Science.gov

Sample records for bone aspects tomodensitometriques

  1. Technical aspects of bone scintigraphy.

    PubMed

    Brown, M L; O'Connor, M K; Hung, J C; Hayostek, R J

    1993-07-01

    Optimal bone scintigraphy is obtained by using a current generation gamma camera with a high-resolution collimator, minimizing the patient-to-collimator distance, using scatter reduction techniques where possible, and obtaining a 500,000 to 1 million count image for 40-cm field of view camera. Hard copy images from an analog or digital formatter should be optimized to display all intensities either on the same images or, when necessary, to display the low count information on one image and the high count information on another. Additional images using different collimators, such as converging or pinhole collimators, and oblique and lateral views should be obtained when necessary to demonstrate or define the pathologic area. To optimize SPECT imaging, the following parameters should be used: a high-resolution collimator, a 128 x 128 acquisition matrix, and minimum separation between the patient and the collimator, which may require the use of an elliptic orbit. Between 64 and 128 views should be obtained, and depending on preference, the planar data should be prefiltered with a Butterworth, order 8-12 and a cutoff at 0.5 Nyquist. The data should then be reconstructed using a simple ramp filter. This method provides a good technique when one is first beginning to perform bone SPECT. Attenuation correction is not generally beneficial for SPECT bone studies, although sometimes weighted backprojection may improve image contrast and resolution. Finally, the use of volume rendering may help clarify the location of suspect lesions.

  2. Organizational and investigational aspects of bone banking in Belgium.

    PubMed

    Delloye, C; De Halleux, J; Cornu, O; Wegmann, E; Buccafusca, G C; Gigi, J

    1991-01-01

    Our experience with the bone banking methodology that we have used over the last years is reported. The technical and investigational aspects of the procurement, storage and treatment of the donor bone and related tissues are presented. For different purposes, we have prepared sterile and nonsterile procured implants. Appropriate donor selection and sterility controls remain the two major concerns of bone banking activities.

  3. Kinetic aspects of bone mineral metabolism

    NASA Technical Reports Server (NTRS)

    Palmer, H. E.

    1973-01-01

    Two techniques were studied for measuring changes in bone mass in rats. One technique measures the Ar-37 produced from calcium during neutron irradiation and the other measures the changes in the Na-22 content which has been incorporated within the rat bone. Both methods are performed in VIVO and cause no significant physiological damage. The Ar-37 leaves the body of a rat within an hour after being produced, and it can be quantitatively collected and measured with a precision of - or + 2% on the same rat. With appropriate irradiation conditions it appears that the absolute quantity of calcuim in any rat can be determined within - or + 3% regardless of animal size. The Na-22 when uniformly distributed in bone, can be used to monitor bone mineral turnover and this has been demonstrated in conditions of calcium deficiency during growth and also pregnancy coupled with calcium deficiency.

  4. Nano-Material Aspects of Shock Absorption in Bone Joints

    PubMed Central

    Tributsch, H; Copf, F; Copf, p; Hindenlang, U; Niethard, F.U; Schneider, R

    2010-01-01

    This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three–dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones. PMID:21625375

  5. Nano-material aspects of shock absorption in bone joints.

    PubMed

    Tributsch, H; Copf, F; Copf, P; Hindenlang, U; Niethard, F U; Schneider, R

    2010-01-01

    This theoretical study is based on a nano-technological evaluation of the effect of pressure on the composite bone fine structure. It turned out, that the well known macroscopic mechano-elastic performance of bones in combination with muscles and tendons is just one functional aspect which is critically supported by additional micro- and nano- shock damping technology aimed at minimising local bone material damage within the joints and supporting spongy bone material. The identified mechanisms comprise essentially three phenomena localised within the three-dimensional spongy structure with channels and so called perforated flexible tensulae membranes of different dimensions intersecting and linking them. Kinetic energy of a mechanical shock may be dissipated within the solid-liquid composite bone structure into heat via the generation of quasi-chaotic hydromechanic micro-turbulence. It may generate electro-kinetic energy in terms of electric currents and potentials. And the resulting specific structural and surface electrochemical changes may induce the compressible intra-osseal liquid to build up pressure dependent free chemical energy. Innovative bone joint prostheses will have to consider and to be adapted to the nano-material aspects of shock absorption in the operated bones.

  6. Qualitative Aspects of Bone Marrow Adiposity in Osteoporosis

    PubMed Central

    Pino, Ana María; Miranda, Melissa; Figueroa, Carolina; Rodríguez, Juan Pablo; Rosen, Clifford J.

    2016-01-01

    The function of marrow adipocytes and their origin has not been defined although considerable research has centered on their presence in certain conditions, such as osteoporosis. Less work has focused on the qualitative aspects of marrow fat. Bone marrow serum is composed of multiple nutrients that almost certainly relate to functional aspects of the niche. Previous studies using non-invasive techniques have shown that osteoporotic individuals have more marrow fat and that the ratio of saturated: unsaturated fatty acid is high. We recently reported that bone marrow sera from osteoporotic patients with fracture showed a switch toward decreased content of total saturated versus unsaturated fatty acids, compared to patients without fracture highlighting a dynamic relationship between the composition of fatty acids in the bone microenvironment and the metabolic requirements of cells. The relative distribution of fatty acids differed considerably from that in the serum providing further evidence that energy utilization is high and that marrow adipocytes may contribute to this pool. Whether these lipids can affect osteoblast function in a positive or negative manner is still not certain but will require further investigation. PMID:27826285

  7. Biomechanical Aspects of the Muscle-Bone Interaction

    PubMed Central

    Avin, Keith G.; Bloomfield, Susan A.; Gross, Ted S.; Warden, Stuart J.

    2014-01-01

    There is growing interest in the interaction between skeletal muscle and bone, particularly at the genetic and molecular levels. However, the genetic and molecular linkages between muscle and bone are achieved only within the context of the essential mechanical coupling of the tissues. This biomechanical and physiological linkage is readily evident as muscles attach to bone and induce exposure to varied mechanical stimuli via functional activity. The responsiveness of bone cells to mechanical stimuli, or their absence, is well established. However, questions remain regarding how muscle forces applied to bone serve to modulate bone homeostasis and adaptation. Similarly, the contributions of varied, but unique, stimuli generated by muscle to bone (such as low-magnitude, high-frequency stimuli) remains to be established. The current article focuses upon the mechanical relationship between muscle and bone. In doing so, we explore the stimuli that muscle imparts upon bone, models that enable investigation of this relationship, and recent data generated by these models. PMID:25515697

  8. [Microradiographic aspects of massive bone allografts in man].

    PubMed

    Coutelier, L; Delloye, C; de Nayer, P; Vincent, A

    1984-01-01

    Two stored frozen massive bone allografts were implanted after resection of femoral and tibial tumours in two patients. Eighteen and thirty months later the authors had the opportunity to make a microscopic examination of the grafts. The cortical bone grafts were incorporated by the classic "creeping substitution." The repair of the cortical transplant was very incomplete and showed large resorption cavities. The newly-formed living bone was not fully mineralized. These phenomena related only to the outer area of the cortical bone, the dead intra-cortical area being left unaffected by the process. Cancellous bone graft repair was faster and more efficient.

  9. Cybernetic aspects of bone modeling and remodeling, with special reference to osteoporosis and whole-bone strength.

    PubMed

    Frost, H M

    2001-01-01

    Assume mythical physiologists were taught that renal physiology and its disorders depend on "kidney cells" and their regulation by nonmechanical factors, but were taught nothing about nephrons. For decades they "knew" that idea was correct, just as Ptolemy "knew" the universe centers on our planet. But then others began to describe nephrons, their roles in renal physiology and disorders, and problems they revealed in former views, so doubts and controversies began. Today real physiologists encounter a similar situation for bone health and its disorders. A 1960 paradigm attributed such things to bone's effector cells (osteoblasts and osteoclasts) and their regulation by nonmechanical factors, without "nephron-equivalent" or biomechanical input. But both mechanical and nonmechanical factors regulate bone's nephron equivalents. Adding features of those equivalents to the 1960 views led to the Utah paradigm, which suggests problems in former views and better explanations for "osteoporosis," whole-bone strength, and other bone disorders. Such things incited controversies among current skeletal physiologists. Cybernetics concerns the relationships, mechanisms, signals, and message traffic that help to control the behavior and other features of dynamic systems. A cybernetic analysis of the bone physiology in the Utah paradigm can add many features to the 1960 paradigm that help to understand osteoporoses, other bone disorders, and whole-bone strength (and bone mass). The added features also show new and pertinent targets for the related research.

  10. Simple and aneurysmal bone cyst: Aspects of jaw pseudocysts based on an experience of Brazilian pathology service during 53 years

    PubMed Central

    Hamilton, Maria-Eduarda; Zanchin-Baldissera, Elaine-de-Fátima; Uchoa-Vasconcelos, Ana-Carolina; Chaves-Tarquinio, Sandra-Beatriz; Neutzling-Gomes, Ana-Paula

    2017-01-01

    Background Jaw pseudocysts are benign osseous lesions of unclear etiology. Among these, the simple bone cyst (SBC) and aneurysmal bone cyst (ABC) are intriguing bone pathologies still rarely studied together. This retrospective study aimed to present the long-term case series of patients with jaw pseudocysts focusing on the clinical, radiographic, and transoperative aspects. Material and Methods A retrospective case series of patients with SBC and ABC was performed. Clinical, radiographic, and transoperative aspects of both pseudocysts were reviewed from the histopathological archives of 20,469 cases between 1959-2012. All descriptive data were summarized. Results Of 354 (15.25%) bone pathologies, 54 cases of jaw pseudocysts were found, with 42 (11.86%) SBC and 12 (3.39%) ABC cases. For both lesions, most of the sample were young Caucasian women with an asymptomatic posterior mandible lesion with undetermined time of evolution and none trauma history. A unique radiolucent scalloped lesion presenting an empty cavity were also observed for both conditions. However, some atypical findings were found for SBC including: the expansion of bone cortical, tooth resorption, displacement of the mandibular canal, and recurrence. The absence of painful symptoms and the lack of classical blood-filled cavity were observed in some cases of ABC. Conclusions The SBC and ABC are bone pathologies with few retrospective studies, no previous studies on the two conditions, varied nomenclature, and atypical aspects in some cases. Therefore, the knowledge of clinical, imaging, and transoperative features of such pseudocysts are clinically valuable as diagnosis hypothesis of radiolucent lesions of the jaws. Key words:Simple bone cyst, aneurysmal bone cyst, pseudocysts, jaws. PMID:27918745

  11. ASPECT

    EPA Pesticide Factsheets

    Able to deploy within one hour of notification, EPA's Airborne Spectral Photometric Environmental Collection Technology (ASPECT) is the nation’s only airborne real-time chemical and radiological detection, infrared and photographic imagery platform.

  12. Histochemical and Morphological Aspects of Fresh Frozen Bone: A Preliminary Study

    PubMed Central

    De Ponte, F.S.; Falzea, R.; Rizzo, G.; Catalfamo, L.; Favaloro, A.; Vermiglio, G.; Runci, M.; Centofanti, A.; Anastasi, G.

    2016-01-01

    Bone graft are used in dentistry for the reconstruction of severely atrophic jaws. Fresh frozen bone has no osteogenic property but it has osteoconductive and osteoinductive properties because its matrix contains growth factors such as vascular endothelial growth factor. The purpose of the present study was to evaluate morphological and protein expression characteristics of fresh frozen bone before graft and after six months of graft in patients who needed maxillary reconstruction. After 6 month of graft we observed the presence of viable bone as evidenced by full osteocyte lacunae and by the presence of RANKR, osteocalcin positive cells and vascular endothelial growth factor. In conclusion, our findings show that the fresh frozen bone after six month of graft is for the most part viable bone, encouraging its use as an alternative to autogenous bone for reconstructing maxillary bone defects prior to implant. PMID:28076936

  13. Mechanistic aspects of fracture and R-curve behavior in elk antler bone

    SciTech Connect

    Launey, Maximilien E.; Chen, Po-Yu; McKittrick, Joanna; Ritchie, Robert O.

    2009-11-23

    Bone is an adaptative material that is designed for different functional requirements; indeed, bones have a variety of properties depending on their role in the body. To understand the mechanical response of bone requires the elucidation of its structure-function relationships. Here, we examine the fracture toughness of compact bone of elk antler which is an extremely fast growing primary bone designed for a totally different function than human (secondary) bone. We find that antler in the transverse (breaking) orientation is one of the toughest biological materials known. Its resistance to fracture is achieved during crack growth (extrinsically) by a combination of gross crack deflection/twisting and crack bridging via uncracked 'ligaments' in the crack wake, both mechanisms activated by microcracking primarily at lamellar boundaries. We present an assessment of the toughening mechanisms acting in antler as compared to human cortical bone, and identify an enhanced role of inelastic deformation in antler which further contributes to its (intrinsic) toughness.

  14. Comparison of structural, architectural and mechanical aspects of cellular and acellular bone in two teleost fish.

    PubMed

    Cohen, Liat; Dean, Mason; Shipov, Anna; Atkins, Ayelet; Monsonego-Ornan, Efrat; Shahar, Ron

    2012-06-01

    The histological diversity of the skeletal tissues of fishes is impressive compared with that of other vertebrate groups, yet our understanding of the functional consequences of this diversity is limited. In particular, although it has been known since the mid-1800s that a large number of fish species possess acellular bones, the mechanical advantages and consequences of this structural characteristic - and therefore the nature of the evolution of this feature - remain unclear. Although several studies have examined the material properties of fish bone, these have used a variety of techniques and there have been no direct contrasts of acellular and cellular bone. We report on a comparison of the structural and mechanical properties of the ribs and opercula between two freshwater fish - the common carp Cyprinus carpio (a fish with cellular bone) and the tilapia Oreochromis aureus (a fish with acellular bone). We used light microscopy to show that the bones in both fish species exhibit poor blood supply and possess discrete tissue zones, with visible layering suggesting differences in the underlying collagen architecture. We performed identical micromechanical testing protocols on samples of the two bone types to determine the mechanical properties of the bone material of opercula and ribs. Our data support the consensus of literature values, indicating that Young's moduli of cellular and acellular bones are in the same range, and lower than Young's moduli of the bones of mammals and birds. Despite these similarities in mechanical properties between the bone tissues of the fish species tested here, cellular bone had significantly lower mineral content than acellular bone; furthermore, the percentage ash content and bone mineral density values (derived from micro-CT scans) show that the bone of these fishes is less mineralized than amniote bone. Although we cannot generalize from our data to the numerous remaining teleost species, the results presented here suggest

  15. Long-term safety of antiresorptive treatment: bone material, matrix and mineralization aspects

    PubMed Central

    Misof, Barbara M; Fratzl-Zelman, Nadja; Paschalis, Eleftherios P; Roschger, Paul; Klaushofer, Klaus

    2015-01-01

    It is well established that long-term antiresorptive use is effective in the reduction of fracture risk in high bone turnover osteoporosis. Nevertheless, during recent years, concerns emerged that longer bone turnover reduction might favor the occurrence of fatigue fractures. However, the underlying mechanisms for both beneficial and suspected adverse effects are not fully understood yet. There is some evidence that their effects on the bone material characteristics have an important role. In principle, the composition and nanostructure of bone material, for example, collagen cross-links and mineral content and crystallinity, is highly dependent on tissue age. Bone turnover determines the age distribution of the bone structural units (BSUs) present in bone, which in turn is decisive for its intrinsic material properties. It is noteworthy that the effects of bone turnover reduction on bone material were observed to be dependent on the duration of the antiresorptive therapy. During the first 2–3 years, significant decreases in the heterogeneity of material properties such as mineralization of the BSUs have been observed. In the long term (5–10 years), the mineralization pattern reverts towards normal heterogeneity and degree of mineralization, with no signs of hypermineralization in the bone matrix. Nevertheless, it has been hypothesized that the occurrence of fatigue fractures (such as atypical femoral fractures) might be linked to a reduced ability of microdamage repair under antiresorptive therapy. The present article examines results from clinical studies after antiresorptive, in particular long-term, therapy with the aforementioned potentially positive or negative effects on bone material. PMID:25709811

  16. CT findings of the temporal bone in CHARGE syndrome: aspects of importance in cochlear implant surgery.

    PubMed

    Vesseur, A C; Verbist, B M; Westerlaan, H E; Kloostra, F J J; Admiraal, R J C; van Ravenswaaij-Arts, C M A; Free, R H; Mylanus, E A M

    2016-12-01

    To provide an overview of anomalies of the temporal bone in CHARGE syndrome relevant to cochlear implantation (CI), anatomical structures of the temporal bone and the respective genotypes were analysed. In this retrospective study, 42 CTs of the temporal bone of 42 patients with CHARGE syndrome were reviewed in consensus by two head-and-neck radiologists and two otological surgeons. Anatomical structures of the temporal bone were evaluated and correlated with genetic data. Abnormalities that might affect CI surgery were seen, such as a vascular structure, a petrosquamosal sinus (13 %), an underdeveloped mastoid (8 %) and an aberrant course of the facial nerve crossing the round window (9 %) and/or the promontory (18 %). The appearance of the inner ear varied widely: in 77 % of patients all semicircular canals were absent and the cochlea varied from normal to hypoplastic. A stenotic cochlear aperture was observed in 37 %. The middle ear was often affected with a stenotic round (14 %) or oval window (71 %). More anomalies were observed in patients with truncating mutations than with non-truncating mutations. Temporal bone findings in CHARGE syndrome vary widely. Vascular variants, aberrant route of the facial nerve, an underdeveloped mastoid, aplasia of the semicircular canals, and stenotic round window may complicate cochlear implantation.

  17. Molecular, Phenotypic Aspects and Therapeutic Horizons of Rare Genetic Bone Disorders

    PubMed Central

    Dhawan, Naveen; Vohra, Shivani; Tu, Khin; Abdelmagid, Samir M.

    2014-01-01

    A rare disease afflicts less than 200,000 individuals, according to the National Organization for Rare Diseases (NORD) of the United States. Over 6,000 rare disorders affect approximately 1 in 10 Americans. Rare genetic bone disorders remain the major causes of disability in US patients. These rare bone disorders also represent a therapeutic challenge for clinicians, due to lack of understanding of underlying mechanisms. This systematic review explored current literature on therapeutic directions for the following rare genetic bone disorders: fibrous dysplasia, Gorham-Stout syndrome, fibrodysplasia ossificans progressiva, melorheostosis, multiple hereditary exostosis, osteogenesis imperfecta, craniometaphyseal dysplasia, achondroplasia, and hypophosphatasia. The disease mechanisms of Gorham-Stout disease, melorheostosis, and multiple hereditary exostosis are not fully elucidated. Inhibitors of the ACVR1/ALK2 pathway may serve as possible therapeutic intervention for FOP. The use of bisphosphonates and IL-6 inhibitors has been explored to be useful in the treatment of fibrous dysplasia, but more research is warranted. Cell therapy, bisphosphonate polytherapy, and human growth hormone may avert the pathology in osteogenesis imperfecta, but further studies are needed. There are still no current effective treatments for these bone disorders; however, significant promising advances in therapeutic modalities were developed that will limit patient suffering and treat their skeletal disabilities. PMID:25530967

  18. Molecular, phenotypic aspects and therapeutic horizons of rare genetic bone disorders.

    PubMed

    Faruqi, Taha; Dhawan, Naveen; Bahl, Jaya; Gupta, Vineet; Vohra, Shivani; Tu, Khin; Abdelmagid, Samir M

    2014-01-01

    A rare disease afflicts less than 200,000 individuals, according to the National Organization for Rare Diseases (NORD) of the United States. Over 6,000 rare disorders affect approximately 1 in 10 Americans. Rare genetic bone disorders remain the major causes of disability in US patients. These rare bone disorders also represent a therapeutic challenge for clinicians, due to lack of understanding of underlying mechanisms. This systematic review explored current literature on therapeutic directions for the following rare genetic bone disorders: fibrous dysplasia, Gorham-Stout syndrome, fibrodysplasia ossificans progressiva, melorheostosis, multiple hereditary exostosis, osteogenesis imperfecta, craniometaphyseal dysplasia, achondroplasia, and hypophosphatasia. The disease mechanisms of Gorham-Stout disease, melorheostosis, and multiple hereditary exostosis are not fully elucidated. Inhibitors of the ACVR1/ALK2 pathway may serve as possible therapeutic intervention for FOP. The use of bisphosphonates and IL-6 inhibitors has been explored to be useful in the treatment of fibrous dysplasia, but more research is warranted. Cell therapy, bisphosphonate polytherapy, and human growth hormone may avert the pathology in osteogenesis imperfecta, but further studies are needed. There are still no current effective treatments for these bone disorders; however, significant promising advances in therapeutic modalities were developed that will limit patient suffering and treat their skeletal disabilities.

  19. New aspects of treatment of renal bone disease in dialysis patients.

    PubMed

    Spasovski, G

    2007-07-01

    The abnormalities in bone and mineral metabolism in chronic kidney disease patients are associated with an increased risk of fractures, vascular calcifications and cardiovascular diseases. A few decades ago hyperphosphatemia and the common development of secondary hyperparathyroidism were thought to be the main problem to deal with. Since dietary phosphate restriction and haemodialysis were not proven to be sufficient measures to reduce phosphorus, phosphate-binding therapy has been widely instituted as a treatment option. Various types of phosphate binders employed over the years have contributed to the changing spectrum of renal osteodystrophy from high to low bone turnover along with the shift from hypocalcemia and negative calcium balance towards hypercalcemia and the positive calcium balance. Thus, hypercalcemia instead of hyperphosphatemia is nowadays associated with the increased risk of vascular calcification, morbidity and mortality in the dialysis population. Besides the very expensive non-calcium based phosphate binders, at least two common tools may be helpful in the treatment of hypercalcemia and adynamic bone. A reduced daily use of calcium carbonate/acetate up to 1g per main meal is an easily manageable and inexpensive tool. The second option for stimulation of parathyroid gland activity and bone turnover is the lowering of the dialysate calcium concentration. In conclusion, an aggressive treatment of hyperphosphatemia and calcium overload might lead towards an opposite effect of hypoparathyroidism and hypercalcemia. Reasonable treatment strategies based on a careful monitoring should be employed in order to prevent related consequences and to contribute to a better long-term quality of life and survival of dialysis patients.

  20. Mechanistic aspects of fracture and R-curve behavior in human cortical bone

    SciTech Connect

    Nalla, Ravi K.; Kruzic, Jamie J.; Kinney, John H.; Ritchie, Robert O.

    2004-04-28

    An understanding of the evolution of toughness is essential for the mechanistic interpretation of the fracture of cortical bone. In the present study, in vitro fracture experiments were conducted on human cortical bone in order to identify and quantitatively assess the salient toughening mechanisms. The fracture toughness was found to rise linearly with crack extension (i.e., rising resistance- or R-curve behavior) with a mean crack-initiation toughness, K0 of B2MPaOm for crack growth in the proximal distal direction. Uncracked ligament bridging, which was observed in the wake of the crack, was identified as the dominant toughening mechanism responsible for the observed R-curve behavior. The extent and nature of the bridging zone was examined quantitatively using multicutting compliance experiments in order to assess the bridging zone length and estimate the bridging stress distribution. Additionally, time-dependent cracking behavior was observed at stress intensities well below those required for overload fracture; specifically, slow crack growth occurred at growth rates of approx. 2 x 10-9 m/s at stress intensities approx. 35 percent below the crack-initiation toughness. In an attempt to measure slower growth rates, it was found that the behavior switched to a regime dominated by time dependent crack blunting, similar to that reported for dentin; however, such blunting was apparent over much slower time scales in bone, which permitted subcritical crack growth to readily take place at higher stress intensities.

  1. Mechanistic aspects of fracture and R-curve behavior in human cortical bone.

    PubMed

    Nalla, R K; Kruzic, J J; Kinney, J H; Ritchie, R O

    2005-01-01

    An understanding of the evolution of toughness is essential for the mechanistic interpretation of the fracture of cortical bone. In the present study, in vitro fracture experiments were conducted on human cortical bone in order to identify and quantitatively assess the salient toughening mechanisms. The fracture toughness was found to rise linearly with crack extension (i.e., rising resistance- or R-curve behavior) with a mean crack-initiation toughness, K0 of approximately 2 MPa square root m for crack growth in the proximal-distal direction. Uncracked ligament bridging, which was observed in the wake of the crack, was identified as the dominant toughening mechanism responsible for the observed R-curve behavior. The extent and nature of the bridging zone was examined quantitatively using multi-cutting compliance experiments in order to assess the bridging zone length and estimate the bridging stress distribution. Additionally, time-dependent cracking behavior was observed at stress intensities well below those required for overload fracture; specifically, slow crack growth occurred at growth rates of approximately 2 x 10(-9) m/s at stress intensities approximately 35% below the crack-initiation toughness. In an attempt to measure slower growth rates, it was found that the behavior switched to a regime dominated by time-dependent crack blunting, similar to that reported for dentin; however, such blunting was apparent over much slower time scales in bone, which permitted subcritical crack growth to readily take place at higher stress intensities.

  2. Bone

    NASA Astrophysics Data System (ADS)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

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

  3. Simulating certain aspects of hypogravity - Effects on bone maturation in the nonweight bearing skeleton

    NASA Technical Reports Server (NTRS)

    Simmons, D. J.; Grazman, B.; Russell, J. E.; Walker, W. V.; Bikle, D. D.; Morey, E. R.

    1983-01-01

    For a determination of how the nonweight-bearing skeletons, i.e., lower jaws, of 41-day and 1-year old rats would respond to 10 or 14 days of partial skeletal unloading by elevating the hindquarters (PULEH), an experimental system to simulate the fluid shifts and unloading of portions of the skeleton which occur during spaceflight was developed. In comparison with the bone matrix mineralization recorded in the mandibles of rats flown in the Soviet 18.5 day Cosmos-1129 mission, the PULEH studies failed to produce spaceflight-like maturation defects.

  4. Technical Aspects on the Use of Ultrasonic Bone Shaver in Spine Surgery: Experience in 307 Patients

    PubMed Central

    Hazer, Derya Burcu; Yaşar, Barış; Rosberg, Hans-Eric; Akbaş, Aytaç

    2016-01-01

    Aim. We discuss technical points, the safety, and efficacy of ultrasonic bone shaver in various spinal surgeries within our own series. Methods. Between June 2010 and January 2014, 307 patients with various spinal diseases were operated on with the use of an ultrasonic bone curette with microhook shaver (UBShaver). Patients' data were recorded and analyzed retrospectively. The technique for the use of the device is described for each spine surgery procedure. Results. Among the 307 patients, 33 (10.7%) cases had cervical disorder, 17 (5.5%) thoracic disorder, 3 (0.9%) foramen magnum disorder, and 254 (82.7%) lumbar disorders. Various surgical techniques were performed either assisted or alone by UBShaver. The duration of the operations and the need for blood replacement were relatively low. The one-year follow-up with Neck Disability Index (NDI) and Oswestry Disability Index (ODI) scores were improved. We had 5 cases of dural tears (1.6%) in patients with lumbar spinal disease. No neurological deficit was found in any patients. Conclusion. We recommend this device as an assistant tool in various spine surgeries and as a primary tool in foraminotomies. It is a safe device in spine surgery with very low complication rate. PMID:27195299

  5. A new bone surgical laser technique: technical aspects and applications in dentistry.

    PubMed

    Lancieri, Luca; Angiero, Francesca; Di Santi, Giuseppe; Carpi, Angelo; Benedicenti, Stefano

    2011-01-01

    Ten patients requiring the extraction of a severely-deteriorated molar or premolar before placement of a dental implant for prosthodontic rehabilitation were selected (6 women; 4 men). The sockets were curetted and decontaminated with an 810 nm wavelength diode laser using a 400 micron fiber at close distance (1 mm) from the target area, power setting 2.5 W, pulsed mode (10 msec t-on, 10 msec t-off for five seconds, three repetitions for each bone wall, 30 seconds pause between each irradiation). The socket filled with beta-TCP plus Tissucol and primary closure was attempted. In addition all patients were treated with a 810 nm GaAlAs laser, in continuous wave mode, defocused hand-piece, 50 J\\cm2 ( 1W for 50 seconds) after surgery and on days 3, 5, 7 postoperatively. At 18 months after prosthodontic treatment and loading, the implant was stable. Laser therapy, combined with a graft of biomaterial composed of beta-TCP and tissucol, prevented alveolar crest resorption following tooth extraction. Formation of new bone of acceptable quality and quantity permitted placement of osseointegrated dental implants.

  6. [Bone marrow immunophenotyping for the diagnosis of multiple myeloma: practical aspects].

    PubMed

    Kurtova, A V; Sivachenko, E B; Utkina, L A; Slobodniuk, K Iu; Stepanova, N V; Iakubovich, M A; Moiseev, S I; Zueva, E E

    2008-01-01

    Multiple myeloma is a malignant proliferative disease of plasma cells. Flow cytometric immunophenotyping makes it possible to identify a malignant clone of myeloma cells in the shortest possible time, to determine its phenotype, and differentiate transformed and preserved plasma cells. The article presents an immunophenotyping strategy using three-color monoclonal antibodies (CD35, CD14, CD38, CD138, and CD19) and an algorithm of verification of transformed plasma cells. Particular emphasis is placed on both the practical aspects of performing this assay and on the clinical application of the obtained results.

  7. Osseointegration aspects of placed implant in bone reconstruction with newly developed block-type interconnected porous calcium hydroxyapatite

    PubMed Central

    DOI, Kazuya; KUBO, Takayasu; MAKIHARA, Yusuke; OUE, Hiroshi; MORITA, Koji; OKI, Yoshifumi; KAJIHARA, Shiho; TSUGA, Kazuhiro

    2016-01-01

    ABSTRACT Artificial bone has been employed to reconstruct bone defects. However, only few reports on implant placement after block bone grafting exist. Objectives The purpose of this study was to evaluate the osseointegration of dental implant in bone reconstructions with interconnected porous calcium hydroxyapatite (IP-CHA). Material and Methods The IP-CHA cylinders (D; 4.3 mm, H; 10.0 mm) were placed into bone sockets in each side of the femurs of four male dogs. The IP-CHA on the right side was a 24-week sample. Twelve weeks after placement, a titanium implant was placed into a socket that was prepared in half of the placed IP-CHA cylinder on the right side. On the left side, another IP-CHA cylinder was placed as a 12-week sample. After another 12 weeks, the samples were harvested, and the bone regeneration and bone-implant contact (BIC) ratios were measured. Results New bone formation area was superior in the 24-week IP-CHA compared with the 12-week IP-CHA. BIC was not significantly different between IP-CHA and the parent sites. Osseointegration was detected around the implant in IP-CHA-reconstructed bone. Conclusion Our preliminary results suggest that IP-CHA may be a suitable bone graft material for reconstructing bones that require implant placement. PMID:27556202

  8. Molecular, Cellular and Pharmaceutical Aspects of bone grafting materials and membranes during maxillary sinus-lift procedures. Part 2: detailed characteristics of the materials.

    PubMed

    Iezzi, Giovanna; Piatelli, Adriano; Giuliani, Alessandra; Mangano, Carlo; Barone, Antonio; Manzon, Licia; Degidi, Marco; Scarano, Antonio; Filippone, Antonella; Perrotti, Vittoria

    2016-12-01

    Various grafts or combination of bone substitute materials have been used in sinus lift procedures. Currently, ongoing developments in several disciplines, from molecular biology and chemistry to computer science and engineering, have contributed to the understanding of biological processes leading to bone healing after the use of bone substitute materials (BSBs) and therefore of the behavior of BSBs. The understanding of the properties of each graft enables individual treatment concepts and therefore allows shift from a simple replacement material to the modern concept of an individually created composite biomaterial. Indeed, the choice of the best BSB still remains crucial for success in maxillary sinus augmentation procedures. The present article provides an overview of most of the materials currently available for sinus lift, with a specific focus on their histological, molecular, cellular and pharmaceutical aspects.

  9. Preliminary study of quantitative aspects and the effect of pulsed electromagnetic field treatment on the incorporation of equine cancellous bone grafts.

    PubMed

    Kold, S E; Hickman, J; Meisen, F

    1987-03-01

    The quantitative aspects of equine cancellous bone graft incorporation and the possibility of influencing graft incorporation by daily exposure to a pulsed electromagnetic field (PEMF) was studied in eight yearling ponies. In order to be able to quantify formative aspects of graft remodelling, a double and treble tetracycline intravital labelling technique was used. Intravital radiographs were obtained at regular intervals throughout the trial, but were found to be of little assistance in assessing any differences between stimulated and non-stimulated grafts. The ponies were humanely destroyed at regular intervals between nine and 241 days after installation of the graft. Light microscopy and fluorescent light microscopy were used to evaluate quantitative aspects of graft incorporation and to compare PEMF-stimulated grafts with control grafts. There was a small but statistically significant effect of PEMF-stimulation on cancellous bone graft incorporation. In view of this, these observations can only be considered as indicative of a possible trend, but should encourage further studies using different signal modalities.

  10. Research trends in biomimetic medical materials for tissue engineering: 3D bioprinting, surface modification, nano/micro-technology and clinical aspects in tissue engineering of cartilage and bone.

    PubMed

    Chen, Cen; Bang, Sumi; Cho, Younghak; Lee, Sahnghoon; Lee, Inseop; Zhang, ShengMin; Noh, Insup

    2016-01-01

    This review discusses about biomimetic medical materials for tissue engineering of bone and cartilage, after previous scientific commentary of the invitation-based, Korea-China joint symposium on biomimetic medical materials, which was held in Seoul, Korea, from October 22 to 26, 2015. The contents of this review were evolved from the presentations of that symposium. Four topics of biomimetic medical materials were discussed from different research groups here: 1) 3D bioprinting medical materials, 2) nano/micro-technology, 3) surface modification of biomaterials for their interactions with cells and 4) clinical aspects of biomaterials for cartilage focusing on cells, scaffolds and cytokines.

  11. Morphological Study: Ultrastructural Aspects of Articular Cartilage and Subchondral Bone in Patients Affected by Post-Traumatic Shoulder Instability.

    PubMed

    Baudi, Paolo; Catani, Fabio; Rebuzzi, Manuela; Ferretti, Marzia; Smargiassi, Alberto; Campochiaro, Gabriele; Serafini, Fabio; Palumbo, Carla

    2016-12-16

    Post-traumatic shoulder instability is a frequent condition in active population, representing one of most disabling pathologies, due to altered balance involving joints. No data are so far available on early ultrastructural osteo-chondral damages, associated with the onset of invalidating pathologies, like osteoarthritis-OA. Biopsies of glenoid articular cartilage and sub-chondral bone were taken from 10 adult patients underwent arthroscopic stabilization. Observations were performed under Transmission Electron Microscopy-TEM in tangential, arcuate and radial layers of the articular cartilage and in the sub-chondral bone. In tangential and arcuate layers chondrocytes display normal and very well preserved ultrastructure, probably due to the synovial liquid supply; otherwise, throughout the radial layer (un-calcified and calcified) chondrocytes show various degrees of degeneration; occasionally, in the radial layer evidences of apoptosis/autophagy were also observed. Concerning sub-chondral bone, osteocytes next to the calcified cartilage also show signs of degeneration, while osteocytes farther from the osteo-chondral border display normal ultrastructure, probably due to the bone vascular supply. The ultrastructural features of the osteo-chondral complex are not age-dependent. This study represents the first complete ultrastructural investigation of the articular osteo-chondral complex in shoulder instability, evaluating the state of preservation/viability of both chondrocytes and osteocytes throughout the successive layers of articular cartilage and sub-chondral bone. Preliminary observations here collected represent the morphological basis for further deepening of pathogenesis related to shoulder instability, enhancing the relationship between cell shape and microenvironment; in particular, they could be useful in understanding if the early surgical treatment in shoulder instability could avoid the onset of OA. Anat Rec, 300:12-15, 2017. © 2016 Wiley

  12. Continued investigation of kinetic aspects of bone mineral metabolism. [determining body calcium by measuring argon after neutron irradiation

    NASA Technical Reports Server (NTRS)

    Palmer, H. E.

    1974-01-01

    The total body calcium in humans was determined by measuring expired Ar-37 after neutron irradiation. The excretion of Ar-37 from humans was found to be much slower than the excretion from rats and dogs, and to be related to the age of a person. A study of the uniformity of the Ar-37 production throughout the thickness of the body was studied using phantoms. The results indicate that it should be possible to obtain a uniformity within plus or minus 3% for the production of Ar-37 per unit of calcium by using a bilateral irradiation. New low background, large volume proportional counters were developed and constructed, for more sensitive measurement of Ar-37 in the expired air from patients. A new irradiation enclosure was developed for measuring total body calcium in rats by the Ar-37 method. With this enclosure the Ar-37 production per gram of calcium is constant with a standard deviation of plus or minus 2.8% for any size rat between 100 and 500 grams. The use of Na-22 as measure of bone replacement in the fractured femur of a dog was not successful.

  13. Bone graft

    MedlinePlus

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

  14. Biological Regulation of Bone Quality

    PubMed Central

    Alliston, Tamara

    2014-01-01

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

  15. Bone tumor

    MedlinePlus

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

  16. [Canine panosteitis: an idiopathic bone disease investigated in the light of a new hypothesis concerning pathogenesis. Part 1: Clinical and diagnostic aspects].

    PubMed

    Schawalder, P; Andres, H U; Jutzi, K; Stoupis, C; Bösch, C

    2002-03-01

    Panosteitis, an idiopathic bone disease of young dogs, was investigated in the light of a new, empirically based hypothesis governing its pathogenesis. Extensive clinical observations suggest a close relationship between the incidence of this disease and the commercialization of various protein-rich, high-calorie dog foods. The theory of an "osseous compartment syndrome" provides a hypothetical pathogenesis, which corroborates this findings. An excessive accumulation of protein causes intraosseous edema due to its osmotic effects. Because bone is a rigid compartment, this leads to an increase in intramedullary pressure and compression of blood vessels. Subsequent osseous ischemia leads to a deficient metabolic state (decreased oxygenation, inadequate influx of nutritive substances, local acidosis, decreased removal of metabolites, disruption of local biochemical processes, etc.), and a vicious circle is created due to the resulting local inflammation. The disease is aggravated by increased metabolism due to excessive physical activity. Within the context of a pilot study, clinical, radiographic, scintigraphic and thermographic examinations and a therapeutic trial with benzopyron were carried out. In addition, more modern investigative tools, including osteomyelography, magnetic resonance tomography and intraosseous pressure measurements were used to provide objective data concerning the pathogenesis of panosteitis. In most cases, clinical remission was seen within days of monotherapy with the proteolytic substance, benzopyron (Cumartrin). This finding appears to corroborate our hypothesis.

  17. Bone Biopsy

    MedlinePlus

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

  18. Mangiferin Reduces the Inhibition of Chondrogenic Differentiation by IL-1β in Mesenchymal Stem Cells from Subchondral Bone and Targets Multiple Aspects of the Smad and SOX9 Pathways

    PubMed Central

    Huh, Jeong-Eun; Koh, Pil-Seong; Seo, Byung-Kwan; Park, Yeon-Chul; Baek, Yong-Hyun; Lee, Jae-Dong; Park, Dong-Suk

    2014-01-01

    Mangiferin is a natural immunomodulator found in plants including mango trees. The effects of mangiferin on chondrogenesis and cartilage repair have not yet been reported. This study was designed to determine the effect of mangiferin on chondrogenic differentiation in IL-1β-stimulated mesenchymal stem cells (MSCs) from subchondral bone and to explore the mechanisms underlying these effects. MSCs were isolated from the subchondral bone of rabbit and treated with mangiferin alone and/or interleukin-1β (IL-1β). Mangiferin induced chondrogenic differentiation in MSCs by upregulating transforming growth factor (TGF)-β, bone morphogenetic protein (BMP)-2, and BMP-4 and several key markers of chondrogenesis, including sex-determining region Y–box (SRY-box) containing gene 9 (SOX9), type 2α1 collagen (Col2α1), cartilage link protein, and aggrecan. In IL-1β-stimulated MSCs, mangiferin significantly reversed the production of TGF-β, BMP-2, BMP-4, SOX9, Col2α1, cartilage link protein, and aggrecan, as well as matrix metalloproteinase (MMP)-1, MMP-13, and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS5). Mangiferin upregulated the phosphorylation of Smad 2, Smad 3, Smad 1/5/8, and SOX9 in IL-1β-stimulated MSCs. In the presence of mangiferin, SOX9 siRNA suppressed the activation of Smad 2, Smad 3, Smad 1/5/8, aggrecan, and Col2α1 expression. In conclusion, mangiferin exhibits both chondrogenic and chondroprotective effects on damaged MSCs and mediates these effects by targeting multiple aspects of the Smad and SOX9 signaling pathways. PMID:25216336

  19. Mineralized Three-Dimensional Bone Constructs

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  20. Mineralized three-dimensional bone constructs

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  1. Living Bones, Strong Bones

    NASA Video Gallery

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

  2. Bone Cancer

    MedlinePlus

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

  3. Bone Diseases

    MedlinePlus

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

  4. Bone Metastasis

    MedlinePlus

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

  5. Bone and bone turnover.

    PubMed

    Crofton, Patricia M

    2009-01-01

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

  6. Bone marrow aspiration

    MedlinePlus

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

  7. Malignant lymphoma of bone.

    PubMed

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

    2002-02-01

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

  8. Bone Scan

    MedlinePlus

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

  9. Bone grafts.

    PubMed

    Hubble, Matthew J W

    2002-09-01

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

  10. Bone cement

    PubMed Central

    Vaishya, Raju; Chauhan, Mayank; Vaish, Abhishek

    2013-01-01

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

  11. Bone Analyzer

    NASA Technical Reports Server (NTRS)

    1985-01-01

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

  12. Bone Infections

    MedlinePlus

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

  13. Osteopontin Deficiency Increases Bone Fragility but Preserves Bone Mass

    PubMed Central

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

    2010-01-01

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

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

    PubMed

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

    2010-06-01

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

  15. Bone poroelasticity.

    PubMed

    Cowin, S C

    1999-03-01

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

  16. Architecture and microstructure of cortical bone in reconstructed canine mandibles after bone transport distraction osteogenesis.

    PubMed

    Zapata, Uriel; Halvachs, Emily K; Dechow, Paul C; Elsalanty, Mohammed E; Opperman, Lynne A

    2011-11-01

    Reconstruction of the canine mandible using bone transport distraction osteogenesis has been shown to be a suitable method for correcting segmental bone defects produced by cancer, gunshots, and trauma. Although the mechanical quality of the new regenerate cortical bone seems to be related to the mineralization process, several questions regarding the microstructural patterns of the new bony tissue remain unanswered. The purpose of this study was to quantify any microstructural differences that may exist between the regenerate and control cortical bone. Five adult American foxhound dogs underwent unilateral bone transport distraction of the mandible to repair bone defects of 30-35 mm. Animals were killed 12 weeks after the beginning of the consolidation period. Fourteen cylindrical cortical samples were extracted from the superior, medial, and inferior aspects of the lingual and buccal plates of the reconstructed aspect of the mandible, and 21 specimens were collected similarly from the contralateral aspect of the mandible. Specimens were evaluated using histomorphometric and micro-computed tomographic techniques to compare their microstructure. Except for differences in haversian canal area, histomorphometric analyses suggested no statistical differences in microstructure between regenerate and control cortical bone. Morphological evaluation suggested a consistent level of anisotropy, possibly related to the distraction vector. After 12 weeks' consolidation, bone created during bone transport distraction osteogenesis was comparable to native bone in microstructure, architecture, and mechanical properties. It is proposed that, after enough time, the properties of the regenerate bone will be identical to that of native bone.

  17. Regulatory aspects

    NASA Astrophysics Data System (ADS)

    Stern, Arthur M.

    1986-07-01

    At this time, there is no US legislation that is specifically aimed at regulating the environmental release of genetically engineered organisms or their modified components, either during the research and development stage or during application. There are some statutes, administered by several federal agencies, whose language is broad enough to allow the extension of intended coverage to include certain aspects of biotechnology. The one possible exception is FIFRA, which has already brought about the registration of several natural microbial pesticides but which also has provision for requiring the registration of “strain improved” microbial pesticides. Nevertheless, there may be gaps in coverage even if all pertinent statutes were to be actively applied to the control of environmental release of genetically modified substances. The decision to regulate biotechnology under TSCA was justified, in part, on the basis of its intended role as a gap-filling piece of environmental legislation. The advantage of regulating biotechnology under TSCA is that this statute, unlike others, is concerned with all media of exposure (air, water, soil, sediment, biota) that may pose health and environmental hazards. Experience may show that extending existing legislation to regulate biotechnology is a poor compromise compared to the promulgation of new legislation specifically designed for this purpose. It appears that many other countries are ultimately going to take the latter course to regulate biotechnology.

  18. [Bone diseases].

    PubMed

    Uebelhart, Brigitte; Rizzoli, René

    2016-01-13

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

  19. Bone cutting.

    PubMed

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

    1991-02-01

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

  20. Postmenopausal osteoporosis - clinical, biological and histopathological aspects.

    PubMed

    Pavel, Oana Roxana; Popescu, Mihaela; Novac, Liliana; Mogoantă, LaurenŢiu; Pavel, LaurenŢiu Petrişor; Vicaş, Răzvan Marius; Trăistaru, Magdalena Rodica

    2016-01-01

    Osteoporosis is one of the most common disorders in postmenopausal women, affecting the quality of life and increasing the risk for fractures in minor traumas. Changes in the bone microarchitecture causes static changes in the body and affects motility. In this study, we analyzed two groups of women, one with physiological menopause and one with surgically induced menopause. The diagnosis of osteoporosis was suspected based on the clinical symptoms and confirmed by assessing bone mineral density by the dual-energy X-ray absorptiometry (DEXA). Comparing some clinical and biological aspects there was noted that a much higher percentage of women with surgically induced menopause exhibited increases in body mass index, changes in serum lipids, cholesterol, triglycerides, blood glucose, serum calcium, magnesemia and osteocalcin. In contrast, no significant differences were observed in the histopathological aspects of bone tissue examined from these two groups. In all patients, there was identified a significant reduction in the number of osteocytes and osteoblasts, the expansion of haversian channels, reducing the number of trabecular bone in the cancellous bone with wide areola cavities often full of adipose tissue, non-homogenous demineralization of both the compact bone and the cancellous bone, atrophy and even absence of the endosteal, and the presence of multiple microfractures. Our study showed that early surgically induced menopause more intensely alters the lipid, carbohydrate and mineral metabolism, thus favoring the onset of osteoporosis.

  1. Your Bones

    MedlinePlus

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

  2. Talking Bones.

    ERIC Educational Resources Information Center

    Johnson, Jaclyn; Kassing, Sharon

    2002-01-01

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

  3. Paget's Disease of Bone

    MedlinePlus

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

  4. New molecular targets in bone metastases.

    PubMed

    Santini, D; Galluzzo, S; Zoccoli, A; Pantano, F; Fratto, M E; Vincenzi, B; Lombardi, L; Gucciardino, C; Silvestris, N; Riva, E; Rizzo, S; Russo, A; Maiello, E; Colucci, G; Tonini, G

    2010-11-01

    Bone metastases have a major impact on morbidity and on mortality in cancer patients. Despite its clinical relevance, metastasis remains the most poorly elucidated aspect of carcinogenesis. The biological mechanisms leading to bone metastasis establishment have been referred as "vicious circle," a complex network between cancer cells and the bone microenvironment. This review is aimed to underline the new molecular targets in bone metastases management other than bisphosphonates. Different pathways or molecules such as RANK/RANKL/OPG, cathepsin K, endothelin-1, Wnt/DKK1, Src have recently emerged as potential targets and nowadays preclinical and clinical trials are underway. The results from those in the advanced clinical phases are encouraging and underlined the need to design large randomised clinical trials to validate these results in the next future. Targeting the bone by preventing skeletal related events (SREs) and bone metastases has major clinical impact in improving survival in bone metastatic patients and in preventing disease relapse in adjuvant setting.

  5. Bone densitometry.

    PubMed

    Chun, Kwang J

    2011-05-01

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

  6. Effects of Dairy Products Consumption on Health: Benefits and Beliefs--A Commentary from the Belgian Bone Club and the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases.

    PubMed

    Rozenberg, Serge; Body, Jean-Jacques; Bruyère, Olivier; Bergmann, Pierre; Brandi, Maria Luisa; Cooper, Cyrus; Devogelaer, Jean-Pierre; Gielen, Evelien; Goemaere, Stefan; Kaufman, Jean-Marc; Rizzoli, René; Reginster, Jean-Yves

    2016-01-01

    Dairy products provide a package of essential nutrients that is difficult to obtain in low-dairy or dairy-free diets, and for many people it is not possible to achieve recommended daily calcium intakes with a dairy-free diet. Despite the established benefits for bone health, some people avoid dairy in their diet due to beliefs that dairy may be detrimental to health, especially in those with weight management issues, lactose intolerance, osteoarthritis, rheumatoid arthritis, or trying to avoid cardiovascular disease. This review provides information for health professionals to enable them to help their patients make informed decisions about consuming dairy products as part of a balanced diet. There may be a weak association between dairy consumption and a possible small weight reduction, with decreases in fat mass and waist circumference and increases in lean body mass. Lactose intolerant individuals may not need to completely eliminate dairy products from their diet, as both yogurt and hard cheese are well tolerated. Among people with arthritis, there is no evidence for a benefit to avoid dairy consumption. Dairy products do not increase the risk of cardiovascular disease, particularly if low fat. Intake of up to three servings of dairy products per day appears to be safe and may confer a favourable benefit with regard to bone health.

  7. Interpreting Bones.

    ERIC Educational Resources Information Center

    Weymouth, Patricia P.

    1986-01-01

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

  8. Bone and bone marrow: the same organ.

    PubMed

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

    2010-11-01

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

  9. Parallel mechanisms suppress cochlear bone remodeling to protect hearing.

    PubMed

    Jáuregui, Emmanuel J; Akil, Omar; Acevedo, Claire; Hall-Glenn, Faith; Tsai, Betty S; Bale, Hrishikesh A; Liebenberg, Ellen; Humphrey, Mary Beth; Ritchie, Robert O; Lustig, Lawrence R; Alliston, Tamara

    2016-08-01

    Bone remodeling, a combination of bone resorption and formation, requires precise regulation of cellular and molecular signaling to maintain proper bone quality. Whereas osteoblasts deposit and osteoclasts resorb bone matrix, osteocytes both dynamically resorb and replace perilacunar bone matrix. Osteocytes secrete proteases like matrix metalloproteinase-13 (MMP13) to maintain the material quality of bone matrix through perilacunar remodeling (PLR). Deregulated bone remodeling impairs bone quality and can compromise hearing since the auditory transduction mechanism is within bone. Understanding the mechanisms regulating cochlear bone provides unique ways to assess bone quality independent of other aspects that contribute to bone mechanical behavior. Cochlear bone is singular in its regulation of remodeling by expressing high levels of osteoprotegerin. Since cochlear bone expresses a key PLR enzyme, MMP13, we examined whether cochlear bone relies on, or is protected from, osteocyte-mediated PLR to maintain hearing and bone quality using a mouse model lacking MMP13 (MMP13(-/-)). We investigated the canalicular network, collagen organization, lacunar volume via micro-computed tomography, and dynamic histomorphometry. Despite finding defects in these hallmarks of PLR in MMP13(-/-) long bones, cochlear bone revealed no differences in these markers, nor hearing loss as measured by auditory brainstem response (ABR) or distortion product oto-acoustic emissions (DPOAEs), between wild type and MMP13(-/-) mice. Dynamic histomorphometry revealed abundant PLR by tibial osteocytes, but near absence in cochlear bone. Cochlear suppression of PLR corresponds to repression of several key PLR genes in the cochlea relative to long bones. These data suggest that cochlear bone uniquely maintains bone quality and hearing independent of MMP13-mediated osteocytic PLR. Furthermore, the cochlea employs parallel mechanisms to inhibit remodeling by osteoclasts and osteoblasts, and by

  10. Microtomographic imaging in the process of bone modeling and simulation

    NASA Astrophysics Data System (ADS)

    Mueller, Ralph

    1999-09-01

    Micro-computed tomography ((mu) CT) is an emerging technique to nondestructively image and quantify trabecular bone in three dimensions. Where the early implementations of (mu) CT focused more on technical aspects of the systems and required equipment not normally available to the general public, a more recent development emphasized practical aspects of micro- tomographic imaging. That system is based on a compact fan- beam type of tomograph, also referred to as desktop (mu) CT. Desk-top (mu) CT has been used extensively for the investigation of osteoporosis related health problems gaining new insight into the organization of trabecular bone and the influence of osteoporotic bone loss on bone architecture and the competence of bone. Osteoporosis is a condition characterized by excessive bone loss and deterioration in bone architecture. The reduced quality of bone increases the risk of fracture. Current imaging technologies do not allow accurate in vivo measurements of bone structure over several decades or the investigation of the local remodeling stimuli at the tissue level. Therefore, computer simulations and new experimental modeling procedures are necessary for determining the long-term effects of age, menopause, and osteoporosis on bone. Microstructural bone models allow us to study not only the effects of osteoporosis on the skeleton but also to assess and monitor the effectiveness of new treatment regimens. The basis for such approaches are realistic models of bone and a sound understanding of the underlying biological and mechanical processes in bone physiology. In this article, strategies for new approaches to bone modeling and simulation in the study and treatment of osteoporosis and age-related bone loss are presented. The focus is on the bioengineering and imaging aspects of osteoporosis research. With the introduction of desk-top (mu) CT, a new generation of imaging instruments has entered the arena allowing easy and relatively inexpensive access to

  11. Bone Densitometry (Bone Density Scan)

    MedlinePlus

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

  12. Bone marrow transplant

    MedlinePlus

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

  13. Bone remodeling as a spatial evolutionary game.

    PubMed

    Ryser, Marc D; Murgas, Kevin A

    2017-04-07

    Bone remodeling is a complex process involving cell-cell interactions, biochemical signaling and mechanical stimuli. Early models of the biological aspects of remodeling were non-spatial and focused on the local dynamics at a fixed location in the bone. Several spatial extensions of these models have been proposed, but they generally suffer from two limitations: first, they are not amenable to analysis and are computationally expensive, and second, they neglect the role played by bone-embedded osteocytes. To address these issues, we developed a novel model of spatial remodeling based on the principles of evolutionary game theory. The analytically tractable framework describes the spatial interactions between zones of bone resorption, bone formation and quiescent bone, and explicitly accounts for regulation of remodeling by bone-embedded, mechanotransducing osteocytes. Using tools from the theory of interacting particle systems we systematically classified the different dynamic regimes of the spatial model and identified regions of parameter space that allow for global coexistence of resorption, formation and quiescence, as observed in physiological remodeling. In coexistence scenarios, three-dimensional simulations revealed the emergence of sponge-like bone clusters. Comparison between spatial and non-spatial dynamics revealed substantial differences and suggested a stabilizing role of space. Our findings emphasize the importance of accounting for spatial structure and bone-embedded osteocytes when modeling the process of bone remodeling. Thanks to the lattice-based framework, the proposed model can easily be coupled to a mechanical model of bone loading.

  14. Design, Materials, and Mechanobiology of Biodegradable Scaffolds for Bone Tissue Engineering

    PubMed Central

    Velasco, Marco A.; Narváez-Tovar, Carlos A.; Garzón-Alvarado, Diego A.

    2015-01-01

    A review about design, manufacture, and mechanobiology of biodegradable scaffolds for bone tissue engineering is given. First, fundamental aspects about bone tissue engineering and considerations related to scaffold design are established. Second, issues related to scaffold biomaterials and manufacturing processes are discussed. Finally, mechanobiology of bone tissue and computational models developed for simulating how bone healing occurs inside a scaffold are described. PMID:25883972

  15. Bone Material Properties in Osteogenesis Imperfecta.

    PubMed

    Bishop, Nick

    2016-04-01

    Osteogenesis imperfecta entrains changes at every level in bone tissue, from the disorganization of the collagen molecules and mineral platelets within and between collagen fibrils to the macroarchitecture of the whole skeleton. Investigations using an array of sophisticated instruments at multiple scale levels have now determined many aspects of the effect of the disease on the material properties of bone tissue. The brittle nature of bone in osteogenesis imperfecta reflects both increased bone mineralization density-the quantity of mineral in relation to the quantity of matrix within a specific bone volume-and altered matrix-matrix and matrix mineral interactions. Contributions to fracture resistance at multiple scale lengths are discussed, comparing normal and brittle bone. Integrating the available information provides both a better understanding of the effect of current approaches to treatment-largely improved architecture and possibly some macroscale toughening-and indicates potential opportunities for alternative strategies that can influence fracture resistance at longer-length scales.

  16. Broken Bones (For Parents)

    MedlinePlus

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

  17. Bone lesion biopsy

    MedlinePlus

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

  18. Bone biopsy (image)

    MedlinePlus

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

  19. Surgery for Bone Cancer

    MedlinePlus

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

  20. Facts about Broken Bones

    MedlinePlus

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

  1. What Is Breast in the Bone?

    PubMed Central

    Shemanko, Carrie S.; Cong, Yingying; Forsyth, Amanda

    2016-01-01

    The normal developmental program that prolactin generates in the mammary gland is usurped in the cancerous process and can be used out of its normal cellular context at a site of secondary metastasis. Prolactin is a pleiotropic peptide hormone and cytokine that is secreted from the pituitary gland, as well as from normal and cancerous breast cells. Experimental and epidemiologic data suggest that prolactin is associated with mammary gland development, and also the increased risk of breast tumors and metastatic disease in postmenopausal women. Breast cancer spreads to the bone in approximately 70% of cases with advanced breast cancer. Despite treatment, new bone metastases will still occur in 30%–50% of patients. Only 20% of patients with bone metastases survive five years after the diagnosis of bone metastasis. The breast cancer cells in the bone microenvironment release soluble factors that engage osteoclasts and/or osteoblasts and result in bone breakdown. The breakdown of the bone matrix, in turn, enhances the proliferation of the cancer cells, creating a vicious cycle. Recently, it was shown that prolactin accelerated the breast cancer cell-mediated osteoclast differentiation and bone breakdown by the regulation of breast cancer-secreted proteins. Interestingly, prolactin has the potential to affect multiple proteins that are involved in both breast development and likely bone metastasis, as well. Prolactin has normal bone homeostatic roles and, combined with the natural “recycling” of proteins in different tissues that can be used for breast development and function, or in bone function, increases the impact of prolactin signaling in breast cancer bone metastases. Thus, this review will focus on the role of prolactin in breast development, bone homeostasis and in breast cancer to bone metastases, covering the molecular aspects of the vicious cycle. PMID:27782069

  2. Chondroblastoma of the Temporal Bone

    PubMed Central

    Selesnick, Samuel H.; Levine, Jennifer M.

    1999-01-01

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

  3. Measures of Complexity to quantify Bone Structure

    NASA Astrophysics Data System (ADS)

    Saparin, Peter; Gowin, Wolfgang; Kurths, Jürgen; Felsenberg, Dieter

    1998-03-01

    We propose a technique to assess structure of the bone in its spatial distribution by describing and quantifying the structural architecture as a whole. The concept of measures of complexity based on symbolic dynamics is applied to computed tomography (CT) - images obtained from human lumbar vertebra. CT-images have been transformed into images consisting of 5 different symbols, whereby both statical and dynamical coding are included. Different aspects of the bone structure are quantified by several measures which have been introduced: index of global ensemble of elements composing the bone; complexity, homogeneity and dynamics within the bone architecture; complexity and inhomogeneity of the trabecular net. This leads to new insides to the understanding of bone's internal structure. The results give the first experimental and quantitative evidence of the theoretical prediction that complexity of bone structure declines rapidly with the increased disintegration of bone structures leading to the loss of bone mass and specify experimentally that bone structure is exponentially related to its density. Especially, osteoporotic vertebrae are less complex organized than normal ones. In addition, this method is significantly sensitive to changes in bone structure and provides improvements of diagnostic of pathological structural loss.

  4. The complexity of bone architecture: A tool to differentiate bone diseases

    NASA Astrophysics Data System (ADS)

    Saparin, Peter I.; Gowin, Wolfgang; Kurths, Jürgen; Felsenberg, Dieter

    2000-02-01

    We introduce a generalization of symbolic dynamics to analyze two-dimensional objects and propose measures of complexity to quantify the structure of symbol encoded images. This technique is applied to evaluate the architecture of human cancellous bone by analyzing computed tomography images of vertebrae acquired from specimens and in vivo. The pixels of the preprocessed images are encoded using a mixture of static and dynamic encoding. The architecture of encoded cancellous bone is evaluated as a whole using measures of complexity. A set of new parameters are introduced to quantify the different aspects of structure: complexity and degree of disorder of the architecture as a whole, or spatial arrangements of hard or soft elements of the bone separately. It is found that the complexity of the bone structure relates to its density exponentially. Normal bone has a complex ordered structure, while the architecture during the initial stage of bone loss is characterized by lower complexity and a maximal level of disorder. Increased bone loss leads again to ordered structure, however, its complexity is minimal. This phenomenon was observed in a series of osteoporotic specimens as well as in vivo in patients treated with fluor, and hormone replacement therapy. We found that different bone diseases demonstrate distinctive features captured by the measurements of complexity of the bone's structural composition. It is shown that the application of the proposed technique leads to new insights for understanding of the bone's response on medical treatment and provide important additional information for the diagnostics of bone diseases.

  5. Bone image segmentation.

    PubMed

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

    1999-05-01

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

  6. Biomaterial aspects of Interpore-200 porous hydroxyapatite.

    PubMed

    White, E; Shors, E C

    1986-01-01

    Interpore-200 is the product of over 11 years of continuous research and development. It has been investigated at over 25 research centers in a wide variety of animal and human implant settings, including alveolar ridge augmentation, periodontics, and orthognathic reconstructions. The biomaterial aspects of Interpore-200 show the following: Interpore-200 has a highly interconnected, three-dimensional porosity that is uniform and consistent. The hydroxyapatite manufactured from marine corals is biocompatible and nontoxic. Interpore-200 is essentially pure hydroxyapatite, with the balance consisting of tricalcium phosphate. Interpore-200 is approximately 55 to 65 per cent porous with nominal pore diameters of 200 micron. Unlike nonporous materials, Interpore-200 is osteoconductive and results, when placed next to a viable bone, in an advancing front of bone into the implant. From 50 to 88 per cent of the porosity within the implant is filled with woven and lamellar bone within 3 months. Moreover, the surfaces of Interpore-200 are intimately bonded with the bone tissue. The biomechanical properties of Interpore-200 blocks are similar to those of a cancellous bone graft. Once ingrown with vascularized bone tissue, the defect site is, in effect, restored. Interpore-200 adequately matches the elastic properties of bone so that stresses necessary to maintain healthy bone are transmitted throughout the regenerated region. Extensive animal and clinical studies have shown that nonporous implants or implants without interconnected porosity can result in aberrant mineralization, stress shielding, low fatigue strength, and bulk displacement. Hydroxyapatite with interconnected porosity like Interpore-200 reacts differently than materials with limited or no porosity. In animals, Interpore-200 exhibits 0 to 5 per cent biodegradation per year. Moreover, this minimal biodegradation is compensated by regeneration of bone. These studies have now been extended for 4 years. Interpore

  7. Pituitary abscess after autologous bone marrow transplantation.

    PubMed

    Leff, R S; Martino, R L; Pollock, W J; Knight, W A

    1989-05-01

    The first case of pituitary abscess arising in a patient during recovery from autologous bone marrow transplantation is reported. A 31-year-old man with a 9 month history of T-cell lymphoma died suddenly more than 60 days after successful treatment with high-dose cyclophosphamide, total body irradiation, and autologous bone marrow infusion. Autopsy revealed a pituitary abscess associated with clinically silent sphenoid sinusitis. Unique aspects of this case are presented and clinical and pathologic features of pituitary abscess are reviewed. Although rare, pituitary abscess may complicate recovery from bone marrow transplantation.

  8. [Radionuclides for metastatic bone pain palliation].

    PubMed

    Lass, Piotr

    2002-10-01

    The paper overviews the role of systemic radionuclide therapy in patients with disseminated bone metastases. Most patients with bone metastases experience painful symptoms. Systemic radioisotope therapy is an alternative to traditional hemibody radiation in cases of multiple, diffuse metastases. Usually given as a single i.v. slow infusion it provides a pain relief beginning in one to three weeks, with a mean duration up to several months, depending on the kind of radioisotope applied. The paper overviews the role of unsealed source therapy with these bone-seeking radiopharmaceuticals in palliating pain, improving quality of life, indications, contraindications and complications of this therapy are discussed, as well as cost-benefit aspects.

  9. Bone Density Test

    MedlinePlus

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

  10. Proximal Tibial Bone Graft

    MedlinePlus

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

  11. Bone scan in metabolic bone diseases. Review.

    PubMed

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

    2012-08-25

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

  12. Bone scan appearances following bone and bone marrow biopsy

    SciTech Connect

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

    1984-01-01

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

  13. Bone development

    PubMed Central

    Berendsen, Agnes D.; Olsen, Bjorn R.

    2015-01-01

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

  14. Menopause and Bone Loss

    MedlinePlus

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

  15. Bone density scan (image)

    MedlinePlus

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

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

    PubMed

    Huang, Tsang-hai; Ables, Gene P

    2016-01-01

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

  17. Recent progresses in gene delivery-based bone tissue engineering.

    PubMed

    Lu, Chia-Hsin; Chang, Yu-Han; Lin, Shih-Yeh; Li, Kuei-Chang; Hu, Yu-Chen

    2013-12-01

    Gene therapy has converged with bone engineering over the past decade, by which a variety of therapeutic genes have been delivered to stimulate bone repair. These genes can be administered via in vivo or ex vivo approach using either viral or nonviral vectors. This article reviews the fundamental aspects and recent progresses in the gene therapy-based bone engineering, with emphasis on the new genes, viral vectors and gene delivery approaches.

  18. Bone marrow transplant - discharge

    MedlinePlus

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

  19. Factors affecting bone growth.

    PubMed

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

    2015-02-01

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

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

    SciTech Connect

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

    1984-10-01

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

  1. Bone Marrow Diseases

    MedlinePlus

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

  2. Metastatic Bone Disease

    MedlinePlus

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

  3. Bone Health and Osteoporosis.

    PubMed

    Lupsa, Beatrice C; Insogna, Karl

    2015-09-01

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

  4. [Imaging of bone metastases].

    PubMed

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

    2013-11-01

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

  5. Assessment of bone quality in osteoporosis treatment with bone anabolic agents: Really something new?

    PubMed

    Ulivieri, Fabio Massimo; Caudarella, Renata; Camisasca, Marzia; Cabrini, Daniela Maria; Merli, Ilaria; Messina, Carmelo; Piodi, Luca Petruccio

    2016-12-01

    Osteoporosis is a chronic pathologic condition, particularly of the elderly, in which a reduction of bone mineral density (BMD) weakens bone, leading to the so-called fragility fractures, most often of spine and femur. The gold standard exam for the quantitative measurement of BMD is the dual X-ray photon absorptiometry (DXA), a radiological method. However, a relevant number of fragility fractures occurs in the range of normal BMD values, meaning that also qualitative aspects of bone play a role, namely bone architecture and bone geometry. Bone structure is investigated by microCT and histomorphometry, which necessitate an invasive approach with a biopsy, usually taken at the iliac crest, not the typical site of fragility fractures. New tools, trabecular bone score (TBS) and hip structural analysis (HSA), obtained during DXA, can supply informations about bone structure of spine and femur, respectively, in a not invasive way. Therapy of osteoporosis is based on two types of drugs leading to an increase of BMD: antiresorptive and anabolic treatments. The antiresorptive drugs inhibit the osteoclasts, whereas teriparatide and, in part, strontium ranelate ameliorate bone structure. The present review deals with the relation between the anabolic drugs for osteoporosis and the cited new tools which investigate bone architecture and geometry, in order to clarify if they represent a real advantage in monitoring efficacy of osteoporosis' treatment. Data from the studies show that increases of TBS and HSA values after anabolic therapy are small and very close to their least significant change at the end of the usual period of treatment. Therefore, it is questionable if TBS and HSA are really helpful in monitoring bone quality and in defining reduction of individual fragility fracture risk during osteoporosis treatment with bone anabolic agents.

  6. [Bone involvement in endocrinopathies].

    PubMed

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

    1994-06-04

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

  7. Powder-based 3D printing for bone tissue engineering.

    PubMed

    Brunello, G; Sivolella, S; Meneghello, R; Ferroni, L; Gardin, C; Piattelli, A; Zavan, B; Bressan, E

    2016-01-01

    Bone tissue engineered 3-D constructs customized to patient-specific needs are emerging as attractive biomimetic scaffolds to enhance bone cell and tissue growth and differentiation. The article outlines the features of the most common additive manufacturing technologies (3D printing, stereolithography, fused deposition modeling, and selective laser sintering) used to fabricate bone tissue engineering scaffolds. It concentrates, in particular, on the current state of knowledge concerning powder-based 3D printing, including a description of the properties of powders and binder solutions, the critical phases of scaffold manufacturing, and its applications in bone tissue engineering. Clinical aspects and future applications are also discussed.

  8. Factors stimulating bone formation.

    PubMed

    Lind, M; Bünger, C

    2001-10-01

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

  9. Regulation of Bone Metabolism

    PubMed Central

    Shahi, Maryam; Peymani, Amir; Sahmani, Mehdi

    2017-01-01

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

  10. Bisphosphonates and bone quality

    PubMed Central

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

    2014-01-01

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

  11. [Microdestruction of the bone].

    PubMed

    Iankovskiĭ, V É

    2014-01-01

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

  12. Regulation of Bone Metabolism.

    PubMed

    Shahi, Maryam; Peymani, Amir; Sahmani, Mehdi

    2017-04-01

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

  13. Bone Loss Triggered by the Cytokine Network in Inflammatory Autoimmune Diseases

    PubMed Central

    Amarasekara, Dulshara Sachini; Yu, Jiyeon; Rho, Jaerang

    2015-01-01

    Bone remodeling is a lifelong process in vertebrates that relies on the correct balance between bone resorption by osteoclasts and bone formation by osteoblasts. Bone loss and fracture risk are implicated in inflammatory autoimmune diseases such as rheumatoid arthritis, ankylosing spondylitis, inflammatory bowel disease, and systemic lupus erythematosus. The network of inflammatory cytokines produced during chronic inflammation induces an uncoupling of bone formation and resorption, resulting in significant bone loss in patients with inflammatory autoimmune diseases. Here, we review and discuss the involvement of the inflammatory cytokine network in the pathophysiological aspects and the therapeutic advances in inflammatory autoimmune diseases. PMID:26065006

  14. Bone-immune cell crosstalk: bone diseases.

    PubMed

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

    2015-01-01

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

  15. Cognitive Aspects of Prejudice

    ERIC Educational Resources Information Center

    Tajfel, Henri

    1969-01-01

    This paper is a slightly revised version of a contribution to a symposium on the "Biosocial Aspects of Race," held in London, September, 1968; symposium was published in the "Journal of Biosocial Science," Supplement No. 1, July, 1969. (RJ)

  16. Biochemical markers of bone turnover for the clinical assessment of metabolic bone disease.

    PubMed

    Delmas, P D

    1990-03-01

    , significant advances have been made in the last few years in the bone marker field. In the future, the development of a battery of several bone-specific markers that indicate various aspects of the complex mechanisms of bone formation, resorption, and mineralization is likely to provide new tools for the diagnosis and management of bone diseases.

  17. High Aspect Ratio Wrinkles

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Cheng; Crosby, Alfred

    2015-03-01

    Buckling-induced surface undulations are widely found in living creatures, for instance, gut villi and the surface of flower petal cells. These undulations provide unique functionalities with their extremely high aspect ratios. For the synthetic systems, sinusoidal wrinkles that are induced by buckling a thin film attached on a soft substrate have been proposed to many applications. However, the impact of the synthetic wrinkles have been restricted by limited aspect ratios, ranging from 0 to 0.35. Within this range, wrinkle aspect ratio is known to increase with increasing compressive strain until a critical strain is reached, at which point wrinkles transition to localizations, such as folds or period doublings. Inspired by the living creatures, we propose that wrinkles can be stabilized in high aspect ratio by manipulating the strain energy in the substrate. We experimentally demonstrate this idea by forming a secondary crosslinking network in the wrinkled surface and successfully achieve aspect ratio as large as 0.8. This work not only provides insights for the mechanism of high aspect ratio structures seen in living creatures, but also demonstrates significant promise for future wrinkle-based applications.

  18. Polyhydramnios and bone development: an unexplored relationship.

    PubMed

    Sekulić, S R; Ilić, D; Novakov-Mikić, A

    2010-09-01

    Immersion of a humans and Macaca mulatta into a pool with fluid whose specific weight is equal to their specific weight cause bone demineralization. Also, in professional scuba divers, bone mineral density is reduced. Because of water immersion, the apparent weight of scuba divers represents 10% of their actual weight. The aim of this paper was to point out a previously unexplored aspect of fetal bone development in an environment lacking adequate mechanical stress on fetal bone, such as polyhydramnios. In the first part of gestation, the human fetus develops under conditions similar to neutral floating and has an apparent weight which is approximately 5% of its actual weight. During the last trimester of gestation, the fetus overgrows the intrauterine cavity and its apparent body weight is 60-80% of its actual weight. Polyhydramnios represents an excess of amniotic fluid in the uterus during gestation and it can reduce the apparent weight of the fetus to 10-20% of its actual weight. Reduction of the mechanical stress on fetal bone caused by polyhydramnios may significantly affect bone development and ossification during the last trimester of gestation. It is necessary to direct further studies towards examining bone development and mineralization in newborns from gestations complicated by polyhydramnios. A complete lack of data and studies on fetal bone development and bone mineralization in pregnancies complicated by polyhydramnios is not surprising. There is still a misleading opinion that the fetus is in weightlessness condition in the intrauterine environment throughout the second half of gestation regardless of the amount of amniotic fluid.

  19. Bone age, social deprivation, and single parent families.

    PubMed Central

    Cole, T J; Cole, A J

    1992-01-01

    It is well known that deprivation affects bone growth. The study was set up to investigate what aspects of deprivation are of greatest importance. Bone ages of 1593 child trauma patients aged 0-19 years from Middlesbrough General Hospital, Cleveland, were related to local authority ward indices of socioeconomic status (51 wards). After adjustment for chronological age and sex, the mean bone ages in each ward were highly significantly negatively associated with five ward indices of deprivation: the rate of single parent families, low care ownership, unemployment, rented housing, and overcrowding. There was a mean four month deficit in bone age among children living in wards with the highest single parent family rates. The inverse association between deprivation and bone age is unlikely to be causal throughout childhood, as older and younger children were affected to the same extent. However the bone age deficit could be caused by deprivation retarding skeletal maturation during a critical period in early life. PMID:1444529

  20. Periosteal Distraction Osteogenesis: An Effective Method for Bone Regeneration

    PubMed Central

    Zhao, Danyang; Wang, Yu

    2016-01-01

    The treatment of bone defects is challenging and controversial. As a new technology, periosteal distraction osteogenesis (PDO) uses the osteogenicity of periosteum, which creates an artificial space between the bone surface and periosteum to generate new bone by gradually expanding the periosteum with no need for corticotomy. Using the newly formed bone of PDO to treat bone defects is effective, which can not only avoid the occurrence of immune-related complications, but also solve the problem of insufficient donor. This review elucidates the availability of PDO in the aspects of mechanisms, devices, strategies, and measures. Moreover, we also focus on the future prospects of PDO and hope that PDO will be applied to the clinical treatment of bone defects in the future. PMID:28078283

  1. Bone marrow culture

    MedlinePlus

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

  2. Bone fracture repair - slideshow

    MedlinePlus

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

  3. Smoking and Bone Health

    MedlinePlus

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

  4. [Hypertension, CKD and bone metabolism].

    PubMed

    Nakagami, Hironori; Morishita, Ryuichi

    2011-05-01

    The patients with "Hypertension" and "Chronic Kidney Disease (CKD) " are accompanied with an osteoporosis. In hypertension patients, excess urinary calcium secretion induces secondary parathyroidsim to increase serum calcium (Ca) level, which may lead to Ca release from bone. In this aspect, there are several reports that anti-hypertensive drugs, especially thiazides, increase bone mineral density and decrease the incidence of bone fracture. In addition, we demonstrated that renin-angiotensin system can be involved in the process of osteoporosis. Angiotensin II significantly induced the expression of RANKL (receptor activator of NF-κB ligand) in osteoblasts, leading to the activation of osteoclasts, while these effects were completely blocked by an Ang II type 1 receptor blockade. As for CKD, excess phosphorus (P) due to renal dysfunction induces secondary parathyroidism to decrease serum P level, which similarly leads to osteoporosis. Moreover, excess P can increase FGF23 expression and decrease activated vitamin D, which also resulted in progression of osteoporosis. Both "Hypertension" and "Chronic Kidney Disease (CKD) " are inducible factor to osteoporosis.

  5. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, J.W.

    1993-01-01

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

  6. Medicines and Bone Loss

    MedlinePlus

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

  7. Temporal bone meningiomas.

    PubMed

    Hooper, R; Siu, K; Cousins, V

    1990-10-01

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

  8. Surgical approach to bone healing in osteoporosis

    PubMed Central

    Pesce, Vito; Speciale, Domenico; Sammarco, Giulio; Patella, Silvio; Spinarelli, Antonio; Patella, Vittorio

    2009-01-01

    Osteoporotic fractures represent one of the most common cause of disability and one of the major voice in the health economic budget in many countries of the world. Fragility fractures are especially meta-epiphyseal fractures, in skeletal sites with particular biomechanic characteristic (hip, vertebrae), complex and with more fragments, with slow healing process (mineralization and remodeling) and co-morbidity. The healing of a fracture in osteoporotic bone passes through the normal stages and concludes with union of the fracture although the healing process is prolonged. Fractures in the elderly osteoporotic patients represent a challenge to the orthopaedic surgeons. Osteoporosis does not only increase the risk of fracture but also represents a problem in osteofixation of fractures in fracture treatment. The major technical problem that surgeons face, is the difficulty to obtain a stable fixation of an implant due to osteoporotic bone. The load transmitted at the bone-implant interface can often exceed the reduced strain tolerance of osteoporotic bone. In the treatment of osteoporotic fractures it is important to consider different aspects: general conditions of elderly patient and comorbidity, the reduced muscular and bone mass and the increased bone fragility, structural modifications as medullary expansion. The aim of surgical treatment is to obtain a stable fixation that reduces pain and permits an early mobilization. PMID:22461162

  9. Requirements Engineering and Aspects

    NASA Astrophysics Data System (ADS)

    Yu, Yijun; Niu, Nan; González-Baixauli, Bruno; Mylopoulos, John; Easterbrook, Steve; Do Prado Leite, Julio Cesar Sampaio

    A fundamental problem with requirements engineering (RE) is to validate that a design does satisfy stakeholder requirements. Some requirements can be fulfilled locally by designed modules, where others must be accommodated globally by multiple modules together. These global requirements often crosscut with other local requirements and as such lead to scattered concerns. We explore the possibility of borrowing concepts from aspect-oriented programming (AOP) to tackle these problems in early requirements. In order to validate the design against such early aspects, we propose a framework to trace them into coding and testing aspects. We demonstrate the approach using an open-source e-commerce platform. In the conclusion of this work, we reflect on the lessons learnt from the case study on how to fit RE and AOP research together.

  10. Organisational aspects of care.

    PubMed

    Bloomfield, Jacqueline; Pegram, Anne

    2015-03-04

    Organisational aspects of care, the second essential skills cluster, identifies the need for registered nurses to systematically assess, plan and provide holistic patient care in accordance with individual needs. Safeguarding, supporting and protecting adults and children in vulnerable situations; leading, co-ordinating and managing care; functioning as an effective and confident member of the multidisciplinary team; and managing risk while maintaining a safe environment for patients and colleagues, are vital aspects of this cluster. This article discusses the roles and responsibilities of the newly registered graduate nurse. Throughout their education, nursing students work towards attaining this knowledge and these skills in preparation for their future roles as nurses.

  11. Postnatal temporal bone ontogeny in Pan, Gorilla, and Homo, and the implications for temporal bone ontogeny in Australopithecus afarensis.

    PubMed

    Terhune, Claire E; Kimbel, William H; Lockwood, Charles A

    2013-08-01

    Assessments of temporal bone morphology have played an important role in taxonomic and phylogenetic evaluations of fossil taxa, and recent three-dimensional analyses of this region have supported the utility of the temporal bone for testing taxonomic and phylogenetic hypotheses. But while clinical analyses have examined aspects of temporal bone ontogeny in humans, the ontogeny of the temporal bone in non-human taxa is less well documented. This study examines ontogenetic allometry of the temporal bone in order to address several research questions related to the pattern and trajectory of temporal bone shape change during ontogeny in the African apes and humans. We further apply these data to a preliminary analysis of temporal bone ontogeny in Australopithecus afarensis. Three-dimensional landmarks were digitized on an ontogenetic series of specimens of Homo sapiens, Pan troglodytes, Pan paniscus, and Gorilla gorilla. Data were analyzed using geometric morphometric methods, and shape changes throughout ontogeny in relation to size were compared. Results of these analyses indicate that, despite broadly similar patterns, African apes and humans show marked differences in development of the mandibular fossa and tympanic portions of the temporal bone. These findings indicate divergent, rather than parallel, postnatal ontogenetic allometric trajectories for temporal bone shape in these taxa. The pattern of temporal bone shape change with size exhibited by A. afarensis showed some affinities to that of humans, but was most similar to extant African apes, particularly Gorilla.

  12. Method for fusing bone

    DOEpatents

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

    1996-01-01

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

  13. Sociological Aspects of Deafness.

    ERIC Educational Resources Information Center

    World Federation of the Deaf, Rome (Italy).

    Nine conference papers treat the sociological aspects of deafness. Included are "Individuals Being Deaf and Blind and Living with a Well Hearing Society" by A. Marx (German Federal Republic), "A Deaf Man's Experiences in a Hearing World" by A. B. Simon(U.S.A.), "Problem of Text Books and School Appliances for Vocational…

  14. Aspects of Marine Ecology.

    ERIC Educational Resources Information Center

    Awkerman, Gary L.

    This publication is designed for use in standard science curricula to develop oceanologic manifestations of certain science topics. Included are teacher guides, student activities, and demonstrations to impart ocean science understanding, specifically, aspects of marine ecology, to high school students. The course objectives include the ability of…

  15. Global aspects of monsoons

    NASA Technical Reports Server (NTRS)

    Murakami, T.

    1985-01-01

    Recent developments are studied in three areas of monsoon research: (1) global aspects of the monsoon onset, (2) the orographic influence of the Tibetan Plateau on the summer monsoon circulations, and (3) tropical 40 to 50 day oscillations. Reference was made only to those studies that are primarily based on FGGE Level IIIb data. A brief summary is given.

  16. Medical Aspects of Surfing.

    ERIC Educational Resources Information Center

    Renneker, Mark

    1987-01-01

    The medical aspects of surfing include ear and eye injuries and sprains and strains of the lower back and neck, as well as skin cancer from exposure to the sun. Treatment, rehabilitation, and prevention of these problems are discussed. Surfing is recommended as part of an exercise program for reasonably healthy people. (Author/MT)

  17. Bone regeneration in dentistry

    PubMed Central

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

    2011-01-01

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

  18. Nanomaterials and bone regeneration

    PubMed Central

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

    2015-01-01

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

  19. Bone scintiscanning updated.

    PubMed

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

    1976-03-01

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

  20. Calcium and bone disease

    PubMed Central

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

    2013-01-01

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

  1. Subduction modelling with ASPECT

    NASA Astrophysics Data System (ADS)

    Glerum, Anne; Thieulot, Cédric; Spakman, Wim; Quinquis, Matthieu; Buiter, Susanne

    2013-04-01

    ASPECT (Advanced Solver for Problems in Earth's ConvecTion) is a promising new code designed for modelling thermal convection in the mantle (Kronbichler et al. 2012). The code uses state-of-the-art numerical methods, such as high performance solvers and adaptive mesh refinement. It builds on tried-and-well-tested libraries and works with plug-ins allowing easy extension to fine-tune it to the user's specific needs. We make use of the promising features of ASPECT, especially Adaptive Mesh Refinement (AMR), for modelling lithosphere subduction in 2D and 3D geometries. The AMR allows for mesh refinement where needed and mesh coarsening in regions less important to the parameters under investigation. In the context of subduction, this amounts to having very small grid cells at material interfaces and larger cells in more uniform mantle regions. As lithosphere subduction modelling is not standard to ASPECT, we explore the necessary adaptive grid refinement and test ASPECT with widely accepted benchmarks. We showcase examples of mechanical and thermo-mechanical oceanic subduction in which we vary the number of materials making up the overriding and subducting plates as well as the rheology (from linear viscous to more complicated rheologies). Both 2D and 3D geometries are used, as ASPECT easily extends to three dimensions (Kronbichler et al. 2012). Based on these models, we discuss the advection of compositional fields coupled to material properties and the ability of AMR to trace the slab's path through the mantle. Kronbichler, M., T. Heister and W. Bangerth (2012), High Accuracy Mantle Convection Simulation through Modern Numerical Methods, Geophysical Journal International, 191, 12-29.

  2. Marble Bone Disease: A Rare Bone Disorder

    PubMed Central

    Harinathbabu, Maheswari; Thillaigovindan, Ranjani; Prabhu, Geetha

    2015-01-01

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

  3. Impact of Orthodontic Decompensation on Bone Insertion

    PubMed Central

    Guedes, Fabio Pinto; Capelozza Filho, Leopoldino; Garib, Daniela Gamba; Nary Filho, Hugo; Borgo, Evandro José; Cardoso, Mauricio de Almeida

    2014-01-01

    There has always been concern in determining the relationship between orthodontic tooth movement and the consequent biological costs to the periodontium and tooth root. The possibility of evaluating the tooth and bone morphology by CBCT allows more accurate analysis of qualitative and quantitative aspects of these processes. This paper presents a case report of a 20-year-old male patient with Class III malocclusion and hyperdivergent facial pattern, who was surgically treated. A significant amount of labial movement of mandibular incisors was performed during orthodontic treatment before surgery. CBCT was used for evaluation of buccal and lingual bone plates before and after tooth decompensation. The changes in the bone insertion level of maxillary and mandibular incisors in the present case encourage a reflection on the treatment protocol in individuals with dentoskeletal discrepancies. PMID:25436157

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

    PubMed

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

    2015-07-01

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

  5. Behavioural aspects of terrorism.

    PubMed

    Leistedt, Samuel J

    2013-05-10

    Behavioural and social sciences are useful in collecting and analysing intelligence data, understanding terrorism, and developing strategies to combat terrorism. This article aims to examine the psychopathological concepts of terrorism and discusses the developing roles for behavioural scientists. A systematic review was conducted of studies investigating behavioural aspects of terrorism. These studies were identified by a systematic search of databases, textbooks, and a supplementary manual search of references. Several fundamental concepts were identified that continue to influence the motives and the majority of the behaviours of those who support or engage in this kind of specific violence. Regardless of the psychological aspects and new roles for psychiatrists, the behavioural sciences will continue to be called upon to assist in developing better methods to gather and analyse intelligence, to understand terrorism, and perhaps to stem the radicalisation process.

  6. ROBOTIC SURGERY: BIOETHICAL ASPECTS

    PubMed Central

    SIQUEIRA-BATISTA, Rodrigo; SOUZA, Camila Ribeiro; MAIA, Polyana Mendes; SIQUEIRA, Sávio Lana

    2016-01-01

    ABSTRACT Introduction: The use of robots in surgery has been increasingly common today, allowing the emergence of numerous bioethical issues in this area. Objective: To present review of the ethical aspects of robot use in surgery. Method: Search in Pubmed, SciELO and Lilacs crossing the headings "bioethics", "surgery", "ethics", "laparoscopy" and "robotic". Results: Of the citations obtained, were selected 17 articles, which were used for the preparation of the article. It contains brief presentation on robotics, its inclusion in health and bioethical aspects, and the use of robots in surgery. Conclusion: Robotic surgery is a reality today in many hospitals, which makes essential bioethical reflection on the relationship between health professionals, automata and patients. PMID:28076489

  7. [Fibrous dysplasia of bone].

    PubMed

    Orcel, Philippe; Chapurlat, Roland

    2007-10-31

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

  8. Macrophage Efferocytosis and Prostate Cancer Bone Metastasis

    DTIC Science & Technology

    2015-10-01

    AWARD NUMBER: W81XWH-14-1-0408 TITLE: Macrophage Efferocytosis and Prostate Cancer Bone Metastasis PRINCIPAL INVESTIGATOR: Jacqueline D. Jones...average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed...and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of

  9. Gamma images in benign and metabolic bone diseases: volume 1

    SciTech Connect

    Sy, W.M.

    1981-01-01

    Volume 1 of ''Gamma images in benign and metabolic bone diseases'' comprises chapters devoted to: general remarks and considerations, radiopharmaceuticals, Paget disease, osteomyelitis, trauma, benign bone tumors, chronic renal dialysis, acute renal failure, osteomalacia and rickets, and osteoporosis. Although published in 1981, the most recent references in the book were 1978 and most are 1977 or earlier. One of the strongest aspects of the volume are tables which categorize diseases, pathophysiology of disease, and image abnormalities. (JMT)

  10. Aspects of B physics

    SciTech Connect

    Gaillard, M.K.

    1987-10-14

    Various aspects of weak decays are commented on. Probing of the standard model and of phenomena beyond the standard model are discussed, followed by a theoretical view of B mesons and some experimental observations on B mesons. The point is made that any data on B decay would be interesting in that it would provide powerful new constraints in analyses of the standard model and extensions thereof. (LEW)

  11. Assessment of Long Bone Flexural Properties from Bone Densitometry

    NASA Technical Reports Server (NTRS)

    Whalen, Robert; Cleek, Tammy; Katz, BethAnn

    1994-01-01

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

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

    PubMed

    Langman, Craig B

    2005-03-01

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

  13. Lead in bone: Implications for toxicology during pregnancy and lactation

    SciTech Connect

    Silbergeld, E.K. Univ. of Maryland, Baltimore )

    1991-02-01

    Advances in understanding the distribution and retention of lead in mineralized tissues are important for two reasons: first, bone lead may be a more accurate dosimeter of integrated absorption associated with chronic exposures, and second, bone lead may be a source of internal exposure to the host organism. Little attention has been paid to this second aspect, the remobilization of lead from bone. Mobilization of lead from bone is likely to occur during periods of altered mineral metabolism; since calciotropic factors determine the uptake and storage of lead in this compartment, changes in calcium-related regulatory factors are likely to affect lead compartmentation. Calcium metabolism changes drastically in humans during preganacy and lactation; although relatively little is known of lead kinetics during these critical periods, it is likely that bone lead is mobilized and transferred to the more bioavailable compartment of the maternal circulation, with potential toxic effects on the fetus and the mother.

  14. Biomaterials and bone mechanotransduction

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    Bone is an extremely complex tissue that provides many essential functions in the body. Bone tissue engineering holds great promise in providing strategies that will result in complete regeneration of bone and restoration of its function. Currently, such strategies include the transplantation of highly porous scaffolds seeded with cells. Prior to transplantation the seeded cells are cultured in vitro in order for the cells to proliferate, differentiate and generate extracellular matrix. Factors that can affect cellular function include the cell-biomaterial interaction, as well as the biochemical and the mechanical environment. To optimize culture conditions, good understanding of these parameters is necessary. The new developments in bone biology, bone cell mechanotransduction, and cell-surface interactions are reviewed here to demonstrate that bone mechanotransduction is strongly influenced by the biomaterial properties.

  15. Bone Surface Mapping Method

    PubMed Central

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

    2012-01-01

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

  16. Biophotonics and Bone Biology

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  17. Biomaterials and bone mechanotransduction.

    PubMed

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

    2001-10-01

    Bone is an extremely complex tissue that provides many essential functions in the body. Bone tissue engineering holds great promise in providing strategies that will result in complete regeneration of bone and restoration of its function. Currently, such strategies include the transplantation of highly porous scaffolds seeded with cells. Prior to transplantation the seeded cells are cultured in vitro in order for the cells to proliferate, differentiate and generate extracellular matrix. Factors that can affect cellular function include the cell-biomaterial interaction, as well as the biochemical and the mechanical environment. To optimize culture conditions, good understanding of these parameters is necessary. The new developments in bone biology, bone cell mechanotransduction, and cell-surface interactions are reviewed here to demonstrate that bone mechanotransduction is strongly influenced by the biomaterial properties.

  18. Sensitivity of bone cell populations to weightlessness and simulated weightlessness

    NASA Technical Reports Server (NTRS)

    Roberts, W. E.; Morey-Holton, E. R.; Gonsalves, M. R.

    1984-01-01

    A rat suspension model for simulating certain aspects of weightlessness is discussed. Perturbations in physiological systems induced by this head down suspension model are verified by flight data. Findings of a suppression of osteoblast differentiation help explain the inhibition of bone formation inflight and during Earth-bound simulations. Since the anatomical site for these studies was in the maxilla, which is gravity loaded but non weightbearing in ground-based simulations, the similarity of bone cell kinetic changes, both inflight and in the ground-based model, suggest that fluid shifts rather than unloading may play an important role in bone alterations, at least at this sampling site.

  19. Electromagnetic fields in bone repair and adaptation

    NASA Astrophysics Data System (ADS)

    McLeod, Kenneth J.; Rubin, Clinton T.; Donahue, Henry J.

    1995-01-01

    The treatment of delayed union of bone fractures has served for the past 20 years as the principal testing ground for determining whether nonionizing electromagnetic fields can have any substantial, long-term effects in clinical medicine. Recent double-blinded clinical trials have confirmed the significance of the reported effects on bone healing and have led to the suggestion that electromagnetic fields may also be useful in the treatment of other orthopedic problems such as fresh fractures, stabilization of prosthetic implants, or even the prevention or treatment of osteoporosis. However, the design of appropriate treatment regimens for these new applications would be greatly facilitated if it were understood how the biological cells within bone tissue sense these low-frequency, and remarkably low level, electromagnetic fields. Here we address the engineering and physical science aspects of this problem. We review the characteristics of clinically used electromagnetic fields and discuss which components of these fields may actually be responsible for altering the activity of the bone cells. We then consider several physical mechanisms which have been proposed to explain how the cells within the bone or fracture tissue detect this field component.

  20. Adrenal gland and bone.

    PubMed

    Hardy, Rowan; Cooper, Mark S

    2010-11-01

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

  1. Nanocomposites and bone regeneration

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  2. Bone scanning in otolaryngology.

    PubMed

    Noyek, A M

    1979-09-01

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

  3. Radionuclide bone imaging and densitometry

    SciTech Connect

    Mettler, F.A.

    1988-01-01

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

  4. Bone scanning in clinical practice

    SciTech Connect

    Fogelman, I. )

    1987-01-01

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

  5. Aging and Bone

    PubMed Central

    Boskey, A.L.; Coleman, R.

    2010-01-01

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

  6. Biophotonics and Bone Biology

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  7. Autoinflammatory bone diseases.

    PubMed

    Stern, Sara M; Ferguson, Polly J

    2013-11-01

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

  8. Hypercalciuric Bone Disease

    NASA Astrophysics Data System (ADS)

    Favus, Murray J.

    2008-09-01

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

  9. Method for fusing bone

    DOEpatents

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

    1996-03-12

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

  10. Bone fractal analysis.

    PubMed

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

    2004-06-01

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

  11. Cellular and molecular toxicity of lead in bone

    SciTech Connect

    Pounds, J.G. ); Long, G.J.; Rosen, J.F. )

    1991-02-01

    To fully understand the significance of bone as a target tissue of lead toxicity, as well as a reservoir of systemic lead, it is necessary to define the effects of lead on the cellular components of bone. Skeletal development and the regulation of skeletal mass are ultimately determined by the four different types of cells: osteoblasts, lining cells, osteoclasts, and osteocytes. These cells, which line and penetrate the mineralized matrix, are responsible for matrix formation, mineralization, and bone resorption, under the control of both systemic and local factors. Systemic components of regulation include parathyroid hormone, 1,25-dihydroxyvitamin D{sub 3}, and calcitonin; local regulators include numerous cytokines and growth factors. Lead intoxication directly alters many aspects of bone cell function. First, lead may indirectly alter bone cell function through changes in the circulating levels of those hormones, particularly 1,25-dihydroxyvitamin D{sub 3}, which modulate bone cell function. Second, lead may directly alter bone cell function by perturbing the ability of bone cells to respond to hormonal regulation. Third, lead may impair the ability of cells to synthesize or secrete other components of the bone matrix, such as collagen or bone sialoproteins (osteopontin). Finally, lead may directly effect of substitute for calcium in the active sites of the calcium messenger system. The effects of lead on the recruitment and differentiation of bone cells remains to be established. Many of the toxic effects of lead on bone cell function may be produced by perturbation of the calcium and cAMP messenger systems in these cells.

  12. Cellular and morphological aspects of fibrodysplasia ossificans progressiva

    PubMed Central

    Martelli, Anderson; Santos, Arnaldo Rodrigues

    2014-01-01

    Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disease that causes bone formation within the muscles, tendons, ligaments and connective tissues. There is no cure for this disorder and only treatment of the symptoms is available. The purpose of this study was to review the literature and describe the clinical, cellular and molecular aspects of FOP. The material used for the study was obtained by reviewing scientific articles published in various literature-indexed databases. In view of its rarity and of the lack of insightful information and the unpredictability of its course, FOP is a challenging disorder for professionals who are confronted by it. However, this rare disease raises a great deal of interest because understanding the mechanism of mature bone formation can encourage research lines related to bone regeneration and the prevention of heterotopic ossification. PMID:25482313

  13. Chiral models: Geometrical aspects

    NASA Astrophysics Data System (ADS)

    Perelomov, A. M.

    1987-02-01

    Two-dimensional classical chiral models of field theory are considered, the main attention being paid on geometrical aspects of such theories. A characteristic feature of these models is that the interaction is inserted not by adding the interaction Lagrangian to the free field Lagrangian, but has a purely geometrical origin and is related to the inner curvature of the manifold. These models are in many respects analogous to non-Abelian gauge theories and as became clear recently, they are also important for the superstring theory which nowadays is the most probable candidate for a truly unified theory of all interactions including gravitation.

  14. The Rare Bone Disease Working Group: report from the 2016 American Society for Bone and Mineral Research Annual Meeting.

    PubMed

    Drake, Matthew T; Collins, Michael T; Hsiao, Edward C

    2017-01-20

    A working group on rare bone diseases was held in Atlanta, Georgia as part of the 2016 annual meeting of the American Society for Bone and Mineral Research. The meeting was organized by Matthew Drake. Given recent advances in our understanding of fibrodysplasia ossificans progressiva (FOP), the initial portion of the program was devoted to basic, translational, and clinical aspects of FOP. The remainder of the program was divided into updates on an array of rare bone diseases as detailed below. In total, there were more than 120 scientists from academia and industry in attendance.

  15. Aspects of Gond astronomy

    NASA Astrophysics Data System (ADS)

    Vahia, M. N.; Halkare, Ganesh

    2013-03-01

    The Gond community is considered to be one of the most ancient tribes of India with a continuing history of several thousand years. They are also known for their largely isolated history which they have retained through the millennia. Several of their intellectual traditions therefore are a record of parallel aspects of human intellectual growth, and still preserve their original flavour and have not been homogenised by the later traditions of India. In view of this, the Gonds provide a special window to the different currents that constitute contemporary India. In the present study, we summarise their mythology, genetics and script. We then investigate their astronomical traditions and try to understand this community through a survey of 15 Gond villages spread over Maharashtra, Andhra Pradesh and Madhya Pradesh. We show that they have a distinctly different view of the sky from the conventional astronomical ideas encountered elsewhere in India, which is both interesting and informative. We briefly comment on other aspects of their life as culled from our encounters with different members of the Gond community.

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

    PubMed

    Benic, Goran I; Hämmerle, Christoph H F

    2014-10-01

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

  17. Exercise, lifestyle, and your bones

    MedlinePlus

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

  18. Children's Bone Health and Calcium

    MedlinePlus

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

  19. Exercise for Your Bone Health

    MedlinePlus

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

  20. Biodegradable synthetic bone composites

    SciTech Connect

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

    2013-01-01

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

  1. Automated trabecular bone histomorphometry

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

  2. BONES, TEACHER'S GUIDE.

    ERIC Educational Resources Information Center

    Elementary Science Study, Newton, MA.

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

  3. Osteocyte and bone structure.

    PubMed

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

    2003-06-01

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

  4. [Metabolic bone diseases].

    PubMed

    Jakob, F

    2007-10-01

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

  5. Bone and Celiac Disease.

    PubMed

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

    2016-04-01

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

  6. Ultrasonic bone densitometer

    NASA Technical Reports Server (NTRS)

    Hoop, J. M. (Inventor)

    1974-01-01

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

  7. Aspects, Wrappers and Events

    NASA Technical Reports Server (NTRS)

    Filman, Robert E.

    2003-01-01

    This viewgraph presentation provides information on Object Infrastructure Framework (OIF), an Aspect-Oriented Programming (AOP) system. The presentation begins with an introduction to the difficulties and requirements of distributed computing, including functional and non-functional requirements (ilities). The architecture of Distributed Object Technology includes stubs, proxies for implementation objects, and skeletons, proxies for client applications. The key OIF ideas (injecting behavior, annotated communications, thread contexts, and pragma) are discussed. OIF is an AOP mechanism; AOP is centered on: 1) Separate expression of crosscutting concerns; 2) Mechanisms to weave the separate expressions into a unified system. AOP is software engineering technology for separately expressing systematic properties while nevertheless producing running systems that embody these properties.

  8. Sprirtual aspects of psychotherapy.

    PubMed

    Prasinos, S

    1992-03-01

    This article addresses the relevance of spirituality to psychology and psychotherapy. It argues that spiritual experience is phenomenologically legitimate and worthy of study, especially by students of mental health. It utilizes Fox's (1985) definition of spirituality as "unitive experience" to show that spiritual experience is often present, overtly or covertly, within the ritual of psychotherapy. The paper argues that the therapist's adoption of an empathic posture is essentially a spiritual position. This position consists of a sense of peace, eternity, forgiveness, faith, love, truth, and God. These aspects are part of an integrated spiritual gestalt which is, though generally unacknowledged, fundamental to the communal healing process of psychotherapy. The paper concludes by asserting that greater involvement with the unitive (as opposed to the disunitive) represents a positive paradigmatic shift for psychology and humanity.

  9. Historical aspects of anxiety

    PubMed Central

    Klein, Donald F.

    2002-01-01

    “Anxiety” is a key term for behavioral, psychoanalytic, neuroendocrine, and psychopharmacological observations and theories. Commenting on its historical aspects is difficult, since history is properly a study of primary data. Unfortunately, much clinical anecdote does not correspond to factual records of a long time ago. Even reports of objective studies may suffer from allegiance effects. This essay therefore primarily reflects the personal impact of others' work against the background of my experiences, clinical and scientific. These lead me to question the assumption that “anxiety”, as it exists in syndromal disturbances, is simply the quantitative extreme of the normal “anxiety” that occurs during the anticipation of danger. An alternative view that emphasizes dysfunctions of distinct evolved adaptive alarm systems is presented. PMID:22033777

  10. Aspects of Plant Intelligence

    PubMed Central

    TREWAVAS, ANTHONY

    2003-01-01

    Intelligence is not a term commonly used when plants are discussed. However, I believe that this is an omission based not on a true assessment of the ability of plants to compute complex aspects of their environment, but solely a reflection of a sessile lifestyle. This article, which is admittedly controversial, attempts to raise many issues that surround this area. To commence use of the term intelligence with regard to plant behaviour will lead to a better understanding of the complexity of plant signal transduction and the discrimination and sensitivity with which plants construct images of their environment, and raises critical questions concerning how plants compute responses at the whole‐plant level. Approaches to investigating learning and memory in plants will also be considered. PMID:12740212

  11. Pharmacotherapeutic Aspects of Space Medicine

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi

    2004-01-01

    Medications are used for a wide variety of indications during space flight. For example, astronauts have taken drugs in flight to ameliorate or prevent symptoms of space motion sickness, headache, sleeplessness, backache, nasal congestion, and constipation. Russian cosmonauts reportedly take medications to prevent metabolic disturbances of the myocardium and intestinal flora, and to optimize their work capacity. Although the discomfort associated with some acute responses to microgravity (e.g., space motion sickness) is expected to diminish with length of time in flight, other responses that have delayed onset (e.g., maintaining nutritional status, bone and muscle strength, and perhaps immune response) may affect health and quality of life during longer missions. Therefore, as the duration of space flights increases, the need for treatment with medications is expected to increase accordingly. Medications carried on Space Shuttle missions have varied somewhat from flight to flight, depending on the individual needs of the crewmembers. Medications use during Shuttle flights seems to be more prevalent than during earlier programs, perhaps because drugs are provided in easy-to-use forms. In fact, nearly all medications taken to date have been ingested orally in tablet form. However, given that the oral route may not be ideal for those suffering motion-sickness symptoms, intramuscular and intranasal preparations are being tested. For example, intramuscular administration of promethazine hydrochloride (Phenergan(Registered TradeMark)) has been reported to be more effective in alleviating motion-sickness symptoms. The difficulties involved in conducting definitive studies of drug efficacy during U.S. space flights have been compounded by the absence of a systematic approach to determining which drugs were taken by whom and under what circumstances. The use of some drugs in space has been less efficacious than expected. The onset, intensity, and duration of the response

  12. Juxtaphyseal aneurysmal bone cysts.

    PubMed

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

    1999-07-01

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

  13. [Bone hydatid cyst: a rare localization at the level of the hip bone].

    PubMed

    Nhamoucha, Yassine; Alaoui, Othmane; Doumbia, Aliou; Oukhoya, Mohammed; Abdellaoui, Hicham; Tazi, Mohammed; Chater, Lamyae; Atarraf, Karima; Arroud, Mounir; Afifi, Abderahman

    2016-01-01

    Hydatid disease is a parasitic disease caused by the development in humans of the larval form of a tapeworm, namely a very small tænia called Echinococcus Granulosus. This anthropozoonosis is characterized by the presence of different types of anatomo-radiologic variants associated with various topographic and evolutionary aspects of the cysts. Bone hydatid disease is a rare condition, it accounts for only 0.9-2.5% of all locations. We report the case of a 9 year old child, who was admitted with febrile lameness and with a mass in the right iliac fossa, revealing a hydatid cyst at the level of the hip bone. Lesion assessment objectified a hydatid cyst of the hip bone with extension into adjacent soft tissues. An infected cyst was detected during surgery, hence the performance of a surgical excision of the cyst with drainage. Hydatic osteopathy is infiltrating, diffuse, slow and gradual, causing delays in diagnosis and compromising the quality of care.

  14. Environmental aspects of wastewater reclamation.

    PubMed

    Sharma, Sunil; Choudhary, Mahendra Pratap

    2007-07-01

    The population is increasing rapidly and the demand for water by cities, industries and agriculture has tended to grow even faster than the population. Wastewater reclamation consists of a combination of conventional and advanced treatment processes employed to return a wastewater to nearly original quality, reclaiming the water. The environmental health aspects associated with reclamation of wastewater include quality aspects and public health aspects. An attempt has been made in the present paper to describe these aspects and to suggest appropriate solutions.

  15. Epidemiological aspects of ageing.

    PubMed

    Khaw, K T

    1997-12-29

    A major societal challenge is to improve quality of life and prevent or reduce disability and dependency in an ageing population. Increasing age is associated with increasing risk of disability and loss of independence, due to functional impairments such as loss of mobility, hearing and vision; a major issue must be how far disability can be prevented. Ageing is associated with loss of bone tissue, reduction in muscle mass, reduced respiratory function, decline in cognitive function, rise in blood pressure and macular degeneration which predispose to disabling conditions such as osteoporosis, heart disease, dementia and blindness. However, there are considerable variations in different communities in terms of the rate of age-related decline. Large geographic and secular variations in the age-adjusted incidence of major chronic diseases such as stroke, hip fracture, coronary heart disease, cancer, visual loss from cataract, glaucoma and macular degeneration suggest strong environmental determinants in diet, physical activity and smoking habit. The evidence suggests that a substantial proportion of chronic disabling conditions associated with ageing are preventable, or at least postponable and not an inevitable accompaniment of growing old. Postponement or prevention of these conditions may not only increase longevity, but, more importantly, reduce the period of illnesses such that the majority of older persons may live high-quality lives, free of disability, until very shortly before death. We need to understand better the factors influencing the onset of age-related disability in the population, so that we have appropriate strategies to maintain optimal health in an ageing population.

  16. Bone Blood Flow During Simulated Microgravity: Physiological and Molecular Mechanisms

    NASA Technical Reports Server (NTRS)

    Bloomfield, Susan A.

    1999-01-01

    determined by 3-point bending (tibia, humerus) or compression (femoral neck) testing to failure. A unique aspect of these studies will be defining the time course of changes in gene expression in bone cell populations with unloading, accomplished with Northern blots, in situ hybridization, and immunohistochemistry. These studies have high relevance for concurrent protocols being proposed by investigators on NSBRI Cardiovascular and Muscle teams, with blood flow data available on a number of tissues other than bone. Further, dobutamine and other Beta-agonists have been tested as countermeasures for altered muscle and cardiovascular function. Results of the intervention tested in our studies have potential relevance for a number of systemic changes seen with prolonged spaceflight.

  17. Cell-to-cell communication in guided bone regeneration: molecular and cellular mechanisms.

    PubMed

    Gruber, Reinhard; Stadlinger, Bernd; Terheyden, Hendrik

    2016-08-23

    This overview provides insights into the molecular and cellular mechanisms involved in guided bone regeneration, in particular focusing on aspects presented in the 3D movie, Cell-To-Cell Communication in Guided Bone Regeneration. The information presented here is based almost exclusively on genetic mouse models in which single genes can be deleted or overexpressed, even in a specific cell type. This information needs to be extrapolated to humans and related to aspects relevant to graft consolidation under the clinical parameters of guided bone regeneration. The overview follows the ground tenor of the Cell-To-Cell Communication series and focuses on aspects of cell-to-cell communication in bone regeneration and guided bone regeneration. Here, we discuss (1) the role of inflammation during bone regeneration, including (2) the importance of the fibrin matrix, and (3) the pleiotropic functions of macrophages. We highlight (4) the origin of bone-forming osteoblasts and bone-resorbing osteoclasts as well as (5) what causes a progenitor cell to mature into an effector cell. (6) We touch on the complex bone adaptation and maintenance after graft consolidation and (7) how osteocytes control this process. Finally, we speculate on (8) how barrier membranes and the augmentation material can modulate graft consolidation.

  18. What Happens After Treatment for Bone Cancer?

    MedlinePlus

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

  19. Distinguishing between the bone fragments of medium-sized mammals and children. A histological identification method for archaeology.

    PubMed

    Cuijpers, Saddha A G F M

    2009-06-01

    In archaeology, it is not always possible to identify bone fragments. A novel approach was chosen to assess the potential of histology as an identification tool. Instead of studying a few bones of different categories from many species, this study concentrated on the diaphyses of long bones in four species of comparable size which are relevant to archaeology; young humans, pigs, sheep and goats, to broaden the insight into variations in diaphyseal bone structure within and between these species. A general difference in the primary bone structure was found between children older than one year and the three medium-sized mammals, namely lamellar vs. fibro-lamellar primary bone. Although, the diaphyseal bone structure of children below the age of one year also showed (developing) fibro-lamellar bone, its composition was distinctive from the medium-sized mammals. A difference in the secondary bone structure was also observed. Connecting (Volkmann's) canals, giving the secondary bone a reticular aspect, were seen in the medium-sized mammals but not in the young human long bones. To confirm the validity and applicability of these observed histological differences, a blind test was conducted on 14 diaphyseal fragments of identified long bones from archaeological sites. The results were very promising. All the bone fragments were correctly attributed using the difference in primary bone structure, even when the bone was severely degraded.

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

    SciTech Connect

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

    1984-01-01

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

  1. SILICON AND BONE HEALTH

    PubMed Central

    JUGDAOHSINGH, R.

    2009-01-01

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

  2. Silicon and bone health.

    PubMed

    Jugdaohsingh, R

    2007-01-01

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

  3. Osterix/Sp7 limits cranial bone initiation sites and is required for formation of sutures.

    PubMed

    Kague, Erika; Roy, Paula; Asselin, Garrett; Hu, Gui; Simonet, Jacqueline; Stanley, Alexandra; Albertson, Craig; Fisher, Shannon

    2016-05-15

    During growth, individual skull bones overlap at sutures, where osteoblast differentiation and bone deposition occur. Mutations causing skull malformations have revealed some required genes, but many aspects of suture regulation remain poorly understood. We describe a zebrafish mutation in osterix/sp7, which causes a generalized delay in osteoblast maturation. While most of the skeleton is patterned normally, mutants have specific defects in the anterior skull and upper jaw, and the top of the skull comprises a random mosaic of bones derived from individual initiation sites. Osteoblasts at the edges of the bones are highly proliferative and fail to differentiate, consistent with global changes in gene expression. We propose that signals from the bone itself are required for orderly recruitment of precursor cells and growth along the edges. The delay in bone maturation caused by loss of Sp7 leads to unregulated bone formation, revealing a new mechanism for patterning the skull and sutures.

  4. Growth and bone development.

    PubMed

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

    2008-01-01

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

  5. Gastric cancer: basic aspects.

    PubMed

    Resende, Carlos; Thiel, Alexandra; Machado, José C; Ristimäki, Ari

    2011-09-01

    Gastric cancer (GC) is a world health burden, ranging as the second cause of cancer death worldwide. Etiologically, GC arises not only from the combined effects of environmental factors and susceptible genetic variants but also from the accumulation of genetic and epigenetic alterations. In the last years, molecular oncobiology studies brought to light a number of genes that are implicated in gastric carcinogenesis. This review is intended to focus on the recently described basic aspects that play key roles in the process of gastric carcinogenesis. Genetic variants of the genes IL-10, IL-17, MUC1, MUC6, DNMT3B, SMAD4, and SERPINE1 have been reported to modify the risk of developing GC. Several genes have been newly associated with gastric carcinogenesis, both through oncogenic activation (GSK3β, CD133, DSC2, P-Cadherin, CDH17, CD168, CD44, metalloproteinases MMP7 and MMP11, and a subset of miRNAs) and through tumor suppressor gene inactivation mechanisms (TFF1, PDX1, BCL2L10, XRCC, psiTPTE-HERV, HAI-2, GRIK2, and RUNX3). It also addressed the role of the inflammatory mediator cyclooxygenase-2 (COX-2) in the process of gastric carcinogenesis and its importance as a potential molecular target for therapy.

  6. Immunological aspects of atherosclerosis.

    PubMed

    Woollard, Kevin J

    2013-09-01

    Cardiovascular disease is the leading cause of death in several countries. The underlying process is atherosclerosis, a slowly progressing chronic disorder that can lead to intravascular thrombosis. There is overwhelming evidence for the underlying importance of our immune system in atherosclerosis. Monocytes, which comprise part of the innate immune system, can be recruited to inflamed endothelium and this recruitment has been shown to be proportional to the extent of atherosclerotic disease. Monocytes undergo migration into the vasculature, they differentiate into macrophage phenotypes, which are highly phagocytic and can scavenge modified lipids, leading to foam cell formation and development of the lipid-rich atheroma core. This increased influx leads to a highly inflammatory environment and along with other immune cells can increase the risk in the development of the unstable atherosclerotic plaque phenotype. The present review provides an overview and description of the immunological aspect of innate and adaptive immune cell subsets in atherosclerosis, by defining their interaction with the vascular environment, modified lipids and other cellular exchanges. There is a particular focus on monocytes and macrophages, but shorter descriptions of dendritic cells, lymphocyte populations, neutrophils, mast cells and platelets are also included.

  7. Strategic Aspects of Communication

    NASA Astrophysics Data System (ADS)

    Hagen, Edward; Hammerstein, Peter; Hess, Nicole

    Rarely do human behavioral scientists and scholars study language, music, and other forms of communication as strategies—a means to some end. Some even deny that communication is the primary function of these phenomena. Here we draw upon selections of our earlier work to briefly define the strategy concept and sketch how decision theory, developed to explain the behavior of rational actors, is applied to evolved agents. Communication can then be interpreted as a strategy that advances the "fitness interests" of such agents. When this perspective is applied to agents with conflicts of interest, deception emerges as an important aspect of communication. We briefly review costly signaling, one solution to the problem of honest communication among agents with conflicts of interest. We also explore the subversion of cooperative signals by parasites and by plants defending themselves against herbivores, and we touch on biases in human gossip. Experiments with artificial embodied and communicating agents confirm that when there are conflicts of interest among agents, deception readily evolves. Finally, we consider signaling among super-organisms and the possible implications for understanding human music and language.

  8. Aspects of cosmological relativity.

    NASA Astrophysics Data System (ADS)

    Carmeli, M.

    1999-07-01

    The author reviews cosmological relativity, a new special theory of relativity that was recently developed for cosmology, and discusses in detail some of its aspects. He recalls that in this theory it is assumed that gravitation is negligible. Under this assumption, the receding velocities of galaxies and the distances between them in the Hubble expansion are united into a four-dimensional pseudo-Euclidean manifold, similarly to space and time in ordinary special relativity. The Hubble law is assumed and is written in an invariant way that enables one to derive a four-dimensional transformation which is similar to the Lorentz transformation. The parameter in the new transformation is the ratio between the cosmic time to the Hubble time. Accordingly, the new transformation relates physical quantities at different cosmic times in the limit of weak or negligible gravitation. The transformation is then applied to the problem of the expansion of the universe at the very early stage when gravity was negligible and thus the transformation is applicable. New applications of the theory are presented. The author shows that there is no need to assume the existence of galaxy dark matter; the Tully-Fisher law is derived from the theory. A completely new picture of the expanding universe is thus obtained and compared to the FRW one.

  9. Cultural aspects of suicide.

    PubMed

    Maharajh, Hari D; Abdool, Petal S

    2005-09-08

    Undefined cultural factors cannot be dismissed and significantly contribute to the worldwide incidence of death by suicide. Culture is an all embracing term and defines the relationship of an individual to his environment. This study seeks to investigate the effect of culture on suicide both regionally and internationally. Culture-bound syndrome with suicidal behaviours specific to a particular culture or geographical region are discussed. Opinions are divided as to the status of religious martyrs. The law itself is silent on many aspects of suicidal behaviour and despite decriminalization of suicide as self-murder, the latter remains on the statutes of many developing countries. The Caribbean region is of concern due to its steady rise in mean suicide rate, especially in Trinidad and Tobago where socio-cultural factors are instrumental in influencing suicidal behaviour. These include transgenerational cultural conflicts, psycho-social problems, media exposure, unemployment, social distress, religion and family structure. The methods used are attributed to accessibility and lethality. Ingestion of poisonous substances is most popular followed by hanging. The gender differences seen with regard to suicidality can also be attributed to gender related psychopathology and psychosocial differences in help-seeking behaviour. These are influenced by the cultural environment to which the individual is exposed. Culture provides coping strategies to individuals; as civilization advances many of these coping mechanisms are lost unclothing the genetic predisposition of vulnerable groups. In the management of suicidal behaviour, a system of therapeutic re-culturation is needed with an emphasis on relevant culture- based therapies.

  10. Electrical aspects of rainout

    SciTech Connect

    Rosenkilde, C.E.

    1981-11-23

    Rainout commonly denotes the aggregate of phenomena associated with precipitation scavenging of radioactivity from a cloud of nuclear debris that is within a natural rain cloud. (In contrast, the term, washout, is applicable when the nuclear cloud is below the rain cloud and the term, fallout, commonly denotes the direct gravitational settling of contaminated solid material from a nuclear cloud.) Nuclear debris aerosols may be scavenged within natural clouds by a variety of different physical processes which may involve diffusion, convection, impaction, nucleation, phoresis, turbulence, and/or electricity among others. Processes which involve electrical aspects are scrutinized for their susceptibility to the intimate presence of the radioactive-cloud environment. This particular choice of electrical processes is not accidental. Nearly all of the listed processes were examined earlier by Williams. His rough estimates suggested that electrical effects, and to a lesser extent turbulence, could enhance the scavenging of those submicron aerosols which reside in the size-range that bridges the minimum in the scavenging rate coefficient which is commonly called the Greenfield gap. This minimum in the scavenging-rate coefficient is created by the simultaneous reduction of scavenging via diffusion and the reduction of scavenging via inertial impaction. However, Williams omitted the specific influence of a radioactive environment. This report aims to remedy this omission.

  11. Craniofacial bone tissue engineering.

    PubMed

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

    2006-04-01

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

  12. Bone graft substitutes.

    PubMed

    Bhatt, Reena A; Rozental, Tamara D

    2012-11-01

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

  13. Paget Disease of Bone.

    PubMed

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

    2015-10-01

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

  14. Some microbiological aspects of inedible rendering processes.

    PubMed

    Hansen, P I; Olgaard, K

    1984-12-01

    Various aspects of the bacteriology of inedible rendering have been investigated in order to establish a solid basis for future decisions concerning an up-to-date and flexible legislation on rendering. Thermal death (TD)-graphs for spores of B. cereus and Cl. perfrigens, PA 3679 (Fig. 3), and heat transmission equations for animal tissues have been determined. By using the heat transmission data for bones and the TD graphs for the spores it is possible to predict the decimal reductions of spores in the centre of the largest pieces present during a given rendering process, thus establishing conditions for bacteriological safe processes. The calculations show that predrying for 45 min followed by cooking at 125 degrees C for 15 min and final drying ensures destruction of non-sporeforming bacteria and Bacillus anthracis spores even in the centre of 70 mm bone particles while heat resistant spores of clostridia are virtually unaffected. By reducing the particle size to less than 40 mm, the same process will result in a reasonable reduction of heat resistant clostridia spores, too (Table 4). In order to verify such theoretically calculated effects a new technique has been developed in which steel tubes containing a paste inoculated with spores were inserted in bones. These were treated in a cooker, were caught during discharge and examined. The results confirmed the calculations (Table 5). Most modern rendering systems (Carver-Greenfield, Stork-Duke, Wet Pressing) are continuous without pressure cooking and a common feature is a fine mincing minimizing the problem of heat penetration. In order to obtain information regarding the thermal sterilizing effect in such systems investigations were made in a pilot cooker using inoculated meat-and-bone meal mixed with water and/or fat. Regardless of whether fat was added or not sterility was found for samples containing water when the temperature during drying reached 110-120 degrees C, whereas cooking in fat only drastically

  15. Multidisciplinary characterization of the long-bone cortex growth patterns through sheep's ontogeny.

    PubMed

    Cambra-Moo, Oscar; Nacarino-Meneses, Carmen; Díaz-Güemes, Idoia; Enciso, Silvia; García Gil, Orosia; Llorente Rodríguez, Laura; Rodríguez Barbero, Miguel Ángel; de Aza, Antonio H; González Martín, Armando

    2015-07-01

    Bone researches have studied extant and extinct taxa extensively trying to disclose a complete view of the complex structural and chemical transformations that model and remodel the macro and microstructure of bone during growth. However, to approach bone growth variations is not an easy task, and many aspects related with histological transformations during ontogeny remain unresolved. In the present study, we conduct a holistic approach using different techniques (polarized microscopy, Raman spectroscopy and X-ray diffraction) to examine the histomorphological and histochemical variations in the cortical bone of sheep specimens from intrauterine to adult stages, using environmentally controlled specimens from the same species. Our results suggest that during sheep bone development, the most important morphological (shape and size) and chemical transformations in the cortical bone occur during the first weeks of life; synchronized but dissimilar variations are established in the forelimb and hind limb cortical bone; and the patterns of bone tissue maturation in both extremities are differentiated in the adult stage. All of these results indicate that standardized histological models are useful not only for evaluating many aspects of normal bone growth but also to understand other important influences on the bones, such as pathologies that remain unknown.

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  17. Bone Grafts in Craniofacial Surgery

    PubMed Central

    Elsalanty, Mohammed E.; Genecov, David G.

    2009-01-01

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

  18. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

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

  19. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

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

  20. Paget disease of the bone

    MedlinePlus

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

  1. Instrumentation for bone density measurement

    NASA Technical Reports Server (NTRS)

    Meharg, L. S.

    1968-01-01

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

  2. Bone Cancer: Questions and Answers

    MedlinePlus

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

  3. What Is Bone Cancer?

    MedlinePlus

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

  4. Healthy Bones Matter

    MedlinePlus

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

  5. Bone marrow biopsy

    MedlinePlus

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

  6. Bone mineral density test

    MedlinePlus

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

  7. Bone pain or tenderness

    MedlinePlus

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

  8. Bone Densitometry in Children.

    PubMed

    Adams, Judith E

    2016-07-01

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

  9. Bone Loss in IBD

    MedlinePlus

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

  10. Alcohol and bone.

    PubMed

    Mikosch, Peter

    2014-01-01

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

  11. Bone x-ray

    MedlinePlus

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

  12. Bone Loss in IBD

    MedlinePlus

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

  13. Children with Brittle Bones.

    ERIC Educational Resources Information Center

    Alston, Jean

    1982-01-01

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

  14. What causes bone loss?

    MedlinePlus

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

  15. What Is Bone?

    MedlinePlus

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

  16. Reduction of bone strength

    NASA Technical Reports Server (NTRS)

    Bingham, Cindy

    1990-01-01

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

  17. Small Animal Bone Biomechanics

    PubMed Central

    Vashishth, Deepak

    2008-01-01

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

  18. [Incretin and bone].

    PubMed

    Yamada, Yuichiro

    2009-09-01

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

  19. Bone morphogenetic protein

    SciTech Connect

    Xiao Yongtao; Xiang Lixin; Shao Jianzhong

    2007-10-26

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

  20. Genetic Regulation of Bone Metabolism in the Chicken: Similarities and Differences to Mammalian Systems

    PubMed Central

    Johnsson, Martin; Jonsson, Kenneth B.; Andersson, Leif; Jensen, Per; Wright, Dominic

    2015-01-01

    Birds have a unique bone physiology, due to the demands placed on them through egg production. In particular their medullary bone serves as a source of calcium for eggshell production during lay and undergoes continuous and rapid remodelling. We take advantage of the fact that bone traits have diverged massively during chicken domestication to map the genetic basis of bone metabolism in the chicken. We performed a quantitative trait locus (QTL) and expression QTL (eQTL) mapping study in an advanced intercross based on Red Junglefowl (the wild progenitor of the modern domestic chicken) and White Leghorn chickens. We measured femoral bone traits in 456 chickens by peripheral computerised tomography and femoral gene expression in a subset of 125 females from the cross with microarrays. This resulted in 25 loci for female bone traits, 26 loci for male bone traits and 6318 local eQTL loci. We then overlapped bone and gene expression loci, before checking for an association between gene expression and trait values to identify candidate quantitative trait genes for bone traits. A handful of our candidates have been previously associated with bone traits in mice, but our results also implicate unexpected and largely unknown genes in bone metabolism. In summary, by utilising the unique bone metabolism of an avian species, we have identified a number of candidate genes affecting bone allocation and metabolism. These findings can have ramifications not only for the understanding of bone metabolism genetics in general, but could also be used as a potential model for osteoporosis as well as revealing new aspects of vertebrate bone regulation or features that distinguish avian and mammalian bone. PMID:26023928

  1. Biomechanics and strain mapping in bone as related to immediately-loaded dental implants

    PubMed Central

    Du, Jing; Lee, Jihyun; Jang, Andrew; Gu, Allen; Hossaini-Zadeh, Mehran; Prevost, Richard; Curtis, Don; Ho, Sunita

    2015-01-01

    The effects of alveolar bone socket geometry and bone-implant contact on implant biomechanics, and resulting strain distributions in bone were investigated. Following extraction of lateral incisors on a cadaver mandible, immediate implants were placed and bone-implant contact area, stability and bone strain were measured. In situ biomechanical testing coupled with micro X-ray microscope (μ-XRM) illustrated less stiff bone-implant complexes (701-822 N/mm) compared with bone-periodontal ligament (PDL)-tooth complexes (791-913 N/mm). X-ray tomograms illustrated that the cause of reduced stiffness was due to reduced and limited bone-implant contact. Heterogeneous elemental composition of bone was identified by using energy dispersive X-ray spectroscopy (EDS). The novel aspect of this study was the application of a new experimental mechanics method, that is, digital volume correlation, which allowed mapping of strains in volumes of alveolar bone in contact with a loaded implant. The identified surface and subsurface strain concentrations were a manifestation of load transferred to bone through bone-implant contact based on bone-implant geometry, quality of bone, implant placement, and implant design. 3D strain mapping indicated that strain concentrations are not exclusive to the bone-implant contact regions, but also extend into bone not directly in contact with the implant. The implications of the observed strain concentrations are discussed in the context of mechanobiology. Although a plausible explanation of surgical complications for immediate implant treatment is provided, extrapolation of results is only warranted by future systematic studies on more cadaver specimens and/or in vivo small scale animal models. PMID:26162549

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

    PubMed Central

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

    2011-01-01

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

  3. Systems analysis of bone.

    PubMed

    Jepsen, Karl J

    2009-01-01

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

  4. Bone nutrients for vegetarians.

    PubMed

    Mangels, Ann Reed

    2014-07-01

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

  5. Boning up on autophagy

    PubMed Central

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

    2014-01-01

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

  6. Bone Remodeling Monitor

    NASA Technical Reports Server (NTRS)

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

    2009-01-01

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

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

    PubMed

    Wongdee, Kannikar; Krishnamra, Nateetip; Charoenphandhu, Narattaphol

    2012-07-01

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

  8. Aspects of flux compactification

    NASA Astrophysics Data System (ADS)

    Liu, Tao

    In this thesis, we study three main aspects of flux compactifications: (1) classify supergravity solutions from flux compactification; (2) construct flux-deformed geometry and 4D low-energy theory to describe these flux vacua; and (3) study 4D particle phenomenology and cosmology of flux vacua. In the first part, we review G-structure, the basic tool to study supersymmetric flux solutions, and some typical solutions obtained in heterotic, type IIA and type IIB string theories. Then we present a comprehensive classification of supersymmetric vacua of M-theory compactification on 7D manifolds with general four-form fluxes. We analyze the cases where the resulting four-dimensional vacua have N = 1, 2, 3, 4 supersymmetry and the internal space allows for SU(2)-, SU(3)- or G 2-structures. In particular, we find for N = 2 supersymmetry, that the external space-time is Minkowski and the base manifold of the internal space is conformally Kahler for SU(2) structures, while for SU(3) structures the internal space has to be Einstein-Sasaki and no internal fluxes are allowed. Moreover, we provide a new vacuum with N = 1 supersymmetry and SU(3) structure, where all fluxes are non-zero and the first order differential equations are solved. In the second part, we simply review the methods used to construct one subclass of fluxed-deformed geometry or the so-called "twisted manifold", and the associated 4D effective theory describing these flux vacua. Then by employing (generalized) Scherk-Schwarz reduction, we construct the geometric twisting for Calabi-Yau manifolds of Voisin-Borcea type (K 3 x T2)/ Z2 and study the superpotential in a type IIA orientifold based on this geometry. The twists modify the direct product by fibering the K 3 over T2 while preserving the Z2 involution. As an important application, the Voisin-Borcea class contains T6/( Z2 x Z2 ), the usual setting for intersecting D6 brane model building. Past work in this context considered only those twists inherited

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

    PubMed

    Ito, Akemi; Yajima, Aiji

    2011-09-01

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

  10. Thrombospondin-2 deficiency in growing mice alters bone collagen ultrastructure and leads to a brittle bone phenotype

    PubMed Central

    Manley, Eugene; Perosky, Joseph E.; Khoury, Basma M.; Reddy, Anita B.; Kozloff, Kenneth M.

    2015-01-01

    Thrombospondin-2 (TSP2) is a matricellular protein component of the bone extracellular matrix. Long bones of adult TSP2-deficient mice have increased endosteal bone thickness due to expansion of the osteoblast progenitor cell pool, and these cells display deficits in osteoblastic potential. Here, we investigated the effects of TSP2 deficiency on whole bone geometric and mechanical properties in growing 6-wk-old male and female wild-type and TSP2-knockout (KO) mice. Microcomputed tomography and mechanical testing were conducted on femora and L2 vertebrae to assess morphology and whole bone mechanical properties. In a second series of experiments, femoral diaphyses were harvested from wild-type and TSP2-KO mice. Detergent-soluble type I collagen content was determined by Western blot of right femora. Total collagen content was determined by hydroxyproline analysis of left femora. In a third series of experiments, cortical bone was dissected from the anterior and posterior aspects of the femoral middiaphysis and imaged by transmission electron microscopy to visualize collagen fibrils. Microcomputed tomography revealed minimal structural effects of TSP2 deficiency. TSP2 deficiency imparted a brittle phenotype on cortical bone. Femoral tissue mineral density was not affected by TSP2 deficiency. Instead, transmission electron microscopy revealed less intensely stained collagen fibrils with altered morphology in the extracellular matrix assembled by osteoblasts on the anterior surface of TSP2-KO femora. Femoral diaphyseal bone displayed comparable amounts of total collagen, but the TSP2-KO bones had higher levels of detergent-extractable type I collagen. Together, our data suggest that TSP2 is required for optimal collagen fibrillogenesis in bone and thereby contributes to normal skeletal tissue quality. PMID:26272319

  11. Methods and theory in bone modeling drift: comparing spatial analyses of primary bone distributions in the human humerus.

    PubMed

    Maggiano, Corey M; Maggiano, Isabel S; Tiesler, Vera G; Chi-Keb, Julio R; Stout, Sam D

    2016-01-01

    This study compares two novel methods quantifying bone shaft tissue distributions, and relates observations on human humeral growth patterns for applications in anthropological and anatomical research. Microstructural variation in compact bone occurs due to developmental and mechanically adaptive circumstances that are 'recorded' by forming bone and are important for interpretations of growth, health, physical activity, adaptation, and identity in the past and present. Those interpretations hinge on a detailed understanding of the modeling process by which bones achieve their diametric shape, diaphyseal curvature, and general position relative to other elements. Bone modeling is a complex aspect of growth, potentially causing the shaft to drift transversely through formation and resorption on opposing cortices. Unfortunately, the specifics of modeling drift are largely unknown for most skeletal elements. Moreover, bone modeling has seen little quantitative methodological development compared with secondary bone processes, such as intracortical remodeling. The techniques proposed here, starburst point-count and 45° cross-polarization hand-drawn histomorphometry, permit the statistical and populational analysis of human primary tissue distributions and provide similar results despite being suitable for different applications. This analysis of a pooled archaeological and modern skeletal sample confirms the importance of extreme asymmetry in bone modeling as a major determinant of microstructural variation in diaphyses. Specifically, humeral drift is posteromedial in the human humerus, accompanied by a significant rotational trend. In general, results encourage the usage of endocortical primary bone distributions as an indicator and summary of bone modeling drift, enabling quantitative analysis by direction and proportion in other elements and populations.

  12. Bone formation: roles of genistein and daidzein

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  13. Ultrasonographic appearance of bony abnormalities at the dorsal aspect of the fetlock joint in geriatric cadaver horses.

    PubMed

    Vanderperren, K; Gielen, I; Van Caelenberg, A; Van der Vekens, E; Raes, E V; Hauspie, S; van Bree, H; Saunders, J H

    2012-07-01

    This article describes the ultrasonographic (US) appearance of bony abnormalities on the dorsal aspect of the third metacarpal/metatarsal bone of the equine fetlock in cadavers with radiographic signs of osteoarthrosis. After US, computed tomography was undertaken to better characterise the lesions. Twelve fetlock joints were collected and all had more than one bone abnormality on US. Normal subchondral bone appeared on US as a well-defined and regular hyperechoic line with distal acoustic shadowing. Bone abnormalities detected on US included (1) gaps in the proximal subchondral bone filled with material of heterogeneous echogenicity, (2) bone fragments represented as small straight smoothly delineated hyperechoic lines with distal shadowing located superficial to the surface of the adjacent bone, (3) proximal new bone formation visible as mild to severe cortical protrusions, (4) marginal osteophytoses seen as an elevation of the hyperechoic surface of the subchondral bone at the edges of the joint surfaces, (5) indentations in subchondral bone seen as a concave deviation of the hyperechoic line without interruption, (6) focal or diffuse irregularities of the subchondral bone seen as disruptions of the normal smooth bony contours, and (7) focal hyperechoic spikes originating from the subchondral plate and invading the articular cartilage. These findings are discussed.

  14. Expanding the utility of modified vascularized femoral periosteal bone-flaps: An analysis of its form and a comparison with a conventional-bone-graft

    PubMed Central

    Hamada, Yoshitaka; Hibino, Naohito; Kobayashi, Anna

    2014-01-01

    Background Vascularized medial femoral condyle (MFC) corticoperiosteal bone-flap is a well-accepted technique when dealing with tissue defects or infection. Its role in refractory conditions and in the possible use for options concerning modifications of this bone-flap compared to a conventional iliac bone graft (conventional-graft) are rarely discussed. Methods We reviewed 21 consecutive cases concerning alternatives with some modifications of original MFC bone-flap surgery used to treat refractory conditions with bone defects, necrosis, or infection in the extremities. We present our devised approaches for this boneflap, and especially modifications of the grafted bone (including strut bone, perforator to the vastus medialis muscle, and the use of one vascular pedicle for some bone flaps) as well as the combined use of artificial bone as hybrid bone transplantation. We also compared the clinical results of 21 cases that received a conventional-graft. Results and Conclusions Following flap placement, 100% of the nonunion sites healed in an average of 2 months, which was significantly shorter than 5.5 months for the conventional-graft. The results showed the expanding possibility for options with regard to the form and options of this bone-flap as well as the shortening the duration of treatment, especially at the site of an infected distal tibia, insertion of the Achilles tendon on the posterior aspect of calcaneal osteomyelitis, distal end of the clavicle, clavicle or forearm with a bone defect, small bones with refractory conditions, and a femur without implant failure. However, it was not efficient for treating a forearm without bone defect. PMID:25983463

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

    PubMed Central

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

    2012-01-01

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

  16. Osteocyte density in woven bone.

    PubMed

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

    2004-11-01

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

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

    PubMed

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

    2017-01-01

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

  18. Cellular and molecular toxicity of lead in bone.

    PubMed Central

    Pounds, J G; Long, G J; Rosen, J F

    1991-01-01

    To fully understand the significance of bone as a target tissue of lead toxicity, as well as a reservoir of systemic lead, it is necessary to define the effects of lead on the cellular components of bone. Skeletal development and the regulation of skeletal mass are ultimately determined by the four different types of cells: osteoblasts, lining cells, osteoclasts, and osteocytes. These cells, which line and penetrate the mineralized matrix, are responsible for matrix formation, mineralization, and bone resorption, under the control of both systemic and local factors. Systemic components of regulation include parathyroid hormone, 1,25-dihydroxyvitamin D3, and calcitonin: local regulators include numerous cytokines and growth factors. Lead intoxication directly and indirectly alters many aspects of bone cell function. First, lead may indirectly alter bone cell function through changes in the circulating levels of those hormones, particularly 1,25-dihydroxyvitamin D3, which modulate bone cell function. These hormonal changes have been well established in clinical studies, although the functional significance remains to be established. Second, lead may directly alter bone cell function by perturbing the ability of bone cells to respond to hormonal regulation. For example, the 1,25-dihydroxyvitamin D3-stimulated synthesis of osteocalcin, a calcium-binding protein synthesized by osteoblastic bone cells, is inhibited by low levels of lead. Impaired osteocalcin production may inhibit new bone formation, as well as the functional coupling of osteoblasts and osteoclasts. Third, lead may impair the ability of cells to synthesize or secrete other components of the bone matrix, such as collagen or bone sialoproteins (osteopontin). Finally, lead may directly effect or substitute for calcium in the active sites of the calcium messenger system, resulting in loss of physiological regulation. The effects of lead on the recruitment and differentiation of bone cells remains to be

  19. Temporal Bone Meningiomas

    PubMed Central

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

    1999-01-01

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

  20. Bone Graft Substitution and Augmentation.

    PubMed

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

    2015-12-01

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

  1. Scaling in Theropod Dinosaurs: Femoral Bone Dimensions

    NASA Astrophysics Data System (ADS)

    Lee, Scott A.

    2014-05-01

    Finding topics that inspire students is an important aspect of any physics course. Virtually everyone is fascinated by Tyrannosaurus rex, and the excitement of the class is palpable when we explore scaling effects in T. rex and other bipedal theropod dinosaurs as part of our discussion of mechanics and elasticity. In this paper, we explore the role of longitudinal stress in the femur bones due to the weight of the dinosaur in determining how the geometry of the femur changes with size of the theropod. This is one area of allometry the study of how different biological characteristics scale with size.

  2. The roles of architecture and estrogen depletion in microdamage risk in trabecular bone.

    PubMed

    Kreipke, Tyler C; Garrison, Jacqueline G; Easley, Jeremiah; Turner, A Simon; Niebur, Glen L

    2016-10-03

    Bone quantity, or density, has insufficient power to discriminate fracture risk in individuals. Additional measures of bone quality, such as microarchitectural characteristics and bone tissue properties, including the presence of damage, may improve the diagnosis of fracture risk. Microdamage and microarchitecture are two aspects of trabecular bone quality that are interdependent, with several microarchitectural changes strongly correlated to damage risk after compensating for bone density. This study aimed to delineate the effects of microarchitecture and estrogen depletion on microdamage susceptibility in trabecular bone using an ovariectomized sheep model to mimic post-menopausal osteoporosis. The propensity for microdamage formation in trabecular bone of the distal femur was studied using a sequence of compressive and torsional overloads. Ovariectomy had only minor effects on the microarchitecture at this anatomic site. Microdamage was correlated to bone volume fraction and structure model index (SMI), and ovariectomy increased the sensitivity to these parameters. The latter may be due to either increased resorption cavities acting as stress concentrations or to altered bone tissue properties. Pre-existing damage was also correlated to new damage formation. However, sequential loading primarily generated new cracks as opposed to propagating existing cracks, suggesting that pre-existing microdamage contributes to further damage of bone by shifting load bearing to previously undamaged trabeculae, which are subsequently damaged. The transition from plate-like to rod-like trabeculae, indicated by SMI, dictates this shift, and may be a hallmark of bone that is already predisposed to accruing greater levels of damage through compromised microarchitecture.

  3. Bone health in eating disorders.

    PubMed

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

    2014-03-01

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

  4. Robots in Space -Psychological Aspects

    NASA Technical Reports Server (NTRS)

    Sipes, Walter E.

    2006-01-01

    A viewgraph presentation on the psychological aspects of developing robots to perform routine operations associated with monitoring, inspection, maintenance and repair in space is shown. The topics include: 1) Purpose; 2) Vision; 3) Current Robots in Space; 4) Ground Based Robots; 5) AERCam; 6) Rotating Bladder Robot (ROBLR); 7) DART; 8) Robonaut; 9) Full Immersion Telepresence Testbed; 10) ERA; and 11) Psychological Aspects

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

    PubMed

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

    2015-12-01

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

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

    PubMed

    Starup-Linde, Jakob

    2013-01-01

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

  7. Microarchitecture of irradiated bone: comparison with healthy bone

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  8. Calcar bone graft

    SciTech Connect

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

    1986-01-01

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

  9. Segmentation of bone CT images and assessment of bone structure using measures of complexity.

    PubMed

    Saparin, Peter; Thomsen, Jesper Skovhus; Kurths, Jürgen; Beller, Gisela; Gowin, Wolfgang

    2006-10-01

    A nondestructive and noninvasive method for numeric characterization (quantification) of the structural composition of human bone tissue has been developed and tested. In order to quantify and to compare the structural composition of bones from 2D computed tomography (CT) images acquired at different skeletal locations, a series of robust, versatile, and adjustable image segmentation and structure assessment algorithms were developed. The segmentation technique facilitates separation from cortical bone and standardizes the region of interest. The segmented images were symbol-encoded and different aspects of the bone structural composition were quantified using six different measures of complexity. These structural examinations were performed on CT images of bone specimens obtained at the distal radius, humeral mid-diaphysis, vertebral body, femoral head, femoral neck, proximal tibia, and calcaneus. In addition, the ability of the noninvasive and nondestructive measures of complexity to quantify trabecular bone structure was verified by comparing them to conventional static histomorphometry performed on human fourth lumbar vertebral bodies. Strong correlations were established between the measures of complexity and the histomorphometric parameters except for measures expressing trabecular thickness. Furthermore, the ability of the measures of complexity to predict vertebral bone strength was investigated by comparing the outcome of the complexity analysis of the CT images with the results of a biomechanical compression test of the third lumbar vertebral bodies from the same population as used for histomorphometry. A multiple regression analysis using the proposed measures including structure complexity index, structure disorder index, trabecular network index, index of a global ensemble, maximal L-block, and entropy of x-ray attenuation distribution revealed an excellent relationship (r=0.959, r2=0.92) between the measures of complexity and compressive bone strength

  10. Segmentation of bone CT images and assessment of bone structure using measures of complexity

    SciTech Connect

    Saparin, Peter; Thomsen, Jesper Skovhus; Kurths, Juergen; Beller, Gisela; Gowin, Wolfgang

    2006-10-15

    A nondestructive and noninvasive method for numeric characterization (quantification) of the structural composition of human bone tissue has been developed and tested. In order to quantify and to compare the structural composition of bones from 2D computed tomography (CT) images acquired at different skeletal locations, a series of robust, versatile, and adjustable image segmentation and structure assessment algorithms were developed. The segmentation technique facilitates separation of trabecular from cortical bone and standardizes the region of interest. The segmented images were symbol-encoded and different aspects of the bone structural composition were quantified using six different measures of complexity. These structural examinations were performed on CT images of bone specimens obtained at the distal radius, humeral mid-diaphysis, vertebral body, femoral head, femoral neck, proximal tibia, and calcaneus. In addition, the ability of the noninvasive and nondestructive measures of complexity to quantify trabecular bone structure was verified by comparing them to conventional static histomorphometry performed on human fourth lumbar vertebral bodies. Strong correlations were established between the measures of complexity and the histomorphometric parameters except for measures expressing trabecular thickness. Furthermore, the ability of the measures of complexity to predict vertebral bone strength was investigated by comparing the outcome of the complexity analysis of the CT images with the results of a biomechanical compression test of the third lumbar vertebral bodies from the same population as used for histomorphometry. A multiple regression analysis using the proposed measures including structure complexity index, structure disorder index, trabecular network index, index of a global ensemble, maximal L-block, and entropy of x-ray attenuation distribution revealed an excellent relationship (r=0.959, r{sup 2}=0.92) between the measures of complexity and

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

    PubMed

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

    2015-01-01

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

  12. Bone cells and bone turnover in diabetes mellitus.

    PubMed

    Rubin, Mishaela R

    2015-06-01

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

  13. Anatomical aspects of sinus floor elevations.

    PubMed

    van den Bergh, J P; ten Bruggenkate, C M; Disch, F J; Tuinzing, D B

    2000-06-01

    Inadequate bone height in the lateral part of the maxilla forms a contra-indication for implant surgery. This condition can be treated with an internal augmentation of the maxillary sinus floor. This sinus floor elevation, formerly called sinus lifting, consists of a surgical procedure in which a top hinge door in the lateral maxillary sinus wall is prepared and internally rotated to a horizontal position. The new elevated sinus floor, together with the inner maxillary mucosa, will create a space that can be filled with graft material. Sinus lift procedures depend greatly on fragile structures and anatomical variations. The variety of anatomical modalities in shape of the inner aspect of the maxillary sinus defines the surgical approach. Conditions such as sinus floor convolutions, sinus septum, transient mucosa swelling and narrow sinus may form a (usually relative) contra-indication for sinus floor elevation. Absolute contra-indications are maxillary sinus diseases (tumors) and destructive former sinus surgery (like the Caldwell-Luc operation). The lateral sinus wall is usually a thin bone plate, which is easily penetrated with rotating or sharp instruments. The fragile Schneiderian membrane plays an important role for the containment of the bonegraft. The surgical procedure of preparing the trap door and luxating it, together with the preparation of the sinus mucosa, may cause a mucosa tear. Usually, when these perforations are not too large, they will fold together when turning the trap door inward and upward, or they can be glued with a fibrin sealant, or they can be covered with a resorbable membrane. If the perforation is too large, a cortico-spongious block graft can be considered. However, in most cases the sinus floor elevation will be deleted. Perforations may also occur due to irregularities in the sinus floor or even due to immediate contact of sinus mucosa with oral mucosa. Obstruction of the antro-nasal foramen is, due to its high location, not a

  14. Microdamage caused by fatigue loading in human cancellous bone: relationship to reductions in bone biomechanical performance.

    PubMed

    Lambers, Floor M; Bouman, Amanda R; Rimnac, Clare M; Hernandez, Christopher J

    2013-01-01

    Vertebral fractures associated with osteoporosis are often the result of tissue damage accumulated over time. Microscopic tissue damage (microdamage) generated in vivo is believed to be a mechanically relevant aspect of bone quality that may contribute to fracture risk. Although the presence of microdamage in bone tissue has been documented, the relationship between loading, microdamage accumulation and mechanical failure is not well understood. The aim of the current study was to determine how microdamage accumulates in human vertebral cancellous bone subjected to cyclic fatigue loading. Cancellous bone cores (n = 32) from the third lumbar vertebra of 16 donors (10 male, 6 female, age 76 ± 8.8, mean ± SD) were subjected to compressive cyclic loading at σ/E0 = 0.0035 (where σ is stress and E0 is the initial Young's modulus). Cyclic loading was suspended before failure at one of seven different amounts of loading and specimens were stained for microdamage using lead uranyl acetate. Damage volume fraction (DV/BV) varied from 0.8 ± 0.5% (no loading) to 3.4 ± 2.1% (fatigue-loaded to complete failure) and was linearly related to the reductions in Young's modulus caused by fatigue loading (r(2) = 0.60, p<0.01). The relationship between reductions in Young's modulus and proportion of fatigue life was nonlinear and suggests that most microdamage generation occurs late in fatigue loading, during the tertiary phase. Our results indicate that human vertebral cancellous bone tissue with a DV/BV of 1.5% is expected to have, on average, a Young's modulus 31% lower than the same tissue without microdamage and is able to withstand 92% fewer cycles before failure than the same tissue without microdamage. Hence, even small amounts of microscopic tissue damage in human vertebral cancellous bone may have large effects on subsequent biomechanical performance.

  15. Periodontitis and bone metabolism

    PubMed Central

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

    2015-01-01

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

  16. Bone healing in 2016

    PubMed Central

    Buza, John A.; Einhorn, Thomas

    2016-01-01

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

  17. Diabetes and bone health.

    PubMed

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

    2013-11-01

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

  18. [Infectious bone diseases].

    PubMed

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

    2011-05-01

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

  19. Analysis of bone biopsies.

    PubMed

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

    1983-11-01

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

  20. Bone-Grafting in Polyostotic Fibrous Dysplasia

    PubMed Central

    Leet, Arabella I.; Boyce, Alison M.; Ibrahim, Khalda A.; Wientroub, Shlomo; Kushner, Harvey; Collins, Michael T.

    2016-01-01

    Background: Polyostotic fibrous dysplasia is a skeletal disease that results from somatic activating mutations in the gene GNAS in skeletal stem cells, leading to proliferation of immature osteogenic cells with replacement of normal marrow and bone with fibro-osseous tissue. Lesions may cause bone deformity or fracture. In the surgical care of polyostotic fibrous dysplasia, the role of grafting and the optimal grafting material are not clear. The purpose of this study was to evaluate the long-term survival of bone-grafting procedures in subjects with polyostotic fibrous dysplasia over time. Methods: The operative reports and radiographs of a cohort of subjects with polyostotic fibrous dysplasia followed in a natural history study were reviewed. Twenty-three subjects (mean age at the time of enrollment, thirteen years [range, two to forty years]) with fifty-two bone-grafting procedures had a mean follow-up time of 19.6 years (range, twenty-nine months to forty-seven years). Kaplan-Meier life table estimates, Cox proportional hazard models, and t tests comparing means were performed to assess various aspects of graft survival. Results: Kaplan-Meier curves showed a 50% estimate of survival of 14.5 years. Cox proportional hazards models showed no advantage comparing allograft with autograft or structural with nonstructural graft materials. The mean age of the patients was significantly greater (p < 0.001) in the subgroup of subjects in whom grafts were maintained over time (20.9 years) compared with the subgroup of patients whose grafts were resorbed over time (9.8 years). Conclusions: Bone-grafting, including both allograft and autograft, is of limited value in ablating the lesions of fibrous dysplasia. The expectations of patients and surgeons should include the high probability of graft resorption over time with return of bone characteristics of fibrous dysplasia, particularly in younger patients. This suggests the maintenance of normal bone mechanics with implant

  1. Biomaterial delivery of morphogens to mimic the natural healing cascade in bone

    PubMed Central

    Mehta, Manav; Schmidt-Bleek, Katharina; Duda, Georg N; Mooney, David J

    2012-01-01

    Complications in treatment of large bone defects using bone grafting still remain. Our understanding of the endogenous bone regeneration cascade has inspired the exploration of a wide variety of growth factors (GFs) in an effort to mimic the natural signaling that controls bone healing. Biomaterial-based delivery of single exogenous GFs has shown therapeutic efficacy, and this likely relates to its ability to recruit and promote replication of cells involved in tissue development and the healing process. However, as the natural bone healing cascade involves the action of multiple factors, each acting in a specific spatiotemporal pattern, strategies aiming to mimic the critical aspects of this process will likely benefit from the usage of multiple therapeutic agents. This article reviews the current status of approaches to deliver single GFs, as well as ongoing efforts to develop sophisticated delivery platforms to deliver multiple lineage-directing morphogens (multiple GFs) during bone healing. PMID:22626978

  2. AST-induced bone loss in men with prostate cancer: exercise as a potential countermeasure.

    PubMed

    Bolam, K A; Galvão, D A; Spry, N; Newton, R U; Taaffe, D R

    2012-12-01

    Androgen suppression treatment (AST) for men with prostate cancer is associated with a number of treatment-related side effects including an accelerated rate of bone loss. This loss of bone is greatest within the first year of AST and increases the risk for fracture. Pharmaceutical treatment in the form of bisphosphonates is currently used to counter the effects of hormone suppression on bone but is costly and associated with potential adverse effects. Recently, exercise has been shown to be an important adjuvant therapy to manage a range of treatment-related toxicities and enhance aspects of quality of life for men receiving AST. We propose that physical exercise may also have an important role in not only attenuating the bone loss associated with AST but in improving bone health and reducing fracture risk. In this review, the rationale underlying exercise as a countermeasure to AST-induced bone loss is provided.

  3. Sex steroids and bone.

    PubMed

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

    2002-01-01

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

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

    PubMed

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

    2010-01-01

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

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

    PubMed

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

    2013-03-01

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

  6. Aspect-Oriented Design with Reusable Aspect Models

    NASA Astrophysics Data System (ADS)

    Kienzle, Jörg; Al Abed, Wisam; Fleurey, Franck; Jézéquel, Jean-Marc; Klein, Jacques

    The idea behind Aspect-Oriented Modeling (AOM) is to apply aspect-oriented techniques to (software) models with the aim of modularizing crosscutting concerns. This can be done within different modeling notations, at different levels of abstraction, and at different moments during the software development process. This paper demonstrates the applicability of AOM during the software design phase by presenting parts of an aspect-oriented design of a crisis management system. The design solution proposed in this paper is based on the Reusable Aspect Models (RAM) approach, which allows a modeler to express the structure and behavior of a complex system using class, state and sequence diagrams encapsulated in several aspect models. The paper describes how the model of the "create mission" functionality of the server backend can be decomposed into 23 inter-dependent aspect models. The presentation of the design is followed by a discussion on the lessons learned from the case study. Next, RAM is compared to 8 other AOM approaches according to 6 criteria: language, concern composition, asymmetric and symmetric composition, maturity, and tool support. To conclude the paper, a discussion section points out the features of RAM that specifically support reuse.

  7. Genetics Home Reference: Paget disease of bone

    MedlinePlus

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

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

    MedlinePlus

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

  9. Vitamin D, Calcium, and Bone Health

    MedlinePlus

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

  10. A review of radiologically important trace elements in human bones.

    PubMed

    Tandon, L; Iyengar, G V; Parr, R M

    1998-08-01

    The authors recently compiled and reviewed the literature for minor and trace elements in human bones and teeth as a part of an International Atomic Energy Agency (IAEA) study. Various aspects of elemental composition, analytical methodologies, quality assurance and quality control methods for hard tissue analysis were evaluated. Important data on selected radiologically important elements (Cs, Pu, Ra, Sr, Th, and U) in calcified tissue from various countries are discussed. The results of this compilation study suggest a need for new reference materials with matrix properties similar to bones including one with separated cortical and trabecular segments.

  11. Metabolic bone diseases during long-term total parenteral nutrition.

    PubMed

    Acca, M; Ragno, A; Francucci, C M; D'Erasmo, E

    2007-01-01

    Long-term total parenteral nutrition (TPN) is a procedure commonly applied to patients with advanced forms of intestinal malabsorption. Among TPN complications, bone metabolic diseases, such as osteoporosis and osteomalacia, are a common finding. Initially considered to be a manifestation of aluminium toxicity which followed massive contamination with the element of the solutions used in TPN, metabolic osteopathy during TPN is currently considered a multiform syndrome, with a multifactorial pathogenesis, which may manifest itself with vague or clear clinical pictures. In this review, we analyse clinical, pathogenetic, and therapeutic aspects of the most common bone metabolic diseases in patients undergoing long-term TPN.

  12. Altered bone turnover during spaceflight

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  13. How Is Bone Cancer Diagnosed?

    MedlinePlus

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

  14. Bone regeneration during distraction osteogenesis.

    PubMed

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

    2009-07-01

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

  15. Pregnancy, Breastfeeding, and Bone Health

    MedlinePlus

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

  16. Graphite-reinforced bone cement

    NASA Technical Reports Server (NTRS)

    Knoell, A. C.

    1976-01-01

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

  17. Cutting thin sections of bone

    NASA Technical Reports Server (NTRS)

    Ashley, W. W.

    1972-01-01

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

  18. Bone and cancer: the osteoncology

    PubMed Central

    Ibrahim, Toni; Mercatali, Laura; Amadori, Dino

    2013-01-01

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

  19. Bone-marrow transplant - slideshow

    MedlinePlus

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

  20. Augmentation of the rat jaw with autogeneic cortico-cancellous bone grafts and guided tissue regeneration.

    PubMed

    Donos, Nikolaos; Kostopoulos, Lambros; Karring, Thorkild

    2002-04-01

    The aim of the present study was to evaluate the effect of augmenting the maxillary alveolar ridge and the lateral aspect of the mandible with onlay autogeneic cortico-cancellous bone grafts that were covered with e-PTFE membranes. The experiment was carried out in 51 rats. In 15 rats, the edentulous maxillary jaw between the incisor and the first molar was augmented by means of an autogeneic ischiac bone graft that was fixed with a gold-coated microimplant. In one side, the graft was covered with an e-PTFE membrane, while the other side, which served as control, was treated without a membrane. In the other 36 rats, the lateral aspect of the mandible was augmented in both sides by means of an autogeneic ischiac bone graft that was fixed with a gold-coated or a titanium microimplant. In one side, the augmented area was covered with an e-PTFE membrane, while the contralateral side was treated without a membrane. Histological analysis at 60, 120 and 180 days after augmentation of the maxilla showed that, in the case of the test sites (where most of the membranes were either exposed or lost), the bone grafts presented extensive resorption and there was a lack of bone continuity between the graft and the recipient site. Similar findings were made at the non-membrane-treated control sides. In the case of augmentation of the mandible with membranes, the bone grafts were not resorbed, but were integrated into newly formed bone at the recipient site. In the control sides, the grafts presented varying degrees of resorption and integration into the recipient bone. It is concluded that, in comparison to bone grafting alone, onlay ischiac bone grafting combined with guided tissue regeneration eliminates the risk of bone graft resorption and ensures integration of the graft into newly formed bone at the recipient site, provided that closure of the operated area can be maintained during healing.

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

    PubMed

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

    2012-07-24

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

  2. Imaging of the temporal bone.

    PubMed

    Abele, Travis A; Wiggins, Richard H

    2015-01-01

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

  3. Transcutaneous Raman Spectroscopy of Bone

    NASA Astrophysics Data System (ADS)

    Maher, Jason R.

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

  4. Chemical Makeup of Microdamaged Bone Differs from Undamaged Bone

    SciTech Connect

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

    2006-01-01

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

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

    PubMed

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

    2006-08-01

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

  6. Implant bone integration importance in forensic identification.

    PubMed

    De Angelis, Danilo; Cattaneo, Cristina

    2015-03-01

    Odontological identification consists of the comparison of antemortem dental information regarding a missing person with postmortem data from an unidentified corpse or human remains. Usually, the comparison concerns morphologic features that the operator chooses among all the visible characteristics because of inter-individual uniqueness; for this reason, implants can be of enormous assistance. A case concerning the recovery of a burnt oral implant, connected to a bone fragment, among 2780 charred bone fragments, suspected to have belonged to a victim of homicide, is presented to demonstrate that dental implants and their site of bone integration represent a very precious element for personal forensic identification. Because of their morphological invariability in time and because of their morphologic uniqueness, they were used as evidence to associate unidentified human charred remains to a missing person where DNA analysis failed to do so. The case illustrates the fundamental contribution, not yet described in literature, given by the clinical aspects of tooth replacement with dental implants to a forensic discipline. Clinical practitioners should therefore be aware of the great importance of their work and of dental records in a forensic identification scenario.

  7. Sexual Aspects of Multilateral Relations

    ERIC Educational Resources Information Center

    Constantine, Joan M.; Constantine, Larry L.

    1971-01-01

    This study involved a variety of data gathering techniques focusing on almost every aspect of multilateral marriages. Specific topics covered included sex as motivation, group sex, sleeping arrangements, cohesion, sexual problems, jealousy, roles and sex differences. (Author/CG)

  8. Administrative Aspects of Human Experimentation.

    ERIC Educational Resources Information Center

    Irvine, George W.

    1992-01-01

    The following administrative aspects of scientific experimentation with human subjects are discussed: the definition of human experimentation; the distinction between experimentation and treatment; investigator responsibility; documentation; the elements and principles of informed consent; and the administrator's role in establishing and…

  9. Topological Aspects of Information Retrieval.

    ERIC Educational Resources Information Center

    Egghe, Leo; Rousseau, Ronald

    1998-01-01

    Discusses topological aspects of theoretical information retrieval, including retrieval topology; similarity topology; pseudo-metric topology; document spaces as topological spaces; Boolean information retrieval as a subsystem of any topological system; and proofs of theorems. (LRW)

  10. Scaffold Design for Bone Regeneration

    PubMed Central

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

    2014-01-01

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

  11. Update on pediatric bone health.

    PubMed

    Henwood, Maria J; Binkovitz, Larry

    2009-01-01

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

  12. Breast Cancer and Bone Loss

    MedlinePlus

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

  13. Tooth dentin defects reflect genetic disorders affecting bone mineralization

    PubMed Central

    Vital, S. Opsahl; Gaucher, C.; Bardet, C.; Rowe, P.S.; George, A.; Linglart, A.; Chaussain, C.

    2012-01-01

    Several genetic disorders affecting bone mineralization may manifest during dentin mineralization. Dentin and bone are similar in several aspects, especially pertaining to the composition of the extracellular matrix (ECM) which is secreted by well-differentiated odontoblasts and osteoblasts, respectively. However, unlike bone, dentin is not remodelled and is not involved in the regulation of calcium and phosphate metabolism. In contrast to bone, teeth are accessible tissues with the shedding of deciduous teeth and the extractions of premolars and third molars for orthodontic treatment. The feasibility of obtaining dentin makes this a good model to study biomineralization in physiological and pathological conditions. In this review, we focus on two genetic diseases that disrupt both bone and dentin mineralization. Hypophosphatemic rickets is related to abnormal secretory proteins involved in the ECM organization of both bone and dentin, as well as in the calcium and phosphate metabolism. Osteogenesis imperfecta affects proteins involved in the local organization of the ECM. In addition, dentin examination permits evaluation of the effects of the systemic treatment prescribed to hypophosphatemic patients during growth. In conclusion, dentin constitutes a valuable tool for better understanding of the pathological processes affecting biomineralization. PMID:22296718

  14. Deformation and Fracture Mechanisms of Bone and Nacre

    NASA Astrophysics Data System (ADS)

    Wang, Rizhi; Gupta, Himadri S.

    2011-08-01

    Bone and nacre are the most-known biological hard tissues to materials researchers. Although highly mineralized, both bone and nacre are amazingly tough and exhibit remarkable inelasticity, properties that are still beyond the reach of many modern ceramic materials. Very interestingly, the two hard tissues seem to have adopted totally different structural strategies for achieving mechanical robustness. Starting from a true nanocomposite of the mineralized collagen fibril and following up to seven levels of hierarchical organization, bone is built on a structure with extreme complexity. In contrast, nacre possesses a structure of surprising simplicity. Polygonal mineral tablets of micrometer size are carefully cemented together into a macroscopic wonder. A comparative analysis of the structure-property relations in bone and nacre helps us to unveil the underlying mechanisms of this puzzling phenomenon. In this review, we critically compare the various levels of structures and their mechanical contributions between bone and nacre, with a focus on inelasticity and the toughening process. We demonstrate that, although nacre and bone differ from each other in many aspects, they have adopted very similar deformation and toughening mechanisms.

  15. Dietary protein's and dietary acid load's influence on bone health.

    PubMed

    Remer, Thomas; Krupp, Danika; Shi, Lijie

    2014-01-01

    A variety of genetic, mechano-response-related, endocrine-metabolic, and nutritional determinants impact bone health. Among the nutritional influences, protein intake and dietary acid load are two of the factors most controversially discussed. Although in the past high protein intake was often assumed to exert a primarily detrimental impact on bone mass and skeletal health, the majority of recent studies indicates the opposite and suggests a bone-anabolic influence. Studies examining the influence of alkalizing diets or alkalizing supplement provision on skeletal outcomes are less consistent, which raises doubts about the role of acid-base status in bone health. The present review critically evaluates relevant key issues such as acid-base terminology, influencing factors of intestinal calcium absorption, calcium balance, the endocrine-metabolic milieu related to metabolic acidosis, and some methodological aspects of dietary exposure and bone outcome examinations. It becomes apparent that for an adequate identification and characterization of either dietary acid load's or protein's impact on bone, the combined assessment of both nutritional influences is necessary.

  16. Chondroblastoma of the temporal bone: consistent middle fossa involvement.

    PubMed

    Selesnick, S H; Levine, J M

    1999-01-01

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

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

    PubMed

    Hosoi, Takayuki

    2010-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

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

  19. Multiscale Modeling of Bone

    DTIC Science & Technology

    2014-12-01

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

  20. Bones of the Earth

    ERIC Educational Resources Information Center

    Correa, Jose Miguel

    2014-01-01

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

  1. Calcium and bones

    MedlinePlus

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

  2. Management of Bone Sarcoma.

    PubMed

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

    2016-10-01

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

  3. Bone Marrow Matters

    ERIC Educational Resources Information Center

    Dunne, Mark; Maklad, Rania; Heaney, Emma

    2014-01-01

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

  4. Are Bones Alive?

    ERIC Educational Resources Information Center

    Caravita, Silvia; Falchetti, Elisabetta

    2005-01-01

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

  5. Calcaneus (Heel Bone) Fractures

    MedlinePlus

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

  6. Infrared laser bone ablation

    SciTech Connect

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

    1988-01-01

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

  7. [Radiotherapy of bone metastases].

    PubMed

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

    2016-09-01

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

  8. Calcium and bones (image)

    MedlinePlus

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

  9. Low Bone Density

    MedlinePlus

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

  10. A Digital Solar Aspect Sensor

    NASA Technical Reports Server (NTRS)

    Albus, James S.

    1961-01-01

    The solar aspect sensor described herein performs the analog-to-digital conversion of data optically. To accomplish this, it uses a binary "Gray code" light mask to produce a digital indication, in vehicle-fixed coordinates, of the elevation and azimuth angles of incident light from the sun. This digital solar aspect sensor system, in Explorer X, provided measurements of both elevation and azimuth angles to +/- 2 degrees at a distance of over 140,000 statute miles.

  11. Hyponatremia and bone disease.

    PubMed

    Negri, Armando Luis; Ayus, Juan Carlos

    2016-09-24

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

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  14. Canine cortical bone autograft remodeling in two simultaneous skeletal sites.

    PubMed

    Delloye, C; Coutelier, L; Vincent, A; d'Hemricourt, J; Bourgois, R

    1986-01-01

    The morphological and physical aspects of cortical bone autografts implanted in dogs for 1-9 months in two differently located skeletal defects are reported with a twofold aim: to provide a reference system for further comparison with various allografts and to delineate a general pattern of cortical bone graft healing. A 3-cm osteoperiosteal gap was created in the diaphyseal segment of the ulna and fibula of mature dogs. The grafts, freed from periosteum and bone marrow, were then inverted and replaced for the autografts in the left limb bone without internal fixation or external splints. On the right side, different allografts were tested. A group of three animals also had an unfilled segmental resection on the right as control. Dogs were observed for 1, 2, 3, 6, and 9 months and were able to bear weight within 3 days. Twenty-eight ulnae and 27 fibulae were available for this autograft study. Fluorochromes were injected at mid-term and at the end of the observation. All the grafts were assessed morphologically by cross-section microradiographs and ultraviolet light microscopy, and a morphometric analysis for porosity and fluorescence was done. To evaluate the physical aspects of graft healing, the recovered ulnar autografts, when available, were submitted to photon absorptiometry and to torsional loading. Morphologically, resorption was found to invade the cortical bone graft transversely through radial tunnels, and in addition to the host-bone-graft junction, the entire transplant surface provided another way for revascularization. The highest porosity level was achieved 2 months after surgery for both ulna and fibula, while new bone formation, as assessed by fluorochromes, was most important at 3 months. At 9 months, porosity remained above the normal range as determined in a set of five nongrafted dogs. While the lack of correlation for porosity between the two grafts suggests that local factors are more important in graft resorption, the observed correlation

  15. Multicellular tumor spheroid interactions with bone cells and bone

    SciTech Connect

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

    1985-10-01

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

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

    PubMed

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

    2013-09-03

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

  17. Polymorphous low grade adenocarcinoma presenting an uncommon radiographic aspect.

    PubMed

    de Magalhães, M H C G; de Magalhães, R P; de Araújo, V C; de Sousa, S O M

    2006-05-01

    The aim of this study was to present clinical, histological and immunohistochemical aspects of a polymorphous low grade adenocarcinoma occurring in the mandible. A radiolucent tumour, located in the right mandible, was removed from a 40-year-old woman. Radiographic and CT exams revealed that the lesion expanded bucco-lingual cortical plates and presented an irregular scalloping of the bone. The surrounding lining mucosa was intact. The patient underwent total surgical removal of the lesion with an intraoperative biopsy. Histological diagnosis was polymorphous low-grade adenocarcinoma confirmed by immunohistochemical study. One-year follow up was uneventful. The accurate diagnosis of lesions presenting unusual clinical aspects, as the one presented here, is critical for correctly handling treatment.

  18. Bone repair and stem cells.

    PubMed

    Ono, Noriaki; Kronenberg, Henry M

    2016-10-01

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

  19. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, J.W.

    1995-05-09

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

  20. Digital electronic bone growth stimulator

    DOEpatents

    Kronberg, James W.

    1995-01-01

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

  1. Probabilistic Risk Assessment for Astronaut Post Flight Bone Fracture

    NASA Technical Reports Server (NTRS)

    Lewandowski, Beth; Myers, Jerry; Licata, Angelo

    2015-01-01

    Introduction: Space flight potentially reduces the loading that bone can resist before fracture. This reduction in bone integrity may result from a combination of factors, the most common reported as reduction in astronaut BMD. Although evaluating the condition of bones continues to be a critical aspect of understanding space flight fracture risk, defining the loading regime, whether on earth, in microgravity, or in reduced gravity on a planetary surface, remains a significant component of estimating the fracture risks to astronauts. This presentation summarizes the concepts, development, and application of NASA's Bone Fracture Risk Module (BFxRM) to understanding pre-, post, and in mission astronaut bone fracture risk. The overview includes an assessment of contributing factors utilized in the BFxRM and illustrates how new information, such as biomechanics of space suit design or better understanding of post flight activities may influence astronaut fracture risk. Opportunities for the bone mineral research community to contribute to future model development are also discussed. Methods: To investigate the conditions in which spaceflight induced changes to bone plays a critical role in post-flight fracture probability, we implement a modified version of the NASA Bone Fracture Risk Model (BFxRM). Modifications included incorporation of variations in physiological characteristics, post-flight recovery rate, and variations in lateral fall conditions within the probabilistic simulation parameter space. The modeled fracture probability estimates for different loading scenarios at preflight and at 0 and 365 days post-flight time periods are compared. Results: For simple lateral side falls, mean post-flight fracture probability is elevated over mean preflight fracture probability due to spaceflight induced BMD loss and is not fully recovered at 365 days post-flight. In the case of more energetic falls, such as from elevated heights or with the addition of lateral movement

  2. Resorbable calcium phosphate bone substitute.

    PubMed

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

    1998-01-01

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

  3. Bone remodeling after renal transplantation.

    PubMed

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

    2003-06-01

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

  4. Space flight and bone formation

    NASA Technical Reports Server (NTRS)

    Doty, St B.

    2004-01-01

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

  5. Function of osteocytes in bone.

    PubMed

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

    1994-07-01

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

  6. [Bone lesion in multiple myeloma].

    PubMed

    Ise, Mikiko; Takagi, Toshiyuki

    2007-12-01

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

  7. [Vitamin K and bone quality].

    PubMed

    Hara, Kuniko; Akiyama, Yasuhiro

    2007-11-01

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

  8. Molecular Mechanisms of Bone Metastasis.

    PubMed

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

    2016-01-01

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

  9. Hypothalamic control of bone metabolism.

    PubMed

    Sharan, Kunal; Yadav, Vijay K

    2014-10-01

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

  10. Cancer to bone: a fatal attraction

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    1993-01-01

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

  12. Blood flow controls bone vascular function and osteogenesis

    PubMed Central

    Ramasamy, Saravana K.; Kusumbe, Anjali P.; Schiller, Maria; Zeuschner, Dagmar; Bixel, M. Gabriele; Milia, Carlo; Gamrekelashvili, Jaba; Limbourg, Anne; Medvinsky, Alexander; Santoro, Massimo M.; Limbourg, Florian P.; Adams, Ralf H.

    2016-01-01

    While blood vessels play important roles in bone homeostasis and repair, fundamental aspects of vascular function in the skeletal system remain poorly understood. Here we show that the long bone vasculature generates a peculiar flow pattern, which is important for proper angiogenesis. Intravital imaging reveals that vessel growth in murine long bone involves the extension and anastomotic fusion of endothelial buds. Impaired blood flow leads to defective angiogenesis and osteogenesis, and downregulation of Notch signalling in endothelial cells. In aged mice, skeletal blood flow and endothelial Notch activity are also reduced leading to decreased angiogenesis and osteogenesis, which is reverted by genetic reactivation of Notch. Blood flow and angiogenesis in aged mice are also enhanced on administration of bisphosphonate, a class of drugs frequently used for the treatment of osteoporosis. We propose that blood flow and endothelial Notch signalling are key factors controlling ageing processes in the skeletal system. PMID:27922003

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

    PubMed Central

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

    2015-01-01

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

  14. Calcium Phosphate Scaffolds Combined with Bone Morphogenetic Proteins or Mesenchymal Stem Cells in Bone Tissue Engineering

    PubMed Central

    Sun, Han; Yang, Hui-Lin

    2015-01-01

    Objective: The purpose of this study was to review the current status of calcium phosphate (CaP) scaffolds combined with bone morphogenetic proteins (BMPs) or mesenchymal stem cells (MSCs) in the field of bone tissue engineering (BTE). Date Sources: Data cited in this review were obtained primarily from PubMed and Medline in publications from 1979 to 2014, with highly regarded older publications also included. The terms BTE, CaP, BMPs, and MSC were used for the literature search. Study Selection: Reviews focused on relevant aspects and original articles reporting in vitro and/or in vivo results concerning the efficiency of CaP/BMPs or CaP/MSCs composites were retrieved, reviewed, analyzed, and summarized. Results: An ideal BTE product contains three elements: Scaffold, growth factors, and stem cells. CaP-based scaffolds are popular because of their outstanding biocompatibility, bioactivity, and osteoconductivity. However, they lack stiffness and osteoinductivity. To solve this problem, composite scaffolds of CaP with BMPs have been developed. New bone formation by CaP/BMP composites can reach levels similar to those of autografts. CaP scaffolds are compatible with MSCs and CaP/MSC composites exhibit excellent osteogenesis and stiffness. In addition, a CaP/MSC/BMP scaffold can repair bone defects more effectively than an autograft. Conclusions: Novel BTE products possess remarkable osteoconduction and osteoinduction capacities, and exhibit balanced degradation with osteogenesis. Further work should yield safe, viable, and efficient materials for the repair of bone lesions. PMID:25881610

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

    PubMed

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

    2013-01-01

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

  16. Matrix Vesicle Enzyme Activity and Phospholipid Content in Endosteal Bone Following Implantation of Osseointegrating and Non-Osseointegrating Implant Materials.

    DTIC Science & Technology

    1991-11-01

    formation of dental calculus by colonies of organized dental plaque (Boyan et al., 1982; Ennever et al., 1978b; and Sidaway, 1980). Although first thought...chamber was achieved by frontal 17 penetration of the antero-medial aspect of the exposed bone with a saline-cooled, round dental burr (#4) and a...penetration of the antero- 24 25 medial aspect of the exposed bone with a saline-cooled, round dental burr (#4) and a 20,000 RPM motor. The bone marrow

  17. Bridge of bone canthopexy.

    PubMed

    Yaremchuk, Michael J; Chen, Yi-Chieh

    2009-01-01

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

  18. Radiotherapy for bone pain.

    PubMed Central

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

    1994-01-01

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

  19. Shang Oracle Bones

    NASA Astrophysics Data System (ADS)

    Pankenier, David W.

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

  20. Supersymmetric chiral models: Geometrical aspects

    NASA Astrophysics Data System (ADS)

    Perelomov, A. M.

    1989-03-01

    We consider classical supersymmetric chiral models of field theory and focus our attention on the geometrical aspects of such theories. A characteristic feature of such models is that the interaction is not introduced by adding the interaction Lagrangian to the free field Lagrangian, but has a purely geometrical origin and is related to the inner curvature of the target manifold. In many aspects these models are analogous to gauge theories and, as became clear recently, they are also important for superstring theory, which nowadays is the most probable candidate for a truly unified theory of all interactions including gravitation.

  1. PSYCHOLOGICAL ASPECTS OF ATOMIC DISASTER

    PubMed Central

    Adams, Edward C.

    1954-01-01

    Increasing attention to the psychological aspects of atomic disaster will help improve the ability of the citizens of this country to withstand attack and survive as a free people. Since an enemy may be expected to exploit any internal weaknesses it can find, preparation must be made against the onslaught. The ability to deal effectively with any situation, even the most awesome, depends on knowledge of what to expect, and there is no reason to believe that facts about atomic disaster are an exception to this time proven truth. The psychological aspects need to be considered from two points of view, namely, the effect on masses of people and on individuals. PMID:13182616

  2. Adult with sacral lipomyelomeningocele covered by an anomalous bone articulated with iliac bone: computed tomography and magnetic resonance images.

    PubMed

    Lee, Seung Hwa; Je, Bo-Kyung; Kim, Sung-Bum; Kim, Baek Hyun

    2012-06-01

    The present paper reports and discusses a case of sacral lipomyelomeningocele with an anomalous long bone articulating with the left iliac bone in a 40-year-old female. That patient had a monozygotic twin sister who had normal spine. The findings were incidental during an evaluation for a urinary tract infection. The computed tomography (CT) and magnetic resonance (MR) images revealed sacral dysraphism, lipomyelomeningocele, tethered spinal cord, and profound subcutaneous fat in the sacrococcygeal region. In addition, an anomalous bony strut was demonstrated on the posterior aspect of the sacrum, covering the sacral defect and the associated lipomyelomeningocele. The 3-D CT images of the anomalous bone associated with the sacral lipomyelomeningocele and the putative embryologic process are presented with a review of the literature.

  3. Androgens and Bone

    PubMed Central

    Clarke, Bart L.; Khosla, Sundeep

    2009-01-01

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

  4. Battling Brittle Bones

    NASA Technical Reports Server (NTRS)

    2002-01-01

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

  5. Bone Metabolism on ISS Missions

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

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

    PubMed

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

    2011-12-01

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

  7. Bone fragility and imaging techniques

    PubMed Central

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

    2009-01-01

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

  8. Bone Morphogenetic Proteins: Periodontal Regeneration

    PubMed Central

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

    2013-01-01

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

  9. [Bone grafts using tissue engineering].

    PubMed

    Delloye, C

    2001-01-01

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

  10. [Forensic medical characteristic of sawed injuries inflicted to the long tubular bones by a power jigsaw].

    PubMed

    Nazarov, Iu V; Tolmachev, I A

    2013-01-01

    The main aspects of investigations devoted to forensic medical characteristic of sawed injuries inflicted to the long tubular bones by a power jigsaw are considered. The mathematical model has been developed making it possible to determine the frequency of backward and forward movements of the jigsaw blade from the morphological features of the injuries to long tubular bones of man and to estimate the sawing rate for the further identification of the instrument of crime.

  11. Bone injury and late giant-cell tumor occurrence: a possible relation. A case report.

    PubMed

    De Nayer, P P; Delloye, C; Malghem, J

    1987-09-01

    A giant-cell tumor of the upper end of the fibula, five years after a documented bone injury at the same site is reported. The histologic diagnosis was corroborated by the patient's age, tumor localization, radiologic and pathologic aspects. The role of a bone injury as a promoting factor in the development of this tumor is discussed. The tumoral occurrence as a reactive process to trauma in this case may not be ruled out.

  12. Gene therapy for bone regeneration.

    PubMed

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

    2005-04-01

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

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

    NASA Astrophysics Data System (ADS)

    Blynskiy, F. Yu

    2016-01-01

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

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

    PubMed

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

    2013-01-01

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

  15. Bone Health in Adolescence.

    PubMed

    Carey, Dennis E; Golden, Neville H

    2015-08-01

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

  16. A New Insight to Bone Turnover: Role of ω-3 Polyunsaturated Fatty Acids

    PubMed Central

    López-Frías, Magdalena; López-Aliaga, Inmaculada; Ochoa, Julio J.

    2013-01-01

    Background. Evidence has shown that long-chain polyunsaturated fatty acids (LCPUFA), especially the ω-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are beneficial for bone health and turnover. Objectives. This review summarizes findings from both in vivo and in vitro studies and the effects of LC PUFA on bone metabolism, as well as the relationship with the oxidative stress, the inflammatory process, and obesity. Results. Some studies in humans indicate that LCPUFA can increase bone formation, affect peak bone mass in adolescents, and reduce bone loss. However, the cellular mechanisms of action of the LCPUFA are complex and involve modulation of fatty acid metabolites such as prostaglandins, resolvins and protectins, several signaling pathways, cytokines, and growth factors, although in certain aspects there is still some controversy. LCPUFA affect receptor activator of nuclear factor κβ (RANK), a receptor found on the osteoclast, causing bone resorption, which controls osteoclast formation. Conclusions. Since fatty acids are an endogenous source of reactive oxygen species, free radicals alter the process of bone turnover; however, although there are clinical evidences linking bone metabolism and dietary lipids, more clinical trials are necessary to prove whether ω-3 PUFA supplementation plays a major role in bone health. PMID:24302863

  17. Modelling the anabolic response of bone using a cell population model.

    PubMed

    Buenzli, Pascal R; Pivonka, Peter; Gardiner, Bruce S; Smith, David W

    2012-08-21

    To maintain bone mass during bone remodelling, coupling is required between bone resorption and bone formation. This coordination is achieved by a network of autocrine and paracrine signalling molecules between cells of the osteoclastic lineage and cells of the osteoblastic lineage. Mathematical modelling of signalling between cells of both lineages can assist in the interpretation of experimental data, clarify signalling interactions and help develop a deeper understanding of complex bone diseases. Several mathematical models of bone cell interactions have been developed, some including RANK-RANKL-OPG signalling between cells and systemic parathyroid hormone PTH. However, to our knowledge these models do not currently include key aspects of some more recent biological evidence for anabolic responses. In this paper, we further develop a mathematical model of bone cell interactions by Pivonka et al. (2008) to include the proliferation of precursor osteoblasts into the model. This inclusion is important to be able to account for Wnt signalling, believed to play an important role in the anabolic responses of bone. We show that an increased rate of differentiation to precursor cells or an increased rate of proliferation of precursor osteoblasts themselves both result in increased bone mass. However, modelling these different processes separately enables the new model to represent recent experimental discoveries such as the role of Wnt signalling in bone biology and the recruitment of osteoblast progenitor cells by transforming growth factor β. Finally, we illustrate the power of the new model's capabilities by applying the model to prostate cancer metastasis to bone. In the bone microenvironment, prostate cancer cells are believed to release some of the same signalling molecules used to coordinate bone remodelling (i.e.,Wnt and PTHrP), enabling the cancer cells to disrupt normal signalling and coordination between bone cells. This disruption can lead to either bone

  18. Additional aspects of elastohydrodynamic lubrication

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.

    1978-01-01

    An up-to-date review of the varying aspects of elastohydrodynamic lubrication is presented.. Some recent work on elastohydrodynamic lubrication of materials of low elastic modulus as well as on hydrodynamic lubrication is included. Both these topics are applicable for contacts with any ellipticity parameter (ranging from a circular contact to a line contact).

  19. TWO ASPECT MARKERS IN MANDARIN.

    ERIC Educational Resources Information Center

    WANG, WILLIAM S-Y.

    TWO ASPECT MARKERS IN MANDARIN CHINESE ARE STUDIED WITHIN THE GENERAL FRAMEWORK OF A TRANSFORMATIONAL GRAMMAR. THEY ARE COMMONLY REPRESENTED AS "-LE," INDICATING COMPLETION OF ACTION, AND "-GUO," INDICATING THAT AN ACTION HAS TAKEN PLACE AT LEAST ONCE. THE PROBLEM INVOLVES SEVERAL SEEMING IRREGULARITIES IN THE FORMATION OF…

  20. Psychosocial Aspects of Heart Transplantation.

    ERIC Educational Resources Information Center

    Suszycki, Lee H.

    1988-01-01

    Presents an overview of medical and psychosocial aspects of heart transplantation, with a focus on the program at Columbia-Presbyterian Medical Center. Describes social workers' interventions which help patients and families to achieve optimal psychosocial functioning before and after transplantation. (Author/ABL)

  1. Legal Aspects of the Web.

    ERIC Educational Resources Information Center

    Borrull, Alexandre Lopez; Oppenheim, Charles

    2004-01-01

    Presents a literature review that covers the following topics related to legal aspects of the Web: copyright; domain names and trademarks; linking, framing, caching, and spamdexing; patents; pornography and censorship on the Internet; defamation; liability; conflict of laws and jurisdiction; legal deposit; and spam, i.e., unsolicited mails.…

  2. Neurologic aspects of drug abuse.

    PubMed

    Goforth, Harold W; Murtaugh, Reed; Fernandez, Francisco

    2010-02-01

    Neurologic aspects of drug abuse vary. This article explains the general nature of drug abuse, identifies the physiologic effects of certain drugs, and briefly describes the neurobiology of addiction. This article also reviews available treatment options for those addicted to substances of abuse, and clarifies common misconceptions, including the differences between tolerance, abuse, and addiction.

  3. Behavioral Aspects of Marijuana Use.

    ERIC Educational Resources Information Center

    Paulson, Patricia

    This paper examines the behavioral aspects of marijuana use. The focus of the study was to investigate the attitudes and practices toward drugs by users and non-users and the relationship of these attitudes and practices to selected psychosocial factors. A survey instrument in the form of an anonymous questionnaire was developed and administered…

  4. Gender Aspects of Human Security

    ERIC Educational Resources Information Center

    Moussa, Ghada

    2008-01-01

    The chapter deals with the gender dimensions in human security through focusing on the relationship between gender and human security, first manifested in international declarations and conventions, and subsequently evolving in world women conferences. It aims at analysing the various gender aspects in its relation to different human security…

  5. [Scientometric aspects of medical eponyms].

    PubMed

    Schubert, András

    2014-09-07

    Eponyms, scientific concepts named after persons, have a long tradition in medical sciences. Their emergence and use are rather instructive from the aspects of scientometrics, as well. Using a medical sample it is shown that although references to publications giving origin to the eponyms inevitably get obliterated, their citation rate is still many times higher than that of other publications of the same age.

  6. Mathematical Aspects of Electoral Systems

    NASA Astrophysics Data System (ADS)

    Konstantinov, M. M.

    2007-10-01

    In this paper we consider some mathematical aspects of electoral systems. Sometimes the results from elections seem paradoxical although they are mathematically correct. These cases are known as electoral paradoxes. A number of paradoxes of proportional and majoritarian electoral systems are considered.

  7. Aspects of Spirituality in Adolescents

    ERIC Educational Resources Information Center

    Bussing, Arndt; Foller-Mancini, Axel; Gidley, Jennifer; Heusser, Peter

    2010-01-01

    This paper analyses which aspects of spirituality are valued by adolescents, and how they are interconnected with youths' life satisfaction and "self-centeredness". The participants were 254 adolescents (11th grade) of four different high schools from west Germany. After re-validation of the 6-factorial student's version of the ASP…

  8. Pragmatic Aspects of Scalar Modifiers

    ERIC Educational Resources Information Center

    Sawada, Osamu

    2010-01-01

    This dissertation investigates the pragmatic aspects of scalar modifiers from the standpoint of the interface between semantics and pragmatics, focusing on (i) the (non) parallelism between the truth-conditional scalar modifiers and the non-truth-conditional scalar modifiers, (ii) the compositionality and dimensionality of non-truth-conditional…

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

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

    Current spaceflight exercise countermeasures do not eliminate bone loss. Astronauts lose bone mass at a rate of 1-2% a month (Lang et al. 2004, Buckey 2006, LeBlanc et al. 2007). This may lead to early onset osteoporosis and place the astronauts at greater risk of fracture later in their lives. NASA seeks to improve understanding of the mechanisms of bone remodeling and demineralization in 1g in order to appropriately quantify long term risks to astronauts and improve countermeasures. NASA's Digital Astronaut Project (DAP) is working with NASA's bone discipline to develop a validated computational model to augment research efforts aimed at achieving this goal.

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

    PubMed

    Chen, Xu Xu; Yang, Tianfu

    2015-09-01

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

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

    SciTech Connect

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

    1980-08-01

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

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

    PubMed

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

    2011-02-11

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-02-01

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

  14. Microgravity and bone cell mechanosensitivity

    NASA Astrophysics Data System (ADS)

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

    2003-10-01

    The capacity of bone tissue to alter its mass and structure in response to mechanical demands has long been recognized but the cellular mechanisms involved remained poorly understood. Bone not only develops as a structure designed specifically for mechanical tasks, but it can adapt during life toward more efficient mechanical performance. Mechanical adaptation of bone is a cellular process and needs a biological system that senses the mechanical loading. The loading information must then be communicated to the effector cells that form new bone or destroy old bone. The in vivo operating cell stress derived from bone loading is likely the flow of interstitial fluid along the surface of osteocytes and lining cells. The response of bone cells in culture to fluid flow includes prostaglandin (PG) synthesis and expression of prostaglandin G/H synthase inducible cyclooxygenase (COX-2). Cultured bone cells also rapidly produce nitric oxide (NO) in response to fluid flow as a result of activation of endothelial nitric oxide synthase (ecNOS), which enzyme also mediates the adaptive response of bone tissue to mechanical loading. Earlier studies have shown that the disruption of the actin-cytoskeleton abolishes the response to stress, suggesting that the cytoskeleton is involved in cellular mechanotransduction. Microgravity, or better near weightlessness, is associated with the loss of bone in astronauts, and has catabolic effects on mineral metabolism in bone organ cultures. This might be explained as resulting from an exceptional form of disuse under near weightlessness conditions. However, under near weightlessness conditions the assembly of cytoskeletal elements may be altered since it has been shown that the direction of the gravity vector determines microtubular pattern formation in vivo. We found earlier that the transduction of mechanical signals in bone cells also involves the cytoskeleton and is related to PGEZ production. Therefore it is possible that the

  15. Animal Models of Bone Metastasis

    PubMed Central

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

    2015-01-01

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

  16. Clinical value of bone densitometry.

    PubMed

    Sartoris, D J

    1994-07-01

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

  17. Bone disease and HIV infection.

    PubMed

    Amorosa, Valerianna; Tebas, Pablo

    2006-01-01

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

  18. Significant forefoot varus deformity resulting in progressive stress fractures of all lesser metatarsal bones.

    PubMed

    van der Vlies, Cornelis H; Ponsen, Kees J; Besselaar, Philip P; Goslings, J Carel

    2007-01-01

    Stress fractures may occur in any bone, but appear most frequently in the metatarsal bones. Consecutive stress fractures of all lesser metatarsals in a short period are rare, and only a few cases have been described in the literature. We report an unusual case of a young man with consecutive stress fractures of four adjacent lesser metatarsal bones. The etiology was in all probability the fixed forefoot varus deformity. This foot deformity may impose increased mechanical loads across the lateral aspect of the foot that, in turn, may result in stress fractures involving the lesser metatarsals. In our patient conservative treatment finally resulted in a satisfactory outcome.

  19. Drinking water fluoridation and bone.

    PubMed

    Allolio, B; Lehmann, R

    1999-01-01

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

  20. Diagnosis of metabolic bone disease

    SciTech Connect

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

    1986-01-01

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

  1. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

  2. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

  3. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  4. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  5. 21 CFR 872.4760 - Bone plate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

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

    PubMed

    Suzuki, Atsushi

    2011-09-01

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

  7. Aneurysmal bone cyst and other nonneoplastic conditions

    SciTech Connect

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

    1982-08-01

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

  8. Bone Transport for Reconstruction in Benign Bone Tumors

    PubMed Central

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

    2015-01-01

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

  9. The biology of bone lengthening.

    PubMed

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

    2016-12-01

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

  10. Bone Disease and Idiopathic Hypercalciuria

    PubMed Central

    Zerwekh, Joseph E.

    2008-01-01

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

  11. Microgravity and Bone Cell Mechanosensitivity

    NASA Astrophysics Data System (ADS)

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

    The capacity of bone tissue to alter its mass and structure in response to mechanical demands has long been recognized but the cellular mechanisms involved remained poorly understood. Bone not only develops as a structure designed specifically for mechanical tasks, but it can adapt during life toward more efficient mechanical performance. Mechanical adaptation of bone is a cellular process and needs a biological system that senses the mechanical loading. The loading information must then be communicated to the effector cells that form new bone or destroy old bone.The in vivo operating cell stress derived from bone loading is likely flow of interstitial fluid along the surface of osteocytes and lining cells. The response of bone cells in culture to fluid flow includes prostaglandin (PG) synthesis and expression of prostaglandin G/H synthase inducible cyclooxygenase (COX-2). Cultured bone cells also rapidly produce nitric oxide (NO) in response to fluid flow as a result of activation of endothelial nitric oxide synthase (ecNOS), which enzyme also mediates the adaptive response of bone tissue to mechanical loading. Disruption of the actin-cytoskeleton abolishes the response to stress, suggesting that the cytoskeleton is involved in cellular mechanotransduction.Microgravity, or better near weightlessness, has catabolic effects on the skeleton of astronauts, and on mineral metabolism in bone organ cultures. This might be explained as resulting from an exceptional form of disuse under near weightlessness conditions. However, under near weightlessness conditions the assembly of cytoskeletal elements may be altered since it has been shown that the direction of the gravity vector determines microtubular pattern formation in vivo. We found that the transduction of mechanical signals in bone cells also involves the cytoskeleton and is related to PGE2 production. Therefore it is possible that the mechanosensitivity of bone cells is altered under near weightlessness conditions

  12. Symmetry analysis of talus bone

    PubMed Central

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

    2014-01-01

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

  13. Biomechanical properties of bone allografts

    SciTech Connect

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

    1983-04-01

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

  14. Reloading partly recovers bone mineral density and mechanical properties in hind limb unloaded rats

    NASA Astrophysics Data System (ADS)

    Zhao, Fan; Li, Dijie; Arfat, Yasir; Chen, Zhihao; Liu, Zonglin; Lin, Yu; Ding, Chong; Sun, Yulong; Hu, Lifang; Shang, Peng; Qian, Airong

    2014-12-01

    Skeletal unloading results in decreased bone formation and bone mass. During long-term space flight, the decreased bone mass is impossible to fully recover. Therefore, it is necessary to develop the effective countermeasures to prevent spaceflight-induced bone loss. Hindlimb Unloading (HLU) simulates effects of weightlessness and is utilized extensively to examine the response of musculoskeletal systems to certain aspects of space flight. The purpose of this study is to investigate the effects of a 4-week HLU in rats and subsequent reloading on the bone mineral density (BMD) and mechanical properties of load-bearing bones. After HLU for 4 weeks, the rats were then subjected to reloading for 1 week, 2 weeks and 3 weeks, and then the BMD of the femur, tibia and lumbar spine in rats were assessed by dual energy X-ray absorptiometry (DXA) every week. The mechanical properties of the femur were determined by three-point bending test. Dry bone and bone ash of femur were obtained through Oven-Drying method and were weighed respectively. Serum alkaline phosphatase (ALP) and serum calcium were examined through ELISA and Atomic Absorption Spectrometry. The results showed that 4 weeks of HLU significantly decreased body weight of rats and reloading for 1 week, 2 weeks or 3 weeks did not recover the weight loss induced by HLU. However, after 2 weeks of reloading, BMD of femur and tibia of HLU rats partly recovered (+10.4%, +2.3%). After 3 weeks of reloading, the reduction of BMD, energy absorption, bone mass and mechanical properties of bone induced by HLU recovered to some extent. The changes in serum ALP and serum calcium induced by HLU were also recovered after reloading. Our results indicate that a short period of reloading could not completely recover bone after a period of unloading, thus some interventions such as mechanical vibration or pharmaceuticals are necessary to help bone recovery.

  15. Bone-related complications of transfusion-dependent beta thalassemia among children and adolescents.

    PubMed

    Mirhosseini, Naghmeh Zahra; Shahar, Suzana; Ghayour-Mobarhan, Majid; Banihashem, Abdullah; Kamaruddin, Nor Azmi; Hatef, Mohammad Reza; Esmaili, Habib Alah

    2013-07-01

    Thalassemia and the blood transfusion complications associated with it predispose children to poor bone health. This study was conducted to determine the prevalence of bone-related abnormalities and identify the bone health predictors within this population. One hundred and forty transfusion-dependent beta thalassemic subjects 8-18 years old in Mashhad, Iran, participated in this cross-sectional study. Anthropometric measures, dietary intake, bone-related biomarkers and bone densitometry, were assessed. The incidence of underweight and short stature was 33.6 and 41.4 %, respectively, which were indicators of malnutrition among thalassemic subjects in this study. Low bone density was detected in the lumbar spine and femoral region in 82 and 52 % of subjects, respectively. Hypocalcemia and hypophosphatemia were seen in 22 and 18.2 %, whilst vitamin D deficiency was present in more than 85 % of thalassemic children and adolescents. The relationships between weight, height and other anthropometric indices, serum calcium and bone markers, intake of macronutrients, zinc and vitamin E with bone mineral density (BMD) and bone mineral content (BMC) in the lumbar spine and femoral area were positively related, indicating that better nutritional status were associated with higher BMD and BMC values. Puberty, gender and serum osteocalcin were negative predictors for BMD and BMC values, whereas age, weight and height were the positive predictors. High incidence of low bone density and deficit in other aspects of bone health among thalassemia patients makes routine bone health assessment necessary for this vulnerable group. Considering influencing factors, dietary counseling and preventive supplementation therapy for this high risk group of children and adolescents may be necessary, although this should be assessed by intervention studies.

  16. Osteoporotic-like effects of cadmium on bone mineral density and content in aged ovariectomized beagles

    SciTech Connect

    Sacco-Gibson, N.; Abrams, J.; Chaudhry, S.; Hurst, D.; Peterson, D.; Bhattacharyya, M.

    1992-12-31

    Our purpose was to evaluate the effects of ovariectomy in conjunction with cadmium (Cd) exposure on bone. Aged female beagles with {sup 45}Ca-labeled skeletons ovariectomized and exposed to Cd. Successive vertebral scans by dual photon absorptiometry monitored changes in bone mineral density (BMD) in each dog with time. Results showed that ovariectomy or Cd exposure alone caused significant decreases in BMD; ovariectomy with Cd exposure caused the greatest decrease. Ovariectomy alone did not decrease BMD in the distal end or mid-shaft of the tibia while BMD of the distal tibia decreased significantly due to Cd exposure alone. Combination treatment resulted in significant decreases in BMD of both tibial regions. At necropsy, tibiae, humeri, lumbar vertebrae and ribs were obtained for biochemical analysis. No group-to-group differences in bone weights (wet, dry, ash), in ash/dry ratios, or in long bone and vertebral Ca/dry or Ca/ash ratios were observed. Significantly higher total {sup 45}Ca content and {sup 45}Ca/dry and {sup 45}Ca/ash ratios were observed in long bones and vertebrae of OV- and OV+ groups. In contrast, intact ribs showed significantly decreased Ca/dry and Ca/ash ratios compared to the SO-group. Quartered ribs demonstrated regional responses to specific treatment; decreases in total Ca content were greatest in the mid-rib region ({minus}36 to {minus}46%). Results suggest that in the aged female beagle, bone mineral loss associated with estrogen depletion is not only related to bone type (trabecular versus cortical) but also to bone Ca pools. Our results also suggest that a regional heterogeneity of bone plays a role in responsiveness to ovariectomy and Cd exposure. These aspects suggest that Cd is an exogenous factor affecting bone mineral loss independently of estrogen depletion. However, estrogen depletion primes bone for responsiveness to Cd-induced bone mineral loss.

  17. Influence of bone volume fraction and architecture on computed large-deformation failure mechanisms in human trabecular bone.

    PubMed

    Bevill, Grant; Eswaran, Senthil K; Gupta, Atul; Papadopoulos, Panayiotis; Keaveny, Tony M

    2006-12-01

    Large-deformation bending and buckling have long been proposed as failure mechanisms by which the strength of trabecular bone can be affected disproportionately to changes in bone density, and thus may represent an important aspect of bone quality. We sought here to quantify the contribution of large-deformation failure mechanisms on strength, to determine the dependence of these effects on bone volume fraction and architecture, and to confirm that the inclusion of large-deformation effects in high-resolution finite element models improves predictions of strength versus experiment. Micro-CT-based finite element models having uniform hard tissue material properties were created from 54 cores of human trabecular bone taken from four anatomic sites (age = 70+/-11; 24 male, 27 female donors), which were subsequently biomechanically tested to failure. Strength predictions were made from the models first including, then excluding, large-deformation failure mechanisms, both for compressive and tensile load cases. As expected, strength predictions versus experimental data for the large-deformation finite element models were significantly improved (p < 0.001) relative to the small deformation models in both tension and compression. Below a volume fraction of about 0.20, large-deformation failure mechanisms decreased trabecular strength from 5-80% for compressive loading, while effects were negligible above this volume fraction. Step-wise nonlinear multiple regression revealed that structure model index (SMI) and volume fraction (BV/TV) were significant predictors of these reductions in strength (R2 = 0.83, p < 0.03). Even so, some low-density specimens having nearly identical volume fraction and SMI exhibited up to fivefold differences in strength reduction. We conclude that within very low-density bone, the potentially important biomechanical effect of large-deformation failure mechanisms on trabecular bone strength is highly heterogeneous and is not well explained by

  18. Environmental aspects of congenital scoliosis.

    PubMed

    Li, Zheng; Yu, Xin; Shen, Jianxiong

    2015-04-01

    Growing evidence has proved that many aspects of our lifestyle and the environment contribute to the development of congenital disease. Congenital spinal deformities are due to anomalous development of the vertebrae including failure of formation and segmentation during embryogenesis. The causes of congenital scoliosis have not been fully identified. A variety of factors are implicated in the development of vertebral abnormalities. Previous studies have demonstrated that both genetics and environmental factors are implicated in the development of vertebral abnormalities. However, no specific cause for congenital scoliosis has been identified. In our review, we focus on the environmental factors for the development of congenital scoliosis. Various maternal exposures during pregnancy including hypoxia, alcohol use, vitamin deficiency, valproic acid, boric acid, and hyperthermia have been observed to be associated with the occurrence of congenital scoliosis. This review describes the major environmental contributors of congenital scoliosis with an emphasis on treatment aspects associated with environmental disposition in congenital scoliosis.

  19. Liposarcome dorsal: aspect clinique rare

    PubMed Central

    Agbessi, Odry; Arrob, Adil; Fiqhi, Kamal; Khalfi, Lahcen; Nassih, Mohammed; El Khatib, Karim

    2015-01-01

    Décrit la première fois par Virchow en 1860, le liposarcome est une tumeur mésenchymateuse rare. Cette rareté est relative car les liposarcomes représentent quand même 14 à 18% de l'ensemble des tumeurs malignes des parties molles et ils constituent le plus fréquent des sarcomes des parties molles. Pour la majorité des auteurs, il ne se développerait jamais sur un lipome ou une lipomatose préexistant. Nous rapportons un cas de volumineux liposarcome de la face dorsale du tronc. L'histoire de la maladie, l'aspect clinique inhabituel « de tumeur dans tumeur », l'aspect de la pièce opératoire nous fait évoquer la possibilité de la transformation maligne d'un lipome bénin préexistant. PMID:26113914

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

    PubMed

    Nieves, Jeri W

    2014-05-01

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

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

    PubMed

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

    2017-03-01

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

  2. Thermodynamic aspects of therapeutic hypothermia.

    PubMed

    Vanlandingham, Sean C; Kurz, Michael C; Wang, Henry E

    2015-01-01

    Therapeutic hypothermia (TH) is an important treatment for post-cardiac arrest syndrome. Despite its widespread practice, only limited data describe the thermodynamic aspects of heat transfer during TH. This paper reviews the principles of human body heat balance and provides a conceptual model for characterizing heat exchange during TH. The model may provide a framework for computer simulation for improving training in or clinical methods of TH.

  3. Legal aspects of satellite teleconferencing

    NASA Technical Reports Server (NTRS)

    Smith, D. D.

    1971-01-01

    The application of satellite communications for teleconferencing purposes is discussed. The legal framework within which such a system or series of systems could be developed is considered. The analysis is based on: (1) satellite teleconferencing regulation, (2) the options available for such a system, (3) regulatory alternatives, and (4) ownership and management aspects. The system is designed to provide a capability for professional education, remote medical diagnosis, business conferences, and computer techniques.

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

    PubMed

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

    2015-10-01

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

  5. Raman spectroscopy of bone metastasis

    NASA Astrophysics Data System (ADS)

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

    2012-02-01

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

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

    PubMed

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

    2009-10-01

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

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

    PubMed Central

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

    2009-01-01

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

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

    PubMed

    Mizuno, Hiroki; Kikuta, Junichi; Ishii, Masaru

    2014-04-01

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

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

    MedlinePlus

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

  10. ISS Update: Bone Health in Space

    NASA Video Gallery

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

  11. Usefulness of a quick decalcification of bone sections embedded in methyl methacrylate[corrected]: an improved method for immunohistochemistry.

    PubMed

    Gomes, Samirah Abreu; dos Reis, Luciene Machado; de Oliveira, Ivone Braga; Noronha, Irene de Lourdes; Jorgetti, Vanda; Heilberg, Ita Pfeferman

    2008-01-01

    Immunohistochemistry of undecalcified bone sections embedded in methyl methacrylate (MMA) is not commonly employed because of potential destruction of tissue antigenicity by highly exothermic polymerization. The aim of the present study was to describe a new technique in which a quick decalcification of bone sections embedded in MMA improves the results for immunohistochemistry. The quality of interleukin 1alpha (IL-1alpha) immunostaining according to the present method was better than the conventional one. Immunostaining for osteoprotegerin (OPG) and the receptor activator of NF-kappaB ligand (RANKL) in bone sections of chronic kidney disease patients with mineral bone disorders (CKD-MBD) was stronger than in controls (postmortem healthy subjects). The present study suggested that this method is easy, fast, and effective to perform both histomorphometry and immunohistochemistry in the same bone fragment, yielding new insights into pathophysiological aspects and therapeutic approaches in bone disease.

  12. Clinical significance of interleukin (IL)-6 in cancer metastasis to bone: potential of anti-IL-6 therapies

    PubMed Central

    Tawara, Ken; Oxford, Julia T; Jorcyk, Cheryl L

    2011-01-01

    Metastatic events to the bone occur frequently in numerous cancer types such as breast, prostate, lung, and renal carcinomas, melanoma, neuroblastoma, and multiple myeloma. Accumulating evidence suggests that the inflammatory cytokine interleukin (IL)-6 is frequently upregulated and is implicated in the ability of cancer cells to metastasize to bone. IL-6 is able to activate various cell signaling cascades that include the STAT (signal transducer and activator of transcription) pathway, the PI3K (phosphatidylinositol-3 kinase) pathway, and the MAPK (mitogen-activated protein kinase) pathway. Activation of these pathways may explain the ability of IL-6 to mediate various aspects of normal and pathogenic bone remodeling, inflammation, cell survival, proliferation, and pro-tumorigenic effects. This review article will discuss the role of IL-6: 1) in bone metabolism, 2) in cancer metastasis to bone, 3) in cancer prognosis, and 4) as potential therapies for metastatic bone cancer. PMID:21625400

  13. Frontal bone fractures.

    PubMed

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

    2014-11-01

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

  14. Bone densitometry in infants

    SciTech Connect

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

    1988-07-01

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

  15. Temporal bone anatomy in Panthera tigris

    NASA Astrophysics Data System (ADS)

    Walsh, Edward J.; Ketten, Darlene R.; Arruda, Julie; Armstrong, Douglas L.; Curro, Thomas; Simmons, Lee G.; Wang, Lily M.; McGee, Joann

    2004-05-01

    Preliminary findings suggest that members of Panthera tigris subspecies may rely on low-frequency acoustic cues when communicating with conspecifics either in the field or in captivity. This view is supported by the observation that individuals are sensitive to tone bursts in the 300-500-Hz range and produce significant acoustic energy in an overlapping frequency band in the case of close encounter roars. Other utterances within the vocal repertoire of tigers also contain, and are often dominated by, low frequency acoustic energy that can extend into the infrasonic range. Efforts to determine temporal bone correlates of P. tigris bioacoustical features were recently initiated using computerized tomography to assess key aspects of middle and inner ear morphology from a small set of adult Siberian tigers (P. tigris altaica) and one neonate. Obvious peripheral auditory specializations were not observed and structures comprising the auditory periphery were consistent with the anatomical character of felids generally. Although cochlear dimensions appeared to be adultlike, or nearly so, in the case of the neonate, other temporal bone features were grossly immature. The relationship between acoustic sensitivity, the spectral character of a subset of close encounter calls and cochlear dimensions will be considered.

  16. Derangements in bone mineral parameters and bone mineral density in south Indian subjects on antiepileptic medications

    PubMed Central

    Koshy, George; Varghese, Ron Thomas; Naik, Dukhabandhu; Asha, Hesargatta Shyamsunder; Thomas, Nihal; Seshadri, Mandalam Subramaniam; Alexander, Mathew; Thomas, Maya; Aaron, Sanjith; Paul, Thomas Vizhalil

    2014-01-01

    Background: Although there are reports describing the association of alternations of bone and mineral metabolism in epileptic patients with long-term anticonvulsant therapy, there are only limited Indian studies which have looked at this aspect. Objectives: This study was done to compare the prevalence of changes in bone mineral parameters and bone mineral density (BMD) in ambulant individuals on long-term anticonvulsant therapy with age- and body mass index (BMI)-matched healthy controls. Materials and Methods: There were 55 men (on medications for more than 6 months) and age- and BMI-matched 53 controls. Drug history, dietary calcium intake (DCI), and duration of sunlight exposure were recorded. Bone mineral parameters and BMD were measured. Results: The control group had a significantly higher daily DCI with mean ± SD of 396 ± 91 mg versus 326 ± 101 mg (P = 0.007) and more sunlight exposure of 234 ± 81 vs 167 ± 69 min (P = 0.05). BMD at the femoral neck was significantly lower in cases (0.783 ± 0.105 g/cm2) when compared to controls (0.819 ± 0.114 g/cm2). Majority of the patients (61%) had low femoral neck BMD (P = 0.04). There was no significant difference in the proportion of subjects with vitamin D deficiency (<20 ng/mL) between cases (n = 32) and controls (n = 37) (P = 0.234). Conclusions: Vitamin D deficiency was seen in both the groups in equal proportions, highlighting the existence of a high prevalence of this problem in India. Low femoral neck BMD found in cases may stress the need for supplementing calcium and treating vitamin D deficiency in this specific group. However, the benefit of such intervention has to be studied in a larger proportion of epileptic patients. PMID:25221394

  17. Space Radiation and Bone Loss.

    PubMed

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

    2011-01-01

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

  18. How Is Bone Cancer Staged?

    MedlinePlus

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

  19. Green Tea and Bone Metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Bone Disease in Multiple Myeloma.

    PubMed

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

    2016-01-01

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

  1. Bone and Spinal Muscular Atrophy.

    PubMed

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

    2015-10-01

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

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

    PubMed

    Roca Espiau, Mercedes

    2011-09-01

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

  3. Bone tissue engineering in osteoporosis.

    PubMed

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

    2013-06-01

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

  4. Gut microbiota-bone axis.

    PubMed

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

    2017-05-24

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

  5. Bad to the Bone: On In Vitro and Ex Vivo Microbial Biofilm Ability to Directly Destroy Colonized Bone Surfaces without Participation of Host Immunity or Osteoclastogenesis

    PubMed Central

    Junka, Adam; Szymczyk, Patrycja; Ziółkowski, Grzegorz; Karuga-Kuzniewska, Ewa; Smutnicka, Danuta; Bil-Lula, Iwona; Bartoszewicz, Marzenna; Mahabady, Susan; Sedghizadeh, Parish Paymon

    2017-01-01

    Bone infections are a significant public health burden associated with morbidity and mortality in patients. Microbial biofilm pathogens are the causative agents in chronic osteomyelitis. Research on the pathogenesis of osteomyelitis has focused on indirect bone destruction by host immune cells and cytokines secondary to microbial insult. Direct bone resorption by biofilm pathogens has not yet been seriously considered. In this study, common osteomyelitis pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Streptococcus mutans) were grown as biofilms in multiple in vitro and ex vivo experiments to analyze quantitative and qualitative aspects of bone destruction during infection. Pathogens were grown as single or mixed species biofilms on the following substrates: hydroxyapatite, rat jawbone, or polystyrene wells, and in various media. Biofilm growth was evaluated by scanning electron microscopy and pH levels were monitored over time. Histomorphologic and quantitative effects of biofilms on tested substrates were analyzed by microcomputed tomography and quantitative cultures. All tested biofilms demonstrated significant damage to bone. Scanning electron microscopy indicated that all strains formed mature biofilms within 7 days on all substrate surfaces regardless of media. Experimental conditions impacted pH levels, although this had no impact on biofilm growth or bone destruction. Presence of biofilm led to bone dissolution with a decrease of total volume by 20.17±2.93% upon microcomputed tomography analysis, which was statistically significant as compared to controls (p <0.05, ANOVA). Quantitative cultures indicated that media and substrate did not impact biofilm formation (Kruskall-Wallis test, post-hoc Dunne’s test; p <0.05). Overall, these results indicate that biofilms associated with osteomyelitis have the ability to directly resorb bone. These findings should lead to a more complete understanding of the etiopathogenesis of

  6. Bad to the Bone: On In Vitro and Ex Vivo Microbial Biofilm Ability to Directly Destroy Colonized Bone Surfaces without Participation of Host Immunity or Osteoclastogenesis.

    PubMed

    Junka, Adam; Szymczyk, Patrycja; Ziółkowski, Grzegorz; Karuga-Kuzniewska, Ewa; Smutnicka, Danuta; Bil-Lula, Iwona; Bartoszewicz, Marzenna; Mahabady, Susan; Sedghizadeh, Parish Paymon

    2017-01-01

    Bone infections are a significant public health burden associated with morbidity and mortality in patients. Microbial biofilm pathogens are the causative agents in chronic osteomyelitis. Research on the pathogenesis of osteomyelitis has focused on indirect bone destruction by host immune cells and cytokines secondary to microbial insult. Direct bone resorption by biofilm pathogens has not yet been seriously considered. In this study, common osteomyelitis pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Streptococcus mutans) were grown as biofilms in multiple in vitro and ex vivo experiments to analyze quantitative and qualitative aspects of bone destruction during infection. Pathogens were grown as single or mixed species biofilms on the following substrates: hydroxyapatite, rat jawbone, or polystyrene wells, and in various media. Biofilm growth was evaluated by scanning electron microscopy and pH levels were monitored over time. Histomorphologic and quantitative effects of biofilms on tested substrates were analyzed by microcomputed tomography and quantitative cultures. All tested biofilms demonstrated significant damage to bone. Scanning electron microscopy indicated that all strains formed mature biofilms within 7 days on all substrate surfaces regardless of media. Experimental conditions impacted pH levels, although this had no impact on biofilm growth or bone destruction. Presence of biofilm led to bone dissolution with a decrease of total volume by 20.17±2.93% upon microcomputed tomography analysis, which was statistically significant as compared to controls (p <0.05, ANOVA). Quantitative cultures indicated that media and substrate did not impact biofilm formation (Kruskall-Wallis test, post-hoc Dunne's test; p <0.05). Overall, these results indicate that biofilms associated with osteomyelitis have the ability to directly resorb bone. These findings should lead to a more complete understanding of the etiopathogenesis of

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

    PubMed

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

    2011-11-01

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

  8. Biomaterials for Bone Regenerative Engineering.

    PubMed

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

    2015-06-24

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

  9. Tissue Engineering Whole Bones Through Endochondral Ossification: Regenerating the Distal Phalanx

    PubMed Central

    Sheehy, Eamon J.; Mesallati, Tariq; Kelly, Lara; Vinardell, Tatiana; Buckley, Conor T.; Kelly, Daniel J.

    2015-01-01

    Abstract Novel strategies are urgently required to facilitate regeneration of entire bones lost due to trauma or disease. In this study, we present a novel framework for the regeneration of whole bones by tissue engineering anatomically shaped hypertrophic cartilaginous grafts in vitro that subsequently drive endochondral bone formation in vivo. To realize this, we first fabricated molds from digitized images to generate mesenchymal stem cell-laden alginate hydrogels in the shape of different bones (the temporomandibular joint [TMJ] condyle and the distal phalanx). These constructs could be stimulated in vitro to generate anatomically shaped hypertrophic cartilaginous tissues that had begun to calcify around their periphery. Constructs were then formed into the shape of the distal phalanx to create the hypertrophic precursor of the osseous component of an engineered long bone. A layer of cartilage engineered through self-assembly of chondrocytes served as the articular surface of these constructs. Following chondrogenic priming and subcutaneous implantation, the hypertrophic phase of the engineered phalanx underwent endochondral ossification, leading to the generation of a vascularized bone integrated with a covering layer of stable articular cartilage. Furthermore, spatial bone deposition within the construct could be modulated by altering the architecture of the osseous component before implantation. These findings open up new horizons to whole limb regeneration by recapitulating key aspects of normal bone development. PMID:26309799

  10. Three-dimensional quantification of structures in trabecular bone using measures of complexity.

    PubMed

    Marwan, Norbert; Kurths, Jürgen; Thomsen, Jesper Skovhus; Felsenberg, Dieter; Saparin, Peter

    2009-02-01

    The study of pathological changes of bone is an important task in diagnostic procedures of patients with metabolic bone diseases such as osteoporosis as well as in monitoring the health state of astronauts during long-term space flights. The recent availability of high-resolution three-dimensional (3D) imaging of bone challenges the development of data analysis techniques able to assess changes of the 3D microarchitecture of trabecular bone. We introduce an approach based on spatial geometrical properties and define structural measures of complexity for 3D image analysis. These measures evaluate different aspects of organization and complexity of 3D structures, such as complexity of its surface or shape variability. We apply these measures to 3D data acquired by high-resolution microcomputed tomography (microCT) from human proximal tibiae and lumbar vertebrae at different stages of osteoporotic bone loss. The outcome is compared to the results of conventional static histomorphometry and exhibits clear relationships between the analyzed geometrical features of trabecular bone and loss of bone density, but also indicate that the measures reveal additional information about the structural composition of bone, which were not revealed by the static histomorphometry. Finally, we have studied the dependency of the developed measures of complexity on the spatial resolution of the microCT data sets.

  11. Research perspectives: The 2013 AAOS/ORS research symposium on Bone Quality and Fracture Prevention.

    PubMed

    Donnelly, Eve; Lane, Joseph M; Boskey, Adele L

    2014-07-01

    Bone fracture resistance is determined by the amount of bone present ("bone quantity") and by a number of other geometric and material factors grouped under the term "bone quality." In May 2013, a workshop was convened among a group of clinicians and basic science investigators to review the current state of the art in Bone Quality and Fracture Prevention and to make recommendations for future directions for research. The AAOS/ORS/OREF workshop was attended by 64 participants, including two representatives of the National Institutes of Arthritis and Musculoskeletal and Skin Diseases and 13 new investigators whose posters stimulated additional interest. A key outcome of the workshop was a set of recommendations regarding clinically relevant aspects of both bone quality and quantity that clinicians can use to inform decisions about patient care and management. The common theme of these recommendations was the need for more education of clinicians in areas of bone quality and for basic science studies to address specific topics of pathophysiology, diagnosis, prevention, and treatment of altered bone quality. In this report, the organizers with the assistance of the speakers and other attendees highlight the major findings of the meeting that justify the recommendations and needs for this field.

  12. HyBAR: hybrid bone-attached robot for joint arthroplasty

    PubMed Central

    Song, S.; Mor, A.; Jaramaz, B.

    2013-01-01

    Background A number of small bone-attached surgical robots have been introduced to overcome some disadvantages of large stand-alone surgical robots. In orthopaedics, increasing demand on minimally invasive joint replacement surgery has also been encouraging small surgical robot developments. Among various technical aspects of such an approach, optimal miniaturization that maintains structural strength for high speed bone removal was investigated. Methods By observing advantages and disadvantages from serial and parallel robot structures, a new hybrid kinematic configuration was designed for a bone-attached robot to perform precision bone removal for cutting the femoral implant cavity during patellofemoral joint arthroplasty surgery. A series of experimental tests were conducted in order to evaluate the performance of the new robot, especially with respect to accuracy of bone preparation. Results A miniaturized and rigidly-structured robot prototype was developed for minimally invasive bone-attached robotic surgery. A new minimally invasive modular clamping system was also introduced to enhance the robotic procedure. Foam and pig bone experimental results demonstrated a successful implementation of the new robot that eliminated a number of major design problems of a previous prototype. Conclusions For small bone-attached surgical robots that utilize high speed orthopaedic tools, structural rigidity and clamping mechanism are major design issues. The new kinematic configuration using hinged prismatic joints enabled an effective miniaturization with good structural rigidity. Although minor problems still exist at the prototype stage, the new development would be a significant step towards the practical use of such a robot. PMID:19347881

  13. Design and validation of bending test method for characterization of miniature pediatric cortical bone specimens.

    PubMed

    Albert, Carolyne I; Jameson, John; Harris, Gerald

    2013-02-01

    Osteogenesis imperfecta is a genetic disorder of bone fragility; however, the effects of this disorder on bone material properties are not well understood. No study has yet measured bone material strength in humans with osteogenesis imperfecta. Small bone specimens are often extracted during routine fracture surgeries in children with osteogenesis imperfecta. These specimens could provide valuable insight into the effects of osteogenesis imperfecta on bone material strength; however, their small size poses a challenge to their mechanical characterization. In this study, a validated miniature three-point bending test is described that enables measurement of the flexural material properties of pediatric cortical osteotomy specimens as small as 5 mm in length. This method was validated extensively using bovine bone, and the effect of span/depth aspect ratio (5 vs 6) on the measured flexural properties was examined. The method provided reasonable results for both Young's modulus and flexural strength in bovine bone. With a span/depth ratio of 6, the median longitudinal modulus and flexural strength results were 16.1 (range: 14.4-19.3)GPa and 251 (range: 219-293)MPa, respectively. Finally, the pilot results from two osteotomy specimens from children with osteogenesis imperfecta are presented. These results provide the first measures of bone material strength in this patient population.

  14. Three-dimensional quantification of structures in trabecular bone using measures of complexity

    NASA Astrophysics Data System (ADS)

    Marwan, Norbert; Kurths, Jürgen; Thomsen, Jesper Skovhus; Felsenberg, Dieter; Saparin, Peter

    2009-02-01

    The study of pathological changes of bone is an important task in diagnostic procedures of patients with metabolic bone diseases such as osteoporosis as well as in monitoring the health state of astronauts during long-term space flights. The recent availability of high-resolution three-dimensional (3D) imaging of bone challenges the development of data analysis techniques able to assess changes of the 3D microarchitecture of trabecular bone. We introduce an approach based on spatial geometrical properties and define structural measures of complexity for 3D image analysis. These measures evaluate different aspects of organization and complexity of 3D structures, such as complexity of its surface or shape variability. We apply these measures to 3D data acquired by high-resolution microcomputed tomography (μCT) from human proximal tibiae and lumbar vertebrae at different stages of osteoporotic bone loss. The outcome is compared to the results of conventional static histomorphometry and exhibits clear relationships between the analyzed geometrical features of trabecular bone and loss of bone density, but also indicate that the measures reveal additional information about the structural composition of bone, which were not revealed by the static histomorphometry. Finally, we have studied the dependency of the developed measures of complexity on the spatial resolution of the μCT data sets.

  15. Vertical Ridge Augmentation of the Atrophic Posterior Mandible with Sandwich Technique: Bone Block from the Chin Area versus Corticocancellous Bone Block Allograft—Clinical and Histological Prospective Randomized Controlled Study

    PubMed Central

    Laino, Luigi; Piattelli, Adriano; Lo Muzio, Lorenzo

    2014-01-01

    The aim of the present study is to compare the histological aspects of bone formation in atrophic posterior mandibles augmented by autologous bone block from chin area with corticocancellous bone block allograft used as inlays with the sandwich technique. Materials and Methods. Sixteen patients with bilateral partial edentulism in the posterior mandible were selected. The residual bone height, preliminarily measured by computed tomography scans, ranged between 5 and 7 mm from the inferior alveolar nerve. All patients required regeneration procedure with autologous bone block from chin area (control group) versus bone block allograft Puros (Zimmer Dental, 1900 Aston Avenue, Carlsbad, CA, USA) (test group). Histological and histomorphometric samples were collected at the time of implant positioning in order to analyze the percentage of newly formed bone, the residual graft material, and marrow spaces/soft tissue. Results. No statistically significant differences between the two groups were found regarding the percentage of newly formed bone. The percentage of residual grafted material was significantly higher in the test group, whilst the percentage of marrow spaces was higher in control group. Conclusions. In conclusion, both procedures supported good results, although the use of bone blocks allograft was less invasive and preferable than harvesting bone from the mental symphysis. PMID:24877155

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

    PubMed Central

    Boskey, Adele L

    2013-01-01

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

  17. Mechanical engineering aspects of TFTR

    SciTech Connect

    Citrolo, J.C.

    1983-04-01

    This paper briefly presents the principles which characterize a tokamak and discusses the mechanical aspects of TFTR, particularly the toroidal field coils and the vacuum chamber, in the context of being key components common to all tokamaks. The mechanical loads on these items as well as other design requirements are considered and the solutions to these requirements as executed in TFTR are presented. Future technological developments beyond the scope of TFTR, which are necessary to bring the tokamak concept to a full fusion-power system, are also presented. Additional methods of plasma heating, current drive, and first wall designs are examples of items in this category.

  18. Practical Aspects of Nonlinear Optimization.

    DTIC Science & Technology

    1981-06-19

    14. E. Levitan and B . Polyak, "Constrained Minimization Methods", USSR Comp. Math. and Math. Physics 6, 1, (1966). 15. J. May, "Solving Nonlinear...AD-AIO 858 MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB F/G 12/1 PRACTICAL ASPECTS OF NONLINEAR OPTIMIZATION.U) JUN 81 R B HOLMES, J W TOLLESON...dj, l<j< m , (2) with the understanding the Q so defined has a non-empty interior (is "solid"). No qualitative assumptions on the objective - i

  19. Nutritional aspects related to endometriosis.

    PubMed

    Halpern, Gabriela; Schor, Eduardo; Kopelman, Alexander

    2015-01-01

    This literature review analyzed the evidence on nutritional aspects related to the pathogenesis and progression of endometriosis. Diets deficient in nutrients result in changes in lipid metabolism, oxidative stress and promote epigenetic abnormalities, that may be involved in the genesis and progression of the disease. Foods rich in omega 3 with anti-inflammatory effects, supplementation with N-acetylcysteine, vitamin D and resveratrol, in addition to the increased consumption of fruits, vegetables (preferably organic) and whole grains exert a protective effect, reducing the risk of development and possible regression of disease. Dietary re-education seems to be a promising tool in the prevention and treatment of endometriosis.

  20. Technical aspects of abdominal stomas.

    PubMed

    Link, Brian A; Kropp, Bradley; Frimberger, Dominic

    2007-01-01

    Continent urinary diversion has gained increasing popularity in the pediatric population during the last few decades. In adults, continent diversions are usually needed to replace a bladder after cystectomy for invasive carcinoma. Subsequently, the creation of functional and cosmetically hidden urinary and cecal abdominal stomas has become an integral part of many urinary reconstructive procedures. These techniques, originally developed for pediatric urinary reconstruction have gained increasing popularity for adult patients in need of a continence procedure. In the current manuscript, we review the technical aspects of site selection, mucocutaneous anastomosis, cosmetic appearance, and management of associated complications.

  1. Immunological aspects of cancer chemotherapy.

    PubMed

    Zitvogel, Laurence; Apetoh, Lionel; Ghiringhelli, François; Kroemer, Guido

    2008-01-01

    Accumulating evidence indicates that the innate and adaptive immune systems make a crucial contribution to the antitumour effects of conventional chemotherapy-based and radiotherapy-based cancer treatments. Moreover, the molecular and cellular bases of the immunogenicity of cell death that is induced by cytotoxic agents are being progressively unravelled, challenging the guidelines that currently govern the development of anticancer drugs. Here, we review the immunological aspects of conventional cancer treatments and propose that future successes in the fight against cancer will rely on the development and clinical application of combined chemo- and immunotherapies.

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

    Ozdemir, Mehmet T; Kir, Mustafa Ç

    2011-01-01

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

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

    PubMed

    Ogawa, Sumito

    2010-02-01

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

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

    PubMed

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

    2014-10-01

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

  6. Investigating legal aspects of cyberbullying.

    PubMed

    Paul, Simone; Smith, Peter K; Blumberg, Herbert H

    2012-11-01

    In the UK schools are required by law to protect students from bullying; the responsibility of teachers to govern such behaviour has been extended outside the school setting to include cyberbullying. In this investigation, cyberbullying in secondary education is explored from the student perspective using a qualitative method of enquiry. Reported awareness and understanding about the legal aspects of cyberbullying are investigated; consideration is given to legislation, cybercrime, children's rights, school sanctions and safeguarding responsibilities. A total of 197 male and female students aged between 11 and 14 years old participated. Despite the availability of information on guidelines and legislation at national, local, and school level, this does not appear to have reached ground level of the individual student. There is a considerable gap between what students should know and what they report to be aware of with regard to legal aspects of cyberbullying. To address concerns of keeping up with the pace of change in cyberbullying, a collaborative approach is required with young people and adults sharing expertise.

  7. Mechanical aspects of CO₂ angiography.

    PubMed

    Corazza, Ivan; Rossi, Pier Luca; Feliciani, Giacomo; Pisani, Luca; Zannoli, Sebastiano; Zannoli, Romano

    2013-01-01

    The aim of this paper is to clarify some physical-mechanical aspects involved in the carbon dioxide angiography procedure (CO₂ angiography), with a particular attention to a possible damage of the vascular wall. CO₂ angiography is widely used on patients with iodine intolerance. The injection of a gaseous element, in most cases manually performed, requires a long training period. Automatic systems allow better control of the injection and the study of the mechanical behaviour of the gas. CO₂ injections have been studied by using manual and automatic systems. Pressures, flows and jet shapes have been monitored by using a cardiovascular mock. Photographic images of liquid and gaseous jet have been recorded in different conditions, and the vascular pressure rises during injection have been monitored. The shape of the liquid jet during the catheter washing phase is straight in the catheter direction and there is no jet during gas injection. Gas bubbles are suddenly formed at the catheter's hole and move upwards: buoyancy is the only governing phenomenon and no bubbles fragmentation is detected. The pressure rise in the vessel depends on the injection pressure and volume and in some cases of manual injection it may double the basal vascular pressure values. CO₂ angiography is a powerful and safe procedure which diffusion will certainly increase, although some aspects related to gas injection and chamber filling are not jet well known. The use of an automatic system permits better results, shorter training period and limitation of vascular wall damage risk.

  8. Ethical aspects on rare diseases.

    PubMed

    Barrera, Luis A; Galindo, Gilberto Cely

    2010-01-01

    In this chapter we discuss several of the most relevant subjects related to ethics on Rare Diseases. Some general aspects are discussed such as the socio-psychological problems that confront the patients and their families that finally lead to marginalization and exclusion of patients affected by these diseases from the health programs, even in wealthy countries. Then we address problems related to diagnosis and some ethical aspects of newborn screening, prenatal, pre-implantation diagnosis and reference centers, as well as some conditions that should be met by the persons and institutions performing such tasks. Alternatives of solutions for the most critical situations are proposed. Subsequently the orphan drugs subject is discussed not only from the availability point of view, prizes, industrial practices, and purchasing power in developed and developing societies. The research related to rare disease in children and other especially vulnerable conditions, the need for informed consent, review boards or ethics comities, confidentiality of the information, biobanks and pharmacogenetics are discussed.

  9. Terminological aspects of data elements

    SciTech Connect

    Strehlow, R.A. ); Kenworthey, W.H. Jr. ); Schuldt, R.E. )

    1991-01-01

    The creation and display of data comprise a process that involves a sequence of steps requiring both semantic and systems analysis. An essential early step in this process is the choice, definition, and naming of data element concepts and is followed by the specification of other needed data element concept attributes. The attributes and the values of data element concept remain associated with them from their birth as a concept to a generic data element that serves as a template for final application. Terminology is, therefore, centrally important to the entire data creation process. Smooth mapping from natural language to a database is a critical aspect of database, and consequently, it requires terminology standardization from the outset of database work. In this paper the semantic aspects of data elements are analyzed and discussed. Seven kinds of data element concept information are considered and those that require terminological development and standardization are identified. The four terminological components of a data element are the hierarchical type of a concept, functional dependencies, schematas showing conceptual structures, and definition statements. These constitute the conventional role of terminology in database design. 12 refs., 8 figs., 1 tab.

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

    PubMed

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

    2016-09-01

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

  11. Deciphering the elusive nature of sharp bone trauma using epifluorescence macroscopy: a comparison study multiplexing classical imaging approaches.

    PubMed

    Capuani, Caroline; Rouquette, Jacques; Payré, Bruno; Moscovici, Jacques; Delisle, Marie Bernadette; Telmon, Norbert; Guilbeau-Frugier, Céline

    2013-01-01

    Characterization of sharp-force trauma on human bones can be extremely useful in providing information regarding the nature and context of death. Nevertheless, in the identification of weapons used to cause sharp-force trauma and analysis of bone wounds, challenging tasks still remain. Current analysis attempting to dissect bone wound characteristics varied quite a lot and mixed different criteria, thus leading sometimes to conflicting results. In this context, the aim of our study is to clarify qualitative aspects of cut marks induced by sharp weapons on human bones. For that purpose, we analyzed bone samples via an original approach based on bone autofluorescence with an epifluorescence macroscope and compared it to previous existing methods. In this study, we used bone sections from human clavicles on which three different kinds of lesions were manually implemented, using different weapons. The bone wounds were analyzed by three different methodologies, light microscopy, scanning electron microscopy (SEM), and micro-computed tomography, and were compared with epifluorescence macroscopy. We paid attention more significantly to the aspect of walls and floor of the kerf, so as to conclude on the nature and distinguish between weapons used. Among all technologies used in this study, the most precise and efficient methods were epifluorescence macroscopy and SEM. Nonetheless, epifluorescence macroscopy is faster, cheaper, and more accessible than SEM. More significantly, this technique, which has the potential to accurately document the nature of the damage, is nondestructive, and could thus be highly useful in forensic science as anthropology.

  12. Diet, nutrition, and bone health.

    PubMed

    Cashman, Kevin D

    2007-11-01

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

  13. Bone as a Structural Material.

    PubMed

    Zimmermann, Elizabeth A; Ritchie, Robert O

    2015-06-24

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

  14. Dilatational band formation in bone

    PubMed Central

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

    2012-01-01

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

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

    PubMed

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

    2012-07-01

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

  16. Hemorrhagic Aspects of Gaucher Disease

    PubMed Central

    Rosenbaum, Hanna

    2014-01-01

    Gaucher disease (GD) is an inherited lysosomal disorder, originating from deficient activity of the lysosomal enzyme glucocerebrosidase (GCase). Normally, GCase hydrolyzes glucocerebroside (GC) to glucose and ceramide; however, impaired activity of this enzyme leads to the accumulation of GC in macrophages, termed “Gaucher cells.” Gaucher disease is associated with hepatosplenomegaly, cytopenias, skeletal complications and in some forms involves the central nervous system. Coagulation abnormalities are common among GD patients due to impaired production and chronic consumption of coagulation factors. Bleeding phenomena are variable (as are other symptoms of GD) and include mucosal and surgical hemorrhages. Four main etiological factors account for the hemostatic defect in GD: thrombocytopenia, abnormal platelet function, reduced production of coagulation factors, and activation of fibrinolysis. Thrombocytopenia relates not only to hypersplenism and decreased megakaryopoiesis by the infiltrated bone marrow but also to immune thrombocytopenia. Autoimmunity, especially the induction of platelet antibody production, might cause persistent thrombocytopenia. Enzyme replacement therapy reverses only part of the impaired coagulation system in Gaucher disease. Other therapeutic and supportive measures should be considered to prevent and/or treat bleeding in GD. Gaucher patients should be evaluated routinely for coagulation abnormalities especially prior to surgery and dental and obstetric procedures. PMID:25386355

  17. Hemorrhagic aspects of Gaucher disease.

    PubMed

    Rosenbaum, Hanna

    2014-10-01

    Gaucher disease (GD) is an inherited lysosomal disorder, originating from deficient activity of the lysosomal enzyme glucocerebrosidase (GCase). Normally, GCase hydrolyzes glucocerebroside (GC) to glucose and ceramide; however, impaired activity of this enzyme leads to the accumulation of GC in macrophages, termed "Gaucher cells." Gaucher disease is associated with hepatosplenomegaly, cytopenias, skeletal complications and in some forms involves the central nervous system. Coagulation abnormalities are common among GD patients due to impaired production and chronic consumption of coagulation factors. Bleeding phenomena are variable (as are other symptoms of GD) and include mucosal and surgical hemorrhages. FOUR MAIN ETIOLOGICAL FACTORS ACCOUNT FOR THE HEMOSTATIC DEFECT IN GD: thrombocytopenia, abnormal platelet function, reduced production of coagulation factors, and activation of fibrinolysis. Thrombocytopenia relates not only to hypersplenism and decreased megakaryopoiesis by the infiltrated bone marrow but also to immune thrombocytopenia. Autoimmunity, especially the induction of platelet antibody production, might cause persistent thrombocytopenia. Enzyme replacement therapy reverses only part of the impaired coagulation system in Gaucher disease. Other therapeutic and supportive measures should be considered to prevent and/or treat bleeding in GD. Gaucher patients should be evaluated routinely for coagulation abnormalities especially prior to surgery and dental and obstetric procedures.

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

    PubMed

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

    2014-02-01

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

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

    PubMed Central

    2016-01-01

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

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

    PubMed

    Ishimi, Yoshiko

    2015-07-01

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

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

    PubMed Central

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

    2013-01-01

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

  2. Avascular necrosis of carpal bones.

    PubMed

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

    1995-05-01

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

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

    PubMed

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

    2011-09-01

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

  4. Freeze-dried bank bone.

    PubMed

    Delloye, C; Buccafusca, G C

    1989-09-01

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

  5. A Boon for Bone Research

    NASA Technical Reports Server (NTRS)

    1996-01-01

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

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

    PubMed

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

    2007-06-01

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

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

    PubMed

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

    2015-04-01

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

  8. [Importance of bone scanning and osteoscintimetry for assessing development of acute haematogenic childhood osteomyelitis (author's transl)].

    PubMed

    Fotter, R; Höllwarth, M

    1980-01-01

    Bone scanning with 99m-Tc-MDP is generally used for the early diagnosis of acute haematogenic childhood osteomyelitis. The combination of this method with radionuclide osteoscintimetry and the evaluation of the relative uptake ratio supply objective criteria for assessing the development of the disease. They permit statements as to the morphological and functional aspects of the disease and thus facilitate clinical assessment.

  9. [Aspects of development of surgical service of modem Navy].

    PubMed

    Kabanov, M Iu; Gaĭdash, A A; Rukhliada, N V; Solov'ev, I A; Titov, R V; Utochkin, A P; Smirnov, S I; Smolin, N V; Tiurin, M V

    2013-06-01

    The article is devoted to the aspects of a current state of surgical service in the Navy, prospects of development of professianl training for navy surgeons, formation of modern training comlex, united electronic library, containig the issues about combat surgical trauma, software technologies, realizing of the application methodology during the process of training and practical activity for the development of the training system for surgeons of Navy and improvement of effectiveness. Formation of normative technical documents, regulating activity of navy surgians is also among the expectations. The authors also touched on the issues of development of modern technologies in bone grafting with the help of domestic implants based on the osteoinductive nanostructured nonorganic matrices (titanium) with defined structure and composition. Department of navy and hospital surgery participate in this debelopment. Due to increased amount of oncologic patients, it was decided to establish the Cancer Center of the Ministry of Defense based on department of navy and hospital surgery of the Kirov Military Medical Academy. It makes possible to perform the following procedures: canser surgery; surgical repair; plastic repair of major vessels, bone and soft tissue grafting, removal of residual cancer cells with the help of loco-regional methods of hyperthermic intracavitary and intravascular chemoperfusion; diagnostics and treatment of recurrent tumors (surgical and radiation treatment, systemic chemotherapy, loco-regional chemoembolization. Each of the given methods help to develop and improve the innovation technologies.

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

    PubMed

    Juárez, Patricia; Guise, Theresa A

    2011-01-01

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

  11. Epidemiological aspects of heart diseases

    PubMed Central

    Shi, Aimin; Tao, Ziqi; Wei, Peng; Zhao, Jing

    2016-01-01

    Cardiovascular diseases (CVDs) are the leading cause of mortality worldwide. Coronary heart disease (CHD) is the main cause of mortality in heart patients following stroke, rheumatic heart disease and myocardial infarctions. Approximately 80% of individuals succumb to CVDs, due to poor living conditions in low and middle income families and malnutrition. Infectious diseases, human immunodeficiency, tuberculosis, malaria, high blood pressure or hypertension, obesity and overweight, and nutritional disorders including smoking, excessive alcohol consumption, high salt and sugar intake, as well as other factors are responsible for CVDs and CHDs in young as well as elderly individuals. The focus of the present review are recent epidemiological aspects of CVD and CHD as well as the usefulness of a Mediterranean diet for heart patients and the prevention of heart diseases. PMID:27602082

  12. Technical aspects of fuel reprocessing

    SciTech Connect

    Groenier, W.S.

    1982-02-01

    The purpose of this paper is to present a brief description of fuel reprocessing and some present developments which show the reliability of nuclear energy as a long-term supply. The following topics are discussed: technical reasons for reprocessing; economic reasons for reprocessing; past experience; justification for advanced reprocessing R and D; technical aspects of current reprocessing development. The present developments are mainly directed at the reprocessing of breeder reactor fuels but there are also many applications to light-water reactor fuel reprocessing. These new developments involve totally remote operation, and maintenance. To demonstrate this advanced reprocessing concept, pilot-scale demonstration facilities are planned with commercial application occurring sometime after the year 2000. (ATT)

  13. Evolutionary Aspects of Enzyme Dynamics*

    PubMed Central

    Klinman, Judith P.; Kohen, Amnon

    2014-01-01

    The role of evolutionary pressure on the chemical step catalyzed by enzymes is somewhat enigmatic, in part because chemistry is not rate-limiting for many optimized systems. Herein, we present studies that examine various aspects of the evolutionary relationship between protein dynamics and the chemical step in two paradigmatic enzyme families, dihydrofolate reductases and alcohol dehydrogenases. Molecular details of both convergent and divergent evolution are beginning to emerge. The findings suggest that protein dynamics across an entire enzyme can play a role in adaptation to differing physiological conditions. The growing tool kit of kinetics, kinetic isotope effects, molecular biology, biophysics, and bioinformatics provides means to link evolutionary changes in structure-dynamics function to the vibrational and conformational states of each protein. PMID:25210031

  14. [Clinical aspects of witchcraft delusions].

    PubMed

    Pashkovskiĭ, V E

    2005-01-01

    To distinguish clinical variants and to specify nosologic entity of witchcraft delusions, 69 patients (10 males, aged 15-72 years) have been examined. It was found that witchcraft delusions exist in passive and active forms. In a passive form, the patient is sure that unknown (mystic) power damaged him/her; in an active form the patient, possessing a gift for unusual abilities, can influence the others (bewitches, heals, etc). Five clinical syndromes, in the structure of which the above delusions were found, namely, paranoiac-hypochondriac, hallucination-paranoid, depressive-paranoid, paraphrenic and delirious, were identified. Psychoses of schizophrenia spectrum were diagnosed in 52 patients, organic--in 8, alcoholic--in 7 and recurrent depressive disorder--in 2. Clinical significance of witchcraft delusions is closely related to its social aspect. Being combined with ideas of persecution, poisoning and damage, it results in the brutal forms of delusions defense and may be considered as an unfavorable prognostic trait.

  15. Immune Aspects of Female Infertility

    PubMed Central

    Brazdova, Andrea; Senechal, Helene; Peltre, Gabriel; Poncet, Pascal

    2016-01-01

    Immune infertility, in terms of reproductive failure, has become a serious health issue involving approximately 1 out of 5 couples at reproductive age. Semen that is defined as a complex fluid containing sperm, cellular vesicles and other cells and components, could sensitize the female genital tract. The immune rejection of male semen in the female reproductive tract is explained as the failure of natural tolerance leading to local and/or systemic immune response. Present active immune mechanism may induce high levels of anti-seminal/sperm antibodies. It has already been proven that iso-immunization is associated with infertility. Comprehensive studies with regards to the identification of antibody-targets and the determination of specific antibody class contribute to the development of effective immuno-therapy and, on the other hand, potential immuno-contraception, and then of course to complex patient diagnosis. This review summarizes the aspects of female immune infertility. PMID:27123194

  16. Scaling Aspects of Lymphocyte Trafficking

    PubMed Central

    Perelson, Alan S.; Wiegel, Frederik W.

    2010-01-01

    We consider the long lived pool of B and T cells that recirculate through blood, tissues and the lymphatic system of an animal with body mass M. We derive scaling rules (allometric relations) for: (1) the rate of production of mature lymphocytes; (2) the accumulation of lymphocytes in the tissues; (3) the flux of lymphocytes through the lymphatic system; (4) the number of lymph nodes, (5) the number of lymphocytes per clone within a lymph node, and (6) the total number of lymphocytes within a lymph node. Mass-dependent aspects of immune learning and of the immunological self are shown to be not very significant. Our treatment is somewhat heuristic and aims at a combination of immunological data with recent progress in biological scaling. PMID:19084024

  17. Sensory aspects of movement disorders.

    PubMed

    Patel, Neepa; Jankovic, Joseph; Hallett, Mark

    2014-01-01

    Movement disorders, which include disorders such as Parkinson's disease, dystonia, Tourette's syndrome, restless legs syndrome, and akathisia, have traditionally been considered to be disorders of impaired motor control resulting predominantly from dysfunction of the basal ganglia. This notion has been revised largely because of increasing recognition of associated behavioural, psychiatric, autonomic, and other non-motor symptoms. The sensory aspects of movement disorders include intrinsic sensory abnormalities and the effects of external sensory input on the underlying motor abnormality. The basal ganglia, cerebellum, thalamus, and their connections, coupled with altered sensory input, seem to play a key part in abnormal sensorimotor integration. However, more investigation into the phenomenology and physiological basis of sensory abnormalities, and about the role of the basal ganglia, cerebellum, and related structures in somatosensory processing, and its effect on motor control, is needed.

  18. Biomedical aspects of artificial gravity.

    PubMed

    Vil-Viliams, I F; Kotovskaya, A R; Shipov, A A

    1997-07-01

    Artificial gravity (AG) is the basic challenge for space biology and medicine. The importance of this problem is associated with the fact that duration of the space missions will become progressively longer, but the presently available countermeasures do not provide reason enough to predict the human health safety during space missions of any duration. The creation of AG could be an efficient method for removing the negative effects of microgravity. Two principle methods of generating AG, rotation of space system (SS) and building of short arm centrifuge (SAC), have been proposed. The purpose of the present work is to review the biomedical aspects of AG in the context of its use in long-term space missions.

  19. Discriminatory aspects of medical screening.

    PubMed

    Rothstein, M A

    1986-10-01

    Presently, there are few legal restrictions on the use of medical screening of workers. The Occupational Safety and Health Act (OSH Act) requires that certain medical tests be performed when workers will be exposed to specific toxic substances. The OSH Act does not, however, prohibit the use of any medical screening measure nor does it indicate what actions an employer may or may not take as a result of such information. (A notable exception is the medical removal provision of the Lead Standard). This paper discusses that protection afforded under Title VII of the Civil Rights Act of 1964, the Age Discrimination in Employment Act, and the Rehabilitation Act of 1973. This paper will demonstrate that the law has, in general, failed to take into account the discriminatory aspects of medical screening.

  20. Psychiatric Aspects of Organ Transplantation

    PubMed Central

    Kalra, G.; Desousa, A.

    2011-01-01

    Surgical transplantation of human organs from deceased as well as living donors to sick and dying patients began after the Second World War. Over the past 50 years the transplantation of human organs, tissues and cells has become a worldwide practice which has extended, and greatly enhanced the quality of hundreds of thousands of lives. The field of transplantation medicine provides an important chance for liaison between psychiatric professionals and other transplant physicians and surgeons. The discrepancy between the ever-increasing demand for organs but the decreasing supply makes it important to evaluate and prioritize individuals who are in dire need of the organ. However, this also gives rise to certain ethical questions. The following paper discusses various psychiatric aspects of organ transplantation in general. PMID:25013589