12 total) and at 14 days (n=6/group, 24 total) following high dose exposure. Tissues were analyzed to 1) evaluate a radio-adaptive response in bone tissue and 2) describe cellular and microstructural effects for two skeletal sites with different rates of bone turnover. One tibia and one lumbar vertebrae (LV2), collected at the 3-day time-point, were analyzed by bone histomorphometry and micro-CT to evaluate the cellular response and any evidence of microarchitectural impact. Likewise, tibia and LV2, collected at the 14-day time-point, were analyzed by micro-CT alone to evaluate resulting changes to bone structure and microarchitecture. The data were analyzed by 2-way ANOVA to evaluate the effects of the priming low dose radiation, of the high dose radiation, and of any interaction between the priming low and high doses of radiation. Bone histomorphometry was performed in the cancellous bone (aka trabecular bone) compartments of the proximal tibial metaphysis and of LV2. RESULTS: Cellular Response @ 3 Days The priming Low Dose radiation decreased osteoblast-covered bone perimeter in the proximal tibia and the total cell density in the bone marrow in the LV2. High Dose radiation, regardless of prior exposure to priming dose, dramatically reduced total cell density in bone marrow of both the long bone and vertebra. However, in the proximal

  5. On exposure to anorexia nervosa, the temporal variation in axial and appendicular skeletal development predisposes to site-specific deficits in bone size and density: a cross-sectional study.

    Science.gov (United States)

    Seeman, E; Karlsson, M K; Duan, Y

    2000-11-01

    Skeletal development is heterogeneous. Throughout growth, bone size is more maturationally advanced than the mineral being accrued within its periosteal envelope; before puberty, appendicular growth is more rapid than axial growth; during puberty, appendicular growth slows and axial growth accelerates. We studied women with differing age of onset of anorexia nervosa to determine whether this temporal heterogeneity in growth predisposed to the development of deficits in bone size and volumetric bone mineral density (vBMD), which varied by site and severity depending on the age at which anorexia nervosa occurred. Bone size and vBMD of the third lumbar vertebra and femoral neck were measured using dual-energy X-ray absorptiometry in 210 women aged 21 years (range, 12-40 years) with anorexia nervosa. Results were expressed as age-specific SDs (mean +/- SEM). Bone width depended on the age of onset of anorexia nervosa; when the onset of anorexia nervosa occurred (1) before 15 years of age, deficits in vertebral body and femoral neck width did not differ (-0.77+/-0.27 SD and -0.55+/-0.17 SD, respectively); (2) between 15 and 19 years of age, deficits in vertebral body width (-0.95+/-0.16 SD) were three times the deficits in femoral neck width (-0.28+/-0.14 SD; p anorexia nervosa. No deficit in bone width was observed at the femoral neck. Deficits in vBMD at the vertebra and femoral neck were independent of the age of onset of anorexia nervosa but increased as the duration of anorexia nervosa increased, being about 0.5 SD lower at the vertebra than femoral neck. We infer that the maturational development of a region at the time of exposure to disease, and disease duration, determine the site, magnitude, and type of trait deficit in anorexia nervosa. Bone fragility due to reduced bone size and reduced vBMD in adulthood is partly established during growth.

  6. Tissue engineering for lateral ridge augmentation with recombinant human bone morphogenetic protein 2 combination therapy: a case report.

    Science.gov (United States)

    Mandelaris, George A; Spagnoli, Daniel B; Rosenfeld, Alan L; McKee, James; Lu, Mei

    2015-01-01

    This case report describes a tissue-engineered reconstruction with recombinant human bone morphogenetic protein 2/acellular collagen sponge (rhBMP-2/ ACS) + cancellous allograft and space maintenance via Medpor Contain mesh in the treatment of a patient requiring maxillary and mandibular horizontal ridge augmentation to enable implant placement. The patient underwent a previously unsuccessful corticocancellous bone graft at these sites. Multiple and contiguous sites in the maxilla and in the mandibular anterior, demonstrating advanced lateral ridge deficiencies, were managed using a tissue engineering approach as an alternative to autogenous bone harvesting. Four maxillary and three mandibular implants were placed 9 and 10 months, respectively, after tissue engineering reconstruction, and all were functioning successfully after 24 months of follow-up. Histomorphometric analysis of a bone core obtained at the time of the maxillary implant placement demonstrated a mean of 76.1% new vital bone formation, 22.2% marrow/cells, and 1.7% residual graft tissue. Tissue engineering for lateral ridge augmentation with combination therapy requires further research to determine predictability and limitations.

  7. Ca/P concentration ratio at different sites of normal and osteoporotic rabbit bones evaluated by Auger and energy dispersive X-ray spectroscopy

    OpenAIRE

    Kourkoumelis, Nikolaos; Balatsoukas, Ioannis; Tzaphlidou, Margaret

    2011-01-01

    Osteoporosis is a systemic skeletal disorder associated with reduced bone mineral density and the consequent high risk of bone fractures. Current practice relates osteoporosis largely with absolute mass loss. The assessment of variations in chemical composition in terms of the main elements comprising the bone mineral and its effect on the bone’s quality is usually neglected. In this study, we evaluate the ratio of the main elements of bone mineral, calcium (Ca), and phosphorus (P), as a suit...

  8. Contribution of the endosteal surface of cortical bone to the trabecular pattern seen on IOPA radiographs: an in vitro study

    Directory of Open Access Journals (Sweden)

    P T Ravikumar

    2012-01-01

    Full Text Available Objectives: A study was conducted to assess the contribution of the cancellous and endosteal surface of the cortical bone to the trabecular pattern seen in an IOPA radiograph. Materials and methods: An in vitro study analyzing the contribution of the endosteal surface of cortical bone and cancellous bone to the trabecular pattern was conducted, using 60 specimens of desiccated human mandibles. The mode of execution involved IOPA radiographic evaluation of premolarmolar segments in the specimens before and after removal of cancellous bone. The radiographs were numbered for identification and subjected to evaluation by 5 dentomaxillofacial radiologists who were doubleblinded to ensure an unbiased interpretation. Results: The trabecular pattern appreciation by the experts in the IOPA radiographs before and after removal of cancellous bone displayed immaculate correlation as per the Goodman-Kruskal Gamma Coefficient values which was 0.78 indicating a very large correlation. The relative density of trabecular pattern was significantly higher in radiograph before than after removal of cancellous bone with p-value less than 0.05. Conclusion: Based on these results it was adjudged that both the cancellous and endosteal surface of cortical bone contributed significantly to the trabecular pattern in an IOPA radiograph.

  9. The effect of bone marrow aspirate, bone graft and collagen composites on fixation of bone implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2007-01-01

     Introduction: Replacement of extensive local bone loss especially in revision joint arthroplasties is a significant clinical challenge. Autogenous and allogenic cancellous bone grafts have been the gold standard in reconstructive orthopaedic surgery, but it is well known that there is morbidity...... associated with harvesting of autogenous bone graft and limitations in the quantity of bone available. Disadvantages of allograft include the risk of bacterial or viral contamination and non union as well as the potential risk of disease transmission. Alternative options are attractive and continue...... to be sought. Hydroxyapatite and collagen composites have the potential in mimicking and replacing skeletal bones. Aim: This study attempted to determine the effect of hydroxyapatite/collagen composites in the fixation of bone implants. The composites used in this study is produced by Institute of Science...

  10. Breast Cancer Cell Colonization of the Human Bone Marrow Adipose Tissue Niche.

    Science.gov (United States)

    Templeton, Zach S; Lie, Wen-Rong; Wang, Weiqi; Rosenberg-Hasson, Yael; Alluri, Rajiv V; Tamaresis, John S; Bachmann, Michael H; Lee, Kitty; Maloney, William J; Contag, Christopher H; King, Bonnie L

    2015-12-01

    Bone is a preferred site of breast cancer metastasis, suggesting the presence of tissue-specific features that attract and promote the outgrowth of breast cancer cells. We sought to identify parameters of human bone tissue associated with breast cancer cell osteotropism and colonization in the metastatic niche. Migration and colonization patterns of MDA-MB-231-fLuc-EGFP (luciferase-enhanced green fluorescence protein) and MCF-7-fLuc-EGFP breast cancer cells were studied in co-culture with cancellous bone tissue fragments isolated from 14 hip arthroplasties. Breast cancer cell migration into tissues and toward tissue-conditioned medium was measured in Transwell migration chambers using bioluminescence imaging and analyzed as a function of secreted factors measured by multiplex immunoassay. Patterns of breast cancer cell colonization were evaluated with fluorescence microscopy and immunohistochemistry. Enhanced MDA-MB-231-fLuc-EGFP breast cancer cell migration to bone-conditioned versus control medium was observed in 12/14 specimens (P = .0014) and correlated significantly with increasing levels of the adipokines/cytokines leptin (P = .006) and IL-1β (P = .001) in univariate and multivariate regression analyses. Fluorescence microscopy and immunohistochemistry of fragments underscored the extreme adiposity of adult human bone tissues and revealed extensive breast cancer cell colonization within the marrow adipose tissue compartment. Our results show that breast cancer cells migrate to human bone tissue-conditioned medium in association with increasing levels of leptin and IL-1β, and colonize the bone marrow adipose tissue compartment of cultured fragments. Bone marrow adipose tissue and its molecular signals may be important but understudied components of the breast cancer metastatic niche. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  11. 75 FR 51053 - Propetamphos; Notice of Receipt of Requests to Voluntarily Cancel Pesticide Registrations

    Science.gov (United States)

    2010-08-18

    ... of Requests to Voluntarily Cancel Pesticide Registrations AGENCY: Environmental Protection Agency... registrant, Wellmark International, to voluntarily cancel its registrations of products containing the... registrations have been canceled only if such sale, distribution, or use is consistent with the terms as...

  12. 75 FR 51048 - Notice of Receipt of Request to Voluntarily Cancel a Pesticide Registration

    Science.gov (United States)

    2010-08-18

    ... Voluntarily Cancel a Pesticide Registration AGENCY: Environmental Protection Agency (EPA). ACTION: Notice... cancel a pesticide registration. DATES: Comments must be received on or before September 17, 2010... the registrant to cancel a technical grade active ingredient pesticide product registered under...

  13. 75 FR 70256 - Tralomethrin; Notice of Receipt of Request To Voluntarily Cancel Pesticide Registrations

    Science.gov (United States)

    2010-11-17

    ... of Request To Voluntarily Cancel Pesticide Registrations AGENCY: Environmental Protection Agency (EPA... voluntarily cancel their registrations of products containing the pesticide tralomethrin. The request would... will cancel the sole technical product registration for tralomethrin. EPA intends to grant this request...

  14. 75 FR 5318 - Notice of Receipt of Requests to Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-02-02

    ... to Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection Agency (EPA... voluntarily cancel certain pesticide registrations. DATES: Unless a request is withdrawn by or March 4, 2010... will be issued canceling these registrations. The Agency will consider withdrawal requests postmarked...

  15. Definition of osteoporosis by bone density criteria in men: effect of using female instead of male young reference data depends on skeletal site and densitometer manufacturer.

    Science.gov (United States)

    Schousboe, John T; Tanner, S Bobo; Leslie, William D

    2014-01-01

    Whether to use young male or young female reference data to calculate bone mineral density (BMD) T-scores in men remains controversial. The third National Health and Nutrition Examination and Survey (NHANES III) data show that the mean and standard deviation of femoral neck and total hip BMD is greater in young men than young women, and therefore differences in T-scores at these sites using NHANES III female vs male norms becomes less as BMD decreases. In contrast, manufacturer-specific reference databases generally assume similar standard deviations of BMD in men and women. Using NHANES III reference data for the femoral neck and total hip, respectively we found that men with T-scores of -2.5 when young male norms are used have T-scores of -2.4 and -2.3 when young female norms are used. Using manufacturer-specific reference data, we found that men with T-scores of -2.5 when young male norms are used at the femoral neck, total hip, lumbar spine, or one-third of the forearm would have T-scores ranging from -2.4 to -0.4 when young female norms are used, depending on skeletal site and densitometer manufacturer. The change of proportions of men diagnosed with osteoporosis when young female norms are used instead of young male reference data differs substantially according to skeletal site and densitometer manufacturer. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  16. Active noise canceling system for mechanically cooled germanium radiation detectors

    Science.gov (United States)

    Nelson, Karl Einar; Burks, Morgan T

    2014-04-22

    A microphonics noise cancellation system and method for improving the energy resolution for mechanically cooled high-purity Germanium (HPGe) detector systems. A classical adaptive noise canceling digital processing system using an adaptive predictor is used in an MCA to attenuate the microphonics noise source making the system more deployable.

  17. 50 CFR 228.13 - Determination to cancel the hearing.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Determination to cancel the hearing. 228.13 Section 228.13 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND...) REGULATIONS § 228.13 Determination to cancel the hearing. (a) If the presiding officer concludes that no...

  18. Outage Performance in Cognitive Radio Systems with Opportunistic Interference Cancelation

    DEFF Research Database (Denmark)

    Di Taranto, Rocco; Popovski, Petar

    2011-01-01

    , respectively. The secondary receiver applies Opportunistic Interference Cancelation (OIC) and Suboptimal Opportunistic Interference Cancelation (S-OIC) thus decoding the primary signal when such an opportunity is created by the rate selected at the primary transmitter and the power received from the primary...

  19. Revenue management under customer choice behaviour with cancellations and overbooking

    NARCIS (Netherlands)

    Sierag, D.D.; Koole, G.M.; Mei, van der R.D.; Zwart, B.; Rest, van der J.I.

    2015-01-01

    In many application areas such as airlines and hotels a large number of bookings are typically cancelled. Explicitly taking into account cancellations creates an opportunity for increasing revenue. Motivated by this we propose a revenue management model based on Talluri and van Ryzin (2004) that

  20. 42 CFR 57.313a - Loan cancellation reimbursement.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Loan cancellation reimbursement. 57.313a Section 57.313a Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GRANTS GRANTS FOR... Loans § 57.313a Loan cancellation reimbursement. In the event that insufficient funds are available to...

  1. 42 CFR 57.213a - Loan cancellation reimbursement.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Loan cancellation reimbursement. 57.213a Section 57... Professions Student Loans § 57.213a Loan cancellation reimbursement. (a) For loans made prior to October 22... credited to this insurance fund), and used only to reimburse the school for the institutional share of any...

  2. 27 CFR 479.87 - Cancellation of stamp.

    Science.gov (United States)

    2010-04-01

    ... OTHER FIREARMS Transfer Tax Application and Order for Transfer of Firearm § 479.87 Cancellation of stamp. The method of cancellation of the stamp required by this subpart as prescribed in § 479.67 shall be used. Exemptions Relating to Transfers of Firearms ...

  3. A new pathway for elective surgery to reduce cancellation rates

    DEFF Research Database (Denmark)

    Hovlid, Einar; Bukve, Oddbjørn; Haug, Kjell

    2012-01-01

    The cancellation of planned surgeries causes prolonged wait times, harm to patients, and is a waste of scarce resources. To reduce high cancellation rates in a Norwegian general hospital, the pathway for elective surgery was redesigned. The changes included earlier clinical assessment of patients...

  4. 78 FR 48456 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2013-08-08

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION: Customs broker license cancellations. SUMMARY: Notice is hereby given that the customs broker...

  5. 76 FR 16843 - Order Cancelling Registrations of Certain Transfer Agents

    Science.gov (United States)

    2011-03-25

    ... existence or has ceased to do business as a transfer agent, the Commission shall by order cancel that... name appears in the attached Appendix either is no longer in existence or has ceased doing business as... cancel the registration of certain transfer agents whom it believed were no longer in existence or had...

  6. RATES OF PHOTOSPHERIC MAGNETIC FLUX CANCELLATION MEASURED WITH HINODE

    International Nuclear Information System (INIS)

    Park, Soyoung; Chae, Jongchul; Litvinenko, Yuri E.

    2009-01-01

    Photospheric magnetic flux cancellation on the Sun is generally believed to be caused by magnetic reconnection occurring in the low solar atmosphere. Individual canceling magnetic features are observationally characterized by the rate of flux cancellation. The specific cancellation rate, defined as the rate of flux cancellation divided by the interface length, gives an accurate estimate of the electric field in the reconnecting current sheet. We have determined the specific cancellation rate using the magnetograms taken by the Solar Optical Telescope (SOT) aboard the Hinode satellite. The specific rates determined with SOT turned out to be systematically higher than those based on the data taken by the Michelson Doppler Imager (MDI) aboard the Solar and Heliospheric Observatory. The median value of the specific cancellation rate was found to be 8 x 10 6 G cm s -1 -a value four times that obtained from the MDI data. This big difference is mainly due to a higher angular resolution and better sensitivity of the SOT, resulting in magnetic fluxes up to five times larger than those obtained from the MDI. The higher rates of flux cancellation correspond to either faster inflows or stronger magnetic fields of the reconnection inflow region, which may have important consequences for the physics of photospheric magnetic reconnection.

  7. 19 CFR 113.55 - Cancellation of export bonds.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Cancellation of export bonds. 113.55 Section 113... export bonds. (a) Manner of cancellation. A bond to assure exportation as defined in § 101.1 of this... shall be signed by a revenue officer of the foreign country to which the merchandise is exported, unless...

  8. Bone allografting in children

    Science.gov (United States)

    Sadovoy, M. A.; Kirilova, I. A.; Podorognaya, V. T.; Matsuk, S. A.; Novoselov, V. P.; Moskalev, A. V.; Bondarenko, A. V.; Afanasev, L. M.; Gubina, E. V.

    2017-09-01

    A total of 522 patients with benign and intermediate bone tumors of various locations, aged 1 to 15 years, were operated in the period from 1996 to 2016. To diagnose skeleton tumors, we used clinical observation, X-ray, and, if indicated, tomography and tumor site biopsy. In the extensive bone resection, we performed bone reconstruction with the replacement of a defect with an allograft (bone strips, deproteinized and spongy grafts), sometimes in the combination with bone autografting. After segmental resection, the defects were filled with bone strips in the form of matchstick grafts; the allografts were received from the Laboratory for Tissue Preparation and Preservation of the Novosibirsk Research Institute of Traumatology and Orthopedics. According to the X-ray data, a complete reorganization of bone grafts occurred within 1.5 to 3 years. The long-term result was assessed as good.

  9. Bone scintiscanning updated.

    Science.gov (United States)

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

    1976-03-01

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

  10. Effects of long-term estrogen replacement therapy on bone turnover in periarticular tibial osteophytes in surgically postmenopausal cynomolgus monkeys

    OpenAIRE

    Olson, Erik J.; Lindgren, Bruce R.; Carlson, Cathy S.

    2007-01-01

    The aims of the present study were to assess the effects of long-term estrogen replacement therapy (ERT) on size and indices of bone turnover in periarticular osteophytes in ovariectomized cynomolgus monkeys and to compare dynamic indices of bone turnover in osteophyte bone with those of subchondral bone (SCB) and epiphyseal/metaphyseal cancellous (EMC) bone. One hundred sixty-five adult female cynomolgus macaques were bilaterally ovariectomized and randomly divided into three age- and weight...

  11. Multilayer porous UHMWPE scaffolds for bone defects replacement

    Energy Technology Data Exchange (ETDEWEB)

    Maksimkin, A.V. [National University of Science and Technology “MISIS”, Moscow (Russian Federation); Senatov, F.S., E-mail: senatov@misis.ru [National University of Science and Technology “MISIS”, Moscow (Russian Federation); Anisimova, N.Yu.; Kiselevskiy, M.V. [National University of Science and Technology “MISIS”, Moscow (Russian Federation); N.N. Blokhin Russian Cancer Research Center, Moscow (Russian Federation); Zalepugin, D.Yu.; Chernyshova, I.V.; Tilkunova, N.A. [State Plant of Medicinal Drugs, Moscow (Russian Federation); Kaloshkin, S.D. [National University of Science and Technology “MISIS”, Moscow (Russian Federation)

    2017-04-01

    Reconstruction of the structural integrity of the damaged bone tissue is an urgent problem. UHMWPE may be potentially used for the manufacture of porous implants simulating as closely as possible the porous cancellous bone tissue. But the extremely high molecular weight of the polymer does not allow using traditional methods of foaming. Porous and multilayer UHMWPE scaffolds with nonporous bulk layer and porous layer that mimics cancellous bone architecture were obtained by solid-state mixing, thermopressing and washing in subcritical water. Structural and mechanical properties of the samples were studied. Porous UHMWPE samples were also studied in vitro and in vivo. The pores of UHMWPE scaffold are open and interconnected. Volume porosity of the obtained samples was 79 ± 2%; the pore size range was 80–700 μm. Strong connection of the two layers in multilayer UHMWPE scaffolds was observed with decreased number of fusion defects. Functionality of implants based on multilayer UHMWPE scaffolds is provided by the fixation of scaffolds in the bone defect through ingrowths of the connective tissue into the pores, which ensures the maintenance of the animals' mobility - Highlights: • Porous UHMWPE scaffold mimics cancellous bone architecture, maintaining its flexibility. • Multilayer UHMWPE scaffold is able to simulate different types of bone tissue. • Fixation of scaffolds in the bone provides through ingrowths of the connective tissue into pores. • Multilayer UHMWPE scaffolds can be used for the formation of bone implants.

  12. Multilayer porous UHMWPE scaffolds for bone defects replacement

    International Nuclear Information System (INIS)

    Maksimkin, A.V.; Senatov, F.S.; Anisimova, N.Yu.; Kiselevskiy, M.V.; Zalepugin, D.Yu.; Chernyshova, I.V.; Tilkunova, N.A.; Kaloshkin, S.D.

    2017-01-01

    Reconstruction of the structural integrity of the damaged bone tissue is an urgent problem. UHMWPE may be potentially used for the manufacture of porous implants simulating as closely as possible the porous cancellous bone tissue. But the extremely high molecular weight of the polymer does not allow using traditional methods of foaming. Porous and multilayer UHMWPE scaffolds with nonporous bulk layer and porous layer that mimics cancellous bone architecture were obtained by solid-state mixing, thermopressing and washing in subcritical water. Structural and mechanical properties of the samples were studied. Porous UHMWPE samples were also studied in vitro and in vivo. The pores of UHMWPE scaffold are open and interconnected. Volume porosity of the obtained samples was 79 ± 2%; the pore size range was 80–700 μm. Strong connection of the two layers in multilayer UHMWPE scaffolds was observed with decreased number of fusion defects. Functionality of implants based on multilayer UHMWPE scaffolds is provided by the fixation of scaffolds in the bone defect through ingrowths of the connective tissue into the pores, which ensures the maintenance of the animals' mobility - Highlights: • Porous UHMWPE scaffold mimics cancellous bone architecture, maintaining its flexibility. • Multilayer UHMWPE scaffold is able to simulate different types of bone tissue. • Fixation of scaffolds in the bone provides through ingrowths of the connective tissue into pores. • Multilayer UHMWPE scaffolds can be used for the formation of bone implants.

  13. Revascularisation of fresh compared with demineralised bone grafts in rats

    DEFF Research Database (Denmark)

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

    2001-01-01

    Revascularisation of bone grafts is influenced by both the anatomical origin and the pre-implantation processing of the graft. We investigated the revascularisation by entrapment of 141Ce (cerium)-labelled microspheres in large, fresh and demineralised syngeneic grafts of predominantly cancellous...... (iliac bone) or cortical (tibial diaphysis) bone three weeks after heterotopic implantation in rats. The mean (SD) 141Ce deposition index (counts per minute (cpm) of mg recovered implant/cpm of mg host iliac bone) was higher in fresh iliac bone grafts, 0.98 (0.46) compared to that of demineralised iliac...... bone, 0.32 (0.20), p bone grafts, 0.51 (0.27), p = 0.007. We found no significant difference in the mean 141Ce deposition index between fresh tibial bone grafts and demineralised tibial bone grafts, 0.35 (0.42), p = 0.4, or between demineralised tibial grafts and demineralised...

  14. Effect of calvarial burring on resorption of onlay cranial bone graft.

    Science.gov (United States)

    Hassanein, Aladdin H; Clune, James E; Mulliken, John B; Arany, Praveen R; Rogers, Gary F; Kulungowski, Ann M; Greene, Arin K

    2012-09-01

    Variable resorption occurs whenever calvarial bone graft is used for onlay cranioplasty. The recipient ectocortex may be burred to expose vessels and osteocytes to maximize healing. The purpose of this study was to determine whether abrading the recipient site improves the volume of onlay graft. The parietal bones of 17 rabbits were sectioned into split-thickness and full-thickness grafts. The right frontal cortex was abraded with a bur to punctate bleeding. Pairs of split-thickness (n = 48) or full-thickness (n = 20) grafts were onlayed to the burred right frontal bone and to the nonburred left frontal bone. Micro-computed tomography was used to determine graft volume immediately postoperatively and 16 weeks later. Histology, including tartrate-resistant acid phosphatase staining, was performed to quantify vascular channels and osteoclasts per high-power field 10 days postoperatively. Split-thickness graft volume decreased 58.0% when placed on the burred calvarial site, compared with grafts on the nonburred cortex (28.4%) (P = 0.01). Full-thickness grafts showed a similar trend: greater resorption (39.1%) when onlayed onto abraded calvaria compared with nonburred ectocortex (26.0%) (P = 0.11). Split-thickness graft orientation (cortical vs cancellous side in contact with the recipient site) did not affect resorption (P = 0.67). Onlay grafts placed on the burred recipient site had more vascular channels (11.8) and osteoclasts (5.7), compared with grafts over nonabraded cortex (3.4 and 4.2, respectively) (P cranial bone grafting promotes resorption, possibly by increasing vascularization and osteoclastic activity. This technique cannot be recommended.

  15. CERN Library - Journal cancellations in 2008

    CERN Multimedia

    2007-01-01

    In 2007, the CERN Library has been allocated a smaller budget than in 2006. Since subscriptions must be paid in advance, the current budget is being used to pay the journal collection for the year 2008 and is unfortunately not sufficient to maintain the information resources at the 2007 level. Consequently, the Working Group for Acquisitions (WGA) was obliged to identify candidates for cancellation for 2008. The list of candidates is shown here. As in the past, readers will be able to order articles from journals not available in the CERN Library through the Interlibrary Loan (ILL) service; generally articles are sent within 24h. Library users are invited to send comments on this proposal not later than 4 August 2007 to the WGA Chairman, Rudiger Voss, with a copy to the Head Librarian, Jens Vigen.

  16. Time Delay Estimation Algoritms for Echo Cancellation

    Directory of Open Access Journals (Sweden)

    Kirill Sakhnov

    2011-01-01

    Full Text Available The following case study describes how to eliminate echo in a VoIP network using delay estimation algorithms. It is known that echo with long transmission delays becomes more noticeable to users. Thus, time delay estimation, as a part of echo cancellation, is an important topic during transmission of voice signals over packetswitching telecommunication systems. An echo delay problem associated with IP-based transport networks is discussed in the following text. The paper introduces the comparative study of time delay estimation algorithm, used for estimation of the true time delay between two speech signals. Experimental results of MATLab simulations that describe the performance of several methods based on cross-correlation, normalized crosscorrelation and generalized cross-correlation are also presented in the paper.

  17. Nuclear cancellations follow-on study

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-29

    The serious reduction in the aggregate commitment to nuclear power by US utilities over the past few years, as well as the serious stretchout of the completion schedules for many ongoing projects, has continued. A 1980 study which studied the factors causing this retrenchment is discussed. In this 1982 study, utilities were interviewed in an attempt to identify possible remedies which the Federal government might take to induce utilities to postpone rather than cancel units less than 10% complete, and to complete expeditiously units in the 10 to 60% completion range. The quality of the reserve margin is examined. The actions of state regulators are considered. Regulatory reform emerges as the key action the Federal government can take. (DLC)

  18. Bone island (enostosis): current concept - a review

    International Nuclear Information System (INIS)

    Greenspan, A.

    1995-01-01

    A bone island can be virtually diagnosed based on its characteristic clinical and radiologic features. Typically asymptomatic, the lesion is usually an incidental finding, with a preference for the pelvis, femur, and other long bones, although it may be found anywhere in the skeleton, including the spine. Plain radiography reveals a homogeneously dense, sclerotic focus in the cancellous bone with distinctive radiating bony streaks (''thorny radiation'') that blend with the trabeculae of the host bone, creating a feathered or brush-like border. On CT scan, a bone island appears as a low-attenuation focus, and on MRI sequences it shows low signal intensity like cortical bone. A distinguishing feature of bone islands is that they are usually ''cold'' on skeletal scintigraphy. Thus, bone scan has been and continues to be the means of differentiating bone islands from the more aggressive entities. However, reports of histologically confirmed bone islands that were scintigraphically active have raised a note of caution about relying on this modality in the differential consideration of lesions otherwise characteristic of bone islands. Guides to the correct diagnosis should be looked for in the individual clinical situation and in the morphologic features of the lesion on plain radiography, CT, and MRI, without regard to the lesion's activity on bone scan. If such a lesion, however, is symptomatic and ''hot'' on scintigraphy, it demands close observation with follow-up imaging studies. (orig./VHE)

  19. The effects of orbital spaceflight on bone histomorphometry and messenger ribonucleic acid levels for bone matrix proteins and skeletal signaling peptides in ovariectomized growing rats

    Science.gov (United States)

    Cavolina, J. M.; Evans, G. L.; Harris, S. A.; Zhang, M.; Westerlind, K. C.; Turner, R. T.

    1997-01-01

    A 14-day orbital spaceflight was performed using ovariectomized Fisher 344 rats to determine the combined effects of estrogen deficiency and near weightlessness on tibia radial bone growth and cancellous bone turnover. Twelve ovariectomized rats with established cancellous osteopenia were flown aboard the space shuttle Columbia (STS-62). Thirty ovariectomized rats were housed on earth as ground controls: 12 in animal enclosure modules, 12 in vivarium cages, and 6 killed the day of launch for baseline measurements. An additional 18 ovary-intact rats were housed in vivarium cages as ground controls: 8 rats were killed as baseline controls and the remaining 10 rats were killed 14 days later. Ovariectomy increased periosteal bone formation at the tibia-fibula synostosis; cancellous bone resorption and formation in the secondary spongiosa of the proximal tibial metaphysis; and messenger RNA (mRNA) levels for the prepro-alpha2(1) subunit of type 1 collagen, osteocalcin, transforming growth factor-beta, and insulin-like growth factor I in the contralateral proximal tibial metaphysis and for the collagen subunit in periosteum pooled from tibiae and femora and decreased cancellous bone area. Compared to ovariectomized weight-bearing rats, the flight group experienced decreases in periosteal bone formation, collagen subunit mRNA levels, and cancellous bone area. The flight rats had a small decrease in the cancellous mineral apposition rate, but no change in the calculated bone formation rate. Also, spaceflight had no effect on cancellous osteoblast and osteoclast perimeters or on mRNA levels for bone matrix proteins and signaling peptides. On the other hand, spaceflight resulted in an increase in bone resorption, as ascertained from the diminished retention of a preflight fluorochrome label. This latter finding suggests that osteoclast activity was increased. In a follow-up ground-based experiment, unilateral sciatic neurotomy of ovariectomized rats resulted in cancellous

  20. Osseointegration of dental implants in 3D-printed synthetic onlay grafts customized according to bone metabolic activity in recipient site.

    Science.gov (United States)

    Tamimi, Faleh; Torres, Jesus; Al-Abedalla, Khadijeh; Lopez-Cabarcos, Enrique; Alkhraisat, Mohammad H; Bassett, David C; Gbureck, Uwe; Barralet, Jake E

    2014-07-01

    Onlay grafts made of monolithic microporous monetite bioresorbable bioceramics have the capacity to conduct bone augmentation. However, there is heterogeneity in the graft behaviour in vivo that seems to correlate with the host anatomy. In this study, we sought to investigate the metabolic activity of the regenerated bone in monolithic monetite onlays by using positron emission tomography-computed tomography (PET-CT) in rats. This information was used to optimize the design of monetite onlays with different macroporous architecture that were then fabricated using a 3D-printing technique. In vivo, bone augmentation was attempted with these customized onlays in rabbits. PET-CT findings demonstrated that bone metabolism in the calvarial bone showed higher activity in the inferior and lateral areas of the onlays. Histological observations revealed higher bone volume (up to 47%), less heterogeneity and more implant osseointegration (up to 38%) in the augmented bone with the customized monetite onlays. Our results demonstrated for the first time that it is possible to achieve osseointegration of dental implants in bone augmented with 3D-printed synthetic onlays. It was also observed that designing the macropore geometry according to the bone metabolic activity was a key parameter in increasing the volume of bone augmented within monetite onlays. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Effects of the 3D bone-to-implant contact and bone stiffness on the initial stability of a dental implant: micro-CT and resonance frequency analyses.

    Science.gov (United States)

    Hsu, J T; Huang, H L; Tsai, M T; Wu, A Y J; Tu, M G; Fuh, L J

    2013-02-01

    This study investigated the effects of bone stiffness (elastic modulus) and three-dimensional (3D) bone-to-implant contact ratio (BIC%) on the primary stabilities of dental implants using micro-computed tomography (micro-CT) and resonance frequency analyses. Artificial sawbone models with five values of elastic modulus (137, 123, 47.5, 22, and 12.4 MPa) comprising two types of trabecular structure (solid-rigid and cellular-rigid) were investigated for initial implant stability quotient (ISQ), measured using the wireless Osstell resonance frequency analyzer. Bone specimens were attached to 2 mm fibre-filled epoxy sheets mimicking the cortical shell. ISQ was measured after placing a dental implant into the bone specimen. Each bone specimen with an implant was subjected to micro-CT scanning to calculate the 3D BIC% values. The similarity of the cellular type of artificial bone to the trabecular structure might make it more appropriate for obtaining accurate values of primary implant stability than solid-bone blocks. For the cellular-rigid bone models, the ISQ increased with the elastic modulus of cancellous bone. The regression correlation coefficient was 0.96 for correlations of the ISQ with the elasticity of cancellous bone and with the 3D BIC%. The initial implant stability was moderately positively correlated with the elasticity of cancellous bone and with the 3D BIC%. Copyright © 2012 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Rapid restoration of bone mass after surgical management of hyperthyroidism: A prospective case control study in Southern India.

    Science.gov (United States)

    Karunakaran, Poongkodi; Maharajan, Chandrasekaran; Mohamed, Kamaludeen N; Rachamadugu, Suresh V

    2016-03-01

    The rate and the extent of bone remineralization at cancellous versus cortical sites after treatment of hyperthyroidism is unclear. Few studies have examined the effect of operative management of hyperthyroidism on recovery of bone mass. To evaluate prospectively the bone mineral density (BMD), bone mineral content (BMC), and bone areal size at the spine, hip, and forearm before and after total thyroidectomy. A prospective case control observational study from August 2011 to July 2014 in a single center. This study evaluated 40 overt hyperthyroid patients and 31 age-matched euthyroid controls who were operative candidates. Bone indices were measured at baseline and 6-month postoperatively using dual energy x-ray absorptiometry. Serum levels of alkaline phosphatase and 25-hydroxy vitamin D3 (25OHD) were assessed. Baseline BMD of hyperthyroid subjects at the spine, hip, and forearm were less than euthyroid controls (P = .001) with concomitant increases in serum alkaline phosphatase (mean ± SD, 143 ± 72 vs 72 ± 23 IU/L control; P hyperthyroid patients, posttreatment BMD expressed as g/cm(2) were 0.97 ± 0.12 (vs pretreatment 0.91 ± 0.14; P = .001) at the spine, 0.87 ± 0.12 (vs pretreatment 0.80 ± 0.13; P = .001) at the hip, and 0.67 ± 0.09 (vs pretreatment 0.64 ± 0.11; P = .191) at the forearm. The percent change in BMD was greatest at spine (8.3%) followed by the hip (7.6%) and forearm (3.0%). Operative management with total thyroidectomy improved the bone loss associated with hyperthyroidism as early as 6 months postoperatively at the hip and spine despite concomitant vitamin D deficiency. Delayed recovery of bone indices at the forearm, a cortical bone, requires further long-term evaluation. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. A preliminary carbon and nitrogen isotopic investigation of bone collagen from skeletal remains recovered from a Pre-Columbian burial site, Matanzas Province, Cuba

    International Nuclear Information System (INIS)

    Buhay, W.M.; Chinique de Armas, Y.; Rodriguez Suárez, R.; Arredondo, C.; Smith, D.G.; Armstrong, S.D.; Roksandic, M.

    2013-01-01

    Highlights: ► Collagen isotope (carbon and nitrogen) based reconstruction of paleodiets. ► Human remains recovered from Canimar Abajo, Matanzas Province, Cuba. ► Individuals consumed marine resource diets supplemented with terrestrial plants. ► Trophic level and isotope shifts for breastfed and weaned infant/juveniles (I/J). ► I/J evidence of weaning through distinct δ 15 N enrichments and δ 13 C depletions. - Abstract: This preliminary study investigates the diet of a population of humans (n = 28) recovered from a shell-matrix site of Canimar Abajo on the Canimar River, Matanzas Province, Cuba. The site is characterized by two cemetery levels separated by a layer of occupation/ritual/midden activity that lasted 1.5 ka. Stable C (δ 13 C) and N (δ 15 N) isotope analysis of human bone collagen samples obtained from individuals (7 infant/juveniles, and 21 adults) from both cemetery levels was conducted in order to reconstruct the diet of these two populations, investigate the relative importance of marine vs. terrestrial resources, and reveal any sex- and age-related distinctions in their food sources. Initial indications suggest that individuals from both cemetery levels consumed diets that were marine resource intensive but also supplemented with varied additions of terrestrial (mostly plant) resources. This supplementation is particularly evident in the later cemetery population. Though there are no significant differences in diet according to sex, there is a trophic level and terrestrial-based shift for breastfed and weaning infant/juveniles. The infant/juveniles showed evidence of being weaned through distinct δ 15 N enrichments and δ 13 C depletions over adult females

  4. Does methamphetamine affect bone metabolism?

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  5. A journal cancellation survey and resulting impact on interlibrary loan.

    Science.gov (United States)

    Nash, Jacob L; McElfresh, Karen R

    2016-10-01

    The research describes an extensible method of evaluating and cancelling electronic journals during a budget shortfall and evaluates implications for interlibrary loan (ILL) and user satisfaction. We calculated cost per use for cancellable electronic journal subscriptions (n=533) from the 2013 calendar year and the first half of 2014, cancelling titles with cost per use greater than $20 and less than 100 yearly uses. For remaining titles, we issued an online survey asking respondents to rank the importance of journals to their work. Finally, we gathered ILL requests and COUNTER JR2 turnaway reports for calendar year 2015. Three hundred fifty-four respondents completed the survey. Because of the level of heterogeneity of titles in the survey as well as respondents' backgrounds, most titles were reported to be never used. We developed criteria based on average response across journals to determine which to cancel. Based on this methodology, we cancelled eight journals. Examination of ILL data revealed that none of the cancelled titles were requested with any frequency. Free-text responses indicated, however, that many value free ILL as a suitable substitute for immediate full-text access to biomedical journal literature. Soliciting user feedback through an electronic survey can assist collections librarians to make electronic journal cancellation decisions during slim budgetary years. This methodology can be adapted and improved upon at other health sciences libraries.

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  7. Design of Cancelable Palmprint Templates Based on Look Up Table

    Science.gov (United States)

    Qiu, Jian; Li, Hengjian; Dong, Jiwen

    2018-03-01

    A novel cancelable palmprint templates generation scheme is proposed in this paper. Firstly, the Gabor filter and chaotic matrix are used to extract palmprint features. It is then arranged into a row vector and divided into equal size blocks. These blocks are converted to corresponding decimals and mapped to look up tables, forming final cancelable palmprint features based on the selected check bits. Finally, collaborative representation based classification with regularized least square is used for classification. Experimental results on the Hong Kong PolyU Palmprint Database verify that the proposed cancelable templates can achieve very high performance and security levels. Meanwhile, it can also satisfy the needs of real-time applications.

  8. Crosstalk cancellation on linearly and circularly polarized communications satellite links

    Science.gov (United States)

    Overstreet, W. P.; Bostian, C. W.

    1979-01-01

    The paper discusses the cancellation network approach for reducing crosstalk caused by depolarization on a dual-polarized communications satellite link. If the characteristics of rain depolarization are sufficiently well known, the cancellation network can be designed in a way that reduces system complexity, the most important parameter being the phase of the cross-polarized signal. Relevant theoretical calculations and experimental data are presented. The simplicity of the cancellation system proposed makes it ideal for use with small domestic or private earth terminals.

  9. Infrared divergence cancellation in pure Yang-Mills theory

    International Nuclear Information System (INIS)

    Alvarez, A.G.

    1977-01-01

    Virtual and real corrections to massless external lines in pure Yang-Mills theory are considered in order to look for general features of the infrared divergence cancellation. Use of the Ward identities and sums over transverse polarization states give rise to terms formally corresponding to real ghost emission, cancelling ghost loop singularities, and to a factorisation of the hard narrow single gauge boson emission. Other virtual corrections are examined in the soft region and a graph by graph cancellation is also found. An illustrative explicit calculation of scattering of a gauge particle in an external scalar potential, including hard narrow angle emission is presented. (Auth.)

  10. Cancellation of soft and collinear divergences in noncommutative QED

    International Nuclear Information System (INIS)

    Mirza, B.; Zarei, M.

    2006-01-01

    In this paper, we investigate the behavior of noncommutative IR divergences and will also discuss their cancellation in the physical cross sections. The commutative IR (soft) divergences existing in the nonplanar diagrams will be examined in order to prove an all-order cancellation of these divergences using the Weinberg's method. In noncommutative QED, collinear divergences due to triple photon splitting vertex, were encountered, which are shown to be canceled out by the noncommutative version of KLN theorem. This guarantees that there is no mixing between the Collinear, soft divergences and noncommutative IR divergences

  11. Cancellation Effects in CSR Induced Bunch Transverse Dynamics in Bends

    International Nuclear Information System (INIS)

    Li, R.

    2002-01-01

    The partial cancellation between the effect of centrifugal space charge force on transverse bunch dynamics and the potential energy effect has been a long-standing controversial issue in the study of coherent synchrotron radiation (CSR) induced bunch dynamics in bends. In this paper, we clarify our definition of the ''centrifugal space charge force,'' and discuss the meaning of the ''cancellation effect'' and its general application. We further use simulation to demonstrate the cancellation in both steady state and transient regimes, and show the behavior of the effective transverse force

  12. Journal cancellations in university libraries in South Africa

    Directory of Open Access Journals (Sweden)

    Ruth Hoskins

    2010-01-01

    Full Text Available This article is based on part of a survey that investigated journal cancellations in university libraries in South Africa. A study population consisting of 17 university libraries in South Africa was surveyed by means of an online questionnaire to establish the factors that influenced journal cancellations. Interpretation of the results revealed that South African university libraries, like most academic and research libraries world wide, have been adversely affected by high priced journal subscriptions and many libraries have simply cancelled subscriptions to pay for ongoing subscriptions. Recommendations are made about enhancing library budgets and access to usage statistics, supporting consortia and avoiding restrictive journal packages.

  13. Group study of an "undercover" test for visuospatial neglect: invisible cancellation can reveal more neglect than standard cancellation.

    Science.gov (United States)

    Wojciulik, E; Rorden, C; Clarke, K; Husain, M; Driver, J

    2004-09-01

    Visual neglect is a relatively common deficit after brain damage, particularly strokes. Cancellation tests provide standard clinical measures of neglect severity and deficits in daily life. A recent single-case study introduced a new variation on standard cancellation. Instead of making a visible mark on each target found, the patient made invisible marks (recorded with carbon paper underneath, for later scoring). Such invisible cancellation was found to reveal more neglect than cancellation with visible marks. Here we test the generality of this. Twenty three successive cases with suspected neglect each performed cancellation with visible or invisible marks. Neglect of contralesional targets was more pronounced with invisible marks. Indeed, about half of the patients only showed neglect in this version. For cases showing more neglect with invisible marks, stronger neglect of contralesional targets correlated with more revisits to ipsilesional targets for making additional invisible marks upon them. These results indicate that cancellation with invisible marks can reveal more neglect than standard cancellation with visible marks, while still providing a practical bedside test. Our observations may be consistent with recent proposals that demands on spatial working memory (required to keep track of previously found items only when marked invisibly) can exacerbate spatial neglect.

  14. Transgenic Mouse Model for Reducing Oxidative Damage in Bone

    Science.gov (United States)

    Schreurs, Ann-Sofie; Torres, S.; Truong, T.; Moyer, E. L.; Kumar, A.; Tahimic, Candice C. G.; Alwood, J. S.; Limoli, C. L.; Globus, R. K.

    2016-01-01

    Bone loss can occur due to many challenges such age, radiation, microgravity, and Reactive Oxygen Species (ROS) play a critical role in bone resorption by osteoclasts (Bartell et al. 2014). We hypothesize that suppression of excess ROS in skeletal cells, both osteoblasts and osteoclasts, regulates skeletal growth and remodeling. To test our hypothesis, we used transgenic mCAT mice which overexpress the human anti-oxidant catalase gene targeted to the mitochondria, the main site for endogenous ROS production. mCAT mice have a longer life-span than wildtype controls and have been used to study various age-related disorders. To stimulate remodeling, 16 week old mCAT mice or wildtype mice were exposed to treatment (hindlimb-unloading and total body-irradiation) or sham treatment conditions (control). Tissues were harvested 2 weeks later for skeletal analysis (microcomputed tomography), biochemical analysis (gene expression and oxidative damage measurements), and ex vivo bone marrow derived cell culture (osteoblastogenesis and osteoclastogenesis). mCAT mice expressed the transgene and displayed elevated catalase activity in skeletal tissue and marrow-derived osteoblasts and osteoclasts grown ex vivo. In addition, when challenged with treatment, bone tissues from wildtype mice showed elevated levels of malondialdehyde (MDA), indicating oxidative damage) whereas mCAT mice did not. Correlation analysis revealed that increased catalase activity significantly correlated with decreased MDA levels and that increased oxidative damage correlated with decreased percent bone volume (BVTV). In addition, ex-vivo cultured osteoblast colony growth correlated with catalase activity in the osteoblasts. Thus, we showed that these transgenic mice can be used as a model to study the relationship between markers of oxidative damage and skeletal properties. mCAT mice displayed reduced BVTV and trabecular number relative to wildtype mice, as well as increased structural model index in the

  15. Polyetheretherketone (PEEK) cage filled with cancellous allograft in anterior cervical discectomy and fusion

    Science.gov (United States)

    Liao, Jen-Chung; Chen, Wen-Jer; Chen, Lih-Huei

    2007-01-01

    From July 2004 to June 2005, 19 patients with 25 discs underwent anterior cervical discectomy and interbody fusion (ACDF) in which polyetheretherketone (PEEK) cages were filled with freeze-dried cancellous allograft bone. This kind of bone graft was made from femoral condyle that was harvested during total knee arthroplasty. Patient age at surgery was 52.9 (28–68) years. All patients were followed up at least 1 year. We measured the height of the disc and segmental sagittal angulation by pre-operative and post-operative radiographs. CT scan of the cervical spine at 1 year was used to evaluate fusion rates. Odom's criteria were used to assess the clinical outcome. All interbody disc spaces achieved successful union at 1-year follow-up. The use of a PEEK cage was found to increase the height of the disc immediately after surgery (5.0 mm pre-operatively, 7.3 mm immediately post-operatively). The final disc height was 6.2 mm, and the collapse of the disc height was 1.1 mm. The segmental lordosis also increased after surgery (2.0° pre-operatively, 6.6° immediately post-operatively), but the mean loss of lordosis correction was 3.3° at final follow-up. Seventy-four percent of patients (14/19) exhibited excellent/good clinical outcomes. Analysis of the results indicated the cancellous allograft bone-filled PEEK cage used in ACDF is a good choice for patients with cervical disc disease, and avoids the complications of harvesting iliac autograft. PMID:17639386

  16. The Anabolic Effect of PTH on Bone is Attenuated by Simultaneous Glucocorticoid Treatment

    DEFF Research Database (Denmark)

    Oxlund, Hans; Ørtoft, Gitte; Thomsen, Jesper Skovhus

    2006-01-01

    . The pronounced anabolic effect of PTH injections on the endocortical and trabecular bone surfaces and less pronounced anabolic effect on periosteal surfaces were partially inhibited, but not prevented, by simultaneous GC treatment in old rats. Both cortical and cancellous bone possessed full mechanical...

  17. The correlation between mineralization degree and bone tissue stiffness in the porcine mandibular condyle

    NARCIS (Netherlands)

    Willems, N.M.B.K.; Mulder, L.; Toonder, den J.M.J.; Zentner, A.; Langenbach, G.E.J.

    2014-01-01

    The aim of this study was to correlate the local tissue mineral density (TMD) with the bone tissue stiffness. It was hypothesized that these variables are positively correlated. Cancellous and cortical bone samples were derived from ten mandibular condyles taken from 5 young and 5 adult female pigs.

  18. Quantification of age-related changes in the structure model type and trabecular thickness of human tibial cancellous

    DEFF Research Database (Denmark)

    Ding, Ming; Hvid, I

    2000-01-01

    Structure model type and trabecular thickness are important characteristics in describing cancellous bone architecture. It has been qualitatively observed that a radical change of trabeculae from plate-like to rod-like occurs in aging, bone remodeling, and osteoporosis. Thickness of trabeculae has...... traditionally been measured using model-based histomorphometric methods on two-dimensional (2-D) sections. However, no quantitative study has been published based on three-dimensional (3-D) methods on the age-related changes in structure model type and trabecular thickness for human peripheral (tibial......, structure model type and trabecular thickness were quantified by means of novel 3-D methods. Structure model type was assessed by calculating the structure model index (SMI). The SMI was quantified based on a differential analysis of the triangulated bone surface of a structure. This technique allows...

  19. 30 CFR 280.27 - When may MMS cancel my permit?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may MMS cancel my permit? 280.27 Section... Part Interrupted Activities § 280.27 When may MMS cancel my permit? The RD may cancel a permit at any time. (a) If we cancel your permit, the RD will advise you by certified or registered mail 30 days...

  20. 30 CFR 285.437 - When can my lease or grant be canceled?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When can my lease or grant be canceled? 285.437... Administration Lease Or Grant Cancellation § 285.437 When can my lease or grant be canceled? (a) The Secretary will cancel any lease or grant issued under this part upon proof that it was obtained by fraud or...

  1. 21 CFR 1.235 - How and when do you cancel your facility's registration information?

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false How and when do you cancel your facility's... for Registration of Food Facilities § 1.235 How and when do you cancel your facility's registration information? (a) Notification of registration cancellation. A facility canceling its registration must do so...

  2. 49 CFR 40.267 - What problems always cause an alcohol test to be cancelled?

    Science.gov (United States)

    2010-10-01

    ... cancelled? 40.267 Section 40.267 Transportation Office of the Secretary of Transportation PROCEDURES FOR... always cause an alcohol test to be cancelled? As an employer, a BAT, or an STT, you must cancel an... the test was cancelled and must be treated as if the test never occurred. These problems are: (a) In...

  3. 30 CFR 250.182 - When may the Secretary cancel a lease at the exploration stage?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may the Secretary cancel a lease at the... Requirements, Lease Term Extensions, and Lease Cancellations § 250.182 When may the Secretary cancel a lease at... be modified to avoid the condition(s). The Secretary may cancel the lease if: (a) The primary lease...

  4. Cancell/Cantron/Protocel (PDQ®)—Health Professional Version

    Science.gov (United States)

    Expert-reviewed information summary about the use of Cancell/Cantron/Protocel as a treatment for people with cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  5. 78 FR 40138 - Chlorpyrifos; Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2013-07-03

    ... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2005-0057; FRL-9389-6] Chlorpyrifos; Cancellation... and accepted by the Agency, of products containing chlorpyrifos, pursuant to the Federal Insecticide... 40139

  6. Vacuum Energy Cancellation in a Non-supersymmetric String

    International Nuclear Information System (INIS)

    Kachru, Shamit; Kumar, Jason; Silverstein, Eva

    1998-01-01

    We present a nonsupersymmetric orbifold of type II string theory and show that it has vanishing cosmological constant at the one and two loop level. We argue heuristically that the cancellation may persist at higher loops

  7. Vacuum energy cancellation in a non-supersymmetric string

    Energy Technology Data Exchange (ETDEWEB)

    Kachru, S. [Univ. of California, Berkeley, CA (US). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (US); Kumar, J.; Silverstein, E. [Stanford Univ., CA (US)

    1998-08-01

    The authors present a nonsupersymmetric orbifold of type 2 string theory and show that it has vanishing cosmological constant at the one and two loop level. They argue heuristically that the cancellation persists at higher loops.

  8. MAGNETIC FLUX CANCELLATION IN ELLERMAN BOMBS

    Energy Technology Data Exchange (ETDEWEB)

    Reid, A.; Mathioudakis, M.; Nelson, C. J.; Henriques, V. [Astrophysics Research Centre, School of Mathematics and Physics, Queen’s University Belfast, BT7 1NN, Northern Ireland (United Kingdom); Doyle, J. G. [Armagh Observatory, College Hill, Armagh, BT61 9DG (United Kingdom); Scullion, E. [Trinity College Dublin, College Green, Dublin 2 (Ireland); Ray, T., E-mail: areid29@qub.ac.uk [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland)

    2016-06-01

    Ellerman Bombs (EBs) are often found to be co-spatial with bipolar photospheric magnetic fields. We use H α imaging spectroscopy along with Fe i 6302.5 Å spectropolarimetry from the Swedish 1 m Solar Telescope (SST), combined with data from the Solar Dynamic Observatory , to study EBs and the evolution of the local magnetic fields at EB locations. EBs are found via an EB detection and tracking algorithm. Using NICOLE inversions of the spectropolarimetric data, we find that, on average, (3.43 ± 0.49) × 10{sup 24} erg of stored magnetic energy disappears from the bipolar region during EB burning. The inversions also show flux cancellation rates of 10{sup 14}–10{sup 15} Mx s{sup −1} and temperature enhancements of 200 K at the detection footpoints. We investigate the near-simultaneous flaring of EBs due to co-temporal flux emergence from a sunspot, which shows a decrease in transverse velocity when interacting with an existing, stationary area of opposite polarity magnetic flux, resulting in the formation of the EBs. We also show that these EBs can be fueled further by additional, faster moving, negative magnetic flux regions.

  9. IMPORTANT NOTICE: Cancellation of shuttle Circuit 3

    CERN Multimedia

    2013-01-01

    Circuit 3 of the CERN Shuttle Service (Point 5), which has served CMS since the start of LS1, will be cancelled with effect from Tuesday 16 April. This decision has been taken in consultation with CMS, as the circuit was seldom used.   In response to increasing demand for Circuit 1 - Meyrin and feedback from passengers, the two Circuit 3 journeys will be switched to Circuit 1 – Meyrin (see new timetable below): Mornings: Four journeys instead of three. Circuit 1 now starts at 8:10 (instead of 8:19 a.m.) and runs until 9:27 a.m. (instead of 9:16 a.m.). Lunchtimes: Five journeys in place between 12:10 p.m. and 1:47 p.m. Evenings: Circuit starts at 5:23 p.m. (instead of 5:03 p.m.) and ends at 6:20 p.m. at Building 33. Please note that the circuit will depart from Building 13 instead of Building 33.  

  10. Collinearity, convergence and cancelling infrared divergences

    International Nuclear Information System (INIS)

    Lavelle, Martin; McMullan, David

    2006-01-01

    The Lee-Nauenberg theorem is a fundamental quantum mechanical result which provides the standard theoretical response to the problem of collinear and infrared divergences. Its argument, that the divergences due to massless charged particles can be removed by summing over degenerate states, has been successfully applied to systems with final state degeneracies such as LEP processes. If there are massless particles in both the initial and final states, as will be the case at the LHC, the theorem requires the incorporation of disconnected diagrams which produce connected interference effects at the level of the cross-section. However, this aspect of the theory has never been fully tested in the calculation of a cross-section. We show through explicit examples that in such cases the theorem introduces a divergent series of diagrams and hence fails to cancel the infrared divergences. It is also demonstrated that the widespread practice of treating soft infrared divergences by the Bloch-Nordsieck method and handling collinear divergences by the Lee-Nauenberg method is not consistent in such cases

  11. Cancelable remote quantum fingerprint templates protection scheme

    International Nuclear Information System (INIS)

    Liao Qin; Guo Ying; Huang Duan

    2017-01-01

    With the increasing popularity of fingerprint identification technology, its security and privacy have been paid much attention. Only the security and privacy of biological information are insured, the biological technology can be better accepted and used by the public. In this paper, we propose a novel quantum bit (qbit)-based scheme to solve the security and privacy problem existing in the traditional fingerprint identification system. By exploiting the properties of quantm mechanics, our proposed scheme, cancelable remote quantum fingerprint templates protection scheme, can achieve the unconditional security guaranteed in an information-theoretical sense. Moreover, this novel quantum scheme can invalidate most of the attacks aimed at the fingerprint identification system. In addition, the proposed scheme is applicable to the requirement of remote communication with no need to worry about its security and privacy during the transmission. This is an absolute advantage when comparing with other traditional methods. Security analysis shows that the proposed scheme can effectively ensure the communication security and the privacy of users’ information for the fingerprint identification. (paper)

  12. Fat, Sugar, and Bone Health: A Complex Relationship

    Directory of Open Access Journals (Sweden)

    Li Tian

    2017-05-01

    Full Text Available With people aging, osteoporosis is expected to increase notably. Nutritional status is a relatively easily-modified risk factor, associated with many chronic diseases, and is involved in obesity, diabetes, and coronary heart disease (CHD, along with osteoporosis. Nutrients, such as fats, sugars, and proteins, play a primary function in bone metabolism and maintaining bone health. In Western nations, diets are generally high in saturated fats, however, currently, the nutritional patterns dominating in China continue to be high in carbohydrates from starch, cereals, and sugars. Moreover, high fat or high sugar (fructose, glucose, or sucrose impart a significant impact on bone structural integrity. Due to diet being modifiable, demonstrating the effects of nutrition on bone health can provide an approach for osteoporosis prevention. Most researchers have reported that a high-fat diet consumption is associated with bone mineral density (BMD and, as bone strength diminishes, adverse microstructure changes occur in the cancellous bone compartment, which is involved with lipid metabolism modulation disorder and the alteration of the bone marrow environment, along with an increased inflammatory environment. Some studies, however, demonstrated that a high-fat diet contributes to achieving peak bone mass, along with microstructure, at a younger age. Contrary to these results, others have shown that a high-fructose diet consumption leads to stronger bones with a superior microarchitecture than those with the intake of a high-glucose diet and, at the same time, research indicated that a high-fat diet usually deteriorates cancellous bone parameters, and that the incorporation of fructose into a high-fat diet did not aggravate bone mass loss. High-fat/high-sucrose diets have shown both beneficial and detrimental influences on bone metabolism. Combined, these studies showed that nutrition exerts different effects on bone health. Thus, a better understanding of

  13. Fat, Sugar, and Bone Health: A Complex Relationship.

    Science.gov (United States)

    Tian, Li; Yu, Xijie

    2017-05-17

    With people aging, osteoporosis is expected to increase notably. Nutritional status is a relatively easily-modified risk factor, associated with many chronic diseases, and is involved in obesity, diabetes, and coronary heart disease (CHD), along with osteoporosis. Nutrients, such as fats, sugars, and proteins, play a primary function in bone metabolism and maintaining bone health. In Western nations, diets are generally high in saturated fats, however, currently, the nutritional patterns dominating in China continue to be high in carbohydrates from starch, cereals, and sugars. Moreover, high fat or high sugar (fructose, glucose, or sucrose) impart a significant impact on bone structural integrity. Due to diet being modifiable, demonstrating the effects of nutrition on bone health can provide an approach for osteoporosis prevention. Most researchers have reported that a high-fat diet consumption is associated with bone mineral density (BMD) and, as bone strength diminishes, adverse microstructure changes occur in the cancellous bone compartment, which is involved with lipid metabolism modulation disorder and the alteration of the bone marrow environment, along with an increased inflammatory environment. Some studies, however, demonstrated that a high-fat diet contributes to achieving peak bone mass, along with microstructure, at a younger age. Contrary to these results, others have shown that a high-fructose diet consumption leads to stronger bones with a superior microarchitecture than those with the intake of a high-glucose diet and, at the same time, research indicated that a high-fat diet usually deteriorates cancellous bone parameters, and that the incorporation of fructose into a high-fat diet did not aggravate bone mass loss. High-fat/high-sucrose diets have shown both beneficial and detrimental influences on bone metabolism. Combined, these studies showed that nutrition exerts different effects on bone health. Thus, a better understanding of the regulation

  14. Task-related modulation of visual neglect in cancellation tasks

    OpenAIRE

    Sarri, Margarita; Greenwood, Richard; Kalra, Lalit; Driver, Jon

    2008-01-01

    Unilateral neglect involves deficits of spatial exploration and awareness that do not always affect a fixed portion of extrapersonal space, but may vary with current stimulation and possibly with task demands. Here, we assessed any ‘top-down’, task-related influences on visual neglect, with novel experimental variants of the cancellation test. Many different versions of the cancellation test are used clinically, and can differ in the extent of neglect revealed, though the exact factors determ...

  15. An improved probe noise approach for acoustic feedback cancellation

    DEFF Research Database (Denmark)

    Guo, Meng; Jensen, Søren Holdt; Jensen, Jesper

    2012-01-01

    The perhaps most challenging problem in acoustic feedback cancellation using adaptive filters is the bias problem. It is well-known that a probe noise approach can effectively prevent this problem. However, when the probe noise must be inaudible and the steady-state error of the adaptive filter...... expressions for its system behavior, and through a simulation experiment in an acoustic feedback cancellation system....

  16. An inductorless wideband LNA with a new noise canceling technique

    OpenAIRE

    MOGHADAM, POURIA PAZHOUHESH; ABRISHAMIFAR, ADIB

    2017-01-01

    An inductorless wideband low-noise amplifier (LNA) employing a new noise canceling technique for multistandard applications is presented. The main amplifier has a cascode common gate structure, which provides good input impedance matching and isolation. The proposed noise canceling technique not only improves the noise figure and power gain but also embeds a g$_{m}$-boosting technique in itself, which reduces the power consumption of the main amplifier. Using current-steering and ...

  17. Noise cancellation properties of displacement noise free interferometer

    International Nuclear Information System (INIS)

    Sato, Shuichi; Kawamura, Seiji; Nishizawa, Atsushi; Chen Yanbei

    2010-01-01

    We have demonstrated the practical feasibility of a displacement- and frequency-noise-free laser interferometer (DFI) by partially implementing a recently proposed optical configuration using bi-directional Mach-Zehnder interferometers (MZIs). The noise cancellation efficiency was evaluated by comparing the displacement noise spectrum of the MZIs and the DFI, demonstrating up to 50 dB of noise cancellation. In addition, the possible extension of DFI as QND device is explored.

  18. Active noise control in a duct to cancel broadband noise

    Science.gov (United States)

    Chen, Kuan-Chun; Chang, Cheng-Yuan; Kuo, Sen M.

    2017-09-01

    The paper presents cancelling duct noises by using the active noise control (ANC) techniques. We use the single channel feed forward algorithm with feedback neutralization to realize ANC. Several kinds of ducts noises including tonal noises, sweep tonal signals, and white noise had investigated. Experimental results show that the proposed ANC system can cancel these noises in a PVC duct very well. The noise reduction of white noise can be up to 20 dB.

  19. On a possible mechanism of cosmological term cancellation

    International Nuclear Information System (INIS)

    Dolgov, A.D.

    1982-01-01

    A model is proposed in which cosmological constant is cancelled automatically because of the back reaction on it of a scalar field PHI. The cancellation takes place if two conditions are imposed on the theory, namely vanishing of mass selfinteraction of field PHI. The vacuum energy in the framework of the model considered does not dissapear completely. This leads to some modification of the standard universe expansion scheme

  20. Adaptive cancellation of motion artifact in wearable biosensors.

    Science.gov (United States)

    Yousefi, Rasoul; Nourani, Mehrdad; Panahi, Issa

    2012-01-01

    The performance of wearable biosensors is highly influenced by motion artifact. In this paper, a model is proposed for analysis of motion artifact in wearable photoplethysmography (PPG) sensors. Using this model, we proposed a robust real-time technique to estimate fundamental frequency and generate a noise reference signal. A Least Mean Square (LMS) adaptive noise canceler is then designed and validated using our synthetic noise generator. The analysis and results on proposed technique for noise cancellation shows promising performance.

  1. Multimodal biometric approach for cancelable face template generation

    Science.gov (United States)

    Paul, Padma Polash; Gavrilova, Marina

    2012-06-01

    Due to the rapid growth of biometric technology, template protection becomes crucial to secure integrity of the biometric security system and prevent unauthorized access. Cancelable biometrics is emerging as one of the best solutions to secure the biometric identification and verification system. We present a novel technique for robust cancelable template generation algorithm that takes advantage of the multimodal biometric using feature level fusion. Feature level fusion of different facial features is applied to generate the cancelable template. A proposed algorithm based on the multi-fold random projection and fuzzy communication scheme is used for this purpose. In cancelable template generation, one of the main difficulties is keeping interclass variance of the feature. We have found that interclass variations of the features that are lost during multi fold random projection can be recovered using fusion of different feature subsets and projecting in a new feature domain. Applying the multimodal technique in feature level, we enhance the interclass variability hence improving the performance of the system. We have tested the system for classifier fusion for different feature subset and different cancelable template fusion. Experiments have shown that cancelable template improves the performance of the biometric system compared with the original template.

  2. Bone Cancer

    Science.gov (United States)

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

  3. Bone Diseases

    Science.gov (United States)

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

  4. The hydroxylapatite-bone interface: 10 years after implant installation.

    NARCIS (Netherlands)

    Beekmans, H.C.; Meijer, G.J.; Barkhuysen, R.; Blijdorp, P.A.; Merkx, M.A.W.; Jansen, J.A.

    2008-01-01

    Reconstruction of a severely atrophied maxilla by sinus augmentation with a mixture of hydroxylapatite (HA) granules and autologous cancellous bone is claimed to be a predictable means to facilitate implant placement. To the authors' knowledge, this is the first human histological case report of

  5. Correlation between bone mineral density of jaws and skeletal sites in an Iranian population using dual X-ray energy absorptiometry.

    Science.gov (United States)

    Esfahanizadeh, Nasrin; Davaie, Sotoudeh; Rokn, A R; Daneshparvar, Hamid Reza; Bayat, Noushin; Khondi, Nasrin; Ajvadi, Sara; Ghandi, Mostafa

    2013-07-01

    The aim of the present study was to evaluate the relationship between the bone density of various regions of jaws and skeletal bones. A total of 110 patients with a mean age of 55.01 ± 10.77 years were selected for the purpose of the present descriptive study. Dual X-ray Energy Absorptiometry (DXA) was carried out to determine bone mineral density (BMD) of the femur and lumbar vertebrae. Then all the subjects underwent DXA of the jaw bones and BMD values were determined at four jaw regions. Data were analyzed by SPSS 16 statistical software, and the correlation between the various BMD values was determined by Pearson's correlation coefficient. The results showed that 42.7% of females had normal BMD values in the femur, and in vertebrae, 20% were osteopenic and 37.3% suffered from osteoporosis, with statistically significant differences in the BMD values of the jaws between the three above-mentioned groups (P < 0.001). There was an increasing tendency toward osteopenia and osteoporosis with age. There was a positive correlation between BMD values of the femur and lumbar vertebrae and those of all the jaw regions under study (P < 0.005). There was a negative correlation (P < 0.01) between age and the BMD values of the femur, lumbar vertebrae and anterior maxilla. The bone density of the maxilla and mandible and presence of osteoporosis or osteopenia in these bones might reflect the same problem in skeletal bones.

  6. [On the preparation and mechanical properties of PVA hydrogel bionic cartilage/bone composite artificial articular implants].

    Science.gov (United States)

    Meng, Haoye; Zheng, Yudong; Huang, Xiaoshan; Yue, Bingqing; Xu, Hong; Wang, Yingjun; Chen, Xiaofeng

    2010-10-01

    In view of the problems that conventional artificial cartilages have no bioactivity and are prone to peel off in repeated uses as a result of insufficient strength to bond with subchondral bone, we have designed and prepared a novel kind of PVA-BG composite hydrogel as bionic artificial articular cartilage/bone composite implants. The effects of processes and conditions of preparation on the mechanical properties of implant were explored. In addition, the relationships between compression strain rate, BG content, PVA hydrogels thickness and compressive tangent modulus were also explicated. We also analyzed the effects of cancellous bone aperture, BG and PVA content on the shear strength of bonding interface of artificial articular cartilage with cancellous bone. Meanwhile, the bonding interface of artificial articular cartilage and cancellous bone was characterized by scanning electron microscopy. It was revealed that the compressive modulus of composite implants was correspondingly increased with the adding of BG content and the augments of PVA hydrogel thickness. The compressive modulus and bonding interface were both related to the apertures of cancellous bone. The compressive modulus of composite implants was 1.6-2.23 MPa and the shear strength of bonding interface was 0.63-1.21 MPa. These results demonstrated that the connection between artificial articular cartilage and cancellous bone was adequately firm.

  7. Can Spatiotemporal Fluoride (18F?) Uptake be Used to Assess Bone Formation in the Tibia? A Longitudinal Study Using PET/CT

    OpenAIRE

    Lundblad, Henrik; Karlsson-Thur, Charlotte; Maguire, Gerald Q.; Jonsson, Cathrine; Noz, Marilyn E.; Zeleznik, Michael P.; Weidenhielm, Lars

    2017-01-01

    Background When a bone is broken for any reason, it is important for the orthopaedic surgeon to know how bone healing is progressing. There has been resurgence in the use of the fluoride (18F?) ion to evaluate various bone conditions. This has been made possible by availability of positron emission tomography (PET)/CT hybrid scanners together with cyclotrons. Absorbed on the bone surface from blood flow, 18F? attaches to the osteoblasts in cancellous bone and acts as a pharmacokinetic agent, ...

  8. Resultados de tratamento cirúrgico da pseudoartrose de fratura diafisária do úmero com placa de compressão dinâmica e enxerto de osso esponjoso Results of surgical treatment of nonunion of humeral shaft fracture with dynamic compression plate and cancellous bone grafting

    Directory of Open Access Journals (Sweden)

    Olasinde Anthony Ayotunde

    2012-01-01

    Full Text Available OBJETIVO: Avaliamos o tratamento da pseudoartrose de fratura diafisária do úmero com placa de compressão dinâmica de janeiro de 2002 a dezembro de 2009. MÉTODOS: Vinte e dois pacientes foram tratados durante o período do estudo. O trauma foi a causa predominante de lesão em 86,4% dos pacientes. RESULTADOS: A pseudoartrose foi atrófica em 81,8% e hipertrófica em 18,2% dos indivíduos. Havia lesão primária do nervo radial nervo em 27,3% dos pacientes. Todos os participantes tinham fratura fechada à apresentação e 81,2% deles tinham recebido tratamento anterior de traditional bone setters (pessoa que faz a redução de ossos quebrados ou deslocados, geralmente sem ser médico licenciado e 18,8% tinham falha do tratamento conservador com gesso. O tempo médio até a união foi 16 semanas. O tratamento anterior com traditional bone setters afetou significantemente o tempo de consolidação da fratura (p OBJECTIVE: We evaluated the treatment of nonunion of humeral shaft fracture with dynamic compression plate from January 2002 to December 2009. METHODS: Twenty two patients were treated over the study period. Trauma was the predominant cause of injury in 86,4% of the patients. RESULTS: Nonunion was atrophic in 81,8% and hypertrophic in 18,2% of the individuals. There was a primary injury of the radial nerve in 27,3% of the patients. All the participants had closed fracture at presentation, and 81,2% had received previous treatment from traditional bone setters and 18,8% had failure of the conservative cast management.The average time to healing was 16 weeks. Previous treatment from traditional bone setters significantly affected the time to fracture healing (p<0,05. All fractures had successful union. CONCLUSION: It was concluded that dynamic compression plating remains an effective treatment option for nonunion of humeral shaft fracture. Level of Evidence III, Retrospective study.

  9. Bone marrow scintigraphy with antigranulocyte antibody in multiple myeloma: comparison with simple radiography and bone scintigraphy

    International Nuclear Information System (INIS)

    Kim, Dong Hwan; Lee, Jae Tae; Baek, Jin Ho

    1998-01-01

    Simple X-ray study and bone scan have limitations for early diagnosis of bone or bone marrow lesions in multiple myeloma. The purpose of this study was to evaluate the diagnostic usefulness of bone marrow immunoscintigraphy using anti-granulocyte monoclonal antibody for the evaluation of bone involvement in multiple myeloma. In 22 patients (Male: 15, Female: 7) with multiple myeloma, we performed whole-body immunoscintigraphy using 99m Tc-labelled antigranulocyte antibody (BW 250/183, Scintimum Granulozyt R CIS, France) and compared the findings with those of simple bone radiography and 99m Tc-MDP bone scan. Abnormal findings in bone marrow scintigraphy were considered to be present in case of expansion of peripheral bone marrow or focal photon defect in axial bones. Marrow expansion was noted in 15 of 22 patients (68%). Focal photon defects were found in 18 patients (82%). While one (33%) of 3 patients with Stage II disease showed focal defects in bone marrow scan, abnormal focal defects were observed in 17 of 19 (90%) patients with Stage III. Among 124 focal abnormal sites which were observed in bone marrow scan, bone scan or simple bone radiography, bone marrow scan detected 92 sites (74%), whereas 82 sites (66%) were observed in simple bone radiogrpahy (58 sites, 47%) or bone scan (40 sites, 32%). Fifty-one(41%) out of 124 bone lesions were detected by bone marrow scan only, and located mostly in thoracolumbar spine. Bone marrow scan using 99m Tc-labelled antigranulocyte antibody seems to be a more sensitive procedure for the detection of pathologic bone lesions than simple bone X-ray or bone scan in patients with multiple myeloma

  10. Experimental variation of the level and the ratio of angiogenic and osteogenic signaling affects the spatiotemporal expression of bone-specific markers and organization of bone formation in ectopic sites.

    Science.gov (United States)

    Moser, Norman; Goldstein, Jan; Kauffmann, Phillip; Epple, Matthias; Schliephake, Henning

    2018-04-01

    The aim of the present study was to test the hypothesis that the ratio of angiogenic and osteogenic signaling affects ectopic bone formation when delivered in different amounts. Porous composite PDLLA/CaCO 3 scaffolds were loaded with rhBMP2 and rhVEGF in different dosage combinations and implanted into the gluteal muscles of 120 adult male Wistar rats. Bone formation and expression of alkaline phosphatase and Runx2 were quantified by histomorphometry. Spatial distribution across the scaffolds was assessed by using a grid that discriminated between the periphery and center of the scaffolds. The evaluation showed that the combined delivery of bone morphogenetic protein BMP2 and VEGF in different dosage combinations did not enhance the overall quantity of ectopic bone formation compared to the delivery of BMP2 alone. The addition of VEGF generally upregulated Runx2 after 4 weeks, which may have retarded terminal osteogenic differentiation. However, slow combined delivery of 1.5-2.0 μg BMP2 combined with 50 ng VEGF165 over a period of 5 weeks supported a more even distribution of bone formation across the implanted scaffolds whereas higher amounts of VEGF did not elicit this effect. The findings suggest that structural organization rather than the quantity of ectopic bone formation is affected by the dosage and the ratio of BMP2 and VEGF levels at the observed intervals. The development of carriers for dual growth factor delivery has to take into account the necessity to carefully balance the ratio of growth release.

  11. The Mechanics of Long Bone Fractures.

    Science.gov (United States)

    1981-01-31

    r = .99) between wet density and ultimate bending strength for 37 specimens of human femoral bone. Evans (1973) studied embalmed human tibial...Work 2 2.2 Methods 6 2.2.1 Torsional Loading 6 2.2.2 The Effects of Combined Loading 10 2.2.3 Cancellous Bone Effects 11 2.3 Results 11 2.3.1...PROPERTIES 21 3.1 Previous Work 22 3.2 Methods 26 3.2.1 Cross Sectional Property Software 26 3.2.2 CT Scanning Procedure 28 3.2.3 Linear Dependency of

  12. Biomechanical competence of six different bone screws for reconstructive surgery in three different transplants: Fibular, iliac crest, scapular and artificial bone.

    Science.gov (United States)

    Pietsch, Arnold P; Raith, Stefan; Ode, Jan-Eric; Teichmann, Jan; Lethaus, Bernd; Möhlhenrich, Stephan C; Hölzle, Frank; Duda, Georg N; Steiner, Timm

    2016-06-01

    The goal of this study was to determine a combination of screw and transplantation type that offers optimal primary stability for reconstructive surgery. Fibular, iliac crest, and scapular transplants were tested along with artificial bone substrate. Six different kinds of bone screws (Medartis(©)) were compared, each type utilized with one of six specimens from human transplants (n = 6). Controlled screw-in-tests were performed and the required torque was protocolled. Subsequently, pull-out-tests were executed to determine the retention forces. The artificial bone substitute material showed significantly higher retention forces than real bone samples. The self-drilling screws achieved the significantly highest retention values in the synthetic bone substitute material. Cancellous screws achieved the highest retention in the fibular transplants, while self-drilling and cancellous screws demonstrated better retention than cortical screws in the iliac crest. In the scapular graft, no significant differences were found between the screw types. In comparison to the human transplant types, the cortical screws showed the significantly highest values in the fibula and the lowest values in the iliac crest. The best retention was found in the combination of cancellous screws with fibular graft (514.8 N + -252.3 N). For the flat bones (i.e., scapular and illiac crest) we recommend the cancellous screws. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    1994-01-01

    Some studies have suggested that membranous bone grafts undergo less resorption than endochondral grafts, and faster revascularization of the former has been proposed as the explanation. We studied fresh syngeneic full-thickness bone grafts from calvaria, mandibula, tibia diaphysis, and iliac bone...... implanted in the back muscles of young Lewis rats. As a measure of the quantity of cancellous bone in grafts before implantation, the ratio of the total area of soft-tissue spaces to the total area of the graft was measured histomorphometrically. Revascularization in grafts 3 weeks postoperatively...... was evaluated by deposit of 141Ce-labeled microspheres. Both the quantity of cancellous bone (before implantation) and the revascularization (3 weeks postoperatively) were greater in the mandibular and iliac bone grafts than in the calvarial and tibia diaphyseal grafts. The results suggest that the anatomical...

  14. A Microwave Photonic Interference Canceller: Architectures, Systems, and Integration

    Science.gov (United States)

    Chang, Matthew P.

    This thesis is a comprehensive portfolio of work on a Microwave Photonic Self-Interference Canceller (MPC), a specialized optical system designed to eliminate interference from radio-frequency (RF) receivers. The novelty and value of the microwave photonic system lies in its ability to operate over bandwidths and frequencies that are orders of magnitude larger than what is possible using existing RF technology. The work begins, in 2012, with a discrete fiber-optic microwave photonic canceller, which prior work had demonstrated as a proof-of-concept, and culminates, in 2017, with the first ever monolithically integrated microwave photonic canceller. With an eye towards practical implementation, the thesis establishes novelty through three major project thrusts. (Fig. 1): (1) Extensive RF and system analysis to develop a full understanding of how, and through what mechanisms, MPCs affect an RF receiver. The first investigations of how a microwave photonic canceller performs in an actual wireless environment and a digital radio are also presented. (2) New architectures to improve the performance and functionality of MPCs, based on the analysis performed in Thrust 1. A novel balanced microwave photonic canceller architecture is developed and experimentally demonstrated. The balanced architecture shows significant improvements in link gain, noise figure, and dynamic range. Its main advantage is its ability to suppress common-mode noise and reduce noise figure by increasing the optical power. (3) Monolithic integration of the microwave photonic canceller into a photonic integrated circuit. This thrust presents the progression of integrating individual discrete devices into their semiconductor equivalent, as well as a full functional and RF analysis of the first ever integrated microwave photonic canceller.

  15. Stress fractures and bone pain

    International Nuclear Information System (INIS)

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

    1984-01-01

    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

  16. Correlation between bone mineral density of jaws and skeletal sites in an Iranian population using dual X-ray energy absorptiometry

    Directory of Open Access Journals (Sweden)

    Nasrin Esfahanizadeh

    2013-01-01

    Full Text Available Background: The aim of the present study was to evaluate the relationship between the bone density of various regions of jaws and skeletal bones. Materials and Methods: A total of 110 patients with a mean age of 55.01 ± 10.77 years were selected for the purpose of the present descriptive study. Dual X-ray Energy Absorptiometry (DXA was carried out to determine bone mineral density (BMD of the femur and lumbar vertebrae. Then all the subjects underwent DXA of the jaw bones and BMD values were determined at four jaw regions. Data were analyzed by SPSS 16 statistical software, and the correlation between the various BMD values was determined by Pearson′s correlation coefficient. Results: The results showed that 42.7% of females had normal BMD values in the femur, and in vertebrae, 20% were osteopenic and 37.3% suffered from osteoporosis, with statistically significant differences in the BMD values of the jaws between the three above-mentioned groups (P < 0.001. There was an increasing tendency toward osteopenia and osteoporosis with age. There was a positive correlation between BMD values of the femur and lumbar vertebrae and those of all the jaw regions under study (P < 0.005. There was a negative correlation (P < 0.01 between age and the BMD values of the femur, lumbar vertebrae and anterior maxilla. Conclusion: The bone density of the maxilla and mandible and presence of osteoporosis or osteopenia in these bones might reflect the same problem in skeletal bones.

  17. Simulation for noise cancellation using LMS adaptive filter

    Science.gov (United States)

    Lee, Jia-Haw; Ooi, Lu-Ean; Ko, Ying-Hao; Teoh, Choe-Yung

    2017-06-01

    In this paper, the fundamental algorithm of noise cancellation, Least Mean Square (LMS) algorithm is studied and enhanced with adaptive filter. The simulation of the noise cancellation using LMS adaptive filter algorithm is developed. The noise corrupted speech signal and the engine noise signal are used as inputs for LMS adaptive filter algorithm. The filtered signal is compared to the original noise-free speech signal in order to highlight the level of attenuation of the noise signal. The result shows that the noise signal is successfully canceled by the developed adaptive filter. The difference of the noise-free speech signal and filtered signal are calculated and the outcome implies that the filtered signal is approaching the noise-free speech signal upon the adaptive filtering. The frequency range of the successfully canceled noise by the LMS adaptive filter algorithm is determined by performing Fast Fourier Transform (FFT) on the signals. The LMS adaptive filter algorithm shows significant noise cancellation at lower frequency range.

  18. Wavelet-LMS algorithm-based echo cancellers

    Science.gov (United States)

    Seetharaman, Lalith K.; Rao, Sathyanarayana S.

    2002-12-01

    This paper presents Echo Cancellers based on the Wavelet-LMS Algorithm. The performance of the Least Mean Square Algorithm in Wavelet transform domain is observed and its application in Echo cancellation is analyzed. The Widrow-Hoff Least Mean Square Algorithm is most widely used algorithm for Adaptive filters that function as Echo Cancellers. The present day communication signals are widely non-stationary in nature and some errors crop up when Least Mean Square Algorithm is used for the Echo Cancellers handling such signals. The analysis of non-stationary signals often involves a compromise between how well transitions or discontinuities can be located. The multi-scale or multi-resolution of signal analysis, which is the essence of wavelet transform, makes Wavelets popular in non-stationary signal analysis. In this paper, we present a Wavelet-LMS algorithm wherein the wavelet coefficients of a signal are modified adaptively using the Least Mean Square Algorithm and then reconstructed to give an Echo-free signal. The Echo Canceller based on this Algorithm is found to have a better convergence and a comparatively lesser MSE (Mean Square error).

  19. Full-duplex wireless communications systems self-interference cancellation

    CERN Document Server

    Le-Ngoc, Tho

    2017-01-01

    This book introduces the development of self-interference (SI)-cancellation techniques for full-duplex wireless communication systems. The authors rely on estimation theory and signal processing to develop SI-cancellation algorithms by generating an estimate of the received SI and subtracting it from the received signal. The authors also cover two new SI-cancellation methods using the new concept of active signal injection (ASI) for full-duplex MIMO-OFDM systems. The ASI approach adds an appropriate cancelling signal to each transmitted signal such that the combined signals from transmit antennas attenuate the SI at the receive antennas. The authors illustrate that the SI-pre-cancelling signal does not affect the data-bearing signal. This book is for researchers and professionals working in wireless communications and engineers willing to understand the challenges of deploying full-duplex and practical solutions to implement a full-duplex system. Advanced-level students in electrical engineering and computer ...

  20. Bone Canopies in Pediatric Renal Osteodystrophy

    DEFF Research Database (Denmark)

    Pereira, Renata C; Levin Andersen, Thomas; Friedman, Peter A

    2016-01-01

    Pediatric renal osteodystrophy (ROD) is characterized by changes in bone turnover, mineralization, and volume that are brought about by alterations in bone resorption and formation. The resorptive and formative surfaces on the cancellous bone are separated from the marrow cavity by canopies...... and their association with biochemical and bone histomorphometric parameters in 106 pediatric chronic kidney disease (CKD) patients (stage 2-5) across the spectrum of ROD. Canopies in CKD patients often appeared as thickened multilayered canopies, similar to previous reports in patients with primary hyperparathyroidism....... This finding contrasts with the thin appearance reported in healthy individuals with normal kidney function. Furthermore, canopies in pediatric CKD patients showed immunoreactivity to the PTH receptor (PTHR1) as well as to the receptor activator of nuclear factor kappa-B ligand (RANKL). The number of surfaces...

  1. Adaptive Feedforward Cancellation of Sinusoidal Disturbances in Superconducting RF Cavities

    CERN Document Server

    Kandil, T H; Hartung, W; Khalil, H; Popielarski, J; Vincent, J; York, R C

    2004-01-01

    A control method, known as adaptive feedforward cancellation (AFC) is applied to damp sinusoidal disturbances due to microphonics in superconducting RF (SRF) cavities. AFC provides a method for damping internal, and external sinusoidal disturbances with known frequencies. It is preferred over other schemes because it uses rudimentary information about the frequency response at the disturbance frequencies, without the necessity of knowing an analytic model (transfer function) of the system. It estimates the magnitude and phase of the sinusoidal disturbance inputs and generates a control signal to cancel their effect. AFC, along with a frequency estimation process, is shown to be very successful in the cancellation of sinusoidal signals from different sources. The results of this research may significantly reduce the power requirements and increase the stability for lightly loaded continuous-wave SRF systems.

  2. Analysis of Intercarrier Interference Cancellation Scheme in OFDM Systems

    Directory of Open Access Journals (Sweden)

    Nasir Salh Almisbah

    2012-06-01

    Full Text Available Abstract: Orthogonal Frequency Division Multiplexing (OFDM is an emerging multi-carrier modulation scheme, which has been adopted for several wireless standards such as IEEE 802.11a and HiperLAN2. In OFDM systems, the performance is very sensitive to subcarrier frequency errors (offset. This paper shows the analysis and derivations of intercarrier interference (ICI complex gain that used in self-cancellation scheme and its dependence on subcarrier frequency offset. Simulation shows that better improvement in performance is achieved for systems that use this cancellation scheme. Moreover, analysis and simulation show that theoretical carrier-to-interference ratio (CIR for OFDM with cancellation scheme is greater than conventional one by more than 14dB.

  3. Development of a Voice Activity Controlled Noise Canceller

    Science.gov (United States)

    Abid Noor, Ali O.; Samad, Salina Abdul; Hussain, Aini

    2012-01-01

    In this paper, a variable threshold voice activity detector (VAD) is developed to control the operation of a two-sensor adaptive noise canceller (ANC). The VAD prohibits the reference input of the ANC from containing some strength of actual speech signal during adaptation periods. The novelty of this approach resides in using the residual output from the noise canceller to control the decisions made by the VAD. Thresholds of full-band energy and zero-crossing features are adjusted according to the residual output of the adaptive filter. Performance evaluation of the proposed approach is quoted in terms of signal to noise ratio improvements as well mean square error (MSE) convergence of the ANC. The new approach showed an improved noise cancellation performance when tested under several types of environmental noise. Furthermore, the computational power of the adaptive process is reduced since the output of the adaptive filter is efficiently calculated only during non-speech periods. PMID:22778667

  4. Beamforming design with proactive interference cancelation in MISO interference channels

    Science.gov (United States)

    Li, Yang; Tian, Yafei; Yang, Chenyang

    2015-12-01

    In this paper, we design coordinated beamforming at base stations (BSs) to facilitate interference cancelation at users in interference networks, where each BS is equipped with multiple antennas and each user is with a single antenna. By assuming that each user can select the best decoding strategy to mitigate the interference, either canceling the interference after decoding when it is strong or treating it as noise when it is weak, we optimize the beamforming vectors that maximize the sum rate for the networks under different interference scenarios and find the solutions of beamforming with closed-form expressions. The inherent design principles are then analyzed, and the performance gain over passive interference cancelation is demonstrated through simulations in heterogeneous cellular networks.

  5. Development of a Voice Activity Controlled Noise Canceller

    Directory of Open Access Journals (Sweden)

    Aini Hussain

    2012-05-01

    Full Text Available In this paper, a variable threshold voice activity detector (VAD is developed to control the operation of a two-sensor adaptive noise canceller (ANC. The VAD prohibits the reference input of the ANC from containing some strength of actual speech signal during adaptation periods. The novelty of this approach resides in using the residual output from the noise canceller to control the decisions made by the VAD. Thresholds of full-band energy and zero-crossing features are adjusted according to the residual output of the adaptive filter. Performance evaluation of the proposed approach is quoted in terms of signal to noise ratio improvements as well mean square error (MSE convergence of the ANC. The new approach showed an improved noise cancellation performance when tested under several types of environmental noise. Furthermore, the computational power of the adaptive process is reduced since the output of the adaptive filter is efficiently calculated only during non-speech periods.

  6. Interference Cancellation Using Space-Time Processing and Precoding Design

    CERN Document Server

    Li, Feng

    2013-01-01

    Interference Cancellation Using Space-Time Processing and Precoding Design introduces original design methods to achieve interference cancellation, low-complexity decoding and full diversity for a series of multi-user systems. In multi-user environments, co-channel interference will diminish the performance of wireless communications systems. In this book, we investigate how to design robust space-time codes and pre-coders to suppress the co-channel interference when multiple antennas are available.   This book offers a valuable reference work for graduate students, academic researchers and engineers who are interested in interference cancellation in wireless communications. Rigorous performance analysis and various simulation illustrations are included for each design method.   Dr. Feng Li is a scientific researcher at Cornell University.

  7. Primary Malignant Bone Tumours at the University Teaching ...

    African Journals Online (AJOL)

    Introduction: Primary malignant bone tumours include malignancies arising primarily from bone tissue. This is opposed to secondary bone tumours in which case the neoplastic elements arise primarily from other sites within the body and secondarily spread to bone. Primary malignant bone tumours are generally ...

  8. Bone marrow aspiration

    Science.gov (United States)

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

  9. Reducing Cancelations on the Day of Scheduled Surgery at a Children's Hospital.

    Science.gov (United States)

    Pratap, Jayant Nick; Varughese, Anna M; Mercurio, Patti; Lynch, Terri; Lonnemann, Teresa; Ellis, Andrea; Rugg, John; Stone, W Ray; Bedinghaus, Cindi

    2015-05-01

    Cancelation on the day of surgery (DoSC) represents a costly wastage of operating room (OR) time and causes inconvenience, emotional distress, and financial cost to families. A quality improvement project sought to reduce lost OR time due to cancelation. Key drivers of the process included effective 2-way communication with families, compliance with fasting rules, and decision-making on patient illness before the day of surgery. A multidisciplinary team conducted serial tests of change addressing the various key drivers. Interventions were simplified, colorful, personalized preoperative instruction sheets and text-message reminders to caregivers' cellphones, as well as a defined institutional decision-making pathway to permit rescheduling before the day of surgery in case of patient illness concerns. After initial smaller-scale testing, the interventions were implemented across all patients and sites. Data were collected from the hospital information technology system and analyzed by using control charts and statistical process control methods. Mean OR time lost due to DoSC was decreased from a baseline of 5.7 to 3.6 hours/day in testing with a subset of surgical services at the hospital's base campus, and then from 6.6 hours to 5.5 hours/day when implemented across all services at both surgical sites. By applying quality improvement methods, significant reductions were made in time lost due to DoSC. The impact can be significant by improving institutional resource utilization. Copyright © 2015 by the American Academy of Pediatrics.

  10. Use of the medial femoral condyle vascularized bone flap in traumatic avascular necrosis of the navicular: a case report.

    Science.gov (United States)

    Holm, Janson; Vangelisti, Garrett; Remmers, Jared

    2012-01-01

    The medial femoral condyle vascularized bone flap has a high success rate in published literature regarding its use in nonunions and avascular necrosis of the upper and lower extremities. It is reported to have minimal donor site morbidity and the ability to provide structural support and torsional strength to load-bearing areas. The flap has found particular success in the treatment of scaphoid nonunions. The tarsal navicular, similar to the scaphoid, is largely articular cancellous bone with little surface area for vascular inflow. These anatomic features make the navicular prone to nonunion and avascular necrosis in traumatic scenarios. We describe a case of nonunion and avascular necrosis of the tarsal navicular occurring as sequelae of a high-impact midfoot injury sustained in an automobile accident. After an initial attempt at open reduction and internal fixation with midfoot bridge plating, subsidence and nonunion resulted. An attempt at arthrodesis of the talonavicular and naviculocuneiform joints was then undertaken. This too failed, leading to the development of additional collapse and avascular necrosis. The site was treated with a medial femoral condyle vascularized bone flap. In this single case, the patient returned to pain-free ambulation and reported excellent outcomes and functional capacity. Although we present a successful case, a larger case series is necessary to establish the use of this flap as a reliable option for the treatment of nonunion and avascular necrosis of the tarsal navicular. Copyright © 2012 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  11. Cancellation Mechanism for Dark-Matter-Nucleon Interaction.

    Science.gov (United States)

    Gross, Christian; Lebedev, Oleg; Toma, Takashi

    2017-11-10

    We consider a simple Higgs portal dark-matter model, where the standard model is supplemented with a complex scalar whose imaginary part plays the role of weakly interacting massive particle dark matter (DM). We show that the direct DM detection cross section vanishes at the tree level and zero momentum transfer due to a cancellation by virtue of a softly broken symmetry. This cancellation is operative for any mediator masses. As a result, our electroweak-scale dark matter satisfies all of the phenomenological constraints quite naturally.

  12. Interference Cancelation Schemes for Uplink Transmission in Femtocells

    DEFF Research Database (Denmark)

    Thai, Chan; Popovski, Petar

    2010-01-01

    We present techniques that solve the near-far problems in femtocell networks. When a co-channel configuration is used, a transmission in the macrocell may cause interference to a femtocell. We introduce methods to cancel the interference caused by the macrocell to a femtocell by using the high......-rate link between the macrocell base station (BS) and the femtocell BS. In such a way, the interference from macrocell transmitters is completely cancelled when uplink transmission is used in the femtocell. Therefore, the allocation of time slots for uplink/downlink in a femtocell can be done by trying only...

  13. Full-duplex MIMO system based on antenna cancellation technique

    DEFF Research Database (Denmark)

    Foroozanfard, Ehsan; Franek, Ondrej; Tatomirescu, Alexandru

    2014-01-01

    The performance of an antenna cancellation technique for a multiple-input– multiple-output (MIMO) full-duplex system that is based on null-steering beamforming and antenna polarization diversity is investigated. A practical implementation of a symmetric antenna topology comprising three dual......-polarized patch antennas operating at 2.4 GHz is described. The measurement results show an average of 60 dB self-interference cancellation over 200 MHz bandwidth. Moreover, a decoupling level of up to 22 dB is achieved for MIMO multiplexing using antenna polarization diversity. The performance evaluation...

  14. Diagrammatic cancellations and the gauge dependence of QED

    Energy Technology Data Exchange (ETDEWEB)

    Kißler, Henry, E-mail: kissler@physik.hu-berlin.de [Department of Mathematical Sciences, University of Liverpool, L69 7ZL, Liverpool (United Kingdom); Department of Mathematics, Humboldt-Universität zu Berlin, Rudower Chaussee 25, D-12489 Berlin (Germany); Kreimer, Dirk, E-mail: kreimer@math.hu-berlin.de [Department of Mathematics, Humboldt-Universität zu Berlin, Rudower Chaussee 25, D-12489 Berlin (Germany)

    2017-01-10

    This letter examines diagrammatic cancellations for Quantum Electrodynamics (QED) in the general linear gauge. These cancellations combine Feynman graphs of various topologies and provide a method to reconstruct the gauge dependence of the electron propagator from the result of a particular gauge by means of a linear Dyson–Schwinger equation. We use this method in combination with dimensional regularization to demonstrate how the 3-loop ε-expansion in the Feynman gauge determines the ε-expansions for all gauge parameter dependent terms to 4 loops.

  15. Successive approximation algorithm for cancellation of artifacts in DSA images

    International Nuclear Information System (INIS)

    Funakami, Raiko; Hiroshima, Kyoichi; Nishino, Junji

    2000-01-01

    In this paper, we propose an algorithm for cancellation of artifacts in DSA images. We have already proposed an automatic registration method based on the detection of local movements. When motion of the object is large, it is difficult to estimate the exact movement, and the cancellation of artifacts may therefore fail. The algorithm we propose here is based on a simple rigid model. We present the results of applying the proposed method to a series of experimental X-ray images, as well as the results of applying the algorithm as preprocessing for a registration method based on local movement. (author)

  16. Noninvadability implies noncoexistence for a class of cancellative systems

    Czech Academy of Sciences Publication Activity Database

    Swart, Jan M.

    2013-01-01

    Roč. 18, č. 38 (2013), s. 1-12 ISSN 1083-589X R&D Projects: GA ČR GAP201/10/0752 Institutional support: RVO:67985556 Keywords : cancellative system * interface tightness * duality * coexistence * Neuhauser-Pacala model * affine voter model * rebellious voter model * balancing selection * branching * annihilation * parity preservation Subject RIV: BA - General Mathematics Impact factor: 0.627, year: 2013 http://library.utia.cas.cz/separaty/2013/SI/swart-noninvadability implies noncoexistence for a class of cancellative systems.pdf

  17. 3D Printed Pediatric Temporal Bone: A Novel Training Model.

    Science.gov (United States)

    Longfield, Evan A; Brickman, Todd M; Jeyakumar, Anita

    2015-06-01

    Temporal bone dissection is a fundamental element of otologic training. Cadaveric temporal bones (CTB) are the gold standard surgical training model; however, many institutions do not have ready access to them and their cost can be significant: $300 to $500. Furthermore, pediatric cadaveric temporal bones are not readily available. Our objective is to develop a pediatric temporal bone model. Temporal bone model. Tertiary Children's Hospital. Pediatric patient model. We describe the novel use of a 3D printer for the generation of a plaster training model from a pediatric high- resolution CT temporal bone scan of a normal pediatric temporal bone. Three models were produced and were evaluated. The models utilized multiple colors (white for bone, yellow for the facial nerve) and were of high quality. Two models were drilled as a proof of concept and found to be an acceptable facsimile of the patient's anatomy, rendering all necessary surgical landmarks accurately. The only negative comments pertaining to the 3D printed temporal bone as a training model were the lack of variation in hardness between cortical and cancellous bone, noting a tactile variation from cadaveric temporal bones. Our novel pediatric 3D temporal bone training model is a viable, low-cost training option for previously inaccessible pediatric temporal bone training. Our hope is that, as 3D printers become commonplace, these models could be rapidly reproduced, allowing for trainees to print models of patients before performing surgery on the living patient.

  18. Low Bone Density

    Science.gov (United States)

    ... Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone density ... people with normal bone density. Detecting Low Bone Density A bone density test will determine whether you ...

  19. New aspects of galectin functionality in nuclei of cultured bone marrow stromal and epidermal cells: biotinylated galectins as tool to detect specific bindong sites

    Czech Academy of Sciences Publication Activity Database

    Purkrábková, T.; Smetana Jr., K.; Dvořánková, B.; Holíková, Z.; Böck, C.; Lensch, M.; André, S.; Pytlík, R.; Liu, F.; Klíma, Jiří; Smetana, K.; Motlík, Jan; Gabius, H. J.

    2003-01-01

    Roč. 95, - (2003), s. 535-545 ISSN 0248-4900 R&D Projects: GA MŠk LN00A065 Institutional research plan: CEZ:AV0Z5045916 Keywords : biotinylation * bone marrow stromal cells * galectin Subject RIV: ED - Physiology Impact factor: 2.159, year: 2003

  20. Unicameral bone cyst of the lunate in an adult: case report.

    Science.gov (United States)

    Gündeş, Hakan; Sahin, Mustafa; Alici, Tugrul

    2010-10-30

    We report a case of a symptomatic unicameral (simple) bone cyst of the lunate in a 42-year- old woman. The lesion was treated with curettage and cancellous autogenous iliac bone grafting. At five years of follow-up the wrist was pain free, there were no limitations of motion, and the radiographs showed complete obliteration of the cavity. To the best of our knowledge, no other unicameral bone cyst of the lunate has been reported in an adult. Cysts with significant cavities at the carpal bones in an adult should be approached cautiously, as they may require early curettage and bone grafting for healing, before collapse and degenerative changes occur.

  1. Effect of water on piezoelectricity in bone and collagen.

    Science.gov (United States)

    Netto, T G; Zimmerman, R L

    1975-01-01

    Interferometric measurements of bovine bone and tendon show that the values of the piezoelectric strain constant d14 decrease with hydration from the dry values of 0.2 X 10(-14) and 2.0 X 10(-14) m/V, respectively. The decrease of piezoelectricity in tendon is exponential with a characteristic hydration of 7% by weight from which an upper limit of the average molecular weight of the responsible electric dipole moments is deduced. The piezoelectricity in bone decreases relatively slowly with hydration indicating that the electric dipoles in bone collagen are subject to a different cancelling mechanism. PMID:1148359

  2. Reduced rates of non-union with modified periacetabular osteotomy using peracetic-acid sterilized cancellous allografts.

    Science.gov (United States)

    Wassilew, Georgi I; Janz, Viktor; Renner, Lisa; Perka, Carsten; Pruss, Axel

    2016-12-01

    The objective of the present study was to analyze the clinical and radiological results of periacetabular osteotomies (PAO) using Kirschner wire fixation and an allogeneic cancellous bone graft. This retrospective cohort study included 73 patients (85 PAOs). The allografts were processed from distal femur of cadaveric donors, defatted, sterilized with a peracetic-acid ethanol solution and freeze-dried. The clinical outcome, as measured by the Harris Hip Scores (HHS), the complication rate and the acetabular correction, as measured by radiological parameters, were compared. The postoperative femoral head coverage and HSS were significantly improved. Major complications occurred in five cases (6 %), but in no case did we observe a non-union or a graft-associated adverse effect. Fixation of the acetabular fragment with Kirschner wires in combination with an allogeneic cancellous bone graft is a safe method, with a low complication rate, no loss of correction and can prevent the occurrence of non-union with a high degree of probability.

  3. Development of parietal bone surrogates for parietal graft lift training

    Directory of Open Access Journals (Sweden)

    Hollensteiner Marianne

    2016-09-01

    Full Text Available Currently the surgical training of parietal bone graft techniques is performed on patients or specimens. Commercially available bone models do not deliver realistic haptic feedback. Thus customized parietal skull surrogates were developed for surgical training purposes. Two human parietal bones were used as reference. Based on the measurement of insertion forces of drilling, milling and saw procedures suitable material compositions for molding cortical and cancellous calvarial layers were found. Artificial skull caps were manufactured and tested. Additionally microtomograpy images of human and artificial parietal bones were performed to analyze outer table and diploe thicknesses. Significant differences between human and artificial skulls were not detected with the mechanical procedures tested. Highly significant differences were found for the diploe thickness values. In conclusion, an artificial bone has been created, mimicking the properties of human parietal bone thus being suitable for tabula externa graft lift training.

  4. Aging and bone. X-ray bone densitometry

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Rikushi (Shiga Univ. of Medical Sciences, Otsu (Japan))

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.).

  5. Aging and bone. X-ray bone densitometry

    International Nuclear Information System (INIS)

    Morita, Rikushi

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.)

  6. 77 FR 64794 - Cancellation of the National Agricultural Research, Extension, Education, and Economics Advisory...

    Science.gov (United States)

    2012-10-23

    ... Cancellation of the National Agricultural Research, Extension, Education, and Economics Advisory Board Meeting AGENCY: Research, Education, and Economics, USDA. ACTION: Notice of intent to cancel meeting. SUMMARY: The meeting of the National Agricultural Research, Extension, Education, and Economics Advisory Board...

  7. 77 FR 69840 - Iodomethane; Notice of Receipt of Request to Voluntarily Cancel Iodomethane Pesticide...

    Science.gov (United States)

    2012-11-21

    ... of Request to Voluntarily Cancel Iodomethane Pesticide Registrations and Amend a Registration AGENCY... voluntarily cancel the registrations of products containing the pesticide iodomethane. In addition, the... deadline identified. [[Page 69841

  8. Effect of vitamin K2 and growth hormone on the long bones in hypophysectomized young rats: a bone histomorphometry study.

    Science.gov (United States)

    Iwamoto, Jun; Takeda, Tsuyoshi; Sato, Yoshihiro; Yeh, James K

    2007-01-01

    The purpose of the present study was to determine whether vitamin K(2) and growth hormone (GH) had an additive effect on the long bones in hypophysectomized young rats. Forty-eight female Sprague-Dawley rats (6 weeks old) were assigned to the following five groups by the stratified weight randomization method: intact controls, hypophysectomy (HX) alone, HX + vitamin K(2) (30 mg/kg, p.o., daily), HX + GH (0.625 mg/kg, s.c., 5 days a week), and HX + vitamin K(2) + GH. The duration of the experiment was 4 weeks. HX resulted in a reduction of the cancellous bone volume/total tissue volume (BV/TV) at the proximal tibial metaphysis, as well as decreasing the total tissue area and cortical area of the tibial diaphysis. These changes resulted from a decrease of the longitudinal growth rate and the bone formation rate (BFR)/TV of cancellous bone, as well as a decrease of the periosteal BFR/bone surface (BS) and an increase of endocortical bone turnover (indicated by the BFR/BS) in cortical bone. Administration of vitamin K(2) to HX rats did not affect the cancellous BV/TV or the cortical area. On the other hand, GH completely prevented the decrease of total tissue area and cortical area in cortical bone, as well as the decrease of marrow area and endocortical circumference, by increasing the periosteal BFR/BS compared with that in intact controls and reversing the increase of endocortical bone turnover (BFR/BS). However, GH only partly improved the reduction of the cancellous BV/TV, despite an increase of the longitudinal growth rate and BFR/TV compared with those of intact controls. When administered with GH, vitamin K(2) counteracted the reduction of endocortical bone turnover (BFR/BS) and circumference caused by GH treatment, resulting in no significant difference of marrow area from that in untreated HX rats. These results suggest that, despite the lack of an obvious effect on bone parameters, vitamin K(2) normalizes the size of the marrow cavity during development of

  9. Evaluating differential nuclear DNA yield rates and osteocyte numbers among human bone tissue types: A synchrotron radiation micro-CT approach.

    Science.gov (United States)

    Andronowski, Janna M; Mundorff, Amy Z; Pratt, Isaac V; Davoren, Jon M; Cooper, David M L

    2017-05-01

    Molecular human identification has conventionally focused on DNA sampling from dense, weight-bearing cortical bone tissue, typically from femora or tibiae. A comparison of skeletal elements from three contemporary individuals demonstrated that elements with high quantities of cancellous bone yielded nuclear DNA at the highest rates, suggesting that preferentially sampling cortical bone may be suboptimal (Mundorff & Davoren, 2014). Despite these findings, the reason for the differential DNA yields between cortical and cancellous bone tissues remains unknown. The primary goal of this work is to ascertain whether differences in bone microstructure can be used to explain differential nuclear DNA yield among bone tissue types observed by Mundorff and Davoren (2014), with a focus on osteocytes and the three-dimensional (3D) quantification of their associated lacunae. Osteocytes and other bone cells are recognized to house DNA in bone tissue, thus examining the density of their lacunae may explain why nuclear DNA yield rates differ among bone tissue types. Lacunae were visualized and quantified using synchrotron radiation-based micro-Computed Tomographic imaging (SR micro-CT). Volumes of interest (VOIs) from cortical and cancellous bone tissues (n=129) were comparatively analyzed from the three skeletons sampled for Mundorff and Davoren's (2014) study. Analyses tested the primary hypothesis that the abundance and density of osteocytes (inferred from their lacunar spaces) vary between cortical and cancellous bone tissue types. Results demonstrated that osteocyte lacunar abundance and density vary between cortical and cancellous bone tissue types, with cortical bone VOIs containing a higher lacunar abundance and density. We found that the osteocyte lacunar density values are independent of nuclear DNA yield, suggesting an alternative explanation for the higher nuclear DNA yields from bones with greater quantities of cancellous bone tissue. The use of SR micro-CT allowed for

  10. Effects of growth hormone and low dose estrogen on bone growth and turnover in long bones of hypophysectomized rats

    Science.gov (United States)

    Kidder, L. S.; Schmidt, I. U.; Evans, G. L.; Turner, R. T.

    1997-01-01

    Pituitary hormones are recognized as critical to longitudinal growth, but their role in the radial growth of bone and in maintaining cancellous bone balance are less clear. This investigation examines the histomorphometric effects of hypophysectomy (Hx) and ovariectomy (OVX) and the subsequent replacement of growth hormone (GH) and estrogen (E), in order to determine the effects and possible interactions between these two hormones on cortical and cancellous bone growth and turnover. The replacement of estrogen is of interest since Hx results in both pituitary and gonadal hormone insufficiencies, with the latter being caused by the Hx-associated reduction in follicle stimulating hormone (FSH). All hypophysectomized animals received daily supplements of hydrocortisone (500 microg/kg) and L-thyroxine (10 microg/kg), whereas intact animals received daily saline injections. One week following surgery, hypophysectomized animals received either daily injections of low-dose 17 beta-estradiol (4.8 microg/kg s.c.), 3 X/d recombinant human GH (2 U/kg s.c.), both, or saline for a period of two weeks. Flurochromes were administered at weekly intervals to label bone matrix undergoing mineralization. Whereas Hx resulted in reductions in body weight, uterine weight, and tibial length, OVX significantly increased body weight and tibial length, while reducing uterine weight. The combination of OVX and Hx resulted in values similar to Hx alone. Treatment with GH normalized body weight and bone length, while not affecting uterine weight in hypophysectomized animals. Estrogen increased uterine weight, while not impacting longitudinal bone growth and reduced body weight. Hypophysectomy diminished tibial cortical bone area through reductions in both mineral appositional rate (MAR) and bone formation rate (BFR). While E had no effect, GH increased both MAR and BFR, though not to sham-operated (control) levels. Hypophysectomy reduced proximal tibial trabecular number and cancellous bone

  11. Spaceflight-induced vertebral bone loss in ovariectomized rats is associated with increased bone marrow adiposity and no change in bone formation

    Science.gov (United States)

    Keune, Jessica A; Philbrick, Kenneth A; Branscum, Adam J; Iwaniec, Urszula T; Turner, Russell T

    2016-01-01

    There is often a reciprocal relationship between bone marrow adipocytes and osteoblasts, suggesting that marrow adipose tissue (MAT) antagonizes osteoblast differentiation. MAT is increased in rodents during spaceflight but a causal relationship between MAT and bone loss remains unclear. In the present study, we evaluated the effects of a 14-day spaceflight on bone mass, bone resorption, bone formation, and MAT in lumbar vertebrae of ovariectomized (OVX) rats. Twelve-week-old OVX Fischer 344 rats were randomly assigned to a ground control or flight group. Following flight, histological sections of the second lumbar vertebrae (n=11/group) were stained using a technique that allowed simultaneous quantification of cells and preflight fluorochrome label. Compared with ground controls, rats flown in space had 32% lower cancellous bone area and 306% higher MAT. The increased adiposity was due to an increase in adipocyte number (224%) and size (26%). Mineral apposition rate and osteoblast turnover were unchanged during spaceflight. In contrast, resorption of a preflight fluorochrome and osteoclast-lined bone perimeter were increased (16% and 229%, respectively). The present findings indicate that cancellous bone loss in rat lumbar vertebrae during spaceflight is accompanied by increased bone resorption and MAT but no change in bone formation. These findings do not support the hypothesis that increased MAT during spaceflight reduces osteoblast activity or lifespan. However, in the context of ovarian hormone deficiency, bone formation during spaceflight was insufficient to balance increased resorption, indicating defective coupling. The results are therefore consistent with the hypothesis that during spaceflight mesenchymal stem cells are diverted to adipocytes at the expense of forming osteoblasts. PMID:28725730

  12. Pharmacokinetics of linezolid in bone tissue investigated by in vivo microdialysis

    DEFF Research Database (Denmark)

    Stolle, L.B.; Plock, N.; Joukhadar, C.

    2008-01-01

    Pharmacokinetics of unbound anti-infectives in bone is difficult to characterize. The aim of this study was to assess the feasibility of the microdialysis technique to cancellous bone for single dose pharmacokinetic investigations of the anti-infective linezolid. Serial bone biopsies (left tibia......) and microdialysate samples (right tibia: 2 catheters) as well as plasma and bone marrow samples were obtained from 10 pigs. The concentrations of linezolid reached bacteriostatic levels in plasma, bone marrow, bone biopsies and microdialysates. With the use of microdialysis we here present the first results...... for unbound linezolid bone penetration. Unbound linezolid concentrations in bone obtained by microdialysis were lower than might have been expected from previous bone biopsy studies. To achieve effective concentrations (24 h) for susceptible organisms the chosen dose of linezolid might not be sufficient...

  13. Photonic-Enabled RF Canceller with Tunable Time-Delay Taps

    Science.gov (United States)

    2016-12-05

    Photonic -Enabled RF Canceller with Tunable Time-Delay Taps Kenneth E. Kolodziej, Sivasubramaniam Yegnanarayanan, Bradley T. Perry MIT Lincoln...canceller design that uses photonics and a vector modulator architecture to provide a high number of canceller taps with tunable time-delays, which allow...microwave photonics , RF cancellation. I. INTRODUCTION In-Band Full-Duplex (IBFD) technologies are being consid- ered for 5th generation (5G) wireless

  14. Chromospheric Heating due to Cancellation of Quiet Sun Internetwork Fields

    Science.gov (United States)

    Gošić, M.; de la Cruz Rodríguez, J.; De Pontieu, B.; Bellot Rubio, L. R.; Carlsson, M.; Esteban Pozuelo, S.; Ortiz, A.; Polito, V.

    2018-04-01

    The heating of the solar chromosphere remains one of the most important questions in solar physics. Our current understanding is that small-scale internetwork (IN) magnetic fields play an important role as a heating agent. Indeed, cancellations of IN magnetic elements in the photosphere can produce transient brightenings in the chromosphere and transition region. These bright structures might be the signature of energy release and plasma heating, probably driven by the magnetic reconnection of IN field lines. Although single events are not expected to release large amounts of energy, their global contribution to the chromosphere may be significant due to their ubiquitous presence in quiet Sun regions. In this paper, we study cancellations of IN elements and analyze their impact on the energetics and dynamics of the quiet Sun atmosphere. We use high-resolution, multiwavelength, coordinated observations obtained with the Interface Region Imaging Spectrograph and the Swedish 1 m Solar Telescope (SST) to identify cancellations of IN magnetic flux patches and follow their evolution. We find that, on average, these events live for ∼3 minutes in the photosphere and ∼12 minutes in the chromosphere and/or transition region. Employing multi-line inversions of the Mg II h and k lines, we show that cancellations produce clear signatures of heating in the upper atmospheric layers. However, at the resolution and sensitivity accessible to the SST, their number density still seems to be one order of magnitude too low to explain the global chromospheric heating.

  15. Reasons for cancellation of elective surgery in Ilorin | Kolawole ...

    African Journals Online (AJOL)

    Background: The rising cost of health care and dwindling economic resources necessitate the need to encourage cost-effectiveness in patient care. Cancellation of cases on the scheduled day of surgery leads to inefficient utilization of theatre space, waste of valuable manpower and scarce resources for patients and ...

  16. Canceling Some d-CON Mouse and Rat Control Products

    Science.gov (United States)

    EPA has reached agreement with the manufacturer, to cancel 12 d-CON products that do not meet our testing protocols that better protect children, pets and non-target wildlife from accidental exposure to the pesticide. These products will be phased out.

  17. 76 FR 16415 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2011-03-23

    ...-00050 1% Rotenone Garden Dust Rotenone Cube Resins other than rotenone. 028293-00042 Unicorn Ear Mite... registrants of the products in Table 1 of this unit, in sequence by EPA company number. This number.... Table 2--Registrants of Canceled Products EPA company No. Company name and address 4 Bonide Products...

  18. 76 FR 10587 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2011-02-25

    ...-00160 Unicorn House and Phenothrin Carpet Spray 11. Tetramethrin 028293-00215 Unicorn IGR Phenothrin... company number. This number corresponds to the first part of the EPA registration numbers of the products listed in this unit. Table 4 --Registrants of Cancelled Products Company No. Company name and address 192...

  19. 77 FR 50702 - Cardiovascular and Renal Drugs Advisory Committee; Cancellation

    Science.gov (United States)

    2012-08-22

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-N-0001] Cardiovascular and Renal Drugs Advisory Committee; Cancellation AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The meeting of the Cardiovascular and Renal Drugs Advisory Committee scheduled for...

  20. 78 FR 68779 - Controlled Group Regulation Examples; Hearing Cancellation

    Science.gov (United States)

    2013-11-15

    ... DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 1 [REG-114122-12] RIN 1545-BK96 Controlled Group Regulation Examples; Hearing Cancellation AGENCY: Internal Revenue Service (IRS), Treasury... controlled group rules related to regulated investment companies. DATES: The public hearing originally...

  1. Imperfect generalized transmit beamforming with co-channel interference cancelation

    KAUST Repository

    Radaydeh, Redha Mahmoud Mesleh

    2010-10-01

    The performance of a generalized single-stream transmit beamforming scheme employing receive co-channel interference -steering algorithms in slowly varying and flat fading channels is analyzed. The impact of imperfect prediction of channel state information (CSI) for the desired user spatially uncorrelated transmit channels is considered. Both dominant interference cancelation and adaptive arbitrary interference cancelation algorithms for closely spaced receive antennas are used. The impact of outdated statistical ordering of the interferers instantaneous powers on the effectiveness of dominant interference cancelation is investigated against the less complex adaptive arbitrary cancelation scheme. For the system models described above, new exact formulas for the statistics of combined signal-to-interference-plus-noise ratio (SINR) are derived, from which results for conventional maximum ratio transmission (MRT) and best transmit channel selection schemes can be deduced as limiting cases. The results presented herein can be used to obtain quantitative measure for various performance metrics, and in addition to investigate the performance-complexity tradeoff for different multiple-antenna system models. © 2010 IEEE.

  2. Incidence, causes and pattern of cancellation of Elective surgical ...

    African Journals Online (AJOL)

    This study was carried out to assess the incidence, causes and pattern of cancellation of elective surgical operations in our setting and to find the appropriate solutions for better patient management. Methods: This was a prospective hospital-based study which was conducted in a teaching hospital at Bugando medical ...

  3. Revenue Management under Customer Choice Behaviour with Cancellations and Overbooking

    NARCIS (Netherlands)

    D.D. Sierag (Dirk); G.M. Koole (Ger); R.D. van der Mei (Rob); JP.I. van der Rest (Jean-Pierre); A.P. Zwart (Bert)

    2015-01-01

    htmlabstractRevenue management is the practice of pricing perishable goods to optimise revenue. A realistic revenue management model allows overbooking and incorporates customer buying behaviour and cancellations. The latter is motivated by our research using real data, which shows that for a

  4. 19 CFR 10.39 - Cancellation of bond charges.

    Science.gov (United States)

    2010-04-01

    ... covering articles entered under other provisions of law shall not be canceled upon proof of destruction... entered temporarily free of duty under bond are destroyed within the bond period by death, accidental fire... (including any lawful extension), the Fines, Penalties, and Forfeitures Officer shall make a demand in...

  5. Laboratory Investigation of Noise-Canceling Headphones Utilizing "Mr. Blockhead"

    Science.gov (United States)

    Koser, John

    2013-01-01

    While I was co-teaching an introductory course in musical acoustics a few years ago, our class investigated several pieces of equipment designed for audio purposes. One piece of such equipment was a pair of noise-canceling headphones. Our students were curious as to how these devices were in eliminating background noise and whether they indeed…

  6. Economic impact of surgery cancellation in a general hospital, Iran

    African Journals Online (AJOL)

    unhcc

    cause of inefficient use of operating room (OR) time and a drain on finite .... of total hospitalizations. In this hospital (270 beds ... Preoperative instructions not followed or patient not instructed. Change in .... concrete possibilities of reducing the level of surgical cancellations by .... room case-mix problem under uncertainty and.

  7. 41 CFR 101-27.303-1 - Cancellation or transfer.

    Science.gov (United States)

    2010-07-01

    ..., including quantities due in from procurement, is greater than 10 percent of the total stock of that item... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Cancellation or transfer. 101-27.303-1 Section 101-27.303-1 Public Contracts and Property Management Federal Property Management...

  8. 75 FR 30824 - Methidathion; Cancellation Order for Pesticide Registrations

    Science.gov (United States)

    2010-06-02

    ... distribution, sale, or use of existing stocks of the products identified in Unit II., Table 1, in a manner..., 2010, Federal Register notice of receipt of requests from the registrants listed in Unit II., Table 2... Table 1 of this unit. Table 1.--Methidathion Product Cancellations Registration Number Product Name...

  9. 78 FR 59019 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2013-09-25

    ... distribution, sale, or use of existing stocks of the products identified in Table 1 of Unit II. in a manner... accepted by the Agency, of the products listed in Table 1 of Unit II., pursuant to the Federal Insecticide... Notice of Receipt of Requests from the registrants listed in Table 2 of Unit II. to voluntarily cancel...

  10. 78 FR 57850 - Product Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2013-09-20

    ... identified in Table 1 of Unit II., in a manner inconsistent with any of the provisions for disposition of... accepted by the Agency, of the products listed in Table 1 of Unit II., pursuant to the Federal Insecticide... Notice of Receipt of Requests from the registrants listed in Table 2 of Unit II. to voluntarily cancel...

  11. 75 FR 40825 - Clofencet; Cancellation Order for Certain Pesticide Registrations

    Science.gov (United States)

    2010-07-14

    ... existing stocks of the products identified in Table 1 of Unit II. in a manner inconsistent with any of the... number in Table 1 of this unit. Table 1.--Clofencet Product Cancellations EPA Registration Number Product... Manufacturing Use Product Table 2 of this unit includes the name and address of record for the registrant of the...

  12. 75 FR 11898 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2010-03-12

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security... 1641), and the U.S. Customs and Border Protection regulations (19 CFR 111.51(b)), the following Customs...

  13. 76 FR 22912 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2011-04-25

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, DHS. ACTION: General Notice. SUMMARY: Pursuant to section 641 of the Tariff Act of 1930, as amended (19 U.S.C. 1641), and the U.S. Customs and...

  14. 77 FR 5819 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2012-02-06

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  15. 75 FR 5618 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2010-02-03

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51(b)), the following Customs...

  16. 76 FR 7873 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2011-02-11

    ... DEPARTMENT OF HOMELAND SECURITY Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security. ACTION...), and the U.S. Customs and Border Protection regulations (19 CFR 111.51(b)), the following Customs...

  17. 77 FR 43609 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2012-07-25

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.53), the following Customs...

  18. 76 FR 44032 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2011-07-22

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  19. 75 FR 47825 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2010-08-09

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51(b)), the following Customs...

  20. 75 FR 76998 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2010-12-10

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  1. 77 FR 74022 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2012-12-12

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, Department of Homeland Security. ACTION...) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs broker...

  2. 76 FR 2918 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2011-01-18

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  3. 75 FR 11899 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2010-03-12

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  4. 76 FR 13205 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2011-03-10

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.45), the following Customs...

  5. 75 FR 75691 - Notice of Cancellation of Customs Broker License

    Science.gov (United States)

    2010-12-06

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker License AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security.... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.45), the following Customs...

  6. 75 FR 47825 - Notice of Cancellation of Customs Broker Licenses

    Science.gov (United States)

    2010-08-09

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Customs and Border Protection Notice of Cancellation of Customs Broker Licenses AGENCY: U.S. Customs and Border Protection, U.S. Department of Homeland Security... 1641) and the U.S. Customs and Border Protection regulations (19 CFR 111.51), the following Customs...

  7. Cut cancellation in the planar integral equation for the Reggeon

    International Nuclear Information System (INIS)

    Bishari, M.; Veneziano, G.

    1975-01-01

    Planar unitarity for the Reggeon, analyticity and the multi-Regge assumption with cluster production lead to integral equations of the Chew-Goldberger-Low type with separable self-consistent kernel. Contrary to common prejudice, the authors show the existence of solutions exhibiting moving poles and exact, non-perturbative cancellation of the cut. Previously studied consistency conditions are rederived. (Auth.)

  8. 78 FR 22846 - Smart Grid Advisory Committee Meeting Cancellation

    Science.gov (United States)

    2013-04-17

    ...The meeting of the Smart Grid Advisory Committee (SGAC or Committee) scheduled for Friday, April 19, 2013 from 8:30 a.m. to 5:00 p.m. Eastern Time is cancelled. Notice of this meeting was published in the Federal Register on March 26, 2013.

  9. Clinical Utility of Cancellation on the WISC-IV

    Science.gov (United States)

    Zhu, Jianjun; Chen, Hsinyi

    2013-01-01

    This study examined empirical evidence for clinical utility of the Wechsler Intelligence Scale for Children, fourth edition (WISC-IV) cancellation subtest by comparing data from 597 clinical and 597 matched control children. The results of dependent t and sequential logistic regression analyses demonstrated that (a) children with intellectual…

  10. 78 FR 64211 - FIFRA Scientific Advisory Panel; Notice of Cancellation

    Science.gov (United States)

    2013-10-28

    ..., Office of Science Coordination and Policy (7201M), Environmental Protection Agency, 1200 Pennsylvania Ave... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OPP-2013-0490; FRL-9902-06] FIFRA Scientific Advisory Panel; Notice of Cancellation AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY...

  11. 75 FR 81283 - Oncologic Drugs Advisory Committee; Cancellation

    Science.gov (United States)

    2010-12-27

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-N-0001] Oncologic Drugs Advisory Committee; Cancellation AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The meeting of the Oncologic Drugs Advisory Committee scheduled for February 9, 2011, is...

  12. 77 FR 63839 - Oncologic Drugs Advisory Committee; Cancellation

    Science.gov (United States)

    2012-10-17

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-N-0001] Oncologic Drugs Advisory Committee; Cancellation AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The meeting of the Oncologic Drugs Advisory Committee Meeting scheduled for November 8, 2012, is...

  13. Bone tumors

    International Nuclear Information System (INIS)

    Moylan, D.J.; Yelovich, R.M.

    1991-01-01

    Primary bone malignancies are relatively rare with less than 4,000 new cases per year. Multiple myeloma (more correctly a hematologic malignancy) accounts for 40%; osteosarcomas, 28%; chondrosarcomas, 13%; fibrosarcomas arising in bone, 4%; and Ewing's sarcoma, 7%. The authors discuss various treatments for bone tumors, including radiotherapy, chemotherapy and surgery

  14. Does methamphetamine affect bone metabolism?

    Science.gov (United States)

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

    2014-05-07

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

  15. 21 CFR 1305.19 - Cancellation and voiding of DEA Forms 222.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Cancellation and voiding of DEA Forms 222. 1305.19... I AND II CONTROLLED SUBSTANCES DEA Form 222 § 1305.19 Cancellation and voiding of DEA Forms 222. (a) A purchaser may cancel part or all of an order on a DEA Form 222 by notifying the supplier in...

  16. 77 FR 59190 - Halofenozide; Notice of Receipt of Requests To Voluntarily Cancel Pesticide Registrations and...

    Science.gov (United States)

    2012-09-26

    ... of Requests To Voluntarily Cancel Pesticide Registrations and Terminate All Uses AGENCY... voluntarily cancel pesticide registrations of all products containing the pesticide halofenozide. The requests would cancel all technical and end-use registrations and delete all halofenozide uses. The requests...

  17. 78 FR 15949 - Notice of Receipt of Request To Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2013-03-13

    ... Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection Agency (EPA). ACTION... is issuing a notice of receipt of requests by a registrant to voluntarily cancel certain pesticide... in this notice will be permitted after the registration has been canceled only if such sale...

  18. 75 FR 68012 - Notice of Intention To Cancel Registrations of Certain Transfer Agents

    Science.gov (United States)

    2010-11-04

    ... SECURITIES AND EXCHANGE COMMISSION [Release No. 34-63211] Notice of Intention To Cancel... Securities Exchange Act of 1934 (``Act''),\\1\\ cancelling the registrations of the transfer agents whose names... 20549-7010 or by e- mail at [email protected] with the phrase ``Notice of Intention To Cancel...

  19. 75 FR 22404 - Clofencet; Notice of Receipt of Request to Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-04-28

    ... Request to Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection Agency (EPA... voluntarily cancel their registrations of certain products containing the pesticide clofencet. The request... cancelled only if such sale, distribution, or use is consistent with the terms as described in the final...

  20. 75 FR 52340 - Fenoxycarb; Notice of Receipt of Request To Voluntarily Cancel Certain Pesticide Registrations

    Science.gov (United States)

    2010-08-25

    ... of Request To Voluntarily Cancel Certain Pesticide Registrations AGENCY: Environmental Protection... registrants to voluntarily cancel registrations of products containing the pesticide fenoxycarb. The request... listed in this notice will be permitted after the registrations have been canceled only if such sale...