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Sample records for canine cortical bone

  1. Biomechanical characteristics of regenerated cortical bone in the canine mandible

    OpenAIRE

    Zapata, Uriel; Opperman, Lynne A.; Kontogiorgos, Elias; Elsalanty, Mohammed E.; Dechow, Paul C.

    2011-01-01

    To test the mechanical properties of regenerate cortical bone created using Mandibular Bone Transport (MBT) distraction, five adult male American foxhound dogs underwent unilateral distraction of the mandible with a novel MBT device placed to linearly repair a 30-35 mm bone defect. The animals were sacrificed 12 weeks after the beginning of the consolidation period. Fourteen cylindrical specimens were taken from the inner (lingual) and outer (buccal) plates of the reconstructed mandible and 2...

  2. Assessment of the relationship between standard probe and implantable fiber measurements of cortical bone blood flow: a canine study.

    Science.gov (United States)

    Jain, R; Podworny, N; Anderson, G I; Schemitsch, E H

    1996-07-01

    Laser Doppler flowmetry (LDF) has been used to assess cortical bone blood flow in various clinical situations, such as osteomyelitis and osteonecrosis. Standard metal-sheathed probes containing optical fibers, applied to cortical bone for perfusion measurements, require direct exposure of the bone surface for each measurement, making nonanesthetized assessments over time impractical. Implantable optical fibers offer a noninvasive method for evaluating cortical bone perfusion without repeated surgical exposure of the bone after initial surgical implantation of the fibers. In vitro studies have shown the reliability of laser Doppler (LD) fibers compared with those of the standard probe. This investigation studied the relationship between measurements of cortical bone perfusion obtained by implanted optical (LD) fibers and standard (LDF) probes in vivo. Midshaft tibial fractures were created in the right hindlimb of 11 adult, large (>25 kg) dogs and stabilized by low contact-dynamic compression plate fixation. Cortical bone blood flow was measured by LDF using standard probes and implantable fibers at five sites along the tibia prefracture, postfracture, immediately postplate application, and at 10 weeks postplating, immediately prior to euthanasia. The implantable fibers were secured onto the cortical bone via the plate and led through a percutaneous exit site. Histological examination of the inguinal and popliteal lymph nodes and soft tissue surrounding the fibers revealed mild inflammation. No significant correlation of blood flow assessed by the implantable fibers and standard probe occurred immediately postfracture (r 0.62). However, a statistically significant correlation was seen postplate application at one of the measurement sites in the distal fracture fragment (r = 0.78, P fibers remained intact and functional until an average of 3 weeks at which time they either fractured or were removed by the animals. This is the first in vivo study assessing the

  3. Triple bone labeling of canine mandibles

    DEFF Research Database (Denmark)

    Pinholt, E M; Kwon, P H

    1990-01-01

    Fluorescence microscopy was used for evaluation of new bone formation in 16 canine mandibles augmented with hydroxylapatite (HA) granules. Three fluorochromes were injected at different time intervals during therapeutic radiation treatment. Oxytetracycline, DCAF, and alizarin-complexone were give...

  4. Osteocyte lacunar properties in rat cortical bone

    DEFF Research Database (Denmark)

    Bach-Gansmo, Fiona Linnea; Weaver, James C.; Jensen, Mads Hartmann;

    2015-01-01

    Recently, the roles of osteocytes in bone maintenance have gained increasing attention. Osteocytes reside in lacunae that are interconnected by canaliculi resulting in a vast cellular network within the mineralized bone matrix. As the structure of the lacuno-canalicular network is highly connected......-species but also inter-site variation in lacunar properties. Here, osteocyte lacunae in rat cortical bone have been studied using synchrotron radiation micro computed tomography (SR μCT) and backscattered electron (BE) microscopy. Quantitative lacunar geometric characteristics are reported based on the synchrotron...... radiation data, differentiating between circumferential lamellar bone and a central, more disordered bone type. From these studies, no significant differences were found in lacunar volumes between lamellar and central bone, whereas significant differences in lacunar orientation, shape and density values...

  5. Cortical bone total ossicular replacement prosthesis

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    Manu Malhotra

    2014-01-01

    Full Text Available Objectives: Evaluate an autologous cortical bone total ossicular replacement prosthesis (B TORP made of cortical bone for cost effective and sustainable hearing results. Materials and Methods: A prospective study was undertaken in the patients who underwent tympanoplasty with new B-TORP from January 2011 to December 2011. All patients had an absent superstructure of the stapes and long process of the incus due to chronic otitis media. Totally 40 patients were evaluated. Hearing results were evaluated using four-frequency average pure tone air conduction and air-bone gap (ABG measured at 0.5, 1, 2, and 3 kHz after a period of 12 months. Pre- and post-operative continuous variables were compared using a paired t-test and data from unequal groups were assessed for significant differences using unpaired t-test. Results: Successful rehabilitation of the ABG to 20 dB or less was achieved in 95% of patients. Overall mean improvement in ABG was 25.8 ± 5.6 dB, which was statistically significant (t = 26.8, P 0.5. Conclusion: The new autologous B-TORP provides sustainable hearing improvement and is bio-compatible, stable, and magnetic resonance imaging compatible.

  6. Cement line staining in undecalcified thin sections of cortical bone

    Science.gov (United States)

    Bain, S. D.; Impeduglia, T. M.; Rubin, C. T.

    1990-01-01

    A technique for demonstrating cement lines in thin, undecalcified, transverse sections of cortical bone has been developed. Cortical bone samples are processed and embedded undecalcified in methyl methacrylate plastic. After sectioning at 3-5 microns, cross-sections are transferred to a glass slide and flattened for 10 min. Sections of cortical bone are stained for 20 sec free-floating in a fresh solution of 1% toluidine blue dissolved in 0.1% formic acid. The section is dehydrated in t-butyl alcohol, cleared in xylene, and mounted with Eukitt's medium. Reversal lines appear as thin, scalloped, dark blue lines against a light blue matrix, whereas bone formation arrest lines are thicker with a smooth contour. With this technique cellular detail, osteoid differentiation, and fluorochrome labels are retained. Results demonstrate the applicability of a one-step staining method for cement lines which will facilitate the assessment of bone remodeling activity in thin sections of undecalcified cortical bone.

  7. Influence of Gastrectomy on Cortical and Cancellous Bones in Rats

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    Jun Iwamoto

    2013-01-01

    Full Text Available The aim of the present study was to examine the influence of gastrectomy (GX on cortical and cancellous bones in rats. Twenty male Sprague-Dawley rats were randomized into the two groups of 10 animals each: a sham operation (control group and a GX group. Seven weeks after surgery, the bone mineral content and density (BMC and BMD, resp. and the mechanical strength of the femur were determined, and bone histomorphometric analyses were performed on the tibia. GX induced decreases in the BMC, BMD, ultimate force, work to failure, and stiffness of the femoral distal metaphysis and the BMC, BMD, and ultimate force of the femoral diaphysis. GX induced a decrease in cancellous bone mass, characterized by an increased osteoid thickness, osteoid surface, osteoid volume, and bone formation. GX also induced a decrease in cortical bone mass, characterized by increased endocortical bone resorption. The GX induced reductions in the bone mass and strength parameters were greater in cancellous bone than in cortical bone. The present study showed that the response of bone formation, resorption, and osteoid parameters to GX and the degree of GX-induced osteopenia and the deterioration of bone strength appeared to differ between cortical and cancellous bones in rats.

  8. Mechanical properties of femoral cortical bone following cemented hip replacement.

    Science.gov (United States)

    Ni, G X; Lu, W W; Chiu, P K Y; Wang, Y; Li, Z Y; Zhang, Y G; Xu, B; Deng, L F; Luk, K D K

    2007-11-01

    Femoral bone remodeling following total hip replacement is a big concern and has never been examined mechanically. In this study, six goats underwent unilateral cemented hip hemiarthroplasty with polymethyl methacrylate (PMMA) bone cement. Nine months later animals were sacrificed, and the femoral cortical bone slices at different levels were analysed using microhardness testing and microcomputed tomography (micro-CT) scanning. Implanted femurs were compared to contralateral nonimplanted femurs. Extensive bone remodeling was demonstrated at both the proximal and middle levels, but not at the distal level. Compared with the nonimplanted side, significant decreases were found in the implanted femur in cortical bone area, bone mineral density, and cortical bone hardness at the proximal level, as well as in bone mineral density and bone hardness at the middle level. However, no significant difference was observed in either variable for the distal level. In addition, similar proximal-to-distal gradient changes were revealed both in cortical bone microhardness and bone mineral density. From the mechanical point of view, the results of the present study suggested that stress shielding is an important mechanical factor associated with bone adaptation following total hip replacement. PMID:17506504

  9. Lumbar pedicle cortical bone trajectory screw

    Institute of Scientific and Technical Information of China (English)

    Song Tengfei; Wellington K Hsu; Ye Tianwen

    2014-01-01

    Objective The purpose of this study was to demonstrate the lumbar pedicle cortical bone trajectory (CBT) screw fixation technique,a new fixation technique for lumbar surgery.Data sources The data analyzed in this review are mainly from articles reported in PubMed published from 1994 to 2014.Study selection Original articles and critical reviews relevant to CBT technique and lumbar pedicle fixation were selected.Results CBT technique was firstly introduced as a new fixation method for lumbar pedicle surgery in 2009.The concepts,morphometric study,biomechanical characteristics and clinical applications of CBT technique were reviewed.The insertional point of CBT screw is located at the lateral point of the pars interarticularis,and its trajectory follows a caudocephalad path sagittally and a laterally directed path in the transverse plane.CBT technique can be used for posterior fixation during lumbar fusion procedures.This technique is a minimally invasive surgery,which affords better biomechanical stability,fixation strength and surgical safety.Therefore,CBT technique has the greatest benefit in lumbar pedicle surgery for patients with osteoporosis and obesity.Conclusion CBT technique is a better alternative option of lumbar pedicle fixation,especially for patients with osteoporosis and obesity.

  10. Influence of cortical endplates on ultrasonic properties of trabecular bone

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    Kim, Yoon Mi; Lee, Kang Il [Dept. of Physics, Kangwon National University, Chuncheon (Korea, Republic of)

    2015-04-15

    The present study investigated the influence of thick cortical endplates on the ultrasonic properties of trabecular bone in a femur with a high fracture risk. Twelve trabecular bone samples were prepared from bovine femurs, and acrylic plates with thicknesses of 1.25, 1.80, and 2.75 mm were manufactured to simulate the cortical endplates using acrylic with a density and a sound speed similar to cortical bone. Although the thickness of the acrylic plates attached to the two sides of the trabecular bone increased, high correlations were observed between the speed of sound and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.80-0.86. High correlations were also observed between the attenuation coefficient at 0.5 mm and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.84-0.91. These results suggest that the speed of sound and attenuation coefficient at a specific frequency measured in a femur with relatively thick cortical endplates compared to the calcaneus could be used as indices for predicting the bone mineral density of the femur.

  11. Probiotics protect mice from ovariectomy-induced cortical bone loss.

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    Claes Ohlsson

    Full Text Available The gut microbiota (GM modulates the hosts metabolism and immune system. Probiotic bacteria are defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host and can alter the composition of the GM. Germ-free mice have increased bone mass associated with reduced bone resorption indicating that the GM also regulates bone mass. Ovariectomy (ovx results in bone loss associated with altered immune status. The purpose of this study was to determine if probiotic treatment protects mice from ovx-induced bone loss. Mice were treated with either a single Lactobacillus (L strain, L. paracasei DSM13434 (L. para or a mixture of three strains, L. paracasei DSM13434, L. plantarum DSM 15312 and DSM 15313 (L. mix given in the drinking water during 6 weeks, starting two weeks before ovx. Both the L. para and the L. mix treatment protected mice from ovx-induced cortical bone loss and bone resorption. Cortical bone mineral content was higher in both L. para and L. mix treated ovx mice compared to vehicle (veh treated ovx mice. Serum levels of the resorption marker C-terminal telopeptides and the urinary fractional excretion of calcium were increased by ovx in the veh treated but not in the L. para or the L. mix treated mice. Probiotic treatment reduced the expression of the two inflammatory cytokines, TNFα and IL-1β, and increased the expression of OPG, a potent inhibitor of osteoclastogenesis, in cortical bone of ovx mice. In addition, ovx decreased the frequency of regulatory T cells in bone marrow of veh treated but not probiotic treated mice. In conclusion, treatment with L. para or the L. mix prevents ovx-induced cortical bone loss. Our findings indicate that these probiotic treatments alter the immune status in bone resulting in attenuated bone resorption in ovx mice.

  12. Independent measurement of femoral cortical thickness and cortical bone density using clinical CT.

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    Treece, G M; Gee, A H

    2015-02-01

    The local structure of the proximal femoral cortex is of interest since both fracture risk, and the effects of various interventions aimed at reducing that risk, are associated with cortical properties focused in particular regions rather than dispersed over the whole bone. Much of the femoral cortex is less than 3mm thick, appearing so blurred in clinical CT that its actual density is not apparent in the data, and neither thresholding nor full-width half-maximum techniques are capable of determining its width. Our previous work on cortical bone mapping showed how to produce more accurate estimates of cortical thickness by assuming a fixed value of the cortical density for each hip. However, although cortical density varies much less over the proximal femur than thickness, what little variation there is leads to errors in thickness measurement. In this paper, we develop the cortical bone mapping technique by exploiting local estimates of imaging blur to correct the global density estimate, thus providing a local density estimate as well as more accurate estimates of thickness. We also consider measurement of cortical mass surface density and the density of trabecular bone immediately adjacent to the cortex. Performance is assessed with ex vivo clinical QCT scans of proximal femurs, with true values derived from high resolution HRpQCT scans of the same bones. We demonstrate superior estimation of thickness than is possible with alternative techniques (accuracy 0.12 ± 0.39 mm for cortices in the range 1-3mm), and that local cortical density estimation is feasible for densities >800 mg/cm(3).

  13. Buccal cortical bone thickness on CBCT for mini-implant

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    Goo, Jong Gook; Lim, Sung Hoon; Lee, Byoung Jin; Kim, Jae Duk [School of Dentistry, Chosun University, Gwangju (Korea, Republic of)

    2010-12-15

    Cortical bone thickness is one of the important factor in mini-implant stability. This study was performed to investigate the buccal cortical bone thickness at every interdental area as an aid in planning mini-implant placement. Two-dimensional slices at every interdental area were selected from the cone-beam computed tomography scans of 20 patients in third decade. Buccal cortical bone thickness was measured at 2, 4, and 6 mm levels from the alveolar crest in the interdental bones of posterior regions of both jaws using the plot profile function of Ez3D2009TM (Vatech, Yongin, Korea). The results were analyzed using by Mann-Whitney test. Buccal cortical bone was thicker in the mandible than in the maxilla. The thickness increased with further distance from the alveolar crest in the maxilla and with coming from the posterior to anterior region in the mandible (p?0.01). The maximum CT value showed an increasing tendency with further distance from the alveolar crest and with coming from posterior to anterior region in both jaws. Interdental buccal cortical bone thickness varied in both jaws, however our study showed a distinct tendency. We expect that these results could be helpful for the selection and preparation of mini-implant sites.

  14. Immunologic studies of canine bone marrow chimeras

    International Nuclear Information System (INIS)

    When prospective male or female recipients from the Cooperstown colony were exposed to supralethal total body irradiation and were reconstituted with bone marrow obtained from genotypically DL-A-identical littermate or nonlittermate donors such treatment resulted, in regularly reproducible fashion, in the establishment of a long-term state of chimerism with no evidence of graft-versus-host disease in any of the recipients. The resulting chimeras have survived thus far for 882-1466 days, with donor red cell antigen and leukocyte sex marker evidence of the persistence of chimerism. Subsequent challenge of the chimeras with renal and skin allografts obtained from the specific donor of marrow resulted in the long-term survival of such transplants without any evidence of rejection for 833--1402 days. Skin allografts obtained from other dogs were, however, accorded first-set rejection times. Recent studies indicate that the state of allogeneic unresponsiveness produced by supralethal total body irradiation and bone marrow transplantation also extends to other organs from the donor of marrow, including heart, liver, pancreas and duodenum, and lung

  15. Canine bone sporotrichosis: a case report

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    Marconi Rodrigues de Farias

    2015-06-01

    Full Text Available Sporotrichosis, a subcutaneous and zoonotic mycosis, is caused by dimorphic fungus Sporothrix schenckii. The infection occurs after a traumatic skin injury, while handling plant materials or animals. This disease commonly occurs in cats and is rarely reported in dogs. Herein we report a case of bone sporotrichosis in a dog that presented at the Hospital Unit for Pets (HUP of the Pontifical Catholic University of Paraná (PUCPR. The animal had a 4-month history of lameness in its thoracic limbs. Haematological, radiological, mycological, and histopathological tests were conducted to confirm the diagnosis. The animal was treated for 2 months with a 10 mg kg-1 PO SID dose of itraconazole, but only partial improvement was observed. A 20% supersaturated potassium iodide solution i.e., a 40 mg kg-1 dose every 24 h was then included for regression and healing of the wounds.

  16. Disuse exaggerates the detrimental effects of alcohol on cortical bone

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    Hefferan, Theresa E.; Kennedy, Angela M.; Evans, Glenda L.; Turner, Russell T.

    2003-01-01

    BACKGROUND: Alcohol abuse is associated with an increased risk for osteoporosis. However, comorbidity factors may play an important role in the pathogenesis of alcohol-related bone fractures. Suboptimal mechanical loading of the skeleton, an established risk factor for bone loss, may occur in some alcohol abusers due to reduced physical activity, muscle atrophy, or both. The effect of alcohol consumption and reduced physical activity on bone metabolism has not been well studied. The purpose of this study was to determine whether mechanical disuse alters bone metabolism in a rat model for chronic alcohol abuse. METHODS: Alcohol was administered in the diet (35% caloric intake) of 6-month-old male rats for 4 weeks. Rats were hindlimb-unloaded the final 2 weeks of the experiment to prevent dynamic weight bearing. Afterward, cortical bone histomorphometry was evaluated at the tibia-fibula synostosis. RESULTS: At the periosteal surface of the tibial diaphysis, alcohol and hindlimb unloading independently decreased the mineralizing perimeter, mineral apposition rate, and bone formation rate. In addition, alcohol, but not hindlimb unloading, increased endocortical bone resorption. The respective detrimental effects of alcohol and hindlimb unloading to inhibit bone formation were additive; there was no interaction between the two variables. CONCLUSIONS: Reduced weight bearing accentuates the detrimental effects of alcohol on cortical bone in adult male rats by further inhibiting bone formation. This finding suggests that reduced physical activity may be a comorbidity factor for osteoporosis in alcohol abusers.

  17. Canine Bone Marrow Stromal Cells Promote Functional Recovery in Mice with Spinal Cord Injury

    OpenAIRE

    Oda, Yasutaka; Tani, Kenji; ASARI, Yusuke; Quintanilha, Luiz Fernando; HARAGUCHI, Tomoya; MOMOTA, Yutaka; Katayama, Masaaki; Itamoto, Kazuhito; Nakazawa, Hiroshi; TAURA, Yasuho

    2014-01-01

    ABSTRACT Regenerative therapy has begun to be clinically applied in humans and dogs to treat neurological disorders, such as spinal cord injury (SCI). Here, we show the therapeutic potential of transplantation of cultured canine bone marrow stromal cells (BMSCs) into mice with SCI. Canine BMSC transplantation therapy was performed, immediately after the spinal cord was injured. Canine BMSC therapy enhanced functional recovery of the hind limbs in mice with SCI. Nestin-positive cells were obse...

  18. Cortical bone distribution in the femoral neck of strepsirhine primates.

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    Demes, B; Jungers, W L; Walker, C

    2000-10-01

    The thickness of the inferior and superior cortices of the femoral neck was measured on X-rays of 181 strepsirhine primate femora representing 24 species. Neck length, neck depth and neck-shaft angle were also measured. The strength of the femoral neck in frontal bending was estimated by modeling the neck as a hollow cylinder, with neck depth as the outer diameter and cortical thickness representing the superior and inferior shell dimensions. Results indicate that the inferior cortex is always thicker than the superior cortex. The ratio of superior to inferior cortical thickness is highly variable but distinguishes two of the three locomotor groups in the sample. Vertical clingers and leapers have higher ratios (i.e., a more even distribution of cortical bone) than quadrupeds. The slow climbers tend to have the lowest ratios, although they do not differ significantly from the leapers and quadrupeds. These results do not confirm prior theoretical expectations and reported data for anthropoid primates that link greater asymmetry of the cortical shell to more stereotypical hip excursions. The ratio of superior to inferior cortical thickness is unrelated to body mass, femoral neck length, and neck-shaft angle, calling into question whether the short neck of strepsirhine primates acts as a cantilever beam in bending. On the other hand, the estimated section moduli are highly correlated with body mass and neck length, a correlation that is driven primarily by body mass. In conclusion, we believe that an alternative interpretation to the cantilever beam model is needed to explain the asymmetry in bone distribution in the femoral neck, at least in strepsirhine primates (e.g., a thicker inferior cortex is required to reinforce the strongly curved inferior surface). As in prior studies of cross-sectional geometry of long bones, we found slightly positive allometry of cortical dimensions with body mass. PMID:11006046

  19. Post-yield and failure properties of cortical bone.

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    Wolfram, Uwe; Schwiedrzik, Jakob

    2016-01-01

    Ageing and associated skeletal diseases pose a significant challenge for health care systems worldwide. Age-related fractures have a serious impact on personal, social and economic wellbeing. A significant proportion of physiological loading is carried by the cortical shell. Its role in the fracture resistance and strength of whole bones in the ageing skeleton is of utmost importance. Even though a large body of knowledge has been accumulated on this topic on the macroscale, the underlying micromechanical material behaviour and the scale transition of bone's mechanical properties are yet to be uncovered. Therefore, this review aims at providing an overview of the state-of-the-art of the post-yield and failure properties of cortical bone at the extracellular matrix and the tissue level. PMID:27579166

  20. Evaluation of trabecular bone patterns on dental radiographic images: influence of cortical bone

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    Amouriq, Yves; Evenou, Pierre; Arlicot, Aurore; Normand, Nicolas; Layrolle, Pierre; Weiss, Pierre; Guédon, Jean-Pierre

    2010-03-01

    For some authors trabecular bone is highly visible in intraoral radiographs. For other authors, the observed intrabony trabecular pattern is a representation of only the endosteal surface of cortical bone, not of intermedullary striae. The purpose of this preliminary study was to investigate the true anatomical structures that are visible in routine dental radiographs and classically denoted trabecular bone. This is a major point for bone texture analysis on radiographs. Computed radiography (CR) images of dog mandible section in molar region were compared with simulations calculated from high-resolution micro-CT volumes. Calculated simulations were obtained using the Mojette Transform. By digitally editing the CT volume, the simulations were separated into trabecular and cortical components into a region of interest. Different images were compared and correlated, some bone micro-architecture parameters calculated. A high correlation was found between computed radiographs and calculated simulations from micro-CT. The Mojette transform was successful to obtain high quality images. Cortical bone did not contribute to change in a major way simulated images. These first results imply that intrabony trabecular pattern observed on radiographs can not only be a representation of the cortical bone endosteal surface and that trabecular bone is highly visible in intraoral radiographs.

  1. Automatic Detection of Cortical Bones Haversian Osteonal Boundaries

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    Ilige Hage

    2015-10-01

    Full Text Available This work aims to automatically detect cement lines in decalcified cortical bone sections stained with H&E. Employed is a methodology developed previously by the authors and proven to successfully count and disambiguate the micro-architectural features (namely Haversian canals, canaliculi, and osteocyte lacunae present in the secondary osteons/Haversian system (osteon of cortical bone. This methodology combines methods typically considered separately, namely pulse coupled neural networks (PCNN, particle swarm optimization (PSO, and adaptive threshold (AT. In lieu of human bone, slides (at 20× magnification from bovid cortical bone are used in this study as proxy of human bone. Having been characterized, features with same orientation are used to detect the cement line viewed as the next coaxial layer adjacent to the outermost lamella of the osteon. Employed for this purpose are three attributes for each and every micro-sized feature identified in the osteon lamellar system: (1 orientation, (2 size (ellipse perimeter and (3 Euler number (a topological measure. From a training image, automated parameters for the PCNN network are obtained by forming fitness functions extracted from these attributes. It is found that a 3-way combination of these features attributes yields good representations of the overall osteon boundary (cement line. Near-unity values of classical metrics of quality (precision, sensitivity, specificity, accuracy, and dice suggest that the segments obtained automatically by the optimized artificial intelligent methodology are of high fidelity as compared with manual tracing. For bench marking, cement lines segmented by k-means did not fare as well. An analysis based on the modified Hausdorff distance (MHD of the segmented cement lines also testified to the quality of the detected cement lines vis-a-vis the k-means method.

  2. Repair of microdamage in osteonal cortical bone adjacent to bone screw.

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    Lei Wang

    Full Text Available Up to date, little is known about the repair mode of microdamage in osteonal cortical bone resulting from bone screw implantation. In this study, self-tapping titanium cortical bone screws were inserted into the tibial diaphyses of 24 adult male rabbits. The animals were sacrificed at 1 day, 2 weeks, 1 month and 2 months after surgery. Histomorphometric measurement and confocal microscopy were performed on basic fuchsin stained bone sections to examine the morphological characteristics of microdamage, bone resorption activity and spatial relationship between microdamage and bone resorption. Diffuse and linear cracks were coexisted in peri-screw bone. Intracortical bone resorption was significantly increased 2 weeks after screw installation and reach to the maximum at 1 month. There was no significant difference in bone resorption between 1-month and 2-months groups. Microdamage was significantly decreased within 1 month after surgery. Bone resorption was predisposed to occur in the region of <100 µm from the bone-screw interface, where had extensive diffuse damage mixed with linear cracks. Different patterns of resorption cavities appeared in peri-screw bone. These data suggest that 1 the complex microdamage composed of diffuse damage and linear cracks is a strong stimulator for initiating targeted bone remodeling; 2 bone resorption activities taking place on the surfaces of differently oriented Haversian and Volkmann canals work in a team for the repair of extensive microdamage; 3 targeted bone remodeling is a short-term reaction to microdamage and thereby it may not be able to remove all microdamage resulting from bone screw insertion.

  3. Anisotropy of bovine cortical bone tissue damage properties.

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    Szabó, M E; Thurner, P J

    2013-01-01

    Bone is a heterogeneous, anisotropic natural composite material. Several studies have measured human cortical bone elastic properties in different anatomical directions and found that the Young's modulus was highest in the longitudinal, followed by the tangential and then by the radial direction. This study compared the Young's modulus, the accumulated microdamage and local strains related to the failure process in these three anatomical directions. Cortical bone samples (≈360 μm×360 μm) were mechanically tested in three-point bending and concomitantly imaged to assess local strains using digital image correlation technique. The bone whitening effect was used to detect microdamage formation and propagation. No statistically significant difference was found between the Young's modulus of longitudinal (9.4±2.0 GPa) and tangential (9.9±1.8 GPa) bovine bone samples, as opposed to previous findings on human bone samples. The same similarity was found for the whitening values (5000±1900 pix/mm(2) for longitudinal, 5800±2600 pix/mm(2) for tangential) and failure strains (16.8±7.0% for longitudinal, 19.1±3.2% for tangential) as well. However, significantly lower values were observed in the radial samples for Young's modulus (5.92±0.77 GPa), whitening (none or minimal) and failure strain (10.8±3.8%). For strains at whitening onset, no statistically significant difference was seen for the longitudinal (5.1±1.6%) and radial groups (4.2±2.0%), however, the tangential values were significantly greater (7.0±2.4%). The data implies that bovine cortical bone tissue in long bones is designed to withstand higher loads in the longitudinal and tangential directions than in the radial one. A possible explanation of the anisotropy in the mechanical parameters derived here might be the structure of the tissues in the three directions tested. PMID:23063771

  4. Age-Related Changes in Trabecular and Cortical Bone Microstructure

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    Huayue Chen

    2013-01-01

    Full Text Available The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT, micro-CT, and high resolution peripheral quantitative CT (HR-pQCT, imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

  5. WNT16 influences bone mineral density, cortical bone thickness, bone strength, and osteoporotic fracture risk.

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    Hou-Feng Zheng

    2012-07-01

    Full Text Available We aimed to identify genetic variants associated with cortical bone thickness (CBT and bone mineral density (BMD by performing two separate genome-wide association study (GWAS meta-analyses for CBT in 3 cohorts comprising 5,878 European subjects and for BMD in 5 cohorts comprising 5,672 individuals. We then assessed selected single-nucleotide polymorphisms (SNPs for osteoporotic fracture in 2,023 cases and 3,740 controls. Association with CBT and forearm BMD was tested for ∼2.5 million SNPs in each cohort separately, and results were meta-analyzed using fixed effect meta-analysis. We identified a missense SNP (Thr>Ile; rs2707466 located in the WNT16 gene (7q31, associated with CBT (effect size of -0.11 standard deviations [SD] per C allele, P = 6.2 × 10(-9. This SNP, as well as another nonsynonymous SNP rs2908004 (Gly>Arg, also had genome-wide significant association with forearm BMD (-0.14 SD per C allele, P = 2.3 × 10(-12, and -0.16 SD per G allele, P = 1.2 × 10(-15, respectively. Four genome-wide significant SNPs arising from BMD meta-analysis were tested for association with forearm fracture. SNP rs7776725 in FAM3C, a gene adjacent to WNT16, was associated with a genome-wide significant increased risk of forearm fracture (OR = 1.33, P = 7.3 × 10(-9, with genome-wide suggestive signals from the two missense variants in WNT16 (rs2908004: OR = 1.22, P = 4.9 × 10(-6 and rs2707466: OR = 1.22, P = 7.2 × 10(-6. We next generated a homozygous mouse with targeted disruption of Wnt16. Female Wnt16(-/- mice had 27% (P<0.001 thinner cortical bones at the femur midshaft, and bone strength measures were reduced between 43%-61% (6.5 × 10(-13bone strength, and risk of fracture.

  6. Tensile behavior of cortical bone: dependence of organic matrix material properties on bone mineral content.

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    Kotha, S P; Guzelsu, N

    2007-01-01

    A porous composite model is developed to analyze the tensile mechanical properties of cortical bone. The effects of microporosity (volksman's canals, osteocyte lacunae) on the mechanical properties of bone tissue are taken into account. A simple shear lag theory, wherein tensile loads are transferred between overlapped mineral platelets by shearing of the organic matrix, is used to model the reinforcement provided by mineral platelets. It is assumed that the organic matrix is elastic in tension and elastic-perfectly plastic in shear until it fails. When organic matrix shear stresses at the ends of mineral platelets reach their yield values, the stress-strain curve of bone tissue starts to deviate from linear behavior. This is referred as the microscopic yield point. At the point where the stress-strain behavior of bone shows a sharp curvature, the organic phase reaches its shear yield stress value over the entire platelet. This is referred as the macroscopic yield point. It is assumed that after macroscopic yield, mineral platelets cannot contribute to the load bearing capacity of bone and that the mechanical behavior of cortical bone tissue is determined by the organic phase only. Bone fails when the principal stress of the organic matrix is reached. By assuming that mechanical properties of the organic matrix are dependent on bone mineral content below the macroscopic yield point, the model is used to predict the entire tensile mechanical behavior of cortical bone for different mineral contents. It is found that decreased shear yield stresses and organic matrix elastic moduli are required to explain the mechanical behavior of bones with lowered mineral contents. Under these conditions, the predicted values (elastic modulus, 0.002 yield stress and strain, and ultimate stress and strain) are within 15% of experimental data. PMID:16434048

  7. A mechanostatistical approach to cortical bone remodelling: an equine model.

    Science.gov (United States)

    Wang, X; Thomas, C D L; Clement, J G; Das, R; Davies, H; Fernandez, J W

    2016-02-01

    In this study, the development of a mechanostatistical model of three-dimensional cortical bone remodelling informed with in vivo equine data is presented. The equine model was chosen as it is highly translational to the human condition due to similar Haversian systems, availability of in vivo bone strain and biomarker data, and furthermore, equine models are recommended by the US Federal Drugs Administration for comparative joint research. The model was derived from micro-computed tomography imaged specimens taken from the equine third metacarpal bone, and the Frost-based 'mechanostat' was informed from both in vivo strain gauges and biomarkers to estimate bone growth rates. The model also described the well-known 'cutting cone' phenomena where Haversian canals tunnel and replace bone. In order to make this model useful in practice, a partial least squares regression (PLSR) surrogate model was derived based on training data from finite element simulations with different loads. The PLSR model was able to predict microstructure and homogenised Young's modulus with errors less than 2.2% and 0.6%, respectively. PMID:25862068

  8. Bone balance within a cortical BMU: local controls of bone resorption and formation.

    Directory of Open Access Journals (Sweden)

    David W Smith

    Full Text Available Maintaining bone volume during bone turnover by a BMU is known as bone balance. Balance is required to maintain structural integrity of the bone and is often dysregulated in disease. Consequently, understanding how a BMU controls bone balance is of considerable interest. This paper develops a methodology for identifying potential balance controls within a single cortical BMU. The theoretical framework developed offers the possibility of a directed search for biological processes compatible with the constraints of balance control. We first derive general control constraint equations and then introduce constitutive equations to identify potential control processes that link key variables that describe the state of the BMU. The paper describes specific local bone volume balance controls that may be associated with bone resorption and bone formation. Because bone resorption and formation both involve averaging over time, short-term fluctuations in the environment are removed, leaving the control systems to manage deviations in longer-term trends back towards their desired values. The length of time for averaging is much greater for bone formation than for bone resorption, which enables more filtering of variability in the bone formation environment. Remarkably, the duration for averaging of bone formation may also grow to control deviations in long-term trends of bone formation. Providing there is sufficient bone formation capacity by osteoblasts, this leads to an extraordinarily robust control mechanism that is independent of either osteoblast number or the cellular osteoid formation rate. A complex picture begins to emerge for the control of bone volume. Different control relationships may achieve the same objective, and the 'integration of information' occurring within a BMU may be interpreted as different sets of BMU control systems coming to the fore as different information is supplied to the BMU, which in turn leads to different observable

  9. Bone balance within a cortical BMU: local controls of bone resorption and formation.

    Science.gov (United States)

    Smith, David W; Gardiner, Bruce S; Dunstan, Colin

    2012-01-01

    Maintaining bone volume during bone turnover by a BMU is known as bone balance. Balance is required to maintain structural integrity of the bone and is often dysregulated in disease. Consequently, understanding how a BMU controls bone balance is of considerable interest. This paper develops a methodology for identifying potential balance controls within a single cortical BMU. The theoretical framework developed offers the possibility of a directed search for biological processes compatible with the constraints of balance control. We first derive general control constraint equations and then introduce constitutive equations to identify potential control processes that link key variables that describe the state of the BMU. The paper describes specific local bone volume balance controls that may be associated with bone resorption and bone formation. Because bone resorption and formation both involve averaging over time, short-term fluctuations in the environment are removed, leaving the control systems to manage deviations in longer-term trends back towards their desired values. The length of time for averaging is much greater for bone formation than for bone resorption, which enables more filtering of variability in the bone formation environment. Remarkably, the duration for averaging of bone formation may also grow to control deviations in long-term trends of bone formation. Providing there is sufficient bone formation capacity by osteoblasts, this leads to an extraordinarily robust control mechanism that is independent of either osteoblast number or the cellular osteoid formation rate. A complex picture begins to emerge for the control of bone volume. Different control relationships may achieve the same objective, and the 'integration of information' occurring within a BMU may be interpreted as different sets of BMU control systems coming to the fore as different information is supplied to the BMU, which in turn leads to different observable BMU behaviors.

  10. Altered Cortical Microarchitecture and Bone Metabolism in Patients with Monoclonal Gammopathy of Undetermined Significance

    OpenAIRE

    Farr, J.N.; W. Zhang; Jacques, R.M.; Ng, A.; McCready, L. K.; Drake, M.T.

    2014-01-01

    Patients with monoclonal gammopathy of undetermined significance (MGUS) are at increased fracture risk, and we have previously shown that MGUS patients have altered trabecular bone microarchitecture compared with controls. However, there are no data on whether the porosity of cortical bone, which may play a greater role in bone strength and the occurrence of fractures, is increased in MGUS. Thus, we studied cortical porosity and bone strength (apparent modulus) using high-resolution periphera...

  11. Compromised cortical bone compartment in type 2 diabetes mellitus patients with microvascular disease

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram Vinod; Hansen, Stinus; Nielsen, Morten Frost Munk;

    2016-01-01

    OBJECTIVE AND DESIGN: Patients with type 2 diabetes mellitus (T2D) have an increased fracture risk despite a normal or elevated bone mineral density (BMD). The aim of this cross-sectional in vivo study was to assess parameters of peripheral bone microarchitecture, estimated bone strength and bone......-resolution peripheral quantitative tomography (HR-pQCT) was used to assess bone structure at the non-dominant distal radius and tibia. Estimated bone strength was calculated using finite element analysis. Biochemical markers of bone turnover were measured in all participants. RESULTS: After adjusting for BMI, MVD......+ patients displayed lower cortical volumetric BMD (P=0.02) and cortical thickness (P=0.02) and higher cortical porosity at the radius (P=0.02) and a trend towards higher cortical porosity at the tibia (P=0.07) compared to controls. HR-pQCT parameters did not differ between MVD- and control subjects...

  12. Enhanced stability of uncemented canine femoral components by bone ingrowth into the porous coatings.

    Science.gov (United States)

    Jasty, M; Bragdon, C R; Zalenski, E; O'Connor, D; Page, A; Harris, W H

    1997-01-01

    The following questions were answered in this study: (1) What is the initial stability of proximally porous-coated canine femoral components? (2) Does bone ingrowth occur under these conditions? (3) Is the stability enhanced by tissue ingrowth in vivo? The stability of proximally porous-coated femoral components of canine total hip arthroplasties after 6 months to 2 years of in vivo service in dogs was measured in vitro using displacement transducers under loads simulating canine midstance. This was compared with the stability of identical components under the same loading conditions immediately after implantation in vitro in the contralateral femurs. The femurs were then sectioned and bone ingrowth into the porous coatings was quantified. The results showed that immediately after implantation the implants can move as much as 50 microns, but that the bone ingrowth into porous coatings of canine femoral components can occur even under such conditions. These data also suggested that the relative motion existing at the time of insertion can be reduced to very small amounts (< 10 microns) by bone ingrowth. PMID:9021510

  13. Aging and Fracture of Human Cortical Bone and Tooth Dentin

    Energy Technology Data Exchange (ETDEWEB)

    Ager, Joel; Koester, Kurt J.; Ager III, Joel W.; Ritchie, Robert O.

    2008-05-07

    Mineralized tissues, such as bone and tooth dentin, serve as structural materials in the human body and, as such, have evolved to resist fracture. In assessing their quantitative fracture resistance or toughness, it is important to distinguish between intrinsic toughening mechanisms which function ahead of the crack tip, such as plasticity in metals, and extrinsic mechanisms which function primarily behind the tip, such as crack bridging in ceramics. Bone and dentin derive their resistance to fracture principally from extrinsic toughening mechanisms which have their origins in the hierarchical microstructure of these mineralized tissues. Experimentally, quantification of these toughening mechanisms requires a crack-growth resistance approach, which can be achieved by measuring the crack-driving force, e.g., the stress intensity, as a function of crack extension ("R-curve approach"). Here this methodology is used to study of the effect of aging on the fracture properties of human cortical bone and human dentin in order to discern the microstructural origins of toughness in these materials.

  14. Osteoblast-derived WNT16 represses osteoclastogenesis and prevents cortical bone fragility fractures

    OpenAIRE

    Movérare-Skrtic, Sofia; Henning, Petra; LIU, XIANWEN; Nagano, Kenichi; SAITO, HIROAKI; Börjesson, Anna E; Sjögren, Klara; Sara H Windahl; Farman, Helen; Kindlund, Bert; Engdahl, Cecilia; Koskela, Antti; Zhang, Fu-Ping; Eriksson, Emma E; Zaman, Farasat

    2014-01-01

    The WNT16 locus is a major determinant of cortical bone thickness and nonvertebral fracture risk in humans. The disability, mortality and costs caused by osteoporosis-induced nonvertebral fractures are enormous. We demonstrate here that Wnt16-deficient mice develop spontaneous fractures as a result of low cortical thickness and high cortical porosity. In contrast, trabecular bone volume is not altered in these mice. Mechanistic studies revealed that WNT16 is osteoblast derived and inhibits hu...

  15. Cancellous Screws Are Biomechanically Superior to Cortical Screws in Metaphyseal Bone.

    Science.gov (United States)

    Wang, Tim; Boone, Christopher; Behn, Anthony W; Ledesma, Justin B; Bishop, Julius A

    2016-09-01

    Cancellous screws are designed to optimize fixation in metaphyseal bone environments; however, certain clinical situations may require the substitution of cortical screws for use in cancellous bone, such as anatomic constraints, fragment size, or available instrumentation. This study compares the biomechanical properties of commercially available cortical and cancellous screw designs in a synthetic model representing various bone densities. Commercially available, fully threaded, 4.0-mm outer-diameter cortical and cancellous screws were tested in terms of pullout strength and maximum insertion torque in standard-density and osteoporotic cancellous bone models. Pullout strength and maximum insertion torque were both found to be greater for cancellous screws than cortical screws in all synthetic densities tested. The magnitude of difference in pullout strength between cortical and cancellous screws increased with decreasing synthetic bone density. Screw displacement prior to failure and total energy absorbed during pullout strength testing were also significantly greater for cancellous screws in osteoporotic models. Stiffness was greater for cancellous screws in standard and osteoporotic models. Cancellous screws have biomechanical advantages over cortical screws when used in metaphyseal bone, implying the ability to both achieve greater compression and resist displacement at the screw-plate interface. Surgeons should preferentially use cancellous over cortical screws in metaphyseal environments where cortical bone is insufficient for fixation. [Orthopedics.2016; 39(5):e828-e832.].

  16. Scanning electron microscopy of human cortical bone failure surfaces.

    Science.gov (United States)

    Braidotti, P; Branca, F P; Stagni, L

    1997-02-01

    Undecalcified samples extracted from human femoral shafts are fractured by bending and the fracture surfaces are examined with a scanning electron microscope (SEM). The investigation is performed on both dry and wet (hydrated with a saline solution) specimens. SEM micrographs show patterns in many respects similar to those observed in fractography studies of laminated fiber-reinforced synthetic composites. In particular, dry and wet samples behave like brittle and ductile matrix laminates, respectively. An analysis carried out on the basis of the mechanisms that dominate the fracture process of laminates shows that a reasonable cortical bone model is that of a laminated composite material whose matrix is composed of extracellular noncollagenous calcified proteins, and the reinforcement is constituted by the calcified collagen fiber system. PMID:9001936

  17. Thermographic image analysis as a pre-screening tool for the detection of canine bone cancer

    Science.gov (United States)

    Subedi, Samrat; Umbaugh, Scott E.; Fu, Jiyuan; Marino, Dominic J.; Loughin, Catherine A.; Sackman, Joseph

    2014-09-01

    Canine bone cancer is a common type of cancer that grows fast and may be fatal. It usually appears in the limbs which is called "appendicular bone cancer." Diagnostic imaging methods such as X-rays, computed tomography (CT scan), and magnetic resonance imaging (MRI) are more common methods in bone cancer detection than invasive physical examination such as biopsy. These imaging methods have some disadvantages; including high expense, high dose of radiation, and keeping the patient (canine) motionless during the imaging procedures. This project study identifies the possibility of using thermographic images as a pre-screening tool for diagnosis of bone cancer in dogs. Experiments were performed with thermographic images from 40 dogs exhibiting the disease bone cancer. Experiments were performed with color normalization using temperature data provided by the Long Island Veterinary Specialists. The images were first divided into four groups according to body parts (Elbow/Knee, Full Limb, Shoulder/Hip and Wrist). Each of the groups was then further divided into three sub-groups according to views (Anterior, Lateral and Posterior). Thermographic pattern of normal and abnormal dogs were analyzed using feature extraction and pattern classification tools. Texture features, spectral feature and histogram features were extracted from the thermograms and were used for pattern classification. The best classification success rate in canine bone cancer detection is 90% with sensitivity of 100% and specificity of 80% produced by anterior view of full-limb region with nearest neighbor classification method and normRGB-lum color normalization method. Our results show that it is possible to use thermographic imaging as a pre-screening tool for detection of canine bone cancer.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    Traditionally, the pharmacokinetics of antimicrobials in bone have been investigated using bone biopsies, but this approach suffers from considerable methodological limitations. Consequently, new methods are needed. The objectives of this study were to assess the feasibility of the microdialysis...... (MD) technique for measurement of cefuroxime in bone, and to obtain pharmacokinetic profiles for the same drug in porcine cortical and cancellous bone. Measurements were conducted in bone-wax sealed and unsealed drill holes in cortical bone, in drill holes in cancellous bone and in subcutaneous tissue....... As reference, free and total plasma concentrations were also measured. The animals received a bolus of 1500 mg cefuroxime over 30 min. No significant differences between key pharmacokinetic parameters for sealed and unsealed drill holes in cortical bone were found. The mean area under the concentration...

  19. Bone scintigraphy for metastasis detection in canine osteosarcoma

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the usefulness of serial bone scintigraphy in the detection of skeletal and extraskeletal metastases in dogs with appendicular osteosarcoma. Twenty-six dogs with primary, appendicular osteosarcoma were entered into a limb-sparing protocol. Bone scintigraphy was performed upon presentation, after neoadjuvant therapy but prior to surgery and at selective intervals after limb-sparing surgery to evaluate for the presence of metastasis. Thoracic radiographs, and radiographs of other sites, were also made at the time of each bone scan. All dogs had a complete necropsy. No dog had bone or lung metastases detected prior to treatment. The bone scans, medical records, and radiographs of each dog were reviewed retrospectively. All but one dog developed metastatic disease. Bone metastatic sites were confirmed at necropsy in 12 of the 26 dogs. Seven of these 12 dogs had bone metastatic sites which were not producing clinical signs, i.e. an occult metastasis. In five of the seven dogs, the occult site was the first metastatic site detected. Extraskeletal metastases were identified scintigraphically in six of the 26 dogs, but these were clinically apparent prior to bone scintigraphy in each dog. Suspected malignant scintigraphic lesions were proven benign in six dogs. In five dogs with malignant bone lesions at necropsy the last bone scan prior to euthanasia was normal. The time interval between scintigraphy and necropsy was variable in these five dogs. All dogs without bone metastases at necropsy had normal bone scans. This study validates the usefulness of bone scintigraphy for detection of occult bone metastasis and improved ability for tumor staging in dogs with appendicular osteosarcoma

  20. Using the gradient of human cortical bone properties to determine age-related bone changes via ultrasonic guided waves.

    Science.gov (United States)

    Baron, Cécile

    2012-06-01

    Bone fragility depends not only on bone mass but also on bone quality (structure and material). To accurately evaluate fracture risk or propose therapeutic treatment, clinicians need a criterion, which reflects the determinants of bone strength: geometry, structure and material. In human long bone, the changes due to aging, accentuated by osteoporosis are often revealed through the trabecularization of cortical bone, i.e., increased porosity of endosteal bone inducing a thinning of the cortex. Consequently, the intracortical porosity gradient corresponding to the spatial variation in porosity across the cortical thickness is representative of loss of mass, changes in geometry (thinning) and variations in structure (porosity). This article examines the gradient of material properties and its age-related evolution as a relevant parameter to assess bone geometry, structure and material. By applying a homogenization process, cortical bone can be considered as an anisotropic functionally graded material with variations in material properties. A semi-analytical method based on the sextic Stroh formalism is proposed to solve the wave equation in an anisotropic functionally graded waveguide for two geometries, a plate and a tube, without using a multilayered model to represent the structure. This method provides an analytical solution called the matricant and explicitly expressed under the Peano series expansion form. Our findings indicate that ultrasonic guided waves are sensitive to the age-related evolution of realistic gradients in human bone properties across the cortical thickness and have their place in a multimodal clinical protocol. PMID:22502890

  1. Cortical and trabecular bone at the forearm show different adaptation patterns in response to tennis playing.

    Science.gov (United States)

    Ducher, Gaële; Prouteau, Stéphanie; Courteix, Daniel; Benhamou, Claude-Laurent

    2004-01-01

    Bone responds to impact-loading activity by increasing its size and/or density. The aim of this study was to compare the magnitude and modality of the bone response between cortical and trabecular bone in the forearms of tennis players. Bone area, bone mineral content (BMC), and bone mineral density (BMD) of the ulna and radius were measured by dual-energy X-ray absorptiometry (DXA) in 57 players (24.5 +/- 5.7 yr old), at three sites: the ultradistal region (50% trabecular bone), the mid-distal regions, and third-distal (mainly cortical bone). At the ultradistal radius, the side-to-side difference in BMD was larger than in bone area (8.4 +/- 5.2% and 4.9 +/- 4.0%, respectively, p < 0.01). In the cortical sites, the asymmetry was lower (p < 0.01) in BMD than in bone area (mid-distal radius: 4.0 +/- 4.3% vs 11.7 +/- 6.8%; third-distal radius: 5.0 +/- 4.8% vs 8.4 +/- 6.2%). The asymmetry in bone area explained 33% of the variance of the asymmetry in BMC at the ultradistal radius, 66% at the mid-distal radius, and 53% at the third-distal radius. The ulna displayed similar results. Cortical and trabecular bone seem to respond differently to mechanical loading. The first one mainly increases its size, whereas the second one preferentially increases its density.

  2. Measurement of strain distribution in cortical bone around miniscrew implants used for orthodontic anchorage using digital speckle pattern interferometry

    Science.gov (United States)

    Kumar, Manoj; Agarwal, Rupali; Bhutani, Ravi; Shakher, Chandra

    2016-05-01

    An application of digital speckle pattern interferometry (DSPI) for the measurement of deformations and strain-field distributions developed in cortical bone around orthodontic miniscrew implants inserted into the human maxilla is presented. The purpose of this study is to measure and compare the strain distribution in cortical bone/miniscrew interface of human maxilla around miniscrew implants of different diameters, different implant lengths, and implants of different commercially available companies. The technique is also used to measure tilt/rotation of canine caused due to the application of retraction springs. The proposed technique has high sensitivity and enables the observation of deformation/strain distribution. In DSPI, two specklegrams are recorded corresponding to pre- and postloading of the retraction spring. The DSPI fringe pattern is observed by subtracting these two specklegrams. Optical phase was extracted using Riesz transform and the monogenic signal from a single DSPI fringe pattern. The obtained phase is used to calculate the parameters of interest such as displacement/deformation and strain/stress. The experiment was conducted on a dry human skull fulfilling the criteria of intact dental arches and all teeth present. Eight different miniscrew implants were loaded with an insertion angulation of 45 deg in the inter-radicular region of the maxillary second premolar and molar region. The loading of miniscrew implants was done with force level (150 gf) by nickel-titanium closed-coil springs (9 mm). The obtained results from DSPI reveal that implant diameter and implant length affect the displacement and strain distribution in cortical bone layer surrounding the miniscrew implant.

  3. Measurement of strain distribution in cortical bone around miniscrew implants used for orthodontic anchorage using digital speckle pattern interferometry

    Science.gov (United States)

    Kumar, Manoj; Agarwal, Rupali; Bhutani, Ravi; Shakher, Chandra

    2016-05-01

    An application of digital speckle pattern interferometry (DSPI) for the measurement of deformations and strain-field distributions developed in cortical bone around orthodontic miniscrew implants inserted into the human maxilla is presented. The purpose of this study is to measure and compare the strain distribution in cortical bone/miniscrew interface of human maxilla around miniscrew implants of different diameters, different implant lengths, and implants of different commercially available companies. The technique is also used to measure tilt/rotation of canine caused due to the application of retraction springs. The proposed technique has high sensitivity and enables the observation of deformation/strain distribution. In DSPI, two specklegrams are recorded corresponding to pre- and postloading of the retraction spring. The DSPI fringe pattern is observed by subtracting these two specklegrams. Optical phase was extracted using Riesz transform and the monogenic signal from a single DSPI fringe pattern. The obtained phase is used to calculate the parameters of interest such as displacement/deformation and strain/stress. The experiment was conducted on a dry human skull fulfilling the criteria of intact dental arches and all teeth present. Eight different miniscrew implants were loaded with an insertion angulation of 45 deg in the inter-radicular region of the maxillary second premolar and molar region. The loading of miniscrew implants was done with force level (150 gf) by nickel-titanium closed-coil springs (9 mm). The obtained results from DSPI reveal that implant diameter and implant length affect the displacement and strain distribution in cortical bone layer surrounding the miniscrew implant.

  4. Canine cancellous bone microarchitecture after one year of high-dose bisphosphonates

    DEFF Research Database (Denmark)

    Ding, Ming; Day, JS; Burr, DB;

    2003-01-01

    We examined the effects of one-year high-dose bisphosphonates (risedronate 0.5 mg/kg/day or alendronate 1.0 mg/kg/day) on the three-dimensional (3-D) microstructural and mechanical properties of canine cancellous bone. A high-resolution micro-CT scanner was used to scan cubic specimens produced....... Our results suggest a bone remodeling-adaptation mechanism stimulated by bisphosphonates that increases bone volume fraction, thickens trabeculae, changes trabeculae towards more plate-like, and increases mechanical properties. The secondary degree of anisotropy contributed significantly...... to the explained variance in bone strength, and the primary or tertiary degree of anisotropy improved the explanation of variances for Young's moduli, i.e., 79% of strength variances or 74-83% of modulus variances could be explained by the combined anisotropy and bone volume fraction. These significant...

  5. Association of Jumping Mechanography-Derived Indices of Muscle Function with Tibial Cortical Bone Geometry.

    Science.gov (United States)

    Verroken, Charlotte; Zmierczak, Hans-Georg; Goemaere, Stefan; Kaufman, Jean-Marc; Lapauw, Bruno

    2016-05-01

    Jumping mechanography has been developed to estimate maximum voluntary muscle forces. This study assessed associations of jumping mechanography-derived force and power measurements with tibial cortical bone geometry, compared to other estimates of muscle mass, size, and function. Healthy men (n = 181; 25-45 years) were recruited in a cross-sectional, population-based sibling-pair study. Muscle parameters include isokinetic peak torque of the quadriceps, DXA-derived leg lean mass, mechanography-derived peak jump force and power, and pQCT-derived mid-tibial (66 %) muscle cross-sectional area (CSA). Mid-tibial cortical bone parameters were assessed by pQCT. In age, height, and weight-adjusted analyses, jump force and power correlated positively with cortical bone area, cortical thickness, and polar strength-strain index (SSIp) (β = 0.23-0.34, p ≤ 0.001 for force; β = 0.25-0.30, p ≤ 0.007 for power) and inversely with endosteal circumference adjusted for periosteal circumference (ECPC) (β = -0.16, p < 0.001 for force; β = -0.13, p = 0.007 for power). Force but not power correlated with cortical over total bone area ratio (β = 0.25, p = 0.002). Whereas leg lean mass correlated with all cortical parameters except cortical over total bone area ratio (β = 0.25-0.62, p ≤ 0.004), muscle CSA only correlated with cortical bone area, periosteal circumference, and SSIp (β = 0.21-0.26, p ≤ 0.001), and quadriceps torque showed no significant correlations with the bone parameters. Multivariate models indicated that leg lean mass was independently associated with overall bone size and strength reflected by periosteal and endosteal circumference and SSIp (β = 0.32-0.55, p ≤ 0.004), whereas jump force was independently associated with cortical bone size reflected by ECPC, cortical thickness, and cortical over total bone area ratio (β = 0.13-0.28; p ≤ 0.002). These data indicate that jumping mechanography provides relevant

  6. Molecular Characterization of Three Canine Models of Human Rare Bone Diseases: Caffey, van den Ende-Gupta, and Raine Syndromes.

    Science.gov (United States)

    Hytönen, Marjo K; Arumilli, Meharji; Lappalainen, Anu K; Owczarek-Lipska, Marta; Jagannathan, Vidhya; Hundi, Sruthi; Salmela, Elina; Venta, Patrick; Sarkiala, Eva; Jokinen, Tarja; Gorgas, Daniela; Kere, Juha; Nieminen, Pekka; Drögemüller, Cord; Lohi, Hannes

    2016-05-01

    One to two percent of all children are born with a developmental disorder requiring pediatric hospital admissions. For many such syndromes, the molecular pathogenesis remains poorly characterized. Parallel developmental disorders in other species could provide complementary models for human rare diseases by uncovering new candidate genes, improving the understanding of the molecular mechanisms and opening possibilities for therapeutic trials. We performed various experiments, e.g. combined genome-wide association and next generation sequencing, to investigate the clinico-pathological features and genetic causes of three developmental syndromes in dogs, including craniomandibular osteopathy (CMO), a previously undescribed skeletal syndrome, and dental hypomineralization, for which we identified pathogenic variants in the canine SLC37A2 (truncating splicing enhancer variant), SCARF2 (truncating 2-bp deletion) and FAM20C (missense variant) genes, respectively. CMO is a clinical equivalent to an infantile cortical hyperostosis (Caffey disease), for which SLC37A2 is a new candidate gene. SLC37A2 is a poorly characterized member of a glucose-phosphate transporter family without previous disease associations. It is expressed in many tissues, including cells of the macrophage lineage, e.g. osteoclasts, and suggests a disease mechanism, in which an impaired glucose homeostasis in osteoclasts compromises their function in the developing bone, leading to hyperostosis. Mutations in SCARF2 and FAM20C have been associated with the human van den Ende-Gupta and Raine syndromes that include numerous features similar to the affected dogs. Given the growing interest in the molecular characterization and treatment of human rare diseases, our study presents three novel physiologically relevant models for further research and therapy approaches, while providing the molecular identity for the canine conditions. PMID:27187611

  7. Molecular Characterization of Three Canine Models of Human Rare Bone Diseases: Caffey, van den Ende-Gupta, and Raine Syndromes.

    Directory of Open Access Journals (Sweden)

    Marjo K Hytönen

    2016-05-01

    Full Text Available One to two percent of all children are born with a developmental disorder requiring pediatric hospital admissions. For many such syndromes, the molecular pathogenesis remains poorly characterized. Parallel developmental disorders in other species could provide complementary models for human rare diseases by uncovering new candidate genes, improving the understanding of the molecular mechanisms and opening possibilities for therapeutic trials. We performed various experiments, e.g. combined genome-wide association and next generation sequencing, to investigate the clinico-pathological features and genetic causes of three developmental syndromes in dogs, including craniomandibular osteopathy (CMO, a previously undescribed skeletal syndrome, and dental hypomineralization, for which we identified pathogenic variants in the canine SLC37A2 (truncating splicing enhancer variant, SCARF2 (truncating 2-bp deletion and FAM20C (missense variant genes, respectively. CMO is a clinical equivalent to an infantile cortical hyperostosis (Caffey disease, for which SLC37A2 is a new candidate gene. SLC37A2 is a poorly characterized member of a glucose-phosphate transporter family without previous disease associations. It is expressed in many tissues, including cells of the macrophage lineage, e.g. osteoclasts, and suggests a disease mechanism, in which an impaired glucose homeostasis in osteoclasts compromises their function in the developing bone, leading to hyperostosis. Mutations in SCARF2 and FAM20C have been associated with the human van den Ende-Gupta and Raine syndromes that include numerous features similar to the affected dogs. Given the growing interest in the molecular characterization and treatment of human rare diseases, our study presents three novel physiologically relevant models for further research and therapy approaches, while providing the molecular identity for the canine conditions.

  8. Cortical bone development under the growth plate is regulated by mechanical load transfer.

    NARCIS (Netherlands)

    Tanck, E.J.M.; Hannink, G.J.; Ruimerman, R.; Buma, P.; Burger, E.H.; Huiskes, R.

    2006-01-01

    Longitudinal growth of long bones takes place at the growth plates. The growth plate produces new bone trabeculae, which are later resorbed or merged into the cortical shell. This process implies transition of trabecular metaphyseal sections into diaphyseal sections. We hypothesize that the developm

  9. Effect of micromorphology of cortical bone tissue on crack propagation under dynamic loading

    Science.gov (United States)

    Wang, Mayao; Gao, Xing; Abdel-Wahab, Adel; Li, Simin; Zimmermann, Elizabeth A.; Riedel, Christoph; Busse, Björn; Silberschmidt, Vadim V.

    2015-09-01

    Structural integrity of bone tissue plays an important role in daily activities of humans. However, traumatic incidents such as sports injuries, collisions and falls can cause bone fracture, servere pain and mobility loss. In addition, ageing and degenerative bone diseases such as osteoporosis can increase the risk of fracture [1]. As a composite-like material, a cortical bone tissue is capable of tolerating moderate fracture/cracks without complete failure. The key to this is its heterogeneously distributed microstructural constituents providing both intrinsic and extrinsic toughening mechanisms. At micro-scale level, cortical bone can be considered as a four-phase composite material consisting of osteons, Haversian canals, cement lines and interstitial matrix. These microstructural constituents can directly affect local distributions of stresses and strains, and, hence, crack initiation and propagation. Therefore, understanding the effect of micromorphology of cortical bone on crack initiation and propagation, especially under dynamic loading regimes is of great importance for fracture risk evaluation. In this study, random microstructures of a cortical bone tissue were modelled with finite elements for four groups: healthy (control), young age, osteoporosis and bisphosphonate-treated, based on osteonal morphometric parameters measured from microscopic images for these groups. The developed models were loaded under the same dynamic loading conditions, representing a direct impact incident, resulting in progressive crack propagation. An extended finite-element method (X-FEM) was implemented to realize solution-dependent crack propagation within the microstructured cortical bone tissues. The obtained simulation results demonstrate significant differences due to micromorphology of cortical bone, in terms of crack propagation characteristics for different groups, with the young group showing highest fracture resistance and the senior group the lowest.

  10. Effect of Cortical Bone Thickness on Detection of Intraosseous Lesions by Ultrasonography

    International Nuclear Information System (INIS)

    Background. Usefulness of ultrasound (US) in detection of intrabony lesions has been showed. A cortical bone perforation or a very thin and intact cortical bone is prerequisite for this purpose. Objective. The current in vitro study was aimed at measuring the cut-off thickness of the overlying cortical bone which allows ultrasonic assessment of bony defects. Materials and Methods. 20 bovine scapula blocks were obtained. Samples were numbered from 1 to 20. In each sample, 5 artificial lesions were made. The lesions were made in order to increase the overlying bone thickness, from 0.1 mm in the first sample to 2 mm in the last one (with 0.1 mm interval). After that, the samples underwent ultrasound examinations by two practicing radiologists. Results. All five lesions in samples numbered 1 to 11 were detected as hypoechoic area. Cortical bone thickness more than 1.1 mm resulted in a failure in the detection of central lesions. Conclusion. We can conclude that neither bony perforation nor very thin cortical bones are needed to consider US to be an effective imaging technique in the evaluation of bony lesion

  11. Effect of Cortical Bone Thickness on Detection of Intraosseous Lesions by Ultrasonography

    Directory of Open Access Journals (Sweden)

    Sadaf Adibi

    2015-01-01

    Full Text Available Background. Usefulness of ultrasound (US in detection of intrabony lesions has been showed. A cortical bone perforation or a very thin and intact cortical bone is prerequisite for this purpose. Objective. The current in vitro study was aimed at measuring the cut-off thickness of the overlying cortical bone which allows ultrasonic assessment of bony defects. Materials and Methods. 20 bovine scapula blocks were obtained. Samples were numbered from 1 to 20. In each sample, 5 artificial lesions were made. The lesions were made in order to increase the overlying bone thickness, from 0.1 mm in the first sample to 2 mm in the last one (with 0.1 mm interval. After that, the samples underwent ultrasound examinations by two practicing radiologists. Results. All five lesions in samples numbered 1 to 11 were detected as hypoechoic area. Cortical bone thickness more than 1.1 mm resulted in a failure in the detection of central lesions. Conclusion. We can conclude that neither bony perforation nor very thin cortical bones are needed to consider US to be an effective imaging technique in the evaluation of bony lesion.

  12. Radiographic, densitometric, and biomechanical effects of recombinant canine somatotropin in an unstable ostectomy gap model of bone healing in dogs

    International Nuclear Information System (INIS)

    Objective: To determine the effect of recombinant canine somatotropin (STH) on radiographic, densitometric, and biomechanical aspects of bone healing using an unstable ostectomy gap model. Study Design: After an ostectomy of the midshaft radius, bone healing was evaluated over an 8-week period in control dogs (n = 4) and dogs receiving recombinant canine STH (n = 4). Animals Or Sample Population: Eight sexually intact female Beagle dogs, 4 to 5 years old. Methods: Bone healing was evaluated by qualitative and quantitative evaluation of serial radiographs every 2 weeks. Terminal dual-energy x-ray absorptiometry and three-point bending biomechanical testing were also performed. Results: Dogs receiving STH had more advanced radiographic healing of ostectomy sites. Bone area, bone mineral content, and bone density were two to five times greater at the ostectomy sites of treated dogs. Ultimate load at failure and stiffness were three and five times greater in dogs receiving STH. Conclusions: Using the ostectomy gap model, recombinant canine STH enhanced the radiographic, densitometric, and biomechanical aspects of bone healing in dogs. Clinical Relevance: Dogs at risk for delayed healing of fractures may benefit from treatment with recombinant canine STH

  13. An approach to the histomorphological and histochemical variations of the humerus cortical bone through human ontogeny.

    Science.gov (United States)

    Cambra-Moo, Oscar; Nacarino Meneses, Carmen; Rodríguez Barbero, Miguel Ángel; García Gil, Orosia; Rascón Pérez, Josefina; Rello-Varona, Santiago; D'Angelo, Manuel; Campo Martín, Manuel; González Martín, Armando

    2014-06-01

    For many years, clinical and non-clinical investigations have investigated cortical bone structure in an attempt to address questions related to normal bone development, mineralisation, pathologies and even evolutionary trends in our lineage (adaptations). Research in the fields of medicine, materials science, physical anthropology, palaeontology, and even archaeobiology has contributed interesting data. However, many questions remain regarding the histomorphological and histochemical variations in human cortical bone during different stages of life. In the present work, we describe a study of long bone cortex transformations during ontogeny. We analysed cross-sections of 15 human humeri histomorphologically and histochemically from perinatal to adult age, marking and quantifying the spatial distribution of bone tissue types using GIS software and analysing the mineral composition and crystallinity of the mineralised cortex using Raman spectroscopy and X-ray diffraction. Our results allowed us to propose that human cortical bone undergoes three main 'events' through ontogeny that critically change the proportions and structure of the cortex. In early development, bone is not well mineralised and proportionally presents a wide cortex that narrows through the end of childhood. Before reaching complete maturity, the bone mineral area increases, allowing the bone to nearly reach the adult size. The medullary cavity is reduced, and the mineral areas have a highly ordered crystalline structure. The last event occurs in adulthood, when the 'oldest' individuals present a reduced mineralised area, with increasing non-mineralised cavities (including the medullary cavity) and reduced crystalline organisation. PMID:24660964

  14. Assessment of the cortical bone thickness using ultrasonic guided waves: modelling and in vitro study.

    Science.gov (United States)

    Moilanen, Petro; Nicholson, Patrick H F; Kilappa, Vantte; Cheng, Sulin; Timonen, Jussi

    2007-02-01

    Determination of cortical bone thickness is warranted, e.g., for assessing the level of endosteal resorption in osteoporosis or other bone pathologies. We have shown previously that the velocity of the fundamental antisymmetric (or flexural) guided wave, measured for bone phantoms and bones in vitro, correlates with the cortical thickness significantly better than those by other axial ultrasound methods. In addition, we have introduced an inversion scheme based on guided wave theory, group velocity filtering and 2-D fast Fourier transform, for determination of cortical thickness from the measured velocity of guided waves. In this study, the method was validated for tubular structures by using numerical simulations and experimental measurements on tube samples. In addition, 40 fresh human radius specimens were measured. For tubes with a thin wall, plate theory could be used to determine the wall thickness with a precision of 4%. For tubes with a wall thicker than 1/5 of the outer radius, tube theory provided the wall thickness with similar accuracy. For the radius bone specimens, tube theory was used and the ultrasonically-determined cortical thickness was found to be U-Th = 2.47 mm +/- 0.66 mm. It correlated strongly (r(2) = 0.73, p < 0.001) with the average cortical thickness, C-Th = 2.68 +/- 0.53 mm, and the local cortical thickness (r(2) = 0.81, p < 0.001), measured using peripheral quantitative computed tomography. We can conclude that the guided-wave inversion scheme introduced here is a feasible method for assessing cortical bone thickness. PMID:17306696

  15. Regional variability in secondary remodeling within long bone cortices of catarrhine primates: the influence of bone growth history.

    Science.gov (United States)

    McFarlin, Shannon C; Terranova, Carl J; Zihlman, Adrienne L; Enlow, Donald H; Bromage, Timothy G

    2008-09-01

    Secondary intracortical remodeling of bone varies considerably among and within vertebrate skeletons. Although prior research has shed important light on its biomechanical significance, factors accounting for this variability remain poorly understood. We examined regional patterning of secondary osteonal bone in an ontogenetic series of wild-collected primates, at the midshaft femur and humerus of Chlorocebus (Cercopithecus) aethiops (n = 32) and Hylobates lar (n = 28), and the midshaft femur of Pan troglodytes (n = 12). Our major objectives were: 1) to determine whether secondary osteonal bone exhibits significant regional patterning across inner, mid-cortical and outer circumferential cortical rings within cross-sections; and if so, 2) to consider the manner in which this regional patterning may reflect the influence of relative tissue age and other circumstances of bone growth. Using same field-of-view images of 100-microm-thick cross-sections acquired in brightfield and circularly polarized light microscopy, we quantified the percent area of secondary osteonal bone (%HAV) for whole cross-sections and across the three circumferential rings within cross-sections. We expected bone areas with inner and middle rings to exhibit higher %HAV than the outer cortical ring within cross-sections, the latter comprising tissues of more recent depositional history. Observations of primary bone microstructural development provided an additional context in which to evaluate regional patterning of intracortical remodeling. Results demonstrated significant regional variability in %HAV within all skeletal sites. As predicted,%HAV was usually lowest in the outer cortical ring within cross-sections. However, regional patterning across inner vs. mid-cortical rings showed a more variable pattern across taxa, age classes, and skeletal sites examined. Observations of primary bone microstructure revealed that the distribution of endosteally deposited bone had an important influence on

  16. Mechanistic fracture criteria for the failure of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-13

    A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the underlying microstructure affects the failure mode in bone is lacking.

  17. Radiographic changes in cortical bone after intramedullary nailing. An experimental investigation on rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Kaartinen, E.; Paavolainen, P.; Silvennoinen, T.; Slaetis, P.; Karaharju, E.

    Transverse osteotomies of the midshaft of the tibia in 75 rabbits were stabilized with intramedullary nails which prevented rotational instability. In a further 36 animals intramedullary nailing was performed without preceding osteotomy. The animals were able to move freely immediately after the operation without any supporting cast or splint. The structural changes in the bones were analysed radiographically 3 to 24 weeks after the operation. Fracture repair was accompanied by moderate periosteal callus formation and remodelling of the callus was seen from 9 weeks on. A sleeve of new endosteal bone surrounding the nail was found after 12 weeks. Porotic transformation of the diaphyseal cortical bone was seen in both osteotomized and non-osteotomized bones from 12 weeks onwards. It is concluded that intramedullary nailing provides favorable conditions for fracture repair and enables accurate radiographic assessment of the healing. Attention is focused on the causes and features of secondary porotic transformation of the cortical bone after intramedullary nailing. (orig.).

  18. Allogeneic stem cell transplantation for bone regeneration of a nonunion defect in a canine

    Directory of Open Access Journals (Sweden)

    Yaneselli K

    2013-10-01

    Full Text Available Kevin Yaneselli,1 Andrea Filomeno,1 Gabriel Semiglia,1 Carolina Arce,1 Analía Rial,2 Natalia Muñoz,2 María Moreno,2 Kent Erickson,3 Jacqueline Maisonnave11Universidad de la República, Facultad de Veterinaria, Montevideo, Uruguay; 2Laboratory for Vaccine Research, Department of Biotechnology, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; 3University of California, Davis, CA, USAAbstract: Nonunion bone defects occur frequently with local pain, functional limitations, muscular atrophy, and fistulas due to osteomyelitis. The application of mesenchymal stem cells (MSCs could improve regeneration of bone following bone defects. The objective of the present study was to evaluate the treatment of a nonunion defect due to chronic osteomyelitis in a greyhound female dog with allogeneic adipose tissue-derived mesenchymal stem cells (AT-MSCs. The implanted cells were adherent to plastic, were of fibroblast type, and expressed the canine stem cell markers CD90low, CD44high, and CD45-. Cell therapy consisted of five percutaneous weekly injections of 2 × 106 allogeneic AT-MSCs into the bone defect (total of 10 × 106 AT-MSCs. The patient was evaluated clinically and radiologically for up to 1 year. The results were clinical improvement, a light lameness score of 1 at week 16, return to use of its forearm, no pain, and increased muscular mass. No signs of osteomyelitis were observed radiologically and clinically there were no fistulas. There was no evidence of local or systemic adverse reactions caused by the aloimplants. The clinical relevance of the cell therapy contributing to repair of bone defects in small animals is a very promising future alternative. These results may have an important impact in new regenerative treatments for animal and human orthopedics.Keywords: allogeneic, AT-MSCs, treatment, nonunion, canine

  19. USE OF CORTICAL STRUCTURAL HOMOLOGOUS BONE GRAFT IN FEMORAL RECONSTRUCTIVE SURGERY

    OpenAIRE

    Roos, Milton Valdomiro; Roos, Bruno Dutra; Giora, Taís Stedile Busin; Taglietti, Thiago Martins

    2015-01-01

    To perform a clinical and radiographic assessment of patients undergoing surgical treatment using a cortical structural homologous bone graft for femoral reconstruction following mechanical failure of total hip arthroplasty and periprosthetic fractures. Methods: A retrospective study was conducted on 27 patients who underwent surgical treatment for femoral reconstruction following mechanical failure of total hip arthroplasty (12 cases) and periprosthetic fractures (15 cases), using a cortical...

  20. A new algorithm to improve assessment of cortical bone geometry in pQCT.

    Science.gov (United States)

    Cervinka, Tomas; Sievänen, Harri; Lala, Deena; Cheung, Angela M; Giangregorio, Lora; Hyttinen, Jari

    2015-12-01

    High-resolution peripheral quantitative computed tomography (HR-pQCT) is now considered the leading imaging modality in bone research. However, access to HR-pQCT is limited and image acquisition is mainly constrained only for the distal third of appendicular bones. Hence, the conventional pQCT is still commonly used despite inaccurate threshold-based segmentation of cortical bone that can compromise the assessment of whole bone strength. Therefore, this study addressed whether the use of an advanced image processing algorithm, called OBS, can enhance the cortical bone analysis in pQCT images and provide similar information to HR-pQCT when the same volumes of interest are analyzed. Using pQCT images of European Forearm Phantom (EFP), and pQCT and HR-pQCT images of the distal tibia from 15 cadavers, we compared the results from the OBS algorithm with those obtained from common pQCT analyses, HR-pQCT manual analysis (considered as a gold standard) and common HR-pQCT analysis dual threshold technique.We found that the use of OBS segmentation method for pQCT image analysis of EFP data did not result in any improvement but reached similar performance in cortical bone delineation as did HR-pQCT image analyses. The assessments of cortical cross-sectional bone area and thickness by OBS algorithm were overestimated by less than 4% while area moments of inertia were overestimated by ~5–10%, depending on reference HR-pQCT analysis method. In conclusion, this study showed that the OBS algorithm performed reasonably well and it offers a promising practical tool to enhance the assessment of cortical bone geometry in pQCT. PMID:26428659

  1. Mandibular Inferior Cortical Bone Thickness on Panoramic Radiographs in Patients using Bisphosphonates

    Science.gov (United States)

    Torres, Sandra R.; Chen, Curtis S. K.; Leroux, Brian G.; Lee, Peggy P.; Hollender, Lars G.; Lloid, Michelle; Drew, Shane Patrick; Schubert, Mark M.

    2015-01-01

    Objective To detect dimensional changes in the mandibular cortical bone associated with bisphosphonate (BP) use and to correlate the measurements of the cortical bone with the cumulative dose of BP therapy. Methods Mandibular inferior cortical bone thickness (MICBT) was measured under the mental foramen from panoramic radiographs of subjects using BP with and without bisphosphonate related osteonecrosis of the jaws (BRONJ) and controls. Results The highest mean MICBT was observed in BRONJ subjects 6.81 (± 1.35 mm), when compared to subjects using BP 5.44 (± 1.09 mm) and controls 4.79 (± 0.85 mm; p<0.01). The mean MICBT of BRONJ subjects was significantly higher than that of subjects using BP without BRONJ. There was a correlation between MICBT and cumulative dose of zolendronate. Conclusion The MICBT on panoramic radiograph is a potentially useful tool for the detection of dimensional changes associated with BP therapy. PMID:25864820

  2. Acute hypothalamic suppression significantly affects trabecular bone but not cortical bone following recovery and ovariectomy surgery in a rat model.

    Science.gov (United States)

    Yingling, Vanessa R; Mitchell, Kathryn A; Lunny, Megan

    2016-01-01

    Background. Osteoporosis is "a pediatric disease with geriatric consequences." Bone morphology and tissue quality co-adapt during ontogeny for sufficient bone stiffness. Altered bone morphology from hypothalamic amenorrhea, a risk factor for low bone mass in women, may affect bone strength later in life. Our purpose was to determine if altered morphology following hypothalamic suppression during development affects cortical bone strength and trabecular bone volume (BV/TV) at maturity. Methods. Female rats (25 days old) were assigned to a control (C) group (n = 45) that received saline injections (.2 cc) or an experimental group (GnRH-a) (n = 45) that received gonadotropin releasing hormone antagonist injections (.24 mg per dose) for 25 days. Fifteen animals from each group were sacrificed immediately after the injection protocol at Day 50 (C, GnRH-a). The remaining animals recovered for 135 days and a subset of each group was sacrificed at Day 185 ((C-R) (n = 15) and (G-R) (n = 15)). The remaining animals had an ovariectomy surgery (OVX) at 185 days of age and were sacrificed 40 days later (C-OVX) (n = 15) and (G-OVX) (n = 15). After sacrifice femurs were mechanically tested and scanned using micro CT. Serum C-terminal telopeptides (CTX) and insulin-like growth factor 1 (IGF-1) were measured. Two-way ANOVA (2 groups (GnRH-a and Control) X 3 time points (Injection Protocol, Recovery, post-OVX)) was computed. Results. GnRH-a injections suppressed uterine weights (72%) and increased CTX levels by 59%. Bone stiffness was greater in the GnRH-a groups compared to C. Ash content and cortical bone area were similar between groups at all time points. Polar moment of inertia, a measure of bone architecture, was 15% larger in the GnRH-a group and remained larger than C (19%) following recovery. Both the polar moment of inertia and cortical area increased linearly with the increases in body weight. Following the injection protocol, trabecular BV/TV was 31% lower in the Gn

  3. A preliminary investigation of the dynamic viscoelastic relaxation of bovine cortical bone

    Directory of Open Access Journals (Sweden)

    Loete T.J.C.

    2015-01-01

    Full Text Available A new experimental approach is proposed to characterize the dynamic viscoelastic relaxation behaviour of cortical bone. Theoretical models are presented to show that a linear viscoelastic material, when allowed to relax between two long elastic bars, will produce stress, strain and strain rate histories that contain characteristic features. Furthermore, typical experimental results are presented to show that these characteristic features are observed during split Hopkinson bar tests on bovine cortical bone using a Cone-in-Tube striker. The interpretation of this behaviour in the context of a standard linear viscoelastic model is discussed.

  4. Weibull analysis of fracture test data on bovine cortical bone: influence of orientation.

    Science.gov (United States)

    Khandaker, Morshed; Ekwaro-Osire, Stephen

    2013-01-01

    The fracture toughness, K IC, of a cortical bone has been experimentally determined by several researchers. The variation of K IC values occurs from the variation of specimen orientation, shape, and size during the experiment. The fracture toughness of a cortical bone is governed by the severest flaw and, hence, may be analyzed using Weibull statistics. To the best of the authors' knowledge, however, no studies of this aspect have been published. The motivation of the study is the evaluation of Weibull parameters at the circumferential-longitudinal (CL) and longitudinal-circumferential (LC) directions. We hypothesized that Weibull parameters vary depending on the bone microstructure. In the present work, a two-parameter Weibull statistical model was applied to calculate the plane-strain fracture toughness of bovine femoral cortical bone obtained using specimens extracted from CL and LC directions of the bone. It was found that the Weibull modulus of fracture toughness was larger for CL specimens compared to LC specimens, but the opposite trend was seen for the characteristic fracture toughness. The reason for these trends is the microstructural and extrinsic toughening mechanism differences between CL and LC directions bone. The Weibull parameters found in this study can be applied to develop a damage-mechanics model for bone. PMID:24385985

  5. Optical phase analysis in drilled cortical porcine bones using digital holographic interferometry

    Science.gov (United States)

    Tavera R., César G.; De la Torre I., Manuel H.; Flores M., J. Mauricio; Luna H., Juan M.; Briones R., Manuel de J.; Mendoza S., Fernando

    2016-03-01

    A study in porcine femoral bones with and without the presence of cortical drilling is presented. An out of plane digital holographic interferometer is used to retrieve the optical phase during the controlled compression tests. These tests try to simulate physiological deformations in postmortem healthy bones and compare their mechanical response with those having a cortical hole. The cortical drilling technique is widely used in medical procedures to fix plaques and metallic frames to a bone recovering from a fracture. Several materials and drilling techniques are used for this purpose. In this work we analyze the superficial variations of the bone when different drilling diameters are used. By means of the optical phase it is possible to recover the superficial deformation of the tissue during a controlled deformation with high resolution. This information could give a better understand about the micro structural variations of the bone instead of a bulk response. As proof of principle, several tests were performed to register the modes and ranges of the displacements for compressive loads. From these tests notorious differences are observed between both groups of bones, having less structural stiffness the drilled ones as expected. However, the bone's characteristic to absorb and adjust itself due the load is also highly affected according to the number of holes. Results from different kind of samples (undrilled and drilled) are presented and discussed in this work.

  6. The effects of bone density and crestal cortical bone thickness on micromotion and peri-implant bone strain distribution in an immediately loaded implant: a nonlinear finite element analysis

    Science.gov (United States)

    2016-01-01

    Purpose This study investigated the effects of bone density and crestal cortical bone thickness at the implant-placement site on micromotion (relative displacement between the implant and bone) and the peri-implant bone strain distribution under immediate-loading conditions. Methods A three-dimensional finite element model of the posterior mandible with an implant was constructed. Various bone parameters were simulated, including low or high cancellous bone density, low or high crestal cortical bone density, and crestal cortical bone thicknesses ranging from 0.5 to 2.5 mm. Delayed- and immediate-loading conditions were simulated. A buccolingual oblique load of 200 N was applied to the top of the abutment. Results The maximum extent of micromotion was approximately 100 μm in the low-density cancellous bone models, whereas it was under 30 μm in the high-density cancellous bone models. Crestal cortical bone thickness significantly affected the maximum micromotion in the low-density cancellous bone models. The minimum principal strain in the peri-implant cortical bone was affected by the density of the crestal cortical bone and cancellous bone to the same degree for both delayed and immediate loading. In the low-density cancellous bone models under immediate loading, the minimum principal strain in the peri-implant cortical bone decreased with an increase in crestal cortical bone thickness. Conclusions Cancellous bone density may be a critical factor for avoiding excessive micromotion in immediately loaded implants. Crestal cortical bone thickness significantly affected the maximum extent of micromotion and peri-implant bone strain in simulations of low-density cancellous bone under immediate loading. PMID:27382504

  7. The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone.

    Science.gov (United States)

    Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

    2014-04-01

    High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network

  8. Modalities for visualization of cortical bone remodeling: the past, present and near future

    Directory of Open Access Journals (Sweden)

    Kimberly Dawn Harrison

    2015-08-01

    Full Text Available Bone’s ability to respond to load-related phenomena and repair microdamage is achieved through the remodeling process which renews bone by activating groups of cells known as Basic Multicellular Units (BMUs. The products of BMUs, secondary osteons, have been extensively studied via classic two-dimensional (2D techniques which have provided a wealth of information on how histomorphology relates to skeletal structure and function. Remodeling is critical in maintaining healthy bone tissue; however, in osteoporotic bone imbalanced resorption results in increased bone fragility and fracture. With increasing life expectancy, such degenerative bone diseases are a growing concern. The three-dimensional (3D morphology of BMUs and their correlation to function, however, are not well characterized and little is known about the specific mechanisms that initiate and regulate their activity within cortical bone. We believe a key limitation has been the lack 3D information about BMU morphology and activity. Thus, this paper reviews methodologies for 3D investigation of cortical bone remodeling and, specifically, structures associated with BMU activity (resorption spaces and the structures they create (secondary osteons, spanning from histology to modern ex vivo imaging modalities, culminating with the growing potential of in vivo imaging. This collection of papers focuses on the theme of putting the why back into bone archytecture. Remodeling is one of two mechanisms how bone structure is dynamically modified and thus an improved 3D understanding of this fundamental process is crucial to ultimately understanding the why.

  9. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone.

    Science.gov (United States)

    Ding, Ming; Danielsen, Carl Christian; Overgaard, Søren

    2012-06-01

    In this study, 18 female skeletally mature sheep were randomly allocated into three groups of six each. Group 1 (glucocorticoid-1) received prednisolone treatment (0.60 mg/kg/day, five times weekly) for 7 months. Group 2 (glucocorticoid-2) received the same treatment regime followed by observation of 3 months without treatment. Group 3 was left untreated and served as controls. All sheep received a restricted diet with low calcium and phosphorus. At sacrifice, cortical bone samples from the femur midshaft of each sheep were harvested, micro-CT scanned and subjected to three-point bending and tensile strength testing. Bone collagen and mineral were determined. Cortical porosity was significantly increased in the glucocorticoid-2 compared with the glucocorticoid-1 and control groups. Apparent density was significantly decreased in the glucocorticoid-2 compared with the glucocorticoid-1 group. Collagen content was significantly increased in the glucocorticoid-2 compared with the glucocorticoid-1 and control groups. Bone mineral content did not differ between the groups. Neither the three-point bending mechanical properties nor the tensile mechanical properties differed significantly between the groups, while there was a trend towards decreasing bending mechanical properties in the glucocorticoid-2 group. In conclusion, 7 months of glucocorticoid treatment with malnutrition had a significant impact on the cortical microarchitecture of the sheep femur midshaft. These observed changes occurred 3 months after glucocorticoid cessation, suggesting a delayed effect of glucocorticoid on cortical bone. Thus, changes in cortical bone beyond cancellous bone might further increase fracture risk in patients treated with glucocorticoids. This model might be used as a glucocorticoid-induced osteoporotic model for orthopaedic biomaterial, joint prosthesis and medical device researches.

  10. How Tough is Human Cortical Bone? In-Situ Measurements on Realistically Short Cracks

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, Robert O; Koester, K. J.; Ager III, J. W.; Ritchie, R.O.

    2008-05-10

    Bone is more difficult to break than to split. Although this is well known, and many studies exist on the behavior of long cracks in bone, there is a need for data on the orientation-dependent crack-growth resistance behavior of human cortical bone which accurately assesses its toughness at appropriate size-scales. Here we use in-situ mechanical testing in the scanning electron microscope and x-ray computed tomography to examine how physiologically-pertinent short (<600 mu m) cracks propagate in both the transverse and longitudinal orientations in cortical bone, using both crack-deflection/twist mechanics and nonlinear-elastic fracture mechanics to determine crack-resistance curves. We find that after only 500 mu m of cracking, the driving force for crack propagation was more than five times higher in the transverse (breaking) direction than in the longitudinal (splitting) direction due to major crack deflections/twists principally at cement sheathes. Indeed, our results show that the true transverse toughness of cortical bone is far higher than previously reported. However, the toughness in the longitudinal orientation, where cracks tend to follow the cement lines, is quite low at these small crack sizes; it is only when cracks become several millimeters in length that bridging mechanisms can develop leading to the (larger-crack) toughnesses generally quoted for bone.

  11. Using smooth particle hydrodynamics to investigate femoral cortical bone remodelling at the Haversian level.

    Science.gov (United States)

    Fernandez, J W; Das, R; Cleary, P W; Hunter, P J; Thomas, C D L; Clement, J G

    2013-01-01

    In the neck of the femur, about 70% of the strength is contributed by the cortical bone, which is the most highly stressed part of the structure and is the site where failure is almost certainly initiated. A better understanding of cortical bone remodelling mechanisms can help discern changes at this anatomical site, which are essential if an understanding of the mechanisms by which hips weaken and become vulnerable to fracture is to be gained. The aims of this study were to (i) examine a hypothesis that low strain fields arise because of subject-specific Haversian canal distributions causing bone resorption and reduced bone integrity and (ii) introduce the use of a meshless particle-based computational modelling approach SPH to capture bone remodelling features at the level of the Haversian canals. We show that bone remodelling initiated by strain at the Haversian level is highly influenced by the subject-specific pore distribution, bone density, loading and osteocyte density. SPH is shown to be effective at capturing the intricate bone pore shapes that evolved over time.

  12. Effect of low intensity pulsed ultrasound on repairing the periodontal bone of Beagle canines

    Institute of Scientific and Technical Information of China (English)

    Xiao-Qi Gu; Yong-Mei Li; Jing Guo; Li-Hua Zhang; Dong Li; Xiao-Dong Gai

    2014-01-01

    Objective: To investigate the repairing effect of low intensity pulsed ultrasound (LIPUS) on the Beagle canines periodontal bone defect. Methods: A total of 12 Beagle dogs with periodontal bone defect model were randomly divided into control group, LIPUS group, guided tissue regeneration (GTR) group and LIPUS+GTR group, with three in each. After completion of the models, no other proceeding was performed in control group; LIPUS group adopt direct exposure to radiation line LIPUS processing 1 week after modeling; GTR group adopted treatment with GTR, following the CTR standard operation reference; LIPUS+GTR group was treated with LIPUS joint GTR. Temperature change before treatment and histopathological change of periodontal tissue after repair was observed. Results: There was no significant difference in temperature changes of periodontal tissue between groups (P>0.05). The amount and maturity of LIPUS+GTR group were superior to other groups; new cementum, dental periodontal bones of GTR group were superior to the control group but less than LIPUS group; new collagen and maturity of the control group is not high relatively. Conclusions: LIPUS can accelerate the calcium salt deposition and new bone maturation, thus it can serve as promoting periodontal tissue repair, and shortening the periodontal tissue repair time.

  13. Genetic algorithms-based inversion of multimode guided waves for cortical bone characterization

    Science.gov (United States)

    Bochud, N.; Vallet, Q.; Bala, Y.; Follet, H.; Minonzio, J.-G.; Laugier, P.

    2016-10-01

    Recent progress in quantitative ultrasound has exploited the multimode waveguide response of long bones. Measurements of the guided modes, along with suitable waveguide modeling, have the potential to infer strength-related factors such as stiffness (mainly determined by cortical porosity) and cortical thickness. However, the development of such model-based approaches is challenging, in particular because of the multiparametric nature of the inverse problem. Current estimation methods in the bone field rely on a number of assumptions for pairing the incomplete experimental data with the theoretical guided modes (e.g. semi-automatic selection and classification of the data). The availability of an alternative inversion scheme that is user-independent is highly desirable. Thus, this paper introduces an efficient inversion method based on genetic algorithms using multimode guided waves, in which the mode-order is kept blind. Prior to its evaluation on bone, our proposal is validated using laboratory-controlled measurements on isotropic plates and bone-mimicking phantoms. The results show that the model parameters (i.e. cortical thickness and porosity) estimated from measurements on a few ex vivo human radii are in good agreement with the reference values derived from x-ray micro-computed tomography. Further, the cortical thickness estimated from in vivo measurements at the third from the distal end of the radius is in good agreement with the values delivered by site-matched high-resolution x-ray peripheral computed tomography.

  14. Accuracy of bone surface size and cortical layer thickness measurements using cone beam computerized tomography

    NARCIS (Netherlands)

    Gerlach, N.L.; Meijer, G.J.; Borstlap, W.A.; Bronkhorst, E.M.; Berge, S.J.; Maal, T.J.J.

    2013-01-01

    OBJECTIVES: The purpose of this study was to determine the accuracy of Cone Beam Computerized Tomography (CBCT) reconstructions in displaying bone surface size and cortical layer thickness. MATERIALS AND METHODS: Two fresh frozen cadaver heads were scanned using a CBCT (i-CAT() 3D Imaging System; Im

  15. USE OF CORTICAL STRUCTURAL HOMOLOGOUS BONE GRAFT IN FEMORAL RECONSTRUCTIVE SURGERY

    Science.gov (United States)

    Roos, Milton Valdomiro; Roos, Bruno Dutra; Giora, Taís Stedile Busin; Taglietti, Thiago Martins

    2015-01-01

    To perform a clinical and radiographic assessment of patients undergoing surgical treatment using a cortical structural homologous bone graft for femoral reconstruction following mechanical failure of total hip arthroplasty and periprosthetic fractures. Methods: A retrospective study was conducted on 27 patients who underwent surgical treatment for femoral reconstruction following mechanical failure of total hip arthroplasty (12 cases) and periprosthetic fractures (15 cases), using a cortical structural homologous bone graft and cemented implants, between June 1999 and February 2008. Of these, 21 fulfilled all the criteria required for this study. The patients underwent pre and postoperative clinical assessments using the Harris Hip Score. Preoperative, immediate postoperative and late postoperative radiographs were also evaluated, with comparisons of fracture consolidation, radiographic signs of graft consolidation, changes to the bone stock and femoral bone quality, and femoral alignment. Results: Nine patients (42.9%) underwent femoral reconstruction following mechanical failure of total hip arthroplasty and 12 cases (57.1%) underwent femoral reconstruction following periprosthetic fracture. Regarding the postoperative clinical classification, the results were considered satisfactory in 85.7% of the cases and unsatisfactory in 14.3%. Radiographic signs of graft consolidation were seen in all cases. There was an increase in bone stock in 90.5% of the hip reconstructions, as measured by the cortical index. Furthermore, the changes to femoral bone quality were considered good in 66.7% of the cases. Conclusion: The use of cortical structural homologous bone grafts for both femoral reconstructive surgery on total hip arthroplasty and periprosthetic fractures is a good treatment option for selected cases, enabling satisfactory clinical and radiographic results. PMID:27026955

  16. Biomedical titanium alloys with Young’s moduli close to that of cortical bone

    OpenAIRE

    Niinomi, Mitsuo; Liu, Yi; Nakai, Masaki; Liu, Huihong; Li, Hua

    2016-01-01

    Biomedical titanium alloys with Young’s moduli close to that of cortical bone, i.e., low Young’s modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti–29Nb–13Ta–4.6Zr referred to as TNTZ, which is highly expected to be us...

  17. Trabecular and cortical bone deficits are present in children and adolescents with cystic fibrosis.

    Science.gov (United States)

    Kelly, Andrea; Schall, Joan; Stallings, Virginia A; Zemel, Babette S

    2016-09-01

    Osteopenia and increased fracture rates are well-recognized in adults with CF, but neither the specific contributions of cortical and trabecular bone deficits to bone fragility nor their presence in youth with CF are well-characterized. This study sought to characterize cortical and trabecular volumetric bone mineral density (vBMD), geometry, and biomechanical competence in children with CF and determine their relationship to growth, body composition, and disease severity. Peripheral quantitative computerized tomography (pQCT) measures of total, cortical, and trabecular vBMD, cortical, muscle, and fat cross-sectional areas (CSA), periosteal and endosteal circumferences, and the polar unweighted section modulus (Zp) of the tibia were converted to age- and tibial length-adjusted Z-scores in 97 CF and 199 healthy children (aged 8-21y). Effects of body composition and pulmonary function (forced expiratory volume in 1s, FEV1) upon pQCT outcomes were determined using linear regression. Children with CF (FEV1%-predicted: 84.4+19.7) had lower weight-, height-, BMI-, and whole body lean mass (LBM)-Z and tibial length. Females with CF had lower (pyoung CF cohort, deficits in trabecular and multiple cortical bone parameters were present. In females, deficits were greater at older ages and were not fully explained by alterations in body composition. In males worsening pulmonary function was associated with greater deficits that was not explained by increasing age or compromised nutritional status. The occurrence of these differences in CF youth highlights the importance of instituting measures to optimize peak bone mass early in the course of CF.

  18. Female Mice Lacking Estrogen Receptor-α in Hypothalamic Proopiomelanocortin (POMC) Neurons Display Enhanced Estrogenic Response on Cortical Bone Mass.

    Science.gov (United States)

    Farman, H H; Windahl, S H; Westberg, L; Isaksson, H; Egecioglu, E; Schele, E; Ryberg, H; Jansson, J O; Tuukkanen, J; Koskela, A; Xie, S K; Hahner, L; Zehr, J; Clegg, D J; Lagerquist, M K; Ohlsson, C

    2016-08-01

    Estrogens are important regulators of bone mass and their effects are mainly mediated via estrogen receptor (ER)α. Central ERα exerts an inhibitory role on bone mass. ERα is highly expressed in the arcuate (ARC) and the ventromedial (VMN) nuclei in the hypothalamus. To test whether ERα in proopiomelanocortin (POMC) neurons, located in ARC, is involved in the regulation of bone mass, we used mice lacking ERα expression specifically in POMC neurons (POMC-ERα(-/-)). Female POMC-ERα(-/-) and control mice were ovariectomized (OVX) and treated with vehicle or estradiol (0.5 μg/d) for 6 weeks. As expected, estradiol treatment increased the cortical bone thickness in femur, the cortical bone mechanical strength in tibia and the trabecular bone volume fraction in both femur and vertebrae in OVX control mice. Importantly, the estrogenic responses were substantially increased in OVX POMC-ERα(-/-) mice compared with the estrogenic responses in OVX control mice for cortical bone thickness (+126 ± 34%, P mass, ERα was silenced using an adeno-associated viral vector. Silencing of ERα in hypothalamic VMN resulted in unchanged bone mass. In conclusion, mice lacking ERα in POMC neurons display enhanced estrogenic response on cortical bone mass and mechanical strength. We propose that the balance between inhibitory effects of central ERα activity in hypothalamic POMC neurons in ARC and stimulatory peripheral ERα-mediated effects in bone determines cortical bone mass in female mice.

  19. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl C; Overgaard, Søren

    treatment. Group 3 was left untreated and served as the controls. All sheep received restricted diet with low calcium and phosphorus. At sacrifice, cortical bone samples from the femur midshaft of sheep were harvested, micro-CT scanned and tested in 3 point bending and in tensile. Bone collagen and mineral......The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone – Validation of large animal model for tissue engineering and biomaterial research Ming Ding,1* Carl Christian Danielsen,2 Søren Overgaard1 1Orthopaedic Research Laboratory......, Department of Orthopaedics and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense C, Denmark 2Department of Connective Tissue Biology, Institute of Anatomy, University of Aarhus, Aarhus C, Denmark Osteopenia in sheep has been successfully induced...

  20. Machining characteristics of the haversian and plexiform components of bovine cortical bone.

    Science.gov (United States)

    Conward, Michael; Samuel, Johnson

    2016-07-01

    This paper investigates the characteristic differences observed while machining the haversian and plexiform components of a bovine cortical femoral bone. To this end micro-milling slotting experiments are performed on both the components by varying both the cutting velocity and the feed-per-tooth values. The scale of machining is chosen specifically to ensure sensitivity to the microstructural variations in the bone. The material properties of the microstructural components and their size-scale relative to the feed-per-tooth values are seen to dictate the failure mechanisms encountered during machining. The cutting force, surface roughness, and tool wear are all uniquely affected by the plexiform and haversian components of the cortical bone. In general, plexiform bone requires a higher cutting force than the haversian bone. While a higher cutting velocity can lower the surface roughness of haversian bone, it typically results in the most surface damage. The cutting force and surface roughness values for both the components show strain rate sensitivity. The tool wear is seen to be the highest while cutting parallel to the lamellar structures seen in the plexiform bone.

  1. Trabecular and cortical bone deficits are present in children and adolescents with cystic fibrosis.

    Science.gov (United States)

    Kelly, Andrea; Schall, Joan; Stallings, Virginia A; Zemel, Babette S

    2016-09-01

    Osteopenia and increased fracture rates are well-recognized in adults with CF, but neither the specific contributions of cortical and trabecular bone deficits to bone fragility nor their presence in youth with CF are well-characterized. This study sought to characterize cortical and trabecular volumetric bone mineral density (vBMD), geometry, and biomechanical competence in children with CF and determine their relationship to growth, body composition, and disease severity. Peripheral quantitative computerized tomography (pQCT) measures of total, cortical, and trabecular vBMD, cortical, muscle, and fat cross-sectional areas (CSA), periosteal and endosteal circumferences, and the polar unweighted section modulus (Zp) of the tibia were converted to age- and tibial length-adjusted Z-scores in 97 CF and 199 healthy children (aged 8-21y). Effects of body composition and pulmonary function (forced expiratory volume in 1s, FEV1) upon pQCT outcomes were determined using linear regression. Children with CF (FEV1%-predicted: 84.4+19.7) had lower weight-, height-, BMI-, and whole body lean mass (LBM)-Z and tibial length. Females with CF had lower (p<0.01) total and trabecular vBMD; cortical, muscle, and fat CSA; Zp and periosteal circumference than females in the healthy reference group. These bone differences persisted after adjustment for BMI-Z and to a great extent following adjustment for muscle CSA. Males with CF had lower (p<0.01) cortical, muscle, and fat CSA and their trabecular vBMD deficit approached significance (p=0.069). Deficits were attenuated by adjustment for BMI-Z and to a greater extent adjustment for muscle CSA-Z. The relationship between FEV1%-predicted and pQCT outcomes persisted only in males following adjustment for age and BMI-Z. The CF cohort had lower tibial muscle CSA than expected for their LBM. In this relatively healthy, young CF cohort, deficits in trabecular and multiple cortical bone parameters were present. In females, deficits were greater

  2. TYMPANOPLASTY WITH SEPTAL CARTILAGE AND CORTICAL MASTOID BONE IN CHOLESTEATOMA PATIENTS

    Directory of Open Access Journals (Sweden)

    Biram Singh

    2015-12-01

    Full Text Available OBJECTIVE This study was conducted to find out the ideal graft between septal cartilage and cortical mastoid bone in Farrior’s type 3 tympanoplasty in cholesteatoma patients in terms of hearing improvement, graft status and recurrence rate of the disease after canal wall down mastoidectomy. METHODS This randomized controlled trial was conducted in a tertiary care centre and the procedure and data collections were carried out for one and a half calendar year with effect from September 2007 and each case was followed up for 6 months. The data were entered and calculated statistically using SPSS16 for windows. RESULTS The study shows significant hearing improvement in both the groups. The tympanoplasty type 3 with cortical mastoid bone had air bone gap less than 20dB in 40% of patients. In septal cartilage, tympanoplasty group air bone gap less than 20dB was observed in 36.4%. Retraction of graft developed in 1(2.4% out of 20 patients among cortical mastoid bone tympanoplasty group. Among 22 patients of septal cartilage tympanoplasty type 3, 2(4.8% patients had cartilage resorption and 3(7.1% had graft displacement. Of the total 42 patients, 2(4.8% developed recurrence of the disease. CONCLUSION Cholesteatoma management is controversial. Canal wall down mastoidectomy can reduce the recurrence of disease. The cortical mastoid bone and septal cartilage grafts can provide hearing improvement after tympanoplasty type 3. There is no significant difference in hearing improvement between the two grafts.

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  4. Mesenchymal stem cells from cortical bone demonstrate increased clonal incidence, potency, and developmental capacity compared to their bone marrow–derived counterparts

    Directory of Open Access Journals (Sweden)

    Daniel Blashki

    2016-08-01

    Full Text Available In this study, we show that matrix dense cortical bone is the more potent compartment of bone than bone marrow as a stromal source for mesenchymal stem cells as isolated from adult rats. Lineage-depleted cortical bone-mesenchymal stem cells demonstrated >150-fold enrichment of colony forming unit–fibroblasts per cell incidence. compared to lineage-depleted bone marrow-mesenchymal stem cells, corresponding to a 70-fold increase in absolute recovered colony forming unit–fibroblasts. The composite phenotype Lin−/CD45−/CD31−/VLA-1+/Thy-1+ enriched for clonogenic mesenchymal stem cells solely from cortical bone–derived cells from which 70% of clones spontaneously differentiated into all lineages of bone, cartilage, and adipose. Both populations generated vascularized bone tissue within subcutaneous implanted collagen scaffolds; however, cortical bone–derived cells formed significantly more osteoid than bone marrow counterparts, quantified by histology. The data demonstrate that our isolation protocol identifies and validates mesenchymal stem cells with superior clonal, proliferative, and developmental potential from cortical bone compared to the bone marrow niche although marrow persists as the typical source for mesenchymal stem cells both in the literature and current pre-clinical therapies.

  5. Mesenchymal stem cells from cortical bone demonstrate increased clonal incidence, potency, and developmental capacity compared to their bone marrow–derived counterparts

    Science.gov (United States)

    Blashki, Daniel; Murphy, Matthew B; Ferrari, Mauro; Simmons, Paul J; Tasciotti, Ennio

    2016-01-01

    In this study, we show that matrix dense cortical bone is the more potent compartment of bone than bone marrow as a stromal source for mesenchymal stem cells as isolated from adult rats. Lineage-depleted cortical bone-mesenchymal stem cells demonstrated >150-fold enrichment of colony forming unit–fibroblasts per cell incidence. compared to lineage-depleted bone marrow-mesenchymal stem cells, corresponding to a 70-fold increase in absolute recovered colony forming unit–fibroblasts. The composite phenotype Lin−/CD45−/CD31−/VLA-1+/Thy-1+ enriched for clonogenic mesenchymal stem cells solely from cortical bone–derived cells from which 70% of clones spontaneously differentiated into all lineages of bone, cartilage, and adipose. Both populations generated vascularized bone tissue within subcutaneous implanted collagen scaffolds; however, cortical bone–derived cells formed significantly more osteoid than bone marrow counterparts, quantified by histology. The data demonstrate that our isolation protocol identifies and validates mesenchymal stem cells with superior clonal, proliferative, and developmental potential from cortical bone compared to the bone marrow niche although marrow persists as the typical source for mesenchymal stem cells both in the literature and current pre-clinical therapies. PMID:27579159

  6. Anisotropy of Longitudinal Wave Velocity and Hydroxyapatite Orientation in Bovine Cortical Bone

    Science.gov (United States)

    Yaoi, Yuichiro; Yamamoto, Kazufumi; Nakatsuji, Tomohiro; Yanagitani, Takahiko; Matsukawa, Mami; Yamazaki, Kaoru; Nagano, Akira

    2009-07-01

    The anisotropy of longitudinal wave velocity and the hydroxyapatite (HAp) crystallite orientation in bovine cortical bone were experimentally investigated in detail. A ring-shaped cortical bone sample was obtained from the midshaft of a 32-month-old bovine femur. Four cylindrical specimens (diameter 11 mm) were taken from the ring-shaped cortical bone specimen along the radial direction. Velocity was measured by a conventional ultrasonic pulse system, by rotating the specimen in the axial-tangential plane. The direction of the fastest wave velocity observed was inclined 5-10° from the axial direction. The HAp crystallite orientation in the specimen was also investigated by X-ray diffraction pole-figure analysis. We observed a strong intensive peak of (0002), indicating HAp crystallite c-axis alignment along the bone axis. However, the pole-figure also revealed a small tilt in the HAp crystallite orientation from the axial direction. Comparing the velocity and X-ray diffraction peak at each angle of the axial-tangential plane, a significant correlation between the velocity and the HAp orientation was observed.

  7. Cortical bone tissue resists fatigue fracture by deceleration and arrest of microcrack growth.

    Science.gov (United States)

    Akkus, O; Rimnac, C M

    2001-06-01

    Knowledge of kinetics of fatigue crack growth of microcracks is important so as to understand the dynamics of bone adaptation, remodeling, and the etiology of fatigue-based failures of cortical bone tissue. In this respect, theoretical models (Taylor, J. Biomech., 31 (1998) 587-592; Taylor and Prendergast, Proc. Instn. Mech. Engrs. Part H 211 (1997) 369-375) of microcrack growth in cortical bone have predicted a decreasing microcrack growth rate with increasing microcrack length. However, these predictions have not been observed directly. This study investigated microcrack growth and arrest through observations of surface microcracks during cyclic loading (R=0.1, 50-80MPa) of human femoral cortical bone (male, n=4, age range: 37-40yr) utilizing a video microscopy system. The change in crack length and orientation of eight surface microcracks were measured with the number of fatigue cycles from four specimens. At the applied cyclic stresses, the microcracks propagated and arrested in generally less than 10,000 cycles. The fatigue crack growth rate of all microcracks decreased with increasing crack length following initial identification, consistent with theoretical predictions. The growth rate of the microcracks was observed to be in the range of 5x10(-5) to 5x10(-7)mmcycle(-1). In addition, many of the microcracks were observed not to grow beyond 150 microm and a cyclic stress intensity factor of 0.5MNm(-3/2). The results of this study suggest that cortical bone tissue may resist fracture at the microscale by deceleration of fatigue crack growth and arrest of microcracks.

  8. Pore network microarchitecture influences human cortical bone elasticity during growth and aging.

    Science.gov (United States)

    Bala, Yohann; Lefèvre, Emmanuelle; Roux, Jean-Paul; Baron, Cécile; Lasaygues, Philippe; Pithioux, Martine; Kaftandjian, Valérie; Follet, Hélène

    2016-10-01

    Cortical porosity is a major determinant of bone strength. Haversian and Volkmann׳s canals are׳seen' as pores in 2D cross-section but fashion a dynamic network of interconnected channels in 3D, a quantifiable footprint of intracortical remodeling. Given the changes in bone remodeling across life, we hypothesized that the 3D microarchitecture of the cortical pore network influences its stiffness during growth and ageing. Cubes of cortical bone of 2 mm side-length were harvested in the distal 1/3 of the fibula in 13 growing children (mean age±SD: 13±4 yrs) and 16 adults (age: 75±13 yrs). The cubes were imaged using desktop micro-CT (8.14µm isotropic voxel size). Pores were segmented as a solid to assess pore volume fraction, number, diameter, separation, connectivity and structure model index. Elastic coefficients were derived from measurements of ultrasonic bulk compression and shear wave velocities and apparent mass density. The pore volume fraction did not significantly differ between children and adults but originates from different microarchitectural patterns. Compared to children, adults had 42% (p=0.033) higher pore number that were more connected (Connective Density: +205%, p=0.001) with a 18% (p=0.007) lower pore separation. After accounting for the contribution of pore volume fraction, axial elasticity in traction-compression mode was significantly correlated with better connectivity in growing children and with pore separation among adults. The changes in intracortical remodeling across life alter the distribution, size and connectedness of the channels from which cortical void fraction originates. These alterations in pore network microarchitecture participate in changes in compressive and shear mechanical behavior, partly in a porosity-independent manner. The assessment of pore volume fraction (i.e., porosity) provides only a limited understanding of the role of cortical void volume fraction in its mechanical properties. PMID:27389322

  9. CD44 deficiency inhibits unloading-induced cortical bone loss through downregulation of osteoclast activity

    Science.gov (United States)

    Li, Yuheng; Zhong, Guohui; Sun, Weijia; Zhao, Chengyang; Zhang, Pengfei; Song, Jinping; Zhao, Dingsheng; Jin, Xiaoyan; Li, Qi; Ling, Shukuan; Li, Yingxian

    2015-01-01

    The CD44 is cellular surface adhesion molecule that is involved in physiological processes such as hematopoiesis, lymphocyte homing and limb development. It plays an important role in a variety of cellular functions including adhesion, migration, invasion and survival. In bone tissue, CD44 is widely expressed in osteoblasts, osteoclasts and osteocytes. However, the mechanisms underlying its role in bone metabolism remain unclear. We found that CD44 expression was upregulated during osteoclastogenesis. CD44 deficiency in vitro significantly inhibited osteoclast activity and function by regulating the NF-κB/NFATc1-mediated pathway. In vivo, CD44 mRNA levels were significantly upregulated in osteoclasts isolated from the hindlimb of tail-suspended mice. CD44 deficiency can reduce osteoclast activity and counteract cortical bone loss in the hindlimb of unloaded mice. These results suggest that therapeutic inhibition of CD44 may protect from unloading induced bone loss by inhibiting osteoclast activity. PMID:26530337

  10. CD44 deficiency inhibits unloading-induced cortical bone loss through downregulation of osteoclast activity.

    Science.gov (United States)

    Li, Yuheng; Zhong, Guohui; Sun, Weijia; Zhao, Chengyang; Zhang, Pengfei; Song, Jinping; Zhao, Dingsheng; Jin, Xiaoyan; Li, Qi; Ling, Shukuan; Li, Yingxian

    2015-01-01

    The CD44 is cellular surface adhesion molecule that is involved in physiological processes such as hematopoiesis, lymphocyte homing and limb development. It plays an important role in a variety of cellular functions including adhesion, migration, invasion and survival. In bone tissue, CD44 is widely expressed in osteoblasts, osteoclasts and osteocytes. However, the mechanisms underlying its role in bone metabolism remain unclear. We found that CD44 expression was upregulated during osteoclastogenesis. CD44 deficiency in vitro significantly inhibited osteoclast activity and function by regulating the NF-κB/NFATc1-mediated pathway. In vivo, CD44 mRNA levels were significantly upregulated in osteoclasts isolated from the hindlimb of tail-suspended mice. CD44 deficiency can reduce osteoclast activity and counteract cortical bone loss in the hindlimb of unloaded mice. These results suggest that therapeutic inhibition of CD44 may protect from unloading induced bone loss by inhibiting osteoclast activity.

  11. Design and validation of bending test method for characterization of miniature pediatric cortical bone specimens.

    Science.gov (United States)

    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.

  12. Guided bone regeneration (GBR) using cortical bone pins in combination with leukocyte- and platelet-rich fibrin (L-PRF).

    Science.gov (United States)

    Toffler, Michael

    2014-03-01

    Two of the fundamental requisites for guided bone regeneration (GBR) are space maintenance and primary soft-tissue closure. Allogeneic cortical bone pins measuring 2 mm in diameter in customized lengths can protect surrounding graft materials, support bioresorbable membrane barriers, and resist wound compression from the overlying soft tissues. In addition, a second-generation platelet concentrate, leukocyte- and platelet-rich fibrin (L-PRF), may be incorporated into the augmentation procedure to provide multiple growth factors, accelerate wound healing, and aid in the maintenance of primary closure over the grafted materials. Highlighting two case reports, this article features a GBR technique that uses bone pins in combination with L-PRF membranes to provide both horizontal and vertical ridge augmentation at severely compromised implant sites.

  13. Effect of Aging on the Toughness of Human Cortical Bone: Evaluation by R-Curves

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, J

    2004-10-08

    Age-related deterioration of the fracture properties of bone, coupled with increased life expectancy, are responsible for increasing incidence of bone fracture in the elderly, and hence, an understanding of how its fracture properties degrade with age is essential. The present study describes ex vivo fracture experiments to quantitatively assess the effect of aging on the fracture toughness properties of human cortical bone in the longitudinal direction. Because cortical bone exhibits rising crack-growth resistance with crack extension, unlike most previous studies the toughness is evaluated in terms of resistance-curve (R-curve) behavior, measured for bone taken from wide range of age groups (34-99 years). Using this approach, both the ex vivo crack-initiation and crack-growth toughness are determined and are found to deteriorate with age; the initiation toughness decreases some 40% over six decades from 40 to 100 years, while the growth toughness is effectively eliminated over the same age range. The reduction in crack-growth toughness is considered to be associated primarily with a degradation in the degree of extrinsic toughening, in particular involving crack bridging in the wake of the crack.

  14. The effect of osteoporosis treatments on fatigue properties of cortical bone tissue

    Directory of Open Access Journals (Sweden)

    Garry R. Brock

    2015-06-01

    Full Text Available Bisphosphonates are commonly prescribed for treatment of osteoporosis. Long-term use of bisphosphonates has been correlated to atypical femoral fractures (AFFs. AFFs arise from fatigue damage to bone tissue that cannot be repaired due to pharmacologic treatments. Despite fatigue being the primary damage mechanism of AFFs, the effects of osteoporosis treatments on fatigue properties of cortical bone are unknown. To examine if fatigue-life differences occur in bone tissue after different pharmacologic treatments for osteoporosis, we tested bone tissue from the femurs of sheep given a metabolic acidosis diet to induce osteoporosis, followed by treatment with a selective estrogen reception modulator (raloxifene, a bisphosphonate (alendronate or zoledronate, or parathyroid hormone (teriparatide, PTH. Beams of cortical bone tissue were created and tested in four-point bending fatigue to failure. Tissue treated with alendronate had reduced fatigue life and less modulus loss at failure compared with other treatments, while tissue treated with PTH had a prolonged fatigue life. No loss of fatigue life occurred with zoledronate treatment despite its greater binding affinity and potency compared with alendronate. Tissue mineralization measured by microCT did not explain the differences seen in fatigue behavior. Increased fatigue life with PTH suggests that current treatment methods for AFF could have beneficial effects for restoring fatigue life. These results indicate that fatigue life differs with each type of osteoporosis treatment.

  15. Study of the mechanical behavior of cortical bone microstructure by the finite element method

    OpenAIRE

    Arango Villegas, Camila

    2016-01-01

    [EN] Cortical bone tissue is the responsible of giving support and structure to vertebrates. For that reason, understanding and analyzing its behavior is needed from each different hierarchical level that composes it. The lower the structural scale is, the greater the complexity and scarcity of studies in literature. These studies are relevant for understanding, preventing and solving important health problems that affect human beings. From a mechanical point of view is interesting to eval...

  16. Identification of anisotropic tensile strength of cortical bone using Brazilian test.

    OpenAIRE

    Allena, Rachele; Cluzel, Christophe

    2014-01-01

    International audience For a proper analysis of cortical bone behaviour, it is essential to take into account both the elastic stiffness and the failure criteria. While ultrasound methods allow complete identification of the elastic orthotropic coefficients, tests used to characterise the various failure mechanisms and to identify the brittle tensile strength in all directions are currently inadequate. In the present work we propose the Brazilian test as a complement to conventional tensil...

  17. Automated classification of mandibular cortical bone on dental panoramic radiographs for early detection of osteoporosis

    Science.gov (United States)

    Horiba, Kazuki; Muramatsu, Chisako; Hayashi, Tatsuro; Fukui, Tatsumasa; Hara, Takeshi; Katsumata, Akitoshi; Fujita, Hiroshi

    2015-03-01

    Findings on dental panoramic radiographs (DPRs) have shown that mandibular cortical index (MCI) based on the morphology of mandibular inferior cortex was significantly correlated with osteoporosis. MCI on DPRs can be categorized into one of three groups and has the high potential for identifying patients with osteoporosis. However, most DPRs are used only for diagnosing dental conditions by dentists in their routine clinical work. Moreover, MCI is not generally quantified but assessed subjectively. In this study, we investigated a computer-aided diagnosis (CAD) system that automatically classifies mandibular cortical bone for detection of osteoporotic patients at early stage. First, an inferior border of mandibular bone was detected by use of an active contour method. Second, regions of interest including the cortical bone are extracted and analyzed for its thickness and roughness. Finally, support vector machine (SVM) differentiate cases into three MCI categories by features including the thickness and roughness. Ninety eight DPRs were used to evaluate our proposed scheme. The number of cases classified to Class I, II, and III by a dental radiologist are 56, 25 and 17 cases, respectively. Experimental result based on the leave-one-out cross-validation evaluation showed that the sensitivities for the classes I, II, and III were 94.6%, 57.7% and 94.1%, respectively. Distribution of the groups in the feature space indicates a possibility of MCI quantification by the proposed method. Therefore, our scheme has a potential in identifying osteoporotic patients at an early stage.

  18. Investigation of hyperelastic models for nonlinear elastic behavior of demineralized and deproteinized bovine cortical femur bone.

    Science.gov (United States)

    Hosseinzadeh, M; Ghoreishi, M; Narooei, K

    2016-06-01

    In this study, the hyperelastic models of demineralized and deproteinized bovine cortical femur bone were investigated and appropriate models were developed. Using uniaxial compression test data, the strain energy versus stretch was calculated and the appropriate hyperelastic strain energy functions were fitted on data in order to calculate the material parameters. To obtain the mechanical behavior in other loading conditions, the hyperelastic strain energy equations were investigated for pure shear and equi-biaxial tension loadings. The results showed the Mooney-Rivlin and Ogden models cannot predict the mechanical response of demineralized and deproteinized bovine cortical femur bone accurately, while the general exponential-exponential and general exponential-power law models have a good agreement with the experimental results. To investigate the sensitivity of the hyperelastic models, a variation of 10% in material parameters was performed and the results indicated an acceptable stability for the general exponential-exponential and general exponential-power law models. Finally, the uniaxial tension and compression of cortical femur bone were studied using the finite element method in VUMAT user subroutine of ABAQUS software and the computed stress-stretch curves were shown a good agreement with the experimental data. PMID:26953961

  19. Bone ingrowth through porous titanium granulate around a femoral stem: histological assessment in a six-month canine hemiarthroplasty model.

    Science.gov (United States)

    Turner, Thomas M; Urban, Robert M; Hall, Deborah J; Andersson, Gunnar B J

    2007-01-01

    The procedure of using of porous titanium granules for cementless fixation of a hip replacement femoral stem was studied in a hemiarthroplasty model in 10 canines for 6 months. A vibrating instrument was used to facilitate both the delivery and distribution of the irregularly shaped porous titanium granules into the femoral canal as well as the subsequent insertion of a titanium alloy stem into the intramedullary bed of granules. Histological examination revealed lamellar bone formation through the mantle of porous titanium granules in continuity with the surrounding cortex resulting in the formation of an integrated mantle of bone and titanium granulate around the prosthesis. PMID:17578819

  20. A mathematical model of cortical bone remodeling at cellular level under mechanical stimulus

    Institute of Scientific and Technical Information of China (English)

    Qing-Hua Qin; Ya-Nan Wang

    2012-01-01

    A bone cell population dynamics model for cortical bone remodeling under mechanical stimulus is developed in this paper.The external experiments extracted from the literature which have not been used in the creation of the model are used to test the validity of the model.Not only can the model compare reasonably well with these experimental results such as the increase percentage of final values of bone mineral content (BMC) and bone fracture energy (BFE) among different loading schemes (which proves the validity of the model),but also predict the realtime development pattern of BMC and BFE,as well as the dynamics of osteoblasts (OBA),osteoclasts (OCA),nitric oxide (NO) and prostaglandin E2 (PGE2) for each loading scheme,which can hardly be monitored through experiment.In conclusion,the model is the first of its kind that is able to provide an insight into the quantitative mechanism of bone remodeling at cellular level by which bone cells are activated by mechanical stimulus in order to start resorption/formation of bone mass.More importantly,this model has laid a solid foundation based on which future work such as systemic control theory analysis of bone remodeling under mechanical stimulus can be investigated.The to-be identified control mechanism will help to develop effective drugs and combined nonpharmacological therapies to combat bone loss pathologies.Also this deeper understanding of how mechanical forces quantitatively interact with skeletal tissue is essential for the generation of bone tissue for tissue replacement purposes in tissue engineering.

  1. Relationships between the anisotropy of longitudinal wave velocity and hydroxyapatite crystallite orientation in bovine cortical bone.

    Science.gov (United States)

    Yamamoto, Kazufumi; Nakatsuji, Tomohiro; Yaoi, Yuichiro; Yamato, Yu; Yanagitani, Takahiko; Matsukawa, Mami; Yamazaki, Kaoru; Matsuyama, Yukihiro

    2012-03-01

    Quantitative ultrasound (QUS) is now widely used for evaluating bone in vivo, because obtained ultrasonic wave properties directly reflect the visco-elasticity. Bone tissue is composed of minerals like hydroxyapatite (HAp) and a collagen matrix. HAp crystallites orientation is thus one parameter of bone elasticity. In this study, we experimentally investigated the anisotropy of ultrasonic wave velocity and the HAp crystallites orientation in the axial-radial and axial-tangential planes in detail, using cylindrical specimens obtained from the cortical bone of three bovine femurs. Longitudinal bulk wave propagation was investigated by using a conventional ultrasonic pulse system. We used the one cycle of sinusoidal pulse which was emitted from wide band transmitter. The nominal frequency of the pulse was 1MHz. First, we investigated the anisotropy of longitudinal wave velocity, measuring the anisotropy of velocity in two planes using cylindrical specimens obtained from identical bone areas. The wave velocity changed due to the rotation angle, showing the maximum value in the direction a little off the bone axis. Moreover, X-ray pole figure measurements also indicated that there were small tilts in the HAp crystallites orientation from the bone axis. The tilt angles were similar to those of the highest velocity direction. There were good correlations between velocity and HAp crystallites orientation obtained in different directions. However, a comparatively low correlation was found in posterior bone areas, which shows the stronger effects of bone microstructure. In the radial-tangential plane, where the HAp crystallites hardly ever align, weak anisotropy of velocity was found which seemed to depend on the bone microstructure. PMID:22014464

  2. Improved accuracy of cortical bone mineralization measured by polychromatic microcomputed tomography using a novel high mineral density composite calibration phantom

    International Nuclear Information System (INIS)

    Purpose: Microcomputed tomography (micro-CT) is increasingly used as a nondestructive alternative to ashing for measuring bone mineral content. Phantoms are utilized to calibrate the measured x-ray attenuation to discrete levels of mineral density, typically including levels up to 1000 mg HA/cm3, which encompasses levels of bone mineral density (BMD) observed in trabecular bone. However, levels of BMD observed in cortical bone and levels of tissue mineral density (TMD) in both cortical and trabecular bone typically exceed 1000 mg HA/cm3, requiring extrapolation of the calibration regression, which may result in error. Therefore, the objectives of this study were to investigate (1) the relationship between x-ray attenuation and an expanded range of hydroxyapatite (HA) density in a less attenuating polymer matrix and (2) the effects of the calibration on the accuracy of subsequent measurements of mineralization in human cortical bone specimens. Methods: A novel HA-polymer composite phantom was prepared comprising a less attenuating polymer phase (polyethylene) and an expanded range of HA density (0-1860 mg HA/cm3) inclusive of characteristic levels of BMD in cortical bone or TMD in cortical and trabecular bone. The BMD and TMD of cortical bone specimens measured using the new HA-polymer calibration phantom were compared to measurements using a conventional HA-polymer phantom comprising 0-800 mg HA/cm3 and the corresponding ash density measurements on the same specimens. Results: The HA-polymer composite phantom exhibited a nonlinear relationship between x-ray attenuation and HA density, rather than the linear relationship typically employed a priori, and obviated the need for extrapolation, when calibrating the measured x-ray attenuation to high levels of mineral density. The BMD and TMD of cortical bone specimens measured using the conventional phantom was significantly lower than the measured ash density by 19% (p<0.001, ANCOVA) and 33% (p<0.05, Tukey's HSD), on

  3. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    McGee, Meghan E; Maki, Aaron J; Johnson, Steven E; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2008-02-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis.

  4. In Vitro Fracture of Human Cortical Bone: Local Fracture Criteria and Toughening Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Nalla, R; Stolken, J; Kinney, J; Ritchie, R

    2004-08-18

    A micro-mechanistic understanding of bone fracture that encompasses how cracks interact with the underlying microstructure and defines their local failure mode is lacking, despite extensive research on the response of bone to a variety of factors like aging, loading, and/or disease. Micro-mechanical models for fracture incorporating such local failure criteria have been widely developed for metallic and ceramic materials systems; however, few such deliberations have been undertaken for the fracture of bone. In fact, although the fracture event in mineralized tissues such as bone is commonly believed to be locally strain controlled, until recently there has been little experimental evidence to support this widely held belief. In the present study, a series of in vitro experiments involving a double-notch bend test geometry are performed in order to shed further light on the nature of the local cracking events that precede catastrophic fracture in bone and to define their relationship to the microstructure. Specifically, crack-microstructure interactions are examined to determine the salient toughening mechanisms in human cortical bone and to characterize how these may affect the anisotropy in fracture properties. Based on preliminary micro-mechanical models of these processes, in particular crack deflection and uncracked ligament bridging, the relative importance of these toughening mechanisms is established.

  5. The use of the HiSPECT bone scan in canine flexor enthesopathy and coronoid pathology.

    Science.gov (United States)

    Peremans, K; Duchateau, L; Vermeire, S; Vandermeulen, E; Dobbeleir, A; Gielen, I; Polis, I; Van Rijssen, B; De Bakker, E; Saunders, J; De Spiegeleer, B; Dik, K

    2013-06-01

    In this study the use of the high resolution Micro-Single Photon Emission Tomography (HiSPECT) system with a radioactive bonemarker, (99m)Tc-oxidronate, was evaluated in dogs with coronoid pathology and/or flexor enthesopathy. Sixty-five elbows of 34 dogs were included. CT and HiSPECT were performed on all elbows, arthroscopy on 59. Tracer uptake in 8 anatomical regions was graded according to two models. Increased activity in the medial epicondylar region was associated with flexor pathology on CT (P=0.0002) and arthroscopy (P<0.0001) and increased uptake in the medial coronoid (P<0.0001) and the medial condylar area (P<0.013) with coronoid pathology. Uptake in the remaining areas was not associated with both pathologies. In conclusion, the improved resolution of the HiSPECT system allows identification of increased tracer uptake in the anatomical regions involved in coronoid pathology and flexor enthesopathy. This modality may improve the diagnostic potential of the bone scan in canine elbow disease.

  6. Remodeling of heat-treated cortical bone allografts for posterior lumbar interbody fusion: serial 10-year follow-up.

    Science.gov (United States)

    Muramatsu, Koichi; Hachiya, Yudo; Izawa, Hiroyuki; Yamada, Harumoto

    2012-12-01

    We have selected heat-treated bone allografts as the graft material since the Tokai Bone Bank, the first regional bone bank in Japan, was established in 1992. In this study, we examined changes in bone mineral density (BMD), and morphology observed by magnetic resonance imaging (MRI), and histological findings of bone grafts in cases followed up for 7-10 years after bone grafting to grasp the remodeling of heat-treated cortical bone allografts for posterior lumber interbody fusion (PLIF). BMD of bone grafts was reduced by half at 10 years after grafting. MRI revealed that bone grafts were indistinguishable initially in only 22.2% of cases, whereas after a lengthy period of 10 years distinguishable in many cases. Histologically, new bone formation at the graft-host interface was observed earlier, at 1 year after grafting, than that at the periphery of canals in the specimens. The laminated structure of the cortical bone eroded over time, and fragmented bone trabeculae were observed in the specimens at 8 years or longer after grafting, though necrotic bone still remained in some sites.

  7. Transcriptional profiling of cortical versus cancellous bone from mechanically-loaded murine tibiae reveals differential gene expression.

    Science.gov (United States)

    Kelly, Natalie H; Schimenti, John C; Ross, F Patrick; van der Meulen, Marjolein C H

    2016-05-01

    Mechanical loading is an anabolic stimulus that increases bone mass, and thus a promising method to counteract osteoporosis-related bone loss. The mechanism of this anabolism remains unclear, and needs to be established for both cortical and cancellous envelopes individually. We hypothesized that cortical and cancellous bone display different gene expression profiles at baseline and in response to mechanical loading. To test this hypothesis, the left tibiae of 10-week-old female C57Bl/6 mice were subjected to one session of axial tibial compression (9N, 1200cycles, 4Hz triangle waveform) and euthanized 3 and 24h following loading. The right limb served as the contralateral control. We performed RNA-seq on marrow-free metaphyseal samples from the cortical shell and the cancellous core to determine differential gene expression at baseline (control limb) and in response to load. Differential expression was verified with qPCR. Cortical and cancellous bone exhibited distinctly different transcriptional profiles basally and in response to mechanical loading. More genes were differentially expressed with loading at 24h with more genes downregulated at 24h than at 3h in both tissues. Enhanced Wnt signaling dominated the response in cortical bone at 3 and 24h, but in cancellous bone only at 3h. In cancellous bone at 24h many muscle-related genes were downregulated. These findings reveal key differences between cortical and cancellous genetic regulation in response to mechanical loading. Future studies at different time points and multiple loading sessions will add to our knowledge of cortical and cancellous mechanotransduction with the potential to identify new targets for mouse genetic knockout studies and drugs to treat osteoporosis. PMID:26876048

  8. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl Christian; Overgaard, Søren

    2011-01-01

    of 3 months without treatment. Group 3 was left untreated and served as controls. All sheep received a restricted diet with low calcium and phosphorus. At sacrifice, cortical bone samples from the femur midshaft of each sheep were harvested, micro-CT scanned and subjected to three-point bending......In this study, 18 female skeletally mature sheep were randomly allocated into three groups of six each. Group 1 (glucocorticoid-1) received prednisolone treatment (0.60 mg/kg/day, five times weekly) for 7 months. Group 2 (glucocorticoid-2) received the same treatment regime followed by observation...... the groups, while there was a trend towards decreasing bending mechanical properties in the glucocorticoid-2 group. In conclusion, 7 months of glucocorticoid treatment with malnutrition had a significant impact on the cortical microarchitecture of the sheep femur midshaft. These observed changes occurred 3...

  9. Interface mechanics and histomorphometric analysis of hydroxyapatite-coated and porous glass-ceramic implants in canine bone

    DEFF Research Database (Denmark)

    Nimb, L; Jensen, J S; Gotfredsen, K

    1995-01-01

    A canine study was performed to make a histological and biomechanical evaluation of the interface between bone and two different bioceramic implants. A newly developed glass-ceramic formed by P2O5, CaO, SiO2, and Al2O3, giving a crystal phase composed of CaP2O6-AlPO4-SiP2O7, was compared to hydro......A canine study was performed to make a histological and biomechanical evaluation of the interface between bone and two different bioceramic implants. A newly developed glass-ceramic formed by P2O5, CaO, SiO2, and Al2O3, giving a crystal phase composed of CaP2O6-AlPO4-SiP2O7, was compared...... analysis. The ultimate shear strength for the HA-coated implants was significantly higher than in the glass-ceramic group. When these values were related to the histomorphometric measurements, the difference could be explained by the tissue-to-implant contact. The glass-ceramic showed direct contact only...... with nonmineralized, osteoid bone. The HA-coated implants, however, were integrated into the bone. The study indicated that porous glass-ceramic containing AlPO4 causes local osteomalacia and might not be suitable for clinical purposes....

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

    Directory of Open Access Journals (Sweden)

    Grażyna E Sroga

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

  11. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    DEFF Research Database (Denmark)

    Wittig, Nina; Bach-Gansmo, Fiona Linnea; Birkbak, Mie Elholm;

    2016-01-01

    Modeling and remodeling induce significant changes of bone structure and mechanical properties with age. Therefore, it is important to gain knowledge of the processes taking place in bone over time. The rat is a widely used animal model, where much data has been accumulated on age-related changes...... orientation with animal age. Hence, the evolution of organ and tissue level properties with age in rat cortical bone is not accompanied by related changes in osteocyte lacunar properties. This suggests that bone microstructure and bone matrix material properties and not the geometric properties...

  12. Selective laser melting-produced porous titanium scaffolds regenerate bone in critical size cortical bone defects.

    Science.gov (United States)

    Van der Stok, Johan; Van der Jagt, Olav P; Amin Yavari, Saber; De Haas, Mirthe F P; Waarsing, Jan H; Jahr, Holger; Van Lieshout, Esther M M; Patka, Peter; Verhaar, Jan A N; Zadpoor, Amir A; Weinans, Harrie

    2013-05-01

    Porous titanium scaffolds have good mechanical properties that make them an interesting bone substitute material for large bone defects. These scaffolds can be produced with selective laser melting, which has the advantage of tailoring the structure's architecture. Reducing the strut size reduces the stiffness of the structure and may have a positive effect on bone formation. Two scaffolds with struts of 120-µm (titanium-120) or 230-µm (titanium-230) were studied in a load-bearing critical femoral bone defect in rats. The defect was stabilized with an internal plate and treated with titanium-120, titanium-230, or left empty. In vivo micro-CT scans at 4, 8, and 12 weeks showed more bone in the defects treated with scaffolds. Finally, 18.4 ± 7.1 mm(3) (titanium-120, p = 0.015) and 18.7 ± 8.0 mm(3) (titanium-230, p = 0.012) of bone was formed in those defects, significantly more than in the empty defects (5.8 ± 5.1 mm(3) ). Bending tests on the excised femurs after 12 weeks showed that the fusion strength reached 62% (titanium-120) and 45% (titanium-230) of the intact contralateral femurs, but there was no significant difference between the two scaffolds. This study showed that in addition to adequate mechanical support, porous titanium scaffolds facilitate bone formation, which results in high mechanical integrity of the treated large bone defects.

  13. Elastic modulus and hardness of cortical and trabecular bovine bone measured by nanoindentation

    Institute of Scientific and Technical Information of China (English)

    WANG X J; CHEN X B; HODGSON P D; WEN C E

    2006-01-01

    The elastic modulus and hardness of several microstructure components of dry bovine vertebrae and tibia have been investigated in the longitude and transverse directions using nanoindentation. The elastic modulus for the osteons and the interstitial lamellae in the longitude direction were found to be (24.7±2.5) GPa and (30.1±2.4) GPa. As it's difficult to distinguish osteons from interstitial lamellae in the transverse direction,the average elastic modulus for cortical bovine bone in the transverse direction was (19.8±1.6) GPa. The elastic modulus for trabecular bone in the longitude and transverse direction were (20±2) GPa and (14.7±1.9) GPa respectively. The hardness also varied among the microstructure components in the range of 0.41-0.89 GPa. Analyses of variance show that the values are significantly different.

  14. Avalanche criticality during compression of porcine cortical bone of different ages

    Science.gov (United States)

    Baró, Jordi; Shyu, Peter; Pang, Siyuan; Jasiuk, Iwona M.; Vives, Eduard; Salje, Ekhard K. H.; Planes, Antoni

    2016-05-01

    Crack events developed during uniaxial compression of cortical bones cut from femurs of developing pigs of several ages (4, 12, and 20 weeks) generate avalanches. These avalanches have been investigated by acoustic emission analysis techniques. The avalanche energies are power-law distributed over more than four decades. Such behavior indicates the absence of characteristic scales and suggests avalanche criticality. The statistical distributions of energies and waiting times depend on the pig age and indicate that bones become stronger, but less ductile, with increasing age. Crack propagation is equally age-dependent. Older pigs show, on average, larger cracks with a time distribution similar to those of aftershocks in earthquakes, while younger pigs show only statistically independent failure events.

  15. Periosteal PTHrP Regulates Cortical Bone Remodeling During Fracture Healing.

    Science.gov (United States)

    Wang, Meina; Nasiri, Ali R; Broadus, Arthur E; Tommasini, Steven M

    2015-12-01

    Parathyroid hormone-related protein (PTHrP) is widely expressed in the fibrous outer layer of the periosteum (PO), and the PTH/PTHrP type I receptor (PTHR1) is expressed in the inner PO cambial layer. The cambial layer gives rise to the PO osteoblasts (OBs) and osteoclasts (OCs) that model/remodel the cortical bone surface during development as well as during fracture healing. PTHrP has been implicated in the regulation of PO modeling during development, but nothing is known as regards a role of PTHrP in this location during fracture healing. We propose that PTHrP in the fibrous layer of the PO may be a key regulatory factor in remodeling bone formation during fracture repair. We first assessed whether PTHrP expression in the fibrous PO is associated with PO osteoblast induction in the subjacent cambial PO using a tibial fracture model in PTHrP-lacZ mice. Our results revealed that both PTHrP expression and osteoblast induction in PO were induced 3 days post-fracture. We then investigated a potential functional role of PO PTHrP during fracture repair by performing tibial fracture surgery in 10-week-old CD1 control and PTHrP conditional knockout (PTHrP cKO) mice that lack PO PTHrP. We found that callus size and formation as well as woven bone mineralization in PTHrP cKO mice were impaired compared to that in CD1 mice. Concordant with these findings, functional enzyme staining revealed impaired OB formation and OC activity in the cKO mice. We conclude that deleting PO PTHrP impairs cartilaginous callus formation, maturation and ossification as well as remodeling during fracture healing. These data are the initial genetic evidence suggesting that PO PTHrP may induce osteoblastic activity and regulate fracture healing on the cortical bone surface. PMID:26164475

  16. Nanoscale examination of microdamage in sheep cortical bone using synchrotron radiation transmission x-ray microscopy.

    Directory of Open Access Journals (Sweden)

    Garry R Brock

    Full Text Available Microdamage occurs in bone through repeated and excessive loading. Accumulation of microdamage weakens bone, leading to a loss of strength, stiffness and energy dissipation in the tissue. Imaging techniques used to examine microdamage have typically been limited to the microscale. In the current study microdamage was examined at the nanoscale using transmission x-ray microscopy with an x-ray negative stain, lead-uranyl acetate. Microdamage was generated in notched and unnotched beams of sheep cortical bone (2×2×20 mm, with monotonic and fatigue loading. Bulk sections were removed from beams and stained with lead-uranyl acetate to identify microdamage. Samples were sectioned to 50 microns and imaged using transmission x-ray microscopy producing projection images of microdamage with nanoscale resolution. Staining indicated microdamage occurred in both the tensile and compressive regions. A comparison between monotonic and fatigue loading indicated a statistically significant greater amount of stain present in fatigue loaded sections. Microdamage occurred in three forms: staining to existing bone structures, cross hatch damage and a single crack extending from the notch tip. Comparison to microcomputed tomography demonstrated differences in damage morphology and total damage between the microscale and nanoscale. This method has future applications for understanding the underlying mechanisms for microdamage formation as well as three-dimensional nanoscale examination of microdamage.

  17. A novel composite material specifically developed for ultrasound bone phantoms: cortical, trabecular and skull.

    Science.gov (United States)

    Wydra, A; Maev, R Gr

    2013-11-21

    In the various stages of developing diagnostic and therapeutic equipment, the use of phantoms can play a very important role in improving the process, help in implementation, testing and calibrations. Phantoms are especially useful in developing new applications and training new doctors in medical schools. However, devices that use different physical factors, such as MRI, Ultrasound, CT Scan, etc will require the phantom to be made of different physical properties. In this paper we introduce the properties of recently designed new materials for developing phantoms for ultrasonic human body investigation, which in today's market make up more than 30% in the world of phantoms. We developed a novel composite material which allows fabrication of various kinds of ultrasound bone phantoms to mimic most of the acoustical properties of human bones. In contrast to the ex vivo tissues, the proposed material can maintain the physical and acoustical properties unchanged for long periods of time; moreover, these properties can be custom designed and created to suit specific needs. As a result, we introduce three examples of ultrasound phantoms that we manufactured in our laboratory: cortical, trabecular and skull bone phantoms. The paper also presents the results of a comparison study between the acoustical and physical properties of actual human bones (reported in the referenced literatures) and the phantoms manufactured by us.

  18. Propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of); Choi, Bok Kyoung [Maritime Security Research Center, KIOST, Ansan (Korea, Republic of)

    2014-12-15

    The present study aims to investigate the propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom. The velocities of the guided waves in a 5-mm-thick acrylic plate were measured by using the axial transmission technique. A pure A0 Lamb mode could be successfully launched in the 5-mm-thick acrylic plate through a time reversal process of Lamb waves, consistent with the fact that the time reversal process can automatically compensate for the dispersive nature of Lamb waves. The experimental velocities of the slow guided wave (SGW) and the time-reversed Lamb wave were found to be in reasonable agreement with the theoretical group velocity of the A0 Lamb mode, suggesting that both the SGW and the time-reversed Lamb wave excited in the 5-mm-thick acrylic plate correspond to the A0 Lamb mode. These results suggest that the time reversal process of Lamb waves can be usefully applied to noninvasive characterization of long cortical bones.

  19. Assessment of the effect of reduced compositional heterogeneity on fracture resistance of human cortical bone using finite element modeling.

    Science.gov (United States)

    Demirtas, Ahmet; Curran, Erin; Ural, Ani

    2016-10-01

    The recent reports of atypical femoral fracture (AFF) and its possible association with prolonged bisphosphonate (BP) use highlighted the importance of a thorough understanding of mechanical modifications in bone due to bisphosphonate treatment. The reduced compositional heterogeneity is one of the modifications in bone due to extensive suppression of bone turnover. Although experimental evaluations suggested that compositional changes lead to a reduction in the heterogeneity of elastic properties, there is limited information on the extent of influence of reduced heterogeneity on fracture resistance of cortical bone. As a result, the goal of the current study is to evaluate the influence of varying the number of unique elastic and fracture properties for osteons, interstitial bone, and cement lines on fracture resistance across seven different human cortical bone specimens using finite element modeling. Fracture resistance of seven human cortical bone samples under homogeneous and three different heterogeneous material levels was evaluated using a compact tension test setup. The simulation results predicted that the crack volume was the highest for the models with homogeneous material properties. Increasing heterogeneity resulted in a lower amount of crack volume indicating an increase in fracture resistance of cortical bone. This reduction was observed up to a certain level of heterogeneity after which further beneficial effects of heterogeneity diminished suggesting a possible optimum level of heterogeneity for the bone tissue. The homogeneous models demonstrated limited areas of damage with extensive crack formation. On the other hand, the heterogeneity in the material properties led to increased damage volume and a more variable distribution of damage compared to the homogeneous models. This resulted in uncracked regions which tended to have less damage accumulation preventing extensive crack propagation. The results also showed that the percent osteonal area

  20. Assessment of the effect of reduced compositional heterogeneity on fracture resistance of human cortical bone using finite element modeling.

    Science.gov (United States)

    Demirtas, Ahmet; Curran, Erin; Ural, Ani

    2016-10-01

    The recent reports of atypical femoral fracture (AFF) and its possible association with prolonged bisphosphonate (BP) use highlighted the importance of a thorough understanding of mechanical modifications in bone due to bisphosphonate treatment. The reduced compositional heterogeneity is one of the modifications in bone due to extensive suppression of bone turnover. Although experimental evaluations suggested that compositional changes lead to a reduction in the heterogeneity of elastic properties, there is limited information on the extent of influence of reduced heterogeneity on fracture resistance of cortical bone. As a result, the goal of the current study is to evaluate the influence of varying the number of unique elastic and fracture properties for osteons, interstitial bone, and cement lines on fracture resistance across seven different human cortical bone specimens using finite element modeling. Fracture resistance of seven human cortical bone samples under homogeneous and three different heterogeneous material levels was evaluated using a compact tension test setup. The simulation results predicted that the crack volume was the highest for the models with homogeneous material properties. Increasing heterogeneity resulted in a lower amount of crack volume indicating an increase in fracture resistance of cortical bone. This reduction was observed up to a certain level of heterogeneity after which further beneficial effects of heterogeneity diminished suggesting a possible optimum level of heterogeneity for the bone tissue. The homogeneous models demonstrated limited areas of damage with extensive crack formation. On the other hand, the heterogeneity in the material properties led to increased damage volume and a more variable distribution of damage compared to the homogeneous models. This resulted in uncracked regions which tended to have less damage accumulation preventing extensive crack propagation. The results also showed that the percent osteonal area

  1. Individual-specific multi-scale finite element simulation of cortical bone of human proximal femur

    Energy Technology Data Exchange (ETDEWEB)

    Ascenzi, Maria-Grazia, E-mail: mgascenzi@mednet.ucla.edu [UCLA/Orthopaedic Hospital, Department of Orthopaedic Surgery, Rehabilitation Bldg, Room 22-69, 1000 Veteran Avenue, University of California, Los Angeles, CA 90095 (United States); Kawas, Neal P., E-mail: nealkawas@ucla.edu [UCLA/Orthopaedic Hospital, Department of Orthopaedic Surgery, Rehabilitation Bldg, Room 22-69, 1000 Veteran Avenue, University of California, Los Angeles, CA 90095 (United States); Lutz, Andre, E-mail: andre.lutz@hotmail.de [Institute of Biomechanics and Numerical Mechanics, Leibniz University Hannover, 30167 Hannover (Germany); Kardas, Dieter, E-mail: kardas@ibnm.uni-hannover.de [ContiTech Vibration Control, Jaedekamp 30 None, 30419 Hannover (Germany); Nackenhorst, Udo, E-mail: nackenhorst@ibnm.uni-hannover.de [Institute of Biomechanics and Numerical Mechanics, Leibniz University Hannover, 30167 Hannover (Germany); Keyak, Joyce H., E-mail: jhkeyak@uci.edu [Department of Radiological Sciences, Medical Sciences I, Bldg 811, Room B140, University of California, Irvine, CA 92697-5000 (United States)

    2013-07-01

    We present an innovative method to perform multi-scale finite element analyses of the cortical component of the femur using the individual’s (1) computed tomography scan; and (2) a bone specimen obtained in conjunction with orthopedic surgery. The method enables study of micro-structural characteristics regulating strains and stresses under physiological loading conditions. The analysis of the micro-structural scenarios that cause variation of strain and stress is the first step in understanding the elevated strains and stresses in bone tissue, which are indicative of higher likelihood of micro-crack formation in bone, implicated in consequent remodeling or macroscopic bone fracture. Evidence that micro-structure varies with clinical history and contributes in significant, but poorly understood, ways to bone function, motivates the method’s development, as does need for software tools to investigate relationships between macroscopic loading and micro-structure. Three applications – varying region of interest, bone mineral density, and orientation of collagen type I, illustrate the method. We show, in comparison between physiological loading and simple compression of a patient’s femur, that strains computed at the multi-scale model’s micro-level: (i) differ; and (ii) depend on local collagen-apatite orientation and degree of calcification. Our findings confirm the strain concentration role of osteocyte lacunae, important for mechano-transduction. We hypothesize occurrence of micro-crack formation, leading either to remodeling or macroscopic fracture, when the computed strains exceed the elastic range observed in micro-structural testing.

  2. Comparison of mechanical and ultrasound elastic modulus of ovine tibial cortical bone.

    Science.gov (United States)

    Grant, Caroline A; Wilson, Lance J; Langton, Christian; Epari, Devakar

    2014-07-01

    Finite element models of bones can be created by deriving geometry from an X-ray CT scan. Material properties such as the elastic modulus can then be applied using either a single or set of homogeneous values, or individual elements can have local values mapped onto them. Values for the elastic modulus can be derived from the CT density values using an elasticity versus density relationship. Many elasticity-density relationships have been reported in the literature for human bone. However, while ovine in vivo models are common in orthopaedic research, no work has been done to date on creating FE models of ovine bones. To create these models and apply relevant material properties, an ovine elasticity-density relationship needs to be determined. Using fresh frozen ovine tibias the apparent density of regions of interest was determined from a clinical CT scan. The bones were the sectioned into cuboid samples of cortical bone from the regions of interest. Ultrasound was used to determine the elastic modulus in each of three directions - longitudinally, radially and tangentially. Samples then underwent traditional compression testing in each direction. The relationships between apparent density and both ultrasound, and compression modulus in each direction were determined. Ultrasound testing was found to be a highly repeatable non-destructive method of calculating the elastic modulus, particularly suited to samples of this size. The elasticity-density relationships determined in the longitudinal direction were very similar between the compression and ultrasound data over the density range examined. A clear difference was seen in the elastic modulus between the longitudinal and transverse directions of the bone samples, and a transverse elasticity-density relationship is also reported.

  3. Growth hormone effects on cortical bone dimensions in young adults with childhood-onset growth hormone deficiency

    DEFF Research Database (Denmark)

    Hyldstrup, L; Conway, G S; Racz, K;

    2012-01-01

    : Patients (n = 160; mean age, 21.2 years; 63% males) with CO GHD were randomised 2:1 to GH or no treatment for 24 months. Cortical bone dimensions were evaluated by digital x-ray radiogrammetry of the metacarpal bones every 6 months. RESULTS: After 24 months, cortical thickness was increased compared...... with the controls (6.43%, CI 3.34 to 9.61%; p = 0.0001) and metacarpal index (MCI) (6.14%, CI 3.95 to 8.38%; p ...

  4. Genome-wide mRNA sequencing of a single canine cerebellar cortical degeneration case leads to the identification of a disease associated SPTBN2 mutation

    Directory of Open Access Journals (Sweden)

    Forman Oliver P

    2012-07-01

    Full Text Available Abstract Background Neonatal cerebellar cortical degeneration is a neurodegenerative disease described in several canine breeds including the Beagle. Affected Beagles are unable to ambulate normally from the onset of walking and the main pathological findings include Purkinje cell loss with swollen dendritic processes. Previous reports suggest an autosomal recessive mode of inheritance. The development of massively parallel sequencing techniques has presented the opportunity to investigate individual clinical cases using genome-wide sequencing approaches. We used genome-wide mRNA sequencing (mRNA-seq of cerebellum tissue from a single Beagle with neonatal cerebellar cortical degeneration as a method of candidate gene sequencing, with the aim of identifying the causal mutation. Results A four-week old Beagle dog presented with progressive signs of cerebellar ataxia and the owner elected euthanasia. Histopathology revealed findings consistent with cerebellar cortical degeneration. Genome-wide mRNA sequencing (mRNA-seq of RNA from cerebellum tissue was used as a method of candidate gene sequencing. After analysis of the canine orthologues of human spinocerebellar ataxia associated genes, we identified a homozygous 8 bp deletion in the β-III spectrin gene, SPTBN2, associated with spinocerebellar type 5 in humans. Genotype analysis of the sire, dam, ten clinically unaffected siblings, and an affected sibling from a previous litter, showed the mutation to fully segregate with the disorder. Previous studies have shown that β-III spectrin is critical for Purkinje cell development, and the absence of this protein can lead to cell damage through excitotoxicity, consistent with the observed Purkinje cell loss, degeneration of dendritic processes and associated neurological dysfunction in this Beagle. Conclusions An 8 bp deletion in the SPTBN2 gene encoding β-III spectrin is associated with neonatal cerebellar cortical degeneration in Beagle dogs

  5. Rapid maxillary expansion in alveolar cleft repaired with a tissue-engineered bone in a canine model.

    Science.gov (United States)

    Huang, Jialiang; Tian, Bo; Chu, Fengting; Yang, Chenjie; Zhao, Jun; Jiang, Xinquan; Qian, Yufen

    2015-08-01

    This study aims to investigate the effects of orthodontic expansion on graft area of a tissue-engineered bone (TEB) BMSCs/β-TCP, and to find an alternative strategy for the therapy of alveolar cleft. A unilateral alveolar cleft canine model was established and then treated with BMSCs/β-TCP under rapid maxillary expansion (RME). Sequential fluorescent labeling, radiography and helical computed tomography were used to evaluate new bone formation and mineralization in the graft area. Hematoxylin-eosin staining and Van Gieson׳s picro fuchsin staining were performed for histological and histomorphometric observation. ALP activity, mineralization and the expression of osteogenic differentiation related genes of BMSCs that grew on the β-TCP scaffold were promoted by their cultivation in osteogenic medium. Based on fact, TEB was constructed. After 8 weeks of treatment with BMSCs/β-TCP followed by RME, new bone formation and mineralization of the dogs were markedly accelerated, and bone resorption was significantly reduced, compared with the untreated dogs, or those only treated with autogenous iliac bone. The treatment with both TEB and RME evidently made the bone trabecula more abundant and the area of bone formation larger. What is more, there were no significant differences between BMSCs/β-TCP group and the group treated with autogenous bone and RME. This study further revealed that TEB was not only a feasible clinical approach for patients with alveolar cleft, but also a potential substituent of autogenous bone, and its combination with RME might be an alternative strategy for the therapy of alveolar cleft.

  6. Elastic moduli of untreated, demineralized and deproteinized cortical bone: validation of a theoretical model of bone as an interpenetrating composite material.

    Science.gov (United States)

    Hamed, E; Novitskaya, E; Li, J; Chen, P-Y; Jasiuk, I; McKittrick, J

    2012-03-01

    A theoretical experimentally based multi-scale model of the elastic response of cortical bone is presented. It portrays the hierarchical structure of bone as a composite with interpenetrating biopolymers (collagen and non-collagenous proteins) and minerals (hydroxyapatite), together with void spaces (porosity). The model involves a bottom-up approach and employs micromechanics and classical lamination theories of composite materials. Experiments on cortical bone samples from bovine femur include completely demineralized and deproteinized bones as well as untreated bone samples. Porosity and microstructure are characterized using optical and scanning electron microscopy, and micro-computed tomography. Compression testing is used to measure longitudinal and transverse elastic moduli of all three bone types. The characterization of structure and properties of these three bone states provides a deeper understanding of the contributions of the individual components of bone to its elastic response and allows fine tuning of modeling assumptions. Very good agreement is found between theoretical modeling and compression testing results, confirming the validity of the interpretation of bone as an interpenetrating composite material.

  7. Development of a Three-Dimensional (3D Printed Biodegradable Cage to Convert Morselized Corticocancellous Bone Chips into a Structured Cortical Bone Graft

    Directory of Open Access Journals (Sweden)

    Ying-Chao Chou

    2016-04-01

    Full Text Available This study aimed to develop a new biodegradable polymeric cage to convert corticocancellous bone chips into a structured strut graft for treating segmental bone defects. A total of 24 adult New Zealand white rabbits underwent a left femoral segmental bone defect creation. Twelve rabbits in group A underwent three-dimensional (3D printed cage insertion, corticocancellous chips implantation, and Kirschner-wire (K-wire fixation, while the other 12 rabbits in group B received bone chips implantation and K-wire fixation only. All rabbits received a one-week activity assessment and the initial image study at postoperative 1 week. The final image study was repeated at postoperative 12 or 24 weeks before the rabbit scarification procedure on schedule. After the animals were sacrificed, both femurs of all the rabbits were prepared for leg length ratios and 3-point bending tests. The rabbits in group A showed an increase of activities during the first week postoperatively and decreased anterior cortical disruptions in the postoperative image assessments. Additionally, higher leg length ratios and 3-point bending strengths demonstrated improved final bony ingrowths within the bone defects for rabbits in group A. In conclusion, through this bone graft converting technique, orthopedic surgeons can treat segmental bone defects by using bone chips but with imitate characters of structured cortical bone graft.

  8. Development of a Three-Dimensional (3D) Printed Biodegradable Cage to Convert Morselized Corticocancellous Bone Chips into a Structured Cortical Bone Graft.

    Science.gov (United States)

    Chou, Ying-Chao; Lee, Demei; Chang, Tzu-Min; Hsu, Yung-Heng; Yu, Yi-Hsun; Liu, Shih-Jung; Ueng, Steve Wen-Neng

    2016-04-20

    This study aimed to develop a new biodegradable polymeric cage to convert corticocancellous bone chips into a structured strut graft for treating segmental bone defects. A total of 24 adult New Zealand white rabbits underwent a left femoral segmental bone defect creation. Twelve rabbits in group A underwent three-dimensional (3D) printed cage insertion, corticocancellous chips implantation, and Kirschner-wire (K-wire) fixation, while the other 12 rabbits in group B received bone chips implantation and K-wire fixation only. All rabbits received a one-week activity assessment and the initial image study at postoperative 1 week. The final image study was repeated at postoperative 12 or 24 weeks before the rabbit scarification procedure on schedule. After the animals were sacrificed, both femurs of all the rabbits were prepared for leg length ratios and 3-point bending tests. The rabbits in group A showed an increase of activities during the first week postoperatively and decreased anterior cortical disruptions in the postoperative image assessments. Additionally, higher leg length ratios and 3-point bending strengths demonstrated improved final bony ingrowths within the bone defects for rabbits in group A. In conclusion, through this bone graft converting technique, orthopedic surgeons can treat segmental bone defects by using bone chips but with imitate characters of structured cortical bone graft.

  9. Tensile material properties of human rib cortical bone under quasi-static and dynamic failure loading and influence of the bone microstucture on failure characteristics

    CERN Document Server

    Subit, Damien; Valazquez-Ameijide, Juan; Arregui-Dalmases, Carlos; Crandall, Jeff

    2011-01-01

    Finite element models of the thorax are under development to assist vehicle safety researchers with the design of countermeasures such as advanced restrain systems. Computational models have become more refined with increasing geometrical complexity as element size decreases. These finite element models can now capture small geometrical features with an attempt to predict fracture. However, the bone material properties currently available, and in particular the rate sensitivity, have been mainly determined from compression tests or tests on long bones. There is a need for a new set of material properties for the human rib cortical bone. With this objective, a new clamping technique was developed to test small bone coupons under tensile loading. Ten coupons were harvested from the cortical shell of the sixth and seventh left ribs from three cadavers. The coupons were tested to fracture under quasi-static (target strain rate of 0.07 %/s) and dynamic loading (target strain rate of 170 %/s). Prior to testing, eac...

  10. Dynamic testing of old and young baboon cortical bone with numerical validation

    Science.gov (United States)

    Chocron, S.; Nicolella, D.; Nicholls, A. E.; Bredbenner, T.; Havill, L.

    2012-08-01

    Cortical bone tensile mechanical properties at quasistatic and high rates (˜300s-1) were determined ex vivo using the right femurs of 12 female baboons, (Papio hamadryas spp.) from the Texas Biomedical Research Institute/Southwest National Primate Research Center in San Antonio, Texas. The animals were divided into two age groups: a young age group (6.63 ± 0.6 years) and an old age group (26.96 ± 1.3 years). Seven specimens per group were monotonically loaded to failure to determine their mechanical properties. The quasistatic strength of the bone for the old group was just a little (but not significantly) lower than the young group. High strain rate tests performed with the Hopkinson bar indicate that baboon bone from the older group was significantly weaker under impact loads than that from the younger group. This observation is particularly important due to the similarities between baboon and human bone tissue. Typical strain rates for these tests ranged from 130s-1 to 250s-1. A full-size 3-D simulation of the Hopkinson bar test was performed to confirm that the bone specimen was under stress equilibrium and to evaluate the consistency of the modulus and strength inferred from the tests. Simulations were performed in which the modulus, strength and failure strain were varied to see the sensitivity of the results. Additionally, simplified simulations were performed to estimate the strain rate environment of a femur during a fall at an impact velocity of 5 m/s, similar to a free fall velocity from a height of 1.3 meters. The simulations confirm that strain rates obtained in the Hopkinson bar are relevant because they are similar to those expected inr such a fall.

  11. A 3D Multiscale Modelling of Cortical Bone Structure, Using the Inverse Identification Method: Microfibril Scale Study

    CERN Document Server

    Barkaoui, Abdelwahed

    2011-01-01

    Complexity and heterogeneity of bone tissue require a multiscale modelling to understand their mechanical behaviour and their remodelling mechanism. Human cortical bone structure consists of six structural scale levels which are the (macroscopic) cortical bone, osteonal, lamellar, fibrous, fibril and microfibril. In this paper, a 3D model based on finite elements method was achieved to study the nanomechanical behaviour of collagen Microfibril. The mechanical properties and the geometry (gap, overlap and diameter) of both tropocollagen and mineral were taken into consideration as well as the effects of cross-links. An inverse identification method has been applied to determine equivalent averaged properties in order to link up these nanoscopic characteristics to the macroscopic mechanical behaviour of bone tissue. Results of nanostructure modelling of the nanomechanical properties of strain deformation under varying cross-links were investigated in this work.

  12. A Surrogate Measure of Cortical Bone Matrix Density by Long T2 -Suppressed MRI.

    Science.gov (United States)

    Seifert, Alan C; Li, Cheng; Wehrli, Suzanne L; Wehrli, Felix W

    2015-12-01

    Magnetic resonance has the potential to image and quantify two pools of water within bone: free water within the Haversian pore system (transverse relaxation time, T2 > 1 ms), and water hydrogen-bonded to matrix collagen (T2 ∼ 300 to 400 μs). Although total bone water concentration quantified by MRI has been shown to scale with porosity, greater insight into bone matrix density and porosity may be gained by relaxation-based separation of bound and pore water fractions. The objective of this study was to evaluate a recently developed surrogate measurement for matrix density, single adiabatic inversion recovery (SIR) zero echo-time (ZTE) MRI, in human bone. Specimens of tibial cortical bone from 15 donors (aged 27 to 97 years; 8 female and 7 male) were examined at 9.4T field strength using two methods: (1) (1)H ZTE MRI, to capture total (1)H signal, and (2) (1)H SIR-ZTE MRI, to selectively image matrix-associated (1)H signal. Total water, bone matrix, and bone mineral densities were also quantified gravimetrically, and porosity was measured by micro-CT. ZTE apparent total water (1)H concentration was 32.7 ± 3.2 M (range 28.5 to 40.3 M), and was correlated positively with porosity (R(2) = 0.80) and negatively with matrix and mineral densities (R(2) =  0.90 and 0.82, respectively). SIR-ZTE apparent bound water (1)H concentration was 32.9 ± 3.9 M (range 24.4 to 39.8 M), and its correlations were opposite to those of apparent total water: negative with porosity (R(2) = 0.73) and positive with matrix density (R(2) = 0.74) and mineral density (R(2) = 0.72). Porosity was strongly correlated with gravimetric matrix density (R(2) = 0.91, negative) and total water density (R(2) = 0.92, positive). The strong correlations of SIR-ZTE-derived apparent bound water (1)H concentration with ground-truth measurements suggest that this quantitative solid-state MRI method provides a nondestructive surrogate measure of bone matrix density

  13. Simultaneous estimation of cortical bone thickness and acoustic wave velocity using a multivariable optimization approach: Bone phantom and in-vitro study.

    Science.gov (United States)

    Tasinkevych, Yuriy; Podhajecki, Jerzy; Falińska, Katarzyna; Litniewski, Jerzy

    2016-02-01

    The paper presents a method that allows the thickness of a compact bone layer and longitudinal wave velocity in the bone to be determined simultaneously with the use of reflected waves, with particular emphasis on the case of layers when the propagation time through the layer is shorter than the time duration of the interrogating pulse. The proposed method estimates simultaneously the thickness of the cortical bone layer and acoustic wave velocity by fitting the temporal spectrum of the simulated reflected wave to the spectrum of the reflected wave measured experimentally. For the purpose of echo-simulations the model of "soft tissue - compact bone layer - cancellous bone" was developed. Next, the cost function was defined as the least square error between the measured and simulated temporal spectra. Minimization of the cost function allowed us to determine the values of the parameters of the cortical bone layer which best fitted the measurements. To solve the optimization problem a simulated annealing algorithm was used. The method was tested using acoustic data obtained at the frequency of 0.6 MHz and 1 MHz respectively for a custom designed bone mimicking phantom and a calf femur. For the cortical shell of the calf femur whose thickness varies from 2.1 mm to 2.4 mm and velocity of 2910 m/s, the relative errors of the thickness estimation ranged from 0.4% to 5.5%. The corresponding error of the acoustic wave velocity estimation in the layer was 3.1%. In the case of artificial bone the thickness of the cortical layer was equal to 1.05 and 1.2 mm and acoustic wave velocity was 2900 m/s. These parameters were determined with the errors ranging from 1.9% to 10.8% and from 3.9% to 4.5% respectively. PMID:26522955

  14. Biomedical titanium alloys with Young's moduli close to that of cortical bone.

    Science.gov (United States)

    Niinomi, Mitsuo; Liu, Yi; Nakai, Masaki; Liu, Huihong; Li, Hua

    2016-09-01

    Biomedical titanium alloys with Young's moduli close to that of cortical bone, i.e., low Young's modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti-29Nb-13Ta-4.6Zr referred to as TNTZ, which is highly expected to be used as a biomaterial for implants replacing failed hard tissue. Furthermore, to satisfy the demands from both patients and surgeons, i.e., a low Young's modulus of the whole implant and a high Young's modulus of the deformed part of implant, titanium alloys with changeable Young's modulus, which are also β-type titanium alloys, for instance Ti-12Cr, have been developed. In this review article, by focusing on TNTZ and Ti-12Cr, the biological and mechanical properties of the titanium alloys with low Young's modulus and changeable Young's modulus are described. In addition, the titanium alloys with shape memory and superelastic properties were briefly addressed. Surface modifications for tailoring the biological and anti-wear/corrosion performances of the alloys have also been briefly introduced. PMID:27252887

  15. Biomedical titanium alloys with Young’s moduli close to that of cortical bone

    Science.gov (United States)

    Niinomi, Mitsuo; Liu, Yi; Nakai, Masaki; Liu, Huihong; Li, Hua

    2016-01-01

    Biomedical titanium alloys with Young’s moduli close to that of cortical bone, i.e., low Young’s modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti–29Nb–13Ta–4.6Zr referred to as TNTZ, which is highly expected to be used as a biomaterial for implants replacing failed hard tissue. Furthermore, to satisfy the demands from both patients and surgeons, i.e., a low Young’s modulus of the whole implant and a high Young’s modulus of the deformed part of implant, titanium alloys with changeable Young’s modulus, which are also β-type titanium alloys, for instance Ti–12Cr, have been developed. In this review article, by focusing on TNTZ and Ti–12Cr, the biological and mechanical properties of the titanium alloys with low Young’s modulus and changeable Young’s modulus are described. In addition, the titanium alloys with shape memory and superelastic properties were briefly addressed. Surface modifications for tailoring the biological and anti-wear/corrosion performances of the alloys have also been briefly introduced. PMID:27252887

  16. Biomedical titanium alloys with Young's moduli close to that of cortical bone.

    Science.gov (United States)

    Niinomi, Mitsuo; Liu, Yi; Nakai, Masaki; Liu, Huihong; Li, Hua

    2016-09-01

    Biomedical titanium alloys with Young's moduli close to that of cortical bone, i.e., low Young's modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti-29Nb-13Ta-4.6Zr referred to as TNTZ, which is highly expected to be used as a biomaterial for implants replacing failed hard tissue. Furthermore, to satisfy the demands from both patients and surgeons, i.e., a low Young's modulus of the whole implant and a high Young's modulus of the deformed part of implant, titanium alloys with changeable Young's modulus, which are also β-type titanium alloys, for instance Ti-12Cr, have been developed. In this review article, by focusing on TNTZ and Ti-12Cr, the biological and mechanical properties of the titanium alloys with low Young's modulus and changeable Young's modulus are described. In addition, the titanium alloys with shape memory and superelastic properties were briefly addressed. Surface modifications for tailoring the biological and anti-wear/corrosion performances of the alloys have also been briefly introduced.

  17. Ultrastructural elastic deformation of cortical bone tissue probed by NIR Raman spectroscopy

    Science.gov (United States)

    Finney, William F.; Morris, Michael D.; Wallace, Joseph M.; Kohn, David H.

    2004-07-01

    Raman spectroscopy is used as a probe of ultrastructural (molecular) changes in both the mineral and matrix (protein and glycoprotein, predominantly type I collagen) components of murine cortical bone as it responds to loading in the elastic regime. At the ultrastructural level, crystal structure and protein secondary structure distort as the tissue is loaded. These structural changes are followed as perturbations to tissue spectra. We load tissue in a custom-made dynamic mechanical tester that fits on the stage of a Raman microprobe and can accept hydrated tissue specimens. As the specimen is loaded in tension and/or compression, the shifts in mineral P-O4 v1 and relative band heights in the Amide III band envelope are followed with the microprobe. Average load is measured using a load cell while the tissue is loaded under displacement control. Changes occur in both the mineral and matrix components of bone as a response to elastic deformation. We propose that the mineral apatitic crystal lattice is deformed by movement of calcium and other ions. The matrix is proposed to respond by deformation of the collagen backbone. Raman microspectroscopy shows that bone mineral is not a passive contributor to tissue strength. The mineral active response to loading may function as a local energy storage and dissipation mechanism, thus helping to protect tissue from catastrophic damage.

  18. Assessing the cortical thickness of long bone shafts in children, using two-dimensional ultrasonic diffraction tomography

    OpenAIRE

    Lasaygues, Philippe

    2006-01-01

    Echography is one of the first-line techniques used in clinical practice to diagnose osteoarticular diseases in children. However, this technique involves the use of standard equipment, which is not adapted to the morphology or the acoustical properties of children's bones. In this study, we developed an ultrasonic tomography method for measuring the cortical thickness of children's long bones. Ultrasonic tomography gives cross-sectional images showing the spatial distribution of some of the ...

  19. MEASUREMENT OF REGIONAL BONE BLOOD FLOW IN THE CANINE MANDIBULAR RAMUS USING RADIOLABELLED TOAD RED BLOOD CELLS

    Institute of Scientific and Technical Information of China (English)

    毛驰; 王翰章

    1994-01-01

    Toad red blood cells were used to measure regional bone blood flow in the canine mandibular ramus.The blood cells were labelled with sodium pertechnetate and fixed in 10% formalin;they were 22×15 μm in size and had a specific gravity close to that of dog red blood cells.These cells had no discernible effect on systemic hemody-namics after injection,did not agglutinate,were well mixed and evenly distributed throughout the body,and were completely extracted in one circulation through the mandible.The mandibular ramus was divided into six regions,and the blood flow rates in each were found to be similar to those reported in previous studies with radiolabelled carbonized,microspheres.Furthermore,the blood flow distribution pattern of the mandibular ramus determined in this study was identical to that of our previous study using the bone-seeking radionuclide method.We suggest that radiolabelled toad red blood cells are an ideal marker for measuring regional blood flow in the canine mandible.

  20. Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ana Carolina Bergmann de; Henriques, Helene Nara [Postgraduate Program in Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Fernandes, Gustavo Vieira Oliveira [Postgraduate Program in Medical Sciences, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Lima, Inaya; Oliveira, Davi Ferreira de; Lopes, Ricardo Tadeu [Nuclear Engineering Program, Federal University of Rio de Janeiro (UFRJ), RJ (Brazil); Pantaleao, Jose Augusto Soares [Maternal and Child Department, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Granjeiro, Jose Mauro [Department of Cellular and Molecular Biology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Silva, Maria Angelica Guzman [Department of Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2012-03-15

    Purpose: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). Methods: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1 mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographs of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05%. Results: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. Conclusion: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head. (author)

  1. Analysis of cortical bone porosity using synchrotron radiation microtomography to evaluate the effects of chemotherapy

    Science.gov (United States)

    Alessio, R.; Nogueira, L. P.; Salata, C.; Mantuano, A.; Almeida, A. P.; Braz, D.; de Almeida, C. E.; Tromba, G.; Barroso, R. C.

    2015-11-01

    Microporosities play important biologic and mechanical roles on health. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to cortical bone changes. In the present work, the femur diaphysis of rats treated with chemotherapy drugs were evaluated by 3D morphometric parameters using synchrotron radiation microtomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the ELETTRA Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur diaphysis of rats.

  2. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    Directory of Open Access Journals (Sweden)

    Nina Kølln Wittig

    2016-06-01

    Full Text Available Modeling and remodeling induce significant changes of bone structure and mechanical properties with age. Therefore, it is important to gain knowledge of the processes taking place in bone over time. The rat is a widely used animal model, where much data has been accumulated on age-related changes of bone on the organ and tissue level, whereas features on the nano- and micrometer scale are much less explored. We investigated the age-related development of organ and tissue level bone properties such as bone volume, bone mineral density, and load to fracture and correlated these with osteocyte lacunar properties in rat cortical bone. Femora of 14 to 42-week-old female Wistar rats were investigated using multiple complementary techniques including X-ray micro-computed tomography and biomechanical testing. The body weight, femoral length, aBMD, load to fracture, tissue volume, bone volume, and tissue density were found to increase rapidly with age at 14–30 weeks. At the age of 30–42 weeks, the growth rate appeared to decrease. However, no accompanying changes were found in osteocyte lacunar properties such as lacunar volume, ellipsoidal radii, lacunar stretch, lacunar oblateness, or lacunar orientation with animal age. Hence, the evolution of organ and tissue level properties with age in rat cortical bone is not accompanied by related changes in osteocyte lacunar properties. This suggests that bone microstructure and bone matrix material properties and not the geometric properties of the osteocyte lacunar network are main determinants of the properties of the bone on larger length scales.

  3. Evaluations of guided bone regeneration in canine radius segmental defects using autologous periosteum combined with fascia lata under stable external fixation

    OpenAIRE

    Yu, Zhe; Geng, Jie; Gao, Haoran; Zhao, Xinwen; Chen, Jingyuan

    2014-01-01

    Background Although bone defect is one of the most common orthopaedic diseases, treatment remains a challenge and an issue of debate. Guided bone regeneration (GBR) is primarily accompanied by barrier membranes; however, optional membranes show some inherent flaws in clinical application. The purpose of this study was to observe the healing velocity and quality of repairing canine radius segmental defect using transferred autologous periosteum combined with fascia lata, which can provide bett...

  4. Multiscale approach including microfibril scale to assess elastic constants of cortical bone based on neural network computation and homogenization method

    CERN Document Server

    Barkaoui, Abdelwahed; Tarek, Merzouki; Hambli, Ridha; Ali, Mkaddem

    2014-01-01

    The complexity and heterogeneity of bone tissue require a multiscale modelling to understand its mechanical behaviour and its remodelling mechanisms. In this paper, a novel multiscale hierarchical approach including microfibril scale based on hybrid neural network computation and homogenisation equations was developed to link nanoscopic and macroscopic scales to estimate the elastic properties of human cortical bone. The multiscale model is divided into three main phases: (i) in step 0, the elastic constants of collagen-water and mineral-water composites are calculated by averaging the upper and lower Hill bounds; (ii) in step 1, the elastic properties of the collagen microfibril are computed using a trained neural network simulation. Finite element (FE) calculation is performed at nanoscopic levels to provide a database to train an in-house neural network program; (iii) in steps 2 to 10 from fibril to continuum cortical bone tissue, homogenisation equations are used to perform the computation at the higher s...

  5. Uncemented Total Hip Replacement Stem Loosening after Long Term Compressive Stress Application: A Simulated FEA Study of Cortical Bone Remodeling

    Science.gov (United States)

    Jung, Duk-Young; Tsutsumi, Sadami; Nakai, Ryusuke; Ikeuchi, Ken; Sekel, Ron

    The purpose of this study is to predict with the use of FEA, the differing predisposition to cortical bone resorption and subsequent distal migration of an un-cemented femoral hip replacement stem subjected to long term biomechanical high compressive stresses, while varying the load angles, the material properties of the stem, and the stem length. A two-dimensional hip model was constructed to estimate the minimum principle stresses (P3) and migration magnitudes. Bone remodeling at the interface between the bone and the prosthesis was performed by comparison of the local compressive stress to physiological stress values governing bone resorption. With respect to load angles, migrations of the hip prosthesis did not occur with load angles between 63° and 74° load angle in relation to the longitudinal axis of the bony femur, as the compressive stress generated on the cortical bone was under the criteria threshold for bone resorption (-50MPa). In addition, the magnitude of migration (17%decrease) was relatively more sensitive to changes in stem length than those (92%decrease) of changes of material properties. In conclusion, using an FEA model for bone remodeling, based on the high compressive stresses exerted on distal cortical bone, it is possible to estimate migration magnitudes of cementless hip prostheses in the long term. The load angles have been shown to be an important parameter affecting the migration magnitudes and furthermore, it can be demonstrated that the stiffer materials and reduction of stem length can decrease the migration of cementless hip prosthesis in the long term.

  6. In vivo evidence of IGF-I-estrogen crosstalk in mediating the cortical bone response to mechanical strain

    Institute of Scientific and Technical Information of China (English)

    Subburaman Mohan; Chetan Girijanand Bhat; Jon E Wergedal; Chandrasekhar Kesavan

    2014-01-01

    Although insulin-like growth factor-I (IGF-I) and estrogen signaling pathways have been shown to be involved in mediating the bone anabolic response to mechanical loading, it is not known whether these two signaling pathways crosstalk with each other in producing a skeletal response to mechanical loading. To test this, at 5 weeks of age, partial ovariectomy (pOVX) or a sham operation was performed on heterozygous IGF-I conditional knockout (H IGF-I KO) and control mice generated using a Cre-loxP approach. At 10 weeks of age, a 10 N axial load was applied on the right tibia of these mice for a period of 2 weeks and the left tibia was used as an internal non-non-loaded control. At the cortical site, partial estrogen loss reduced total volumetric bone mineral density (BMD) by 5%in control pOVX mice (P50.05, one-way ANOVA), but not in the H IGF-I KO pOVX mice. At the trabecular site, bone volume/total volume (BV/TV) was reduced by 5%-6%in both control pOVX (P,0.05) and H IGF-I KO pOVX (P50.05) mice. Two weeks of mechanical loading caused a 7%-8%and an 11%-13%(P,0.05 vs. non-loaded bones) increase in cortical BMD and cortical thickness (Ct.Th), respectively, in the control sham, control pOVX and H IGF-I KO sham groups. By contrast, the magnitude of cortical BMD (4%, P50.13) and Ct.Th (6%, P,0.05) responses were reduced by 50%in the H IGF-I KO pOVX mice compared to the other three groups. The interaction between genotype and estrogen deficiency on the mechanical loading-induced cortical bone response was significant (P,0.05) by two-way ANOVA. Two weeks of axial loading caused similar increases in trabecular BV/TV (13%-17%) and thickness (17%-23%) in all four groups of mice. In conclusion, partial loss of both estrogen and IGF-I significantly reduced cortical but not the trabecular bone response to mechanical loading, providing in vivo evidence of the above crosstalk in mediating the bone response to loading.

  7. Liver-derived IGF-I regulates cortical bone mass but is dispensable for the osteogenic response to mechanical loading in female mice.

    Science.gov (United States)

    Svensson, Johan; Windahl, Sara H; Saxon, Leanne; Sjögren, Klara; Koskela, Antti; Tuukkanen, Juha; Ohlsson, Claes

    2016-07-01

    Low circulating IGF-I is associated with increased fracture risk. Conditional depletion of IGF-I produced in osteoblasts or osteocytes inhibits the bone anabolic effect of mechanical loading. Here, we determined the role of endocrine IGF-I for the osteogenic response to mechanical loading in young adult and old female mice with adult, liver-specific IGF-I inactivation (LI-IGF-I(-/-) mice, serum IGF-I reduced by ≈70%) and control mice. The right tibia was subjected to short periods of axial cyclic compressive loading three times/wk for 2 wk, and measurements were performed using microcomputed tomography and mechanical testing by three-point bending. In the nonloaded left tibia, the LI-IGF-I(-/-) mice had lower cortical bone area and increased cortical porosity, resulting in reduced bone mechanical strength compared with the controls. Mechanical loading induced a similar response in LI-IGF-I(-/-) and control mice in terms of cortical bone area and trabecular bone volume fraction. In fact, mechanical loading produced a more marked increase in cortical bone mechanical strength, which was associated with a less marked increase in cortical porosity, in the LI-IGF-I(-/-) mice compared with the control mice. In conclusion, liver-derived IGF-I regulates cortical bone mass, cortical porosity, and mechanical strength under normal (nonloaded) conditions. However, despite an ∼70% reduction in circulating IGF-I, the osteogenic response to mechanical loading was not attenuated in the LI-IGF-I(-/-) mice.

  8. Mechanical and material properties of cortical and trabecular bone from cannabinoid receptor-1-null (Cnr1(-/-)) mice.

    Science.gov (United States)

    Khalid, Aysha B; Goodyear, Simon R; Ross, Ruth A; Aspden, Richard M

    2016-10-01

    The endocannabinoid system is known for its regulatory effects on bone metabolism through the cannabinoid receptors, Cnr1 and Cnr2. In this study we analysed the mechanical and material properties of long bones from Cnr1(-/-) mice on a C57BL/6 background. Tibiae and femora from 5- and 12-week-old mice were subjected to three-point bending to measure bending stiffness and yield strength. Elastic modulus, density and mineral content were measured in the diaphysis. Second moment of area (MOA2), inner and outer perimeters of the cortical shaft and trabecular fractional bone volume (BV/TV) were measured using micro-CT. In Cnr1(-/-) males and females at both ages the bending stiffness was reduced due to a smaller MOA2. Bone from Cnr1(-/-) females had a greater modulus than wild-type controls, although no differences were observed in males. BV/TV of 12-week-old Cnr1(-/-) females was greater than controls, although no difference was seen at 5-weeks. On the contrary, Cnr1(-/-) males had the same BV/TV as controls at 12-weeks while they had significantly lower values at 5-weeks. This study shows that deleting Cnr1 decreases the amount of cortical bone in both males and females at 12-weeks, but increases the amount of trabecular bone only in females.

  9. Isolation and Assessment of Mesenchymal Stem Cells Derived From Bone Marrow: Histologic and Histomorphometric Study in a Canine Periodontal Defect.

    Science.gov (United States)

    Paknejad, Mojgan; Eslaminejad, Mohamadreza Baghaban; Ghaedi, Baharak; Rokn, Amir-Reza; Khorsand, Afshin; Etemad-Moghadam, Shahroo; Alaeddini, Mojgan; Dehghan, Mohammad Mehdi; Moslemi, Neda; Nowzari, Hessam

    2015-06-01

    The aim of the present study was to investigate an isolation procedure to culture mesenchymal stem cells derived from bone marrow and evaluate their potential in periodontal regeneration. Potential stem cells from bone marrow, aspirated from the iliac crest of nine mongrel canines 1 to 2 years of age, were cultivated. After the examination of surface epitopes of the isolated cells, the total RNA from osteogenic, adipogenic, and chondrogenic cell cultures were analyzed by reverse transcription polymerase chain reaction (RT-PCR) to confirm stem cell gene expressions. 2 × 10(7) mL of the stem cells were loaded on 0.2 mL of anorganic bovine bone mineral (ABBM) granules. In each animal, bilateral acute/chronic intrabony periodontal defects were created surgically and by placement of ligatures around the cervical aspect of the teeth. At week 5, after flap debridement, the bilateral defects were randomly assigned to 2 treatment groups: the control group received ABBM, and the test group received BMSCs-loaded ABBM. Eight weeks after transplantation, regenerative parameters were analyzed histologically and histometrically. The RNA expressions confirmed the cultivation of mesenchymal stem cell. More new cementum and periodontal ligament (PDL) were measured in the test group (cementum: 3.33 ± 0.94 vs 2.03 ± 1.30, P = 0.027; PDL: 2.69 ± 0.73 vs 1.53 ± 1.21, P = 0.026). New bone formation was similar in both groups (2.70 ± 0.86 vs 1.99 ± 1.31; P = 0.193). Mesenchymal stem cells derived from bone marrow should be considered a promising technique for use in patients with periodontal attachment loss and merits further investigations. PMID:24383495

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

    Science.gov (United States)

    2016-01-01

    Purpose The aim of the present study was to evaluate the effectiveness of using a mineralized bone cortical allograft (MBCA), with or without a resorbable collagenous membrane derived from bovine pericardium, on alveolar bone remodeling after immediate implant placement in a dog model. Methods Six mongrel dogs were included. The test and control sites were randomly selected. Four biradicular premolars were extracted from the mandible. In control sites, implants without an allograft or membrane were placed immediately in the fresh extraction sockets. In the test sites, an MBCA was placed to fill the gap between the bone socket wall and implant, with or without a resorbable collagenous membrane. Specimens were collected after 1 and 3 months. The amount of residual particles and new bone quality were evaluated by histomorphometry. Results Few residual graft particles were observed to be closely embedded in the new bone without any contact with the implant surface. The allograft combined with a resorbable collagen membrane limited the resorption of the buccal wall in height and width. The histological quality of the new bone was equivalent to that of the original bone. The MBCA improved the quality of new bone formation, with few residual particles observed at 3 months. Conclusions The preliminary results of this animal study indicate a real benefit in obtaining new bone as well as in enhancing osseointegration due to the high resorbability of cortical allograft particles, in comparison to the results of xenografts or other biomaterials (mineralized or demineralized cancellous allografts) that have been presented in the literature. Furthermore, the use of an MBCA combined with a collagen membrane in extraction and immediate implant placement limited the extent of post-extraction resorption. PMID:27800212

  11. 应用锥形束CT探究上颌前牙区颌骨微种植支抗钉植入的安全区%Quantitative study of maxillary anterior bone depth and labial cortical bone thickness for micro- implant anchorage placement using cone beam CT

    Institute of Scientific and Technical Information of China (English)

    赵岩; 吴平

    2012-01-01

    目的:对上颌前牙区颌骨的骨量及唇侧骨皮质厚度进行测量分析,为正畸治疗植入微种植支抗钉的安全区提供参考.方法:对25例成人患者上颌前牙区行锥形束CT扫描及三维重建,测量距上颌牙槽嵴顶3、6、9、12mm水平上颌中切牙、侧切牙、尖牙根间区近远中向、唇腭向的距离以及唇侧骨皮质厚度.结果:在距上颌牙槽嵴顶3、6、9mm水平中切牙根间近远中向距离均最宽,唇侧骨皮质均最薄;在距牙槽嵴顶9mm水平中切牙与侧切牙根间近远中向距离最窄;在4个测量水平侧切牙与尖牙根间唇侧骨皮质均最厚;唇腭向在距牙槽嵴顶9mm及以上水平,中切牙根间骨厚度最薄,中切牙与侧切牙根间骨厚度最厚.25例中仅3例前牙区各牙根长度超过12mm,在距牙槽嵴顶12mm水平测出的根间近远中向距离均较宽.结论:通过对扫描后颌骨影像的分析,明确了前牙区颌骨的骨量及唇侧骨皮质厚度,为植入微种植支抗钉的安全区提供参考.%Objective: To investigate the bone depth and labial cortical bone thickness of maxillary anterior interdental area for orthodontic micro-implant anchorage. Methods; Maxillary anterior alveolar bone of 25 adults was scanned and reconstructed by cone beam CT, the mesio-distal interdental distance, labial-palatal bone depth and labial cortical bone thickness were measured at 3, 6, 9 and 12 mm from the alveolar crest between upper anterior dental roots. Results; The mesio-distal distance between central incisors was the widest in all measurement levels, while the labial cortical bone thickness was the thinnest. At the 9 mm-level, the shortest mesio-distal distance was between the roots of central and lateral incisors. The labial cortical bone thickness between lateral incisors and canines was the thickest in all measurement levels. At or above the 9 mm-level, the labial-palatal bone depth was the thinnest between central incisors, but the thickest

  12. Development of a strain rate dependent material model of human cortical bone for computer-aided reconstruction of injury mechanisms.

    Science.gov (United States)

    Asgharpour, Zahra; Zioupos, Peter; Graw, Matthias; Peldschus, Steffen

    2014-03-01

    Computer-aided methods such as finite-element simulation offer a great potential in the forensic reconstruction of injury mechanisms. Numerous studies have been performed on understanding and analysing the mechanical properties of bone and the mechanism of its fracture. Determination of the mechanical properties of bones is made on the same basis used for other structural materials. The mechanical behaviour of bones is affected by the mechanical properties of the bone material, the geometry, the loading direction and mode and of course the loading rate. Strain rate dependency of mechanical properties of cortical bone has been well demonstrated in literature studies, but as many of these were performed on animal bones and at non-physiological strain rates it is questionable how these will apply in the human situations. High strain-rates dominate in a lot of forensic applications in automotive crashes and assault scenarios. There is an overwhelming need to a model which can describe the complex behaviour of bone at lower strain rates as well as higher ones. Some attempts have been made to model the viscoelastic and viscoplastic properties of the bone at high strain rates using constitutive mathematical models with little demonstrated success. The main objective of the present study is to model the rate dependent behaviour of the bones based on experimental data. An isotropic material model of human cortical bone with strain rate dependency effects is implemented using the LS-DYNA material library. We employed a human finite element model called THUMS (Total Human Model for Safety), developed by Toyota R&D Labs and the Wayne State University, USA. The finite element model of the human femur is extracted from the THUMS model. Different methods have been employed to develop a strain rate dependent material model for the femur bone. Results of one the recent experimental studies on human femur have been employed to obtain the numerical model for cortical femur. A

  13. Cortical bone resorption rate in elderly persons: Estimates from long-term in vivo measurements of 90Sr in the skeleton

    Energy Technology Data Exchange (ETDEWEB)

    Shagina, N. B.; Tolstykh, E. I.; Degteva, M. O.; Anspaugh, L. R.; Napier, Bruce A.

    2012-06-01

    The rate of cortical bone resorption was assessed from long-term in vivo measurements of 90Sr content in the skeleton for men aged 50-80 years and for women 0-30 years after menopause. Measurements of 90Sr were conducted with a whole body counter for residents of the Techa Riverside communities (Southern Urals, Russia), who ingested large amounts of 90Sr as a result of releases of liquid radioactive wastes into the river from the Mayak plutonium facility in early 1950s. The results of this study showed an increase in the rate of cortical bone resorption in both men and women, as based on the use of accidentally ingested 90Sr as a tracer for bone metabolism. In men there was a continuous gradual increase in the rate of cortical bone resorption after 55 years from 2.8 to 4.5%/year by the age of 75 years. In women, there was a doubled increase in the rate of cortical bone resorption after menopause of up to 6%/year; then the rate remained unchanged for 10-12 years with a subsequent gradual decline down to 5-5.5%/year. Comparison of the rate of cortical bone resorption in men and women older than 55 years showed that women expressed significantly higher levels of cortical bone resorption.

  14. The significance of crack-resistance curves to the mixed-mode fracture toughness of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Elizabeth A.; Launey, Maximilien E.; Ritchie, Robert O.

    2010-03-25

    The majority of fracture mechanics studies on the toughness of bone have been performed under tensile loading. However, it has recently been shown that the toughness of human cortical bone in the transverse (breaking) orientation is actually much lower in shear (mode II) than in tension (mode I); a fact that is physiologically relevant as in vivo bone is invariably loaded multiaxially. Since bone is a material that derives its fracture resistance primarily during crack growth through extrinsic toughening mechanisms, such as crack deflection and bridging, evaluation of its toughness is best achieved through measurements of the crack-resistance or R-curve, which describes the fracture toughness as a function of crack extension. Accordingly, in this study, we attempt to measure for the first time the R-curve fracture toughness of human cortical bone under physiologically relevant mixed-mode loading conditions. We show that the resulting mixed-mode (mode I + II) toughness depends strongly on the crack trajectory and is the result of the competition between the paths of maximum mechanical driving force and 'weakest' microstructural resistance.

  15. Hybrid technique of cortical bone trajectory and pedicle screwing for minimally invasive spine reconstruction surgery : A technical note

    OpenAIRE

    Takata, Yoichiro; Matsuura, Tetsuya; Higashino, Kosaku; Sakai, Toshinori; Mishiro, Takuya; Suzue, Naoto; Kosaka, Hirofumi; Hamada, Daisuke; Goto, Tomohiro; Nishisho, Toshihiko; Goda, Yuichiro; Sato, Ryosuke(Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Oho, Tsukuba, 305-0801, Japan); Tsutsui, Takahiko; Tonogai, Ichiro; Tezuka, Fumitake

    2014-01-01

    The pedicle screw (PS) system is widely used for spinal reconstruction. Recently, screw insertion using the cortical bone trajectory (CBT) technique has been reported to provide increased holding strength of the vertebra, even in an osteoporotic spine. CBT is also beneficial due to its low invasiveness. We have been performing hybrid reconstruction with CBT at the cranial level and PS at the caudal level based on the concept of minimal invasiveness. We applied this hybrid technique to 6 cases...

  16. Preliminary determination of calcium, phosphorus, and the calcium/phosphorus ratio in cortical bone of Chinstrap penguin using synchrotron X-ray fluorescence analysis

    Institute of Scientific and Technical Information of China (English)

    Xie Zhouqing; Cheng Bangbo; Sun Liguang; Huang Yuying; He Wei; Zhao Sanping

    2006-01-01

    Synchrotron radiation X-ray fluorescence (SR-XRF) approach was applied to analyzing of Chinstrap penguin (Pygoscelis Antarctica) cortical bone. The method enabled the in situ determination of Ca and P concentrations and the Ca/P ratio in cortical bone. The preliminary results show that: (1) there is the bone site-related difference for Ca and P concentrations. The mean values for the investigated parameters ( on a dry-weight basis) are: 30.7% (Ca) and 14.9% (P) for the femoral cortical bone, 21.4% (Ca) and 11.5% (P) for wing cortical bone. (2) The variation for the Ca/P ratio in cortical bone is lower than those for Ca and P separately.This is in agreement with the previous report that the specificity of the Ca/P ratio is better than that of Ca and P concentrations and is more reliable for the diagnosis of bone disorders. The authors suggest that further studies be conducted to establish normal values of Ca, P and Ca/P ratio for polar animals and provide a basis for the diagnosis of bone disorders.

  17. Comparison of lyophilization, and freezing in honey as techniques to preserve cortical bone allografts used to repair experimental femoral defects in domestic adult cats

    Directory of Open Access Journals (Sweden)

    M.P. Ferreira

    2012-04-01

    Full Text Available Cats with orthopedic conditions are a prominent part of the clinical work of veterinary. Conditions such as comminuted fractures, bone tumors and non-unions are often difficult to repair and may require the use of bone grafts for treatment. This study evaluated cortical bone allografts preserved in honey, frozen or lyophilized for correcting long bone defects created in the diaphysis of the right femur of domestic cats (n=24. In the control group (n=6, the defect was repaired using autogenous cortical bone graft. In the remaining animals (n=6/group, the defect was repaired with cortical bone allografts preserved in honey, frozen or lyophilized. Success of graft incorporation and length of time for consolidation were assessed through clinical, radiographic and histological evaluations performed up to 180 days. In the control, frozen, honey and lyophylized groups, respectively, success of graft incorporation was 91.6%, 83.3%, 75%, and 25%, with corresponding mean length of time for consolidation of 83.1, 78, 105 and 120 days. Incorporation percentage in the lyophilized group was significantly lower than in the frozen and control groups. In conclusion, bone grafts preserved in honey or frozen were effective for repairing cortical defects in the femurs of cats as compared to autogenous cortical bone grafts.

  18. Comparison of lyophilization, and freezing in honey as techniques to preserve cortical bone allografts used to repair experimental femoral defects in domestic adult cats

    OpenAIRE

    Ferreira, M. P.; M.M. Alievi; C.A.C. Beck; I.S. Dal-Bó; P.C. Gonzalez; F.S. Nóbrega; de Silva, L M; R. Stédile; Scherer, S.; J.P.V. Rocha; A.P.F. Silva Filho; B. Svierk; Costa, G.

    2012-01-01

    Cats with orthopedic conditions are a prominent part of the clinical work of veterinary. Conditions such as comminuted fractures, bone tumors and non-unions are often difficult to repair and may require the use of bone grafts for treatment. This study evaluated cortical bone allografts preserved in honey, frozen or lyophilized for correcting long bone defects created in the diaphysis of the right femur of domestic cats (n=24). In the control group (n=6), the defect was repaired using autogeno...

  19. Long-term results of the use of autogenous cortical bone columellas to replace the stapes at stapedectomy.

    Science.gov (United States)

    Bauer, Miklós; Pytel, József; Vóna, Ida; Gerlinger, Imre

    2011-05-01

    The first author has been using an autogenous cortical bone columella to replace the stapes removed during stapedectomy since 1965. The audiograms of 21 of the 271 patients operated on with this method between 1965 and 1989 (i.e. 7.7% of the possible candidates) were available 20-35 (average 26.8) years postoperatively. The operation could be regarded as successful in 20 and unsuccessful in 1 patient in the long run. The audiological data are presented individually as averages of the values obtained at 0.5, 1, 2 and 3 kHz. The averaged data (n = 21): preoperative air conduction, 58.27; bone conduction, 24.46; and air-bone gap, 33.81 dB. Postoperative best air conduction, 19.07; bone conduction, 14.10; and air-bone gap, 4.97 dB. Postoperative recent air conduction, 45.77; bone conduction, 38.45; and air-bone gap, 7.32 dB. The best values were measured 1-8 (average 1.57) years postoperatively. In relation to the postoperative best value, the recent value of the air-bone gap had deteriorated by 2.35 dB, and that of the bone conduction by 24.35 dB. The small air-bone gap indicates that the deterioration of the hearing is mainly caused by the deterioration of the function of the inner ear and not by that of the conductive apparatus. The progression of the deterioration differs individually (0.3-1.6, average 0.93 dB/year) and accelerates with age. This finding seems to be a problem that does not depend on the operative technique. The data show that the autogenous bone columella ensures the same good and lasting results as the alloplastic solutions; moreover, there is no problem with the incus-prosthesis connection.

  20. Quantification of Age-Related Tissue-Level Failure Strains of Rat Femoral Cortical Bones Using an Approach Combining Macrocompressive Test and Microfinite Element Analysis.

    Science.gov (United States)

    Fan, Ruoxun; Gong, He; Zhang, Rui; Gao, Jiazi; Jia, Zhengbin; Hu, Yanjuan

    2016-04-01

    Bone mechanical properties vary with age; meanwhile, a close relationship exists among bone mechanical properties at different levels. Therefore, conducting multilevel analyses for bone structures with different ages are necessary to elucidate the effects of aging on bone mechanical properties at different levels. In this study, an approach that combined microfinite element (micro-FE) analysis and macrocompressive test was established to simulate the failure of male rat femoral cortical bone. Micro-FE analyses were primarily performed for rat cortical bones with different ages to simulate their failure processes under compressive load. Tissue-level failure strains in tension and compression of these cortical bones were then back-calculated by fitting the experimental stress-strain curves. Thus, tissue-level failure strains of rat femoral cortical bones with different ages were quantified. The tissue-level failure strain exhibited a biphasic behavior with age: in the period of skeletal maturity (1-7 months of age), the failure strain gradually increased; when the rat exceeded 7 months of age, the failure strain sharply decreased. In the period of skeletal maturity, both the macro- and tissue-levels mechanical properties showed a large promotion. In the period of skeletal aging (9-15 months of age), the tissue-level mechanical properties sharply deteriorated; however, the macromechanical properties only slightly deteriorated. The age-related changes in tissue-level failure strain were revealed through the analysis of male rat femoral cortical bones with different ages, which provided a theoretical basis to understand the relationship between rat cortical bone mechanical properties at macro- and tissue-levels and decrease of bone strength with age. PMID:26902102

  1. Effect of morselized bones on binding of the canine hydroxyapatite-coated femoral stem

    Institute of Scientific and Technical Information of China (English)

    SONG Ke-guan; MA De-sheng; HOU Jian-wen; WANG Huan; YAN Jing-long; YU Zhan-ge; LIANG Zhi-zhong

    2010-01-01

    Background Non-cement femoral stems are recognized in clinical use, but there are still some problems. The aim of this research was to make non-cement femoral stems to be press-fit with the medullary cavity. Methods Twenty-four healthy adult mongrel dogs were randomly divided into experimental and control groups. In the right hip joint, an artificial femoral bone replacement surgery was conducted. For the experimental group, the replacement surgery of hydroxyapatite (HA)-coated femoral stems was done, while autogeneous morselized bone was implanted into the medullary cavity. For the control group, morselized bone was not implanted. At postoperative 1, 3, 6 months, a test for interfacial shear characteristics was conducted in the MTS810 Tester. The comparison between the two groups' bone-prostheses in shear strength for their interface from shearing destruction was made. A histological observation to check prosthesis-bone interface contact ratios and bone growth was carried out. Results For the experimental group, shear strength was 0.317 MPa in 1 month, 1.447 MPa in 3 months, and 1.621 MPa in 6 months. For the control group, shear strength was 0.195 MPa in 1 month, 1.023 MPa in 3 months, and 1.483 MPa in 6 months. The difference was statistically significant. Stereomicroscope-based observation showed that the number of trabecular bones in the experimental group was larger than that of the control group, and bone growth of the former group was better than that of the latter group. Inverted microscopic observation showed that the binding degree between the prosthesis and trabecular bone of the experimental group was higher than that of the control group. Comparatively, the experimental group's trabecular bone had more stromal cells. Conclusions The morselized bones can effectively improve the biological bonding strength and bone-contact ratios in the short term for the HA-coated femoral stem and accelerate the bonding process. The use of morselized autogenous bones

  2. Multiscale approach including microfibril scale to assess elastic constants of cortical bone based on neural network computation and homogenization method.

    Science.gov (United States)

    Barkaoui, Abdelwahed; Chamekh, Abdessalem; Merzouki, Tarek; Hambli, Ridha; Mkaddem, Ali

    2014-03-01

    The complexity and heterogeneity of bone tissue require a multiscale modeling to understand its mechanical behavior and its remodeling mechanisms. In this paper, a novel multiscale hierarchical approach including microfibril scale based on hybrid neural network (NN) computation and homogenization equations was developed to link nanoscopic and macroscopic scales to estimate the elastic properties of human cortical bone. The multiscale model is divided into three main phases: (i) in step 0, the elastic constants of collagen-water and mineral-water composites are calculated by averaging the upper and lower Hill bounds; (ii) in step 1, the elastic properties of the collagen microfibril are computed using a trained NN simulation. Finite element calculation is performed at nanoscopic levels to provide a database to train an in-house NN program; and (iii) in steps 2-10 from fibril to continuum cortical bone tissue, homogenization equations are used to perform the computation at the higher scales. The NN outputs (elastic properties of the microfibril) are used as inputs for the homogenization computation to determine the properties of mineralized collagen fibril. The mechanical and geometrical properties of bone constituents (mineral, collagen, and cross-links) as well as the porosity were taken in consideration. This paper aims to predict analytically the effective elastic constants of cortical bone by modeling its elastic response at these different scales, ranging from the nanostructural to mesostructural levels. Our findings of the lowest scale's output were well integrated with the other higher levels and serve as inputs for the next higher scale modeling. Good agreement was obtained between our predicted results and literature data. PMID:24123969

  3. High Insulin Levels in KK-Ay Diabetic Mice Cause Increased Cortical Bone Mass and Impaired Trabecular Micro-Structure

    Directory of Open Access Journals (Sweden)

    Cen Fu

    2015-04-01

    Full Text Available Type 2 diabetes mellitus (T2DM is a chronic disease characterized by hyperglycemia, hyperinsulinemia and complications, including obesity and osteoporosis. Rodents have been widely used to model human T2DM and investigate its effect on the skeleton. We aimed to investigate skeletal alterations in Yellow Kuo Kondo (KK-Ay diabetic mice displaying high insulin and glucose levels. Bone mineral density (BMD, micro-architecture and bone metabolism-related genes were analyzed. The total femoral areal BMD (aBMD, cortical volumetric BMD (vBMD and thickness were significantly increased in KK-Ay mice, while the trabecular vBMD and mineralized bone volume/tissue volume (BV/TV, trabecular thickness and number were decreased compared to C57BL mice. The expression of both osteoblast-related genes, such as osteocalcin (OC, bone sialoprotein, Type I Collagen, osteonectin, RUNX2 and OSX, and osteoclast-related genes, such as TRAP and TCIRG, were up-regulated in KK-Ay mice. Correlation analyses showed that serum insulin levels were positively associated with aBMD, cortical vBMD and thickness and negatively associated with trabecular vBMD and micro-architecture. In addition, serum insulin levels were positively related to osteoblast-related and osteoclast-related gene expression. Our data suggest that high insulin levels in KK-Ay diabetic mice may increase cortical bone mass and impair trabecular micro-structure by up-regulating osteoblast-and osteoclast-related gene expression.

  4. Inhibition of cathepsin K increases modeling-based bone formation, and improves cortical dimension and strength in adult ovariectomized monkeys.

    Science.gov (United States)

    Pennypacker, Brenda L; Chen, Charles M; Zheng, Helen; Shih, Mei-Shu; Belfast, Mary; Samadfam, Rana; Duong, Le T

    2014-08-01

    Treatment with the cathepsin K (CatK) inhibitor odanacatib (ODN) protects against bone loss and maintains normal biomechanical properties in the spine and hip of ovariectomized (OVX) preclinical models. Here, we characterized the effects of ODN on the dynamics of cortical modeling and remodeling, and dimension and strength of the central femur in adult OVX-rhesus monkeys. Animals were treated with vehicle or ODN (6 or 30 mg/kg, once per day [q.d., p.o.]) in prevention mode for 21 months. Calcein and tetracycline double-labeling were given at 12 and 21 months, and the femoral cross-sections were subjected to dynamic histomorphometric and cement line analyses. ODN treatment significantly increased periosteal and endocortical bone formation (BFR/BS), accompanied with an increase in endocortical mineralizing surface (102%, p < 0.01) with the 6 mg/kg dose. ODN at both doses reduced remodeling hemiosteon numbers by 51% and 66% (p < 0.05), respectively, and ODN 30 mg/kg numerically reduced activation frequency without affecting wall thickness. On the same endocortical surface, ODN increased all modeling-based parameters, while reducing intracortical remodeling, consistent with the observed no treatment effects on cortical porosity. ODN 30 mg/kg markedly increased cortical thickness (CtTh, p < 0.001) and reduced marrow area (p < 0.01). Lastly, ODN treatment increased femoral structural strength (p < 0.001). Peak load was positively correlated with the increases in bone mineral content (BMC) (r(2)  = 0.9057, p < 0.0001) and CtTh (r2  = 0.6866, p < 0.0001). Taken together, by reducing cortical remodeling-based and stimulating modeling-based bone formation, ODN significantly improved cortical dimension and strength in OVX monkeys. This novel mechanism of CatK inhibition in stimulating cortical formation suggests that ODN represents a novel therapeutic approach for the treatment of osteoporosis. PMID:24591096

  5. Three-dimensional observation of internal structure of canine mandible by microcomputed tomography. Morphometric differences between loaded and unloaded cancellous bone around implants

    International Nuclear Information System (INIS)

    Morphological differences in cancellous bone around fixtures when loaded and unloaded were investigated by observation with micro-CT in canine mandibles. Three months after extraction of premolers, fixtures were installed in the edentulous ridge of the canine mandible, and three months later, superstructures were added. At three months after functional loading of the fixture surrounding cancellous bone was observed with micro-CT. Micro-CT showed a clear three-dimensional image of the cancellous bone around the fixture. There was much continuous trabecular bone corresponding to functional loading on the loaded side, with lessdirectional and thinner trabecular boneon the unloaded side. For morphological analysis, bone volume fraction (BV/TV), trabecular thickness (Tb. Th), and trabecular number (Tb. N) were calculated. For cancellous bone, the values on the loaded side were larger than on the unloaded side, and there was a significant difference in the BV/TV and Tb. N between the loaded and unloaded sides. Moreover, a comparison of the cancellous bone between the near zone and the far zone around the fixture showed that the values at the near zone of the loaded side were the maximum, and the values at the far zone of the loaded side were second. However, all values at the unloaded side were small, with scarcely any difference between them. There was a significant difference between the values at the near zone of the loaded side and the far zone of the loaded side and between at the near zone of the loaded side and the far zone of the unloaded side for BV/TV, Tb. Th, and Tb. N. This suggests that functional loading of fixtures enlarges the values of the bone parameters around the fixture, and that functional loading changes the from of the bone at the near zone of cancellous bone around fixtures. (author)

  6. Preliminary estimates of the calcium/phosphorus ratio at different cortical bone sites using synchrotron microCT

    International Nuclear Information System (INIS)

    The Ca/P ratio was measured in cortical bone samples from the femoral neck, front and rear tibia of female rats (1.5 years of age), using synchrotron radiation microtomography. The use of a monoenergetic x-ray beam, as provided by the synchrotron facility, generates accurate 3D maps of the linear attenuation coefficient within the sample and hence gives the ability to map different chemical components. Data sets were taken at 20 keV for each bone sample and calibration phantoms. From the 3D data sets, multiple 2D slices were reconstructed with a slice thickness of ∼28 μm and converted to Ca/P ratios using the calibration phantom results. Mean values (M ± SD) for cortical femoral, front and rear tibias are 2.12 ± 0.08, 1.75 ± 0.06 and 1.94 ± 0.07 respectively. These values were compared with those derived from different animals. Differences between the same bone sites from different animals are not significant (0.1 -3) demonstrating a dependence upon life style and bone use

  7. A rate-dependent microcrack-bridging model that can explain the strain rate dependency of cortical bone apparent yield strength.

    Science.gov (United States)

    Yeni, Yener N; Fyhrie, David P

    2003-09-01

    Although there are empirical correlations between strain rate, cortical and cancellous bone apparent stiffness, apparent yield strength, apparent ultimate strength and cortical bone fracture toughness, a mechanistic description for these phenomena is lacking. Microcracking is a major mechanism in cortical and cancellous bone failure, however, microdamage content alone cannot explain the strain rate dependence of bone strength without considering time-dependent behavior of the crack. Using a rate-dependent model of a fiber-bridged microcrack and data from the literature, we demonstrate that the experimental apparent yield strength of bone can be predicted directly from measurements of apparent moduli of elasticity of bone constituents and failure strain of the collagenous matrix. Yield strength predictions for estrogen depleted bone were made using the model and data from ovariectomized sheep. It was predicted that the yield strength of estrogen-deficient bone is comparable to that of normal bone within strain rates associated with physiological activities. For high strain rates, however, the strength of estrogen-depleted bone was predicted to be much weaker than normals suggesting a higher fracture risk due to impact from falls, for individuals with estrogen-depleted bones such as in post-menopausal osteoporosis. PMID:12893043

  8. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    Science.gov (United States)

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

  9. 'Universal' microstructural patterns in cortical and trabecular, extracellular and extravascular bone materials: micromechanics-based prediction of anisotropic elasticity.

    Science.gov (United States)

    Fritsch, Andreas; Hellmich, Christian

    2007-02-21

    Bone materials are characterized by an astonishing variability and diversity. Still, because of 'architectural constraints' due to once chosen material constituents and their physical interaction, the fundamental hierarchical organization or basic building plans of bone materials remain largely unchanged during biological evolution. Such universal patterns of microstructural organization govern the mechanical interaction of the elementary components of bone (hydroxyapatite, collagen, water; with directly measurable tissue-independent elastic properties), which are here quantified through a multiscale homogenization scheme delivering effective elastic properties of bone materials: at a scale of 10nm, long cylindrical collagen molecules, attached to each other at their ends by approximately 1.5nm long crosslinks and hosting intermolecular water inbetween, form a contiguous matrix called wet collagen. At a scale of several hundred nanometers, wet collagen and mineral crystal agglomerations interpenetrate each other, forming the mineralized fibril. At a scale of 5-10microm, the extracellular solid bone matrix is represented as collagen fibril inclusions embedded in a foam of largely disordered (extrafibrillar) mineral crystals. At a scale above the ultrastructure, where lacunae are embedded in extracellular bone matrix, the extravascular bone material is observed. Model estimates predicted from tissue-specific composition data gained from a multitude of chemical and physical tests agree remarkably well with corresponding acoustic stiffness experiments across a variety of cortical and trabecular, extracellular and extravascular materials. Besides from reconciling the well-documented, seemingly opposed concepts of 'mineral-reinforced collagen matrix' and 'collagen-reinforced mineral matrix' for bone ultrastructure, this approach opens new possibilities in the exploitation of computer tomographic data for nano-to-macro mechanics of bone organs. PMID:17074362

  10. Does the presence of tumor-induced cortical bone destruction at CT have any prognostic value in newly diagnosed diffuse large B-cell lymphoma?

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Hugo J.A.; Nievelstein, Rutger A.J.; Kwee, Thomas C. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Klerk, John M.H. de [Meander Medical Center, Department of Nuclear Medicine, Amersfoort (Netherlands); Fijnheer, Rob [Meander Medical Center, Department of Hematology, Amersfoort (Netherlands); Heggelman, Ben G.F. [Meander Medical Center, Department of Radiology, Amersfoort (Netherlands); Dubois, Stefan V. [Meander Medical Center, Department of Pathology, Amersfoort (Netherlands)

    2015-05-01

    To determine the prognostic value of tumor-induced cortical bone destruction at computed tomography (CT) in newly diagnosed diffuse large B-cell lymphoma (DLBCL). This retrospective study included 105 patients with newly diagnosed DLBCL who had undergone CT and bone marrow biopsy (BMB) before R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisolone) chemo-immunotherapy. Cox regression analyses were used to determine the associations of cortical bone status at CT (absence vs. presence of tumor-induced cortical bone destruction), BMB findings (negative vs. positive for lymphomatous involvement), and dichotomized National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) strata (low risk vs. high risk) with progression-free survival (PFS) and overall survival (OS). Univariate Cox regression analysis indicated that cortical bone status at CT was no significant predictor of either PFS or OS (p = 0.358 and p = 0.560, respectively), whereas BMB findings (p = 0.002 and p = 0.013, respectively) and dichotomized NCCN-IPI risk strata (p = 0.002 and p = 0.003, respectively) were significant predictors of both PFS and OS. In the multivariate Cox proportional hazards model, only the dichotomized NCCN-IPI score was an independent predictive factor of PFS and OS (p = 0.004 and p = 0.003, respectively). The presence of tumor-induced cortical bone destruction at CT was not found to have any prognostic implications in newly diagnosed DLBCL. (orig.)

  11. On the effect of x-ray irradiation on the deformation and fracture behavior of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Holly D.; Launey, Maximilien E.; McDowell, Alastair A.; Ager III, Joel W.; Ritchie, Robert O.

    2010-01-10

    In situ mechanical testing coupled with imaging using high-energy synchrotron x-ray diffraction or tomography imaging is gaining in popularity as a technique to investigate micrometer and even sub-micrometer deformation and fracture mechanisms in mineralized tissues, such as bone and teeth. However, the role of the irradiation in affecting the nature and properties of the tissue is not always taken into account. Accordingly, we examine here the effect of x-ray synchrotron-source irradiation on the mechanistic aspects of deformation and fracture in human cortical bone. Specifically, the strength, ductility and fracture resistance (both work-of-fracture and resistance-curve fracture toughness) of human femoral bone in the transverse (breaking) orientation were evaluated following exposures to 0.05, 70, 210 and 630 kGy irradiation. Our results show that the radiation typically used in tomography imaging can have a major and deleterious impact on the strength, post-yield behavior and fracture toughness of cortical bone, with the severity of the effect progressively increasing with higher doses of radiation. Plasticity was essentially suppressed after as little as 70 kGy of radiation; the fracture toughness was decreased by a factor of five after 210 kGy of radiation. Mechanistically, the irradiation was found to alter the salient toughening mechanisms, manifest by the progressive elimination of the bone's capacity for plastic deformation which restricts the intrinsic toughening from the formation 'plastic zones' around crack-like defects. Deep-ultraviolet Raman spectroscopy indicated that this behavior could be related to degradation in the collagen integrity.

  12. Functional adaptation of long bone extremities involves the localized ``tuning'' of the cortical bone composition; evidence from Raman spectroscopy

    Science.gov (United States)

    Buckley, Kevin; Kerns, Jemma G.; Birch, Helen L.; Gikas, Panagiotis D.; Parker, Anthony W.; Matousek, Pavel; Goodship, Allen E.

    2014-11-01

    In long bones, the functional adaptation of shape and structure occurs along the whole length of the organ. This study explores the hypothesis that adaptation of bone composition is also site-specific and that the mineral-to-collagen ratio of bone (and, thus, its mechanical properties) varies along the organ's length. Raman spectroscopy was used to map the chemical composition of long bones along their entire length in fine spatial resolution (1 mm), and then biochemical analysis was used to measure the mineral, collagen, water, and sulfated glycosaminoglycan content where site-specific differences were seen. The results show that the mineral-to-collagen ratio of the bone material in human tibiae varies by 10% toward the flared extremities of the bone. Comparisons with long bones from other large animals (horses, sheep, and deer) gave similar results with bone material composition changing across tens of centimeters. The composition of the bone apatite also varied with the phosphate-to-carbonate ratio decreasing toward the ends of the tibia. The data highlight the complexity of adaptive changes and raise interesting questions about the biochemical control mechanisms involved. In addition to their biological interest, the data provide timely information to researchers developing Raman spectroscopy as a noninvasive tool for measuring bone composition in vivo (particularly with regard to sampling and measurement protocol).

  13. Alveolar bone preservation subsequent to miniscrew implant placement in a canine model

    DEFF Research Database (Denmark)

    Melsen, Birte; Huja, Sarandeep; Chien, Hua-Hong;

    2015-01-01

    below the alveolar crest on the experimental side in the region of the extraction. The dogs were killed after 12 weeks. The bone at the extraction sites was analyzed using μCT and 3D analysis. A cylindrical core was placed around the actual and a virtual screw placed in the identical location...

  14. Odanacatib treatment affects trabecular and cortical bone in the femur of postmenopausal women: results of a two-year placebo-controlled trial.

    Science.gov (United States)

    Engelke, Klaus; Fuerst, Thomas; Dardzinski, Bernard; Kornak, John; Ather, Shabana; Genant, Harry K; de Papp, Anne

    2015-01-01

    Odanacatib, a selective cathepsin K inhibitor, increases areal bone mineral density (aBMD) at the spine and hip of postmenopausal women. To gain additional insight into the effects on trabecular and cortical bone, we analyzed quantitative computed tomography (QCT) data of postmenopausal women treated with odanacatib using Medical Image Analysis Framework (MIAF; Institute of Medical Physics, University of Erlangen, Erlangen, Germany). This international, randomized, double-blind, placebo-controlled, 2-year, phase 3 trial enrolled 214 postmenopausal women (mean age 64 years) with low aBMD. Subjects were randomized to odanacatib 50 mg weekly (ODN) or placebo (PBO); all participants received calcium and vitamin D. Hip QCT scans at 24 months were available for 158 women (ODN: n = 78 women; PBO: n = 80 women). There were consistent and significant differential treatment effects (ODN-PBO) for total hip integral (5.4%), trabecular volumetric BMD (vBMD) (12.2%), and cortical vBMD (2.5%) at 24 months. There was no significant differential treatment effect on integral bone volume. Results for bone mineral content (BMC) closely matched those for vBMD for integral and trabecular compartments. However, with small but mostly significant differential increases in cortical volume (1.0% to 1.3%) and thickness (1.4% to 1.9%), the percentage cortical BMC increases were numerically larger than those of vBMD. With a total hip BMC differential treatment effect (ODN-PBO) of nearly 1000 mg, the proportions of BMC attributed to cortical gain were 45%, 44%, 52%, and 40% for the total, neck, trochanter, and intertrochanter subregions, respectively. In postmenopausal women treated for 2 years, odanacatib improved integral, trabecular, and cortical vBMD and BMC at all femur regions relative to placebo when assessed by MIAF. Cortical volume and thickness increased significantly in all regions except the femoral neck. The increase in cortical volume and BMC paralleled the increase in

  15. Allogeneic stem cell transplantation for bone regeneration of a nonunion defect in a canine

    OpenAIRE

    Yaneselli K; Filomeno A; Semiglia G; Arce C; Rial A.; Muñoz N; Moreno M; Erickson K; Maisonnave J

    2013-01-01

    Kevin Yaneselli,1 Andrea Filomeno,1 Gabriel Semiglia,1 Carolina Arce,1 Analía Rial,2 Natalia Muñoz,2 María Moreno,2 Kent Erickson,3 Jacqueline Maisonnave11Universidad de la República, Facultad de Veterinaria, Montevideo, Uruguay; 2Laboratory for Vaccine Research, Department of Biotechnology, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay; 3University of California, Davis, CA, USAAbstract: Nonunion bone defects oc...

  16. Inflammatory response and bone healing capacity of two porous calcium phosphate ceramics in critical size cortical bone defects.

    Science.gov (United States)

    Chatterjea, Anindita; van der Stok, Johan; Danoux, Charlène B; Yuan, Huipin; Habibovic, Pamela; van Blitterswijk, Clemens A; Weinans, Harrie; de Boer, Jan

    2014-05-01

    In the present study, two open porous calcium phosphate ceramics, β-tricalcium phosphate (β-TCP), and hydroxyapatite (HA) were compared in a critical-sized femoral defect in rats. Previous comparisons of these two ceramics showed significantly greater osteoinductive potential of β-TCP upon intramuscular implantation and a better performance in a spinal fusion model in dogs. Results of the current study also showed significantly more bone formation in defects grafted with β-TCP compared to HA; however, both the ceramics were not capable of increasing bone formation to such extend that it bridges the defect. Furthermore, a more pronounced degradation of β-TCP was observed as compared to HA. Progression of inflammation and initiation of new bone formation were assessed for both materials at multiple time points by histological and fluorochrome-based analyses. Until 12 days postimplantation, a strong inflammatory response in absence of new bone formation was observed in both ceramics, without obvious differences between the two materials. Four weeks postimplantation, signs of new bone formation were found in both β-TCP and HA. At 6 weeks, inflammation had subsided in both ceramics while bone deposition continued. In conclusion, the two ceramics differed in the amount of bone formed after 8 weeks of implantation, whereas no differences were found in the duration of the inflammatory phase after implantation or initiation of new bone formation.

  17. Intralesional Application of Autologous Bone Marrow Stem Cells with Scaffold in Canine for Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Justin William B

    2009-01-01

    Full Text Available A three year old male non-descriptive companion dog was presented to the Small Animal Orthopedic Unit of Madras Veterinary College Teaching Hospital (MVC with paraplegia of fourth degree neurological deficit of hind limbs due to automobile trauma. Radiographic views were suggestive of dislocation at T8-T9 vertebral segment with fracture of L2 vertebra. Myelography confirmed the signs of abrupt stoppage of the contrast column cranial to dislocated area and was interpretive of transected spinal cord at L2 level. Construct was prepared with bone marrow mononuclear cells (BMMNC isolated from bone marrow aspirate of femur and the cells were seeded in Thermoreversible Gelatin Polymer (TGP at the cell processing facility of Nichi-In Centre for Regenerative Medicine (NCRM as per GMP protocols and was engrafted after hemilaminectomy and durotomy procedures in the MVC. Postoperatively the animal was clinically stable; however the animal died on the 7th day. Autopsy revealed co-morbid conditions like cystitis, nephritis and transmissible venereal tumor. Histopathology of the engrafted area revealed sustainability of aggregated stem cells that were transplanted revealing an ideal biocompatibility of the construct prepared with bone marrow mononuclear cells and polymer hydrogel for spinal cord regeneration in dogs. Further studies in similar cases will have to be undertaken to prove the long term efficacy.

  18. Small-Angle X-ray Scattering Demonstrates Similar Nanostructure in Cortical Bone from Young Adult Animals of Different Species.

    Science.gov (United States)

    Kaspersen, Jørn Døvling; Turunen, Mikael Juhani; Mathavan, Neashan; Lages, Sebastian; Pedersen, Jan Skov; Olsson, Ulf; Isaksson, Hanna

    2016-07-01

    Despite the vast amount of studies focusing on bone nanostructure that have been performed for several decades, doubts regarding the detailed structure of the constituting hydroxyapatite crystal still exist. Different experimental techniques report somewhat different sizes and locations, possibly due to different requirements for the sample preparation. In this study, small- and wide-angle X-ray scattering is used to investigate the nanostructure of femur samples from young adult ovine, bovine, porcine, and murine cortical bone, including three different orthogonal directions relative to the long axis of the bone. The radially averaged scattering from all samples reveals a remarkable similarity in the entire q range, which indicates that the nanostructure is essentially the same in all species. Small differences in the data from different directions confirm that the crystals are elongated in the [001] direction and that this direction is parallel to the long axis of the bone. A model consisting of thin plates is successfully employed to describe the scattering and extract the plate thicknesses, which are found to be in the range of 20-40 Å for most samples but 40-60 Å for the cow samples. It is demonstrated that the mineral plates have a large degree of polydispersity in plate thickness. Additionally, and equally importantly, the scattering data and the model are critically evaluated in terms of model uncertainties and overall information content. PMID:26914607

  19. Characterization of the effects of x-ray irradiation on the hierarchical structure and mechanical properties of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Holly; Zimmermann, Elizabeth; Schaible, Eric; Tang, Simon; Alliston, Tamara; Ritchie, Robert

    2011-08-19

    Bone comprises a complex structure of primarily collagen, hydroxyapatite and water, where each hierarchical structural level contributes to its strength, ductility and toughness. These properties, however, are degraded by irradiation, arising from medical therapy or bone-allograft sterilization. We provide here a mechanistic framework for how irradiation affects the nature and properties of human cortical bone over a range of characteristic (nano to macro) length-scales, following x-­ray exposures up to 630 kGy. Macroscopically, bone strength, ductility and fracture resistance are seen to be progressively degraded with increasing irradiation levels. At the micron-­scale, fracture properties, evaluated using in-situ scanning electron microscopy and synchrotron x-ray computed micro-tomography, provide mechanistic information on how cracks interact with the bone-matrix structure. At sub-micron scales, strength properties are evaluated with in-situ tensile tests in the synchrotron using small-/wide-angle x-ray scattering/diffraction, where strains are simultaneously measured in the macroscopic tissue, collagen fibrils and mineral. Compared to healthy bone, results show that the fibrillar strain is decreased by ~40% following 70 kGy exposures, consistent with significant stiffening and degradation of the collagen. We attribute the irradiation-­induced deterioration in mechanical properties to mechanisms at multiple length-scales, including changes in crack paths at micron-­scales, loss of plasticity from suppressed fibrillar sliding at sub-­micron scales, and the loss and damage of collagen at the nano-­scales, the latter being assessed using Raman and Fourier-Transform-Infrared spectroscopy and a fluorometric assay.

  20. Accounting for beta-particle energy loss to cortical bone via paired-image radiation transport (PIRT).

    Science.gov (United States)

    Shah, Amish P; Rajon, Didier A; Patton, Phillip W; Jokisch, Derek W; Bolch, Wesley E

    2005-05-01

    Current methods of skeletal dose assessment in both medical physics (radionuclide therapy) and health physics (dose reconstruction and risk assessment) rely heavily on a single set of bone and marrow cavity chord-length distributions in which particle energy deposition is tracked within an infinite extent of trabecular spongiosa, with no allowance for particle escape to cortical bone. In the present study, we introduce a paired-image radiation transport (PIRT) model which provides a more realistic three-dimensional (3D) geometry for particle transport in the skeletal site at both microscopic and macroscopic levels of its histology. Ex vivo CT scans were acquired of the pelvis, cranial cap, and individual ribs excised from a 66-year male cadaver (BMI of 22.7 kg m(-2)). For the three skeletal sites, regions of trabecular spongiosa and cortical bone were identified and segmented. Physical sections of interior spongiosa were taken and subjected to microCT imaging. Voxels within the resulting microCT images were then segmented and labeled as regions of bone trabeculae, endosteum, active marrow, and inactive marrow through application of image processing algorithms. The PIRT methodology was then implemented within the EGSNRC radiation transport code whereby electrons of various initial energies are simultaneously tracked within both the ex vivo CT macroimage and the CT microimage of the skeletal site. At initial electron energies greater than 50-200 keV, a divergence in absorbed fractions to active marrow are noted between PIRT model simulations and those estimated under existing techniques of infinite spongiosa transport. Calculations of radionuclide S values under both methodologies imply that current chord-based models may overestimate the absorbed dose to active bone marrow in these skeletal sites by 0% to 27% for low-energy beta emitters (33P, 169Er, and 177Lu), by approximately 4% to 49% for intermediate-energy beta emitters (153Sm, 186Re, and 89Sr), and by

  1. Comparison of Osteogenesis between Adipose-Derived Mesenchymal Stem Cells and Their Sheets on Poly-ε-Caprolactone/β-Tricalcium Phosphate Composite Scaffolds in Canine Bone Defects.

    Science.gov (United States)

    Kim, Yongsun; Lee, Seung Hoon; Kang, Byung-Jae; Kim, Wan Hee; Yun, Hui-Suk; Kweon, Oh-Kyeong

    2016-01-01

    Multipotent mesenchymal stem cells (MSCs) and MSC sheets have effective potentials of bone regeneration. Composite polymer/ceramic scaffolds such as poly-ε-caprolactone (PCL)/β-tricalcium phosphate (β-TCP) are widely used to repair large bone defects. The present study investigated the in vitro osteogenic potential of canine adipose-derived MSCs (Ad-MSCs) and Ad-MSC sheets. Composite PCL/β-TCP scaffolds seeded with Ad-MSCs or wrapped with osteogenic Ad-MSC sheets (OCS) were also fabricated and their osteogenic potential was assessed following transplantation into critical-sized bone defects in dogs. The alkaline phosphatase (ALP) activity of osteogenic Ad-MSCs (O-MSCs) and OCS was significantly higher than that of undifferentiated Ad-MSCs (U-MSCs). The ALP, runt-related transcription factor 2, osteopontin, and bone morphogenetic protein 7 mRNA levels were upregulated in O-MSCs and OCS as compared to U-MSCs. In a segmental bone defect, the amount of newly formed bone was greater in PCL/β-TCP/OCS and PCL/β-TCP/O-MSCs/OCS than in the other groups. The OCS exhibit strong osteogenic capacity, and OCS combined with a PCL/β-TCP composite scaffold stimulated new bone formation in a critical-sized bone defect. These results suggest that the PCL/β-TCP/OCS composite has potential clinical applications in bone regeneration and can be used as an alternative treatment modality in bone tissue engineering. PMID:27610141

  2. Differentiation of human bone marrow precursor cells into neuronal-like cells after transplantation into canine spinal cord organotypic slice cultures

    Institute of Scientific and Technical Information of China (English)

    FEI Zhi-qiang; XIONG Jian-yi; CHEN Lei; SHEN Hui-yong; Ngo Stephanie; Wang Jeffrey; WANG Da-ping

    2012-01-01

    Background Treatments to regenerate different tissue involving the transplantation of bone marrow derived mesenchymal precursor cells are anticipated.Using an alternative methods,in vitro organotypic slice culture method,would be useful to transplant cells and assessing the effects.This study was to determine the possibility of differentiating human bone marrow precursor cells into cells of the neuronal lineage by transplanting into canine spinal cord organotypic slice cultures.Methods Bone marrow aspirates were obtained from posterior superior iliac spine(PSIS)of patients that had undergone spinal fusion due to a degenerative spinal disorder.For cell imaging,mesenchymal precursor cells(MPCs)were pre-stained with PKH-26 just before transplantation to canine spinal cord slices.Canine spinal cord tissues were obtained from three adult beagle dogs.Spinal cords were cut into transverse slices of 1 mm using tissue chopper.Two slices were transferred into 6-well plate containing 3 ml DMEM with antibiotics.Prepared MPCs(1×104)were transplanted into spinal cord slices.On days 0,3,7,14,MPCs were observed for morphological changes and expression of neuronal markers through immunofluorescence and reverse transcription-polymerase chain reaction(RT-PCR).Results The morphological study showed:spherical cells in the control and experiment groups on day 0;and on day 3,cells in the control group had one or two thick,short processes and ones in the experiment group had three or four thin,long processes.On day 7,these variously-sized processes contacted each other in the experiment group,but showed typical spindle-shaped cells in the control group.Immunofluorescence showed that PKH-26(+)MPCs stained positive for NeuN(+)and GFAP(+)in experimental group only.Also RT-PCR showed weak expression of β-tubulinⅢ?and GFAP.Conclusions Human bone marrow mesenchymal precursor cells(hMPCs)have the potential to differentiate into the neuronal like cells in this canine spinal cord organotypic

  3. High-calcium diet modulates effects of long-term prolactin exposure on the cortical bone calcium content in ovariectomized rats.

    Science.gov (United States)

    Charoenphandhu, Narattaphol; Tudpor, Kukiat; Thongchote, Kanogwun; Saengamnart, Wasana; Puntheeranurak, Supaporn; Krishnamra, Nateetip

    2007-02-01

    High physiological prolactin induced positive calcium balance by stimulating intestinal calcium absorption, reducing renal calcium excretion, and increasing bone calcium deposition in female rats. Although prolactin-induced increase in trabecular bone calcium deposition was absent after ovariectomy, its effects on cortical bones were still controversial. The present investigation, therefore, aimed to study the effect of in vivo long-term high physiological prolactin induced by either anterior pituitary (AP) transplantation or 2.5 mg/kg prolactin injection on cortical bones in ovariectomized rats. Since the presence of prolactin receptors (PRLR) in different bones of normal adult rats has not been reported, we first determined mRNA expression of both short- and long-form PRLRs at the cortical sites (tibia and femur) and trabecular sites (calvaria and vertebrae) by using the RT-PCR. Our results showed the mRNA expression of both PRLR isoforms with predominant long form at all sites. However, high prolactin levels induced by AP transplantation in normal rats did not have any effect on the femoral bone mineral density or bone mineral content. By using (45)Ca kinetic study, 2.5 mg/kg prolactin did not alter bone formation, bone resorption, calcium deposition, and total calcium content in tibia and femur of adult ovariectomized rats. AP transplantation also had no effect on the cortical total calcium content in adult ovariectomized rats. Because previous work showed that the effects of prolactin were age dependent and could be modulated by high-calcium diet, interactions between prolactin and these two parameters were investigated. The results demonstrated that 2.0% wt/wt high-calcium diet significantly increased the tibial total calcium content in 9-wk-old young AP-grafted ovariectomized rats but decreased the tibial total calcium content in 22-wk-old adult rats. As for the vertebrae, the total calcium contents in both young and adult rats were not changed by high

  4. Effects of high-dose gamma irradiation on tensile properties of human cortical bone: Comparison of different radioprotective treatment methods.

    Science.gov (United States)

    Allaveisi, Farzaneh; Mirzaei, Majid

    2016-08-01

    There are growing interests in the radioprotective methods that can reduce the damaging effects of ionizing radiation on sterilized bone allografts. The aim of this study was to investigate the effects of 50kGy (single dose, and fractionated) gamma irradiation, in presence and absence of l-Cysteine (LC) free radical scavenger, on tensile properties of human femoral cortical bone. A total of 48 standard tensile test specimens was prepared from diaphysis of femurs of three male cadavers (age: 52, 52, and 54 years). The specimens were assigned to six groups (n=8) according to different irradiation schemes, i.e.; Control (Non-irradiated), LC-treated control, a single dose of 50kGy (sole irradiation), a single dose of 50kGy in presence of LC, 10 fractions of 5kGy (sole irradiation), and 10 fractions of 5kGy in presence of LC. Uniaxial tensile tests were carried out to evaluate the variations in tensile properties of the specimens. Fractographic analysis was performed to examine the microstructural features of the fracture surfaces. The results of multivariate analysis showed that fractionation of the radiation dose, as well as the LC treatment of the 50kGy irradiated specimens, significantly reduced the radiation-induced impairment of the tensile properties of the specimens (Ptest results. In summary, this study showed that the detrimental effects of gamma sterilization on tensile properties of human cortical bone can be substantially reduced by free radical scavenger treatment, dose fractionation, and the combined treatment of these two methods. PMID:27124804

  5. MO-G-17A-03: MR-Based Cortical Bone Segmentation for PET Attenuation Correction with a Non-UTE 3D Fast GRE Sequence

    Energy Technology Data Exchange (ETDEWEB)

    Ai, H; Pan, T [The University of Texas MD Anderson Cancer Center, Houston, TX (United States); The University of Texas Graduate School of Biomedical Science, Houston, TX (United States); Hwang, K [GE Healthcare, Houston, TX (United States)

    2014-06-15

    Purpose: To determine the feasibility of identifying cortical bone on MR images with a short-TE 3D fast-GRE sequence for attenuation correction of PET data in PET/MR. Methods: A water-fat-bone phantom was constructed with two pieces of beef shank. MR scans were performed on a 3T MR scanner (GE Discovery™ MR750). A 3D GRE sequence was first employed to measure the level of residual signal in cortical bone (TE{sub 1}/TE{sub 2}/TE{sub 3}=2.2/4.4/6.6ms, TR=20ms, flip angle=25°). For cortical bone segmentation, a 3D fast-GRE sequence (TE/TR=0.7/1.9ms, acquisition voxel size=2.5×2.5×3mm{sup 3}) was implemented along with a 3D Dixon sequence (TE{sub 1}/TE{sub 2}/TR=1.2/2.3/4.0ms, acquisition voxel size=1.25×1.25×3mm{sup 3}) for water/fat imaging. Flip angle (10°), acquisition bandwidth (250kHz), FOV (480×480×144mm{sup 3}) and reconstructed voxel size (0.94×0.94×1.5mm{sup 3}) were kept the same for both sequences. Soft tissue and fat tissue were first segmented on the reconstructed water/fat image. A tissue mask was created by combining the segmented water/fat masks, which was then applied on the fast-GRE image (MRFGRE). A second mask was created to remove the Gibbs artifacts present in regions in close vicinity to the phantom. MRFGRE data was smoothed with a 3D anisotropic diffusion filter for noise reduction, after which cortical bone and air was separated using a threshold determined from the histogram. Results: There is signal in the cortical bone region in the 3D GRE images, indicating the possibility of separating cortical bone and air based on signal intensity from short-TE MR image. The acquisition time for the 3D fast-GRE sequence was 17s, which can be reduced to less than 10s with parallel imaging. The attenuation image created from water-fat-bone segmentation is visually similar compared to reference CT. Conclusion: Cortical bone and air can be separated based on intensity in MR image with a short-TE 3D fast-GRE sequence. Further research is required

  6. MO-G-17A-03: MR-Based Cortical Bone Segmentation for PET Attenuation Correction with a Non-UTE 3D Fast GRE Sequence

    International Nuclear Information System (INIS)

    Purpose: To determine the feasibility of identifying cortical bone on MR images with a short-TE 3D fast-GRE sequence for attenuation correction of PET data in PET/MR. Methods: A water-fat-bone phantom was constructed with two pieces of beef shank. MR scans were performed on a 3T MR scanner (GE Discovery™ MR750). A 3D GRE sequence was first employed to measure the level of residual signal in cortical bone (TE1/TE2/TE3=2.2/4.4/6.6ms, TR=20ms, flip angle=25°). For cortical bone segmentation, a 3D fast-GRE sequence (TE/TR=0.7/1.9ms, acquisition voxel size=2.5×2.5×3mm3) was implemented along with a 3D Dixon sequence (TE1/TE2/TR=1.2/2.3/4.0ms, acquisition voxel size=1.25×1.25×3mm3) for water/fat imaging. Flip angle (10°), acquisition bandwidth (250kHz), FOV (480×480×144mm3) and reconstructed voxel size (0.94×0.94×1.5mm3) were kept the same for both sequences. Soft tissue and fat tissue were first segmented on the reconstructed water/fat image. A tissue mask was created by combining the segmented water/fat masks, which was then applied on the fast-GRE image (MRFGRE). A second mask was created to remove the Gibbs artifacts present in regions in close vicinity to the phantom. MRFGRE data was smoothed with a 3D anisotropic diffusion filter for noise reduction, after which cortical bone and air was separated using a threshold determined from the histogram. Results: There is signal in the cortical bone region in the 3D GRE images, indicating the possibility of separating cortical bone and air based on signal intensity from short-TE MR image. The acquisition time for the 3D fast-GRE sequence was 17s, which can be reduced to less than 10s with parallel imaging. The attenuation image created from water-fat-bone segmentation is visually similar compared to reference CT. Conclusion: Cortical bone and air can be separated based on intensity in MR image with a short-TE 3D fast-GRE sequence. Further research is required to optimize the strategy to reduce Gibbs artifacts

  7. 犬牙槽骨种植实验及种植体-骨结合评价方法%The evaluation methods of dental implant in canine alveolar bone and bone integration

    Institute of Scientific and Technical Information of China (English)

    冯丽芳(综述); 吴琳(审校)

    2013-01-01

    种植体与骨形成良好的骨结合界面是种植义齿修复成功的重要标志之一,而动物实验是评价种植体与骨结合界面的重要手段,其中犬牙槽骨是研究牙种植体植入的理想部位之一。本文就犬牙槽骨内植入种植体的实验方法及种植体与骨结合情况的评价方法做一综述。%Good osseointegration interface of implant and bone form is one of important signs of the success of implant denture restoration. Animal experiment is one important means to evaluate dental implant and osseointegration interface. One of ideal sites for dental implant implanted is canine alveolar bone . In this paper the experiment method of dental im-plant implanted in canine alveolar bone and the evaluation methods of dental implant and bone integration will be re-viewed.

  8. Histopathological and Histomorphometrical Effects of Atorvastatin on Experimental Femoral Cortical Bone Defect Healing in Rats

    Directory of Open Access Journals (Sweden)

    M Valilu

    2012-05-01

    Full Text Available Background: Bone remodeling has always been the goal of surgeons for a long time. Recently, it was shown that statins that are commonly prescribed for lowering cholesterol also have beneficial effects on bone healing. Therefore, the present study was undertaken to evaluate the probable effects of atorvastatin on osteogenesis in the rat femur. Methods: This experimental study was conducted on 30 male Sprague-Dawley (SD rats. The animals were divided randomly into one control and two experiment groups. After induction of anesthesia, a hole of 2 mm in diameter was made in femur width. The control group received physiological serum but the experiment groups one and two, respectively, received 10 and 20 mg/kg/PO of atorvastatin on daily basis. After euthanizing the rats, histopathological and histomorphometrical evaluations of the bones were performed 45 days after the intervention. Results: In the control group, the defects seemed to be filled with woven bone and bone marrow, depictive of a poor osteogenic activity. In the experiment groups, many osteoblast groupings and young bone trabeculae had been formed and bone trabeculae were more organized. Histomorphometric results, showed that atorvastatin had significantly promoted bone healing in the experiment groups compared with the controls (P<0.001. Moreover, the analysis showed that atorvastatin had more significant effects in group three receiving high doses of the medication in comparison with group two (P<0.001. Conclusion: The findings of this study showed that atorvastatin is capable of stimulating osteogenesis in rats.

  9. Vitamin D supplementation prevents hypocalcemia and cortical bone loss associated with chronic feeding in female mice

    Science.gov (United States)

    Dietary cholecalciferol supplementation alone or combined with calcium has shown great promise in improving bone health, which has been attributed to endocrine actions involved in calcium regulation and/or paracrine/autocrine actions within bone. Indeed, we and others have suggested that dietary su...

  10. Cortical bone growth and maturational changes in dwarf rats induced by recombinant human growth hormone

    Science.gov (United States)

    Martinez, D. A.; Orth, M. W.; Carr, K. E.; Vanderby, R. Jr; Vailas, A. C.

    1996-01-01

    The growth hormone (GH)-deficient dwarf rat was used to investigate recombinant human (rh) GH-induced bone formation and to determine whether rhGH facilitates simultaneous increases in bone formation and bone maturation during rapid growth. Twenty dwarf rats, 37 days of age, were randomly assigned to dwarf plus rhGH (GH; n = 10) and dwarf plus vehicle (n = 10) groups. The GH group received 1.25 mg rhGH/kg body wt two times daily for 14 days. Biochemical, morphological, and X-ray diffraction measurements were performed on the femur middiaphysis. rhGH stimulated new bone growth in the GH group, as demonstrated by significant increases (P GH group (P < 0.05). Our findings suggest that the processes regulating new collagen accretion, bone collagen maturation, and mean hydroxyapatite crystal size may be independently regulated during rapid growth.

  11. Osteocyte Apoptosis Caused by Hindlimb Unloading is Required to Trigger Osteocyte RANKL Production and Subsequent Resorption of Cortical and Trabecular Bone in Mice Femurs.

    Science.gov (United States)

    Cabahug-Zuckerman, Pamela; Frikha-Benayed, Dorra; Majeska, Robert J; Tuthill, Alyssa; Yakar, Shoshana; Judex, Stefan; Schaffler, Mitchell B

    2016-07-01

    Osteocyte apoptosis is essential to activate bone remodeling in response to fatigue microdamage and estrogen withdrawal, such that apoptosis inhibition in vivo prevents the onset of osteoclastic resorption. Osteocyte apoptosis has also been spatially linked to bone resorption owing to disuse, but whether apoptosis plays a similar controlling role is unclear. We, therefore, 1) evaluated the spatial and temporal effects of disuse from hindlimb unloading (HLU) on osteocyte apoptosis, receptor activator of NF-κB ligand (RANKL) expression, bone resorption, and loss in mouse femora, and 2) tested whether osteocyte apoptosis was required to activate osteoclastic activity in cortical and trabecular bone by treating animals subjected to HLU with the pan-caspase apoptosis inhibitor, QVD (quinolyl-valyl-O-methylaspartyl-[-2,6-difluorophenoxy]-methylketone). Immunohistochemistry was used to identify apoptotic and RANKL-producing osteocytes in femoral diaphysis and distal trabecular bone, and µCT was used to determine the extent of trabecular bone loss owing to HLU. In both cortical and trabecular bone, 5 days of HLU increased osteocyte apoptosis significantly (3- and 4-fold, respectively, p 1.5-fold versus Ctrl, p data indicate that osteocyte apoptosis plays a central and controlling role in triggering osteocyte RANKL production and the activation of new resorption leading to bone loss in disuse. © 2016 American Society for Bone and Mineral Research. PMID:26852281

  12. Age-related changes in the plasticity and toughness of human cortical bone at multiple length-scales

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Elizabeth A.; Schaible, Eric; Bale, Hrishikesh; Barth, Holly D.; Tang, Simon Y.; Reichert, Peter; Busse, Bjoern; Alliston, Tamara; Ager III, Joel W.; Ritchie, Robert O.

    2011-08-10

    The structure of human cortical bone evolves over multiple length-scales from its basic constituents of collagen and hydroxyapatite at the nanoscale to osteonal structures at nearmillimeter dimensions, which all provide the basis for its mechanical properties. To resist fracture, bone’s toughness is derived intrinsically through plasticity (e.g., fibrillar sliding) at structural-scales typically below a micron and extrinsically (i.e., during crack growth) through mechanisms (e.g., crack deflection/bridging) generated at larger structural-scales. Biological factors such as aging lead to a markedly increased fracture risk, which is often associated with an age-related loss in bone mass (bone quantity). However, we find that age-related structural changes can significantly degrade the fracture resistance (bone quality) over multiple lengthscales. Using in situ small-/wide-angle x-ray scattering/diffraction to characterize sub-micron structural changes and synchrotron x-ray computed tomography and in situ fracture-toughness measurements in the scanning electron microscope to characterize effects at micron-scales, we show how these age-related structural changes at differing size-scales degrade both the intrinsic and extrinsic toughness of bone. Specifically, we attribute the loss in toughness to increased non-enzymatic collagen cross-linking which suppresses plasticity at nanoscale dimensions and to an increased osteonal density which limits the potency of crack-bridging mechanisms at micron-scales. The link between these processes is that the increased stiffness of the cross-linked collagen requires energy to be absorbed by “plastic” deformation at higher structural levels, which occurs by the process of microcracking.

  13. Multiscale approach including microfibril scale to assess elastic constants of cortical bone based on neural network computation and homogenization method

    OpenAIRE

    Barkaoui, Abdelwahed; Chamekh, Abdessalem; Tarek, Merzouki; Hambli, Ridha; Ali, Mkaddem

    2013-01-01

    The complexity and heterogeneity of bone tissue require a multiscale modelling to understand its mechanical behaviour and its remodelling mechanisms. In this paper, a novel multiscale hierarchical approach including microfibril scale based on hybrid neural network computation and homogenisation equations was developed to link nanoscopic and macroscopic scales to estimate the elastic properties of human cortical bone. The multiscale model is divided into three main phases: (i) in step 0, the e...

  14. Does the cortical bone resorption rate change due to 90Sr-radiation exposure? Analysis of data from Techa Riverside residents

    Energy Technology Data Exchange (ETDEWEB)

    Tolstykh, E I; Shagina, N B; Degteva, M O; Anspaugh, L R; Napier, Bruce A

    2011-08-01

    The Mayak Production Association released large amounts of 90Sr into the Techa River (Southern Urals, Russia) with peak amounts in 1950-1951. Techa Riverside residents ingested an average of about 3,000 kBq of 90Sr. The 90Sr-body burden of approximately 15,000 individuals has been measured in the Urals Research Center for Radiation Medicine in 1974-1997 with use of a special whole-body counter (WBC). Strontium-90 had mainly deposited in the cortical part of the skeleton by 25 years following intake, and 90Sr elimination occurs as a result of cortical bone resorption. The effect of 90Sr-radiation exposure on the rate of cortical bone resorption was studied. Data on 2,022 WBC measurements were selected for 207 adult persons, who were measured three or more times before they were 50-55 years old. The individual-resorption rates were calculated with the rate of strontium recirculation evaluated as 0.0018 year-1. Individual absorbed doses in red bone marrow (RBM) and bone surface (BS) were also calculated. Statistically significant negative relationships of cortical bone resorption rate were discovered related to 90Sr-body burden and dose absorbed in the RBM or the BS. The response appears to have a threshold of about 1.5-Gy RBM dose. The radiation induced decrease in bone resorption rate may not be significant in terms of health. However, a decrease in bone remodeling rate can be among several causes of an increased level of degenerative dystrophic bone pathology in exposed persons.

  15. Irradiation conditions for fiber laser bonding of HAp-glass ceramics with bovine cortical bone.

    Science.gov (United States)

    Tadano, Shigeru; Yamada, Satoshi; Kanaoka, Masaru

    2014-01-01

    Orthopedic implants are widely used to repair bones and to replace articulating joint surfaces. It is important to develop an instantaneous technique for the direct bonding of bone and implant materials. The aim of this study was to develop a technique for the laser bonding of bone with an implant material like ceramics. Ceramic specimens (10 mm diameter and 1 mm thickness) were sintered with hydroxyapatite and MgO-Al2O3-SiO2 glass powders mixed in 40:60 wt% proportions. A small hole was bored at the center of a ceramic specimen. The ceramic specimen was positioned onto a bovine bone specimen and a 5 mm diameter area of the ceramic specimen was irradiated using a fiber laser beam (1070-1080 nm wavelength). As a result, the bone and the ceramic specimens bonded strongly under the irradiation conditions of a 400 W laser power and a 1.0 s exposure time. The maximum shear strength was 5.3 ± 2.3 N. A bonding substance that penetrated deeply into the bone specimen was generated around the hole in the ceramic specimen. On using the fiber laser, the ceramic specimen instantaneously bonded to the bone specimen. Further, the irradiation conditions required for the bonding were investigated.

  16. Toxicological effects of pet food ingredients on canine bone marrow-derived mesenchymal stem cells and enterocyte-like cells.

    Science.gov (United States)

    Ortega, M T; Jeffery, B; Riviere, J E; Monteiro-Riviere, N A

    2016-02-01

    We developed an in vitro method to assess pet food ingredients safety. Canine bone marrow-derived mesenchymal stem cells (BMSC) were differentiated into enterocyte-like cells (ELC) to assess toxicity in cells representing similar patterns of exposure in vivo. The toxicological profile of clove leave oil, eugenol, guanosine monophosphate (GMP), GMP + inosine monophosphate, sorbose, ginger root extract, cinnamon bark oil, cinnamaldehyde, thyme oil, thymol and citric acid was assessed in BMSC and ELC. The LC50 for GMP + inosine monophosphate was 59.42 ± 0.90 and 56.7 ± 3.5 mg ml(-1) for BMSC and ELC; 56.84 ± 0.95 and 53.66 ± 1.36 mg ml(-1) for GMP; 0.02 ± 0.001 and 1.25 ± 0.47 mg ml(-1) for citric acid; 0.077 ± 0.002 and 0.037 ± 0.01 mg ml(-1) for cinnamaldehyde; 0.002 ± 0.0001 and 0.002 ± 0.0008 mg ml(-1) for thymol; 0.080 ± 0.003 and 0.059 ± 0.001 mg ml(-1) for thyme oil; 0.111 ± 0.002 and 0.054 ± 0.01 mg ml(-1) for cinnamon bark oil; 0.119 ± 0.0004 and 0.099 ± 0.011 mg ml(-1) for clove leave oil; 0.04 ± 0.001 and 0.028 ± 0.002 mg ml(-1) for eugenol; 2.80 ± 0.11 and 1.75 ± 0.51 mg ml(-1) for ginger root extract; > 200 and 116.78 ± 7.35 mg ml(-1) for sorbose. Lemon grass oil was evaluated at 0.003-0.9 in BMSC and .03-0.9 mg ml(-1) in ELC and its mechanistic effect was investigated. The gene toxicology studies showed regulation of 61% genes in CYP450 pathway, 37% in cholestasis and 33% in immunotoxicity pathways for BMSC. For ELC, 80% for heat shock response, 69% for beta-oxidation and 65% for mitochondrial energy metabolism. In conclusion, these studies provide a baseline against which differential toxicity of dietary feed ingredients can be assessed in vitro for direct effects on canine cells and demonstrate differential toxicity in differentiated cells that represent gastrointestinal epithelial cells. PMID

  17. Cortical bone growth and maturational changes in dwarf rats induced by recombinant human growth hormone

    Science.gov (United States)

    Martinez, D. A.; Orth, M. W.; Carr, K. E.; Vanderby, R. Jr; Vailas, A. C.

    1996-01-01

    The growth hormone (GH)-deficient dwarf rat was used to investigate recombinant human (rh) GH-induced bone formation and to determine whether rhGH facilitates simultaneous increases in bone formation and bone maturation during rapid growth. Twenty dwarf rats, 37 days of age, were randomly assigned to dwarf plus rhGH (GH; n = 10) and dwarf plus vehicle (n = 10) groups. The GH group received 1.25 mg rhGH/kg body wt two times daily for 14 days. Biochemical, morphological, and X-ray diffraction measurements were performed on the femur middiaphysis. rhGH stimulated new bone growth in the GH group, as demonstrated by significant increases (P growth.

  18. Segmentation of nanotomographic cortical bone images for quantitative characterization of the osteoctyte lacuno-canalicular network

    Energy Technology Data Exchange (ETDEWEB)

    Ciani, A.; Kewish, C. M. [Synchrotron Soleil, L’Orme des Merisiers, 91192 Saint-Aubin (France); Guizar-Sicairos, M.; Diaz, A.; Holler, M. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Pallu, S.; Achiou, Z.; Jennane, R.; Toumi, H.; Lespessailles, E. [Univ Orléans, I3MTO, Ea 4708, 45000 Orléans (France)

    2016-01-28

    A newly developed data processing method able to characterize the osteocytes lacuno-canalicular network (LCN) is presented. Osteocytes are the most abundant cells in the bone, living in spaces called lacunae embedded inside the bone matrix and connected to each other with an extensive network of canals that allows for the exchange of nutrients and for mechanotransduction functions. The geometrical three-dimensional (3D) architecture is increasingly thought to be related to the macroscopic strength or failure of the bone and it is becoming the focus for investigating widely spread diseases such as osteoporosis. To obtain 3D LCN images non-destructively has been out of reach until recently, since tens-of-nanometers scale resolution is required. Ptychographic tomography was validated for bone imaging in [1], showing clearly the LCN. The method presented here was applied to 3D ptychographic tomographic images in order to extract morphological and geometrical parameters of the lacuno-canalicular structures.

  19. Effects of alendronate and strontium ranelate on cancellous and cortical bone mass in glucocorticoid-treated adult rats.

    Science.gov (United States)

    Sun, P; Cai, D H; Li, Q N; Chen, H; Deng, W M; He, L; Yang, L

    2010-06-01

    We studied the effects of alendronate (Aln) and strontium ranelate (SrR) administration on cancellous and cortical bone in glucocorticoid (GC)-treated rats. Thirty-two 3.5-month male Sprague-Dawley rats were randomized into four groups: age-matched normal control (Nrm), methylprednisolone (Met; 5.0 mg/kg/day, sc, for 5 days/week), Met plus Aln orally (1.0 mg/kg/day), and Met plus SrR orally (900 mg/kg/day). The study period was 9 weeks. DXA was used to evaluate the femoral diaphysis and fifth lumbar vertebra (L5). Histomorphometry was performed in the proximal tibial metaphysis and tibial diaphysis. Met significantly decreased body weight and bone mineral density (BMD) compared with Nrm. Aln and SrR significantly increased body weight and BMD compared with Met. SrR resulted in significantly higher BMD than Aln. Met markedly decreased BV/TV, Tb.Th, and Tb.N and increased Tb.Sp compared with Nrm. Aln and SrR showed significantly increased of BV/TV, Tb.Th, and Tb.N and improved bone architecture. Moreover, Met reduced %Ct.Ar, enlarged %Ma.Ar, and decreased bone formation indices in the periosteum as well as increased ES/BS in the endosteum compared with Nrm. Aln significantly decreased endosteal ES/BS compared with Met. SrR significantly increased %Ct.Ar and bone formation indices in the periosteum as well as the endosteum and decreased endosteal ES/BS compared with Met. Furthermore, SrR led to a significantly higher cancellous and endocortical MS/BS and endocortical bone formation compared with Aln. Our findings suggest SrR at a dose of 900 mg/kg has a greater effect than Aln at 1.0 mg/kg, according to BMD and histomorphometric analysis, in preventing GC-induced osteopenia. Therefore, SrR might be applicable as a bone therapeutic agent to treat secondary osteoporosis in the clinic. PMID:20390406

  20. Effects of Habitual Physical Activity and Fitness on Tibial Cortical Bone Mass, Structure and Mass Distribution in Pre-pubertal Boys and Girls: The Look Study.

    Science.gov (United States)

    Duckham, Rachel L; Rantalainen, Timo; Ducher, Gaele; Hill, Briony; Telford, Richard D; Telford, Rohan M; Daly, Robin M

    2016-07-01

    Targeted weight-bearing activities during the pre-pubertal years can improve cortical bone mass, structure and distribution, but less is known about the influence of habitual physical activity (PA) and fitness. This study examined the effects of contrasting habitual PA and fitness levels on cortical bone density, geometry and mass distribution in pre-pubertal children. Boys (n = 241) and girls (n = 245) aged 7-9 years had a pQCT scan to measure tibial mid-shaft total, cortical and medullary area, cortical thickness, density, polar strength strain index (SSIpolar) and the mass/density distribution through the bone cortex (radial distribution divided into endo-, mid- and pericortical regions) and around the centre of mass (polar distribution). Four contrasting PA and fitness groups (inactive-unfit, inactive-fit, active-unfit, active-fit) were generated based on daily step counts (pedometer, 7-days) and fitness levels (20-m shuttle test and vertical jump) for boys and girls separately. Active-fit boys had 7.3-7.7 % greater cortical area and thickness compared to inactive-unfit boys (P < 0.05), which was largely due to a 6.4-7.8 % (P < 0.05) greater cortical mass in the posterior-lateral, medial and posterior-medial 66 % tibial regions. Cortical area was not significantly different across PA-fitness categories in girls, but active-fit girls had 6.1 % (P < 0.05) greater SSIpolar compared to inactive-fit girls, which was likely due to their 6.7 % (P < 0.05) greater total bone area. There was also a small region-specific cortical mass benefit in the posterior-medial 66 % tibia cortex in active-fit girls. Higher levels of habitual PA-fitness were associated with small regional-specific gains in 66 % tibial cortical bone mass in pre-pubertal children, particularly boys.

  1. Intra- and inter-observer variation in histological criteria used in age at death determination based on femoral cortical bone

    DEFF Research Database (Denmark)

    Lynnerup, N; Thomsen, J L; Frohlich, B

    1998-01-01

    The microscopic method of age at death determination was introduced by Kerley in 1965. The method, which relies on the quantification of selected elements in cortical bone tissue, has been widely used, and several other researchers have modified or added to the method. Yet, very few studies have...... been carried out dealing with the intra- and inter-observer error. Furthermore, when such studies have been completed, the statistical tools for assessing variability have not been adequate. This study presents the results of applying simple quantitative statistics on several counts of microscopic......, precluding the use of osteon fragments and Haversian canals. The observers in this study included experienced and inexperienced users of the microscopic method, yet the variability was uniformly large for all observers, suggesting fundamental problems in definition and identification of the structural...

  2. Investigation of the effect of movement and irrigation systems on temperature in the conventional drilling of cortical bone.

    Science.gov (United States)

    Gehrke, Sergio Alexandre; Loffredo Neto, Henrique; Mardegan, Fábio E C

    2013-12-01

    We have compared the results of the external irrigation technique with those of a double irrigation technique with continuous intermittent movement. Maximum thermal measurements were made in the cortical part of 10 samples of bovine ribs during osteotomy to simulate the preparation of a surgical bed for the installation of dental implants at a depth of 10 mm. Twenty specimens were drilled for each group: external irrigation and continuous movement (control group 1, CG1); external irrigation and intermittent movement (control group 2, CG2); double irrigation and continuous movement (test group 1, TG1); and double irrigation and intermittent movement (test group 2, TG2). The double irrigation technique gave significantly better results regardless of the drilling movement used. Thermal increases between samples was 19.2% in group CG1, 10.4% in CG2, 5.4% in TG1, and 3.4% in TG2. The double irrigation technique produced a significantly smaller increase in temperature in the cortical bone during both types of drilling (p=0.001), which illustrated its greater efficiency compared with that of the external irrigation technique.

  3. Short-term and long-term site-specific effects of tennis playing on trabecular and cortical bone at the distal radius.

    Science.gov (United States)

    Ducher, Gaële; Tournaire, Nicolas; Meddahi-Pellé, Anne; Benhamou, Claude-Laurent; Courteix, Daniel

    2006-01-01

    Mechanical loading during growth magnifies the normal increase in bone diameter occurring in long bone shafts, but the response to loading in long bone ends remains unclear. The aim of the study was to investigate the effects of tennis playing during growth at the distal radius, comparing the bone response at trabecular and cortical skeletal sites. The influence of training duration was examined by studying bone response in short-term (children) and long-term (young adults) perspectives. Bone area, bone mineral content (BMC), and bone mineral density (BMD) of the radius were measured by DXA in 28 young (11.6 +/- 1.4 years old) and 47 adult tennis players (22.3 +/- 2.7 years old), and 70 age-matched controls (12 children, 58 adults) at three sites: the ultradistal region (trabecular), the mid-distal region, and the third-distal region (cortical). At the ultradistal radius, young and adult tennis players displayed similar side-to-side differences, the asymmetry in BMC reaching 16.3% and 13.8%, respectively (P < 0.0001). At the mid- and third-distal radius, the asymmetry was much greater in adults than in children (P < 0.0001) for all the bone parameters (mid-distal radius, +6.6% versus +15.6%; third-distal radius, +6.9% versus +13.3%, for BMC). Epiphyseal bone enduring longitudinal growth showed a great capacity to respond to mechanical loading in children. Prolonging tennis playing into adulthood was associated with further increase in bone mineralization at diaphyseal skeletal sites. These findings illustrate the benefits of practicing impact-loading sports during growth and maintaining physical activity into adulthood to enhance bone mass accrual and prevent fractures later in life.

  4. Computed tomography evaluation of human mandibles with regard to layer thickness and bone density of the cortical bone; Computertomografische Auswertung von humanen Unterkiefern hinsichtlich der Schichtstaerke und Knochendichte der Kortikalis

    Energy Technology Data Exchange (ETDEWEB)

    Markwardt, Jutta [TU Dresden Universitaetsklinikum (Germany). Klinik und Poliklinik fuer MKG-Chirurgie; Meissner, H.; Weber, A.; Reitemeier, B. [TU Dresden Universitaetsklinikum (Germany). Poliklinik fuer Zahnaerztliche Prothetik; Laniado, M. [TU Dresden Universitaetsklinikum (Germany). Inst. und Poliklinik fuer Radiologische Diagnostik

    2013-01-15

    Application of function-restoring individual implants for the bridging of defects in mandibles with continuity separation requires a stable fixation with special use of the cortical bone stumps. Five section planes each of 100 computed tomographies of poly-traumatized patients' jaws were used for measuring the thickness of the cortical layer and the bone density of the mandible. The CT scans of 28 female and 72 male candidates aged between 12 and 86 years with different dentition of the mandible were available. The computed tomographic evaluations of human mandibles regarding the layer thickness of the cortical bone showed that the edge of the mandible in the area of the horizontal branch possesses the biggest layer thickness of the whole of the lower jaws. The highest medians of the cortical bone layer thickness were found in the area of the molars and premolars at the lower edge of the lower jaws in 6-o'clock position, in the area of the molars in the vestibular cranial 10-o'clock position and in the chin region lingual-caudal in the 4-o'clock position. The measurement of the bone density showed the highest values in the 8-o'clock position (vestibular-caudal) in the molar region in both males and females. The average values available of the bone density and the layer thickness of the cortical bone in the various regions of the lower jaw, taking into consideration age, gender and dentition, are an important aid in practice for determining a safe fixation point for implants in the area of the surface layer of the mandible by means of screws or similar fixation elements. (orig.)

  5. Mechanical tests on the reconstructed anterior cruciate ligament fixed with allogenetic cortical bone cross-pin on the femoral side

    Institute of Scientific and Technical Information of China (English)

    Liu Chang; Liu Yujie; Zhang Yingze; Qu Feng; Li Shuyuan; Wang Junliang; Qi Wei

    2014-01-01

    Background Anterior cruciate ligament reconstruction (ACLR) has developed dramatically in the last century.Now,ACLR has become a reliable and productive procedure.Patients feel satisfied in >90% cases.The aim of this study was to evaluate the feasibility of allogenetic cortical bone cross-pin (ACBCP) used as a clinical fixation method in anterior cruciate ligament reconstruction on the femoral side based on biomechanical tests in vitro.Methods The specimens were provided by the bone banks of the First Affiliated Hospital of People's Liberation Army of General Hospital from September 2011 to June 2012.Fresh deep frozen human allogenetic cortical bone was machined into cross-pins which is 4.0 mm in diameter and 75.0 mm in length.Biomechanical parameters compared with Rigidfix were collected while cross-pins were tested in double-shear test.The load-to-failure test and cycling test were carried out in a goat model to reconstruct anterior cruciate ligament with Achilles tendon autograft on the femoral side fixed by human 4.0 mm ACBCP and 3.3 mm Rigidfix served as control.Maximum failure load,yield load,and stiffness of fixation in single load-to-failure test were compared between the two groups.Cycle-specific stiffness and displacement at cycles 1,30,200,400,and 1 000 were also compared in between.Results In double-shear test both maximum failed load and yield load of 4.0 mm humanACBCP were (1 236.998±201.940) N.Maximum failed load and yield load of Rigidfix were (807.929±110.511) N and (592.483±58.821) N.The differences of maximum failed load and yield load were significant between ACBCP and Rigidfix,P <0.05.The shear strength of ACBCP and Rigidfix were (49.243±8.039) MPa and (34.637±3.439) MPa,respectively,P <0.05.In the load-to-failure test ex vivo,yield load and maximum failed load of ACBCP fixation complexity ((867.104±132.856)N,(1 032.243±196.281) N) were higher than those of Rigidfix ((640.935±42.836) N,(800.568±64.890) N,P <0.05).However

  6. Selective Retention of Bone Marrow-Derived Cells to Enhance Spinal Fusion

    OpenAIRE

    Muschler, George F.; Matsukura, Yoichi; Nitto, Hironori; Boehm, Cynthia A.; Valdevit, Antonio D.; Kambic, Helen E.; Davros, William J.; Easley, Kirk A.; Powell, Kimerly A.

    2005-01-01

    Connective tissue progenitors can be concentrated rapidly from fresh bone marrow aspirates using some porous matrices as a surface for cell attachment and selective retention, and for creating a cellular graft that is enriched with respect to the number of progenitor cells. We evaluated the potential value of this method using demineralized cortical bone powder as the matrix. Matrix alone, matrix plus marrow, and matrix enriched with marrow cells were compared in an established canine spinal ...

  7. Cortical bone thickness in the buccal posterior region of the upper and lower jaw for orthodontic mini-implants%后牙区颊侧牙槽骨微植体支抗植入区域骨皮质厚度CBCT测量分析

    Institute of Scientific and Technical Information of China (English)

    王谋; 张定铭; 周建萍; 戴红卫

    2012-01-01

    Objective:To evaluate the thickness of buccal cortical bone at different height in posterior area of maxilla and mandible where mini-plants was inserted. Methods-.Thirty cone-beam CT(CBCT) images were selected from the Affilited Stomatology Hospital, Chongqing Medical University. Thickness of cortical bone between canine distal and second molar mesial at the height of 3,5, and 7 mm from the alveolar crest was determined. The data were analyzed statistically. Results-.The thickness of buccal cortical bone in the mandible posterior area was greater than that of maxilla(P<0.001). Between canine and first molar in maxilla the thickness was the minimum at the height of 5 mm from the alveolar crest.The thickness of cortical bone between first molar and second molar in maxilla and mandible became greater along with the distance increase from the alveolar crest. Conclusion:The thickness of buccal cortical bone changes along with the position changing sagittally and vertically, which should be considered in mini-plants implantation. Between canine and first molar in maxilla,a position as far from or close to the alveolar crest as possible is optimal,while in mandible and between first molar and second molar in maxilla,a position as far from the alveolar crest as possible is the best.%目的:通过对上下颌骨后牙区颊侧在不同高度下的骨皮质厚度进行测量和统计分析,为选择微植体支抗植入的最适位点提供理论依据,提高植入后的稳定性.方法:选择重庆医科大学附属口腔医院正畸科患者锥形束CT(Cone-beam CT,CBCT)影像资料30例,测量上下颌骨尖牙远中到第二磨牙间根间区距牙槽嵴顶3、5、7 mm位点处骨皮质厚度,并对测量数据进行统计分析.结果:下颌后牙区颊侧骨皮质厚度大于上颌(P<O.001),上颌在尖牙到第一磨牙间骨皮质厚度在距离牙槽嵴顶5mm处最小,下颌及上颌第一磨牙和第二磨牙间颊侧骨皮质随距牙槽嵴顶增大而增大.

  8. Curcumin deteriorates trabecular and cortical bone in mice bearing metastatic Lewis lung carcinoma

    Science.gov (United States)

    Bone is a major target of metastasis for many malignancies; curcumin has been studied for its role in cancer prevention including early phase clinical trials for its efficacy and safe use with cancer patients. The present study investigated the effects of dietary supplementation with curcumin (2% a...

  9. Curcumin reduces trabecular and cortical bone in naive and Lewis lung carcinoma-bearing mice

    Science.gov (United States)

    The present study investigated the effects of dietary supplementation with curcumin on bone microstructural changes in female C57BL/6 mice in the presence or absence of Lewis lung carcinoma. Morphometric analysis showed that in tumor-bearing mice curcumin at 2% and 4% dietary levels (w/w) significa...

  10. Relating age and micro-architecture with apparent-level elastic constants: a micro-finite element study of female cortical bone from the anterior femoral midshaft.

    Science.gov (United States)

    Donaldson, F E; Pankaj, P; Cooper, D M L; Thomas, C D L; Clement, J G; Simpson, A H R W

    2011-06-01

    Homogenized elastic properties are often assumed for macro-finite element (FE) models used in orthopaedic biomechanics. The accuracy of material property assignments may have a strong effect on the ability of these models to make accurate predictions. For cortical bone, most macro-scale FE models assume isotropic elastic material behaviour and do not include variation of material properties due to bone micro-architecture. The first aim of the present study was to evaluate the variation of apparent-level (homogenized) orthotropic elastic constants of cortical bone with age and indices of bone micro-architecture. Considerable age-dependent differences in porosity were noted across the cortical thickness in previous research. The second aim of the study was to quantify the resulting differences in elastic constants between the periosteum and endosteum. Specimens were taken from the anterior femoral midshaft of 27 female donors (age 53.4 +/- 23.6 years) and micro-FE (gFE) analysis was used to derive orthotropic elastic constants. The variation of orthotropic elastic constants (Young's moduli, shear moduli, and Poisson's ratios) with various cortical bone micro-architectural indices was investigated. The ratio of canal volume to tissue volume, Ca.V/TV, analogous to porosity, was found to be the strongest predictor (r2(ave) = 0.958) of the elastic constants. Age was less predictive (r2(ave) = 0.385) than Ca.V/TV. Elastic anisotropy increased with increasing Ca.V/TV, leading to lower elastic moduli in the transverse, typically less frequently loaded, directions. Increased Ca.V/TV led to a more substantial reduction in elastic constants at the endosteal aspect than at the periosteal aspect. The results are expected to be most applicable in similar midshaft locations of long bones; specific analysis of other sites would be necessary to evaluate elastic properties elsewhere. It was concluded that Ca.V/TV was the most predictive of cortical bone elastic constants and that

  11. Canine Distemper

    Science.gov (United States)

    Although this brochure provides basic information about canine distemper, your veterinarian is always your best source of ... Consult your veterinarian for more information about canine distemper and its prevention. And Now A Note On ...

  12. Radiographic evaluation of the symphysis menti as a donor site for an autologous bone graft in pre-implant surgery

    Energy Technology Data Exchange (ETDEWEB)

    Bari, Roberto Di; Cicconetti, Andrea [Dept. of Oral and Maxillofacial Sciences, School of Dentistry, Sapienza University of Rome, Rome (Italy); Coronelli, Roberto [Dr. Coronelli Dental Clinic, Rome (Italy)

    2013-09-15

    This study was performed to obtain a quantitative evaluation of the cortical and cancellous bone graft harvestable from the mental and canine regions, and to evaluate the cortical vestibular thickness. This study collected cone-beam computed tomographic (CBCT) images of 100 Italian patients. The limits of the mental region were established: 5 mm in front of the medial margin of each mental foramen, 5 mm under the apex of each tooth present, and above the inferior mandibular cortex. Cortical and cancellous bone volumes were evaluated using SimPlant software (SimPlant 3-D Pro, Materialize, Leuven, Belgium) tools. In addition, the cortical vestibular thickness (minimal and maximal values) was evaluated in 3 cross-sections corresponding to the right canine tooth (3R), the median section (M), and the left canine tooth (3L). The cortical volume was 0.71±0.23 mL (0.27-1.96 mL) and the cancellous volume was 2.16±0.76 mL (0.86-6.28 mL). The minimal cortical vestibular thickness was 1.54±0.41 mm (0.61-3.25 mm), and the maximal cortical vestibular thickness was 3.14±0.75mm(1.01-5.83 mm). The use of the imaging software allowed a patient-specific assessment of mental and canine region bone availability. The proposed evaluation method might help the surgeon in the selection of the donor site by the comparison between bone availability in the donor site and the reconstructive exigency of the recipient site.

  13. An alternative ultrasonic method for measuring the elastic properties of cortical bone

    CERN Document Server

    Pithioux, M; Chabrand, P; Pithioux, Martine

    2002-01-01

    We studied the elastic properties of bone to analyze its mechanical behavior. The basic principles of ultrasonic methods are now well established for varying isotropic media, particularly in the field of biomedical engineering. However, little progress has been made in its application to anisotropic materials. This is largely due to the complex nature of wave propagation in these media. In the present study, the theory of elastic waves is essential because it relates the elastic moduli of a material to the velocity of propagation of these waves along arbitrary directions in a solid. Transducers are generally placed in contact with the samples which are often cubes with parallel faces that are difficult to prepare. The ultrasonic method used here is original, a rough preparation of the bone is sufficient and the sample is in rotation. Moreover, to analyze heterogeneity of the structure we measure velocities in different points on the sample. The aim of the present study was to determine in vitro the anisotropi...

  14. Evaluation of cortical bone mass, thickness and density by z-scores in osteopenic conditions and in relation to menopause and estrogen treatment

    International Nuclear Information System (INIS)

    Z-scores express, differences from normals in standard deviation units, and are particularly useful for comparison of changes where normal values are age- and sex-dependent. We determined z-scores for bone mineral mass, cortical thickness, and bone mineral density in the radius in various conditions and diseases in both sexes. In the males, z-scores were calculated for age, but in the females z-scores for menopausal status (years postmenopausal exclusive of years on estrogen treatment) were found to be more appropriate. With few exceptions, changes in a disease were of a similar order in both sexes. For bone minerals mass few mean z-scores were significantly increased, but diseases with significantly decreased mean z-scores were numerous. The usefulness of z-scores in diagnosis and study of metabolic bone disease is discussed. (orig.)

  15. Comparison of interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns using cone-beam computed tomography

    Science.gov (United States)

    Khumsarn, Nattida; Patanaporn, Virush; Jotikasthira, Dhirawat

    2016-01-01

    Purpose This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Materials and Methods Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at p<0.05. Results Patients with a Class II skeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. Conclusion In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns. PMID:27358819

  16. Influence of the pulse frequency and water cooling on the femtosecond laser ablation of bovine cortical bone

    International Nuclear Information System (INIS)

    Ultrafast lasers are extremely promising tools for minimally-invasive orthopedic surgery, but the ablated volumes per pulse are low, so a high pulse frequency is necessary to reach practical ablation rates. The purpose of this work was to study in vitro the influence of the pulse repetition rate on the ablation rate, surface topography and surface composition of bone using of bovine cortical femur as a model. The tests were carried out by scanning the laser beam in relation to the sample, using pulse frequencies between 50 and 3000 Hz, scanning velocities from 0.5 to 10 mm/s and average pulse energy of 650 μJ. The experiments were performed in dry conditions and with water irrigation. The higher ablation rates were obtained at high scanning velocity without water irrigation but severe thermal effects such as resolidification, cracking and, eventually, carbonization occurred in these conditions due to heat accumulation in the tissue. Thermal damage was avoided for all the laser processing parameters ranges tested by using water cooling. The highest ablation rate achieved was 1.4 mm3/min for a scanning velocity of 10 mm/s at 2 kHz pulse repetition rate under water irrigation.

  17. Fracture mechanics of human cortical bone: The relationship of geometry, microstructure and composition with the fracture of the tibia, femoral shaft and the femoral neck

    Science.gov (United States)

    Yeni, Yener Nail

    influence of bone quality, i.e., mineralization, water content, osteon size, area and number, microdamage and crystallinity differed between different locations, age groups and fracture mode. Fracture toughness was also significantly correlated with clinical parameters such as cortical index and Singh index, significance level being dependent upon bone location, fracture mode and age. Several mechanistic models to predict how bone microstructure influences bone fracture toughness were proposed based on experimental results and available literature.

  18. The effect of excitation and preparation pulses on nonslice selective 2D UTE bicomponent analysis of bound and free water in cortical bone at 3T

    Energy Technology Data Exchange (ETDEWEB)

    Li, Shihong [Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Department of Radiology, Hua Dong Hospital, Fudan University, Shanghai 200040 (China); Yancheng Medical College, Jiangsu (China); The First People' s Hospital of Yancheng City, Jiangsu 224005 (China); Chang, Eric Y.; Chung, Christine B. [VA San Diego Healthcare System, San Diego, California 92161 and Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Bae, Won C.; Du, Jiang, E-mail: jiangdu@ucsd.edu [Department of Radiology, University of California, San Diego, California 92103-8226 (United States); Hua, Yanqing [Department of Radiology, Hua Dong Hospital, Fudan University, Shanghai 200040 (China); Zhou, Yi [The First People' s Hospital of Yancheng City, Jiangsu 224005 (China)

    2014-02-15

    Purpose: The purpose of this study was to investigate the effect of excitation, fat saturation, long T2 saturation, and adiabatic inversion pulses on ultrashort echo time (UTE) imaging with bicomponent analysis of bound and free water in cortical bone for potential applications in osteoporosis. Methods: Six bovine cortical bones and six human tibial midshaft samples were harvested for this study. Each bone sample was imaged with eight sequences using 2D UTE imaging at 3T with half and hard excitation pulses, without and with fat saturation, long T2 saturation, and adiabatic inversion recovery (IR) preparation pulses. Single- and bicomponent signal models were utilized to calculate the T2{sup *}s and/or relative fractions of short and long T2{sup *}s. Results: For all bone samples UTE T2{sup *} signal decay showed bicomponent behavior. A higher short T2{sup *} fraction was observed on UTE images with hard pulse excitation compared with half pulse excitation (75.6% vs 68.8% in bovine bone, 79.9% vs 73.2% in human bone). Fat saturation pulses slightly reduced the short T2{sup *} fraction relative to regular UTE sequences (5.0% and 2.0% reduction, respectively, with half and hard excitation pulses for bovine bone, 6.3% and 8.2% reduction, respectively, with half and hard excitation pulses for human bone). Long T2 saturation pulses significantly reduced the long T2{sup *} fraction relative to regular UTE sequence (18.9% and 17.2% reduction, respectively, with half and hard excitation pulses for bovine bone, 26.4% and 27.7% reduction, respectively, with half and hard excitation pulses for human bone). With IR-UTE preparation the long T2{sup *} components were significantly reduced relative to regular UTE sequence (75.3% and 66.4% reduction, respectively, with half and hard excitation pulses for bovine bone, 87.7% and 90.3% reduction, respectively, with half and hard excitation pulses for human bone). Conclusions: Bound and free water T2{sup *}s and relative fractions can

  19. Fetal and neonatal exposure to the endocrine disruptor, methoxychlor, reduces lean body mass and bone mineral density and increases cortical porosity.

    Science.gov (United States)

    Fagnant, Heather S; Uzumcu, Mehmet; Buckendahl, Patricia; Dunn, Michael G; Shupper, Peter; Shapses, Sue A

    2014-12-01

    Endogenous estrogen has beneficial effects on mature bone and negatively affects the developing skeleton, whereas the effect of environmental estrogens is not known. Methoxychlor (MXC) is a synthetic estrogen known as a persistent organochlorine and used as a pesticide. Methoxychlor and its metabolites display estrogenic, anti-estrogenic and anti-androgenic activity and may therefore influence bone. Fifty-eight male fetal and neonatal rats were exposed to either: a negative control (DMSO), 0.020, 100 mg/kg MXC, or 1 mg/kg β-estradiol-3-benzoate (EB; positive control). Rats were treated daily for 11 days, from embryonic day 19 to postnatal day (PND) 7 or for 4 days during the postnatal period (PND 0-7). All rats were analyzed at PND-84. Total body, femur, spine, and tibia areal bone mineral density (BMD) and content (BMC), lean body mass (LBM) and fat were measured by dual energy X-ray absorptiometry. Bone geometry and volumetric (v) BMD were measured using micro-computed tomography and biomechanical properties using three-point bending were assessed. Rats exposed to EB or MXC (at either the high and/or low dose), independent of exposure interval showed lower body weight, LBM, tibia and femur BMD and length, and total body BMD and BMC than DMSO control group (p ≤ 0.05). Methoxychlor and EB exposure increased cortical porosity compared to DMSO controls. Trabecular vBMD, number and separation, and cortical polar moment of inertia and cross-sectional area were lower due to EB exposure compared to control (p < 0.05). Early MXC exposure compromises cortical porosity and bone size at maturity, and could ultimately increase the risk of fracture with aging.

  20. BMP2基因修饰犬脂肪源性基质细胞修复自体大段骨缺损%Repairing canine segmental bone defects using BMP2 gene modified adipose-derived stromal cells

    Institute of Scientific and Technical Information of China (English)

    李慧武; 戴尅戎; 汤亭亭; 张晓玲; 唐坚; 孙晓江; 张双燕; 楼觉人

    2008-01-01

    Objective To evaluate osteogenetic effectiveness of porous β-tricalcium phosphate(β-TCP) ceramic mixed with human bone morphogenetic protein2 gene(Adv-hBMP2)modified adipose derived stromal cells (ADSCs) in the repair of critical-sized bone defects..Methods The ADSCs taken from the back of beagle dogs were modified by the BMP2 gene.The expression and bone-induction ability of BMP2 was identified by ELISA and ectopic bone formation in nude mice.The cells were applied to a β-tricalcium phosphate (TGP)carrier and implanted into ulnar bone defects in the canine model.18 ulnar bone defects were divided into three groups randomly and filled with granular TCP alone,granular TCP and ADSCs,or TCP and ADSCs transduced with Adv-hBMP2 respectively.All dogs were followed clinically and roentgenographically for 16 weeks and then sacrificed.Results ELISA and ectopic bone formation in nude mice showed the recombinant ADSCs could express BMP2 highly and stably.No bone defects healed after implanting granular TCP alone or granular TCP and ADSCs.In the TCP and ADSCs transduced with AdvhBMP2 group,two defects healed,four partly healed.Histological examination showed woven bone at the both end of the cortices but entirelv fibrous tissue in the middle in which defects filled with TCP alone or TCP and ADSCs.Defects filled with TCP and transduced ADSCs showed substatial new bone formation.Histomorphometry showed TCP combined with ADSCs did not significantly increase new bone area compared with TCP alone.TCP and recombinant ADSCs produced a significant increase in newly formed bone area.Conclusion ADSCs tansduced with BMP2 gene in a TCP carrier can enhance bone regeneratmn to repair the critically-sized bone defect.%目的 评价BMP2基因修饰的犬脂肪源性基质细胞(ADSCs)与β-磷酸三钙(β-TCP)复合修复自体大段骨缺损的疗效.方法 从比格犬背部脂肪组织中提取基质细胞,转染腺病毒介导的人BMP2基因(Adv-hBMP2),通过ELISA和裸鼠体

  1. MRI of the temporo-mandibular joint: which sequence is best suited to assess the cortical bone of the mandibular condyle? A cadaveric study using micro-CT as the standard of reference

    Energy Technology Data Exchange (ETDEWEB)

    Karlo, Christoph A. [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); University Children' s Hospital Zurich, Department of Diagnostic Imaging, Zurich (Switzerland); Patcas, Raphael; Signorelli, Luca; Mueller, Lukas [University of Zurich, Clinic for Orthodontics and Pediatric Dentistry, Center of Dental Medicine, Zurich (Switzerland); Kau, Thomas; Watzal, Helmut; Kellenberger, Christian J. [University Children' s Hospital Zurich, Department of Diagnostic Imaging, Zurich (Switzerland); Ullrich, Oliver [University of Zurich, Institute of Anatomy, Faculty of Medicine, Zurich (Switzerland); Luder, Hans-Ulrich [University of Zurich, Section of Orofacial Structures and Development, Center of Dental Medicine, Zurich (Switzerland)

    2012-07-15

    To determine the best suited sagittal MRI sequence out of a standard temporo-mandibular joint (TMJ) imaging protocol for the assessment of the cortical bone of the mandibular condyles of cadaveric specimens using micro-CT as the standard of reference. Sixteen TMJs in 8 human cadaveric heads (mean age, 81 years) were examined by MRI. Upon all sagittal sequences, two observers measured the cortical bone thickness (CBT) of the anterior, superior and posterior portions of the mandibular condyles (i.e. objective analysis), and assessed for the presence of cortical bone thinning, erosions or surface irregularities as well as subcortical bone cysts and anterior osteophytes (i.e. subjective analysis). Micro-CT of the condyles was performed to serve as the standard of reference for statistical analysis. Inter-observer agreements for objective (r = 0.83-0.99, P < 0.01) and subjective ({kappa} = 0.67-0.88) analyses were very good. Mean CBT measurements were most accurate, and cortical bone thinning, erosions, surface irregularities and subcortical bone cysts were best depicted on the 3D fast spoiled gradient echo recalled sequence (3D FSPGR). The most reliable MRI sequence to assess the cortical bone of the mandibular condyles on sagittal imaging planes is the 3D FSPGR sequence. (orig.)

  2. Sequential Fluorescent Labeling Observation of Maxillary Sinus Augmentation by a Tissue-engineered Bone Complex in Canine Model

    Institute of Scientific and Technical Information of China (English)

    Xin-quan Jiang; Shao-yi Wang; Jun Zhao; Xiu-li Zhang; Zhi-yuan Zhang

    2009-01-01

    Aim To evaluate the effects of maxillary sinus floor elevation by a tissue-engineered bone complex of β-tricalcium phosphate (β-TCP) and autologous osteoblasts in dogs. Methodology Autologous osteoblasts from adult Beagle dogs were cultured in vitro. They were further combined with β-TCP to construct the tissue-engineered bone complex. 12 cases of maxillary sinus floor elevation surgery were made bilaterally in 6 animals and randomly repaired with the following 3 groups of materials: Group A (osteoblasts/β-TCP); Group B (β-TCP); Group C (autogenous bone) (n-4 per group). A polychrome sequential fluorescent labeling was performed post-operatively and the animals were sacrificed 24 weeks after operation for histological observation.Results Our results showed that autologous osteoblasts were successfully expanded and the osteoblastic phenoltypes were confirmed by ALP and Alizarin red staining. The cells could attach and proliferate well on the surface of the β-TCP scaffold. The fluorescent and histological observation showed that the tissue-engineered bone complex had an earlier mineralization and more bone formation inside the scaffold than β-TCP along or even autologous bone. It had also maximally maintained the elevated sinus height than both control groups. Conclusion Porous β-TCP has served as a good scaffold for autologous osteoblasts seeding. The tissue-engineered bone complex with β-TCP and autologous osteoblasts might be a better alternative to autologous bone for the clinical edentulous maxillary sinus augmentation.

  3. INAA applications in the age dynamics assessment of Ca, Cl, K, Mg, Mn, Na, P, and Sr contents in the cortical bone of human Iliac crest

    International Nuclear Information System (INIS)

    Full text: Senile osteoporosis and particularly osteoporosis among postmenopausal women represents an urgent problem of modern medicine. The effect of age and sex on chemical element contents in intact cortical bone of iliac crest of 80 relatively healthy 15-55 years old women (n=36) and men (n=44) was investigated. All subjects had died suddenly and bone samples were obtained at necropsy from the right side within twenty-four hours after death. A tool made of titanium and plastic was used to clear samples from soft tissues and blood and to cut cortical part of bone. The IAEA and NIST reference materials (H-5 animal bone and SRM1486 bone meal) were used to estimate the precision and accuracy of results. Contents of Ca, Cl, K, Mg, Mn, Na, P, and Sr in intact bone samples were determined by instrumental neutron activation analysis using short-lived radionuclides. Our mean data for each element of reference materials were within the certified 95% confidence interval, and indicate an acceptable accuracy of the obtained results. Mean values (M ±S.E.M.) for mass fraction of the investigated elements (on dry weight basis) for female and male all together were: 20.8 ± 0.3%, 1390 ± 55 μg/g, 746 ±41 μg/g, 2070 ±65 μg/g, <0.36 ± 0.02 μg/g, 5590 ± 1200 μg/g, 9.53 ± 1.7%, and 308 ± 18 μg/g respectively. The contents of elements such as Ca, Mg, and P in the cortical iliac crest tend to decrease with age to a certain degree for both women and men. This tendency is more pronounced for men. Sex-related comparison did not show any differences in Ca, Cl, Mg, Mn, Na, and Sr mass fractions. Statistical little significant (p≥0.05, t-test) higher mass fraction of P in the female and K in the male cortical iliac crest were found. (author)

  4. USO DO ENXERTO ÓSSEO CORTICAL BOVINO CONSERVADO EM GLICERINA A 98% NA OSTEOTOMIA FEMORAL EM GATOS USE BOVINE CORTICAL BONE, PRESERVED IN 98% GLICERIN IN FEMORAL OSTEOTOMY IN CATS.

    Directory of Open Access Journals (Sweden)

    Lucia Helena de Carvalho Penha

    2008-12-01

    . The objective of this study was to evaluate clinically and radiographically the efficacy of xenografts as a substitute for methalic implants. Animals were divided into two groups: five young cats and five adult cats. Clinically, the weight-bearing on the operated limb was observed the day after surgery in all animals, with complete remission of lameness at 15 days and bone union in 16.6 weeks. In five young animals, in two of them, the grafts were fractured carrying a serious bone bending without fracture of feline femur. In the last two young cats, remodeling was noted in mean time of 75 days or 10.7 weeks. In five adult cats, all of them suffered overriding of the fragments of osteotomized bone with various degrees, where two cases were considered severe cases dut to fracture of feline femur without bone bending. In the three remaining animals with slightly overriding, one was a case of delayed union, one suffered tow surgical procedures due to graft fracture and one did not show a radiographic exuberant bone callus, with remodeling at 110 days. The use of the bonive xenograft preserved in 98% glycerol in young and adult cats used as intramedularry nails was perfectly employed, offering mechanical support in time of bone consolidation in all of 10 animals.

    KEY WORDS: Cortical bovine graft, cats, femur, fracture, osteotomy.

  5. 皮质骨块加松质骨治疗牙槽嵴裂的临床研究%Clinical study on the treatment of alveolar cleft with cortical bone block affiliate with cancellous bone

    Institute of Scientific and Technical Information of China (English)

    陈恒丕; 王涛

    2013-01-01

    目的:牙槽嵴裂常与唇腭裂伴发,表现为牙槽嵴的骨质缺损。目前,自体髂骨移植治疗牙槽嵴裂是目前的最广泛治疗方式。但髂骨松质骨移植吸收率高,移植的最终治疗效果并不能完全满足临床要求。本研究采用皮质骨块加松质骨移植治疗牙槽嵴裂,了解是否能提高治疗效果。材料和方法:牙槽嵴裂患者21例,采用髂骨植骨,包括髂骨皮质骨块加骨松质移植和单纯松质骨移植两种方式。术后6个月,采用锥形束CT复查获取影像学资料,对比两种治疗方式的影像学资料中的牙槽骨的剩余量,确定治疗效果。结果:通过髂骨皮质骨块加松质骨移植后的牙槽骨的剩余量大于单纯松质骨移植的牙槽骨的剩余量。结论:对于治疗牙槽嵴裂,皮质骨块加松质骨移植作为一种治疗方法能够提高治疗效果。%Objective :Autologous bone grafts are widely used to treat alveolar cleft associated with cleft lip and palate , showing alveolar bone defects . However ,due to the high absorption rate of iliac cancellous bone grafts ,the clinical requirements are not fully satisfied .In this study ,cortical bone block affiliate with cancellous bone were used to treat alveolar cleft to determine whether there could be any improvement on therapeutic results .Materials and Methods :21 patients with alveolar cleft were treated with cortical bone block affiliate with cancellous bone grafts and cancellous bone grafts from iliac .Six months after the surgical procedures ,Cone-beam CT scanning were executed and the volume of bone of each type of the two treatment methods was calculated to find out the therapeutic results .Results :The volume of alveolar bone formed from cortical bone block affiliate with cancellous bone grafts is greater than cancellous bone grafts alone .Conclusions :For treatment of alveolar cleft ,cortical bone block affiliate with cancellous bone grafts is one method

  6. Results of screw fixation combined with cortical drilling for treatment of dorsal cortical stress fractures of the third metacarpal bone in 56 Thoroughbred racehorses

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate screw fixation with cortical drilling as a surgical treatment for dorsal cortical stress fractures of MCIII in the Thoroughbred racehorse. Details of age, sex, limb affected, fracture assessment, and post operative recommendations were obtained from medical records and radiographs. Fracture healing was assessed radiographically at the time of screw removal. Performance evaluation was determined from race records obtained from The Jockey Club Information System, Lexington, Kentucky. Fifty-six Thoroughbred racehorses were treated surgically for stress fracture of MCIII with screw fixation and cortical drilling. Stress fractures occurred primarily in the left front limb of the male 3-year-olds, in the dorsolateral cortex of the middle third of MCIII. Ninety-seven percent of the fractures travelled in a dorsodistal to palmaroproximal direction. Median period to screw removal was 2.0 months. Evaluation at time of screw removal revealed 98% of single stress fractures of the left front limb were healed radiographically. Median period to resume training was 2.75 months (single stress fractures); median period to race was 7.62 months. There was no statistically significant difference in earnings/start before and after surgical intervention. Of the 63 fractures treated, two recurred. There were no catastrophic failures, and no incisional infections

  7. Bone graft revascularization strategies

    NARCIS (Netherlands)

    W.F. Willems

    2014-01-01

    Reconstruction of avascular necrotic bone by pedicled bone grafting is a well-known treatment with little basic research supporting its application. A new canine model was used to simulate carpal bone avascular necrosis. Pedicled bone grafting proved to increase bone remodeling and bone blood flow,

  8. Uso de enxerto ósseo homólogo estrutural cortical em cirurgias de reconstrução femoral Use of cortical structural homologous bone graft in femoral reconstructive surgery

    Directory of Open Access Journals (Sweden)

    Milton Valdomiro Roos

    2010-01-01

    periprotéticas é uma boa opção de tratamento em casos selecionados, permitindo resultados clínicos e radiográficos satisfatórios.OBJECTIVE: To perform a clinical and radiographic assessment of patients submitted to cortical structural homologous bone graftsurgical treatment for femoral reconstruction following mechanical failure of total hip arthroplasty and periprosthetic fractures. METHODS: A retrospective study with 27 patients submitted to surgical treatment for femoral reconstruction following mechanical failure of total hip arthroplasty (12 cases and periprosthetic fractures (15 cases, using cortical structural homologous bone graft and cemented implants, in the period of June 1999 to February 2008 was performed. Of these, 21 fulfilled the criteria required for this study. Patients were submitted to a pre and postoperative clinical assessment according to Harris Hip Score. Pre-operative, immediate and late postoperative radiographs were also evaluated by comparing fracture consolidation, radiographic signs of graft integration, changes in bone stock and femoral bone quality, as well as femoral alignment. RESULTS: Nine patients (42.9% were submitted to femoral reconstruction following mechanical failure of total hip arthroplasty. The other 12 cases (57.1%, were submitted to femoral reconstruction following periprosthetic fracture. Results were considered satisfactory in 85.7% and unsatisfactory in 14.3% of cases. Radiographic signs of graft integration to the host's bone were seen in all cases. There was an increase of bone stock in 90.5% of hip reconstructions, according to cortical index measurement. Furthermore, changes in femoral bone quality were considered good in 66.7% of cases. CONCLUSION: The use of cortical structural homologous bone grafts for both femoral reconstructive surgeries of total hip arthroplasty and periprosthetic fractures is a good treatment option for selected cases, allowing for satisfactory clinical and radiographic results.

  9. Effect of weight-bearing exercise and calcium supplement on cortical and trabecular bone in the proximal tibia metaphyseal- an experimental protocol in ovariectomized rats

    Directory of Open Access Journals (Sweden)

    Valliollah Dabidy Roshan1

    2009-01-01

    Full Text Available (Received 4 April, 2009; Accepted 17 June, 2009AbstractBackground and purpose: Osteoporotic fractures are much more common in older post-menopausal women and account for significant morbidity and mortality. Although age is an independent risk factor for fractures, bone micro-architecture is the predictor of subsequent fractures. Adequate calcium and Weight-bearing exercise are known to affect skeletal development, however, the effects of calcium supplement and treadmill endurance running on bone micro-architecture are not well known. The objective of this study was to determine the effects of treadmill endurance running training and calcium supplement, on micro-architectures of cortical and trabecular bone in the proximal tibia metaphyseal in ovariectomized Sprague Dawley rats.Materials and methods: Forty-three rats were randomly divided into endurance running training, calcium supplement, control, pre-test and base groups. The rats in the treadmill running group performed the progressive running exercise in 12 to 20 m/minutes for a total of 10 to 60 minutes, 5 times a week. Calcium group received ca supplement using Gavage (35 mg/kg/day for 8 weeks. After 8 weeks, micro-architecture parameters in the proximal tibia metaphyseal were measured by using a semi-automated image analysis system.Results: The ovariectomay was associated with a significant decrease in the trabecular volume and thickness, while separation insignificantly decreased in the cortical volume and thickness in the proximal tibia metaphyseal. The treadmill running exercise and calcium supplement significantly increased cortical or trabecular volume and also thickness and the trabecular separation compared with age-matched controls. Furthermore, the micro-architectures of cortical and trabecular bone in the proximal tibia metaphyseal was insignificant between the treadmill endurance running and calcium supplement groups.Conclusion: Skeletal benefits can be obtained by changes in

  10. Histomorphometric Assessment of Cancellous and Cortical Bone Material Distribution in the Proximal Humerus of Normal and Osteoporotic Individuals: Significantly Reduced Bone Stock in the Metaphyseal and Subcapital Regions of Osteoporotic Individuals.

    Science.gov (United States)

    Sprecher, Christoph M; Schmidutz, Florian; Helfen, Tobias; Richards, R Geoff; Blauth, Michael; Milz, Stefan

    2015-12-01

    Osteoporosis is a systemic disorder predominantly affecting postmenopausal women but also men at an advanced age. Both genders may suffer from low-energy fractures of, for example, the proximal humerus when reduction of the bone stock or/and quality has occurred.The aim of the current study was to compare the amount of bone in typical fracture zones of the proximal humerus in osteoporotic and non-osteoporotic individuals.The amount of bone in the proximal humerus was determined histomorphometrically in frontal plane sections. The donor bones were allocated to normal and osteoporotic groups using the T-score from distal radius DXA measurements of the same extremities. The T-score evaluation was done according to WHO criteria. Regional thickness of the subchondral plate and the metaphyseal cortical bone were measured using interactive image analysis.At all measured locations the amount of cancellous bone was significantly lower in individuals from the osteoporotic group compared to the non-osteoporotic one. The osteoporotic group showed more significant differences between regions of the same bone than the non-osteoporotic group. In both groups the subchondral cancellous bone and the subchondral plate were least affected by bone loss. In contrast, the medial metaphyseal region in the osteoporotic group exhibited higher bone loss in comparison to the lateral side.This observation may explain prevailing fracture patterns, which frequently involve compression fractures and certainly has an influence on the stability of implants placed in this medial region. It should be considered when planning the anchoring of osteosynthesis materials in osteoporotic patients with fractures of the proximal humerus.

  11. Compressive mechanical compatibility of anisotropic porous Ti6Al4V alloys in the range of physiological strain rate for cortical bone implant applications.

    Science.gov (United States)

    Li, Fuping; Li, Jinshan; Kou, Hongchao; Huang, Tingting; Zhou, Lian

    2015-09-01

    Porous titanium and its alloys are believed to be promising materials for bone implant applications, since they can reduce the "stress shielding" effect by tailoring porosity and improve fixation of implant through bone ingrowth. In the present work, porous Ti6Al4V alloys for biomedical application were fabricated by diffusion bonding of alloy meshes. Compressive mechanical behavior and compatibility in the range of physiological strain rate were studied under quasi-static and dynamic conditions. The results show that porous Ti6Al4V alloys possess anisotropic structure with elongated pores in the out-of-plane direction. For porous Ti6Al4V alloys with 60-70 % porosity, more than 40 % pores are in the range of 200-500 μm which is the optimum pore size suited for bone ingrowth. Quasi-static Young's modulus and yield stress of porous Ti6Al4V alloys with 30-70 % relative density are in the range of 6-40 GPa and 100-500 MPa, respectively. Quasi-static compressive properties can be quantitatively tailored by porosity to match those of cortical bone. Strain rate sensitivity of porous Ti6Al4V alloys is related to porosity. Porous Ti6Al4V alloys with porosity higher than 50 % show enhanced strain rate sensitivity, which is originated from that of base materials and micro-inertia effect. Porous Ti6Al4V alloys with 60-70 % porosity show superior compressive mechanical compatibility in the range of physiological strain rate for cortical bone implant applications.

  12. Microcomputed tomographic analysis of human condyles in unilateral condylar hyperplasia: increased cortical porosity and trabecular bone volume fraction with reduced mineralisation.

    Science.gov (United States)

    Karssemakers, L H E; Nolte, J W; Tuinzing, D B; Langenbach, G E J; Raijmakers, P G; Becking, A G

    2014-12-01

    Unilateral condylar hyperplasia or hyperactivity is a disorder of growth that affects the mandible, and our aim was to visualise the 3-dimensional bony microstructure of resected mandibular condyles of affected patients. We prospectively studied 17 patients with a clinical presentation of progressive mandibular asymmetry and an abnormal single-photon emission computed tomographic (SPECT) scan. All patients were treated by condylectomy to arrest progression. The resected condyles were scanned with micro-CT (18 μm resolution). Rectangular volumes of interest were selected in 4 quadrants (lateromedial and superoinferior) of the trabecular bone of each condyle. Variables of bone architecture (volume fraction, trabecular number, thickness, and separation, degree of mineralisation, and degree of structural anisotrophy) were calculated with routine morphometric software. Eight of the 17 resected condyles showed clear destruction of the subchondral layer of cortical bone. There was a significant superoinferior gradient for all trabecular variables. Mean (SD) bone volume fraction (25.1 (6) %), trabecular number (1.69 (0.26) mm(-1)), trabecular thickness (0.17 (0.03) mm), and degree of mineralisation (695.39 (39.83) mg HA/cm(3)) were higher in the superior region. Trabecular separation (0.6 (0.16) mm) and structural anisotropy (1.84 (0.28)) were higher in the inferior region. The micro-CT analysis showed increased cortical porosity in many of the condyles studied. It also showed a higher bone volume fraction, greater trabecular thickness and trabecular separation, greater trabecular number, and less mineralisation in the condyles of the 17 patients compared with the known architecture of unaffected mandibular condyles. PMID:25219775

  13. Plasma rico em plaquetas para reparação de falhas ósseas em cães Platelet-rich plasma for canine bone restoration

    Directory of Open Access Journals (Sweden)

    Anna Laeticia Trindade Barbosa

    2008-08-01

    a protocol to PRP formulation and demonstrates some aspects about the use in canine bone repair. In this protocol blood was obtained from the jugular ven of tree adult dogs with medium weight of 20kg to produce PRP. Two defects in the medial aspect of proximal third of the tibia were surgically created to evaluate the clinical and radiographic aspect of PRP. The control defect wasn’t treated.The defect 2 was filled with 3 mg of autogenous bone graft from the tibia crest. The defect 3 was filled with PRP alone and the number 4 with PRP in the combination with 3mg autogenous bone graft. The proposed laboratory protocol demonstrated to be easy to execute at low cost. Further, it was adequate to concentrate platelets in final PRP, whose number was dependent on the blood from each dog. Comparing the defect regions, was concluded that the association of PRP and bone graft showed greater precocity and uniform radiopacity than the PRP or bone graft isolated, although both determine better results than the defect without treatment.

  14. Odanacatib Restores Trabecular Bone of Skeletally Mature Female Rabbits With Osteopenia but Induces Brittleness of Cortical Bone: A Comparative Study of the Investigational Drug With PTH, Estrogen, and Alendronate.

    Science.gov (United States)

    Khan, Mohd Parvez; Singh, Atul Kumar; Singh, Abhishek Kumar; Shrivastava, Pragya; Tiwari, Mahesh Chandra; Nagar, Geet Kumar; Bora, Himangshu Kousik; Parameswaran, Venkitanarayanan; Sanyal, Sabyasachi; Bellare, Jayesh R; Chattopadhyay, Naibedya

    2016-03-01

    Cathepsin K (CK), a lysosomal cysteine protease, is highly expressed in mature osteoclasts and degrades type 1 collagen. Odanacatib (ODN) is a selective and reversible CK inhibitor that inhibits bone loss in preclinical and clinical studies. Although an antiresorptive, ODN does not suppress bone formation, which led us to hypothesize that ODN may display restorative effect on the osteopenic bones. In a curative study, skeletally mature New Zealand rabbits were ovarectomized (OVX) and after induction of bone loss were given a steady-state exposure of ODN (9 mM/d) for 14 weeks. Sham-operated and OVX rabbits treated with alendronate (ALD), 17b-estradiol (E2), or parathyroid hormone (PTH) served as various controls. Efficacy was evaluated by assessing bone mineral density (BMD), bone microarchitecture (using micro-computed tomography), fluorescent labeling of bone, and biomechanical strength. Skeletal Ca/P ratio was measured by scanning electron microscopy (SEM) with X-ray microanalysis, crystallinity by X-ray diffraction, and bone mineral density distribution (tissue mineralization) by backscattered SEM. Between the sham and ODN-treated osteopenic groups, lumbar and femur metaphyseal BMD, Ca/P ratio, trabecular microstructure and geometric indices, vertebral compressive strength, trabecular lining cells, cortical parameters (femoral area and thickness and periosteal deposition), and serum P1NP were largely comparable. Skeletal improvements in ALD-treated or E2-treated groups fell significantly short of the sham/ODN/PTH group. However, the ODN group displayed reduced ductility and enhanced brittleness of central femur, which might have been contributed by higher crytallinity and tissue mineralization. Rabbit bone marrow stromal cells expressed CK and when treated with ODN displayed increased formation of mineralized nodules and decreased apoptosis in serum-deficient medium compared with control. In vivo, ODN did not suppress remodeling but inhibited osteoclast activity

  15. A new implementation of digital X-ray radiogrammetry and reference curves of four indices of cortical bone for healthy European adults

    DEFF Research Database (Denmark)

    Thodberg, Hans Henrik; Böttcher, Joachim; Lomholt, Jens;

    2016-01-01

    UNLABELLED: Digital X-ray radiogrammetry performs measurements on a hand radiograph in digital form. We present an improved implementation of the method and provide reference curves for four indices for the amount of bone. We collected 1662 hand radiographs of healthy subjects of age 9-100 years....... PURPOSE: The digital X-ray radiogrammetry (DXR) method has been shown to be efficient for diagnosis of osteoporosis and for assessment of progression of rheumatoid arthritis. The aim of this work is to present a new DXR implementation and reference curves of four indices of cortical bone and to compare...... health index (BHI) data are consistent with the Jena data and also with the published BHI reference for healthy children. BHI is found to have smaller relative SD than the other three indices in the Jena cohort over the age range 20-80 years. CONCLUSION: The new DXR method is an extension of the existing...

  16. Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells with Platelet-Rich Plasma Accelerate Distraction Osteogenesis in A Canine Model

    OpenAIRE

    2015-01-01

    Objective: Distraction osteogenesis (DO) is a surgical procedure used to generate large volumes of new bone for limb lengthening. Materials and Methods: In this animal experimental study, a 30% lengthening of the left tibia (mean distraction distance: 60.8 mm) was performed in ten adult male dogs by callus distraction after osteotomy and application of an Ilizarov fixator. Distraction was started on postoperative day seven with a distraction rate of 0.5 mm twice per day and car...

  17. Mid-thigh cortical bone structural parameters, muscle mass and strength, and association with lower limb fractures in older men and women (AGES-Reykjavik Study).

    Science.gov (United States)

    Johannesdottir, Fjola; Aspelund, Thor; Siggeirsdottir, Kristin; Jonsson, Brynjolfur Y; Mogensen, Brynjolfur; Sigurdsson, Sigurdur; Harris, Tamara B; Gudnason, Vilmundur G; Lang, Thomas F; Sigurdsson, Gunnar

    2012-05-01

    In a cross-sectional study we investigated the relationship between muscle and bone parameters in the mid-thigh in older people using data from a single axial computed tomographic section through the mid-thigh. Additionally, we studied the association of these variables with incident low-trauma lower limb fractures. A total of 3,762 older individuals (1,838 men and 1,924 women), aged 66-96 years, participants in the AGES-Reykjavik study, were studied. The total cross-sectional muscular area and knee extensor strength declined with age similarly in both sexes. Muscle parameters correlated most strongly with cortical area and total shaft area (adjusted for age, height, and weight) but explained lower limb fractures. Small muscular area, low knee extensor strength, large MA, low cortical thickness, and high BR were significantly associated with fractures in both sexes. Our results show that bone and muscle loss proceed at different rates and with different gender patterns.

  18. Intrinsic mechanical behavior of femoral cortical bone in young, osteoporotic and bisphosphonate-treated individuals in low- and high energy fracture conditions

    Science.gov (United States)

    Zimmermann, Elizabeth A.; Schaible, Eric; Gludovatz, Bernd; Schmidt, Felix N.; Riedel, Christoph; Krause, Matthias; Vettorazzi, Eik; Acevedo, Claire; Hahn, Michael; Püschel, Klaus; Tang, Simon; Amling, Michael; Ritchie, Robert O.; Busse, Björn

    2016-02-01

    Bisphosphonates are a common treatment to reduce osteoporotic fractures. This treatment induces osseous structural and compositional changes accompanied by positive effects on osteoblasts and osteocytes. Here, we test the hypothesis that restored osseous cell behavior, which resembles characteristics of younger, healthy cortical bone, leads to improved bone quality. Microarchitecture and mechanical properties of young, treatment-naïve osteoporosis, and bisphosphonate-treated cases were investigated in femoral cortices. Tissue strength was measured using three-point bending. Collagen fibril-level deformation was assessed in non-traumatic and traumatic fracture states using synchrotron small-angle x-ray scattering (SAXS) at low and high strain rates. The lower modulus, strength and fibril deformation measured at low strain rates reflects susceptibility for osteoporotic low-energy fragility fractures. Independent of age, disease and treatment status, SAXS revealed reduced fibril plasticity at high strain rates, characteristic of traumatic fracture. The significantly reduced mechanical integrity in osteoporosis may originate from porosity and alterations to the intra/extrafibrillar structure, while the fibril deformation under treatment indicates improved nano-scale characteristics. In conclusion, losses in strength and fibril deformation at low strain rates correlate with the occurrence of fragility fractures in osteoporosis, while improvements in structural and mechanical properties following bisphosphonate treatment may foster resistance to fracture during physiological strain rates.

  19. The use of piezoelectric surgery to lateralize the inferior alveolar nerve with simultaneous implant placement and immediate buccal cortical bone repositioning: a prospective clinical study.

    Science.gov (United States)

    de Vicente, J C; Peña, I; Braña, P; Hernández-Vallejo, G

    2016-07-01

    A prospective study was conducted to assess a variation of inferior alveolar nerve (IAN) lateralization. This study included 13 patients. An osteotomy was made with a piezoelectric device, and the IAN bundle was moved buccally. Dental implants were then inserted medial to the nerve bundle, and the inner surface of the buccal cortical bone plate was shaped to reduce its thickness. Finally, the bone plate was repositioned to restore the original shape and contour of the mandible. Neurosensory examinations of the lower lip and chin were performed using three tests: light touch, pain, and two-point discrimination. Three months after surgery, the function of the IAN was judged to be completely restored at 11 of the 13 surgical sites. Differences in the tests comparing the operated and non-operated sides were not significant. No implants were lost, and all patients were satisfied with the result. Although IAN lateralization in conjunction with dental implant placement is rarely indicated, the use of a piezoelectric device to perform a buccal osteotomy with final repositioning of the buccal cortical plate over the bony defect contributes to the recovery of the contour and shape of the mandible, without impairment of IAN function. PMID:26897328

  20. Intrinsic mechanical behavior of femoral cortical bone in young, osteoporotic and bisphosphonate-treated individuals in low- and high energy fracture conditions.

    Science.gov (United States)

    Zimmermann, Elizabeth A; Schaible, Eric; Gludovatz, Bernd; Schmidt, Felix N; Riedel, Christoph; Krause, Matthias; Vettorazzi, Eik; Acevedo, Claire; Hahn, Michael; Püschel, Klaus; Tang, Simon; Amling, Michael; Ritchie, Robert O; Busse, Björn

    2016-01-01

    Bisphosphonates are a common treatment to reduce osteoporotic fractures. This treatment induces osseous structural and compositional changes accompanied by positive effects on osteoblasts and osteocytes. Here, we test the hypothesis that restored osseous cell behavior, which resembles characteristics of younger, healthy cortical bone, leads to improved bone quality. Microarchitecture and mechanical properties of young, treatment-naïve osteoporosis, and bisphosphonate-treated cases were investigated in femoral cortices. Tissue strength was measured using three-point bending. Collagen fibril-level deformation was assessed in non-traumatic and traumatic fracture states using synchrotron small-angle x-ray scattering (SAXS) at low and high strain rates. The lower modulus, strength and fibril deformation measured at low strain rates reflects susceptibility for osteoporotic low-energy fragility fractures. Independent of age, disease and treatment status, SAXS revealed reduced fibril plasticity at high strain rates, characteristic of traumatic fracture. The significantly reduced mechanical integrity in osteoporosis may originate from porosity and alterations to the intra/extrafibrillar structure, while the fibril deformation under treatment indicates improved nano-scale characteristics. In conclusion, losses in strength and fibril deformation at low strain rates correlate with the occurrence of fragility fractures in osteoporosis, while improvements in structural and mechanical properties following bisphosphonate treatment may foster resistance to fracture during physiological strain rates.

  1. Autologous grafts of double-strut fibular cortical bone plate to treat the fractures and defects of distal femur: a case report and review of literature

    Institute of Scientific and Technical Information of China (English)

    CHEN Xu; LI Jian-jun; KONG Zhan; YANG Dong-xiang; YUAN Xiang-nan

    2011-01-01

    We reported a 23-year-old man who was involved in a high-speed motorcycle accident. He sustained a closed fracture at the right distal femur. The primary fracture happened on February 2008. He underwent open reduction and internal fixation with cloverleaf plate. And one hundred days after the surgery, the proximal screws were pulled-out, but the bone union was not achieved. Treat ment consisted of exchanging the cloverleaf plate with a locking compression plate and using an auto-iliac bone graft to fill the nonunion gap. In July 2009, the patient had a sharp pain in the right lower limb. The X-ray revealed that the plate implanted last year was broken, causing a nonunion at the fracture site. Immediately the plate and screws were removed and an intramedullary nail was inserted reversely from the distal femur as well as a 7 cm long bone from the right fibula was extracted and longitudinally split into two pieces to construct cortical bone plates. Then we placed them laterally and medially to fracture site, drilled two holes respectively, and fastened them with suture. We carried on auto-iliac bone grafting with the nonunion bone grafts. The follow-up at 15 months after operation showed that the treatment was successful, X-ray confirmed that there was no rotation and no angular or short deformity. We briefly reviewed the literature regarding such an unusual presentation and discussed in details the possible etiology and the advantages of autologous double-strut fibular grafts to cope with such an intractable situation.

  2. Hypoxia/Reoxygenation-Preconditioned Human Bone Marrow-Derived Mesenchymal Stromal Cells Rescue Ischemic Rat Cortical Neurons by Enhancing Trophic Factor Release.

    Science.gov (United States)

    Kim, Young Seo; Noh, Min Young; Cho, Kyung Ah; Kim, Hyemi; Kwon, Min-Soo; Kim, Kyung Suk; Kim, Juhan; Koh, Seong-Ho; Kim, Seung Hyun

    2015-08-01

    Bone marrow-derived mesenchymal stromal cells (BM-MSCs) represent a promising tool for stem cell-based therapies. However, the majority of MSCs fail to reach the injury site and have only minimal therapeutic effect. In this study, we assessed whether hypoxia/reoxygenation (H/R) preconditioning of human BM-MSCs could increase their functional capacity and beneficial effect on ischemic rat cortical neurons. Human BM-MSCs were cultured under hypoxia (1% O2) and with long-term reoxygenation for various times to identify the optimal conditions for increasing their viability and proliferation. The effects of H/R preconditioning on the BM-MSCs were assessed by analyzing the expression of prosurvival genes, trophic factors, and cell migration assays. The functionally improved BM-MSCs were cocultured with ischemic rat cortical neurons to compare with normoxic cultured BM-MSCs. Although the cell viability and proliferation of BM-MSCs were reduced after 1 day of hypoxic culture (1% O2), when this was followed by 5-day reoxygenation, the BM-MSCs recovered and multiplied extensively. The immunophenotype and trilineage differentiation of BM-MSCs were also maintained under this H/R preconditioning. In addition, the preconditioning enhanced the expression of prosurvival genes, the messenger RNA (mRNA) levels of various trophic factors and migration capacity. Finally, coculture with the H/R-preconditioned BM-MSCs promoted the survival of ischemic rat cortical neurons. H/R preconditioning of BM-MSCs increases prosurvival signals, trophic factor release, and cell migration and appears to increase their ability to rescue ischemic cortical neurons. This optimized H/R preconditioning procedure could provide the basis for a new strategy for stem cell therapy in ischemic stroke patients. PMID:25288154

  3. The application of heat-deproteinization to the morphological study of cortical bone: A contribution to the knowledge of the osteonal structure.

    Science.gov (United States)

    Pazzaglia, Ugo E; Congiu, Terenzio; Basso, Petra; Alessandri, Ivano; Cucca, Lucia; Raspanti, Mario

    2016-08-01

    Observation of heat-deproteinized cortical bone specimens in incident light enabled the high definition documentation of the osteonal pattern of diaphyseal Haversian bone. This prompted a study to compare these images with those revealed by polarized light microscopy, carried out either on decalcified or thin, undecalcified, resin-embedded sections. Different bone processing methods can reveal structural aspects of the intercellular matrix, depending on the light diffraction mode: birefringency in decalcified sections can be ascribed to the collagen fibrils orientation alone; in undecalcified sections, to both the ordered layout of collagen and the inorganic phase; in the heat-deproteinized samples, exclusively to the hydroxyapatite crystals aggregation mode. The elemental chemical analysis documented low content of carbon and hydrogen, no detectable levels of nitrogen and significantly higher content of calcium and phosphorus in heat-deproteinized samples, as compared with dehydrated controls. In both samples, the X-ray diffraction (XRD) pattern did not show any significant difference in pattern of hydroxyapatite, with no peaks of any possible decomposition phases. Scanning electron microscopic (SEM) morphology of heat-deproteinized samples could be documented with the fracturing technique facilitated by the bone brittleness. The structure of crystal aggregates, oriented in parallel and with marks of time periods, was documented. Comparative study of deproteinized and undecalcified samples showed that the matrix inorganic phase did not undergo a coarse grain thermal conversion until it reached 500°C, maintaining the original crystals structure and orientation. Incident light stereomicroscopy, combined with SEM analysis of deproteinized bone fractured surfaces, is a new enforceable technique which can be used in morphometric studies to improve the understanding of the osteonal dynamics. Microsc. Res. Tech. 79:691-699, 2016. © 2016 Wiley Periodicals, Inc. PMID

  4. Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study

    Directory of Open Access Journals (Sweden)

    Ahmad Mogharehabed

    2014-01-01

    Full Text Available Background: The accelerating effect of plasma rich in growth factors (PRGFs in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA. Materials and Methods: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA. Significant levels were set at 0.05. Results: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm. The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm². The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm². The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm². Conclusion: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant.

  5. Computed tomography to evaluate the association of fragmented heterolog cortical bone and methylmethacrylate to repare segmental bone defect produced in tibia of rabbits; Tomografia computadorizada da matriz ossea mineralizada heterologa fragmentada e metilmetacrilato na reparacao de falhas osseas segmentares produzidas em tibia de coelhos

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, S.H. [Universidade Federal de Sao Paulo (USP), SP (Brazil); Doria, R.G.S. [Universidade Federal de Sao Paulo (USP), SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos; Mendonca, F.S.; Santos, M.D.; Moreira, R. [Universidade de Cuiaba, MT (Brazil). Faculdade de Medicina Veterinaria; Simoes, R.S. [Universidade Federal de Sao Paulo (USP), SP (Brazil). Hospital Universitario; Camargo, L.M.; Simoes, M.J. [Universidade Federal de Sao Paulo (USP), SP (Brazil). Escola Paulista de Medicina; Marques, A.T.C. [Universidade de Cuiaba, MT (Brazil). Faculdade de Odontologia

    2012-11-15

    A 6mm segmental defect was performed on the metaphyseal region of the tibia of 12 rabbits and the autoclaved fragmented heterolog cortical bone conserved in glycerin (98%) and methylmethacrylate was used as a bone graft for the reconstruction. The graft was placed in the receptor bed and its integration was evaluated by computed tomography after 30, 60 and 90 days. There was gradual bone graft incorporation in the receptor bed during the time in 100% of the cases. Fragmented cortical bone heterograft and methylmethacrylate was biologically compatible and promotes bone defect reparation without signs of infection, migration and or rejection, featuring a new option of osseous substitute to fill in bone defects. (author)

  6. A comparative study between tibia unilateral cortical bone defect model and radius bone defect model of rabbits%兔胫骨单皮质骨缺损模型和桡骨缺损模型比较研究

    Institute of Scientific and Technical Information of China (English)

    李福兵; 金涛; 李霞; 刘华; 杨杜明; 徐永清; 潘兴华; 庞荣清; 朱跃良; 邓永丽; 丁晶; 李军; 石健

    2013-01-01

    Objective To make comparison of differences between the reparation of 8 mm unilateral cortical bone defect in the superior segment of tibia and 15 mm bone defect in the middle radius in rabbits. Methods Ten three - month - old male New Zealand white rabbits with the weight of( 2. 5 ± 0. 3 )kg were selected and randomly divided into two groups. Dental burr was used to prepare the single cortical bone defect model with the diameter of 8 mm in superior tibia and the model of 15 mm bone defect in middle radius. After the modeling,the traditional change of dressing on the wound was carried out for 3-5 d,and 4 and 12 w after the operation, those rabbits received the X - ray radiography. Twelve weeks after the modeling,CT plain scanning and bone tissue 3D imaging of the bone defect reparation were made by micro CT. Twelve weeks after the modeling of bone defect, the specimens of the tibia and radius from defect reparation segments were taken out and fixed by 4% paraformaldehyde/PBS. After the decalcification with 10% EDTA/PBS, conventional dehydration, embedding, and slicing were carried out, and the bone defect reparation was detected by the HE staining. Results Twelve weeks after the bone defect, X - ray film showed that the bone defect failed to repair when the 8 mm single bone cortical defect in superior tibia had no external and internal fixation. And there was the formation of cancellated bone within the medullary cavity; under the condition without internal and external fixation and the occurrence of other implants, the 15 mm defect in middle radius also failed to repair. Conclusion The models of 15 mm bone defect in rabbits' middle radius and 8 mm single bone cortical bone defect in the superior segment of tibia can both be used as the animal models of bone defect disunion.%目的 比较兔胫骨上段单皮质8 mm骨缺损与桡骨中段15 mm骨缺损修复差异.方法 取3月龄雄性新西兰大白兔10只,体重(2.5±0.3)kg,随机分为两组,利用牙科

  7. A new method for rapid Canine retraction

    Directory of Open Access Journals (Sweden)

    "Khavari A

    2001-06-01

    Full Text Available Distraction osteogenesis method (Do in bone lengthening and rapid midpalatal expansion have shown the great ability of osteognic tissues for rapid bone formation under distraction force and special protocol with optimum rate of one millimeter per day. Periodontal membrane of teeth (PDM is the extension of periostium in the alveolar socked. Orthodontic force distracts PDM fibers in the tension side and then bone formation will begin.Objects: Rapid retraction of canine tooth into extraction space of first premolar by DO protocol in order to show the ability of the PDM in rapid bone formation. The other objective was reducing total orthodontic treatment time of extraction cases.Patients and Methods: Tweleve maxillary canines in six patients were retracted rapidly in three weeks by a custom-made tooth-born appliance. Radiographic records were taken to evaluate the effects of heavy applied force on canine and anchorage teeth.Results: Average retraction was 7.05 mm in three weeks (2.35 mm/week. Canines rotated distal- in by mean 3.5 degrees.Anchorage loss was from 0 to 0.8 mm with average of 0.3 mm.Root resorption of canines was negligible, and was not significant clinically. Periodontium was normal after rapid retraction. No hazard for pulp vitality was observed.Discussion: PDM responded well to heavy distraction force by Do protocol. Rapid canine retraction seems to be a safe method and can considerabely reduce orthodontic time.

  8. Probing physical and chemical changes in cortical bone due to osteoporosis and type 2 diabetes by solid-state NMR

    Science.gov (United States)

    Zhou, Donghua; Taylor, Amanda; Rendina, Beth; Smith, Brenda; Department of Physics Collaboration; Department of Nutritional Sciences Collaboration

    2013-03-01

    Approximately 1.5 million fractures occur each year in the U.S. due to osteoporosis, which is characterized by decreased bone mineral density and deterioration of bone micro-architecture. On the other hand, type 2 diabetes also significantly increases fracture risks, despite having a normal or even higher bone mineral density. Solid-state NMR has been applied to bone tissues from normal and disease-inflicted mouse models to study structural and chemical dynamics as the disease progresses. Proton relaxation experiments were performed to measure water populations in the bone matrix and pores. Collagen-bound water has strong influence on bone resilience, while water content in the pores reveals amount and size of pores from micro- to millimeter range. Other biochemical and atomic-scale structural alterations in the mineral and organic phases and their interface were investigated by proton, phosphorus, and carbon NMR spectroscopy. Experiments were designed to individually detect different types of phosphorus environments: near the mineral surface, similar to hydroxyapatite, and deficient of hydrogens due to substitution of the hydroxyl group by other ions. A new method was also developed for accurate quantification of each phosphorus species. The authors appreciate financial support for this project from the College of Human Sciences and the College of Arts and Sciences, Oklahoma State University.

  9. Orchidectomy-induced alterations in volumetric bone density, cortical porosity and strength of femur are attenuated by dietary conjugated linoleic acid in aged guinea pigs.

    Science.gov (United States)

    DeGuire, Jason R; Mak, Ivy L; Lavery, Paula; Agellon, Sherry; Wykes, Linda J; Weiler, Hope A

    2015-04-01

    Age-related osteoporosis and sarcopenia are ascribed in part to reductions in anabolic hormones. Dietary conjugated linoleic acid (CLA) improves lean and bone mass, but its impact during androgen deficiency is not known. This study tested if CLA would attenuate the effects of orchidectomy (ORX)-induced losses of bone and lean tissue. Male guinea pigs (n=40; 70-72 weeks), were randomized into four groups: (1) SHAM+Control diet, (2) SHAM+CLA diet, (3) ORX+Control diet, (4) ORX+CLA diet. Baseline blood sampling and dual-energy X-ray absorptiometry (DXA) scans were conducted, followed by surgery 4 days later with the test diets started 7 days after baseline sampling. Serial blood sampling and DXA scans were repeated 2, 4, 8 and 16 weeks on the test diets. Body composition and areal BMD (aBMD) of whole body, lumbar spine, femur and tibia were measured using DXA. At week 16, muscle protein fractional synthesis rate (FSR), volumetric BMD (vBMD), microarchitecture and bone strength were assessed. Body weight declined after SHAM and ORX surgery, with slower recovery in the ORX group. Dietary CLA did not affect weight or lean mass, but attenuated gains in fat mass. Lean mass was stable in SHAM and reduced in ORX by 2 weeks with whole body and femur bone mineral content (BMC) reduced by 4 weeks; CLA did not alter BMC. By week 16 ORX groups had lower free testosterone and myofibrillar FSR, yet higher cortisol, osteocalcin and ionized calcium with no alterations due to CLA. ORX+Control had higher prostaglandin E2 (PGE2) and total alkaline phosphatase compared to SHAM+Control whereas ORX+CLA were not different from SHAM groups. Femur metaphyseal vBMD was reduced in ORX+CTRL with the reduction attenuated by CLA. Femur cortical thickness (Ct.Th.) and biomechanical strength were reduced and cortical porosity (Ct.Po.) elevated by ORX and attenuated by CLA. This androgen deficient model with a sarcopenic-osteoporotic phenotype similar to aging men responded to dietary CLA with

  10. Deciphering seasonal variations in the diet and drinking water of modern White-Tailed deer by in situ analysis of osteons in cortical bone

    Science.gov (United States)

    Larson, T. E.; Longstaffe, F. J.

    2007-12-01

    In situ carbon and oxygen isotope values for bioapatite were obtained from longitudinal slices of cortical bone from modern domesticated sheep and free-range White-Tailed deer. The analyses were obtained using an IR-laser coupled to a GC-IRMS interface. Ablation pits averaged 200 × 50 μm, making it possible to sample individual or small bundles of osteons. Cortical bone is remodeled along osteons throughout a mammal's life. Therefore, data at this scale can record seasonal variations in diet and drinking water during the adult stages of a mammal, whereas teeth provide may provide information about the juvenile years of a mammal. Average δ18O and δ13C values for the sheep from southwestern Ontario, Canada, were 14.0 and -16.1‰, respectively. No trend was observed in the isotopic composition of the sheep's osteons, consistent with its constant diet and water supply. The δ18O (14.2 to 16.6‰) and δ13C (-19.2 to -15.6‰) values of osteons from White-Tailed deer from nearby Pinery Provincial Park, however, varied systematically and were negatively correlated. Oxygen isotope values of the osteons correlated well with changes in the δ18O values of the main water source for these deer: winter average, -10.7‰; summer average, -8.6‰. The variation in δ13C values of the osteons reflects changes in diet; summer diet consisted mainly of leafy C3 vegetation (-28.4‰), whereas winter diet comprised bark (-25.6‰), C4 grasses (δ13C, -12.7‰), and corn stalks and husks (-11.3‰).

  11. Effects of repetitive loading on the growth-induced changes in bone mass and cortical bone geometry: a 12-month study in pre/peri- and postmenarcheal tennis players.

    Science.gov (United States)

    Ducher, Gaele; Bass, Shona L; Saxon, Leanne; Daly, Robin M

    2011-06-01

    Pre- and early puberty may be the most opportune time to strengthen the female skeleton, but there are few longitudinal data to support this claim. Competitive female premenarcheal (pre/peri, n = 13) and postmenarcheal (post, n = 32) tennis players aged 10 to 17 years were followed over 12 months. The osteogenic response to loading was studied by comparing the playing and nonplaying humeri for dual-energy X-ray absorptiometry (DXA) bone mineral content (BMC) and magnetic resonance imaging (MRI) total bone area (ToA), medullary area (MedA), cortical area (CoA), and muscle area (MCSA) at the humerus. Over 12 months, growth-induced gains (nonplaying arm) in BMC, ToA, and CoA were greater in pre/peri (10% to 19%, p < .001) than in post (3% to 5%, p < .05 to .001) players. At baseline, BMC, ToA, CoA, and MCSA were 8% to 18% greater in the playing versus nonplaying arms in pre/peri and post players (all p < .001); MedA was smaller in the playing versus nonplaying arms in post only players (p < .05). When comparing the annual gains in the playing arm relative to changes in the nonplaying arm, the increases in ToA and CoA were greater in pre/peri than post players (all p < .05). The smaller the side-to-side differences in BMC and CoA at baseline, the larger the exercise benefits at 12 months (r = -0.39 to -0.48, p < .01). The exercise-induced change in MCSA was predictive of the exercise benefits in BMC in pre/peri players only (p < .05). In conclusion, both pre/peri- and postmenarcheal tennis players showed significant exercise-induced skeletal benefits within a year, with greater benefits in cortical bone geometry in pre/perimenarcheal girls.

  12. Mechanically-induced osteogenesis in the cortical bone of pre- to peripubertal stage and peri- to postpubertal stage mice

    Directory of Open Access Journals (Sweden)

    Plochocki Jeffrey H

    2009-06-01

    Full Text Available Abstract Background Exercise during postnatal development plays a key role in determining adult bone mass and reducing the risk of fracture and osteoporosis later in life. However, the relationship between mechanically-induced osteogenesis and age is unclear. Elevated levels of estrogen during puberty may inhibit periosteal bone formation. Thus, magnitudes of mechanically-induced osteogenesis may be vary with pubertal state. Methods The present study uses a murine model to examine age-related changes in bone formation at the femoral midshaft with voluntary exercise. Pre- to peripubertal mice aged 3 weeks and peri- to postpubertal mice aged 7 weeks were randomly divided into sedentary and exercised groups and subjected to histomorphometric comparison after 4 weeks of treatment. Results Results of the experiment indicate that exercise significantly increased osteogenesis on the periosteal and endocortical surface of the mice in the older age group (P P Conclusion These findings suggest that the amount and location of mechanically-induced osteogenesis differs by age during skeletal development. Late adolescence may be the optimal time to accrue bone mass and maximize bone strength.

  13. Mecânica e microbiologia de placas produzidas a partir de osso cortical bovino, conservadas em diferentes meios Mechanic and microbiology of plates produced from bovine cortical bone, conserved in several means

    Directory of Open Access Journals (Sweden)

    Edson Vilela de Melo Filho

    2011-04-01

    Full Text Available Objetivou-se com este trabalho avaliar a resistência mecânica de placas ósseas produzidas a partir de osso cortical bovino, conservadas em diferentes meios, e a eficiência desses meios em inibir o crescimento de microrganismos. Foram utilizadas 168 placas confeccionadas a partir de tíbia bovina e conservadas em glicerina a 98%, solução salina a 150%, solução de açúcar a 300%, líquido de Dakin, congeladas em N2L a -196°C, ou esterilizadas em óxido de etileno. Após reidratação em solução de cloreto de sódio a 0,9% por seis horas, elas foram submetidas a ensaios mecânicos de tração, compressão, flexão e torção. Foi realizada avaliação microbiológica das placas anterior e imediatamente após a reidratação, com ou sem adição de enrofloxacina a 0,5%. Não se observou diferença significativa (PThe objective of this study was to evaluate the mechanical strength of bone plates yielded from bovine cortical bone, conserved in different solutions, and the efficiency of these solutions in the inhibition of microorganism's growth. A hundred and sixty eight plates yielded from bovine tibiae were conserved in 98% glycerin, 150% saline solution, 300% sugar solution, Dakin solution, frozen in N2L at - 196°C, or sterilized in ethylene oxide gas. After rehydration in NaCl 0.9% solution for six hours, plates were subjected to tensile, compression, bending and twisting testing. The microbiological evaluation of bone plates was s carried out before and immediately after rehydration, with or without enrofloxacin 0.5% addition. There was no significant difference (P<0.01% on resistance to the rupture point in plates conserved in different solutions, frozen-thawed or sterilized. Microorganisms were isolated from plates conserved in satured salt solution, sugar satured solution, Dakin solution or frozen in N2L, before and after rehydraion However, after the use of NaCl 0.9% solution added of enrofloxacin 0.5%, microorganisms were not

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

    Science.gov (United States)

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

    2008-11-01

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

  15. Sirtuin1 (Sirt1) promotes cortical bone formation by preventing β-catenin sequestration by FoxO transcription factors in osteoblast progenitors.

    Science.gov (United States)

    Iyer, Srividhya; Han, Li; Bartell, Shoshana M; Kim, Ha-Neui; Gubrij, Igor; de Cabo, Rafael; O'Brien, Charles A; Manolagas, Stavros C; Almeida, Maria

    2014-08-29

    A decline of the levels and activity of Sirtuin1 (Sirt1), a NAD(+) class III histone deacetylase, with age contributes to the development of several diseases including type 2 diabetes, neurodegeneration, inflammation, and cancer. The anti-aging effects of Sirt1 evidently result from the deacetylation of many transcription factors and co-factors including members of the Forkhead box O (FoxO) family and β-catenin. Wnt/β-catenin is indispensable for osteoblast generation. FoxOs, on the other hand, sequester β-catenin and inhibit osteoprogenitor proliferation. Here, we have deleted Sirt1 in osteoprogenitors expressing Osterix1 (Osx1)-Cre and their descendants. Sirt1(ΔOsx1) mice had lower cortical thickness in femora and vertebrae because of reduced bone formation at the endocortical surface. In line with this, osteoprogenitor cell cultures from the Sirt1(ΔOsx1) mice exhibited lower alkaline phosphatase activity and mineralization, as well as decreased proliferation and increased apoptosis. These changes were associated with decreased Wnt/β-catenin signaling and expression of cyclin D1 and resulted from increased binding of FoxOs to β-catenin. These findings demonstrate that Sirt1-induced deacetylation of FoxOs unleashes Wnt signaling. A decline in Sirt1 activity in osteoblast progenitors with aging may, therefore, contribute to the age-related loss of bone mass. Together with evidence that Sirt1 activators increase bone mass in aged mice, our results also suggest that Sirt1 could be a therapeutic target for osteoporosis. PMID:25002589

  16. Microstructure control of TCP/TCP-(t-ZrO2)/t-ZrO2 composites for artificial cortical bone

    International Nuclear Information System (INIS)

    In this study, bone like continuously porous TCP/TCP-(t-ZrO2)/t-ZrO2 composites with a central channel were fabricated using a multi-pass extrusion process and their mechanical properties and microstructure at different sintering temperatures were investigated. Hydroxyapatite (HAp) powder was used as the raw powder which undergoes a phase transformation into the α-tricalcium phosphate phase (α-TCP) at a sintering temperature of 1500 deg. C. The external diameter and inside cylindrical hollow core were approximately 10.3 mm and 4.8 mm, respectively. The frame region contained numerous microchannels that extended from one side of the fabricated body to the other. The channeled frame region had a multi-layer microstructure with a TCP/TCP-(t-ZrO2)/t-ZrO2 layer configuration. The inner layer consisted of TCP, which make the wall of the microchannel. The material properties were characterized and microstructural analysis was carried out. The maximum pore size, compressive strength, and relative density of the fabricated system were approximately 86 μm, 53 MPa, and 77% when sintered at 1500 deg. C. The composites exhibited excellent biocompatibility and cell proliferation behavior resulted in the MTT assay and cell adhesion test using osteoblast-like MG-63 cells. Highlights: → In this work we fabricated a composites preform that is a biomimetic structure of bone architecture. → Unidirectional porous channel with lamellar elcloser, like that of the natural bone was fabricated. → The HAp-ZrO2 composites system was mechanically strong and showed excellent biocompatibility to be used as an artificial bone.

  17. Bone

    Science.gov (United States)

    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.

  18. Periodontal ligament distraction: A simplified approach for rapid canine retraction

    Directory of Open Access Journals (Sweden)

    K C Prabhat

    2012-01-01

    Full Text Available Distraction osteogenesis is a method of inducing new bone formation by applying mechanical strains on preexisting bone. The process of osteogenesis in the periodontal ligament during orthodontic tooth movement is similar to the osteogenesis in the midpalatal suture during rapid palatal expansion. A new concept of "distracting the periodontal ligament" is proposed to elicit rapid canine retraction in two weeks. At the time of first premolar extraction, the interseptal bone distal to the canine was undermined with a bone bur, grooving vertically inside the extraction socket along the buccal and lingual sides and extending obliquely toward the socket base. Then, a tooth-borne, custom-made, intraoral distraction device was placed to distract the canine distally into the extraction space. It was activated 0.5 mm/day, immediately after the extraction. Canine was distracted 6.5 mm into the extraction space within two weeks.

  19. Bone

    International Nuclear Information System (INIS)

    Bone scanning provides information on the extent of primary bone tumors, on possible metastatic disease, on the presence of osteomyelitis prior to observation of roentgenographic changes so that earlier therapy is possible, on the presence of collagen diseases, on the presence of fractures not disclosed by x-ray films, and on the evaluation of aseptic necrosis. However, the total effect and contribution of bone scanning to the diagnosis, treatment, and ultimate prognosis of pediatric skeletal diseases is, as yet, unknown. (auth)

  20. Secondary alveolar bone grafting in combination with autologous iliac crest cortical plate and concellous bone for 19 adult cleft patients%自体髂骨皮质骨块与松质骨联合移植修复成人牙槽突裂19例分析

    Institute of Scientific and Technical Information of China (English)

    李增健; 卢利; 金山; 任媛媛; 刘强; 张斌; 张蕾; 吴楠; 杨鸣良; 王绪凯

    2012-01-01

    Objective To retrospectively study secondary alveolar bone grafting in combination with autologous iliac crest cortical bone and concellous bone for adult cleft patients. Methods Analveolar bone grafting procedure in combination with autologous illiac crest cortical bone and concellous bone has been applied in 19 adult cleft patients since 2008. A water-tight mucocusperiosteum pocket was formed around the alveolar cleft. The iliac concellous bone was put into the alveolar cleft with tender pressing. The carved iliac crest cortical bone was then covered on to the labial surface of alveolar cleft and pyriform aperture with titanium screws. Results Based on Bergland's criterion, the overall survival rate of bone grafting was 84.2% , clinical success rate was 73.7% , clinical failure rate was 26. 3%. Oral-nasal fistular recurred in 2 patients. Conclusion Secondary alveolar bone grafting in combination with autologous iliac crest cortical bone and concellous bone can effectively improve the grafting survival rate and keep a sufficient volume in regions of cleft and the pyriform aperture of adult cleft patients.%目的 观察自体髂骨块和松质骨联合移植修复成人牙槽突裂的效果.方法 对2008年以来在我院就诊的成人牙槽突裂患者19例采用自体髂骨块和松质骨联合移植修复.将髂松质骨填充牙槽突裂间隙内,用骨块恢复梨状孔边缘形态和鼻翼基底部高度后,采用微型钛板和单皮质钛钉固定.术后1年复查进行Bergland 分级评价.结果 植入骨成活率(Ⅰ~Ⅲ级)为84.2%,临床成功率(Ⅰ、Ⅱ级)为73.7%,临床失败率(Ⅲ、Ⅳ级)为26.3%.2例患者再次出现口鼻瘘孔.结论 自体髂骨块和松质骨联合移植修复成人牙槽突裂可以有效恢复牙槽突高度,增加患侧梨状孔周围骨量.

  1. 皮质骨通道置椎弓根螺钉技术的研究进展%Cortical bone trajectory for pedicle screws

    Institute of Scientific and Technical Information of China (English)

    宣俊; 徐道亮; 王向阳

    2016-01-01

    Pedicle screw fixation is widely used in spine surgery, which allows 3⁃dimensional fixation with a more rigid construct and permits a shorter fusion length. However, conventional pedicle screw fixation has some drawbacks, including signifi⁃cant muscle dissection for the exposure of bone marks. Although percutaneous pedicle screw technique can compensate for above defects, it requires an additional approach for decompression and bone graft insertion. Besides, the percutaneous pedicle screw technique depends on intraoperative multiplanar fluoroscopy, which results in high risk of radiation exposure of the surgeons and patients. Screw loosening is a well⁃known complication, especially in osteoporosis patients. Several methods can enhance screw stability, for example, modifying screw design and augmenting vertebral bodies with reinforcing materials that can improve the structural capacity of the deteriorated tissue, however, they also have some disadvantages. Although we can enhance bone⁃screw by modifying screw design, it is not useful in severe osteoporosis patients. At the same time, bone cement can increase pedicle screw axial pullout strength and fatigue resistance, however, it is associated with a number of inherent disadvantages such as its high exothermic polymerizing temperature, toxicity of the monomer, and risk of leakage to the spinal canal. Santoni et al. intro⁃duced cortical bone trajectory (CBT) for lumbar pedicle screw with a new screw design that is shorter and smaller in diameter which has been proposed to maximize the thread contact with this higher density bone surface. In addition, the CBT technique fol⁃lows a caudocephalad path sagittally and a laterally directed path in the transverse plane, engaging only cortical bone in the pedi⁃cle without the involvement of the vertebral body trabecular space. Finally, the screw insertion point of this technique locates around lateral pars, enabling less tissue dissection. Therefore, it can be

  2. Deciphering Seasonal Variations of Diet and Water in Modern White-Tailed Deer by In Situ Analysis of Osteons in Cortical Bone

    Science.gov (United States)

    Larson, T. E.; Longstaffe, F. J.

    2004-12-01

    In situ stable carbon and oxygen isotope compositions of biogenic apatite were obtained from longitudinally-cut sections of cortical bone from femurs of modern domesticated sheep and free-range White-Tailed deer, using an IR-laser and a GC-continuous flow interface. Ablation pits averaged 200x50 microns, making it possible to analyze individual osteons. Since cortical bone is remodelled along osteons throughout a mammal's lifetime, isotopic data at this resolution provides information about seasonal variations in diet and drinking water. The O-isotope results were calibrated using laser analyses of NBS-18 and NBS-19, which produced a value of 26.39±0.46 permil (n=27) for WS-1 calcite (accepted value, 26.25 permil). C-isotope results were calibrated using a CO2 reference gas, producing a value of 0.76±0.40permil (n=27) for WS-1, also in excellent agreement with its accepted value of 0.74 permil. Average O- and C-isotope values for a local domestic sheep (southwestern Ontario, Canada) were 12.20±0.58 and -15.70±0.35 permil (n=27), respectively. No isotopic trend occurred along or across individual osteons. This pattern is consistent with the sheep's relatively unchanging food and water sources. The free-range White-Tailed deer came from Pinery Provincial Park (PPP), southwestern Ontario. Its O- and C-isotope compositions varied systematically across individual osteons and were negatively correlated (R2=0.56). O-isotope values ranged from 13.4 to 15.5 permil; the highest values correlated with summer and the lowest values, with winter. The O-isotope compositions of the main water source (Old Ausable River Channel) varied similarly during the deer's lifetime: winter average, -10.7±0.5 permil; summer average, -8.6±0.4 permil. The C-isotope results for the deer osteons varied from -19.7 to -15.9 permil. This variation can be explained by changes in food sources. Summer diets of deer in PPP consist mainly of leafy fractions of C3 vegetation, especially sumac, cedar

  3. The Observation on Development of Thickness of Cortical Bone in Children of Different Age%不同年龄组小儿骨皮质发育状况观察

    Institute of Scientific and Technical Information of China (English)

    宁刚; 吴康敏; 伍家农; 张光鹏; 杨定焯

    2000-01-01

    【 Objective】 In order to find out the pattern of development in cortical bone, a study of cortical bone in normal in-fants、 children、adolescence and adults were carried out. 【Methods】 The authors measured the transverse and inner diameter inmidpoint of the second metacarpal bone from 1 017 X- ray films of right wrist of normal infants、children、 adolescence and adults inthe urban and of infants in the suburban. The thickness and index of cortical bone in midpoint of the second metacarpal were calculat-ed by Microsoft Excel 97. 【 Results】 The increase of thickness of cortical bone was respectively 3.06 mm、2.89 mm for boys andgirls from 1.0 to 15.0 vr of age ,the average amplitude was respectively 4.0% 、4.3%, the latter was 8.2% 、6.9% for male and fe-male infants , 2.3 %、 2.0 % for infancy and preschool children, 10.7 % for girls at 11~13yr of age ,7.8 % for boys of 13~15yr ofage. Between urban areas and a rural area there were not significant differences between the transverse diameters in the secondmetacarpal of boys and girls at 1.0yr of age, but the average thickness of cortical bone were decreased of 0.39 mm in rural area ( P< 0.001 ). 【Conclusions】 The thickness of cortical bone increased significantly with age in children and adolescence , the in-creased velocity was more rapid during infncy nd puberty , with the pek thickness of corticl bone round puberty.%【目的】通过对正常婴幼儿、青少年及部分成年人骨皮质发育的横向观察,了解小儿骨皮质发育的规律。【方法】市郊农村健康婴儿,城区婴幼儿、青少年及部分成年人,共1 017例摄右手腕正位X光片,测量第二掌骨中点横径及内径,用Microsoft Excel97软件计算出骨皮质厚度、皮质指数并作统计学处理。【结果】从1岁组到15岁组男、女童骨皮质厚度分别增加了3.06mm及2.89mm,平均年增幅分别为4.0%及4.3%;婴儿期平均年增幅分别为8.2

  4. Alveolar Bone Housing- A Modified Wilkodontics Approach- A Case Report.

    Science.gov (United States)

    Awasthi, Eshan; Sanjay, Kothamachu; Bhongade, M L; Shrivastav, Sunita

    2016-08-01

    Accelerated orthodontic treatment is the need of the hour in current scenario as the conventional orthodontics is time taking. Corticotomy assisted orthodontics have been used for years to reduce the treatment duration by reducing the resistance provided by alveolar bone housing. This case report describes the orthodontic treatment combined with the modification in conventional wilkodontic technique in a patient to accelerate tooth movement and shorten the treatment time with an anterior open bite and flared and spaced upper and lower incisors. Firstly plaque control was achieved with supra and subgingival scaling. A modified approach using periodontal access flap followed by vertical bone cuts in the cortical bone from the crest of the alveolar bone margin to 2mm-3mm below the apices of all the anterior teeth extending from upper left canine to upper right canine were performed. These vertical cuts were joined by horizontal cuts apically and flap repositioned. An MBT 0.018 inch appliance was bonded. Orthodontic therapy proceeded with frequent activation of the appliances to retract the incisors every two weeks. The total treatment time was four and half months with active period of two months and no adverse effects were observed at the end of active treatment. The modified decortication technique reduced the treatment time to a considerable extent. The interdental spacing closed and optimum overjet and overbite was achieved. PMID:27656577

  5. Bone Regeneration of Hydroxyapatite/Alumina Bilayered Scaffold with 3 mm Passage-Like Medullary Canal in Canine Tibia Model

    Directory of Open Access Journals (Sweden)

    Jong Min Kim

    2015-01-01

    Full Text Available The aim of this study was to evaluate the bone regeneration of hydroxyapatite (HA/alumina bilayered scaffold with a 3 mm passage-like medullary canal in a beagle tibia model. A porous HA/alumina scaffold was fabricated using a polymeric template-coating technique. HA/alumina scaffold dimensions were 10 mm in outer diameter, 20 mm in length, and with either a 3 mm passage or no passage. A 20 mm segmental defect was induced using an oscillating saw through the diaphysis of the beagle tibia. The defects of six beagles were filled with HA/alumina bilayered scaffolds with a 3 mm passage or without. The segmental defect was fixated using one bone plate and six screws. Bone regeneration within the HA/alumina scaffolds was observed at eight weeks after implantation. The evaluation of bone regeneration within the scaffolds after implantation in a beagle tibia was performed using radiography, computerized tomography (CT, micro-CT, and fluorescence microscopy. New bone successfully formed in the tibia defects treated with 3 mm passage HA/alumina scaffolds compared to without-passage HA/alumina scaffolds. It was concluded that the HA/alumina bilayered scaffold with 3 mm passage-like medullary canal was instrumental in inducing host-scaffold engraftment of the defect as well as distributing the newly formed bone throughout the scaffold at 8 weeks after implantation.

  6. Cooperative Effects of PRF and BMSCs in Alveolar Bone Regeneration in a Canine Model%犬PRF复合BMSCs修复拔牙窝颊侧骨壁缺损的实验研究

    Institute of Scientific and Technical Information of China (English)

    于佳; 郝永明; 陆家瑜; 邹德荣

    2014-01-01

    (P<0.05). In animal experiments, PRF showed early healing wound ability. On repairing bone defects, at 6 weeks in the tissue engineering group, the bone hight [(2.63 ±0.57) mm] and bone mineral density [(765.19±59.70) HU] was significantly increased (P<0.05), which compared with blood clots group [(5.65± 2.91) mm, (599.08 ±53.88) HU] and PRF group [(4.14 ±1.16) mm, (644.76 ±65.39) HU]. Conclusion: Cooperative of PRF and BMSCs can effectively repair mandible alveolar bone defects in canine model.

  7. Finite element analysis of rapid canine retraction through reducing resistance and distraction

    Directory of Open Access Journals (Sweden)

    Junjie XUE

    2014-01-01

    Full Text Available Objective: The aims of this study were to compare different surgical approaches to rapid canine retraction by designing and selecting the most effective method of reducing resistance by a three-dimensional finite element analysis. Material and Methods: Three-dimensional finite element models of different approaches to rapid canine retraction by reducing resistance and distraction were established, including maxillary teeth, periodontal ligament, and alveolar. The models were designed to dissect the periodontal ligament, root, and alveolar separately. A 1.5 N force vector was loaded bilaterally to the center of the crown between first molar and canine, to retract the canine distally. The value of total deformation was used to assess the initial displacement of the canine and molar at the beginning of force loading. Stress intensity and force distribution were analyzed and evaluated by Ansys 13.0 through comparison of equivalent (von Mises stress and maximum shear stress. Results: The maximum value of total deformation with the three kinds of models occurred in the distal part of the canine crown and gradually reduced from the crown to the apex of the canine; compared with the canines in model 3 and model 1, the canine in model 2 had the maximum value of displacement, up to 1.9812 mm. The lowest equivalent (von Mises stress and the lowest maximum shear stress were concentrated mainly on the distal side of the canine root in model 2. The distribution of equivalent (von Mises stress and maximum shear stress on the PDL of the canine in the three models was highly concentrated on the distal edge of the canine cervix. . Conclusions: Removal of the bone in the pathway of canine retraction results in low stress intensity for canine movement. Periodontal distraction aided by surgical undermining of the interseptal bone would reduce resistance and effectively accelerate the speed of canine retraction.

  8. Evidence of bone formation in the nasal floor around polished surface bi-cortical screw implants after indirect nasal lift in an atrophied maxilla: Cone beam computed tomography-based case report.

    Science.gov (United States)

    Khairnar, Mayur; Gaur, Vivek

    2015-01-01

    Maxillary jaw is restricted superiorly with maxillary sinus in the posterior region and nasal cavity in the anterior region. Augmentation of distal maxilla with recessed maxillary sinus has been documented since, last few decades. Sinus lifts the procedure either through crestal or lateral approach proves to be an effective way for augmenting bone for the placement of dental implants in atrophied posterior maxilla. However, when it comes to vertically deficient anterior maxilla, lifting of the nasal membrane is not considered. Perhaps, recent studies have shown greater success of dental implant placed after augmentation of the nasal floor. This report emphasizes on an observation of significant bone formation after indirect lifting of the nasal membrane with smooth polished surface bi-cortical implants. PMID:26015681

  9. The Effect of Bone Loss Pattern on the Structural Capacity of the Proximal Femur

    Institute of Scientific and Technical Information of China (English)

    FAN Li-xia; Eric Wang

    2006-01-01

    The effect of age-related bone loss on the structural capacity of the proximal femur were investigated by Finite Element Analysis(FEA). Four bone loss patterns were considered. These were "uniform cortical bone loss", "neck cortical bone loss", "intertrochanteric cortical bone loss" and "uniform trabecular bone loss". The results show that the two "non-uniform cortical bone loss" patterns are more dangerous than the "uniform cortical bone loss" pattern, and that the cortical bone loss in intertrochanteric region is associated with a greater reduction in cortical failure load than the cortical bone loss in the femoral neck. The trabecular bone loss causes a limited decrease in both cortical failure and trabecular failure loads. This research should be helpful to the clinical assessment of femur fracture risk due to age-related bone loss.

  10. Quantitative CT assessment of bone mineral density in dogs with hyperadrenocorticism.

    Science.gov (United States)

    Lee, Donghoon; Lee, Youngjae; Choi, Wooshin; Chang, Jinhwa; Kang, Ji-Houn; Na, Ki-Jeong; Chang, Dong-Woo

    2015-01-01

    Canine hyperadrenocorticism (HAC) is one of the most common causes of general osteopenia. In this study, quantitative computed tomography (QCT) was used to compare the bone mineral densities (BMD) between 39 normal dogs and 8 dogs with HAC (6 pituitary-dependent hyperadrenocorticism [PDH]; pituitary dependent hyperadrenocorticism, 2 adrenal hyperadrenocorticism [ADH]; adrenal dependent hyperadrenocorticism) diagnosed through hormonal assay. A computed tomogaraphy scan of the 12th thoracic to 7th lumbar vertebra was performed and the region of interest was drawn in each trabecular and cortical bone. Mean Hounsfield unit values were converted to equivalent BMD with bone-density phantom by linear regression analysis. The converted mean trabecular BMDs were significantly lower than those of normal dogs. ADH dogs showed significantly lower BMDs at cortical bone than normal dogs. Mean trabecular BMDs of dogs with PDH using QCT were significantly lower than those of normal dogs, and both mean trabecular and cortical BMDs in dogs with ADH were significantly lower than those of normal dogs. Taken together, these findings indicate that QCT is useful to assess BMD in dogs with HAC. PMID:26040613

  11. Transmigration of mandibular canine – case report

    International Nuclear Information System (INIS)

    Transmigration is a phenomenon of movement of an unerupted tooth in the bone across the midline. This anomaly is not often found. Transmigration is more prevalent in females than in males, and more often encountered in the mandible than maxilla, it affects mostly canines. The aim of this study was to present a case report of a mandibular canine transmigration in a patient aged 12. Intraoral examination determined hypodontia of right second premolar and delayed eruption of left second premolar in maxilla, as well as persistent deciduous teeth: right second molar, left canine and second molar. The patient was referred for a Cone-Beam CT examination, which allowed precise visualization of the transmigrating canine as well as ruled out resorption of roots of mandibular incisors. The treatment with a maxillary fixed orthodontic appliance was finished after obtaining a satisfactory result. Proper alignment of the incisors in the anterior-posterior plane and correct midline position were accepted by the patient. Transmigrating canine after consultation with the surgeon was designed to further radiological observation

  12. Orthodontic-surgical treatment of four impacted canines in an adult patient: A case report

    Directory of Open Access Journals (Sweden)

    Pavlović Jasna

    2016-01-01

    Full Text Available Introduction. Full impaction of canines, in both jaws, is a rare phenomenon. It is usually coupled with the persistence of deciduous canines, or any other irregularity in the dental arch. Case report. Panoramic radiograph of a 24-year-old female patient showed bilateral canine impaction in both jaws. Due to vestibular, apical and medial position of canines in the upper jaw, the surgical approach implied the apically positioned flap technique. The position of impacted mandibular canines was vertical with more coronal position relative to the upper canines, thus requiring a closed eruption technique. Conclusion. Inadequate position of impacted canines in the bone fully justifies the use of orthodontic-surgical treatment.

  13. Canine retraction with J hook headgear.

    Science.gov (United States)

    Ayala Perez, C; de Alba, J A; Caputo, A A; Chaconas, S J

    1980-11-01

    Several methods have been described for accomplishing distal movement of canines without losing posterior anchorage. An accepted method in canine retraction is the use of headgear with J hooks. Since it incorporates extraoral anchorage, it is most effective in maximum-anchorage cases. It was the purpose of this study to analyze the distribution of force transmitted to the alveolus and surrounding structures by means of photoelastic visualization, utilizing J hook headgear for maxillary canine retraction. A three-dimensional model representing a human skull was used. This model was constructed with different birefringent materials to simulate bone, teeth, and periodontal membranes. Three different vectors of force were applied representing high-, medium-, and low-pull headgear, which were placed at angles of 40, 20, and 0 degrees to the occlusal plane. The photoelastic analysis was made by means of a circular-transmission polariscope arrangement, and the photoelastic data were recorded photographically. The stress areas created by the three different vectors of force were associated with various degrees of canine tipping. This effect was greater with the low-pull force component than with the medium-pull traction. The high-pull headgear produced the least tipping tendency, being closer to a bodily movemment effect. Further, stresses were transmitted to deeper structures of the simulated facial bones; these regions were the frontozygomatic, zygomaticomaxillary, and zygomaticotemporal sutures.

  14. The contribution of the nonporous distal stem to the stability of proximally porous-coated canine femoral components.

    Science.gov (United States)

    Jasty, M; Krushell, R; Zalenski, E; O'Connor, D; Sedlacek, R; Harris, W

    1993-02-01

    The contribution of the distal nonporous-coated stem to the stability of the uncemented femoral components, which were porous coated only proximally, was investigated under two conditions: (1) immediately after insertion and (2) at 6 months, 1 year, and 2 years after surgery in a canine model. The relative motion of the femoral components at the bone porous-coating interface under loads simulating the canine midstance was measured at these time periods using displacement transducers. The measurements were repeated after severing the connection between the porous-coated proximal body and the nonporous-coated distal stem through a small hole in the anterior cortex. The results showed that while the distal nonporous-coated stem enhanced the immediate stability of the proximally porous-coated uncemented femoral components, it contributed little to the long-term stability of the femoral components after bony ingrowth had occurred in vivo. The mean relative motion between the body of the prosthesis and the cortical bone increased from 12 microns (+/- 7 microns) to 31 microns (+/- 34 microns) in the posterior transverse direction when the stem was immediately severed after the surgery. However, at 6 months, 1 year, and 2 years after surgery, extensive bone ingrowth had occurred into the proximal porous-coated regions of the body and provided excellent stability to the femoral components. With bone ingrowth, the mean relative motion was less than 5 microns at any site. Under these conditions, severing the stem did not increase the relative motion of the prostheses significantly.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8436987

  15. 人工耳蜗植入术中自体乳突皮质骨重建乳突腔骨质缺损%Using Autologous Mastoid Cortical Bone during Cochlear Implantation

    Institute of Scientific and Technical Information of China (English)

    刘丛利; 孙家强; 侯晓燕; 陈建文; 孙敬武

    2015-01-01

    目的:探讨在成人人工耳蜗植入术中,应用自体乳突区皮质骨回放覆盖乳突切开后骨质缺损的临床效果。方法以58例行人工耳蜗植入的成人极重度感音神经性聋患者为研究对象(修复组),术中均采用切除的自体乳突区皮质骨片回放重建乳突切开后骨缺损的手术方式,术后观察患者耳后伤口痊愈情况、有无并发症;于术后1月开机时及术后3、6月检测助听听阈,并与同期未行自体乳突皮质骨重建乳突腔骨质缺损的同类患者(对照组)比较。结果修复组术后无一例出现耳后皮肤凹陷,均没有发生创面感染、急慢性中耳炎及颅内并发症,回放的皮质骨片愈合良好;术后复查所有患者耳蜗植入体无移位,术后1月开机时患者的平均助听听阈较术前提高约70 dB(P<0.05),术后1、3、6月平均助听听阈与对照组差异无统计学意义(均为 P>0.05),效果良好。结论在成人人工耳蜗植入手术中,应用自体乳突区皮质骨重建乳突腔皮质骨缺损能够避免耳后的凹陷,保证乳突的通气,有利于植入体的稳定性,且术后助听效果良好。%Objective To assessment the effect of autologous mastoid cortical bone to cover the mastoidetomy defect via transmastoid and posterior tympanotomy approach surgical technique during cochlear implantation in a ‐dults .Methods A total of 58 adults patients with profound sensorineural hearing loss accepted cochlear implantation from January 2010 and June 2014 ,which were using autologous mastoid cortical bone to cover the mastoidetomy de‐fect via transmastoid and posterior tympanotomy approach surgical technique .By observing postoperation complica‐tion the effect of surgery was evaluated .ABR were obtained for each patients at first ,third and sixth month after op‐eration .The patients which were not using autologous mastoid cortical bone to cover the mastoidetomy

  16. Long-term voluntary exercise of male mice induces more beneficial effects on cancellous and cortical bone than on the collagenous matrix

    OpenAIRE

    2009-01-01

    Abstract The effects of lifelong physical exercise on the composition, structure and mechanical properties of bone are not well understood. Earlier, we found that voluntary physical exercise improved various properties of bone in maturing male mice up to 6 months of age. In the present study, we extended the previous study to 18 months. Half of the mice (total N=144) had access to running wheels while half were kept sedentary. The collagen network was assessed biochemically and by ...

  17. Preliminary study of influence of bone tissue from osteonecrosis of femoral head on the proliferation and differentiation of canine bone marrow mesenchymal stem cells%股骨头坏死骨组织对骨髓间充质干细胞增殖分化的影响

    Institute of Scientific and Technical Information of China (English)

    王萌; 廖琦; 周斌; 仇志强; 程立明

    2013-01-01

    Objective To examine the effects of bone tissue from osteonecrosis of femoral head on the proliferation and differentiation of canine bone marrow mesenchymal stem cells in vitro culture.Methods A canine model of femoral head osteonecrosis was induced by liquid nitrogen freezing.BMSC were isolated from dog ilium bone marrow by a combination of gradient centrifugation and adherent wall culture.Different bone tissues and BMSC were cultivated indirectly in vitro by co-cultured in Transwell plate.According to the culture media,3 groups were established:blank group (10% FBS/DMEM),control group (10% FBS/DMEM + bone tissue from natural femoral head) and experimental group(10% FBS/DMEM + bone tissue from osteonecrosis of femoral head).Cell proliferation was measured by methylthiazol tetrazolium (MTT)method.Cell differentiation was examined by alkaline phosphatase (ALP) staining and its concentration examined.Alizarin red staining method was used to study the calcification effects and Oil red O staining method was used to detect if there was fat emergence.Results As compared with the blank group,the proliferation in the control and experiment groups were significantly promoted after culturing for Days 1,3 and 5 (P < 0.05).The proliferation of the experiment group was higher than the control group at Day 5 and 7 day (P < 0.05).After a 7-day co-culturing,ALP staining was positive in the control and experiment groups.At Day 7 and 9,the ALP activity in culture fluid was in this order:control group > experiment group >blank group(P <0.05).Alizarin red staining show control group had the most calcium nodules(12.17 ±2.48,P < 0.05) and the number of calcium nodules in the experiment group was more than the blank group (P <0.05).Oil red O staining show there was no fat emergence after 21 days in every group.Conclusion Both natural and osteonecrotic bone tissue of femoral head could promoted the proliferation of canine BMSC and induces them osteogenic

  18. Study of Osteoclast Adhesion to Cortical Bone Surfaces: A Correlative Microscopy Approach for Concomitant Imaging of Cellular Dynamics and Surface Modifications.

    Science.gov (United States)

    Shemesh, Michal; Addadi, Sefi; Milstein, Yonat; Geiger, Benjamin; Addadi, Lia

    2016-06-22

    Bone remodeling relies on the coordinated functioning of osteoblasts, bone-forming cells, and osteoclasts, bone-resorbing cells. The effects of specific chemical and physical bone features on the osteoclast adhesive apparatus, the sealing zone ring, and their relation to resorption functionality are still not well-understood. We designed and implemented a correlative imaging method that enables monitoring of the same area of bone surface by time-lapse light microscopy, electron microscopy, and atomic force microscopy before, during, and after exposure to osteoclasts. We show that sealing zone rings preferentially develop around surface protrusions, with lateral dimensions of several micrometers, and ∼1 μm height. Direct overlay of sealing zone rings onto resorption pits on the bone surface shows that the rings adapt to pit morphology. The correlative procedure presented here is noninvasive and performed under ambient conditions, without the need for sample labeling. It can potentially be applied to study various aspects of cell-matrix interactions. PMID:26682493

  19. 老年肱骨近端骨折患者皮质骨厚度与骨密度相关性分析%Analysis of the association between proximal humeral cortical bone thickness and bone mineral ;density in elderly proximal humeral fracture patients

    Institute of Scientific and Technical Information of China (English)

    张玺; 胡永成; 耿欣; 陈菲; 李健

    2015-01-01

    Objective To explore the possible association between proximal humeral cortical bone thickness and bone mineral density (BMD) in elderly patients with proximal humeral fractures. Methods We scaned 69 cases of the shoulders in elderly proximal humeral fracture patients and measured the average cortical bone thickness in two different CT layers with picture archiving and communication system (PACS). BMD was measured with dual-energy x-ray absorptiometry (DXA). Spearman correlations were used to assess the relationship between cortical bone thickness and BMD of femoral neck and lumbar vertebra. Results The study group was consisted of 69 cases, including 18 males and 51 females. About 65% of female and 16% of male were complicated by osteoporosis, The BMD of lumber and femoral neck were better in male patients than female patients (P<0.05), and in male osteoporosis patients than female osteoprosis patients (P<0.05). The BMD of lumber and femoral neck in all patients were closely related to average cortical bone thickness, and the same result was found in osteoporosis patients. Conclusion The measurement technique of average cortical bone thickness with CT and PACS is a quick and accurate method, which complements for DXA.%目的探讨老年肱骨近端骨折患者肱骨近端骨皮质厚度与骨密度(bone mineral density,BMD)的相关性。方法使用螺旋CT机对69例老年肱骨近端骨折患者的肩关节进行扫描后在图像工作站影像归档和通信系统处理软件中对两个水平层面图像的皮质骨厚度进行测量并取平均数,BMD值使用双能X线BMD测量仪测量获得,采用Spearman等级相关分析方法对腰椎和股骨颈处BMD与平均皮质骨厚度相关性进行计算。结果69例患者中,男18例、女51例,女性骨质疏松者占全部病例的65%,男性骨质疏松者占全部病例的16%。男性患者腰椎、股骨颈处BMD和平均皮质骨厚度均优于女性(P<0.05),骨质疏松患者

  20. Experimental Forelimb Allotransplantation in Canine Model

    Science.gov (United States)

    2016-01-01

    As reconstructive transplantation is gaining popularity as a viable alternative for upper limb amputees, it is becoming increasingly important for plastic surgeons to renew surgical skills and knowledge of this area. Forelimb allotransplantation research has been performed previously in rodent and swine models. However, preclinical canine forelimb allotransplantation studies are lacking in the literature. The purpose of this paper is to provide an overview of the surgical skills necessary to successfully perform forelimb transplantation in canines as a means to prepare for clinical application. A total of 18 transplantation operations on canines were performed. The recipient limb was shortened at the one-third proximal forearm level. The operation was performed in the following order: bones (two reconstructive plates), muscles and tendons (separately sutured), nerves (median, ulnar, and radial nerve), arteries (two), and veins (two). The total mean time of transplantation was 5 hours ± 30 minutes. All of the animals that received transplantation were treated with FK-506 (tacrolimus, 2 mg/kg) for 7 days after surgery. Most allografts survived with perfect viability without vascular problems during the early postoperative period. The canine forelimb allotransplantation model is well qualified to be a suitable training model for standard transplantation and future research work. PMID:27597952

  1. Experimental Forelimb Allotransplantation in Canine Model.

    Science.gov (United States)

    Hong, Sa-Hyeok; Eun, Seok-Chan

    2016-01-01

    As reconstructive transplantation is gaining popularity as a viable alternative for upper limb amputees, it is becoming increasingly important for plastic surgeons to renew surgical skills and knowledge of this area. Forelimb allotransplantation research has been performed previously in rodent and swine models. However, preclinical canine forelimb allotransplantation studies are lacking in the literature. The purpose of this paper is to provide an overview of the surgical skills necessary to successfully perform forelimb transplantation in canines as a means to prepare for clinical application. A total of 18 transplantation operations on canines were performed. The recipient limb was shortened at the one-third proximal forearm level. The operation was performed in the following order: bones (two reconstructive plates), muscles and tendons (separately sutured), nerves (median, ulnar, and radial nerve), arteries (two), and veins (two). The total mean time of transplantation was 5 hours ± 30 minutes. All of the animals that received transplantation were treated with FK-506 (tacrolimus, 2 mg/kg) for 7 days after surgery. Most allografts survived with perfect viability without vascular problems during the early postoperative period. The canine forelimb allotransplantation model is well qualified to be a suitable training model for standard transplantation and future research work. PMID:27597952

  2. Three-dimensional reconstruction of Haversian systems in human cortical bone using synchrotron radiation-based micro-CT: morphology and quantification of branching and transverse connections across age.

    Science.gov (United States)

    Maggiano, Isabel S; Maggiano, Corey M; Clement, John G; Thomas, C David L; Carter, Yasmin; Cooper, David M L

    2016-05-01

    This study uses synchrotron radiation-based micro-computed tomography (CT) scans to reconstruct three-dimensional networks of Haversian systems in human cortical bone in order to observe and analyse interconnectivity of Haversian systems and the development of total Haversian networks across different ages. A better knowledge of how Haversian systems interact with each other is essential to improve understanding of remodeling mechanisms and bone maintenance; however, previous methodological approaches (e.g. serial sections) did not reveal enough detail to follow the specific morphology of Haversian branching, for example. Accordingly, the aim of the present study was to identify the morphological diversity of branching patterns and transverse connections, and to understand how they change with age. Two types of branching morphologies were identified: lateral branching, resulting in small osteon branches bifurcating off of larger Haversian canals; and dichotomous branching, the formation of two new osteonal branches from one. The reconstructions in this study also suggest that Haversian systems frequently target previously existing systems as a path for their course, resulting in a cross-sectional morphology frequently referred to as 'type II osteons'. Transverse connections were diverse in their course from linear to oblique to curvy. Quantitative assessment of age-related trends indicates that while in younger human individuals transverse connections were most common, in older individuals more evidence of connections resulting from Haversian systems growing inside previously existing systems was found. Despite these changes in morphological characteristics, a relatively constant degree of overall interconnectivity is maintained throughout life. Altogether, the present study reveals important details about Haversian systems and their relation to each other that can be used towards a better understanding of cortical bone remodeling as well as a more accurate

  3. Biomechanics of cortical bone allografts among different fixation modes%异体皮质骨板不同固定方式的生物力学比较

    Institute of Scientific and Technical Information of China (English)

    张仁明; 廖瑛; 李宝兴; 余黎明

    2008-01-01

    BACKGROUND:The materials for internal fixation of bone allografts have been used in the clinic.However,they are only used in the regions bearing little stress because of low strength.The focus of current studies is how to enhance the fixation strength of the materials to expand application range.OBJECTIVE:To compare the strength difference of cortical bone allografts among different fixation modes and to investigate the possible mechanisms of action.DESIGN,TIME AND SETTING:An in vitro biomechanical experiment was performed at the Laboratory of Biomechanics,Nanhua University between October 2005 and March 2006.MATERIALS:Twenty-seven pieces of cadaveric femurs were included in this study.A total of 45 cortical bone allografts with a size of 110 mm×10 mm×3 mm and 90 bone screws were also used.METHODS:Twenty-seven femurs were made into simulated fracture models and randomized to 3 groups,with 9 models per group:A,B,and C.In the group A,the models were fixed with two cortical bone all6grafts; the models from the groups B and C were fixed with two bone allografts plus 5 bone screws and one bone allograft plus 5 bone screws accordingly.MAIN OUTCOME MEASURES:Biomechanical tests were performed in the above-mentioned 3 groups to measure compressive,bending and torsional stiffness as well as the maximum loads.RESULTS:Different fixation models displayed different mechanical characteristics.The group A exhibited similar compressive stiffness compared to the group B,but the level was significantly higher compared to the group C (P < 0.05).The other two stiffness parameters including bending and torsion were significantly greater in the group A than in the groups B and C (P < 0.05).The maximum loads of compression,bending,and torsion were significantly greater in the group A compared to the group B (P < 0.05) and group C (P < 0.01).CONCLUSION:The strength of bone allograft is highly related to fixation mode. The two bone allografts showed greater strength and stiffness

  4. Tissue-engineering bone with ADSCs and coral scaffold for repairing of cranial bone defect in canine%自体脂肪干细胞复合珊瑚修复犬颅骨标准缺损的初步研究

    Institute of Scientific and Technical Information of China (English)

    刘波; 崔磊; 刘广鹏; 曹谊林; 朱金土; 曹毅

    2009-01-01

    Objective To investigate the application of tiasue-engineering bone with ADSCs(adipese-derived stem cells) and coral scaffold for repairing of cranial bone defect in canine. Methods Autelogons ADSCs isolated from canine subcutaneous fat were expanded, osteoganicaily induced, and seeded on coral scaffolds. Bilateral full-thickness defects(20 mm x 20 mm) of parietal bone were created (n = 7). The defects were either repaired with ADSC-coral constructs (experimental group) or with coral alone (control group). Radiological, gross, biomechanical and histological observations were done to evaluate the bone regeneration. Results Three-dimensional CT scan showed that new bones were formed in the experimental group at 12 weeks after implantation, while coral scaffolds were partially degraded in the control group. By radiographic analysis at 24 weeks post-transplantation, it showed that an average repair percentage of each defect was (84.19:1:6.45) % in experimental group, and (25.04 ± 18.82) % in control group(P < 0.01). The maximum compression loading was (73.45±17.26) N in experimental group, and (104.27± 22.71) N in control group (P < 0.01).Hislological examination revealed that the defect was repaired by typical bone tissue in experimental group, while only minimal bone formation with fibrous connection in the control group. Conclusions The tissue-engineering bone with autologous osteogenic ADSCs and scaffold could successfully repair the cranial defects in canine models.%目的 应用自体脂肪干细胞(adipose-derived stem cells,ADSCs)复合珊瑚构建组织工程化骨,修复犬颅骨标准缺损.方法 体外扩增培养、成骨诱导Beagle犬ADSCs,将第2代细胞接种在珊瑚支架上共同培养.制造实验犬双侧颅骨全层标准缺损(20 mm×20 mm),一侧以细胞材料复合物修复作为实验组(n=7),另一侧以单纯珊瑚材料修复作为对照组(n=7).术后24周分别通过影像学、大体形态观察、生物力学检测、组织学

  5. Distribution of beta-amyloid in the canine brain.

    Science.gov (United States)

    Hou, Y; White, R G; Bobik, M; Marks, J S; Russell, M J

    1997-03-01

    The distribution of amyloid-beta protein (A beta) in the canine brain was demonstrated by immunochemistry on serially sectioned tissues from 10 aged mixed breed dogs. Summation of quantitative data and relegation to anatomical sites for the 10 dogs showed A beta to be widely distributed in the cortex and hippocampus while completely absent in the brain stem and cerebellum. The highest density of A beta was in the dentate gyrus of the hippocampus. Cortical areas exhibiting the greatest A beta deposition were the posterior and medial suprasylvius gyrus and the proreus gyrus of the frontal lobe. Unlike humans the canine entorhinal cortex, amygdala, basal ganglia and olfactory bulbs were rarely affected. This suggested that the highly developed olfactory pathways of the canine are generally spared from A beta deposition. PMID:9141082

  6. Cell tracking and therapy evaluation of bone marrow monocytes and stromal cells using SPECT and CMR in a canine model of myocardial infarction

    Directory of Open Access Journals (Sweden)

    Merrifield Peter

    2009-04-01

    Full Text Available Abstract Background The clinical application of stem cell therapy for myocardial infarction will require the development of methods to monitor treatment and pre-clinical assessment in a large animal model, to determine its effectiveness and the optimum cell population, route of delivery, timing, and flow milieu. Objectives To establish a model for a in vivo tracking to monitor cell engraftment after autologous transplantation and b concurrent measurement of infarct evolution and remodeling. Methods We evaluated 22 dogs (8 sham controls, 7 treated with autologous bone marrow monocytes, and 7 with stromal cells using both imaging of 111Indium-tropolone labeled cells and late gadolinium enhancement CMR for up to12 weeks after a 3 hour coronary occlusion. Hearts were also examined using immunohistochemistry for capillary density and presence of PKH26 labeled cells. Results In vivo Indium imaging demonstrated an effective biological clearance half-life from the injection site of ~5 days. CMR demonstrated a pattern of progressive infarct shrinkage over 12 weeks, ranging from 67–88% of baseline values with monocytes producing a significant treatment effect. Relative infarct shrinkage was similar through to 6 weeks in all groups, following which the treatment effect was manifest. There was a trend towards an increase in capillary density with cell treatment. Conclusion This multi-modality approach will allow determination of the success and persistence of engraftment, and a correlation of this with infarct size shrinkage, regional function, and left ventricular remodeling. There were overall no major treatment effects with this particular model of transplantation immediately post-infarct.

  7. Case Report: Canine Fossa Abscess; A Rare Etiological Factor: The Lower Canine Tooth

    OpenAIRE

    Agacayak, K. Serkan; Atılgan, S. Serhat; GORGUN, Belgin; Yaman, Ferhan; Ucan, M. Can; Atalay, Yusuf

    2013-01-01

    Odontogenic infection may be dangerous; especially when life-threatening complications occur. Infection spreads through the bone and periosteum toward nearby or more distant structures and spaces. Canine fossa abscess is an odontogenic infection that can lead to life-threatening complications. Successful treatment requires early recognition, determination of etiological factors, and proper medical and surgical management. The aim of this paper is to emphasize different and rare etiological fa...

  8. Canine hypertrophic osteopathy associated with extra-thoracic lesions

    OpenAIRE

    Headley Selwyn Arlington; Ribeiro Eduardo Alcântara; Santos Gustavo José Von G. dos; Bettini Carlos Maia; Mattos Júnior Ewaldo

    2005-01-01

    Canine hypertrophic osteopathy is described in a dog that presented extra-thoracic lesions, mainly in the liver. Hepatic lesions were characterized by necrosis, hemorrhage, severe hydropic degeneration of centrolobular hepatocytes, proliferation of epithelial cells of bile ducts, and mild biliary stasis. The disease syndrome was diagnosed based on clinical signs, radiological evaluation, and inspection of macerated bones.

  9. Growth and Age-Related Abnormalities in Cortical Structure and Fracture Risk.

    Science.gov (United States)

    Seeman, Ego

    2015-12-01

    Vertebral fractures and trabecular bone loss have dominated thinking and research into the pathogenesis and the structural basis of bone fragility during the last 70 years. However, 80% of all fractures are non-vertebral and occur at regions assembled using large amounts of cortical bone; only 20% of fractures are vertebral. Moreover, ~80% of the skeleton is cortical and ~70% of all bone loss is cortical even though trabecular bone is lost more rapidly than cortical bone. Bone is lost because remodelling becomes unbalanced after midlife. Most cortical bone loss occurs by intracortical, not endocortical remodelling. Each remodelling event removes more bone than deposited enlarging existing canals which eventually coalesce eroding and thinning the cortex from 'within.' Thus, there is a need to study the decay of cortical as well as trabecular bone, and to develop drugs that restore the strength of both types of bone. It is now possible to accurately quantify cortical porosity and trabecular decay in vivo. The challenges still to be met are to determine whether measurement of porosity identifies persons at risk for fracture, whether this approach is compliments information obtained using bone densitometry, and whether changes in cortical porosity and other microstructural traits have the sensitivity to serve as surrogates of treatment success or failure. PMID:26394727

  10. Multiple quantitative trait loci for cortical and trabecular bone regulation map to mid-distal mouse chromosome 4 that shares linkage homology to human chromosome 1p36.

    Science.gov (United States)

    Beamer, Wesley G; Shultz, Kathryn L; Coombs, Harold F; Horton, Lindsay G; Donahue, Leah Rae; Rosen, Clifford J

    2012-01-01

    The mid-distal region of mouse chromosome 4 (Chr 4) is homologous with human Chr 1p36. Previously, we reported that mouse Chr 4 carries a quantitative trait locus (QTL) with strong regulatory effect on volumetric bone mineral density (vBMD). The intent of this study is to utilize nested congenic strains to decompose the genetic complexity of this gene-rich region. Adult females and males from 18 nested congenic strains carrying discrete C3H sequences were phenotyped for femoral mineral and volume by pQCT and for trabecular bone volume (BV), tissue volume (TV), trabecular number (Trab.no), and trabecular thickness (Trab.thk) by MicroCT 40. Our data show that the mouse Chr 4 region consists of at least 10 regulatory QTL regions that affected either or both pQCT and MicroCT 40 phenotypes. The pQCT phenotypes were typically similar between sexes, whereas the MicroCT 40 phenotypes were divergent. Individual congenic strains contained one to seven QTL regions. These regions conferred large positive or negative effects in some congenic strains, depending on the particular bone phenotype. The QTL regions II to X are syntenic with human 1p36, containing from 1 to 102 known genes. We identified 13 candidate genes that can be linked to bone within these regions. Six of these genes were linked to osteoblasts, three linked to osteoclasts, and two linked to skeletal development. Three of these genes have been identified in Genome Wide Association Studies (GWAS) linked to 1p36. In region III, there is only one gene, Lck, which conferred negative pQCT and MicroCT 40 phenotypes in both sexes. This gene is important to development and functioning of T cells, has been associated with osteoclast activity, and represents a novel bone regulatory gene that merits further experimental evaluation. In summary, congenic strains are powerful tools for identifying regulatory regions that influence bone biology and offer models for testing hypotheses about gene-gene and gene

  11. Why segment the maxilla between laterals and canines?

    Directory of Open Access Journals (Sweden)

    Lucas Senhorinho Esteves

    2016-02-01

    Full Text Available Introduction: Maxillary surgery on a bone segment enables movement in the sagittal and vertical planes. When performed on multiple segments, it further provides movement in the transverse plane. Typical sites for interdental osteotomies are between laterals and canines, premolars and canines, or between incisors. Additionally, osteotomies can be bilateral, unilateral or asymmetric. The ability to control intercanine width, buccolingual angulation of incisors, and correct Bolton discrepancy are some of the advantages of maxillary segmentation between laterals and canines. Objective: This article describes important features to be considered in making a clinical decision to segment the maxilla between laterals and canines when treating a dentoskeletal deformity. It further discusses the history of this surgical approach, the indications for its clinical use, the technique used to implement it, as well as its advantages, disadvantages, complications and stability. It is therefore hoped that this paper will contribute to disseminate information on this topic, which will inform the decision-making process of those professionals who wish to make use of this procedure in their clinical practice. Conclusions: Segmental maxillary osteotomy between laterals and canines is a versatile technique with several indications. Furthermore, it offers a host of advantages compared with single-piece osteotomy, or between canines and premolars.

  12. Clinical application of canal wall reconstruction with homograft cortical bone plate in canal wall down tympanoplasty%自体皮质骨外耳道重建在开放式鼓室成形术中的应用

    Institute of Scientific and Technical Information of China (English)

    马喆; 习国平; 张社江; 蔡爱军; 郝艳芳; 梁宝莲

    2012-01-01

    目的 对开放式鼓室成形术中利用自体皮质骨行外耳道重建的方法及疗效进行评价.方法 将接受手术治疗的胆脂瘤型中耳炎患者49例(49耳)分为两组.实验组,行开放式鼓室成形术+自体皮质骨外耳道重建术25例(耳);对照组,行常规开放式鼓室成形术+耳甲腔成形术24例(耳).术后随访6 ~ 36个月,观察两组患者术后听力结果、干耳率情况.结果 以术后语言频率气骨导差缩小>15 dB或气导听阈<40 dB为有效标准,实验组有效率68% (17/25),对照组有效率62.5% (15/24),组间比较无统计学意义(x2=0.1635,P>0.05).实验组干耳率为92.5%(23/25),明显高于对照组58.33%(14/24),差异有统计学意义(x2=4.363 6,P <0.05).实验组重建后的外耳道结构正常,无闭锁或狭窄情况发生.中耳乳突腔均接近正常.全部病例均无胆脂瘤复发.结论 开放式鼓室成形术加自体皮质骨外耳道重建术,能有效清除中耳病灶组织、恢复外耳道和中耳的结构,术后听力结果满意,干耳率高,是较为理想的手术方式.%Objective To evaluate the therapy of canal wall down tympanoplasty and canal reconstruction with homo-graft cortical bone plate. Methods Retrospective case review. 49 patients were divided into 2 groups. The experimental group that included 25 ears underwent canal wall down tympanoplasty and canal reconstruction with homograft cortical bone plate, while the control group that included 24 ears underwent regular canal wall down tympanoplasty with canal reconstruction. Follow up lasted 6-36 months and postoperative hearing and dry ear rate were evaluated. Results The criteria for success were defined as AB gap closure over 15 dB HL or air conduction threshold less than 40 dB HL (using the mean of 0. 5-, 1-, and 2-KHz threshold values). The experimental group's effective rate was 68% (17/25) and the control group's was 62. 5% (15/24). No significant difference was found between the

  13. Comparação da resistência à tração da âncora metálica rosqueada inserida no osso cortical e no osso esponjoso Comparison of the tensile strength of threaded metal anchors inserted on cortical and spongy bones

    Directory of Open Access Journals (Sweden)

    Lucas Busnardo Ramadan

    2006-01-01

    Full Text Available A rotura do manguito rotador é uma afecção freqüente com repercussão na vida diária do paciente causando incapacidade funcional e dor. Um número considerável de pacientes necessita de reparação tendínea. A tendência atual na cirurgia do ombro é a utilização de técnicas minimamente invasivas com menor morbidade operatória e reabilitação mais precoce. A partir dos anos 90 houve um grande desenvolvimento da artroscopia do ombro e na utilização de âncoras para fixação das suturas tendíneas. Essa evolução técnica tem permitido resultados da cirurgia artroscópica comparáveis aos da cirurgia aberta. Um dos possíveis problemas do uso de âncoras nas cirurgias artroscópicas do ombro é sua soltura da superfície óssea. O presente estudo tem o objetivo de comparar a resistência à tração das âncoras metálicas rosqueadas inseridas no osso cortical e no osso esponjoso.Rotator cuff rupture is a common affection causing an impact on the daily lives of patients, resulting in functional disability and pain. A reasonable number of patients need tendinous repair. Current trends on shoulder surgery are the use of minimally invasive techniques with lower per-operative morbidity and earlier rehabilitation. From the 1990's on, shoulder arthroscopy was largely developed, as well as the use of anchors for tendinous sutures fixation. This technical evolution has allowed for arthroscopic surgery outcomes comparable to those in open surgeries. One of the potential problems for the use of anchors in shoulder arthroscopic surgeries is related to its loosening from bone surface. The present study has as an objective to compare the tensile strength of threaded metal anchors inserted on cortical and spongy bones.

  14. Vaccines for Canine Leishmaniasis

    Directory of Open Access Journals (Sweden)

    Faeze Foroughi-Parvar

    2014-01-01

    Full Text Available Leishmania infantum is the obligatory intracellular parasite of mammalian macrophages and causes zoonotic visceral leishmaniasis (ZVL. The presence of infected dogs as the main reservoir host of ZVL is regarded as the most important potential risk for human infection. Thus the prevention of canine visceral leishmaniasis (CVL is essential to stop the current increase of the Mediterranean visceral leishmaniasis. Recently considerable advances in achieving protective immunization of dogs and several important attempts for achieving an effective vaccine against CVL lead to attracting the scientists trust in its important role for eradication of ZVL. This paper highlights the recent advances in vaccination against canine visceral leishmaniasis from 2007 until now.

  15. Vaccines for canine leishmaniasis

    Directory of Open Access Journals (Sweden)

    Clarisa B. Palatnik-De-Sousa

    2012-04-01

    Full Text Available Leishmaniasis is the third most important vector-borne disease worldwide. Visceral leishmaniasis (VL is a severe and frequently lethal protozoan disease of increasing incidence and severity due to infected human and dog migration, new geographical distribution of the insect due to global-warming, co-infection with immunosuppressive diseases and poverty. The disease is an anthroponosis in India and Central Africa and a canid zoonosis (ZVL in the Americas, the Middle East, Central Asia, China and the Mediterranean. The ZVL epidemic has been controlled by one or more measures including the culling of infected dogs, treatment of human cases and insecticidal treatment of homes and dogs. However, the use of vaccines is considered the most cost-effective control tool for human and canine disease. Since the severity of the disease is related to the generation of T-cell immunosuppression, effective vaccines should be capable of sustaining or enhancing the T-cell immunity. In this review we summarize the clinical and parasitological characteristics of ZVL with special focus on the cellular and humoral canine immune response and review state-of-the-art vaccine development against human and canine visceral leishmaniasis. Experimental vaccination against leishmaniasis has evolved from the practice of leishmanization with living parasites to vaccination with crude lysates, native parasite extracts to recombinant and DNA vaccination. Although more than 30 defined vaccines have been studied in laboratory models no human formulation has been licensed so far; however three second-generation canine vaccines have already been registered. As expected for a zoonotic disease, the recent preventive vaccination of dogs in Brazil has led to a reduction in the incidence of canine and human disease. The recent identification of several Leishmania proteins with T-cell epitopes anticipates development of a multiprotein vaccine that will be capable of protecting both humans

  16. 新型人工生物活性接骨板治疗犬股骨骨折%LIM mineralization protein 1 gene transfected bone marrow mesenchymal stem cells combined with nano-hydroxyapatite/polyamide 66 plate in the treatment of canine femoral fractures

    Institute of Scientific and Technical Information of China (English)

    徐小平; 倪卫东; 高仕长; 蒲超; 黄伟弘

    2012-01-01

    BACKGROUND: Studies have shown that nano-hydroxyapatite/polyamide 66 (n-HA/PA66) is a kind of high-strength and high-toughness composite material with excellent biocompatibility, biological safety, biological activity and bone conduction ability.OBJECTIVE: To investigate the effect and feasibility of n-HA /PA66 plate combined with bone marrow mesenchymal cells (BMSCs) transfected with human LIM mineralization protein 1 (LMP-1) gene for treatment of canine femoral fractures. METHODS: Canine BMSCs were isolated and cultured with density gradient centifugation method and adhesive culture method. The third-generation BMSCs were transfected with Adv-hLMP-1, and then combined with n-HA /PA66 plate. The dog models of femoral fractures were established in 48 dogs and were divided into four groups: Ad-LMP-1 transfection group, non-transfected group, n-HA/PA66 alone group and plate and screw groups.RESULTS AND CONCLUSION: The failure rate in the transfection group was lower than that in non-transfected group and n-HA/ PA66 plate group at 8 or 12 weeks postoperatively (P 0.05). The healing time of the transfection group was shorter than that of the other three groups. The plate in the transfection group was completely fused with canine femoral lateral cortex after 12 weeks of operation, and there was obvious bone formation between material and bone. The plate and canine lateral femoral cortex were only partially fused in the non-transfected group and n-HA/PA66 plate group, and there was no or a small amount of bone tissue formation between material and bone. The treatment of canine femoral fractures with n-HA/PA66 plate combined with BMSCs transfected with LMP-1 gene can get good fixation effects, promote the fracture healing and fusion with autogenous bone, without the need for a second operation to take out, but the strength of materials have some limitations, which must be combined with external fixation in the treatment of canine femoral fractures.%背景:研究表明纳

  17. Bone Regeneration in Odontostomatology

    OpenAIRE

    Tonelli, P; Duvina, M.; Brancato, L.; Delle Rose, G.; Biondi, E.; Civitelli, V.

    2010-01-01

    Maxillary edentulism, together with periodontal disease, is the condition that most frequently induces disruption of alveolar bone tissue. Indeed, the stimulus of the periodontal ligament is lost and the local bone tissue becomes subject to resorption processes that, in the six months following the loss of the tooth, result in alveolar defects or more extensive maxillary atrophy. In both cases, loss of vestibular cortical bone is followed by reduction in the vertical dimension of the alveolar...

  18. Biotinylated dextran amine anterograde tracing of the canine corticospinal tract

    Institute of Scientific and Technical Information of China (English)

    Xiao Han; Guangming Lv; Huiqun Wu; Dafeng Ji; Zhou Sun; Yaofu Li; Lemin Tang

    2012-01-01

    In this study, biotinylated dextran amine (BDA) was microinjected into the left cortical motor area of the canine brain. Fluorescence microscopy results showed that a large amount of BDA-labeled pyramidal cells were visible in the left cortical motor area after injection. In the left medulla oblongata, the BDA-labeled corticospinal tract was evenly distributed, with green fluorescence that had a clear boundary with the surrounding tissue. The BDA-positive corticospinal tract entered into the right lateral funiculus of the spinal cord and descended into the posterior part of the right lateral funiculus, close to the posterior horn, from cervical to sacral segments. There was a small amount of green fluorescence in the sacral segment. The distribution of BDA labeling in the canine central nervous system was consistent with the course of the corticospinal tract. Fluorescence labeling for BDA gradually diminished with time after injection. Our findings indicate that the BDA anterograde tracing technique can be used to visualize the localization and trajectory of the corticospinal tract in the canine central nervous system.

  19. Morphological study of maxillary canine region based on CT

    International Nuclear Information System (INIS)

    The maxilla is generally known as a site where anatomical limitations make it difficult to obtain sufficient bone volume. A large amount of bone exists in the canine region between the anterior margin of the maxillary sinus and the piriform aperture margin. Although this region is crucial for implant treatments, there have not been any reports on morphological studies of the region. In this study, we investigated the morphology of the canine region based on CT, and also the morphology and position of the maxillary sinus located posterior to the canine region. The results were as follows: In the area above the anterior nasal spine, the higher the level, the smaller the mesio-distal length and the bucco-lingual width tended to become. In the area above the anterior nasal spine, the mesio-distal length and the bucco-lingual width tended to be smaller in female patients than in male patients. In the area above the anterior nasal spine, no significant differences in mesio-distal length and bucco-lingual width were observed between dentulous and edentulous jaws. The morphology of the maxillary sinus was mainly of an inverse-trapezoidal, circular, or triangular form. The position of the anterior wall of the maxillary sinus was most frequently found at the site corresponding to the second premolar. Through this study, we have reconfirmed that the canine region is vital for implant treatments in the maxilla. (author)

  20. [Bone transplant].

    Science.gov (United States)

    San Julián, M; Valentí, A

    2006-01-01

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

  1. [Bone transplant].

    Science.gov (United States)

    San Julián, M; Valentí, A

    2006-01-01

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

  2. The canine vomeronasal organ.

    OpenAIRE

    Adams, D. R.; Wiekamp, M D

    1984-01-01

    The vomeronasal organ was studied in mature dogs with the optical, transmission electron, and scanning electron microscopes. The canine vomeronasal complex is structurally well developed. Large blood vessels are present deep to both the lateral, 'non-receptor' and medial, 'receptor' epithelia. In addition to the unmyelinated vomeronasal nerves in the lamina propria deep to the 'receptor' epithelium, numerous nerves containing both myelinated and unmyelinated fibres are present deep to the 'no...

  3. Bone grafting: An overview

    Directory of Open Access Journals (Sweden)

    D. O. Joshi

    2010-08-01

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

  4. Bone grafting, corticotomy, and orthodontics: treatment of cleft alveolus in a chinese cohort.

    Science.gov (United States)

    Mao, Li-Xia; Shen, Guo-Fang; Fang, Bing; Xia, Yun-Hui; Ma, Xu-Hui; Wang, Bo

    2013-11-01

    Objective : A multimodal therapy was applied to solve a set of related problems including collapse of the posterior segment, high level gingival margin of canine, and resorption of grafted bone in a cohort of Chinese youngsters with cleft lip and palate. This study aimed to evaluate the benefits of this treatment procedure. Methods : Thirty patients with unilateral cleft lip and palate were included in this prospective study. All patients had previously undergone only cleft lip and palate repair and presented with alveolar cleft and an obvious step in the gingival margin between the canine tooth and the teeth beside it. A multimodal therapy that included bone grafting, corticotomy, and orthodontics was applied to solve these problems. Grafted bone volume, parallelism of the roots, root resorption, gingival margin, and mobility of the canine on the cleft side were established before surgery, 1 week after surgery, and after straightening of the canine. Results : Less than 25% of the grafted bone was reabsorbed in 25 of the 30 patients, while less than 50% was resorbed in the remaining five. The roots of the canines on the cleft side were mostly parallel to the adjacent teeth. Root resorption and mobility of the canines were slight. The difference in the gingival margin between the canines on the cleft side and the other side was small. Conclusions : Canines moved into the grafted bone safely and effectively, thus achieving a normal gingival margin and retaining grafted bone volume in one operation. PMID:22849663

  5. Novel canine bocavirus strain associated with severe enteritis in a dog litter.

    Science.gov (United States)

    Bodewes, Rogier; Lapp, Stefanie; Hahn, Kerstin; Habierski, André; Förster, Christine; König, Matthias; Wohlsein, Peter; Osterhaus, Albert D M E; Baumgärtner, Wolfgang

    2014-11-01

    Bocaviruses are small non-enveloped viruses with a linear ssDNA genome, that belong to the genus Bocaparvovirus of the subfamiliy Parvovirinae. Bocavirus infections are associated with a wide spectrum of disease in humans and various mammalian species. Here we describe a fatal enteritis associated with infection with a novel strain of canine bocavirus 2 (CaBoV-2), that occurred in a litter of German wirehaired pointers. Necropsy performed on three puppies revealed an enteritis reminiscent of canine parvovirus associated enteritis, accompanied with signs of lymphocytolytic disease in bone marrow, spleen, lymph nodes and thymus. While other major causes of enteritis of young dogs, including canine parvovirus, were excluded, by random PCR in combination with next-generation sequencing, a novel CaBoV-2 strain was detected. Phylogenetic analysis of the genome of this novel canine bocavirus strain indicated that this virus was indeed most closely related to group 2 canine bocaviruses. Infection with canine bocavirus was confirmed by in situ hybridization, which revealed the presence of CaBoV-2 nucleic acid in the intestinal tract and lymphoid tissues of the dogs. In a small-scale retrospective analysis concerning the role of CaBoV-2 no additional cases were identified. The findings of this study provide novel insights into the pathogenicity of canine bocaviruses.

  6. Micro-computed tomography (CT) based assessment of dental regenerative therapy in the canine mandible model

    Science.gov (United States)

    Khobragade, P.; Jain, A.; Setlur Nagesh, S. V.; Andreana, S.; Dziak, R.; Sunkara, S. K.; Sunkara, S.; Bednarek, D. R.; Rudin, S.; Ionita, C. N.

    2015-03-01

    High-resolution 3D bone-tissue structure measurements may provide information critical to the understanding of the bone regeneration processes and to the bone strength assessment. Tissue engineering studies rely on such nondestructive measurements to monitor bone graft regeneration area. In this study, we measured bone yield, fractal dimension and trabecular thickness through micro-CT slices for different grafts and controls. Eight canines underwent surgery to remove a bone volume (defect) in the canine's jaw at a total of 44 different locations. We kept 11 defects empty for control and filled the remaining ones with three regenerative materials; NanoGen (NG), a FDA-approved material (n=11), a novel NanoCalcium Sulfate (NCS) material (n=11) and NCS alginate (NCS+alg) material (n=11). After a minimum of four and eight weeks, the canines were sacrificed and the jaw samples were extracted. We used a custombuilt micro-CT system to acquire the data volume and developed software to measure the bone yield, fractal dimension and trabecular thickness. The software used a segmentation algorithm based on histograms derived from volumes of interest indicated by the operator. Using bone yield and fractal dimension as indices we are able to differentiate between the control and regenerative material (p<0.005). Regenerative material NCS showed an average 63.15% bone yield improvement over the control sample, NCS+alg showed 55.55% and NanoGen showed 37.5%. The bone regeneration process and quality of bone were dependent upon the position of defect and time period of healing. This study presents one of the first quantitative comparisons using non-destructive Micro-CT analysis for bone regenerative material in a large animal with a critical defect model. Our results indicate that Micro-CT measurement could be used to monitor invivo bone regeneration studies for greater regenerative process understanding.

  7. Role of trabecular bone in visibility of laminadura: A cross-sectional radiographic study

    Directory of Open Access Journals (Sweden)

    T Rajesh Singh

    2015-01-01

    Conclusion: There was statistically significant difference in the visibility of loss of LD when trabecular bone is lost. LD can be visible only if the endosteal surface of the cortical bone and trabecular bone is intact.

  8. Genetic selection for fast growth generates bone architecture characterised by enhanced periosteal expansion and limited consolidation of the cortices but a diminution in the early responses to mechanical loading.

    OpenAIRE

    Rawlinson, S. C.; Murray, D. H.; Mosley, J. R.; Wright, C. D.; Bredl, J. C.; Saxon, L. K.; Loveridge, N; Leterrier, C.; Constantin, P.; Farquharson, C.; Pitsillides, A. A.

    2009-01-01

    Bone strength is, in part, dependent on a mechanical input that regulates the (re)modelling of skeletal elements to an appropriate size and architecture to resist fracture during habitual use. The rate of longitudinal bone growth in juveniles can also affect fracture incidence in adulthood, suggesting an influence of growth rate on later bone quality. We have compared the effects of fast and slow growth on bone strength and architecture in the tibiotarsi of embryonic and juvenile birds. The l...

  9. In vitro evaluation of three different biomaterials as scaffolds for canine mesenchymal stem cells

    Directory of Open Access Journals (Sweden)

    Oduvaldo Câmara Marques Pereira-Junior

    2013-05-01

    Full Text Available PURPOSE: To evaluate in vitro ability the of three different biomaterials - purified hydroxyapatite, demineralized bone matrix and castor oil-based polyurethane - as biocompatible 3D scaffolds for canine bone marrow mesenchymal stem cell (MSC intending bone tissue engineering. METHODS: MSCs were isolated from canine bone marrow, characterized and cultivated for seven days with the biomaterials. Cell proliferation and adhesion to the biomaterial surface were evaluated by scanning electron microscopy while differentiation into osteogenic lineage was evaluated by Alizarin Red staining and Sp7/Osterix surface antibody marker. RESULTS: The biomaterials allowed cellular growth, attachment and proliferation. Osteogenic differentiation occurred in the presence of hydroxyapatite, and matrix deposition commenced in the presence of the castor oil-based polyurethane. CONCLUSION: All the tested biomaterials may be used as mesenchymal stem cell scaffolds in cell-based orthopedic reconstructive therapy.

  10. Osteobiol (r) enhances osteogenic differentiation in bone marrow derived stem cells

    OpenAIRE

    D. Lauritano; Carinci, F.; Zollino, I; A. Hassanipour; Saggese, V; A. Palmieri; Girardi, A; Cura, F; A. Piras; Zamboni, P.; Brunelli, G

    2012-01-01

    OsteoBiol (R) (OsteoBiol, Tecnoss Dental, Turin, Italy) a cortical collagenated porcine bone is largely employed in oral implant techniques for bone regeneration thanks to its biocompatibility and osteoconductivity To study the mechanism by which cortical porcine bone promotes osteoblast differentiation and bone regeneration, changes in expression level of bone related genes were investigated by real time RT-PCR, in bone marrow derived stem cells and human osteoblasts cultivated with OsteoBio...

  11. The reliability and representativity of non-dynamic bone histomorphometry in uremic osteodystrophy

    DEFF Research Database (Denmark)

    Heaf, J G; Pødenphant, J; Gammelgaard, Bente

    1993-01-01

    trabecular bone indices are reliable variables and, with the possible exception of bone mass determination, indicative of systemic bone disease. Bone aluminium concentration and cortical bone indices are unreliable measures of uremic bone disease. These reservations apply to the diagnostic use of biopsy...

  12. Computed Tomography Imaging of the Topographical Anatomy of Canine Prostate

    International Nuclear Information System (INIS)

    AIM: To investigate the topographical anatomy of canine prostate gland by computed tomography (CT) for diagnostic imaging purposes. ÐœATERIAL AND METHODS: Seven clinically healthy mongrel male dogs at the age of 3−4 years and body weight of 10−15 kg were submitted to transverse computerized axial tomography (CAT) with cross section thickness of 5 mm. RESULTS: The CT image of canine prostate is visualized throughout the scans of the pelvis in the planes through the first sacral vertebra (S1) dorsally; the bodies of iliac bones laterally and cranially to the pelvic brim (ventrally). The body of prostate appears as an oval homogenous relatively hypo dense finding with soft tissue density. The gland is well differentiated from the adjacent soft tissues. CONCLUSION: By means of CT, the cranial part of prostate gland in adult dogs aged 3−4 years exhibited an abdominal localization. (author)

  13. 9 CFR 113.305 - Canine Hepatitis and Canine Adenovirus Type 2 Vaccine.

    Science.gov (United States)

    2010-01-01

    ... STANDARD REQUIREMENTS Live Virus Vaccines § 113.305 Canine Hepatitis and Canine Adenovirus Type 2 Vaccine. Canine Hepatitis Vaccine and Canine Adenovirus Type 2 Vaccine shall be prepared from virus-bearing cell... hepatitis, the test is inconclusive and may be repeated. (B) If at least 19 of the 20 vaccinates do...

  14. 庆大霉素脂质体同种异体骨体外抑制金黄色葡萄球菌生物膜的研究%Liposomal gentamicin-impregnated allogeneic cortical bone inhibits S.aureus biofilms

    Institute of Scientific and Technical Information of China (English)

    唐辉; 陆声; 朱跃良; 汤迅; 李军; 丁晶; 徐永清; 郑天娥; 李刚; 游永刚; 陆华拓; 赵万秋; 马涛; 周田华

    2009-01-01

    Objective To explore the effect of a new antibiotic-delivery system on inhibition of staphylococcus aureus biofilm infection. Methods Liposomal gentamicin-impregnated allogeneic cortical bone was prepared by combining cationic liposomal gentamicin and allogeneic cortical bone of rabbit through hypothermia vacuum aspiration. Models of staphylococcus aureus biofilm were established and used for ex-ploriag the effect of cationic liposomal gentamicin released from the allogeneic cortical bone on anti-biofilm activities in vitro. Results The combination of liposomal gentamiein and allogeneic cortical bone showed burst-release of active liposomal gentamicin for initial 3 days and had continuous-release for 12 days. The liposomal gentamicin released from allogeneic cortical bone had the same anti-biofilm activity as the liposomal gentamicin freshly prepared. Both agents were more effective than free gentamicin at low drug concentration. Conclusions The anti-biofilm efficiency of liposomal gentamicin may not be affected by the impregnation process. Compared with free drug, liposomal gentamicin is more effective in inhibiting bac-terial regrowth on S. aureus biofilms at low drug concentration.%目的 探讨一种新的抗生素缓释系统的制备,为金黄色葡萄球菌生物膜感染的治疗提供新思路. 方法制备庆大霉素阳离子脂质体及兔同种异体骨,并采用低温真空负压吸引法将二者复合,制备成庆大霉素脂质体同种异体骨,并行阳离子脂质体抗生素释放试验.构建金黄色匍萄球菌生物膜模型,于体外探讨由庆大霉素脂质体同种异体骨中释放出的阳离子脂质体庆大霉素对细菌生物膜的抑制作用. 结果成功制备庆大霉素脂质体同种异体骨,可持续释放庆大霉素脂质体达12d,前3 d释放具有爆发效应,所释放的庆大霉素脂质体对金黄色葡萄球菌生物膜生长的抑制作用与新制备的庆大霉素脂质体相似,在低浓度(3.2 mg/L)时二

  15. New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

    International Nuclear Information System (INIS)

    Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr−/−) and wild-type (Ahr+/+) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr+/+ mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr−/− mice displayed a slightly modified bone phenotype as compared with untreated Ahr+/+ mice, while TCDD exposure caused only a few changes in bones of Ahr−/− mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr+/+ mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation results in increased trabecular bone and softer

  16. Bone regeneration by implantation of adipose-derived stromal cells expressing BMP-2

    International Nuclear Information System (INIS)

    In this study, we reported that the adipose-derived stromal cells (ADSCs) genetically modified by bone morphogenetic protein 2 (BMP-2) healed critical-sized canine ulnar bone defects. First, the osteogenic and adipogenic differentiation potential of the ADSCs derived from canine adipose tissue were demonstrated. And then the cells were modified by the BMP-2 gene and the expression and bone-induction ability of BMP-2 were identified. Finally, the cells modified by BMP-2 gene were applied to a β-tricalcium phosphate (TCP) carrier and implanted into ulnar bone defects in the canine model. After 16 weeks, radiographic, histological, and histomorphometry analysis showed that ADSCs modified by BMP-2 gene produced a significant increase of newly formed bone area and healed or partly healed all of the bone defects. We conclude that ADSCs modified by the BMP-2 gene can enhance the repair of critical-sized bone defects in large animals

  17. Experimental determination of bone cortex holding power of orthopedic screw

    Directory of Open Access Journals (Sweden)

    Bolliger Neto Raul

    1999-01-01

    Full Text Available Cylindrical specimens of bone measuring 15 mm in diameter were obtained from the lateral cortical layer of 10 pairs of femurs and tibias. A central hole 3.2 mm in diameter was drilled in each specimen. The hole was tapped, and a 4.5 mm cortical bone screw was inserted from the outer surface. The montage was submitted to push-out testing up to a complete strip of the bone threads. The cortical thickness and rupture load were measured, and the shear stress was calculated. The results were grouped according to the bone segment from which the specimen was obtained. The results showed that bone cortex screw holding power is dependent on the bone site. Additionally, the diaphyseal cortical bone tissue is both quantitatively and qualitatively more resistant to screw extraction than the metaphyseal tissue.

  18. Alterações citológicas do sangue periférico e da medula óssea de cães com cinomose Cytological alterations of the bone marrow and peripheral blood of dogs with canine distemper

    Directory of Open Access Journals (Sweden)

    R.K. Almeida

    2009-12-01

    Full Text Available Avaliaram-se o mielograma, o hemograma e a ocorrência de apoptose no sangue periférico e na medula óssea de cães com cinomose de ocorrência natural. Foram utilizados 15 cães distribuídos em dois grupos: (a controle - seis animais clinicamente saudáveis com RT-PCR negativa para o vírus da cinomose canina (CC; (b infectado - nove animais com manifestações clínicas de CC e RT-PCR positiva. Dos cães com CC, oito (88,9% apresentaram anemia discreta a moderada (hematócrito: 30,6%, normocítica (VCM: 67,9fL e normocrômica (CHCM: 34,1g/dL. Todos os animais apresentaram contagens médias normais de leucócitos totais (11600 células/µL e neutrófilos segmentados (8802 células/µL. Linfopenia foi observada em cinco animais (55,6% e desvio nuclear dos neutrófilos para a esquerda em oito (88,9%. As contagens médias de linfócitos e neutrófilos bastonetes foram, respectivamente, 1054 e 1508células/µL. No mielograma, todos os animais apresentaram celularidade e relação M:E dentro dos limites de referência. O hemograma e a medula óssea dos cães-controle não apresentaram alteração e não havia células em apoptose no esfregaço sanguíneo desses animais. Nos cães com CC, a média do índice apoptótico foi 0,73% no esfregaço sanguíneo e 1,87% na medula óssea. A apoptose, portanto, pode estar envolvida na patogênese das alterações hematológicas observadas na CC.The myelogram, the hemogram, and the occurrence of apoptosis in peripheral blood and bone marrow in dogs with canine distemper (CD of natural occurrence were studied. Fifteen dogs were distributed into two groups: (a control - six clinically healthy animals with RT-PCR negative for canine distemper virus (CDV; and (b infected - nine animals showing clinical CD manifestations and RT-PCR positive. The majority of dogs with CD (88.9% presented discrete to moderate (hematocrit: 30.6%, normocytic (MCH: 67.9fL and normochromic (MCHC: 34.1g/dL anemia. All animals showed

  19. 混合附载内皮细胞与成骨细胞的nHA/RHLC/PLA复合支架材料修复犬股骨头缺损的观察%Experimental study of repairing femoral bone defects with nHA/RHLC/PLA scaffold composite with endothelial cells and osteoblasts in canines

    Institute of Scientific and Technical Information of China (English)

    吕玉明; 程立明; 裴国献; 蔡哲; 潘琳; 舒峻; 张可华; 郭丽丽; 俞庆声

    2013-01-01

    new bioresorbable nano-hydroxyapatite/recombinant human-like collagen/polylactic acid (nHA/RHLC/PLA)would enhance bone regeneration and repair femoral head defects in canine models.Methods The bone marrow stem cells (BMSCs) were isolated from bone marrow of canine ilium and cultured in Dulbecco's modified eagle medium:nutrient mixture F-12 culture media for 1 week and the second-generation BMSCs were further induced by osteogenic medium (1 × 10-8 mol/L dexamethasone,10 mmol/L B-sodium glycerophosphate and 50 μg/ml vitamin C) and by endothelial cell grow medium (vascular endothelial growth factor and basic fibroblast growth factor) for 14 days in vitro.Thus BMSCs were induced into ECs and OBs.After the second passage,cells were digested and collected.And cell density was adjusted to 1.0 × 106/ml.The cells and nHA/RHLC/PLA scaffold were co-cultured for 2-4 hours then nHA/RHLC/PLA scaffold composites prepared.Cavity defects of 8 mm in diameter and 10 mm in height were made in femoral heads.The nHA/RHLC/PLA scaffold composited with ECs and osteoblasts (OBs) (group A) and composited with OBs (group B) were inserted into different defects while cell-free nHA/RHLC/PLA scaffold served as controls (group C).New bone formation and defect repair were evaluated at 3 and 6 months by radiographic examination,histology and bone histomorphometry.Results New bone formation was evident as early as 3 months in groups A,B and C.At 6 months,abundant bone tissue within defects was observed in group A.The control animals with cell-free scaffold showed less bone formation at both timepoints.The scaffold of nHA/RHLC/PLA was degraded and absorbed gradually with the formation of new bone tissues.Histology and bone histomorphometry further revealed significantly increased trabecular bones in group A compared with groups B and C at 6 months postimplantation (P <0.01).Conclusion More abundant new bone tissue may be found in the bone defect areas implanted with osteoblast

  20. Cortical Lewy Body Dementia

    Directory of Open Access Journals (Sweden)

    W. R. G. Gibb

    1990-01-01

    Full Text Available In cortical Lewy body dementia the distribution of Lewy bodies in the nervous system follows that of Parkinson's disease, except for their greater profusion in the cerebral cortex. The cortical tangles and plaques of Alzheimer pathology are often present, the likely explanation being that Alzheimer pathology provokes dementia in many patients. Pure cortical Lewy body dementia without Alzheimer pathology is uncommon. The age of onset reflects that of Parkinson's disease, and clinical features, though not diagnostic, include aphasias, apraxias, agnosias, paranoid delusions and visual hallucinations. Parkinsonism may present before or after the dementia, and survival duration is approximately half that seen in Parkinson's disease without dementia.

  1. Mechanical properties of femoral trabecular bone in dogs

    Directory of Open Access Journals (Sweden)

    Nolte Ingo

    2005-03-01

    Full Text Available Abstract Background Studying mechanical properties of canine trabecular bone is important for a better understanding of fracture mechanics or bone disorders and is also needed for numerical simulation of canine femora. No detailed data about elastic moduli and degrees of anisotropy of canine femoral trabecular bone has been published so far, hence the purpose of this study was to measure the elastic modulus of trabecular bone in canine femoral heads by ultrasound testing and to assess whether assuming isotropy of the cancellous bone in femoral heads in dogs is a valid simplification. Methods From 8 euthanized dogs, both femora were obtained and cubic specimens were cut from the centre of the femoral head which were oriented along the main pressure and tension trajectories. The specimens were tested using a 100 MHz ultrasound transducer in all three orthogonal directions. The directional elastic moduli of trabecular bone tissue and degrees of anisotropy were calculated. Results The elastic modulus along principal bone trajectories was found to be 11.2 GPa ± 0.4, 10.5 ± 2.1 GPa and 10.5 ± 1.8 GPa, respectively. The mean density of the specimens was 1.40 ± 0.09 g/cm3. The degrees of anisotropy revealed a significant inverse relationship with specimen densities. No significant differences were found between the elastic moduli in x, y and z directions, suggesting an effective isotropy of trabecular bone tissue in canine femoral heads. Discussion This study presents detailed data about elastic moduli of trabecular bone tissue obtained from canine femoral heads. Limitations of the study are the relatively small number of animals investigated and the measurement of whole specimen densities instead of trabecular bone densities which might lead to an underestimation of Young's moduli. Publications on elastic moduli of trabecular bone tissue present results that are similar to our data. Conclusion This study provides data about directional elastic

  2. Effect of rhBMP-2 on tibial plateau fractures in a canine model.

    Science.gov (United States)

    Schaefer, Susan L; Lu, Yan; Seeherman, Howard; Li, X Jian; Lopez, Mandi J; Markel, Mark D

    2009-04-01

    This study was to determine the efficacy of recombinant human bone morphogenetic protien-2 (rhBMP-2)/calcium phosphate matrix (CPX) paste to accelerate healing in a canine articular fracture model with associated subchondral defect. rhBMP-2/CPX (BMP), CPX alone (CPX) or autogenous bone graft (ABG) was administered to a canine articular tibial plateau osteotomy with a subchondral defect in each of 21 female dogs. The unoperated contralateral limbs served as controls. Ground reaction forces, synovial fluid, radiographic changes, mechanical testing, bone density, and histology of bone and synovium were analyzed at 6 weeks after surgery. Radiographic analysis demonstrated that the BMP and CPX groups showed improved bony healing compared to the ABG group at week 6. Histomorphometric analysis demonstrated that the BMP group had significantly increased trabecular bone volume compared to the CPX and ABG groups. Mechanical testing revealed that the BMP group had significantly greater maximum failure loads than the ABG group. Histological analysis demonstrated that the BMP group had significantly less sub-synovial inflammation than CPX group. This study demonstrated that rhBMP-2/CPX accelerated healing of articular fractures with subchondral defect compared to ABG in most of the parameters evaluated, and had less subsynovial inflammation than the CPX alone in a canine model.

  3. Effect of Low-Intensity Pulsed Ultrasound Combined with Guided Bone Regeneration on Canine Periodontal Fenestration Defect in Beagle Dogs%低强度脉冲超声波联合引导骨再生术对Beagle犬牙周骨开窗缺损修复效应的研究

    Institute of Scientific and Technical Information of China (English)

    高翔; 宋锦璘; 邓锋; 赵纯亮; 王智彪

    2012-01-01

    The aim of this work is to investigate the effect of combined application of low-intensity pulsed ultrasound (LIPUS) and guided bone regeneration (GBR) on canine periodontal fenestration defect in Beagle dogs. In the experiments, five Beagle dogs were used for establishing 5 mm ×5 mm periodontal fenestration defect. Four canines in each dog were randomly divided into LIPUS (90 mW/cm , 20 min/d) group, LIPUS (90 mW/cm , 20 min/d) + GBR group, GBR group and Control group. Each group had 5 teeth. In order to compare the tissue repair among the groups, the specimens of periodontal fenestration were obtained for histological analysis (HE and Masson staining) , Micro-CT test and histometric analysis (the measurement of new bone area, NBA and its percentage in initial defect area, NBA% ) after 4 weeks. Micro-CT test results showed that the area of new alveolar bone from large to small was LIPUS + GBR group, GBR group, LIPUS group, and Control group. Histological analysis showed that the Masson staining of new bone in LIPUS and LIPUS + GBR group was mainly red while GBR and control group was mainly blue.. It suggested the new bone collagen in LIPUS group and LIPUS + GBR group was more mature than in GBR group and control group. Histometric analysis showed that NBA and NBA% were 0. 39 mm and 7. 74% in respectively LIPUS group; 0. 52 mm2 and 10. 30% respectively in LIPUS + GBR group; 0. 41 mm2 and 7. 44% respectively in GBR group; 0. 24 mm and 4. 64% respectively in Control group. Differences between groups were significant (P <0. 05). It suggested the amount of new alveolar bone from large to small was LIPUS + GBR group, GBR group, LIPUS group, and Control group. LIPUS combined with guided bone regeneration (GBR) can promote early repair of periodontal fenestration defect.%本研究探讨了低强度脉冲超声波(LIPUS)联合引导骨再生术(GBR),对Beagle犬牙周骨开窗缺损的修复效应.构建5只Beagle犬尖牙颊侧根中1/3处5 mm×5 mm矩形牙周骨开

  4. Bone tumor

    Science.gov (United States)

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

  5. Mesenchymal stem cells with rhBMP-2 inhibits the growth of canine osteosarcoma cells

    Directory of Open Access Journals (Sweden)

    Grassi Rici Rose

    2012-02-01

    Full Text Available Abstract Background The bone morphogenetic proteins (BMPs belong to a unique group of proteins that includes the growth factor TGF-β. BMPs play important roles in cell differentiation, cell proliferation, and inhibition of cell growth. They also participate in the maturation of several cell types, depending on the microenvironment and interactions with other regulatory factors. Depending on their concentration gradient, the BMPs can attract various types of cells and act as chemotactic, mitogenic, or differentiation agents. BMPs can interfere with cell proliferation and the formation of cartilage and bone. In addition, BMPs can induce the differentiation of mesenchymal progenitor cells into various cell types, including chondroblasts and osteoblasts. The aim of this study was to analyze the effects of treatment with rhBMP-2 on the proliferation of canine mesenchymal stem cells (cMSCs and the tumor suppression properties of rhBMP-2 in canine osteocarcoma (OST cells. Osteosarcoma cell lines were isolated from biopsies and excisions of animals with osteosarcoma and were characterized by the Laboratory of Biochemistry and Biophysics, Butantan Institute. The mesenchymal stem cells were derived from the bone marrow of canine fetuses (cMSCs and belong to the University of São Paulo, College of Veterinary Medicine (FMVZ-USP stem cell bank. After expansion, the cells were cultured in a 12-well Transwell system; cells were treated with bone marrow mesenchymal stem cells associated with rhBMP2. Expression of the intracytoplasmic and nuclear markers such as Caspase-3, Bax, Bad, Bcl-2, Ki-67, p53, Oct3/4, Nanog, Stro-1 were performed by flow citometry. Results We evaluated the regenerative potential of in vitro treatment with rhBMP-2 and found that both osteogenic induction and tumor regression occur in stem cells from canine bone marrow. rhBMP-2 inhibits the proliferation capacity of OST cells by mechanisms of apoptosis and tumor suppression mediated by p

  6. BNCT of canine osteosarcoma

    International Nuclear Information System (INIS)

    A dog was diagnosed with osteosarcoma (8x6x5cm) in the right wing of ilium by radiography, radionuclide scintigraphy and histological study of biopsy material. The treatment plan was as follows: γ-therapy in combination with chemotherapy; prevention of hematogenous pulmonary metastases by the transfusion of 130 ml of allogenic marrow from a healthy donor; administration of 11.4g 10B-boronphenylalanine into the right iliac artery; resection of the right iliac wing with the osteosarcoma lesion; neutron irradiation (MEPhI Reactor) of the bone fragment (dose on healthy osteocytes - 15±4 Gy (W), on tumor - 50±9 Gy (W); reimplantation and fixation of the fragment; three courses of adjuvant chemotherapy. The doses were determined in full-scale calculations of the reactor radiation fields with a model of the bone under the code RADUGA. The 10B concentration (μg/g) in the bone was: normal tissue - 9±3, tumor - 28±5. In 24 hours post operation the dog was able to walk using the treated limb, and 6 months later it moved freely. The patient has been under observation for 30 months. The results of the research demonstrate complete cure. The use of similar treatment plans improves the therapeutic efficiency of BNCT. (author)

  7. Engraftment of allogeneic dog bone marrow

    International Nuclear Information System (INIS)

    Resistance to allogeneic bone-marrow grafts (AR) was found to occur in many species, including the dog. The i.v. administration of silica particles suppressed Ar in vivo in this species. Genetic studies provide suggestive evidence for the existence of a previously unrecognized system or systems in the canine major histocompatibility complex controlling AR

  8. Amelioration of biomechanical property of cortical bone in osteoporotic model rats with the kidney tonifying compound of traditional Chinese medicine%补肾中药复方改善骨质疏松模型大鼠皮质骨生物力学性能的实验

    Institute of Scientific and Technical Information of China (English)

    朱太咏; 杜天信; 张国梁; 周亚; 杜志谦; 李根林; 刘又文

    2005-01-01

    BACKGROUND: The biomechanical property(BP) of the bone is decided by its geometric structure and component material. Merely pursuing increase of the bone mineral density(BMD) might lead to deterioration of bone BP.However at present, some researohes on therapeutic action on osteoporosis emphasize excessively medical influence to BMD, and the change in the holistic BP of the bone in osteoporotic zone and its mechanism still need to investigate deeply.OBJECTIVE: To probe into the action and its mechanism of "the kidney tonifying compound of the Traditional Chinese Medical (TCM) "on BP of cortical bone in ovariectomized osteoporotic model rats.DESIGN: Completely randomized controlled experiment based on experimental animals.SETTING: Laboratory of Biomedical Engineering, Luoyang Hospital and Institute of Traditional Chinese Orthopedics and Traumatology in Henan Province.MATERIALS: The experiment was completed from November 2000 to July 2001 at Research Laboratory of Biomedical Engineering,Luoyang Institute of Traditional Chinese Orthopedics and Traumatology of Henan Province. The healthy Wistar female rats aged 10 months,weighing(350±20) g.METHODS: Fifty Whistar female rats aged 10 months were randomly divided into 5 groups: the normal, model, premarin-treated, xianling gubao-treated and migu capsule-treated with 10 in each group. The normal group was only given sham operation and the other four groups were ovariectomized. The rats after operation were fed normally for ninety days.Since the 91st day after operation,the rats had been given the medicines for 90 days and then killed. The thighbones were taken out,then BMD,femoral geometry sizes and BP were determined.MAIN OUTCOME MEASURES: ① The primary sequel was the comparison of the parameters of femoral BP. ② The secondary sequel was the changes in parameters of femoral geometric structure, area of cortical bone and BMD of every midsectional fomur.RESULTS: Femoral BP worsened significantly,its mechanical

  9. Current developments in canine genetics.

    Science.gov (United States)

    Marschall, Yvonne; Distl, Ottmar

    2010-01-01

    In recent years, canine genetics had made huge progress. In 1999 the first complete karyotype and ideogram of the dog was published. Several linkage and RH maps followed. Using these maps, sets of microsatellite markers for whole genome scans were compiled. In 2003 the sequencing of the DNA of a female Boxer began. Now the second version of the dog genome assembly has been put online, and recently, a microchip SNP array became available. Parallel to these developments, some causal mutations for different traits have been identified. Most of the identified mutations were responsible for monogenic canine hereditary diseases. With the tools available now, it is possible to use the advantages of the population structure of the various dog breeds to unravel complex genetic traits. Furthermore, the dog is a suitable model for the research of a large number of human hereditary diseases and particularly for cancer genetics, heart and neurodegenerative diseases. There are some examples where it was possible to benefit from the knowledge of canine genetics for human research. The search for quantitative trait loci (QTL), the testing of candidate genes and genome-wide association studies can now be performed in dogs. QTL for skeletal size variations and for canine hip dysplasia have been already identified and for these complex traits the responsible genes and their possible interactions can now be identified. PMID:20690545

  10. Prognostic markers of canine pyometra

    OpenAIRE

    M.C. Sant'Anna; L.G.P. Giordano; K.K.M.C. Flaiban; Muller, E.E.; M.I.M. Martins

    2014-01-01

    The pyometra is a disease that affects middle age and elderly female dogs during diestrus. Hormonal, microbiological, biochemical and hematological aspects are well described. However, few studies have evaluated the role of each in the prognosis of canine pyometra. The aim of this study was to identify markers associated with clinical worsening of dogs with pyometra. We prospectively evaluated 80 dogs with pyometra tre...

  11. Surgical innovations in canine gonadectomy

    NARCIS (Netherlands)

    Van Goethem, Bart

    2016-01-01

    In this thesis some recent technological developments in human surgery are evaluated for their potential use in veterinary medicine by introducing them as surgical innovations for canine gonadectomy. Barbed sutures achieve wound apposition without surgical knot tying and thus avoid knot-associated n

  12. Androgen and bone mass in men

    Institute of Scientific and Technical Information of China (English)

    AnnieW.C.Kung

    2003-01-01

    Androgens have multiple actions on the skeleton throughout life. Androgens promote skeletal growth and accumulation of minerals during puberty and adolescence and stimulate osteoblast but suppress osteoclast function,activity and lifespan through complex mechanisms. Also androgens increase periosteal bone apposition, resulting in larger bone size and thicker cortical bone in men. There is convincing evidence to show that aromatization to estrogens was an important pathway for mediating the action of testosterone on bone physiology. Estrogen is probably the dominant sex steroid regulating bone resorption in men, but both testosterone and estrogen are important in maintaining bone formation. ( Asian J Androl 2003 Jun; 5: 148-154)

  13. Single cortical locking plate combined intramedullary nail and bone grafting in the treatment of femoral nonunion with clinical analysis%单皮质锁定钢板联合髓内钉加植骨治疗股骨骨不连临床分析

    Institute of Scientific and Technical Information of China (English)

    米宁

    2012-01-01

      目的:观察单皮质锁定板联合髓内钉加植骨治疗股骨骨不连临床疗效并对影响因素加以分析.方法:2008年5月至2012年5月对使用单皮质锁定板联合髓内钉固定加植骨治疗的股骨骨不连患者34例进行回顾性分析.抽取同期单纯使用带锁髓内钉加植骨治疗股骨骨不连29例进行对比分析并进行疗效评定,HSS评分检验膝关节功能恢复情况.结果:所有患者均在4~8个月内获得性骨愈合,两组优良率分别为88.23%和86.02%.术后对患者膝关节功能进行HSS评分两组患者平均(85.14±5.14)和(82.4±4.52).结论:单皮质锁定板联合髓内钉加植骨治疗股骨骨不连效果较好,有利于肢体早期功能恢复,可作为股骨骨不连治疗的一种有效方法.%  Objective:Observation of single cortical locking plate combined with intramedullary nail and bone grafting in the treatment of femoral nonunion with clinical efficacy and influence factors analysis. Methods:2008 May to 2012 May on the use of single cortical locking plate combined with intramedullary nail fixation and bone grafting for the treatment of nonunions of the femur in 34 cases were retrospectively analyzed. Extraction compared with use of interlocking intramedullary nail and bone grafting for the treatment of femoral nonunion in 29 cases were analyzed and the curative effect was studied, HSS score test knee joint function recovery. Results:All patients were in the 4 to 8 months of acquired bone healing, two groups of the excellent and good rate respectively is 88.23% and 86.02%. On postoperative patients with knee joint function of two groups of patients the mean HSS score ( 85.14± 5.14 ) and ( 82.4 ±4.52). Conclusion:Single cortical locking plate combined with intramedullary nail and bone grafting in the treatment of femoral nonunion with good effect, is beneficial to early limbs function recovery of femoral nonunion, can be used as an effective method to treat.

  14. Minor histocompatibility antigens on canine hemopoietic progenitor cells.

    Science.gov (United States)

    Weber, Martin; Lange, Claudia; Günther, Wolfgang; Franz, Monika; Kremmer, Elisabeth; Kolb, Hans-Jochem

    2003-06-15

    Adoptive immunotherapy with CTL against minor histocompatibility Ags (mHA) provides a promising way to treat leukemia relapse in allogeneic chimeras. Here we describe the in vitro generation of CTL against mHA in the dog. We tested their inhibitory effect on the growth of hemopoietic progenitor cells stimulated by hemopoietic growth factors in a 4-day suspension culture. CTL were produced by coculture of donor PBMC with bone marrow-derived dendritic cells (DCs). These DCs were characterized by morphology, high expression of MHC class II and CD1a, and the absence of the monocyte-specific marker CD14. Characteristically these cells stimulated allogeneic lymphocytes (MLR) and, after pulsing with a foreign Ag (keyhole limpet hemocyanin), autologous T cells. CTL were generated either ex vivo by coculture with DCs of DLA-identical littermates or in vivo by immunization of the responder with DCs obtained from a DLA-identical littermate. In suspension culture assays the growth of hemopoietic progenitor cells was inhibited in 53% of DLA-identical littermate combinations. In canine families mHA segregated with DLA as restriction elements. One-way reactivity against mHA was found in five littermate combinations. In two cases mHA might be Y chromosome associated, in three cases autosomally inherited alleles were detected. We conclude that CTL can be produced in vitro and in vivo against mHA on canine hemopoietic progenitor cells using bone marrow-derived DCs. PMID:12794111

  15. Bone Biopsy

    Science.gov (United States)

    ... 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 ...

  16. Bone Diseases

    Science.gov (United States)

    ... avoid smoking and drinking too much alcohol. Bone diseases can make bones easy to break. Different kinds ... break Osteogenesis imperfecta makes your bones brittle Paget's disease of bone makes them weak Bones can also ...

  17. Periostin action in bone.

    Science.gov (United States)

    Bonnet, Nicolas; Garnero, Patrick; Ferrari, Serge

    2016-09-01

    Periostin is a highly conserved matricellular protein that shares close homology with the insect cell adhesion molecule fasciclin 1. Periostin is expressed in a broad range of tissues including the skeleton, where it serves both as a structural molecule of the bone matrix and a signaling molecule through integrin receptors and Wnt-beta-catenin pathways whereby it stimulates osteoblast functions and bone formation. The development of periostin null mice has allowed to elucidate the crucial role of periostin on dentinogenesis and osteogenesis, as well as on the skeletal response to mechanical loading and parathyroid hormone. The use of circulating periostin as a potential clinical biomarker has been explored in different non skeletal conditions. These include cancers and more specifically in the metastasis process, respiratory diseases such as asthma, kidney failure, renal injury and cardiac infarction. In postmenopausal osteoporosis, serum levels have been shown to predict the risk of fracture-more specifically non-vertebral- independently of bone mineral density. Because of its preferential localization in cortical bone and periosteal tissue, it can be speculated that serum periostin may be a marker of cortical bone metabolism, although additional studies are clearly needed. PMID:26721738

  18. Stress Distribution on Short Implants at Maxillary Posterior Alveolar Bone Model With Different Bone-to-Implant Contact Ratio: Finite Element Analysis.

    Science.gov (United States)

    Yazicioglu, Duygu; Bayram, Burak; Oguz, Yener; Cinar, Duygu; Uckan, Sina

    2016-02-01

    The aim of this study was to evaluate the stress distribution of the short dental implants and bone-to-implant contact ratios in the posterior maxilla using 3-dimensional (3D) finite element models. Two different 3D maxillary posterior bone segments were modeled. Group 1 was composed of a bone segment consisting of cortical bone and type IV cancellous bone with 100% bone-to-implant contact. Group 2 was composed of a bone segment consisting of cortical bone and type IV cancellous bone including spherical bone design and homogenous tubular hollow spaced structures with 30% spherical porosities and 70% bone-to-implant contact ratio. Four-millimeter-diameter and 5-mm-height dental implants were assumed to be osseointegrated and placed at the center of the segments. Lateral occlusal bite force (300 N) was applied at a 25° inclination to the implants long axis. The maximum von Mises stresses in cortical and cancellous bones and implant-abutment complex were calculated. The von Mises stress values on the implants and the cancellous bone around the implants of the 70% bone-to-implant contact group were almost 3 times higher compared with the values of the 100% bone-to-implant contact group. For clinical reality, use of the 70% model for finite element analysis simulation of the posterior maxilla region better represents real alveolar bone and the increased stress and strain distributions evaluated on the cortical and cancellous bone around the dental implants.

  19. Stress Distribution on Short Implants at Maxillary Posterior Alveolar Bone Model With Different Bone-to-Implant Contact Ratio: Finite Element Analysis.

    Science.gov (United States)

    Yazicioglu, Duygu; Bayram, Burak; Oguz, Yener; Cinar, Duygu; Uckan, Sina

    2016-02-01

    The aim of this study was to evaluate the stress distribution of the short dental implants and bone-to-implant contact ratios in the posterior maxilla using 3-dimensional (3D) finite element models. Two different 3D maxillary posterior bone segments were modeled. Group 1 was composed of a bone segment consisting of cortical bone and type IV cancellous bone with 100% bone-to-implant contact. Group 2 was composed of a bone segment consisting of cortical bone and type IV cancellous bone including spherical bone design and homogenous tubular hollow spaced structures with 30% spherical porosities and 70% bone-to-implant contact ratio. Four-millimeter-diameter and 5-mm-height dental implants were assumed to be osseointegrated and placed at the center of the segments. Lateral occlusal bite force (300 N) was applied at a 25° inclination to the implants long axis. The maximum von Mises stresses in cortical and cancellous bones and implant-abutment complex were calculated. The von Mises stress values on the implants and the cancellous bone around the implants of the 70% bone-to-implant contact group were almost 3 times higher compared with the values of the 100% bone-to-implant contact group. For clinical reality, use of the 70% model for finite element analysis simulation of the posterior maxilla region better represents real alveolar bone and the increased stress and strain distributions evaluated on the cortical and cancellous bone around the dental implants. PMID:26867093

  20. Cortical myoclonus and cerebellar pathology

    NARCIS (Netherlands)

    Tijssen, MAJ; Thom, M; Ellison, DW; Wilkins, P; Barnes, D; Thompson, PD; Brown, P

    2000-01-01

    Objective To study the electrophysiologic and pathologic findings in three patients with cortical myoclonus. In two patients the myoclonic ataxic syndrome was associated with proven celiac disease. Background: The pathologic findings in conditions associated with cortical myoclonus commonly involve

  1. Surgical innovations in canine gonadectomy

    OpenAIRE

    Van Goethem, Bart

    2016-01-01

    In this thesis some recent technological developments in human surgery are evaluated for their potential use in veterinary medicine by introducing them as surgical innovations for canine gonadectomy. Barbed sutures achieve wound apposition without surgical knot tying and thus avoid knot-associated negative consequences (lengthy placement, impaired wound healing around bulky knots, and the effect of unsightly knots on cosmetics). A study in 9 dogs found that celiotomy closure was easily achiev...

  2. Genome Sequence of Canine Herpesvirus.

    Directory of Open Access Journals (Sweden)

    Konstantinos V Papageorgiou

    Full Text Available Canine herpesvirus is a widespread alphaherpesvirus that causes a fatal haemorrhagic disease of neonatal puppies. We have used high-throughput methods to determine the genome sequences of three viral strains (0194, V777 and V1154 isolated in the United Kingdom between 1985 and 2000. The sequences are very closely related to each other. The canine herpesvirus genome is estimated to be 125 kbp in size and consists of a unique long sequence (97.5 kbp and a unique short sequence (7.7 kbp that are each flanked by terminal and internal inverted repeats (38 bp and 10.0 kbp, respectively. The overall nucleotide composition is 31.6% G+C, which is the lowest among the completely sequenced alphaherpesviruses. The genome contains 76 open reading frames predicted to encode functional proteins, all of which have counterparts in other alphaherpesviruses. The availability of the sequences will facilitate future research on the diagnosis and treatment of canine herpesvirus-associated disease.

  3. Distribution Principle of Bone Tissue

    CERN Document Server

    Fan, Yifang; Fan, Yubo; Xu, Zongxiang; Li, Zhiyu

    2009-01-01

    Using the analytic and experimental techniques we present an exploratory study of the mass distribution features of the high coincidence of centre of mass of heterogeneous bone tissue in vivo and its centroid of geometry position. A geometric concept of the average distribution radius of bone issue is proposed and functional relation of this geometric distribution feature between the partition density and its relative tissue average distribution radius is observed. Based upon the mass distribution feature, our results suggest a relative distance assessment index between the center of mass of cortical bone and the bone center of mass and establish a bone strength equation. Analysing the data of human foot in vivo, we notice that the mass and geometric distribution laws have expanded the connotation of Wolff's law, which implies a leap towards the quantitative description of bone strength. We finally conclude that this will not only make a positive contribution to help assess osteoporosis, but will also provide...

  4. Custom-made polyglycolic acid/polylactic acid scaffolds cocultured with bone marrow stroma cells of canine in vitro%定制型聚羟基乙酸/聚乳酸支架与犬骨髓基质细胞的体外复合培养

    Institute of Scientific and Technical Information of China (English)

    徐华; 韩冬; 董佳生; 沈国雄; 俞哲元; 柴岗; 艾松涛

    2011-01-01

    背景:聚羟基乙酸、聚乳酸均属于脂肪族聚酯,是一种具有一定机械强度和良好成型性能的生物可降解材料,在体内无毒,不聚积,且有良好的生物相容性.目的:应用CAD、CAM、快速成型和激光扫描技术等组成的数字医学系统制作聚羟基乙酸/聚乳酸三维仿真的下颌支髁突形态模型,并检测其细胞生物相容性.方法:通过CT扫描获得犬头颅骨影像信息,以CAD和CAM实现下颌骨髁突形态的三维重建影像,快速成型技术获得下颌骨髁突的树脂阳模.阴阳模转换获得相应石膏阴模,聚羟基乙酸/聚乳酸在阴模内成型.抽取犬髂骨骨髓获得骨髓基质细胞,与定制型聚羟基乙酸/聚乳酸支架在体外复合培养,检测支架材料的生物相容性.结果与结论:定制型聚羟基乙酸/聚乳酸支架和影像原型比较,当测试点误差小于1.0 mm时,复合率大于95%.通过CAD、CAM、快速成型技术、预压成型技术和激光扫描技术等组成的数字医学系统可实现颅颌面下颌骨髁突形态结构聚羟基乙酸/聚乳酸生物材料的三维仿真.体外复合培养结果表明,定制型聚羟基乙酸/聚乳酸支架和骨髓基质细胞具有良好的生物相容性.%BACKGROUND: Polyglycolic acid (PGA) and polylactic acid (PLA) are belonging to the aliphatic polyester, which is a certainmechanical strength and good shaping properties of biodegradable material, innocuity in vivo, without accumulation, and has agood biocompatibility.OBJECTIVE: To produce PGA/PLA three-dimensional simulation of the mandibular condylar shape model by using of CAD, CAM,rapid prototyping and laser scanning technology and other components of digital medical systems, and to detect its cellbiocompatibility.METHODS: Parietal bone image information of canine was obtained by CT scan, condyle of mandible morphologythree-dimensional reconstruction images were performed by CAD and CAM, resin male of condyle of mandible was obtained

  5. The efficacy of mineralized allograft cortical and cancellous chips in maxillary sinus augmentations.

    Science.gov (United States)

    Nevins, Myron; Parma-Benfenati, Stefano; Janke, Ulrich W; Kleyer, Aimé; Rasperini, Giulio; Tinti, Carlo; Schupbach, Peter; Kim, David M

    2014-01-01

    A mixture of mineralized allograft cortical and cancellous chips was used to augment the maxillary sinuses of 10 patients. Eleven sinus augmentation procedures were performed, and 19 bone cores were obtained at reentry after 6 to 7 months. Computed tomography at 6 months postaugmentation demonstrated bone formation in all sites. Light microscopic and histomorphometric evaluation confirmed bone formation at the treatment site that would receive osseointegrated implants to replace the missing maxillary posterior teeth. These encouraging results support the use of a mixture of mineralized allograft cortical and cancellous chips for sinus augmentation.

  6. Evidence of bone formation in the nasal floor around polished surface bi-cortical screw implants after indirect nasal lift in an atrophied maxilla: Cone beam computed tomography-based case report

    OpenAIRE

    Khairnar, Mayur; Gaur, Vivek

    2015-01-01

    Maxillary jaw is restricted superiorly with maxillary sinus in the posterior region and nasal cavity in the anterior region. Augmentation of distal maxilla with recessed maxillary sinus has been documented since, last few decades. Sinus lifts the procedure either through crestal or lateral approach proves to be an effective way for augmenting bone for the placement of dental implants in atrophied posterior maxilla. However, when it comes to vertically deficient anterior maxilla, lifting of th...

  7. Medullary bone and humeral breaking strength in laying hens

    International Nuclear Information System (INIS)

    To test the hypothesis that large amounts of medullary bone in the humeral diaphysis may increase breaking strength, various parameters of bone quality and quantity were examined in two large flocks of hens near end of lay. We conclude that the amount of medullary bone in the humerus of hens during the laying period influences bone strength. This medullary bone may not have any intrinsic strength, but may act by contributing to the fracture resistance of the surrounding cortical bone. Using a quantitative, low dose, radiographic technique, we can predict, from early in the laying period, those birds which will develop large amounts of medullary bone in their humeri by the end of the laying period. The formation of medullary bone in the humeral diaphysis is not at the expense of the surrounding radiographed cortical bone

  8. Effect of chronic metabolic acidosis on bone density and bone architecture in vivo in rats.

    Science.gov (United States)

    Gasser, Jürg A; Hulter, Henry N; Imboden, Peter; Krapf, Reto

    2014-03-01

    Chronic metabolic acidosis (CMA) might result in a decrease in vivo in bone mass based on its reported in vitro inhibition of bone mineralization, bone formation, or stimulation of bone resorption, but such data, in the absence of other disorders, have not been reported. CMA also results in negative nitrogen balance, which might decrease skeletal muscle mass. This study analyzed the net in vivo effects of CMA's cellular and physicochemical processes on bone turnover, trabecular and cortical bone density, and bone microarchitecture using both peripheral quantitative computed tomography and μCT. CMA induced by NH4Cl administration (15 mEq/kg body wt/day) in intact and ovariectomized (OVX) rats resulted in stable CMA (mean Δ[HCO3(-)]p = 10 mmol/l). CMA decreased plasma osteocalcin and increased TRAP5b in intact and OVX animals. CMA decreased total volumetric bone mineral density (vBMD) after 6 and 10 wk (week 10: intact normal +2.1 ± 0.9% vs. intact acidosis -3.6 ± 1.2%, P effect attributable to a decrease in cortical thickness and, thus, cortical bone mass (no significant effect on cancellous vBMD, week 10) attributed to an increase in endosteal bone resorption (nominally increased endosteal circumference). Trabecular bone volume (BV/TV) decreased significantly in both CMA groups at 6 and 10 wk, associated with a decrease in trabecular number. CMA significantly decreased muscle cross-sectional area in the proximal hindlimb at 6 and 10 wk. In conclusion, chronic metabolic acidosis induces a large decrease in cortical bone mass (a prime determinant of bone fragility) in intact and OVX rats and impairs bone microarchitecture characterized by a decrease in trabecular number. PMID:24352505

  9. 9 CFR 113.306 - Canine Distemper Vaccine.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Canine Distemper Vaccine. 113.306... Virus Vaccines § 113.306 Canine Distemper Vaccine. Canine Distemper Vaccine shall be prepared from virus... distemper virus, each of five canine distemper susceptible ferrets shall be injected with a sample of...

  10. Canine and feline parasitic zoonoses in China

    Directory of Open Access Journals (Sweden)

    Chen Jia

    2012-07-01

    Full Text Available Abstract Canine and feline parasitic zoonoses have not been given high priority in China, although the role of companion animals as reservoirs for zoonotic parasitic diseases has been recognized worldwide. With an increasing number of dogs and cats under unregulated conditions in China, the canine and feline parasitic zoonoses are showing a trend towards being gradually uncontrolled. Currently, canine and feline parasitic zoonoses threaten human health, and cause death and serious diseases in China. This article comprehensively reviews the current status of major canine and feline parasitic zoonoses in mainland China, discusses the risks dogs and cats pose with regard to zoonotic transmission of canine and feline parasites, and proposes control strategies and measures.

  11. Purely cortical anaplastic ependymoma.

    Science.gov (United States)

    Romero, Flávio Ramalho; Zanini, Marco Antônio; Ducati, Luis Gustavo; Vital, Roberto Bezerra; de Lima Neto, Newton Moreira; Gabarra, Roberto Colichio

    2012-01-01

    Ependymomas are glial tumors derived from ependymal cells lining the ventricles and the central canal of the spinal cord. It may occur outside the ventricular structures, representing the extraventicular form, or without any relationship of ventricular system, called ectopic ependymona. Less than fifteen cases of ectopic ependymomas were reported and less than five were anaplastic. We report a rare case of pure cortical ectopic anaplastic ependymoma.

  12. Purely Cortical Anaplastic Ependymoma

    Directory of Open Access Journals (Sweden)

    Flávio Ramalho Romero

    2012-01-01

    Full Text Available Ependymomas are glial tumors derived from ependymal cells lining the ventricles and the central canal of the spinal cord. It may occur outside the ventricular structures, representing the extraventicular form, or without any relationship of ventricular system, called ectopic ependymona. Less than fifteen cases of ectopic ependymomas were reported and less than five were anaplastic. We report a rare case of pure cortical ectopic anaplastic ependymoma.

  13. Radiogrammetric analysis of upper limb long bones

    Directory of Open Access Journals (Sweden)

    Stojanović Zlatan

    2011-01-01

    Full Text Available Radiogrammetry is radiological method of bone mineral density quantification. Besides giving an insight in diagnostics and evolution of metabolic bone disorders (osteoporosis, osteomalacia, osteitis deformans- Paget's disease, it can also explain some specific biomechanical characteristics of bone structures. The aim of this study is to evaluate the significance and perspectives of radiogrammetry as a scientific model for further inquiry of skeletal system. The work demonstrates mathematical parameters (Ca-Cortical area, CI- Cortical index, GI- Garn's index, ESI- Exton Smith's index of upper limb long bones (humerus, radius, ulna. Two standard radiological projections of bones were taken: antero-posterior (AP and latero-lateral (LL. Correlation with metacarpal and lower limb bones was also performed. The value of the cortical area of humerus is significantly higher comparing with the two other examined bones (Xmean 2,2443 cm2, p < 0.01. Radial bone has the highest values of the relational mathematical parameters, which implicates its higher strength by volumetric unit concerning humerus and ulna. Despite the development of contemporary osteometric procedures (ultrasound densitometry, dual X-ray absorptiometry, digital X-ray radiogrammetry, the classical radiogrammetry sustains its important role in diagnostics of metabolic bone disorders and it can be successfully used for biomechanical inquiry of skeletal system.

  14. Bone Grafts

    Science.gov (United States)

    ... repair and rebuild diseased bones in your hips, knees, spine, and sometimes other bones and joints. Grafts can also repair bone loss caused by some types of fractures or cancers. Once your body accepts the bone ...

  15. High-strength mineralized collagen artificial bone

    Science.gov (United States)

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

    2014-03-01

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

  16. Alpha-1-antitrypsin studies: canine serum and canine surfactant protein

    International Nuclear Information System (INIS)

    Canine serum alpha-1-antitrypsin was isolated by gel filtration and affinity chromatography and characterized by polyacrylamide gel electrophoresis and immunoelectrophoresis. Measurement of the trypsin inhibitory capacity of the separated protein indicated a ninefold concentration of functional trypsin inhibitor during the isolation procedure. Electrophoresis demonstrated the presence of a single protein with alpha-globulin mobility and a molecular weight near that of human alpha-1-antitrypsin. The trypsin inhibitory capacity of pulmonary surfactant protein from five Beagle dogs was measured, related to total surfactant protein concentration, and compared with similar measurements on whole serum from the same animals. Results indicated a variable concentration of trypsin inhibitor in the canine pulmonary surfactant protein. However, the concentration in the surfactant protein was always significantly higher than that in the corresponding serum sample. Preliminary experiments designed to separate the trypsin inhibitory fraction(s) from the other surfactant proteins by gel filtration chromatography indicated that the trypsin inhibitor was probably a single protein with a molecular weight near that of alpha-1-antitrypsin. (U.S.)

  17. Bone within a bone

    Energy Technology Data Exchange (ETDEWEB)

    Williams, H.J.; Davies, A.M. E-mail: wendy.turner@roh.nhs.uk; Chapman, S

    2004-02-01

    The 'bone within a bone' appearance is a well-recognized radiological term with a variety of causes. It is important to recognize this appearance and also to be aware of the differential diagnosis. A number of common conditions infrequently cause this appearance. Other causes are rare and some remain primarily of historical interest, as they are no longer encountered in clinical practice. In this review we illustrate some of the conditions that can give the bone within a bone appearance and discuss the physiological and pathological aetiology of each where known.

  18. Analysis of Cortical Morphometric Variability Using Labeled Cortical Distance Maps

    OpenAIRE

    Ceyhan, E.; Nishino, T.; Botteron, K. N.; Miller, M. I.; Ratnanather, J. T.

    2015-01-01

    Morphometric differences in the anatomy of cortical structures are associated with neuro-developmental and neuropsychiatric disorders. Such differences can be quantized and detected by a powerful tool called Labeled Cortical Distance Map (LCDM). The LCDM method pro-vides distances of labeled gray matter (GM) voxels from the GM/white matter (WM) surface for specific cortical structures (or tissues). Here we describe a method to analyze morphometric variability in the particular tissue using LC...

  19. Clinical and serological response of wild dogs (Lycaon pictus) to vaccination against canine distemper, canine parvovirus infection and rabies

    OpenAIRE

    J. Van Heerden; J. Bingham; M. Van Vuuren; R.E.J. Burroughs; E. Stylianides

    2002-01-01

    Wild dogs Lycaon pictus (n = 8) were vaccinated 4 times against canine distemper (n = 8) (initially with inactivated and subsequently with live attenuated strains of canine distemper) and canine parvovirus infection (n = 8) over a period of 360 days. Four of the wild dogs were also vaccinated 3 times against rabies using a live oral vaccine and 4 with an inactivated parenteral vaccine. Commercially-available canine distemper, canine parvovirus and parenteral rabies vaccines, intended for use ...

  20. Spatial distribution of the trace elements zinc, strontium and lead in human bone tissue ☆

    OpenAIRE

    Pemmer, B.; Roschger, A.; Wastl, A.; Hofstaetter, J.G.; Wobrauschek, P.; Simon, R.; Thaler, H. W.; Roschger, P; Klaushofer, K.; Streli, C.

    2013-01-01

    Trace elements are chemical elements in minute quantities, which are known to accumulate in the bone. Cortical and trabecular bones consist of bone structural units (BSUs) such as osteons and bone packets of different mineral content and are separated by cement lines. Previous studies investigating trace elements in bone lacked resolution and therefore very little is known about the local concentration of zinc (Zn), strontium (Sr) and lead (Pb) in BSUs of human bone. We used synchrotron radia...

  1. Cortical-Marrow Ratio

    DEFF Research Database (Denmark)

    Viberg, Bjarke; Harbo, Frederik; Lauritsen, Jens;

    Background Osteoporosis is associated with hip fractures. The gold standard to assess osteoporosis is to measure bone mineral density (BMD) by dual-energy x-ray absorptiometri, which is quick and reliable but not available in most orthopaedic departments. A fast and feasible way to assess bone...... extracted all consecutive patients with femoral neck fractures referred for BMD measurements, n=133 patients (mean 78.1 years, 100 female). On preoperative digital AP hip x-rays two observers measured the outer cortex diameter just below the minor trochanter (TM) on a 20 inch screen or larger with maximal...

  2. Prognostic markers of canine pyometra

    Directory of Open Access Journals (Sweden)

    M.C. Sant'Anna

    2014-12-01

    Full Text Available The pyometra is a disease that affects middle age and elderly female dogs during diestrus. Hormonal, microbiological, biochemical and hematological aspects are well described. However, few studies have evaluated the role of each in the prognosis of canine pyometra. The aim of this study was to identify markers associated with clinical worsening of dogs with pyometra. We prospectively evaluated 80 dogs with pyometra treated surgically. Group 1 consisted of dogs that were discharged within 48 hours after surgery and Group 2 consisted of those who required prolonged hospitalization or died. The findings of hematological, biochemical and blood lactate levels were compared between groups and variables such as bacterial multidrug resistance, systemic inflammatory response syndrome (SIRS, hyperlactatemia and increased creatinine were analyzed through the dispersion of frequencies between groups. Among the variables studied, the presence of SIRS and elevated serum creatinine >2.5mg/mL were effective in predicting the worsening of the disease and can be used as prognostic markers of canine pyometra.

  3. Adynamic Bone Decreases Bone Toughness During Aging by Affecting Mineral and Matrix.

    Science.gov (United States)

    Ng, Adeline H; Omelon, Sidney; Variola, Fabio; Allo, Bedilu; Willett, Thomas L; Alman, Benjamin A; Grynpas, Marc D

    2016-02-01

    Adynamic bone is the most frequent type of bone lesion in patients with chronic kidney disease; long-term use of antiresorptive therapy may also lead to the adynamic bone condition. The hallmark of adynamic bone is a loss of bone turnover, and a major clinical concern of adynamic bone is diminished bone quality and an increase in fracture risk. Our current study aims to investigate how bone quality changes with age in our previously established mouse model of adynamic bone. Young and old mice (4 months old and 16 months old, respectively) were used in this study. Col2.3Δtk (DTK) mice were treated with ganciclovir and pamidronate to create the adynamic bone condition. Bone quality was evaluated using established techniques including bone histomorphometry, microcomputed tomography, quantitative backscattered electron imaging, and biomechanical testing. Changes in mineral and matrix properties were examined by powder X-ray diffraction and Raman spectroscopy. Aging controls had a natural decline in bone formation and resorption with a corresponding deterioration in trabecular bone structure. Bone turnover was severely blunted at all ages in adynamic animals, which preserved trabecular bone loss normally associated with aging. However, the preservation of trabecular bone mass and structure in old adynamic mice did not rescue deterioration of bone mechanical properties. There was also a decrease in cortical bone toughness in old adynamic mice that was accompanied by a more mature collagen matrix and longer bone crystals. Little is known about the effects of metabolic bone disease on bone fracture resistance. We observed an age-related decrease in bone toughness that was worsened by the adynamic condition, and this decrease may be due to material level changes at the tissue level. Our mouse model may be useful in the investigation of the mechanisms involved in fractures occurring in elderly patients on antiresorptive therapy who have very low bone turnover. PMID:26332924

  4. Caffey Disease or Infantile Cortical Hyperostosis: A Case Report

    OpenAIRE

    Narayanan Kutty; Doylene Thomas; Lionel George; Thomas B. John

    2010-01-01

    Caffey disease or Infantile Cortical Hyperostosis (ICH) is a rare and mostly self limiting condition affecting young infants. It is characterized by acute inflammation of the periostium and the overlying soft tissue and is accompanied by systemic changes of irritability and fever. Diagnosis may be delayed as this disorder mimics a wide range of diseases including osteomyelitis, hypervitaminosis A, scurvy, bone tumors and child abuse. The emphasis here is to remind clinicians about the existen...

  5. Bone mineral measurements of subchondral and trabecular bone in healthy and osteoporotic rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, S [Universidad Autonoma, Rheumatology Department, Hospital de la Princesa, Madrid (Spain); Largo, R.; Marcos, M.E.; Herrero-Beaumont, G. [Universidad Autonoma, Inflammation Research Unit, Rheumatology Department, Fundacion Jimenez Diaz, Madrid (Spain); Calvo, E. [Universidad Autonoma, Inflammation Research Unit, Rheumatology Department, Fundacion Jimenez Diaz, Madrid (Spain); Universidad Autonoma, Department of Orthopaedic Surgery, Fundacion Jimenez Diaz, Madrid (Spain); Rodriguez-Salvanes, F. [Universidad Autonoma, Clinical Epidemiology Unit, Hospital de la Princesa, Madrid (Spain); Diaz-Curiel, M. [Universidad Autonoma, Department of Internal Medicine, Fundacion Jimenez Diaz, Madrid (Spain)

    2006-01-01

    Experimental models of osteoporosis in rabbits are useful to investigate anabolic agents because this animal has a fast bone turnover with predominant remodelling over the modelling processes. For that purpose, it is necessary to characterize the densitometric values of each type of bony tissue. To determine areal bone mass measurement in the spine and in trabecular, cortical and subchondral bone of the knee in healthy and osteoporotic rabbits. Bone mineral content and bone mineral density were measured in lumbar spine, global knee, and subchondral and cortical bone of the knee with dual energy X-ray absorptiometry using a Hologic QDR-1000/W densitometer in 29 skeletally mature female healthy New Zealand rabbits. Ten rabbits underwent triplicate scans for evaluation of the effect of repositioning. Osteoporosis was experimentally induced in 15 rabbits by bilateral ovariectomy and postoperative corticosteroid treatment for 4 weeks. Identical dual energy X-ray absorptiometry (DXA) studies were performed thereafter. Mean values of bone mineral content at the lumbar spine, global knee, subchondral bone and cortical tibial metaphysis were: 1934{+-}217 mg, 878{+-}83 mg, 149{+-}14 mg and 29{+-}7.0 mg, respectively. The mean values of bone mineral density at the same regions were: 298{+-}24 mg/cm{sup 2}, 455{+-}32 mg/cm{sup 2}, 617{+-}60 mg/cm{sup 2} and 678{+-}163 mg/cm{sup 2}, respectively. (orig.)

  6. Extrusion processing : effects on dry canine diets

    NARCIS (Netherlands)

    Tran, Q.D.

    2008-01-01

    Keywords: Extrusion, Canine diet, Protein, Lysine, Starch gelatinization, Palatability, Drying. Extrusion cooking is a useful and economical tool for processing animal feed. This high temperature, short time processing technology causes chemical and physical changes that alter the nutritional and

  7. Bone compaction enhances implant fixation in a canine gap model

    DEFF Research Database (Denmark)

    Kold, Søren; Rahbek, Ole; Toft, Marianne;

    2005-01-01

    ) were bilaterally inserted into cavities initially expanded to 8 mm diameters in the proximal humeri. Each dog served as its own control; thus, one humerus had the implant cavity prepared with compaction, the other with drilling. Eight dogs were euthanized after 2 weeks, and 7 dogs after 4 weeks. Humeri...

  8. Comparison of Multidetector Computed Tomography and Flat-Panel Computed Tomography Regarding Visualization of Cortical Fractures, Cortical Defects, and Orthopedic Screws

    Science.gov (United States)

    Neubauer, Jakob; Benndorf, Matthias; Lang, Hannah; Lampert, Florian; Kemna, Lars; Konstantinidis, Lukas; Neubauer, Claudia; Reising, Kilian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Goerke, Sebastian M.

    2015-01-01

    Abstract To compare the visualization of cortical fractures, cortical defects, and orthopedic screws in a dedicated extremity flat-panel computed tomography (FPCT) scanner and a multidetector computed tomography (MDCT) scanner. We used feet of European roe deer as phantoms for cortical fractures, cortical defects, and implanted orthopedic screws. FPCT and MDCT scans were performed with equivalent dose settings. Six observers rated the scans according to number of fragments, size of defects, size of defects opposite orthopedic screws, and the length of different screws. The image quality regarding depiction of the cortical bone was assessed. The gold standard (real number of fragments) was evaluated by autopsy. The correlation of reader assessment of fragments, cortical defects, and screws with the gold standard was similar for FPCT and MDCT. Three readers rated the subjective image quality of the MDCT to be higher, whereas the others showed no preferences. Although the image quality was rated higher in the MDCT than in the FPCT by 3 out of 6 observers, both modalities proved to be comparable regarding the visualization of cortical fractures, cortical defects, and orthopedic screws and of use to musculoskeletal radiology regarding fracture detection and postsurgical evaluation in our experimental setting. PMID:26252281

  9. Comparison of Multidetector Computed Tomography and Flat-Panel Computed Tomography Regarding Visualization of Cortical Fractures, Cortical Defects, and Orthopedic Screws: A Phantom Study.

    Science.gov (United States)

    Neubauer, Jakob; Benndorf, Matthias; Lang, Hannah; Lampert, Florian; Kemna, Lars; Konstantinidis, Lukas; Neubauer, Claudia; Reising, Kilian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Goerke, Sebastian M

    2015-08-01

    To compare the visualization of cortical fractures, cortical defects, and orthopedic screws in a dedicated extremity flat-panel computed tomography (FPCT) scanner and a multidetector computed tomography (MDCT) scanner.We used feet of European roe deer as phantoms for cortical fractures, cortical defects, and implanted orthopedic screws. FPCT and MDCT scans were performed with equivalent dose settings. Six observers rated the scans according to number of fragments, size of defects, size of defects opposite orthopedic screws, and the length of different screws. The image quality regarding depiction of the cortical bone was assessed. The gold standard (real number of fragments) was evaluated by autopsy.The correlation of reader assessment of fragments, cortical defects, and screws with the gold standard was similar for FPCT and MDCT. Three readers rated the subjective image quality of the MDCT to be higher, whereas the others showed no preferences.Although the image quality was rated higher in the MDCT than in the FPCT by 3 out of 6 observers, both modalities proved to be comparable regarding the visualization of cortical fractures, cortical defects, and orthopedic screws and of use to musculoskeletal radiology regarding fracture detection and postsurgical evaluation in our experimental setting. PMID:26252281

  10. Canine babesiosis: from molecular taxonomy to control

    Directory of Open Access Journals (Sweden)

    Irwin Peter J

    2009-03-01

    Full Text Available Abstract Canine babesiosis is a clinically significant emerging vector-borne disease caused by protozoan haemoparasites. This review article considers recent literature pertaining to the taxonomic classification of Babesia and Theileria species affecting dogs and the geographical distribution of these parasites. The diagnosis of canine babesiosis by traditional, molecular and serological methods is reviewed, together with recent advances in our understanding of the pathophysiology of piroplasmosis, and of the treatment and prevention of this disease.

  11. [Nonsurgical endodontic treatment of an invaginated canine].

    Science.gov (United States)

    Fernández Guerrero, F; Miñana Laliga, R; Bullon Fernandez, P

    1989-01-01

    We present a case of a maxillary canine with a dens invaginatus treated successfully. The patient had pain, swelling and a sinus tract coming from the inmature apex of the canine. The canals were enlarged and cleaned and the main canal was filled with Calcium Hydroxide to allow the root development. Seven months later, the patient was asymptomatic and the tooth was obturated with guttapercha. One year later it was confirm the success in the treatment. PMID:2638021

  12. Systemic inflammarory response in canine pyometra

    OpenAIRE

    Fransson, Boel

    2003-01-01

    Research efforts have focused mainly on the hormonal aspects of canine pyometra for more than 6 decades. However, this disease is often manifested as systemic illness in response to the bacterial uterine infection. Studies I-II were undertaken to clarify bacteriological aspects of canine pyometra; i.e. the origin of the infecting bacteria, the infecting bacteria’s impact on severity of the systemic illness and the presence of bacterial endotoxin in the systemic circulation. Study I, a bacteri...

  13. [Nonsurgical endodontic treatment of an invaginated canine].

    Science.gov (United States)

    Fernández Guerrero, F; Miñana Laliga, R; Bullon Fernandez, P

    1989-01-01

    We present a case of a maxillary canine with a dens invaginatus treated successfully. The patient had pain, swelling and a sinus tract coming from the inmature apex of the canine. The canals were enlarged and cleaned and the main canal was filled with Calcium Hydroxide to allow the root development. Seven months later, the patient was asymptomatic and the tooth was obturated with guttapercha. One year later it was confirm the success in the treatment.

  14. Treatment modalities of palatal impacted canines

    OpenAIRE

    Dimova, Cena; Papakoca, Kiro; Ristoska, Sonja; Kovacevska, Ivona

    2012-01-01

    Introduction: The orthodontic treatment of impacted maxillary canine remains a challenge to today’s clinicians. The treatment of this clinical entity usually involves surgical exposure of the impacted tooth, followed by orthodontic traction to guide and align it into the dental arch. The impacted palatal canine requires a combination of both treatment modalities: orthodontic management and oral surgical treatment. Two types of approach are commonly used: simple exposure, or exposure with brac...

  15. Proliferative histiocytic disorders of canine skin.

    Science.gov (United States)

    Middleton, D J

    1997-06-01

    Proliferative histiocytic disorders of canine skin present a clinical spectrum from the innocuous self-limiting solitary dermal lesion of cutaneous histiocytoma, through the recurrent deep dermal nodules of cutaneous histiocytosis to the generally fatal condition of Bernese Mountain Dogs termed systemic histiocytosis, in which visceral involvement is commonly encountered. Immunocytochemical characterization of the constituent histiocytic cells and accompanying lymphoid infiltrate using canine species specific reagents has elucidated considerably the mechanism by which these conditions exhibit their various biologic behaviours.

  16. The synergistic induction of bone formation by the osteogenic proteins of the TGF-β supergene family.

    Science.gov (United States)

    Ripamonti, Ugo; Parak, Ruqayya; Klar, Roland M; Dickens, Caroline; Dix-Peek, Thérèse; Duarte, Raquel

    2016-10-01

    The momentum to compose this Leading Opinion on the synergistic induction of bone formation suddenly arose when a simple question was formulated during a discussion session on how to boost the often limited induction of bone formation seen in clinical contexts. Re-examination of morphological and molecular data available on the rapid induction of bone formation by the recombinant human transforming growth factor-β3 (hTGF-β3) shows that hTGF-β3 replicates the synergistic induction of bone formation as invocated by binary applications of hOP-1:hTGF-β1 at 20:1 by weight when implanted in heterotopic sites of the rectus abdominis muscle of the Chacma baboon, Papio ursinus. The rapid induction of bone formation in primates by hTGF-β3 may stem from bursts of cladistic evolution, now redundant in lower animal species but still activated in primates by relatively high doses of hTGF-β3. Contrary to rodents, lagomorphs and canines, the three mammalian TGF-β isoforms induce rapid and substantial bone formation when implanted in heterotopic rectus abdominis muscle sites of P. ursinus, with unprecedented regeneration of full thickness mandibular defects with rapid mineralization and corticalization. Provocatively, thus providing potential molecular and biological rationales for the apparent redundancy of osteogenic molecular signals in primates, binary applications of recombinant human osteogenic protein-1 (hOP-1) with low doses of hTGF-β1 and -β3, synergize to induce massive ossicles in heterotopic rectus abdominis, orthotopic calvarial and mandibular sites of P. ursinus. The synergistic binary application of homologous but molecularly different soluble molecular signals has indicated that per force several secreted molecular signals are required singly, synchronously and synergistically to induce optimal osteogenesis. The morphological hallmark of the synergistic induction of bone formation is the rapid differentiation of large osteoid seams enveloping

  17. Cortico-cortical communication dynamics

    Directory of Open Access Journals (Sweden)

    Per E Roland

    2014-05-01

    Full Text Available IIn principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG, and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

  18. New insights to the role of aryl hydrocarbon receptor in bone phenotype and in dioxin-induced modulation of bone microarchitecture and material properties

    Energy Technology Data Exchange (ETDEWEB)

    Herlin, Maria, E-mail: maria.herlin@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Finnilä, Mikko A.J., E-mail: mikko.finnila@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Zioupos, Peter, E-mail: p.zioupos@cranfield.ac.uk [Biomechanics Laboratories, Department of Engineering and Applied Science, Cranfield University, Shrivenham SN6 8LA (United Kingdom); Aula, Antti, E-mail: antti.aula@gmail.com [Department of Medical Physics, Imaging Centre, Tampere University Hospital, Tampere (Finland); Department of Biomedical Engineering, Tampere University of Technology, Tampere (Finland); Risteli, Juha, E-mail: juha.risteli@ppshp.fi [Department of Clinical Chemistry, Oulu University Hospital, Oulu (Finland); Miettinen, Hanna M., E-mail: hanna.miettinen@crl.com [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Jämsä, Timo, E-mail: timo.jamsa@oulu.fi [Department of Medical Technology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Department of Diagnostic Radiology, Oulu University Hospital, Oulu (Finland); Tuukkanen, Juha, E-mail: juha.tuukkanen@oulu.fi [Department of Anatomy and Cell Biology, Institute of Biomedicine, University of Oulu, Oulu (Finland); Korkalainen, Merja, E-mail: merja.korkalainen@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Håkansson, Helen, E-mail: Helen.Hakansson@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Viluksela, Matti, E-mail: matti.viluksela@thl.fi [Department of Environmental Health, National Institute for Health and Welfare, Kuopio (Finland); Department of Environmental Science, University of Eastern Finland, Kuopio (Finland)

    2013-11-15

    Bone is a target for high affinity aryl hydrocarbon receptor (AHR) ligands, such as dioxins. Although bone morphology, mineral density and strength are sensitive endpoints of dioxin toxicity, less is known about effects on bone microarchitecture and material properties. This study characterizes TCDD-induced modulations of bone tissue, and the role of AHR in dioxin-induced bone toxicity and for normal bone phenotype. Six AHR-knockout (Ahr{sup −/−}) and wild-type (Ahr{sup +/+}) mice of both genders were exposed to TCDD weekly for 10 weeks, at a total dose of 200 μg/kg bw. Bones were examined with micro-computed tomography, nanoindentation and biomechanical testing. Serum levels of bone remodeling markers were analyzed, and the expression of genes related to osteogenic differentiation was profiled using PCR array. In Ahr{sup +/+} mice, TCDD-exposure resulted in harder bone matrix, thinner and more porous cortical bone, and a more compact trabecular bone compartment. Bone remodeling markers and altered expression of a number of osteogenesis related genes indicated imbalanced bone remodeling. Untreated Ahr{sup −/−} mice displayed a slightly modified bone phenotype as compared with untreated Ahr{sup +/+} mice, while TCDD exposure caused only a few changes in bones of Ahr{sup −/−} mice. Part of the effects of both TCDD-exposure and AHR-deficiency were gender dependent. In conclusion, exposure of adult mice to TCDD resulted in harder bone matrix, thinner cortical bone, mechanically weaker bones and most notably, increased trabecular bone volume fraction in Ahr{sup +/+} mice. AHR is involved in bone development of a normal bone phenotype, and is crucial for manifestation of TCDD-induced bone alterations. - Highlights: • TCDD disrupts bone remodeling resulting in altered cortical and trabecular bone. • In trabecular bone an anabolic effect is observed. • Cortical bone is thinner, more porous, harder, stiffer and mechanically weaker. • AHR ablation

  19. Despre babesioza canină

    Directory of Open Access Journals (Sweden)

    Andrei Nanu

    2016-06-01

    Full Text Available The objective of this bibliographic essay, addressed both to veterinary clinicians and researchers, is to bring to mind the disease in terms of etiology, clinical manifestations and therapeutic and prophylactic management, as well as to remind the issues arising from recent researches. Depending on the virulence of the parasite species, body's immune response and therapeutic management approached, the plateau of disease evolution can be quite wide - from a favorable prognosis to a lethal outcome of the animal. The complexity of the pathogenic mechanism in babesiosis is due to soluble parasite antigens (SPA which, according to recent studies, have been obtained in vitro and then used as immunological product in disease prevention. Producing a vaccine against canine babesiosis with parasite antigens of local strains could play an important role to prevent the clinical expression of this disease in Romania.

  20. Environmental contamination by canine geohelminths.

    Science.gov (United States)

    Traversa, Donato; Frangipane di Regalbono, Antonio; Di Cesare, Angela; La Torre, Francesco; Drake, Jason; Pietrobelli, Mario

    2014-01-01

    Intestinal nematodes affecting dogs, i.e. roundworms, hookworms and whipworms, have a relevant health-risk impact for animals and, for most of them, for human beings. Both dogs and humans are typically infected by ingesting infective stages, (i.e. larvated eggs or larvae) present in the environment. The existence of a high rate of soil and grass contamination with infective parasitic elements has been demonstrated worldwide in leisure, recreational, public and urban areas, i.e. parks, green areas, bicycle paths, city squares, playgrounds, sandpits, beaches. This review discusses the epidemiological and sanitary importance of faecal pollution with canine intestinal parasites in urban environments and the integrated approaches useful to minimize the risk of infection in different settings. PMID:24524656

  1. Biomarkers in canine parvovirus enteritis.

    Science.gov (United States)

    Schoeman, J P; Goddard, A; Leisewitz, A L

    2013-07-01

    Canine parvovirus (CPV) enteritis has, since its emergence in 1978, remained a common and important cause of morbidity and mortality in young dogs. The continued incidence of parvoviral enteritis is partly due to the virus' capability to evolve into more virulent and resistant variants with significant local gastrointestinal and systemic inflammatory sequelae. This paper reviews current knowledge on historical-, signalment-, and clinical factors as well as several haematological-, biochemical- and endocrine parameters that can be used as diagnostic and prognostic biomarkers in CPV enteritis. These factors include season of presentation, purebred nature, bodyweight, vomiting, leukopaenia, lymphopaenia, thrombocytopaenia, hypercoagulability, hypercortisolaemia, hypothyroxinaemia, hypoalbuminaemia, elevated C-reactive protein and tumour necrosis factor, hypocholesterolaemia and hypocitrullinaemia. Factors contributing to the manifestations of CPV infection are multiple with elements of host, pathogen, secondary infections, underlying stressors and environment affecting severity and outcome. The availability of several prognosticators has made identification of patients at high risk of death and their subsequent targeted management more rewarding.

  2. CANINE: a robotic mine dog

    Science.gov (United States)

    Stancil, Brian A.; Hyams, Jeffrey; Shelley, Jordan; Babu, Kartik; Badino, Hernán.; Bansal, Aayush; Huber, Daniel; Batavia, Parag

    2013-01-01

    Neya Systems, LLC competed in the CANINE program sponsored by the U.S. Army Tank Automotive Research Development and Engineering Center (TARDEC) which culminated in a competition held at Fort Benning as part of the 2012 Robotics Rodeo. As part of this program, we developed a robot with the capability to learn and recognize the appearance of target objects, conduct an area search amid distractor objects and obstacles, and relocate the target object in the same way that Mine dogs and Sentry dogs are used within military contexts for exploration and threat detection. Neya teamed with the Robotics Institute at Carnegie Mellon University to develop vision-based solutions for probabilistic target learning and recognition. In addition, we used a Mission Planning and Management System (MPMS) to orchestrate complex search and retrieval tasks using a general set of modular autonomous services relating to robot mobility, perception and grasping.

  3. Temperatures achieved in human and canine neocortex during intraoperative passive or active focal cooling.

    Science.gov (United States)

    Smyth, Matthew D; Han, Rowland H; Yarbrough, Chester K; Patterson, Edward E; Yang, Xiao-Feng; Miller, John W; Rothman, Steven M; D'Ambrosio, Raimondo

    2015-06-01

    Focal cortical cooling inhibits seizures and prevents acquired epileptogenesis in rodents. To investigate the potential clinical utility of this treatment modality, we examined the thermal characteristics of canine and human brain undergoing active and passive surface cooling in intraoperative settings. Four patients with intractable epilepsy were treated in a standard manner. Before the resection of a neocortical epileptogenic focus, multiple intraoperative studies of active (custom-made cooled irrigation-perfused grid) and passive (stainless steel probe) cooling were performed. We also actively cooled the neocortices of two dogs with perfused grids implanted for 2 hours. Focal surface cooling of the human brain causes predictable depth-dependent cooling of the underlying brain tissue. Cooling of 0.6-2°C was achieved both actively and passively to a depth of 10-15 mm from the cortical surface. The perfused grid permitted comparable and persistent cooling of canine neocortex when the craniotomy was closed. Thus, the human cortex can easily be cooled with the use of simple devices such as a cooling grid or a small passive probe. These techniques provide pilot data for the design of a permanently implantable device to control intractable epilepsy. PMID:25902001

  4. Population response characteristics of intrinsic signals in the cat somatosensory cortex following canine mechanical stimulation.

    Science.gov (United States)

    Tao, Jianxiang; Wang, Jian; Li, Zhong; Meng, Jianjun; Yu, Hongbo

    2016-08-01

    Intrinsic signal optical imaging has been widely used to measure functional maps in various sensory cortices due to better spatial resolution and sensitivity for detecting cortical neuroplasticity. However, application of this technique in dentistry has not been reported. In this study, intrinsic signal optical imaging was used to investigate mechanically driven responses in the cat somatosensory cortex, when punctate mechanical stimuli were applied to maxillary canines. The global signal and its spatial organization pattern were obtained. Global signal strength gradually increased with stimulus strength. There was no significant difference in response strength between contralateral and ipsilateral mechanical stimulation. A slightly greater response was recorded in the sigmoidal gyrus than in the coronal gyrus. The cat somatosensory cortex activated by sensory inputs from mechanical stimulation of canines lacks both topographical and functional organization. It is not organized into columns that represent sensory input from each tooth or direction of stimulation. These results demonstrate that intrinsic signal optical imaging is a valid tool for investigating neural responses and neuroplasticity in the somatosensory cortex that represents teeth. PMID:27163378

  5. Cephradine (Velosef) penetration of mandibular bone.

    Science.gov (United States)

    Middlehurst, R J; Rood, J P

    1990-04-01

    The concentration of cephradine in serum and mandibular bone was assayed in 28 patients undergoing 3rd molar surgery following a single 1 g intravenous injection. Serum and cortical bone samples taken simultaneously, contained mean cephradine concentrations of 42.11 micrograms/ml and 2.61 micrograms/g respectively. These results, when compared with those reported for other bony sites including the femoral head and knee, show a reduced bone penetration with a bone-to-serum ratio of approximately 0.06:1. PMID:2111359

  6. Cortical plasticity and rehabilitation.

    Science.gov (United States)

    Moucha, Raluca; Kilgard, Michael P

    2006-01-01

    The brain is constantly adapting to environmental and endogenous changes (including injury) that occur at every stage of life. The mechanisms that regulate neural plasticity have been refined over millions of years. Motivation and sensory experience directly shape the rewiring that makes learning and neurological recovery possible. Guiding neural reorganization in a manner that facilitates recovery of function is a primary goal of neurological rehabilitation. As the rules that govern neural plasticity become better understood, it will be possible to manipulate the sensory and motor experience of patients to induce specific forms of plasticity. This review summarizes our current knowledge regarding factors that regulate cortical plasticity, illustrates specific forms of reorganization induced by control of each factor, and suggests how to exploit these factors for clinical benefit.

  7. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  8. Micro-CT analyses of historical bone samples presenting with osteomyelitis

    International Nuclear Information System (INIS)

    Osteomyelitis is an inflammation of the bone marrow mainly caused by bacteria such as Staphylococcus aureus. It typically affects long bones, e.g. femora, tibiae and humeri. Recently micro-computed tomography (μCT) techniques offer the opportunity to investigate bone micro-architecture in great detail. Since there is no information on long bone microstructure in osteomyelitis, we studied historic bone samples with osteomyelitis by μCT. We investigated 23 femora of 22 individuals suffering from osteomyelitis provided by the Collection of Anatomical Pathology, Museum of Natural History, Vienna (average age 44 ±19 years); 9 femora from body donors made available by the Department of Applied Anatomy, Medical University of Vienna (age range, 56-102 years) were studied as controls. Bone microstructure was assessed by μCT VISCOM X 8060 II with a minimal resolution of 18 μm. In the osteomyelitic femora, most prominent alterations were seen in the cortical compartment. In 71.4 % of the individuals with osteomyelitis, cortical porosity occurred. 57.1 % of the individuals showed cortical thinning. In 42.9 % trabecularisation of cortical bone was observed. Osteomyelitis is associated with severe alterations of cortical bone structure otherwise typically observed at old age such as cortical porosity and cortical thinning. (orig.)

  9. Micro-CT analyses of historical bone samples presenting with osteomyelitis

    Energy Technology Data Exchange (ETDEWEB)

    Lamm, C.; Pietschmann, P. [Medical University Vienna (MUV), Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Vienna (Austria); Dockner, M.; Weber, G.W. [University of Vienna, Department of Anthropology, Vienna (Austria); University of Vienna, Core Facility for Micro-Computed Tomography, Vienna (Austria); Pospischek, B.; Winter, E.; Patzak, B. [Museum of Natural History (NHM), Collection of Anatomical Pathology in the Madhouse Tower, Vienna (Austria); Pretterklieber, M. [Medical University of Vienna (MUV), Department of Applied Anatomy, Vienna (Austria)

    2015-10-15

    Osteomyelitis is an inflammation of the bone marrow mainly caused by bacteria such as Staphylococcus aureus. It typically affects long bones, e.g. femora, tibiae and humeri. Recently micro-computed tomography (μCT) techniques offer the opportunity to investigate bone micro-architecture in great detail. Since there is no information on long bone microstructure in osteomyelitis, we studied historic bone samples with osteomyelitis by μCT. We investigated 23 femora of 22 individuals suffering from osteomyelitis provided by the Collection of Anatomical Pathology, Museum of Natural History, Vienna (average age 44 ±19 years); 9 femora from body donors made available by the Department of Applied Anatomy, Medical University of Vienna (age range, 56-102 years) were studied as controls. Bone microstructure was assessed by μCT VISCOM X 8060 II with a minimal resolution of 18 μm. In the osteomyelitic femora, most prominent alterations were seen in the cortical compartment. In 71.4 % of the individuals with osteomyelitis, cortical porosity occurred. 57.1 % of the individuals showed cortical thinning. In 42.9 % trabecularisation of cortical bone was observed. Osteomyelitis is associated with severe alterations of cortical bone structure otherwise typically observed at old age such as cortical porosity and cortical thinning. (orig.)

  10. Computer-aided system for measuring the mandibular cortical width on panoramic radiographs in osteoporosis diagnosis

    Science.gov (United States)

    Arifin, Agus Zainal; Asano, Akira; Taguchi, Akira; Nakamoto, Takashi; Ohtsuka, Masahiko; Tanimoto, Keiji

    2005-04-01

    Osteoporotic fractures are associated with substantial morbidity, increased medical cost and high mortality risk. Several equipments of bone assessment have been developed to identify individuals, especially postmenopausal women, with high risk of osteoporotic fracture; however, a large segment of women with low skeletal bone mineral density (BMD), namely women with high risk of osteoporotic fractures, cannot be identified sufficiently because osteoporosis is asymptomatic. Recent studies have been demonstrating that mandibular inferior cortical width manually measured on panoramic radiographs may be useful for the identification of women with low BMD. Automatic measurement of cortical width may enable us to identify a large number of asymptomatic women with low BMD. The purpose of this study was to develop a computer-aided system for measuring the mandibular cortical width on panoramic radiographs. Initially, oral radiologists determined the region of interest based on the position of mental foramen. Some enhancing image techniques were applied so as to measure the cortical width at the best point. Panoramic radiographs of 100 women who had BMD assessments of the lumbar spine and femoral neck were used to confirm the efficacy of our new system. Cortical width measured with our system was compared with skeletal BMD. There were significant correlation between cortical width measured with our system and skeletal BMD. These correlations were similar with those between cortical width manually measured by the dentist and skeletal BMD. Our results suggest that our new system may be useful for mass screening of osteoporosis.

  11. Three-dimensional canine loop for management of buccally erupted canines

    Directory of Open Access Journals (Sweden)

    Praveen Mehrotra

    2015-01-01

    Full Text Available Maxillary canines are known as the cornerstones of mouth. They are considered to be important for esthetics and for functional occlusion. Any disturbance in the eruption process leading to an aberrant position will hamper esthetics as well as function. Orthodontic tooth movement of total buccally blocked-out canine is usually difficult as it is related with the problems of severe crowding, midline deviation, involvement of long root movement and risk of gingival recession. Such conditions can be treated orthodontically in various ways, but this clinical innovation helps to correct the buccally placed canines into the arch with a precise control of the canine in all the Three-dimensions (3D of space as well as providing maximum comfort to the patient by placing the canine loop on the palatal surface of the tooth, reducing soreness on the labial mucosa. It can be easily fabricated and activated at chairside for either simultaneous or sequential control in 3D.

  12. Intracortical bone metastasis mimicking intracortical osteoid osteoma: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Yu Ri; Kim, Jee Young [St. Vincent' s Hospital, The Catholic University of Korea, Suwon (Korea, Republic of)

    2007-08-15

    Cortical metastasis usually occurs in the diaphysis of the long bones with the appearance of a cookie-bite pattern; this is associated with cortical destruction extending into the soft tissue as well as into the medullary cavity, or there can be a periosteal reaction. We report here on a 66-year-old woman who was diagnosed with intracortical metastasis in the proximal metaphysis of the right femur as an initial metastatic focus from primary lung cancer. CT detected an intracortical osteolytic lesion without cortical destruction or thickening. The MR images showed extensive peritumoral edema in the surrounding soft tissue and adjacent bone marrow edema, and this all mimicked osteoid osteoma.

  13. Cardiac atrioventricular conduction improved by autologous transplantation of mesenchymal stem cells in canine atrioventricular block models

    Institute of Scientific and Technical Information of China (English)

    Xiaoqing Ren; Jielin Pu; Shu Zhang; Liang Meng; Fangzheng Wang

    2007-01-01

    Objective Atrioventricular block (AVB) is a common and serious arrhythmia. At present, there is no perfect method of treatment for this kind of arrhythmia. The purpose of this study was to regenerate cardiac atrioventricular conduction by autologous transplantation of bone marrow mesenchymal stem cells (MSCs), and explore new methods for therapy of atrioventricular block. Methods Eleven Mongrel canines were randomized to MSCs transplantation (n=6) or control (n=5) group. The models of permanent and complete AVB in 11 canines were established by ablating His bundle with radiofrequency technique. At 4 weeks after AVB, bone marrow was aspirated from the iliac crest. MSCs were isolated and culture-expanded by means of gradient centrifugal and adherence to growth technique, and differentiated by 5-azacytidine in vitro. Differentiated MSCs (1ml, 1.5×107cells) labeled with BrdU were autotransplanted into His bundle area of canines by direct injection in the experimental group, and 1ml DMEM in the control group. At 1-12 weeks after operation,the effects of autologous MSCs transplantation on AVB models were evaluated by electrocardiogram, pathologic and immunohistochemical staining technique. Results Compared with the control group, there was a distinct improvement in atrioventricular conduction function in the experimental group. MSCs transplanted in His bundle were differentiated into analogous conduction system cells and endothelial cells in vivo, and established gap junction with host cardiomyocytes. Conclusions The committed-induced MSCs transplanted into His bundle area could differentiate into analogous conduction system cells and improve His conduction function in canine AVB models.

  14. Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Tsuneda, H.; Matsukawa, S.; Takayanagi, S.; Matsukawa, M., E-mail: mmatsuka@mail.doshisha.ac.jp [Wave Electronics Research Center, Laboratory of Ultrasonic Electronics, Doshisha University, 1-3, Tatara Miyakodani, Kyotanabe, Kyoto 610-0321 (Japan); Mizuno, K. [Underwater Technology Collaborative Research Center, Institute of Industrial Science, The University of Tokyo, 4-6-1, Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Yanagitani, T. [Graduate School of Engineering, Nagoya Institute of Technology, Gokiso cho, Showa-ku, Nagoya 466-8555 (Japan)

    2015-02-16

    The healing mechanism of bone fractures by low intensity pulse ultrasound is yet to be fully understood. There have been many discussions regarding how the high frequency dynamic stress can stimulate numerous cell types through various pathways. As one possible initial process of this mechanism, we focus on the piezoelectricity of bone and demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. We have fabricated ultrasonic bone transducers using bovine cortical bone as the piezoelectric device. The ultrasonically induced electrical potentials in the transducers change as a function of time during immersed ultrasonic pulse measurements and become stable when the bone is fully wet. In addition, the magnitude of the induced electrical potentials changes owing to the microstructure in the cortical bone. The potentials of transducers with haversian structure bone are higher than those of plexiform structure bone, which informs about the effects of bone microstructure on the piezoelectricity.

  15. Bone growth in electric fields

    International Nuclear Information System (INIS)

    Research performed in several laboratories has shown that artificially induced currents affect bone growth. Studies of various current characteristics produced by implanted electrodes indicate that continuous dc, interrupted dc, and asymmetric ac all increase osteogenesis at the cathode. Stimulation from an externally applied balanced ac field was reported to reduce bone loss from disuse. The purpose of the study being reported here was to examine the influence of a uniform ac electric field on the normal skeletal growth pattern of rats. Juvenile rats received whole body exposure to uniform, vertical 60-Hz electric fields at 100 kV/m for 30 days. There were no marked alterations in the general growth pattern of the exposed animals compared to controls maintained under similar conditions. Bone growth rate, measured by tetracycline labeling, morphology of lumbar vertebrae and tibias and cortical bone area and marrow space area of tibias were not disturbed by exposure to the electric fields. (author)

  16. Canine distemper virus detection in asymptomatic and non vaccinated dogs

    OpenAIRE

    Del Puerto, Helen L; Vasconcelos, Anilton C.; Luciana Moro; Fabiana Alves; Braz, Gissandra F; Almir S. Martins

    2010-01-01

    A quantitative real time polymerase chain reaction (PCR) revealed canine distemper virus presence in peripheral blood samples from asymptomatic and non vaccinated dogs. Samples from eleven domestic dogs with no signs of canine distemper and not vaccinated at the month of collection were used. Canine distemper virus vaccine samples in VERO cells were used as positive controls. RNA was isolated with Trizol®, and treated with a TURBO DNA-free kit. Primers were designed for canine distemper virus...

  17. The peak bone mass concept: is it still relevant?

    Science.gov (United States)

    Schönau, Eckhard

    2004-08-01

    researchers is shifting away from bone mass to bone geometry or bone strength. Bone mass is one surrogate marker of bone strength. Widely available techniques for measurement of bone mass, such as dual-energy X-ray absorptiometry, radiogrammetry, and computed tomography, can also be used to measure variables of bone geometry such as cortical thickness, cortical area, and moment of inertia. PMID:15197638

  18. 9 CFR 113.201 - Canine Distemper Vaccine, Killed Virus.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Canine Distemper Vaccine, Killed Virus..., DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.201 Canine Distemper Vaccine, Killed Virus. Canine Distemper...

  19. Canine hypothyroidism. A diagnostic challenge?

    International Nuclear Information System (INIS)

    Hypothyroidism is one of the most common endocrinopathies in dogs. Clinical symptoms and hematological and biochemical parameters lead to a first suspicion. To confirm diagnosis can be challenging, however. Determination of total serum T4 concentration is accepted as the primary screening test for the disease, and low serum T4 concentrations are intuitively suggestive of hypothyroidism. However it is well known that low T4 concentrations are frequently encountered in euthyroid dogs with various nonthyroidal diseases and in dogs receiving certain pharmacologic agents. Since assessment of endogenous TSH (canine TSH) using current canine TSH assays shows normal values in a high percentage of hypothyroid dogs (up to 40%), its diagnostic value is only limited. The TSH-stimulation test can still be recognized as the gold standard for the diagnosis of hypothyroidism in dogs. Determination of circulating T4 concentration before and 6 hours after the administration of exogenous TSH (recombinant human TSH, Thyrogen registered) provides an assessment of the functional reserve capacity of the thyroid gland with minimal change in post-TSH T4 concentration, compared with the basal concentration, expected in dogs with hypothyroidism. Also this test can be influenced by nonthyroidal illness and by medications known to affect thyroid function. This suppressing influence seems to be less pronounced using a higher dose of TSH. Therefore, to improve the discriminatory power of the TSH stimulation test to differentiate between euthyroid-sick and primary hypothyroidism, the higher dose should be used in cases in which testing cannot be delayed. More recently, ultrasonography and scintigraphy have been used for the diagnosis of primary hypothyroidism. Using ultrasonography, a sensitivity of 98% was reported if size and echogenicity of the gland were combined. However, specificity was as low as 77%. and care must be taken when measuring the gland because of a relatively high interobserver

  20. Bisphosphonates inhibit the adhesion of breast cancer cells to bone matrices in vitro.

    OpenAIRE

    van der Pluijm, G.; Vloedgraven, H; van Beek, E; van der Wee-Pals, L; Löwik, C; Papapoulos, S

    1996-01-01

    Bisphosphonates are used with increasing frequency in the management of skeletal complications in patients with breast cancer. In this paper, we have investigated whether bisphosphonates, besides their known beneficial effects on tumor-associated osteoclastic resorption, are capable of inhibiting breast cancer cell adhesion to bone matrix. For that we used two in vitro models for bone matrix (cortical bone slices and cryostat sections of trabecular bone from neonatal mouse tails). Four bone m...

  1. The behavior of adaptive bone-remodeling simulation models

    NARCIS (Netherlands)

    H.H. Weinans (Harrie); R. Huiskes (Rik); H.J. Grootenboer

    1992-01-01

    textabstractThe process of adaptive bone remodeling can be described mathematically and simulated in a computer model, integrated with the finite element method. In the model discussed here, cortical and trabecular bone are described as continuous materials with variable density. The remodeling rule

  2. Levels of serotonin, sclerostin, bone turnover markers as well as bone density and microarchitecture in patients with high bone mass phenotype due to a mutation in Lrp5

    DEFF Research Database (Denmark)

    Nielsen, Morten Frost; Andersen, Tom E.; Gossiel, F;

    2011-01-01

    CONTEXT: Patients with an activation mutation of the Lrp5 gene exhibit high bone mass (HBM). Limited information is available regarding compartment specific changes in bone. The relationship between the phenotype and serum serotonin is not well documented. Objective: to evaluate bone, serotonin...... and forearm and cortical thickness were positively and trabecular area negatively associated with age (r =0.49, 0.57, 0.74 and -0.61, respectively, p ...

  3. Image-Based Macro-Micro Finite Element Models of a Canine Femur with Implant Design Implications

    Science.gov (United States)

    Ghosh, Somnath; Krishnan, Ganapathi; Dyce, Jonathan

    2006-06-01

    In this paper, a comprehensive model of a bone-cement-implant assembly is developed for a canine cemented femoral prosthesis system. Various steps in this development entail profiling the canine femur contours by computed tomography (CT) scanning, computer aided design (CAD) reconstruction of the canine femur from CT images, CAD modeling of the implant from implant blue prints and CAD modeling of the interface cement. Finite element analysis of the macroscopic assembly is conducted for stress analysis in individual components of the system, accounting for variation in density and material properties in the porous bone material. A sensitivity analysis is conducted with the macroscopic model to investigate the effect of implant design variables on the stress distribution in the assembly. Subsequently, rigorous microstructural analysis of the bone incorporating the morphological intricacies is conducted. Various steps in this development include acquisition of the bone microstructural data from histological serial sectioning, stacking of sections to obtain 3D renderings of void distributions, microstructural characterization and determination of properties and, finally, microstructural stress analysis using a 3D Voronoi cell finite element method. Generation of the simulated microstructure and analysis by the 3D Voronoi cell finite element model provides a new way of modeling complex microstructures and correlating to morphological characteristics. An inverse calculation of the material parameters of bone by combining macroscopic experiments with microstructural characterization and analysis provides a new approach to evaluating properties without having to do experiments at this scale. Finally, the microstructural stresses in the femur are computed using the 3D VCFEM to study the stress distribution at the scale of the bone porosity. Significant difference is observed between the macroscopic stresses and the peak microscopic stresses at different locations.

  4. Cortical surface segmentation and mapping

    OpenAIRE

    Tosun, Duygu; Rettmann, Maryam E.; Han, Xiao; Tao, Xiaodong; Xu, Chenyang; Resnick, Susan M.; Pham, Dzung L.; Prince, Jerry L.

    2004-01-01

    Segmentation and mapping of the human cerebral cortex from magnetic resonance (MR) images plays an important role in neuro-science and medicine. This paper describes a comprehensive approach for cortical reconstruction, flattening, and sulcal segmentation. Robustness to imaging artifacts and anatomical consistency are key achievements in an overall approach that is nearly fully automatic and computationally fast. Results demonstrating the application of this approach to a study of cortical th...

  5. Effect of long-term growth hormone treatment on bone mass and bone metabolism in growth hormone-deficient men

    NARCIS (Netherlands)

    Bravenboer, N; Holzmann, PJ; ter Maaten, JC; Stuurman, LM; Roos, JC; Lips, P

    2005-01-01

    Long-term GH treatment in GH-deficient men resulted in a continuous increase in bone turnover as shown by histomorphometry. BMD continuously increased in all regions of interest, but more in the regions with predominantly cortical bone. Introduction: Adults with growth hormone (GH) deficiency have r

  6. Composite mandibular allografts in canines

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To evaluate the feasibility of transplanting composite mandibular allografts to repair large mandibular defects. Methods: Three composite mandibular transplantation models were established. The first model consisted of hemimandible with the attached teeth, muscle and skin, and oral mucosa. The second model was transplanted in the same way with the first one excluding oral mucosa and some teeth, and third one excluding the oral mucosa and all dental crowns. Fourteen transplanting operations were performed in canines. Cyclosporine A and methylprednisone were given for immunosuppression. Results: The composite mandibular organs had an effective and closed return circuit. Transplantation of vascularized allograft of mandibular compound organs was feasible. Two longest time survivors of 67 d and 76 d were in the third model group. Cyclosporine A was successful in suppressing rejection of transplanted composite allograft and prolonging survival time of transplantation models. Conclusions: The composite mandibular allografts were available with large block of living composite tissue,and helpful in restoration of appearance and function for severe mandibular defects.

  7. Hiperostosis cortical infantil

    Directory of Open Access Journals (Sweden)

    Salvador Javier Santos Medina

    2015-04-01

    Full Text Available La enfermedad de Caffey, o hiperostosis cortical infantil, es una rara enfermedad ósea autolimitada, que aparece de preferencia en lactantes con signos inespecíficos sistémicos; el más relevante es la reacción subperióstica e hiperostosis en varios huesos del cuerpo, con predilección en el 75-80 % de los casos por la mandíbula. Su pronóstico es bueno, la mayoría no deja secuelas. El propósito del presente trabajo es describir las características clínicas, presentes en un lactante de cinco meses de edad, atendido en el Hospital Pediátrico Provincial “Mártires de Las Tunas” con este diagnóstico, quien ingresó en el servicio de miscelánea B por una celulitis facial. Presentaba aumento de volumen en la región geniana izquierda, febrícola e inapetencia. Se impuso tratamiento con cefazolina y se egresó a los siete días. Acudió nuevamente con tumefacción blanda y difusa de ambas hemicaras, irritabilidad y fiebre. Se interconsultó con cirugía maxilofacial, se indicaron estudios sanguíneos y radiológicos. Se diagnosticó como enfermedad de Caffey, basado en la edad del niño, tumefacción facial sin signos inflamatorios agudos e hiperostosis en ambas corticales mandibulares a la radiografía AP mandíbula; unido a anemia ligera, leucocitosis y eritrosedimentación acelerada. El paciente se trató sintomáticamente y con antinflamatorios no esteroideos. Esta rara entidad se debe tener presente en casos de niños y lactantes con irritabilidad y fiebre inespecífica

  8. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... of DXA Bone Densitometry? What is a Bone Density Scan (DXA)? Bone density scanning, also called dual-energy x-ray absorptiometry ( ... is today's established standard for measuring bone mineral density (BMD). An x-ray (radiograph) is a noninvasive ...

  9. Oncolytic Virotherapy of Canine and Feline Cancer

    Directory of Open Access Journals (Sweden)

    Ivaylo Gentschev

    2014-05-01

    Full Text Available Cancer is the leading cause of disease-related death in companion animals such as dogs and cats. Despite recent progress in the diagnosis and treatment of advanced canine and feline cancer, overall patient treatment outcome has not been substantially improved. Virotherapy using oncolytic viruses is one promising new strategy for cancer therapy. Oncolytic viruses (OVs preferentially infect and lyse cancer cells, without causing excessive damage to surrounding healthy tissue, and initiate tumor-specific immunity. The current review describes the use of different oncolytic viruses for cancer therapy and their application to canine and feline cancer.

  10. Tooth fractures in canine clinical practice

    International Nuclear Information System (INIS)

    Tooth fractures constitute a considerable fraction of all tooth diseases. Out of the 5,370 dogs treated during four years, 492 were presented with dental problems and 28.3 % of the latter were treated for tooth fractures. Canines were the most frequently affected teeth (38.8 %), followed by premolars (33.1 %), incisors (25.9 %), and molars (2.2 %), 55.4 % of the patients with canine and incisor fractures being large breed dogs. Fractures of premolars (mostly of 108, 208) were divided evenly irrespective of breed or body size. Nonsurgical endodontic treatment yielded good therapeutic results in most cases, but repeated treatment was necessary in some patients

  11. A Study of Transmigrated Canine in an Indian Population

    Science.gov (United States)

    Sharma, Gaurav; Nagpal, Archna

    2014-01-01

    Aim. The purpose of this study was to investigate the prevalence of transmigrated canines in a north Indian population and association with gender, side, associated pathologies, and dental anomalies. Subjects and methods. The prospective study consisted of panoramic radiographs of 3000 patients from two dental colleges in north India. The panoramic radiographs were screened for radiographically identified position of the transmigrated tooth, retained canine, and other coexisting dental anomalies. Results. The overall prevalence of transmigrated canines (15 mandibular and 5 maxillary) was 0.66%. The prevalence of mandibular transmigrated canine was 0.5% and maxillary transmigrated canine was 0.16%. All the transmigrated canines were unilateral. The age range was 15–53 years (average age 24.1 years) and there were 12 males (60%) and 8 females (40%). Type 1 mandibular canine transmigration was the commonest type found in our study (10 cases), followed by types 2 and 4 (2 cases each) and 1 case of type 5 transmigration. Conclusion. The prevalence of transmigrated canines in the north Indian population was 0.66% and no gender predilection was evident. The transmigrated canines have a low complication rate (10.0%) and no correlation with other dental anomalies was found. Type 3 canine is the rarest form of mandibular canine transmigration. PMID:27433532

  12. Bone lead measured by X-ray fluorescence: epidemiologic methods.

    OpenAIRE

    Hu, H; Aro, A; Rotnitzky, A

    1995-01-01

    In vivo X-ray fluorescence (XRF) measurement of bone lead concentration (XRF) has emerged as an important technique for future epidemiological studies of long-term toxicity. Several issues germane to epidemiologic methodology need to be addressed, however. First, sources of variability in measurements of bone lead need to be quantified, including imprecision related to the physical measurement itself and the variability of lead deposition over the two main compartments of bones (cortical vs. ...

  13. Imaging appearance of bone tumors of the maxillofacial region

    OpenAIRE

    Razek, Ahmed Abdel Khalek Abdel

    2011-01-01

    This paper reviews the imaging appearance of benign and malignant bone tumors of the maxillofacial region. A benign bone tumor commonly appears as a well circumscribed lesion. The matrix of the tumor may be calcified or sclerotic. Malignancies often display aggressive characteristics such as cortical breakthrough, bone destruction, a permeative pattern and associated soft-tissue masses. Computed tomography scan is an excellent imaging modality for accurate localization of the lesion, characte...

  14. Bone Cell Autophagy Is Regulated by Environmental Factors

    OpenAIRE

    Zahm, Adam M.; Bohensky, Jolene; Adams, Christopher S.; Shapiro, Irving M.; Srinivas, Vickram

    2011-01-01

    The goal of this investigation was to ascertain whether bone cells undergo autophagy and to determine if this process is regulated by environmental factors. We showed that osteocytes in both murine and human cortical bone display a punctuate distribution of microtubule-associated protein light chain 3, indicative of autophagy. In addition, we noted a basal level of autophagy in preosteocyte-like murine long bone-derived osteocytic (MLO)-A5 cells. Autophagy was upregulated following nutrient d...

  15. Low Bone Density

    Science.gov (United States)

    ... Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone density ... people with normal bone density. Detecting Low Bone Density A bone density test will determine whether you ...

  16. Canine neoplasia and exposure to uranium mill tailings in Mesa County, Colorado

    International Nuclear Information System (INIS)

    A canine cancer registry was established for Mesa County, Colorado in order to collect material for a case control analysis of exposure to uranium tailings. Between 1979 and 1981, 212 cases of canine cancer were confirmed histologically. Based on the address provided at the time of diagnosis, 33 dogs (15.6%) lived in a house with some exposure to uranium tailings. A control group, comprised of dogs with a histologic diagnosis other than cancer, was stratified according to hospital and matched with cases on a 1:1 basis. No significant differences were noted with respect to exposure to uranium tailings for total cancers or cancers of specific sites including lymph node, breast, liver, testicle and bone. The overall estimated relative risk was 0.70 (95% CI 0.04 to 1.16). Canine population estimates were derived for Mesa County in order to develop crude incidence rates for the major types and sites of cancer. Crude rates were compared with those published previously for Alameda County, California and Tulsa County, Oklahoma. Mesa County rates for total cancer incidence, connective tissue tumors and non melanoma skin cancer were higher than those reported for Alameda County. When compared with Tulsa County, Mesa County rates for total cancer, breast cancer, melanoma and mastocytoma were lower than expected while rates for osteosarcoma, hemangiosarcoma and fibrosarcoma significantly exceeded expected values

  17. External bone remodeling after injectable calcium-phosphate cement in benign bone tumor: two cases in the hand.

    Science.gov (United States)

    Ichihara, S; Vaiss, L; Acciaro, A L; Facca, S; Liverneaux, P

    2015-12-01

    Bone remodeling commonly occurred after fracture and curettage benign bone tumor. A lot of previous articles reported "internal" trabecular bone remodeling. There were no previous clinical reports about "external" cortical bone remodeling. We present here 2 clinical cases of "external" bone remodeling after injectable calcium-phosphate in benign bone tumor in the hand. In two cases of benign bone tumor, we performed complete removal of the tumor and immediate filling of the metacarpal bone with injectable calcium-phosphate cement Arexbone(®) from the mechanical viewpoint. With respect to the shape of the calcium-phosphate, by using an injection-type, calcium-phosphate is adhered uniformly to the bone cortex by injecting, remodeling has been promoted. After 5 and 8years, both cases were no recurrences, and the shape of the metacarpal looked close to the contralateral side. These findings supposed to be concerned with potential self-healing and self-protection mechanism in human body.

  18. Metaphyseal cortical irregularities in children: A new perspective on a multi-focal growth variant

    International Nuclear Information System (INIS)

    The occurrence of metaphyseal cortical irregularities in adolescents in many different bones indicates a commonality of these lesions as a variation of normal growth, rater than a stress or avulsive by-product. The histologically recognized incomplete nature of the metaphysical cortex in children offers an attractive explanation for this phenomenon. (orig.)

  19. Temporal response of bone to unloading

    International Nuclear Information System (INIS)

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

  20. Temporal response of bone to unloading

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-02-01

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

  1. 腰椎皮质骨钉道螺钉在骨质疏松症患者中应用的三维有限元分析%Biomechanical evaluation of lumbar pedicle screws using cortical bone trajectory in osteoporosis:a finite element study

    Institute of Scientific and Technical Information of China (English)

    邵明昊; 吕飞舟; 马晓生; 夏新雷; 王洪立; 郑超君; 张帆; 姜建元

    2015-01-01

    目的:比较椎弓根皮质骨钉道(cortical bone trajectory,CBT)螺钉和传统椎弓根钉道(traditional trajectory,TT)螺钉抗拔出力、螺钉及椎体稳定性的差异。方法回顾性选取复旦大学附属华山医院2015年3月至9月骨质疏松症患者7例,年龄57~63岁,平均(61.4±3.1)岁,均为女性,骨密度T值均<-2.5 SD。使用Mimics和Abaqus 6.9建立L4椎体模型,选用TT螺钉(直径为6.5 mm、长度为45 mm)和CBT螺钉(直径为5.0 mm、长度为35 mm)模拟置钉,分析并比较两种螺钉的轴向抗拔出力、上下左右载荷情况下螺钉载荷位移比及前屈后伸、轴向及侧屈旋转工况下椎体载荷位移比情况。结果CBT螺钉组的抗拔出力[(1013.2±279.1)N]较TT螺钉组[(1277.1±331.3)N]高出26.04%(t=3.128,P=0.024)。CBT螺钉组在受到上下左右应力时载荷位移比明显大于TT螺钉组(t=3.217,P=0.021;t=3.216,P=0.021;t=3.214,P=0.017;t=3.221, P=0.016)。CBT螺钉组椎体前屈、后伸载荷位移比明显大于TT螺钉组(t=2.733,P=0.034;t=2.712,P=0.031);而TT螺钉组椎体轴向、侧屈旋转载荷位移比较CBT螺钉组高(t=3.941, P=0.011;t=4.432,P=0.007)。结论相比TT螺钉,CBT螺钉具有更强的抗拔出力及螺钉稳定性,且椎体前屈、后伸的稳定性强于TT螺钉固定。CBT螺钉内固定为骨质疏松患者的腰椎手术提供了更多的选择。%ObjectiveThe purpose of the present study was to evaluate the differences of pull-out strength and stability of screw and vertebrae between two models using cortical bone trajectory (CBT) screw and traditional trajectory (TT) screw and provide theoretical basis for the clinical application of CBT screw.Methods Finite element models of L4 vertebrae were builded using Mimics and Abaqus 6.9, according to 7 osteoporotic patients, ranging in age from 57 to 63 years, at average age of (61.4±3.1) years, admitted to

  2. Bone Cancer

    Science.gov (United States)

    ... cancer. Surgery is often the main treatment for bone cancer. Other treatments may include amputation, chemotherapy, and radiation therapy. Because bone cancer can come back after treatment, regular follow-up visits are important. NIH: National ...

  3. Seroprevalence of Canine Distemper Virus in Cats

    OpenAIRE

    Ikeda, Yasuhiro; Nakamura, Kazuya; Miyazawa, Takayuki; Chen, Ming-Chu; Kuo, Tzong-Fu; Lin, James A; Mikami, Takeshi; Kai, Chieko; TAKAHASHI, Eiji

    2001-01-01

    A seroepidemiological survey of canine distemper virus (CDV) infection in Asian felids revealed that the prevalence of antibodies varied depending on region and, in some cases, exposure to dogs. The serologic pattern in cats with antibodies indicated that they had likely been exposed to field strains rather than typical CDV vaccine strains.

  4. Canine Distemper Outbreak in Rhesus Monkeys, China

    OpenAIRE

    Qiu, Wei; Zheng, Ying; Zhang, Shoufeng; Fan, Quanshui; Liu, Hua; Zhang, Fuqiang; Wang, Wei; Liao, Guoyang; Hu, Rongliang

    2011-01-01

    Since 2006, canine distemper outbreaks have occurred in rhesus monkeys at a breeding farm in Guangxi, People’s Republic of China. Approximately 10,000 animals were infected (25%–60% disease incidence); 5%–30% of infected animals died. The epidemic was controlled by vaccination. Amino acid sequence analysis of the virus indicated a unique strain.

  5. Overexpression of vimentin in canine prostatic carcinoma

    DEFF Research Database (Denmark)

    Rodrigues, M M P; Rema, A; Gärtner, F;

    2011-01-01

    is associated with the invasive phenotype of human prostate cancer cells. The aim of the present study was to characterize immunohistochemically the expression of vimentin by canine prostatic carcinomas. Primary carcinomas and metastatic tumour foci both showed vimentin expression. This finding suggests...

  6. Canine specific ELISA for coagulation factor VII

    DEFF Research Database (Denmark)

    Knudsen, Tom; Kjelgaard-Hansen, Mads; Tranholm, Mikael;

    2011-01-01

    available to date. In this study, a canine specific ELISA for measurement of FVII:Ag in plasma was developed and validated. The FVII:Ag ELISA correctly diagnosed homozygous and heterozygous hereditary FVII deficiency. Together with activity based assays, such as FVII:C, the FVII:Ag ELISA should be valuable...

  7. Canine notoedric mange: a case report.

    Science.gov (United States)

    Leone, Federico

    2007-04-01

    Notoedric mange is a cutaneous ectoparasitic disease of cats caused by Notoedres cati, a mite belonging to the Sarcoptidae family. The disease occurs in felids, occasionally in other mammals and in humans. The canine form, even if cited by some authors, has never been documented. This report describes for the first time a case of notoedric mange in a dog.

  8. Radiological aspects of prenatal-onset cortical hyperostosis [Caffey Dysplasia

    International Nuclear Information System (INIS)

    Objective: Cortical hyperostosis is a bone disease that may, at times, occur with a prenatal onset. This study seeks to present the characteristic patterns of prenatal-onset cortical hyperostosis (PCH) with regard to the radiographic features, and tries to ascertain whether PCH is a separate entity from infantile cortical hyperostosis (ICH), known as classic Caffey Disease. Materials and methods: This retrospective study identified cases with PCH based upon abnormal radiographic and chondro-osseous morphological and clinical findings, as available, from the International Skeletal Dysplasia Registry between 1987 and 2009. Outcomes and clinical information were also identified from medical records. Results: Based upon radiographic results, we found 20 individuals with PCH, of whom 10 neonatally survived, and 10 died. Hyperostosis of the mandible was found in 18/20, and of the skull base in 16/20 cases. Hyperostosis of the ribs was found in 17/20 cases, of the scapulae in 14/20, and of the clavicles in 4/20. Hyperostosis of the ileum was found in 11/20 cases, and of the long bones in all 20/20 cases, of which three cases had fibula sparing. No hyperostosis of the hands, feet, and spine was found. Conclusions: Our results suggest that, based upon clinical features and radiographic expression, ICH and PCH represent two separate entities, and that ICH should continue to be referred to as Caffey Disease and that PCH should be called Caffey Dysplasia. The findings of symmetrical hyperostosis of the mandible, ribs, scapulae, ilea, and long bones in any combination should suggest the diagnosis of PCH.

  9. Grid cells and cortical representation.

    Science.gov (United States)

    Moser, Edvard I; Roudi, Yasser; Witter, Menno P; Kentros, Clifford; Bonhoeffer, Tobias; Moser, May-Britt

    2014-07-01

    One of the grand challenges in neuroscience is to comprehend neural computation in the association cortices, the parts of the cortex that have shown the largest expansion and differentiation during mammalian evolution and that are thought to contribute profoundly to the emergence of advanced cognition in humans. In this Review, we use grid cells in the medial entorhinal cortex as a gateway to understand network computation at a stage of cortical processing in which firing patterns are shaped not primarily by incoming sensory signals but to a large extent by the intrinsic properties of the local circuit.

  10. Horizontal integration and cortical dynamics.

    Science.gov (United States)

    Gilbert, C D

    1992-07-01

    We have discussed several results that lead to a view that cells in the visual system are endowed with dynamic properties, influenced by context, expectation, and long-term modifications of the cortical network. These observations will be important for understanding how neuronal ensembles produce a system that perceives, remembers, and adapts to injury. The advantage to being able to observe changes at early stages in a sensory pathway is that one may be able to understand the way in which neuronal ensembles encode and represent images at the level of their receptive field properties, of cortical topographies, and of the patterns of connections between cells participating in a network.

  11. Imprinting and recalling cortical ensembles.

    Science.gov (United States)

    Carrillo-Reid, Luis; Yang, Weijian; Bando, Yuki; Peterka, Darcy S; Yuste, Rafael

    2016-08-12

    Neuronal ensembles are coactive groups of neurons that may represent building blocks of cortical circuits. These ensembles could be formed by Hebbian plasticity, whereby synapses between coactive neurons are strengthened. Here we report that repetitive activation with two-photon optogenetics of neuronal populations from ensembles in the visual cortex of awake mice builds neuronal ensembles that recur spontaneously after being imprinted and do not disrupt preexisting ones. Moreover, imprinted ensembles can be recalled by single- cell stimulation and remain coactive on consecutive days. Our results demonstrate the persistent reconfiguration of cortical circuits by two-photon optogenetics into neuronal ensembles that can perform pattern completion. PMID:27516599

  12. Paroxysmal kinesigenic dyskinesia : Cortical or non-cortical origin

    NARCIS (Netherlands)

    van Strien, Teun W.; van Rootselaar, Anne-Fleur; Hilgevoord, Anthony A. J.; Linssen, Wim H. J. P.; Groffen, Alexander J. A.; Tijssen, Marina A. J.

    2012-01-01

    Paroxysmal kinesigenic dyskinesia (PKD) is characterized by involuntary dystonia and/or chorea triggered by a sudden movement. Cases are usually familial with an autosomal dominant inheritance. Hypotheses regarding the pathogenesis of PKD focus on the controversy whether PKD has a cortical or non-co

  13. Canine visceral leishmaniasis in Sicily.

    Science.gov (United States)

    Orndorff, G R; Cooper, B A; Smith, W; Ryan, J R

    2000-01-01

    The Sicilian province of Catania is an active foci for human visceral leishmaniasis (VL) in the Mediterranean area. Approximately 10 to 15 cases of VL are diagnosed via hospital admissions each year in this community. Recently, an increase in VL case reporting by Sicilian physicians was noted, with 38 and 37 VL cases in 1996 and 1997, respectively. Before 1995, there were no reported VL cases among U.S. military personnel or their family members living in Sicily. However, since 1996, there have been four cases referred to Walter Reed Army Medical Center for diagnosis and treatment, all involving the children of personnel assigned to Naval Air Station Sigonella. Exposure histories for all infected individuals excluded exposure to Leishmania parasites outside of Sicily. All patients lived in areas where vectoring sandflies are present. All had dogs as family pets. To evaluate the level of infection among dogs owned by Navy personnel and their families, U.S. Navy Environmental and Preventive Medicine Unit 7, in a collaborative study with the U.S. Army Veterinary Clinic, Naval Air Station Sigonella, and the Walter Reed Army Institute of Research, performed clinical evaluation and serological testing of 50 dogs residing with U.S. personnel assigned to Naval Air Station Sigonella. The data indicate a high exposure rate to Leishmania (60% of the animals tested had elevated immunoglobulin M antibody levels) in the study population, suggesting that they were infected with Leishmania infantum. Distribution of seropositive dogs by sex was equal. Most of the dogs studied appeared to be in good health. However, inapparent infection of dogs, seen by Italian veterinarians, has been observed throughout all areas of Catania. Sandflies responsible for vectoring L. infantum were trapped in the same locations as the dogs sampled in this study. The level of subclinical infection was 75% among seropositive dogs. The overall level of canine infection observed was higher than expected

  14. Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2009-12-01

    Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

  15. Scintigraphic appearance of infantile cortical hyperostosis (Caffey's disease)

    International Nuclear Information System (INIS)

    Two patients with infantile cortical hyperostosis (Caffey's disease) are presented in whom radionuclide imaging with sup(99m)Tc-MDP and sup(67)Gallium-citrate was performed to eliminate multifocal osteomyelitis as a diagnosis. The scintigraphic appearance of this relatively uncommon disease of children was similar to that obtained in multifocal osteomyelitis; all osseous lesions showed a marked uptake of both radio-tracers. However, the distribution of abnormalities (mandible, scapulae) and the degree of extension (mainly diaphyseal) of the lesions are important characteristics in the scintigraphic differential diagnosis but bone radiographs are best used in making the diagnosis

  16. Caffey Disease or Infantile Cortical Hyperostosis: A Case Report

    Directory of Open Access Journals (Sweden)

    Narayanan Kutty

    Full Text Available Caffey disease or Infantile Cortical Hyperostosis (ICH is a rare and mostly self limiting condition affecting young infants. It is characterized by acute inflammation of the periostium and the overlying soft tissue and is accompanied by systemic changes of irritability and fever. Diagnosis may be delayed as this disorder mimics a wide range of diseases including osteomyelitis, hypervitaminosis A, scurvy, bone tumors and child abuse. The emphasis here is to remind clinicians about the existence of the disease in this country.

  17. [Palliative surgery for bone metastases].

    Science.gov (United States)

    Oetiker, R F; Meier, G; Hefti, F; Bereiter, H

    2001-12-01

    Advances in the treatment of patients who have bone metastases are an issue of high importance to the orthopaedic surgeon. Early diagnosis requires knowledge of the pathogenesis of bone metastases. A primary route of metastatic cells is via Batson's vertebral vein plexus. An understanding of the pathophysiology enables the surgeon to plan effective treatment. As many patients continue to survive for prolonged periods following the detection of bone metastases, it is important to plan treatment that relieves pain and is functional. In long bones non-operative treatment with radiotherapy, patient education to avoid excessive torsional loads and systemic chemotherapy or hormonal therapy as well as diphosphonates are utilized for small lesions with less than 25 percent of the cortical diameter. The indications for surgical treatment include lesions with elevated fracture risk according to Mirels score. Special emphasis is led on the surgical treatment of spinal metastasis. Early and effective treatment improves the remaining quality of life in patients with metastatic bone disease. However a firm knowledge of the pathogenesis and pathophysiology helps the clinician in making an early diagnosis. Nevertheless the orthopaedic surgeon must recognize the need to approach management of these patients from a multidisciplinary perspective in cooperation with the oncologist, radiotherapist, rehabilitation medicine specialist, radiologist, and pathologist. The cooperation among all members of the team will assure the best possible care for the patient who has metastatic bone disease. PMID:11797537

  18. Honey preserved cortical allografts in the repair of diaphyseal femoral defect in dogs: clinical and radiographic

    International Nuclear Information System (INIS)

    Fourteen adult mongrel dogs were used to evaluate the honey preserved cortical allografts in the repair of diaphyseal femoral defect. The allografts were inserted into a 5cm segmental defect created in the mid-diaphysis of the right femur in each dog. The bones were stabilized with a dynamic compression plate and eight bone screws. Healing was followed clinically and femora were evaluated radiographically, periodically. Nineteen (79.2%) of the twenty-four host-graft interfaces were radiographically incorporated. Average time to allograft incorporation was 67.1 days (range 45 days to 90 days). There was no statistical difference in the allograft incorporation time between proximal and distal host-graft interfaces. Complications observed were nonunion, allograft fracture, and allograft resorption. The conclusion is that despite the complications, honey preserved cortical allografts are a viable option to bone reconstruction

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-01

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

  20. Expression of fibroblast growth factor 23 by canine soft tissue sarcomas.

    Science.gov (United States)

    Hardcastle, M R; Dittmer, K E

    2016-09-01

    Tumour-induced osteomalacia (TIO) is a rare paraneoplastic syndrome of humans. Some mesenchymal tumours (often resembling haemangiopericytomas) express molecules that normally regulate phosphorus metabolism; most frequently, fibroblast growth factor 23. Patients develop renal phosphate wasting and inappropriately low serum concentrations of 1, 25 (OH)2 vitamin D3 , leading to osteomalacia. Surgical removal of the tumour is curative. The authors examined expression of canine fibroblast growth factor 23 in 49 soft tissue sarcomas, and control tissues from normal adult dogs. RNA extracted from bone or formalin-fixed, paraffin-embedded tissues was analysed by end point and quantitative reverse transcriptase-polymerase chain reaction. Fibroblast growth factor 23 expression was detected in bone, lung, kidney, lymph node and thymus. Fifteen of 49 sarcomas (31%) expressed fibroblast growth factor 23, three of these had high relative expression and some features resembling phosphatonin-expressing mesenchymal tumours of humans. Further work is required to determine whether TIO may occur in dogs. PMID:24923416

  1. Effects of canine serum collected from dogs at different estrous cycle stages on in vitro nuclear maturation of canine oocytes.

    Science.gov (United States)

    Oh, Hyun Ju; Fibrianto, Yuda Heru; Kim, Min Kyu; Jang, Goo; Hossein, M Shamim; Kim, Hye Jin; Kang, Sung Keun; Lee, Byeong Chun; Hwang, Woo Suk

    2005-08-01

    Canine oocytes are ovulated at prophase of the first meiotic division and undergo maturation in the distal part of the oviduct for at least 48-72 h. Because of these differences from other domestic mammals, the efficiency of in vitro maturation (IVM) of canine oocyte is very low. The present study was conducted to evaluate the effects of canine serum on IVM of canine oocytes recovered from ovaries in various reproductive states (follicular, luteal or anestrous stages). Oocytes were recovered by mincing ovaries from bitches presented for ovariohysterectomy at various stages of the estrous cycle. Heat-inactivated canine serum was prepared with blood taken from dogs at the anestrous, estrous or diestrous stage of the estrous cycle as determined by progesterone concentration and vaginal cytology. Oocytes were cultured for 72 h in tissue culture medium (TCM)-199 supplemented with 10% canine anestrous, estrous or diestrous serum or fetal bovine serum (FBS) (experiment 1), or supplemented with 0 (control), 5%, 10% or 20% canine estrous serum (experiment 2). In experiment 1, IVM of oocytes collected at the follicular stage of the estrous cycle to metaphase II (MII) stage was higher (p < 0.05) with canine estrous serum (14.2%) than with canine anestrous (5.2%) or diestrous serum (6.3%), FBS (2.2%) or in the control (2.2%). In experiment 2, oocytes collected at the follicular stage of the estrous cycle cultured in TCM-199 with 10% canine estrous serum showed a higher maturation rate to MII stage (13.5%, p < 0.05) compared with those cultured with 5% (1.3% MII) or 20% canine estrous serum (5.1% MII) or the control (2.7% MII). In conclusion, our results demonstrate that supplementing culture medium with 10% canine estrous serum improves IVM of canine follicular stage oocytes. PMID:16261767

  2. Tooth Movement out of the Bony Wall Using Augmented Corticotomy with Nonautogenous Graft Materials for Bone Regeneration

    OpenAIRE

    Kye-Bok Lee; Dong-Yeol Lee; Hyo-Won Ahn; Seong-Hun Kim; Eun-Cheol Kim; Igor Roitman

    2014-01-01

    This prospective randomized split-mouth study was performed to compare the effects of augmented corticotomy with those of different nonautogenous bone graft materials combined with orthodontic tooth movement in dogs. Decortication was performed on the buccal bone surface of 6 male beagle dogs that were randomly assigned to receive grafts of deproteinized bovine bone mineral, irradiated cortical bone, or synthetic bone. Immediate orthodontic force was applied to the second and third premolars ...

  3. Cortical thickness mapping to identify focal osteoporosis in patients with hip fracture.

    Directory of Open Access Journals (Sweden)

    Kenneth E S Poole

    Full Text Available BACKGROUND: Individuals with osteoporosis are predisposed to hip fracture during trips, stumbles or falls, but half of all hip fractures occur in those without generalised osteoporosis. By analysing ordinary clinical CT scans using a novel cortical thickness mapping technique, we discovered patches of markedly thinner bone at fracture-prone regions in the femurs of women with acute hip fracture compared with controls. METHODS: We analysed CT scans from 75 female volunteers with acute fracture and 75 age- and sex-matched controls. We classified the fracture location as femoral neck or trochanteric before creating bone thickness maps of the outer 'cortical' shell of the intact contra-lateral hip. After registration of each bone to an average femur shape and statistical parametric mapping, we were able to visualise and quantify statistically significant foci of thinner cortical bone associated with each fracture type, assuming good symmetry of bone structure between the intact and fractured hip. The technique allowed us to pinpoint systematic differences and display the results on a 3D average femur shape model. FINDINGS: The cortex was generally thinner in femoral neck fracture cases than controls. More striking were several discrete patches of statistically significant thinner bone of up to 30%, which coincided with common sites of fracture initiation (femoral neck or trochanteric. INTERPRETATION: Femoral neck fracture patients had a thumbnail-sized patch of focal osteoporosis at the upper head-neck junction. This region coincided with a weak part of the femur, prone to both spontaneous 'tensile' fractures of the femoral neck, and as a site of crack initiation when falling sideways. Current hip fracture prevention strategies are based on case finding: they involve clinical risk factor estimation to determine the need for single-plane bone density measurement within a standard region of interest (ROI of the femoral neck. The precise sites of focal

  4. Combined orthodontic-surgical management of a transmigrated mandibular canine.

    Science.gov (United States)

    Cavuoti, Serena; Matarese, Giovanni; Isola, Gaetano; Abdolreza, Jamilian; Femiano, Felice; Perillo, Letizia

    2016-07-01

    The presence of an impacted mandibular canine is one of the most difficult challenges that an orthodontist will meet. Orthodontic treatment is planned on an individual basis after thoroughly considering the patient's overall facial and dentoskeletal characteristics; the duration, risks, and costs of treatment; patient preferences; and the orthodontist's experience. This article reports an orthodontic treatment of a boy, age 12.9 years, with an impacted mandibular canine in the permanent dentition that was successfully managed. Radiographic analysis indicated a transmigration of the mandibular right canine. The orthodontic treatment plan included extraction of the deciduous right canine followed by surgical exposure and ligation of the permanent canine. Eruption was properly guided, and the correct position of the tooth was achieved. This challenging treatment approach is described in detail, including the mechanics used to align the impacted canine. PMID:26502299

  5. Canine oral biofilms: Cultural, molecular, and in vitro studies.

    OpenAIRE

    Elliott, D. R.

    2006-01-01

    The canine oral microbiota is poorly understood compared to that of humans. The aim of this work was to improve understanding of the canine oral microbiota. This was achieved by surveying the canine oral microbiota, determining coaggregation interactions between its members, and developing a laboratory microcosm. Bacteria were isolated from the dental plaque and saliva of dogs, and isolates were identified by comparative 16S rRNA gene sequencing. From 339 isolates, 84 phylotypes belonging to ...

  6. Portrait of a Canine Probiotic – from Gut to Gut

    OpenAIRE

    O'Mahony, D.; Murphy, K. Barry; MacSharry, J.; Boileau, T.; Sunvold, G.; Reinhart, G.; Kiely, B.; Shanahan, F; O'Mahony, L.

    2009-01-01

    Abstract The gastrointestinal environment is a complex interactive system involving the host, ingested dietary components, and numerous microbial species. We hypothesised that isolation and screening of Lactobacilli and Bifidobacteria adherent to healthy canine gastrointestinal tissue would yield strains with commensal activity in canines. The aims of this study were 1) to isolate a bank of commensal organisms from the canine gastrointestinal tract; 2) to screen these novel microbi...

  7. Internal channel structures in trabecular bone

    Science.gov (United States)

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

    2004-10-01

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

  8. Reversibility of cortical hyperostosis following long-term prostaglandin E1 therapy in infants with ductus-dependent congenital heart disease

    DEFF Research Database (Denmark)

    Høst, A; Halken, S; Andersen, P E

    1988-01-01

    Two neonates with complex cyanotic congenital heart disease, receiving long-term prostaglandin E1 infusion, for 59 and 78 days respectively, demonstrated significant radiographic changes of symmetric cortical hyperostosis of the long bones. Bone biopsies from one of the patients elucidated...

  9. Tongue nodules in canine leishmaniosis — a case report

    Directory of Open Access Journals (Sweden)

    Viegas Carlos

    2012-06-01

    Full Text Available Abstract Background Canine leishmaniosis (CanL caused by Leishmania infantum is an endemic zoonosis in southern European countries. Infected dogs can present rare or atypical forms of the disease and diagnosis can be challenging. The present report describes a case of tongue nodules in a 3-year-old neutered female Labrador Retriever dog with leishmaniosis. Findings A fine needle aspiration of the lingual nodules revealed amastigote forms of Leishmania inside macrophages. Differential diagnosis ruled out neoplasia, calcinosis circumscripta, solar glossitis, vasculitis, amyloidosis, eosinophilic granulomas, chemical and electrical burns, uremic glossitis and autoimmune diseases. Combined therapy with antimoniate meglumine and allopurinol for 30 days resulted in the normalization of hematological and biochemical parameters. Two months after diagnosis and the beginning of treatment, a mild inflammatory infiltrate was observed by histopathology, but an anti-Leishmania immunofluorescence antibody test (IFAT was negative as well as a PCR on both tongue lesions and a bone marrow aspirate. Seven months after diagnosis, the dog’s general condition appeared good, there were no tongue lesions and a new IFAT was negative. Fifteen months after diagnosis this clinically favourable outcome continued. Conclusions The dog could have suffered a relapsing episode of CanL, but a new systemic or local infection cannot be excluded. Regular clinical re-evaluation should be maintained, as a future relapse can potentially occur. In conclusion, CanL should be considered in the differential diagnosis of nodular glossitis in dogs.

  10. Canine small clear cell/T-zone lymphoma: clinical presentation and outcome in a retrospective case series.

    Science.gov (United States)

    Martini, V; Marconato, L; Poggi, A; Riondato, F; Aresu, L; Cozzi, M; Comazzi, S

    2016-08-01

    Published studies, taken together, suggest the existence of a single canine lymphoma entity, with a small clear cell appearance by cytological evaluation, a histopathological T-zone pattern and an aberrant CD45-negative T-cell phenotype, mostly characterized by long-term survival. We describe clinical presentation and outcome in a retrospective case series of canine small clear cell/T-zone lymphoma. Despite the reported predisposition of Golden retriever, this breed was not represented in our case series. Most dogs presented with stage V disease, whereas only few had clinical signs or peripheral cytopenias. Blood was almost always more infiltrated than bone marrow. Median survival confirmed the favourable prognosis described in literature, but a few dogs died within a short time. Also, a subgroup of dogs developed second malignancies, eventually leading to death. We did not investigate possible prognostic factors because of the wide variety in treatments, and further studies are needed to identify high-risk animals.

  11. Validation of commercially available automated canine-specific immunoturbidimetric method for measuring canine C-reactive protein

    DEFF Research Database (Denmark)

    Hillström, Anna; Hagman, Ragnvi; Tvedten, Harold;

    2014-01-01

    with a human CRP assay previously validated for canine CRP determination. Samples from 40 healthy dogs were analyzed to establish a reference interval. RESULTS: Total imprecision was ..., there was good agreement between the validated human CRP assay and the new canine-specific assay. Healthy dogs had CRP concentrations that were less than the limit of quantification of the Gentian cCRP method (6.8 mg/L). CONCLUSIONS: The new canine-specific immunoturbidimetric CRP assay is a reliable and rapid......BACKGROUND: Measurement of C-reactive protein (CRP) is used for diagnosing and monitoring systemic inflammatory disease in canine patients. An automated human immunoturbidimetric assay has been validated for measuring canine CRP, but cross-reactivity with canine CRP is unpredictable. OBJECTIVE...

  12. Lanthanum carbonate stimulates bone formation in a rat model of renal insufficiency with low bone turnover.

    Science.gov (United States)

    Fumoto, Toshio; Ito, Masako; Ikeda, Kyoji

    2014-09-01

    Control of phosphate is important in the management of chronic kidney disease with mineral and bone disorder (CKD-MBD), for which lanthanum carbonate, a non-calcium phosphate-binding agent, has recently been introduced; however, it remains to be determined whether it has any beneficial or deleterious effect on bone remodeling. In the present study, the effects of lanthanum carbonate were examined in an animal model that mimics low turnover bone disease in CKD, i.e., thyroparathyroidectomized (TPTX) and 5/6 nephrectomized (NX) rats undergoing a constant infusion of parathyroid hormone (PTH) and thyroxine injections (TPTX-PTH-5/6NX). Bone histomorphometry at the second lumbar vertebra and tibial metaphysis revealed that both bone formation and resorption were markedly suppressed in the TPTX-PTH-5/6NX model compared with the sham-operated control group, and treatment with lanthanum carbonate was associated with the stimulation of bone formation but not an acceleration of bone resorption. Lanthanum treatment caused a robust stimulation of bone formation with an activation of osteoblasts on the endosteal surface of femoral diaphysis, leading to an increase in cortical bone volume. Thus, lanthanum carbonate has the potential to stimulate bone formation in cases of CKD-MBD with suppressed bone turnover. PMID:24126694

  13. Bone compaction enhances fixation of weight-bearing hydroxyapatite-coated implants

    DEFF Research Database (Denmark)

    Kold, Søren; Rahbek, Ole; Vestermark, Marianne;

    2006-01-01

    The effect of bone compaction vs conventional drilling on the fixation of hydroxyapatite-coated implants was examined in a weight-bearing canine model. In each dog, one knee joint had the implant cavity prepared with drilling, the other with compaction. Eight dogs were euthanized after 2 weeks...

  14. Wnt16 Is Associated with Age-Related Bone Loss and Estrogen Withdrawal in Murine Bone.

    Science.gov (United States)

    Todd, Henry; Galea, Gabriel L; Meakin, Lee B; Delisser, Peter J; Lanyon, Lance E; Windahl, Sara H; Price, Joanna S

    2015-01-01

    Genome Wide Association Studies suggest that Wnt16 is an important contributor to the mechanisms controlling bone mineral density, cortical thickness, bone strength and ultimately fracture risk. Wnt16 acts on osteoblasts and osteoclasts and, in cortical bone, is predominantly derived from osteoblasts. This led us to hypothesize that low bone mass would be associated with low levels of Wnt16 expression and that Wnt16 expression would be increased by anabolic factors, including mechanical loading. We therefore investigated Wnt16 expression in the context of ageing, mechanical loading and unloading, estrogen deficiency and replacement, and estrogen receptor α (ERα) depletion. Quantitative real time PCR showed that Wnt16 mRNA expression was lower in cortical bone and marrow of aged compared to young female mice. Neither increased nor decreased (by disuse) mechanical loading altered Wnt16 expression in young female mice, although Wnt16 expression was decreased following ovariectomy. Both 17β-estradiol and the Selective Estrogen Receptor Modulator Tamoxifen increased Wnt16 expression relative to ovariectomy. Wnt16 and ERβ expression were increased in female ERα-/- mice when compared to Wild Type. We also addressed potential effects of gender on Wnt16 expression and while the expression was lower in the cortical bone of aged males as in females, it was higher in male bone marrow of aged mice compared to young. In the kidney, which we used as a non-bone reference tissue, Wnt16 expression was unaffected by age in either males or females. In summary, age, and its associated bone loss, is associated with low levels of Wnt16 expression whereas bone loss associated with disuse has no effect on Wnt16 expression. In the artificially loaded mouse tibia we observed no loading-related up-regulation of Wnt16 expression but provide evidence that its expression is influenced by estrogen receptor signaling. These findings suggest that while Wnt16 is not an obligatory contributor to

  15. Wnt16 Is Associated with Age-Related Bone Loss and Estrogen Withdrawal in Murine Bone.

    Directory of Open Access Journals (Sweden)

    Henry Todd

    Full Text Available Genome Wide Association Studies suggest that Wnt16 is an important contributor to the mechanisms controlling bone mineral density, cortical thickness, bone strength and ultimately fracture risk. Wnt16 acts on osteoblasts and osteoclasts and, in cortical bone, is predominantly derived from osteoblasts. This led us to hypothesize that low bone mass would be associated with low levels of Wnt16 expression and that Wnt16 expression would be increased by anabolic factors, including mechanical loading. We therefore investigated Wnt16 expression in the context of ageing, mechanical loading and unloading, estrogen deficiency and replacement, and estrogen receptor α (ERα depletion. Quantitative real time PCR showed that Wnt16 mRNA expression was lower in cortical bone and marrow of aged compared to young female mice. Neither increased nor decreased (by disuse mechanical loading altered Wnt16 expression in young female mice, although Wnt16 expression was decreased following ovariectomy. Both 17β-estradiol and the Selective Estrogen Receptor Modulator Tamoxifen increased Wnt16 expression relative to ovariectomy. Wnt16 and ERβ expression were increased in female ERα-/- mice when compared to Wild Type. We also addressed potential effects of gender on Wnt16 expression and while the expression was lower in the cortical bone of aged males as in females, it was higher in male bone marrow of aged mice compared to young. In the kidney, which we used as a non-bone reference tissue, Wnt16 expression was unaffected by age in either males or females. In summary, age, and its associated bone loss, is associated with low levels of Wnt16 expression whereas bone loss associated with disuse has no effect on Wnt16 expression. In the artificially loaded mouse tibia we observed no loading-related up-regulation of Wnt16 expression but provide evidence that its expression is influenced by estrogen receptor signaling. These findings suggest that while Wnt16 is not an

  16. Effects of denosumab, alendronate, or denosumab following alendronate on bone turnover, calcium homeostasis, bone mass and bone strength in ovariectomized cynomolgus monkeys.

    Science.gov (United States)

    Kostenuik, Paul J; Smith, Susan Y; Samadfam, Rana; Jolette, Jacquelin; Zhou, Lei; Ominsky, Michael S

    2015-04-01

    Postmenopausal osteoporosis is a chronic disease wherein increased bone remodeling reduces bone mass and bone strength. Antiresorptive agents including bisphosphonates are commonly used to mitigate bone loss and fracture risk. Osteoclast inhibition via denosumab (DMAb), a RANKL inhibitor, is a newer approach for reducing fracture risk in patients at increased risk for fracture. The safety of transitioning from bisphosphonate therapy (alendronate; ALN) to DMAb was examined in mature ovariectomized (OVX) cynomolgus monkeys (cynos). One day after OVX, cynos (7-10/group) were treated with vehicle (VEH, s.c.), ALN (50 μg/kg, i.v., twice monthly) or DMAb (25 mg/kg/month, s.c.) for 12 months. Other animals received VEH or ALN for 6 months and then transitioned to 6 months of DMAb. DMAb caused significantly greater reductions in serum CTx than ALN, and transition from ALN to DMAb caused further reductions relative to continued ALN. DMAb and ALN decreased serum calcium (Ca), and transition from ALN to DMAb resulted in a lesser decline in Ca relative to DMAb or to VEH-DMAb transition. Bone histomorphometry indicated significantly reduced trabecular and cortical remodeling with DMAb or ALN. Compared with ALN, DMAb caused greater reductions in osteoclast surface, eroded surface, cortical porosity and fluorochrome labeling, and transition from ALN to DMAb reduced these parameters relative to continued ALN. Bone mineral density increased in all active treatment groups relative to VEH controls. Destructive biomechanical testing revealed significantly greater vertebral strength in all three groups receiving DMAb, including those receiving DMAb after ALN, relative to VEH controls. Bone mass and strength remained highly correlated in all groups at all tested skeletal sites, consistent with normal bone quality. These data indicate that cynos transitioned from ALN to DMAb exhibited reduced bone resorption and cortical porosity, and increased BMD and bone strength, without

  17. Breed predisposition to canine gastric carcinoma

    DEFF Research Database (Denmark)

    Seim-Wikse, Tonje; Jörundsson, Einar; Nødtvedt, Ane;

    2013-01-01

    Previous research has indicated a breed predisposition to gastric carcinoma in dogs. However, results to date are inconsistent since several studies have failed to prove such a predisposition. Better knowledge of breeds at risk could facilitate early detection of gastric carcinoma in dogs. The ai...... of the study was to retrospectively investigate the proportion and possible breed predisposition to canine gastric carcinoma using the Norwegian Canine Cancer Register for calculations of proportional morbidity ratios (PMRs) for the period 1998-2009.......Previous research has indicated a breed predisposition to gastric carcinoma in dogs. However, results to date are inconsistent since several studies have failed to prove such a predisposition. Better knowledge of breeds at risk could facilitate early detection of gastric carcinoma in dogs. The aim...

  18. Antigenic typing Polish isolates of canine parvovirus

    Energy Technology Data Exchange (ETDEWEB)

    Mizak, B. [National Veterinary Research Institute, Pulawy (Poland); Plucienniczak, A. [Polish Academy ofd Sciences. Microbiology and Virology Center, Lodz (Poland)

    1995-12-31

    Polish strains of canine parvovirus isolated between 1982 and 1993 were examined to determine the extent to which the virus has evolved antigenically and genetically over eleven years. Two CPV isolates obtained in Warsaw in 1982 and Pulawy in 1993, were examined using monoclonal antibody typing, restriction analysis and sequencing VP-2 protein gene. Five other isolates from Warsaw and Pulawy were tested with the panel of monoclonal antibodies specific to CPV-2, CPV-2a and common for canine parvovirus, feline panleukopenia virus and milk enteritis virus. Results of the studies demonstrated that all isolates tested represented CPV-2a antigenic type. Rapid antigenic strain replacement recorded by Parrish and Senda in the U.S.A and Japan was not confirmed in Poland. (author). 30 refs, 2 tabs.

  19. Coryneform bacteria associated with canine otitis externa

    DEFF Research Database (Denmark)

    Aalbæk, Bent; Bemis, David A.; Schjærff, Mette;

    2010-01-01

    This study aims to investigate the occurrence of coryneform bacteria in canine otitis externa. A combined case series and case-control study was carried out to improve the current knowledge on frequency and clinical significance of coryneform bacteria in samples from canine otitis externa. A total...... of 16 cases of otitis externa with involvement of coryneform bacteria were recorded at two referral veterinary hospitals in Denmark and the US, respectively. Coryneform bacteria were identified by partial 16S rRNA gene sequencing. Corynebacterium auriscanis was the most common coryneform species (10...... cases). Small colony variants of this species were also observed. Other coryneform isolates were identified as Corynebacterium amycolatum (3 cases), Corynebacterium freneyi (2 cases) and an Arcanobacterium-like species (1 case). The coryneform bacteria were in all cases isolated together with other...

  20. 儿童前牙区牙槽骨和基骨骨密度的锥形束CT测量%Density of the anterior area of alveolar and basal bones on the children measured by cone beam computed tomography

    Institute of Scientific and Technical Information of China (English)

    王军; 任卫萍; 龙飞; 栗震亚

    2012-01-01

    Objective The purpose of this investigation was to evaluate density value on anterior of the alveolar and basal bones on children. Methods 138 cases cone beam computed tomography images were selected. The densities of these bones were measured in Hounsfield units(Hu) for the incisor, canine of the anterior area of alveolar and basal bones on the children. Results There is no significant difference on the same position of the maxillary bilateral(right and left) incisors of the density value(P>0.05). To compare with the incisors of the density value on the same position of the mandibule on left and right, there is significant difference on the base bone on cortical bone density of lingual, P=0.012. There is no significant difference on the same position of the maxillary bilateral(right and left) canine of the density value. To compare with the canine of the density value on the same position of the mandibule on left and right, there is significant difference on the alveolar bone and basal bone cancellous density, P=0.046 and 0.002, respectively. Conclusion These might provide determinate data for anterior teeth zone when selecting sites and placement methods for microscrew implants in the dental arch.%目的 评估儿童前牙区上下颌牙槽骨和基骨的骨密度.方法 选择138例患者的锥形束CT扫描图像,以亨斯菲尔德单位(X线衰减单位Hu)来测定其上下颌切牙区、尖牙区牙槽嵴和基骨骨密质及骨松质的骨密度.结果 上颌切牙区左右两侧相同部位间的骨密度值相比较,差异没有统计学意义(P>0.05);下颌切牙区左右两侧相同部位的骨密度值相比较,基骨区舌侧骨密质的骨密度值差异有统计学意义(P=0.012);上颌尖牙区左右两侧相同部位的骨密度值相比较,差异没有统计学意义(P>0.05):下颌尖牙区左右两侧相同部位的骨密度值相比较,牙槽骨和基骨区骨松质的骨密度值差异有统计学意义,P值分别为0.046和0.002.结

  1. Extrusion processing : effects on dry canine diets

    OpenAIRE

    Tran, Q.D.

    2008-01-01

    Keywords: Extrusion, Canine diet, Protein, Lysine, Starch gelatinization, Palatability, Drying. Extrusion cooking is a useful and economical tool for processing animal feed. This high temperature, short time processing technology causes chemical and physical changes that alter the nutritional and physical quality of the product. Effects of extrusion on the feed quality for other animals than pets have been well recognized. Our studies investigated to what extent extrusion and/or drying of a c...

  2. Cardiac troponin I levels in canine pyometra

    OpenAIRE

    Hagman Ragnvi; Lagerstedt Anne-Sofie; Fransson Boel A; Bergström Annika; Häggström Jens

    2007-01-01

    Abstract Background Myocardial injury may contribute to unexpected deaths due to pyometra. To detect myocardial damage, measurement of cardiac troponin I (cTnI) is currently the most sensitive and specific method. The aims of the present study were to evaluate presence of myocardial damage in canine pyometra by analysis of cTnI, to explore whether myocardial injury was associated with systemic inflammatory response syndrome (SIRS) and to evaluate whether other clinical or laboratory parameter...

  3. Microbiological and histopathological aspects of canine pyometra

    OpenAIRE

    Coggan, Jennifer Anne; Melville, Priscilla Anne; de Oliveira, Clair Motos; Faustino, Marcelo; Moreno, Andréa Micke; Benites, Nilson Roberti

    2008-01-01

    As pyometra is recognized as one of the main causes of disease and death in the bitch the purposes of this study were to evaluate microbiological and histopathological aspects of canine pyometra and to research the virulence factors of the E. coli isolates identifying possible risks to human health. The microbiological isolation from the intrauterine contents of 100 dogs with pyometra was carried out and the virulence factors in the E. coli strains were identified using PCR method. This study...

  4. Remote detection of explosives using trained canines

    International Nuclear Information System (INIS)

    Use of dogs is a search method which combines high probability of detection, speed of search, and low cost. It was concluded that the canine could be used for explosive screening of personnel, but that it was imperative that the dog be in a position remote from employees and employee traffic. A study was made of the design of booths and air flow for this purpose. Results of tests and conclusions are given and discussed

  5. Treatment of canine scabies with milbemycin oxime.

    Science.gov (United States)

    Miller, W H; de Jaham, C; Scott, D W; Cayatte, S M; Bagladi, M S; Buerger, R G

    1996-04-01

    The purpose of this study was to determine the efficacy of orally administered milbemycin oxime in the treatment of canine scabies. Forty dogs were treated. Mean drug dosage for all dogs was approximately 2 mg/kg body weight. Twenty-seven dogs received 3 doses separated by 7 d, and 13 dogs received 2 doses separated by 14 d. All dogs were clinically normal following treatment and no adverse reactions were detected.

  6. Microbial profile of canine persistent wound infections

    Directory of Open Access Journals (Sweden)

    A. Padhy

    2014-04-01

    Full Text Available Aim: To analyse the microbial profile of canine persistent wound infections. Materials and Methods: The total wound samples (n=172 taken from both traumatic (140 and post-surgical (32 persistent wounds in canines were processed for routine microbial isolation and identification during a period of 15 months. Results: Staphylococcus intermedius was found to be the predominant isolate from all types of wounds under study. It was followed by Staphylococcus aureus, Pseudomonas aeruginosa, E. coli, Pasteurella spp., Corynaebacterium spp. and Bacillus spp. From different traumatic wounds of dogs, S. intermedius (92/140=65.7% and from surgical wounds, P. aeruginosa (24/32=75% were found to be the predominant isolates recovered whereas the most commonly isolated bacterial genus in both traumatic and surgical wounds of dogs was Staphylococcus spp. Conclusion: Canine wounds are polymicrobial in nature. Hence proper microbial laboratory diagnosis and presence of multiple organisms in a wound are to be taken into consideration for effective treatment of persistent wound infections in dogs.

  7. Canine kobuviruses in diarrhoeic dogs in Italy.

    Science.gov (United States)

    Di Martino, Barbara; Di Felice, Elisabetta; Ceci, Chiara; Di Profio, Federica; Marsilio, Fulvio

    2013-09-27

    Canine kobuviruses (CaKVs) are newly recognized picornaviruses recently detected in dogs in the US. By molecular analysis of the whole genome, CaKV that appeared genetically closest to the murine kobuvirus (MuKV) and to the human Aichi virus (AiV), may be classified in the Kobuvirus genus as new genotype (CaKV type 1) within the species Aichivirus A. To date, there are no information on the epidemiology of these novel viruses in other continents. In this study, by screening a collection of 256 dog fecal samples either from diarrhoeic or asymptomatic animals, CaKV was identified in six specimens with an overall prevalence of 2.34% (6/256). All the positive dogs presented diarrhea and were found to be infected by CaKV alone or in mixed infections with canine coronavirus (CCoV) and/or canine parvovirus type 2 (CPV-2). By molecular analysis of the partial 3D gene, all the strains detected displayed a close relatedness with the CaKVs recently identified in the US. This study provides evidence that CaKVs circulate in diarrhoeic dogs in Italy and are not geographically restricted to the North American continent, where they were first signaled. PMID:23806200

  8. Cytodiagnostics of canine lymphomas - possibilities and limitations.

    Science.gov (United States)

    Sapierzyński, R; Kliczkowska-Klarowicz, K; Jankowska, U; Jagielski, D

    2016-01-01

    Malignant lymphomas are one of the most common malignant tumours occurring in dogs. The basic method of lymphoma diagnosis in human, as well as in canine oncology is histopathology supported by immunohistochemistry. It was suggested that in veterinary medicine excisional biopsy of lymph node and histopathology should be considered only where the cytologic diagnosis is equivocal or needs to be confirmed. There are at least three basic reasons for which cytological examination ought to be accepted as a sufficient and reliable diagnostic method for lymphoma in dogs. Firstly, most dog owners consider the fine-needle biopsy as an acceptable non-harmful method of sample collection. Secondly, an increasing number of studies recommend cytology as an accurate test for diagnosing and subtyping canine lymphoma. Finally, the vast majority of canine lymphoma subtypes belong to 4-5 categories characterized by a typical cytological picture. Immunocytochemical staining of cytological smears gives new diagnostic possibilities, such as detection of markers better characterizing given growth or a potential goal for target therapy in individual cases (for example inhibitors of platelet-derived growth factor). PMID:27487521

  9. [Bone diseases].

    Science.gov (United States)

    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. PMID:26946704

  10. Gene expression profiling of canine osteosarcoma reveals genes associated with short and long survival times

    Directory of Open Access Journals (Sweden)

    Rao Nagesha AS

    2009-09-01

    Full Text Available Abstract Background Gene expression profiling of spontaneous tumors in the dog offers a unique translational opportunity to identify prognostic biomarkers and signaling pathways that are common to both canine and human. Osteosarcoma (OS accounts for approximately 80% of all malignant bone tumors in the dog. Canine OS are highly comparable with their human counterpart with respect to histology, high metastatic rate and poor long-term survival. This study investigates the prognostic gene profile among thirty-two primary canine OS using canine specific cDNA microarrays representing 20,313 genes to identify genes and cellular signaling pathways associated with survival. This, the first report of its kind in dogs with OS, also demonstrates the advantages of cross-species comparison with human OS. Results The 32 tumors were classified into two prognostic groups based on survival time (ST. They were defined as short survivors (dogs with poor prognosis: surviving fewer than 6 months and long survivors (dogs with better prognosis: surviving 6 months or longer. Fifty-one transcripts were found to be differentially expressed, with common upregulation of these genes in the short survivors. The overexpressed genes in short survivors are associated with possible roles in proliferation, drug resistance or metastasis. Several deregulated pathways identified in the present study, including Wnt signaling, Integrin signaling and Chemokine/cytokine signaling are comparable to the pathway analysis conducted on human OS gene profiles, emphasizing the value of the dog as an excellent model for humans. Conclusion A molecular-based method for discrimination of outcome for short and long survivors is useful for future prognostic stratification at initial diagnosis, where genes and pathways associated with cell cycle/proliferation, drug resistance and metastasis could be potential targets for diagnosis and therapy. The similarities between human and canine OS makes the

  11. Deletion of FGFR3 in Osteoclast Lineage Cells Results in Increased Bone Mass in Mice by Inhibiting Osteoclastic Bone Resorption.

    Science.gov (United States)

    Su, Nan; Li, Xiaogang; Tang, Yubin; Yang, Jing; Wen, Xuan; Guo, Jingyuan; Tang, Junzhou; Du, Xiaolan; Chen, Lin

    2016-09-01

    Fibroblast growth factor receptor 3 (FGFR3) participates in bone remodeling. Both Fgfr3 global knockout and activated mice showed decreased bone mass with increased osteoclast formation or bone resorption activity. To clarify the direct effect of FGFR3 on osteoclasts, we specifically deleted Fgfr3 in osteoclast lineage cells. Adult mice with Fgfr3 deficiency in osteoclast lineage cells (mutant [MUT]) showed increased bone mass. In a drilled-hole defect model, the bone remodeling of the holed area in cortical bone was also impaired with delayed resorption of residual woven bone in MUT mice. In vitro assay demonstrated that there was no significant difference between the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts derived from wild-type and Fgfr3-deficient bone marrow monocytes, suggesting that FGFR3 had no remarkable effect on osteoclast formation. The bone resorption activity of Fgfr3-deficient osteoclasts was markedly decreased accompanying with downregulated expressions of Trap, Ctsk, and Mmp 9. The upregulated activity of osteoclastic bone resorption by FGF2 in vitro was also impaired in Fgfr3-deficient osteoclasts, indicating that FGFR3 may participate in the regulation of bone resorption activity of osteoclasts by FGF2. Reduced adhesion but not migration in osteoclasts with Fgfr3 deficiency may be responsible for the impaired bone resorption activity. Our study for the first time genetically shows the direct positive regulation of FGFR3 on osteoclastic bone resorption. © 2016 American Society for Bone and Mineral Research.

  12. Cortical Microstimulation for Neural Prostheses

    OpenAIRE

    Venkatraman, Subramaniam

    2010-01-01

    Brain-controlled prostheses have the potential to improve the quality of life of a large number of paralyzed persons by allowing them to control prosthetic limbs simply by thought. An essential requirement for natural use of such neural prostheses is that the user should be provided with somatosensory feedback from the artificial limb. This can be achieved by electrically stimulating small populations of neurons in the cortex; a process known as cortical microstimulation. This dissertation de...

  13. The origin of cortical neurons

    OpenAIRE

    Parnavelas J.G.

    2002-01-01

    Neurons of the mammalian cerebral cortex comprise two broad classes: pyramidal neurons, which project to distant targets, and the inhibitory nonpyramidal cells, the cortical interneurons. Pyramidal neurons are generated in the germinal ventricular zone, which lines the lateral ventricles, and migrate along the processes of radial glial cells to their positions in the developing cortex in an `inside-out' sequence. The GABA-containing nonpyramidal cells originate for the most part in the gangli...

  14. Functional anatomy and ultrasound examination of the canine penis.

    Science.gov (United States)

    Goericke-Pesch, Sandra; Hölscher, Catharina; Failing, Klaus; Wehrend, Axel

    2013-07-01

    The aim of this study was to identify the functional-anatomical structures of the canine penis during and after erection to demonstrate the respective changes to provide a basis for further examinations of pathological conditions like priapism. Additionally, a gray-scale analysis was performed to quantify results from the ultrasound examination. In total, 80 dogs were examined. In group (Gr.) A, 44 intact or castrated dogs were examined, and in Gr. B, 36 dogs were examined during erection and after complete detumescence of the penis. The following parameters were assessed: (1) using physical measurements: length of the Pars longa glandis [Plg] and length of the Bulbus glandis [Bg]; and (2) using ultrasound: total penile diameter, width of the erectile tissue of the Plg, diameter of the Corpus spongiosum [Cs] including the penile bone and urethra, vertical diameter, circumference of the penis, cross-sectional area, and area of the Cs including the urethra. The mentioned parameters could be assessed in all dogs of Gr. A and Gr. B with the only exception being the urethra that could be visualized using ultrasound in some dogs only and predominantly in the erected penis (Gr. B). Concomitantly, the erectile tissue of the Plg and the Cs was more heterogenous and hypo- to anechoic during erection compared with dogs in Gr. A and Gr. B after detumescence. Comparing the results in Gr. B, the length of the Plg and the Bg were decreased approximately 40.6% and 38.0%, the total width of the penis 40.5%, the total width of the erectile tissue of the Plg 48.0%, and the width of the Cs 15.6% during detumescence compared with erection. Comparing the decrease in size at the different locations (apex penis, middle of Plg, middle of Bg) for vertical diameter, total circumference, and cross-section area, it was largest at the Bg. B-mode ultrasound is a suitable tool to investigate not only the morpho-functional structures of the resting canine penis, but also of the erected and

  15. Bilateral hemimelia of radio in canine – case report
    Hemimelia bilateral de rádio em canino – relato de caso

    OpenAIRE

    Thalita Priscila da Silva Peres; Wilma Neres da Silva Campos; Thaís Ruiz; Yara Silva Meireles; Pedro Brandini Néspoli; Roberto Lopes de Souza

    2013-01-01

    Hemimelia or agenesis is a congenital morphological change that may affect the appendicular skeleton. This rare anomaly is the total or partial absence of one or more bones matched. It may present unilaterally or bilaterally, with the most frequent unilateral. In dogs, the most common form of the radial hemimelia is that causes deformity of the affected limb and severe functional limitations. Was Veterinary Hospital of the Federal University of Mato Grosso (HOVET/UFMT), a canine, female mongr...

  16. Canine hypertrophic osteopathy associated with extra-thoracic lesions Osteopatia hipertrófica canina associada com lesões extratorácicas

    OpenAIRE

    Selwyn Arlington Headley; Eduardo Alcântara Ribeiro; Gustavo José Von G. dos Santos; Carlos Maia Bettini; Ewaldo de Mattos Júnior

    2005-01-01

    Canine hypertrophic osteopathy is described in a dog that presented extra-thoracic lesions, mainly in the liver. Hepatic lesions were characterized by necrosis, hemorrhage, severe hydropic degeneration of centrolobular hepatocytes, proliferation of epithelial cells of bile ducts, and mild biliary stasis. The disease syndrome was diagnosed based on clinical signs, radiological evaluation, and inspection of macerated bones.Osteopatia hipertrófica canina é descrita em um cão que apresentou lesõe...

  17. Probing the micro-mechanical behavior of bone via high-energy x-rays.

    Energy Technology Data Exchange (ETDEWEB)

    Almer, J.; Stock, S. R.; X-Ray Science Division; Northwestern Univ.

    2006-01-01

    Bone is a highly-adaptive, particulate-reinforced composite which, through a complex hierarchical structure, achieves excellent mechanical performance. The composite preserves, to a large degree, the desirable properties of the individual components: high toughness of the bone matrix, collagen fibrils stabilized by water, and high stiffness of the reinforcing phase, nano-sized crystallites of carbonated apatite. Understanding bone fragility (osteoporosis) requires quantifying mechanical input to bone and identifying 'weak-link' microstructures. This mechanical input has been quantified in vivo with strain gages attached to cortical bone, but attached strain gages do not probe subsurface mechanical response. We addressed this shortcoming recently by appling wide- and small-angle x-ray scattering to canine fibula sections, to study the micro-mechanical response of bone on different length scales. These data provide a unique view of load partition betw